Synergistic influence of jet structural parameters on turbulent kinetic energy and decomposition efficiency in a fluidized magnesia calcination furnace

Abstract

In response to the common issues in traditional light‐burned magnesium oxide fluidized bed calcination furnaces, such as uneven particle distribution, non‐uniform temperature fields, and low reaction efficiency, this study proposes a jet‐pulse fluidized bed roasting device with a contraction‐expansion mechanism. By establishing a coupled CFD‐DPM numerical model, the study systematically analyzes the influence mechanisms of key geometric parameters, such as jet spacing, contraction angle, throat length, and contraction ratio, on the gas–solid two‐phase flow characteristics and the decomposition behaviour of magnesite within the furnace. Based on the results of single‐factor experiments that clarified the independent effects of various parameters, the response surface methodology was used for multi‐objective collaborative optimization of the throat length, contraction ratio, and contraction angle. The results show that when the throat length is 185 mm, the contraction ratio is 0.5, and the contraction angle is 26°, the predicted decomposition rate of magnesite is 98.84%, with a corresponding predicted turbulent kinetic energy of 5 m ² /s ² . Pilot‐scale experimental results show that the average decomposition rate reaches 98.54%, with a prediction error of only −0.3%, validating the model's good predictive accuracy and engineering applicability. This study provides theoretical basis and methodological support for the structural design and performance optimization of jet‐pulse fluidized bed calcination furnaces.