An industrial furnace, such as a blast furnace, molten salt furnace and a basic oxygen furnace, is a popular reactor, where the distribution of liquid, flow pattern of the fluid and the velocity of the fluid determine the energy distribution and chemical reaction in the reactor. Taking a furnace as the research object, this paper studies the effects of different inlet velocities, liquid densities and viscosity on bubble and velocity distribution. A three-dimensional mathematical model of the furnace is set up by a numerical simulation, and the volume-of-fluid (VOF) method is used to study the behavior of bubbles. The accuracy of the simulation parameters selected in the simulation calculation is verified by comparing the simulation with the experimental results. The findings show that an excessive or too small an inlet velocity will lead to an uneven distribution of chlorine in the furnace, therefore, an inlet velocity of about 30 m/s is more appropriate. In addition, changing the liquid density has little effect on the bubble and velocity distribution while choosing the appropriate liquid viscosity can ensure the proper gas holdup and fluidity of chlorine in the furnace.

Pellets are raw materials for blast furnace (BF) production, and a comprehensive understanding of the reaction process of pellets is of great significance for the operational optimization of BF production, energy saving, and emission reduction. The present study focuses on the structural evolution of pellets at different reduction stages. Combined with micro‐computed tomography (micro‐CT), interrupted reduction experiments are designed to analyze the different reduction stages of the pellet. The effects of the gas composition and temperature on the reduction are investigated. The results demonstrate that the combination of interrupted reduction experiments and micro‐CT can effectively illustrate the internal information of the pellets at different stages. The reduction products of H2 are dense iron phases, resulting in a clear pore stratification inside the pellet, and the outer pores almost disappear. In addition, the internal structure of the pellet is complex and the degree of reaction is uneven. The cracks generated during the reduction reaction become gas channels, which lead to a higher local reduction rate than in the others. Notably, the reduction expansion of pellets at 1000 °C is faster than that at 700 °C and the surface cracking is more severe.