Ma electromagnetic flow meter(EMFs) amagwiritsidwa ntchito kwambiri m'mafakitale chifukwa cha kulondola kwawo kwakukulu komanso kudalirika poyesakuchuluka kwa madzizamadzimadzi oyendetsera magetsi. Mamita awa amagwira ntchito motsatira lamulo la Faraday la Electromagnetic Induction, lomwe ndi mfundo yofunika kwambiri pa electromagnetism. Nkhaniyi ikufotokoza mwatsatanetsatane momwe ma electromagnetic flow mita amagwirira ntchito, kuyambira pa chiphunzitso choyambira mpaka zigawo ndi ntchito zothandiza.
1. Maziko a Chiphunzitso: Lamulo la Faraday la Kuyambitsa Magetsi
Lamulo la Faraday limati pamene kondakitala akuyenda kudzera mu mphamvu ya maginito, mphamvu yamagetsi (EMF) imayendetsedwa kudutsa kondakitala. Pankhani ya mita yoyendera magetsi yamagetsi, madzi oyendetsera magetsi omwe akuyenda kudzera mu mita amagwira ntchito ngati "kondakitala," pomwe mphamvu yamkati ya kondakitala imakhala ngati mphamvu yakunja ya maginito. EMF yoyambitsidwa imagwirizana mwachindunji ndi liwiro la madzi, mphamvu ya mphamvu ya maginito, ndi mtunda pakati pa ma electrodes omwe amayesa EMF.
Mwa masamu, lamulo la Faraday likhoza kufotokozedwa motere:
E=k×B×v×D
kumene:
- E ndi mphamvu yamagetsi yochokera ku magetsi (voltage)
- k ndi chinthu chosasintha
- B ndi mphamvu ya mphamvu ya maginito
- v ndi liwiro lapakati la madzi
- D ndi m'mimba mwake wa chubu choyezera (chomwe chikuyimira kutalika kwa kondakitala mu mphamvu ya maginito)
Popeza mphamvu ya mphamvu ya maginito (B) ndi m'mimba mwake wa chubu (D) zimakhazikika pa mita yoyezera kuyenda kwa madzi, mphamvu yamagetsi (E) imakhala muyeso wolunjika wa liwiro la madzi (V). Mwa kuphatikiza liwiro pakapita nthawi, liwiro la kuyenda kwa madzi (voliyumu pa nthawi ya unit) likhoza kuwerengedwa.
2. Zigawo Zachilengedwe za Chiyeso Choyendera Maginito
Ma Coil a Magnetic kapena Magnet Assembly
Thechoyezera kuyenda kwa madziIli ndi ma coil a maginito kapena gulu la maginito lokhazikika lomwe limapanga mphamvu ya maginito yofanana yolunjika kunjira ya madzi. Mphamvu ya maginito ikhoza kukhala DC (direct - current) kapena AC (alternating - current), ndipo minda ya AC imakhala yofala kwambiri chifukwa cha kuthekera kwawo kuchepetsa polarization ya electrode ndi kusokoneza phokoso. Pamene mphamvu ya maginito ya AC ikugwiritsidwa ntchito, EMF yomwe imayambitsa madzi imasinthasinthanso sinusoidal, zomwe zimapangitsa kuti ntchito ya ma signal ikhale yosavuta.
Chubu Choyezera
Chitoliro choyezera ndi gawo lomwe madzi amalowakuyendas. Nthawi zambiri imapangidwa ndi zinthu zopanda maginito komanso zopanda mphamvu (monga chitsulo chosapanga dzimbiri chophimbidwa ndi PTFE, rabala, kapena ceramic) kuti zisasokoneze mphamvu ya maginito ndikuwonetsetsa kuti muyeso wake ndi wolondola. Pamwamba pa chubucho ndi posalala kuti muchepetse kukangana ndi kutayika kwa mphamvu, zomwe zimathandiza kuti madzi aziyenda momasuka.
Ma electrode
Ma electrode awiri amayikidwa moyang'anizana pakhoma la chubu choyezera, molunjika ku mbali zonse ziwiri za kayendedwe ka madzi ndi mphamvu ya maginito. Ma electrode awa amakhudzana mwachindunji ndi madzi ndipo amagwiritsidwa ntchito kuzindikira EMF yomwe yayambitsidwa. Ma electrode nthawi zambiri amapangidwa ndi zinthu zosagwira dzimbiri (monga Hastelloy, platinum - iridium alloy) kuti athe kupirira kukhudzana ndi madzi osiyanasiyana, makamaka omwe ali ndi mphamvu zowononga kapena zowononga.
Chosinthira Zizindikiro
EMF yomwe imayambitsidwa ndi ma electrode ndi chizindikiro chamagetsi chofooka kwambiri, nthawi zambiri chimakhala mu microvolt range. Chosinthira chizindikiro, chomwe chimadziwikanso kuti chotumizira, chimakulitsa, chimasefa, ndikuchigwiritsa ntchito kuti chisinthe kukhala chotulutsa chomwe chingagwiritsidwe ntchito. Chikhoza kusintha chizindikirocho kukhala mawonekedwe okhazikika a mafakitale monga ma loops a 4 - 20 mA current, ma signal a digito (monga HART, Modbus), kapena kulumikizana popanda waya ndi makina owongolera, zomwe zimathandiza kuyang'anira nthawi yeniyeni ndikuwongolera kuchuluka kwa kayendedwe ka magetsi.
