Kev lag luam ib puag ncig nthuav tawm cov teeb meem tshuaj lom neeg uas sai sai degrade tsis txaus cov ntsiab lus cua sov. Cov neeg ua haujlwm tu hauv cov chaw ntug dej hiav txwv, cov chaw tsim tshuaj lom neeg, thiab kev tsim khoom noj khoom haus sib koom ua ke ntawm cov khoom siv hluav taws xob ua kom tsis muaj hnub nyoog vim yog sheath corrosion, seal degradation, los yog cov kab mob hauv lub cev. Cov kev ua tsis tiav no feem ntau tshwm sim los ntawm kev xaiv cov khoom siv raws li tus nqi pib es tsis yog tag nrho cov nqi ntawm cov tswv cuab, lossis los ntawm kev nkag siab tsis tiav ntawm cov tshuaj lom neeg muaj nyob rau hauv cov kev ua haujlwm tiag tiag. Cov tswv yim xaiv cov khoom siv los daws cov teeb meem no los ntawm kev qhia tshwj xeeb ntawm cov hlua khi, cov khoom siv sab hauv, thiab kev tiv thaiv kev kho mob.
Stainless hlau 304 ua haujlwm raws li cov khoom siv hauv paus rau kev siv cov khoom siv hluav taws xob dav dav, muab cov khoom tsim nyog corrosion, zoo txhua yam khoom, thiab tus nqi nruab nrab. 18 feem pua ntawm cov ntsiab lus chromium tsim cov txheej txheem oxide passive uas tiv thaiv oxidation atmospheric thiab zam cov tshuaj me me. Txawm li cas los xij, cov kev txwv ntawm 304 stainless hlau tau pom tseeb hauv ib puag ncig uas muaj cov tshuaj chlorides, txawm tias los ntawm cov huab cua hauv hiav txwv, cov txheej txheem tshuaj, lossis cov ntsev ntsev. chloride ions nkag mus rau hauv cov txheej txheem oxide passive, pib pitting corrosion uas tuaj yeem perforate cov phab ntsa sheath thiab tso cai rau cov txheej txheem xov xwm nkag mus rau hauv lub tshuab cua sov. Thaum muaj kev sib kis sab hauv, hluav taws xob tsis ua haujlwm sai sai, feem ntau nrog kev puas tsuaj luv luv lossis hauv av txhaum cai uas cuam tshuam kev ua haujlwm thiab tsim kev nyab xeeb.
Stainless hlau 316 thiab 316L muab kev ua tau zoo hauv chloride- muaj ib puag ncig los ntawm kev sib ntxiv ntawm 2 mus rau 3 feem pua molybdenum rau cov ntsiab lus 304. Qhov no alloying tseem ceeb txhim khu kev tiv thaiv rau pitting thiab crevice corrosion, ncua kev pab cuam lub neej nyob rau hauv marine daim ntaub ntawv, tshuaj ua nrog chloride raug, thiab zaub mov ua ib puag ncig siv ntsev los yog acidic cov khoom xyaw. Qhov qis -carbon 316L variant tiv thaiv rhiab heev thiab intergranular corrosion uas tuaj yeem tshwm sim hauv cov qauv welded, txawm hais tias cartridge rhaub sheaths feem ntau yog seamless drawn tubes. Lub thermal conductivity ntawm 316 stainless hlau tseem piv rau 304, kom tsis txhob muaj thermal ua haujlwm raug nplua thaum muab kev txhim kho ruaj khov nyob rau hauv ib puag ncig hnyav. Tus nqi qis tshaj tus nqi tshaj tus qauv 304 feem ntau rov qab muaj nuj nqis ntau zaus dhau los ntawm kev ua haujlwm txuas ntxiv thiab txo cov kev tu ncua.
