12.48 Moist air enters a device

operating at steady state at 1

atm with a dry-bulb

temperature of 55°C and a wet-

bulb temperature of 25°C.

Liquid water at 20°C is sprayed

into the air stream, bringing it to

40°C, 1 atm at the exit.

Determine

a. the relative humidities at

the inlet and exit.

b. the rate that liquid water

is sprayed into the air

stream, in kg per kg of dry

air.