ANALYSIS OF CRITERIA FOR EVALUATING THE PERFORMANCE OF TRIERES

The analysis of the studies of the technological process of indented cleaning of grain mixtures is performed. It is noted that the experimental studies of most authors are characterized by typical shortcomings and objective limitations: imperfection of the experimental base, biased initial information on the problem of indented technologies, inadequate criteria for assessing the efficiency of indented cleaning, underestimating or ignoring the quality indicators of the process. It is established that the criterion of "scooping capacity" used by many authors to assess the results of experimental studies is not related to the functional purpose of indented cleaning technologies, which consists in the qualitative separation of grain mixture components based on the length of particles. The erroneous assertion of a number of authors about the linear relationship between the "scoopability" criterion and the speed mode of the indenter operation has been revealed, since this does not take into account the influence of the physical effect of "eating" grains from the cells with an excessively large number of circulating layers of the grain mixture in the segment and the physical effect of inertial retention of the contacting layer, which manifests itself when the number of circulating layers in the segment is reduced to 4-5 pieces. It has been established that the frequently used criterion for assessing the efficiency of indenters (E), expressed as "the ratio of the weight of the main crop in the original mixture and the weight of impurities found in the main crop after processing the mixture" is of little use and excludes comparison of assessments. When separating a long impurity, the residual contamination exceeds the initial content of the short fraction, and when separating a short one, the residual contamination exceeds the initial content of the long impurity. When assessing the efficiency of the indenter unit, when the short impurity component is initially separated, the numerator of the criterion E is zeroed for assessing the process of separating long impurities. In addition, the criterion E has a weak connection with the modern understanding of the technical level of indenters in terms of the qualitative indicators of their use: the degree of separation of impurities; residual contamination; technological losses of full-value grain of the main crop.