Rau ib puag ncig tshuaj lom neeg uas muaj cov kua qaub muaj zog, cov tshuaj caustic, lossis siab -kub oxidation, Inconel alloys muab kev ua tau zoo tshaj plaws uas ua pov thawj lawv cov nqi khoom siv ntau dua. Inconel 600, nrog rau cov muaj pes tsawg leeg ntawm kwv yees li 72 feem pua nickel, 15 feem pua chromium, thiab 8 feem pua ntawm hlau, tswj cov oxidation zoo heev ntawm qhov kub txog li 1100 degrees Celsius thiab tiv thaiv ntau yam ntawm corrosive media. Cov ntsiab lus siab nickel muab tshwj xeeb tsis kam rau chloride kev nyuaj siab corrosion cracking, hom tsis ua hauj lwm uas cuam tshuam rau austenitic stainless hlau nyob rau hauv tensile kev nyuaj siab nyob rau hauv kub chloride ib puag ncig. Inconel 800 thiab 840 alloys, nrog cov ntsiab lus hlau ntau dua thiab ntxiv ntawm txhuas thiab titanium rau oxidation kuj, muaj kev txhim kho kev tiv thaiv rau carburization thiab nitridation nyob rau hauv siab - kub txheej txheem ib puag ncig. Cov ntaub ntawv no pom daim ntawv thov nyob rau hauv cov tshuaj reactors, kho cua sov rauv, thiab semiconductor ua cov khoom uas lub rhaub tsis ua hauj lwm yuav ua rau tsis tshua muaj nqi downtime los yog khoom paug.
titanium sheath cov ntaub ntawv hais txog qhov kev nruj nruj heev, tshwj xeeb tshaj yog cov uas muaj cov roj chlorine ntub dej, cov tshuaj hypochlorite, lossis muaj zog txo cov kua qaub. Titanium qhov tshwj xeeb corrosion kuj muab los ntawm tenacious oxide zaj duab xis uas ua raws li nws tus kheej thiab hloov kho sai yog tias muaj kev puas tsuaj. Cov txheej txheem passive no tiv thaiv kev tawm tsam los ntawm kev tshaj tawm uas sai sai corrode stainless hlau thiab txawm ntau nickel alloys. Txawm li cas los xij, titanium cov thermal conductivity, kwv yees li 17 W / m·K piv rau 16-24 W / m·K rau stainless hlau, yuav tsum tau ua tib zoo thermal tsim los xyuas kom meej cov cua sov txaus los ntawm cov khoom tiv thaiv rau cov txheej txheem. Tsis tas li ntawd, titanium tus cwj pwm galvanic xav tau kev saib xyuas kom tsis txhob muaj kev sib cuag nrog cov hlau tsis sib xws hauv cov kev daws teeb meem, uas tuaj yeem tsim cov galvanic corrosion hlwb uas tawm tsam cov khoom tsis zoo. Kev siv hauv cov khoom siv tshawb fawb hauv hiav txwv, kev ua tshuaj chlorine, thiab qee yam khoom siv kho mob tsim tau txais txiaj ntsig los ntawm titanium cov khoom tshwj xeeb.
Internal tivthaiv cov ntaub ntawv ntsib ib tug xav tau ntawm ib puag ncig tej yam kev mob, kev khiav hauj lwm ntawm qhov kub thiab txias heev saum lub sheath sab nrauv vim lub thermal kuj ntawm magnesium oxide rwb thaiv tsev. Cov hlau tsis kam yuav tsum muaj hluav taws xob tiv thaiv kev ruaj ntseg, oxidation tsis kam, thiab txhua yam kev ncaj ncees thoob plaws qhov kub thiab txias. Nickel-chromium alloys, tshwj xeeb tshaj yog NiCr 80/20, ua tus thawj daim ntawv thov no vim lawv cov kev sib xyaw ua ke ntawm kev tiv thaiv siab, ruaj khov kub coefficient ntawm kev ua haujlwm, thiab zoo heev oxidation kuj nyob rau hauv huab cua puag ncig mus txog 1100 degrees Celsius. Lub chromium oxide txheej uas tsim rau ntawm cov hlau saum npoo muab hluav taws xob rwb thaiv tsev ntawm cov coil uas nyob ib sab tig thaum tiv thaiv oxidation ntxiv. Rau cov ntawv thov tshwj xeeb uas suav nrog kev txo qis hauv huab cua, qhov chaw nqus tsev, lossis sulfur- muaj cov xov xwm, lwm yam alloys xws li hlau -chromium- txhuas tuaj yeem muab kev ua tau zoo dua txawm tias tsis tshua muaj kev tiv thaiv zoo.
