PET yog qhov chaw siv tshuab ntxuav khoom loj tshaj plaws hauv no. Vim li cas PET tuaj yeem tau rau ib qho chaw tsis muaj keeb kwm, zoo siab ntau thiab yooj yoo xwm rau cov khoom siv PET los ntawm kev sov tshuab ntau, thaum siv ua chaw ntxuav khoom, PET tuaj yeem tsim rau ib qho chaw ntxuav khoom uas muaj ob sab zoo siab, thiab tuaj yeem tsim rau ib qho chaw ntxuav khoom zoo siab ntau thiab zoo tshaj plaws los ntawm kev sov tshuab ntau. Nws kuj tuaj yeem tsim rau ib qho chaw ntxuav khoom PET tsis xwm rau kev sov tshuab. Chaw ntxuav khoom PET, tshpecially cov chaw ntxuav khoom uas tau sov tshuab ntau, tau siv txoj caij pet zoo tshaj plaws, muab ib qho kev saib xyuas zoo rau cov khoom ntxuav khoom. Qhov tshwm sim thiab nqi ntawm nws zoo li ib yam li lwm yam chaw ntxuav khoom. Yog li, thaum PET siv ua chaw ntxuav khoom, nws feem ntau yog tsim los ntawm kev sov tshuab ntau. Hauv no, cov chaw ntxuav khoom me me tshaj plaws yog tshuab ntxuav khoom ntawm ib nrab milliliters mus rau 2 liters, thiab kuj muaj cov chaw ntxuav khoom loj tshaj 30 liters. Ntawm lub caug pib ntawm xyoo 1980s, vim li cas nws muaj nyiaj noj qab loj, yooj yoo tsim, nqi tsuas, thiab yooj yoo tsim ntau, nws tau hlobo nrog ib qhov siab tshaj plaws tom qab nws tau raug tso cai. Nyob rau saib li 20 xyoo, nws tau hlobo mus rau ib qhov chaw ntxuav khoom loj tshaj plaws hauv lub ntiaj teb. Nws tsis yog tsuas siv ntau hauv chaw ntxuav khoom ntawm cov khoom ntxuav khoom muaj kab mob, tshuab ntxuav khoom muaj dej, khoom siv, khoom siv neeg, white spirits, kab mob thiab lwm yam, tab sis cov chaw ntxuav khoom uas tau muab kho tshaj plaws kuj tuaj yeem siv rau chaw ntxuav khoom ntawm cov khoom ntxuav khoom muaj dej thiab tshuab ntxuav khoom muaj dej. Cov chaw ntxuav khoom PET uas tau muab kho nrog cov kev tshuaj tshaj plaws kuj tau tso cai rau hauv qhov chaw ntxuav khoom, thiab cov chaw ntxuav khoom PET uas tau muab kho nrog cov kev tshuaj tshaj plaws kuj tau hlobo nrog ib qhov siab tshaj plaws. Tus poj niam tuaj yeem hais tias kev hlobo ntawm kev tshuaj tau txhim kho siv sijhawm PET ntau dua. Lawv tsis yog tsuas yog hlobo qhov chaw ntxuav khoom tseem ceeb hauv dej thiab khoom ntxuav khoom muaj kab mob, tab sis lawv kuj tau tshaj tshuj rau qhov chaw ntxuav khoom tshaj plaws ntawm chaw ntxuav khoom muaj dej thiab aluminum can rau beer thiab lwm yam khoom.
Qhov kev tsim khoom ntawm PET bottle-grade chips muaj ob qhov sib txawv tshaj plaws. Qhov thawj yog kev tsim khoom ntawm cov chips pheej, yog li, kev tsim khoom polyester. Qhov kev tsim khoom ntawm cov chips bottle-grade pheej yog tib yam li cov chips tshaiv tshwj xeeb. Tom qab ntawd, kom pom zoo ntau yam kev tshwm sim ntawm cov chips bottle-grade, tus IPA thiab lwm yam khoom siv tau los ntxiv. Qhov ob yog qhov kev sib kis hauv qhov chaw tseemceeb ntawm cov khoom pheej.
