Optimization Study Of Pulse Metal Long Filter Bag Filter Line Injection Cleaning Performance

Metal long filter bag dust collector is applied in the area of high temperature dust governance.Due to improper cleaning device and parameter setting,uneven cleaning phenomenon occurs between different filter bags during the line injection cleaning process.This study adopts the method of numerical simulation combined with pulse injection experiment to explore the influence law of injection pipe with different aperture distribution mode and nozzle with different structure on the cleaning uniformity of metal long filter bag in line injection,so as to further improve the structure design of injection pipe and achieve the goal of optimizing the cleaning performance of metal long filter bags in row injection.（1）Computed by Fluent numerical simulation,the distribution of airflow pressure,velocity,and mass flow rate at the outlet of injection hole of injection pipe with different injection aperture distribution patterns were compared and studied.The results indicate that the pressure,velocity and mass flow rate of each hole on the injection pipe increase gradually when the diameter of injection holes（K₁～K₉:16 mm）and the diameter of nozzles（P₁～P₉:12 mm）are the same.When the diameter of injection holes decreases gradually（K₁:17 mm,K₂～K₅:16mm,K₆～K₉:15 mm）,the airflow distribution of injection pipe is more homogeneous.（2）By means of the pulse injection experiments,the effects of injection height and pressure changes on the peak pressure distribution on the sidewall of metal long filter bag during injection were investigated using injection pipe T₁ with equal injection hole diameters（K₁ to K₉:16 mm）.The range of injection height and pressure are 160～240 mm and 0.2～0.5 MPa,respectively.The peak pressure distribution of the side wall of metal long filter bag F₁～F₉presents a gradually increasing trend.The peak pressure of S₄ and S₅ in the middle and lower part of the measurement points does not meet the requirements when the injection pressure is0.2 and 0.3 MPa.The experimental results indicate that the cleaning effect of metal long filter bag is the best under injection height of 200 mm and injection pressure of 0.4 and 0.5 MPa.（3）Aiming at the problem of uneven ash cleaning in the injection pipe T₁,the distribution mode of injection pipe aperture is improved to obtain the optimized injection pipe T₂ and T₃.When the aperture distribution of injection pipe T₂（K₁:17 mm,K₂～K₇:16 mm,K₈～K₉:15mm）was adopted,the variance of peak pressure at some measuring points is greater than 0.01.The variances of peak pressure at measuring points S₁～S₇ were all less than 0.01 when the aperture distribution of injection pipe T₃（K₁:17 mm,K₂～K₅:16 mm,K₆～K₉:15 mm）was adopted,indicating that the aperture distribution of injection pipe T₃ could greatly improve the cleaning uniformity of metal long filter bags in line injection.The nozzle can effectively improve the cleaning strength of metal long filter bag.In the design of injection pipe of metal long bag dust collector,the diameter of injection holes should be gradually reduced from the front end to the end.