CFD APPLICATIONS ON HIGH-PERFORMANCE COMPUTERS IN … · potpunija optimizacija sistema. Iako }e svi ovi pozitivni u~inci vjerovatno obezbijediti sve potrebne preduslove za “zlatne

PRIMJENA CFD-a NA RAÛNARIMA VISOKIH PERFORMANSI U RJE[AVANJU IN@ENJERSKIH PROBLEMA

D. Stojkovi, N.Jovi~i, E.Mei, F.Durst, Friedrich-Alexander-Univerzitet Erlangen-Nirnberg, Institut za Mehaniku Fluida, Cauerstraße 4, D-91058 Erlangen, Njema~ka

REZIME U ovom radu predstavljen je dio dosadanjih istraìvanja u Institutu za mehaniku fluida - LSTM (Lehrstuhl für StömunErlangen-Nurnberg). Mogunosti CFD tehnika konstantno rasove tehnike ranije je bilo mogue rjeiti samo pojednostaDanas je mogue rjeiti mnogo sloènije tro-dimenzionalne,kojima su opisana strujanja u proizvoljnim geometrijama. Iprethodnom periodu, izazov koji se nudi njihovim daljim razna~ajnijih su simulacije turbulentnih i hemijski reaktivnih stje razvila nekoliko ra~unarskih programa za simulaciju tokoovih programa u rjeavanju inènjerskih problema ilustrirana

Klju~ne rije~i: CFD, LES, turbulencija, hemijski reaktivna str

CFD APPLICATIONS ON HIGCOMPUTERS IN SOLVING ENG

D.Stojkovi, N.Jovi~i, E.Mei, F.Durst, FriedNuremberg, Institute of Fluid Mechanics, Cauerstra

SUMMARY This paper deals with the part of ongoing research in th(CFD) at the Lehrstuhl für Stömungsmechanik, Friedrich-A(LSTM). The power of the CFD techniques have been instages only the solution of the simplified Navier-Stokes equNowadays, the scope of these techniques is extended to Stokes equations in complex geometries. In addition to tremains. Some of the major challenges are the sim-ulatiflows. The CFD research group at the LSTM has developepracticably relevant fluid flows. How the codes of this kproblems is demonstrated with help of three examples.

Key words: CFD, LES, turbulence, chemically reactive flows,

1 UVOD Ra~unarske performanse uporedo sa CFD tehnikama neprekidno se razvijaju ve godinama. Prirataj amplitude razvoja je odprilike reda veli~ine 101 svakih pet godina. Brzina mikroprocesora se poveava pribli`no sa istim gradijentom. Paralelno sa ekspanzijom ovih razvoja, CFD je prihvaen kao vaàn alat za obavljanje fundamentalnih istraìvanja i prora~un strujanja interesantnih za praksu. Ovo favoriziranje CFD-a je opravdano i ~injenicom da sveobuhvatno eksperimentalno istraìvanje sa kompleksnim modelima rezultira visokom cijenom i velikim utrokom vremena.

1 IN Compufluid ddeveloincreasthe spthe develotool fopracticalso suinvestigcost a

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polju numeri~ke mehanike fluida (CFD) na gsmechanik, Friedrich-Alexander Universität tu ve nekoliko zadnjih decenija. Koristei vljene oblike Navier-Stokesovih jedna~ina. nestacionarne Navier-Stokesove jedna~ine ako su ove tehnike zna~ajno razvijene u zvojem jo uvijek nije zanemariv. Neki od rujanja. CFD istraìva~ka grupa na LSTM-u va fluida od prakti~nog zna~aja. Primjena je kroz tri razli~ita primjera.

PRETHODNO SAOP[TENJE

ujanja, rast kristala

H-PERFORMANCE INEERING PROBLEMS

rich-Alexander-University Erlangen-ße 4, D-91058 Erlangen, Germany

e lexcreatiothrhesonsd sind

cry

TR

ter ynapede oeedsampmer pally ppoationd

field of Computational Fluid Dynamics ander Universität Erlangen-N¨ urnberg asing for sev-eral decades. In earlier ns by these techniques was possible. ee-dimensional, time-dependent Navier-e achievements, challenging work still of turbulent and chemically reactive everal codes for the prediction of the can be used in solving engineering

PRELIMINARY NOTES

stal growth

ODUCTION

performances together with computa-tional mics (CFD) techniques have con-tinuously over the years. An order of magnitude ccurs approximate every five years. Also, of microprocessors increases at roughly e rate. Concomitantly with these nts, CFD has been accepted as a valuable erforming basic research and for solving relevant flows. This usefulness of CFD was rted by the fact that intensive exper-imental ns of the complex models result in a high-time-consuming investigations

Da bi se sa~uvali novac i vrijeme pribjegava se reduciranju broja varijacija parametara. Ovo direktno ima za posljedicu nepotpunu optimizaciju sistema. S druge strane, dananji nivo CFD-a je sposoban rijeiti kompletne Navier-Stokesove jedna~ine uklju~ujui energetsku jedna~inu kao i jedna~ine koje opisuju hemijske reakcije. Koristei CFD, broj varijacija parametra moè biti zna~ajno povean sa minimalnim poveanjem trokova i vremena potrebnog za optimizaciju, ~ime se obezbje|uje potpunija optimizacija sistema. Iako e svi ovi pozitivni u~inci vjerovatno obezbijediti sve potrebne preduslove za “zlatne godine” mehanike fluida, mora se imati na umu da CFD tehnike jo uvijek teè ka novim poboljanjima kao to su porast ta~nosti numeri~kog rjeenja, analize strujanja u proizvoljnim geometrijama i obuhvaanje vie fizi~kih i hemijskih fenomena kao to su transport energije i mase, radijacija, hemijske reakcije, turbulencija, sagorijevanje, viefazni tokovi, strujanja sa slobodnim povr¡inama, itd. CFD istraìva~ka grupa na LSTM-u ima dugogodinje iskustvo u razvoju CFD softvera. Na bazi tog iskustva razvijeno je nekoliko programa za rjeavanje Navier-Stokesovih jedna~ina. Ovi programi se primjenjuju za razli~ite probleme strujanja. Svi oni su paralelizovani i mogu biti pokrenuti na ra~unarima visokih preformansi i razli~ite arhitekture. Ovo je veoma zna~ajno i predstavlja jednu od glavnih prednosti programa, jer implementacija numeri~kog metoda na paralelnim i vektor-paralelnim mainama omoguava poveanje brzine ra~unanja i ima veoma zna~ajnu ulogu kod numeri~ke simulacije sloènih strujanja. Ovaj rad je koncipiran u ~etiri poglavlja. Sljedee poglavlje daje kratak pregled osnovnih jedna~ina i numeri~ki metod na kojemu su bazirani koriteni programi. U treem poglavlju je ilustrovana primjena CFD-a kroz tri razli~ita primjera. Opisi primjera i rezultati su tako|e dati u treem poglavlju. Kona~no u zadnjem poglavlju su dati zaklju~ci.

In order to save money and time, the number of parameter variations need to be reduced. That di-rectly leads to incomplete equipment optimization. On the other hand, nowadays CFD is able to solve the full Navier-Stokes equations describing the con-servation of mass, momentum and energy, including chemical reactions. Using the CFD the number of parameter variations can be rapidly increased with only minor increases in cost and time consumption of investigation. At the same time full equipment optimization might be achieved. Although all these positive developments will probably provide all the necessary preconditions for “the golden years” of fluid mechanics, one must be aware that the CFD techniques still require further improvements such as increasing the accuracy of the numerical solution, flow predictions in more complex three-dimensional geometries and inclusion of more physical and chemical phenomena such as heat and mass transfer, radiation, chemical reactions, turbulence, combustion, multi-phase flows, free-surface flows, etc. The CFD research group at the LSTM has extensive experience in the development of CFD codes. As an outcome of that experience several codes for the solution of Navier-Stokes equations have been developed. These solvers are applied in a variety of flow problems. All these codes are parallelized and can be run on high-performance computers with a different parallel architecture. This represents one of the main advantages because an implementation of the numerical method on parallel and vector-parallel machines allows faster calculations and plays an important role in permitting a numerical simulation of complex flows. The paper is organized in four sections. The next section gives a brief review of the governing equations and numerical method on which the codes used are based. In the third section, CFD applications are illustrated through three different examples with descriptions and computational results. The last section draws conclusions.

2 OSNOVNE JEDNAÎNE Rezultati prezentovani u ovom radu su dobijeni uz koritenje veoma efikasnih programa za simulaciju strujanja LESOCC i FASTEST (2D i 3D verzije). Diskretizacija osnovnih jedna~ina je bazirana na metodi kona~nih volumena koristei blok-strukturirane mreè sa neortogonalnim kontrolnim volumenima (CV) i svim zavisnim varijablama lociranim u centru svakog CV-a (kolocirane mreè). Zamjenjujui sa φ transportnu varijablu u svakoj jedna~ini, integralna forma svih osnovnih jedna~ina moè biti izraèna u optem obliku:

2 GOVERNING EQUATIONS The results presented in this paper were obtained by using the highly efficient flow simulation codes LESOCC and FASTEST (2D and 3D versions). The codes are based on finite volume discretization of the governing set of equations using a block-structured mesh of non-orthogonal control volumes (CV) with all dependent variables located at the center of each CV (colocated grid). Representing by φ the transported quantity in each equation, the in-tegral form of all governing equations can be ex-pressed in a general form as:

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( ) ( )∫∫∫ ∫ Ω ΦΩ ΦΩ Ω

Ω+Ω

∂

Φ∂Γ

∂∂

=

Ω

∂∂

+Ω∂

∂dQd

xxd

x

Ud

t iii

iφρφρς (1)

gdje su Ω volumen CV-a, Γφ difuzioni koeficijent i Qφ izvorni ~lan: Vrijednosti ovih varijabli, za svaku od osnovnih jedna~ina, su date u tabeli 1 u kojoj su µ i µt molekularna i turbulentna viskoznost, cp specifi~na toplota pri konstantnom pritisku, T temperatura, λ toplotna provodljivost, h toplotni izvor ili ponor, ωs maseni udio s-te gasne

komponente (GK), ρ gustina, Ds i standardni

i termodifuzioni koeficijent s-te GK-e, m

TsD

k−R

TsD

k k−R

s molna masa s-te GK-e, νsk stehiometrijski koeficijent s-te GK-e u k-toj hemijskoj reakciji i R i brzine

konverzije i sinteze hemijskih komponenata u k-toj hemijskoj reakciji. Toplota transportovana radijacijom je uzeta u obzir preko grani~nih uslova.

k

Ra~unarski program LESOCC je vie-blokovski visoko vektorizirani kod, namijenjen za simulacije strujanja bazirane na ra~unanju velikih strujnih vrtloga (LES) na vektor-paralelnim mainama kao to su NEC SX-4 ili Fujitsu VPP 700. Kod LES-a se samo veliki vrtlozi ra~unaju direktno, dok uticaj malih vrtloga mora biti modeliran. Iz tog razloga Navier-Stokesove jedna~ine su filterovane. zapravo sve φ varijable u jedna~ini kontinuiteta i jedna~ini koli~ine kretanja u tabeli 1 su u ovom slu~aju filterovane varijable. Filterovana jedna~ina koli~ine kretanja uklju~uje dodatni ~lan za napone Tij koji rezultira iz filterovanih nelinearnih konvektivnih flukseva. ovaj efekat je uzet u obzir modeliranjem turbulentnog viskoziteta µt. U primjeru strujanja oko aeroprofila prostorna diskeretizacija je bazirana na emi centralnog diferenciranja koja je drugog reda ta~nosti. Vremenske promjene (nestacionarnost) su modelirane koritenjem prediktor-korektor eme. Memorijski-malo-zahtjevni viestepeni Runge-Kuta metod (tri pod-koraka, drugi red ta~nosti u vremenu) je primijenjen za integriranje jedna~ine za koli~inu kretanja u prediktor koraku. unutar korektor koraka Poisonova jedna~ina za korekciju pritiska (SIMPLE) je rjeavana implicitno koristei nekompletni LU dekompozicioni metod (SIP algoritam). Eksplecitno "vremensko mariranje" radi dobro za LES sa malim vremenskim koracima neophodnim za rjeavanje turbulentnog kretanja u vremenu. za modeliranje veli~ina koje nisu obuhvaene filterovanim varijablama, implementirana su dva razli~ita modela, Smagorinsky model [4] sa Van Driest priguivanjem blizu ~vrstog zida i dinami~ki model originalno predloèn od strane Germano i dr. [5] i kasnije modifikovan od strane Lilly [6]. Detalji o svim karakteristikama LESOCC-a su dati u referencama Breuer i Rodi [7], [8] i Breuer [9].

where Ω is the volume of CV, Γφ is a diffusion coefficient and Qφ is a source term. The values of these variables in different governing equations are shown in Table 1, in which µ and µt represent the molecular and turbulent viscosity, cp is specific heat at constant pressure, T is temeprature, λ is thermal conductivity, h is heat source or sink, ωs is mass fraction of the sth species, ρ is density, Ds and

are ordinary and thermo-diffusion coefficients of the

sth species, ms is molar mass of the sth species, νsk is stoichiometric coefficient of the sth species in the kth chemical reaction and R and are the

forward and reverse reaction rates in the kth chemical reaction. The heat produced or consumed by chemical reactions in taken into account over the h term in the energy equation and heat transported by radiative mechanism is included in the boundary conditions. The solver LESOCC is a multi-block and highly vectoried code, intended for Large Eddy Simulations (LES) on vector-parallel machines such as the NEC SX-4 or Fujitsu VPP 700. In LES only the large energy-carrying eddies are computed directly whereas the influence of the small eddies has to be modelled by a subgrid scale model. In order to separate the large – and small-scale motions, the Navier-Stokes equations are filtered. In fact, all φ quantities in continuity and momentum equations in Table 1 are in this case filtered quantities. The filtered momentum equations include an additional term for the non-resolvable subgrid scale stresses Tij which results from filtering the nonlinear convective fluxes. This effect is taken into account by modelling turbulent viscosity µt. In the present study, for the flow around an airfoil spatial discretization is based on central differences of second-order accuracy. Time advancement is performed by a predictor-corrector scheme. A low-storage multi-stage Runge-Kutta method (three substeps, second-order accurate in time) is applied for integrating the momentum equations in the predictor step. Within the corrector step the Poisson equation for the pressure correction (SIMPLE) is solved implicitly by an incomplete LU decomposition method (SIP solver). An explicit time marching works well for LES with the small time steps necessary to resolve turbulent motion in time. For modelling the non-resolvable subgrid scales, two different models are implemented, the Smagorinsky model [4] with Van Driest damping near solid walls and the dynamic model originally proposed by Germano et al. [5] and later modified by Lilly [6]. Details of all features of LESOCC are given by Breuer and Rodi [7], [8] and Breuer [9].

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Tabela 1: Vrijednosti varjabli u optoj transportnoj jedna~ini Table1: Values of variables in the general transport equation

Jedna~ina - Eqouation ζ φ ГΓφ Qφ

Kontinuiteta – Continuity 1 1 0 0

Koli~ine kretanja – Momentum

1 Uj µ+µt

Energije – Energy cp T λ h

Gasnih komponenata – Species

1 ωs ρ Ds ( )−+ −=∑ kk

K

k sksj

vm RR1

∂∂

∂∂ T

sj x

T

TxD 1

Kineti~ke energije turbul. Turbulent kinetic energy

1 k Gk - ρε

Disipcije energije turbul. Dissipation rate

1 ε s

t

σµ

µ + ε

∂∂

∂∂

+∂∂

−j

i

ij x

U

x

p

x

pµ

k

t

σµ

µ +

( )ρε21 CGCk

k −

Ra~unarski program FASTEST je namijenjen za direktne numeri~ke simulacije (DNS), simulacije koristei Reynoldosve usrednjene Navier-Stokesove (RANS) jedna~ine sa k-ε modelom kao statisti~kim turbulentnim modelom i simulacije hemijski reaktivnih strujanja. kada su u pitanju turbulentna strujanja dvije dodatne skalarne jedna~ine, za kineti~ku energiju turbulencije k i njenu disipaciju ε, moraju biti rijeene. Odgovarajue veli~ine za specifi~nu formu opte transportne jedna~ine su date u tabeli 1, gdje intenzitet turbulencije Gk i turbulentni viskozitet µt imaju sljedee oblike

The FASTEST solver in intended for Direct Numerical Simulations (DNS), simulations using the Reynolds-averaged Navier-Stokes (RANS) equations with the k-ε model as a statistical turbulence model and simulations of chemically reactive flows. Concerning the turublent flows, the two additional scalar equations for turbulent kinetic energy k and dissipation rate ε must be resolved. Appropriate quantities for the specific form of general transport equation are given in Table 1, where the rate of turbulence production Gk and turbulent viscosity µt have the following forms,

,j

i

i

j

j

itk

x

U

x

U

x

UG

∂∂

∂∂

+∂∂

= µ (2)

εµρµ

2kCt =

(3)

Cµ C1 C2 σk σε Cε3

0.09 1.44 1.92 1.0 1.3 1.87 [to se ti~e hemijski reaktivnih strujanja, hemijski mehanizam koji se javlja u ovakvim strujanjima moè se u globalu podijeliti na dva dijela. prvi dio uklju~uje homogene hemijske reakcije u gasnoj fazi. Ovaj fenomen je implementiran u numeri~ki model preko jedna~ine odrànja GK-ta (~lan

Pretpostavljajui da postoji

N hemijski reaktivnih GK-ta i K reverzibilnih hemijskih reakcija, sve hemijske reakcije mogu biti opisane sljedeom optom jedna~inom

( )).1∑ = −−

K

k kksksm RRν ( )).1∑ = −−

K

k kksksm RRν

Regarding the chemically reactive flows, the chemical mechanism appeared in this kind of flow can be mainly divided into two parts. The first includes homogeneous chemical reactions in the gas phase and ins modelled over the species conservation equation (the term

Assuming N chemically

reactive species and K reversible chemical reactions, these reactions are described by the following general equation,

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( )Kks

N

ssk

N

s

k

kssk

k

k

,111

=− ∑∑=− −

PI νν (4)

gdje su Is i Ps reaktanti i produkti u k-toj reakciji orijentisanoj u pozitivnom smjeru. Veli~ine kk i k-k konstante brzina konverzije i sinteze hemijskih komponenata u k-toj reakciji. Definisanje ovih konstanti se vri uz pomo eksperimentalnih podataka i prema Arrheniusovom zakonu (kao jed. 6). Sada se brzine konverzije i sinteze hemijskih komponenata u k-toj reakciji mogu definisati kao

where Is and Ps are the initial reactants and products in the kth forward reaction. The quantities kk and k-k are the forward and reverse reaction rate constants in the kth reaction defined with the help of experimental data in the Arrhenius form (as Eq. 6). Now, the reaction rates are defined in the forms,

∏∏=

−−=

− ==N

sskk

N

sskk

sksk CkCk11

, νν RR (5)

gdje su cs molna koncentracija s-te GK-e. U drugi dio hemijskog mehanizma uklju~ene su samo heterogene hemijske reakcije koje se odvijaju na reaktivnim povrinama unutar domena strujanja. uticaj ovog dijela hemijskog mehanizma seuzima u obzir preko grani~nih uslova. Heterogene hemijske reakcije su uglavnom karakteristika hemijskih procesa izdvajanja materijala iz reaktivnih gasova (CVD procesi). Opti numeri~ki model kojim se opisuju heterogene hemijske reakcije je dat u istom obliku kao i jed. (6). Za vie detalja o hemijskom mehanizmu i njegovom modeliranju pogledati reference [10], [11], [12] i [13]. U FASTEST-u koritena diskretizacija drugog reda za sve ~lanove (centralno diferenciranje, linearna interpolacija) uz koritenje naknadne korekcije za konvektivni fluks. za razliku od LESOCC koda, FASTEST primjenjuje implicitnu vremensku diskretizaciju. Bazirana na jedna~ini kontinuiteta, jedna~ina za korekciju pritiska je izvedena prema SIMPLE algoritmu. Linearizovanje jedna~ine za komponente brine, korekciju pritiska i druge skalarne varijable (temperatura, koncentracija, turbulentna energija, njena disipacija) su povezane (kuplovane) i rjeavane sekvencijalno. I ovdje je, kao i prije, ILU pristup uzet za rjeavanje linearnog sistema. Vanjske iteracije se izvode tako da se uzima u obzir nelinearnost, kuplovanje varijabli i efekti koji se javljaju zbog neortogonalnosti mreè. Prenos toplote radijacijom je tako|e uzet u obzir u FASTEST programu: Ra~unanje je bazirano na radijativnom povrinskom modelu uklju~ujui ra~unanje faktora vidljivosti. za izra~unavanje ovih faktora algoritam "sjen~enja" je implementiran u programu [14]. Vie detalja o FASTEST-u mogue je nai u referencama Durst i dr. [15] i Durst i Schäfer [16].

where cs is the molr concentration of the sth species. The influence of the second part of the chemical mechanism consists of only the heterogeneous chemical reactions on the reactive surfaces inside the flow domain being taken into account over the boundary conditions. The heterogeneous chemical reactions are mainly connected to the Chemical Vapour Deposition (CVD) processes. The general numrical model for the heterogeneous reactions is given in the same form as Eq (6). For more details about the chemical mechanism and its modelling, see the references [10], [11], [12] and [13]. Second-order discretization in FASTEST is used for all terms (central differences, linear interpolation) with the deferred correction approach for convective fluxes. In contrast to the LESOCC code, FASTEST applies an implicit time discreatization either by a three-time-level, second-order fully implicit scheme or by a Crank-Nicolson scheme. Based on the continuity equation, a presure-correction equation is derived according to the SIMPLE algorithm. The linearized equations for the velocity components, the pressure correction and other scalar variables (temperature, concentration, turbulent energy dissipation rate) are assembled and solved sequentially, where the same ILU approach as above is employed as a linear system solver. Outer iterations are performed to take into account the non-linearities, the coupling of the variables and the effects of grid non-orthogonality, which are treated explicitly in all equations. The radiative heat transfer is also included in the FASTEST code. The calculation is based on a radiating surface model including the view factor calculation. In order to calculate these factors, a shadowing algorithm is implemented [14]. More details on FASTEST are given by Durst et al. [15] and Durst and Schäfer [16].

