| This topic originates from a key R?D project of military-civilian integration in Shandong Province.At the request of the cooperative unit,in order to solve the disadvantages of artificial mixing of composite coatings,such as low efficiency in construction,many wastes,large mixing resistance,and short pot life,improve the degree of construction automation,carry out Analysis and research of key components of composite paint mixing device.Firstly,based on the CFD theory,the conservation law that the paint mixing process needs to satisfy is analyzed,and the basic equation of CFD simulation is established.The interaction between the paint micro-element and the pin during the mixing process was analyzed,and combined with the flow characteristics of the extrusion flow field of the composite paint,the force and power consumption of the mixing pin on the paint were obtained.The interaction between the screw and the paint during the mixing extrusion process in the internal flow field was analyzed,and the influence of the screw structure on the performance of the device was explored.Based on theoretical analysis,the flow law and its influencing factors of the internal flow field of the device are explored to provide a theoretical reference for CFD simulation.Secondly,combined with the difficulties of automatic construction and mixing design of composite coatings,the structure scheme of composite coating mixing device and its feeding and unloading system,as well as the design points and structural components of each component,are given.The rod length of each part of the swing blanking is obtained by graphical analysis,and the complex vector method is used to analyze the blanking process of the device,and the motion equation of the blanking of the device is obtained.The results are compared to verify the rationality of the device design.The blanking process is simulated by motion analysis,the blanking curve in the device plane is obtained,and the initial blanking position is adjusted according to the actual working conditions to optimize the blanking curve.Thirdly,using the Mixture model of the multiphase flow module of Fluent software,taking the internal flow channel of the device as the research object,the influence of ordinary screw,radial pin and axial pin on the flow law of the internal flow field of the device is analyzed,and the internal flow field velocity of different devices is obtained,dynamic pressure,and volume fraction of paint,and compare and analyze the simulation results to select the screw structure with the best mixing effect,which provides a reference for the following screw optimization analysis and test.From time to time,the Fluent-DPM analysis method was applied,and the continuous discrete coupling model was used to analyze the paint mixing extrusion flow field in the Fluent software,and the influence of changing the number of pin rows,the number of pins in the circumferential direction,and the diameter of the pins on the mixing efficiency and mixing time of the device was investigated.Combined with the response surface method,the interactive effects of three pin parameter changes on the mixing capability of the device were explored through the quadratic polynomial fitting method,and the pin parameters were optimized based on the simulation results to improve the mixing capability of the device.Finally,in order to check the influence of radial pins and axial pins on the mixing effect of the device,the impact test was carried out by extruding the mixed paint to make a test plate,and the mixing effect of the two devices was compared to verify the correctness of the simulation analysis.The standard compression test specimens made of mixed-extruded coatings were used for compression test,and the compressive strength of the commonly used hand-stirred specimens was compared.The research results show that the radial pin mixing device has the best mixing effect,can solve the shortcomings of the current manual mixing construction,and meet the actual construction needs. |
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