| In China, environmental pollution and waste of resources caused by massive mixed waste plastics is more and more serious. Because the efficiency of recycling technology is relatively low at the present stage, it is great significance finding new method of separating mixed waste plastics which is efficient and clean. Sorting mixed waste plastics based on NIR spectra identification technology is more advanced processing, which is still in the experimental stage, and there is few research on applying this technology to Industrial assembly line.Firstly In this paper, Identification and sorting system is preliminary design. Sorting system for plastic recognition is divided into the following three parts: Separation identification equipment, logistics system, Control & information system. Modeling and run a single recognition sorting line to find the bottleneck station by the use of Plant Simulation software. The final conclusion is that the effect of Identification and separation is related to the control of the feed flow, the operation ability of device and The speed of conveyor belt. It determines the efficiency of the prototype system and needs to be designed and optimized.Secondly, the key part of the bottleneck station is designed and optimized.In this paper, The separation nozzle, which is key components in the sorting station, is designed and optimized. The motion mode of sorting objects is analyzed under the consideration of air resistance. The relationship between the placement and the initial speed of the sorting objects is Established. Several parameters such as sorting border are identified. Using the Realizable k-ε model in Fluent could do numerical simulation analysis for each size parameters of Air nozzles, and discuss the impact on the physical placement of sorting objects and sorting accuracy. The result indicate: the horizontal displacement of sorting objects’ placement increases with the increase of entrance velocity and bore of pipe, so does the sorting accuracy. The length and angle of the sorting accuracy has complex effect as well. Finally, we have identified the highest sorting precision :the length of 20 mm, the contraction angle of 5 °.In this paper, the experiments were designed and analyzed for obtaining Distribution of material on the conveyor belt and Parameters’ effect on the recognition efficiency, such as the belt speed and the mean of feed distribution. The results show that the mean of feed distribution In the direction of travel of the conveyor belt showed normal distribution,and when the mean of distribution is much larger than 5 pieces per metre, the population variance has little difference;when the mean of distribution is close to or less than 5 pieces per metre, the belt speed has Significant effect on Distribution and recognition efficiency. Monte-carlo generator was established according to the results of experiments. At last, each sorting accuracy the Optimization parameters of System Efficiency Recognition rate more than 99% was identified.The separation mode and silo is designed and optimized, and then verified in experiment. The results show that vertical injection blowing separation method is better than Free fall and lateral blowing. So the vertical injection blowing separation method should be used in sorting station of prototype system. Silo is suit for sorting operation of small volume of plastic products, such as PET,PE,PP. large hollow plastic bottle need to go through flattening, then rate of the correct selection is increased.Finally The mixed model scheduling of Sorting line is optimized, including sorting order, equipment layout, the speed of Conveyor belt and carrier. The results show that Identification station and sorting station has been balanced after optimized. The probability of Overload and idle condition is reducing. Average resource utilization rate is rising. The overall performance of sorting line is greatly improved. |
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