Practical tipsOil nozzles

DANFOSSBuRNeR cOmPONeNTS

Dear Danfosspartner

Dear Danfoss partner

As one of the most important oil nozzle manu-facturers Danfoss wants with this booklet to be of assistance to you in your daily work.

With this booklet you can choose and fit Danfoss oil nozzles for all purposes and for any demand.

In addition to that you get valuable tips and refer-ences to how to fit oil nozzles in your working area.

How important the function of the oil nozzle is to the oil burner appears clearly from this booklet.

Danfoss assists you in handling these mechanically complicated products which are of vital importance for the function and the output of the oil nozzle.

For further help in your work with oil burner com-ponents Danfoss refers to our Service handbook about burner components and to our homepage burner.danfoss.com

�

PageTheoilnozzleandthecompleteoilheatingplant.............................................................. 3

Whatyoushouldknowatleastaboutoilnozzles.................................................................. 4

Howdoesanoilnozzlework?................................ 5

Spraypatternsandsprayanglesofoilnozzles...... 6

Markingontheoilnozzle........................................ 7

Howisthecorrectoilnozzlechosen?.................... 8

Boilercapacityandnozzlesizing............................ 9

Calculationofoilnozzlecapacity........................... 10

Isitpossibletocompareoilnozzlesofdifferentmakes?........................................................................ 11

Conversiontableforoilnozzles............................. 12

Forhowlongcananoilnozzlebeused?............... 13

Whateffectsthefunctionoftheoilnozzle?.......... 14

Tipsaboutreplacementoftheoilnozzle............... 15

Whateffecthavedirtandsedimentsinfueloil?.. 16

Whatcausesanoilnozzletodrip?......................... 17

Whatcausesanafterdripofoilwhentheburnerstops?.......................................................................... 18

Practical tips about Danfoss oil nozzles

Table of contents:

�

Whatcausestheoiltocokeontheoilnozzleandtheignitionelectrodes?.................................................. 19

Whatisthecauseofnooilfromtheoilnozzle?... 20

Whattodowiththeoldoilnozzles?...................... 21

Whatmattersarethedetails............................. 22,23

Practical tips about Danfoss oil nozzles

Table of contents:

�

The oil nozzle and the complete oil

heating plant

Acompleteoilheatingplantbeginsattheoiltankfillingconnectionandendsatflueorthechimneypipe.

Almostattheheartoftheplant,hiddenfromalleyes,isasmallinterestinggadget–theoilnoz-zle.Theoilnozzleplaysavitalroleincombustion,becauseitwouldbeabsolutelyimpossibletogetCLEAN,STABLEandECONOMICplantoperationifitisnothandledcorrectly.

Theoilnozzleshouldbetreatedlikeadearfriend,i.e.protectivelyandconsiderately.Becarefulnevertotouchthetipofthenozzleandthenozzleorificewithdirtyfingers,asthismightcausethenozzleorificetoclog.Topickupthenozzle,alwaysgripthespannerflatsonly.

Storing:Alwaysleavethenozzleinitsprotectivecoveringuntilitistobeinstalledintheburner.

Transport:AlwaysusetheDanfossnozzlecasefortransport;thenozzlewillbewell-protectedinthisway.

�

What you should know at least

about oil nozzles

Theoilnozzleisofvitalimportancetothecombustion.Itisonlypossibletogetatclean,stableandeconomi-calplantoperationwhentheoilnozzlefunctionstoperfection.

The best result is obtained when the oil nozzle is replaced once a yearThereasonisthatinthecourseoftheheatingseason,dirtparticlesgatherinthenozzlefilterandintheoilnozzlesandruinorhinderaperfectatomizing.

Boththeenvironmentandtheoilaccountwillprofitfromaperfectoilatomizing.Furtherservicevisitsduetocloggedoilnozzlesshouldnotbenecessary.

Danfoss oil nozzles are extremely precise and meet the requirements of the actual EN-norm of a capacity tolerance of ±4%

NozzlesproducedbyDanfossaretested100%intestoilforkeepingthetolerancespermitted.Beyondthis,theatomizingpatternsaretestedvisuallyforregularityandatomizingfaults,ifany.

