Studies on the rate of heat transfer in agitated vessels with special types of impellers were carried out. The impellers used were a double helical ribbon, a quadruple helical ribbon and a helical screw. The liquid media investigated were water, bitumen and aqueous glycerine solutions. Vessel-wall heat transfer coefficients were obtained for each impeller. For the helical screw, an off-centered system was studied and the impeller surface heat transfer coefficients were also obtained. Experimental data were correlated using dimensional analysis.