Hammers Arrangement Optimization And Rotor Dynamics Analysis On Scrap Metal Shredder

The scrap steel processing production line is essential to the processing of scrap steel or other metallic material in steel production industries and the scrap metal shredder is the most important link of the production line. The characteristics including crushing ability, working efficiency and service life of the shredder can directly influence the utilization rate of scrap steel. It's important to study the reliability of shredder to ensure the shredder is safe and efficient. The rotor is the most important component of the hammer crusher. The lopsided parts on the rotor will cause vibration, noise when the crushers running, even cause the life of the crusher shorter. The structural design and the dynamic balance design are two critical problems of the rotor.In this paper, the author completed the dynamic analysis of a simplified model of the PFY2026 scrap steel crusher's rotor and wrote out the differential equations of equilibrium about the hammer's motion. The author carried out the angle curve and angle velocity curve of the runout of the hammer by MATLAB. With the curves, we can get a intuitionist knowledge about how the mass, barycenter position, coefficient of friction of the hammer and the power of the crusher will influence the motion of the model. The simulation can also provide reference for the design of the rotor.Not only because of their initial production but also the wear and tear during the operation the mass of the hammers may cause large difference. Hammers'difference of mass is the critical reason of the dynamic unbalance of the rotor. For the dynamic balance design of the rotor, it's not simply to increase two balancing mass blocks, we have to minish the mass of the blocks to minish the mass of the whole machine. For the PFY2026 scrap steel hammer crusher, the author set up optimized math model of the dynamic balance design. The optimizing goal is getting an arrangement of the hammers and protection plates to minimize the unbalanced force. This optimized math model is an NP-hard combinatorial optimization problem.Ant Colony Optimization Algorithms (ACOA) is a popular combinatorial optimization algorithm in recent years. Inspired by the action of ant colonies–foraging, the Italian researchers M.Dorigo initially proposed Ant Colony Optimization Algorithms in 1991. There are a lot of researchers studied this algorithms with which they had solved several problems, such as Traveling Salesman Problems, quadratic programming, 0-1 knapsack problems, etc. Until now, researchers continuously study to improve the ACOA and the ACOA show the better and better performance.Because of its advantages in resolving combinatorial optimization problem, the author chose the ACOA to solve the optimized math model of the dynamic balance design of the PFY2026 scrap steel hammer crusher. The theory and development was introduced first, and then the author presented some improvement for this math model, including establishing a multi-dimensional matrix to store the pheromones released by the ants, separating the first cycle from others, altering the pseudorandom number q₀ according to the convergence. The author finally got a reasonable arrangement of the hammers and protection plates on rotor by the ACOA; the unbalanced force was reduced remarkably. That means the ACOA can be used on the arrangement of hammers of PFY2026 scrap steel hammer crusher and is of significant reference to design the dynamic balance of the rotor.