Abstract
When centrifugal pumps are used for pumping high viscosity liquids, it is a problem that pump performance decreases as the viscosity of pumped liquids is higher. The causes of this, i.e., the change of influence on the efficiency of various losses accompanying the change of flow within the pumps, will be considered. In addition, friction loss reduction with viscosity increase is possible because outlet angle was 90° impeller has a shorter blade channel than outlet angle was under 90° impeller. In this study, it is a purpose to clarified about pump performance, internal flow, and shaft power when it changed the blade number of 90° impeller.
