I S2117: 1991 SrrTdtSqTWaI ndian Standard GUIDEFORMANUFACTUREOFHAND-MADE COMMONBURNTXLAYBUILDINGBRICKS ( Third Revision / UDC691,421 @BIS1991 BUREAUOFIN-DIA-NSTANDARDS MANAKBHAVAN,9BAHADURSHAHZAFARMARG NEWDELHI110002 May1991 PriceGroup7 ( Reaffirmed 2002 )ClayProductsforBuildingsSectionalCommittee,CED30 FOREWORD ThisIndianStandard(ThirdRevision)wasadoptedbytheBureauofIndianStandards,afterthe draftfinalizedbytheClayPcoductsforBuildingsSectionalCommitteehadbeenapprovedbytheCivil EngineeringDivisionCouncil. Differentpracticesforthemanufactureofhand-madecommonbricksareadoptedindifferentregionsof thecountry.Itwillbeadvantageoustogivetheexistingknowledgeandexperiencesofargainedinthe formofguideinordertospecifytheminimumrequirementsforvariousmanufacturingoperations. Inbrickindustryalloperations,suchaspreparationofclay,moulding,dryingandfiringarecarriedout in theopen.Thekilnmostcommonlyusedisthebullstrench.Thedesignandconstructionofsuchakilnof optimumcapacityhasbeencoveredinIS4805:1978.Thisstandardhasbeenpreparedtofurnishgeneral guidanceintheselectionofrawmaterialsandtheprocessesofmanufactureofhand-mouldedbricks(from clay-alluvialandblackcotton). Bricksmaybemadefromamixtureofplasticclaysandflyashfromthermalpowerstations.However, asthecompositionofthesematerialvariesoverawiderangeitisnecessarytodetermineasuitablebatch compositionafterlaboratorytests.Twomaterialsmaybemixedweteithermanuallyorinamachine.The processesof moulding,dryingandfiringaresimilarto thosedescribedinthisstandard. Thisstandardwasfirstpublishedin1963andrevisedin1967and1975.Thisrevisionhasbeenprepared toincludesuchof thedatawhichhavebeenestablishedsinceitwaslastrevised,likemanufacturingbricks withvariousadditiveslikeflyash,sandyloam,ricehuskash,basaltstonedustanddetailsoffiringprocess besidesmakingothercontentsuptodate. lS2117: 1991 I ndian Standard GUIDEFORMANUFACTUREOFHAND-MADE COMMONBURNT-CLAY BUILDINGBRICKS (Third Revision J 1SCOPE Thestandardcoverstheselectionofsite,raw materials,methodofmouldingandburning~of hand-madecommonburnt-claybuildingbricks. 2REFERENCES TheIndianStandardlistedinAnnexAareneces- saryadjunctstothisstandard. 3TERMNOLOGY Forthepurposeofthisstandard,definitionsgiven inIS2248:1981shallapply. 4SELECTIONOFSITEFORTHEMANU- FACTUREOFHAND-MADECOMMON BURNT-CLAYBUILDlNGBRICKS 4.1Thesiteshouldbeselectedaftergivingdue considerationtothesuitabilityofsoilandthe locationofwater-table. NOTE-Itis a goodpracticetoselectasitewherethe water-tableduringburningseasonremainsatleast about2 metresbelowkilnfloor. 4.2Thesiteshouldbelocatedinconformitywith theprevailingtownplanningregulationsorother bye-lawsofsimilarnature,particularlyinviewof thesmokeofthekilnwhichmayprovea nuisance. 4.3Theavailabilityofsuitableclayconformingto therequirementslaiddownin5,withinanecono- micaldistance,willbeanimportantfactor influencingthelocationofthekiln;greaterconsi- derationshall,however,begiventothedistance ofthedistributioncentreofthefinishedbricks ratherthanonlytoavailabilityoftherawmate- rialsfromthesource,asotherwiseitmayprove morecostlytoarrangethedistributionanddes- patchoffinishedbricks. 4.4Thenearnesstoarailheadortransport facilitiesthroughroadorwatershallbeimportant considerationsinthefinalselectionofakiln. 5SELECTIONOFRAWMATERIALS 5.1SelectionofClay 5.1.1Theclayormixtureofclaysselectedshould preferablyconformtothefollowingmechanical composition: Clay20to30percentbymass Silt20to35percentbymass Sand35to50percentbymass 5.1.2Thetotalcontentofclay-andsiltmaypre- ferablybenotlessthan50percentbymass. NOTE-Thelimitsforparticlesizegradingspecified abovearenotapplicabletoblackcottonsoilandlateri- ticsoils. 