HasanewDanfossoilnozzlebeeninstalled?

�

The function of the oil nozzle

Fig.1showsthewaythefueloilrunsthroughtheoilnozzle:Thefueloilisputunderpressurebytheoilpumpandrunsintotheoilnozzleandisfilteredinthenozzlefilter.Intheswirlchamberthefueloil“rotates”andleavestheoilnozzleforbeingburstinmanyfinesmalldrops.Theorificeandtheconeslotsdeterminethespraycharacteristics.

Fig. 1: The way the fuel oil travels through the oil nozzle

Burnersusedtoday,designedexactlytotheheatre-quirementofthehouse,haveresultedinareductionoftheburnercapacities.Sothecrosssectionintheoilnozzlehadtobereduced,too.Theorificediameteronanoilnozzleisthusonlyafewtenthsofamillimetre(fig.2),whichmeansthatnon-professionaltreatmentmaycauseimmediateoperationalproblems.

Fig. 2: Nozzle orifice compared with a hair from a human being

�

Thepropertiesoftheoilnozzleappearfromthenozzlemarkings.Oilnozzlesareavailablewithdifferentspraypatternsandsprayangles.Thesemustfittheburnerinquestionandofcoursealsothecombus-tionchamberoftheboiler.

ThedesignationsofthespraypatternsonDanfossoilnozzlesareS(Solid);H(Hollow)andB(Universal=semisolid).Othermarkshavesimilardesignations.

Fig. 3: Spray patterns of the oil nozzleFrom left to right: Spray patterns B, S and H.

Thesizesofthesprayanglesarenormally30°,45°,60°and80°.

Fig. 4: Spray angles 30°, 45°, 60° and 80°

Spray patterns and spray angles of oil

nozzles

�

FromthemarkingonDanfossoilnozzlesitiseasytoreadthecapacity,spraypatternandsprayangle.DanfossoilnozzlestypesEHandESforkeroseneareavailablewith60°and80°SandH.Thenozzlesaremarkedwiththefollowinginformation:

Marking on an oil nozzle type ES with a capacity of 1.80 kg/h

• 1.80kg/h=specifiedcapacityat8bar,1.65cSt,790kg/h

• OK=OFTECcertification• Thefiguresinthesquarebrackets[]arean internalseriescode• 0.60=referencecapacityinUSgal/h• 60°ES=sprayangleandpattern

Somecountrieshavespecificdemandsoncapacitydefinition(e.g.JapanandtheUSA).Sometypesalsoprovideinformationonnormspecificpropertiesac-cordingtothenorminquestion,e.g.EN293and299.

Marking on an oil nozzle type OD with a capacity of2.37 kg/h

• 2.37kg/h=specifiedcapacityat10bar,3.4cSt,840kg/m3

• ENstatesthattheoilnozzleisinaccordancewith thenormsEN293andEN299.• 80°IIstatestheangleindexandatomizingindex accordingtoENNorm.• Thefiguresinthesquarebrackets[]areaninternal seriescode.• 0.60USgal/h=referencecapacityat7bar,3.4cSt,

820kg/m3

Marking on the oil nozzle

�

How is the correct oil nozzle chosen?

WhenaDanfossnozzleneedsreplacingandallthathastobedoneisswapoldfornew,itisasimplemattertomakesurethatthenumbersandlettersoneachnozzlecorrespond.Ifthedesignationontheoldnozzlehasbecomeillegible,somethingthathappensmostoftenbecauseofclumsyhandling,theinstruc-tionbookwillcontaindetailsastotherighttypeandsizetouse.Shouldthenozzledesignationbeillegibleandtheinstructionbooklost,thesizeofnozzlemustbechosentomatchtheboilercapacity.Thisinformationwillbeonatypeplatefittedontheboiler,failingthisitisrecommendedthatyoucon-tacttheboilermanufacturer.

