Experimental Research On The Influence Of The Cold Electrode Charged Dual-zone ESP To The High Specific Resistance Dust Collection Efficiency

Electrostatic precipitator owns some outstanding advantages, such as:high collection efficiency, high temperature adaptability, low equipment resistance, low energy consumption, low operating costs in long-term, no secondary pollution etc. Due to this the electrostatic precipitator was used widely in industrial circle. As the environmental protection requirements’ improving day by day, the new national institute of standards to the coal-fired power plants’ flue dust emission limits is 30mg/m3. The collection efficiency of electrostatic precipitator must be improved to reach the new standard requirement. Thus plenty of researches are needed.In the electrostatic precipitation circle, low collection efficiency of high specific resistivity dust (ρd>1011Ω·cm) is one of the main reasons about the lower collection efficiency. From equation E= jρd≥Ed it was shown that reducing the specific resistivity dust not only reduce the field strength of dust layer but also prevent the back corona. Then the collection efficiency was improved. Base on this, the new technology of "Cold Electrode Charged dual-zone ESP" which was used to remove the high specific resistivity dust was put forward. To cold electrode charged dual-zone ESP, Board-board structure was used in the dust collecting area, and there were no ion current produced; The charge district was combined with anode tube grid row and cathode wire grid row, one end of anode tube grid row’s cold water pipe was connected with feed pipe, and the other end of the cold water pipe was connected with return pipe. When dust collector was working, the cold water flowing in the anode gate tube for cooling the surface of the gate tube. Therefore the temperature of dust layer on the surface of the gate tube was reduced, and then the specific resistivity dust layer was reduced. The adversely affect to dust charge was eliminated, which was caused by reverse electric field and back corona due to the high specific resistance deposit dust layer on the surface of positive pole. Hence, dust charge and collection was enhanced.In our research, base on the study of theory, the influence of cold electrode charged dual-zone ESP and cold electrode charged dual-zone ESP to fly ash removal was investigated. The research was combined with two parts:one part was the measurement of V-j characteristic curve and dust removal efficiency in dust exist and no-load condition, when the smoke temperature was room temperature and 150℃; the other part was the measurement of V-j characteristic curve and dust removal efficiency in dust exist and no-load condition, when the smoke temperature was 150 ℃ and different temperature of cold pipe. The experiment results showed that the way of cold electrode charged could reduce specific resistivity dust. In this way, the accumulated charge generation anti-corona condition was eliminated fundamentally, and the supply voltage of charge district was improved. Hence, the dust collection efficiency of electrostatic precipitator increased.The experiment was mainly about the influence of cold electrode charged dual-zone ESP to the high specific resistivity dust collection performance, and the experiment results showed that cold electrode charged dual-zone ESP could solve the problem that low dust collection efficiency to the high specific resistivity dust.