Xaiv cov khoom siv rau koj lub foob yog qhov tseem ceeb vim nws yuav ua lub luag haujlwm hauv kev txiav txim siab qhov zoo, kev ua neej thiab kev ua haujlwm ntawm daim ntawv thov, thiab txo cov teeb meem yav tom ntej. Ntawm no, peb saib yuav ua li cas ib puag ncig yuav cuam tshuam rau kev xaiv cov khoom siv foob, nrog rau qee yam ntawm cov khoom siv tshaj plaws thiab cov ntawv thov twg uas lawv tsim nyog tshaj plaws.
Environmental yam
Ib puag ncig lub foob yuav raug nthuav tawm yog qhov tseem ceeb thaum xaiv cov qauv tsim thiab cov khoom siv. Muaj ntau yam khoom tseem ceeb uas cov ntaub ntawv foob xav tau rau txhua qhov chaw, suav nrog kev tsim lub ntsej muag ruaj khov, muaj peev xwm ua kom sov, tshuaj tiv thaiv, thiab hnav tsis kam.
Hauv qee qhov chaw, cov khoom no yuav tsum muaj zog dua li lwm tus. Lwm cov khoom siv uas yuav tsum tau coj mus rau hauv tus account thaum xav txog ib puag ncig muaj xws li hardness, nruj, thermal expansion, hnav thiab tshuaj tiv thaiv. Ua raws li cov lus qhia no yuav pab koj nrhiav cov khoom zoo tshaj plaws rau koj lub foob.
Ib puag ncig tuaj yeem txiav txim siab seb tus nqi lossis qhov zoo ntawm lub foob tuaj yeem ua ntej. Rau qhov chaw abrasive thiab hnyav, cov ntsaws ruaj ruaj yuav kim dua vim cov khoom siv yuav tsum muaj zog txaus los tiv thaiv cov xwm txheej no.
Rau cov chaw ib puag ncig zoo li no, kev siv nyiaj rau lub foob zoo yuav them rov qab rau lub sijhawm raws li nws yuav pab tiv thaiv kom tsis txhob raug kaw, kho, thiab kho dua tshiab lossis hloov lub foob uas lub foob tsis zoo yuav ua rau. Txawm li cas los xij, hauv kev siv cov twj siv nrog Cov kua dej huv heev uas muaj cov khoom siv lubricating, lub foob pheej yig dua tuaj yeem yuav hauv kev pom zoo ntawm cov kabmob zoo dua.
Cov khoom siv foob
Cov pa roj carbon
Cov pa roj carbon siv hauv lub ntsej muag foob yog sib xyaw ntawm amorphous carbon thiab graphite, nrog rau feem pua ntawm txhua qhov kev txiav txim siab lub cev ntawm qib kawg ntawm carbon. Nws yog ib qho inert, ruaj khov khoom uas tuaj yeem ua tus kheej lubricating.
Nws yog dav siv los ua ib qho ntawm ob lub ntsej muag kawg hauv cov tshuab ntsaws ruaj ruaj, thiab nws kuj yog cov khoom siv nrov rau segmented circumferential seals thiab piston rings nyob rau hauv qhuav lossis me me ntawm lubrication. Cov pa roj carbon / graphite sib xyaw no tuaj yeem raug impregnated nrog lwm cov ntaub ntawv los muab nws cov yam ntxwv sib txawv xws li txo qhov porosity, txhim kho hnav kev ua haujlwm lossis txhim kho lub zog.
Lub thermoset resin impregnated carbon foob yog feem ntau rau cov neeg kho tshuab ntsaws ruaj ruaj, nrog rau feem ntau resin impregnated carbons muaj peev xwm ua hauj lwm nyob rau hauv ib tug ntau yam ntawm cov tshuaj los ntawm lub hauv paus muaj zog mus rau muaj zog acids. Lawv kuj muaj cov khoom sib txhuam zoo thiab cov qauv tsim nyog los pab tswj cov kev sib hloov siab. Cov khoom siv no haum rau lub luag haujlwm dav dav rau 260 ° C (500 ° F) hauv dej, cov khoom ua kom txias, roj, roj, cov tshuaj lom neeg lub teeb, thiab kev siv zaub mov thiab tshuaj.
Antimony impregnated carbon seals kuj tau ua pov thawj tias muaj kev vam meej vim yog lub zog thiab cov qauv ntawm antimony, ua rau nws zoo rau cov ntawv thov siab thaum xav tau cov khoom muaj zog thiab tawv. Cov ntsaws ruaj ruaj no kuj muaj peev xwm tiv taus blistering nyob rau hauv daim ntawv thov nrog cov kua viscosity siab los yog lub teeb hydrocarbons, ua rau nws tus qauv qib rau ntau refinery daim ntaub ntawv.
