| Facing the increasingly serious air pollution problems,it is necessary to pay close attention to the study of filter.Cartridge filter is a new type of filter developed on the basis of bag filter,which has a small size,large filter area,easy maintenance,high filtration efficiency and many other advantages.However,now the cartridge filter research is less among scholars at home and abroad,not to mention its internal flow field characteristics.Therefore,it is of great engineering significance to maintain the uniformity of the flow field inside the filter cartridge,which can guarantee the operation life and the filtration efficiency of the filter.The paper introduces the structure,material and cleaning method of cartridge filter,and the basic operating parameters of cartridge filter were recorded and studied by experiment.During the experimental test,it found the initial internal and external pressure difference of the coated cartridge was 39.8 Pa,the initial filtration efficiency was around 98%.Internal and external pressure difference and filtration efficiency of cartridge have improved after pulse jet cleaning.Meanwhile,it also found that there was an internal flow field disorder in the cartridge filter.In order to solve the disorder problem of the flow field of cartridge filter used in experiment,the paper establishes the experimental cartridge filter model with the help of computational fluid dynamics(CFD)software and the parameters of the inlet and outlet velocity,the internal and external pressure difference obtained from test.The velocity relative mean square(RMS)difference value is 0.43 from simulation analysis,which means that the cartridge filter has poor flow field uniformity.In order to study the influence of deflector,the flow layout board and the hopper windshield on the uniformity of the flow field of the filter,the paper sets up the orthogonal test of 5factors and 4 levels,and analyzes it through the establishment of 16 different cartridge filter model.The results show that appropriately increasing the windshield length E of the dust hopper,adding the number of flow layout board C and decreasing its angle D can improve the uniformity of the flow field effectively,and the dust hopper windshield can effectively prevent secondary dust.The pairs of deflector A and its angle B have little influence on the flow field.Thus,the degree rank of the influence on the flow field uniformity is the hopper windshield length E> the flow layout board angle D> the flow layout board number C> the deflector pairs A> the deflector angle B.Using the optimal level of the established new style filter,the uniformity of flow field could be improved by39.5%.Beside the above factors,the air inlet position is another major factor that affects the internal flow field of the cartridge filter.In order to accurately reflect the internal flow field of the cartridge filter at three different air inlet position,lower,side and top of the filter,the paper not only analyzes it from the velocity trace diagram,the velocity and pressure contour diagram,but also analyzes the flow field through 6 pressure monitor lines located inside and outside the cartridge.The results show that the flow field uniformity of side inlet cartridge filter is best,the top inlet is second,and the lower is last.The maximum flow deviation(35)qiK for side inlet cartridge filter is 0.192,and its integrated flow amplitude?(35)Kis 0.069.The internal flow field characteristics of side inlet cartridge filter and top inlet cartridge filter have certain similarities,and both of them face the problem that the velocity between two cartridges is too high,which scours cartridge seriously.The flow field uniformity of up inlet cartridge filter is significantly improved by arranging the opening ratio of30% on the uniform board,the maximum flow deviation(35)qiK decreased by 46.2%,and the integrated flow amplitude?(35)Kdecreased by 42.3%. |
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