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This article presents the analytical expression for the determination of the degree of milling of particles in a centrifugal counter-flow mill with a selective effect on the material to be milled. The degree of milling is one of the most important factors characterizing the efficiency of particle collisions in the opposite intersecting flows in the tangential sleeve. The projection w x of the velocity of interaction of particles with an oblique impact is determined on the basis of the value of the tangential stresses in the zone of opposing intersecting flows. In this case, the density of counter-intersecting flows should be such that the collision of particles occurs in the zone of milling. The structural design of the mill rotors provides separation of the particle fluxes in the tangential sleeve depending on their size. This design of the rotors improves the efficiency of grinding and fineness of the finished product. A design diagram is given in order to describe the process of milling of a material in the zone of opposing intersecting flows. As a result of theoretical studies, the analytical expression was obtained that allows determining the degree of milling of material particles in the zone of tangential collisions depending on the design and technological parameters of a centrifugal counter-flow mill.

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The calculation of the design parameters of a disc mill equipped with a feeder made in the form of a conical hopper is given. For shredders of the disintegrator type, it is very important to ensure the uniformity of loading of the crushed material of the working zone of active impact on particles. In addition, the most important factor is the throughput capacity of all sections of the grinding plant. The throughput should be determined by the design and technological parameters of the working chamber of the mill. Its overload can lead to a blockage of the working chamber, and insufficient throughput will negatively affect the intensity and effectiveness of the impact on the particles of the material. For example, insufficient concentration of particles in the secondary zone of the grinding chamber leads to a decrease in the efficiency of mutual abrasion. The article attempts to determine the design and technological parameters in the loading and accelerating parts of the disk mill. At the same time, it is necessary to coordinate the throughput of the disk spreader and the volumetric flow rate of the material particles flowing from the hopper. In this case, it is advisable to take into account that as a result of a rather high rotational speed and the size of the initial particles, with the wrong height of the radial blade of the spreader, material particles can roll over the radial blades, which leads to a delay of the material in the zone of the spreading disc. Therefore, it is necessary to determine the calculation formulas for finding the required height of the radial blade of the spreading disc, depending on the size of the initial particles. The formula demonstrates that the height of the separating blade depends on the particle size, the speed of rotation of the disks and the distance to the point of meeting of the particle with the radial blade.