ÿWPCó ¬);t\:"&TÉÄ‚ÿ‘9Žö{·zL£0ýUߊ#¢Ñòò¤V­~ ÆsWÒ7 .èíhãï¹­ìE™ÊldÁ¤™Ó†P¥ãRÄíc›&æBÔZÐèÝíI˜z8_Ÿƒó‚-‚{æÄ¹ÐìB‹ñR°Å ‚µ¿ãðÖŽá+8wmj"…Xí~ÀßîÏoÁÒîä'Ö$àGI\#X¼Kd^†7f%oÕ Kj6ƾÔN€Msê·G«†ƒ1.‹~ å(ÀžR$æèZ‹aݼ>²Ì^ƒ%Éo,Cÿ!Ï=XòÐPjå¤í µþC †¸ yhÊM…8ÍÔ$š&%XÆÌD´;íX •(×L8d㡤ëïÙšþ&PÛ7ô†f÷[„ó)Óþfcö`¢ï’”(~$TÓ?‚L0¶Ü:¹žØ. Kqò¸Ê*wþÀ¿Ë ŽUsB»Ãø~I‰òEy_W>—CΉ{·£?jNÄ%²¡NÆ/ßk)•’±Óñj‹UdkLéJˆuÖPF°ð\±×˜3ò§Ú‚ZÊá¼”:e‘Nܽ3ôƒß—Câíþ6ŠE®É;N•(iÄŸ’ÜÎé(ã¶§¥`L£ÀL®dCUP4 %„BŠ 0CÌE U:¦K 0Cñ4nXD B œ ¹ 0(¹ *á UP U:[ ª• UP?U:wÉ4ß=>´Š y`$8Lucida Sans TypewriterTTï 8Ý ƒL)ÝÝ  ÝÒ„°ÒÒX°Òß?€ '„ü!dE„ü!?ßÔ€X+DXïïÔÔ€Xî€XXX+DÔß?€ '„dE„?ßÌPrepared€by€ò òPeter€R.€Westlinó ó,€EMCà ì àà D àà œ àà ô àò òEMC€€GD„008ó óÐ „Ô ÐEMAD,€OAQPS,€QPAà ä àà < àà ” àà ì àà D àà œ àà ô àOctober€3,€1989Ð d´ Ðß?€ '„,ü!dE„,ü!?ß(2L$©©Ý ƒ !ÝÝ  Ý<þ6X9`("Courier NewTT œÝ ƒL'ÝÝ  ÝÒ„°ÒÒX°Òß?€ '„<ü!dE„<ü!?ßß?€ '„ü!dE„ü!?ßÌò òÔ€X+DXïïÔÔ€Xî€XXX+DÔEMC€GD„008à Œ àà ä àEMC€GUIDELINE€DOCUMENTà œ àà ô àà L àPAGE€Ô@  ÔÚ  Ú1Ú  ÚÔA  ÔÐ tÄ Ðó ó(2L$§§Ý ƒ !ÝÝ  Ý#|d«=>´Š y`$8Lucida Sans TypewriterTTïïd>´Š@XhïQï@<þ6X9`("Courier NewTTriterTTXXxþ6X@ÉDQX@ d($¡¡ Ý ƒL)ÝÝ  ÝÒ„°ÒÒX°Òß?€ '„ü!dE„ü!?ßÔ€X+DXïïÔÔ€Xî€XXX+DÔß?€ '„dE„?ßÌPrepared€by€ò òPeter€R.€Westlinó ó,€EMCà ì àà D àà œ àà ô àò òEMTIC€€GD„008ó óÐ „Ô ÐTechnical€Support€Division,€OAQPS,€QPAà D àà œ àà ô àOctober€3,€1989Ð d´ Ðß?€ '„,ü!dE„,ü!?ß=>´Š y`$8Lucida Sans TypewriterTT<þ6X9`("Courier NewTT  Ý ƒL'ÝÝ  ÝÒ„°ÒÒX°Òß?€ '„<ü!dE„<ü!?ßß?€ '„ü!dE„ü!?ßÌò òÔ€X+DXïïÔÔ€Xî€XXX+DÔEMTIC€GD„008à Œ àà ä àEMTIC€GUIDELINE€DOCUMENTà œ àà ô àà L àPAGE€Ô@  ÔÚ  Ú1Ú  ÚÔA  ÔÐ tÄ Ðó ó=>´Š y`$8Lucida Sans TypewriterTT<þ6X9`("Courier NewTTô{‡$„€%<Ý ƒ !ÝÝ  ÝÑ,°ÑññÖ€ÿÿÖññññÖ€ÿÿÖññññÖ€ÿÿÖññññÖ€ÿÿÖññÑ  ÑÒ„°ÒÒX°ÒÓ  Óß?€ '„$ü!dE„$ü!?ßÔ€X+DXïïÔÔ€Xî€XXX+DÔÌÓ  Óò òEMISSION€MEASUREMENTññ€TECHNICAL€INFORMATIONññ€CENTERÐ „Ô ÐGUIDELINE€DOCUMENTó óÐ d´ Ðß?€ '„,$ü!dE„,$ü!?ßò òÌÌPARTICULATE€SAMPLING€IN€CYCLONIC€FLOWó óÐ  T ÐÓ  ÓÌÌò òSUMMARYó óÐ Œ Ü ÐÌÓ  ÓParticulate€emission€sampling€in€stacks€or€ducts€with€cyclonic€flowÏpatterns€presents€significant€problems€in€obtaining€representativeÏmeasurements€of€concentrations€and€flow€rates.€€Difficulties€also€arise€inÏestablishing€the€correct€velocity€for€determining€the€isokinetic€samplingÏrate.€€Sections€2.4€and€2.5€of€Method€1€describe€procedures€for€verifyingÏthe€absence€of€cyclonic€or€other€flow€patterns€not€parallel€to€the€stackÏor€duct€axis.€€These€sections€also€specify€limits€of€acceptability€for€theÏangles€of€flow€using€the€described€procedures.€€The€purpose€of€thisÏguideline€is€to€determine€options€for€consider€when€the€acceptable€limitsÏof€angular€or€cyclonic€flow€are€exceeded.