Magnesium oxide rwb thaiv tsev purity cuam tshuam rau ob qho tib si hluav taws xob thiab tshuaj lom neeg ua haujlwm. Technical- qib magnesium oxide muaj calcium, hlau, silica, thiab lwm yam impurities uas tuaj yeem hydrate lossis hnov mob ntawm qhov kub thiab txias, txo cov rwb thaiv tsev tiv thaiv thiab muaj peev xwm tsim cov kab hluav taws xob ntawm cov hlau tsis kam thiab cov ntaub qhwv. High-purity magnesium oxide, ua tiav kom tshem tawm cov kab mob no kom qis dua 1 feem pua, tuav cov rwb thaiv tsev tiv thaiv siab tshaj 1000 megohms txawm nyob rau qhov kub siab thiab tiv thaiv cov dej noo uas tuaj yeem cuam tshuam lub zog dielectric. Lub particle loj tis thiab compaction ceev, tiav los ntawm precision swaging, txiav txim siab thermal conductivity thiab tshuaj stability ntawm rwb thaiv tsev txheej. Dense, high-purity insulation prevents process media migration through the heater body even if the sheath integrity is compromised.
Cov ntaub ntawv foob thiab cov hlau lead hlau rwb thaiv tsev yuav tsum tiv thaiv cov tshuaj lom neeg tshwj xeeb tam sim no ntawm qhov txias kawg ntawm lub rhaub. Silicone roj hmab tebchaw muab cov dej noo zoo heev thiab ua kom yooj yim ntawm qhov kub txog 200 degrees Celsius, haum rau ntau daim ntawv thov kev lag luam. Txawm li cas los xij, silicone tebchaw yuav degrade nyob rau hauv kev sib cuag nrog tej yam hydrocarbons, concentrated acids, los yog muaj zog bases. Epoxy resin seals muaj cov tshuaj tiv thaiv zoo tshaj plaws thiab muaj peev xwm kub txog 300 degrees Celsius lossis siab dua, txawm tias muaj kev hloov pauv tsawg dua li silicone. Ceramic seals siv alumina lossis steatite ceramics sib txuas rau cov hlau sheath ua tiav qhov ntsuas kub siab tshaj plaws thiab cov tshuaj tiv thaiv zoo tshaj plaws tab sis yuav tsum tau ceev faj tuav kom tsis txhob muaj kev puas tsuaj. Cov khoom siv hluav taws xob hluav taws xob, suav nrog Teflon, fiberglass, thiab cov khoom siv tshwj xeeb, yuav tsum tau xaiv rau kev sib raug zoo nrog cov khoom siv hluav taws xob thiab qhov kub thiab txias.
Kev kho deg thiab txheej txheej tuaj yeem txuas ntxiv kev siv ntawm cov ntaub ntawv hauv paus dhau ntawm lawv qhov kev txwv. Electroless npib tsib xee plating muab ib qho sib xws, txheej tawv uas txhim kho corrosion kuj thiab txo cov nplaum hauv cov ntawv siv yas. Cov npib tsib xee-phosphorus alloy deposit, feem ntau 25-50 micrometers tuab, muaj cov tshuaj tiv thaiv zoo heev thiab hnav cov khoom thaum muaj kev cuam tshuam tsawg heev ntawm thermal hloov vim yog txheej nyias thiab thermal conductivity ntawm npib tsib xee. Passivation kev kho mob siv nitric acid los yog citric acid daws txhim khu lub ntuj oxide txheej ntawm stainless hlau, txhim kho corrosion kuj tsis muaj qhov hloov pauv. Cov txheej txheem tshwj xeeb xws li ceramics lossis fluoropolymer tuaj yeem muab hluav taws xob rwb thaiv tsev, cov khoom tsis yog nplaum, lossis cov tshuaj tiv thaiv ntxiv rau cov ntawv thov tshwj xeeb, txawm tias lawv cuam tshuam rau kev ua haujlwm thermal yuav tsum tau ua tib zoo soj ntsuam.
