Me yasa yake da wahala a canza manyan bawul ɗin caliber? Menene mafita?

(Takaitaccen bayanin)Daga cikin masu amfani waɗanda ke amfani da manyan - diamita globe valves a rayuwar yau da kullun.

Daga cikin masu amfani da manyan - diamita globe valves a rayuwar yau da kullun, mutane sukan bayar da rahoton wata matsala, wato manyan - -ruwa matsa lamba. Daga cikin masu amfani da ke amfani da manyan bawul na tsayawar diamita a kullum, mutane sukan bayar da rahoton wata matsala, wato manyan- da ruwa mai yawa - matsa lamba. Yadda za a rufe shi da ƙarfi, koyaushe ana gano cewa za a sami ɗigogi, kuma yana da wuya a rufe. Dalilin wannan matsala yana faruwa ne ta hanyar tsarin tsarin bawul da kuma rashin ƙarancin matakan fitarwa na ɗan adam.

Binciken dalilai na wahalar buɗewa da rufe manyan - valves caliber

Ƙarshen ƙarfin fitarwa na kwance na matsakaicin babba shine 60-90kg, ya danganta da nau'ikan jiki daban-daban.

Gabaɗaya, an ƙera alkiblar ƙwanƙwasa - kashe bawul ɗin don zama ƙasa da ƙasa a ciki da sama. Lokacin da mutum ya rufe bawul ɗin, jikin ɗan adam yana tura ƙafar hannu a kwance don matsar da faifan bawul ɗin ƙasa don cimma rufewa. A wannan lokaci, akwai bukatar a shawo kan hadakar karfi guda uku, wato:

1) Axial tura Fa;

2) Tsayawa tsakanin shiryawa da bawul mai tushe Fb;

3) Tuntuɓi ɓangarorin Fc tsakanin bawul mai tushe da maɓallin bawul

Jimlar lokacin shine ∑M=(Fa+Fb+Fc)R

Ana iya ganin cewa mafi girma diamita na fitarwa, mafi girma da ƙarfin axial. Lokacin da yake kusa da yanayin da aka rufe, ƙarfin motsa jiki na axial yana kusan kusa da ainihin matsa lamba na cibiyar sadarwar bututu (saboda P1 - P2≈P1, P2=0)

Misali, idan aka yi amfani da bawul tasha DN200 akan bututun tururi mai lamba 10, abu na farko ne kawai zai rufe karfin turawa axial Fa=10×πr2=3140kg, kuma karfin da'irar da ake bukata don rufewa yana kusa da fitowar dawafi na kwance. jikin mutum na al'ada. Iyakar ƙarfi, don haka yana da matukar wahala mutum ɗaya ya rufe bawul ɗin gaba ɗaya a ƙarƙashin irin waɗannan yanayi.

Tabbas, wasu masana'antu suna ba da shawarar cewa yakamata a sanya irin waɗannan bawul ɗin ta hanyar baya, wanda ke magance matsalar wahalar rufewa, amma matsalar wahalar buɗewa bayan an rufe ta ta bayyana.

Binciken dalilan da ya sa manyan - diamita globe bawul suna da wuyar zubar da ciki

Ana amfani da manyan bawul ɗin tsayawar diamita gabaɗaya a cikin kantunan tukunyar jirgi, manyan ƙananan silinda, bututun tururi, da sauransu. Waɗannan wuraren suna da matsaloli masu zuwa:

1) Gabaɗaya, bambance-bambancen matsa lamba a madaidaicin tukunyar jirgi yana da girma sosai, don haka yawan kwararar tururi shima ya fi girma, kuma zaizayar ƙasa da lalacewar wurin rufewa shima ya fi girma. Bugu da ƙari, ƙwarewar konewa na tukunyar jirgi ba zai iya zama 100% ba, wanda zai haifar da tururi a mashigin tukunyar jirgi don samun babban abun ciki na ruwa, wanda zai iya haifar da cavitation da cavitation lalacewa ga valve sealing surface.