�

Boiler capacity and nozzle size

Thecapacityofaboilerisnormallystatedeitheraskcal/horaskW

a) kcal/h = kilo calorie per hourAseachkilogramoffueloilatcombustionyields10,000kcal=10Mcal,itiseasytocalculatewhatnozzlesizetochoose.

Example:Foraboilerstamped25,000kcal/h,chooseanoilnozzleof2.5kg/hatapumppressureof10bar.(25,000:10,000=2.5kg).Thisunitcapacitywasalsointroducedinthenozzlestandard.

b) kW = kilowattThedesignationkWwillbeusedmorefrequentlyinfuture,astheunitformspartoftheSI-systemofmeasurements.

1litreoffueloilyieldsatcombustionapprox.10kW.ItisthereforeeasytochoosetherightsizeofaDanfossoilnozzleforaboilerifthecapacityisstatedinkW.AsDanfossoilnozzlesaremarkedwithkg/h,acon-versionmustbemade.

1litreoffueloil=0.84kg,e.g.20kWboilercapacity=2litresor1.68kg/hatapumppressureof10bar.

Theexamplesoverleafshowhowsimpleitistocal-culatethenozzlesizesforadifferentpressure.

�0

Calculating examples for

choice of oil nozzles

Example 1:Herewewanttherequiredpressuresettingwithanoilnozzleof2.11kg/htoobtainaflowrateof2.5kg/h.

V2=2.5kgwantedflowrateV1=2.11kg/hnozzlecapacityat10barP1 =pumppressureat10barP2 =thewantedpumppressure

V2= V1× √P2:P1;P2=V2²:V1²×P1;P2 = 2.5²:2.11²×10=14barPressuresettingwithanoilnozzleof2.11kg/hmustbe14bartoobtainaflowrateof2.5kg/h.

Example 2:Herewewanttheflowrateofanoilnozzleof2.11kg/hatapumppressureof12bar.

V2=wantedflowrateV1=2.11kg/hflowrateat10barP2 =pumppressureat12barP1 =pumppressureat10bar

V2= V1× √P2:P1=2.11×√P2:P1=2.31kg/hAtapumppressureof12baritispossibletoobtainaflowrateof2.31kg/hwithanoilnozzleofacapacityof2.11kg/h.Afurtherhelpforquickdeterminationofasuitableoilnozzleisthenozzlecalculatororthenozzlecapacitytable.

Danfosshasthusplacedanozzlecalculatorontheinternet,withwhichtherightoilnozzlecanbefoundquickly(seeburner.danfoss.com).

��

ThesituationmayarisewhereanozzleofanothermakeistobereplacedbyaDanfossoilnozzleandthequestionariseshowtocomparethedifferentmakes.Theinstructionbookoftheoilheatingplantoftencontainsadviceandgivesinformationonthedifferentmakesandtypestouse.Capacitiesgivenforthedifferentnozzletypescanbedirectlycom-pared.Sprayanglestoocanbecomparedasthesizeoftheangleisstampedontheoilnozzle.

Is it possibleto compare

oil nozzles ofdifferent makes?

��

Conversion to Danfoss OD nozzlesDelavan A ➨ Danfoss HDelavan B ➨ Danfoss SDelavan W ➨ Danfoss BFluidics SF ➨ Danfoss SFluidics HF ➨ Danfoss HFluidics S ➨ Danfoss SFluidics H ➨ Danfoss HMonarch PL ➨ Danfoss H/BMonarch NS ➨ Danfoss HMonarch PLP ➨ –Monarch AR ➨ Danfoss SMonarch R ➨ Danfoss SHago B ➨ Danfoss SHago H ➨ Danfoss HHago SS ➨ Danfoss H/BHago P ➨ Danfoss SHago ES ➨ Danfoss SSteinen PH ➨ Danfoss H/BSteinen H, HAT ➨ Danfoss HSteinen SS ➨ –Steinen Q ➨ Danfoss SSteinen S, ST ➨ Danfoss S

The stated values are based on experience and are thus only to be considered as a guideline. When replacing oil nozzles, first and foremost use oil nozzles with the same shape of head.

