摘要
在直径为0.476m的椭圆底搅拌槽中,采用以半椭圆管盘式涡轮(HEDT)为底桨、上提操作的宽叶翼形桨(WH_U)为中、上层桨的三层组合桨,研究24℃～95℃范围内不同温度下气-液-固体系中搅拌功率、气含率及固体颗粒完全离底悬浮特性。结果表明,体系相对功率需求(通气功率与不通气功率之比)RPD随温度的升高而增大,但随固含率的提高,温度对RPD的影响程度减弱。气含率随温度的升高而明显下降,其下降的幅度也随固含率增加而减小。本文结果及通气功率、气含率关联式对于工业热态通气三相搅拌反应器设计和操作具有一定的参考价值。
Power consumption, gas hold-up and critical impeller speed for just complete off-bottom solid suspension have been measured in a triple-impeller stirred tank of 0.476m diameter with dished base under six different temperatures from 24℃ to 95℃. The impeller combination consisted of a half elliptical disk turbine （HEDT） as the bottom and two up-pumping wide-blade hydrofoils （WHU） above HEDT. The results show that temperature has a great effect on the hydrodynamic characteristics. Relative power demand （RPD） increases for the higher temperature, but the effect of temperature on RPD becomes weaker when more solids added in the system. Gas holdup decreases apparently with the increasing of temperature, which becomes less at higher solid concentration. The results and the correlations are of particular relevance to the design and operation of hot sparged three-phase reactors.
基金
国家自然科学基金项目(20576009)