3. Njira Yogwirira Ntchito Gawo ndi Gawo
- Kupanga Magnetic Field: Magnetic coils kapena maginito assembling amapanga maginito olimba kudutsa chubu choyezera. Munda uwu ndi wolunjika ku mbali ya kayendedwe ka madzi, kuonetsetsa kuti madzi oyenda mu chubucho amadula mizere ya mphamvu ya maginito.
- Kuyambitsa kwa EMF: Pamene madzi oyendetsera magetsi akuyenda kudzera mu chubu choyezera, amagwira ntchito ngati choyendetsa magetsi mu mphamvu ya maginito. Malinga ndi lamulo la Faraday, mphamvu yamagetsi (EMF) imayendetsedwa kudzera mumadzi. Kukula kwa EMF iyi kumagwirizana ndi liwiro la madzi, mphamvu ya mphamvu ya maginito, ndi kukula kwa chubu choyezera.
- Kuzindikira Zizindikiro: Ma electrode awiri omwe amaikidwa pakhoma la chubu amazindikira EMF yomwe yayambitsidwa. Popeza ma electrodewo amakhudzana ndi madzi, amajambula kusiyana kwa mphamvu zamagetsi komwe kumachitika chifukwa cha madzi oyenda mu mphamvu ya maginito.
- Kukonza Zizindikiro: Chizindikiro chofooka cha EMF chomwe chapezeka ndi ma electrode chimatumizidwa ku chosinthira zizindikiro. Apa, chizindikirocho chimakulitsidwa kuti chiwonjezere mphamvu yake, kusefa kuti chichotse phokoso ndi kusokoneza, ndikusinthidwa kukhala chizindikiro chotulutsa chokhazikika (monga, 4 - 20 mA, deta ya digito).
- Kuwerengera Kuchuluka kwa Mayendedwe: Chizindikiro chokonzedwacho chimagwiritsidwa ntchito kuwerengera kuchuluka kwa madzi. Chosinthira chizindikirocho chimagwiritsa ntchito ma algorithms a masamu kutengera zokhazikika zodziwika za mita yoyendera (mphamvu ya maginito, m'mimba mwake wa chubu) kuti chisinthe EMF yoyezedwa kukhala mtengo wa kuchuluka kwa mayendedwe, womwe ungawonetsedwe komweko pa mitayo kapena kutumizidwa ku makina owunikira akutali.
4. Zofunika Kuziganizira ndi Zolepheretsa
Kufunika kwa Kuyendetsa Madzi
Ma electromagnetic flow meterimatha kuyeza kuyenda kwa madzi oyendetsera mpweya okha. Mphamvu yocheperako yofunikira imasiyana malinga ndi wopanga koma nthawi zambiri imakhala pakati pa 5 mpaka 50 μS/cm (micro - Siemens per centimeter). Madzi okhala ndi mphamvu yotsika kwambiri, monga madzi oyera kwambiri kapena ma hydrocarbon, sali oyenera kuyeza ndi ma EMF wamba. Komabe, mitundu yapadera yopangidwira madzi oyendetsera mpweya otsika imatha kuwonjezera kuchuluka kwa mphamvu yoyezera.
Kusokoneza kwa Magnetic Field
Maginito akunja amatha kusokoneza magwiridwe antchito a maginito oyendera magetsi. Pofuna kuchepetsa izi, kutchinga bwino ndi kuyika pansi kwa mita ndikofunikira. Kuphatikiza apo, malo oyikamo ayenera kusankhidwa mosamala kuti apewe kuyandikira zida zazikulu zamagetsi kapena magwero ena a maginito.
Kukhazikitsa ndi Kukonza
Kukhazikitsa koyenera ndikofunikira kwambiri kuti muyeze molondola.choyezera kuyenda kwa madziIyenera kuyikidwa mu gawo lolunjika la payipi yokhala ndi kutalika kokwanira kwa mapaipi owongoka okwera ndi otsika (nthawi zambiri 5 - 10 kuposa mainchesi a payipi okwera ndi 3 - 5 pansi) kuti zitsimikizire kuti mayendedwe ake ndi okhazikika komanso ofanana. Kuwunikira nthawi zonse, kaya kudzera mu kutsimikizira komwe kuli pamalopo kapena kufananiza ndi miyezo yodziwika bwino ya mayendedwe, ndikofunikiranso kuti musunge kulondola kwa muyeso pakapita nthawi.
Pomaliza, ma electromagnetic flow mita amagwiritsa ntchito lamulo la Faraday la Electromagnetic Induction kuti apereke zolondola komanso zodalirika.miyeso ya kayendedwe ka madziza madzi oyendetsera mpweya. Kumvetsetsa mfundo yogwirira ntchito yawo ndikofunikira kwambiri posankha, kukhazikitsa, ndi kugwiritsa ntchito bwino ntchito zosiyanasiyana zamafakitale, kuyambira kuyeretsa madzi ndi kukonza mankhwala mpaka kupanga chakudya ndi zakumwa.
Nthawi yotumizira: Juni-24-2025