Local void fraction and bubble size distributions in cold-gassed and hot-sparged stirred reactors
Local void fraction and bubble size distributions in cold-gassed and hot-sparged stirred reactors
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DOI：
10.1016/j.ces.2009.09.051
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发表时间：
2010-01
影响因子：
4.7
通讯作者：
Yuyun Bao;Lei Chen;Zhengming Gao;Jianfeng Chen
中科院分区：
文献类型：
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作者：
Yuyun Bao;Lei Chen;Zhengming Gao;Jianfeng Chen
在直径为0.48m、装有0.145m3液体的全挡板底搅拌槽中，用双电导探针测量了24和81 ℃下空气-水分散体系中局部空隙率、气泡尺寸和气液界面面积的垂直分布。搅拌器是一个中空叶片分散涡轮机下面的两个向上泵送水翼。在热条件下的空隙率的垂直分布是类似的，在环境温度下，虽然空隙率是显着较低的热系统。气泡尺寸的垂直分布在底部叶轮上方、顶部叶轮附近和靠近自由表面处具有最大值。在给定的操作条件下，热系统中的整体Sauter平均气泡尺寸似乎比冷系统大约21%。局部界面面积的估计值在顶部叶轮的水平上方显示出最大值。
Vertical distributions of local void fraction, bubble size and gas–liquid interfacial area in air–water dispersions at 24 and 81°C have been measured with a dual electric conductivity probe in a fully baffled dished base stirred vessel of 0.48m diameter holding 0.145m3liquid. The agitator was a hollow blade dispersing turbine below two up-pumping hydrofoils. The vertical distribution of the void fraction in the hot conditions is similar to that at ambient temperature though the void fraction is significantly lower in the hot system. The vertical distributions of bubble size show maxima with large bubbles above the bottom impeller, near the top impeller and close to the free surface. With given operating conditions, the overall Sauter means bubble size in the hot systems appears to be about 21% greater than when cold. Estimates of the local interfacial area show a maximum just above the level of the top impeller.