| Wet desulfurization flue gas whitening and latent heat recovery is one of research hotspots in the field of the depth of coal-fired flue gas purification,but an additional flue gas cooling or heating equipment is required,which increases the flue gas resistance,the equipment investment and use of space.If the air pressure margin of the induced draft fan is insufficient,the fan needs to be replaced or retrofitted,which limits the promotion and implementation of flue gas whitening and heat recovery technology.This article proposes an integrated idea of cooling dehumidification and defogging.The cooling dehumidification demister can not only improve the demisting efficiency on the basis of the original baffle demister,but also reduce the resistance of the whole flue gas whitening system and save the installation space.In this paper,the performance parameters of the new cooling dehumidification demister and the ordinary baffle demister are compared by building a cold experimental platform.The experimental results show that as the airflow velocity increases,the demisting efficiency of these demisters increases firstly and then decreases,and the maximum difference of the two types of defogging devices is about 13%.The critical flow velocity which is measured in the test is about 6m/s.The efficiency of the new cooling dehumidifier demister is 20%higher than that of the ordinary baffle-plate demister for droplets with particle size range of 10?15?m;and 40%higher for droplets with particle size range of 15?25?m.When the particle size is greater than 30?m,the efficiency of the new cooling dehumidifier demister is basically 100%.This indicates that the new cooling dehumidifier demister makes up for the defect that the ordinary baffle demister can't capture the small droplets.On the whole,the pressure drop value of the new cooling dehumidifier demister is larger than that of the ordinary baffle-plate demister,but none of them exceeds 140Pa,which meets the requirement that the pressure drop value in the actual engineering is less than 200Pa.At the same time,CFD numerical simulation is used to conduct auxiliary research,and simulates the flow field in the new cooling dehumidifier demister,the ordinary baffle demister and the barbed baffle demister,and analyzes the influence of the structure parameters and operation parameters of the demister on the performance of the demister theoretically.Ordinary baffle demister is not very effective in defogging ultra-fine particle droplets in the range of 10?m?20?m particle size,less than 20%.However,the demisting efficiency of new cooling dehumidifier demister and baffle demister with barb for the 10?m droplet is much higher than that of ordinary baffle demister,the minimum is not less than 10%,and the demisting efficiency for the 20?m droplet is higher than 80%,and the removal effect is 100%when the droplet size is larger than 30?m.Simulation results show that the new cooling dehumidification mist eliminator and barbed baffle demister has improved the problem of poor defogging effect of ordinary baffle demister.The demisting efficiency of new cooling demister is lower than but close to that of baffled demister with barb,and the pressure drop of the barbed baffle demister is the highest among the three types of defogger,followed by the new type of cooling dehumidifier demister,the ordinary baffle demister is the lowest.Compared and analyzed the experimental data with the simulation data,it is concluded that although the experimental and simulated values are different to some extent,the laws of change consistent.Comprehensive defogging efficiency,energy consumption and other factors,the new cooling dehumidification demister is a better choice.The conclusion of this paper provides the theoretical basis and design reference for the design and modification of the demister. |
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