Assessing the Effect of an Exhaust Fan on the Performance of a Rice Husk Fuelled, Flat Bed Paddy Dryer

Abstract

Considering the increasing cost of fossil fuels and its effect on the environment, most countries are turning to using renewable energy sources like Wind, Solar and Biomass. Kenya has abundant sources of  Biomass energy in the form of agricultural  and forest wastes (Agricultural wastes include, coconut husk, maize cobs, cotton stalks, sawdust, rice husks, etc).These abundant wastes  can  be utilized with appropriate combustion technologies   for drying the   grains  in order to reduce post harvest losses..

A flat bed paddy dryer  using rice husks as fuel   with the capacity  to dry  100 to 250kg  paddy was fabricated and its performance assessed at the Kenya Industrial Research and Development Institute (KIRDI).The tests were performed with  and without an exhaust fan and  paddy being  dried at three different depths that is 0.1m ,0.2m and 0.3m. Paddy at a moisture content (MC) of between 25-26% dried to moisture content of between 10% to14%.

The results showed that with paddy at 0.1 m it is possible to achieve safe storage Final Moisture Content of below 14% moisture content dried paddy at the top and bottom of the flatbed dryer. But at 0.2m depth of paddy and above the safe storage a uniform Final Moisture Content (FMC) was achieved with the use of an Exhaust Fan