Conversion tables for oil nozzles

Conversion to Danfoss EH/ES nozzles Hago H.SS ➨ Danfoss EH Hago P, ES ➨ Danfoss ES Delavan A ➨ Danfoss EHDelevan B, W ➨ Danfoss ESMonarch NS ➨ Danfoss EH Monarch PLP, AR, R ➨ Danfoss ES Steinen H, PH ➨ Danfoss EH Steinen SS, Q ➨ Danfoss ES

��

Anoilnozzlecanbeusedforaslongasareasonablecarbondioxidepercentage(CO2%)andasuitablylowsootnumbercanbemaintained.Whetherthelifeofanoilnozzlewillbe1yearormoreishardtopre-dict,asitdependsverymuchonhowmanyhourstheplanthasbeenoperatingandhowcleantheoilisandtheconditionofthetank.

Thelifeofanoilnozzleisshortenedconsiderablyif,say,nozzlefilterandpumpfilter,ifany,aremissingorthesepartsaredefectiveordirty.Iftheoilnozzleisexposedtostrongradiantheatfrom,say,heavilyglowingincombustiblematerial,thelifewillbeshortenedtoo,asthestrongheatmaycausetheoiltocokeandcollectaroundthenozzle.

For how long can an oil nozzle

be used?

��

Inconnectionwithservicevisitsthequestionisoftenaskedwhathascausedtheoilnozzletofail?Wewillheretrytodescribesomeofthemostfrequentfaultsandhowtheycanberectified.

Setting of the burnerThemostfrequentfaultisprobablywrongsettingoftheburner.Thevaluesstatedbytheburnermanufac-turermustbeobserved,suchaspumppressure,ad-justmentofignitionelectrodes,etc.Itisespeciallyimportantthattheadjustmentofthetwoignitionelectrodesisstrictlyaccurate(fig.5andfig.6).Itisoffrequentoccurrencethattheignitionelectrodesarenotadjustedcorrectlyandtheignitiongoesfromanelectrodetotheoilnozzle.Thisisclearlyseenfromburnedspotsorfromadvancedgroovesintheoilnozzle.Nowadaysthelocationoftheoilnozzleinrelationtothebaffleplateisoftenoptimizedwithfirmimpactrimsintheburner.Therightsprayangleisalsoveryimportant,bothtopreventtheoilfromtheoilnozzlesprayingagainstthebaffleplateandtopreventthemixtureproportionbetweenairandoilmisttochangebecauseofatoosmallsprayangle.

Fig. 5 and fig. 6: Examples of distance between electrodes

What can disturb the function of the

oil nozzle?

��

The right way to change an oil nozzleWhenchanginganoilnozzle,itisespeciallyimpor-tantthatthenozzleholderisbledwellandtheoilpassagesarecleaned.Afterdemountingoftheoldoilnozzleinahorizontalposition(pos.1),thenoz-zleholderiscleanedwithaclean,flockfreecloth.Thentheburnerisplacedinserviceposition(pos.2)andinthisposition,verticallyupwards,thenozzleholderisfilledtotherimwithfueloil.

Pos.1 Pos. 2

Nowthenewoilnozzleisslowlyscrewedinsothattheairintheoilnozzlecanbeletout.Afterthenewoilnozzlehasbeeninserted,thenozzleplateshouldnotbetouchedwiththefingersanymoretopreventdirtinthenozzleorifices.

Bydoingso,itispreventedthatdirtlooseneddur-ingdemountingoftheoilnozzlestaysinthenozzleholderandlatercausesthenozzletofail.Neveruseaggressionwhenmountingthenozzleasthiscanruinthesealingsurfacebetweentheoilnozzleandthenozzleholder.

