Abstract
For the present problems of farmers regarding climate change and economic crisis, this study aimed to design and construct an improvised mechanical grain dryer that can dry newly harvested palay to the desired moisture content for longer storage and with less operating cost. The dryer is a flat bed, batch-in-bin type of which some parts were recycled and improvised. The dryer uses the principle of heat convection in the drying process. The design was made such that after harvesting and drying the palay, the dryer can also serve as storage of dried palay. Rice hulls served as fuel for the dryer. It can dry to a maximum of 20 sacks per drying period. The performance and efficiency of the dryer were tested as the drying rate, final weight of the grain, moisture reduction per hour, fuel consumption rate, operating cost, return-on-investment, benefit-cost ratio and the payback period. There were three trials during the testing and each trial dried 15 sacks for 8 hours. Results showed that in average, the drying rate was 81.6 kg of palay per hour and the final weight of the grains was 606.83 kg. The moisture reduction rate was 5.75 kg/hr; the fuel consumption rate was 6.85 kg of rice hulls per hour. It also showed that the operating cost of the dryer was 0.27 peso per kilo which is half the cost of drying of a local rice mill. The Return-On-Investment was 47.5%, the Benefit-Cost Ratio was 1.34 and the Payback Period was 210.17 days. This means that the farmer will benefit for every peso spent for the dryer and save money in drying their grains and at the same time, the cost of the construction of the dryer will be recovered for the said period of time based on the set-up of the trials. This study will greatly help