Failure Mechanism of the Gate of the Solid Pump for Urban Hazardous Waste Disposal

Urban disposal of hazardous waste is a key project for the country to solve the problem of hazardous waste. Conducting analysis and research on gate fracture failure not only provides basic data for product design in the hazardous waste disposal industry, but also breaks the monopoly of foreign equipment in China, breaks through the bottleneck technology blockade, develops core components to replace imports, and reduces maintenance costs for hazardous waste disposal units. This project first analyzes the three forms of fracture failure of solid pump gate plates. Macroscopic morphology observation, material chemical element determination, mechanical properties, hardness measurement, metallographic analysis, and SEM morphology analysis are carried out on the fracture surface. The transverse and longitudinal sections of the gate plate and the pits at the grain source show obvious loose characteristics. Then, based on the basic morphology of the fracture surface, it is determined that the fracture failure is caused by residual internal stress. Based on finite element simulation research, a mechanical model is established to determine the applied load, divide the grid, and determine whether the material strength meets the strength design requirements through finite element analysis. At the same time, it is found that the stress concentration position at the thread and the circular arc edge are the locations where fracture is prone to occur. Finally, the mechanical structure and heat treatment process were optimized, and the new gate was able to fully meet performance requirements by using stress reduction, deep cooling, and multiple tempering processes. No gate fracture failure occurred in engineering applications.