半椭圆管盘式涡轮搅拌桨气-液分散特性

在直径为0.476 m的椭圆底搅拌槽中，采用半椭圆管盘式涡轮桨，研究桨径与槽径比D/T变化(分别为0.28, 0.33, 0.4及0.5)对气液两相体系中临界分散、通气功率和气含率的影响. 结果表明，对于D/T较小的搅拌桨，采用由载气到气泛测得的泛点比气泛到载气测得的泛点明显滞后，但随D/T增大泛点滞后现象消失；在相同通气量下，D/T对相对功率需求(Pg/P0)的影响不大；功率消耗相同时，低通气量时气含率随D/T增大略有增大，但高通气量时恰好相反. 研究结果及泛点、通气功率、气含率关联式对工业气液搅拌反应器设计操作具有参考价值.

Gas-Liquid Dispersion by Hollow-blade Disk Turbines

The influences of impeller diameter (0.28T, 0.33T, 0.40T and 0.5T) on critical impeller speed for gas dispersion, gassed power consumption and gas holdup were studied in a 0.476 m i.d. stirred tank with dished base agitated by a hollow-blade disk turbine. The results show that the flooding transitions measured from loading to flooding (L-F) and from flooding to loading (F-L) by means of increasing and falling gas rates show a hysteresis for low D/T, which becomes indistinct with the increase of D/T. At certain gas rates, D/T has no effect on relative power demand (RPD, the ratio of gassed power to ungassed power). For given power consumption, gas holdup increases slightly with increasing D/T at low gas rate, whereas it decreases apparently at high gas rate. The results and the correlations are of particular relevance to the design and operation of sparged gas-liquid stirred reactors.