Uma uhamba uzungeza indawo yokusebenzela yezitshalo zamakhemikhali, nakanjani uzobona amanye amapayipi afakwe ama-valve anamakhanda ayindilinga, angamavalvu alawulayo.
I-valve yokulawula i-diaphragm ye-pneumatic
Ungathola ulwazi oluthile mayelana ne-valve elawulayo egameni layo.Igama eliyisihluthulelo elithi “isimiso” liwukuthi uhla lwayo lokulungisa lungalungiswa ngokungafanele phakathi kuka-0 no-100%.
Abangane abacophelelayo kufanele bathole ukuthi kunomshini olenga ngaphansi kwekhanda levalvu yokulawula ngayinye.Abajwayelene nayo kumele bazi ukuthi lena yinhliziyo yevalvu elawulayo, i-valve positioner.Ngalesi sisetshenziswa, ivolumu yomoya engena ekhanda (ifilimu yomoya) ingalungiswa.Lawula ngokunembile indawo ye-valve.
Ama-valve positioners afaka phakathi ama-positioners ahlakaniphile kanye ne-mechanical positioners.Namuhla sixoxa ngomshini wokugcina wokumisa indawo, ofanayo nalowo oboniswe esithombeni.
Umgomo wokusebenza we-mechanical pneumatic valve positioner
Umdwebo wesakhiwo sendawo yevalvu
Isithombe sichaza ngokuyisisekelo izingxenye ze-mechanical pneumatic valve positioner ngayinye ngayinye.Isinyathelo esilandelayo ukubona ukuthi isebenza kanjani?
Umthombo womoya uvela emoyeni ocindezelwe wesiteshi se-air compressor.Kunevalvu yokunciphisa umfutho womoya phambi kwendawo yokungena yomthombo womoya ye-valve positioner ukuze kuhlanzwe umoya ocindezelwe.Umthombo womoya ophuma lapho kuphuma khona i-valve yokunciphisa ingcindezi ungena usuka endaweni yokubeka i-valve.Inani lomoya ongena ekhanda le-membrane le-valve linqunywa ngokusho kwesignali yokuphuma yesilawuli.
Ukukhishwa kwesignali kagesi ngesilawuli kungu-4~20mA, futhi isignali yomoya ingu-20Kpa~100Kpa.Ukuguqulwa kusuka kusignali kagesi kuya kusignali ye-pneumatic kwenziwa ngesiguquli sikagesi.
Uma isignali kagesi ephumayo yisilawuli iguqulwa ibe isignali yegesi ehambisanayo, isignali yegesi eguquliwe ibe seyenza ngokuvuthela.I-Lever 2 izungeza i-fulcrum, futhi ingxenye engezansi ye-lever 2 iya kwesokudla futhi isondele emlonyeni.Ingcindezi yangemuva ye-nozzle iyanda, futhi ngemva kokukhuliswa yi-amplifier ye-pneumatic (ingxenye enophawu olungaphansi kwesithombe), ingxenye yomthombo womoya ithunyelwa ekamelweni lomoya le-diaphragm ye-pneumatic.Isiqu se-valve sithwala i-valve core siye phansi futhi ngokuzenzakalelayo sivula i-valve.ube mncane.Ngalesi sikhathi, induku yempendulo (induku yokushwiba esesithombeni) exhunywe esiqwini se-valve iya phansi izungeze i-fulcrum, okwenza ukuthi ingaphambili le-shaft liye phansi.I-eccentric cam exhunywe kuyo izungeza ngokuphambene newashi, futhi irola lizungeza ngokwewashi bese liya kwesokunxele.Yelula intwasahlobo yempendulo.Njengoba ingxenye engezansi yesiphethu sempendulo yelula i-lever 2 futhi ihambela kwesokunxele, izofinyelela ibhalansi yamandla ngomfutho wesignali osebenza ku-bellows, ngakho-ke i-valve igxilwe endaweni ethile futhi ayinyakazi.
Ngalesi singeniso esingenhla, kufanele ube nokuqonda okuthile kwesimo sevalvu sikamishini.Uma unethuba, kungcono kakhulu ukuyiqaqa kanye ngenkathi uyisebenza, futhi ujulise indawo yengxenye ngayinye yesihleli kanye negama lengxenye ngayinye.Ngakho-ke, ingxoxo emfushane yama-valve emishini iyaphela.Okulandelayo, sizokwandisa ulwazi ukuze sithole ukuqonda okujulile kwama-valve okulawula.
ukwandiswa kolwazi
Ukunwetshwa kolwazi
Ivalvu elawula i-diaphragm yomoya osesithombeni iwuhlobo oluvalwe ngomoya.Abanye abantu bayabuza, kungani?
Okokuqala, bheka isiqondiso se-air inlet ye-aerodynamic diaphragm, okuwumphumela omuhle.
Okwesibili, bheka isiqondiso sokufakwa kwe-valve core, okuyinto enhle.
