Txhua xyoo Terminal Foob thiab Hluav Taws Xob Kev Txuas Txuas Kev Kho rau PTFE Cua Kub Tubes

Thaum lub PTFE sheath yuav luag tiv thaiv cov tshuaj, qhov kawg ntawm lub davhlau ya nyob twg, qhov twg cov xov hlau tawm, yog qhov chaw tsis muaj zog. Rov ua dua qhov kub thiab txias tuaj yeem ua rau lub epoxy lossis silicone foob, ua rau muaj magnesium oxide rwb thaiv tsev rau ya raws thiab corrosive fumes. Tus yuam sij rau kev tiv thaiv qhov kev zais zais tsis ua haujlwm yog kev saib xyuas txhua xyoo.
Lub davhlau ya nyob twg foob yog lub tshuab cua sov txoj kab kawg ntawm kev tiv thaiv; hwm nws. Cov hlau tsis muaj zog sab hauv hauv PTFE lub raj cua sov yog txuas nrog lub zog sab nraud ua rau hauv lub thawv kaw lub thawv lossis hauv cov pwm epoxy / silicone potting. Lub foob no tiv thaiv ya raws, tshuaj vapors, thiab condensation ntawm ntws mus rau hauv MgO rwb thaiv tsev. Thaum cov dej noo nkag mus rau hauv, rwb thaiv tsev tsis ua hauj lwm thiab av faults, tripped breakers los yog tiav cov khoom tsis ua hauj lwm tshwm sim. Kev tawg tuaj yeem tshwm sim los ntawm kev rov nthuav dav thiab kev sib cog lus thaum lub sij hawm caij tsheb kauj vab, kev co kis tau los ntawm lub tank, lossis ntev ntev - raug ultraviolet lub teeb thiab cov tshuaj muaj zog. Ob peb feeb ntawm kev saib xyuas zaum kawg txhua xyoo tuaj yeem ntxiv xyoo rau lub neej ntawm lub raj. Yog li ntawd, kev tshuaj xyuas txhua xyoo thiab rov- sealing yuav tsum yog lub hauv paus tseem ceeb ntawm txhua qhov kev tiv thaiv kev tiv thaiv rau PTFE immersion heaters.
Work should only be done after the heater has been de-energized, locked out and tagged out per plant safety protocols. Allow tube to cool to room temperature and remove from tank if practicable, else work carefully with tube still mounted. Begin with a visual inspection of the terminal seal, factory-applied epoxy or silicone potting or compression gland. Check for hairline cracks, shrinkage, discolouration or separation of the seal material from the wire insulation or tube body. Be sure to note where the leads depart the seal, this is the transition zone and the most stressed area. Visible gaps >0.5 hli los yog pov thawj ntawm cov hmoov dawb paug (thaum MgO hydration) yog qhov qhia tau hais tias cov dej nkag tau tshwm sim lawm.

Tom qab ntawd xyuas cov kev sib txuas hluav taws xob lawv tus kheej. Tshem lub hau npog ntawm lub davhlau ya nyob twg yog tias tam sim no thiab xyuas qhov nruj ntawm txhua tus ntsia hlau, txiv ntseej lossis crimp kev twb kev txuas siv lub calibrated torque screwdriver los yog ciaj ntswj. Loose terminals nce kev tiv thaiv, ua kom sov nyob rau hauv load thiab ceev corrosion. Txawm tias me me looseness yuav tawm cov cim ntawm arcing los yog blackening ntawm kov nto. Ntxuav tej corrosion/oxidation tawm ntawm cov hlau terminals thiab lugs nrog ib tug uas tsis yog - abrasive contact cleaner los yog, yog hais tias tsim nyog, zoo heev emery ntaub (220 grit los yog finer). Ceev faj tsis txhob khawb cov PTFE sheath los yog puas cov hlau strands. Ntxuav thiab so cov neeg nrog isopropyl cawv kom tshem tawm tag nrho cov seem.