Cov pa roj carbon kuj tseem tuaj yeem raug impregnated nrog zaj duab xis qub xws li fluorides rau kev ua haujlwm qhuav, cryogenics thiab lub tshuab nqus tsev, lossis oxidation inhibitors zoo li phosphates rau qhov kub thiab txias, kev kub ceev, thiab turbine daim ntawv thov rau 800ft / sec thiab nyob ib ncig ntawm 537 ° C (1,000 ° F).
Ceramic
Ceramics yog inorganic non-metallic cov ntaub ntawv ua los ntawm ntuj los yog hluavtaws compounds, feem ntau yog alumina oxide los yog alumina. Nws muaj lub siab melting point, siab hardness, siab hnav tsis kam thiab oxidisation tsis kam, yog li nws yog dav siv hauv kev lag luam xws li tshuab, tshuaj, roj av, tshuaj thiab tsheb.
Nws kuj muaj cov khoom zoo heev dielectric thiab feem ntau yog siv rau cov hluav taws xob insulators, hnav cov khoom tiv thaiv, sib tsoo xov xwm, thiab cov khoom kub kub. Nyob rau hauv siab purities, alumina muaj cov tshuaj tiv thaiv zoo heev rau cov txheej txheem cov kua dej ntau dua li qee cov kua qaub uas muaj zog, ua rau nws siv rau hauv ntau daim ntawv thov foob. Txawm li cas los xij, alumina tuaj yeem tawg yooj yim nyob rau hauv thermal shock, uas tau txwv nws txoj kev siv hauv qee qhov kev siv qhov no tuaj yeem yog qhov teeb meem.
Silicon carbide yog tsim los ntawm kev sib xyaw silica thiab coke. Nws yog chemically zoo ib yam li ceramic, tab sis muaj zoo lubrication zoo thiab yog ib qho nyuaj, ua rau nws ib tug zoo hard-hnav tshuaj rau hnyav hnyav.
Nws tseem tuaj yeem rov lapped thiab polished yog li lub foob tuaj yeem hloov kho ntau zaus hauv nws lub neej. Nws feem ntau yog siv ntau dua mechanically, xws li hauv cov tshuab foob rau nws cov tshuaj zoo corrosion kuj, siab zog, siab hardness, zoo hnav tsis kam, me me kev sib txhuam coefficient thiab kub tsis kam.
Thaum siv rau lub ntsej muag lub ntsej muag, silicon carbide ua rau kev ua haujlwm tau zoo, ua kom lub neej muaj zog, txo tus nqi kho, thiab txo cov nqi khiav lag luam xws li turbines, compressors, thiab centrifugal twj. Silicon carbide tuaj yeem muaj cov khoom sib txawv nyob ntawm seb nws tau tsim li cas. Reaction bonded silicon carbide yog tsim los ntawm kev sib txuas ntawm silicon carbide hais rau ib leeg hauv cov txheej txheem tshuaj tiv thaiv.
Cov txheej txheem no tsis cuam tshuam rau feem ntau ntawm lub cev thiab thermal zog ntawm cov khoom, tab sis nws txwv tsis pub cov tshuaj tsis haum ntawm cov khoom. Cov tshuaj feem ntau uas muaj teeb meem yog caustics (thiab lwm yam tshuaj pH siab) thiab cov kua qaub uas muaj zog, thiab yog li cov tshuaj tiv thaiv-bonded silicon carbide yuav tsum tsis txhob siv nrog cov ntawv thov no.
Tus kheej-sintered silicon carbide yog tsim los ntawm sintering silicon carbide hais ncaj qha ua ke siv cov non-oxide sintering pab nyob rau hauv ib qho chaw inert ntawm kub tshaj 2,000 ° C. Vim tias tsis muaj cov khoom siv thib ob (xws li silicon), cov khoom siv sintered ncaj qha yog tshuaj tiv thaiv rau yuav luag txhua cov kua thiab cov txheej txheem txheej txheem yuav pom hauv lub twj tso kua mis centrifugal.
Tungsten carbide yog cov khoom siv ntau yam zoo li silicon carbide, tab sis nws yog qhov haum rau cov ntawv thov siab dua vim nws muaj elasticity ntau dua uas tso cai rau nws yooj yim me ntsis thiab tiv thaiv lub ntsej muag distortion. Zoo li silicon carbide, nws tuaj yeem rov lapped thiab polished.
Tungsten carbides feem ntau yog tsim los ua cemented carbides yog li tsis muaj kev sim ua kom sib txuas tungsten carbide rau nws tus kheej. Cov hlau thib ob yog ntxiv rau khi lossis cement cov tungsten carbide hais ua ke, ua rau cov khoom uas muaj cov khoom sib xyaw ua ke ntawm ob qho tib si tungsten carbide thiab cov hlau khi.
