Q1: Interstage coolers are provided in a multistage compressor to

ANS:A - save power in compressing a given volume to a given pressure.

Interstage coolers are provided in a multistage compressor primarily to save power in compressing a given volume to a given pressure.

Explanation:

1. Multistage Compression:
   • In a multistage compressor, the compression of gas or air occurs in multiple stages, with each stage increasing the pressure of the gas step by step.
   • Interstage coolers are installed between stages to reduce the temperature of the compressed gas before it enters the next stage.
2. Purpose of Interstage Coolers:
   • Saving Power: As gas is compressed, its temperature increases due to the adiabatic compression process. Higher temperatures increase the work required for further compression stages. Interstage coolers remove some of this heat, reducing the temperature of the gas before it enters the next stage. This reduces the work required for compression in subsequent stages, thereby saving power.
   • Efficiency: Cooler gas is denser, which reduces the volume and pressure ratio requirements for subsequent stages, improving overall efficiency.
3. Other Functions:
   • While interstage coolers primarily save power by reducing the work input required for compression, they also indirectly contribute to cooling the delivered air to some extent. However, their primary role is power saving rather than cooling the delivered air or achieving exact delivery pressure.
4. Conclusion:
   • Therefore, the main purpose of interstage coolers in a multistage compressor is to save power in compressing a given volume to a given pressure by reducing the temperature of the compressed gas between stages.