5.1.2.1Thetotallime(CaO)andmagnesia (MgO)(seeIS1727:1967)inthecaseof alluvialsoilwillbenotmorethanone percentandinothercasesshallnotpreferablybe morethan15percent.Thelimeshallbeinfinely dividedform.Thetotalwatersolublematerial shallnotbemorethanonepercentbymass[see IS2720(Part21):19771. NOTE-Thedataforthechemicalandmineralogical compositionofthesoilas rawmaterialforthemanu- factureofbuildingbricksarenotyetconclusively established. 5.1.2.2Thechemicalanalysisofthesoilshallbe madeinaccordancewithIS1727:1967and IS2720(Part21):1977. 5.1.3Theplasticpropertiesoftheclayshallbe determinedbyfindingtheplasticityindexbythe methodgiveninIS2720(Part5):1985.Tht rangeofplasticityindexshallbe15to25. 5.1.3.1Forquickfieldobservationsandintermit- tentchecks,sampletestsas giveninAnnexBmay befounduseful. 5.2Additives Certainadditivessuchasflyash,sandyloam. ricehuskash,basaltstonedust,etcareofterA requirednotonlytomodifytheshaping,drying andfiringbehaviourofclaymassbuthelpsin theconservationofagriculturallandandutilisa- tionofwastematerialsavailableinlargequanti- ties.Theseadditivesshould,however,havea desirablelevelofphysicalandchemicalcharater- isticssoastomodifythebehaviourofclaymass withintheoptimumrangewithoutanyadverse effectontheperformanceanddurabilityofbricks. Someofthebasicphysico-chemicalrequirements ofconventionaladditivesareasunder: 1 IS2117:1991 5.2.1FlyAsh 5.2.1.1Flyashisawastematerialavailablein largequantitiesfromthermalpowerplantsand canbemixedtothebrickearthsasalluvial,red, black,marineclays,etcusedforbrickmaking. TheIndianflyashcontainsamorphousglassy material,mullite,haematite,magnetite,etcand showsachemicalcompositionsimilartobrick earths.Thesesilicatesalsohelptowardsstrength developmentinclaybodiesonfiring,whenmixed inoptimumproportiondependingonthephysico- chemicalandplasticpropertiesofsoilstobeused forbrickmaking.Theproportionofflyashmixed asanadditivetothebrickearthshouldbeopti- mumtoreducedryingshrinkage,checkdrying lossesandtodevelopstrengthonfiringw:thout bloatingorblackcoringinfiredproduct.The crystallitespresentintheflyashshouldcomply withtheresultanthightemperaturephasesinthe finishedproduct. 5.2.1.2Thedesirablecharacteristicsofflyash whichcouldbeusedasanadditivetothesoil massaregiveninTable1. Table1DesirableCharacteristicsof FlyAshforUseasanAdmixturewith BrickEarths SlNo.CharacteristicsDesiredLevel (1)(2)(3) i)TextureFine,2000to3 000ems/g ii)Coarsematerial05percent (+lmm),Mex iii)Unburntcarbonper-15percent centbymass,Max iv)Watersolubleper-0 1 percent centbymass,Max 5.2.2SandyLoam Additionofsandyloamisoftenfoundeffectivein controllingthedryingbehaviourofhighlyplastic soilmasscontainingexpandinggroupofclay minerals.Sandyloamshouldpreferablyhave mechanicalcompositionasunder: Clay(2micron8- 10percent SiltZ-20micron30-50percent SandP20micron40-60percent Thematerialshould,however,meettheother requirementsasspecifiedunder5.0. 5.2.3RiceHuskAsh Theashshouldpreferablyhavingunburntcarbon contentintherangeof3-5percent(determined asLO1)andfreefromextraneousmaterialcan beusedwithplasticblackandredsoilsshowing excessiveshrinkages. 5.2.4BasaltStoneDust Basaltstoneoccursunderneaththeblackcotton soilanditsdustisawastematerialavailablein largequantitiesfromstonecrushers.Thefiner fractionfrombasaltstonecrushingunitscansuir- ablybemixedwithsoilmasstomodifythe shaping,dryingandfiringbehaviourofbricks. Thedustrecommendedforuseasanadditivewith brickearthshouldbefine(passing1 mmscreenj freefromcoarsematerialsormicaflakesand shouldbeofnon-calciticordolomiticorigin. 6PREPARATIONOFCLAY(ALLUVIAL) CLAYADMIXTURES 6.0Thesoilusedformakingbuildingbricks shouldbeprocessedsoastobefreefromgravel, coarsesand(practicalsizemorethan2mm) limeandkankerparticles,vegetablematter,etc. 6.1Requisitepredeterminedproportionsofaddi- tivessuchasflyash,sandyloam,ricehuskash, stonedust,etcasindicatedaboveshouldbespread overtheplaingroundsurfaceonvolumebas:s. Thesoilmassisthenmanuallyexcavated, puddled,wateredandleftoverforweatheringand subsequentprocessing. 