Pump-down model of vacuum chambers with adsorbing walls

25th International Conference on Vacuum Technique and Technology

Rozanov, L.N.^1

Peter the Great St. Petersburg Polytechnic University, Politechnicheskaya Str. 29, St. Petersburg

195251, Russia^1

关键词: Adsorbed gas;    Adsorption heats;    Coverage degree;    Freundlich adsorption isotherms;    Gas release;    Initial pressure;    Internal surfaces;    Vacuum chambers;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/387/1/012067/pdf
DOI  :  10.1088/1757-899X/387/1/012067

来源: IOP

【 摘 要 】

The mathematical model is considered for the calculation of the pump-down characteristics of vacuum chambers with adsorbing walls. This model uses the dependence of the absorption heat on the logarithm of the coverage degree, which is obtained from the Freundlich adsorption isotherm. The dependences of pressure, gas release, adsorption heat and the amount of adsorbed gas on the pump-down time have been calculated. It is shown that there is a steady pump-down mode for water at 298 K, which does not depend on the chamber volume and the initial pressure, but is determined only by the area of the internal surface of the chamber.