American Association for Aerosol Research - Abstract Submission

AAAR 39th Annual Conference
October 18 - October 22, 2021

Virtual Conference

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Size Distribution and Electrostatic Charge Measurements for Disinfectant Droplets of Electrosprays

QINGFENG CAO, Seong Chan Kim, Qisheng Ou, Chenxing Pei, David Y. H. Pui, University of Minnesota

     Abstract Number: 634
     Working Group: Instrumentation and Methods

Abstract
The COVID-19 disease has caused significant harm to the societies of many countries worldwide. Thus, it is crucial to conduct proper indoor cleaning with disinfectant to reduce the possibility of transmission of the coronavirus. This study is aimed to evaluate the droplet size distributions and mean charge level of two electrosprays that are commonly used for spraying disinfectant on indoor surfaces. One sprayer has three nozzle settings with the nominal droplet size being 40 μm, 80 μm and 110 μm, respectively, while the other sprayer has only one nozzle setting with a finer droplet size distribution. Two different disinfectant solutions were tested during our measurements. The Global Sizing Velocimeter (GSV) system (TSI Model GSV-1000) was applied to characterize the droplet size distributions generated by the two sprayers, which is a global imaging technique for simultaneous size and velocity measurement of transparent and spherical particles over a two-dimensional measurement region. The deflection velocity method was then applied to determine the droplet charge, where two parallel metal plates with an electric field intensity of 1 kV/cm was installed at the measurement area, deflecting the charged droplets in between. The GSV system was then applied to track the deflection velocity in the horizontal direction for each detected droplet, based on which the corresponding electrostatic charge was calculated. This investigation provides an effective approach for measuring the size distribution and electrostatic charge for disinfectant droplets of electrosprays.