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3. PRIMJENA CFD-a 3.1. Rotirajui Cilindar Dvodimenzionalno strujanje oko cilindra koji rotira konstantnom ugaonom brzinom ω predstavlja veoma sloèno strujanje za koje ne postoji adekvatno analiti~ko rjeenje. Iz tog razloga postoje brojne eksperimentalne i od skora numeri~ke studije koje se bave ovim problemom. Fluidna struja se ubrzava sa jedne strane cilindra dok se sa druge usporava uzrokujui razliku pritisaka koja dovodi do pojave uzgonske sile. Ovaj efekat se u literaturi naziva Magnusov efekat. za razliku od strujanja fluida oko fiksnog cilindra u kojem sve strujne veli~ine zavise samo od Reynoldsovog broja Re, u ovom slu~aju se mora uzeti u obzir i koeficijent α koji uzima u obzir intenzitet ugaone brzine kojom se cilindar okree (α = Rω/U). U ovom slu~aju je R polupre~nik cilindra, a U predstavlja brzinu neuznemirene struje. Reynoldsov broj je definisan na uobi~ajen na~in Re = UD/ν gdje je D = 2R i ν predstavlja kinematsku viskoznost. Veoma detaljna numeri~ka analiza ovog problema ura|ena je na LSTM-u sa namjerom da se dobije kompletan set podataka za koeficijente otpora i uzgona (cD , cL) kao i bolji uvid u fiziku ovog problema. U slu~aju stacionarnog strujanja simulacija je izvedena za Re ≤ 45 i 0 ≤ α ≤ 6. Isto tako izvedeni su prora~uni i za nestacionarno strujanje za Re = 100. Prora~un je izveden sa programom FASTEST 2D koristei razli~ite tipove i veli~ine mreà sa ciljem da se ispita uticaj veli~ine domena na dobijene rezultate prilikom strujanja pri malim Re. Prema dobijenim rezultatima za stacionaran slu~aj (slike 1 i 2), o~igledno je da vrijednost koeficijenta otpora cD opada, a vrijednost koeficijenta uzgona cL raste sa porastom brzine rotiranja cilindra α. Kao to se moglo i o~ekivati uticaj rasporeda pritiska je dominantniji u odnosu na uticaj trenja. U slu~aju kada fluid struji s lijeva na desno brzinom U, a cilindar se obre u smijeru kazaljke na satu, rezultujua sila pritiska rotira u suprotnom smijeru sa porastom α to ima za posljedicu smanjenje cD odnosno poveanje cL. U slu~aju fiksnog cilindra, raspored pritisaka (i brzina) je simetri~an u odnosu na osu koja je paralelna vektoru brzine neuznemirene struje. Veoma je interesantno da za α ≤ 3 vrijednosti cL ne zavisi od Re. Vrtloènje iza cilindra pojavljuje se pri veim Re nego to je to slu~aj kod fiksnog cilindra. U slu~aju nestacionarnog strujanja simulacija je ura|ena za slu~aj R = 100 (vizualizacija strujanja je pokazana na slici 3) i α ≤ 2. Srednja vrijednost za cL raste dok za cD opada sa porastom α. Veoma je interesantno da vrijednost α nema veliki uticaj na promjenu Strouhalovog broja St. za Re = 100 i α ≥ 1,8 ne postoji vrtlo`ni trag iza cilindra to je direktna posljedica rotacije cilindra. Svi ovi efekti ukazuju na ~injenicu da rotacija cilindra ima zna~ajan uticaj na raspored pritisaka i brzina u strujnom polju.

3. CFD APPLICATIONS 3.1. Rotating Cylinder The 2D laminar viscous flow around a rotating circular cylinder represents a complicated flow case for which a complete analytical solution does not exist, hence existing treatments of rotating flows are either experimental or numerical: The flow is accelerated on one side of the cylinder and decelerated on the other side, causing the pressure on the accelerated side, resulting in a mean lift force. Such a phenomenson is referred to as the Magnus effect. This effect has fascinated many fluid mechanics researchers and has triggered various investigations of the cross-flow around rotating cylindres. In contrast to the flow past stationary cylinders in which quantities of the flow field depend on the Reynolds number Re only, in this case the ratio of peripheral Rω (ω beting the angular velocity) to free-stream velocity U constitutes a parameter α which also must be taken into consideration: The Reynolds number is defined in the usual way as Re = U D/ν, where U is velocity of undisturbed flow, D is cylinder diameter and ν is kinematic viscosity. Since only some values of Re are covered in available numerical studies, the aim of the investigations performed at LSTM Erlangen has been to obtain a consistent set of data for drag and lift coefficients (cD, cL) and a deeper insight into pressure distribution and vortex development behind the body, covering the whole range of Re for the steady flow case (Re ≤ 45), and treating 0 ≤ α ≤ 6 as a parameter. Furthermore, simultions for unsteady flows, Re=100, have also been carried out. The simulations were done with FASTEST 2D code using differents sizes of circular and rectangular domains in order to investigate the dependence of the results obtained on Re. According to the results obtained for the steady flow case (Figs. 1 and 2), it is obvious that the value of cD decreases with increasing rotational velocity α and the value of the lift coefficient increases with increasing rotational velocity of the cylinder. As expected, the influence of pressure distribution is stronger than that of friction, resulting in a decrease in the drag coefficient and an increase in the lift coefficient. If the flow is from left to the right and the cylinder protates in a clockwise direction, the pressure minimum moves in a counterclockwise direction, making the projection of the resulting force on the flow direction smaller and smaller. In the case of a nonrotating cylinder, the pressure distribution remains symmetric to the axis of flow direction. It is very interesting that for α ≤ 3 the value of the lift coefficient is almost insensitive to the value of Re. It has also been noted that by rotation of the cylinder the apprearance of vortices is suppressed and they appear for higher Re (Re > 20) than it is the case with a non-rotating cylinder (5 ≤ Rw ≤ 10).

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In the case of unsteady flow, calcultions have been carried out for Re = 100 (flow visualization is presented in Fig. 3) and α ≤ 2. According to the results obtained for α > 0, it is obvious that the average value of the drag coefficient decreases and the average value of the lift coefficient increases when the rotational velocity of the

cylinder grows. Surprisingly, the value of α seems not to have a large influence on the Strouhal number St. In the case when α ≥ 1.8, vortex shedding no longer exists because it is suppressed by the effect of rotation. All these of fects clearly demonstrate that rotation of a cylinder has a substantial effect on the flow pattern.

Slika 1: cD = cD (Re, α) Slika 2: cL = cL (Re, α) Figure 1. cD = cD (Re, α) Figure 2. cL = cL (Re, α) 3.2. Strujanje s odvajanjem iza aeroprofila Simulacija velikih vrtloga (Large Eddy Simulation – LES) predstavlja opte prihvaenu tehniku za numeri~ku simualciju nestacionarnih turbulentnih strujanja u kojima dolazi do odvajanja grani~nog sloja. Me|utim, ova tehnika ima bitnih nedostataka kao to su, nedostatak adekvatnog modela pomou kojeg bi se efikasno mogli modelirati mali vrtlozi (subgrid scale modeli) ili adekvatni grani~ni uslovi na zidu (wall modeli) koji bi mogli da pomognu da se vrijeme ra~unanja zna~ajno skrati. Usljed izuzetne ekspanzije u razvoju informacione tehnologije otvara se mogunost simulacije strujanja u izuzetno sloènim geometrijama sa veoma sloènim mreàma. Trenutno se na LSTM-u vri simulacija strujanja oko aeroprofila (NACA-4415) unutar kanala.

3.2. Separated Flow Past an Airfoil It is generally accepted that the large eddy simulation (LES) approach is a promising tool for highly unsteady turbulent flows with large separation and recirculation regions. However, LES is still suffering from some deficiencies such as proper subgrid scale modelling, wall boundary conditions and numerical methods. Ehereas much effort in the past was directed towards simple geometries and flow configurations, currently a strong tendency towards more realistic test cases is observed, which is crucial in order to make LES a well-established technique for complex and practically relevant flow. There is ongoing research at LSTM concerning a nominally 2D airfoil, based on an NACA-4415 profile, mounted inside a channel.

Slika 3: Vizuealizacija strujanja za Re=100 i α=1,5 Figure 3. Flow vizualisation for Re=100 and α=1,5

Slika 4: Blok-struktuirana mreà oko aeroprofila Figure 4. Block grid around the airfoil

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Reynoldov broj se kree u intervalu Re = 8. 104 – 106. Trenutna vrijednost ugla pod kojim je profil postavljen iznosi α = 18o, a predvi|eno je da se mijenja u intervalu 0o ≤ 22.5o. Cilj ovog istraìvanja je da se detaljno ispitaju svi fizi~ki aspekti ovog problema kao i da se procijene mogunosti LES tehnike za ovaj tip strujanja. U prvom dijelu projekta bie ispitano strujanje pri Rec = 20,000 koji e sistematski biti poveavan. Simulacije se vre sa programom LESOCC. Da bi se skratilo vrijeme ra~unanja grani~ni sloj na zidovima kanala nije rijeen na uobi~ajen na~in nego je iskoriten grani~ni uslov simetrije. Periodi~ni grani~ni uslov je koriten u pravcu koji je normalan na ravan koju obrazuju vektor brzine fluidne struje i tetiva profila. krivolinijska blok-struktuirana mreà (slika 4) sastoji se od 12 blokova i 8,33 miliona kontrolnih volumena (76 kontrolnih volumena u pravcu u kojem je koriten periodi~ni grani~ni uslov). Dobijeni rezultati pokazuju da vrtloènje na silaznoj ivici profila ima veliki uticaj na strujno polje u cjelini. Strouhalov broj vrtlo`nog ciklusa je St = fc/u∞ = 0.63 i St' = fc ⋅ sin α/u∞ = 0.195. Ove vrijednsoti se slaù sa eksperimentalnim podacima za nagnutu tanku plo~u za koju je St' ≈ 0.15 za 20o≤ α ≤90o a kada je α ≤20o dolazi do porasta St (vidjeti npr. [19]). Strujno polje za vremenski usrednjeno strujanje prikazano je na slici 5. Tokom po~etne faze ovaj vrtlog je vezan za silaznu ivicu profila. Tokom vremena on raste da bi se u jednom trenutku odvojio, nakon ~ega ga fluidna struja odnosi nizstrujno. Tada po~inje novi vrtlo`ni ciklus. Simulacija strujanja oko tanke plo~e nagnute pod istim uglom kao i profil dala je kvalitativno iste rezultate. Ovo je sasvim o~ekivano jer je za oba slu~aja razlika u geometriji silazne ivice (koja ima dominantan efekat) neznatna. na prednjoj ivici profila dolazi do odvajanja grani~nog sloja koje je praeno efektom koji je u literaturi poznat kao Kelvin-Helmholtzova nestabilnost. Prilikom strujanja, na gornjoj strani profila dolazi do vrtloènja fluida u smijeru kazaljke na satu (vidjeti sliku 5). U ovom dijelu strujnog polja pritisak je skoro konstantan. Veli~ina ovog vrtloga je strogo zavisna od veli~ine i ja~ine vrtloga koji nastaje na silaznoj ivici profila (koji ima orijentaciju u smijeru suprotnom od kazaljke na satu). Dok vrtlog koji ima orijentaciju u smjeru suprotnom od kazaljke na satu raste, vrtlog koji ima orijentaciju u smijeru kazaljke na satu postaje sve manji.

The Reynolds number rangs from 8⋅104 to 106. The angle of attack α can be varied between 0o and 22.5o and is currently fixed at α=18o. The goal is to study the physics of stalled airfoil flows in detail and to evaluate the usefulness of LES for this kind of flow. Therefore, this study first concentrates on a comparatively low Rec=20,000, which will be increased systematically in the ongoing project. This ensures a rasonable resolution and therefore reliable results. Furthermore, it admits the application of no slip conditions at the surface of the airfoil. In order to save grid points the boundary layers of the channel walls are not resolved and approximated by slip conditions. Periodicity in the spanwise direction is asumed and calculations are performed with the LESOCC code. A curvilinear block-structured grid (see Fig. 4) consists of 12 blocks with a total of ≈ 8.33 milion control volumes (76 CVs in spanwise direction). The grid points are clustered in the vicinity of the airfoil and at the leading and trailing edges. The LES results show that the entire flow field is strongly dominated by the development and shedding behaviour of trailing edge vortices. The Strouhal number of this shedding dycle is St = fc/u∞ = 0.63 i St'=fc⋅sinα/u∞ = 0.195. These values are consistent with experimental findings for inclined thin plates which observed a nearly constant St' ≈ 0.15 for 20o≤ α ≤90o and a strong increase of St' for α ≤ 20o (see. e.g., [19]). The flow structure is also visible in the time-averaged flow field shown in Fig. 5. During its initial phase this vortex is attached to the trailing edge of the airfoil while vorticity is accumulated in it, being fed by the corresponding shear layer. The vortex size is continuously increasing. After it has reached a certain diameter, the vortex is shed and convected downstream, while diffusion of vorticity tekes place. Then a new shedding cycle begins. Simulations of the flow around an inclined flat plate under the same flow conditions indicate very similar flow features as observed for the airfoil. Owing to the konwledge of the dominance of the railing edge vortex, this obeservation is not unexpected. In both cases the geometry of the trailing edge is only slightly different, leading to comparable trailing edge vortices. In addition to the shear layer developing at the trailing edge, a second one of weaker strength is generated near the leading edge. The flow separates shortly after the leading edge forming the free shear layer in which a Kelvin-Helmholth instability is detected in the instantaneous flow field. Furthermore, fluid circulation in a clockwise direction is observed, leading to a large recirculation region on the leeward side of the airfoil (see Fig. 5). A nearly constant pressure distribution is found in the separation region on the leeward side. However, no regular shedding motion of vortices generated at the leading edge is visible

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Slika 5: Vremenski usrednjeno strujno polje Slika 6. Iso-povrine pritiska p za dati polje, strujne linije i pritisak vremenski trenutak pFigure 5: Time-averaged flow field, streamlines Figure 6: The instantaneous iso-surfaces of and presure presure p p Poslije odre|enog vremena dolazi do odvajanja vrtloga na silaznoj ivici tako da preostali vrtlog ima dovoljno prostora da se rairi do pojave novog vrtloga. za razliku od klasi~nog vrtlo`nog strujanja iza tupog tijela (npr. oko fiksnog clindra) kod kojeg postoje vrtlozi istog intenziteta i suprotne orijentacije, kod strujanja oko aeroprofila i nagnute plo~e pri postojeem uglu α dolazi do pojave izrazito asimetri~nog vrtlo`nog traga. Vizualizacija ovog trodimenzionog efekta prikazana je na slici 6. na kojoj su jasno vidljive vrtlo`ne strukture koje se javljaju iza tijela.

The size of the attached clockwise rotating recirculation region is strongly dependent on the presence, the size and the strangth of the counter-clockwise vortex structure arising at the trailing edge. While the counterclockwise vortex is increasing in size and strength, the region of clockwise rotating fluid is decresing. However, after the trailing edge vortex is shed and convected downstream, teh clockwise vortex has enough space to extend in size until the next trailing edge vortex is developing. In contrast to classical vortex shedding past bluff bodies showing well-established staggered arrangements of vortices of opposite sign and equal strength, for the inclined flat plate and the airfoil at the present α a highly asymmetric wake with vortices of unequal strength is observed. A 3-D visualization of the flow field by isto-surfaces of the instantaneous pressure is shown in Fig. 6. It clearly shows large-scale vortical structures in the wake and also the breakup of shear layers into smaller structures behind the leading and trailing edges.

Slika 7: Geometrija reaktora zajedno sa numeri~kom mreòm Figure 7: Reactor geometry with the reactor mesh

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3.3. Hemijski procesi izdvajanja materijala iz reaktivnih gasova

Hemijski proces izdvajanja materijala iz reaktivnih gasova (CVD proces) predstavlja jedan od moguih postupaka za proizvodnju kristala. Druga dva veoma dobro poznata postupka su ~o~larski (CZ) proces [10], [20], i [21] i fizi~ki proces transportovanja materijala kroz inertnu gasnu sredinu (PVT proces) [10], [22], i [23]. Ovi postupci zajedno sa dobivenim materijalima se upotrebljavaju u mnogim tehni~kim granama, npr. u mikroelektronici (tranzistori), opti~ki ure|aji (laseri, vlakna), magnetni materijali (magnetne trake), ure|aji za iskoritenje sun~eve energije (solarne elije) i ~ak za dekorativna ili zatitna presvla~enja u automobilskoj industriji. U osnovi CVD procesi mogu biti veoma jednostavno opisani. Reaktivne GK-e koje sadrè atome materijala koji e biti taloèn uvode se u reaktor u gasnoj smjei sa transportnim gasom. Sasceptor na kome se vri taloènje materijala se nalazi u kontrolisanom dijelu reaktora. Sa dolaskom gasne smjee reaktanata i transportnog gasa u kontrolisani dio reaktora mogue je odpo~injanje homogenih hemijskih reakcija. U tom slu~aju (u suprotnom, samo reaktivne GK-e) reaktanti i produkti homogenih reakcija se transportuju do reaktivnih povrina sasceptora gdje se odvijaju heterogene hemijske reakcije. ovo ima za posljedicu formiranje tankog ~vrstog sloja. Na kraju se gasni produkti reakcija, konvekcijom i/ili difuzijom, transportuju do izlaza iz reaktora. koristei CVD tehniku mogue je proizvesti veoma tanke slojeve kristala visoke ~istoe. Zahtjevi kod primjene ovakvih kristala su visoke elektri~ne, opti~ke, hemijske i mehani~ke osobine samog kristala. Sve ove osobine su zna~ajno definisane interakcijom hidrodinamike, transportnih procesa i hemijskih reakcija u CVD reaktoru, koje opet jako zavise od parametara procesa i geometrije reaktora. Dosadanji razvoj i optimizacija CVD procesa i reaktora su bili bazirani uglavnom na empirijskim podacima i postepenim unaprije|enjima metodom "pokuaja-i-greke". Tokom zadnjih godina napravljen je zna~ajan proces u matematskom modeliranjU CVD procesa. Tako su razvijeni brojni matematski modeli koji se koriste za numeri~ke simulacije. naàlost, nijedan od ovih modela nije u potpunosti baziran na fizici nego na korealcijama zavisnim od procesa i geometrije reaktora i eksperimentalno dobivenim konstantama. I pored ovoga, razvijeni modeli omoguavaju bolje razumijevanje va`nih pojava u CVD procesima i osnaùju poboljanja u optimizacijama procesa i sistema. Optimizacija procesa se odnosi na ispitivanje i poboljanje samog procesa (njegove hemije), dok je optimizacija sistema bazirana na poboljanju radnih parametara (ulazni protok, pritisak, temperatura, koncentracija GK-ta) i geometrije reaktora koja direktno uti~e na uniformnost i ~istou kristala [24].

