Isolation of long impurities from grain material on flat sieves

The presence of weed seeds in the seed material, such as oatgrass, Tatar buckwheat, as well as cultivated plants such as oats and barley, significantly reduce its quality. The isolation of these impurities is often a difficult task, which leads to additional energy and material costs. The analysis shows that the cost of seed preparation is about 25% of the total cost of grain production. Currently, the separation of grain material into two fractions along the length of the particles is carried out mainly by cellular surfaces of triers, the specific productivity of which remains low. It is possible to ensure an increase in the productivity of the separation of long impurities from the grain material by using flat sieves with round holes. In this case, a prerequisite is the movement of grain on the working surface of the sieve. Separation occurs when short particles pass through round holes, while long ones remain on its surface. In order to ensure high-quality separation of grain material into long and short particles, it is necessary to prevent the passage of long particles through the round holes of the sieve. As a result of the research, an equation of the probability of a long particle passing through the hole was obtained. It shows that the probability significantly depends on the length of the particle L , the radius of the sieve hole R and the maximum distance between the surface of the sieve and the end of the particle h . The probability of a long particle passing through the hole depends significantly on the ratio of the diameter of the hole to the length of the seeds l , so when l 1 = 0.50 the probability of a long particle passing through the hole will be P = 0.410, and when l 2 = 0.44, the probability is P = 0.039.