2) Ga kushe - bawul ɗin da ke kusa da madaidaicin tukunyar tukunyar jirgi da silinda, saboda tururin da ke fitowa daga tukunyar jirgi yana da yanayin zafi mai tsauri, a cikin aiwatar da jikewa, idan maganin tausasa ruwan tukunyar ba shi da kyau sosai. , wani ɓangare na acid zai sau da yawa a haɗe. Abubuwan Alkali za su haifar da lalata da yashewa zuwa saman rufewa; wasu abubuwa masu kyalli kuma na iya mannewa saman bawul ɗin rufewa da yin crystallize, yana haifar da bawul ɗin ya kasa rufewa sosai.

3) Ƙaƙƙarfan mashigai da maɓuɓɓugar ruwa na silinda, saboda yawan tururi bayan bawul wani lokaci yana da girma ko karami saboda bukatun samarwa da wasu dalilai, yana da sauƙi don haifar da walƙiya, cavitation da sauran abubuwan mamaki lokacin da yawan ruwa ya canza sosai. Wurin rufewar bawul yana haifar da illa mai lalacewa kamar yashwa da cavitation.

4) Gabaɗaya, idan aka buɗe bututun mai girma - diamita, bututun yana buƙatar dumama bututun, kuma tsarin zafin jiki gabaɗaya yana buƙatar ɗan ƙaramin tururi don wucewa, ta yadda bututun ya kasance mai zafi a hankali kuma daidai gwargwado zuwa wani matsayi. za'a iya buɗe bawul ɗin tsayawa gabaɗaya don guje wa bututun gaggawar Faɗawa da yawa da ke haifar da dumama, lalata ɓangaren haɗin gwiwa. Koyaya, a cikin wannan tsari, buɗewar bawul sau da yawa ƙanƙanta ne, yana haifar da ƙimar zaizayarwa ya zama mafi girma fiye da tasirin amfani na yau da kullun, kuma da gaske yana rage rayuwar sabis na filin rufe bawul.

Magani ga wahalar buɗewa da rufe manyan - diamita globe valves

1) Da farko, ana ba da shawarar a zaɓi ƙwanƙwasa - rufewa - kashe bawul don guje wa juriyar juriya na bawul ɗin plunger da bawul ɗin shiryawa da sauƙaƙa sauyawa.

2) Bawul core da wurin zama dole ne a yi da kayan da kyau yashwa juriya da lalacewa kaddarorin, kamar Stellite cemented carbide.

3) An ba da shawarar yin amfani da tsarin murɗa mai bawul guda biyu don kauce wa yashwa mai yawa saboda ƙananan buɗewa, wanda zai shafi rayuwar sabis da tasirin rufewa. Lokacin da aka rufe, koyaushe ana gano cewa za a sami ɗigogi, kuma yana da wuya a rufe. Dalilin wannan matsala yana faruwa ne ta hanyar tsarin tsarin bawul da kuma rashin ƙarancin matakan fitarwa na ɗan adam.

Binciken dalilai na wahalar buɗewa da rufe manyan - valves caliber

Ƙarshen ƙarfin fitarwa na kwance na matsakaicin babba shine 60-90kg, ya danganta da nau'ikan jiki daban-daban.

Gabaɗaya, an ƙera alkiblar ƙwanƙwasa - kashe bawul ɗin don zama ƙasa da ƙasa a ciki da sama. Lokacin da mutum ya rufe bawul ɗin, jikin ɗan adam yana tura ƙafar hannu a kwance don matsar da faifan bawul ɗin ƙasa don cimma rufewa. A wannan lokaci, akwai bukatar a shawo kan hadakar karfi guda uku, wato:

1) Axial tura Fa;

2) Tsayawa tsakanin shiryawa da bawul mai tushe Fb;

3) Tuntuɓi ɓangarorin Fc tsakanin bawul mai tushe da maɓallin bawul

Jimlar lokacin shine ∑M=(Fa+Fb+Fc)R

Ana iya ganin cewa mafi girma diamita na fitarwa, mafi girma da ƙarfin axial. Lokacin da yake kusa da yanayin da aka rufe, ƙarfin motsa jiki na axial yana kusan kusa da ainihin matsa lamba na cibiyar sadarwar bututu (saboda P1 - P2≈P1, P2=0)

Misali, idan aka yi amfani da bawul tasha DN200 akan bututun tururi mai lamba 10, abu na farko ne kawai zai rufe karfin turawa axial Fa=10×πr2=3140kg, kuma karfin da'irar da ake bukata don rufewa yana kusa da fitowar dawafi na kwance. jikin mutum na al'ada. Iyakar ƙarfi, don haka yana da matukar wahala mutum ɗaya ya rufe bawul ɗin gaba ɗaya a ƙarƙashin irin waɗannan yanayi.

