EXPERIMENTAL MEASUREMENTS OF LASER-DOPPLER ANEMOMETRY IN A BAFFLED MIXING TANK.

摘要

Experiments were conducted for extremely high turbulent mixing operations without chemical reaction in a standard geometry, baffled mixing tank. Three components of the mean and root-mean-square velocities were measured using a laser-Doppler anemometer. The impeller rotation rate, the impeller type, and the impeller location were considered. Water was mixed with polystyrene by a six-bladed Rushton turbine impeller and a four-bladed inclined paddle impeller at 100, 200, and 400 revolutions per minute rotation rates. The impellers were located at one-half or one-third of the liquid height in the tank.; Due to the complexity of flow in a baffled mixing tank, there are still several fundamental modeling and computational difficulties in simulating the flow. Thus, these experimental data based on the sophisticated and extensive measurements may improve fundamental modeling methods.; The results show that the flow patterns depend on the impeller type. The effect of the impeller location on flow was small. The axial direction of the flow was caused by the baffles. The flow was three-dimensional, rotational, periodic, and statistically random. This information sucessfully characterizes the flow in the baffled mixing tank.