Evaluation of Geothermal Grain Dryers

Alternative applications of geothermal energy, also known as direct uses have over the years gained popularity globally. One of the major applications is drying where geothermal heat is used to raise temperatures over a product to reduce their moisture content. Different types of dryers are designed to utilise geothermal energy depending on the product to be dried. In order to maintain a quality product after drying, a good dryer design with optimal drying parameters must be emphasized. Different geothermal dryers have been constructed and used in different countries to dry different food agricultural products. Among these countries is Kenya whose first geothermal dryer was constructed in the 1920s through a community project, and has since been used in small scale to dry pyrethrum and maize in the Eburru geothermal region. Kenya has recently registered a new milestone after Geothermal Development Company (GDC) installed a modern semi-commercial batch grain dryer in the Menengai Geothermal Field.
This paper explores the various types of geothermal grain dryers, their design, technical parameters and operational costs in comparison with the new grain dryer in Menengai with an aim to establish an optimal design and size of a grain dryer.