Experimental Study Of The Wire-to-cylinder High-temperature Electrostatic Precipitation Characteristic

During the process of chemical, petroleum, metallurgy, electric power and other industries, a lot of dusty gas generate at high temperature, which contains large amounts of physical sensible heat, latent heat of chemical and power energy. In order to reduce dust emissions and effectively use the huge heat contained in high-temperature gas, the high-temperature electrostatic precipitation technology gets more and more attention. The present work conducts some basic research about high-temperature electrostatic precipitator with a wire-to-cylinder configuration. Experiments mainly study on the DC discharge characteristics of wire-to-cylinder configuration with the heteropolar distance of5mm,29mm and99mm at different temperature. In addition, dust removing experiments are investigated in the wire-to-cylinder high-temperature electrostatic precipitator with the heteropolar distance of99mm.The DC discharge experiments are investigated in the wire-to-cylinder configuration with different heteropolar distance. The results show that the discharge current increases as the temperature increases at the same voltage. Corona onset voltage and spark breakdown voltage decreases as the temperature increases, but the spark breakdown voltage drop faster. At the same temperature, it increases the difference between the corona onset voltage and the breakdown voltage when increasing the heteropolar distance. After the occurrence of spark breakdown, it is more prone to observe glow discharge with the higher ambient temperature and smaller heteropolar distance.The numerical simulation is investigated in the wire-to-cylinder configuration with the heteropolar distance of29mm during the corona discharge phase. The simulation results show that charge density is near constant at low voltage. As the voltage increases, charge density increases sharply around the corona electrode while the change of charge density is relatively flat away from the corona electrode. At the same temperature, the electric field strength is greater near the corona electrode while the electric field strength tends to be uniform away from the corona electrode. As the voltage increases, the electric field distribution will be more uniform. Volt-ampere characteristic curves are compared with experimental and simulated results, which shows that at high temperature and high voltage, corona current is mainly carried by ions and electrons. With the increase of temperature and voltage, the ratio of the electron current is increased gradually.Experiments investigate the wire-to-cylinder high-temperature electrostatic precipitator with the heteropolar distance of99mm. The results show that dust slightly decreases the corona current. Collection efficiency of particles of all sizes increases as the voltage increases, but the rate of increase is different. The highest collection efficiency is for dust particles above10μm while the lowest collection efficiency is for particles of1～2.5μm. In the range of350℃～450℃and14000V～15000V, collection efficiency of the electric precipitator can remain above90%.