| In order to achieve high efficiency, energy saving,pollution-free production of rice straw crude fiber and provide equipment support for the comprehensive utilization of crop straw resources.The study has done a optimal design, a structural optimization and a optimization of making straw fiber process through a research method which is the combination of theoretical analysis, 3d modeling and the structural analysis by ANSYS.The main content and achievements are summarized as follows:(1) The study on the theory of the straw fiber extrusion machine.The study summarized the working process which is composed of charging, transmission, compression, molten, mixing, exhaust.and their influencing factors on the basis of the non- plug flow solid conveying theory. Analysed the physical models of three sections and seven area when the extrusion machine is working emphatically and the pressure and the relationship of power,the screw rotation speed and the screw torque.Provided a important theoretical basis for the optimal design of straw fiber extrusion machine.(2)The optimal design of straw fiber extrusion machine.The study did a optimal design for the problem of production capacity insufficiency,the transmission system was not reasonable, the cooling effect was not ideal and the machining was difficult.1) Changed the constant pitch spiral of the second part of the feeding period to the varying pitch screw which pitch changes along the straw transportation direction evenly and redesign the pitch of extrusion section. redesign the pitch of extrusion section.The tests showed that the optimal design improves the production and processing capacity of extrusion machine.2) To improve the barrel structure of extrusion machine.Changed the structure form of internal set and external set Inlaid and welded cooling jacket to the coat surface which was derived from the original design to the form of the water jacket and coat as a whole and welded cooling jacket to the internal set.The practice has proved that the optimal design improved the cooling efficiency and reduced the processing cost3) To improve the transmission system. Identified the transmission scheme which adjusted the motor speed by frequency transformer and Transmission power by the combination of the belt and reducer.The tests showed that the optimal transmission system improved the production capacity of extrusion machine can meet the requirements of the extrusion machine.(3) Structural optimization test of extrusion machine. Get the result that the inner diameter of regulating ring is 164 mm,the length of extrusion section is 240 mm,the pitch of extrusion section screw is 40 mm,the second feeding section screw uses the varying pitch screw, the external diameter of diffuse ring is 195 mm is the optimal structure for crop straw fiber extrusion machine by the orthogonal test of five factors with two levels.(4) Process optimization of making rice straw fiber by extrusion machine.Get the technology of making rice straw fiber,that are the length of straw is 12 cm,soak time is 15 h,extrusion sleeve temperature is 90 ℃,the spindle speed is 85 r/min, the feeding amount of sample is 600 kg/h by five factors with five levels of quadratic orthogonal rotation combination experiment. |
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