A Study On Dust-cleaning Performance Of Pulse-jet Cartridge Filter With Tapered Diffusers Based On Porous Media

Compared with other kinds of dusters,filter dusters have numerous advantages such as high efficiency,large gas flow rate,long material life,and safe and reliable work.Hence it has been widely applied in controlling the dust pollution.The filter dusters’ performance is highly depended on its dust-cleaning system.The main factor influences the efficiency of the dust-cleaning system is the air injecting method,which should be carefully manipulated in practice.Bad air injecting method may cause many problems such as filter material damage and reduction of filter efficiency.To improve the injecting effect,diffusers are always placed under the nozzles to obtain a strong and uniform air flow.In the present work,to improve the filter dusters’ efficiency,different kinds of diffusers(porous media diffusers,reticular diffusers and porous aluminum diffusers)are made and studied on the dust-cleaning heterogeneity and losing efficacy of partial filter material.A φ325×1000mm cartridge filter and a self-made pulse injection laboratory bench are applied in the study.It is proved by experimental results that,by using these new diffusers,the uniformity of the peak pressures of filter on side wall is effectively improved,while the dust-cleaning strength is ensured.Specific results are given as follows.The peak pressures of the filter without a diffuser are 1.61/1.72/2.91 KPa for top/medium/bottom side wall,respectively.The peak pressures of the filter with a tapered nickel foam diffusers are 1.60/1.20/1.37 KPa for top/medium/bottom side wall,respectively.The peak pressures of the filter with a reticular stainless steel tapered diffuser are 1.37/0.51/1.01 KPa for top/medium/bottom filter side wall,respectively.The peak pressures of the filter with a porous aluminum sheet(holes on the side wall)tapered diffuser are 1.58/0.59/1.13 KPa for the top/medium/bottom filter side wall,respectively.The peak pressures of the top/medium/bottom filter side wall are1.89/1.20/1.37 KPa for the filter with porous aluminum sheet(a holes on the top).These results show that,compared with the case without a diffuser,porous media diffusers can obviously reduce the overlarge pressure at the bottom cartridge filter and improve the dust-cleaning uniformity along the axial direction of the cartridge filter,which is good for extend the service life of the cartridge filter and increase dust collection efficiency.The dust-cleaning flow field within the cartridge filter with porous media diffusers and without a diffuser is further numerically studied with a CFD software.The simulation results indicate that,Compared with the traditional dust-cleaning method,the uniformity along the axial direction and the dust-cleaning effect of the cartridge filter is improved with a porous media diffuse,and the dust-cleaning uniformity along the axial direction of the cartridge filter is increased with the increase of the porosity,which matches the experimental results.The research results indicate that the dust-cleaning uniformity along the axial direction of the cartridge filter can be improved by using porous media diffusers,and it provides a feasible method to improve the dust-cleaning performance of filter dusters.