Mixing Process in a Stirred Tank

Abstract

Study for mixing process in a stirred tank with paddle-type impeller was carried out with the method of impulse response under the turbulent flow region.
A correlation of circulation time with impeller variables and the effects of measuring positions on response lag were obtained by measuring the period and the response time for the peaks or valleys of observed curves, respectively.
On the other hand, a mixing model with a recirculation process composed of a series of perfect mixing tanks was proposed on the basis of experimental information for the circulation flow patterns.
By making a comparison between model response characteristics and experimental ones, two mixing parameters were decided and the model curves calculated by these parameters agreed approximately with the corresponding experimental curves. It was also shown that the relation between mixing rate and circulation rate could be correlated with power number of impeller.