Cooling tower operation for Example

Amount of process water sent to the tower per unit mass of air is 

The exiting temperature of the water for this operation can be computed from a total energy balance about the tower. Reviewing each term in the energy balance  

In writing Equation 5.7 we have used a reference temperature of 0°F for air. Note that Hj 2 s enthalpy per pound of dry air and includes the heat of the vapor associated with a pound of dry air. 

An energy balance for the water component alone gives 

The amount of makeup water that is needed to compensate for evaporation losses is 

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