Wall-liquid heat transfer coefficients in batch intensive mixers

摘要

An empirical correlation that predicts the wallliquid heat transfer coefficient, h, in batch intensive mixers for neat polymers and polymer blend systems has been tested and verified. The correlation predicts the heat transfer coefficient using the Nusselt number, Nu, the Reynolds number, Re, the Prandtl number, Pr and the viscosity ratio, #mu#_r. The correlation takes the form Nu = #alpha#(Re)~#beta#(Pr)~#gamma#(#mu#_r)~#delta# Experiments were carried out with ten different amorphous and semicrystalline neat polymers over different operating conditions including different processing temperatures, degrees of fill and shear rates. Polymer blend systems were also studied. Further testing of the polymers with different blade geometries also yielded heat transfer coefficients predicted by the correlation.