CAVERN SIZES IN AGITATED FLUIDS WITH A YIELD STRESS
CAVERN SIZES IN AGITATED FLUIDS WITH A YIELD STRESS
复制标题
具有屈服应力的搅拌流体中的洞穴尺寸
DOI：
10.1080/00986448108910992
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发表时间：
1981
影响因子：
2.5
通讯作者：
G. Pace
中科院分区：
文献类型：
--
作者：
J. Solomon;T. Elson;A. Nienow;G. Pace
在直径0.29m的搅拌容器中，研究了高粘性非牛顿黄原胶溶液和两种具有相似神学性质的透明模型流体，分别在充气（高达1vvm）和不充气的条件下进行。尺寸1/3和1/2的坦克直径的拉什顿盘式涡轮机已经单独使用，也与6叶片，45°-螺距轴流涡轮机的相同尺寸的速度高达24转/秒，使特定的功率输入高达15 W/kg被传授。采用流动可视化和热膜风速法研究了流动模式。当流体存在屈服应力时，流体分裂成一个紊流的均匀混合洞室，洞室的大小随速度的增加而增大，其余部分停滞不前。在加气和不加气混合条件下，溶洞尺寸模型与实验数据吻合较好。大直径组合在约1至2 W/kg时产生良好的混合，约为小直径组合所需的1/3至1/4。单盘式涡轮叶轮…
Abstract Highly viscous, non-Newtonian Xanthan gum solutions and two transparent model fluids with similar Theological properties have been studied under aerated (up to 1 vvm) and unaerated conditions in a 0.29m diameter agitated vessel. Rushton disc turbines of size 1/3 and 1/2 of the tank diameter have been used alone and also in conjunction with 6-bladed, 45°-pitch axial flow turbines of the same size at speeds up lo 24 rev/s, enabling specific power inputs of up to 15 W/kg to be imparted. Flow patterns were studied by flow visualisation and hot film anemometry. When the fluids have a yield stress, the fluid divides into a turbulent well-mixed cavern which increases in size with increasing speed with the remainder stagnant. A model for the size of the cavern fits the experimental data well for both aerated and unaerated mixing. Large diameter combinations produce good mixing at about 1 to 2 W/kg which is about 1/3 to 1/4 of that required with small diameter combinations. Single disc turbine impellers a...