Modification of A Locally Made Electric Crop Dryer

Abstract

Physic nut is a biomaterial that litters villages during the seasonal period which requires effective drying for oil and bio-fuel production. However, the natural method of drying and the existing dryer are found ineffective due to prolonged drying time leading to poor quality control. Processing of dried physic nut is required to ensure preservation, availability throughout the year, easy shelling and extraction. The main objectives of this study were to improve on the design of an existing electric crop dryer with a view to optimize its efficiency, reduce the drying time and produce hygienic and quality dried physic nuts. The improvements on the design of the existing dryer were achieved by increasing the throughput on the capacity by improving the material selection for the various key component parts. An adequate size of electrical heating element with thermo-sensor which regulates the drying temperature and a centrifugal fan to blow hot air from the heat supply unit to the drying chamber were installed in the dryer. The results of the improvements carried out on the design of this dryer show that maintenance cost is reduced, since the fan is the only moving part which may rarely be faulty, drying time of physic nut was reduced, operation of the dryer does not require any specialization, the dryer is safer to operate, the energy required for loading and unloading have reduced since the trays provided are removable. Higher production rate and quality of dried physic nuts are achieved because drying temperature and air velocity can be regulated. The throughput capacity, efficiency and drying capacity of the modified crop dryer are 20 kg/batch, 79.84 % and 0.73 kg/h, respectively. This dryer is recommended for medium and large scale processors and dried products can be used for further application.

Keywords: physic nut, electric crop dryer, improvement on the existing design, temperature, drying  time.