Research And Application Of High Temperature Electrostatic Precipitator Before Denitration Of Cement Kiln Flue Gas

The total output of domestic cement is increasing,and the discharge of pollutants is also rising.The NOx emission standard of cement kiln is becoming more and more strict.In order to deal with the more stringent NOx emission standard in the future,this paper carries out research and application on the high-temperature electrostatic precipitator in the process route of cement 5000t/d production line which adopts"high-temperature dust collector+SCR"to reduce NOx emission.In this paper,the high temperature application of high temperature electrostatic precipitator in cement kiln is studied,and the discharge performance at 300℃～350℃is determined by high temperature discharge experiment According to the change of high temperature conditions,compared with the application of conventional electrostatic precipitator,the matching parts of electrostatic precipitator adapted to high temperature conditions were selected,and 95 porcelain insulator,C220 pole plate,barbed wire and high frequency power supply were selected to match the operation conditions of electrostatic precipitator at 300℃～350℃,and the specifications of high temperature electrostatic precipitator matched with the scale of 5000t/d cement production line were selected.By means of finite element analysis,the expansion strength and deflection of the top beam and side plate,which are the main bearing components of high temperature electrostatic precipitator,are checked.Compared with the application of conventional electrostatic precipitator,Q345 material suitable for high temperature conditions is selected to ensure the safety and stability of the structure.The problem of thermalexpansion under high temperature conditions starts with the influence of thermal expansion on the anode system.The results show that the anode rapping shaft is greatly affected by high temperature thermal expansion,and a coupling is added to solve the problem of thermal expansion of rapping transmission shaft.Using CFD simulation analysis method,the relative standard deviation of wind speed distribution in one electric field section of high-temperature electrostatic precipitator is reduced from 39.32%to 24.95%after adding a guide plate at the air inlet of high-temperature electrostatic precipitator,which improves the air flow uniformity in high-temperature electrostatic precipitator,improves the dust collection efficiency and improves the ammonia water distribution effect.The resistance of high temperature electrostatic precipitator is calculated,and the running resistance of high temperature electrostatic precipitator is 137Pa,which meets the design index.According to the research results in this paper,it is applied to the high-temperature electrostatic precipitator,and the demonstration project of high-temperature electrostatic precipitator is built.The case of 5000t/d cement kiln flue gas purification project is tested,and the concentration of high-temperature electrostatic precipitator outlet is from94.15g/Nm~3To 19.05g/Nm~3.The design goal is achieved and the project runs successfully.