Improved Lower Particle Size Limit for Aerosol Time-of-Flight Mass Spectrometry

Laboratory and field tests have shown that electrostatic precharging can lead to a substantial decrease in the flow resistance of fabric filters. For lead smelter dust, the effectiveness of the precharger is dependent on the relative humidity of the suspending gas. For relative humidities below 5%, severe back corona occurs in the precharger, which results in poor particle charging and little improvement in filter performance. For relative humidities between 5% and 40%, little or no back corona occurs, precharging is effective and results in a reduction of up to 60% in the flow resistance of the fabric filter. The operational range of the precharger can be extended to lower relative humidities by cooling the earthed electrode. The improvement in filter performance can be achieved without the precipitation of large quantities of dust in the precharger.