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1、Prof.JiakuanYangHuazhongUniversityofScienceandTechnologyAirPollutionControlEngineeringLecture7-1GeneralideasinairpollutioncontrolⅠThreealternativesforairpollutioncontrolⅡAirpollutioncontrolsystemsandequipmentⅢFluidvelocitiesinairpollutioncontrolequipmentⅣMinimizingvolumetricflo
2、wrateandpressuredropⅤEfficiency,penetration,ninesⅠThreealternativesforairpollutioncontrolImprovingthedispersionofouremissionandtherebydilutingthepollutantsandlowertheconcentrationnearthegroundlevelwherepeopleoftenexist.BasicideaThresholdvalue(1)improvedispersionThepopulationden
3、sityis1person/km2Inasparelypopulatedarea,thepollutantemissionsareeliminatedbynaturalremovalmechanismsandwithoutcausinganydamagetotheneighbors.Inadenselypopulatedworld,dispersionisnotasatisfactoryapproach.ForexampleThepopulationdensityis29,000persons/km2(Manhattan)(1)improvedisp
4、ersion(1)improvedispersion①Tallstacktheground-levelconcentrationHchProblem(1)improvedispersionItwillcertainlydecreasealltheground-levelconcentrationnearthestack,butitmayincreasesomeconcentrationfarfromstackwithatallstack.SO2ultimatelycomestoground,mostlywithrainorsnowforfaraway
5、fromthetallstack.Raisingtheemissionpointofstack,mayraisetheconcentrationfardownwind.Forexample:Acid-raincontroversy①Tallstack2001年度二氧化硫浓度区域分布2001年度全国将水pH值分布(1)improvedispersion②IntermittentcontrolschemesExample1,predictivecontrolschemedownwindStackAfire-electricplantmorningexer
6、cise6:30~8:00A.M.Openingcenter-park(1)improvedispersionhTBefore9:00A.m.Shutofftheproductionandstringentcontrolofstackemission.TemperatureInversion②Intermittentcontrolschemes(1)improvedispersionExample2,observationcontrolsystemHomeswoodstoves:PM10Oxygenatedmotorfuels:CO②Intermit
7、tentcontrolschemes(1)improvedispersion③relocatetheplantTheemissionsourceshouldbefarawayfrompopulatedareas.Suchasresidentialareas,commercialcenters.Reduceemissionbyprocesschange,pollutionpreventionwater-basedpaintsCleanerproduction,fromrawmaterial,oldprocess,oldtechnology,chang
8、edintoacleanerprocess,topreventpollution.BasicideaCoal