Vertical gas holdup distributions in ambient gassed, hot sparged and boiling systems in stirred tanks using multiple 6 hollow blade disc turbines(CD-6)are reported.The local gas holdup in the boiling system is dramati...Vertical gas holdup distributions in ambient gassed, hot sparged and boiling systems in stirred tanks using multiple 6 hollow blade disc turbines(CD-6)are reported.The local gas holdup in the boiling system is dramatically different from that in the ambient gassed or hot sparged system whether in terms of value or distribution.Under the same total gas flow rate and impeller speed,the local gas holdup is much smaller in the boiling system than that in the ambient gassed or hot sparged system.The hot sparged system has similar vertical gas holdup distributions,with maxima in similar locations but with smaller local gas holdup overall,to those of the ambient gassed system.The designs of existing hot sparged and boiling reactors are based on the ambient gassed system and not optimal.The results are of particular relevance to the design and operation of reactors with hot sparged or boiling liquids.展开更多
在实验室提出的新型三相搅拌槽——自吸式龙卷流型搅拌槽中,采用六直叶圆盘涡轮桨进行三相混合性能的实验。从固液悬浮、气液分散和传质性能等方面对搅拌槽进行了研究,探讨了固相颗粒对气含率和传质性能的影响,得到了搅拌槽中不同性能...在实验室提出的新型三相搅拌槽——自吸式龙卷流型搅拌槽中,采用六直叶圆盘涡轮桨进行三相混合性能的实验。从固液悬浮、气液分散和传质性能等方面对搅拌槽进行了研究,探讨了固相颗粒对气含率和传质性能的影响,得到了搅拌槽中不同性能参数的变化规律。结果表明:自吸式龙卷流型搅拌槽作为一种新型的三相搅拌槽,能够获得良好的固液悬浮和气液分散效果;当搅拌槽内固相体积分率较低(φ<20%)时,可采用颗粒的壁面堆积高度作为完全悬浮状态的判定标准;固相颗粒的存在会使气含率明显降低,但对传质性能的影响较为复杂,φ<5%时的体积传氧系数K L a高于纯溶液,φ>5%时的K L a低于纯溶液,但都随固相体积分率的增加而降低。展开更多
文摘Vertical gas holdup distributions in ambient gassed, hot sparged and boiling systems in stirred tanks using multiple 6 hollow blade disc turbines(CD-6)are reported.The local gas holdup in the boiling system is dramatically different from that in the ambient gassed or hot sparged system whether in terms of value or distribution.Under the same total gas flow rate and impeller speed,the local gas holdup is much smaller in the boiling system than that in the ambient gassed or hot sparged system.The hot sparged system has similar vertical gas holdup distributions,with maxima in similar locations but with smaller local gas holdup overall,to those of the ambient gassed system.The designs of existing hot sparged and boiling reactors are based on the ambient gassed system and not optimal.The results are of particular relevance to the design and operation of reactors with hot sparged or boiling liquids.
文摘在实验室提出的新型三相搅拌槽——自吸式龙卷流型搅拌槽中,采用六直叶圆盘涡轮桨进行三相混合性能的实验。从固液悬浮、气液分散和传质性能等方面对搅拌槽进行了研究,探讨了固相颗粒对气含率和传质性能的影响,得到了搅拌槽中不同性能参数的变化规律。结果表明:自吸式龙卷流型搅拌槽作为一种新型的三相搅拌槽,能够获得良好的固液悬浮和气液分散效果;当搅拌槽内固相体积分率较低(φ<20%)时,可采用颗粒的壁面堆积高度作为完全悬浮状态的判定标准;固相颗粒的存在会使气含率明显降低,但对传质性能的影响较为复杂,φ<5%时的体积传氧系数K L a高于纯溶液,φ>5%时的K L a低于纯溶液,但都随固相体积分率的增加而降低。