6.2Weathering Thesoilshouldbeleftinheapsandexposedto weatheraslongaspossibleandforeatleastone monthincaseswheresuchweatheringisconsi- derednecessaryforthesoil.Thisisdoneto developahomogeneityinthemassofsoils,parti- cularlyiftheyarefromdifferentsources,and alsotoeliminatetheimpuritieswhichgetoxidized. Solublesaltsintheclaywouldalsobewashedoff byraintosomeextent~by this,whichotherwise, maycausescummingatthetimeofburningthe bricksinthekiln.Thesoilshouldbeturnedover atleasttwiceanditshouldbeensuredthatthe entiresoiliswetthroughouttheperiodof weathering. NOTE-Inordertokeepthesoilwet,watermaybe sprayedas oftenasnecessary. 6.3Tampering 6.3.1Additionofwatertothesoilatthedumps isnecessaryfortheeasymixingandworkability, buttheadditionofwatershouldbecontrolledin suchawaythatitmaynotcreateproblemin mouldinganddrying.Excessivemoisturecontent mayaffectthesizeandshapeofthefinishedbrick. Thetemperingoftheclayshouldpreferablybe carriedoutbystoringthesoilinacoolplacein layersofabout30cmthickfornotlessthan 36hours.Thiswillproducehomogeneityinthe massofclayforsubsequentprocessing. 6.3.2Afterweathering,therequiredquantityof watershouldbemixedwiththesoilssoasto obtaintherightconsistencyformoulding.Addi- tionsofsandandothermaterials,ifnecessary, mayalsobemadeatthisstagetomodifythe 2 IS2117 :I991 compositionofthesoil.Thequantityofwater mayrangefroml/ 4tol/ 3bymassofthesoil, sandysoilsrequiringlesswaterandclayeysoils morewater.Natureanddegreeofwetnessofthe soilatthestageofwateradditionshallalsobe dulyconsideredinthisrespectandtheobserva- tionsmadeinpreliminarytest(see 5.1.3.1)may beusefulforthejudgement.Themoistenedsoil maybekneadedwithspadesorothermanualor mechanicalequipmentintoaplasticmass. 6.3.3Afteradditionofwaterandkneading,the soilmaybepuggedinapug-millofsuitablesize correspondingtothequantityofproductionof bricks.Thepug-millmaybemechanicallyopera- tedormaybeasimpleanimaldriventype. Salientfeaturesofthesimpledesignofapug-mill aregiveninAnnexC.Theplasticmassasgiven in6.3.1willbeconveyedandfedintothepug. mill,andthetemperedsoilissuingfromthepug. millwillbecollectedformouldingoperations. 6.4Mixing Twoormoresoilsmayhavetobemixedsoasto conformtotherequirementsofclayaslaiddown in5.1.1.Themixingmaybedoneina vat,before temperingorinthepug-milldescribedin AnnexC. 7PREPARATiONOFCLAYTBLACK) COTTONANDALLIED 7.0Intheareaswhereblackcottonsoilsoccur, amoreelaboratemethod*ofprocessingasgiven in7.1shallbefollowed. 7.1Theclay,whichmaybeblackoramixture -ofblackandyellow,isfirstwashedfreeofthe limekankerintheGHOLtanks.Theslurryis thenrunofftothesettlingtanks.After3-4 days, whentheclayhassettleddown,thesupernatant waterisbucketedoff.Openingmateriallike powderedgrogoffinecoalash( passing200mm- ISSieve),whichopensupthetextureofclay mass,is thenaddedin predeterminedproportions. Thisisusually30to40percentofthemassof clay.Asolutionof0.5percentsodiumchloride mayalsobeaddedatthisstagetopreventlime bursting,Theclayisthenthoroughlymixedwith theopeningmaterialaddedandallowedtodry furtherforaperiodof3-4daystillthemix attainsthecorrectmouldingconsistency. 7.~1PreflarationofGrog Grogispreparedbylightlycalcininglumpsof blackcottonsoil(about10to15cmdia)ina clampatabout700to750C.Coalash,firewood, brambles,etc,maybeusedasfuel.Thefuel andclaylumpsarearrangedinalternatelayers intheclamp.Aftercalcination,theclayispulveri- zedinamachine,suchasadisintegrator,a hammermillorapan-mill,toafinenessofless than2.0mm. -----:---- *A detaIledlayout of theprocessing plantmaybeobtain- ed fromCentralBuildingResearchInstitute,Roorkee. 