Experimental Study On Fine Dust Pre-agglomeration Combined With Bag Dust Removal

At present,the disorderly emission of dust particles has become the main cause of frequent occurrence of smog in major cities,seriously affecting the production and life of human beings.With the increasingly stringent particulate emission standards,traditional dust removal technology has been difficult to meet the requirements.Pre-agglomeration can agglomerate fine dust into large-sized particles,which can effectively improve the dust removal efficiency of traditional dust removal technology.Therefore,this paper compares the coagulation effect of sonic coagulation and chemical agglomeration on fine dust,and uses sonic coagulation in combination with a bag filter to explore the dust removal characteristics and optimal working conditions of the combined device through mechanism analysis,experiments and numerical simulations.The details are as follows:（1）Design and build an experimental platform for chemical agglomeration and sonic coagulation.Relying on the experimental platform,the influence of factors such as the type,concentration,and surfactant addition of chemical agglomeration agents on the effect of chemical agglomeration was firstly analyzed,and the optimal parameters of chemical agglomeration were determined.Secondly,the influence of the influence factors such as sound pressure level,sound wave frequency,and residence time on the sound wave coagulation effect was analyzed,and the optimal parameter range of the sound wave coagulation was determined.The results show that the agglomeration effect of the three chemical agglomerators is KGM>PAM>PAC.The peak particle size ratio of fine dust under the action of KGM reached 4.65,and the volume percentages of PM₁₀ and PM_2.5decreased by 66.48%and 17.48%,respectively;with the increase of the concentration of chemical agglomeration agent solution,the agglomeration effect of fine dust was enhanced.The chemical agglomeration agent added with surfactant can significantly improve the agglomeration effect of dust;with the increase of sound pressure level,the maximum particle size and peak particle size of dust increase.At 1400 Hz and 136 db,dust The maximum particle size reached 359.85μm,and the volume percentages of PM₁₀and PM_2.5 decreased by 66.92%and 18.3%,respectively.The optimal frequency of sonic agglomeration is between 1400 Hz and 1600 Hz;compared with chemical agglomeration,the pre-agglutination effect of sonic agglomeration is better.（2）A three-dimensional model was established with the actual model of the sonic coagulation chamber as a prototype,and the Fluent software was used to simulate the sonic coagulation and the volume ratio of fine dust.The results show that with the increase of the sound pressure level,the volume proportion of the agglomerates increases.At 130db,the volume proportion of the agglomerates can reach about 80%;there is an optimal sound wave frequency,which is about 1400 Hz.（3）Design and build an experimental platform for bag dust removal and pre-aggregation combined bag dust removal.Relying on the experimental platform,the influencing factors such as filtration wind speed,filtration time,filter material type,dust particle size,sound pressure level,and sound wave frequency are analyzed.The influence of dust removal of the device is determined,and the optimal operating condition of the compound device is determined.The results show that:when the filtration air speed is 1.2m/min,when the filtration time reaches 25 min,the operating resistance of the filter material rises to about 550 Pa.With the increase of the filtration air speed,the filtration efficiency of dust continues to decrease,and the filtration air speed is 0.6 m/min,the dust removal efficiency of iron ore dust and lime dust is 99.2%and 98.7%.When the sound pressure level is 136 db and the sound wave frequency is 1400 Hz,the dust removal efficiency of mine dust and lime dust is more than 99.8%.Compared with the single function of the bag filter,the dust removal efficiency is increased by 0.7%and 1.1%respectively,and the running resistance is reduced by 70 Pa.