10中英文双语外文文献翻译成品大气污染的防控 – 一条综合性的设计方法.doc

10中英文双语外文文献翻译成品大气污染的防控 – 一条综合性的设计方法.doc

《10中英文双语外文文献翻译成品大气污染的防控 – 一条综合性的设计方法.doc》由会员分享，可在线阅读，更多相关《10中英文双语外文文献翻译成品大气污染的防控 – 一条综合性的设计方法.doc（18页珍藏版）》请在冰点文库上搜索。

外文标题：

AirPollutionPreventionandControl-AnIntegratedDesignedApproach

外文作者：

Dr.AksheyBhargava,M.tech,Ph.D.,LLB

文献出处：

InternationalJournalofEngineeringScienceandComputing,April2016,Volume6,IssueNo.4

英文2873单词，14698字符，中文4589汉字。

此文档是外文翻译成品，无需调整复杂的格式哦！

下载之后直接可用，方便快捷！

价格不贵。

原文：

AirPollutionPreventionandControl-AnIntegratedDesignedApproach

Dr.AksheyBhargava,M.tech,Ph.D.,LLB

Abstract:

ThePlanning,ManagementandControlofAirPollutionneedtobeaddressedsimultaneouslytoachievethemaximumoutput.Thepresentpapersignifytheimportanceandhighlightanintegratedapproachneedstobeinfusedintothesystemwhichinter-aliaincludeSourcecontrol,Pathwaycontrol,andReceptorcontrol.AnefforthasbeenmadeinthepresentpapertobrieflydescribePathwayandReceptorcontrolwithmainemphasisondesignoftheAirPollutionControlSystems,particularlyBagFilterstocontroldustemissionsandWetScrubberstocontrolgaseousemissionsbywayofThrowawayscrubbingprocesses,RegenerativeScrubbingProcesses,DryProcessesandSprayTowers.

KeyWords:

AirPollution,IntegratedApproach,DesignofControlSystems.

Introduction:

Theterm“AirPollution”isusedtodescribesubstancesthatareartificiallyintroducedintotheairintheformofgasesandairborneparticleswhich,inexcess,areharmfultohumanhealth,buildingsandecosystems.Airpollutionismainlycausedbycombustionoffossilfuel,processingofmaterialsanddecompositionoforganicmatters.Themainsourcesofairpollutionisfromindustrialactivities,transportsector,householdfuelburning,andothercommercialactivities.Thepresentpaperhighlightanintegratedapproachwhichinter-aliaincludeSourceControl,Pathwaycontrol,andReceptorcontrol.AnefforthasbeenmadeinthepresentpapertobrieflydescribePathwayandReceptorcontrolwithmainemphasisondesignoftheAirPollutionControlSystems,thedetailsofwhichareasunder:

PathwayControl:

Pathwaycontrolisacontrolsystemthroughwhichtheairpollutantsarerestrictedorarrestedbetweenasourceandreceptorthroughthemechanismofscavengingandfiltration.Thiscanbeachievedbyhavingagreenbeltofsuitablespeciesbetweensourceandreceptor.Suchagreenbeltwouldbeabletoabsorbtheairpollutiongasesandwouldalsoactasfilteringmediafortheparticulatematter.Sometimesincertainsituations,curtainsintheformofhighwallsorothermeansarealsoprovidedbetweensourcesandreceptortorestrictairpollutantstoreachreceptors.

ReceptorControl:

Receptorcontrolisgovernedbyanintegratedurbanandruralplanningwhichshouldinvariablyincorporateenvironmentalpolicyparametersintheformoffollowing:

-Atmosphericstabilitycondition

-Aerodynamiceffects

-Albedo-effect

-Heatislandeffect

-Ventilationcoefficients

-Optimizationbetweenconcretingandnon-concretingsurfacearea

-Optimizationbetweenverticaltohorizontalexpansionofurbanarea

Iftheaboveissuesareadequatelyandscientificallyaddressed,thelevelofairpollutionatthereceptorurbanareashallbesignificantlylow.

