| A large amount of waste is generated in the agricultural production process,and the annual agricultural waste generated in China reaches 1.4 billion tons.Due to the lack of reasonable technical treatment,these organic wastes cannot realize the recycling of green ecology.To this end,this paper aims to develop and utilize agricultural and forestry waste,and has developed a prototype of organic waste aerobic-anaerobic fertilizer with little impact on the environment and simple operation,which provides a reference for practical application.The main contents and conclusions of this paper are as follows:(1)Structural design and parameter determination of the test prototype.According to the actual production needs and related theoretical knowledge,the volume and the reaction device and basic size of the organic matter experimental device,the selection and design parameters of the agitator,the design of the ventilation system and other auxiliary control devices are calculated.It is concluded that the effective volume of the reactor composting area is about 240 L,the diameter of the stirring shaft is 50 mm,and the material is 304 stainless steel.Determine the parameters such as the outer diameter of the shaft of the agitator,the inner diameter,the diameter of the agitator,and the diameter of the disc.By calculating the power of the agitator,a 1.1 kW three-phase asynchronous AC motor was determined,and the designed agitator shaft was subjected to strength check under stress.The selection of the fan should meet the air volume of 10.8 cubic meters per hour,the full pressure is not less than 1000 Pa,and the selected fan is a 220 V air compressor.(2)Test sample heat transfer and return pump hydraulic calculation and performance.Using the relevant theoretical knowledge of heat transfer and fluid mechanics to analyze and calculate the water absorption and heat release of organic raw materials in the aerobic composting process and the hydraulic characteristics of the leachate reflux spray process.It was found by calculation that the heat consumption at the top of the reactor was 54.6 W,the heat consumption of the wall was 103.8 W,and the heat consumption at the bottom was 23.7 W.Under the same surface area,the top heat dissipation is the highest,so in order to reduce the heat consumption of the device,the top is as close as possible to the closed structure,and the wall and bottom insulation work is done.The use of the temperature drop law of the material during the composting process has an important guiding role in the selection of the thermal insulation material of the experimental device.Through the hydraulic calculation of the water distribution network and the sprinkler system,the head loss on the branch pipe is 0.59 m,and the head loss on the main pipe is 0.169 m.The analysis found that it can meet the specification requirements.It is equipped with HQB-5500 pump with power of 200 W.(3)Test prototype production and experimental research.Using the test prototype as a device,the potato stems and leaves,corn stover and pig manure were used as raw materials for experimental research,and the comprehensive performance of the reaction test prototype was comprehensively analyzed through various indicators.The test results show that in the composting process,the material undergoes the process of first heating and then cooling,and the reduction of the water content in the middle stage of composting is obviously increased.From the beginning of composting to the 20 th day,the moisture content of the material is reduced by 55.4%,when the compost is decomposed.The pH value is basically maintained at about 7.5,and the compost maturity is evaluated by the seed germination index value(GI),and the GI value exceeds 50%,indicating that the compost is basically mature.This also shows that the organic waste aerobic-anaerobic fertilizer preparation prototype has good performance and basically meets the design requirements. |
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