Author(s): Yifan Zheng

Linked Author(s): Yifan Zheng

Keywords: Lift Pump Station; Compact Design; Formed Suction Inlet; Siphon Action;

Abstract: Lift stations have been frequently used for flood control and power plant cooling water applications. While lift pump capacity varies, it is not uncommon to have high capacity of up to 500,000 gpm for each lift pump. With the large capacity pumps, it is very important to be able to design the lift station within a compact foot print to be cost effective. In this paper, discussions on the effective use of formed suction inlets (FSIs) to achieve the compact lift station hydraulic design will be provided.
For a lift station with pumping over a levee or a berm, a siphon recovery scheme is typically used to reduce the motor size and satisfy economical lift station operation requirements. The resulting pumping head simply equals the pool-to-pool lift head, plus the internal friction and minor losses of the pump suction and discharge piping. The siphon formation can be created and maintained via a priming system (the assisted siphon generation), or by purging the air out of discharge line at sufficient critical velocity as part of the lift pump starting process (the unassisted siphon generation). Key considerations for the unassisted siphon generation will be discussed.
As a case study, the paper will describe the hydraulic design of a lift station for a thermal power plant using once through cooling water from Lake Michigan. The lift station has four lift pumps, each with a capacity of about 200,000 gpm. The paper will discuss various design considerations to achieve a compact hydraulic design and describe steps to achieve efficient use of unassisted siphon. The paper also describes findings from the physical model testing of this lift station using FSIs.

DOI: https://doi.org/10.3850/38WC092019-1002

Year: 2019