Yuav Ua Li Cas Thermal Conductivity ntawm Polypropylene (PP) Exchanger Piv rau PTFE nyob rau hauv qis-Tub Kub Acid Service?

PTFE yog huab tais ntawm cov tshuaj tiv thaiv thiab yog li qhov kev xaiv ua ntej rau kev ua kom txias txias, dilute hydrochloric acid yuav yog PTFE cua sov exchanger. Tab sis PTFE raug nqi ntau heev. Polypropylene (PP) yog lwm qhov, cov khoom yas uas raug nqi ib feem ntau rau qhov tshwj xeeb no qis - kub, tsis yog - oxidizing kev pab cuam. Nws yog nyob rau hauv tib yam qeeb qis rau thermal conductivity li no nws tsis yog ib qho kev txhim kho thermal. Kev xaiv ntawm PP yog tsuas yog kev lag luam, ua rau muaj kev kub ntxhov ntau thiab kev tiv thaiv universal rau tus nqi qis dua.

Thermal conductivity: Yuav luag zoo meej Match
Lub thermal conductivity ntawm polypropylene (PP) ntawm chav tsev kub yog li 0.2 W / m·K. Lub thermal conductivity ntawm PTFE (polytetrafluoroethylene) yog me ntsis siab dua ntawm 0.25 W / m·K. Hauv kev xyaum, qhov 20 feem pua ​​​​qhov sib txawv no ua rau muaj kev cuam tshuam me me hauv feem ntau ntawm cov khoom siv hluav taws xob hloov pauv qhov ntsuas. Ob leeg yog thermal insulators piv rau cov hlau (xws li stainless hlau ~ 15 W / m·K). Yog li ntawd, PP lub tshav kub exchanger yuav xav tau ib yam ntawm cov tshav kub hloov qhov chaw raws li ib tug PTFE chav tsev rau tib lub luag hauj lwm, dej velocities thiab kub. Tsis muaj laj thawj xaiv PP tshaj PTFE, los yog rov ua dua, raws li kev ua haujlwm zoo thermal.

Qhov kawg xaus ntawm ib tug PP vs PTFE exchanger thermal conductivity uas tsis muaj kub acid kawm yog meej: xaiv tsis ua thermal conductivity. Ob cov ntaub ntawv poob rau hauv tib chav kawm qis conductivity thiab ib qho kev hloov tsim tsis tseem ceeb.

Vim li cas PP? Txoj Cai Economic
Qhov txiaj ntsig tseem ceeb ntawm polypropylene yog qhov pheej yig. PP yog cov khoom siv thermoplastic uas ua rau ntau qhov ntau. Cov nqi raw khoom feem ntau yog 5-10 npaug qis dua PTFE. Tsis tas li ntawd pheej yig dua txoj kev ntawm fabrication xws li kub roj vuam, extrusion thiab txhaj molding muaj nyob rau hauv kev sib piv rau tshwj xeeb sintering thiab compression molding ntawm PTFE. Lub plhaub-thiab- raj lossis coil- hom PP cov khoom siv hluav taws xob yog ua los ntawm ib lub hlis twg ntawm tus nqi ntawm cov khoom siv PTFE ntawm tib qhov loj. Cov nqi txuag no tuaj yeem loj rau qhov kev pabcuam tsis ua rau cov kua qaub ntawm qhov kub thiab txias.

Kev tiv thaiv kub thiab tshuaj lom neeg: Qhov txwv ntawm PP
PP yog kev lag luam zoo nkauj tab sis muaj lub qhov rai ua haujlwm nqaim. Polypropylene tsuas tuaj yeem siv txuas ntxiv ntawm qhov kub txog li 80℃(176℃F). Thaum kub saum toj no PP yuav mos, thiab poob nws cov neeg kho tshuab lub zog thiab pib nkag rau hauv siab. Hloov pauv, PTFE tuaj yeem khiav tsis tu ncua ntawm 200℃(392℃F) thiab sib nrug mus txog 260 degree. Qhov kev txwv no tau txais nyob rau hauv qhov ntsuas kub ntawm cov kua qaub (piv txwv li hauv qab 60 degree); Txawm li cas los xij, ib qho txheej txheem chim siab lossis chav ntxuav tuaj yeem tshaj qhov txwv ntawm PP.

Los ntawm cov tshuaj lom neeg pom PP yog resistant rau ntau dilute acids, bases thiab aqueous ntsev daws. Nws cuam tshuam los ntawm cov muaj zog oxidising acids, xws li concentrated nitric acid, sulfuric acid saum 70% thiab chromic acid. Nws kuj tseem nthuav lossis yaj hauv ntau cov kuab tshuaj organic xws li cov tshuaj tsw qab hydrocarbons, cov kuab tshuaj chlorinated thiab ketones. Txawm li cas los xij, PTFE tiv taus yuav luag txhua yam khoom tshwj tsis yog cov hlau molten alkali thiab cov tshuaj fluorine ntawm qhov kub thiab txias. PP yog li no tus kws tshaj lij rau txias, huv, tsis yog - oxidizing acids (xws li dilute HCl, dilute H 2 SO 4 , acetic acid). PTFE yog lub cev tiv thaiv kab mob, siab kub thiab nyab xeeb rau txhua tus.

