EXPERIMENTAL-STUDY OF HUMIDIFICATION-DEHUMIDIFICATION DESALINATION SYSTEM

The object of this research is to investigate experimentally the princ ipal parameters concerning a system for water desalination by air humi dification-dehumidification. A test rig was designed and constructed t o carry out this investigation. The main parts are the humidifier, the dehumidifier, and the heating equipment for heating both air and feed water before humidification. The variables examined are the inlet wate r and air temperatures to the humidifier, both water and airflow rates through the system, and the inlet cooling-water temperature through t he dehumidifier. Computer programs were developed to correlate the exp erimental data using multiregression and variance techniques. The rela tionships obtained were utilized to study the influence of the differe nt parameters on the system responses: the system productivity, perfor mance, feedwater recovery ratio, and size and productivity factors of the main system components. It was found that the inlet water temperat ure to the humidifier has the most important positive effect on the pr oductivity of the system and feedwater recovery ratio. Increasing both the inlet water and air dry-bulb temperatures to the humidifier cause s the system productivity and performance to increase appreciably. Mor eover, the size factors of both the humidifier and dehumidifier will d ecrease. Recycling of air coming out of the dehumidifier has the advan tages of increasing the system performance and decreasing the size fac tors of both the humidifier and dehumidifier.