Iinkqubo zokutywina eziKhawulezayo: Nini kwaye kutheni kufuneka uzisebenzise

Intshayelelo

Itywina eliphindwe kabini loomatshini lidla ngokukhethwa xa ukuvuza kungenakuthatyathwa njengomcimbi omncinci wokugcinwa kodwa njengomngcipheko wokhuseleko, okusingqongileyo, okanye wokuthembeka. Kwiimpompo eziphatha ulwelo oluyingozi, oluguquguqukayo, olurhabaxa, okanye olungathambisanga kakuhle, ulungiselelo lwetywina eliphindwe kabini longeza umqobo wesibini wokuthintela kwaye luhlala lusebenza nenkqubo yokuxhasa ukuzinzisa iimeko zokusebenza. Eli nqaku lichaza xa olo bunzima longeziweyo lufanelekile, zeziphi izinto zenkqubo eziqhuba isigqibo, kunye nesizathu sokuba ukukhetha itywina kuchaphazela ulawulo lokukhupha umbane, ubomi bezixhobo, kunye nexesha lokungasebenzi elingacwangciswanga. Ukusuka ekunciphiseni umngcipheko ukuya kuqoqosho lokusebenza, ingxoxo ibonelela ngesakhelo esisebenzayo sokugqiba ukuba itywina eliphindwe kabini lolona khetho lufanelekileyo lobunjineli.

Kutheni Ukukhetha Izitywina Ezimbini Kubalulekile

Kwimisebenzi yanamhlanje yokuphatha ulwelo kunye nokujikeleza izixhobo,isitywino soomatshini sisebenza njengomqobo oyintlokophakathi kolwelo lwenkqubo kunye nokusingqongileyo kwangaphandle. Nangona izitywino zoomatshini ezizodwa zanele ukusetyenziswa okungenabungozi, ukucaciswa kwenkqubo yokutywina yoomatshini ephindwe kabini kuba ngumyalelo obalulekileyo wobunjineli xa umda wempazamo usondela kwi-zero. Ukukhetha iteknoloji yokutywina efanelekileyo ayisiyonto nje yokuthintela ulwelo; sisizathu esisisiseko sokhuseleko lwezityalo, ukuthobela okusingqongileyo, kunye nenzuzo yokusebenza kwexesha elide.

Isigqibo sokusebenzisa ulungiselelo lwe-dual seal ngokusisiseko sitshintsha uyilo lwenkqubo yokumpompa. Sizisa ukugcinwa kwesibini, iinkqubo zenkxaso ezincedisayo, kunye ne-fluid dynamics entsonkothileyo ekufuneka ilawulwe ngononophelo. Ukuqonda iiprofayili zomngcipheko kunye nemiphumo yokusebenza ebangela olu phuculo linyathelo lokuqala kubunjineli bezixhobo ezijikelezayo ezinoxanduva.

Ukuthembeka kunye neengozi zokhuseleko

Eyona ndlela ifanelekileyo yokulungisa izitywino eziphindwe kabini kukunciphisa umngcipheko wokungaphumeleli okukhulu. Kwizicelo zoxinzelelo oluphezulu okanye zobushushu obuphezulu ezibandakanya ulwelo olunokutsha, olunetyhefu, okanye oluqhumayo, ukungaphumeleli ngequbuliso kwesitywino sokuqala kunokukhokelela kwiingozi ezikufutshane. Ulwelo oluneendawo zokukhanya ezingaphantsi kwama-60°C (140°F), ukulinganiswa kweengozi zempilo ze-NFPA ezingama-3 okanye ama-4, okanye ezo ziqulethe ungcoliseko lomoya oluyingozi (ii-HAP) zifuna ukuthintelwa okungafunekiyo ukuthintela ukwakheka kwelifu lomphunga okanye umlilo.

