Design and performance test of a fluidized bed dryer using dry cold air flow for drying marungga leaves

Abstract

Abstract The Marungga tree is a plant that offers numerous benefits. Its leaves can be processed into flour for further processing for various needs. Marungga leaves need to be dried before they can be made into flour. Marungga leaves are sensitive to heat, so high temperature drying should be avoided. Drying in the sun, or at room temperature takes a long time and is unhygienic. To address these issues, a fluidized bed dryer that utilises dry, cold air flow through dehumidification of the air is required. This research aims to design and test the performance of a fluidized bed dryer that uses dry cold air flow. The method used in the research starts from literature study, design, component manufacturing, assembly and performance testing of the dryer. The design results resulted in specifications of the dryer components as follows: dimensions of the drying chamber 500 mm in diameter and 800 mm in height, evaporator, condenser, compressor, blower each 1 HP. The results of the dryer performance test are as follows: dryer air temperature 34.2 °C, relative humidity 54.3%, and dryer air mass rate 0.25 kg/s, with a drying rate of 0.57 kgH2O/s. The evaporator of the cooling system can decrease the absolute humidity of the drying air by 1.6 kgH2O/kg dry air.