8MOULDING 8.1 DesignandConstructionoftheBrick Mould 8.1.1Themouldshouldbeconstructedprefera- blyofmetal.Seasonedwoodwithorwithout sheetmetalliningmayalsobeused(seeFig.1). Thethicknessofthesidesofthemouldshallbe notlessthan3mmifofmetal,andnotlessthan 10mmifofwood. 8.1.2Theinnerfacesofthemouldshallbe smooth.Allanglesbetweenadjacentintetiiorfaces ofthemouldasassembledshouldbe90f0.5. 8.1.3Thebaseofthemouldshouldhaveapro- jectioncorrespondingtothefrogofthebricka?. showninFig.1. 8.1.4Thesizeofthemouldmayincorporatedue allowanceforthetotallinearshrinkageofthe mouldedbrickondryingandburningasshowrl inFig.1,soastoobtainthespecifiedsizeforthe finishedproduct.Gangmouldssuitablefor mouldinganumberofbricksatatimemayalso beemployed. NOTE-ValuesoftheallowanceforshrinkagenL, nB,AH,AD,AX,AY,etcaspercentageoftht corresponding dimensionsofthe finished brickand frog, willdepend notonlyupon thenatureofrawmaterial butalsoon auantitvofwateraddedinthemouldinr andbuildmgoperations.iSormalIytotallinearshrinkagts allowance( inclusiveoffiringshrinkage)willvat-v between8and15 percent.Foriargescaleproductionit is recommendedthatbeforefinalizingthemouldsize, experimentallotsofbrickswillbeactuallyburntinthr, kilnanda statisticalanalysismadeforthesizeofbricks producedandthemouldsizewillbeadjustedaccord- ingly. 8;2MouldingProcedure 8.2.1Hand-madebricksmaybeeitherground. mouldedortable-moulded.Alevel,firmsurface ofground,willbeusedintheformercase.Typica! specificationforaccessoriesfortablemouldingare giveninAnnexD. 8.2.2Beforemoulding,theinsideofthemould willbecleanedandthensprinkledwithsandor ash.Ifslopmouldingisadoptedthemouldshould bedippedinwaterandcleaned.Themouldwill thenbesetfirnilyonthelevelsurface. 8.2.3Aquantityofclayslightlymorethanthe volumeot themould,shouldbetaken,rolledin sand,iffoundnecessary,thenshapedsuitably intoasinglelumpanddashedfirmlyintothe mouldwithaforce(thatistobejudgedbythe moulderbyexperience)SOthattheclaycomple- telyoccupiesthemould~withoutairpocketsand withtheminimumsurplusforremoval. 8.2.4Thesurplusclayshouldbescrapedoffwith asharpstraightedgeorastretchedwireandthe topsurfacelevelled. 3 IS2117:1991 ,,-0430mmTHICK , MS'MEETLINING /e---X+AX-----w SECTIONAA Y+AY--j---P- SECTIONBB FIG.1DETAILSOF MOULD 8.3Thewholeassemblyofmouldshouldthenbe lifted,givenaslightjerk,andinvertedtorelease themouldedbrickonapalletboardinrhecase oftablemouldingorondrylevelsurfaceofthe groundinthecaseofgroundmoulding.The groundmaybeadvantageouslysprinkledwith sandbeforereleasingthebrickoverit,sothatthe brickdoesnotsticktotheground. 8.4OperationofBrickMouldingTable 8.4.1Alternatively,animprovedhandmoulding tableforshapingbuildingbricksmaybeused. DetailsofthesamearegiveninAnnexE. 8.4.2Formouldingbricks,clayismixedwith waterandkneadedinthesamemanneras detailed under6.0and7.0.Theconsistencyofrheclay shouldbeplasticandpreferablybekeptmargi- nallystiff. 8.4.3Atthemouldingtableaquantityofclayis rolledintoclotsslightlylargerinvolumethan the~mould.Theclotisthenrolledoverfinesand andthrownwithlittleforceintothemouldsothat theclaycompletelyoccupiesthemouldwithout airpocketsandwithminimumsurplusfor removal. NOTE-Before throwing the clotintothemould.the insideofthemouldshouldhecleanedandthensprink- ledwithsandorash.However,incaseofhighlysticky orplasticsoilmix,theinnersideof themouldmaybe wipedoff withwetoroilyragforeasydemoulding. Thismaybedonewhenevernecessary,andpreferably, aftershaping4 or5bricksfromthemould. 8.4.4Thesurplusclayis removedoffwithasharp straightedgeorastretchedwireandtopsurface levelled. 8.4.5Theshapedbrickisthenejectedbypressing downthepedalwhentheloosebottomsteelplate alongwiththeshapedbrickisliftedoutofthe mould.Awoodplankofsimilarsizeasthatofa brickisplacedovertheshapedbrickandis manuallyliftedalongwiththeloosebaseplate. 