381159 Pressure Drop Recovery in Uniflow Cyclones By a Special Vortex Finder Design
M. Kraxner, M. Lindl, T. Kofler and M. Pillei
MCI – The Entrepreneurial School, Environmental, Process & Energy Engineering, Maximilianstraße 2, A-6020 Innsbruck, AUSTRIA
Uniflow cyclones are constructed as cylindrical pipes with gas and particles passing through them in only one direction. In principle they can be used in all industrial applications where conventional reverse flow cyclones are applied. Advantageous compared to reverse flow cyclones is their compact design and their easy implementation into piping systems. These characteristics minimize manufacturing and installation costs.
Even though their principle is known since a long time, not as much literature can be found on how to design uniflow cyclones. 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 studies. Results from these investigations provide useful insights into the operation of such devices and means to design them.
Up to now, the separation efficiency of uniflow cyclones is not as good as the efficiency of standard reverse flow cyclones. A size reduction of the cross section area, leads to a higher superficial velocity within the cyclone and raises the separation efficiency. Beside this positive effect, the pressure drop raises too. Investigations on a special vortex finder design show that the pressure drop could be reduced significantly . A special design of a vane pack - installed in the vortex finder - changes the angular momentum flow back into an axial momentum flow, which allows a pressure drop reduction up to approximately 50%. These investigations have been carried out at a cyclone diameter of 0,1m. Measurements show, that bigger cyclones allow higher pressure recoveries caused by the comparatively thinner vane blades.
These results extend the field of application for uniflow cyclones widely.
 Greif, V., Reduzierung des Druckverlustes von Zyklonabscheider durch Rückgewinnung der Drallenergie sowie Abscheidung bei kleinen und kleinsten Staubeladungen, VDI-Fortschrittberichte, Reihe 3: Verfahrenstechnik, Nr.470, 1995.