Umthombo wokungenisa komoya we-diaphragm we-pneumatic diaphragm, i-diaphragm icindezela phansi imithombo eyisithupha embozwe i-diaphragm, ngaleyo ndlela iphushe isiqu se-valve siye phansi.Isiqu se-valve sixhunywe kumongo we-valve, futhi i-valve core ifakwe phambili, ngakho umthombo womoya i-valve Hambisa endaweni yokucisha.Ngakho-ke, kubizwa ngokuthi i-valve yokuvala umoya.Ukuvuleka kwephutha kusho ukuthi lapho ukunikezwa komoya kuphazamiseka ngenxa yokwakhiwa noma ukugqwala kwepayipi lomoya, i-valve isethwe kabusha ngaphansi kwamandla okusabela entwasahlobo, futhi i-valve isendaweni evuleke ngokugcwele futhi.
Ungayisebenzisa kanjani i-valve yokuvala umoya?
Indlela yokuyisebenzisa ibhekwa ngokombono wokuphepha.Lesi yisimo esidingekayo sokukhetha ukuthi uvule noma uvale umoya.
Isibonelo: isigubhu sesitimu, enye yezinto ezisetshenziswa kubhayela, kanye nevalvu elawulayo esetshenziswa ohlelweni lokuphakelwa kwamanzi kumele kuvalwe ngomoya.Kungani?Isibonelo, uma umthombo wegesi noma ukunikezwa kwamandla kuphazamiseka ngokuzumayo, isithando somlilo sisavutha ngamandla futhi sishisa ngokuqhubekayo amanzi esigubhu.Uma igesi isetshenziselwa ukuvula i-valve yokulawula futhi amandla aphazamisekile, i-valve izovalwa futhi isigubhu sizoshiswa ngemizuzu ngaphandle kwamanzi (ukuvutha okomile).Lokhu kuyingozi kakhulu.Akunakwenzeka ukubhekana nokuhluleka kwe-valve elawulayo ngesikhathi esifushane, okuzoholela ekuvaleni kwesithando somlilo.Izingozi zenzeka.Ngakho-ke, ukugwema ukushisa okomile noma ngisho nezingozi zokuvala isithando somlilo, i-valve yokuvala igesi kufanele isetshenziswe.Nakuba amandla ephazamisekile futhi i-valve elawulayo isendaweni evuleke ngokugcwele, amanzi anikezwa ngokuqhubekayo emgqonyeni we-steam, kodwa ngeke kubangele imali eyomile esigubhu se-steam.Kusekhona isikhathi sokubhekana nokuhluleka kwe-valve elawulayo futhi isithando somlilo ngeke sivalwe ngokuqondile ukuze sibhekane nakho.
Ngalezi zibonelo ezingenhla, kufanele manje ube nokuqonda kokuqala kokuthi ungakhetha kanjani amavalvu okulawula avula umoya namavalvu okulawula ukuvala umoya!
Ukwandiswa kolwazi 2
Lolu lwazi oluncane lumayelana nezinguquko emiphumeleni emihle nemibi yesitholi.
I-valve elawulayo esithombeni isebenza kahle.I-eccentric cam inezinhlangothi ezimbili u-AB, u-A umele uhlangothi olungaphambili kanti u-B umele uhlangothi.Ngalesi sikhathi, uhlangothi luka-A lubheke ngaphandle, futhi ukuphendulela uhlangothi luka-B ngaphandle kuwukusabela.Ngakho-ke, ukushintsha isiqondiso esingu-A esithombeni siye esiqondisweni esingu-B kuyisimo sevalvu yokusabela.
Isithombe sangempela esisesithombeni siyindawo yevalvu esebenza kahle, kanti isilawuli esiphumayo singu-4-20mA.Uma i-4mA, isignali yomoya ehambisanayo ingu-20Kpa, futhi i-valve elawulayo ivuleke ngokugcwele.Uma i-20mA, isignali yomoya ehambisanayo ingu-100Kpa, futhi i-valve elawulayo ivalwe ngokugcwele.
Ama-valve ama-mechanical positioners anezinzuzo kanye nokubi
Izinzuzo: ukulawula okunembile.
Ukubi: Ngenxa yokulawula umoya, uma isignali yendawo izobuyiselwa egumbini lokulawula eliphakathi, idivayisi eyengeziwe yokuguqula ugesi iyadingeka.
Ukunwetshwa kolwazi lwesithathu
Izindaba ezihlobene nokuhlukaniswa kwansuku zonke.
Ukwehluleka ngesikhathi sokukhiqiza kujwayelekile futhi kuyingxenye yenqubo yokukhiqiza.Kodwa ukuze kugcinwe izinga, ukuphepha, kanye nenani, izinkinga kufanele zisingathwe ngesikhathi.Leli inani lokuhlala enkampanini.Ngakho-ke, sizocubungula kafushane izingqinamba eziningi ezihlangatshezwane nazo:
1. Umphumela we-valve positioner ufana nofudu.
Ungavuli ikhava yangaphambili ye-valve positioner;lalela umsindo ukuze ubone ukuthi ipayipi lomthombo womoya liqhekekile futhi libangela ukuvuza.Lokhu kungahlulelwa ngeso lenyama.Futhi lalela ukuthi ukhona yini umsindo ovuzayo ophuma egumbini lokufaka lomoya.