€Following€are€three€options€andÏrecommendations€for€each€for€addressing€the€measurement€of€particulateÏemissions€when€cyclonic€or€nonparallel€flow€patterns€exist.ÌÌò òRECOMMENDATIONSó óÐ T ÐÌ1.€€Find€another€location.Ì€€€€€ÌIn€many€situations,€sampling€can€be€conducted€downstream€of€the€originalÌlocation€at€a€point€exhibiting€less€cyclonic€flow€tendencies.€€For€example,Ïmoving€from€a€duct€immediately€downstream€of€a€venturi€scrubber€exit€to€aÏlocation€in€a€stack€multiple€equivalent€diameters€downstream€of€the€duct„¼stack€intersection€can€often€solve€a€cyclonic€flow€situation.€€Extra€costÏis€sometimes€incurred€in€such€a€move€(e.g.,€new€ports€and€samplingÏplatforms);€however,€this€option€is€often€less€costly€or€disruptive€to€theÏprocess€operation€and€produces€more€reliable€emission€measurement€data€thanÏdo€other€options€described€below.ÌÌ2.€€Install€flow€straightening€vanes€upstream€of€the€sampling€location.ÌÌFlow€straightening€vanes,€such€as€are€described€in€Figure€5D„1€of€MethodÌ5D,€Appendix€A€of€40€CFR€Part€60,€may€be€used.€€Note€that€the€criteria€forÏlocating€the€measurement€site€downstream€of€the€straightening€vanes€areÏbased€on€the€average€equivalent€diameter€of€the€straightening€vane€openingsÏrather€than€the€stack€diameter€(Section€4.1.1,€Method€5D).€€However,Ïstraightening€vanes€may€disrupt€the€process€and€may€affect€controlÏefficiency.ÌÌOther€means€of€straightening€gas€flow,€such€as€addition€of€stack€extensionsÏtangential€to€the€stack€axis,€may€suffice.Ð Ä,(0 Ї3.€€Apply€one€of€the€modified€sampling€procedures.ÌÌòòThe€Alignment€ApproachóóÐ ˜ ¨ ÐÌThis€approach€involves€turning€the€sampling€nozzle€into€the€direction€ofÌgas€flow€assuming€essentially€tangential€flow€and€ignoring€the€radial€flowÏvector.€€The€procedure€is€as€follows:ÌÌConduct€a€preliminary€velocity€traverse€of€the€stack€to€establish€the€angleÏof€flow€at€each€sample€point€located€as€defined€in€Method€1.€€Using€anÏunobstructed€type„S€pitot€(i.e.,€no€nozzle€attached),€rotate€the€pitotÏuntil€a€null€reading€is€obtained€and€determine€the€flow€angle€relative€toÏthe€stack€axis€from€corrected€protractor€readings.€€Conduct€the€samplingÏisokinetically€at€each€point€rotating€the€sampling€nozzle€to€point€into€theÏgas€flow€and€using€the€velocity€values€determined€during€the€preliminaryÏvelocity€traverse.€€Conduct€a€post„test€velocity€traverse€in€the€sameÏmanner€as€the€preliminary€traverse€to€verify€the€velocity€(within€5Ïpercent)€and€angle€values€(within€5€òòoóó).€€Calculate€the€stack€velocity€byÐ  Ðdetermining€the€velocity€vector€parallel€to€the€axis€using€the€velocityÏvalues€measured€at€each€sampling€point€and€the€cosines€of€the€measuredÏangles.