Upload
clarence-james
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
SEPARATOR Design of Equipments Process
Chemical Engineering 2012 – B Class
Second Group
1. Winda Rahma Tiara
(03121403018)
2. Ana Barika
(03121403038)
3. Abiyyu Ahmad
(03121403056)
Terminology / Definitions of Separators
Separator is a pressure vessel to separate the fluid mixture (liquid or gas) based on differences in density;1. Separator is one of the major
equipment that have an important role in the operation of oil refineries and natural gas;
2. Separator is used to separate production fluids from the production wells into two or three phases.
The Principle of Design
Separator works on the principle of separation by specific gravity / density where required vessel volume and specific retention time, so that existing phases can be separated . Determination of the design of the separator is an important thing that will determine the production capacity of all existing facilities.
A. Based on the Phase Separation, Separator can devided into:1. Two Phase Separator
To seperate the liquid phase and gas phase; 2. Three Phase Separator
To seperate liquid, oil, and gas;
B. Based the shapes of Separator can be divided into:1. Horizontal Separator
Used to a flow that have ratio of gas to liquid(Gas-Oil Ratio) is high, for the bubbly flow / for the liquid that comes out from the previous separator;
2. Vertical SeparatorUsed for a fluid flow that have ratio gas-liquid (Gas-Oil Ratio) is low to medium and is expected to occur a liquid that coming shock (slug) in a relatively frequent;
3. Spherical SeparatorSpherical separator is usually only used for small production capacity
THE FACTORS THAT INFLUENCE THE
DESIGN OF SEPARATOR
1.Difference of Density / Mass type; ;
2.Deposition Time A time at which the fluid
stay in the separator;
3.Contact of Surface;
Formula for Design a Separator
21
420
/
m
D
gl
ggeff d
C
ρρ
ρ
P
QZTLd
Keterangan :
d = diameter separator,inLeff = the effective length of the separator where separation
occurs, ftT = operating temperature, oRQg = gas flow rate, (known from experimental data)P = operating pressure, PsiaZ = gas compressibilityρg = density of gas, kg/m3
ρl = density of liquid, kg/m3
CD = coefficient of dragdm = grain size of the liquid to be separated, micron
The capacity of the gas needed to give the combination equations diameter (d) and the effective length of the separator (Leff). The equation used for the separator liquid filled 50% (one-half of the separator) and for the separation of liquid grain diameter of 100 microns is as follows:
persamaan (1)
Calculation procedures of sizing three-phase of horizontal separator are as follows:Preparing Data QL, Qg-, ρg, ρl, m, P, and T;Determining the value of tR;
Calculate d.Leff equation (1) for d <dmax gas that meets the restriction for capacity of gas;
Grain size (dm) that used is 100 microns if the information about it was not available;
Z values obtained by gas compressibility chart;In calculating d.Leff value for gas capacity, the necessary value
coefficient drag (CD) from grain liquid that fall from the gas. CD Rates are determined by the following iteration steps:1. Calculate Vt with this formula : 2/1
0204,0
g
mglt
dV
2. Calculate the value of Re with this formula :
tmg Vd
0049,0Re
34,0Re
3
Re
242/1DC
3. Calculating the value of the CD with the Re value were obtained :
4. Re-count Vt with this formula : 2/1
0119,0
D
m
g
glt C
dV
5. Re-count the Re value (back to the second step) and iterating till the value of CD obtained to constant; Calculate d.Leff equation (1) for d <dmax gas that meets the
restriction of water by equation (1); Determining seam-to-seam length by using one of the following
equations:
Selected combinations of d and LSS that ideal with slenderness ratio (LSS / d) between 3 and 4.