1. Cov ntsiab lus ncaj ntawm cov khoom siv raw material slices
Ob txhiaj xwm ntawm transesterification thiab esterification yog qhov rooj kaw. Thiaj li, kom txeej xyuas rau sab laug ntawm kev sib hlo tshiab, yuav tsum tshem tawm cov duab ntsiab ntawm cov khoom tsawg uas muaj qhov mob nyuaj siab. Muaj ob qho kev ua siab ntawm cov khoom tsawg uas tau tsim los ntawm kev sib tham hluas hluas los ntawm chaw sib tham mus rau lwm chaw, yog li ntawd yog qhov kev sib txawv ntawm cov khoom tsawg uas sib txawv los ntawm hauv mus rau sab nraud ntawm chaw sib tham thiab qhov kev sib txawv los ntawm sab nraud mus rau sab nrauv ntawm chaw sib tham. Nyob hauv no, qhov teeb meem ntawm kev sib txawv los ntawm sab nraud ntawm chaw sib tham mus rau sab nrauv yog sib npaug nrog sab ntau thiab qhov ceev ntawm nitrogen. Txhawm rau SSP production, nyob rau sab ntau thiab qhov ceev, qhov teeb meem ntawm kev sib txawv ntawm cov khoom tsawg hauv chaw sib tham yog tsaus dua li qhov sib txawv los ntawm sab nraud ntawm chaw sib tham mus rau sab nrauv. Yog li, thiaj li, kom tshem tawm cov khoom tsawg hauv chaw sib tham, qhov kev ua siab yuav tsum tau ntev dua. Vim tias qhov teeb meem ntawm kev sib txawv ntawm cov khoom tsawg hauv cov khoom tsawg yog tshaum dua li hauv cov khoom loj, lawv yog yooj yim dua los tshem tawm. Tom qab ntawv, nrog rau cov khoom tsawg, qhov nruab nrab ntawm cov khoom tsawg loj, qhov teeb meem ntawm kev sib txawv loj, thiab qhov teeb meem ntawm kev sib tham loj. Yog li, nyob rau hauv ib qho chaw, qhov teeb meem ntawm kev sib tham hluas hluas ntawm PET yog sib npaug nrog qhov loj ntawm cov khoom tsawg. Tab sis, yog tias cov khoom tsawg yog tshaum heev, lawv yog tshaum heev rau kev sib tham, uas pheej hmog tshwm sim. Ntxiv mus, daim ntawv ntawm cov khoom tsawg kuj sib txawv nrog qhov teeb meem ntawm kev sib tham. Daim ntawv tsis zoo kuj yog tshaum heev rau kev sib tham. Yog li, qhov kev xav tau rau cov khoom tsawg yog txaus siab, thiab tsis muaj cov khoom tsawg yooj yim yuav tsum tau mus rau hauv qhov kev sib tham hluas hluas.
2. Qhov muaj zog ntawm xim ntawm cov khoom siv raw
Daim ntawv sau ntsuas tus lej ntawm daim phiaj raw material yog tsim nyog rau tus lej ntawm daim phiaj finished product. Muaj ntau yam cuab yeej uas txhawb kev sib txuas ntawm daim phiaj pheej. Txhawb kev sib txuas yog qhov chaw tshwm sim tias muaj kev sib txuas zoo tshaj plaws ntawm qhov chaw. Nws cov ntsuas tau los ntawm kev sib piv thiab kev ntsuas, thiab ntsuas kev tswj hwm ntawm qhov chaw International Commission on Illumination. Feem ntau, siv tus ntsuas siv cov Hunter (L,a,b) method rau kev ntsuas, qhov L pom zoo li tus lej ntawm kev ua white thiab brightness. a yog tus lej ntawm green/red; b pom zoo li tus lej ntawm yellow. Muaj ntau yam cuab yeej uas txhawb kev sib txuas ntawm daim phiaj pheej, feem ntau los ntawm kev sib txuas ntawm raw material, hom thiab ntau yam ntawm additives, kev tsim kho, kev tswj hwm kev tsim kho, thiab kev sib txuas ntawm kev lag luam [3]. Nyob rau hnub no, qhov kev tswj hwm siv cov kev tswj hwm siv cov kev tswj hwm yog, nyob rau hauv qhov chaw tswj hwm zoo ib yam thiab zoo tshaj plaws ntawm raw thiab auxiliary materials, tus nqi ntawm red thiab blue degree agents tuaj yeem hloov tau tus lej b ntawm daim phiaj. Cov cuab yeej uas txhawb kev sib txuas ntawm daim phiaj finished product yog dav dua. Tab sis, cov daim phiaj bottle-grade muaj qhov kev xav tau siab tshaj plaws rau tus lej ntawm kev sib txuas ntawm kev lag luam. Yog li, qhov kev tswj hwm yuav tsum raug hloov tam sim thaum muaj kev xav tau ntawm tus neeg siv khoom kom raug kev xav tau.
