Desain dan Uji Kinerja Pengering Surya Tipe Terowongan Konveksi Bebas untuk Pengeringan Pisang

Abstract

Solar tunnel dryer is one type of solar dryers that is usually used. Main problem of this dryer is the electricity needs to turn on fan which is not available in isolate areas and heat flow distribution that have not been spread evenly. This research aims to design a solar tunnel dryer with air exchange process occurs naturally due to free convection, and to test performance of the dryer for banana chips drying and compare the results between the dryers which designed with sun drying. The observation parameters are solar radiation, themperature, ratio of humidity, and moisture content, whereas the total energy consumption used declared as specific energy consumption. Total drying time is 13.25 hours, total irradiation received is 26.23 MJ/m2, able to reduce the moisture content up to 14.58 % from the initial moisture content of 70.03 % with a specific energy consumption of 14.05 MJ/kg water evaporated. The dryer designed produce free convection air flow, heat flow pattern shows the distribution pattern of temperatures that peaked in the middle. Average air flow velocity at the inlet is 0.09 m/s, at the outlet is 0.12 m/s, and at around dryer is 0.59 m/s. The result showed that final moisture content of the dryer (14.58 %) is lower than the moiture content of sun dried sample placed 100 cm above the floor which as high as sample on dryer (24.42 %), but its still higher than sun dried sample placed 10 cm above the floor (13.21 %).