Ngokusebenzisa ubuso besitywina sesibini, izixhobo ziphucula kakhulu iMean Time Between Failures (MTBF) yezixhobo, zihlala zandisa ubomi bokusebenza nge-150% ukuya kwi-300% xa kuthelekiswa nezitywina ezizodwa kwiinkonzo ezifanayo. Ukuba isitywina sangaphakathi sichaphazelekile, isitywina sangaphandle siqulathe okwethutyana ulwelo lwenkqubo okanye ulwelo lomqobo, okuvumela abaqhubi ukuba benze ukuvalwa okulawulwayo endaweni yokujongana nokukhululwa okungxamisekileyo.

Iingxaki zokukhupha umbane kunye nokuvuza kwamanzi

Imithetho engqongqo yokusingqongileyo inyanzela izakhiwo zanamhlanje ukuba zifikelele kwi-fugitive emissions eziphantse zingabikho. Izikhokelo zomthetho, ezifana ne-EPA's Method 21 e-United States okanye i-Industrial Emissions Directive eYurophu, zinyanzelisa imiqathango yokuvuza kwe-volatile organic compound (VOC), zihlala ziyalela imida engaphantsi kwama-500 parts per million (ppm), kwaye kwezinye iindawo, iphantsi njenge-50 ppm.

Itywina elinye, ngokwendlela eliyilwe ngayo, lixhomekeke kwifilimu yolwelo oluncinci ukuze luthambise ubuso balo, nto leyo ebangela ukuba kubekho umphunga omncinci (ngesiqhelo i-1 ukuya kwi-5 grams ngeyure) kunye nokukhutshwa komoya emoyeni.Izitywino zoomatshini ezimbini, ingakumbi abo basebenzisa ulwelo oluthintela umoya oluxinzelelweyo (i-API 682 Arrangement 3), basusa ngokupheleleyo ukukhutshwa kolwelo oluthintela umoya emoyeni, bethatha indawo yokuvuza okunokwenzeka ngomlinganiselo omncinci wolwelo oluthintela umoya oluthintela umoya.

Impembelelo kwimveliso nakwilondolozo

Ngaphandle kwemiyalelo yokhuseleko kunye nokusingqongileyo, ukukhethwa kwetywina kuchaphazela kakhulu ukufumaneka kwezityalo kunye nohlahlo-lwabiwo mali lokugcinwa kwazo.Ukusilela kwetywina loomatshini kubalelwa phantse kwi-70%kuzo zonke iindlela zokulungisa ipompo ye-centrifugal. Ukutshintshwa kwetywina lepompo eqhelekileyo kufuna phakathi kweeyure ezi-8 ukuya kwezingama-24 zomsebenzi kunye nexesha lokungasebenzi elihambelanayo, elinokubangela ilahleko yemveliso ukusuka kwi-$10,000 ukuya ngaphezulu kwe-$50,000 ngeyure kwiinkqubo zepetrochemical eziqhubekayo.

Izitywino ezimbini ezisebenza ngoomatshini zahlula ubuso bezitywino eziqhotyoshelweyo ngokuchanekileyo kwiimeko ezinzima zenkqubo. Ngokubonelela ngolwelo olucocekileyo, olupholileyo, nolunamafutha amaninzi, ubuso bezitywino bukhuselekile ekusebenzeni okomileyo, ukuguguleka okurhabaxa, kunye nokuphambuka kobushushu, nto leyo eyandisa kakhulu umjikelo wobomi bepompo kwaye inciphisa amanyathelo okulungisa angacwangciswanga.

Yintoni iTywina leMishini eliBini

Isitywino soomatshini esiphindwe kabini, edla ngokubizwa ngokuba yi-dual seal kwimigangatho yobunjineli yanamhlanje, inezitywino ezimbini ezizimeleyo zoomatshini ezisebenza ngochungechunge okanye ngaxeshanye kwigumbi elinye lesitywino. Olu lwakhiwo lwenza umngxuma phakathi kwezitywino ezimbini ozaliswe lulwelo lwesibini, olwaziwa ngokuba yi-buffer okanye i-barrier fluid, olusebenza ukuthambisa ubuso besitywino, ukukhupha ubushushu, kunye nokubonelela ngomaleko wesibini wokuthintela.

