Development And Optimization Of High-speed Horizontal Calcium Desulfurization Reactor

With the gradual deterioration of China's environmental situation and the country's gradual improvement of environmental protection standards,sulfur dioxide flue gas has different degrees of harm to the ecological environment,building facilities,and human health,and its emissions have become increasingly important.After more than 70 years of development,China's aluminum industry has achieved an internationally advanced level of overall technology.With the advancement of technology,the discharge of major industrial pollutants such as fluorine-containing gases has been effectively controlled,but the treatment of sulfur dioxide in industrial waste gas has lagged behind.In September 2010,the country issued and implemented the"Aluminum Industry Pollutant Emission Standards"(GB25465-2010),which stipulates that the concentration limit of flue gas sulfur dioxide emission in the production process of electrolytic aluminum industry enterprises will be adjusted from 400mg/m~3(N)to 200mg/m~3(N).Therefore,the task of reducing and controlling sulfur dioxide emissions from the flue gas of the aluminum industry is very arduous and urgent.Horizontal spray desulfurization tower is a high-efficiency and low-cost calcium desulfurization and dedusting new technology developed in the United States in recent years.Compared with ordinary vertical scrubber desulfurization technology,it has the advantages of low investment,compact structure,small footprint,and production operation.And other characteristics,but there are few domestic studies on this.Therefore,to accelerate the localization of flue gas desulfurization technology of horizontal spray desulfurization tower,it is necessary to explore its desulfurization process.In this paper,the following aspects of the desulfurization process of the horizontal desulfurization tower were studied:Firstly,based on the actual physical structure of the spiral nozzles of the key components inside the horizontal desulfurization tower,mathematical modeling was performed using the Euler-Lagrangian model to simulate the atomization process.The simulation found that the value of the atomizing cone angle gradually increased to the maximum with the increase of the inlet pressure,and the maximum atomizing cone angle was related to the inner diameter of the nozzle.At the same time,the axial velocity and radial velocity of the droplet also increase gradually with the increase of pressure.Through the nonlinear regression of the simulation data,the empirical equation of the distance between the maximum axial velocity and the nozzle is fitted.Secondly,by establishing a flue gas flow model of the horizontal desulfurization tower,the internal velocity,pressure,and turbulent flow distribution of the flue gas under different inlet speeds,different inlet directions,and different inlet modes are compared.It has little effect on the trajectory of smoke in the tower,and the pressure drop and turbulent flow energy in the tower will also increase,but the area of the low-pressure return zone in the tower will gradually decrease.When the flue gas inlet speed is 5m/s,the pressure distribution in the desulfurization tower is the most uniform,which is beneficial to the desulfurization reaction.When the flue gas enters the desulfurization tower in the horizontal direction,the velocity fluctuation is small,the velocity distribution is more uniform,the flue gas flow is relatively stable,and the overall performance in the tower is better.The design of the gradually expanding circular tube inlet method is better than the straight-through circular tube inlet method design.Finally,on the basis of the desulfurization tower optimized by the structure simulation,the calcium desulfurization process was used as a treatment method.A series of parameters such as PH value,liquid-gas ratio,calcium-sulfur ratio,and SO2 concentration of the slurry that affected the desulfurization efficiency were experimentally studied and analyzed.Influence of various parameters on desulfurization efficiency.The results show that when the SO2 concentration in the flue gas is 200?300mg/m~3(N),the liquid-gas ratio is 15/1,the calcium-sulfur ratio is 1/1,and the SO2 in the horizontal desulfurization tower can reach up to more than 90%.The flue gas sulfur dioxide emission concentration after the reactor desulfurization treatment?200mg/m3(N)has reached GB2546-2010 aluminum industry pollutant emission standards.