Liu Kuang-Yu, Wey Ming-Yen
Department of Environmental Engineering, National Chung-Hsing University, Taichung 402, Taiwan, ROC.
Chemosphere. 2005 Sep;60(10):1341-8. doi: 10.1016/j.chemosphere.2005.02.025. Epub 2005 Apr 1.
Fluidized bed filtration classified as granular bed filtration is a solution for removing particles from flue gas. Fine particles are captured by colliding with bed material. Binary mixtures including fines exist in the fluidized bed; the situation becomes more complex because the fines increases with time as particles enter continuously. Coal ash was put into the inlet gas of a gas-solid fluidized bed with silica sand and the variations in concentration with time was monitored, to elucidate the dynamic purification of fines by bed material and the interaction therewith. Water was injected into the inlet gas also to study the influence of water content on the removal of particles. Experimental results showed that the particle concentration rapidly increased with time until equilibrium was achieved. The outlet concentrations exceeded the inlet concentration (such that the removal efficiency was negative) at operating time between 26 and 30 min, yielding an efficiency as low as -35%. The removal efficiency increased with the relative humidity from 30% to 70%. The maximum cumulative collection ratios of particles (by mass) were 20%, 22% and 27% at humidities of 30%, 50% and 70%, declining to 7%, 13%, and 19% at the end.
作为颗粒床过滤的一种，流化床过滤是一种从烟气中去除颗粒的解决方案。细颗粒通过与床层材料碰撞而被捕集。流化床中存在包括细颗粒在内的二元混合物；由于随着颗粒不断进入，细颗粒随时间增加，情况变得更加复杂。将煤灰放入含有硅砂的气固流化床的进气中，并监测其浓度随时间的变化，以阐明床层材料对细颗粒的动态净化及其相互作用。还将水注入进气中，以研究含水量对颗粒去除的影响。实验结果表明，颗粒浓度随时间迅速增加，直至达到平衡。在运行时间为26至30分钟时，出口浓度超过入口浓度（使得去除效率为负），效率低至-35%。去除效率随着相对湿度从30%增加到70%而提高。在湿度为30%、50%和70%时，颗粒的最大累积收集率（按质量计）分别为20%、22%和27%，最终降至7%、13%和19%。
