多级搅拌槽内流动特性实验及模型研究

利用隔盘、环板等内构件将搅拌槽内分为四级,采用饱和KCl溶液作示踪剂,利用特制的电导率仪微机系统进行动态数据采集,测定了不同的操作参数和内构件尺寸对停留时间分布(RTD)的影响,分析了影响返混的主要因素。环板与槽壁的间隙、隔盘外径与环板内径的影响较强,盘、板间距的影响相对较弱。利用MonteCarlo方法(MCM)对系统的停留时间分布进行了数值模拟计算。

Experimental and model study on flow characteristics in a tank with multistage agitation

In a stirred cylindrical tank, disks and ring disks were used to divide the tank into four stages. Saturated solution of KCl was used as tracer and a special system of conductivity meter and computer was used to collect data. Influences of different parameters of the structure and operation to residence time distribution (RTD) were measured. The key parameters to back mixing were the gap between the ring disk and the tank wall, the inner diameter of the ring disk and outer diameter of the disk, while the spacing between the disk and ring disk had little influence. The choice of flow rate and rotation speed should have the consideration of the requirements of both flow and mixing. Monte Carlo method(MCM) was used to predict RTD in stirred tank. The results are in agreement with what was measured in the experiments.