PositiveDisplacementPump

Process Description

Positive displacement pump delivering constant volumetric flow regardless of discharge pressure. Essential for precise metering, high-pressure applications, and viscous fluid handling in chemical processes.

Key Equations

Volumetric Flow:

\[Q = \eta_{vol} \times V_d \times N\]

Power Relationship:

\[P = \frac{Q \times \Delta P}{\eta_{overall}}\]

Slip Flow (Gear Pumps):

\[Q_{slip} = \frac{\Delta P \times clearance^3}{12\mu L}\]

Torque Requirement:

\[T = \frac{\Delta P \times V_d}{2\pi \times \eta_{mech}}\]

Process Parameters

Parameter	Symbol	Range	Units	Description
Displacement	V_d	1 - 1000	cm³/rev	Volume per revolution
Volumetric Efficiency	η_vol	0.85 - 0.98	dimensionless	Accounts for slip
Overall Efficiency	η	0.70 - 0.90	dimensionless	Combined efficiency
Max Pressure	P_max	10 - 700	bar	Design pressure limit

Industrial Example

Results

Process Behavior

../../../_images/PositiveDisplacementPump_example_plots.png

Application Analysis

../../../_images/PositiveDisplacementPump_detailed_analysis.png

References

Wright, W.A. “Pumping Manual, 9th Edition” Elsevier, 1999
Volk, M. “Pump Characteristics and Applications, 2nd Edition” CRC Press, 2005
ANSI/HI Standards “Positive Displacement Pumps for Nomenclature, Definitions, Application, and Operation” HI, 2017