3. IPA thiab DEG neeg
Qhov ntau ntawm IPA thiab DEG hauv cov kab ntsug siv los ntawm kev tsim kho tawv, thiab lawv cov ntaub ntawv tsis suav ntau hauv kev tsim kho tawv.
Cov khoom siv ntawm IPA yog txaus txhij rau kev cuam tshwm ntawm kev nyiaj loj ntawm cov chips. Qhov siv IPA yog los txav tsis pub kev ceev ceev ntawm qhov chaw ntawm PET macromolecules nrog qhov twg, thiab tom qab ntawd los txo qhov kev ua haujlwm ntawm cov chips. Thaum pib, nws tuaj yeem pab txhim kho kev ua haujlwm thaum siv kev ntxig thiab kev muaj zog, thiab txo qhov ntsuas kub ntawm kev tsim khoom. Thaum kawg, nws tuaj yeem pab nce qhov zoo siab ntawm cov duab thiab lub chai. Tab sis, qhov siv IPA los txo qhov ntsuas kub thiab qhov ntsuas kub ntawm PET, uas txawv mus rau kev txwv tsis zoo dua ntawm cov chai uas tsim tau thiab kev nyiaj. Yog li, cov khoom siv ntawm IPA yuav tsum tau raug npaj raws li qhov xyaum tseem ceeb thiab tsim nyog. Nyob no, lub chaw tsim khoom tau tsim ob hom bottle-grade slices raws li qhov xyaum ntawm cov neeg siv: ib qhov yog cov bottle-grade slices rau cov beverages carbonated tshaib, thiab lwm qhov yog cov bottle-grade slices rau cov beverages juice uas muaj kub. Lub thib ob no xav tau kev nyiaj zoo dua ntawm kub. Yog li, nyob rau hauv kev tsim khoom, zoo li siv kev txheej txheem kub thiab npaj qhov ntsuas kub ntawm lub mold, ntxiv mus rau, cov khoom siv ntawm IPA tau raug txo nrog qhov tseem ceeb (los ntawm 1.5%, uas yog qhov hli ntawm lub hle) los nce qhov kev cuam tshwm ntawm PET thiab txhawis cov xyaum ntawm kub rau cov chai beverages. Ntxiv mus rau, cov khoom siv ntawm IPA kuj muaj qhov tshwm sim rau kev sib sau hluav taws xob. Yog tias cov khoom siv ntawm IPA tsis raug, piv txwv li, thaum nws ntau heev, nws yuav tshwm sim rau kev cuam tshwm tsis tiag tsis tag ntawm cov slices nyob rau hauv pre-crystallization thiab crystallizer, uas tshwm sim rau kev nyob ruaj ruaj ntawm cov slices nyob rau hauv kev nce nyiaj.
Zaj lwm ntawm diethylene glycol feem ntau txiav rau qhov kev tsim hluas thiab tuaj yeem hloov kho los ntawm kev saib xyuas tus ratio ntawm daim duab (xws li hloov ratio ntawm EG mus rau PTA). Nyob rau hnub no, cov neeg tsim khoom feem ntau tsim khoom diethylene glycol uas siv rau tshuab khw muag tsev tsim khoom nyob ze 1.1%±0.2% (siv feem pua) tej zaum. Hauv qhov chaw no, qhov ntau dua ntawm diethylene glycol zoo rau kev txhim kho qhov siab tshaj plaws ntawm cov khoom. Vim tias cov khoom sib thooj hauv diethylene glycol muaj qhov tshaj tshuab me me, uas tuaj yeem pheej siab ntau dua ntawm PET. Tab sis qhov no tsis txhob ntau heev, vim tias qhov muaj khaub npawg hauv khoom sib thooj cuam tshuam rau qhov ceev npaum ntawm cov moleculer PET thiab cuam tshuam rau qhov siab tshaj plaws ntawm PET, ua rau nws yuav tsum tau ntxig thaum kev sau khoom. Yog tias qhov ntau ntawm no tseem ntau dua, nws yuav cuam tshuam rau qhov tseeb ntawm kev sau thiab tshuab khw.
