Cov txheej txheem kub, corrosive kwj ntawm 150 degree. PTFE, cov fluoropolymer classic rau cov khoom siv hluav taws xob, yog qhov tsis zoo ntawm qhov kub thiab txias; nws yuav soften thiab tsis. PFA, nws cov txheeb ze tshuaj lom neeg, zoo kawg nkaus nyiam. Ob qho khoom siv yog cov insulators zoo heev, thiab lawv cov khoom nyoos, muaj peev xwm ua kom sov yog ze li zoo ib yam. Lub thermal yeej ntawm PFA exchanger ntawm 150℃tsis yog vim hais tias nws yog ib tug zoo conductor, tab sis tsuas yog vim hais tias nws tseem yog ib tug khoom, muaj zog tube ntawm qhov kub thiab txias, ua rau lub tshav kub exchanger lub luag hauj lwm uas PTFE tsis tau txawm sim. To taub covPFA vs PTFE tshav kub hloov coefficient 150 degreeKev sib piv yuav tsum tau saib dhau tus lej thermal conductivity thiab tsom mus rau qhov kev pabcuam siab tshaj plaws.

Thermal conductivity: Ib qho ze li qhov zoo tib yam rwb thaiv tsev

Lub thermal conductivity ntawm ob qho tib si PTFE (polytetrafluoroethylene) thiab PFA (perfluoroalkoxy alkane) yog nyob rau hauv thaj tsam ntawm 0.20-0.25 W / m·K ntawm cov txheej txheem raug kub. Cov nqi no yuav luag indistinguishable rau engineering lub hom phiaj. Nyob rau tib lub phab ntsa tuab (xws li, 1 hli rau lub raj me me los yog 2 hli rau lub plhaub loj-thiab-lub raj sib hloov), cov thermal conductive ntawm lub raj ua los ntawm ob qho khoom siv yuav zoo ib yam. Yog li ntawd, tag nrho cov tshav kub hloov pauv coefficient (U-tus nqi) ntawm PFA exchanger zoo ib yam li PTFE exchanger rau qhov sib npaug tsim-xav tias ob qho tib si ua haujlwm nyob rau hauv lawv cov kev txwv kub.

Qhov tseem ceeb, qhov txiaj ntsig zoo ntawm PFA yog nws qhov kev pabcuam txuas ntxiv ntawm 260 degree, piv rau qhov kev txwv ntawm PTFE rau kev siv lub tshuab cua sov lossis cov khoom siv hluav taws xob, uas yog kwv yees li 110-120℃nyob rau hauv ib puag ncig aqueous (thiab siab dua me ntsis hauv qee qhov qhuav lossis tsis-oxidizing). Qhov no tso cai rau PFA exchanger ua cov kua dej ntawm 150 degree, siv qhov sib txawv ntawm qhov sib txawv ntawm logarithmic qhov ntsuas kub ntau dua (LMTD) rau tib lub luag haujlwm, uas ua rau cov khoom siv hluav taws xob me me thiab muaj txiaj ntsig zoo dua. Kev yeej tsis yog nyob rau hauv tus xov tooj conductivity, tab sis nyob rau hauv cov ntaub ntawv muaj peev xwm los qhia rau kev sib ntaus.

PFA yeej qhov kev sib ntaus sib tua thermal tsis yog los ntawm kev khiav nrawm dua, tab sis los ntawm kev tso cai ntawm kev khiav txhua. Ntawm 150℃, PTFE tsis yog tus neeg sib tw - nws tau tawm ntawm qhov chaw.

Vim li cas PTFE siv tsis tau ntawm 150℃hauv Exchanger Service

Mechanical softening thiab creep

PTFE pib soften thiab poob txhua yam muaj zog saum toj no kwv yees li 110-120℃nyob rau hauv tas li immersion kev pab cuam. Thaum PTFE muaj qhov theoretical melting point ntawm 327 degree, nws dhau los ua ib qho kev hloov pauv ntawm crystalline ntawm txog 19℃thiab lwm qhov ntawm ib ncig ntawm 30 degree, thiab siab dua 100℃cov cheeb tsam amorphous dhau los ua mobile. Nyob rau hauv lub tshav kub exchanger, qhov twg cov hlab yuav raug rau sab hauv, siab sab nraud, thiab thermal expansion stresses, PTFE hlab ntawm 150℃yuav nkag, deform, thiab nws thiaj li vau los yog rupture. Cov khoom siv kuj nthuav tawm cov coefficient siab ntawm thermal expansion (kwv yees li 10 npaug ntawm cov hlau), uas ua rau lub raj ntau dhau sagging thiab txhua yam qaug zog ntawm qhov kub siab.

