Models for mixing in stirred vessels

A generally applicable model for mixing in stirred vessels is derived; it is based on the flow patterns and internal circulation rates produced by the impeller which behaves as a submerged pump. The model is solved by means of a new and powerful numerical technique which can be applied to mixing models consisting of any configuration of well mixed stages; it is based on a probabilistic treatment of an ideal mixing stage and leads to a flexible, easy to use and efficient computer programme. The truncated moments, a set of easily measureable and model - independent parameters, are suggested for the characterisation of dynamic responses; the first of these moments provides a measure of the most significant features of the proposed model and, for certain applications, gives a,direct indication of the optimal mode of operation. A simplified version of the general model is shown to fit three quite different turbine stirred systems over a wide range of operating conditions.