Experiment And Simulation Of Venturi Fiber Grid Composite Mechanism Dust Removal Technology

With the improvement of emission standards in the steel industry,it has become a difficult problem to effectively remove the fine particles in the rolling steel flue gas.The traditional bag dust collector and electric dust collector are easy to block the filter material and the airflow distribution is not uniform,while the wet dense fiber grid has low resistance and low dust removal efficiency.Venturi dust remover has simple structure and wide application range.It can deal with high humidity,high temperature and inflammable gases,but its wide application is limited by high energy consumption and low removal efficiency of fine dust.In this paper,based on the advantages of all kinds of dust collectors,the venturi fiber grid wet composite mechanism dust removal technology was proposed.The dust removal characteristics of the self-made dust collector model were analyzed,tested and simulated.The experimental platform of wet composite dust removal device was established.The experimental study and numerical simulation of dust particles produced in steel rolling process were carried out by using venturi tube fiber grid wet composite dust removal technology.Firstly,the influences of throat wind speed,diffuser angle,liquid gas ratio,annular gap spacing,inlet wind speed,fiber diameter,and number of fiberboard layers on the filtration performance of embedded adjustable venturi and wet dense fiber grid were analyzed,and the optimal parameter range was preliminarily determined.Secondly,through orthogonal experiment and single-factor experiment,the influence factors such as throat wind speed,fiber diameter,fiber grid spacing,fiber grid layer number,liquid-gas ratio,diffusion tube angle,and annular gap spacing were studied to determine the optimal parameter range of ventural-fiber grid wet composite mechanism dust collector.Finally,a three-dimensional model was established based on the actual model.FLUENT software was used to simulate the overall wind speed,pressure distribution and particle trajectory cloud picture of Venturi fiber grid wet composite dust removal device under different inlet wind speed conditions.The results showed that the optimal dust removal efficiency of the wet multi-mechanism composite dust collector was 99%when the throat wind speed was 22.73m/s?33.66 m/s,the fiber diameter was 0.3 mm,the fiber board spacing was 3 cm?5 cm,the fiber board layer number was 2?4 layers,the liquid-gas ratio was 0.3 L/m~3?0.6 L/m~3,and the diffusion tube angle was 5°?6°.Compared with the performance of a single dust collector,the removal efficiency of fine dust with particle size less than 3?m was 6.6%and 5.4%higher respectively.Within the range of the best parameters,the dust removal efficiency and purification resistance of the dust removal device could be adjusted online by changing the size of the cylinder embedded in the throat.The larger the gap spacing was,the smaller the purification resistance value was,while the filtration efficiency tended to increase first and then decrease.When the gap spacing was 5.1cm,the removal efficiency was the highest.With the continuous increase of inlet wind speed,the simulated overall wind speed showed a trend of first increasing and then slowly decreasing,while the overall pressure difference gradually decreased.Negative pressure was generated in the throat section,which led to whirlpool of different sizes.The dust particles in the Venturi segment rotated in a spiral fashion to the filter-gate filter segment,and the particle trajectory became disordered due to the wall rebound and the blocking action of the fiber board.Compared with the experimental results,the simulated data showed the same trend and good consistency.