(749a) Reducing Cut Size of Uniflow Cyclones with Optimized Swirl Vane Design

Uniflow cyclones are constructed as cylindrical separators with gas and particles passing through them in only one direction. Advantageous compared to reverse flow cyclones is their compact design and their easy implementation into piping systems [1]. These characteristics minimize manufacturing and installation costs. Approved calculation models for uniflow cyclones, which are valid for a wide range of applications, are missing up to now. MCI intends to develop design fundamentals for this cyclone type on the basis of systematic experimental and numerical studies. Results from these investigations provide useful insights into the operation of such devices and means to identify design criteria.
The influence of the swirl vane inlet (SVI) to the separation performance is mainly associated with following effects. The direct relation between small vane angles leading in higher separation efficiencies due to higher swirl intensities [2,3]. A second effect is the flow velocity within the vane channels itself which is accounted by geometry of the SVI. Vane optimizations in this work show high separation efficiencies linked with significant lower pressure drop based on reduced flow velocities within the swirl vane channels [4]. This reduction of energy demand due to reduced flow velocities leads in optimized vane angles to force cyclones cut size to a lower level. All investigations have been carried out at a test stand with a cyclone diameter of 0.1m. The results of the performance tests showed good compliance with additional optical investigations within the separation chamber carried out with high speed camera equipment. Moreover, a critical sedimentation path within the separation chamber could be determined, which is correlating to relevant vane design parameters.

[1] Hoffmann, A.C., Stein, L.E., Gas Cyclones and Swirl Tubes - Principles, Design and Operation. Berlin, Heidelberg: Springer, 1. au. ed., 2002.
[2] Kraxner, M., Empirische Ermittlung von Auslegungskriterien für Gleichstromzyklone in Multizyklonblöcken, phd thesis, TU Munich, 2013.
[3] Kraxner, M., Muschelknautz, U., Wechner, S., Ackermann, S., Greif, V., Bolda, J., Influence of the Inlet Vane Geometry On the Uniflow Cyclones Performance (639f). AIChE 2012 Annual Meeting, 2012.
[4] Kraxner, M., Skarke, B., Kofler, T., Pillei, M., Pressure Drop in Uniflow Cyclones: Investigation on an Empirical Calculation Model. CFB11, 2014.