Development of mobile dryer for freshly harvested paddy

Abstract

Presently, due to an increase in usage of large scale mechanical threshers and combine harvesters, moisture content of freshly harvested paddy is being high as much as 18-24%. The mechanical threshers or combine harvesters with elevated capacity enable for both harvesting and threshing at once. Thus the paddy harvested all over persists with high moisture content that affects adversely in unit operations of paddy processing such as cleaning, storing, and milling. The research was conducted to overcome this problem by developing a mobile paddy dryer that can be used at field level for freshly harvested paddy. A mobile dryer, one ton capacity, was developed and tested for drying freshly harvested paddy. The performance of the mobile dryer was evaluated in terms of overall thermal efficiency, heat utilization factor, coefficient of performance, total heat efficiency and head rice yields. The overall thermal efficiency of this dryer was 46.83%. The average heating efficiencies namely heat utilization factor and total heat efficiency were 0.82 and 0.72 respectively. The coefficient of performance of the developed dryer was 0.18. The head rice yields of freshly harvested paddy after drying at 60 ºC air temperature was of 73.78%. The overall drying performance of the dryer was found to be good.