Study of Heat Supply in Taro Tuber Drying Process (Colocasia Esculenta (L.)) Using a Rack Type Dryer

Abstract

The rack type dryer is one of the artificial drying technologies for drying agricultural products. The drying process is highly dependent on the provision of heat. The purpose of this study was to determine the available temperature in the combustion chamber, the temperature generated in the drying chamber, the temperature in the heat conducting medium, and the outlet temperature in the taro tuber drying process using a rack type dryer. The method used in this research is experimental which is carried out in the laboratory of power and agricultural machinery. This test was conducted using a rack type dryer with taro tuber material. The number of shelves in the dryer is 8 shelves, consisting of 4 shelves on the left and 4 shelves on the right. The thickness of the sliced material is ±1 mm which will be dried with a temperature range of 40-45^oC until it reaches a constant material moisture content. In the drying process, taro slices were placed one by one without stacking on each shelf. The parameters observed were heat energy, heat supply to the drying chamber, the amount of heat in the heat conducting medium, heat loss and the amount of heat given to the drying chamber. The results showed that the average temperature available in the combustion chamber of the rack type dryer with coconut shell fuel is 92.39^oC with the energy generated from combustion of 78,260kJ and a combustion rate of 1.97 kJ/s, and the average temperature in the drying chamber of 39.58^oC. The average temperature on the heat conducting medium of the rack-type dryer on the inside and the pipe wall is 56.68^oC and 50.87^oC and the average outlet temperature of the rack-type dryer is 33.53^oC.