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Low density polyethylene (LDPE)ndi polymerized ethylene monga polymerization monomer, peroxide monga initiator, thermoplastic utomoni wopezedwa ndi ufulu kwakukulu polymerization anachita, maselo kulemera zambiri mu 100000 ~ 500000, kachulukidwe ndi 0.91 ~ 0.93g/cm3, ndi opepuka mitundu polyethylene utomoni. .

Ili ndi kufewa kwabwino, kufalikira, kutsekemera kwamagetsi, kuwonekera, kukonza kosavuta komanso kutulutsa mpweya wina.Good mankhwala bata, kukana alkali, kukana zosungunulira ambiri organic, ali osiyanasiyana ntchito, kuphatikizapo extrusion ❖ kuyanika, kuwombera filimu, waya ndi ❖ kuyanika chingwe, jekeseni akamaumba ndi kuwomba akamaumba dzenje akamaumba, etc.

Chifukwa cha moyo waufupi wa ma radicals aulere opangidwa ndi woyambitsa, ethylene imapanikizidwa kwambiri ndikuwonjezera kuthamanga kwa zomwe (110 ~ 350MPa), kotero kuti kachulukidwe kake kawonjezeke mpaka 0.5g/cm3, yomwe ili yofanana ndi madzi omwe sangathe. kukanikizidwa kachiwiri.Pofuna kufupikitsa katayanidwe ka maselo a ethylene ndikuwonjezera mwayi wogundana pakati pa ma radicals aulere kapena unyolo wokangalika ndi mamolekyu a ethylene, machitidwe aulere a polymerization amachitika.Polyethylene yotsika kwambiri imapangidwa, motero polyethylene yotsika kwambiri imatchedwanso kuti polyethylene yotsika kwambiri.

Low osalimba polyethylene kupanga ndondomeko

Kupanga otsika osalimba polyethylene makamaka zikuphatikizapo ethylene magawo awiri psinjika, initiator ndi owongolera jekeseni, polymerization anachita dongosolo, mkulu ndi otsika kuthamanga kulekana ndi dongosolo kuchira, extrusion granulation ndi pambuyo mankhwala dongosolo, etc.

Malinga ndi mitundu yosiyanasiyana ya riyakitala, imatha kugawidwa m'mitundu iwiri: njira yothamanga kwambiri yamachubu ndi njira ya autoclave.

Njira ya tubular ndi ndondomeko ya ketulo ili ndi makhalidwe awoawo: makina opangira ma tubular ali ndi dongosolo losavuta, kupanga ndi kukonza bwino, ndipo amatha kupirira kuthamanga kwambiri;Kapangidwe ka riyakitala ndizovuta, ndipo kukonza ndi kukhazikitsa kumakhala kovuta.Panthawi imodzimodziyo, voliyumu ya riyakitala nthawi zambiri imakhala yaying'ono chifukwa cha mphamvu zochepa zochotsa kutentha.

Nthawi zambiri, njira ya chubu imagwiritsidwa ntchito pakuyika kwakukulu, pomwe njira ya ketulo imagwiritsidwa ntchito poyika zinthu zomwe zimapanga zinthu zambiri zamtengo wapatali monga EVA ya kalasi yapadera komanso kuchuluka kwa vinyl acetate.

Chifukwa cha mawonekedwe a njira zosiyanasiyana, njira ya ketulo imakhala ndi maunyolo ambiri okhala ndi nthambi komanso mphamvu yabwino, yomwe ili yoyenera kutulutsa utomoni wopaka.Njira ya chubu imakhala ndi kugawa kolemetsa kwa maselo, unyolo wocheperako komanso malo abwino owoneka bwino, omwe ndi oyenera kusinthidwa kukhala makanema owonda.

High kuthamanga chubu njira otsika kachulukidwe polyethylene kupanga luso

The m'mimba mwake wa riyakitala tubular zambiri 25 ~ 82mm, kutalika ndi 0.5 ~ 1.5km, mbali chiŵerengero chachikulu kuposa 10000: 1, m'mimba mwake m'mimba mwake m'mimba mwake chiŵerengero zambiri zosakwana 2mm, ndi jekete madzi ndi ntchito kuchotsa mbali ya anachita kutentha.