8.4.6Thepedalisthenreleasedandthebase platedropstoitsoriginalposition. 8.4.7Themouldedbrickisthenturnedonthe side,overthewoodenpallet.Boththeplates looselyadheringtothebricksurfacearegently removed.Thebaseplateisreturnedtothemould boxforsubsequentshapingofotherbricksfrom thebrickmouldingtable. 8.4.8Anotherwoodenpalletisthenplacedon -thetopfaceofthebrickwhichisthencarried awaytothedryinggroundwhereitisplacedon edgetodry. 9DRYlNG 9.1Themouldedbrickshouldbeallowedtodry toanapproximatemoisturecontentof5to7 percent.Therecommendedmethodofdryingis showninFig.2. 9.1.1Itmaybenotedthatallthechannelsinthe longitudinalandtransversedirectionsarecross ventilated. 3 IS2117t 1991 COURSES1,3,5,7,ETC COURSES2468ETC ,9*9 FIG.2METHOD OF 9.2Asfaraspossiblethemouldedbricksshould beprotectedeffectivelyagainstrainanddampness tilltheyarestackedinsidethekiln. i0HANDLINGANDTRANSPORTOF MOULDEDBRICKS 10.1Duringconveyancetothekiln,themoulded bricksshouldbeloadedorunloadedonebyone. 11SETTINGBRICKSINTHEKILN 11.1Patternofsettingofbricksinbullstrench kilnsisshowninFig.3A.Thedetailsofbrick settingbasedon24bricklength*isshowninFig. 3B.Thepatternofsettingshowninthisfigureis forcoalfiring.Thepatternshallbeslightlydiffe- rentforwoodfiring. *Detailed drawingsforotherbricklengthsareavailable atCentralBuildingResearchInstitute,Roorkee. DRYINGOF BRICKS 11.2Themouldedbricksshouldbesetina uniformpatterninthekilnwithtraceholes,fuel shafts,flues,etc,inaccordancewiththedesignof kiln.Whilearrangingthebricksaminimum spaceof10mmshallbegivenbetweenadjacent bricksintheheaderandstretchercourses. 11.2.1Inthefuelshaft,bricks,shouldbesuitably arrangedtoprojectinsuchamannersoasto formaseriesofledgesonwhichthefuelcould restandburn,withonlyasmallportionfalling directtothefloorof thekiln. 11.3ThetoptwocoursesofKACHCHAbricksin thekiln,shouldbesetascloseaspossiblewith littleornospacingbetweenthemsoastoforma completeroofcoveringforthekiln-setting.Holes of sizenotlessthan100x100mmshallbeleft intherooffor feedoffuelintothefuelshafts. 5 IS2117 :1991 11.4 Thetopofthesettingexcludingportions occupiedbyfeedholesshouldbecoveredwitha fineashabout200mmthick.Thefeedholes shouldbetightlyclosedwithcastironpotand caps. 11.5Aftereverysecondchamberagapofabout 120mmshouldbeleftforinsertingthesheetiron crossdampersalongtheentirewidthofthe chamber. 11.6 Thewicketopeningtochambersshouldbe sealedbytemporarycavitywalls.Thecavity (about50mmwidth)maybefilledwithfinekiln ashandtheoutsideofthewalls-maybeplastered overwithathicklayerofmud. 12INLTIATiONOFFIRE 12.1 Firingmaybestartedafternearlythree- fourthofthetrenchhasbeenloaded.The chimneysmaybepositionedabout5.5to60m awayfromthefirstrowoffeedholes.Whenstart- ingthefire,atemporarycrosswall,one-brick thick,isconstructedatadistanceof250mmfrom thefirstrowofbrickcolumns,Anumberofair holes(100x100mm)(seeFig.4)areleftat thefootofthiswall.Thetopopeningbetween thiswallandthemainsettingisclosedupbv projectingbricksfromeithersideandtheusual coverofashislaidon.Anumberoffeed-holes areprovidedonthisspace(see Fig.5),theactual numberdependingonthewidthofthetrench. 12.2Initiallylogwood(100to150mmdiaand 1.5to2mlong)soakedinkeroseneoilisfed throughthetopfeedholesoverthetemporary wallandareignitedbyintroducinglightedrags throughtheairholesatthebottom.Feedingof firewoodriscontinuedat20-30minintervals,the holesbeingkeptclosedbymetalliccapsbetween thefeeds.Theredhotcharcoalthatcollectson thefloormustbepushedforwardthroughthe traceholesinthesettingbylongironpackers (about3mlong).Thechimneysshouldbeob- servedforformationofdenseblacksmokewhich shouldnotpersistformorethan~3 to4minafter eachfeed.Observationshouldalsobemadeof theconditionofthefireandthemovementof flamesandhotgasesthroughthebricksettingto getanideaofthedraughtIfdraughtappearsto beslack,thechimneysmaybeheatedupbylight- ingsmallfiresatthechimneybases(externally). 