Effect of particle size distribution on the performance of electrodynamic screens

Electrodynamic screens (EDS) consist of rows of parallel electrodes deposited on a dielectric substrate covered by a thin insulating coating. The EDS electrodes are connected to a single or multi-phase AC high voltage source to generate an alternating electric field between the electrodes. Such screens have been shown to remove accumulated dust when an alternating voltage is applied. The effect of dust particle size distribution (PSD) on the dust removal efficiency (DRE) of the EDS was analyzed for its application to lunar and Mars missions. Samples of JSC Mars-1 dust simulant were classified into two different particle size distributions. The PSD difference was measured using an electronic single particle relaxation time (ESPART) analyzer. The classified powder was then used to test the performance of electrodynamic screens with two different electrode geometries. The DRE for powder with a count median diameter (CMD) of 5.8 /spl mu/m was 77.3%, where as for a CMD of 5.2 /spl mu/m the DRE was 47.1%.