(Inkcazo yesishwankathelo)Phakathi kwabasebenzisi abasebenzisa iivalvu ezinkulu - ububanzi beglowubhu kubomi bemihla ngemihla.
Phakathi kwabasebenzisi abasebenzisa iivalvu zeglowubhu ezinkulu - ububanzi beglowubhu kubomi bemihla ngemihla, abantu bahlala bexela ingxaki, oko kukuthi, iivalvu zeglowubhu ezinkulu - - uxinzelelo lwamanzi. Phakathi kwabasebenzisi abasebenzisa iivalvu zokumisa ezinkulu - i-diameter yokumisa yonke imihla, abantu bahlala bechaza ingxaki, oko kukuthi, iivalvu zokumisa ezinkulu - idiameter yokumisa idla ngokuba nzima ukuvala xa zisetyenziswa kumajelo eendaba kunye nomahluko omkhulu woxinzelelo, onjengomphunga. kunye namanzi aphezulu-noxinzelelo. Indlela yokuyivala ngamandla, isoloko ifunyenwe ukuba kuya kubakho ukuvuza, kwaye kunzima ukuvala. Isizathu sale ngxaki sibangelwa kuyilo lwesakhiwo sevalve kunye nokungabikho kwetorque yokuphuma kwinqanaba lomntu.
Uhlahlelo lwezizathu zobunzima bokuvula nokuvala iivalvu ezinkulu-zecaliber
Awona mandla emveliso ethe tye okugqibela yomntu omdala yi-60-90kg, ngokuxhomekeke kumzimba ohlukeneyo.
Ngokubanzi, indlela yokuhamba kwevalve yokuvala - yokuvala yenzelwe ukuba ibephantsi kwaye ibephezulu ngaphandle. Xa umntu evala ivalve, umzimba womntu utyhala ivili lesandla ngokuthe tye ukuhambisa idisk yevalve ezantsi ukuze ivalwe. Ngeli xesha, indibaniselwano yamandla amathathu kufuneka yoyiswe, ezizezi:
1) I-axial thrust Fa;
2) Ukungqubana phakathi kokupakisha kunye ne-valve stem Fb;
3) Ukungqubana kwe-Fc phakathi kwesiqu sevalve kunye ne-valve core
Isimbuku semizuzu ngu-∑M=(Fa+Fb+Fc)R
Ingabonwa ukuba ubukhulu bedayamitha yokuphuma, kokukhona inkulu i-axial thrust force. Xa ikufuphi nemeko evaliweyo, i-axial thrust force iphantse isondele kuxinzelelo lwangempela lombhobho wombhobho (ngenxa ye-P1-P2≈P1, P2=0)
Umzekelo, ukuba i-valve yokumisa i-DN200 isetyenziswa kumbhobho womphunga we-10bar, kuphela into yokuqala evala amandla okutyhala i-axial Fa=10×πr2=3140kg, kwaye amandla omjikelezo othe tye ofunekayo ekuvaleni asondele kwisiphumo esithe tye se-axial. umzimba womntu oqhelekileyo. Umda wamandla, ngoko kunzima kakhulu kumntu omnye ukuvala ngokupheleleyo i-valve phantsi kweemeko ezinjalo.
Ngokuqinisekileyo, ezinye iifektri zicebisa ukuba iivalve ezinjalo kufuneka zifakwe kwicala elingasemva, elisombulula ingxaki yobunzima bokuvala, kodwa kuye kwavela ingxaki yobunzima bokuvula emva kokuvalwa.
Uhlalutyo lwezizathu zokuba kutheni iivalvu zeglowubhu ezinkulu - ezidayamitha zithande ukuvuza ngaphakathi
Iivalvu zokumisa ezinkulu-nobubanzi bobubanzi zidla ngokusetyenziswa kwibhoyila, iisilinda ezingundoqo, imibhobho engundoqo yomphunga, njl.njl. Ezi ndawo zinezi ngxaki zilandelayo:
1) Ngokuqhelekileyo, umahluko woxinzelelo kwindawo yokuphuma kwibhoyila mkhulu, ngoko ke isantya sokuhamba komphunga sikhulu, kwaye ukhukuliseko kunye nomonakalo kwindawo yokutywina nako kukhulu. Ukongezelela, ukusebenza kakuhle kokutsha kwebhoyili akunakuba yi-100%, okuya kubangela ukuba i-steam kwi-outlet yebhoyili ibe nomthamo omkhulu wamanzi, onokuthi ubangele umonakalo we-cavitation kunye ne-cavitation kwindawo yokutywinwa kwe-valve.
