Design and modelling of vacuum experimental set-ups

Abstract

This thesis deals with study, modelling and designing of some laboratory apparatus in Cryogenics Engineering and Vacuum Technology field. The project is totally educational oriented. Project's aim is to give a clear idea about vacuum technology and modelling of such vacuum experimental set-ups which can serve as the laboratory experiments for both undergraduate and post graduate students. This project work is broadly classified into three parts:-- (i) Study, selection techniques and designing of some vacuum components. (ii) Modelling and operation of vacuum experimental set-ups. (iii) Making bills of materials for the proposed experimental se-ups. The experiments to be done are namely; (i) Study & Calculation of pumping speed of diffusion pump. (ii) Study & Calculation of pumping speed of roots pump. (iii) Study & Calculation of pumping speed of vacuum ejector pump. (iv) Study & Calculation of pumping speed of cryopump. (v) Calibration of vacuum gauges using primary gauges. (vi) Study and calculation of boil-off rate & heat transfer characteristics of vacuum insulation. Design of various components is done like vacuum chambers, thickness and length of pipe lines etc. So many calculations are done like calculation of pumping speed & flow rate of rotary pump, diffusion pump, roots pump and cryopump. Also calculation of boil-off rate of LN2 in vacuum insulation experiments is carried out. Constant volume method and constant pressure methods are used for pumping speed calculation. Vacuum insulation is studied in three ways one is with plain vacuum, second is with powder vacuum and the third one is with multilayer insulation.