英语翻译Lesson10GasAbsorptionGasabsorptionisanimportantunitoperationchemicalengineering,particularlyintheheavychemicalindustry.Inthepurificationofcoalgasandsyntheticgasaswellasinthemanufactureofhydrochloricacid,sul
英语翻译
Lesson10
GasAbsorption
Gasabsorptionisanimportantunitoperationchemicalengineering,particularlyintheheavychemicalindustry.Inthepurificationofcoalgasandsyntheticgasaswellasinthemanufactureofhydrochloricacid,sulphuricacid,metricacid,sodaashandbleachinglyes,tomentiononlythemoststrikingexamples,gasabsorptionistheessentialfeatureoftheprocess.Sincethetwentiesextensiveresearchhasbeencarriedoutwiththeresultthattheknowledgeofthisunitoperationhasincreasedconsiderably.
Theessentialelementingasabsorptionisthemasstransferbetweentwofluidphases,ifnecessary,combinedwithchemicalreactions.Thelatteraremainlyrestrictedtotheliquidphasesalthough,forinstanceinthemanufactureofnitricacid,thechemicalreactionmayalsooccurinthegasphase.
Itwillbeunderstoodthatinsuchaheterogeneousprocessasgasabsorptionalargecontactareaisaprimaryrequisiteforrapidtransfer.
Therearethreewaysinwhichalargecontactareacanbeestablished:
1.Theliquidisbroughtincontactwiththegasintheformofthinfilms(filmscrubbers).
2.Theliquidisdispersedinthegasintheformofminutedrops(sprayscrubbers).
3.Thegasisdispersedintheliquidintheformofsmallbubbles(bubblescrubbers).
Allapparatusappliedingasabsorptionpracticeisbasedononeofthesethreeprinciplesoronacombinationofthem.
Hereseriousproblemsareencounteredwhichhaveonlybeenpartlysolved.Thefirstthingstodiscoverwhendealingwithaprocessofmasstransferarethesizeofthecontactareaandthewayinwhichthissizedependsonthevariousconditionoftheexperiment.Themostcompleteanswertothisquestioncanbeevenforapparatusoftype1.Thesimplestrepresentativeofthistypeisthewettedwallcolumn,thecontactareaofwhichmaybedeterminedwithgreataccuracy.Forpackedcolumnthequestioncannotbeansweredsoeasily,sinceitcannotbeexactlyascertainedwhichpartofthepackingwillbewetted.Forthesakeofsimplicitythecontactareamaybeconsideredtobeequaltothetotalareaofthepackingmaterial.Inapparatusinwhichgasesorliquidsaredispersed,type2and3,determinationofthe