10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Performance of Compact Cyclones with Taper-Shaped Bodies
PENG WANG, Di Liu, Da-Ren Chen, Virginia Commonwealth University
Abstract Number: 400 Working Group: Control and Mitigation
Abstract Cyclones have been widely used in a variety of industrial sectors for either removing or recovering particulate matter (PM). It is because of the low cost of machining, operation and maintenance of cyclones. Extended researches have been performed to investigate the performance of cyclones in various geometrical designs. This study introduces a new type of cyclones whose bodies are tapered instead of straight in conventional cyclones. The performance of cyclones with three different contraction angles of 0°, 30° and 60° were experimentally evaluated to study the effect of contraction angle on the cyclone performance. Two experimental setups were used to measure the penetration of particles through the studied cyclones. Polydisperse KCl particles were generated in both experimental setups. In one setup, the large particle aerosol generator (TSI 8180) was used to generate supermicrometer particles, and the optical particle spectrometer (OPS TSI 3330) was applied to measure the particle size distributions both upstream and downstream of studied cyclones. A make-up flow line (with HEPA filter and flow controller) was also included in the setup to vary the cyclone flow rates. In the other setup, a custom-made Collison atomizer was utilized to generate submicrometer particles, and the scanning mobility particle sizer (TSI 3096) was used to measure the particle size distributions both upstream and downstream of studied cyclones.
Our study shows that, the cut-off particle size for each taper-shaped cyclone decreased with the increase of cyclone flow rates. Under the same cyclone flow rate, the cut-off size would decrease with the increase of contract angles. For instance, at the cyclone flow rate of 2 L/min, the cut-off particle size for the cyclone with the 60°-taper-shaped body is ~ 1.7 μm with the pressure drop of 2.26 inH2O, while for the cyclone whose contraction angle is 0°, the cut-off size is ~ 2.6 μm with a pressure drop of 2.14 inH2O. The linear correlation between the dimensionless cutoff particle size and annual flow Reynolds number for studied cyclones was further found in this cyclone study. The regression of the linear correlation could be useful in the future design of cyclones with taper-shaped bodies.
The pressure drop of cyclones at different operational flow rates was also characterized. It is found that the cyclone pressure drop increases quadratically with the operational flow rate for all the studied cyclones. At the same flow rate, the 60°-taper-shaped cyclone has the highest pressure drop and the 0°-taper-shaped cyclone has the lowest drop. On the other hand, it is observed that, among three studied cyclones, the pressure drop of the 60°-taper-shaped cyclone is the lowest for the same cut-off particle size. The above finding implies that cyclones with taper-shaped bodies can effectively remove particles at the lower operational flow rate. Consequently, cyclones with tapered-shaped bodies can save more energy than conventional ones. Because of their compact design, studied cyclones can also be applied as the size-selective inlets for miniature aerosol sensors.