Experimental And Numerical Simulation Study On A Combined Mist Eliminator

At present,my country’s power industry is mainly based on thermal power generation.The sulfide and nitrogen oxides produced after coal combustion enter the flue with the flue gas.After desulfurization and denitrification,some of the flue gas will continue to flow.Part of the sulfide is mainly removed by the mist eliminator.The mist eliminator has an indispensable position in the entire flue gas cleaning process.This requires higher and higher requirements for the mist eliminator.This article combines experiments and simulations.The method used to study the performance of mist eliminators with different structures.In the experimental part,the defogging efficiency and pressure drop of the mist eliminator under cold conditions were analyzed by setting up a test bench.The defogging performance of the combined defogger,the folded plate defogger and the single hook plate folded plate defogger are studied in detail.A ccording to the data analysis: with the increase of the flue gas inlet speed,the defogging efficiency of the mist eliminator first increases and then decreases,the maximum difference is 15%,and the critical flow rate is about 5m/s.For droplets with a p article size of 10～15μm,the defogging efficiency of the combined defogger is about 30% higher than that of a folded plate defogger;for droplets with a particle size of 15～20μm,the defogging efficiency is about 40% higher;When the droplet size is great er than 30μm,the combined defogger defogging efficiency basically reaches 100%.Therefore,the combined defogger makes up for the shortcomings of other types of defoggers that are poor in capturing small particle size droplets.In terms of pressure drop,under the experimental conditions,the maximum pressure drop of the combined demister is120 Pa,which meets the requirement of reducing the pressure to 200 Pa in the actual project.In the simulation part,this paper uses CFD numerical simulation software t o simulate the flow field in the channel of the combined demister,folded plate demister,single hook plate folded plate demister,and tubular demister.The simulation results show that for droplets with a particle size of 10-20μm,the defogging efficiency of the folded plate demister is not very high,the defogging efficiency of the single-hook plate folded plate defogging device is significantly improved,and the defogging efficiency of the combined defogging device highest.Moreover,for the combined defogger,the defogging efficiency increases with the increase in the number of tube rows and the tube diameter of the tubular defogger.Through the comparison of the results of the experiment and the numerica l simulation,it is found that although the experimental data and the numerical simulation results are different to a certain extent,the overall trend is consistent.The conclusions of this paper will provide theoretical data support for the selection and modification of mist eliminators in practical engineering applications in the future.