Theoretical and experimental study of dry scroll vacuum pump

The rarefied gas flows through suction port, scroll clearance and discharge port are treated as leakage of dry scroll vacuum pump (DSVP). The models for predicting the above-mentioned leakage rate were derived in this paper. The model for predicting the heat transfer rate between rarefied gas and working chamber wall was also developed. Then, a general model for describing the working process of DSVP was set up according to the energy and mass conservation principle. This model can be applied to predict the performance of DSVP. The pumping speed for different suction pressures was obtained. Furthermore, the ultimate pressure and power consumption for different speeds were gotten. A good agreement between the theoretical results and experimental data was obtained. Finally, the volume ratio of prototype was changed and its influence on the performance was studied by experiment.