Effect Of Pituitary-like Scattering Structure On Pulse Ash Cleaning Of Filter Cylinder

The folded cartridge filter is widely used for its large filtering area and high filtering efficiency.However,during the process of pulse jet cleaning,there are problems such as uneven distribution of jet airflow energy in the cartridge along the axial direction and low cleaning efficiency.In order to solve the above problems,a pituitary-like scattering structure is designed to be used in the process of pulse spray ash cleaning.(1)Preliminary tests and model validation were carried out on the solid pituitary-like scattering structure without opening(type A),the solid pituitary-like scattering structure with opening(type b),the upper opening scatterer and the non scattering structure.The results show that the minimum value of side wall pressure peak is 570 pa,505.2pa,394.6pa and 348.6pa when the type A,type B,upper opening scatterer and non scatterer structure are installed,and the minimum value of side wall pressure peak increases by 63.5%,44.9% and 13.2% respectively when the three structures are installed.When type A,type B and upper opening scatterers are installed respectively,the peak pressure of the side wall at the measuring point 1 of the filter cartridge is 847.7pa,648.7pa and 465.8pa,respectively.Type A and type B weaken the entrainment effect of the negative pressure area at the tail of the scattering structure on the guided air flow,and the guided air flow can directly impact the upper side wall of the filter cartridge.The comprehensive pressure PC is obtained by assigning the weight coefficient to the peak value of the side wall pressure at each measuring point of the filter cartridge,which can represent the overall ash removal effect of the filter cartridge.The comprehensive pressure PC corresponding to the installation of type A,type B and upper opening scatterers are 646.9pa,589.9pa and450.1pa respectively.The comprehensive pressure also shows that the two kinds of pituitary-like scattering structures are better.(2)On the basis of type A and type B,the solid pituitary-like scattering structure is designed with openings and increased diameter(type C).The working conditions are changed by changing the injection pressure,installation position,injection distance,etc.The experimental results show that when the injection pressure is0.4MPa,the high-efficiency injection distance of type A is 0 ～ 120 mm,that of type B is 120 ～ 300 mm,and that of type C is 90 ～ 180 mm.When the opening of the pituitary-like scattering structure makes part of the air flow reach the fully expanded state,it needs a longer movement distance,so the efficient injection distance of type B and type C is larger than that of type A.(3)According to the results of multiple linear regression analysis,the injection pressure,installation position and injection distance are the main factors affecting the sidewall pressure peak at the measuring point 1.The standardized regression coefficients of the three are 0.255,0.115 and 0.196,respectively.The increase of the three factors will increase the sidewall pressure peak.The main factors affecting the peak pressure on the side wall of measuring point 5 are injection pressure,installation position and diameter.The standardized regression coefficients of injection pressure and installation position are 0.882 and 0.159,respectively.When the injection pressure and installation position increase,the peak value of sidewall pressure will also increase.The standardized regression coefficient of the diameter of the pituitary-like scattering structure is-0.218,and the increase of the diameter is not conducive to the role of the jet energy at the bottom of the filter cartridge..