(365e) Empirical Erosion Tests: Uniflow Cyclones As An Alternative to Reverse Flow Cyclones for Longer Life Time?

Empirical Erosion Tests: Uniflow Cyclones as an Alternative to Reverse Flow Cyclones for longer Life Time?

M. Kraxner¹, M. Portenkirchner¹, M. Pillei¹, T. Kofler¹, U. Muschelknautz¹

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

Erosion, as main cause for the lifetime of cyclones, is in some cases more interesting for plant operators than high separation efficiency. The lifetime of cyclones depends mainly on the solids loading and the solids properties, as well as the operating parameters (e.g. gas temperature, flow rate) and the geometric design parameters. Y.-M. Chen identifies the erosion of cyclones in the FCC-process as the most expensive part of the working expenses in petroleum refineries [1]. To increase the lifetime of cyclones S.B. Karri et al. investigated the influence of solids loading, gas velocity and geometric design of cyclones to reduce the erosion [2]. The most erosion-sensitive region in a standard reverse flow cyclone is the lower cone and in second stage cyclones the upper dipleg.

An alternative cyclone type where the gas passes through in one direction is the uniflow cyclone. 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. Therefore emissions of fine dust can be reduced by a low fabrication effort. The simple design of this cyclone type leads to a low erosion potential compared to the standard reverse flow cyclone.

Erosion tests with quartz dust show a relative abrasion of the uniflow cyclone compared to the erosion in standard cyclones. Additionally the most critical area of abrasion can be located.

[1] Chen, Y.-M., Evolution of FCC – Past Present and Future – and the Challenges of Operating a High-Temperature CFB-System, CFB10 – 10th International Conference on Circulating Fluidized Beds and Fluidized Bed Technology, Sunriver/OR, 2011.

[2] Karri, S.B., Cocco, R., Knowlton, T.M., Erosion in Second Stage Cyclones: Effects of Cyclone Length and Outlet Gas Velocity, CFB10 – 10th International Conference on Circulating Fluidized Beds and Fluidized Bed Technology, Sunriver/OR, 2011.