Research And Demonstration On Treatment Process Of Wet Plume From Steel Sintering

Compared with other types of flue gas,steel sintering flue gas has higher dust content and viscosity,so the wet plume of sintering flue gas is enriched with higher concentrations of pollutants,and direct emission is not conducive to the stable realization of ultra-low emission targets;At the same time,the steel sintering process often needs to add an appropriate amount of water to the mixture,so the moisture content of the sintering flue gas is higher,and the wet plume phenomenon is more prominent.In this paper,in the context of the domestic tightening of sintering flue gas pollutant emission control,a more detailed study has been carried out on the wet plume control of steel sintering flue gas,hoping to improve the energy-saving and consumption-reduction level of the steel industry and reduce the steel industry.The potential risks that the industry brings to environmental quality will help my country win the battle to defend the blue sky and achieve the strategic goals of greener mountains,greener waters,and bluer sky.This research was built based on basic characteristics of air pollution in the iron and steel sintering industry,emission status,and control policies,introduces the formation mechanism of wet smoke plume,and collects the theoretical and practical progress of wet smoke plume treatment at home and abroad.At the same time,CFD software was used in related fields.The application was introduced briefly.Aiming at the refined research field of iron and steel sintering flue gas wet plume treatment,based on the optional process technology,according to the characteristics of sintering flue gas pollution and treatment,a set of economically reasonable and technically suitable for my country's national conditions is proposed.The process system can effectively control the wet plume while realizing the further synergistic removal of multiple pollutants.On the basis of the feasible steel sintering flue gas wet plume treatment process system,a calculation model for the key parameters of gas-liquid contact heat and mass transfer in the wet plume treatment process was established,and the input and output values of the model were calculated.Secondly,based on the CFD software platform,optimized selection and layout of the core components inside the spray condensation tower.Based on the demonstration project,the gas-liquid two-phase heat and mass transfer process in the spray condensing tower was studied in detail:a numerical simulation method for the gas-liquid contact heat and mass transfer in the spray condensing tower was established.Based on the working conditions of the demonstration project,a numerical simulation of the temperature field of the gas-liquid two-phase flow in the spray condensing tower is performed on the basis of a given initial spray layer layout.The SST k-w model was used on gas phase,the DPM model was adopted on liquid phase during the numerical simulation.Through the numerical simulation under the initial conditions of the demonstration project of temperature field in the spray condensing tower,the temperature distribution in the spray condensing tower was clarified,and then the optimized spray layer spray water distribution plan was proposed.Through the control variables,the different optimized distribution modes under different flue gas loads are repeatedly simulated to achieve a better flue gas cooling effect under the same spray water volume.Finally,the process system,calculation model and simulation results determined in this study was applied to the design and construction of the demonstration project.the construction of the demonstration project was completed.The data during the stable operation of the demonstration project verified the reliability of the numerical simulation method,the accuracy of the calculation model,the flue gas cooling effect of the process system,and the removal ability of various pollutants.The simulation results was showed:under the same amount of spray water,making full use of the unevenness of the flue gas load distribution in the tower to change the distribution of each layer of spray water can make the temperature field distribution in the tower more uniform and the flue gas The outlet temperature is lower than before optimization;at the same time,the gas-liquid heat exchange effect in the spray condensing tower can be improved by increasing the upper spray water volume,thereby reducing the flue gas outlet temperature,which is more conducive to the treatment of wet plumes.In the spraying method used,the average absolute error between the measured value and the simulated value of the flue gas temperature at 50%load is 2.02%,and the average absolute error of the measured value and the simulated value of the flue gas temperature at100%load The error is 2.25%,and the average absolute error is controlled within 5%under the two working conditions,at the same time the numerical simulation results were better consistent with the measured values.The calculation model results show that the proposed wet smoke plume treatment gas-liquid contact heat and mass transfer calculation model has high accuracy for engineering calculations:for the calculation of condensate water volume,the maximum percentage error of the system under 50%load is only 3.17%,the maximum percentage error of the system under 100%load is 3.27%;for the cooling effect,the calculation model can ensure 100%of the expected cooling rate of 15%under the monitoring conditions and no white plume.The results of the process system show that the proposed sintering flue gas wet plume treatment process system has a good emission reduction effect:the average removal rate of SO₂ can reach 68.5%,and the average removal rate of particulate matter can reach 62.02%,which is treated by the spray condensing tower After that,the average emission concentration of SO₂ decreased to 8.92 mg/m³,and the average emission concentration of particulate matter decreased to 3.13 mg/m³;the sintering flue gas wet plume treatment technical route based on condensation reheat technology can well meet the economic requirements,and the demonstration project unit the annual operating free has been about 890,000 yuan.