Uyilo olusisiseko luxhomekeke kunxibelelwano phakathi kwetywina elingaphakathi (elidibana ngqo nolwelo lwenkqubo) kunye netywina elingaphandle (elidibana nomoya). I-dynamics yolwelo lwesibini ilawula ulwahlulo oluchanekileyo kunye nobuchule bokusebenza kwendibano yesitywina esiphindwe kabini.

Inkcazo engundoqo kunye nomgaqo wokusebenza

Umgaqo wokusebenza kwesitywino esiphindwe kabini uxhomekeke ngokupheleleyo kumahluko oxinzelelweyo ogcinwe kwindawo ephakathi kwezitywino zangaphakathi kunye nezangaphandle. Xa ulwelo lwendawo lugcinwa kwindawo ephantsi koxinzelelo lwebhokisi yokuzalisa inkqubo, lubizwa ngokuba yi-"buffer fluid" (Ulungiselelo 2). Kule meko, isitywino sangaphakathi sithambisa lulwelo lwenkqubo, kwaye naluphi na ukuvuza kwenkqubo kubanjwa lulwelo lwe-buffer.

Ngokwahlukileyo koko, xa ulwelo lwe-cavity lucinezelwe kwinqanaba eliphezulu kunoxinzelelo lwenkqubo—ngokuvamile lugcinwa kwi-1.5 ukuya kwi-2.0 bar (22 ukuya kwi-29 psi) ngaphezulu koxinzelelo lwebhokisi yokuzalisa olunamandla, oludla ngokufuna amazinga okujikeleza kwegazi e-2 ukuya kwi-8 litres ngomzuzu—lubizwa ngokuba “lulwelo lwe-barrier” (Ulungiselelo 3). Phantsi kwezi meko, ulwelo lwe-barrier luthambisa zombini ubuso be-inboard kunye ne-outboard seal. Ukuba i-inboard seal iyawohloka, ulwelo lwe-barrier luvuza ngaphakathi kwinkqubo, okuqinisekisa ukuba akukho kuvuza ngaphandle kwe-process medium enobungozi.

Ukuthelekisa nezitywina ezingatshatanga

Ukuqonda umahluko ochanekileyo phakathi koqwalaselo lwesitywina esinye nesiphindwe kabini kubalulekile kuhlalutyo lweendleko zomjikelo wobomi kunye nomngcipheko. Ukongezwa kwesitywina sesibini kuyitshintsha kakhulu indlela esebenza ngayo ipompo.

Ukulungiswa kwesitywino kunye nokujonga ubuso

Iiseal ezimbini zenziwe ngeendlela ezahlukeneyo zejometri ukuze zilungelelanise imida eyahlukeneyo yendawo kunye neemfuno zoxinzelelo. Isigama esidala esithi “ukubuyelana,” “ubuso nobuso,” kunye nesithi “i-tandem” sithatyathelwe indawo luhlelo lwe-API 682, nangona iindlela ezisetyenziswa ngayo izinto zemvelo zisebalulekile.

Ukujongwa ngasemva kubeka amaringi esitywino ajikelezayo ajongane kude, nto leyo elunge kakhulu kwiincindi zomqobo ezithintela uxinzelelo oluphezulu (ezidla ngokulinganiselwa kwi-40 ukuya kwi-60 bar / 580 ukuya kwi-870 psi) kodwa iveza izixhobo zesitywino sangaphakathi kulwelo lwenkqubo. Ukujongwa buso ngobuso kwabelana ngeringi efanayo yokumanyana engashukumiyo kwaye idla ngokusetyenziswa kwiibhokisi zokuzalisa ezixineneyo. Ukujongwa ngokulandelelana (ngokuqhelekileyo yi-Arrangement 2) kubeka zombini izitywino zijonge kwicala elinye, okuvumela isitywino sangaphandle ukuba siphathe uxinzelelo olupheleleyo lwenkqubo ukuba isitywino sangaphakathi siyasilela, nto leyo eyenza kube lolona khetho lukhethwayo kwiinkonzo zokufunxa uxinzelelo oluphezulu.

