PRESSURE DISTRIBUTION ALONG THE CASING OF A CENTRIFUGAL PUMP AND ITS EFFECT ON SUPPORT BEARING TEMPERATURE DISTRIBUTION

摘要

In a centrifugal pump, impeller transfer energy to liquids and a part of the transferred kinetic energy converts into the pressure energy in the surrounding casing. Any asymmetric pressure distribution around the impeller gives rise to radial force, which increases temperature at support bearings of the pump. An effort has been made in the present work to relate rise in the bearing temperature with the pressure distribution around the impeller with and without minor change in its position (by 0.5 - 1.0 mm) relative to the casing. The maximum bearing temperature is found at full open delivery valve (low delivery pressure). It has been observed that the reduction in asymmetric pressure distribution reduces the bearing temperature rise to the order of 10℃. It is seen that a small eccentricity of 1.0 mm in the position of impeller with respect to the volute casing gives less asymmetric pressure distribution at the low delivery pressure where as at high delivery pressures, it results in higher asymmetric pressure distribution compare to the concentric mounting of the impeller.