Simulation of gas flow and particle behavior with diluted oxygen injection in an iron-making fluidized bed reactor

Abstract

Computational simulations were performed to investigate the gas flow and behavior of iron particles with diluted oxygen burners in an industrial-scale fluidized bed reactor. The multiphase particle-in-cell (MP-PIC) method (Andrews & O'Rourke 1996) was applied to represent the behavior of iron particles. The developed library and solver were validated for a lab-scale reactor (Patil et al. 2015), showing good agreement with measured data in the industrial-scale reactor. It was shown that iron ore particles were heated by a diluted oxygen flame attached to the oxygen nozzle. Parametric simulations were conducted to determine the optimal oxygen injection conditions to reduce hot regions. The results indicated that peak temperature and hot spot size decreased with the diluted oxygen jets' higher injection velocity, higher nitrogen fraction, and lower collision angle. Among these factors, a high jet velocity significantly reduced the number of particles above the critical defluidization temperature.