Chemical Engineering Basics - Engineering

Q1:

When water is sprayed on air, passing through an insulated chamber maintained at a temperature higher than the dew point of entering air but lower than its dry bulb temperature, then the air is

A cooled and dehumified.

B heated and humidified.

C cooled and humidified.

D heated and dehumidified.

ANS:C - cooled and humidified.

When water is sprayed on air passing through an insulated chamber maintained at a temperature higher than the dew point of entering air but lower than its dry bulb temperature, it undergoes an adiabatic saturation process. In this process:

  • The water droplets evaporate into the air, absorbing heat from the surrounding air.
  • The evaporation causes the air temperature to decrease (cooling effect) and its humidity to increase (humidification).
  • Since the chamber is insulated and no heat is added or removed from the system, the process is adiabatic, meaning there is no heat exchange with the surroundings.
So, the correct option is: cooled and humidified.