Chemical Engineering Basics - Engineering

Q1:

The suction and delivery pressure for a two stage compressor are 1 and 25 atm respectively. The intermediate stage pressure would be around __________ atm.

A 5

B 10

C 15

D 20

ANS:A - 5

To find the intermediate stage pressure in a two-stage compressor, we can use the concept of pressure ratio. The pressure ratio r for each stage of compression in a multi-stage compressor is typically the same. It's the ratio of the delivery pressure P2​ to the suction pressure P1​. Given:

  • Suction pressure �1=1P1​=1 atm
  • Delivery pressure �2=25P2​=25 atm
The pressure ratio r is calculated as: r=P1​P2​​=125​=25 Since it's a two-stage compressor, each stage will increase the pressure by the same factor r. Therefore, the intermediate stage pressure intermediatePintermediate​ would be the square root of the delivery pressure: intermediate=Pintermediate​=P1​×P2​​ Substituting the given values: Pintermediate​=1×25​=25​=5 atm So, the intermediate stage pressure would be around 5 atm.