Development of a Domestic Water Medium Rice De-Stoning Machine

Local rice processing by small scale agro-processor has suffered tremendous setback ranging from stone presence and foreign materials in processed rice. It has become critical to develop a domestic rice de-stoning machine that can be utilized by small scale agro-processors. As a result of these bottlenecks this paper has focused on developing a destoning machine that utilizes water medium for stone separation. The design was built using locally accessible materials. Major components of the machine being reservoir, hopper, de-stoning chamber, washing chamber, impeller, water filter, and brush drum. The developed de-stoning machine was powered by a 1.8 kW variable electric motor that communicated the rotating motion of the driving pulley to the driven pulley, which was supported by bearings, through a V-belt. The machine was developed and evaluated for its efficiencies with respect to stone separation and rice cleaning using 2 kg clean rice with 20 incorporated small stones of different sizes. It was discovered that 2 kg/10minutes and 20.04 kg/hour of processed rice were de-stoned at a speed of 400 rpm, which is the optimal speed for maximum separation process. The de-stoning machine's effectiveness in terms of stone removal is approximately approaching 100 percent free of impurities. This discovery elucidates the potential to deal with the challenges of stone removal from locally produced rice using hand and manual method, which are inefficient, time and energy consuming, therefore this developed machine acts as a rice processing industry innovation.