Study on the Calculation Method for Pumping Process in as Vacuum System

Abstract

The calculation methods for vacuum system pumping were usually based on some simple theoretical models, the corresponding results had significant deviations from actual situations. In this study, medium and low vacuum systems (including vacuum chambers, pipes and pumps) were taken as research objects. With a measured vacuum system, and relationship between pump’s suction flowrate and inlet pressure, a new calculation method for vacuum pumping time was proposed, in which laminar or turbulent model was selected according to the pipeline’s flow state. New and traditional laminar method were used to calculate the pumping process of the measured system, which found that in the middle and high pressure stage, the pipeline flow was in turbulent state and the resistance was non-negligible. If the influence of turbulence was ignored, the calculated pressure drop would be faster than actual situation. The calculation result was verified by actual measurement result, indicating that new method is practical for vacuum pumping time calculation.

Development and Performance Evaluation of a Vacuum Drum Based Water Pumping System

“…The operation of pumping process takes longer time in the low pressure stage. The pumping time is more sensitive to the variation of the pumping speed in the low pressure stage [8]. A vacuum based water pumping system there has no moving parts, that's eliminating wear and particulate creation of vacuum inside the closed chamber and increasing reliability, also the power required is low as there has no valve are required, and the pumping system is silent, without noise being generated [9,10].…”