Characteristics of different pump types operating with ice slurry

The characteristics of three different principles of pumps centrifugal, side-channel and screw-were investigated. For each type, the pump characteristics at three speeds of rotation and for four different ice fractions between 0 and 25% were determined. The pump total head, overall efficiency, and electrical power input in function of the volume flow rate were continuously measured. In the case of a centrifugal- or a side channel-pump, the measured pump characteristics with ice fractions between 0 and 15% were nearly of equal value. Marked differences were observed with ice fractions of 25%. In the case of a screw pump, characteristics and behaviour were different compared to the centrifugal and side channel-pump. For increasing ice fractions, the obtained values show a gradually altering behaviour. If the pressure and the speed of rotation are constant, the volume rate of flow increases with growing ice mass fraction. The overall efficiency is significantly lower without ice particles than with ice mass fractions of 5-25%. All tested pumps were running over hundreds or thousands of hours and were suitable for ice stuffy applications. (C) 2004 Elsevier Ltd and IIR. All rights reserved.