| The "Industrial Structure Adjustment Guidance Catalogue(2019Edition)" compiled in 2019 proposed that high-tech materials represented by graphene and high-purity quartz raw materials as encouraged/building materials have become one of the key areas encouraged by the state,and the raw materials of high-tech materials It will develop from a traditional resource industry to a new material industry.At the same time,for nonrenewable non-metallic mineral resources,traditional industries must be transformed and upgraded to promote the transformation and upgrading of non-metallic mining.Therefore,higher requirements are put forward for the separation of fine powders.This paper simulates the flow field in the classifier cavity,analyzes the flow field movement in the classifier cavity,and compares the influence of different structural parts in the separation cavity on the flow field,so as to improve the separation performance of the classifier and reduce the content of large particles in the product.Than the purpose.The main research contents are as follows:(1)Introduce the working principle of the classifier to separate particles,and put forward an improvement plan that can reduce the content of large particles by analyzing the results of the flow field in the cavity.Model and assemble the separation device of the classifier,and use Ansys Workbench to simulate the flow field in the classifier cavity when no particles are added.(2)Analyze the flow fields in the cavities of the two classifiers with and without windshield structures,and compare the flow fields in the cavities with different numbers of windshields.The simulation results show that when the flow field flows through the wall of the windshield,the velocity distribution in the annular area between the cavity and the rotating cage will be changed.The velocity fluctuations and turbulence here affect the classification accuracy together.The flow field loses part of its energy when it passes the windshield,and changes the trajectory of the particles when they flow through the wall,which is conducive to the sedimentation of the particles in the cavity.The simulation results of different numbers of windshields show that the classifier with 8 windshields has a better separation effect.(3)Analyze the flow field in the classifier cavity with and without openings,and study the influence of the openings on the flow field in the cavity.The simulation results show that after the openings are added,there is no obvious sudden change in velocity in the air column formed by the air inlet,the velocity vector range of the air column at the air inlet is significantly reduced,and the high-speed vector area is reduced.There is no significant change in the pressure in the cavity,but the pressure peak changes from the area in the cavity to the opening of the cavity.And as the number of openings increases,the peak value at the openings also increases.(4)Install an experimental platform to detect the percentage of large particles in the finished product of the classifier with improved structure,and compare with the simulation results.The results show that:(1)In the powder separated by the powder classifier with the structure improvement device,the proportion of large-diameter particles is reduced by 10%,and the structure design meets the requirements for improving the powder separation effect.(2)The experimental data show that the improved structure has a promoting effect on the separation effect,which is verified by the experimental results,and there is an error within a certain reasonable range.(3)The separation efficiency of the powder classifier is about 4% before and after the improvement of the classifier.The result of the separation efficiency is not large,which can meet the original powder separation production requirements.The classifier with improved structure designed in this paper can improve the separation effect. |
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