Qhov no tau siv los ua kom zoo dua los ntawm kev muab cov tawv tawv ntau dua thiab muaj zog cuam tshuam ntau dua li ua tau nrog tungsten carbide ib leeg. Ib qho tsis muaj zog ntawm cemented tungsten carbide yog nws qhov ntom ntom. Yav dhau los, cobalt-bound tungsten carbide tau siv, txawm li cas los xij nws tau maj mam hloov los ntawm nickel-bound tungsten carbide vim nws tsis muaj ntau yam tshuaj lom neeg uas xav tau rau kev lag luam.
Nickel-bound tungsten carbide yog dav siv rau lub ntsej muag sealing qhov twg siab zog thiab siab toughness zog yog xav tau, thiab nws muaj cov tshuaj zoo sib xws feem ntau txwv los ntawm cov npib tsib xee dawb.
GFPTFE
GFPTFE muaj cov tshuaj tiv thaiv zoo, thiab cov iav ntxiv txo qhov kev sib txhuam ntawm lub ntsej muag sealing. Nws yog qhov zoo tagnrho rau cov ntawv thov huv thiab pheej yig dua li lwm cov ntaub ntawv. Muaj cov kev hloov pauv muaj nyob rau kom zoo dua lub foob rau cov kev xav tau thiab ib puag ncig, txhim kho nws qhov kev ua tau zoo tag nrho.
Buna
Buna (tseem hu ua nitrile roj hmab) yog tus nqi-zoo elastomer rau O-rings, sealants thiab molded khoom. Nws yog lub npe hu rau nws cov neeg kho tshuab kev ua tau zoo thiab ua tau zoo hauv kev siv roj, petrochemical thiab tshuaj lom neeg. Nws kuj yog dav siv rau cov roj crude, dej, ntau yam cawv, silicone roj thiab hydraulic kua siv vim nws inflexibility.
Raws li Buna yog cov khoom siv roj hmab copolymer, nws ua tau zoo nyob rau hauv daim ntawv thov xav tau hlau adhesion thiab abrasion-resistant khoom, thiab cov tshuaj tom qab no kuj ua rau nws zoo tagnrho rau sealant daim ntaub ntawv. Tsis tas li ntawd, nws tuaj yeem tiv taus qhov kub thiab txias vim tias nws tau tsim los nrog cov kua qaub tsis zoo thiab tsis zoo alkali tsis kam.
Buna txwv tsis pub siv rau hauv cov ntawv thov nrog cov xwm txheej hnyav xws li kub siab, huab cua, hnub ci thiab chav ua haujlwm tsis zoo, thiab tsis haum rau cov tshuaj ntxuav hauv qhov chaw (CIP) cov tshuaj tua kab mob uas muaj cov kua qaub thiab peroxides.
EPDM
EPDM yog cov roj hmab hluavtaws feem ntau siv hauv tsheb, kev tsim kho thiab kev siv tshuab rau cov ntsaws ruaj ruaj thiab O-rings, tubing thiab ntxhua khaub ncaws. Nws yog kim dua Buna, tab sis tuaj yeem tiv taus ntau yam thermal, huab cua thiab cov khoom siv kho tshuab vim nws lub zog tensile ntev ntev. Nws yog ntau yam thiab zoo tagnrho rau kev siv dej, tshuaj chlorine, tshuaj dawb thiab lwm yam ntaub ntawv alkaline.
Vim nws cov khoom elastic thiab nplaum, ib zaug ncab, EPDM rov qab los rau nws cov qauv qub txawm tias qhov kub thiab txias. EPDM tsis pom zoo rau cov roj av, kua dej, chlorinated hydrocarbon lossis hydrocarbon hnyav daim ntawv thov.
Viton
Viton yog cov khoom siv ntev ntev, kev ua haujlwm siab, fluorinated, hydrocarbon roj hmab cov khoom siv feem ntau siv hauv O-Rings thiab cov ntsaws ruaj ruaj. Nws yog kim dua li lwm yam khoom siv roj hmab tab sis nws yog qhov kev xaiv zoo tshaj plaws rau qhov nyuaj thiab xav tau kev sib khi.
Resistant rau ozone, oxidation thiab huab cua huab cua, nrog rau cov ntaub ntawv xws li aliphatic thiab aromatic hydrocarbons, halogenated kua thiab muaj zog acid cov ntaub ntawv, nws yog ib qho ntawm cov fluoroelastomers muaj zog dua.
Xaiv cov khoom raug rau kev sib khi yog qhov tseem ceeb rau kev ua tiav ntawm daim ntawv thov. Txawm hais tias muaj ntau cov ntaub ntawv foob zoo sib xws, txhua tus ua haujlwm ntau lub hom phiaj kom tau raws li qhov xav tau tshwj xeeb.
Post lub sij hawm: Lub Xya hli ntuj-12-2023