A cikin zaɓin famfo na ruwa, idan zaɓin bai dace ba, farashin zai iya zama babba ko kuma ainihin aikin famfo bazai dace da bukatun wurin ba. Yanzu ba da misali don kwatanta wasu ƙa'idodin da famfon ruwa ya buƙaci bi.
Zaɓin famfon tsotsa biyu ya kamata a kula da waɗannan abubuwan:
1. Gudun:
An ƙayyade saurin al'ada bisa ga buƙatun da abokin ciniki ya bayar. Ƙarƙashin saurin famfo guda ɗaya, madaidaicin magudanar ruwa da ɗagawa zai ragu. Lokacin zabar samfurin, wajibi ne a yi la'akari ba kawai aikin tattalin arziki ba, har ma da yanayin shafin, kamar: danko na matsakaici, juriya na juriya, ikon kai tsaye, abubuwan girgizawa, da dai sauransu.
2. Tabbatar da NPSH:
Ana iya ƙayyade NPSH bisa ga ƙimar da abokin ciniki ya bayar, ko bisa ga yanayin shigar famfo, matsakaicin zafin jiki da matsa lamba na kan-site:
Lissafi na tsayin shigarwa na famfo na ruwa (algorithm mai sauƙi: bisa ga daidaitattun yanayin yanayi da ruwan zafi na al'ada) shine kamar haka:
Daga cikin su: hg - tsayin shigarwa na geometric (tabbatacciyar ƙima ita ce tsotsa, ƙimar mara kyau ita ce ta juyawa);
- Shugaban ruwan matsa lamba na yanayi a wurin shigarwa (ƙididdige shi azaman 10.33m ƙarƙashin madaidaicin yanayin yanayi da ruwa mai tsabta);
hc - tsotsa asarar hydraulic; (idan bututun shigar ya kasance gajere kuma ba shi da rikitarwa, yawanci ana ƙididdige shi azaman 0.5m)
- Shugaban matsa lamba na vaporization; (ana ƙididdige ruwa mai tsabta a ɗakin dakuna kamar 0.24m)
- NPSH mai halatta; (don tabbatar da aminci, lissafta bisa ga NPSHr × 1.2, NPSHr duba kundin)
Misali, NPSH NPSHr=4m: Sannan: hg=10.33-0.5-0.24-(4×1.2)=4.79m (sakamakon sasantawa yana da ma'ana mai kyau, yana nufin yana iya tsotsewa har zuwa ≤4.79m, wato. , matakin shigar ruwa zai iya zama a cikin impeller A cikin 4.79m a ƙarƙashin layin tsakiya idan yana ƙarƙashin mummunan matsa lamba, dole ne a sake dawo da shi; kuma darajar zubar da baya dole ne ta fi kimar da aka ƙididdigewa, wato, matakin shigar ruwa zai iya zama sama da ƙimar da aka ƙididdige sama da layin tsakiya na impeller).
Ana ƙididdige abin da ke sama a ƙarƙashin yanayin zafin jiki na al'ada, ruwa mai tsabta da tsayin daka. Idan yanayin zafi, yawa da tsayin matsakaici ba su da kyau, don guje wa cavitation da sauran matsalolin da ke shafar aikin al'ada na saitin famfo, ya kamata a zaɓi ƙimar da ta dace kuma a canza su cikin dabarar lissafi. Daga cikin su, ana ƙididdige yawan zafin jiki da yawa na matsakaici bisa ga ma'auni masu dacewa a cikin "Matsayin Vaporization and Density of Water at Temperatures daban-daban", kuma an ƙididdige tsayin daka bisa ga ma'auni masu dacewa a cikin "Tsawon Tsayi da Yanayin yanayi na Manyan Cities kasar". Wani halattaccen NPSH shine tabbatar da aminci, bisa ga NPSHr × 1.4 (wannan darajar shine akalla 1.4).
3. Lokacin da matsa lamba na famfo na al'ada shine ≤0.2MPa, lokacin da matsa lamba + kai × 1.5 sau ≤ matsa lamba, zaɓi bisa ga kayan al'ada;
Matsakaicin shigarwa + kai × 1.5 sau> matsa lamba, ya kamata a yi amfani da daidaitattun kayan da suka dace da buƙatun; idan matsa lamba mai shiga ya yi yawa ko gwajin gwajin ya yi yawa, da dai sauransu waɗanda ba su dace da buƙatun ba, don Allah tabbatar da fasaha don maye gurbin kayan aiki ko gyara ƙirar kuma ƙara girman bango;
4.Conventional famfo inji hatimi model ne: M7N, M74 da kuma M37G-G92 jerin, wanda daya don amfani dogara a kan famfo zane, na al'ada inji hatimi abu: wuya / taushi (tungsten carbide / graphite); lokacin da matsa lamba mai shiga ya kasance ≥0.8MPa, Dole ne a zaɓi hatimin madaidaicin injin;
5. An ba da shawarar cewa matsakaicin zafin jiki na famfo mai tsotsa biyu kada ya wuce 120 ° C. Lokacin da 100 ° C ≤ matsakaicin zafin jiki ≤ 120 ° C, famfo na al'ada yana buƙatar gyarawa: rami mai rufewa da ɓangaren ɗamara dole ne a sanye da ruwan sanyi a waje da rami mai sanyaya; duk O-zoben famfo ana yin su ne da Dukansu ana amfani da su: roba mai fluorine (ciki har da hatimin inji).
Lokacin aikawa: Mayu-10-2023