Ixesha lokusebenzisa isitywina se-Double Mechanical

Ukucacisa isitywino esiphindwe kabini soomatshini kufuna ukulinganisela inkcitho ephezulu yokuqala yemali ngokuchasene neemfuno zokusebenza. Ayizizo zonke ii-fluid ezirhabaxa ezifuna ii-dual seals; ukuphuculwa kwezinto zobuso besitywino esinye kunye nezicwangciso zokugungxula kuye kwandisa amandla azo. Nangona kunjalo, imida ethile yokusebenza kunye neempawu ze-fluid zenza imiyalelo engenakuphikiswana yokuphunyezwa kwesitywino esiphindwe kabini.

Iinjineli kufuneka zihlole ngokucwangcisiweyo iipropati zomzimba ze-process fluid, imeko-bume yokusebenza, kunye nemiphumo yokungaphumeleli ukumisela ukuba utshintsho oluvela kwi-single ukuya kwi-dual seal lufanelekile na ngokwetekhnoloji nangokwezoqoqosho.

Iimeko zenkonzo ezithethelela ukusetyenziswa

Iimeko ezininzi ezinzima zenkonzo ziyayithethelela ngokwemvelo ubunzima besitywina esiphindwe kabini. Ulwelo olunezinga eliphezulu lezinto ezirhabaxa—ngokuvamile ezidlula i-10% yezinto eziqinileyo ngobunzima—luya kutshabalalisa ngokukhawuleza ubuso besitywina esinye. Isitywina esiphindwe kabini esicinezelweyo sahlula obu buso kwizinto ezirhabaxa ngokupheleleyo.

Ukongeza, ulwelo olune-lubricity ephantsi, njengee-hydrocarbons ezikhaphukhaphu ezine-viscosities engaphantsi kwe-0.5 cP, izinyibilikisi ezingatshisi, okanye amanzi ashushu, zihlala zijika zibe ngumphunga kubuso obunye be-seal, nto leyo ebangela ukuba kusebenze ukoma kunye nokuqhekeka kobushushu. Ulwelo lwenkqubo olusebenza kufutshane noxinzelelo lwalo lomphunga lufuna ukuseta i-seal kabini apho ulwelo oluzinzileyo, olutshisi olunokutshiza lunokugcina ifilimu yolwelo olubalulekileyo phakathi kobuso obujikelezayo nobungashukumiyo.

Iikhrayitheriya zokukhetha eziphambili

Iikhrayitheriya eziphambili zokukhetha zijikeleze ubushushu, uxinzelelo, ubuthi, kunye nemingcipheko yokupholisha. Usetyenziso olusebenza kumaqondo obushushu aphezulu (umz., ngaphezulu kwama-200°C / 400°F) ludla ngokufuna izitywino eziphindwe kabini ezineluphu yokupholisa yangaphandle ukugcina ubuso besitywino bungaphakathi kwemida yabo yobushushu kwaye kuthintelwe ukubola kwe-elastomer.

Ulwelo oluyi-polymerizing, oluqina okanye oluyi-crystallize xa ludibana ne-oxygen yomoya, lubangela umngeni okhethekileyo. Ukuba kusetyenziswa isitywina esinye, ukuvuza okuncinci komoya kuya kuyi-crystallize kwicala lomoya lophawu, nto leyo ekhokelela ekugugulekeni ngokukhawuleza kunye nokuxhonywa kwee-O-rings ezinamandla. Isitywina esiphindwe kabini esinolwelo oluthintelayo oluhambelanayo sithintela ukuvezwa komoya kunye nokwakheka kwe-crystallize okulandelayo.

Umsebenzi wokukhetha osebenzayo

Indlela yokusebenza esebenzayo yokukhetha isitywinakufuneka zilandele izikhokelo zoshishino ezimiselweyo, ezifana nenkqubo yokukhetha i-API 682 Annex A. Umsebenzi uqala ngokuchonga udidi lwengozi yolwelo. Ukuba ulwelo lunetyhefu kakhulu okanye luvutha kakhulu, i-Arrangement 3 (i-pressurized double seal) ikhethwa ngokuzenzekelayo.