3.3. Chemical Vapour Deposition Processes The Chemical Vapour Deposition (CVD) process represents one of the possible techniques for crystal growth. Another two well known techniques are the Czochralski (CZ) process [10], [20] and [21] and Physical Vapour Transport (PVT) process [10], [22] and [23]. These techniques and their products are applied in many technological areas, e.g. in microelectronics (transistors), optical devices (lasers, fibres), magnetic materijals (recording tapes), solar energy conversion (solar cells) and even for decorative or protective coatings in the automoible industry. The background of the CVD processes is actually very simple. The reactive species which contain the atoms of a materijal to be deposited are introduced into a reactor as a gas diluted with an inert carrier gas. The susceptor on which the deposition takes place is positioned in the controlled environment of the reactor chamber. When a gas mixture of the reactants and carrier gas is transported within the reactor chamber, homogeneous gas-phase reactions may tanke place. If this is case (otherwise only the reactive species), the initial reactants and products from previous reactions are transported to the susceptor reactive surfaces where the heterogeneous surface reactions take place, leading to the formation of a solid film. At the and of reactions, reaction products are transported by convection and/or diffusion away from the reactor chamber to the out-let of the reactor. By the CVD technique, deposition of very thin solid films with high purity is provided. Applications of these films require the highlevel electrical, optical, chemical nad mechanical properties. All of these properties are greatly determined by interactions of hydrodynamics, transport phenomena and chemical reactions in the CVD reactor chamber, which are, in turn strongly dependent on the process parameters and reactor geometry. In the past, the development and optimization of CVD processes and reactors have been based largely on empirical findings and step-by-step improvements by the methods of trial-and-error. However, in recent years considerable progress in the mathematical modelling of CVD processes has been made and various mathematical models employed in numerical simulations have been developed. Unfortunately, none of them is fully based on fundamental physics but on the process – and reactor – dependent correlations and fitting constants. However, the developed CVD models lead to a batter understanding of the important basic aspects of the CVD processes and enhanced improvements in process and design optimizations. The process optimization is related to the investigation of the process itself (chemistry), while the design optimization is based on the improvement of the operating conditions (inflow rate, pressure, temperature, apecies concentrations) and the reactor geometry, which directly influence the uniformity and purity of the crystal [24].

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Numeri~ki model za rast kristala razvijen na LSTM-u opisuje strujanje, prenos toplote i mase uklju~ujui homogene i heterogene reakcije. prenos toplote tako|e uklju~uje i radijaciju, dok prenos mase uklju~uje konvektivni, difuzioni i termodifuzioni transport svih GK-ta. ovaj model implementiran u FASTEST (2D i 3D verzije) ra~unarske programe je primijenjen na razli~ite vrste CVD procesa (aksijalno orijentisani rast silicijum kristala, silicijum dioksid, titan dioksid, III-V jedinjenja (MOVPE procesi) kao to su GaAs, AlxGa1-xAs i InxGa1-xAs1-yPy). U ovom poglavlju su pokazana dva primjera primjene CFD-a. U prvom primjeru je prezentirana primjena CFD-a u optimizaciji titan dioksid (TiO2) CVD procesa. Drugi primjer je orijentisan na optimizaciju sistema koritenog za aluminijum-galijum-arsenid (AlGaAs) MOVPE proces. U oba slu~aja strujanje je laminarno a prora~uni su ura|ene u FASTEST-u i na vektor-paralelnoj maini. Numeri~ka simulacija u prvom primjeru je ra|ena na geometriji koja je pokazana na slici 7. Ulaz u reaktor je obezbije|en u vertikalnom pravcu kroz dvije male rupe, obje pre~nika 8 mm. Silicijumski sabstrejt se nalazi u oblasti gdje strujanje, nakon ulaznog poremeaja, postaje sporije i nastoji biti redistribuirano. nerotirajui vejfer na sasceptoru ima pre~nik 100 mm. Numeri~ka mreà ima 315392 CVs. Sasceptor se zagrijava u podru~ju izme|u 553 i 683 K, dok je totalni pritisak fiksiran na 0,5 mbar. Izvan ovog temperaturnog opsega, za slu~aj titan dioksid (TiO2) CVD procesa, gotovo da i nema formiranja kristala na sabstrejtu. kao transportni gas koriten je nitrogen (N2). Cilj projekta je bio razviti nove titan predreaktante za TiO2 CVD proces. Rad je bio motivisan poboljanjem upotrebnih i talo`nih karakteristika Ti jedinjenja. Numeri~ki model je razvijen na bazi veoma jednostavnog hemijskog mehanizma koji je izveden iz eksperimentalnih podataka i koriten za objanjenje eksperimentalnih istraìvanja. Pokazano je da eksperimentalni rezultati mogu biti perfektno opisani ovim jednostavnim modelom (jed. 6) za sve reìme u podru~ju izme|u kineti~ki i difuziono ograni~enih reìma, uklju~ujui i grani~ne reìme. Jo jedna od glavnih uspjenosti tog rada je podrka razvoju procesa. Zbog nepozantih konstanti homogenih reakcija modeliran je samo transprotni mehanizam za glavni produkt i to bez uzimanja u obzir efekata homogenih reakcija. prema Arrheniusovom zakonu, sveobuhvatna heterogena reakcija je modelirana jedna~inom

4)(exp OHTiA

on cTR

Ekj ⋅

⋅−⋅=− (6)

4)(OHTi

gdje je EA energija aktivacije dobivena eksperimentalno, ko je konstanta uzeta iz dvo-dimenzionalnog modela, j je normalni molni fluks

glavnog produkta i c je njegova molna

koncentracija na povrini sabstrejta.

The numerical model for crystal growth developed at the LSTM describes the flow and heat and mass transfer with homogeneous and heterogeneous reactions included. The heat transfer also includes radiative heat transport, whereas the mass transfer includes the convective, diffusive and termodiffusive transprot of all species. This model implemented in FASTEST (2D and 3D versions) computer codes was applied to the various kinds of CVD processes (epitaxial silicom, silicom dioxide, titanium dioxide and III-V compounds such as GaAs, AlxGa1-xAs i InxGa1-xAs1-yPy). In this section the examples of two CFD applications are shown. In the first example, the application of CFD in a process optimization of a titanium dioxide (TiP2) CVD process is presented. The second example is dedicated to the design optimization for an aluminium-gallium-arsenide (AlGaAs) MOVPE process. In both cases the flow is laminar and the calculations were done with FASTEST and carried out on a vector-parallel machine. The simulation in the first example was performed on the geometry shown in Fig. 7. An inlet is provided in a vertical direction through two small holes both with a diameter of 8 mm. The silicon substrate is positioned in the region where the flow, after an inlet disturbance, becomes slow and is to be redistributed. The wafer at the susceptor is not rotated and has a diameter of 100 mm. The mesh has 315392 CVs. The susceptor is heated in the range 553 – 683 K and the total pressure is fixed at 0,5 mbar. Beyond this temeprature range in the case of titanium dioxide deposition there is almost no deposition at the substrate. Nitrogen (N2) was used as a carrier gas. The aim of the project was the development of new titanium precursors for TiO2 deposition. The motivation for this work lies in the improvement of the handling and deposition characteristics of Ti compounds. The numerical model was based on a very simple chemical mechanism derived from experimental data and is used to explain the experimental observations. It was found that the experimental deposition results may be perfectly deserbed by that simple model (Eq.6) for all intermediate, kinetic–and diffusion-limited regimes. Also support for the process development is the major goal of that work. Because of the unknown homogeneous decomposition reaction constants, only the transport of main decomposition product was modelled without any homogeneours reactions. According to the Arrhenius'law, the overall heterogeneous reaction was modelled by the equation

4)(exp OHTiA

on cTR

Ekj ⋅

⋅−⋅=−

4)(OHTi

(6)

where EA is the activation energy derived from experimental data, ko is a constant fitted from the two-dimensional modelling, j is the normal molar flux

of the main decomposition product and c is

its concentration at the substrate surface.

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Slika 8. Komparacija numeri~kih (2D i 3D) i Slika 9: Komparacija numeri~kih (pune linije eksperimentalnih vrijednosti rasta kristala u srednjem i eksperimentalnih (isprekidane linije) vrijednosti popre~nom presjeku (y = 0) za sve reìme rasta kristala na vejferu za slu~aj T=673 K Figure 8. Comparison of calculated (2D and 3D Figure 9. Comparison of calculated (solid lines) calculations) and measured growth rates along the and measured (dashed lines) growth rates on middle cross-section (y=0) for all regimes the wafer for the case T=673 K Na slici 8 je pokazana komparacija numeri~kih i eksperimentalnih rezultata u srednjom popre~nom presjeku vejfera (y = 0) za sve radne reìme. Slaganje izme|u njih je veoma dobro za sve reìme i indicira dobru predvidljivost razvijenog modela. Kao to se moè vidjeti najloije slaganje je kod temperature 673 K. Komparacija numeri~kih i eksperimentalnih rezultata rasta kristala na povrini vejfera za ovaj slu~aj je pokazana na slici 9. Odstupanje raste od centra ka periferiji. ovo bi moglo biti objanjeno ili razlikom pretpostavljenog i stvarnog koeficijenta difuzije ili nehomogenom distribucijom temperature na sabstrejtu. Trea mogunost moè biti zbog nepoznatog mehanizma homogenih reakcija.

In Fig. 8 a comparison of the calculated and measured growth rates along the middle cross-section (y = 0) for all regimes is shown. The agreement between them is very good in all regimes and indicates a good predictability of the ceveloped model. As can be seen, the worst agreement is for the temperature 673 K. The comparision of the calculated and measured growth rates on the wafer surface for this case is shown in Fig. 9. The deviation increases from the centre to the periphery. This could be explained ether by the difference in the estimated and real diffusion coefficients or by the non-homogeneous temperature distribution on the substrate. Another possibility might be the unknown homoeneous chemistry.

Slika 10: [ema poboljane geometrije na ulazu u Slika 11: Rast kristala na rotirajuem reaktor. Ulazi za razli~ite vrste gasova su odvojeni vejferu za slu~aj Qtot. = 2.9 slm Figure 10: Scheme of the improved inlet geometry Figure 11: Growth rate on the rotated wafer for with a separated inlet for different gas species the case Qtot. = 2.9 slm

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Drugi primjer se bavi problemom optimizacije sistema za AlGaAs MOVPE proces. Kao rezultat ovog istraìvanja dobijeni su poboljana geometrija na ulazu u reaktor (prikazana na slici 10) i parametri strujanja T=1003 K, p=20 mbar, QIII/Qv = 1.4 i Qtot. = (2-2.9) slm. Standardni prereaktanti T M Al, TMGa i AsH3 i nitrogen kao transportni gas su koriteni. Sabstrejt je napravljen od GaAs materijala. Vejfer ima pre~nik 2" i rotira se sa Ω=100 min-1. Poboljana geometrija je ilustrovana kroz odvojeni ulaz grupa flowMO i flowHydride. Najzna~ajnije prednsoti ovakve ulazne geometrije u pore|enju sa konvencionalnim ulazom, gdje sve GK-e u reaktor ulaze zajedno, su: (a) mogunost za prereakciju je smanjena, tako da ne bi trebalo biti formiranih ~estica sa prerakcijom, (b) ubrizgavanje hidrida bliè povrini sabstrejta poboljava izdvajanje karbona i oksigena poveavajui ~istou kristala i (c) umjesto prinudnog mijeanja, sada je mijeanje gasova prouzrokovano difuzijom i konvekcijom. ovo poboljava transferzibilnost procesa rasta kristala od jednog do drugog reaktora. Poboljana geometrija je ilustrovana kroz odvojeni ulaz grupa flowMO i flowHydride. Najzna~ajnije prednsoti ovakve ulazne geometrije u pore|enju sa konvencionalnim ulazom, gdje sve GK-e u reaktor ulaze zajedno, su: (a) mogunost za prereakciju je smanjena, tako da ne bi trebalo biti formiranih ~estica sa prerakcijom, (b) ubrizgavanje hidrida bliè povrini sabstrejta poboljava izdvajanje karbona i oksigena poveavajui ~istou kristala i (c) umjesto prinudnog mijeanja, sada je mijeanje gasova prouzrokovano difuzijom i konvekcijom. ovo poboljava transferzibilnost procesa rasta kristala od jednog do drugog reaktora. Uniformnost kristala zna~ajno zavisi od rotacije vejfera. kako rotacija uti~e na uniformnost kristala pokazano je na slici 11. Na slici 12 pokazani su eksperimentalni rezultati relativne debljine kristala u odnosu na centar vejfera za pet razli~itih slu~ajeva. Slika 13 pokazuje numeri~ke rezultate dobivene za iste radne uslove u kojima su dobiveni i eksperimentalni rezultati. Ako je apsolutno odstupanje manje od 1% smatra se da je uniformnost kristala idealna. Iako su optimalni totalni ulazni protoci razli~iti za ekspeirmente i numeri~ke prora~une, numeri~ko ispitivanje je dragocjeno za razumijevanje i optimizaciju procesa rasta kristala. osim toga ono pomaè da se odrede parametri koji moraju biti varirani da bi se dobio uniforman rast kristala.

The second example concerns a problem of design optimization for an AlGaAs MOVPE process. As an outcome of that investigation the improved inlet geometry shown in Fig. 10 and the flow parameters T = 1003 K, p = 20 mbar, QIII/QV = 1.4 and Qtot. = (2-2.9) slm were achieved. The standard precursors TM Al, TMGa and AsH3 and nitrogen as carrier gas were used. The substrate is made from GaAs material. TGhe water has a diameter of 2 in and rotates with Ω = 100 rpm. The improved geometry is illustrated through a separated inflow of the groups flowMO and flowHydride. The major advantages of this kind of inlet compared with a conventional inlet, where all species are introduced into a reactor together, are (a) the probability of prereactions is reduced, so the particles should not form by prereactions, (b) the injection of the hydride nearer to the substrate surface improves the segregation of carbon and oxygen species, increasing the crystal purity and (c) instead of the forced gas mixing, gas mixing is caused by diffusion and convection, which improves the transferability of the crystal growth processes from one reactor to another. The uniformity of the crystal depends considerably on the wafer rotation. How the rotation influences the crystal uniformity is shown in Fig. 11. In Fig. 12 the exprimental results for the relative crystal thickness with respect to the wafer centre for five different cases are shown. Fig. 13. shows the computation results obtained under same conditions as the experimental results. If the absolute deviation is smaller than 1%, one concludes there is perfect crystal uniformity. Although the optimal total inflow rates are different for experiments and calculations, the numerical investigation is valuable for the understanding and optimization of the crystal growth processes. Additionally, that helps to fix the parameters which have to be varied in order to obtain uniform crystal growth.

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Slika 12: Eksperimentalne vrijednosti relativnih Slika 13: Numeri~ke vrijednosti relativnih debljina debljina kristala u odnosu na centar vejfera za kristala u odnosu na centar vajfera za ~etiri pet razli~itih slu~ajeva razli~ita slu~aja Figure 12: Experimental relativ crystal thickness Figure 13: Computational relative crystal thickness with respect to the wafer centre for five with respect to the wafer centre for four different cases different cases

4. ZAKLJUÂK Progres u jednoj nau~noj oblasti obi~no ima za posljedicu razvoj durgih prateih nau~nih oblasti. ovo je naro~ito izraèno u slu~aju CFD-a. Bolje hardverske performanse kombinovane sa brzim razvojem numeri~kih metoda stimulisale su razvoj razli~itih dijelova CFD-a, kao to su turbulencija ili simulacija hemijski reaktivnih strujanja. Ovaj rad je pokazao kako smimulacija strujanja na ra~unarma visokih performansi moè biti upotrebljena u razli~itim strujnim reìmima i geometrijama sa ili bezhemijskih reakcija do kompleksnog turbulentnog strujanja. iako CFD tehnike jo uvijek teè ka novim poboljanjima, kao to su porast ta~nosti numeri~kog rjeenja, analiza strujanja u proizvoljnim tro-dimenzionalnim geometrijama i obuhvaanje vie fizi~kih i hemijskih fenomena, rezultati predstavljeni u ovom radu nagovijestili su da numeri~ka mehanika fluida zajedno sa eksperimentalnim i dostupnim analiti~kim metodama obezbje|uje jaku osnovu za nadu da "zlatno doba" mehanike fluida tek dolazi.

4. CONCLUSIONS Technological progress in one field typically has a strong impact on many other fields, promoting developments which are otherwise not possible. This is especially true in the case of CFD. Increased hardware performance combined with the rapid development of numerical methods triggered different fields of CFD, such as turbulence and simulation of chemically reactive flows. The present work has demonstrated how high-performance computing can be used in different flow regimes and geometries, ranging from laminar steady flow with or without chemical reactions to complex turbulent flow. Although the CFD techniques are still tending toward new improvements such as increasing the accuracy of the numerical solution, flow predictions in more complex three-dimensional geometries and inclusion of more physical and chemical phenomena, tehe results presented here have indicated that numerical fluid mechanics together with experimental and available analytical methods give a strong basis for having the hope that "a golden era" of fluid mechanics is coming.

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[2] J.H.Ferziger, M.Peri (1996): Computational Methods for Fluid Dynamics. Pringer, Berlin.

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[4] J.Smagorinsky (1963): General Circulation Experiments with Primitive Equations, I. The Basic Experiment. Mon. Weather Rev., 91, 99-165.

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Three-Dimensional Simulation of Flow and Thermal Field in a Czochralski Melt Using a Block-Structurated Finite-Volume Method.J. Cryst. Growth, in press.

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[25] T.Leistner, L.Frey, A.Bauer, C.Schmidt, K.Lehmbacher, P.Härter, W. Herrmann, E. Mei, P. Kaufmann, L.Kadinski, F.Durst (2001): Experimental and Numerical Study of TiO2 CVD Using the New Titanium Precursors. 199th Meeting of The Electrochemical Society, March 25-29, 2001, Washington DC.

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G.Strauch, H.Jürgensen (1997). ECS 192, CVD XIV, p. 230.

[27] M. Dauelsberg, H. Hardtdegen, L.Kadinski, A.Kaluza, P.Kaufmann (2001): Modeling and Experimental Verification of Deposition Behaviour During AlGaAs Growth; a Comparison for the Carrier Gases N2 and H2. J.Cryst. Growth, 223, 21-28.

[28] H.Hardtdegen, A.Kaluza, D.Gauer, M.v.d. Ahe,

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Mainstvo 3(5), 159 – 170, (2001) Stuchl V.;.....: [TA BI TREBALO DA BUDE OSNOVA...

[TA BI TREBALO DA BUDE OSNOVA ZA NOVI SISTEM ODR@AVANJA SLOVA^KIH @ELJEZNICA?

