Research On Trapping Technology Of The Submicron Particles

Because of complex movement and charge characteristics,the submicron particle was difficultied to be trapped,so the technology and result of trapping submicron particle was worth to be study.On the basis of the research on the theory of the electroststic trapping of submicron particles,the trap result and the influencing factor of the electroststic trapping device were studied by experimented and simulation,and the particle size spectrum of before and after trapping particles were compared and analyzed.The experimental platform of electroststic trap device was set up for measuring particles' quantitative concentration and mass concentration of before and after trapping by fast mobility particle sizer and mass concentration sampling analyzer,the effect of trapping particles with positive and negative ion charge,the number of electrodes,the background concentration and the voltage were studied,and analysis the transformation of the particles size spectra.The results show that the trap results with the number and the mass of the negative ion charge were better than those of the positive ion charge.It is obviously improved that increase the number of layers of the electrode,but the increase of the efficiency were not double and gradually decreases.The trap efficiency increased first and then decreased with the increase of the voltage,each electrode had an optimum voltage.The trapping efficiency increases exponentially with the background concentration,and the trapping efficiency increase rapidly with the increase of the background concentration before reaching 90%.The particles size distribution of particles was s single peak distribution both before and after trapping,and the peak between 100 nm and 200 nm,but the peak of after trapping was much smoother than before.The particles trail was studied by fluent software,it was influenced by electric field force that simulation in the fluent through UDF program,the voltage and the distance between plates have been studied to effecting the particles trail.The simulation shows that the larger the voltage is,the greater the offset of the particle's trajectory is when the other condition are the same.The larger the plate spacing is,the smaller the particle's trajectory.With the same plate spacing and the same voltage,the particle's trajectory increase with the increase of particle size by the particle trapping device.The collector efficiency increase rapidly when the particle size was 200 nm,and decreased when the particle size was 500 nm.The reason was the particle that the particle size between 200 nm and 500 nm was charged both diffusion charging and electric field charging.