SourceControl:

Mainstressisusuallylaidonsourcecontroltechniqueswiththefocusontwofronts,oneon“transformationofwastegasses/materialsintousableproducts”andsecondon“endofthepipetreatment“.Thefirstapproachisgraduallycomingtoforefrontwiththeadvancementofresearchanddevelopmentalactivitiesandwhichhaseconomicvalueaddition.Thesecondapproachiscostintensiveinwhichpollutioncontrolequipmentordevicesareinstalledtorestrictairpollutionintoatmosphere.Sourcecontrolisalsoassociatedwithintroductionofcleanertechnologies,optimizationofprocesses,controlledcombustions,useofcleanerrawmaterialsorfuelsetc.

DesignofAirPollutioncontrolsystems:

A.ParticulateMattercontrol:

Therearevariousairpollutioncontrolequipmentforthecontrolofdustemissionsdependinguponparticlesize,minimumloading,desiredefficiency,typicalvelocity,maximumgaspressuredrop,andspacerequirements.Thesecontrolequipment’saredrycollectors,aswellas,wetcollectorsdependinguponthebasiccharacterisesofgasandlocalconditions.

Thedrycollectingdevicesare:

1.Settlingchambers

2.Bafflechambers

3.Lowerchambers

4.Cyclonechambers

5.Multiplecyclones

6.Impingement

7.FabricFilters

8.Electrostaticprecipitators

Thewetdevicesareusedwhereinwaterorscrubbingmediaisusuallyusedtocontrolemissions.Thesecontroldevicesare

1.Gravityspraytower

2.CentrifugalCollectors

3.Impingementchambers

4.Packedtower

5.Jetsprayscrubbingtower

6.Venturyscrubber

Bagfiltersdesign:

Introduction:

Filtrationisamongthemostreliable,efficient,andrathereconomicalmethodsbywhichparticulatemattermayberemovedfromgases.

·Suchtypeoffiltersarerepresentedbyvariousfabricbagarrangementsandcapableofhighdustloading,morethan1gm/m3

·In-depthorbedfilters

·Representedbyfibrousarray,apaperlikemat,andoccasionally,asadeeppackedbed.Packedbedsareappliedwhenparticulateconcentrationismuchless

.Deeppackedbedsarepreparedfromcrushedstoneorbricks,wirescreens,orfibersofmanytypesarrangedindividuallyorincombination

Fabricbagfilters:

·Employedtocontrolemissionsinvolvingabrasives,irritatingchemicaldusts,andexhaustsfromelectricfurnaces,oilfiredboilers,oxygenfedconvertersforsteelmaking.

Principleofoperation:

Filtrationisprincipallyaccomplishedbytheparticlelayerthataccumulatesonthefabricsurface.Pressurelossincreaseswithaccumulateddustlayer,therebygasvelocitydecreases.Thus,dustdislodgingoperationisundertakentohaveproperfiltration.Manyfabricbagfiltersassembledinoneunitiscalledbaghouse.

Classificationoffilters:

·Fabricorclothfilters

Propertiesoffibermaterials:

Resistancetoattackby:

Fiber

Strength

Temp.F

Acid

Base

Organic

solvent

Cost&others

Cotton

Strong

180

Poor

Medium

Good

Low

Wool

Medium

210

Medium

Poor

Good

-

Paper

Weak

180

Poor

Medium

Good

Low

Nylon

Strong

220

Medium

Good

Good

Easy

toclean

Dacron

Strong

280

Good

Medium

Good

-

Orlon

Medium

250

Good

Medium

Good

-

Vinylidenechloride

Medium

210

Good

Medium

Good

-

Polyethylene

Strong

250

Medium

Medium

Medium

-

Tetrafluoro

ethylene

Medium

500

Good

Good

Good

Expensive

Polyvinyl

acetate

Strong

250

Medium

Good

Poor

-

Glass

Strong

550

Medium

Medium

Good

PoorResistancetoabrasion

Graphitizedfiber

Weak

500

Medium

Good

Good

Expensive

Asbestos

Weak

500

Medium

Medium

Good

-

Nomexnylon

Strong

450

Good

Medium

Good

PoorResistancetomoisture

DesignofBagFilter:

