Improvement on the Design of a Cabinet Grain Dryer

Abstract

Problem statement: Grains are routinely seen dumped in villages and major cities during the peak of harvest. Therefore it is necessary that these grains are properly dried and stored to ensure availability and wholesomeness throughout the year. Advancements have taken place in the practice of drying since the first world war. Manufacturing methods have greatly improved production rate and the production line bottle-neck created by extended drying time inherent in the use old drying methods can no longer be tolerated. Main objectives of this study were to improve on the design of an existing cabinet grain dryer (to redesign the already existing cabinet grain dryer so as to: (i) Optimize efficiency at low cost (ii) Reduce total time of drying (iii) Produce viable and quality grain. Approach: The improvement on the design of the existing cabinet dryer had been achieved through proper focus on the selection of power source, materials and other design criteria for the various components of the existing one. The dryer consists of a cabinet containing trays in which the grains to be dried are spread. After the grains were loaded, the cabinet closed and heated air of about 35-40°C blown across the grains. Heat was supplied by an electrical heating coil and hot air was blown from the heater housing to the drying chamber by the aid of a fan. The dryer also consisted of a thermostat which turns off the machine if inlet temperature exceeds 40°C. Results: The result of the improvement on the design of a cabinet grain dryer showed that; (i) It was less costly (ii) It was cheap to maintain since the fan is the only moving component and can hardly become faulty (iii) drying time of the grain was reduced (iv) The machine ergonomic; operation of the machine does not require specialization (v) The machine is safer to operate since the use of gas has been eliminated (vi) Time between two batches was reduced with the introduction of a trolley (vii) Energy for loading or unloading reduced since the trays can be loaded and unloaded outside the cabinet. Conclusion: Drying of grains safer since fire hazards were reduced owing to the use of gas in the previous design. Heater supplied the right quantity of heat and incorporates a fan which supplies right quantity of air needed to distribute this heat evenly to all grains in drying chamber. This made drying faster and grains are moderately dried.