The Utilization of Solar Heat with Variations of Roofing Materials in Drying Equipment

Abstract

AbstractSolar heat is often used as a heater in the drying process, both traditional/conventional and mechanical drying with drying equipment. The objective of using a mechanical dryer is to increase the air temperature in the drying chamber by using heating from a solar collector or fuel. Heating from the solar collector commonly generates temperatures between 50 ℃ to 70 ℃ in the drying chamber. Many studies on collectors use a bottom absorber system with a glass cover. However, there are not many studies on the collector with an upper absorber system as a heater or upper heater. Solar collectors use materials with high thermal conductivity (materials with the ability to conduct heat), such as aluminum, copper and iron. In addition to high thermal conductivity, the material is also expected to function as a high absorber. This study examined the reduction in moisture content of agricultural products by utilizing heat from the roof as a solar heat absorber equipped with a heat collection channel to transfer heat into the drying room. Variations in roofing materials tested were aluminum, iron, iron coated with iron sand and zinc. To increase the temperature of the drying air in the heating channel, a sharp turn channel system was formed. Based on results obtained in this line of research, it indicated that the heater with the iron roof type was the best heater to distribute temperature, with discharge pipe of 63 ℃ and room temperature of 41.1 ℃. The four roof variations met the requirements for standards quality of agricultural product with an average reduction in moisture content of 9.7%. The iron roof type generated the fastest reduction rate in mass of agricultural product, while the aluminum roof type generated the longest reduction rate in mass of agricultural product.KeywordsDrying processSolar collectorsAbsorberRoof materialAgriculture product