ÌÌThe€potential€bias€resulting€from€the€use€of€this€approach€relative€to€aÌsample€result€from€a€location€with€acceptable€flow€conditions€is€affectedÏby€particle€size€and€degree€of€cyclonic€flow€formation.€€The€particulateÏconcentration€measurement€(e.g.,€gm/mòò3óó,€ng/J)€bias€may€be€from€„15€to€0Ð ¤´ Ðpercent.€The€particulate€concentration€bias€will€approach€zero€with€aÏdecrease€in€average€particle€size.€€The€stack€flow€rate€measurement€(e.g.,Ïmòò3óó/min)€bias€may€be€from€„10€to€0€percent.€€The€resulting€mass€emissionÐ  0 Ðrate€measurement€(e.g.,€g/hr)€will€reflect€a€negative€bias€of€about€„20€toÏ0€percent.ÌÌòòTime„Weighted€Alignment€Methodóó€(Texas€ACB€Procedure)Ð p"€  ÐÌThe€time„weighted€approach€is€a€refinement€of€the€alignment€method€in€whichÏa€compensation€is€made€in€the€sampling€time€at€each€point€by€adjusting€theÏdwell€time€proportional€to€the€cosine€of€the€angle€of€flow€at€that€point.€ÏThe€purpose€of€the€adjustment€is€to€account€for€the€stratification€ofÏparticulate€matter€caused€by€the€centrifugal€action€of€the€cyclonic€flow.€ÏThe€gas€velocities,€flow€angles,€and€stack€flow€rate€are€calculated€asÏdescribed€for€the€alignment€method.€€The€sampling€is€conductedÏisokinetically€in€the€same€manner€as€described€above€except€for€theÏadjusted€sample€time€at€each€traverse€point.ÌÌThe€potential€biases€that€result€form€the€use€of€the€time„weightedÏalignment€method€relative€to€a€sample€result€from€an€acceptable€samplingÐ 4-D%- Ðlocation€may€be€affected€by€the€sampling€time€adjustments.€€The€particulateÏconcentration€(e.g.,€g/mòò3óó,€ng/J)€measurement€may€be€from€0€to€+25€percent.€Ð ÄÔ ÐThe€stack€flow€rate€measurement€(mòò3óó/min)€is€conducted€in€the€same€mannerÐ ˜ ¨ Ðas€for€the€alignment€method€and€the€potential€bias€will€be€similar€(i.e.,Ï„10€to€0€percent).€€The€resulting€mass€emission€rate€measurement€(e.g.,Ïg/hr)€will€reflect€a€bias€range€of€about€„10€to€+25€percent€with€a€tendencyÏtoward€an€overall€positive€bias.€€€€€ÌÌò òREFERENCESó óÐ   ÐÌ1.à Ü àPeeler,€James,€Isokinetic€Particulate€Sampling€in€Non„Parallel€Flow€Ð DT  Ðà Ü àSystems„Cyclonic€Flow,€Entropy€Environmentalists,€Inc,€RTP,€NC,€1977.ÌÌ2.à Ü àStack€Sampling€Cyclonic€Flow,€Appendix€H,€Texas€Air€Control€Board€òòÐ ÀÐ  Ðà Ü àSampling€Procedures€Manualóó,€Texas€Air€Control€Board,€6330€Hwy€290€Ð ”¤  Ðà Ü àEast,€Austin,€TX€78723,€Revised€July€1985.ÌÌ2.à Ü àWestlin,€P.R.,€and€K.€Alexander,€Evaluation€of€Particulate€Sampling€Ð   Ðà Ü àMethods€for€Cyclonic€Flow,€EPA€memorandum,€EPA€MD„19,€RTP,€NC,€à T$ àÐ äô Ð27711,€August€1979.Ì