Design of a Gas Scrubber The Adiabatic Case

Combining tirese equations, we obtain for the local temperature rise 

To construct the adiabatic equilibrium curve, one chooses a pair of values (X, Y) on the operating line, calculates Ti from Equation 9.8d, and with the 

Note the simplification that results from confining the heat effects to the liquid phase and assuming thermal equilibrium between the two phases. 

Had this not been done, an additional enthalpy balance for the gas phase would have been required, and the concept of the adiabatic equilibrium curve would have been jeopardized. Once the temperature rise has been accounted for and used in the construction of the adiabatic equilibrium curve, the entire procedure reverts to the familiar ferrifory of fhe isothermal case. The comfort and value of familiarity is not to be xmderestimated. 

An air dryer requires 1 kg/min (dry base) of air at 80dC and RH = 20%. The available air is at 25dC and RH = 50%, and is to be brought to the desired conditions by direct injection of steam. What is the minimum rate at which steam must be supplied, given that its latent heat is 2450 kj/kg  

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