4. Qhov chaw ntawm carboxyl
Under certain other conditions, a high content of terminal carboxyl groups is conducive to increasing the reaction rate. From the equation of the SSP reaction, it can be seen that there are two types: transesterification and esterification. The high content of terminal carboxyl groups is conducive to the esterification reaction between PET chains and increases the reaction rate. In PET slices, an increase in H+ concentration is also beneficial to the self-catalytic effect of the catalyst. However, an increase in the content of terminal carboxyl groups will affect the subsequent processing performance of the slices. Therefore, the terminal carboxyl groups of basic slices should be controlled within a certain range, generally ranging from 30 to 40mol/t, while those of bottle-grade slices should be 30mol/t.
5. Cov nqi txiaj ntsim
Cov hom thiab tus nqi siv rau cov khoom siv hluav taws xob hauv qhov chaw siv khoom siv yuav tseem muaj kev pheej nyav txog qhov kualitè ntawm cov khoom finished. Kev tsim kho khoom rau cov chips zoo li chai muaj feem caij nrog cov cuab yeej kho tshuaj, polyphosphoric acid. Qhov kev ua haujlwm ntawm polyphosphoric acid yog mus kuaj cov teb ntawm cov PET molecular chain nrog cov phosphate group, tso kom tau zoo dua qhov thermal stability ntawm cov PET chain. Tab sis, vim li cas cov phosphate group kuj tuaj yeem hla mus ua rau ib qho nucleating agent rau PET crystals, nws yuav muaj kev pheej nyav ntau rau kev injection molding blow molding ntawm cov chips chai. Hauv qhov kev tsim kho chai, oligomers, metal oxides (xws li antimony trioxide), phosphates, thiab lwm yam, yog tag nrho cov nucleating agents rau PET crystallization. Tom qab ntawv, ib co cov compounds tsov me me, xws li polyethylene glycol, thaum hais tias lawv tsis muaj kev pab rau kev nucleation, tab sis yog ib qho catalyst rau kev crystallization. Yog tias qhov nqi ntawm cov khoom no hauv PET loj dua ib qho tshaj tawm, nws yuav tso kev pib siab dua rau kev crystallization ntawm PET (xws li, kom cold crystallization temperature kom me dua), uas yuav pheej nyav rau qhov kualitè ntawm kev tsim kho chai, tshwm sim daim kab npawb dawb hauv sab qab thiab sab ntawm chai, thiab tseem pheej nyav rau qhov transparency ntawm tag nrho cov chai. Vim li no, nyob rau hauv qhov kev tswj xyuas kualitè ntawm cov khoom thiab qhov kev pib (qhov kev tsim kho ntawm chaw tsim khoom), qhov nqi ntawm cov khoom siv, xws li cov catalysts, yuav tsum me dua li loj.
6. Qhov kev tshwm sim ntawm cov chaw tsim khoom ua ntej thiab chaw tsim khoom rau cov khoom siv nyob hauv qhov chaw tsim khoom rau cov khoom
Tus nqi kub tshaj tawg ntawm qhov thawj crystallizer yog 145 mus rau 150℃ (cov ntaub ntawv muab los los ntawm lub teb chaws xa). Yog tias qhov kub tsis sib xws, vim qhov nyuaj siab ntawm kev tshem tawm cov hmoob dej hauv daim ntawv, qhov khib nyiab yav tom ntej yuav yooj yav, thiab qhov khib nyiab yuav tsis txaus nrog rau sijhawm luv, uas tsis tuaj yeem txhim kho tau yam tiag yam txwv. Tab sis, tus nqi kub khib nyiab yuav tsum tsis txhob nce ntau heev, vim tias thaum qhov kub cia nce, cov daim ntawv yog qhuav kub rau oxidation thiab degradation nrog hauv duab ntawm pre-crystallizer thiab crystallizer, yog li ntsws txoj hlua ntawm qhov khoom. Tus nqi kub ntawm qhov mold yog 170 mus rau 175℃ (cov ntaub ntawv