Application And Evaluation Of WEAP Technology In Sintering Of Steel Industry

There are many common problems in the flue gas emission from sintering process of steel industry in baotou,such as high concentration of particulate matter（PM）,low pass rate of Continuous Emission Monitoring System（CEMS）effectiveness audit,tail gas and gypsum rain,which make it difficult to meet the increasingly strict national flue gas emission standards and management requirements for steel industry.In this paper,the working principle of wet electrostatic precipitator（WESP）is analyzed,combined with the successful experience of applying the WESP to the thermal power plant,the original and net flue gas between the C thermal power plant and the A sintering plant in the city of Baoou are compared and analyzed.Theoretical analysis is carried out on the practical problems of flue gas in A and B sintering plants in Baoou city,in order to investigate the operation of the WESP transformation project of sintering machine between the two sintering plants.The main research results are as follows:（1）There are differences in the flue gas volume,flue gas temperature,sulfur content,moisture content and other emission characteristics of the raw flue gas between the thermal power plant and the sintering plant.Because the flue gas treatment facilities all use wet flue gas desulfurization（WFGD）,they have similarities in the emission characteristics of terminal particulate matter.At the same time,the proportion of small-sized particulate matter in the terminal flue gas of the power plant is higher than that of sintered flue gas.Wet Electrostatic Precipitator（WESP）,which is widely used in ultra-low emission renovation of power plants,can be used for in-depth treatment of sintered flue gas.（2）Combined with domestic and foreign research results,experimental monitoring data and theoretical analysis,it can be determined that for the sintering enterprises in Baotou City,the excessively high content of fine particles and SO₃ in the flue gas results in insufficient emission reduction capacity of the particles and low rate qualified CEMS audit,tail gas smoke,blue smoke,gypsum rain and so on.The installation of WESP device at the end of flue gas can solve the above problems effectively.（3）The analysis results from the application examples of the WESP renovation projects of the two sintering companies A and B show that the removal efficiency of particulate matter reaches 55.9%and 44.5%,respectively,which confirms that WESP is effective in solving the particulate matter reduction,CEMS effectiveness audit,flue gas tailing,and gypsum rain;however,there are certain deficiencies in the deep removal of particles with low concentration and small particle size.For companies whose emission concentration of sintered flue gas is less than 20 mg/m³,WESP’s dust removal efficiency is significantly reduced.If further reduction of particulate concentration is required,other types of dust removal equipment should be considered comprehensively,otherwise it is difficult to meet the national regulations for emission requirements of less than 10 mg/m³.The two sintering enterprises in Baotou City,A and B,are typical representative projects for the application of wet electric dust collectors in small iron and steel enterprises in northern China.These research results will provide important scientific information and theoretical basis for the comprehensive treatment of flue gas in small and medium-sized smelters..