Optimization Design And Analysis Of Mixing Device Of Local Cold Regenerator

As the main means of road restoration,in-situ cold regeneration technology has attracted the attention of the road community for its advantages of "energy saving,environmental protection,and short construction period".Efficient and uniform mixing of recycled asphalt mixture is the prerequisite for ensuring road quality.The mixing device is the key equipment of the on-site cold recycling machine,which directly affects the mixing efficiency and mixing uniformity of the recycled asphalt mixture.The thesis takes the in-situ cold recycling machine mixing device as the research object,and aims to produce uniformly regenerated asphalt mixture with high efficiency and high quality,and conducts research on the optimal design of the in-situ cold recycling machine mixing device.Based on the theory of discrete element similarity,dimensional analysis,discrete element method and other related theories,the particle model and contact model representing the physical characteristics of particles are established by the combination of theoretical analysis and numerical simulation,and the comprehensive index of mixing efficiency and mixing uniformity is constructed,The influence of key parameters of mixing plant on mixing performance is explored,and the main structural parameters of mixing bin are further optimized.The specific research contents are as follows:1.Deeply analyze the cold regeneration process in place,explore the particle movement law in the mixing process,and determine the key parameters of the mixing device.Based on the study of cold recycling technology in place,the paper analyzes the throwing process of particles and the collision process between particles and mixing bin in the mixing process of recycled asphalt mixture,and preliminarily designs the mixing device of cold recycling machine in place by analogy method of similar equipment.2.Based on the similar theory of discrete element,the characteristic model of Engineering particles is established by the superposition method.Based on the analysis of particle characteristics,it is found that the resistance of non spherical particles is greater than that of spherical particles.In many non spherical particle modeling methods,the superposition method can not only ensure the authenticity of particle shape factors,but also not make the simulation calculation too large.3.Explore the influence rule of the key parameters of the mixing bin of the local cold regenerator on the mixing performance.Because the particles in the mixing process of recycled asphalt mixture have the characteristics of "loose" and "dynamic",the discrete element method is used to simulate the mixing process of recycled asphalt mixture under the key parameters of mixing bin.The milling depth,front wall angle,top wall height and top wall length were selected as the experimental factors,and 27 groups of mixing bin models were established by using the orthogonal experimental design method,and then the mixing process and mixing rules of recycled asphalt mixture were analyzed.4.Optimize the design and analysis of the key parameters of the cold regeneration mixing bin.The multiple nonlinear regression method is used to establish the regression model,which is used as the fitness function.The key parameters of the mixing bin are optimized by the particle swarm optimization algorithm with the goal of high-efficiency mixing uniform recycled asphalt mixture.The research results of this paper put forward new ideas and methods for the mechanical design and optimization under the action of fluid structure coupling,and laid a theoretical foundation for the development of the cold regenerator mixing bin.