(398a) Effective Separation Chamber Length of Uniflow Cylones for Optimal Separation Efficiencies

Effective Separation Chamber Length of Uniflow Cylones for optimal Separation Efficiencies

M. Kraxner¹, F. Lauterbach¹, M. Pillei¹, T. Kofler¹, J. Bolda², B. Huurdeman², U. Muschelknautz¹

¹MCI – The Entrepreneurial School, Environmental, Process & Energy Engineering, Maximilianstraße 2, A-6020 Innsbruck, AUSTRIA

²MANN+HUMMEL GmbH, Brunckstraße 15, D-67346 Speyer, GERMANY

Uniflow cyclones used for the separation of particles from gases are characterized, compared to standard reverse flow cyclones, by its compactness and its low energy consumption. The compact construction gives plant operators the possibility of easy implementation in piping systems. The length of the separation chamber affects the particle collection efficiency considerably. The separation procedure of particles in a uniflow cyclone is physically identical to a sedimentation process in a centrifugal field. Therefore it can be assumed that elongating the separation chamber length increases the separation efficiency. On the other hand Gauthier et al. showed in the early 1990 that the length of the separation chamber should be kept short (L/D ≤ 4), to achieve highest collection efficiencies [1].

The aim of this work is to shed more light on the observation of an optimum separation chamber length. For this purpose 2D/3C-PIV measurements have been carried out to evaluate the change of the gas velocities and thus of the swirl rate as a function of the separation chamber length. The PIV laser measurements of the flow field and dedusting tests, which were performed parallel, show that the length of the separation chamber should be within 1≤ L/D ≤2 to generate highest separation efficiencies. The solids-loaded gas flow in the outer layer of the separation chamber suffers high friction between at the wall and leads to a rapid decrease of the centrifugal forces.

[1] Gauthier, T.A., Briens, C.I., Bergougnou, M.A., Galtier, P., Uniflow cyclone efficiency study, Powder Technology, Nr.62: 217-225, 1990.