Fashewar Shenhai-Hujja
A daidaitattun yanayin gwaji, iyakar maida hankali wanda iskar gas ko tururi gauraye da iskar da ke haifar da fashewa ana kiranta iyakar fashewa.. Yawanci, kalmar ‘iyakar fashewa’ yana nufin iyakoki na iskar gas masu ƙonewa ko tururi a cikin iska. Mafi ƙasƙanci na iskar gas mai ƙonewa wanda zai iya haifar da fashewa ana san shi da ƙananan fashewa (LAL), da mafi girman maida hankali kamar iyakar fashewar babba (UEL).
Lokacin da iskar gas mai ƙonewa ko tururin ruwa suna cikin iyakar fashewa kuma suna fuskantar tushen zafi (kamar bude wuta ko babba zafin jiki), harshen wuta yana bazuwa cikin sauri ta cikin iskar gas ko ƙura. Wannan saurin sinadarai yana sakin zafi mai yawa, samar da iskar gas da ke fadada saboda zafi, haifar da yanayin zafi mai zafi da matsi tare da yuwuwar lalacewa mai yawa.
Iyakokin fashewa sune maɓalli masu mahimmanci a cikin bayanin haɗarin m gas, tururi, da ƙura mai ƙonewa. Yawanci, iyakar fashewar iskar gas mai ƙonewa da tururi ana bayyana su azaman adadin iskar gas ko tururi a cikin cakuda..
Misali, da 20°C, dabarar jujjuya don juzu'in juzu'i da yawan taro na iskar gas mai ƙonewa shine:
Y = (L/100) × (1000M/22.4) × (273/(273+20)) = L × (M/2.4)
A cikin wannan tsari, L shine juzu'in juzu'i (%), Y shine yawan taro (g/m³), M shine dangi na kwayoyin halitta na iskar gas mai ƙonewa ko tururi, kuma 22.4 shine girma (lita) shagaltar da su 1 mol na wani abu a cikin yanayin gaseous karkashin daidaitattun yanayi (0°C, 1 atm).
Misali, idan methane gas maida hankali a cikin yanayi ne 10%, yana juyawa zuwa:
Y = L × (M/2.4) = 10 × (16/2.4) = 66.67g/m³
Manufar iyakar fashewa don iskar gas mai ƙonewa, tururi, kuma ana iya bayyana kura ta hanyar ka'idar fashewar thermal. Idan maida hankali na wani flammable gas, tururi, ko kura tana ƙasa da LEL, saboda yawan iska, tasirin sanyaya iska, da kuma rashin isasshen taro na konewa, tsarin yana rasa zafi fiye da yadda yake samu, kuma martanin baya ci gaba. Hakazalika, idan maida hankali yana sama da UEL, zafin da ake samu bai kai zafin da aka rasa ba, hana dauki. Bugu da kari, wuce kima kona gas ko kura ba kawai kasa amsawa da kuma haifar da zafi saboda rashin oxygen amma kuma yana sanyaya cakuda, hana yaduwar harshen wuta. Haka kuma, ga wasu abubuwa kamar ethylene oxide, nitroglycerin, da kura mai ƙonewa kamar foda, UEL na iya isa 100%. Wadannan kayan suna ba da iskar oxygen yayin bazuwar, kyale daukin ya ci gaba. Ƙara matsa lamba da zafin jiki yana ƙara sauƙaƙe rushewar su da fashewa.