2) Ukuvalwa kwevalve kufutshane nendawo yokuphuma yebhoyila kunye ne-sub-cylinder, kuba umphunga ophuma nje kwibhoyila unezinto ezigqithiselayo ezigqithisayo, kwinkqubo yokugcwalisa, ukuba unyango lokuthambisa amanzi kwibhoyila alulunganga kakhulu. , inxalenye yeasidi iya kuhlala igalelwe. Izinto zealkali ziya kubangela umhlwa kunye nokhukuliseko kumphezulu wokutywina; ezinye izinto ezikhazimlayo zinokuncamathela kumphezulu wevalvu yokutywina kwaye zibe yikristale, nto leyo ebangela ukuba isivalo sisilele ukutywina ngokuqinileyo.
I-3) I-valve ye-inlet kunye ne-outlet ye-cylinders, kuba ubuninzi be-steam emva kwe-valve ngamanye amaxesha bukhulu okanye buncinci ngenxa yeemfuno zokuvelisa kunye nezinye izizathu, kulula ukubangela ukukhanya, i-cavitation kunye nezinye izinto xa izinga lokuhamba litshintsha kakhulu. Umphezulu wokutywina wevalve ubangela iziphumo ezinobungozi ezifana nokukhukuliseka kunye ne-cavitation.
4) Ngokubanzi, xa kuvulwe umbhobho omkhulu we-diameter, umbhobho kufuneka ufudunyezwe kwangaphambili, kwaye inkqubo yokufudumeza ifuna ngokubanzi umsinga omncinci wokudlula, ukuze umbhobho uhambe kancinane kwaye ufudunyezwe ngokulinganayo ukuya kwinqanaba elithile, kwaye ivalve yokumisa inokuvulwa ngokupheleleyo ukuphepha umbhobho okhawulezayo Ukwandiswa okugqithisileyo okubangelwa kukufudumeza, ukonakalisa inxalenye yenxalenye yoqhagamshelo. Nangona kunjalo, kule nkqubo, ukuvulwa kwevalve kuhlala kuncinci kakhulu, okubangela ukuba izinga lokukhukuliseka libe likhulu kakhulu kunesiphumo esiqhelekileyo sokusetyenziswa, kunye nokunciphisa kakhulu ubomi benkonzo yendawo yokutywinwa kwevalve.
Izisombululo kuvula nokuvalwa okunzima-iivalvu zeglowubhu ezinkulu
1) Okokuqala, kucetyiswa ukuba ukhethe i-valve-etywiniweyo evaliweyo-vala ivelufa ukunqanda ukuxhathisa kwevalve yeplunger kunye nevalve yokupakisha kwaye wenze utshintsho lube lula.
2) Undoqo wevalve kunye nesihlalo kufuneka senziwe ngezinto ezinokuxhathisa ukhukuliseko oluhle kunye neempawu zokunxiba, ezifana ne-Stellite cemented carbide.
3) Kunconywa ukuba uthabathe isakhiwo se-valve ye-flap ephindwe kabini ukuze ugweme ukukhukuliseka okugqithiseleyo ngenxa yokuvula okuncinci, okuya kuchaphazela ubomi benkonzo kunye nesiphumo sokutywinwa. Xa ivaliwe, isoloko ifunyenwe ukuba kuya kubakho ukuvuza, kwaye kunzima ukuvala. Isizathu sale ngxaki sibangelwa kuyilo lwesakhiwo sevalve kunye nokungabikho kwetorque yokuphuma kwinqanaba lomntu.
Uhlahlelo lwezizathu zobunzima bokuvula nokuvala iivalvu ezinkulu-zecaliber
Awona mandla emveliso ethe tye okugqibela yomntu omdala yi-60-90kg, ngokuxhomekeke kumzimba ohlukeneyo.
Ngokubanzi, indlela yokuhamba kwevalve yokuvala - yokuvala yenzelwe ukuba ibephantsi kwaye ibephezulu ngaphandle. Xa umntu evala ivalve, umzimba womntu utyhala ivili lesandla ngokuthe tye ukuhambisa idisk yevalve ezantsi ukuze ivalwe. Ngeli xesha, indibaniselwano yamandla amathathu kufuneka yoyiswe, ezizezi:
1) I-axial thrust Fa;
2) Ukungqubana phakathi kokupakisha kunye ne-valve stem Fb;
3) Ukungqubana kwe-Fc phakathi kwesiqu sevalve kunye ne-valve core
Isimbuku semizuzu ngu-∑M=(Fa+Fb+Fc)R
Ingabonwa ukuba ubukhulu bedayamitha yokuphuma, kokukhona inkulu i-axial thrust force. Xa ikufuphi nemeko evaliweyo, i-axial thrust force iphantse isondele kuxinzelelo lwangempela lombhobho wombhobho (ngenxa ye-P1-P2≈P1, P2=0)
Umzekelo, ukuba i-valve yokumisa i-DN200 isetyenziswa kumbhobho womphunga we-10bar, kuphela into yokuqala evala amandla okutyhala i-axial Fa=10×πr2=3140kg, kwaye amandla omjikelezo othe tye ofunekayo ekuvaleni asondele kwisiphumo esithe tye se-axial. umzimba womntu oqhelekileyo. Umda wamandla, ngoko kunzima kakhulu kumntu omnye ukuvala ngokupheleleyo i-valve phantsi kweemeko ezinjalo.