muab los los ntawm lub teb chaws xa). Yog tias qhov kub nce dua 175℃, thaum sijhawm nyob ntawm cov daim ntawv hauv pre-crystallizer thiab crystallizer nce, qhov hlua yuav nce ntau dua, tab sis qhov khib nyiab yuav tsis hlo li cas. Tom qab no, nyob hauv kev lag luam, tsis tuaj yeem siv qhov khib nyiab ntau dua los nrhiav qhov b zoo dua. Vim tias thaum qhov kub yog qhov tsis sib xws, qhov khib nyiab tsis txaus ntawm cov daim ntawv yuav ua rau cov daim ntawv nyob ib leeg hauv qhov thawj preheater thiab reactor, thiab cov dej hauv qhov khib nyiab kuj nyuaj siab tshem tawm tag. Qhov no yuav txwv rau qhov viscosity ntawm cov daim ntawv thiab yog li ntawd txoj hlua ntawm cov daim ntawv pib. Tsuas yog tsim cov daim ntawv khib nyiab zoo, ces thiaj tuaj yeem tau cov daim ntawv loj zoo. Lub tswv yim ntawm cov daim ntawv khib nyiab zoo feem ntau hais txog qhov khib nyiab ntawm cov daim ntawv txog qhov nqi tshwj xeeb, xws li qhov khib nyiab ntawm qhov thawj crystallizer yog ≥30%, qhov khib nyiab ntawm qhov outlet ntawm crystallizer yog ≥40%, thiab qhov khib nyiab ntawm qhov outlet ntawm preheater yog ≥45%. Txawm li cas los xij, nws yuav ua rau cov daim ntawv nyob ib leeg hauv qhov kev nce loj. Qhov lwm yog tias qhov khib nyiab ntawm saum npoo ntawm cov daim ntawv yuav tsum zoo ib yam.
7. Qhov kev siv ntawm qhov chaw ntxuav taws thiab qhov chaw pab cuam tshwm sim rau cov khoom lag luam
Ob qhov no hla tshaj zog ntawm cov hnub ci los ntawm qhov chaw tsis tshooj. Muaj ob qhov kev txiav txim siab thermodynamic thiab kinetic uas txiav txim siab txog kev pab cuam ntawm kev sib thooj hmoob: tebchaws kev sib thooj thiab qhov siab ntawm cov by-products leegvaj tshwm ntau tshaj li los ntawm cov hnub ci. Qhov thawj txiav txim siab nyob ntawm qhov kub ntawm kev siv nitrogen.
Kev siv txhuab kub ntawm kev sib ntxiv yog tias muaj ob tog neeg zoo thiab tsis zoo. Rau qhov zoo, khiav txhuab kub tuaj yeem pheej siab ntau dua rau kev sib ntxiv. Nyob rau hauv qhov chaw muaj kev pheej siab ntau ntawm kev nyiaj ruam, nws tuaj yeem pab txhim kho lub sijhawm tsim khoom. Ntawm qhov chaw muaj kev pheej siab tshwm sim, nws kuj tuaj yeem pab txhim kho kev pheej siab ntau ntawm kev nyiaj ruam. Tab sis, qhov txhuab kub nce yuav tsum muaj kev sib ntxiv ntxiv ntau, uas tom qab no yuav tsum muaj kev txwv tsis tau rau qhov cim ntawm khoom lag luam. Yog li, nyob rau hauv kev tsim khoom nyob ze, yuav tsum pom qhov txhuab kub xws li yuav tsum tau, uas yuav tsum xav txog ob qhov. Nyob rau hauv chav no, qhov txhuab kub ntawm chav sib ntxiv yog qhov txhuab kub ntawm qhov tawm ntawm chav sov ua ntej. Qhov txhuab kub ntawm chav sib ntxiv tuaj yeem sau ua ntej los ntawm kev hloov qhov txhuab kub ntawm qhov tawm ntawm chav sov ua ntej thiab qhov ntev ntawm nitrogen sov nyob rau saum toj ntawm chav sov ua ntej. Qhov txhuab kub ntawm qhov nkag mus rau chav sib ntxiv yog ncaws mus saum toj, thiab kev sib ntxiv ntawm qhov chaw system kuj yog ncaws. Lub sijhawm rov kho qhov tseeb tom qab muaj kev hloov yog ib xyuas dua li sijhawm chav sib ntxiv nyob. Tom qab ntawd, qhov hloov ntawm qhov ntaub ntawv nyiaj ruam ntawm khoom lag luam kuj tseem xav tau sijhawm. Txawm li cas los xij, kev sib ntxiv yuav tsis zoo ib yam, uas yuav tsum muaj kev pheej siab ntau tsis zoo ib yam rau cov khoom thiab yog li yuav tsum muaj kev txwv tsis tau rau kev tsim khoom tom ntej.
