Author(s): M. Naghash; Y. Zheng
Linked Author(s): Yifan Zheng
Keywords: No Keywords
Abstract: The guidelines for hydraulic design of pump intake structures, using vertical wet pit pumps, recommend the application of a pump bell design diameter (D) as the length scale for setting the dimensions of the pump intake structure [Hydraulic Institute 1998]. For design engineers, this length scale frequently is an unknown parameter prior to the purchase of the pump; consequently, the use of an estimated average design bell inlet velocity is recommended for estimating the length scale by design guides. Due to large range of velocity variations (about 75%) by the Hydraulic Institute 1998 design guide, the pump intake structure can be oversized or undersized based on the selected average design bell velocity criteria. For intake structures housing large multiple pumps, such criteria can result in either substantial additional cost to the project or underestimating the required size of the pump intake structure. The objectives of this paper are to evaluate the relationships between actual pump flow, pump bell diameter, pump discharge diameter, and pump rotational speed for pump capacities ranging from 5 m3/s to 26 m3/s and to provide recommendations to narrow the average design bell inlet velocity range criteria related to the large vertical pumps. In addition, the relationship between the pump bay average design velocities and design bell length scale selection is addressed. Applying the findings of this investigation, suggestions for the selection of a proper length scale for design of pump intake structures that house large vertical pumps are made.
Year: 2009