Evaluation of solid desiccant drying system for drying grains

Present study provides the applicability of desiccant drying system (DDS) for the drying of freshly harvested cereals grains in order to remove the moisture and safe level storage. Drying air conditions including the temperature and humidity affect the quality and appearance of the dried product. High temperature and higher humidity cause to loss of nutrient and color. Control of the latent load of drying air prior to use for drying seems more effective approach towards delicate and temperature sensitive grains like seeds of crop. DDS remove the moisture from the drying air and make it possible to dry at low temperature and low humidity. In present work the pertinence of DDS with two desiccant materials LiCl and Silica gel were analyzed. Drying of grains (wheat and rice) is studied for regeneration temperature 50-80ºC. Results showed that in case of desiccant material LiCl, process air temperature is higher and humidity is lowers as compared to the silica gel. Drying air potential per watt also showed that desiccant material LiCl found more economical to use as compared to silica gel for all range of regeneration temperature. However for different type of grains, there is optimum regeneration temperatures that give maximum drying potential per watt. For wheat and corn optimum regeneration temperature range found was 55-60ºC whereas for barly and rice was above 60ºC. Regarding the appropriate desiccant material used, LiCl was found appropriate choice for economical point of view however silica gel is appropriate choice for second approach.