Xyaum xyaum

Cov kev paub dhau los thiab cov chaw tsim khoom cov txheej txheem tso qhov kev nyab xeeb tsis tu ncua kev ua haujlwm txwv rau PTFE cov cua kub hloov pauv ntawm 110℃rau feem ntau cov kev pabcuam aqueous. Rau kev mus ncig luv luv txog li 120 degree, qee qhov qauv tsim tuaj yeem siv tau, tab sis 150℃yog ruaj khov sab nraum lub hnab ntawv. Los ntawm qhov sib txawv, PFA tuav nws cov neeg kho tshuab kev ncaj ncees thiab tshuaj tiv thaiv mus txog 260 degree, tsis muaj kev hloov pauv uas ua rau muaj qhov tsis txaus ntseeg.

Tag Nrho Cov Hluav Taws Kub Kub Hloov Coefficient (U-Value) ntawm 150 degree

Zoo sib xws U-Value ntawm Equivalent Design

Rau qhov kev xav tsis zoo uas PTFE tuaj yeem muaj sia nyob ntawm 150 degree, U-tus nqi ntawm PFA exchanger thiab PTFE exchanger nrog zoo tib yam geometry (tube txoj kab uas hla, phab ntsa thickness, raj layout, thiab cov dej velocities) yuav luag tib yam. Lub conductive kuj ntawm lub raj phab ntsa yog tsuas yog ib feem ntawm tag nrho cov thermal kuj. Lwm yam khoom siv -tube-sab convection, plhaub-sab convection, thiab fouling resistances- zoo tib yam rau tib cov kua dej thiab tshaj tawm. Txij li cov thermal conductivity ntawm PTFE thiab PFA zoo ib yam, U-tus nqi sib txawv los ntawm tsawg dua 5%.

Tswv yim zoo: Loj dua LMTD

Vim tias PTFE tsis tuaj yeem ua haujlwm ntawm 150 degree, qhov kev sib piv zoo tsis yog ntawm ob yam khoom ntawm qhov kub thiab txias. Hloov chaw, PFA exchanger tuaj yeem siv los ua kom txias 150℃kwj nrog, piv txwv li, 30℃dej txias, ua LMTD ntawm kwv yees li 80-100 degree. PTFE exchanger, txwv rau qhov kub-sab inlet kub ntawm 110 degree, yuav muaj ib tug LMTD ntawm tsuas yog 40-50℃rau tib cov dej txias. Txhawm rau hloov cov dej kub tib yam, PTFE exchanger yuav xav tau kwv yees li ob zaug ntawm thaj chaw saum npoo -yog tias nws tuaj yeem ua haujlwm txhua. Hauv kev muaj tiag, qhov kev xaiv PTFE tsuas yog tsis muaj rau qhov kub siab.

Cov txheej txheem xaiv tswv yim

Xaus: Ciaj sia nyob raws li Kev Txiav Txim Siab

Kev sib piv ntawm PFA thiab PTFE exchanger ntawm qhov kub thiab txias yog ib qho teeb meem yooj yim ntawm kev ciaj sia, tsis yog kev ua haujlwm ntawm cov khoom siv thermal. Ntawm 150 degree, PTFE softens, creeps, thiab tsis, thaum PFA tseem muaj zog, ruaj khov, thiab tshuaj inert. Tag nrho cov thermal hloov coefficients ntawm ob cov ntaub ntawv yog ze li zoo tib yam ntawm tib phab ntsa tuab, tab sis qhov tseeb tsis muaj feem xyuam vim PTFE siv tsis tau ntawm qhov kub ntawd. PFA yog qhov kev sib tw thermal tsuas yog vim nws tuaj yeem siv cua sov. Cov khoom siv zoo tshaj plaws yog ib qho uas tseem sawv ntawm cov txheej txheem kub, thiab rau 150℃corrosive kwj, PFA yog cov khoom ntawd.