Pengaruh getaran dan energi panas pada alat pengering surya ghe tipe kabinet

Abstract

Increasing heat and vapor transfer between air and product to be dried is an important issue in drying of agricultural products. Generally, manual mixing is used in order to increase the contact area between air and product to be dried. However in most types of dryer including GHE solar dryer this method will result in significant heat loss and inconvenient operation. In order to overcome the problem, a GHE solar dryer prototype equipped with vibrating method on drying cabinet was designed in this study. The objective of this study is to perform analysis and simulation about vibration and heat transfer process in cashew nut drying by using cabinet type GHE solar dryer. The designed prototype had dimensions namely length, width, and height respectively of 1 m, and drying capacity of 30 kg of cashew nuts. The heat source was solar energy and coal fuels. The vibration components were placed just below the drying rack serves to smooth the flow of hot air into the cashews which was put on the drying trays. The vibration component consist of motor, shaft and unbalance mass mounted to the shaft. Based on the experimental result, the effective motion of the samples being dried occured at rotational speed near its natural frequency for total mass of 20 kg as well as of 40 kg. The final moisture content of vibrated samples was lower (i.e. 3.5%) than the samples without vibration (i.e. 4.2%). The results of testing of cabinet type GHE solar dryer is obtained that the utilization of solar energy just as energy sources drying will result dryer air temperature below 60 ° C. Therefore, additional heat energy required from coal-burning fuels that can raise the temperature of air in the drying chamber. Increased air temperature in the drying chamber requires heat energy and heat exchanger out of qAPK = 23.3 kJ / s, and the results obtained through experiments showed that the average air temperature in the drying chamber can be reached, Trg = 59.6 °C. This heat exchanger has a length of 40 cm, width 60 cm, 30 cm high and made of aluminum material with a thickness of each plate of 1 mm. Furnace fuel placed under the heat exchanger and is equipped with manual equipment that can raise and lower positions of fuel so that the temperature varies in the drying chamber during the experiment can be minimized.