Kutheni iivalve zebhola zinokuvulwa kwaye zivalwe ngokukhawuleza?

Isizathu sokubaiivalve zebholabanokufikelela ekuvuleni ngokukhawuleza kunye nokuvala ubuxoki kwisakhiwo sabo esisodwa somatshini kunye noyilo lwe-fluid dynamics. Icandelo lokuvula kunye nokuvala yingqukuva enesetyhula ngomngxuma wokutyhutyha, enokuthi iqhutywe yi-valve stem ukujikeleza i-90 degrees malunga ne-axis yayo ukugqiba ukutshintshela kombuso - xa umngxuma wokudlula we-sphere uhambelana ne-axis yombhobho, ivalve ivuliwe ngokupheleleyo; Emva kokujikeleza i-90 degrees, i-hole-hole i-perpendicular kumbhobho kwaye i-valve ivalwe ngokupheleleyo. Olu luyilo lwe "quarter turn" lwenza lula ukuvula kunye nokuvala isenzo kwintshukumo ejikelezayo ngaphakathi kwenqwelomoya enye, inciphisa kakhulu indlela yokusebenza.

Ukususela kumbono wesakhiwo soomatshini, ibhola yeivalve yebholawamkela "umfowunelwa welayini" okanye "uqhagamshelwano lomphezulu" indlela yokutywina ngesitulo sevalvu. Ukuthatha ivalve yebhola edadayo njengomzekelo, ibhola iya kuhambela kwisitulo sevalve yokuphuma phantsi koxinzelelo lwesixhobo esiphakathi, yenze itywina eliziqinisayo kwaye inciphise ukuxhathisa kokukhuhlana ngexesha lokuvula nokuvala; I-valve yebhola esisigxina ixhaswa yi-bearings ye-valve ye-valve ephezulu kunye nesezantsi, ukwenzela ukuba ibhola idinga kuphela ukunqoba amandla amancinci phakathi kwesihlalo sevalve kunye nebhola xa ijikeleza. Olu yilo lwenza ukuba i-sphere iphantse ingachatshazelwa kukunganyangeki kwamanzi ngexesha lokujikeleza, ngokukodwa ilungele iimeko zoxinzelelo oluphezulu. Ngokomzekelo, kwishishini le-petrochemical, i-DN300 i-valve yebhola ye-pneumatic inokugqiba ukuvula nokuvala ngemizuzwana eyi-0.5, ngokukhawuleza kakhulu kuneevalve zesango okanye iivalve zeglobhu ezifuna ukujikeleza okuninzi.

Iimpawu ze-fluid dynamics ziphucula ngakumbi amandla okuphendula ngokukhawuleza kweivalve yebhola. Umjelo wokuqukuqela wevalve yebhola egcweleyo uhambelana ngokupheleleyo nedayamitha yangaphakathi yombhobho, kwaye akukho phantse ukuhla koxinzelelo xa ulwelo ludlula. Akuyi kubakho ukuchasana okongeziweyo ngenxa ye-inertia ye-medium ngexesha lokuvula nokuvalwa. Ngokwahlukileyo, i-disc ye-butterfly valve inokuthintela ezinye zeendlela zokuhamba ngexesha lokujikeleza, okubangela ukuba i-fluid iqhube i-reverse thrust kwi-disc kwaye ichaphazele isantya sokuvula nokuvala; Isango le-valve yesango kufuneka liphakanyiswe ngokuthe nkqo kwaye lithotywe, kunye ne-stroke ende kwaye lichaphazeleka lula yi-viscosity ye-medium. Idatha yovavanyo ibonisa ukuba kwimibhobho ye-DN200, ixesha lokuvula kunye nokuvala i-valve yebhola yi-40% mfutshane kunaleyo ye-butterfly valves yenkcazo efanayo kunye ne-70% emfutshane kuneevalve zesango.

Ukongezelela, indlela yokuqhuba i-valve yebhola ikwabonelela ngenkxaso yokuvula nokuvalwa kwayo ngokukhawuleza. I-pneumatic, i-electric, okanye i-hydraulic actuators inokukhupha ngokukhawuleza i-torque ephezulu, iqhube i-sphere ukugqiba ukujikeleza kwe-90 degree ngaphakathi kwe-0.1 imizuzwana. Ngokomzekelo, kwinkqubo yokuvala ngokukhawuleza kwegesi yendalo, i-valve yebhola ye-pneumatic inokunqumla ukuhamba komoya ngaphakathi kwemizuzwana ye-0.3 ngokufumana iimpawu zombane, ukukhusela ngokufanelekileyo izingozi ukuba zinyuke. Eli "nqanaba le-millisecond" lokuphendula lingenakuthelekiswa nezivalo zezandla zemveli.