Mpaka pano, chitoliro ndi pafupifupi njira yomweyo pokonza otaya zofunika, kukhazikitsidwa kwa osiyana riyakitala chakudya mfundo, osiyana maselo kulemera regulator, woyambitsa ndi jekeseni malo, ndi njira zosiyanasiyana za jekeseni feteleza, processing mankhwala, kuchuluka kwa kubwerera ethylene ndi kutumiza malo, wapanga mbali zosiyanasiyana za ndondomeko.

Pakadali pano, ukadaulo wokhwima wa tubular process makamaka umaphatikizapo LyondellBasell's Lupotech T process, Exxon Mobil's tubular process ndi DSM's CTR process.

Lupotech T ndondomeko

Njira ya LyondellBasell Lupotech T imagwiritsidwa ntchito pafupifupi 60% ya mphamvu zopangira m'nyumba za zomera zotsika kwambiri za polyethylene.The kuthamanga anachita 260 ~ 310MPa, anachita kutentha 160 ~ 330 ℃, njira imodzi kutembenuka mlingo wa 35%, mankhwala osalimba 0.915 ~ 0.935g/cm3, kusungunuka index 0.15 ~ 50g/10min, limodzi mzere kupanga mphamvu 45× 104T/A, ndondomekoyi ali ndi makhalidwe asanu luso:

(1) Ukadaulo waukadaulo wa Pulse reactor umatengedwa kuti uzindikire kutsegulira kwa valve, nthawi yotsegulira ma valve ndi ma frequency osinthira kumapeto kwa riyakitala.Kugunda ntchito akhoza kusintha zotsatira kusanganikirana mu riyakitala, zabwino anachita bata, mkulu kutembenuka mlingo, kuchepetsa riyakitala khoma adhesion, kusintha kutentha kutengerapo coefficient, ndi bwino kutentha kuchotsa zotsatira za jekete madzi;

(2) Peroxides anali jekeseni m'madera osiyanasiyana a riyakitala pa mfundo zinayi kupanga zigawo zinayi za zone anachita;

(3) Ndi propylene, propanaldehyde monga molecular kulemera regulator, anayambitsa ndi kompresa polowera, ndi ethylene mu riyakitala, lonse mankhwala osiyanasiyana;

(4) Kuthamanga kwambiri kwa mpweya wozungulira mpweya kumatha kuzindikira kudziyeretsa, kusungunula ndi kutaya ntchito pogwiritsa ntchito sequential control, kuchepetsa kukhudzidwa kwa ntchito zopangira;

(5) Khazikitsani malo opangira madzi otentha kuti muchepetse kugwiritsa ntchito madzi ozizira, ndikubwezeretsanso kutentha kwapolima ndi kupanikizika kwambiri kwa gasi pazida zina.

Njira ya Exxon Mobil tubular

Kuthamanga kwa njira ya Exxon Mobil chubu ndi 250 ~ 310MPa, kutentha kwa 215 ~ 310 ℃, kutembenuka kumafika 40%, kachulukidwe ka mankhwala ndi 0.918 ~ 0.934g / cm3, ndondomeko yosungunuka ndi 0.2 ~ 50g / (10min), ndi mzere umodzi kupanga mphamvu ndi 50×104T/A.Njirayi ili ndi mawonekedwe asanu ndi limodzi aukadaulo:

(1) The yopingasa Kankhani otaya chubu riyakitala anatengera, ndi awiri a riyakitala ndi kukodzedwa sitepe ndi sitepe pamodzi axial malangizo kukhathamiritsa mlingo otaya mpweya ndi riyakitala kuthamanga dontho.Kuonjezera bata zimene, kuchepetsa kuwonongeka anachita, kuchepetsa sikelo mkati riyakitala, kusintha kutentha kutengerapo dzuwa la riyakitala;

(2) The initiator ndi jekeseni pamodzi axial malangizo a riyakitala, amene akhoza kupanga 4 ~ 6 madera anachita, kusintha mlingo kutembenuka ndi kusinthasintha ntchito, ndi lonse mankhwala osiyanasiyana;

(3) Nthawi zambiri ntchito propylene monga chowongolera kulamulira kusungunuka index, kupanga sing'anga-kachulukidwe mankhwala ntchito propanaldehyde monga regulator, owongolera kudzera mkulu kuthamanga diaphragm mpope jekeseni kwa kompresa polowera kawiri, ndiyeno ndi ethylene mu riyakitala;