gaskapasitasuntukd
LL effss 12
cairankapasitasuntukLL effss .3
4
Example of Calculating
ProblemSteps of Calculation :1. Determine tR
2. tR = 2 min 2. Counting d.Leff for d <dmax that
meets the capacity restriction of gas. Where dmax = 50
3. We use grain size (dm) 100 micron :
ITEM UNIT VALUE
QgMMSCFD 53,36
QlBLPD 3205,6711
PoperasiPsig 613,8
ToperasioF 42,56
η cp 0,0112
ρgkg/m3 59,8770
ρlkg/m3 529,6824
tRmin 2
Mass flow
gas (m)
ton/day 1216
Mass flow
liquid
ton/day 277,8
Data Calculation of Inlet Separator (Design)
2/1
420
m
D
gl
ggeff d
C
P
QZTLd
Iterating:
*CD = 0,4336Vt = 0,8465
ft/sRe =
2217,5073CD = 0,4145
*CD = 0,4145Vt = 0,8658
ft/sRe =
2268,0659CD = 0,4136
*CD = 0,4136Vt =
0,8667 ft/sRe =
2270,4236CD =
0,4136
Calculate the value of CD Calculate Vt with this formula :
Re-count Vt with this formula :
Calculating the value of the CD with the Re value were obtained :
Calculate the value of Re with this formula :
1495,8023 =0112,0
5710,0.100.8770,590049,00049,0Re
tmg Vd
0,571ft/s
8770,59
100.8770,596824,5290204,00204,0
2/12/1
g
mglt
dV
0,4336 =34,01495,8023
3
1495,8023
2434,0
Re
3
Re
242/12/1DC
2/12/1
0,4336
100
8770,59
8770,596824,5290119,00119,0
D
m
g
glt C
dV
ft/s 0,8465 =
(a.) By using the data comparison of pressure (P) and temperature (T), then the obtained value of Z (compressibility factor). From the graph (Appendix G) obtained Z = 0.84 (Mc Graw-Hill Second Edition).
effss LL .3
4
Counting seam-to-seam length(Lss) with equations for fluid capacity:
(b.) Calculate d.Leff untuk d <dmax that meet the restriction of retention time for oils and water.
7,0.2 lR
eff
QtLd
7,0
)6711,3205(2.2 effLd = 9159,0603
2/1
420
m
D
gl
ggeff d
C
P
QZTLd
2/1
100
4136,0
8770,596824,529
8770,59
8,613
36,53.84,0).56,502(420
effLd = 353,8188 (inch.ft)
Counting seam-to-seam length (LSS) with the equation for Gas capacity:
By Using30<d<5012
dLL effss
Thank You
d Leff LssSlenderness
Ratio Gas
(12Lss/d)
30 11,79396 14,29396 5,717584
32 11,0568375 13,72350417 5,146314063
34 10,40643529 13,23976863 4,672859516
36 9,8283 12,8283 4,2761
38 9,311021053 12,47768772 3,940322438
40 8,84547 12,17880333 3,653641
42 8,424257143 11,92425714 3,406930612
44 8,041336364 11,70800303 3,193091736
46 7,691713043 11,52504638 3,006533837
48 7,371225 11,371225 2,84280625
50 7,076376 11,24304267 2,69833024
The value combination of D and Leff for liquid retention time limits tabulated as
follows:
Cause of Leff in capacity of gas > capacity of liquid. Selected combinations of d and LSS that ideal with slenderness ratio between 3-4. Obtained from the table ,that the ideal size of the separator is :Diameter 38 inch and Lenght 12,4777 ft.
d Leff LssSlenderness
Ratio Gas
(12Lss/d)
30 10,17673365 13,5689782 5,42759128
32 8,94439481 11,92585975 4,472197405
34 7,923062531 10,56408337 3,728500015
36 7,067176146 9,422901529 3,140967176
38 6,342839533 8,457119377 2,670669277
40 5,724412679 7,632550238 2,289765071
42 5,192211046 6,922948062 1,977985161
44 4,730919569 6,307892759 1,720334389
46 4,328478396 5,771304528 1,505557703
48 3,975286582 5,30038211 1,325095527
50 3,663624114 4,884832152 1,172359717
The Value Combination of d, Leff, Lss, & Lss/d for Inlet Separator based Capacity of gas
(Design):