Research On Dust Removal Characteristics Of Rare Earth Tungsten Thermionic Emission Dust Pre-charged High Temperature Particle Layer Dust Collector

High temperature dust collection is the important link to put IGCC and PFBC into practical use.However,there is some limit in every present technology.In order to explore a new kind of high temperature dust removal technology,we developed a high temperature granular layer dust where the dust was collected after charged by rare earth tungsten thermionic emission cathode and studied its dust removal characteristics from the theory and experiment.Based on the theoretical analysis,the feasibility of this technology for high temperature dust removal was discussed.Then we designed and set up a thermionic emission cathode high temperature discharge device and used different rare earth tungsten cathodes to conduct discharge experiments in N2,CO2 and N2/CO2 atmosphere.Through the experiments,the effect of temperature,atmosphere and cathode materials on current density and halo voltage was showed.On the basis of experimental research,we corrected the Peek formula and fit out the halo voltage semi-empirical formula.With the semi-empirical formula,the influence of temperature,atmosphere,cathode materials and environmental pressure on halo voltage was further revealed.At last,we established a dust removal test system and conducted experiments on it respectively from two aspects of cold and hot condition.Through the experiments,the influence of filtration time,particle layer thickness,temperature and charging voltage on the dust removal efficiency was studied and the fact that charging the dust could obviously improve the dust removal efficiency of fine particles was found.