Control Valve Phokoso ndi Cavitation

Mawu Oyamba

Phokoso limapangidwa kuchokera kukuyenda kwamadzimadzi kudzera mu valve.Ndi pamene phokoso losafunikira limatchedwa 'phokoso'.Ngati phokosolo liposa milingo ina ndiye kuti likhoza kukhala lowopsa kwa ogwira ntchito.Phokoso ndi chida chabwino chodziwira matenda.Pamene phokoso kapena phokoso limapangidwa ndi kukangana, phokoso lalikulu limasonyeza kuwonongeka komwe kungachitike mkati mwa valve.Kuwonongeka kungayambitsidwe ndi kukangana komweko kapena kugwedezeka.

Pali magwero atatu akuluakulu a phokoso:

-Kugwedezeka kwamakina
- Phokoso la Hydrodynamic
- Phokoso la Aerodynamic

Mechanical Vibration

Kugwedezeka kwa makina ndi chizindikiro chabwino cha kuwonongeka kwa zigawo za valve.Chifukwa phokoso lopangidwa nthawi zambiri limakhala locheperako komanso pafupipafupi, nthawi zambiri si vuto lachitetezo kwa ogwira ntchito.Kugwedezeka ndi vuto lalikulu la ma valve oyambira poyerekeza ndi ma valve a khola.Mavavu a khola ali ndi malo okulirapo ochirikiza motero samayambitsa vuto la kugwedezeka.

Phokoso la Hydrodynamic

Phokoso la Hydrodynamic limapangidwa mumayendedwe amadzimadzi.Pamene madzimadzi akudutsa choletsa ndi kusintha kuthamanga kumachitika n'zotheka kuti madzimadzi amapanga nthunzi thovu.Izi zimatchedwa kung'anima.Cavitation ndi vuto, kumene thovu kupanga koma kenako kugwa.Phokoso lopangidwa nthawi zambiri silikhala lowopsa kwa ogwira ntchito, koma ndi chidziwitso chabwino
za kuwonongeka zotheka chepetsa zigawo zikuluzikulu.

Phokoso la Aerodynamic

Phokoso la Aerodynamic limapangidwa ndi chipwirikiti cha mpweya ndipo ndiye gwero lalikulu la phokoso.Phokoso lomwe limapangidwa likhoza kukhala lowopsa kwa ogwira ntchito, ndipo zimadalira kuchuluka kwa kuthamanga komanso kutsika kwamphamvu.

Cavitation ndi Flashing

Kuthwanima

Kuwala ndi gawo loyamba la cavitation.Komabe, ndizotheka kuti kung'anima kuchitike palokha popanda cavitation kuchitika.
Kuthwanima kumachitika mumadzi oyenda pamene madzi ena asintha kukhala nthunzi.Izi zimabweretsedwa ndi kuchepetsa kukakamiza kukakamiza madzi kuti asinthe kukhala mpweya.Kuchepetsa kupanikizika kumayambitsidwa ndi kuletsa kwa mtsinje wothamanga kutulutsa kuthamanga kwapamwamba kupyolera muzoletsa kotero kuti kuchepetsa kupanikizika.
Mavuto akulu awiri omwe amayambitsa kung'anima ndi awa:

- Kukokoloka
- Kuchepetsa mphamvu

Kukokoloka

Pamene kung'anima kumachitika, kutuluka kwa valavu kumapangidwa ndi madzi ndi nthunzi.Ndi kung'anima kowonjezereka, nthunziyo imanyamula madziwo.Pamene liwiro la flowstream likuwonjezeka, madziwo amakhala ngati tinthu tating'onoting'ono tating'onoting'ono tating'onoting'ono ta mkati mwa valve.Kuthamanga kwa kutuluka kwa mpweya kumatha kuchepetsedwa poonjezera kukula kwa valve yomwe ingachepetse kuwonongeka.Njira zogwiritsira ntchito zida zolimba ndi njira ina.Ma valve a ngodya ndi oyenera kugwiritsa ntchito izi chifukwa kunyezimira kumachitika kumunsi kwa mtsinje kutali ndi gulu la trim ndi valve.

Kuchepetsa Mphamvu

Pamene flowstream pang'ono kusintha nthunzi nthunzi, monga mu nkhani ya kung'anima, danga kuti amatenga kuchuluka.Chifukwa cha kuchepa kwa malo omwe alipo, mphamvu ya valavu yogwiritsira ntchito maulendo akuluakulu ndi yochepa.Kutuluka kwatsamwitsidwa ndi mawu omwe amagwiritsidwa ntchito pamene mphamvu yothamanga imakhala yochepa motere

Cavitation

Cavitation n'chimodzimodzi ndi kung'anima kupatula kuti kuthamanga ndi anachira mu kubwereketsa flowstream kotero kuti nthunzi anabwerera madzi.Kuthamanga kwakukulu ndi kuthamanga kwa nthunzi wamadzimadzi.Kung'anima kumachitika kumunsi kwa nthiti ya valve pamene kuthamanga kumatsika pansi pa nthunzi, ndiyeno ming'oma imagwa pamene kuthamanga kumabwereranso pamwamba pa nthunzi.Pamene thovu likugwa, amatumiza mafunde owopsa mumtsinje wothamanga.Chodetsa nkhaŵa chachikulu ndi cavitation ndi kuwonongeka kwa nthiti ndi thupi la valve.Izi zimayamba chifukwa cha kugwa kwa thovu.Malingana ndi momwe cavitation imapangidwira, zotsatira zake zimatha kuchokera ku a
Phokoso laling'ono lokhala ndi phokoso lochepa kapena lopanda kuwonongeka kwa chipangizo choyikirapo phokoso lalikulu lomwe limayambitsa kuwonongeka kwakukulu kwa valavu ndi mapaipi otsika pansi Kutsekemera kwakukulu kumakhala phokoso ndipo kumamveka ngati miyala ikudutsa mu valve.
Phokoso lopangidwa silili lodetsa nkhawa kwambiri poyang'ana chitetezo chamunthu, chifukwa nthawi zambiri limakhala lochepa pafupipafupi komanso mwamphamvu ndipo motero sizibweretsa vuto kwa ogwira ntchito.