Tabbas, wasu masana'antu suna ba da shawarar cewa yakamata a sanya irin waɗannan bawul ɗin ta hanyar baya, wanda ke magance matsalar wahalar rufewa, amma matsalar wahalar buɗewa bayan an rufe ta ta bayyana.

Binciken dalilan da ya sa manyan - diamita globe bawul suna da wuyar zubar da ciki

Ana amfani da manyan bawul ɗin tsayawar diamita gabaɗaya a cikin kantunan tukunyar jirgi, manyan ƙananan silinda, bututun tururi, da sauransu. Waɗannan wuraren suna da matsaloli masu zuwa:

1) Gabaɗaya, bambance-bambancen matsa lamba a madaidaicin tukunyar jirgi yana da girma sosai, don haka yawan kwararar tururi shima ya fi girma, kuma zaizayar ƙasa da lalacewar wurin rufewa shima ya fi girma. Bugu da ƙari, ƙwarewar konewa na tukunyar jirgi ba zai iya zama 100% ba, wanda zai haifar da tururi a mashigin tukunyar jirgi don samun babban abun ciki na ruwa, wanda zai iya haifar da cavitation da cavitation lalacewa ga valve sealing surface.

2) Ga kushe - bawul ɗin da ke kusa da madaidaicin tukunyar tukunyar jirgi da silinda, saboda tururin da ke fitowa daga tukunyar jirgi yana da yanayin zafi mai tsauri, a cikin aiwatar da jikewa, idan maganin tausasa ruwan tukunyar ba shi da kyau sosai. , wani ɓangare na acid zai sau da yawa a haɗe. Abubuwan Alkali za su haifar da lalata da yashewa zuwa saman rufewa; wasu abubuwa masu kyalli kuma na iya mannewa saman bawul ɗin rufewa da yin crystallize, yana haifar da bawul ɗin ya kasa rufewa sosai.

3) Ƙaƙƙarfan mashigai da maɓuɓɓugar ruwa na silinda, saboda yawan tururi bayan bawul wani lokaci yana da girma ko karami saboda bukatun samarwa da wasu dalilai, yana da sauƙi don haifar da walƙiya, cavitation da sauran abubuwan mamaki lokacin da yawan ruwa ya canza sosai. Wurin rufewar bawul yana haifar da illa mai lalacewa kamar yashwa da cavitation.

4) Gabaɗaya, idan aka buɗe bututun mai girma - diamita, bututun yana buƙatar dumama bututun, kuma tsarin zafin jiki gabaɗaya yana buƙatar ɗan ƙaramin tururi don wucewa, ta yadda bututun ya kasance mai zafi a hankali kuma daidai gwargwado zuwa wani matsayi. za'a iya buɗe bawul ɗin tsayawa gabaɗaya don guje wa bututun gaggawar Faɗawa da yawa da ke haifar da dumama, lalata ɓangaren haɗin gwiwa. Koyaya, a cikin wannan tsari, buɗewar bawul sau da yawa ƙanƙanta ne, yana haifar da ƙimar zaizayarwa ya zama mafi girma fiye da tasirin amfani na yau da kullun, kuma da gaske yana rage rayuwar sabis na filin rufe bawul.

Magani ga wahalar buɗewa da rufe manyan - diamita globe valves

1) Da farko, ana ba da shawarar a zaɓi ƙwanƙwasa - rufewa - kashe bawul don guje wa juriyar juriya na bawul ɗin plunger da bawul ɗin shiryawa da sauƙaƙa sauyawa.

2) Bawul core da wurin zama dole ne a yi da kayan da kyau yashwa juriya da lalacewa kaddarorin, kamar Stellite cemented carbide.

3) Ana ba da shawarar yin amfani da tsarin ɓoyayyiyar bawul guda biyu don kauce wa yashwa mai yawa saboda ƙananan buɗewa, wanda zai shafi rayuwar sabis da tasirin rufewa.


Lokacin aikawa: 2020-11-10:00:00
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