Siv lub tsho nyias nyias ntawm cov roj dielectric (siab kub silicone raws li, ntsuas tsawg kawg 200 degree) ntawm txhua qhov kev sib cuag hlau thiab cov xov. Cov roj thawb tawm cua thiab noo noo, tiv thaiv oxidation ntxiv. Tseem tso cai xa hluav taws xob. Tsis txhob overdo nws. Cov roj ntau dhau tuaj yeem cuam tshuam cov kab mob lossis ua rau lub zog tsis zoo thaum muab nws rov qab ua ke.
Kev kho feem ntau tuaj yeem ua tau yog tias tsuas muaj cov kab nrib pleb me me lossis qhov khoob me me. Ntxuav thaj chaw tawg kom zoo nrog isopropyl cawv thiab cia nws qhuav tag. Siv ob-ib feem epoxy lossis silicone sealant haum rau kev siv tas li ntawm qhov kub siab tshaj 200℃thiab sib haum nrog cov txheej txheem ib puag ncig. Siv cov cuab yeej yas, ua hauj lwm lub sealant rau hauv qhov tawg thiab du nws los ua ib qho kev thaiv tsis tu ncua. Tso cai rau cov khoom siv kho kom zoo ua ntej muaj kev tuav pov hwm ntxiv raws li cov chaw tsim khoom cov lus qhia - feem ntau 24 teev ntawm chav tsev kub. Hnyav xeb ntawm cov khoom hlau sab hauv lossis pom tseeb tias ya raws hauv lub thawv davhlau ya nyob twg-rau kev puas tsuaj loj-tso tseg ntawm lub foob- lub raj yog tej zaum puas sab hauv. Hloov nws sai sai. Yog tias koj sim kho lub davhlau ya nyob twg tsis zoo, nws yuav luag feem ntau ua tsis tau ntxov.
Tom qab kho lossis tu, rov txuas lub hwj chim coj thiab hloov lub thawv lub thawv npog thiab ua qhov kev ntsuas kev tiv thaiv kev tiv thaiv ib puag ncig ib ntus. Ua ntej xa cov raj xa mus rau kev pabcuam kev nyeem ntawv yuav tsum yog> 100 MΩ ntawm 500 V lossis 1000 V DC. Foob qhov xwm txheej thiab kho hauv cov khoom siv tu lub chaw sau ntawv sau ua ntej thiab tom qab ntsuas.
Hauv kev teeb tsa tshiab lossis thaum rov kho cov kav dej qub, xav txog qhov muaj peev xwm muab qhov kawg ntawm lub davhlau ya nyob twg rau hauv lub thawv dej tsis sib haum siab tshaj qib ntawm cov kua tank. Qhov kev thaiv ntxiv ntawd ua rau txo qis qhov cuam tshuam rau kev tawg thiab ya raws, ua kom ntev lub neej foob.
Kev saib xyuas lub davhlau ya nyob twg ib xyoos ib zaug yog kev nqis peev me me uas tiv thaiv feem ntau ua rau ntxov ntxov PTFE cua sov raj tsis ua haujlwm: noo noo infiltration. Qhov no yuav tsum yog ib feem ntawm txhua lub tsev kho mob lub sijhawm tiv thaiv. Kev tshuaj xyuas cov ntsaws ruaj ruaj, kev sib txuas ceev ceev, kev tu kom huv thiab tiv thaiv cov roj siv los ntawm kev saib xyuas cov neeg ua haujlwm tiv thaiv qhov degradation los ntawm kev ncav cuag MgO rwb thaiv tsev. Qhov no txhais tau hais tias tsawg dua kev poob qis, txo cov nqi hloov pauv thiab muaj kev nyab xeeb thiab txhim khu kev qha ua haujlwm ntawm PTFE cua sov tubs txawm tias nyob rau hauv qhov chaw hnyav tshaj plaws. Kev tshuaj xyuas tsis tu ncua ntawm qhov no qee zaum tsis quav ntsej thaj chaw them rov qab rau lub sijhawm ua haujlwm thiab kev nyab xeeb rau xyoo tom ntej.