A Low-Cost Solid Aerosol Generator of High Stability

RYAN WARD, Miranda Hack, V. Faye McNeill, Columbia University

     Abstract Number: 432
     Working Group: Instrumentation and Methods

Abstract
A technique is described to aerosolize granular solid materials. A low-frequency audio speaker (subwoofer) is used to drive the airborne dispersion and entrainment of solid nanopowders into a continuous flow reactor. Surface area (SA) concentrations exceeding 10,000 μm² cm^-3 at the outlet of the generator can be generated stably on the order of hours (~ 2% variation in SA concentration). Variation of the subwoofer's driving frequency between 40 and 100 Hz shows a surface area production maximum between 70 and 80 Hz, likely due to the resonance of the rubber dam upon which the granular material rests. Reproducible control over the SA is achievable in replicate trials of the same frequency, though some day-to-day output variability exists. Stable generation of particle SA is achievable for over 6 hours, a desirable outcome for experiments in a variety of contexts, in particular for steady-state flow reactors.