基于Fluent分析的棉田废地膜秸秆分离装置设计

Design of separation device for waste film and straw in cotton field based on Fluent analysis

针对棉田机械化回收的废地膜与棉秆、土壤等杂质混合难以分离,无法资源化再利用,且随意掩埋或焚烧易造成环境二次污染的问题,拟开展膜杂混合物分离技术研究,提出筛筒式膜杂分离原理,为膜杂分离机的设计提供参考。以残膜回收机回收的膜杂混合物为研究对象,开展物理特性研究,测出废膜、秸秆、土壤颗粒的悬浮速度,利用SPSS软件统计分析物料悬浮速度与受风面积的相关性,通过搭建膜杂混合物料风选试验台,分析膜杂混合物各组分在风选试验台气流场中的运动轨迹和沉降规律,确定了筛筒式膜杂分离装置关键部件最佳尺寸和工作参数,并采用Fluent进行流体域数值模拟,确定地膜和杂质分离效果的最佳进风速度为8.0 m/s,最优入风角度为6.00°。通过验证试验可知当筛筒转速为40 r/min,进风速度8.0 m/s,入风角度6.00°时,试验所得的膜中含杂率为9.73%、杂中含膜率为0.261%,验证了理论分析和结构设计的合理性及流体域数值模拟分析的正确性。本研究结果可为废地膜杂质分离及废地膜资源化再利用提供参考。

It’s difficult to separate the waste mulch film from cotton stalks,soil and other impurities after mechanically recycled,and the waste mulch film can’t be reused as a resource.Besides,randomly burying or burning of the waste mulch film may cause secondary environmental pollution.Aiming at the above problems,a study on the separation technology of membrane and impurity mixture was carried out,and the separation principle of roller screen type was proposed to provide a reference for the design of membrane-impurity separator.Taking the membrane impurity mixture recycled by the residual membrane recycling machine as the research object,the physical characteristics research was carried out to measure the suspension velocity of waste film,straw and soil particles.The correlation between material suspension velocity and windward area was analyzed by SPSS statistical software.By building the air separation test bench for membrane-impurity mixture,the movement track and settlement law of each component of the membrane-impurity mixture in the air flow field of the air separation test bench were analyzed,the optimal size and working parameters of the key components of the roller screen type membrane-impurity separation device were determined,and the fluid domain numerical simulation was carried out by using Fluent software.The optimal air inlet velocity for the separation effect of mulch and impurities was 8.0 m/s,and the optimal angle was 6.00°.According to the verification test,when the rotating speed of the rotary screen was 40 r/min,the air inlet speed was 8.0 m/s,and the air inlet angle was 6.00°,the impurity rate in membranes was 9.73%,and the membrane content rate in the impurities was 0.261%,which verified the rationality of theoretical analysis and structural design,as well as the correctness of numerical simulation analysis in fluid domain.The results can provide reference for the separation of impurities in waste mulch film and recycling of waste mulch film.