Structural Optimization Design Of Agitator In Composting Reactor

In recent years,with the continuous development of the breeding industry,the production of livestock and poultry manure and its impact on the environment have attracted more and more attention.Turning waste into treasure and solving the problem of environmental pollution has become a research hotspot and one of the effective solutions.It uses livestock and poultry breeding waste as raw material and fully mixes it with crop straw for aerobic composting.Carry out the optimization and test of the structural parameters of the agitator of the composting reaction device to improve the mixing uniformity of the materials.The research conclusions can provide a reference for the raw material mixing components of aerobic composting equipment.In this paper,the whole structure design of the composting reaction device is carried out.The effective volume of the fermentation box is 144 L,and the single treatment of pig manure is 40 kg.Based on EDEM,the structural parameter optimization and static stress analysis of the agitator,the core component of the device,were carried out.First,the basic characteristics of compost materials(pig manure and cotton stalks)were tested: moisture content,bulk density,stacking angle,particle size.The pig manure accumulation angle test was carried out by the method of combining EDEM and lifting hollow cylinder,and then the pig manure discrete element parameter significant factor screening test,the steepest climbing test,and the center composite test were used to calibrate the contact parameters.Modern management data statistical software(Minitab 18)establishes a quadratic equation between the screened significant factors and the accumulation angle of pig manure,and the coefficients of the significant factors of the discrete element parameters of pig manure particles are 0.6 and 0.65,respectively;Focusing on the auger-type blade mixer as the research object,and the obtained pig manure contact parameters as the experimental basis,the mixing simulation experiment was carried out to compare and analyze the mixing performance of the two mixers.The dispersion coefficient results showed that the pig manure samples in the auger mixer were discrete The coefficient is 0.008 smaller than that of the segmented agitator,so the vertical auger agitator is determined as the mixing component of the composting reaction device;the structural parameters of the agitator are optimized according to the characteristics of low fluidity and high viscosity of the composting material,and the influence of the mixed material The two factors of uniformity: the helix angle of the agitator blade and the rotational speed were optimized,and the best combination of the structural parameters of the agitator was obtained: the blade helix angle was 30°,and the rotational speed was 50r/min.After the parameters are optimized,the composting reaction device is used to mix pig manure and cotton stalk materials,and the coefficient of variation method is mainly used to evaluate the mixing uniformity of the compost material to verify the material mixing test results.The test results of the coefficient of variation method show that the working performance of the agitator meets the requirements,the mixing uniformity of the materials is good,and the mixing uniformity requirements of the compost can be met.After the composting test was carried out in the composting reactor,the physical and chemical indicators of the collected samples were detected and analyzed.From the results of the measured data,it was concluded that the compost body met the harmless standard,and all physical and chemical indicators were in line with the(NY/T 525-2021)standard.