Qhov kev cuam tshuam ob ntawm qhov chaj hluav taws xob nyuj yooj nyob rau hauv qhov sib txig thiab qhov saum npoo ntawm cov xa. Ntawm no, hluav taws xob yog ib qhlo ntaus (txhooj tshuaj) (tsuav rau hauv qhov kheej tshuaj), thiab lwm qhlo ntaus uas tshem tawm cov khoom lag luam leeg. Txog li cas los, muaj ob qho kev sib txig uas cov khoom lag luam leeg tsim los ntawm kev sib sau ua ke tawm ntawm qhov chaw. Nyob rau hauv lawv, qhov kev sib txig ntawm cov khoom leeg sib dhos los ntawm saum npoo mus rau sab nrauv yog sib phim txig nrog qhov chaj hluav taws xob thiab teeb liab. Ntawm no, hluav taws xob thiab cov xa nyob ib ncig thiab muaj kev pheej hmong, uas tuaj yeem pab txhim kho qhov kheej tshuaj thiab tshem tawm cov khoom lag luam leeg. Qhov kheej tshuaj ntawm qhov chaw BUHLER siv daim duab roing, siv hluav taws xob kheej rau hauv qab thiab hluav taws xob kheej nyob hauv plha, uas pab kheej tshuaj zoo dua thiab tshem tawm cov ceev. Nyob rau hauv qhov chaw sib txig, thaum cov xa nyob rau hauv qhov nce nqi ntau dua rau hauv qab, tus teeb liab ntawm qhov kheej tshuaj rau hauv qab yog tsim nyog rau qhov teeb liab tsawg dua ntawm li 190 degrees, uas pab tso cov xa tsis txhob nyuj. Qhov chaj hluav taws xob, uas siv los yog ib qhlo ntaus kheej tshuaj, txhaj tshuaj ntawm qhov teeb liab thiab qhov loj ntawm kev tsim khoom (yaos li, qhov xav tau ntawm qhov sib piv ntawm dej thiab khoom lag luam). Nyob rau hauv qhov sib piv uas teeb liab thiab qhov loj ntawm kev tsim khoom yog tseem ceeb, muaj ib qhov chaw tseem ceeb rau qhov chaj hluav taws xob. Yaos li, thaum pib ntau dua li qhov no, qhov chaj tsis txeem ceeb rau kev sib txig vim qhov sib piv ntawm dej thiab khoom lag luam tau pib tshwm sim lawm. Tab sis thaum teeb liab nce, qhov sib piv no yuav raug tshem tawm. Qhov ntau ntawm cov khoom leeg nyob rau hauv qhov sib piv ntawm dej thiab khoom lag luam yuav tso tseg thaum qhov chaj hluav taws xob nce mus, mus txog thaum muaj ib qhov sib piv tshiab.
Muaj lwm qhov rais uas txiav txim siab rau qhov kev hloov ntawm SSP, thiab ntawd yog qhov ceev foom tshuam - qhov ceev foom tshuam ntawm catalyst. Yog li, qhov loj ntawm cov duab ntaub ntawv catalyst nyob rau hauv qhov chaw pib, cov duab ntaub ntawv catalyst nyob rau hauv qhov chaw A yog ib feem ob ntawm qhov chaw B. Nyob rau hauv cov nqi uas txiav txim siab rau qhov kev tshuam tawm ntawm catalyst, nyob zoo li cov duab ntaub ntawv catalyst, lub teb degrees yog tseem ceeb dua.
