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Abstract:
In order to study the effect of dust outlet geometry on the performance of cyclone separators, the gas-solid flow characteristics in four cyclone separators with different dust outlet geometries (without dustbin, with dustbin, with dipleg and with dustbin plus dipleg) have been computationally simulated. The gas flow fields were simulated with Reynolds Stress Model(RSM).The effect of instantaneous turbulence on particle tracking was taken into account by mean of the stochastic tracking approach and the two-way coupling between gas and solid was considered. The results show that the value and the distribution of tangential velocity is similar for the four cyclone separators, and the difference of the maximum tangential velocity between those cyclones is within 2 m/s. The axial velocity curves of all cyclones show bimodal asymmetric distribution , The inner axial velocity of the cyclone separator with dustbin plus diplegis 3m/s, larger than that the other separators because of sudden decrease of diameter. The shapes of the grade collection efficiency curves of all models have a so-called "S" shape. The cyclone separator with dipleg and dustbin has an efficient separation efficiency, because of the provision of an additional separation space for ash dust, creating a favorable condition for its further separation. The influence of the dust outlet geometry on the pressure drop is small, and the separation efficiency is greatly influenced. If the cyclone performance parameters are estimated without the dust outlet geometry, an error will exist in the performance prediction and numerical simulation.
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