The Development And Research On Aerobic Fermentation Equipment For Organic Waste

With the development of society and economy, solid waste was increasing greatly which led to serious environmental pollution, such as manure, city garbage and so on. In recent years, country pay more and more attention to environmental protection, and put forward to the harmless treatment and comprehensive utilization of solid waste. Composting and fermentation technology is a process of organic matter degraded by microbes, the volatile organic matter in composting materials degraded gradually as composting product by high temperature aerobic fermentation which is stable and harmless to crops. For the production requirements of a company in Henan, this paper developed a set of 100 cubic meters of aerobic fermentation device independently, the particular work in this paper were as follows:(1)Design of fermentation tank: according to the related standards, the ratio of height to diameter of 100m~3 fermentation tank were designed as 1.2. The thickness of inner wall was 9 mm and the outer wall was 3 mm. In order to ensure that the materials had been fermented which out of discharge port, the drain plate which welded on the inner wall of the fermentation tank was designed by the change of volume. The materials that on the drain plate was not fermented, the volume of materials became smaller after fermentation, it reached storage bin through stirring blade stirred. The finite method was used to analyze the stress of the fermentation tank, drain plate was depressed to the center, so the structural stiffness can't meet the requirements. An improved solution was proposed for the problem and the modified model was done the stress analysis. The result showed that the maximum deformation of drain plate was in the allowable range, so the improved solution was reliable.(2) Design of mixing shaft: a segmented and hollow stepped shaft is designed by comparing with the traditional shaft according to the difference of torque in different positions of the mixer shaft. The characteristic of the shaft is greatly reducing spindle material in the case of meeting the torque. These made detailed introduction in the course of design concretely. Agitating vanes which were welded on the agitating shaft were studied with force analysis, and the structure size of the agitating shaft was designed by the resistance torque, which was calculated by force analysis when the agitating shaft was working. The position of maximum resistance torque on the fourth section of the shaft was obtained by theoretical calculation. It was concluded that the position of maximum press was weld root of agitating vanes by making finite element stress analysis of the fourth shaft. Considered safety factor and compared with the yield strength of No.45 steel, it was obtained that the design of mixer can meet the requirements of the working conditions.(3)Design of transmission device: this paper designed a transmission device through the resistance torque which mixer shaft suffered. It adopted the pawl mechanism. Ratchet wheel and mixer shaft was connected by a involute spline, the active pawl was driven by hydraulic cylinder. Then modeling and assembling of transmission device by Inventor.(4) Auxiliary system design: the auxiliary system design included feedstock, discharge system, the fence, the ladder and so on. The feedstock system was designed including material lifting mechanism and feedstock port. Material lifting mechanism was a hopper overturn structure. The feedstock port was using chain drive. Discharge system was using gear and gear rack drive. The fence and ladder design was by the relevant standards.(5)Assembly check: using Inventor to assemble all of the parts and check interference, making final changes to the model.Through the theoretical calculation and software analysis, it was great significance to solve and recycle the pollution of organic waste.