Related Resources: fluid flow
Vacuum Pumping Speed per. ISO 21360-1 Formulas
Fluid Dynamics Vacuum Engineering and Design
Vacuum Pumping Speed per. ISO 21360-1 Formulas
Vacuum pump performance is rated in terms of throughput, pumping speed, and vacuum pressure capability. They are rated for either intermittent or continuous duty. Throughput is the product of volumetric flow rate and pressure. Pumping speed has units of volume/time and is the mean volume flow through the cross section of the inlet port of a vacuum pump. Determination of the pumping speed is described in ISO 21360-1.
Vacuum pump performance curves are plots of pumping speed as a function of inlet pressure. The lowest pressure that can be achieved by a vacuum pump can be calculated using the following calculator and equation:
pmin = p0 e ( -Sefft / V ) ) + Qo / Seff + QD / Seff + QK / Seff
Where:
pmin = deepest vacuum achievable,
p0 = initial pressure,
t = time,
Seff = effective pumping speed,
V = evacuation volume,
Qo = Outgassing flow rate,
QD = Diffusion flow rate,
QK = Permeation flow rate
Related:
- Converting scfm to acfm Equations and Calculator Flow Rate Measurement scfm (Standard Cubic Feet per Minute) and acfm (Actual Cubic Feet per Minute) Calculator
- Equivalence Table for Pressure/Vacuum Measurements (pressure reduction of 2 torr corresponds to 0.232% vacuum)
- Fundamentals of Vacuum Technology Dr. Walter Umrath, 200 Pages
- Knudsen Number (Kn) Equation and Calculator
- High Vacuum Technology fundamental properties of gases and vapors and their flow behavior
- Pressure Drop High Vacuum System Pipes per. Outlet Branch
- Pressure Loss Data for Sizing Vacuum Pipe, Low Pressure Vacuum System
- Time for Pump to Reach Rated Vacuum The time a given pump will take to reach its rated vacuum pressure depends on the volume of the system in cubic feet (cubic meters) and the capacity of the pump in scfm (sL/s) at the vacuum-rated pressure.
- Thermal Molecular Velocity of Gas Molecules Vacuum System Formulas and Calculator
- Vacuum Pressure Units Conversion From Torr to Various Units Calculator
- Vacuum Mean Gas Velocity Equations and Calculator
- Vacuum Technology and Space Simulation, NASA, 315 Pages
- Vacuum Engineering Calculations and Applications
References:
- Karl Jousten (Hrsg.), Wutz Handbuch Vakuumtechnik,
- Pupp / Hartmann, Vakuumtechnik Carl Hanser Verlag
- Schweitzer, Bleuler, Traxler, Active Magnetic Bearings, Hochschulverlag AG an der ETH Zürich
- Fremerey, Vacuum 32 (1982) S.
- Hobson und Redhead, Can. J. Phys. 36 (1958)
- Redhead, Electron Stimulated Desorption, Vacuum 12 (1962)
- Dawson, Quadrupol Mass Spectrometry, Elsevier Amsterdam (1976)
- Brubaker, 14th National Symposium, Am. Vac. Soc. (1967)
- Fachbericht Balzers BG 800003 Das Funktionsprinzip des Quadrupol Massenspektrometers. (1990)