Design and Testing of a Passive Solar Dryer for Banana Drying

Abstract

    Objective: This research objective was to study the design, construction and testing of a passive solar dryer for banana drying to suit the use of agriculturists. The solar dryer must decrease the moisture content of the bananas to between approximately 10 and 20 percent.

     Methods: The passive solar dryer that was designed and built had a transparent chamber with the dimensions of 0.8 × 1 × 1 m. The chimney was 0.2 meters in diameter,

1 meter in height, and was installed at the top of the drying room to increase air circulation

from the drying room to the outside. The solar collector, which the dimension was 0.8 × 1.25 × 0.05 meters, was installed in front of the drying room to increase the air temperature through the solar collector into the drying room.

     Results: The experimental results showed that the solar collector could increase the temperature at the entrance of the drying room to an average of 55 degrees Celsius, when the average ambient temperature was 35 degrees Celsius, and the average temperature inside the drying room was 53 degrees Celsius. Drying test was performed on 5 kg bananas on each testing. The bananas used in the test had 80 percent initial moisture content. To obtain 10 to 20 percent moisture content, the drying time was 36 hours at 526 watts of solar power per square meter. The dried bananas weighed 1.565 kg containing 11.28 percent moisture content, which was suitable for storage. It also saved time in drying bananas compared to traditional bananas drying.