LOCAL HEAT-TRANSFER IN A STIRRED VESSEL WITH AND WITHOUT AERATION

A positive temperature coefficient thermister is devised as a thermal probe to determine local heat transfer coefficients in a stirred vesse l with a standard Rushton turbine impeller, The effects of aeration an d flow patterns on the value of local heat transfer coefficients are d iscussed. Under most operating conditions, the highest flux is found a t the impeller discharge region and the front side of the baffle plate s. The mean Nusselt number for Jacket and baffle type heat exchange el ements is presented in terms of the modified Reynolds number and the o ther dimmensionless groups, as the results of the integration of the d etermind values of local heat transfer coefficients.