Experimental Study on the Performance Characteristics of a Microwave - Solar Heating Dryer

Abstract

The use of microwave energy for drying of agricultural products is recently developed due to the advantageous of heating the product much faster and more effective than conventional methods. Moisture content of agricultural product should be evaporated immediately after harvesting in order to inhibit microbial growth and decrease enzymes activity. This work aim to investigate characteristics of microwave-solar hot air drying of agricultural products such as rice grain and potato using a commercial microwave oven and hot air from a can solar collector. A domestic microwave oven was modified in order to operate as a microwave dryer device. The state of the art of microwave-solar heating was developed for investigation on drying performance of agricultural products such as grains and potato slices. Measurements on the temperature of drying chamber and moisture content of the product were conducted under different power inputs of microwave (low, middle and high) and intensity of solar drying. It was observed that microwave-solar air dryer proposed good heating performance and quality of products. Furthermore, temperature, moisture changes and drying rate could be controlled during the drying process.