Experiments on maldistribution were conducted in a 8.5 m high, 1 m0.3 m cross-section circulating flu-idized bed equipped with a 33 bubble-cap distributor. There exists an uneven distribution in flow rate, the bubble ...Experiments on maldistribution were conducted in a 8.5 m high, 1 m0.3 m cross-section circulating flu-idized bed equipped with a 33 bubble-cap distributor. There exists an uneven distribution in flow rate, the bubble caps in the center region having larger flow rates than those next to the wall. Flow resistance has been found to be the domi-nating factor influencing gas flow rate distribution. Increasing superficial gas velocity improves flow rate distribution for a low pressure-drop distributor. For a high pressure-drop distributor, superficial gas velocity has little effect on flow rate distribution. A ratio of maximum flow rate through a bubble cap to average flow rate through all bubble caps (Vmax/Vav) characterizes the flow rate distribution. Distributor-to-bed pressure drop ratio (DPd/DPr) is another necessary parameter to achieve even flow distribution. A correlation between these two ratios is developed for predicting flow rate maldistribution in CFB bubble-cap distributor.展开更多
文摘Experiments on maldistribution were conducted in a 8.5 m high, 1 m0.3 m cross-section circulating flu-idized bed equipped with a 33 bubble-cap distributor. There exists an uneven distribution in flow rate, the bubble caps in the center region having larger flow rates than those next to the wall. Flow resistance has been found to be the domi-nating factor influencing gas flow rate distribution. Increasing superficial gas velocity improves flow rate distribution for a low pressure-drop distributor. For a high pressure-drop distributor, superficial gas velocity has little effect on flow rate distribution. A ratio of maximum flow rate through a bubble cap to average flow rate through all bubble caps (Vmax/Vav) characterizes the flow rate distribution. Distributor-to-bed pressure drop ratio (DPd/DPr) is another necessary parameter to achieve even flow distribution. A correlation between these two ratios is developed for predicting flow rate maldistribution in CFB bubble-cap distributor.