Tips for change of the oil nozzle

Tightening torque for oil nozzles

Recommended torque 15-20 Nm

Maximum torque 25 Nm

��

Dirt/sediments in fuel oilTheoilnozzleisequippedwithdifferentfilters,de-pendentonthesizeofthenozzle.Thesenozzlefiltersarenormallyalwayssinteredbronzefiltersinthelowestcapacityareaandhaveverygoodproperties,especiallywhererod-shapedandthreadydirtpraticlesareconcerned.Whensuchparticleshavereachedtheinteriorofthenozzle,theywillsoonruinthenozzle(fig.7).Therefore,therightchoiceofprefilterisofdecisiveimportanceforthelifeoftheoilnozzle(fig.8).

Fig. 7: Dirt sediments in the swirl chamber

Ruined/dirty–newFig. 8: Ruined cartridge filter

Nowadayscartridgefiltersofdifferentfinenessandsizesareavailable.Thusthefinenessfornormaluseisrangingfrom100µover50-75µto25-40µ.Butalsocartridgeswithfinenessesof5µareoffered.Afinerpre-filterisalwaystobepreferredtoacoarsepre-filter.Measuremax.vacuumregularly!Atoohighvalueindicatesachokedfilter.

What effect have dirt and sediments

in fuel oil?

��

Infairnessithasbeenmaintainedfromthebeginningthatinmostcasestheoilnozzleisnotthecauseofafterdripping.Butwhateverthecausemaybe,afterdrippingfromtheoilnozzlemustinanycircumstancesbestoppedasquicklyaspossibletopreventsoothingupoftheburnerheadortheareaarounditorthecombustionchamber.

Oil drips when the burner startsThiscanhappenduringpreheatingintheoilpreheaterwhentheoilexpandsorduringprepurgeduetoadirtyordefectiveclosingvalveintheoilpump.

Oil is dripping during operation• Theoilnozzleislocatedtoofarfromthebaffle

plateortheburnerhead.• Ignitonelectrodesprotrudeintotheoilmist,so

theyareplacedincorrectly.• Dirtintheoilnozzleoroilcokeinandonthe

nozzleorifice.• Thenozzleorificeisdefective,becauseofattempts

tocleanit.• Toolowoilpressure.Remembertochecknow

andthen.

What causes an oil nozzle to drip?

��

What causes after-drip of oil when the

burner stops?

Afterdrip of oil when the burner stopsWhentheburnerstopsandtheoilnozzlespraysajetofoilinsteadofcuttingofftheoilsupplywithlighteningrapidity,themostlikelyreasonsare:Aslightleakinthesuctionlinemayresultintinyamountsofairgettingintotheoilpump,thepressurelineortheoilnozzle.

Suchanamountofairis,however,notsufficienttodisturbthefunctionoftheburner,butlargeenoughtoproduceanafterdripandevenanoiljetwhentheburnerstops.Thiswilleventuallyleadtothepartsgettingdirtyandcausemalfunction.

Theoilintheoilpressurelinebetweenthepumpandtheoilnozzlecontainsair.

Evenwithaperfectlyoperatingclosingvalveandathoroughbleedingofthepressurelines,afterdripofoilcanbeseenbecauseoftheradiationofheatfromthecombustionchamber,whichexpandstheoilandforcesitintotheoilnozzleaftertheburnerhasstopped.

��

What causesoil coke on theoil nozzle and

ignition electrodes?

Whenliquidoilisheatedaboveacertaintemperatureaprocesstakesplacecalled“cracking”andastone-hardblackcarbonsettles.Undernormaloperatingcondition,theamountofcarbondepositedonthenozzleandignitionelectrodeswillbeunnoticeable.Butjustaslightscratchonthetipofthenozzlecancreateapathalongwhichsmallamountsofoilcanfindtheirway.Thisoilisexposedtoaverystrongra-diantheatandwill,consequently,producecarbononthetipofthenozzleandcauseinterferencewiththeamomizingprocessandcancausepoorercombus-tion.Thesamethinghappenswhentheoilnozzledrips.