Prof. dr. Vladimir Stuchl1, Prof. dr. Juraj Gren~ik2, Prof. dr. Peter Zvolensk3, Univerzitet u @ilini, Mainski fakultet, Department of Machinery Maintenance Engineering, 010 26 @ilina SLOVAKIA, e-mail1: [email protected]; e-mail2: [email protected]; e-mail3: [email protected]

REZIME:

Na osnovu analize odràvanja voznog parka slova~kih èljeznica, te na osnovu trenutnih trendova razvoja sistema za odràvanje, predloèna su na~ela i osnove za promjenu sistema za odràvanje, a koji su zasnovani na analizama RCM i LCC. Nadalje predstavljeni su preduslovi za stvaranje informacionog sistema za odràvanje kojeg podràva CMMS, a koji su zasnovani na analizama pouzdanosti.

PRETHODNO SAOP[TENJE

,

t

Klju~ne rije~i: Sistem odràvanja, Informacioni sistem, Vozila èljeznice, Pouzdanost

WHAT SHOULD BE A BASIS FOR THE NEW MAINTENANCE SYSTEM ON THE SLOVAK RAILWAYS?

Prof. dr. Vladimir Stuchl1, Prof. dr. Juraj Gren~ik2, Prof. dr. Peter Zvolensk3, University of @ilina, Faculty of Mechanical Engineering, 010 26 @ilina SLOVAKIA, e-mail1: [email protected]; e-mail2: [email protected]; e-mail3: [email protected]

SUMMARY PRELIMINARY NOTES

Based on the analysis of rolling stock maintenance on the Slovak railways and current trends in maintenance systems developments, principles and fundaments for change in maintenance system are suggested, which are based on the RCM and LCC analyses. Furthermore prerequisites for creation of maintenance informa ion system supported by CMMS, based on reliability analysis are presented as well.

Key words: Maintenance system, Information system, Railway vehicles, Reliability

1. UVOD "Odràvanje nije cilj, ve na~in da se ostvare ciljevi jedne firme." Sve vea va`nost odràvanja je uzrok operativno-ekonomskih i tehni~kih utjecaja. Pored toga, postoje i brojni zahtjevi koji se postavljaju odràvanju, a koji se odnose na okoli, zdravlje i sigurnost. Sve vea sloènost proizvodnih sistema i sistema usluga postavlja sve vee zahjteve za vjetinama radnika na odràvanju. Dalji napredak u postizanju bolje operativnosti i unapre|enju nivoa automatizacije poveao je nivo ulaganja u kupovinu proizvodnih i transportnih sredstava. Zbog sve vee zavisnosti i me|usobne povezanosti objekata, kvarovi izazivaju visoke trokove usljed prekida proizvodnog toka i nastalih gubitaka.

1. INTRODUCTION "Maintenance is not a goal but a means to achieve a company’s goals." Growing importance of maintenance is caused by operational-economical and technological influences. Besides that, there are numerous other environmental, health and safety requirements asked from maintenance. Growing complexity of production and service systems raises high demands on skills of maintenance workers. Further developments in achieving higher performance and growing level of automation have increased the level of capital investments for the purchase of production as well as transport facilities. With growing dependence and interconnection of facilities, a failure causes high costs for a breakdown of production flow and consequent losses.

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Stoga odràvanje ima velik stepen odgovornosti u proizvodnim i operativnim trokovima. Niski proizvodni trokovi, zajedno sa odràvanjem rasporeda i kvaliteta i efektivnim odràvanjem, doprinose uspjehu firme na trìtu. Nema razloga da ovi osnovni postulati ne vaè kad je rije~ o vozilima èljeznice.

That is why maintenance has high degree of responsibility for production and operational costs. Low production costs together with keeping delivery schedule and quality, and with effective maintenance, contribute to success of a company in the market. There is no reason why these basic postulates would not be valid also in case of railway vehicles.

2. ODR@AVANJE I ORGANIZACIJA VOZILA @ELJEZNICE

Organizacija odràvanja vozila èljeznice se vri u skladu sa propisom V25 @SR-a (slova~kih èljeznica) "Propisi za popravke elektri~nih i dizel lokomotiva koji je doìvio sljedei napredak: a) Stupio na snagu u januaru 1967., b) Izmjena propisa V25, stupila na snagu u

januaru 1975., c) Nova verzija, stupila na snagu u januaru 1975., d) Proirenje norme milja izme|u povremenih

tehni~kih provjera i popravki dizel i elektri~nih lokomotiva, od februara 1978.,

e) Eksperimentalno provo|enje smanjenih remonta elektri~nih lokomotiva, od januara 1980.,

f) Registracija i obrada neplanskih popravki, od marta 1978.,

g) Transport i popravka tehni~kog stanja èljeznica izba~enih iz tra~nica od maja 1979.,

h) Nadgledanje opravki upotrebom integrisanih dokumenata, od januara 1979.,

i) Garniture to~kova lokomotiva – biljeènje popravki, biljeènje broja opravke, od januara 1981.,

j) Obnova profila to~ka bez podizanja teretnim kolima, od avgusta 1979.,

k) Daljina centra to~ka lokomotive, od aprila 1979., l) Nova verzija propisa V25, stupila na snagu u

julu 1982., m) Izmjena propisa V25, stupila na snagu u

januaru 1999. Ve u prvoj verziji propisa V25 (a) svrha odràvanja lokomotive je definirana na sljedei na~in: "Svrha odràvanja lokomotive je da se otklone utjecaji habanja na sastavne jedinice vozila, i da se preventivno stvore uslovi za rad bez kvarova u periodu izme|u planiranih pregleda i popravki. Osnova sistema za odràvanje su preventivni planirani pregledi i popravke koji se sprovode detaljno i na vrijeme, ~ime se uklanjaju utjecaji habnja i stvaraju se uslovi za ekonomi~an rad bez kvarova i za smanjenje obima opravki." Odràvanje lokomotiva se u osnovi dijeli na sljedee osnovne elemente: a) Servisiranje vozila koje je u funkciji, b) Periodi~ni pregledi i popravke vozila, c) Neplanirane popravke vozila.

2. MAINTENANCE AND ORGANI-SATION OF RAILWAY VEHICLES

Organisation of railway vehicle maintenance is being carried out in accordance with @SR (Slovak Railways) regulation V25 "Regulations for repairs of electric and diesel locomotives" that underwent the following evolution: a) Put into effect in January 1967, b) Modification of V25 regulation, put into effect

in January 1971, c) New version, put into effect in January 1975, d) extending of mileage norms between periodic

technical checks and repairs of diesel and electric locomotives, in February 1978,

e) Experimental carrying of reduced overhauls of electric locomotives, in January1980,

f) Registration and processing of unplanned repairs, in March 1978,

g) Transportation and fixing of technical state of derailed locomotives, in May 1979,

h) Monitoring of repairing works by use of integrated document, in January 1979,

i) Locomotive wheel-sets – marking of repairs, numbering and record-keeping, in January 1981,

j) Renewal of wheel profile without bogie lifting, in August 1979,

k) Locomotive wheel-centre distance, in April 1979 l) New version of V 25 regulation, put into

effect in July 1982, m) Modification of V 25 regulation, put into effect

in January 1999. Already in the first version of V25 regulation (a) purpose of locomotive maintenance is defined as follows: "Purpose of locomotive maintenance is to remove effects of wear on vehicle components and preventively create conditions for failure-free operation between planned inspections and repairs. Fundament of maintenance system is based on preventive planned inspections and repairs carried thoroughly and early enough, by which any effects of wear are removed and conditions for failure-free and economic operation and for decreasing volume of repairing work are created". Maintenance of locomotives was basically divided into the following principal elements: a) Vehicle servicing in operation, b) Periodical inspections and repairs of vehicles, c) Unplanned repairs of vehicles.

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Stoga preglede i opravke treba provoditi u tom obimu i tako kvalitetno da vozila rade ekonomi~no u periodu izme|u dva remonta, kao i dvije opravke na nièm nivou. To zna~i da bi opravke na nièm nivou trebale otkloniti utjecaje djelimi~nog habanja komponenti vozila. Remonte bi trebalo raditi u tom obimu da potpuno habanje vozila ne premai dozvoljene granice rada. U novoj verziji propisa V25 (c) iz 1975., definicija "osnove" sistema za odràvanje se promijenila samo dodavanjem "i servisiranje u toku rada" u: "Osnove sistema za odràvanje su preventivni planirani pregledi, popravke i servisiranje u toku rada, ~ime se otklanjaju utjecaji habanja i stvaraju se uslovi za ekonomi~an rad bez kvarova, kao i za poveanje obima popravki." Ali, podjela rada na odràvanju je promijenjena u sljedee kategorije: a) Servisiranje vozila za vrijeme rada, b) Pregledi vozila za vrijeme rada (uklju~ujui i

pregled nakon popravke u radionici), c) Periodi~ne popravke vozila, d) Planirane popravke vozila koje se vre u

peirodu izme|u periodi~nih popravki (pored radova koji se vre pod a), b) i c),

e) Popravke koje vri osoblje lokomotive, f) Neplanirane popravke vozila koje se vre poed

a), b), c), d) i e). Podjela radova na odràvanju vaì i u 2001. Elektri~ne i dizel lokomotive su uvijek bile podijeljene u grupe za odràvanje; izmjene su se vrile samo u dodjeli pojedina~nih serija lokomotiva u pojedina~ne grupe. U skladu sa samim propisom, elektri~ne lokomotive se dijele u IX grupa za odràvanje, a dizel lokomotive u VII (ta~ke 1 i 2).

Preventive maintenance system is based on the principle that periodical inspections and repairs should be carried out in such extent and quality to ensure failure-free, safe and economical operation between individual inspections and repairs while keeping given performance norm. Therefore, they must be carried out in such extent and in such quality so that the vehicles work economically in operation between two overhaul repairs as well as between repairs of lover level. That means that repair works on lover levels should remove effects of partial wear of vehicle components. Overhaul repairs should be done in such an extent so that total vehicle wear would not exceed permitted operational limits. In the new version of V25 regulation (c) from1975, the definition of maintenance system "fundament" changed only by adding "and on servicing in operation " to: " Fundament of maintenance system is based on preventive planned inspections, repairs and servicing in operation, by which effects of wear are removed and conditions for failure-free and economic operation and for decreasing volume of repairing work are created". But division of locomotive maintenance works was changed into following categories: a) Vehicle servicing in operation, b) Vehicle inspections in operation (including

inspection after repair in workshop), c) Periodical repairs of vehicles d) Planned repairs of vehicles carried between

periodic repairs (besides works carried in a),b) and c)),

e) Repairs carried by locomotive staff, f) Unplanned repairs of vehicles, carried besides

works in a), b), c), d) and e). This division of maintenance works is valid also in the year 2001. Electric and diesel locomotives were always divided in maintenance groups; changes were done only in assigning of individual locomotive series into the individual groups. According to the actual regulation, the electric locomotives are divided into IX maintenance groups and diesel locomotives into VII (Tables 1 and 2).

Tabela 1. Podjela lokomotiva u grupe za odr avanje i norme kilometraè izme|u radova na odr avanju (u hiljadama km) Table 1 - Division of electric locomotives into maintenance groups and norms of mileage between

maintenance works (in thousands km)

Nivoi odràvanja – Maintenance levels Grupa za odràvanje Mainten. group

Serija vozila Vehicle series EO EM EV ES/EH

I 199 7 dana 7 days

30 dana 30 days

24 mjes. 24 months

4 godine 4 year

II 405+905,411+911,420,495 0,6-0,9 6-9 54 216 III 460+063 4,0-5,5 12-16,5 90 360 IV 560+060 4,5-6,0 13,5-18 90 360 V 110,210 1,3-2,5 10-15 90 270 VI 131 3,0-4,0 19-22 150 450 VII 125,121,140,182,183 1,3-2,5 16-22 130 520 VIII 240 2-4 22-30 210 420 IX 162,163,263,350,362,363 1,5-5,5 22-30 240 480

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Tabela 2. Podjela dizel lokomotiva u grupe za odràvanje i norme kilometraè izme|u radova na odràvanju (u hiljadama km)

Table 2 - Division of diesel locomotives into maintenance groups and norms of mileage between maintenance works (in thousands km)

Nivoi odràvanja – Maintenance levels Grupa za odràvanje Maint. group

Serija vozila Vehicle series MO MM MV MS/MH

I 701,702,706,710,726 0,4-0,8 4-6 56-75 112-150 II 820,892 0,4-0,8 4-6 60-90 120-180 III 830,850,851 0,5-0,8 6-8 80-120 160-240 IV 810,811 0,9-1,2 6-9 100-140 200-280

V 720,721,731,735,742, 770,771

0,7-1,1 9-13 112-150 224-300

VI 751,752,753 0,8-1,2 12-16 125-170 250-340 VII 750,754,781 0,9-1,3 15-20 125-175 250-350 Zanimljivo je pratiti trendove norma kilometraè za neke serije lokomotiva:

It is interesting to follow trends in mileage norms for some locomotive series:

V25 EO EM EV ES1975 2,5 16 158 3841982 2,5 19 133 5321999 2,5 22 130 520

Maintenance category mileage (1000km)

Kilometraà kategorije za odràvanje (100 km)

Vehicle series 140, 141

0100200300400500600

EO EM EV ES

197519821999

V25 EO EM EV ES1975 2,5 16 128 3841982 0,9 22 154 6161999 4 30 210 420



Vehicle series 230, 240, 241

0100200300400500600700

EO EM EV ES

197519821999

V25 EO EM EV ES1975 2,5 16 128 3841982 0,9 22 154 6161999 5,5 30 210 480



Vehicle series 163, 162, 350, 363

0100200300400500600700

EO EM EV ES

197519821999

- 162 -


V25 MO MM MV MS1975 1,2 16 160 3601982 1,2 16 160 3201999 1,2 16 170 3401999 1,3 20 175 350


Kilometraà kategorije za odràvanje (100 km) podaci u drugom redu za 1999. vaè za seriju lokomotiva 754 data in the second line for the year 1999 are valid for loco series 754

Vehicle series 751, 752, 753, 754

0

100

200

300

400

MO MM MV MS

1975198219991999

Napomena: U ovim tabelama, kolona V25 ozna~ava godine kad je propis V25 bio izijenjen. Note: In the above tables, the column V25 stands for the years when the V25 regulation was modified.

O~igledno je iz grafikona da su predloène norme kilometraè ve u 1975. bile optimalne, tako da nije trebalo vriti nikakve izmjene ili nije bilo dovoljno podataka potrebnih za pravljenje izmjena. Isti trendovi se mogu zapaziti kod vagona za putnike i teret, dok tu postoje pokuaji da se izmijeni periodi~nost, pa da kao kod lokomotiva postoji kilometraà umjesto vremenskog perioda.

From the graphs that mileage norms were either already in 1975 proposed so it is evident optimally that there was no need to make any changes, or there were not sufficient data needed for making changes. The same trends could be observed also in case of passenger and freight wagons, while there are efforts to change periodicity from time periods to mileage as it is in case of locomotives.

3. PROJEKAT IZMIJENA ODR@AVANJA VOZILA @ELJEZNICE

Trenutno se slova~ke èljeznice nalaze u procesu transformacije, to tako|e utje~e i na sistem odràvanja voznog pogona. Osnovni zahtjev je stvaranje efektivnog sistema odràvanja uz minimalne trokove ali visoku korisnost vozila. Operator vozila èljeznice bi trebao nai optimum izme|u trokova za odràvanje i gubitaka koje uzrokuju kvarovi pri radu. Stoga e operator morati izabrati odgovarajua vozila za vozove koje opsluùje i obezbjedi njihov rad i pouzdanost, u skladu sa va`nou vozova. Transformacija bi trebala poveati pouzdanost usvajanjem novog sistema odràvanja i unaprije|enog menad`menta tog sistema. Ovo e se zasnovati na: • analizi potrebnih vozila u budunoti na osnovu

obima saobraaja, • analizi parametara i trokova vozila za njihov

rad (LCC), • analizi uloge skladita, • odlu~ivanju strukture, funkcija i obimnosti koje

se odràvaju u skladitima, • procjena efektivnosti rada u skladitima i vani

(nabavka izvana), • trokova odràvanja u skladitima, njihovoj

strukturi i vrstama, • na~inima pisanja propisa, • procjeni tehnoloke osnove (postojee i

potrebne/bezkorisne maine i oprema),

3. PROJECT OF CHANGES IN RAILWAY VEHICLE MAINTENANCE

At present @SR are in the transformation process, which also affects the maintenance system of rolling stock. The basic requirement is to create an effective maintenance system at minimum costs but ensuring high availability of vehicles. Railway vehicles operator should find optimum between costs for maintenance and losses caused by breakdowns in operation. That is why the operator will have to select proper vehicles for operated trains, and ensure performance and dependability of vehicles in accordance with importance of trains carried. The transformation should bring increased reliability by adopting new maintenance system and advanced maintenance management system. This will be based on: • analysis of needed vehicles in future in

accordance with traffic volumes, • analysis of vehicle parameters and costs for

theuir ooperation (LCC), • analysis of role of depots, • determination of structure, functions and

activities carried in depot, • assessment of work effectiveness carried in

depot and outside (outsourcing), • maintenance costs in depots, their structure,

types, • methodology for making regulations, • assessment of technological base (existing and

required/useless machines and equipment),

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• radnoj snazi – organizacija, opis posla, • protoku informacija – analizi potrebnih

informacija, informacionim sistemima, (vidi sljedee poglavlje),

• procjeni optimalnog broja skladita èljeznice u novim situaicjama,

• analizi tehnolokog nivoa opravki i odràvanja, • analizi sistema za odràvanje koji se koristi za

unapre|ene èljeznice (DB,¸ÓBB, DSB).

• human resources - organisation, work description,

• information flows - analysis of necessary infor-mation, information systems (see following chapter),

• assessment of optimum number of railway depots under new situation,

• analysis of repair and maintenance technological level,

• analysis of maintenance systems used on advanced railways (DB, ÖBB, DSB).

4. INFORMACIONI SISTEMI OD@AVANJA

Neemo analizirati sve aspekte sadanjeg sistema za odràvanje vozila èljeznice, ali mi vjerujemo da je slova~kim èljeznicama (@SR-u) potrebna nova strategija odràvanja. Jedan od moguih pristupa, pored upotrebe novih metoda (TPM i RCM) je uvo|enje odgovarajueg informacionog sistema odràvanja za prijevozna sredstva i ostale kapacitete. Kod izbora informacionog sistema odràvanja treba odgovoriti na sljedea pitanja:

Koji e informacioni sistem odràvanja doprinijeti poboljanju odràvanja? Da li e ga i jedan sistem poboljati?

[ta se treba postii provo|enjem informacionog sistema odràvanja – smanjenje trokova odràvanja, ili poveanje operativne dostupnosti? (Trokovi odràvanja uklju~uju smanjenje broja osoblja i materijalnih trokova). Da bi se dolo do pouzdanosti, posebno do rada bez kvarova, te da bi se postigle karakteristike raspoloìvosti, neophodno je razmotriti sljedea pitanja (ali treba imati na umu da je pouzdanost ve upotrebljavanih i odràvanih maina i kapaciteta stvorena jo u fazi konstrukcije, u proizvodnji, te tokom prethodnog odràvanja. Samo odràvanje ne moè poboljati postojee karakteristike pouzdanosti: Kako se moè postii pouzdanost, posebno karakteristike rada bez kvarova? Da li postoji razlog za njihovo postizanje? Treba li pregledati komponente ili cijeli sistem? Koje karakteristike pouzdanosti i rada bez kvarova su najva`nije za odràvanje i koliko su one va`ne? Kako, kada, gdje i u kojem obimu treba postii karakteristike pouzdanosti i rada bez kvarova? Na koji na~in bi predvi|ene karakteristike pouzdanosti i rada bez kvarova mogle pomoi pri konstrukciji sistema za odràvanje?

4. MAINTENANCE INFORMATION SYSTEMS

We are not going to analyse all the aspects of current maintenance system of railway vehicles here. But we believe that @SR must search for new maintenance strategy. One of possible approaches, besides the use of new methods (TPM and RCM) is introduction of suitable maintenance information system for transport means and other facilities. When considering maintenance information system the following questions should be answered: What maintenance information system will

contribute to improvement of maintenance? Will any improve it?