12.3Afterabout10to12hoursoffiringthekiln floorandthebricksinthefirstrowofcolumns shouldbeheatedtoredheat(thatis750to 800C)andfeedingofblackcoalinthefirstrow offeedholesinthemainsettingstarted.Within 5to6hoursafterthisagoodbottomheatinthe furancebeyondthefirstrowoffeedholesshould beobtained.Feedinginallthefeedholesinthe Ii- FEEDHOLES LKILNWALL 3AGeneralArrangements -FIG. 3PATTERNOF SETTING OF BRICKS IN KILN-Contd 6 IS2117 :1991 rFEE0tiCtESTrASHLAYER I--2ee-l ENLARGEDSECTIONAA bdmml 49d+- ENLARGEDSECTIONBB 36DetailsofBrickSettingBasedon23BrickLength All dimensionsin millimetres. FIG.3PATTERN OF SETTING OF BRICKS INKILN A FEEDHOLES DPOFSETTING FIG.4LAYOUTOF AIRHOLES IN BRICK KILN 7 3S2117:1991 temporarywallaswellasthefirstrowofcolumns shouldbecontinuedtillsufficientbottomheatis builtup. 12.4Whenasufficientlystrongdraughthasbeen builtup,thechimneymaybeadvancedby5to 6mandthepositionofthecrossdamperreadjus- ted.Thuswithin24to30hthekilnshouldbe broughtuptofullfiringorder.Firinginthefeed holesofthetemporarywallshouldbecontinued tillthefirehasadvancedbyatleast10 to12mand thebricksinthefirstrowhavebeenfullyburnt. Thetemporarywallcanbepulleddownonly afterthefirehasgoneroundthecurvedpartof thetrenchandthebricksinthefirstrowhave cooleddownsufficientlytopermitunloadingto start. 13CONTROLOFBURNING 13.1ScheduleofFiring Inalargecapacitykiln,therearenormally30 chambers(seeIS4805:1978).Whenthekiln hasbeenbroughtuptotheregularfiringorder, thescheduleoffiringthatshouldgenerallybe maintainedisindicatedbelow: Loading1chamber Unloading 3, Firing ;,, Preheat 3, Cooling2: Empty 4 ,, 30 CROSSDAMPER Thescheduleoffiringmay,however,varyaccord-- ingtotherequirementsofakilnfiringaparticular clayusingaparticulartypeofcoal.Itwillalso varyifcoalashorflyashcontainingacertain amountofunburntcarbon,isadmixedwiththe clay. 13.1.1BituminousslackcoalGradeIshould preferablybeusedforfiringbrick. 13.1.2Whenadvancingthefire,afreshrow shouldbeopenedonlywhenthetemperatureat thebaseofthesettingoronthekilnfloorhas reachedatleast750C.Thisisindicatedbythe appearanceofadullredglow.Initiallysmall quantitiesofcoal,say,260to500gshouldbefed atatimeineachfeedhole;theamountoffeed shouldberaisedgraduallyto1 to2kg/ feed-hole asthetemperaturerises.Aftereachfeedthe feed-holecapsshouldbetightlyreplacedtopre- ventin-leakageofcoldair.Whilefeedingfuel,. looseashfromthetopcoveringshouldnotbe allowedtodropintothefeedhole. 13.2Thetemperatureatwhichbricksaretobe firedmayrangefrom900to1 000Cdepending uponthetypeofclay.Thetemperaturemaybe observedbymeansofsuitabletemperature measuringdevices,andthefuelfeedanddraught adjustedforcontrol. NOTE-Eitherapyrometerorpyrometriccones. whichever is suitable may be used forthe measurement of temperature. FEEDHOLES A CHIMNEY TRENCHWIDTH FIG.5PLANSHOWINGDETAILSOF FEEDHOLESA-NDTEMPORARYWALLFORINITIATINGFIRE 8 13.2.1Therateoffiretravelshouldgenerallybe notlessthan5m/ 24h.Operationofdampers, settingofbricksandemptyingofbrickswillkeep pacewiththeadvancingfirecycle. 13.3Therearefivedistinctstagesinthefiring cycle,suchas(a)smoking,(b)pre-heating,(c ) firing,(d)soaking,and(e)cooling,towhich thebricksinthekilnshouldbesubjectedto. Theproperandefficientcontrolofthesestages greatlydependuponthetechniqueandexperience oftheburner. 13.4Undernormalconditions,thepairof chimneysaremaintainedatadistanceof10to 15mfromthefirstrowunderfire,andare shiftedonceevery12hours.However,ifany combustiblematterhasbeenmixedwiththeclay thenthechimneysshouldbemaintainedata ,distanceof20morso. 