【作者】 张旭；

【导师】 陈海涛；

【作者基本信息】 东北农业大学 ， 农业机械化工程， 2020， 硕士

【摘要】 秸秆纤维地膜原料制取机采用物理方法对秸秆进行加工处理,生产出的秸秆纤维可为植物纤维地膜的制备提供原料,实现了秸秆资源化与减量化。但由于秸秆在收获打包过程中掺入大量杂质,若直接用于生产加工,不仅磨损机器,降低机器使用寿命,还将影响纤维加工效果,降低生产效率。为实现农作物秸秆的清洗除杂,设计了针对秸秆纤维地膜原料制取机的清洗供给系统。清洗供给系统采用机械搅拌清洗技术,不但可以去除秸秆中掺入的杂质,而且可以形成搅拌流场作用下秸秆流,便于输送装置捞取秸秆。清洗供给系统内秸秆流动与分散特性对清洗供给系统的供给能力及供给连续性与均匀性具有至关重要的作用,因此本文以提高清洗供给系统供料性能为出发点,将创新设计、理论分析与试验相结合,对清洗供给系统开展深入研究,研究主要内容与成果如下:(1)小麦秸秆原料预处理技术研究以制备秸秆纤维地膜为目的,对小麦秸秆原料预处理工艺进行参数优化分析,采用三因素五水平二次回归正交旋转中心组合试验,得到优化参数组合为:小麦秸秆喂入量1000 kg/h、含水率18～29%、揉切机主轴转速1625 r/min,此时经预处理后可得到破碎长度为100～150 mm,揉切度≥80%的小麦秸秆原料,并测定预处理后饱和含水率小麦秸秆的堆密度与视密度,为仿真模型建立与参数选择提供参考。(2)清洗供给系统设计与分析采用机械搅拌清洗技术,设计了针对秸秆纤维地膜原料制取机的清洗供给系统,阐述分析该系统总体结构与工作原理,并根据实际作业工况,对清洗供给系统桶体结构参数进行设计。(3)清洗供给系统内秸秆流动与分散特性数值模拟研究采用DEM-CFD耦合技术,应用单因素五水平仿真试验方法,重点探究搅拌器叶片倾角、叶片长度、叶片转速、料液比对小麦秸秆流动与分散特性的影响机理,并以捞取处秸秆流速、秸秆体积分数、秸秆流量为指标对清洗供给系统秸秆供给性能进行预测分析,为物理试验参数范围选取与理论分析提供支撑。(4)清洗供给系统性能试验研究应用四因素四水平正交试验方法,对小麦秸秆流动供给性能进行参数优化分析,得到优化参数组合为:叶片倾角55°,叶片长度300 mm,叶片转速80 r/min,料液比25 g/L。对优化前后作业工况进行对比试验,试验结果表明:优化后工况组合单耙捞取量均值提升24.97%,变异系数降低0.018。更多还原

【Abstract】 The straw fiber extruder uses physical methods to process straw.The straw fiber produced can provide raw materials for the preparation of plant fiber mulch.It realizes the resourcing and reduction of crop straw.A lot of impurities will be mixed into straw in the process of harvest packaging.If it is used directly in production without being cleaned,it will not only wear down the machine but also reduce production efficiency.In order to realize the impurity removal of crop straw,the cleaning supply system was designed.The cleaning supply system uses mechanical agitation cleaning technology to remove impurities from straw.Straw forms a flow supply under the action of stirring flow fie ld to facilitate straw fishing by the fishing transport system.The flow and dispersion characteristics of straw in the cleaning supply system play an important role in the feeding capacity and the continuity and uniformity of the feeding of cleaning supply system.Therefore,in order to improve the feeding performance of the cleaning supply system,the innovative design and theoretical analysis were combined to carry out in-depth research on the cleaning supply system.The main research contents were as follows:(1)Study on pretreatment technology of wheat strawFor the purpose of preparing straw fiber mulch,lots of optimization experiments have been done on wheat straw pretreatment technology.The results showed that: wheat straw materials with length in the rage of 100～150 mm and rubbing-cutting degree surpassed 80% could be produced by the parameter combination of feeding amount at 1000 kg/h,moisture content of wheat straw within18～29% and spindle speed of the rubbing-cutting machine at 1625 r/min.(2)Design and analysis of the cleaning supply systemUsing mechanical agitation cleaning technology,the cleaning supply system was designed.The overall structure and working principle of this system were elaborated.The structure parameters of the barrel of the cleaning supply system were designed according to actual operating conditions.(3)Numerical simulation study on the flow and dispersion characteristics of straw in cleaning supply system.DEM-CFD coupling technology was used to simulate the working process of the cleaning supply system.The effects of blade angle,blade length,blade speed and solid-liquid ratio on the flow and dispersion characteristics of wheat straw were studied.And the velocity,volume fraction and flow rate of straw were used to predict and analyze the flow supply performance of the cleaning supply system.It provided support for the determination of the range of parameters and theoretical analysis in the physical tests.(4)Research on performance test of the cleaning supply systemFour-factor four-level orthogonal test method was used to optimize the parameters of flow supply performance of the cleaning supply system.The better combination of parameters of the cleaning supply system was obtained as follows: blade angle at 55°,blade length at 300 mm,blade speed at 80 r/min,solid-liquid ratio at 25 g/L.The comparative experiment showed that the average value of feeding amount of single rake increased by 24.97%,and the coefficient of variation decreased by 0.018.更多还原