Kev ntsuas tshuaj sib raug zoo yuav tsum tau saib dhau qhov kev ntsuas ntawm cov khoom siv rau kev sib xyaw ntawm cov tshuaj, qhov kub thiab txias, qhov xav tau, thiab cov kev ntxhov siab ntawm cov khoom siv tam sim no hauv daim ntawv thov. Cov kab kos kev sib raug zoo muab cov ntsiab lus pib muaj txiaj ntsig, tab sis cov kev ua haujlwm tiag tiag yuav cuam tshuam nrog kev sib xyaw ua ke, sib txawv ntawm qhov sib txawv, lossis qhov cuam tshuam tsis sib xws tsis raug ntes hauv cov qauv siv. Kev ntsuas kub ntawm kev ua haujlwm thiab qhov chaw nyob ib puag ncig tuaj yeem cuam tshuam cov khoom sib cuam tshuam thiab tsim cov hom kev ua tsis tiav uas tsis tau kwv yees los ntawm cov ntaub ntawv tsis sib xws hauv xeev. Mechanical kev nyuaj siab los ntawm thermal expansion, kev co, los yog installation rog tuaj yeem ua kom cov tshuaj tua kab mob los ntawm kev ntxhov siab corrosion cracking mechanisms. Kev ntsuam xyuas zoo los txiav txim siab tag nrho cov xwm txheej no tiv thaiv kev xaiv cov khoom kim heev.
Kev tswj xyuas kev ua tau zoo thiab kev soj ntsuam xyuas kom ntseeg tau tias cov khoom siv tshwj xeeb txhais ua cov khoom ua tau zoo. Cov ntaub ntawv pov thawj los ntawm cov neeg muag khoom sau cov tshuaj lom neeg muaj pes tsawg leeg thiab cov khoom siv kho tshuab, muab traceability thiab kev lees paub tias alloys ua tau raws li cov lus qhia. Kev tshuaj xyuas tuaj xyuas qhov ntev thiab kuaj xyuas qhov tsis xws luag uas tuaj yeem cuam tshuam kev tiv thaiv corrosion. Tom qab-Kev sim tsim khoom suav nrog siab- qhov muaj peev xwm dielectric xeem, ntsuas kev tiv thaiv hluav taws xob, thiab kev ntsuas helium leak rau cov ntawv thov tseem ceeb tau lees paub tias kev tsim kho kev ncaj ncees ua tau raws li qhov yuav tsum tau ua. Cov txheej txheem zoo no ntxiv tus nqi tab sis muab qhov tseem ceeb txo kev pheej hmoo rau cov ntawv thov uas lub tshuab cua sov tsis ua haujlwm muaj kev nyab xeeb loj lossis muaj txiaj ntsig nyiaj txiag.
Kev txheeb xyuas kev lag luam ntawm kev xaiv cov khoom siv rau kev ua phem ib puag ncig yuav tsum xav txog tag nrho cov nqi ntawm cov tswv cuab es tsis yog thawj tus nqi tau txais ib leeg. Cov ntaub ntawv hwm zoo xws li Inconel lossis titanium cov nqi hais ntau zaus ntau dua li cov qauv stainless hlau, tab sis lub neej ntev kev pab cuam thiab txo cov kev tu ncua feem ntau ua rau qhov kev nqis peev no. Tus nqi ntawm kev poob qis, kev kho thaum muaj xwm txheej ceev, thiab cov khoom muaj feem cuam tshuam los yog teeb meem kev nyab xeeb cuam tshuam nrog lub tshuab hluav taws xob ntxov ntxov feem ntau tshaj cov khoom siv tus nqi them los ntawm cov npoo tseem ceeb. Kev txheeb xyuas tus nqi ntawm lub neej suav nrog kev kwv yees qhov tseeb ntawm kev pabcuam lub neej, kev saib xyuas ntau zaus, thiab qhov tshwm sim tsis ua haujlwm ua rau muaj kev txiav txim siab uas ua kom zoo dua tus nqi nyiaj txiag thaum ua kom muaj kev tsim nyog.
