Numerical Simulation And Experimental Study Of Airflow Baffle Improving The Performance Of Pulse Jet Dust Cleaning For Filter Cartridge

Industrial processes generate large amounts of dust particles,which can cause ecological pollution,induce diseases such as pneumoconiosis in workers,cause dust explosions and unpredictable damage,as well as hindering the growth of trees and crops.Filter cartridge dust collectors are playing an increasingly widespread role in dust control due to their excellent filtration effect.The filter cleaning is an important part of the filter cartridge,providing a guarantee of the filter cartridge’s efficient operation.However,the current common use of pulse-jet cleaning for the filter cartridge suffers from poor uniformity and low upper jet intensity,which restricts the development of dust collectors.In this paper,we proposed to improve the cleaning performance of the filter cartridge by setting up an airflow baffle inside the filter cartridge.The main research contents and conclusions are as follows.(1)Using the CFD numerical simulation method,The temporal and spatial evolution of the injection pressure before and after setting the airflow baffle in the filter cartridge were investigated.The influence of the size,position of the airflow baffle and jet distance on the jet intensity and uniformity was analyzed.It was found that the setting of the airflow baffle could improve the performance of pulse-jet cleaning;the airflow baffle mainly reduced the airflow range through the sealing effect,suppressed the static pressure energy escaping from the opening of the filter cartridge,and was beneficial to the accumulation of energy inside the filter cartridge;The optimal size and position of the airflow baffle([outer diameter,inner diameter] = [120,60] mm,located in the open section of the filter cartridge)resulted in a 2.11 and 4.68 times increase in jet intensity and uniformity respectively.(2)Four factors,including the outer and inner diameter of the airflow baffle,the inner diameter of the filter cartridge and the jet distance,were selected.Their effects on the cleaning performance were investigated by the orthogonal experiment method,and also studied the importance of each factor affecting the jet intensity and uniformity.The regular change of cleaning performance was analyzed,and the mathematical formula of four factors affecting injection intensity was obtained by fitting.(3)An experimental platform for a pleated filter cartridge dust collector was built.Through offline pulse-jet experiments,the injection pressure changes in the filter cartridge before and after setting the airflow baffle were compared,and the influence of the air bag pressure and the jet distance were investigated.It was found that the setting of the airflow baffle increased the cleaning performance of close-range(≤350mm)dust cleaning,which was in line with the current trend of miniaturization of dust removal devices;through online filtration and cleaning experiments,it was found that the setting of the airflow baffle improved the cleaning performance and prolonged the cleaning interval of the filter cartridge.Under the condition of talcum powder filtration,the setting of the airflow baffle reduced the residual pressure difference of the filter cartridge by 10.6%,prolonged the cleaning interval by 88.1%,and increased the quality of the flaking dust cake by 67.6%.The effect on the average dust emission concentration was small and the filtering performance was improved by 20.4%.