Industrial practice and CFD investigation of a multi-chamber fluidized bed reactor for MnO2 ore reduction

Abstract

The multi-chamber fluidized bed reactor (MCFBR) is beneficial to the higher solids conversion rate, but the complex configuration needs special methodology for the rational design and smooth operation. In this study, an actual plant data of MCFBR for the reduction of MnO2 ore were analyzed, which indicated that the recovery rate of Mn was confirmed to be kept above 95% normally. To investigate the multi-chamber fluidized bed hydrodynamics and reaction characteristics, the 3D computational fluid dynamics (CFD) numeration coupled with structure-based transfer model and multi-chamber calculation method was established. The effect of mesoscale structure on the prediction of multi-chamber reaction process was evaluated as well. The simulation results showed that the model was able to calculate the gas–solid reaction behavior more accurately than the traditional model without taking mesoscale structure into account. The computed tanks-in-series number of 2.0 is less than the actual chamber number of 4.0 for the wide gap between the vertical baffle and the side wall. The quantitative effects of partition configuration, fluidized structure, and operating condition on the solids conversion rate were estimated as well.