Design guidelines for alternative formed suction inlets

Abstract

Formed suction inlets are often used to improve approach flow hydraulics to large vertical turbine pumps. Current design guidelines require that the pump bell be removed and the pump modified to allow for attachment of the formed suction inlet. The present research study was aimed at developing a dimensionless design procedure for a formed suction inlet based on pump bell diameter, which does not require removal of the bell, allowing for greater flexibility and economic feasibility for use in existing pump intakes. Model studies have shown this type of inlet to be successful at alleviating adverse hydraulic phenomena, but the results and design procedures are typically private and proprietary and are not readily available in the public domain. A formed suction inlet which can be constructed outside the sump and consists primarily of flat sides has been developed. The relatively simple geometry should minimise construction costs. In addition, the inlet is designed for use under existing pumps and does not require pump removal or modification.