A study on flow in horizontal agitated thin-film evaporators. 5th report. Influence of the shape of the liquid fillet.

In the preceding paper, the axial flow of the liquid fillet generated by a paddle of a rotor was analyzed and compared with experimental data, where it was assumed that the cross section of the liquid fillet was a triangle. However, it was observed that the cross section was a trapezoid rather than a triangle if the width of the liquid fillet was wide, and a wide fillet was observed in the upstream zone when the flow rate was large. The critical width of the liquid fillet was experimentally related to the thickness of the fillet. By utilizing this relationship, the preceding analysis was generalized so that it could handle a trapezoidal liquid fillet for the case of a wide fillet exceeding the critical width. Good agreement of the prediction with experimental data was secured in a wide range of operating conditions.