UTILIZATION OF SILICA GEL AS A DESICCANT MATERIAL OF MOIST AIR USING IN DRING PROCESS

The dehumidifying process of moist air before using in drying process not only reduces the energy consumption in drying process but also improve the performance of the process. In this work, a new concept is developed by making the ambient air flows parallel on silica gel bed. A certain amount of the humidity of incoming air, which is removed by silica gel, depends on many parameters; the weight and thickness of silica gel, air flow rate and the bed diameter. The experimental work was carried out to investigate the performance and energy saving during drying process using the silica gel bed system. The obtained results indicated that the silica gel can be used as a desiccant material for removing the ambient air humidity and therefore increasing its efficiency during drying process of the agricultural products. The optimal conditions were; 12.5 cm bed diameter, 0.053 kg/s air flow rate and 1.2 kg silica gel weight. At these conditions the maximum values of water absorption rate, temperature increase and energy saving were; 6.4 g/kg air, 11 Cº, and 0.586 kW, respectively, and the minimum value of air moisture content (2.59 g/kg air) can be achieved.