(365f) Effect of the Solids Loading On the Uniflow Cyclone Performance At Low Solids Concentrations

Effect of the Solids Loading on the Uniflow Cyclone Performance at Low Solids Concentrations

T. Kofler¹, M. Kraxner¹, M. Pillei¹, R. Lanthaler¹, C. Illchmann¹, R. Goller¹, U. Muschelknautz¹

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

Uniflow cyclones have gas and particles passing through them in only one direction and are preferably used for applications with space limitations. Recently comprehensive information has been gained on the design criteria of uniflow cyclones by systematic experiments. However, limited knowledge about the impact of solids loading on the separation efficiency and the pressure drop requires a systematic investigation.

In standard reverse flow cyclone separators the solids loading of the entering gas flow is a key parameter strongly affecting their performance. The separation efficiency increases and the pressure drop decreases with growing solids loading. The effect can be calculated by a well proven mechanistic model which states that the gas can carry only a maximum amount of solids, called the critical loading. If the solids loading exceeds this critical loading, the solids are immediately separated from the gas in the entrance zone of the cyclone. The solids remaining in the gas are then separated in the inner vortex of the cyclone. The critical solids loading derived from this model typically comprises some grams solids per cubic meter gas. In most industrial applications of reverse flow cyclones the total separation efficiency is essentially affected by the separation due to exceeding the critical loading.

For our analysis of uniflow cyclones, we assumed that the gas separation is governed by the same physical principles as in reverse flow cyclones. Experimental studies on uniflow cyclones have been performed in order to identify the critical loading as a function of relevant parameters, such as the cyclone geometry and the particle size of the feed. It is shown that the values of the critical loading are within the same range compared to reverse flow cyclones. Furthermore, the experiments indicate that for particle loadings up to 60 g/m³ the separation efficiency of uniflow cyclones increases considerably slower with rising solids loading than that of reverse flow cyclones.