(4) ntchito otentha tubular riyakitala wa ethylene vinilu patsogolo chakudya ndi ozizira multipoint kudyetsa kuphatikiza ofananira nawo, yunifolomu kutentha kumasulidwa ndipo mwina ndi zotsatira za kuchotsa kutentha anachita, riyakitala wokometsedwa jacketed kuzirala katundu, kuchepetsa kutalika kwa riyakitala. , ndi kupanga riyakitala kutentha kugawa mu yosalala, kusintha ethylene kutembenuka mlingo.Panthawi imodzimodziyo, chifukwa cha chakudya chamagulu ambiri, kupitirira kwa ethylene chakudya chambiri cha riyakitala kumachepetsedwa, kutentha kwa riyakitala yolowera kumachepa kumachepetsedwa, ndipo kugwiritsira ntchito kuthamanga kwambiri ndi nthunzi yapakati kumachepetsedwa.

(5) The chatsekedwa kutentha malamulo dongosolo madzi ntchito kupereka madzi riyakitala jekete kuchotsa kutentha anachita.Mwa kukhathamiritsa kutentha kwa madzi amadzi a jekete, kutentha kwa kutentha kumakhala bwino, kutalika kwa riyakitala kumafupikitsidwa, ndipo kutembenuka kumawonjezeka;

(6) Kubwezeretsa ndi kugwiritsa ntchito kuthamanga kwambiri ndi mphamvu yamadzimadzi otentha kwambiri yotulutsidwa kuchokera pamwamba pa cholekanitsa chapamwamba.

Njira ya CTR

DSM CTR ndondomeko anachita kuthamanga ndi 200 ~ 250MPa, kutentha anachita ndi 160 ~ 290 ℃, kutembenuka mlingo ndi 28% ~ 33.1%, pazipita akhoza kufika 38%, kachulukidwe mankhwala ndi 0.919 ~ 0.928g/cm3, kusungunuka index ndi 0.3 ~ 65g / (10min), The pazipita limodzi waya mphamvu akhoza kufika 40× 104T/A.Njirayi ili ndi mawonekedwe asanu:

(1) Kugwiritsa ntchito sanali zimachitika, ndi riyakitala ntchito kuthamanga ndi otsika ndipo amasunga zonse, otaya mlingo mu riyakitala ndi mkulu, ali wabwino scouring tingati, si kubala khoma kumamatira chodabwitsa, riyakitala safuna kuyeretsa ndi descaling, ndi kuchepetsa mtengo wa ntchito;

(2) The riyakitala chitoliro m'mimba mwake amasungidwa mosalekeza, mwachindunji "chiphaso-chiphaso" mfundo anatengera, palibe zovuta mbali mzere kudyetsa dongosolo, riyakitala ndi thandizo kapangidwe ndi yosavuta, ndi ndalama ndi m'munsi;

(3) jekete la riyakitala utakhazikika ndi madzi ozizira, omwe amatha kupanga nthunzi ndi mankhwala;

(4) Kugwiritsa ntchito peroxide woyambitsa, mankhwala gel osakaniza zikuchokera ndi yaing'ono, palibe chothandizira zotsalira, chilengedwe chitetezo zotsatira zabwino;Ma oligomer ochepera adapangidwa, ndipo njira yobwezeretsanso mpweya wozungulira idakhala yosavuta.

(5) Good ntchito zinthu ndipo palibe kusinthasintha kuthamanga pa polymerization kupanga mankhwala apamwamba, makamaka mankhwala filimu, ndi katundu kwambiri kuwala ndi katundu processing, akhoza kutulutsa osachepera filimu makulidwe a 10μm filimu mankhwala, koma osiyanasiyana mankhwala ndi yopapatiza, sangapange mankhwala a copolymer (EVA) okhala ndi index yotsika yosungunuka.

Ukadaulo wopanga wa polyethylene yotsika kachulukidwe ndi njira ya autoclave

The autoclave ndondomeko ntchito thanki riyakitala ndi oyambitsa dongosolo, ndi mbali chiŵerengero akhoza kukhala kuchokera 2:1 mpaka 20:1, voliyumu thanki riyakitala ndi 0.75 ~ 3m3.The kutentha anachita zambiri 150 ~ 300 ℃, kuthamanga anachita zambiri 130 ~ 200MPa, mlingo kutembenuka ndi 15% ~ 21%.

