Research On The Optimization Design And Application Of Horizontal Aerobic Composting Equipment For Livestock And Poultry Manur

In recent years,the rapid development of livestock and poultry breeding,the environmental pollution problem is becoming increasingly prominent.The discharge of livestock and poultry manure causes serious pollution to the environment.If it is not dealt with effectively,it will cause great health problems.Aerobic fermentation composting is an important way to utilize livestock and poultry waste resources,and reactor composting is a more widely used treatment means of aerobic fermentation composting.At present,the commonly used aerobic composting reactors in China mainly rely on the heat energy released by the degradation of organic matter by microorganisms when dealing with livestock and poultry manure.The material temperature rises slowly,is greatly affected by the ambient temperature,and the equipment operation and maintenance are difficult,which can no longer meet the needs of rapid treatment of livestock and poultry manure.To solve the above problems,this paper designs a horizontal aerobic fermentation composting equipment for auxiliary heating of livestock and poultry manure,which can not only quickly kill pathogens and remove odor,but also shorten the heating time of materials,so as to accelerate decomposition and fermentation,and quickly realize the utilization of livestock and poultry manure resources.According to the requirements of composting technology and equipment,the whole machine scheme of aerobic composting equipment and the structure were designed,including fermentation treatment area and auxiliary control area.The fermentation treatment area is composed of fermentation bin,aeration system and stirring system.Through the analysis and calculation from the material and heat balance,biological fermentation,material stress and other aspects,the design of fermentation warehouse single processing capacity is 2000 kg,heat conduction oil heating layer is 50 mm,inner diameter of the stirring shaft is 210 mm,and outer diameter is 263mm;The mixing of materials in aerobic composting process is simulated by using EDEM discrete element software.The results show that the mixing effect of materials can be achieved by mixing blades with different installation angles,but the dispersion of materials with installation Angle of 60° is lower than that of other two installation angles,and the mixing degree of materials is better.The auxiliary control area consists of heating system,waste gas treatment system and control system.Through thermodynamic analysis,the structure of the heating system is designed,and FLUENT fluid simulation software is used to simulate and analyze the flow path,temperature and wall temperature of the heat conduction oil in the heating oil circuit with different structures.The results show that when 18 and 24 baffles are added in the heat conduction oil circuit,the temperature difference between the heat conduction oil inlet and outlet is the largest,and the wall temperature difference is small,so the heat transfer to the outside can be more uniform.Considering the production cost and manufacturing difficulty of the equipment,the final heat conduction oil circuit adopted 18 baffles;Aerobic composting equipment adopts spray atomizing tower for harmless treatment of the odor produced in the composting process,and the control system can realize automatic control of mixing,aeration and other functions.The performance test of aerobic composting equipment was carried out by using chicken manure and paulownia chaff as raw materials.The experimental results show that the heat transfer efficiency of heat conducting oil is relatively stable when it is kept above 100 ℃,and the temperature difference between import and export is about 8 ℃,which can continuously provide the heat required by aerobic fermentation.In the three tests,the material temperature can be maintained above 60 ℃ for a long time,reaching the temperature of killing pathogenic bacteria,and higher than the temperature standard in the national fecal harmless hygiene requirements.The material moisture content is basically maintained below 48%,and the water removal effect is ideal.The contents of organic matter,nitrogen,phosphorus and potassium of the treated materials are higher than the organic fertilizer standard of the Ministry of Agriculture and Rural Affairs of the People’s Republic of China,indicating that the equipment could quickly realize the resource utilization of livestock and poultry waste.