Question

Derive an expression for pump-down time.

Answer 1

HEY MATE HERE IS YOUR ANSWER:-

The compression ratio K0 eof a Roots pump is typically between 5 and 70. To determine this ratio, we first consider the volume of gas pumped and the backflow by means of conductivity CR, as well as the return flow of gas from the discharge chamber at pumping speed SR:

The compression ratio K0 eof a Roots pump is typically between 5 and 70. To determine this ratio, we first consider the volume of gas pumped and the backflow by means of conductivity CR, as well as the return flow of gas from the discharge chamber at pumping speed SR:pa⋅S=pa⋅S0−CR(pv−pa)−SR⋅pv

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