Optimal Design And Experimental Study Of Spiral Feeding Device For Wheat Flour

The screw feeder can realize the functions of stable flow conveying,quantitative feeding,and precise control of powder materials.It is suitable for continuous measurement and batching of powder materials in various industries.It adopts a number of advanced technologies to ensure reliable operation and high control accuracy.Most of the powder materials are conveyed and measured on the automatic packaging production line using spiral feeding equipment.The reasonable design of the spiral feeding device is the key factor to improve the material transportation efficiency and packaging accuracy.This article takes the round tube spiral feeder as the research object Based on the particle swarm multi-objective optimization algorithm,the parameters of the wheat flour spiral feeder are optimized.The main work and results are as follows:(1)Aiming at the problem that the calculated value of the wheat flour screw feeder’s flow calculation formula is far from the actual flow value,The orthogonal test is designed by taking the difference between the actual flow rate and the theoretical flow rate as the response value,and using the inner shaft diameter,pitch,and speed that have a significant effect on the flow rate difference as variables.A second-order regression equation between the three variables and the response value is established,and the modified wheat flour flow calculation formula is obtained.(2)Aiming at the problem that the variable-pitch spiral is mainly based on empirical design and lacks a system design method,this paper proposes three new design methods.The first uses a quadratic function and double fitting of the linear function;the second uses a derived pitch function.The pitch design is carried out by using the formula;the third is to consider the number of different dead zones for analysis.Based on the three variable pitch design theories,design simulation experiments,use Soliworks software to build a three-dimensional model,and import EDEM software for discrete element analysis.The design and the existing design methods are compared and selected,and the best spiral structure design scheme is the design method considering two dead zones.(3)Based on the modified wheat flour flow calculation formula and the best test plan,based on the particle swarm algorithm,the flow and mass are used as the two goals,and the pipe diameter,pitch,inner shaft outer diameter,and inner shaft inner diameter are used as variables to the spiral.Optimize the feed structure parameters to obtain the optimal parameter combination.According to the best pipe diameter parameters and the selected optimal variable pitch design method,the screw pitch combination of the feeding section of the screw feeder is obtained.Provide a reference for the structural design of wheat flour feeder.(4)In order to obtain the precise contact parameters of wheat flour discrete element simulation,based on the principle of particle scaling,the "Hertz–Mindlin with JKR" contact model was selected,and the contact parameters were calibrated using the angle of repose.According to the wheat flour simulation parameter calibration results and particle swarm algorithmoptimization Asaresult,athree-dimensionalmodelwascreated and introduced into the EDEM software for discrete element simulation.The uniformity,axial speed,filling rate,and feed flow of wheat flour inthehopperwereanalyzed,andcomparedwiththetraditionaldesignand the existing design.Compared with the traditional design and the existing design,the optimized design of the screw is more uniform,the conveying is stable,and the feeding accuracy is high.(5)To further verify the rationality of the spiral structure design,process the screw according to the optimized parameters,use acrylic plates to build the transparent feeding device of the transparent barrel,and observe the feeding stability of the wheat flour feeding section.Use a flat load cell to detect the spiral feeding amount,When r=100r/min,the average feed flow rate of the conventional equidistant screw is 0.642kg/s,the flow fluctuation range is0.425kg/s-0.767kg/s,and the fluctuation percentage is ±19.47%.Within this article,the average feed flow of the designed screw is 0.445kg/s,the flow fluctuation range is0.406kg/s-0.485kg/s,and the fluctuation percentage is within ± 8.98%.From the test data,it can be seen that the material is more uniform.The flow fluctuation of the screw designed in this article is relatively small and the feeding accuracy is high.