5-STAGE CYCLONE SYSTEM FOR INSITU SAMPLING

This paper describes the development and calibration of a five-stage cyclone system for in situ sampling of process streams. Cyclones may be used to advantage for collecting large samples and in sampling aerosols of high particulate concentration. The cyclone system was calibrated using a vibrating orifice aerosol generator and a pressurized Collison nebulizer to disperse monodisperse latex particles. At 25 °C, 28.3 L/min, and for a particle density of 1.0 g/cm3, the D50 cut points of the cyclone system were 5.4, 2.1, 1.4, 0.65, and 0.32 nm for cyclones numbered I-V, respectively. Results from calibrating the cyclones at several conditions of flow rate, temperature, and particle density suggest that the D50 cut points are: (a) proportional to the flow rate of the gas raised to a negative exponent that is between —0.63 and —1.11, (b) linearly proportional to the viscosity of the gas, and (c) proportional to the reciprocal of the square root of the particle density. © 1979, American Chemical Society. All rights reserved.