Development of a Threshing Device for Pearl Millet

Abstract

Millets are high energy and nutritious foods recommended for the health and well- being of infants, lactating mothers and elderly people. Threshing of this crop still poses a lot of problems to local farmers. To make millet farming integral in Ghana, engineers are making concerted efforts to produce simple farm implements. This will complement other measures adopted by other stake holders to ensure that there is food security. This paper therefore presents a community based millet thresher to reduce the burden farmers go through in threshing pearl millet. The millet thresher has a thresher welded to a steel shaft and then supported on a frame. Connected to the thresher are; an input mounted on the thresher and an output fitted to the exit of the thresher. The output comprises a sieve and a tray. A centrifugal fan supported on the frame supplies air that winnows the threshed grain coming out of the tray and the cleaned millet grains fall into a collector. The millet thresher mainly employs the effects of friction (taking advantage of the fact that millets can be effectively threshed by rubbing the panicles on a rough surface) for threshing. Results show that the thresher rotates in the anticlockwise direction at a speed of 950 revolutions per minute with shaft diameter of 30.88 mm calculated from the equivalent torque. The millet thresher would reduce the long laborious hours spent in threshing and improve the quality of the grains since the possibility of the wind introducing foreign materials into the millet is reduced.