粮食伴生粉尘最低着火温度的实验研究

按照IEC标准建立了工业粉尘云和粉尘层最低着火温度(MIT)测试装置,对8种取自工业现场的粮食伴生粉尘进行了粉尘云和粉尘层MIT实验测试,并对灰分、粒径、水分对MIT的影响进行了实验研究和分析·发现粮食储运系统后期工艺比早期危险,按照粮食精粉或淀粉实验数据进行工业实际防爆设计的安全裕度过大,并提出了可行的防爆温度组别·所得结论为粮食行业的防爆设备选型提供了实验依据,对于粉尘着火和爆炸危险性评价具有借鉴意义·

Experimental Investigation on Minimum Ignition Temperature(MIT) of Dust Concomitant with Grain

An experimental setup was established according to IEC standard to investigate 8 kinds of dust concomitant with grain for their MITs of dust cloud and layer(MITC and MITL), which were sampled in-situ from actual grain processing line. The influences of inorganic ash, particle size and moisture on MIT were thus tested. It was found that in grain handling process the late phase is even more hazardous than the early phase, and the safety margin in existing explosion-proof design procedure based on the data of refined flour and starch is excessive in practice. Some parameter sets as practical temperature criteria are therefore put forward on the experimental basis for selecting properly explosion-proof equipment in grain processing industry. They will be of importance to the evaluation of dust ignition/explosion hazards.