Collectionefficiencyandpressuredropforasinglelayerorbagfilter

∆P=（K1+K2*Cma）*Vo=（K1+K2*Cma）*Q/AfWhere,

Cma=massareaconcentrationinkg/m2andrepresentsmassofdustpresentinthedustcakeattachedtounitareaoffilter,alsoproportionaltothicknessofdustcake

K1,K2=constantsinN-sec/m3orkg/m2/sTypicalvaluesofK1andK2

12000

10000

Thethicknessofdustcakeincreaseswithtime,itsgrowthcanbepredictedifflowrateanddustconcentrationareknown.Theequationis:

Cma=Q*Cmv*t/Af=Vo*Cmv*tWhere,

Cmv=massvolumeconcentration

t=timesincefilterwaslastcleaned

BagfiltersandBaghouses:

·Bagfiltermostcommonlyusedisintheshapeofalongcylinderwherefilterisclampedaroundasleeveatthebottomandaroundacapatthetop.

·Theairentersatthebottom,flowsthroughfilteralongitssides,leavingthedusttoformacakeontheinsideofthefilter,andflowsoutsidethefiltertotheexitduct.

·Generally,bagsdiameterrangesfrom12.5to30cmwithlengthsfrom2to6meters.Lengthtodiameterratioshouldnotusuallyexceed20:

1

·Bagsinthebaghousearesewedtoastrapwhichisfastenedtoahangeratthetopendofeachbag.Thehangerisattachedtotheshakermechanism.

·Largebaghousesarebuiltwithseveralcompartmentsoutofwhichatleast2compartmentsshouldbeoff-line,oneforcleaningandoneforrepairorreplacementofbags

Bagsshouldbearrangedwithineachcompartmentinsuchawayastoutilizethespaceeffectivelyandyetprovideaccesstoeachindividualbagforreplacement.Thisisdonebyplacingthebagsclosetogether,about5cmapart,whileleavingwidespacesof1/3to2/3meterbetweeneveryfourthtoeighthrowofbags.

Cleaningcyclesforbaghouses

·Cleaningisessentialwheneverthepressuredropacrossthefilterreachesacertainpresetvalue.Thelengthofcleaningcycle,thatis,thetimeperiodbetweenthestartofonecleaningprocessandthestartofnextcleaningprocessneedstobecalculated.Followingassumptionsaremade:

n =numberofcompartmentsinbaghouseQ =totalflowrate

n–1=activecompartments,asonewillalwaysbekeptforcleaning

∆P =pressuredrop

∆Pm=maximumvalueofpressuredrop

Cmai=weightofdustcakeoneachfilter,wheresubscriptirepresentstheithcompartment

t1 =lengthofcleaningcycle

Qi =flowratethroughithcompartment

Afi =filterareaineachcompartmentwhichissameforallcompartments

∆tc =lengthofcleaningprocess

ø1andǿ1aretheconstants,valueofø1canbeobtainedfromgraphdrawnbetweenø1andQK1/Afi*∆Pm

ǿ1canbecalculatedfromequationbelow:

ǿ1 =ø1–2K2*Cmv*∆Pm*∆tc/K12

t1canbecalculatedfromequation:

t1 =（Afi*K1/K2*Cmv*Q）*（√1+ǿ1+ø1*（n–1）-1））

DesignofWetScrubber:

Particulatescrubber

Inallscrubbersdropletsofthescrubbingmediaareformed,generally