13.4.1Thedraughtofthekilnshouldbeobser- vedbysuitabledraughtgaugesatthebaseof chimneyandshouldbeadjustedbyoperating thetemperatureasspecifiedbythedesignerof .-thekiln. 1s2117:1991 13.5Cooling Coolingofthebrickinthekilnshouldbegra- dual.Normallyabout15to-20chambersare ma.intainedinthecoolingzone. 14UNLOADINGOFBRICKSFROMTHE KILN,SORTINGANDSTACKING 14.1Thebricksshouldbeunloadedfromthe kilnandconveyedtothesortingareawithmini- mumbreakage. 14.1.1Inthecaseofbricksmadefromclays containinglimekanker,thebricksinstack shouldbethoroughlysoakedinwater(docked) topreventlimebursting. 14.2Thebricksshouldbesortedoutintothe variousclasses. 14.3Bricks,whichremainunderburntmaybe stackedalongthewallsoffreshlyloaded~cham- bers. 14.4Forproperinspectionofthequalityand countofbricks,theymaybearrangedmstackson drysurface,thestacksbeingtwo-brickthickup toten-coursehighanduptohundred-bricklong andthedistancebetweentwoadjacentstacks beingnotlessthan08m. ANNEXA (Clause2.1) LISTOFREFERREDINDIANSTANDARDS ISNo.TitleJSflo.Title1727:1967Methodsoftestforpozzolanic2720Methodsoftestforsoils: materials( jirstrevision) (Part5):1985Determinationofliquidand plasticlimits( secondrevision) (Part21):1977Determinationoftotalsoluble 2218:1981Glossaryoftermsrelatingtoclay solids( jrstrevision) productsforbuilding(jrstrevision)4805:1978Guideforconstructionof brickkiln( jhtrevision) ANN-EXI& ( Clause 5.1.3.1) FIELDTESTSFORSOILFORBRICKSMANUFACTURE B-lTESTINGSOILFORDRYING SHRINKAGE B-l.1Thesoilshouldbegroundtoafine powerandmixedwithsufficientwater,addedin smallquantities,Themixshouldthenbekneat- edintoaplasticmassoftherequired consistency. B-1.2Takeahandfulofthesoilpreparedas inB-l.1and-formintoaballofabout80mm -diameter. B-l.3Keeptheballinthesunfordrying. Whendried,examinetheballforlossofshape andsurfacecracks,ifany. B-l.4Conclusions B-1.4.1Iftheballhasdeformedondrying andcrumbleseasilywhenpressedlightly,itmay beinferredthatsandcontentisexcessive. B-1.4.2Iftheballishardbutshowscrackson thesurface,thenthesandcontentisinsufficient. 9 B-l.5Ifthesoilisnotfoundsuitableasinferred inB-1.4,thetestshouldberepeatedaftermodi- B-2.2Bricksofstandardsizeshouldbeactually fyingthecompositionofthesoil,suchasby mouldedfromthesoilaspreparedinB-2.1and mixingdifferentproportionsoftwosoilsorby examinedforsharpnessofedgesandcornersin additionofsand,etc,forcheckingthesuitability. greencondition. B-2TESTINGSOILMOULDING B-2.3Ifedgesandcornersarenotsharp,the CHARACTERISTCS testshouldberepeatedvaryingthequantityof B-2.1Aquantityofsoilasadjustedforcomposi- wateradded,sothatfinally_a satisfactoryresult tionshouldbetakenandwatershouldbeadded isobtained. injustenoughquantitiesandthemixkneaded wellsoastoattainaplasticconsistencyatwhich B-2.4Themouldedbricksshouldbelefttodry itispossibletorollthreadsofabout3mmout fourdaysinthesunandexaminedforshrinkage ofthesoil.cracks. ANNEXC (CZauses6.3.3and6 4) SALIENTFEATURESOFASIMPLETYPEOFANIMALDRIVENPUG-MILL C-lSALIENTFEATURES C-l.1Thepug-mill(seeFig.6)consistsofa conicaltubmadeofstrongtimberoriron,typical dimensionsbeing1to1.8mhigh,and1toI *2 m ~diameterattop.Thetubisfittedinthecentre witharevolvingupright,ironshaftcarrying horizontalknives,theshapeandinclinationof whichmaybeasrequiredforthetypeofsoil beingworked.Theknivesatthetopandbottom aresuchthattheyexertinadditiontocuttinga downwardforceontheclayduringrotation. Crossknivesmayalsobefittedtothemiddle horizontalknivesforcuttingthroughandbreak- ingallclaylumps.Thereisasquareorrectan- gularopeningatthebottomasshowninFig.6, throughwhichthepuggedclaywillbeforced out. f!lrSHAFT LOPENING FIG.6DETAILSOF PUG-MILL 10 IS2117:1991 ANNEXD (Clause 8.2.1) TYPICALSPECIFICATIONSFORACCESSORIESFORMOULDINGTABLE D-lMOULDINGTABLE D-l.1Themouldingtableis1.2to1.8mlong andO-6to1-O mwide,andmadeofwoodor iron(see