Determination of Cyclone Model Variability Using a Time-of-Flight Instrument

A test method for the measurement of the internal penetration of personal cyclones using a modified TSI Aerodynamic Particle Sizer (APS) is presented. A new method to generate a polydisperse polystyrene aerosol has been developed. The effects of phantom particle generation in the recorded size distributions determined were reduced mainly by using the Large Particle Processor (LPP) data and extending the particle-size range of the LPP by reducing the threshold voltage of the LPP. The performance of five commercially available versions of the Higgins-Dewell-type cyclone has been tested using this method. The cyclones have virtually identical internal geometric dimensions but are machined from different materials and have different internal surfaces. It was found that the measured penetration curve for each model has a unique combination of cutoff diameter and slope. It was also shown that accurate determinations of cyclone penetration require particle loading to be considered.