Feem ntau muaj ntau cov impurities nyob rau hauv cov dej ntuj, cov uas tseem ceeb uas cuam tshuam rau lub boiler yog: tshem tawm cov teeb meem, colloidal teeb meem thiab yaj teeb meem.
1. Cov khoom raug tshem tawm thiab cov khoom siv sib xyaw yog tsim los ntawm cov xuab zeb, tsiaj txhu thiab cov nroj tsuag corpses, thiab qee qhov qis-molecular aggregates, uas yog cov ntsiab lus tseem ceeb uas ua rau cov dej turbid. Thaum cov impurities nkag mus rau hauv ion exchanger, lawv yuav pollute resin thiab cuam tshuam cov dej zoo. Yog tias lawv nkag mus rau hauv boiler ncaj qha, qhov zoo ntawm chav yuav yooj yim deteriorate, sib sau ua av nkos, thaiv cov kav dej, thiab ua rau cov hlau overheat.Suspended solids thiab colloidal tshuaj yuav raug tshem tawm los ntawm pretreatment.
2. Cov tshuaj yaj yeeb feem ntau yog hais txog cov ntsev thiab qee cov roj uas yaj hauv dej. Ntuj dej, kais dej uas zoo li ntshiab heev kuj muaj ntau yam ntsev yaj, xws li calcium, magnesium, thiab ntsev. Cov khoom siv tawv yog lub ntsiab ua rau boiler fouling.Vim tias nplai muaj teeb meem heev rau boilers, tshem tawm hardness thiab tiv thaiv nplai yog lub luag haujlwm tseem ceeb ntawm boiler dej kho, uas tuaj yeem ua tiav los ntawm kev kho tshuaj sab nraud ntawm boiler lossis tshuaj kho hauv boiler.
3. Cov pa oxygen thiab carbon dioxide feem ntau cuam tshuam rau cov khoom siv roj boiler hauv cov pa yaj, uas ua rau oxygen corrosion thiab acid corrosion rau lub boiler. Oxygen thiab hydrogen ions tseem ua tau zoo dua depolarizers, uas ua kom cov electrochemical corrosion. Nws yog ib qho tseem ceeb ua rau boiler corrosion. Dissolved oxygen tuaj yeem raug tshem tawm los ntawm deaerator lossis ntxiv cov tshuaj txo qis. Nyob rau hauv cov ntaub ntawv ntawm carbon dioxide, tuav ib tug tej yam pH thiab alkalinity ntawm lub lauj kaub dej yuav tshem tawm nws cov nyhuv.