Experimental Study of Humidification-Dehumidification Desalination System

Abstract

Abstract The object of this research is to investigate experimentally the principal parameters concerning a system for water desalination by air humidification-dehumidification. A test rig was designed and constructed to carry out this investigation. The main parts are the humidifer, the dehumidifer, and the heating equipment for heating both air and feedwater before humidification. The variables examined are the inlet water and air temperatures to the humidifier, both water and airflow rates through the system, and the inlet cooling-water temperature through the dehumidifier. Computer programs were developed to correlate the experimental data using multiregression and variance techniques. The relationships obtained were utilized to study the influence of the different parameters on the system responses: the system productivity, performance, feedwater recovery ratio, and size and productivity factors of the main system components. It was found that the inlet water temperature to the humidifier has the most important positive effect on the productivity of the system and feedwater recovery ratio. Increasing both the inlet water and air dry-bulb temperatures to the humidifier causes the system productivity and performance to increase appreciably. Moreover, the size factors of both the humidifier and dehumidifer will decrease. Recycling of air coming out of the dehumidifier has the advantages of increasing the system performance and decreasing the size factors of both the humidifier and dehumidifier.