Sheng-Hsiu Huang1, Yu-Mei Kuo 2, Chih-Wei Lin1, Wei-Ren Ke1, Chih-Chieh Chen 1

Graduate Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei 10055, Taiwan
Department of Occupational Safety and Health, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan

Received: May 14, 2018
Revised: October 14, 2018
Accepted: October 21, 2018
Download Citation: ||  

  • Download: PDF

Cite this article:
Huang, S.H., Kuo, Y.M., Lin, C.W., Ke, W.R. and Chen, C.C. (2019). Experimental Characterization of Aerosol Suspension in a Rotating Drum. Aerosol Air Qual. Res. 19: 688-697.


  • The rotation of a drum chamber enhances particle suspension greatly.
  • The optimal rotation rate varies from 2 to 7 rpm.
  • The optimal rotation rate is proportional to particle size.
  • Suspension of small particles in a rotating drum can be correctly predicted.


Rotating drum chambers are simple and effective devices for retaining particles in the airborne state for prolonged periods. Many studies, including inhalation toxicology, environmental fate, and survivability of airborne pathogens, can benefit from using them. Particle size is the major factor governing aerosol suspension, yet reliable experimental data on the optimal rotation rate as a function of particle size are limited. Therefore, this study aims to experimentally characterize a rotating drum and to optimize the rotation rate for the bioaerosol size spectrum. Moreover, the sampling methodology for evaluating the performance of a rotating drum is investigated. Charge-neutralized potassium sodium tartrate (PST) particles generated by an ultrasonic atomizer are used as surrogates of bioaerosols to characterize the performance of the rotating drum. The aerosol number concentrations and size distributions in the rotating drum are both continuously and intermittently measured by an aerodynamic particle sizer (APS) in real time. Then, the decay constants of the aerosol number concentrations as functions of particle size, elapsed time, and rotation rate are calculated. The experimental results reveal that the rotation of the drum chamber greatly enhances particle suspension and the rotation rate can be optimized to prolong the suspension for an extended period. With the current drum geometry, the optimal rotation rate varies from 2 to 7 rpm for the particle size range of 1 to 7 µm and is proportional to the particle size. At the optimal rotation rate (2–4 rpm) for 1-µm particles, 5% of them can remain suspended for over 24 hours. However, this rate must be adjusted for large particles in order to maximize the period of suspension.

Keywords: Rotating drum; Decay constant; Suspension time; Optimal rotation rate.


Don't forget to share this article 


Subscribe to our Newsletter 

Aerosol and Air Quality Research has published over 2,000 peer-reviewed articles. Enter your email address to receive latest updates and research articles to your inbox every second week.

Latest coronavirus research from Aerosol and Air Quality Research

2018 Impact Factor: 2.735

5-Year Impact Factor: 2.827

SCImago Journal & Country Rank