Vula ikhava yangaphambili ye-valve positioner;1. Ukuthi i-orifice engashintshi ivinjiwe yini;2. Hlola ukuma kwe-baffle;3. Hlola ukunwebeka kwentwasahlobo yempendulo;4. Hlukanisa i-valve yesikwele bese uhlola i-diaphragm.
2. Ukukhishwa kwesimo se-valve kuyabhora
1. Hlola ukuthi ingcindezi yomthombo womoya ingaphakathi kwebanga elishiwo nokuthi ingabe i-feedback rod iwile yini.Lesi isinyathelo esilula.
2. Hlola ukuthi izintambo zomugqa wesiginali zilungile yini (izinkinga eziphakama kamuva azinakwa)
3. Kukhona yini okunamathiselwe phakathi kwekhoyili nezikhali?
4. Hlola ukuthi ukuma okuhambisanayo kwenozzle kanye ne-baffle kufanelekile.
5. Hlola isimo sekhoyili yengxenye ye-electromagnetic
6. Hlola ukuthi indawo yokulungisa ibhalansi yesiphethu inengqondo yini
Khona-ke, isignali iwukufaka, kodwa ingcindezi yokuphumayo ayishintshi, kukhona okukhiphayo kodwa akufinyeleli inani eliphakeme, njll. Lawa maphutha aphinde ahlangabezane namaphutha ansuku zonke futhi ngeke kuxoxwe ngawo lapha.
Ukwandiswa kolwazi ezine
Ukulungiswa kwe-valve stroke
Ngesikhathi senqubo yokukhiqiza, ukusebenzisa i-valve yokulawula isikhathi eside kuzoholela ekushayweni okungalungile.Ngokuvamile, kuhlale kunephutha elikhulu lapho uzama ukuvula indawo ethile.
I-stroke ingu-0-100%, khetha iphuzu eliphezulu lokulungiswa, okungu-0, 25, 50, 75, no-100, konke okuvezwe njengamaphesenti.Ikakhulukazi kuma-valve positioners, lapho kulungiswa, kuyadingeka ukwazi izindawo zezingxenye ezimbili zemanuwali ngaphakathi kwesimo, okungukuthi indawo ye-zero yokulungisa kanye ne-span yokulungisa.
Uma sithatha i-valve elawulayo evula umoya njengesibonelo, yilungise.
Isinyathelo 1: Endaweni yokulungisa iqanda, igumbi lokulawula noma ijeneretha yesiginali inikeza i-4mA.I-valve yokulawula kufanele ivalwe ngokuphelele.Uma ingakwazi ukuvalwa ngokugcwele, yenza ukulungisa uziro.Ngemuva kokuthi ukulungiswa kwe-zero kuqediwe, lungisa ngokuqondile iphuzu le-50%, futhi ulungise isikhathi ngokufanele.Ngesikhathi esifanayo, phawula ukuthi induku yempendulo kanye nesiqu se-valve kufanele kube sesimweni esiqondile.Ngemva kokuqedwa kokulungiswa, lungisa iphuzu elingu-100%.Ngemuva kokuthi ukulungiswa kuqediwe, lungisa ngokuphindaphindiwe kusukela kumaphuzu amahlanu phakathi kuka-0-100% kuze kube yilapho ukuvulwa kunembile.
Isiphetho;kusukela ku-positioner yemishini ukuya endaweni ehlakaniphile.Ngokombono wesayensi nobuchwepheshe, ukuthuthuka okusheshayo kwesayensi nobuchwepheshe kuye kwanciphisa umfutho wezisebenzi zabasebenzi abaphambili bokunakekela.Ngokwami, ngicabanga ukuthi uma ufuna ukusebenzisa amakhono akho okusebenza nokufunda amakhono, indawo yokubeka imishini iyona engcono kakhulu, ikakhulukazi kubasebenzi bezinsimbi ezintsha.Ukukubeka ngokungagwegwesi, isitholi esihlakaniphile singaqonda amagama ambalwa kumanuwali futhi sivele sinyakazise iminwe yakho.Izolungisa ngokuzenzakalelayo yonke into kusukela ekulungiseni iphoyinti elinguziro kuya ekulungiseni ububanzi.Vele ulinde ukuthi iqede ukudlala futhi uhlanze indawo yesehlakalo.Vele uhambe.Ohlotsheni lwemishini, izingxenye eziningi zidinga ukuhlakazwa, zilungiswe futhi zifakwe kabusha uwena.Lokhu kuzothuthukisa ikhono lakho lokusebenzisa izandla futhi kukwenze uhlabeke umxhwele ngesakhiwo sangaphakathi.
Kungakhathaliseki ukuthi ihlakaniphile noma ayihlakaniphile, idlala indima enkulu kuyo yonke inqubo yokukhiqiza okuzenzakalelayo.Uma "ishaya", ayikho indlela yokulungisa futhi ukulawula okuzenzakalelayo akusho lutho.
Isikhathi sokuthumela: Aug-31-2023