The Furnace on Molten Slag Metal CFD simulation is a vital technology for the steel industry. In a Basic Oxygen Furnace (BOF), oxygen is blown at very high speeds onto hot liquid metal. This process removes impurities through a “slagging reaction.” However, it is impossible to see inside the furnace because the temperature is around 1600 K. Therefore, engineers use Furnace Fluent simulations to visualize the process on a computer.

By performing a Furnace CFD simulation, we can predict how the gas jet hits the liquid surface. This interaction creates a cavity and stirs the metal, which is essential for mixing. This report uses Slag metal ANSYS Fluent tools to analyze the velocity, the shape of the liquid surface, and the heat transfer. The goal of this Furnace on Molten Slag Metal CFD study is to help manufacturers design better oxygen lances that save energy and speed up production without damaging the furnace walls. For more details on simulating chemical reactions and mixing, please explore our Chemical Engineering tutorials: https://cfdland.com/product-category/engineering/cfd-in-chemical-engineering/

• Reference [1]: Yin, Zichao, et al. “Optimized scheme for accelerating the slagging reaction and slag–metal–gas emulsification in a basic oxygen furnace.” Applied Sciences15 (2020): 5101.

Figure 1: Basic oxygen furnace steelmaking and slagging reaction [1]

Simulation Process: Fluent VOF Setup and Mesh Configuration

The simulation process for this Furnace on Molten Slag Metal CFD project began with creating a precise 2D geometry. To ensure the results are accurate, we generated a “hybrid mesh” using both triangular and quadrilateral shapes. The final grid contained 77,238 cells. This specific mesh type is very flexible. It allows ANSYS Fluent to curve around the splashing liquid without crashing the calculation.

Inside the software, we selected the Volume of Fluid (VOF) model. This is the standard method in Furnace CFD simulation for tracking the sharp line between gas and liquid. We defined two phases: Oxygen gas and Molten Steel. The boundary conditions were set based on real industrial data. The oxygen enters the domain at a cold temperature of 300 K, while the molten steel bath sits at a very high temperature of 1600 K. We used a transient (time-dependent) solver to watch how the cavity grows over time. This setup allows the Slag metal ANSYS Fluent solver to calculate the complex mixing and heat transfer simultaneously.

Post-processing: Jet Penetration, Cavity Formation, and Thermal Analysis

The post-processing analysis provides a critical look into the furnace dynamics. We must analyze the contours to understand how the oxygen lance performs. First, we look at the Volume Fraction contour (Figure 3). The Furnace on Molten Slag Metal CFD results clearly show a deep “dimple” or cavity forming in the red liquid. This is caused by the physical impact of the gas. The contour proves that the jet is strong enough to push the heavy steel aside. For a manufacturer, the depth of this cavity is the most important achievement. If it is too shallow, the chemicals will not mix. If it is too deep, it will damage the bottom of the furnace. This simulation confirms the depth is stable and safe.

Next, we examine the Velocity Magnitude contour (Figure 2). The red zone in the center represents the supersonic oxygen jet. The analysis shows that this high-speed gas transfers its “kinetic energy” to the stationary liquid. This energy transfer creates a circulation loop in the bath. This implies that the stirring effect is active, which is necessary to speed up the slagging reaction.

Figure 2: Velocity Magnitude contours showing the high-speed oxygen jet transferring kinetic energy to the static molten bath.

Figure 3: Volume Fraction contours from the Furnace on Molten Slag Metal CFD study, revealing the formation of a deep cavity and the splashing of molten steel.

Finally, the Temperature contour (Figure 4) reveals the thermal physics. We see a distinct blue stream (300 K) piercing into the red hot bath (1600 K). This is a very interesting engineering finding. It shows that the gas travels so fast that it does not heat up instantly. It creates a localized cool zone deep inside the melt. This proves that the Furnace Fluent model is correctly solving the “non-adiabatic” energy equation. By seeing this thermal pattern, a designer can optimize the blowing time to ensure the bath stays hot enough for refining while protecting the lance tip from melting. This detailed analysis transforms simple colors into a strategy for optimizing steel production.

Figure 4: Temperature contour illustrating the thermal interaction where the cold oxygen jet (300 K) penetrates the hot molten steel bath (1600 K).