8. Qhov kev tshuam tawm ntawm cov tsiaj nitrogen rau properties ntawm khoom
(1)Peb yuav tsum muaj oxygen
Muab ib qhov leej leeb ntawm cov hluav taws instrument mus rau hauv qhov chaw sau nrog nitrogen kom tshem tawm cov dundanj ntsuab hauv av uas tsim nyog hauv qhov chaw sau nrog nitrogen. Txhiaj li ntawm cov lus paub los ntawm 1-3, daim ntawv thaj plig tseem ceeb hauv kev sib txawv yog ethylene glycol, thiab kuj muaj ib co acetaldehyde, oligomers, thiab lwm yam uas tsim tawm los ntawm kev sib txawv pheej, uas tau raug oxidized catalytically los ntawm oxygen mus rau carbon dioxide thiab dej hauv qhov chaw catalyst Pt/Pd hauv qhov chaw sib txawv catalyst. Tab sis, cov nuj nqaij oxygen yuav tsum raug tswj xyuas meej pem, vim tias cov nuj nqaij oxygen molecules yuav tshwm sim kev cuam tshwv kawg hauv kev txhim kho viscosity, uas tshwm sim kev hloov color value ntawm khoom lag luam, kev txo viscosity, thiab kev nthuav dav ntawm cov carboxyl groups. Cov nuj nqaij oxygen hauv cov av nitrogen tawm los ntawm qhov chaw sau nrog nitrogen hauv qhov chaw no yog tswj hauv 10ppm. Nyob rau hnub no, raws li cov yam ntxwv ntawm cov qhov chaw sau nrog nitrogen, nyob zoo li catalytic oxidation, cold EG spray kuj tuaj yeem siv los tshem tawm cov dundanj ntsuab hauv av los ntawm nitrogen. Qhov kev ua no tuaj yeem tshem tawm cov nuj nqaij oxygen hauv nitrogen, tab sis tsis muaj zog loj hauv kev tshem tawm cov dundanj ntsuab hauv av uas muaj boiling point tsuas, xws li acetaldehyde
(2) Qhov loj ntawm kev saib xyuas nitrogen
Qhov tshaiv ntawm nitrogen muaj qhov ntxiv rau kev ntxiv ntawm qhov loj ntawm cov kab ntsug thiab qhov txheej xwm ntawm cov kab ntsug. Thaum ua ntej, cov dundev ntsiab hluav taws xob hnav tshab nyob hauv nitrogen tuaj yeem pab tso cai rau qhov khib nyiab ntxiv mus rau sab rooj laug, uas tsis pab rau kev ntxiv qhov loj ntawm cov kab ntsug. Tom qab ntawd, nws kuj tseem yuav tfeem cuab rau kev tshem tawm aldehyde nyob hauv cov kab ntsug, yog li nws tfeem cuab rau qhov ntau ntawm aldehyde hauv cov kab ntsug. Tab sis, vim qhov kev sib raug zoo tshaj plaws ntawm cov dundev ntsiab hluav taws xob, qhov kev suv ntxiv rau qhov ntau ntawm cov dundev ntsiab hluav taws xob hauv nitrogen rau qhov ntau ntawm aldehyde yuav tsum tau suv ntxiv ntxiv.
(3) Qhov chaw tshwm sim dew ntawm qhov kev lag luam nitrogen
Nyob hauv tib siab kawg, cov molej hauv dej tuaj yeem tsim qhov hydrolysis rau cov macromolecules polyester, yog li ntawd ntxiv rau kev tsim khoom nyob rau hauv qhov chaw tsim khoom, yuav tsum sau hauv dew point ntawm cov nitrogen system, yog li yuav tsum sau hauv qhov ntau ntawm cov molej hauv dej nyob rau hauv cov nitrogen system. Rau cov chaw tsim khoom BUHLER, cov dew point ntawm nitrogen yuav tsum nyob qis dua -30 degrees Celsius, thiab rau cov chaw tsim khoom SINCO, yuav tsum nyob qis dua -40 degrees Celsius.
Xaus
Thiab chaw txhaj siv duv PET hluvcua tshuab rau kev sib cuag khoom, cov ntsiab lus ntau tshaj plaws txog kev tsim khoom muaj li cov yam ntxwv no: kev pom zoo, kev nyob deb, kev sau ua haujlwm, thiab tsis muaj qhov chou lossis txoj caij nyoog. Muaj ntau thiab kev pheej hmong nyob rau hauv kev tsim khoom ntawm duv, thiab cov ntsiab lus tseem ceeb tseem ceeb yog cov yam ntxwv uas tau suav dav hlub. Sib txuas rau leej twg xav tau, tus lej formulas, kev tshuaj xyuas thiab kev tshuaj xyuas ntawm cov duv pheej hmong tuaj yeem raug hloov kho kom raug rau cov ntsiab lus saum toj no, kom ua rau raug siab rau lub laij lej. Thiab tshawb fwb rau kev tshuaj xyuas kev tsim khoom SSP nyob rau hauv lub tebchaws.
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