PEELING OF WHITE LUPINE GRAIN IN ROLLER MILLS

Abstract

In cereal production, there are a number of methods for grain peeling. The process of peeling lupine grain having a specific form, which differs from the spherical one, includes grain crushing, sieve screening, and pneumatic separating. Independent variables characterizing the processing conditions include the gap between the rollers, grain moisture content, the speed of the rollers, and their slippage. Roller mills (crushers) were used for crushing. The rotational speed of the rollers was 300 and 600 min-1. During pneumatic separation, the air speed in the pneumatic duct corresponded to 7.5 m/s. It has been established that the gap between the rollers and the grain moisture content significantly affect the quality indicators of the ground product. As a result of the experiments, it has been found that an increase in the gap in the range of 1.0...2.5 mm and an increase in the grain moisture content from 8 to 13.2% result in the increased output of middlings and the average size of particles. However, the number of core particles with shell remnants increases too, and the output of tailings (mainly, shells) decreases after pneumatic separation. The output of marketable kernel middlings was about 70%. The technological process of white lupine grain peeling is based on the traditional equipment of cereal production. The results obtained suggest the possibility of the primary processing of white lupine grain with such crushers to produce kernel middlings of the required fractional composition.