What should be achieved by implementation of maintenance information system lowering of maintenance costs, or increasing operational availability? (Maintenance costs comprise decreasing personnel and material costs). In order to achieve reliability failure-free operation and availability characteristics, it is necessary to decide on the following issues (but one should consider that reliability of the already operated and maintained machines and facilities was created during design stage, production and previous maintenance. Maintenance itself cannot improve inherent reliability characteristics):

How can reliability, resp. failure-free operation characteristics be obtained?

Is there a reason to get them? Should the components or the whole system be examined

Which reliability and failure-free operation characteristics are the most important for maintenance and how important are they?

How, when, where, and in what extent should the reliability and failure-free operation characteristics be obtained?

How could the anticipated reliability and failure-free operation characteristics could help in designing the maintenance systems?

- 164 -


Ve po~etkom 80-tih godina, odsjek za mainsko odràvanje je pokuavao da prona|e metode za uvo|enje pouzdanosti u konstrukciju sistema za odràvanje. Kasnije smo se okrenuli ka metodi odràvanja sa teìtem na pouzdanosti – RCM, s obzirom da ona uklju~uje odgovarajuu kombinaciju statisti~ke, historijske i unaprijed napravljene pouzdanosti (FMEA, FMECA i FTA). Informacioni sistem odràvanja bi trebao pomoi u optimalizaciji obima i sadràja aktivnosti na odràvanju. Drugim rije~ima – informacioni sistem odràvanja bi trebao "primorati" firmu da razmilja o promjeni svog sistema za odràvanje, te da postepeno po~ne usmjeravati pa`nju na posljedice kvarova, a ne na izvravanje planiranog obima radova na odràvanju. Kad firma po~ne razmiljati o primjeni informacionog sistema za odràvanje, ovlateni rukovodioci bi prvenstveno trebali razmotriti ciljeve koje èle postii jednom tako obimnom promjenom u firmi. Nakon postavljanja ciljeva, koje odrede nadle`ni rukovodioci koji imaju odgovarajua ovlatenja, autoritet i sposobnost da sprovedu nove ideje, treba zapo~eti projekat primjene novog sistema za odra`vanje. Ovaj projekat, u pojednostavljenoj verziji, bi mogao da se sastoji od est koraka: 1. Odre|ivanje radne grupe, 2. Stvaranje vremenskog rasporeda, 3. Prijedlog sistema obu~avanja, 4. Pravljenje analiza, 5. Konstrukcija sistema za odràvanje, 6. Projekat i stvaranje informacionog sistema. Iz ovih koraka se moè vidjeti da samo stvaranje informacionog sistema bi trebalo po~eti nakon savladavanja prethodnih pet koraka projekta, u kojima ~lanovi radne grupe razumijevaju sve vezane zadatke. Nakon ovih koraka mogu definirati funkcionalnost informacionog sistema, promjene u metodama odràvanja, kao i nu`not sakupljanja i analize historijskih podataka o mainama i opremi. Iz ovih ta~aka se jasno vidi da, ako se èli da informaiconi sistem donese korist jednoj firmi, on treba da ispunjava sljedee osnovne funkcije: • biljeènje stanja imovine firme, • mogunost pravljenja analize kriti~nosti

kapaciteta, • definiranje politike snabdijevanja i upravljanja

skladitima, • mogunost provo|enja analize RCM ili neke

druge analize kapaciteta FMEA ili FMECA, • definiranje, planiranje i upravljanje radovima na

odràvanju, • upravljanje ljudskim resursima (radnicima).

In the early 80ties a department of machinery maintenance engineering had been working out methods for implementation of reliability into the design of maintenance systems. But later on we turned to the method of reliability centred maintenance - RCM, as it comprises the proper combination of statistic, historical, and a-priori reliability (FMEA, FMECA, and FTA). A maintenance information system should assist in optimisation of extent and content of maintenance activities. In other words - maintenance information system should "force" a company to think about change of its maintenance system and gradually focus attention to failure consequences and not to executing planned extent of maintenance works. When a company starts thinking about the implementation of maintenance information system, the competent managers should first of all consider goals they want to achieve by such a great change in a company. After setting goals, stated by the competent managers, who have sufficient powers, authority, and ability to pursue the new ideas, one should start a project of the implementation of new maintenance system. This project, in a simplified version, could be composed of six consequent steps: 1. Establishing a working group, 2. Creation of time schedule, 3. Proposal of training system, 4. Making analysis, 5. Design of maintenance system, 6. Project and creation of information system. From these steps one can see that the creation of information system itself should start after overcoming tasks given in the first five steps of the project, in which members of working group understand all the related matters. After these steps, they are able to define the functionality of the information system, changes in the maintenance methods, as well as necessity to collect and analysis of historical data on machines and equipment. From these points it is evident that, if the information system should bring benefits for a company it should fulfil following basic functions: •

•

•

•

•

•

record keeping on physical assets of the company, possibility to make criticality analysis of facilities, definition of supply policy and management of stores, possibility to carry out RCM or other analysis of facilities, FMEA or FMECA analysis, definition, planning and management of maintenance works, management of human resources (workers).

- 165 -


Ako radi uprava sistema za odràvanje, ona mora biljeìti sve potrebne podatke o odràvanim mainama i objektima, ali istovremeno treba obezbijediti podatke za operativnu kontrolu analize odràvanja i analize sistema. Prili~an broj firmi koristi centralizirani informacioni sistem koji ~esto sadrì i komponentu za upravljanje odràvanjem. Ovi informacioni sistemi su ipak specijalizirani za ekonomske i logisti~ke svrhe (ra~unovodstvena pitanja osoblja, skladita, naloge, itd.), pa se komponenta odràvanja podudara s tim. S druge strane, postoje i specijalizirani sistemi odràvanja ~ija je glavna svrha upravljanje odràvanjem, poznati kao CMMS – Kompjuterski sistem za upravljanje odràvanjem. Njegova osnovna karakteristika je utemeljenost na osnovnim komponentama: registar firme, odràvanje i opravke u skladu sa tehni~kim uslovima, komponenta RCM skladita, planiranje, budèti. Na slici 1 se mogu vidjeti uzajamne veze izme|u komponenata. Grafikon u dodatku pokazuje protok informacija i baze podataka koji bi trebalo koristiti u informacionim sistemima za odràvanje èljezni~kih lokomotiva. Potoji mnogo vie problemskih podru~ja koja jedan sistem odràvanja treba rijeiti nego to se to moè ~initi na prvi pogled. Prvo problemsko podru~je je ope podru~je i uklju~uje pitanja na koja firma treba odgovoriti prije nego to uvede informacioni sistem odràvanja: Ima li dovoljno vremena, novca i interesa za

analizu svih nivoa odràvanja u sklopu procesa odlu~ivanja o kupovini sistema za upravljanje odràvanjem? Da li vrh rukovodstva to podràva?

Da li e ljudi na odràvanju i rukovodioci biti obu~eni, da li e imati znanje, pozitivan stav i pristup informacionom sistemu odràvanja kad se on po~ne primjenjivati? Da li e ljudi na odràvanju imati brz pristup terminalima i kompjuterima?

Da li postoji stav u organizaciji koji garantuje da se u sistem nee unositi beskorisne i la`ne informacije? Drugim rije~ima, da li e se davanje la`nih i neta~nih informacija smatrati krivi~nim djelom ili alom?

Da li e biti neko ko e imati vremena da istraì i analizira historiju opravki, da otkrije ponovljene opravke, tendencije i nove probleme?

Drugo problemsko podru~je pokriva izbor informacionog sistema koji e pomoi da se izbjegnu zamke u odabiru, kupovini i provo|enju informacinog sistema za odràvanje. osnovna pitanja su sljedea:

Da li je mogue napraviti jednostavnu i brzu upotrebu radnih naloga?

If a maintenance management system is operating working, it must keep records on all the necessary data on maintained machines and facilities but at the same time it has to provide data for operative control of maintenance and system analysis. Quite a few companies are using centralised information system, which also often comprises a module for maintenance management. However these information systems are mostly specialised in economic and logistic purposes (accounting, personnel matters, stores, orders, etc.) and the maintenance module corresponds with this. On the other hand, there are specialised maintenance systems whose main purpose is maintenance management, generally known as CMMS - Computerised Maintenance Management System. The basis feature is modularity with basic modules: company register, maintenance and repairs according with technical conditions, RCM module, stores, planning, budgets. In the Figure 1, mutual links between modules can be seen. The graph in the appendix shows database information flows that should be used for railway locomotives maintenance information system. There are many more problem areas that a maintenance management system needs to solve than it may seam. The first problem area is general and it comprises questions that must be answered before a company introduces maintenance information system:

Is there enough time, money and interest to analyse all the maintenance levels within the decision process on purchasing a maintenance management system? Does the top management support it?

Will the maintenance people and managers be trained, have knowledge, positive attitude and access to the maintenance information system once it is in operation? Will the maintenance people have easy access to terminals or computers?

Is there a will in the organisation guaranteeing that useless and false information will not be given into the system? In other words, will the giving of false or incorrect data be considered a criminal act or a joke?

Will somebody have time to investigate and analyse the history of repairs to find out the repeated repairs, trends and new problems?

The second problem area covers the choice of information system that helps to avoid pitfalls in selection, purchase and implementation of maintenance information system. The basic questions are:

Is it possible to create a simple and easy use of work orders?

- 166 -


Da li je mogue traìti rezervne dijelove koritenjem komponente za skladita, koja je dio sistema? Moè li ova komponenta predloìti, preporu~iti i rukovoditi sistemom materijala u skladitu, moè li ograni~iti koli~ine u skladitu ili poru~ene koli~ine?

Da li sistem biljeì historijat odràvanja koji dovoljno detaljno govori ko je i ta je neko radio, kad, zato i na kojoj maini ili objektu?

Da li je lako koristiti sistem za opisivanje kvarova koje otkriju kontrole, te moè li sistem automatski napraviti i traìti radne naloge.

I mnoga druga pitanja....

Is it possible to search for the spare parts by using the stores module, which is part of the system? Is this module able to suggest, recommend and manage the system of material in stock, limit the amounts in stock or the ordered amounts?

Does the system keep records on maintenance history that in sufficient details tells about who and what was done, when, why and on which machine or facility?

Is the system easy to use for describing failures that are found under inspections and is the system able to automatically create and search for work orders?

And many more....

over 30%VERY CRITICAL

under20%LOW CRITICAL

about 50%CRITICAL

Criticality assessmentSorted decresingly

Criticality analysis offacilities

Company facilities:Creation of company register

Computerized Maintenance Management SystemCMMS

RCM Proactivemaintenance

Reactivemainatence

FMEA

failure intensityfailue consequences

Hiddenstate

Evidentstate

Low

Periodicmaintenance

Predictivemaintenance

Change of asset design

High

Improved reliability / availability / maintainability

RandomDetermined life

Operatedto failure

Maintenanceafter failure

Software module "Company Register"

Software module FCA

Periodic data collection duringoperation

Material support:Definition of supply

policy

Material support:Definition of

supply policy

Software moduleRCM Software module

FMEA - FMECA

Softwaremodule

PM

Softwaremodule

Maintenance

SoftwaremoduleStores

Outsourcing in the company can becomplete or partial, from this important

elemetns result

STR

ATE

GY

PLA

NN

ING

* Maitenance in accordance with technical conditions

Softwaremodule

Maintenance

Slika 1. Strategija i planiranje u informacionim sistemima odràvanja Figure 1. Strategy and planning in maintenance informa ion system. t

- 167 -


Prvi problem i pitanje pokazuju samo osnovne teme koje treba razraditi i na koje treba detaljnije odgovoriti. Drugo problemsko podru~je uklju~uje mnogo vie pitanja koja mogu pomoi u odabiru i efikasnom uvo|enju informacionog sistema odràvanja. Odsjek za mainsko odràvanje ima iskustva i moè pomoi u rjeavanju ovih problemskih podru~ja da bi se donijele prave odluke.

The first problem and question area shows only basic topics that must be worked out and answered in more details. The second problem area comprises many more questions that can help in choosing and in effective introduction of management information system. The department of machinery maintenance engineering has the experience and is able to assist in solving these problem areas in order to the to make right decisions.

5. LITERATURA - REFERENCES

[1] V25 - Predpis pre opravy elektrických a motorových hnacích vozidiel, (V25 - Regulation for repairs of electric and diesel locomotives) ^SD, @SR 1967, 1975, 1982, 1999

[2] Stuchlý, V.: Teória údr`by, skriptá, Edi~né stredisko V[DS, @ilina, 1993

[3] Moubray, J.: RCM – Die Hohe Schule der Zuverlässigkeit von Produkten und Systemen, mi verlag, Lansberg, 1996

[4] Nakajima, S.: Management der Produktion-seinrichtungen (Total Productive Maintenance) Campus Verlag, Frankfurt/New York, 1995

- 168 -

Databases and information flows

OTHER DATABASES FOREMEN, LOCO ENGINEER REPAIR WORKSHOPS REPAIRING WORKS FAILURES PERFORMANCE WORK ORDERS MATERIAL CONSUMPTION RECORDS MEASUREMENT SHEETS OF RUNNING GEAR CORRECTION OF IS DATA RAILWAY STATIONS, KM DISTANCES

LIST OF EXCHANGABLE UNITS sign of exchangeable unit sign new or after repair year of production total km during life date of failure finding names of components that caused a failure decision: place of repair of the unit extent and content of repair work orders for unit repair records on material consumed for repair of the unit description of really work done description of really worked hours number of workers working at the same time wages costs material costs total costs date of finish of unit repair

MATERIAL STORE list of exchangeable units list of components of exchangeable units material of a component

date of taking loco from maintenance chief of repairs

wheel-set measurement sheet on running gear diagnostics records records from chemical laboratory

DATA ON CARRIED MAINTENANCE WORK description of really done works records on really worked hours number of workers working at the same time wages costs material costs total costs date of finish of maintenance work

DATA ON EXCHANGABLE UNITS production serial number name of the unit date of assembly onto loco km run of the unit - on the loco - total during life date of failure finding cause of failure method of failure correction (exchange, repair) date of dismantling

RECORDS ON MAINTENANCE type of maintenance work serial number of maintenance work date of entering repair loco engineer foreman extent and content of maintenance work work orders records on material list of exchangable units of loco

PLANNING OF MAINTENANCE type of maintenance scheduled date of beginning foreman other data

LOCOMOTIVE RECORDS Operational Loco Number Performance of loco with actual date and time type of departure RailSt Arrival RailSt distance run (km) total km of loco Repairing type of loco year of loco production manufacturer of loco years of operation home depot number of maintenance works actualisation by last maintenance date, type of maintenance

Protok informacija i baze podataka

OSTALE BAZE PODATAKA POSLOVO\E, IN@ENJER ZA LOKOMOTIVE RADIONICE ZA POPRAVKE OPRAVCI KVAROVI RAD RADNI NALOZI PODACI O UTRO[ENIM MATERIJALIMA TABELE MJERENJA BRZINE OBRTANJA ISPRAVKE PODATAKA @ELJEZNI^KE STANICE, UDALJENOST U KM

SPISAK ZAMJENJIVIH JEDINICA znak zamjenjivih jedinica novi znak nakon popravke godina proizvodnje ukupna km za vrijeme trajanja datum pronalaska kvara nazivi dijelova koji su uzrokovali kvar odluka: mjesto popravke jedinice obim i sadràj popravke radni nalozi za opravak jedinice podaci o utroku materijala za opopravak jedinice opis radnog ure|enog posla opis radno utroenih sati broj radnika koji istovremeno rade trokovi dnevnica trokovi materijala ukupni trokovi datum zavretka popravke jedinice

SKLADI[TENJE MATERIJALA spisak zamjenjivih jedinica spisak dijelova zamjenjivih jedinica materijal dijela

datum preuzimanja lokom. od odràvanja ef opravki

garnitura to~kova papir s mjerama na brzini obrtanja dijagnosti~ki podaci podaci iz hemijske laboratorije

PODACI O IZVR[ENIM RADOVIMA NA ODR@AV. opis ura|enih radova podaci o radnim satima rada broj radnika koji istovremeno rade trokovi dnevnica utroak materijala ukupni troak datum zavretka rada na odràvanju

PODACI O ZAMJENJIVIM JEDINICAMA proizvodni serijski broj naziv jedinice datum montiranja na lokom. pre|ena km jedinice - na lokom. - ukupna za

vrijeme trajanja datum pronalaska kvara uzrok kvara na~ini kvara popravka (zamjena, popravka) datum razmontiranja

PODACI O ODR@AVANJU vrsta rada na odràvanju serijski broj rada na odràvanju datum unoenja popravke

om. inìnjer lokposlovo|a obim i sadràj rada na odr`. radni nalozi podaci o materijalu podaci o zamjenjivim edinicama lokom. j

PLANIRANJE ODR@AVANJA vrsta odràvanja planirani datum po~etka poslovo|a ostali podaci

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Mainstvo 3(5), 171 – 181, (2001) [ii I;...: KONSTRUKTIVNO-TEHNOLO[KE KARAKTERISTIKE..

KONSTRUKTIVNO-TEHNOLO[KE KARAKTERISTIKE DINAMI^KIH KRU@NIH VIBRACIONIH SITA

Mr. Ifet [ii dipl. in`. – Ministarstvo privrede Unsko-sanskog kantona, Biha V.prof.dr. Jovan Sredojevi dipl. in`. – Mainski fakultet u Zenici

REZIME

Data je klasifikacija dinami~kih sita prema putanji kretanja zrna materijalPrikazane su konstruktivno-tehnoloke karakteristike kru`nih vibracionih sina~inu putanje vibracija. Data je metodologija utvr|ivanja kapaciteta koritenjem empirijskih formula, tabela i dijagrama .

f

Klju~ne rije~i: dinami~ka sita, kru`na vibraciona sita, konstruktivno-teh

karakteristike, kapacitet kru`nih vibracionih sita

CONSTRUCTIVE-TECHNOLOGICAL CHARATHE DYNAMIC VIBRATING TROM

Ifet [ii, graduate engineer – Manistry of Economy of the UnaS.Ph.D. professor Jovan Sredojevi, graduate engineer – Engineering in Zenica

SUMMARY

The maper presents the classification of the dynamic trommels on the baof the material grains along the sieving surface. The constructive technolovibrating trommels are presented, together with their classification on the bThe paper also presents the methodology of estabilishing the capacity o using empirical formulas, charks, and diagrams.

Key words: dynamic sieves, vibrating trommels, constructive-tehnocapacity of the vibrating trommels

1. UVOD Klasiranje je proces razdvajanja materijala po krupnoi zrna. U zavisnosti od krupnoe zrna, odnosno granulometrijskog sastava materijala, klasiranje se vri pomou dvije osnovne metode: • prosijavanjem, koja predstavlja proces

razdvajanja materijala prema krupnoi, zasnovan na geometrijskom upore|enju oblika i veli~ine zrna sa oblikom i veli~inom otvora prosjevne povrine, koja je pri~vrena za ram ure|aja za prosijavanje – sita i

• klasifikacijom, koja predstavlja proces razdvajanja

zrna po klasama krupnoe, koja se zasniva na razli~itim brzinama kretanja zrna razli~ite krupnoe u nekom fluidu (zrak ili tekuina), a pod dejstvom zemljine teè ili centrifugalne sile.

1. INTRODUCTIO Sorting is a process basis of coarseness. Di.e. the granulometric csorting is done with th • siening, which is

separation accordion the geometricshapes and coarssize of the sievingsiening device fram

• classification, whic

separation into dothe different scoarseness in a flinfluence of gravita

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STRU^NI RAD

a du` prosjevne povrine. ta sa klasifikacijom prema kru`nih vibracionih sita

noloke

CTERISTCS OF MELS

-Sana Canton, Biha Faculty of Mechanical
PROFESSIONAL PAPER
sis of the movement path gical characteristics of the asis of their vibrating path. the vibrating trommels by

logical characteristic, the

N

of material separation on the epeading on the coarseness, omposition of the materijal, the e aid of two basic methods:

a process of the materijal ng to the coarscness, based al comperison of the grain eness with the shape and surface opening fixed to the e – the sieve, and

h is a process of grain arseness classes, based on peeds of different grain uid (air or uquid), under the tion of centrifugal force.