Ukuba ulwelo alunabungozi, injineli ihlola iipropati zomzimba zolwelo (umz., imida yomphunga engaphantsi kwe-0.35 bar, i-viscosities engaphantsi kwe-0.5 cP, okanye imithwalo yamasuntswana edlula i-10%). Ukuba ezi mpawu ziwela ngaphandle kwemida yokusebenza yesitywina esinye, ukuhamba komsebenzi kuya kutshintshela kwi-Arrangement 2 (i-unpressurized dual seal) okanye kwi-Arrangement 3, kuxhomekeke ekubeni injongo ephambili kukugcina ulwelo okanye ukuhlukaniswa kobuso ngokupheleleyo.

Utshintshiselwano loBunjineli kunye nokuThotyelwa kweMithetho

Ukwenziwa kwesitywino esiphindwe kabini soomatshini akusokuze kube yinto yokuphucula izixhobo ezizimeleyo; kuyalela ukuhlanganiswa kweenkqubo ezincedisayo ezintsonkothileyo. Ezi nkqubo zilawula uxinzelelo, ubushushu, kunye nokucoceka kwe-buffer okanye ulwelo lomqobo, kwaye uyilo lwazo lubaluleke kakhulu njengesitywino ngokwaso.

Iinjineli zijongene notshintsho oluninzi xa ziyila ezi nkqubo, zilungelelanisa ukuthotyelwa ngokungqongqo kwemigangatho yamazwe ngamazwe ngokuchasene nemida yendawo ebonakalayo yesityalo, ukufumaneka kwezinto eziluncedo, kunye nokuhambelana kwezinto.

Iinkqubo zenkxaso kunye nezicwangciso ze-API

Iiseal ezimbini zixhomekeke ngokupheleleyo kwizicwangciso zepayipi ze-API ukuze zisebenze. Iseal ezimbini ezingacinezelwanga zihlala zisebenzisa i-API Plan 52, ejikeleza ulwelo lwe-buffer ukusuka kwindawo yokugcina amanzi yangaphandle (ngokuvamile inomthamo weelitha ezili-12 ukuya kwezingama-20, eyenzelwe ukukhupha ubushushu bobuso beseal obuyi-1 ukuya kwi-5 kW). Esi sicwangciso sifuna uqhagamshelo kwinkqubo yokubuyisa i-flare okanye umphunga ukuze kulawulwe ngokukhuselekileyo ukuvuza kweseal ngaphakathi.

Izitywino ezimbini ezixinzelelweyo zisebenzisa i-API Plan 53 (A, B, okanye C) okanye iPlani 54. IPlani 53A isebenzisa i-reservoir exinzelelweyo ngegesi, elinganiselwe kwi-10.3 bar (150 psi) ukuthintela ukufunxwa kwegesi kulwelo oluthintelayo. Kwiingcinezelo eziphezulu, iPlani 53B isebenzisa i-bladder accumulator, ngelixa iPlani 53C isebenzisa i-piston accumulator eqhutywa luxinzelelo lwenkqubo. IPlani 54, eyona inzima, isebenzisa i-centralized external lubrication skid ukubonelela ngolwelo oluthintelayo kwiimpompo ezininzi ngaxeshanye.

Izixhobo, ukupholisa, kunye noyilo lwemibhobho

Ukukhethwa kwezinto ngaphakathi kwenkqubo yesitywino kunye nenkxaso kufuneka kuthathelwe ingqalelo zombini indlela yokusebenza kunye nolwelo lokuthintela. Ubuso besitywino buhlala bukhiwe ngezinto eziphambili ezifana ne-sintered Silicon Carbide (SiC) okanye i-Nickel-bound Tungsten Carbide (TC) ukuze kusingathwe amaxabiso aphezulu oxinzelelo (PV), adla ngokudlula i-35,000 bar-m/s (1,000,000 psi-ft/min).