Fig.7). D-1.2Itissmoothlyfinishedattopandsuppor- tedhorizontaliyataheightof1to1.2m.The tablealsohasholestoaccommodateaccurately, thebottompinsofthestockboard(see D-2). D-2STOCKBOARD D-2.1Awoodenboardhasironliningaround theupperedgeandwithsuchdimensionsasto fitaccuratelybutlooselytheinteriorofthemould Thestockboardisprovidedwithfourpinsone ateachcornerofthebottomside,whichwhen fittedintocorrespondingholesonthemoulding tableholdtheboardtightlyinpositionduring moulding.Thestockboardalsohasaprojection atthetopsoastoformthefrogofthebrick beingmoulded(see Fig.8). D-3PALLETBOARDS D-3.1Thesearerectangularpiecesofwoodof size30cmx15cmand10mmthickwith smoothsurfaceononeside.Thepalletboards areusedconveyingforthemouldedbricksinthe dryingyard(see Fig.7). MOULDERSSAND-, rWATERCONTAINER / PALLETTESINPRO POSiT!ONFORUSE -STOCK-BOARD PUGGEDCLAY CLOTMOULDERSPLACE CLOTMOULDERSSAND MOULDERSPLACE iTAKING-OFFPLACE FIG.7DETAILS OF MOULDINGTABLE /-PROJECTION FORFROG FIG.8DBTA~LSOF STOCKBOARD 11 IS 2117: 1991 +NNEXE ( Clause 8.4.1) IMPROVEDBRICK E-lDESIGNANDCONSTRUCTIONOF BRICKMOULDINGTABLE E-l.1Variouspartsofthemouldingtableare ~showninFig.9.Thebrickmouldingtable essentiallyconsistsofawoodentabletowhicha metallicmouldisfixed.Themouldisprovided withamovablemildsteelbottomplateattached toaverticalejectorsystem.Theverticalshaftis actuatedbyafootlevermechanism.Twoguide rollersareprovidedforthesmoothvertical movementoftheshaft.Onreleasingthepedal, thebaseplatedropsdown~to restonfourcorner blocks,thepositionofwhichisalsoadjustable. ,CLAY MASS MOULDINGTABLE E-2Theinnerfacesofthemouldshallbe smooth.Allanglesbetweenadjacentinterior facesofthemouldasassembledshouldbe90 f0.5. E-2.1Thefrogshallbefixedtothebaseplate immediatelyabovewhichafalsebottomplate withitscentrecutouttoaccommodatethefrog islooselyfitted. E-2.2Thesizeofthemouldmayincorporatedue allowanceforthetotallinearshrinkageofthe mouldedbricksondryingandburningsoasto obtainthespecifiedsizeofthefinishedbrick. MOULDING %$-VERTICAL SHAFT I TABLE DETAILS AT A-A ROLLERS FIG.9IMPROVEDBRICK MOULDINGTABLE ( ASSEMBLYDRAWING)-Contd 12 IS2117 : 1991 WOODENSCREW SECTIONALELEVATIONSECTIONATA-A SlNo.LegendMaterialSlNo. 11TableWood6 2IBrickMouldM.S.7 3~EjectorM.S.8 4~EjectorTopPlateM.S.9 5LeverGuideM.S.10 5AAngleIronMS.11 LegendMaterial FootLeverMS. FrogWood FlangeM.S. AngleIron EjectorSupportM.S. LoosePlateM.S. RollerM.S.2Nos. \ - .411 dimensionsinmillimetrs. FIG9IMPROVED BRICKMOULDINGTABLE 13 StandardMark TheuseoftheStandardMarkis governedby theprovisionsof theBureauofIndianStandards Act,1986andtheRulesandRegulationsmadethereunder.TheStandardMarkonproducts coveredbyanIndianStandardconveystheassurancethattheyhavebeenproducedtocomply withtherequirementsofthatstandardunderawelldefinedsystemofinspection,testingand qualitycontrolwhichisdevisedandsupervisedbyBISandoperatedbytheproducer.Standard markedproductsarealsocontinuouslycheckedbyBISforconformitytothatstandardasa furthersafeguard,Detailsofconditionsunderwhichalicencefortheuseof theStandardMark maybegrantedtomanufacturersorproducersmaybeobtainedfromtheBureauof IndianStandards. Bt w eau_of IndianSt andar d*BISisastatutoryinstitutionestablishedundertheBureauofIndianStandardsAct,1986topromote harmoniousdevelopmentoftheactivitiesofstandardization,markingandqualitycertificationofgoods andattendingtoconnectedmattersinthecountry. Copyright BIShas thecopyrightofallits publications.Nopartofthesepublicationsmaybereproducedinanyform withoutthepriorpermissioninwritingofBIS.Thisdoesnotprecludethefreeuse,inthecourseof implementingthestandard,ofnecessarydetails,suchassymbolsandsizes,typeorgradedesignations. EnquiriesrelatingtocopyrightbeaddressedtotheDirector(Publications),BIS. 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