Experimental investigation of multi-effect regenerator for desiccant dehumidifier: Effects of various regeneration temperatures and solution flow rates on system performances

Abstract

We have experimentally measured the thermal performances (PR) of vacuum assisted multi-effect regenerator, which employs hydrophobic membrane to separate water vapor from LiCl solution with higher evaporation rates. We have modified the working principles of the conventional multi-effect membrane distillation (MEMD) by the transfer of heat from one stage to the other stage of regenerating module such that more energy can be recovered through multi-effect evaporation generated in each regenerating module with enhanced liquid vapor separation in the membrane. The PR and percentage change in desiccant concentration are measured for the temperatures ranging from 50 °C to 75 °C. The experimental results show that the conventional MEMD is not suitable for dehumidification applications due to higher feed concentration. We have modified the conventional MEMD system employing (i) one-steam-three-solution passes and (ii) two-steam-four-solution passes, which handles higher feed concentrations. The PR is found 0.7 for one steam three solution passes system.