Iftheignitionelectrodesareplacedincorrectly,sothattheycanbehitbytheinjectedoil,theheatfromtheflamewillintimestartcarbondepositstobuilduponthetipoftheelectrodes.Eventually,theelectrodeswillshortcircuitandtherewillbenoignitionsparkandplantrestartwillbeimpossible.Cokeformationonoilnozzleandignitionelectrodeswillinevitablyleadtooperatingproblemsandpoorcombustionandmustatallcostsbeavoided.

�0

Tosaytheleast,itisirritatingifnotonedropofoilemergesfromthenozzle.Toeliminatetheproblem,followtherulesbelowfor“immediatehelp”stepbystep.

• Isthereoilinthetank?• Isthevalveonthesuctionlineopenorclosed?• Isthecheck-valveonthesuctionlinethewrong

wayround?• Doesthepumpshaftrotate?• Istheconnectionbetweenpumpandmotorok?• Cananysuctioneffectofthepumpbeseen?• Howmuchvacuumdoesthevacuummeter

show?• Canthepresenceofairbeseeninoneofthe

transparenttesthosesonthesuctionsideofthepump?

Thereasonmaybeatoohighvacuumoraleakysuctionline.

• Isthepumpfiltercleanandingoodorder?• Arethevalves(thehydraulicvalveorthesolenoid

valveofthepump)openandworkingproperly?• Istheredirtintheoilpressurelinetotheoilnozzle?• Isthenozzlefiltercleanandingoodorder?• Istheoilnozzleblocked?• Istheoilverycoldandthick? Perhapssomewaterintheoilhasturnedintoice.

Ifallthesefactorsarecheckedandorderedasnecessary,theoilnozzleshouldsprayoil.

What is the cause of no oil from the

nozzle?

��

Wasteandre-usearetopicalsubjectsatthemomentandthoughtherearemanythingswhichcanbeusedagainandagain,itcannotbeexpectedthatanoldanddirtyoilnozzlewillbeofusetoanybody.Sore-useofanoilnozzlemustthereforebedeprecated.

Forsafety’ssake,oldoilnozzlesmustbethrownawayimmediately.

What to do with the oil nozzle?

What matters are the detailsThesimpleappearanceoftheoilnozzlethrowsitscomplicatedmechanismintotheshade.Thenarrowtolerancesoftheoilnozzleandthefinedetailsplayadecisiveroleforfunctionandperformance.

Accurate toolsAccuracyisthekeytoanoptimumfunction.Sodoestheproductionde-mandthehighestprecision.Danfosstakesmanymeasurestoensurethequality.Thesealsoincludeproductionofembossingarborswhicharegrindedwithtolerancesofonlyafewµm.Thisensurestheformintheinletandtheoutletofthenozzle.

Maximum repititionThefineconeslotsarecutwitharealdiamondtoensurehighestprecisionandthebestsurface.Theprecisemanufactureofthenozzleplateandmeasurementswiththepaternatoren-suremaximumrepetitionofspraypat-tern,sprayangleandperformance.

Compliance with the strictest standardsDanfossoilnozzlesaresecondtononewhencompliancewithinternationalnormsandstandardsareconcerned.Thisappearsfromthelistbelow:• FirstmanufactureroftheEN-oil

nozzle(1992)• Firstoilnozzlemanufacturer

whomettherequirementsoftheOFTEC-standards(1995)

• TheoilnozzleshavebeenapprovedaccordingtoCSA-standard

DanfosshasalsobeenISO-9001certifiedandourproductionplantsmeettheenvironmentalauthorities’conditionsinISO14001.

We are a leading global producer of components for combustible liquid burners used in domestic,

commercial and industrial applications. Our position has been achieved by exceeding the expectations

of our customers; by responding quickly to their needs, by providing top quality in all respects and by

offering competitive prices – all this and still with due consideration to the environment.

Our range of products for oil burners and boilers comprises oil pumps, oil nozzles, preheaters,

ignition units, burner controls and thermostats.

520F0660 DKBD.PS.060.B1.12

burner.danfoss.com

Produced by Danfoss Industri Service - Advertising 06.07 FO.HP.RO

The Heart of Heating