U industrijskoj praksi metoda prosijavanja se primjenjuje za razdvajanje zrna materijala krupnoe d > 1 mm, a metode klasifikacije za zrna materijala manje krupnoe. Donja granica za tehni~ku primjenu metode prosijavanja nalazi se u granicama izme|u 1,0 i 0,1 mm veli~ine zrna materijala. Gornja granica za tehni~ku primjenu metode klasifikacije iznosi oko 4 mm veli~ine zrna materijala. Metoda prosijavanja mineranih sirovina koristi se u oblastima: - pripreme metalnih i nemetalnih mineralnih sirovina

za industrijske potrebe i za gra|evinarstvo, - pripreme uglja, - obrade otpadnih mateirjala: stakla, gra|evinski

otpad, kompostiranje i u niz drugih oblasti.

U zavisnosti od na~ina kretanja materijala po prosjevnoj povrini izvrena je podjela postrojenja za prosijavanje (slika1).

In industry, sreving method is used in grain separation for the materijals of d > 1 mm in coarseness, whercas the classification method for the materijal with coarseness less than this. The lower limit for the technical application of the siening method is between 1.0 and 0.1 mm of the material coarsences. The upper limit for the technical application of the classification method is around 4 mm of the materijal coarsemess. The sieving method of the mineral raw materials is used in the following arreas: - the preparation of the metal and how-metal

mineral raw materials for industry and construction trade,

- the construction trade, - the preparation of coal, - the processing of waste materials: glass,

construction waste, composting, and many other areas.

Depending on the manner of the materijal movement on the sieving surface, a classification of the sieving machines has been made (Figure 1).

1. Stabilne reetke 1. Stabile grid

2. Maine za prosijavanje 2. Siening machines 2.1. Reetke sa valjcima 2.1. Grid roller

2.2. Rotaciona sita 2.2. Trommel

3. Lu~na sita 3. Arched sieves

2.3. Dinami~ka sita 2.3. Dinami~ka sita

Slika 1. Podjela postrojenja za prosijvanje prema na~inu kretanja materijala po prosjevnoj povrini

Figure 1. Classification of the siening machines on the basis of the material movement along the siening surface

2. KLASIFIKACIJA DINAMI^KIH SITA Za prosijavanje raznih materijala prema veli~ini zrna najiru primjenu imaju dinami~ka sila. Kod najveeg broja dinami~kih sita vibrira ram sita, dok kod nekih tipova za fino i najfinije prosijavanje vibrira samo prosjevna povrina. Prva grupa dinami~kih sita se dijele prema obliku putanje vibracija. Prema tom svojstvu razlikuju se:

• kru`na vibraciona sita, • elipsasta vibraciona sita i • linearna vibraciona sita.

2. THE CLASSIFICATION OF THE DYNAMIC SIEVES

The dynamic sieves have the widest application in the field of sieving different materijals according to their coarseness. The greatest number of the dynamic sieves have a vibrating sieve frame, but some sieves for fine and the finest sieving have only a vibrating sieving surface. The first group of the dynamic sieves are classified according to the vibration path shape. There are: • vibrating trommets, • elliptic vibrating sieves, and • linear vibrating sieves.

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Sljedee veli~ine uti~u na putanju kretanja prosjevne povrine sita, a samim tim i na kretanje materijala na njoj:

r – amplituda prosjevne povrine sita, ω - ugaona brzina, α - ugao odbacivanja zrna materijala (slika 2), β - ugao nagiba prosjevne povrine,

The following values affect the moverment path of the sieving surface, affecting this the movement of the materijal on it: r – amplitude of the sieving surface, ω - angular speed, α - materijal grain repulsion angle (Figure 2), β - sieving surface indination angie,

Slika 2. Dejstvo ubrzanja i odnosi odbacivanja zrna materijala: b – ubrzanje prosjevne povrine

Figure 2. Acceleration effect and materijal grain repulsion ratios: b – sieving surface accelevation

Za ocjenu odnosa kretanja prosjevne povrine i materijala na njoj podesni su sljedei bezdimenzionalni pokazatelji:

• Pokazatelj pogona sita K (tzv. Froudov broj) - koji ozna~ava inercijalnu silu pogona, odnosno ubrzanje u odnosu na silu zemljine teè. Kod dinami~kih sita putanja vibracija prosjevne povrine prete`no se ostvaruje od kru`nog kretanja pogona, pri ~emu vaì:

grK

2ω⋅= (1)

Pokazatelj pogona sita K je mjera za dinami~ko naprezanje sita.

• Pokazatelj sita ili pokazatelj odbacivanja Kv - predstavlja maksimalnu vertikalnu komponentu ubrzanja prosjevne povrine sita u odnosu na odgovarajuu komponentu ubrzanja zemljine teè:

αcos)( max

⋅=gb

K sv (2)

Ovaj pokazatelj predstavlja ubrzanje materijala, koje prima od prosjevne povrine sita. Ako je Kv < 1, zrno materijala ostaje stalno u kontaktu sa prosjevnom povrinom. Teoretski zrno se po~inje odvajati od prosjevne povrine ako je Kv = 1,0. Me|utim, proces prosijavanja u tehni~kom smislu po~inje kod vrijednsoti Kr > 1,5. Putanja vibracija moè biti posljedica krute veze rama sita sa ~vrstim pogonskim organom (nap. ekscentri~na vibraciona sita, potisno koljenasto linearno vibraciono sito). Kod drugih vibracionih sita nema krute veze, kod tih sita ram je elasti~no ograni~en (nap. kru`no debalansno vibraciono sito, rezonantno linearno sito).

The following dimensionless indexes are used for the evaluation of the sieving surface movement ratio: • Sleve drive index K (so called Froud's number)

– which denstes the inertial drive force, i.e. acceleration in relation to the gravity force. Eith the dynamic sieves, the sieving surface vibration path is usually a result of the rotational drive moverment, with:

grK

2ω⋅= (1)

The sieve drive index K is a measure for the dynamic sieve stress.

• Sieve index, or the repulsion index Kv – represents the maximum vertical component of the sieving surface acceleration in realtion to the appropriate component of the gravity acceleration:

αcos)( max

⋅=gb

K sv (2)

This index represents the material acceleration, which it accepts from the sieving surface. If Kv < 1, the material grain remains in a continual contact with the sieving surface. Tteoretically, the grain starts separating from the sieving surface if Kv = 1.0. However, the sifting starts, in technological terms, at the value of Kr > 1.5. The vibration path can be a consequance of a rigid relationship of the sieve frame with the solid drive organ (e.g. eccentric vibrating sieves, cranked linear pressure vibrating sieve). Eith other vibrating sieves, there is no rigid realtionship: with such sieves, the frame is alasticaqlly adgad (e.g. debalanced vibrating trommel, resonant linear trommel).

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3. KRU@NA VIBRACIONA SITA U ovu grupu spadaju sljedee vrste sita (slika 3):

• dvo koljenasta vibraciona sita, • ekscentri~na vibraciona sita i • kru`na debalansna vibraciona sita.

3.1. Dvokoljenasta vibraciona sita Kod dvokoljenastih vibracionih sita ram sita je vezan za dva ~vrsta koljena i pri tome prinudno opisuje kru`nu putanju (slika 3.a). Centrifugalna sila koja se javlja pri obrtanju rama sita ponitava se od debalansnih masa koje se nalaze na zamajcima koljenastih osovina, a postavljene su pod uglom od 1800 na tim osovinama. Dvokoljenata vibraciona sita se proizvode do 6 m duìne i irine do oko 2,2 metra. Pre~nik koljena iznosi 40 do 100 mm, a broj obrtaja se nalazi izme|u 120 i 200 min-1. Da bi se materijal kretao du` prosjevne povrine, mora prosjevna povrina kao i kod svih kru`nih vibracionih sita biti nagnuta. Dvokoljenasta vibraciona sita zahtijevaju relativno otar materijal i sna`no odbacuje nadreetnu frakciju. Uprkos robusnosti i sigurnosti pogona ova sita zadovoljavaju moderne tehni~ke uslove samo u ograni~enoj mjeri.

3. VIBRATING TROMMELS This group includes the following sieve types: • • •

double-crank vibrating sieves, escentric vibrating sieves, deballanced vibrating trommels.

3.1. Double-crank vinrating sieves With the double-crank vibrating sieves, the sieve frame is connected with two rigid cranks, thus emposing the circular path (Figure 3.a). The centrifugal force, resulting from the sieve frame rotation, is anulled by the deballanced masses at the flywheels of the crank axes, set at the angle of 1800 on those axles. The double-crank vibrating sieves are produced up to 6 m in length and 2.2 m in width. The diameter of the cranks is 40 to 100 mm, and the rotation number is between 120 and 200 min-1. In order for the material to move along the sieving surface, the surface, similarly to other vibrating trommels, has to be inclined. Double crank vibrating sieves require a relatively sharp material and it repulses forcibly the overgrid fraction. Despite the drive robustness and its safety, these sieves satisfy modern technical requirements only to a certain exfent.

Slika 3. [ematski prikaz kru`nih vibracionih sita: a) dvokoljenasta vibraciona sita,

b) ekscentri~na vibraicona sita, c) kru`na debalansna vibraciona sita Figure 3. Diagrammatic drawing of the vibrating trommels: a) dauble-crank vibrating sieve, b) eccentric

vibrating sieve, c) circular deballanced vibrating sieves

3.2. Ekscentri~na vibraciona sita Ekscentri~na vibraciona sita imaju jednu centralnu ekscentri~nu kruto ograni~enu osovinu (slika 3.b), koja je ematski prikazana na slici 4.

3.2. Eccentric vibrating sieves The eccebtruc vubratubg sueves gave ibe cebtrak eccebtruc ruguckky kunuted axue /Fugzre 3.b) which is diagrammatically drawn in the Figure 4.

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Slika 4. Ekscentar vibracionog sita sa kruto ograni~enom putanjom kretanja –ematski presjek kroz ekscentri~nu osovinu: 1.ekscentri~na osovina, 2. ~vrsti leàj, 3. nosea konstrukcija, 4. ram sita, 5. leàjevi

rama sita, 6. debalansna masa, 7. zamajac Figure 4. The eccenter of the vibrating sieve with the rigidly limited movement path – diagrammatic cross-section of an eccentric axle: 1. eccentric axle, 2. rigid bearing, 3. support structure, 4. sieve frame, 5.

sieve frame bearings, 6. deballanced mass, 7. flywheel

Ekscentri~na osovina obre se u ~vrstim leàjevima (2) na noseoj konstrukciji sita (3). Ram sita vezan je za leàjeve (5), a na krajevima je elasti~no vezan preko opruga za osovnu konstrukciju sita. Kod obrtanja rama sita centrifugalne sile se ponitavaju od debelousnih masa (6), koji su postavljene na zamajcima (7), kada su ispunjeni sljedei uslovi:

22 ωω ⋅⋅=⋅⋅ rmrm uu (3)

odnosno:

rmrm uu =⋅ (4)

gdje je: m – masa rama sita mu – masa debalansa r – radius vibracije (ekscentricitet) ru – radius teìta debalansnih masa ω - ugaona brzina Pri tome samo je ~vrsti leàj (2) rastereen. Zbog ovih ujedna~enih masa pokazatelj sita moè iznositi do Kv = 4-6. Leàjevi na ramu sita (5) moraju primiti sve sile od mase rama sita i materijala koji se nalazi na prosje~noj ovrini. Da bi se vibracije rama sita smanjile zbog elasti~nih veza, frekvencija pogona treba imati viestruku vrijednost u odnosu na sopstvenu frekvenciju. U zavisnosti od materijala koji se prosijava nagib prosjevne povrine se nalazi u granicama od 120 do 250. Ekscentri~na vibraciona sita su podesna za suha i mokra prosijavanja u oblasti finih i grubih zrna, ali prije svega za srednja i gruba zrna. Odgovarajua robusna izvedba podesna je za gruba prosijavanja. Tipi~ni predstavnik ove grupe je univerzalno ekscentri~no vibraciono sito (slika 5). Ram sita (1) oslanja se na ~etiri sna`na gumena amortizera (2). Bo~ni amortizeri sa svake strane sita su me|usobno povezana vijacima (3) za noseu traverznu (4). Ekscentri~na osovina (5) prolazi kroz teìte rama sita i obre ga u prisilne kru`ne vibracije.

The eccentric axle is rotated m the rigid bearings (2) on the gieve's support structure (3). The sieve frame is compled with the bearings (5), and at its ends, it is elastically coupled with the sieve's base construction through springs. When the sieve frame is rotated, the centrifugal forces are annulled by the deballanced masses (6), which are placed at the flywheals (7), if the flollowing conditions are fulfilled:

22 ωω ⋅⋅=⋅⋅ rmrm uu (3)

i.e.:

rmrm uu =⋅ (4)

where: m – sieve frame mass - mu – deballance mass - r – vibration radius (exentricity) - ru – deballanced masses'center of gravity radius ω - angzkar soeed Only the rigid bearing (2) is unloaded. Due to these ballanced masses, the sieve index can be up to Kv = 4-6. The bearings on the sieve frame (5) have to accept all the forces from the sieve frame mass and the material which is placed on the sieving surface. In order to reduce the vibratious of the sieve frame because of elastic couplings, the drive frequency should have a multiple value in relation to its own frequency. Depending on the materijal which is being sifted, the sieving surface inclination is between 120 and 250. The eccentric vibrating sieves are used for dry and wet sieving of the fine and coarse grains, but mostly for middle and coarse grains. A typical representative of this group is a universal eccentria vibrating sieve (Figure 5). The sieve frame (1) relies on four strong rubber absorbers (2). Side absorbers on each side of the sieve are linhed to the supporting eross rail (4) with serews (3). The eccentric axle (5) goes

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through the sieve frame centre of gravity, reuslving it in compulsory rotating vibrations.

Slika 5. Ekscentri~no vibraciono sito: 1. ram sita, 2. gumeni amortizer, 3. vezni vijak, 4. traverzna, 5. ekscentri~na osovina

Figure 5. Eccentric vibrating sieve: 1. sieve frame, 2. rubber absorber, 3. coupling serew, 4. cross rail, 5. eccentric axle

Ekscentri~na osovina se obre u leàjevima rama sita koji su zatieni protiv prodora praine i prljavtine. Centrifugalna sila koja se javlja pri rotaciji ekscentri~ne osovine ponitava se od debalansnih masa na zamajcima koji su postalvjeni pod uglom od 1800 u odnosu na poloàj ekscentra osovine. Kod ugradnje ekscentri~ne osovine u ram sita gumeni amortizeri se postavljaju u prenapregnutom stanju. Ova sita se izra|uju sa brojem obrtaja izme|u 1200 do 2000 min-1 i radiusom vibracija r izme|u 1,5 do 5 mm. Ona se izra|uju u lakoj i tekoj izvedbi za prosijavanje finih i grubih zrna mateirjala. Nosea konstrukcija moè se postaviti kao leèa ili visea.

The eccentric axle is rotated in the beartings of the sieve frame, which are protected against the penebration of dust and dirt. The centrifugal force occuring during the rotation of the eccentric axle is annulled by the deballanced masses at the flywheels which are inclined under the angle of 1800 to the axle's eccentre position. Ehen the eccentric axle is buit into the sieve frame, the rubber absarbers are set in overstrained condution. The number of revolutions of these sieves ranges between 1.200 and 2.00 min-1, with the radius of vibrations r between 1.5 and 5 mm. They are produced light and heavy performance for sieving fine and coarse grain materijals. The supporting construction can be a lying, or a hanging one.

3.3. Kru`na debalansna vibraciona sita

Kru`na debalansna vibraciona sita (sl. 3.c) izra|uju se sa centralnom osovinom u ramu (naj~ee u teìtu) i nije vezna za noseu konstrukciju sita. Na osovini se nalaze debalansne mase koje se mogu regulisati (samopodesive debalansne mase). Ram sita je elasti~no oslonjen na krajevima preko elasti~nih opruga na noseu konstrukciju sita, tako da u svim pravcima djeluju kru`ne vibracije koje imaju pribli`no iste povratne sile. Zbog toga se koriste relativno meke opruge (konstanta opruge se moè zanemariti, odnosno c → 0), tako da zajedno rotiraju ram sita i debalansne mase oko zajedni~kog teìta. To zna~i da se sistem samocentrira (slika 6), pri ~emu vaì:

uu rmrm ≅⋅ (5)

3.3. Deballanced vibrating trommels Deballanced vibrating trommels (Figure 3c) are made with the control axle within the frame (usually in the centre of gravity), and it is not linked with the sieve's supporting construction. There are deballanced masses on the axle, which can be regulated (self-regulating deballanced masses). The sieve frame is elastically rested to the sieve's supporting construction at its ends through elastic aprings, so that rotating vibrations, which have approximately the same reversible forces, worh in all directions. Due to this, relatively soft springs are used (the spring constant can be neglocted, i.e. c → 0), so that the sieve frame and the deballanced masses rotote around the common centre of granity. This means that the system is self-centred (Figure 6), with:

uu rmrm ≅⋅ (5)

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Kod jednostavnih pogona (slika 6.a) masa rama sita m (teìte A) i debalansne mase mu (teìte B) rotiraju oko zajedni~kog teìta C. Osovina pogonske remenice sa radiusom r tako|e rotira oko zajedni~kog teìta C i zbog toga je potreban relativno dugi klinasti remen. Smanjenje duìne klinastog remena se postiè kod pogona sa ekscentri~nom osovinom (slika 6.b), ako je pri tome ispunjena jedna~ina (5). U tom slu~aju pogonska remenica rotira oko zajedni~kog teìta C, koje leì u osi pogonske osovine.

Whith the simple drives (Figure 6.a), the sieve frame mass m (centre of gravity A) and the deballanced mass mu (contre of gravity B) rotate around the some centre of gravity C. The axle of the drive's belt-pulley, with the radius r also rotates around the common centre of gravity C, due to which a relatively long wedge-shaped belt is needed. The reduction in the length of the wedge-shaped belt is achieved with the drives with eccentric axle (Figure 6.b), if the equation (5) is fulfilled. In that case, the drive wadge-shaped belt rotates around the common centre of gravity C, which lies in the drive's axle centre line.

Slika 6. Pogon kru`nih debalansnih sita: a. jednostavni pogon, b. pogon sa ekscentri~nom osovinom

Figure 6. The drive of the rotating deballanced sieves: a. a simple drive, b. a drive with the eccentric axle Konstanta opruge ne smije biti suve mala u interesu stabilnog poloàja rama sita kod promjenljivog optereenja rama sita od materijala na prosjevnoj povrini. Ova sita se izra|uju sa pokazateljem sita Kv = 4 – 6, odnosno sa brojem obrtaja od 750 – 2000 min-1 i amplitudom r = 1,5 – 7,5 mm. Koriste se za prosijavanje suvih i vla`nih materijala sa veli~inom zrna od 1 do 50 mm. Brzina transportovanja materijala po prosjevnoj povrini se regulie promjenom nagiba prosjevne povrine. Kru`na debalansna sita se izra|uju do 6 m duìne i 2,8 m irine sa centralnom osovinom. Tipi~ni predstavnik ovih sita je kru`no debalansno sito sa gornjim pogonom (slika 7). Ova sita se izra|uju sa brojem obrtaja od 900 do 1200 min-1 i amplitudom od 2 do 5,5 mm. Najvea sita imaju prosjevnu povrinu do 14,4 m2.

The spring constant must not be too low, in the interest of the stabile position of the sieve frame when the sieve frame is changable due to the material on the sieving surface. These sieves are constructed with the sieve index Kv = 4-6, i.e. with the number of revolutions from 750-2.000 min-1, and the amplitude r = 1.5-7.5 mm. They are used for sieving dry and wet materials with 1 to 50 mm in coarseness. The speed of the materijal transportation along the sievingf surface is regulated ba changing the sieving surface indination. The rotating deballanced sieves (trommels) are up to 6 m in length and 2.8 m in width with the central axle. A typical representative of thase sieves is a deballanced trommel with the top drive (Figure 7). These sieves have the number of revolutions from 900 to 1.200 min-1, and the amplitude from 2 to 5.5 mm. The biggest sieves have the sieving surface up to 14.4 m2.

