| The coal somking type pollution is the main form of atmospheric environmental pollution in our country; the main pollutant is dust particles and SO2which emit from Boiler combustion. Because of air pollution is more and more serious in our country, for The improvement of the quality of atmospheric environment in our country researching and developing flue gas purification device has very important significance which suit for Chinese national conditions. The dust removal desulfurization technology of large coal-fired boiler flue gas develops early and relatively matures in our country. And we can reference related technical specification in the actual operation. On the other hand, the system runs stably, and dust particles and SO2emissions can strictly comply with the country of atmospheric pollutant emission standards. The middle and small coal-fired boiler flue gas dust removal desulfurization technology needs to be improved by the contrast in our country. Middle and small coal-fired boiler, with large quantity, wide distribution, load change and coal is put in bigger difference, the characteristics of dust removal desulfurization costs is not enough, For these reasons, dust particles and SO2pollution produced by middle and small coal-fired boiler cannot be ignored.Self-excited SXJ type dust removal desulfurization device is a kind of wet dust removal desulfurization device. Because of simple structure, low manufacture cost, convenient maintenance and management, and operation cost is moderate, etc. It is widely used in middle and small coal-fired boiler flue gas purification processing in our country. But the dust removal desulfurization rate is not very ideal in the process of actual use. And after purification gas with water is serious, easy to form the wet air blower, greatly reduce the service life of induced draft fan. Numerical simulation to analyze the flow condition of the internal flow field, which in order to improve the performance needs of the device, so that provide a basis for optimal design of the device. Therefore, the research content of this article mainly has the following two aspects:(1) Studying the dust removal and desulfurization mechanism of SXJ type self-excited dust removal desulfurization device. Which depend on the airflow of containing dust particles and SO2to shock free surface or liquid membrane containing lye, and forming a large number of droplets or water curtain to capture the dust particles, At the same time, the SO2of flue gas and droplet of alkaline substance happen acid and alkali neutralization reaction so as to achieve the purpose of desulfurization. First of all, declaring the three ways of droplet capture dust capture (inertia collision, interception, diffusion settlement), summarizing calculation formula of a single droplet capture efficiency which uses these three ways; and then declaring the double alkali desulfurization method which device use. Secondly, using the double membrane mass transfer theory study the two processes which are physical absorption and chemical absorption of SO2Finally, the paper analyzes the main influencing factors of absorption efficiency.(2) Using FLUENT software simulate numerically the internal flow field of this device. Gas phase using standard k-ε turbulence model, particle phase discrete phase model (DPM), and using SIMPLE algorithm to calculate it. Get the every phase flow field of the device velocity, pressure and the distribution of dust particle trajectory parameters etc. The analysis results show that will produce obvious pressure drop and low speed area when the gas flows through the double cross type damper. By the same time, the double staggered type guide baffle prolong the gas residence time in the tower to a certain extent, and Enhances the turbulent effect of the device, thereby improving the efficiency of flue gas purification. Numerical simulation results have guiding significance to actual operation of the device, and laid a theoretical basis for the optimization design. |
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