Di Liu1, Peng Wang1, Ta-Chih Hsiao2, Da-Ren Chen 1 1 Particle Laboratory, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
2 Graduate Institute of Environmental Engineering, National Central University, Taoyuan 32001, Taiwan
Received:
May 17, 2018
Revised:
July 27, 2018
Accepted:
July 30, 2018
Download Citation:
||https://doi.org/10.4209/aaqr.2018.05.0166
Cite this article:
Liu, D., Wang, P., Hsiao, T.C. and Chen, D.R. (2018). Small Cyclones with Conical Contraction Bodies.
Aerosol Air Qual. Res.
18: 2519-2528. https://doi.org/10.4209/aaqr.2018.05.0166
HIGHLIGHTS
ABSTRACT
The performance (i.e., cyclone pressure drop and particle penetration curve) of small cyclones with conical contraction bodies was investigated, with the cyclone used either as the size-selective inlet of a miniature/compact particle sensor/monitor or as a personal particle sampler. Prototype cyclones having inner bodies with conical contraction angles of 0°, 15° and 30° were constructed, and their performance was evaluated at various operational flow rates (viz., 1.0–7.0 L min–1); the results indicate that a cyclone with a high body contraction angle is capable of collecting smaller particles than one with a low contraction angle at the same cyclone pressure drop. The effect of the vortex finder insertion length on the cyclone’s performance was also studied and was found to be negligible. A linear relationship between the dimensionless particle cut-off size and the annular flow Reynolds number, Reann (in the log-log plot), could be found for the studied cyclones with characteristic cyclone velocity, calculated with the assumption of conservation of angular momentum for the swirling flow in a cyclone. Compared with previous studies, cyclones with conical contraction bodies have an advantage during lower pressure drops (up to 50%) for the same dimensionless particle cut-off size.
Keywords:
Cyclone; Conical contraction body; Cyclone pressure drop; Cyclone particle cut-off size.