Preliminary design and development of grain dryer fired by microwave

Abstract

This project aimed is to determine the potential of obtaining dryer grain in a microwave energy. Grain drying is one of the most energy consuming processes on farms. It has also a lot of potential for energy savings. Grain drying can be divided into different processes that is heat generation, heat transport, and drying. Drying process energy efficiency depends on the dryer heat losses, which are caused by the hot dryer surfaces. Furthermore, it also depends on the design of the dryer, the air distribution inside the dryer, and on air volume flow amount. Completely drying at the high mode of setting by microwave at 60-70 º C. The weight of grain become decrease by increase the temperature and increase the time. By doing a humidity test, increase a temperature become effect the decrease of humidity in the microwave drawer. At high mode setting, in 30 minutes the humidity in the drawer become lower to 33 % RH. It means that microwave are effectively drying the grain without damaged the quality of grain. The objectives of drying are the same as for any other unit operation is to process maximum product at minimum cost whilst maintaining adequate quality. Airflow rate, air temperature and air relative humidity influence drying speed. In general, higher airflow rates, higher air temperatures and lower relative humidity increase drying speed. Raising the temperature of the drying air decreases the moisture-carrying capacity of the air and decreases the relative humidity. The airflow rate also affects drying rate.