Analysis of the research of the processes of crushing and crushing units in the department of machines and devices of chemical and silicate production
The article presents the results of scientific work on the study of grinding processes over the past twenty years. The objects of study were medium and high-speed grinding units, which have great prospects for use in production. A characteristic feature of such aggregates is a significant influence on the grinding process of inertia forces. To assess this effect, an inertial factor is introduced, representing the ratio of all inertial forces to gravity. The main research method is modeling, and in relation to the movement of the working bodies of shredders and the carrier medium. Additional method - experimental studies with a transition to industrial testing. Mathematical models of the movement of the crushed material on the surface of a rotating disk, which is an integral part of many mills, have been compiled. The trajectory of movement of single particles without contact with others, and taking into account mutual friction and even in the form of a layer of granular medium, is determined. The conditions for particles falling under the grinding roll, the size and direction of their velocity at the exit from the disk are established. The movement of grinding bodies and grinding material in high-speed centrifugal ball and planetary mills is considered. Modes of motion were determined, the influence of inertial forces on the destructive ability of the balls was evaluated. Experimental studies on superfine grinding in ball mills with mixers have been carried out. It is shown that nanoparticles can be obtained under appropriate conditions. Prospects for further scientific work are outlined. They consist both in the expansion of the number of objects and in a deeper study of the process of destruction, taking into account the influence of inertial forces. The following processes are obligatory for research: aero- and hydrodynamics, classification in combination with a closed-loop operation of shredders, and also abrasive wear.