Centrifugal Pump Lab Report

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This report examines a study on the performance characteristics of a centrifugal pump; conditions under which cavitation appears and the net positive suction head, and power consumption in a stirred tank. The performance of a centrifugal pump was evaluated by determining the total head, power consumption, and efficiency. Cavitation was measured and used to determine the net positive suction head (NPSH). Additionally the power consumption for different mixing agitators was calculated using the Reynolds number, Power number, and Froude number.
The experiment was divided into two parts using two different pieces of machinery, a centrifuge pump and a mixing tank. Part one studied two different aspects of pumping, the performance characteristics of a pump and conditions that cavitation occurs under. The performance conditions part of the experiment was conducted at three flow rates from 1000-3000-rpm. The total head decreased as the volumetric flow decreased, but had higher values under higher pump speeds. Power consumption and efficiency of the pump increased with flow rate and pump speed. The cavitation
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These values are in Appendix A. Bubbles from cavitation occur when suction pressure was raised higher than the vapor pressure. Cavitation causes harm to a system as it “reduces the pump capacity and causes severe erosion” [2]. Cavitation can be prevented by the vapor pressure being exceeded by the inlet pump pressure, or the NPSH [2]. A cavitation experiment was performed to determine the NPSH at a pump speed of 3000-rpm, using the pressure drop and flow rate. Determination of this value was used to establish safe ranges that the NPSH could operate within to prevent cavitation in the future. The safe change in the net positive suction head for the system over volumetric flow rate is shown in Figure