Study on Separating by Shape Using Test Rice Grader (Part 3)

Analysis of Thickness Grader and Separating Standard

Abstract

1. An attempt was made to analyse the separating mechanism of Thickness Grader in which the separation was based on the thickness of the rice grain.
2. The separating process of Thickness Grader was observed by the application of the separating theory of screen. Since the clearance of the slit (s) and the thickness of the rice grain (t) are not uniform, therefore Monte Carlo simulation was used to derive the separating coefficient (K) expressed by the function of t/s and the residual quantity (Q) as shown in Equation 13.
3. The separating characteristics varied with the ratio of the clearance of slit and the thickness of rice grain; the revolution speed of cylinder in the range of 45-65 r. p. m. is preferable.
4. Any type of distribution of the clearance of slit and the thickness of rice grain can be used in the separating model; and the fractional recovery curve, the separating process and efficiency can be observed.
5. In order to increase the separating accuracy and rapidity, the improvement of uniformity of clearance of slit becomes necessary.
6. The following separating conditions are recommended to measure the ratio of rice grain of which the thickness is smaller or greater than the boundary thickness: supplied quantity is 100g, and separating time is 10sec. (standard revolution speed of cylinder is 67 r. p. m.). For the practical purpose of separation of Thickness Grader, it is important to consider the separating conditions from the fractional recovery curve.