Ngokuqinisekileyo, ezinye iifektri zicebisa ukuba iivalve ezinjalo kufuneka zifakwe kwicala elingasemva, elisombulula ingxaki yobunzima bokuvala, kodwa kuye kwavela ingxaki yobunzima bokuvula emva kokuvalwa.
Uhlalutyo lwezizathu zokuba kutheni iivalvu zeglowubhu ezinkulu - ezidayamitha zithande ukuvuza ngaphakathi
Iivalvu zokumisa ezinkulu-nobubanzi bobubanzi zidla ngokusetyenziswa kwibhoyila, iisilinda ezingundoqo, imibhobho engundoqo yomphunga, njl.njl. Ezi ndawo zinezi ngxaki zilandelayo:
1) Ngokuqhelekileyo, umahluko woxinzelelo kwindawo yokuphuma kwibhoyila mkhulu, ngoko ke isantya sokuhamba komphunga sikhulu, kwaye ukhukuliseko kunye nomonakalo kwindawo yokutywina nako kukhulu. Ukongezelela, ukusebenza kakuhle kokutsha kwebhoyili akunakuba yi-100%, okuya kubangela ukuba i-steam kwi-outlet yebhoyili ibe nomthamo omkhulu wamanzi, onokuthi ubangele umonakalo we-cavitation kunye ne-cavitation kwindawo yokutywinwa kwe-valve.
2) Ukuvalwa kwevalve kufutshane nendawo yokuphuma yebhoyila kunye ne-sub-cylinder, kuba umphunga ophuma nje kwibhoyila unezinto ezigqithiselayo ezigqithisayo, kwinkqubo yokugcwalisa, ukuba unyango lokuthambisa amanzi kwibhoyila alulunganga kakhulu. , inxalenye yeasidi iya kuhlala igalelwe. Izinto zealkali ziya kubangela umhlwa kunye nokhukuliseko kumphezulu wokutywina; ezinye izinto ezikhazimlayo zinokuncamathela kumphezulu wevalvu yokutywina kwaye zibe yikristale, nto leyo ebangela ukuba isivalo sisilele ukutywina ngokuqinileyo.
I-3) I-valve ye-inlet kunye ne-outlet ye-cylinders, kuba ubuninzi be-steam emva kwe-valve ngamanye amaxesha bukhulu okanye buncinci ngenxa yeemfuno zokuvelisa kunye nezinye izizathu, kulula ukubangela ukukhanya, i-cavitation kunye nezinye izinto xa izinga lokuhamba litshintsha kakhulu. Umphezulu wokutywina wevalve ubangela iziphumo ezinobungozi ezifana nokukhukuliseka kunye ne-cavitation.
4) Ngokubanzi, xa kuvulwe umbhobho omkhulu we-diameter, umbhobho kufuneka ufudunyezwe kwangaphambili, kwaye inkqubo yokufudumeza ifuna ngokubanzi umsinga omncinci wokudlula, ukuze umbhobho uhambe kancinane kwaye ufudunyezwe ngokulinganayo ukuya kwinqanaba elithile, kwaye ivalve yokumisa inokuvulwa ngokupheleleyo ukuphepha umbhobho okhawulezayo Ukwandiswa okugqithisileyo okubangelwa kukufudumeza, ukonakalisa inxalenye yenxalenye yoqhagamshelo. Nangona kunjalo, kule nkqubo, ukuvulwa kwevalve kuhlala kuncinci kakhulu, okubangela ukuba izinga lokukhukuliseka libe likhulu kakhulu kunesiphumo esiqhelekileyo sokusetyenziswa, kunye nokunciphisa kakhulu ubomi benkonzo yendawo yokutywinwa kwevalve.
Izisombululo kuvula nokuvalwa okunzima-iivalvu zeglowubhu ezinkulu
1) Okokuqala, kucetyiswa ukuba ukhethe i-valve-etywiniweyo evaliweyo-vala ivelufa ukunqanda ukuxhathisa kwevalve yeplunger kunye nevalve yokupakisha kwaye wenze utshintsho lube lula.
2) Undoqo wevalve kunye nesihlalo kufuneka senziwe ngezinto ezinokuxhathisa ukhukuliseko oluhle kunye neempawu zokunxiba, ezifana ne-Stellite cemented carbide.
3) Kunconywa ukuba uthabathe isakhiwo se-valve ye-flap ephindwe kabini ukuze ugweme ukukhukuliseka okugqithiseleyo ngenxa yokuvula okuncinci, okuya kuchaphazela ubomi benkonzo kunye nesiphumo sokutywinwa.
Ixesha lokuposa: 2020-11-10 00:00:00