Izinto zokuvala zesibini (ii-O-rings) zilawula imida yobushushu benkqubo. Ngelixa iiFluoroelastomers eziqhelekileyo (FKM) zifanelekile ukuya kuthi ga kwi-200°C, iiPerfluoroelastomers ezikhethekileyo (FFKM) ziyafuneka kumaqondo obushushu afikelela kwi-320°C (608°F). Ngaphezu koko, uyilo lwemibhobho yeeluphu zokupholisa kufuneka lunciphise ilahleko zokungqubana; ukusebenzisa iityhubhu ezincinci kune-0.5 intshi (12.7 mm) ububanzi kunokuthintela ukuhamba kwe-thermosyphon, okukhokelela ekutshisweni kakhulu kwetywina.

Ukuthobela imithetho kunye nemigangatho yezityalo

Ukuthobela imigangatho yamazwe ngamazwe kuqinisekisa ukhuseleko olusisiseko kunye nokuthembeka kodwa kungenisa imida ebalulekileyo yobunjineli. Kwicandelo leoyile, igesi, kunye ne-petrochemical, i-API 682 (uHlelo lwesi-4) kunye ne-ISO 21049 ziyalela iimfuno ezingqongqo zobungakanani begumbi lesitywino, iinkqubo zovavanyo lwe-dynamic qualification lweeyure ezili-100, kunye nezixhobo.

Kwizakhiwo ezisebenza kwiindawo eziqhumayo, ukuthotyelwa kwe-ATEX Directive (eYurophu) okanye

Indlela Yokwenza Isigqibo Sokugqibela

Izinto ezibalulekileyo ekufuneka ziqwalaselwe

• Izigqibo ezibalulekileyo kunye nesizathu seDouble Mechanical Seal
• Iinkcukacha, ukuthobela imithetho, kunye nokuhlolwa komngcipheko okufuneka kuqinisekiswe ngaphambi kokuba uzibophelele
• Amanyathelo alandelayo asebenzayo kunye nezilumkiso abafundi abanokuzisebenzisa ngoko nangoko

Imibuzo ebuzwa qho

Isetyenziswa nini itywina yoomatshini ephindwe kabini?

Yisebenzise xa i-media epompelwayo inetyhefu, itsha, irhabaxa, ishushu kakhulu, okanye inokuba yikristale, kwaye xa ukuvuza kufuneka kuncitshiswe ngenxa yokhuseleko okanye ukuthobela imithetho.

Kutheni isitywino esiphindwe kabini singcono kunesitywino esinye esikwinkonzo enobungozi?

Yongeza i-interface yesibini yokutywina kunye ne-buffer okanye i-barrier fluid, ngoko ke ukuba i-primary seal yonakala, ukuvuza kuyagcinwa ixesha elide ngokwaneleyo ukuze kugcinwe okanye kucinywe.

Yintoni umahluko phakathi kolwelo oluyi-buffer kunye nolwelo oluyi-barrier?

Ulwelo lwe-buffer ludla ngokungacinezelwa kwaye luxhasa isitywino sangaphandle; ulwelo oluthintelayo lucinezelwa ngaphezu koxinzelelo lwegumbi lesitywino ukuthintela ulwelo lwenkqubo ukuba lungafikeleli emoyeni.

Ngaba iVictor Seals inokubonelela ngee-seal ezimbini ezihambelana ne-OEM kwiimpompo zemizi-mveliso?

Ewe. I-Victor Seals ibonelela ngezisombululo zokutywina ezihambelana ne-OEM kunye nezokutshintsha ezinye kwiimpompo ezininzi ezisetyenziswa kwiikhemikhali, zaselwandle, kwioyile nakwigesi, namanzi.

Itywina eliphindwe kabini loomatshini linganciphisa njani ixesha lokungasebenzi kwepompo?

Ngokugcina ubuso be-seal bupholile, bucocekile, kwaye buthanjiswe ngcono, kunciphisa ukoma, ukuguguleka, kunye nokuvuza ngequbuliso, okunceda ukwandisa ubomi be-seal kunye nokunciphisa ukumiswa okungacwangciswanga.