Design And Optimization Of Nearinfrared Sorting And Blowing Device For Waste Plastics

Sorting and sorting of mixed plastics is an effective measure to achieve high value recycling of waste plastics.Plastic near-infrared recognition sorting is a green and environmentally friendly physical sorting method.No pollution occurs during the sorting process.The separation device directly affects the sorting efficiency and accuracy of the near-infrared sorting equipment.The nozzle is a key component in the sorting and separating device.This subject mainly studies the design and optimization of the streamlined contraction nozzle in the plastic near-infrared sorting and separation device,which is of great significance for the structural optimization design of sorting equipment,energy saving and noise reduction.The finite element software Fluent was used to numerically analyze the two types of streamline curve contraction nozzles——Vickers curve nozzles and double cubic curve nozzles.As a factor,the length of the core section of the jet and the noise value are used as indicators,and the two orthogonal nozzles are subjected to interactive orthogonal tests.The study found that the outlet radius has the greatest influence on the length of the nozzle jet core,and the shrinkage ratio and the interaction between the outlet radius and the shrinkage ratio have the greatest influence on the nozzle noise value.Through the comparative analysis of the two optimal structure curve nozzles,it is found that the velocity vectors of the two types of nozzles are stable,and the double cubic curve nozzle is superior to the Vickers curve nozzle in the radial velocity distribution of velocity;Through the analysis of the FW-H noise model and the broadband noise model,the noise value of the external flow field of the double cubiccurve nozzle is less than the Vickers curve nozzle.Therefore,the performance of the double cubic curve nozzle is better than the Vickers curve nozzle.The optimal structure of the corresponding double cubic curve nozzle is: the outlet radius is 4mm,the shrinkage ratio is 2,and the length of the shrinkage section is 4mm.According to the nozzle structure used,the nozzle holder structure design and modal analysis are performed to obtain the first 6 natural frequencies and vibration modes of the nozzle holder structure,and all belong to low-order frequencies.Provide support for the structural design of subsequent plastic near-infrared sorters.Taking the numerical simulation results of the double cubic curve nozzle as training samples,and using extreme learning machine and radial basis neural network to simulate and predict the nozzle performance.The results show that the ELM neural network can accurately predict the noise value of the nozzle.The maximum error,goodness of fit and mean square error of the prediction results are 1.22%,0.9997 and0.2108.The RBF neural network can accurately predict the length of the core section of the nozzle jet.The maximum error,goodness of fit and mean square error of the prediction results are 2.19%,0.9981 and 0.5793.This paper mainly optimizes the design of the separation device for plastic sorting equipment through theoretical analysis,numerical simulation and interactive orthogonal test,in order to improve the nozzle blowing level and equipment sorting ability,and promote the application of plastic near infrared sorting equipment.