Study On Key Technologies Of Continuous Forced Asphalt Mixing Equipment

With the development of China’s construction of resource-saving and environment-friendly society,the shortcomings of high energy consumption and high sewage discharge of intermittent asphalt mixing equipment are increasingly prominent.Continuous asphalt mixing equipment is characterized by energy saving,environmental protection and high efficiency.It shows good application prospects,but the problems of inaccurate gradation and uneven mixing have yet to be solved.In view of the above problems,this paper has developed a new type of continuous forced mixing equipment with the advantages of continuous and batch mixing equipment,and has studied the key technologies of continuous forced mixing equipment from the following aspects:The grading accuracy of the continuous forced mixing equipment depends on the cold material grading method and the measurement accuracy of the belt scale.In order to improve the grading accuracy of the cold material supply system,based on the asphalt mixture gradation design theory,the mixing of coarse and fine aggregates is analyzed.The influence of the material performance has determined the key particle size to control the production quality of the mixture,and obtained the optimal number of silos;combined with the measurement principle of the belt scale,the structure design of the belt scale has been optimized to avoid the "belt effect" on the measurement results.As a result,the measurement error of the belt scale is reduced,and the self-calibration device of the belt scale is designed to realize the automatic calibration of the cold material measurement system.Aiming at the measurement error in the working process of the screw scale,based on the measurement principle of the screw scale,a mathematical model of the measurement error in the adjustment process was established,and the relationship between the measurement quality and the actual quality was analyzed using MATLAB software to determine the angular velocity of the feed screw flow change Under the condition of 5～20rad/s,the ratio of the length of the spiral scale to the moving speed of the material flow in the spiral scale should be8～4s.The structural parameters of the spiral scale are optimized.The online calibration system of the spiral scale is designed to achieve online automatic correction.In order to rationally design the parameters of the continuous forced mixer,based on the mixing mechanism,a mathematical model of the working process of the continuous forced mixer was established,the relationship between the number of mixing and the mixing uniformity of the mixture was studied,and the maximum production capacity of 480t/h was determined.The mixing parameters of the continuous forced mixing asphalt mixing equipment for hare: the agitator is set in two stages,the effective length of each stage mixer is2.527 m,the agitator width is 1.127 m,the agitating radius is 0.330 m,and the agitating shaft speed is 41r/min;The stirring blades are arranged in a positive and positive manner,with a phase difference of 90°,and the installation angle of the stirring blades is 45°;the angle between the center of the stirring shaft and the center of the bottom of the agitator is 45°;the part above the central axis of the agitator is 0.363 m.Through on-site mixing test verification,the continuous forced mixing asphalt mixing equipment is stable in operation,has high gradation accuracy,and has a good mixing effect,which can meet the requirements of asphalt mixture production.In this paper,the research on the key technology of continuous forced mixing equipment can provide a theoretical basis for the design and optimization of continuous forced mixing asphalt mixing equipment.