Kev txiav txim siab ntxiv
Brittleness thiab UV rhiab heev
Polypropylene tsis tiv taus ultraviolet (UV) lub teeb. Yog tias qhov sib pauv nyob rau sab nraum zoov lossis hauv thaj chaw uas muaj teeb pom kev zoo, UV raug ua rau daim duab -oxidation uas tuaj yeem ua rau tawg thiab poob ntawm lub zog. PP exchangers yuav tsum tau tiv thaiv los yog txau nrog UV-cov txheej tiv thaiv rau kev siv sab nraum zoov. PTFE yog ib txwm UV resistant thiab yuav tsis deteriorate nyob rau hauv tshav ntuj.

Hluav taws kub tsis kam
PP yog cov khoom siv hluav taws xob, nrog rau Limiting Oxygen Index (LOI) txog 18%. Thaum ignited, nws hlawv yooj yim nrog cov pa luam yeeb thiab khiav ntawm molten polymer. Cov teeb meem kev nyab xeeb hluav taws muaj xws li cov tshuaj tua hluav taws, cov khoom thaiv hluav taws, thiab kev faib hluav taws xob hauv cheeb tsam. PTFE yog non-flammable nrog ib tug LOI ntawm 95%, nws yuav tsis txhawb combustion thiab nws tus kheej - tua thaum lub nplaim taws raug tshem tawm. Qhov no ua rau PTFE qhov kev xaiv muaj kev nyab xeeb dua hauv thaj chaw muaj kev phom sij.

Mechanical zog ntawm qhov kub thiab txias
Thaum qhov kub thiab txias (piv txwv li qis dua 10 degree), PP yuav nkig, thiab muaj kev cuam tshuam rau kev puas tsuaj los ntawm dej rauj lossis dej khov. PTFE muaj zog thiab hloov tau mus rau qhov kub thiab txias (-200 degree). Rau cov kev pab cuam txias acid xws li dej txias los yog cov tub yees txias, PP exchangers yuav tsum tau ua tib zoo tiv thaiv los ntawm mechanical shock.

Kev taw qhia Kev Xaiv Xaiv Cov Khoom Siv Zoo rau Kev Pabcuam
Kev xaiv ntawm PP lossis PTFE exchanger rau cov kua qaub qis tsis yog kev xaiv thermal, tab sis tsuas yog kev xaiv kev lag luam thiab tshuaj lom neeg. Thaum siv PP:

Cov kua qaub yog diluted, tsis yog -oxidizing thiab huv si (HCl < 20%, H2SO4 < 50%, acetic acid).

Kev khiav hauj lwm kub qis dua 60℃(nrog rau kev nyab xeeb qis dua 80 degree).

Nws tsis muaj cov kuab tshuaj organic lossis muaj zog oxidants.

Lub exchanger yog muab tso rau hauv tsev los yog nyob rau hauv ib cheeb tsam UV shielded.

Kev phom sij hluav taws kub tsawg lossis tswj tau zoo.

qis tshaj. Kev tsav tsheb yog thawj tus nqi peev.

Siv PTFE rau:

Cov kua qaub yog kub (siab tshaj 80 degree), concentrated los yog oxidising (xws li nitric, chromic los yog kub sulfuric).

Aggressive organic solvents nyob rau hauv cov kua.

Cov txheej txheem ntxhov siab tuaj yeem luv luv tshaj PP qhov ntsuas kub.

Kev nyab xeeb hluav taws kub lossis UV raug yog kev txhawj xeeb.

Tus nqi pib nce ntxiv yog tsim nyog los ntawm kev siv lub neej ntev thiab kev saib xyuas qis.

Tus nqi pheej yig, tsis muaj-cov neeg ua haujlwm tsis zoo rau qhov txias, maj mam acid yog polypropylene. Qhov siab - kawg, invincible warrior rau cov kub, wilder thiab ntau unpredictable chemistry yog PTFE. Tsis yog ib txwm zoo dua, qhov kev txiav txim siab yog tag nrho cov txheej txheem lub hnab ntawv nyob ntawm.

Cov ntsiab lus: thermal conductivity tsis yog qhov txiav txim siab
Nyob rau hauv qis -kub acid daim ntawv thov, lub thermal conductivity ntawm PP thiab PTFE yog li ze li qhov sib txawv ntawm qhov kub thiab txias thiab kev ua tau zoo yog qhov sib piv. Yog li nws los txog rau cov tshuaj sib xyaw ua ke, kev txwv kub, kev nyab xeeb thiab tus nqi. PP muab kev txuag nyiaj ntau thiab kev pabcuam txhim khu kev qha rau cov kev pabcuam txias txias me ntsis. Tsis muaj lwm cov yas tuaj yeem phim PTFE qhov kev tiv thaiv rau ib qho nyuaj, rhuab los yog aggressive chemical thiab yog vim li cas nws raug nqi ntau dua. Cov khoom siv zoo tshaj plaws rau txoj haujlwm yog qhov kev lag luam zoo tshaj plaws uas tuaj yeem nyob ntawm -thiab rau qis- qhov kub thiab txias, tsis yog - oxidizing acids, cov khoom ntawd yuav zoo yog polypropylene.