Development of a microwave continuous flow grain dryer.

Abstract

Maize (Zea Mays Li) was introduced in Uganda in 1.861 and the. estimated production is currently at 1.5 tonnes per hectare in the Tropics, Grains are usually harvested- when the moisture content is in the range of 25—33% which is too high for safe storage. This high moisture content sustains the bacterial and fungal activity, leads. to growth of mycotoxins, insect infestation; putrefaction: algal growth and other factors that compromise the quality and quantity of the grain, thus, drying is a necessity. More so, the functionality of the most common traditional method of drying i.e.: sun drying depends largely on weather conditions. The World Bank in 2012 estimated that Uganda loses 515% of the maize produced during the drying stage. due to generally poor drying methods. This report therefore shows the various design procedures and methods for the construction of a microwave continuous flow grain dryer. for off farm maize drying as a solution for the above mentioned problems; its performance and economic evaluation. The dryer has an efficiency of 62.5% and an average percentage shrinking rate of 0.064 %/s, it is easy to operate and requires one operator. The machine cost was UG Shs 1,154,000 and. has a payback period of I .92 years which can be afforded by most of the targeted people. This machine is adaptable and can be used in Uganda since it can be fabricated from any workshop using the available technology. The design of the dyer is a simple one for easy cleaning, assembly and disassembly; and safe operation, Since the quality of dried maize was high, it can be packed and sold at a higher market value. hence improving on the farmer's income. -Thig machine can reduce on maize drying time and labour as compared to the traditional drying method.