Power consumption and gas–liquid mass transfer in a hot-sparged three-phase stirred reactor
Power consumption and gas–liquid mass transfer in a hot-sparged three-phase stirred reactor
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DOI：
10.1016/j.powtec.2019.05.065
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发表时间：
2019-09
影响因子：
5.2
通讯作者：
Jinjin Zhang;Dengfei Wang;Zhengming Gao;Yating Cai;Ziqi Cai;Yuyun Bao
中科院分区：
文献类型：
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作者：
Jinjin Zhang;Dengfei Wang;Zhengming Gao;Yating Cai;Ziqi Cai;Yuyun Bao
体积传质系数kLa是气液固三相机械搅拌釜式反应器设计和放大的重要参数之一。本文讨论并定量分析了搅拌速度、表观气速、温度和固体体积浓度（CV）对功率消耗和kLa的影响。在空气-水-玻璃微珠体系中，充气功率数（NPG）和kLa随温度的升高而显著增大。在室温下，kLa随CV的增加而显著降低，其幂律指数为3.10，但这种降低效应在较高温度下变得较弱。在热喷射三相体系中，固体颗粒的加入减缓了NPG随温度的上升趋势，但增强了kLa的上升趋势。温度的升高减弱了La对CVonkLa的降低作用。与温度的影响相比，CV的影响几乎可以忽略。作为工业应用的实际指导，通过提高温度或功率消耗来强化气液传质比通过改变CV或提高表观气速更有效。所得的功率消耗与kLa的经验关联式可为热鼓泡三相搅拌釜式反应器的工业设计和操作提供有益的指导。
The volumetric mass transfer coefficient (kLa) is one of the most important parameters for design and scale-up of gas–liquid–solid three-phase mechanically stirred tank reactors. In this work, the effects of agitation speed, superficial gas velocity, temperature, and volumetric solid concentration (CV) on the power consumption andkLawere discussed and quantitatively analyzed. In an air-water-glass beads system, the gassed power number (NPG) andkLaincrease remarkably with the temperature. At ambient temperature,kLadecreases significantly with increasingCVwith a power law exponent of 3.10, but this decreasing effect becomes weaker at higher temperatures. In this hot-sparged three-phase system, the addition of solids slows down the increasing tendency ofNPGwith the temperature, but enhances the increasing tendency ofkLa. The increase in temperature weakens the decreasing effect ofCVonkLa. Compared with the effect of temperature onNPGandkLa, the effect ofCVis nearly negligible. As a practical guide to industrial applications, it is more effective to enhance the gas–liquid mass transfer by increasing the temperature or power consumption than by changingCVor increasing superficial gas velocity. The empirical correlations of power consumption andkLaobtained in this work can provide helpful guidance for the industrial design and operation of hot-sparged three-phase stirred tank reactors.