Loss Analysis of a New Type of Sewage Pump

Abstract

Authors have been proposing a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. And pump performance, internal flow and behavior of the radial thrust have been clarified by LDV measurement and CFD analysis. However, hydraulic design of pumps is integral calculus operation whereas flow analysis is differential calculus operation. Therefore, even if complicated internal flow was clarified by CFD analysis, it is difficult to improve pump performance if the cause and outbreak mechanism of each hydraulic loss were not clarified. This paper proposes loss analytical method of this pump equipped with a single blade impeller. As a result of having compared experimental values and CFD analysis values with loss analysis values about the head curve, they almost matched in a wide range of flow rates. When the flow flows backward to the impeller from the volute casing, the hydraulic loss becomes small in an appearance, but the power loss becomes excessive and the pump efficiency decreases.