DEVELOPMENT AND PERFORMANCE EVALUATION OF A STATIONARY RICE GRAIN DESTONER
The quality of local rice is a major concern for the future of the Nigerian rice sector. The major problem being the appearance and cleanliness of the rice delivered to the market. They are characterized by high percentage of impurities like husk and stones as well as under size/broken grains which reduces its economic value and makes it difficult to compete favourably with imported ones. Therefore, one of the important quality addition is reduction of contaminants especially stones to the barest minimum. In this research work, a rice grain destoning machine was developed based on the physical and aerodynamic properties of rice and machine characteristics. The dimensions and physical characteristics of three rice varieties; Kano, Zaria, and Mario were determined in the laboratory. The calculated destoning efficiency was 80% at a speed of 284 rpm and feed rate of 94 kg/hr. It was observed that physical properties like surface area, sphericity, and geometric mean diameter of rice increased with increase in moisture content from 10% to 16% with a regression coefficient of (R2) values of 0.96, 0.86 and 0.95 respectively. However, porosity of rice decreased with increase in moisture content with a regression coefficient of (R2) = -0.97. It was recommended that for enhanced separation of rice from stones the sieve tilt angle should be reduced from 15o to 8o so as to allow rice have enough resident time on the sieves.
Authors : Y. I. Tashiwa, S. A. Iya, B. Aliyu, and H. U. Kabri
Category : Open Access Volume (Issue) : 5(1) Date Uploaded : 22nd July 2019