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Slika 7. Kru`no debalansno vibraciono sito, proizvo|aa SKET: 1. Ram sita sa dvije prosjevene povrine – mreè, 2. pogon, 3. pogonska remenica sa klinastim remenom, 4. motor, 5. travezna, 6. podupira~ opruge, 7. meka opruga Figure 7. The rotating deballanced sieve (trommel), produced ba SKET: 1. sieve frame with two sieving surfaces – grids, 2. drive, 3. drive bolt with the wedge-shaped belt, 4. engine, 5. cross rail, 6. spring supporter, 7. soft spring

4. KAPACITET KRU@NIH VIBRACIONIH SITA

Prora~un kapaciteta kru`nih vibracionih sita je dosta sloèn zbog mnogobrojnih uticajnih faktora. Zbog toga se utvr|ivanje kapaciteta vri empirjski, pri ~emu se koriste dvije metode: ⇒ utvr|ivanje kapaciteta pomou tabela ili grafikona koji se zasnivaju na iskustvenim vrijednostima i ⇒ utvr|ivanje kapaciteta na osnovu labaratorijskih ili poluindustrijskih istraìvanja. Utvr|ivanje kapaciteta pomou empirijskih formula uz koritenje tabela ili grafikona vri se ili prema ulaznom kapacitetu ili prema izlazu podreetne frakcije. Zbog mnogobrojnih uticajnih faktora u tim tabelama ili grafi~kim prikazima daju se samo prera~unate vrijednosti. Radi toga se kod razli~itih autora vie ili manje razlikuju dobiveni rezultati. Pomou sljedeih empirijskih formula utvr|uje se kapacitet prolaza podeetnih frakcija Qp kao i ulazni kapacitet Qu:

sattkkkkkkAqQ nspp /,654321 ⋅⋅⋅⋅⋅⋅⋅⋅= γ (6)

i

satts

QQfp

pu /,100

..

⋅= (7)

gdje je: qsp – specifi~ni kapacitet prolaza podreetnih frakcija (slika 8), m3/(m2⋅h) A – povrina prosjevne povrine – mreè, m2 γn – nasipna masa materijala, t/m3 k1 do k6 – korekcioni faktori (tabela 1) sp.f. – sadràj podreetne frakcije u ulaznom materijalu, %

4. VIBRATING TROMMELS CAPACITY Vibrating trommels capacity calculation is quite complex due to many influential factors. Therefore, the capacity is determined empirically and two methods are applied: ⇒ establishing capacity by using chrts and grpha based on empirical values and ⇒ establishing capacity following laboratory or semi-industrial research. Estabilishing capacity with the empirical formulas by using charts or graphs is performed either on the basis of the input capacity or on the basis of the output undergrid fraction. Due to many factors, the charts or graphs present only the calculated values. Therefore, the results might vary with the different authors. The following empirical formulas are used to estabilish the capacity of the undergrid fraction passages Qp, as well as the input capacity Qu:

hourtkkkkkkAqQ nspp /,654321 ⋅⋅⋅⋅⋅⋅⋅⋅= γ (6)

hourts

QQfp

pu /,100

..⋅= /7)

where: qsp – specific capacity of the undergrid fraction passage (Figure 8), m3/(m2⋅h) A – sieving surface – grid surface, m2 γn – material filling, t/m3 K1 to K6 – correction factors (table 1) Sp.f. _ the content of the undergrid fraction in the input materijal, %

- 178 -


Specifi~ni kapacitet prolaza podreetkastih frakcija vaì za usitnjene mineralne sirovine, ali ne za materijale kao to su koks, pijesak, ljunak i dr. Za okrugla zrna materijala, kao to su pijesak i ljunak, potrebno je uvesti dodatni korekcioni faktor k7 = 1,2; a za pljosnata zrna materijala k7 = 0,8.

The specific capacity of the undergrid fraction passage is only for the ground mineral raw materials, but not for the materijals such as coke sand, gravel, etc. For the round grain materijals, such as sand and gravel, it is necessery to infrocluce the additional correction factor k7 = 1.2; and for the flat materijals kz = 0.8.

Tabela 1. Korekcioni faktori za obra~un kapaciteta kru`nih vibracionih sita prema jedna~ini (6)

a. Korekcioni faktor k1 koji uzima u obzir udio masa < w/2 u ulaznom materijalu

Udio <w/2 u masi, % 0 20 30 40 50 60 70 80 85 90 95

k1 0,44 0,70 0,80 1,00 1,20 1,40 1,80 2,20 2,50 3,00 3,75

b. Korekcioni faktor k2 koji uzima u obzir prolaz Rp zrna kroz prosjevnu povrinu

Rp, % 70 80 85 90 95

k2 2,25 1,75 1,50 1,25 1,00

c. Korekcioni faktor k3 koji uzima u obzir oblik otvora prosjevne povrine (slika 9)

Oblik otvora kvadratni i duguljasti w′<2w

duguljasti 2w<w′<4w

prosjepni 4w<w′<25w

procjepni w′>25w

k3 1,0 1,15 1,2 a. Procjepi paralelni pravcu transporta: 1,4 b. Procjepi okomiti na pravac transporta: 1,3

d. Korekcioni faktor k4 koji uzima u obzir poloàj prosjevne povrine kod vie etaà Gornja prosjevne povrine: k4 = 1,00 2. prosjevne povrina: k4 = 0,90 3. prosjevna povrina: k4 = 0,80

e. Korekcioni faktor koji uzima u obzir otvorenost prosjevne povrine

∗

=ot

ot

AA

k5 gdje je: ,%100⋅=AA

A oot

Ao – ukupna povrina svih otvora na prosjevnoj povrini, m2

As – ukupna povrina prosjevne povrine, m2

- vrijednost sa dijagrama na slici 8. ∗otA

f. Korekcioni fakto koji uzima u obzir vla`nost matrijala (minimalna koli~ina vode za prskanje 25 l/min⋅mr 3 ulaznog materijala

[irina otvora w,mm ≤0,8 1,6 5 8 13 20 25 50 k6 1,25 3,00 3,50 3,00 1,75 1,35 1,25 1,00

Slika 8. Specifi~ni kapacitet prolaza podreetkastih frakcija za usitnjene mineralne sirovine za kru`na vibraciona sita [5] Figure 8. Specific capacity of the undergrid fraction passage for the ground mineral raw materijal for the vibrating trommels [5]

- 179 -


Table 1. Correction factor for the capacity calculation of the vibrating trommels according the equation (6)

a. Correction factor k1 which considers the mass portions < w/2 in the input material 0 20 30 40 50 60 70 80 85 90 95 Portow < w/2 in

the mass, % k1 o,44 0,70 0,80 1,00 1,20 1,40 1,80 2,20 2,50 3,00 3,75

b. Correction factor k2 which considers the grain passing Rp through the sieving surface 70 80 85 90 95 Rp %

k2 2,25 1,75 1,50 1,25 1,00

c. Correction factor k3 considers the shape of the sieving surface opening (Figure 5) The shape of the opr+ening

Square and elaugated w > 25 w

elongoted

gapped

gapped w > 25 w

a. Gapped, parallel to the transport direction: 1.4 b. Gapped: perpendicular to the

transport direction: 1.3

d. Correction factor k4 which considers the sieving surface position in several storeys 1. Upper sieving surface: k4 = 1.00 2. Sieving surface k4 = 0.90 3. Sieving surface k4 = 0.80

e. Correction factor which considers the sieving surface opening

,%100:*5 ⋅==AAAwhere

AAk o

otot

ot

Ao – total surface of all the sieving surface openings, m2 As – total surface of the sieving surface, m2

- value from the diagram in the Figure 8. *otA

f. Correction factor which considers the materijal humiclity the minimal quantily of water for spraying 25 l/min m3 of the input materijal

≤0,8 1,6 5 8 13 20 25 50 Opening width w/mm, k6 1,25 3,00 3,50 3,00 1,75 1,35 1,25 1,00

Slika 9. Oblici otvora prosjevnih povrina: a. okrugli, b. kvadratni, c. duguljasti, d. procjepni

Figure 9. The slapes of the sieving surface operings: a) round, b) square, c) elongated, d) gapped

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5. ZAKLJUÂK

U radu je data podjela vibracionih maina za prosijavanje prema na~inu kretanja materijala na prosjevnoj plo~i ili mraì. Posebno su obra|ene konstruktivno-tehnoloke karakteristike kru`nih vibracionih sita sa pokazateljima za ocjenu odnosa kretanja projevne povrine i kretanja materijala na njoj, kao i metodologija utvr|ivanja kapaciteta tih sita uz koritenje empirijskih formula, tabela i grafikona. U ovom radu su obra|ena samo kru`na vibraciona sita, a u sljedeem radu obradie se elipsasta i linearna dinami~ka sita sa uticajnim faktorima na efikasnost procesa prosijavanja i zna~aja istih u tehnologiji pripreme i prerade nemetalnih mineralnih sirovina.

5. CONCLUSION The paper presents the division of the vibrating machines used in sifting, on the basis of the material movement on the sieving surface or grid. It also deals with the constructive-technological claracteristics of the vibrating trommels with the indexcs for evaluating the relation between the sieving surface movement and the mateirjal movement, as well as the methodology of establishing the capacity of these sieves ba using empirical formulas, tables and graphs. The paper deseribes only the vibrating trommels, and the following paper will present the elliptical and the linear dynamic sieves with the factors affecting the efficiency of the sieving process, as well as the importance of there sieves in the preparation and processing technology for the hou-metal mineral raw-materials.

6. LITERATURA - REFERENCES [1] M. Plavi (1990): Gra|evinske maine, "Nau~na knjiga", Beograd. [2] A.Stefanovi (1980):Gra|evinske maine I, "Gra|evinska knjiga" , Beograd. [3] N. Magdalinovi (1991): Usitnjavanje i klasiranje mineralnih sirovina, "Nau~na knjiga", Beograd. [4] N. âli (1990): Teoretski osnovi pripreme mineralnih sirovina, Rudarsko- geoloki fakultet Beograd. [5] H. Schubert (1987): Aufbereitung fester mineralischer Rohsoffe – Band I, VEB Deutscher Verlag fuer Grundstoffindustrie, Leipzig. [6] J.Sredojevi (2001): Rudarska tehnologija, mainski fakultet u Zenici.

[7] J. Sredojevi (1998): Maine za povrinsku eksploataciju, Mainski fakultet u Zenici. [8] I. [ii (2000): Analiza uticajnih faktora na izbor maina za drobljenje, Nauka i razvoj u praksi – Broj 2, Privredna komora Unsko-sanskog kantona, Biha. [9] I. [ii (2001): Tehni~ke i tehnoloke karakteristike postrojenja za preradu nemetalnih mineralnih sirovina u pogledu zahtjeva u kvaliteti proizvoda, kontroli i modernizaciji proizvodnje, Revitalizacija i modernizacija 2001, Tehni~ki fakultet – Biha. [10] I. [ii (1999): Investicioni program proizvodnje gra|evinskih agregata i suhih veziva – maltera u Rudniku mangana Buìn. [11] ^. Jevremovi (1984): Priprema mineralnih sirovina, Rudarsko-geoloki fakultet u Tuzli.

- 181 -

Mainstvo, 3(5), 183 – 194, (2001) O. Juki: TRETMAN OTPADNIH VODA...

TRETMAN OTPADNIH VODA U SEPARACIJAMA UGLJA

Dr Sc. Omer Juki, dipl.ing.ma., Rudnik mrkog uglja “Kakanj”, d.o.o. Zgoanska 17 – 72240 Kakanj

REZIME

Otpadna voda iz separacija uglja (kao i ostalih mineralnih sirovina u Btokom usmjerava direktno u otvorene vodotokove. Kako se u otpadnositnog uglja i zanemarljive koli~ine ~estica materijala npr. magnetitauglja, namee se potreba da se iz ekolokih (sprje~avanje zaga|enrazloga (sitni ugalj iz o padne vode se nakon prirodnog suenja i prodati) vri pre~iavanje otpadne vode. Pre~iavanje o padne vodsistema za pre~iavanje koji se sastoji iz bazena o padne vodeodgovarajueg cjevovoda.

)

(

tt

t

ifir

Klju~ne rije~i: otpadna voda, pumpni agregat, filter, cjevovod

THE TREATMENT OF WASTE WATERS IN C

Omer Juki, Ph.D., B.Sc.Mech.Eng., Brown Coal Mine “KaZgoanska 17 – 72240 Kakanj

SUMMARY

In BiH, the waste waters from the coal separation (as well as fromostly directed streight into open watercourse by the gravitation. Therefine coal and an insign cant quantity of the material particles (e.g. o iginating from the suspension for coal separation, a need occurreddue to ecollogical (the prevention of the watercourse pollution) andcoal from the waste water can be sold after it is naturally dried and it. Waste water can be treated by forming a system for water treatmewater tank, pump generator, filters and an adequatue pipeline.

Key words: waste water, pump generato, filter, pipeline

1. SISTEM ZA PREÎ[]AVANJE OTPADNIH VODA

1.1. Uvod Otpadna voda iz sistema za preradu uglja u Pogonu “Separacija” – RMU “Kakanj” se gravitacionim tokom, podzemnim kanalom i otvorenim odvodnim kanalom, usmjerava direktno u rijeku Bosnu. Postojei sabirnik otpadne vode je van upotrebe, kao i postojei talo`nici uglja i magnetita iz otpadne vode T–1 i T–2. Kako se u otpadnoj vodi nalaze zna~ajne koli~ine sitnog uglja i zanemarljive koli~ine ~estica magnetita, namee se potreba da se iz ekolokih (sprje~avanje zaga|enja rijeke Bosne) i komercijalnih razloga (sitni ugalj iz otpadne vode se nakon prirodnog suenja i eliminiranja grube vlage moè prodati) vri pre~iavanje otpadne vode.

1. SYSTEM CLEANIN

1.1. Introdu The waste waterthe “Separation” “Kakanj” is directhe gravitational the open tail racout of use, as coal and magne2. Since there aand insignificant there is a needto ecological (thBosna) and thefrom the waste wdried and the fre

- 183 -

STRU^NI RAD

iH se, uglavnom, gravitacionim j vodi nalaze zna~ajne koli~ine ) iz suspenzije za separiranje ja vodotokova i komercijalnih eliminiranja grube vlage moè e je mogue vriti formiranjem , pumpnog agregata, filtera i

)

OAL SEPARATIONS

kanj”, d.o.o.
PROFESSIONAL PAPER
t rf

t

m o her mineral materials) a e being a significant quantity o magnetite). In the waste water for the waste water treatment, commercial reasons ( he fine the moisture is elimnated from nt, which consists of the waste

FOR WASTE WATER G ction

from the coal proccesing system in section – Brown Coal Mine (RMU) ted straight into the river Bosne by course, the underground canal and e. The existing waste water basin is are the existing settling basins for tite from the waste water T-1 and T-re significant quantities of fine coal quantities of the magnetite perticles, for the waste water treatmenty due e prevention of pollution of the river commercial reasons (the fine coal ater can be sold after it is naturally e moisture is eliminated from it).


Pre~iavanje otpadne vode je mogue vriti formiranjem sistema za pre~iavanje koji se sastoji iz bazena otpadne vode, pumpnog agregata, filtera i odgovarajueg cjevovoda.

1.2. Analiza otpadnih voda i uzoraka sitnog uglja iz talo`nika Da bi se mogli izvriti adekvatni hidrauli~ni prora~uni i na osnovu toga izbor opreme za pre~iavanje otpadnih voda, izvrena je analiza otpadnih voda iz separacije (sadràj krutih ~estica – magnetita i uglja), te analiza uzoraka prirodno osuenog uglja iz talo`nika T–1 i T–2 (granulometrijski sastav, sadràj vlage, pepela, sagorivih materija i donja toplotna vrijednost). Rezultati ovih analiza su sljedei:

The waste water can be reclaimed by forming a system consisting of the waste water tank, the pump generator, filters and an eduquatue pipeline.

1.2. The analysis of the waste water and fine coal samples from the setting basins

In oreder to make adequatue hydraulic estimates to be able to choose the equipment for the waste water treatmnet, the waste water from the separation was analysed (the quantity of the stiff particles of magnetite and coal), as well as the samples of the naturally dried coal from the settling basin T-1 and T-2 (granulometric composition, the concentration of moisture, ash, and combustible materials, and the lower heat value). The results of these analyses are as follows:

Tabela 1: Rezultati analiza uzoraka prirodno osuenog uglja u talo`nicima otpadnih voda Table 1: The results of the analysis of the naturally dried coal in the waste water settling basins

Sadràj vlage Moisture content

[%]

Asortiman uglja

Commercial grade of coal

[mm]

Broj uzorka Sample number Gruba

Free Higroskopna Hygroscopic

Ukupna Total

Sadràj pepela The

content. of ash

[%]

Sagorive materije

Combustible material [%]

Toplotna mo

Heating value

[MJ/kg]

Sitni ugalj Fine coal (0,0 + 2,0)

1. 23,8 4,07 27,87 32,47 39,66 10,71-DTM


2. 38,3 3,78 42,08 17,40 40,52 10,27-DTM


3. 36,8 3,70 40,50 24,33 35,17 8,52-DTM

Prosjek: Average:

33,0 3,85 36,85 24,73 38,42 9,83 - DTM

Napomena: S obzirom na ~injenicu da sitni ugalj u talo`nicima sadrì visok procenat vlage (28 % - 41 %), donja toplotna mo (DTM) je niska. Prirodnim suenjem (eliminiranjem grube vlage) donja toplotna mo sitnog uglja iz talo`nika dostiè zadovoljavajuu vrijednost od 13 - 15 MJ/kg.

Remark: Taking into account that the fine coal from the settling basins has a high pertentage of moisture (28-41%), the lower heating value (DTM) is low. By natural drying (by eliminating the free moisture), the lower heating value of the fine coal from the settling basin reaches a satisfactory value of 13-15 MJ/kg.

- 184 -


Tabela 2: Sadràj krutih ~estica (ugalj i magnetit) u otpadnoj vodi iz separacije Table 2: The concentration of the stif particles (coal and magnetite) in the waste water from the separation

Gubitak magnetita u otpadnoj vodi Loss of magnetite in to waste water [g/l]

Datum uzimanja uzorka

Sampling date

Drugi magnetni separator

Second magnetic separator

Preljev velikog zgunjiva~a Big thickener

overflow

Otpadne vode ì~are

Ropeway waste waters

Gustina magnetitne suspenzije Magnetite suspension dens g/l] ity [k

êstice uglja u otpadnoj vodi Coal particles in waste water

qu [g/l] 14.11.2000. 0,048 0,349 0,024 1,60 01.12.2000. 0,099 0,0183 0,035 1,47 6,1 25.12.2000. 0,075 0,019 0,025 1,51 9,0 03.01.2001. 0,071 0,010 0,015 1,57 5,0

... ... ... ... ... ... 05.01.2001. 0,081 0,032 0,019 1,65 9,0 19.01.2001. 0,099 0,020 0,031 1,60 11,0

... ... ... ... ... ... 25.01.2001. 0,040 0,016 0,015 1,54

Prosjek - Average:

0,131 0,081 0,031 1,53 8,60

Tabela 3: Granulometrijski sastav prirodno osuenog uglja u talo`nicima otpadnih voda Table 3: Granulometric composition of the naturally dried coal in the waste water settling basins

UZORCI SAMPLES

GRANULACIJA GRADATION [mm]

TE@INA WEIGHT [g]

UÊ[]E PARTICIPATION [%]

+ 2,000 391,38 45,84 1,000 – 2,000 28,41 3,33 1,000 – 0,710 54,00 6,33 0,710 – 0,500 77,65 9,10 0,500 – 0,250 132,52 15,52 0,250 – 0,125 116,51 13,65 0,125 – 0,075 39,79 4,66

– 0,075 13,50 1,58

UZORAK Br.1 SAMPLE No.1

UKUPNO - TOTAL: 853,76 100,00

+ 2,000 99,75 14,25 1,000 – 2,000 29,15 4,16 1,000 – 0,710 72,06 10,30 0,710 – 0,500 103,97 14,85 0,500 – 0,250 168,91 24,13 0,250 – 0,125 119,59 17,08 0,125 – 0,075 63,82 9,12

– 0,075 42,74 6,11

UZORAK Br.5 SAMPLE No.5

UKUPNO - TOTAL: 699,99 100,00

1.3. Opis tehnolokog postupka Iz bazena otpadne vode centrifugalna pumpa crpi vodu i usmjerava je u filter koji sve ~estice uglja i magnetita ispod 50 µm proputa s pre~ienom vodom u odvodni kanal, a ~estice uglja i magnetita iznad 50 µm zadràva i usmjerava u talo`nike T–1, odnosno T–2.

