Pumps and Gas-Moving

Equipment

Outline

Pump Power Positive-Displacement Pumps Centrifugal Pumps ComparisonCentrifugal Pump Performance Characteristics and Operating PointPumps in Series and Parallel

Outline (Continued)

•Scaling Laws •Net Positive Suction Head •Gas-Moving Machinery•Power•Isentropic Efficiency•Two-Stage Compressor

Objectives

•Introduce and compare the different types of pumps.•Calculate the electric and brake powers. •Calculate the volumetric flowrate in the case of reciprocating pumps.

Objectives (Continued)

Determine the operating point for centrifugal pump. Consider the case of pumps in series and parallel.Introduce scaling laws.Know how to avoid cavitation.

Objectives (Continued)

Introduce and compare the different types of gas-moving machinery.Calculate the brakepower.Minimize power in a two-stage compressor.

SummaryHead rise gained by the fluid

Brake power

Electric power

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Summary (Continued)

Positive-displacement pumps include rotary and reciprocating pumps.The different types of pumps have been discussed and compared.The operating point is found as the intersection of the pump performance curve, and the system curve.

Summary (Continued)

For pumps in series and parallel, new pump curves can be calculated, which allows to calculate the new operating points knowing the single pump performance curve.Scaling laws allow to estimate the new performance curves if we change rpm or impeller diameter.

Summary (Continued)

Requirement to avoid cavitation:

The different types of gas-moving machinery have been discussed and compared.

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Summary (Continued)

Brake power

Isentropic efficiency

To minimize compression power, a two-stage compression is used with intercooling.

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