Computer Simulation and Performance Analysis of a Purged Rotary Dehumidifier

The performance of a counterflow rotary dehumidifier can be enhanced if a portion of the process outlet stream is purged from the bulk flow, and the purged stream can be recirculated and introduced at the inlet of the regenerating period. In this study, the performance as well as the optimal design of such a purged rotary dehumidifier are studied. The heat and mass transfer phenomena involved in the purged rotary dehumidifier can be described by a transient one-dimensional mathematical model which is then solved by a rigorous finite-difference technique. In order to verify the feasibility of the dehumidifier model, model predictions are compared with experimental data of a commercial rotary dehumidifier which shows the overall relative error to be within 10%. Using computer simulation, the optimal purge angles for various operating conditions (air flow rates, rotational speeds) are investigated.