Popeza ketulo riyakitala ndi wandiweyani-mipanda chotengera, kutentha kutengerapo mwa riyakitala khoma ndi woletsedwa kuposa riyakitala tubular, choncho zimene kwenikweni ndi adiabatic ndondomeko, ndipo palibe kutentha zoonekeratu amachotsedwa riyakitala.The kutentha anachita makamaka ankalamulidwa ndi Mipikisano mfundo jekeseni ozizira ethylene chakudya moyenera mmene kutentha.The riyakitala ali okonzeka ndi galimoto lotengeka stirrer kuti osakaniza riyakitala yunifolomu ndi kupewa m'deralo otentha mawanga.Woyambitsa ndi organic peroxide, omwe amatha kubayidwa m'malo osiyanasiyana motsatira njira ya axial ya riyakitala kuti apange zigawo zingapo zomwe zimakhala ndi kutentha kosiyanasiyana.Palibe kusanganikirana pakati pa magawo ochitira, magwiridwe antchito osinthika ndi mitundu yosiyanasiyana yazinthu, zomwe zimatha kupanga copolymerized EVA yokhala ndi 40% vinilu acetate.

Lupotech A ndondomeko

Njira ya Lupotech A imagwiritsa ntchito riyakitala yotenthetsera, voliyumu ya riyakitala ndi 1.2m3, zida zopangira ndi zoyambitsa zimalowetsedwa mu riyakitala ndi mfundo zingapo, kuthamanga kwa zomwe zimachitika ndi 210 ~ 246MPa, kutentha kwambiri ndi 285 ℃, chowongolera ndi propylene kapena propane, yowonjezeredwa ndi cholowera chachiwiri cha kompresa, imatha kupanga Zinthu zosiyanasiyana za LDPE/EVA, Kachulukidwe kazinthu ndi 0.912 ~ 0.951g/cm3, index yosungunuka ndi 0.2 ~ 800g/ (10min), zomwe zili mu vinyl acetate zitha kukwera. mpaka 40%, njira imodzi kutembenuka mlingo wa riyakitala ndi 10% ~ 21%, pazipita limodzi mzere kapangidwe lonse akhoza kufika 12,5×104t/a.

LupotechA ndondomeko sangakhoze kokha kutulutsa utomoni wokutidwa extruded ndi unyolo zambiri nthambi ndi zotsatira zabwino, komanso kupanga mankhwala woonda mafilimu ndi yotakata maselo kulemera kugawa.Mlozera wosungunuka ndi kachulukidwe ka zinthu za LDPE/EVA zitha kuwongoleredwa bwino ndi dongosolo lowongolera la APC, ndipo zinthu zofananira zitha kupezeka.Waukulu zoweta oyamba a ndondomekoyi ndi Sirbon petrochemical, Yangzi petrochemical, Shanghai petrochemical, etc., mphamvu chipangizo ndi 10 × 104T / a.

Njira ya Exxon Mobil kettle

Njira ya thanki ya Exxon Mobil imagwiritsa ntchito chojambulira chodzipangira chokha cha 1.5m3 multizone tank.The riyakitala ali lalikulu mbali chiŵerengero, yaitali posungira nthawi, apamwamba Initiator dzuwa ndi yopapatiza mankhwala maselo kulemera kugawa, amene amathandiza kuti kupanga mankhwala woonda filimu ndi khalidwe ofanana ndi chubu ndondomeko.

Wowongolera ndi wosiyana ndi njira ya Exxon Mobil chubu.Isobutene kapena n-butane imagwiritsidwa ntchito, yomwe imakwezedwa ku 25 ~ 30MPa kudzera papampu ya diaphragm yothamanga kwambiri, jekeseni kawiri pa cholowera cha compressor, ndikulowa mu reactor ndi ethylene.

The riyakitala kuthamanga osiyanasiyana ndi lonse, ndipo pazipita anachita kuthamanga ndi 200MPa, amene akhoza kupanga LDPE homopolymer ndi otsika kusungunuka index ndi EVA copolymer ndi mkulu vinilu acetate okhutira.

Njira ya thanki ya Exxon Mobil imatha kupanga mankhwala a LDPE homopolymer okhala ndi index yosungunuka ya 0.2 ~ 150g/ (10min) ndi kachulukidwe ka 0.910 ~ 0.935g/cm3.Sungunulani index 0.2 ~ 450g/ (10min) vinilu acetate zili mpaka 35% ethylene - vinyl acetate copolymer (EVA) mankhwala.Waukulu zoweta kuyambitsa ndondomeko ndi Lianhong Gulu (omwe kale anali Shandong Hauda), mphamvu chipangizo ndi 10 × 104T / a, TRINA, mphamvu chipangizo ndi 12 × 104T / a, etc.