Biomass Burner with Flue Gas to Air Heat Exchanger for Rubber Sheet Drying

Drying is one of means for preservation of many kinds of agricultural products, food and rubber. The aim of this paper is to design and construct biomass-fueled dryer which its operation subject to forced convection to dry the rubber sheets. The multi-pass shell and tube heat exchanger was fabricated and installed inside a small biomass oven to produce hot air and supply to the drying chamber. This dryer is designed for small-scale commercial producers of agricultural products in non-electrified locations. Several stainless steel tubes and junction boxes were connected to build the air flow path through the heat exchanger. A 370W centrifugal blower was employed to force the air to flow throughout the piping system. A return air duct was constructed for efficient use of combustion energy. To effectively run the system, the preheating period should be set in the first hour by providing 5 kg firewood at the beginning. Next, the rubber sheets were loaded into the drying chamber and the firewood feed rate was 1 kg per hour. During 4 hours of drying, the system was able to keep the temperature in drying room at 54.3  3.5 C o and the total weight loss of a sample rubber sheet was 90 gram.