1.3. The description of the technical procedure

The centrifugal pump suchs the water from the waste water tank and directs it into the filter which passes all the coal and magnetite particles under 50 µm with reclaimed water into the fal race, and retains and directs those above 50 µm in the settling basins T-1, i.e. T-2.

- 185 -


êstice uglja i magnetita ispod 50 µm u pre~ienoj vodi se istaloè u odvodnom kanalu, tako da se potpuno ~ista voda isputa u rijeku Bosnu. êstice uglja i magnetita preko 50 µm se istaloè u talo`nicima T–1, odnosno T–2 (naizmjeni~no), izvuku iz talo`nika, prirodno osue i usmjere u sistem otpreme uglja prema termoelektrani (TE) “Kakanj”. Dekantirana voda se preko preljeva na talo`nicima T–1, odnosno T–2 usmjerava u odvodni kanal kao i pre~iena voda iz filtera. Na osnovu analize otpadnih voda iz separacije i uzoraka prirodno osuenog uglja iz talo`nika, te, u tom kontekstu, prora~unatih hidrauli~nih parametara sistema za pre~iavanje otpadnih voda, odabrana je filtracijska tehnologija izraelske firme AMIAD. Filtracijski ciklus AMIAD se izvodi pomou sitastog filtera modela 4" SAF 4500 veli~ine prirubnice DN 150 mm i filterskim ulokom od 50 µm. Filterska tehnologija je zasnovana na potpuno automatskom radu.

The particles of coal and magnetite under 50 µm in the reclaimed water setlle in the fail race, and the totally clean water is let into the river Bosna. The particles of coal and magnetite above 50 µm setlle in the settling basins T-1, i.e. T-2 (alternately), they are then taken out of the them, they are naturally tried and directed int the coal dispatchement system towards the Thermoelectric Power Plant (TE) “”Kakanj”. The decanted water, as well as the reclaimed water from the filter, is directed into the fail race through the overflows on the settling basins T-1, i.e. T-2. On the basis of the analysis of the waste water from the separation and the analysis of the samples of the naturally dried coal from the settling basins, and on the basis of the calculated hydraulic parameters of the qaste water treatment system, the filtration technology of the Israeli company AMIAD was chosen. The filtration cyclus AMIAD is performed with the aid of the strainer filter, model 4” SAF 4500, with the size of the flange DN 150 mm and the filter gasket of 50 µm. The filters technology is fully automatic.

TANK

TOWARDS THE TAIL RACE

T

Slika 1. – S

Figure 1. – T

TOWARDS THE SETTLING BASIN

hema filtracijske tehnologije AMIhe filtration technology AMIAD c

- 186 -

OWARDS THE SETTLING BASIN

AD hart


Slika 2. – Dispozicija postrojenja i objekata za pre~iavanje otpadnih voda

Figure 2. – Disposition of plants and waste water treatment objects

- 187 -


2. HIDROTRANSPORT SITNOG UGLJA IZ BAZENA OTPADNE VODE U TALO@NIK

Otpadna voda iz separacije u svom toku do bazena otpadne vode i od bazena do talo`nika nosi ~estice uglja i magnetita granulacije od 0,0 do + 2,0 mm. Ova voda je, u sutini, pulpa i njen gravitacioni tok do bazena i prinudni tok od bazena do talo`nika je hidrotransport uglja navedene granulacije u talo`nik. Prisustvo ~estica magnetita se zbog niske koncentracije

zanemaruje. Kapacitet toka otpadne vode

[movQ

3/h] je potrebno izmjeriti i time kompletirati parametre potrebne za prora~un hidrotransporta uglja tretirane granulacije iz bazena otpadne vode u talo`nike.

2.1. Gustina otpadne vode (pulpe):

( )

( )εερρ

−+−+

=1

1

v

uvvov q

qρ [t/m3]

ovρ [t/m3] - gustina otpadne vode (mjeavina

vode i sitnog uglja – pulpa) [1,5,6,7]

vq [m3/m3] - koli~ina vode u pulpi u odnosu na

koli~inu sitnog uglja

vρ [t/m3] - gustina vode

uρε

[t/m3] - gustina uglja u ~vrstom stanju

- koeficijent poroznosti uglja

2. HYDROTRANSPORT OF THE FINE COAL FROM THE WASTE WATER TANK TO THE SETTLING BASIN

The waste water from the separation carries on its course to the waste water tank and from the tank to the settling basin perticles of coal and magnetite 0,0 to 2,0 mm of gradation. This water is basicaly pulp and its gravitational flow to the tank and the forced flow from the tank to the settling basin is reffered to as the hydrotransport of the coal of the above gradation into the settling basin. The presence of the magnetite perticles is neglected, due to their low concentration. The capacity of the waste water flow Qov [m3/h] should be measured and thus complete the parametres necessary for the estimate of hydrotransport of the coal with the treated gradation from the waste water tank to the settling basin.

2.1. Waste water density (pulp)

( )

( )εερρ

−+−+

=1

1

v

uvv

qq

ρov [t/m3]

ovρ [t/m3] - waste water density (mixture of

water and fine coal – pulp) [1,5,6,7]

vq [m3/m3] - waste water quantity in the pulp

compared to the fine coal quantity

vρ [t/m3] - water density

uρ [t/m3] - coal density in the solid state

ε - coefficient of coal porosity

2.2. Me|usobni odnosi kapaciteta sitnog uglja i vode u pulpi:

u

v1q

q = [m3/m3]

uq [m3/m3] - koli~ina sitnog uglja u pulpi u

odnosu na koli~inu vode

2.2. Interrelations of the fine coal capacity and of water in the pulp:

u

v1q

=q [m3/m3]

uq [m3/m3] - fine coal quantity in the pulp

compared to the quantity of water

2.3. Kapaciteti sitnog uglja i vode u pulpi:

Zapreminski kapaciteti:

)1( uvvvuvuov +=+=+= qQQQqQQQ

vuu QqQ = [m3/h]

1u

ovv +=qQQ [m3/h]

vovu QQQ −= [m3/h]

2.3. The capacity of the coal and the water in the pulp:

Volume capacities:

)1( uvvvuvuov +=+=+= qQQQqQQQ

vuu QqQ = [m3/h]

1u

ovv +=qQQ [m3/h]

vovu QQQ −= [m3/h]

- 188 -


Maseni kapaciteti:

[t/h] uuumQQ ρ=

[t/h] vvvmQQ ρ=

ovQ [m3/h] - koli~ina otpadne vode (pulpe)

uQ [m3/h] - koli~ina sitnog uglja u pulpi

vQ [m3/h] - koli~ina vode u pulpi

2.4. Kriti~na brzina hidrotransporta sitnog uglja:

Kako je ugao nagiba cjevovoda za hidrotransport sitnog uglja iz bazena otpadne vode u talo`nike α < 20º , hidrotransport se tretira horizontalnim, pa je kriti~na brzina hidrotransporta:

3

ovo

kvovk

)(ρλψρρ

kCDgv −

⋅= [m/s]

kv [m/s] - kriti~na brzina za horizontalni

hidrotransport sitnog uglja [1,5,6,7] g [m/s2] - gravitaciono ubrzanje D [m] - pre~nik cjevovoda za hidrotransport sitnog uglja

kC - korektivni faktor uticaja ~estica uglja

granulacije ispod 2 mm [1,5,6,7]

100

10075,0 kk

CC −⋅=

P [%] - procenat u~ea mase ~vrste komponente (sitnog uglja) u pulpi k - empirijski faktor za ugalj

oλ - koeficijent trenja u cjevovodu

ψ - koeficijent otpora slobodnom padanju

~estica uglja u vodi [1,5,6,7] Prema Rittinger – u:

6

vu

66065,0ρρ

ψ−

⋅=

Mass capacities::

[t/h] uuumQQ ρ=

[t/h] vvvmQQ ρ=

ovQ [m3/h] - waste water quantity (pulp)

uQ [m3/h] - fine coal quantity in the pulp

vQ [m3/h] - water quantity in the pulp

2.4. The critical speed of the fine coal hydrotransport: Since the angle of the pipeline inclination for the fine coal hydrotransport from the waste water tanks into the settling basins is <20o, the hydrotransport is horizontal. Therefore, the critical hydrotransport speed is:

3

ovo

kvovk

)(ρλψρρ

kCDgv −

⋅= [m/s]

kv [m/s] - critical speed for the horizontal

hydrotransport of fine coal [1,5,6,7] g [m/s2] - gravitational acceleration D [m] - pipeline diameter for the fine coal hydrotransport

kC - corrective factor of the influence of coal

particles with the gradation below 2 mm [1,5,6,7]

100

10075,0 kk

CC −⋅=

P [%] - participation percent of solid component mass (fine coal) in the pulp k - empirical factor for coal

oλ - friction coefficient in the pipeline

ψ - resistance coefficient to free dropping of

coal particles in water [1,5,6,7] By Rittinger:

6

vu

66065,0ρρ

ψ−

⋅=

2.5. Brzina strujanja pulpe kroz potisni cjevovod:

p

ovov A

Qv = [m/s]

ovv [m/s] - brzina strujanja pulpe kroz potisni

cjevovod

2.5. Speed of pulp flowing through the suppresioned pipeline:

p

ovov A

Qv = [m/s]

ovv [m/s] – pulp flow speed through the

displacement pipeline

- 189 -


ovQ [m3/s] - protok pulpe kroz cjevovod

pA [m2] - povrina popre~nog presjeka toka

pulpe

π2ov

p

ovov

4DQ

AQ

v == [m/s] > [m/s] kv

< < v kv ovv doz

... to predstavlja uslov da nema taloènja neizdvojenih ~estica sitnog uglja i magnetita (– 50 µm) iz pulpe u filteru AMIAD, odnosno iz pre~iene otpadne vode na dno potisnog cjevovoda, te da se brzina strujanja pulpe kroz potisni cjevovod kree u dozvoljenim granicama.

2.6. Brzina slobodnog padanja (tonjenja) frakcija uglja u vodi:

)()1(6 uo dfdg

=−= ρψ

πω [m/s]

oω [m/s] - brzina slobodnog padanja (tonjenja)

frakcija uglja u vodi [1,5,6,7] d [m] - srednji ekvivalentni pre~nik granulata (frakcije) uglja

ovQ [m3/s] - pulp flow through the pipeline

pA [m2] - cross section surface of the pulp flow

π2ov

p

ovov

4DQ

AQ

v == [m/s] > v [m/s] k

< < kv ovv dozv ... which represents a condition that there is no settling of the non separated fine coal particles and magnetite particles (-50µm) from the pulp in the filter AMIAD, respectively from the cleaned waste water on the bottom of the displacement pipeline. Therefore the pulp flow speed through the displacement pipeline is within the tolerable limits.

2.6. The free fall (the sinking) velocity of the coal fractions in water:

)()1(6 uo dfdg

=−= ρψ

πω [m/s]

oω [m/s] - The free fall (the sinking) velocity of

the coal fractions in water [1,5,6,7] d [m] - average equivalent diameter of the granulate (fraction) of coal

Tabela 4: Brzina slobodnog padanja (tonjenja) frakcija uglja u vodi Table 4: The free fall (the sinking) velocity of the coal fractions in water

d [mm] 0,01 0,02 0,03 0,04 0,05 0,075 0,125 0,25 0,50 0,71 1,00 2,00

ωo [m/s] 0,118 0,167 0,204 0,236 0,264 0,323 0,417 0,590 0,834 0,994 1,180 1,669

2.7. Hidrauli~ni parametri strujanja pre~iene otpadne vode u odvodnom kanalu:

U kanalu stalnog popre~nog presjeka strujanje vode je jednoliko (vt = const.).

2.7. Hydraulic parameters of the reclaimed waste water in the tail race: The water flow in the canal with the the permanent cross section is constant (vt = const.).

Slika 3. – Shema kretanja ~estice uglja u odvodnom kanalu Slika 4. – Popre~ni presjek odvodnog kanala Figure 3. – Scheme of coal particles motion in dewatered Figure 4. – The cross section o f

canal dewatering canal

- 190 -


H [m] αsinL1 = [m)( ikFuovpv QQQQQ ++−= 3/h]

[movF 03,0 QQ = 3/h]

[m] αsinLH1 = [m)( ikFuovpv QQQQQ ++−= 3/h]

[movF 03,0 QQ = 3/h]

pvQ [m3/h] - koli~ina pre~iene otpadne vode

ovQ [m3/h] - koli~ina otpadne vode (pulpe)

uQ [m3/h] - koli~ina sitnog uglja u otpadnoj vodi

(pulpi)

ikQ [m3/h] - gubitak vode isparavanjem u

odvodnom kanalu

FQ [m3/h] - koli~ina vode koju zadràva filter AMIAD (3 % od koli~ine vode koja prolazi kroz filter – dekantirana voda) vu [m/s] - brzina strujanja preostalih ~estica uglja u pre~ienoj otpadnoj vodi l [m] - put taloènja preostalih ~estica uglja u pre~ienoj otpadnoj vodi na dno kanala

pvQ [m3/h]- quantity of the reclaimed waste water

ovQ [m3/h] - quantity of waste water (pulp)

uQ [m3/h] - quantity of fine coal in the waste

water (pulp)

ikQ [m3/h] – the loss of water by evaporation in

the tail race

FQ [m3/h] – the quantity of water which retains the filter AMIAD (3 % of the water quantity which passes through the filter – decanted water) vu [m/s] – the flow speed of the remaining coal particles in the reclaimed waste water l [m] – the direction of settling of the remaining coal particles on the bottom of the canal in the reclaimed waste water.

2.7.1. Povrina popre~nog presjeka strujnog toka pre~iene otpadne vode u odvodnom kanalu:

)(H2

a-Ba 1 hfhhA =⋅

⋅+= [m2]

2.7.2. Okvaeni obim popre~nog presjeka odvodnog kanala:

)(

1H2

a-B

2asin2a 22

hfhhO =

+

+=+=

β

2.7.3. Hidrauli~ni radijus odvodnog kanala:

)(

1H2

a-B

2a

H2a-Ba

3

2

h hfh

h

OAR =

+

+

⋅+== [m]

2.7.4. Relativan pad odvodnog kanala:

αα sinL

sinLL

H1 ===I [‰]

2.7.1. Cross section surface of reclaimed waste water flow in the tail race:

)(H2

a-Ba 1 hfhhA =⋅

⋅+= [m2]

2.7.2. The watted circumference of the tail race cross section:

)(

1H2

a-B

2asin2a 22

hfhhO =

+

+=+=

β

2.7.3. Hydraulic radius of the tail race:

)(

1H2

a-B

2a

H2a-Ba

3

2

h hfh

h

OAR =

+

+

⋅+== [m]

2.7.4. Relative drop of the tail race:

αα sinL

sinLL

H1 ===I [‰]

- 191 -


2.7.5. Teoretska brzina strujanja vode u odvodnom kanalu:

Prema Chezy – ju:

ht RICv = [m/s]

Prema Bazain – u:

h

B1

87

Rn

C+

=

C - Chezy – jev koeficijent [3]

Bn - koeficijent hrapavosti stijenki odvodnog

kanala [3]

hR [m] - hidrauli~ni radijus odvodnog kanala [3]

2.7.6. Stvarna brzina strujanja vode u odvodnom kanalu:

)(

H2a-Ba

4pvpv

s hfhh

QAQ

v =⋅

⋅+

==

2.7.5. The theoretical speed of the water flow in the tail race:

By Chezy:

ht RICv = [m/s]

By Bazain:

h

B1

87

Rn

C+

=

C - Chezy‘s coefficient [3]

Bn - roughness coefficient of the tail race sheets [3]

hR [m] - hydraulic radius of the tail race [3]

2.7.6. The real speed of the water flow in

the tail race:

)(

H2a-Ba

4pvpv

s hfhh

QAQ

v =⋅

⋅+

==

3. PRORAÛN PRELJEVA

3.1. Preljevi P1 i P2 (iz talo`nika T–1 i T–2 u sabirni kanal):

3. OVERFLOW CALCULATION

3.1. Overflows P1 and P2 (from the settling basin T–1 and T–2 into the settling canal):

Slika 6. – Uzdu`ni presjek talo`nika uglja Slika 7. – Popre~ni presjek talo`nika uglja Figure 6. – Longitudina section of coal Figure 7. – The cross section of coal l settling basin settling basin

3.1.1. Preljevni protoci: Protok dekantirane vode iz talo`nika T–1, odnosno T–2 u sabirni kanal:

[mTFSK WWQ −= 3/h]

3.1.1. Overflowed flows:

The flow of the decanted water from the settling basin T–1, respectively T–2 in the settling canal:

[mTFSK WWQ −= 3/h]

- 192 -


FW [m3/h] - koli~ina otpadne vode koju filter

izbaci u talo`nik

TW [m3/h] - isparena koli~ina vode iz talo`nika

FW [m3/h] - of the waste water discharced by

the filter into the settling basin

TW [m3/h] - evaporated quantity of water from

the settling basin 3.1.2. Preljevni mlaz:

3.1.2. Overflowed jet:

Slika 8. – Izgled preljevnog mlaza

Figure 8. – The view o the ovewflowed jet f Visina preljevnog mlaza:

23

pmSK 2 hgbmQ ⋅= [m3/s]

32

SKpm 2

=

gbmQh [m]

m - koeficijent prelijevanja [3,7] b [m] - irina preljevnog praga

pmh [m] - visina preljevnog mlaza [3,7]

Overflowed jet height:

23

pmSK 2 hgbmQ ⋅= [m3/s]

32

SKpm 2

=

gbmQh [m]

m – coefficient of overflowing [3,7] b [m] - overflowed sill width

pmh [m] - overflowed jet height [3,7]

Brzina preljevnog mlaza:

pm

SK1 hb

Qc = [m/s]

Overflowed jet speed:

pm

SK1 hb

Qc = [m/s]

- 193 -


4. LITERATURA – REFERENCES:

[1] S. Hodì, “Transport u rudarstvu”, Rudarsko – geoloki fakultet u Tuzli, Tuzla, 1998.

[2] S. Hodì & S. Mili – MaI, “Odvodnjavanje u rudarstvu”, Rudarsko – geoloki fakultet u Tuzli, Tuzla, 1996.

[3] M. Dobri, “Hidraulika”, [kolska knjiga, Zagreb, 1979.

[4] H.Recknagel & E. Sprenger, “Grijanje i klimatizacija”, Gra|evinska knjiga, Beograd, 1984.

[5] O. Juki, “Hidrauli~ni transport elektrofilterskog pepela u jamama Rudnika Kakanj”, Referat na nau~no – stru~nom skupu “Tendencije u razvoju mainskih konstrukcija i tehnologija”, Zenica, 1994.

[6] O. Juki, “Doprinos postavljanju metodolokih principa projektovanja i primjene hidrotransportnih postrojenja za izradu jamskih baraà”, Doktorska disertacija, Mainski fakultet u Zenici, Zenica 2000.

[7] O. Juki, “Pranje i hidrotransport separiranog materijala filtriranom vodom u recirkulacionom toku”, Referat na nau~no – stru~nom skupu “Tendencije u razvoju mainskih konstrukcija i tehnologija”, Zenica, 2000.

[8] ... , “Amiad Filtration Systems – Products Overview”, Ref.92-4330-2/5.96, Izrael

[9] ... , “Amiad SAF Filters”, Ref.92-3460, Izrael

[10] ... , “Amiad Automatic Filters”, Catalogue No.2-64, Ref.92-9431-1/7.95, Izrael

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