Justification of kinematic, power and design parameters of a roller crusher for disintegration of composite materials waste

The relevance of the work is explained by the significant problems of the modern aerospace industry, mechanical engineering, energy, mining, processing and other industries in the disposal of waste products made of composite materials and products based on composites of various functional purposes (carbon fiber, fiberglass, metal-ceramic and cast glass reinforced). The aim of the work is to increase the efficiency of processes for obtaining micron fractions of composite materials waste through the use of an upgraded roller crusher-shredder design. Computational and experimental studies have substantiated the possibility of increasing the efficiency of waste recycling of composite materials due to their gradual (step-by-step) disintegration. Based on analytical calculations and finite element analysis methods, a kinematic scheme, layout and design of an upgraded prefabricated roller crusher-shredder with working bodies (discs) in the form of an equiaxed contour – a Relo triangle – have been developed. The new design implements a more complex system of forces (compression, friction, alternating cyclic loads) compared to analogues, which makes it possible to increase the speed and productivity of the crushing process. The process of cutting the material using the “rotating scissors” mechanism is implemented between adjacent counter knives of the PK profile, which also contributes to more intensive grinding of the material (especially when processing lamellar or long fragments of waste). The original location and inconsistency of the contact points of the oncoming profiles, the gap between the discs during their rotation creates a rolling effect due to the reciprocating movement of the crushed material, which reduces the risk of jamming and increases the throughput of the grinding rolls and the intensity of the disintegration processes. In order to determine the best performance in terms of the size of the working bodies of the crusher, the gap between them when grinding materials with different sizes and properties, kinematic models were created to simulate the grinding processes and conduct a numerical experiment using finite element analysis methods. It is shown that due to the effective combination of various fracture mechanisms (abrasion, crushing, cutting, alternating loads), the intensity of deformation processes and specific loads on the material increases, but the stresses on the working surfaces of the crusher vary in the range of 430–580 MPa, the safety margin of the working bodies increases to 0.43–0.65, which is a prerequisite for increasing the service life of the workers. grinding elements. The results of calculations using new methods and kinematic schemes show that the design of the upgraded prefabricated roller crusher with working bodies in the form of a Relo triangle has an increased resultant speed (by 30 %) and productivity is almost 2 times higher than the prototype with cylindrical rolls (with the same or comparable sizes of working bodies, kinematic parameters in terms of rotation speed and drive power). Design and technological preparation was carried out and a prototype of the installation for experimental studies was made, which confirmed a good agreement between the calculated and experimental data on the size of the gap, the speed and productivity of the crushing and crushing process.