废混合塑料精准识别分离流水线优化与仿真

发布时间：2017-12-31 17:16

本文关键词：废混合塑料精准识别分离流水线优化与仿真　出处：《天津理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国大量的废混合塑料造成的环境污染以及资源浪费愈发严重。由于现阶段使用的回收利用技术回收效率比较低,因此建立新型高效率清洁环保无污染的废混合塑料分选回收利用方法具有重大意义。基于NIR光谱识别技术分选废混合塑料制品是比较先进的处理方法,现仍处于实验阶段,目前仍缺乏将此项技术应用于工业化流水作业的研究。本文首先对识别分选系统进行初步设计。论文将塑料识别分选系统分为以下三个部分:分选识别设备,物流系统,识别分选控制信息系统。运用Plant Simulation软件对单次识别分选线进行建模并运行寻找瓶颈工位。最后得出识别分选的效果与投料流的控制、装置运作能力和输送带的速度等因素相关,是导致原型系统的瓶颈效率低下的原因,需对其进行优化设计。其次,本文对瓶颈工位中的关键部分进行了设计与优化。文中针对废旧塑料近红外光谱识别分选系统中物料在输送带上的分布规律,以及输送带速度、物料分布均值等参数对识别效率的影响方式进行了实验方案设计和结果讨论。结果表明:输送带行进方向的物料分布均值呈正态分布,且分布均值远大于5件/m时,总体方差不存在明显差异;当分布均值接近或小于5件/m时,输送带速度变化对物料分布规律及分选效率影响显著。根据实验结果建立蒙特卡洛随机数模型,针对四种不同尺寸的塑料对应的分选精度得到识别率大于99%的系统效率优化参数。文中对分选工位中的关键部件空气喷嘴进行详细设计并优化。分析了分选物在考虑空气阻力下的运动模式,建立了分选物落点与初始速度的关系,并确定分选边界等参数。运用Fluent软件中Realizable k-ε模型对空气喷嘴各尺寸参数进行数值模拟分析,讨论其对分选物落点以及分选精度的影响。结果表明:分选物落点水平位移随入口流速增大,随管径增大而明显增加,分选精度随之提高。管长和收缩角对分选精度有复杂影响。最后确定了管长为20mm,收缩角为5°时,分选精度最高。文中对分选模式和料仓设计优化并进行实验验证,实验结果表明:纵向喷吹分选法总体优于自由落体和侧向喷吹两种方法。因此原型系统的分选工位采用纵向喷吹分选法;料仓设计适合小体积塑料制品的分选作业,对小体积(PET)、聚乙烯(PE)、聚丙烯(PP)塑料瓶和塑料碎片分选具有很高的正确率,超过1L的中空塑料瓶需经过压扁工序后分选正确率明显提高。最后对分选流水线混流调度进行优化。首先对分选的顺序以及设备布局进行优化,由若干个单次识别分选工位组成,各工位间通过轨道以及输送带相连。对输送带速度以及输送小车的速度进行了模拟实验分析并选取了最优参数组合。结果表明:经过瓶颈的优化以及非瓶颈中的物流调度优化后,识别与分选工位负荷得到了有效的平衡,工位超负荷运作状态与空闲状态的时间大幅减少,提高了平均资源利用率,分选流水线整体性能得到很大提高。
[Abstract]:A large number of China's waste plastic mixture caused by environmental pollution and waste of resources become more and more serious. The recycling technology is currently using relatively low efficiency, waste plastic mixture separation and recovery so as to establish new high-efficiency clean utilization method is of great significance. Based on NIR spectrum identification technology separation of waste plastics is mixed processing method the more advanced, we are still in the experimental stage, there is still a lack of the research of this technology applied to industrial production. This paper first carries on the preliminary design of the sorting system. The identification of plastic sorting and recognition system is divided into the following three parts: sorting equipment, logistics system, sorting and recognition of control information system using Plant Simulation software. Modeling of the single recognition sorting line and run for bottleneck stations. Finally identify the separation effect and the feeding flow Control device, operation ability and the speed of the conveyor belt and other factors, is the cause of the bottleneck of low efficiency of the prototype system, it is necessary to optimize the design. Secondly, the design and optimization of the key part of the bottleneck in this paper. According to the distribution of material waste plastics near infrared spectra identification and sorting system in the conveyor belt, and the speed of the conveyor belt, influence of material parameters on the distribution of the mean recognition efficiency of the experimental design and results are discussed. The results show that the material distribution mean was the normal distribution with the direction of travel, and the distribution of mean is far greater than 5 /m, the overall variance is not significantly different when the distribution; the mean close to or less than 5 /m, the speed of the conveyor belt changes significantly affect the law of material distribution and separation efficiency. According to the experimental results of Monte Carlo random number model of four kinds of needle The sorting accuracy corresponding with the size of the plastic by parameter optimization of system efficiency recognition rate is more than 99%. The key components of the sorting station in the detailed design and optimization of air nozzle. Analyzed in consideration of sorting movement patterns of air drag, to establish the relationship between the impact and the initial velocity of the material sorting, sorting and determining the boundary other parameters. Using the Realizable k- model in Fluent software numerical simulation analysis on air nozzle parameters were discussed, the sorting of object placement and sorting accuracy. The results show that the horizontal displacement increases with the separation material placement entrance velocity, and increased as the diameter increases, the separation accuracy is increased. The length and angle of contraction the sorting accuracy has complex effect. The length is 20mm, the contraction angle is 5 degrees, sorting the highest accuracy. Real separation mode and optimization and the silo design Verified, the experimental results show that the longitudinal injection of two methods of blowing separation method is better than that of free fall and lateral jet. So the sorting station prototype system using vertical jet separation method; silo design for sorting operation of small volume of plastic products, the small volume (PET), polyethylene (PE), polypropylene (PP) plastic bottles and plastic debris separation has a high accuracy, hollow plastic bottles more than 1L after flattening after sorting correct rate increased. At the end of the sorting line scheduling optimization. Firstly, Francis of sorting order and optimization of equipment layout, is composed of a plurality of single recognition sorting stations, each station. The track and the conveyer belt is connected. The speed of the conveyor belt and conveying speed of car simulation experiments conducted to analyze and select the optimal parameters. The results showed that after the bottleneck and non bottleneck in optimization After the optimization of logistics scheduling, the load balance between identification and sorting is effectively balanced, the time of overload operation and idle state is greatly reduced, the average resource utilization is increased, and the overall performance of the sorting pipeline is greatly improved.

【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X705

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