Design and construction of a solar biomass powdered continuous grain drying chamber.

Abstract

Well dried maize grains have an increased value in the daily living of humans it is used as food in many institutions and also as a poultry and animal feed. However, its seasonal quantitative and qualitative loss is high due to the improper methods of drying used at farm level (the most growers). Drying. grains below MC of 13% causes loss in quantity sold by weight, while above 13% causes mould and fungal growth resulting in qualitative loss. This has discouraged many growers resulting in decreased production. Therefore, the objective of this study is to design and construct a continuous flow drying chamber that will dry maize grains to required moisture content. This chamber reduces the, losses, labor expenses and non-uniformities in the dried grains, The chamber was designed with conveyors at three levels that move the grains. Heated air is allowed in the chamber from the bottom resulting in a counter current flow with grains. The conveyers receive motion from motor and convey grains up to exit. Grains are conveyed as they gradually increase temperature and loose MC. Hence the conveyors- are made steel which has good thermal conductivity, food grade and durable. The different components were designed basing on the strength requirement, constructed and assembled. It is a continuous system for heat and mass balance. Also the project has a payback period of 3.09 months and 59% efficiency. I recommend the drying chamber to have an increased insulation so that less heat is encountered. Also it requires the chamber to be taken nearer to grain growers who will be taught to operate it using user guide. Generally, with this chamber implemented, the losses will approximately reduce by 90%.