Numerical Simulation of Fluid Flow and Interfacial Behavior in Three‐phase Argon‐Stirred Ladles with One Plug and Dual Plugs

Abstract

A numerical investigation is performed to describe the quasi‐steady fluid flow and interfacial behavior in a three‐phase argon gas‐stirred ladle with off‐centered bottom Ar injection through a plug and two plugs placed in 180° and 90°configurations, respectively. The flow of the fluid phase is solved in an Eulerian frame of reference together with the motion of every individually injected Ar bubble, tracked in its own Lagrangian frame. Volume of fluid (VOF) model is used to track any interface between two or more immiscible phases, which include slag/metal, slag/gas and metal/gas. The characteristics of fluid flow in a gas‐stirred ladle with one plug or two plugs configuration are described when the slag layer and the top gas are presented. The slag layer deformation and slag open‐eye formation at different Ar gas flow rates for three types of plug arrangements are given. The comparison of the mixing time, the deformation of slag layer and the behavior of slag/steel interface between one‐plug and two‐plug system is made. Several implications for ladle operational issues during a gas‐stirred ladle refining cycle are discussed. It is found that the proper selection of Ar gas flow rate and plug arrangements during a ladle refining cycle is required for different refining purposes considering the mixing and metallurgical reaction in a three‐phase ladle system.

Effect of Gas Blown Modes on Mixing Phenomena in a Bottom Stirring Ladle with Dual Plugs

“…The multiphase flow in a gas-stirred ladle was simulated by the volume of fluid (VOF) model, and the control equations were described as follows: 5,8,[31][32][33][34] (1) Continuity equation…”

“…Moreover, for high-capacity ladles used in many steel factories of China, two porous plugs are usually utilized, and their positions and relative angle have effect on the homogenization of molten steel. 1,6) For the function of argon gas in ladle refining, many studies were performed in the earlier years through water model 1,2,4,6) and mathematical simulation 5,[7][8][9] from different aspects such as (a) gas injection and transport, [10][11][12][13] (b) the effect of top slag layer, [14][15][16][17][18][19] (c) stirring and mixing. [20][21][22][23][24][25][26][27][28] In 1975, Nakanishi et al 10) investigated the correlation between gas mixing efficiency and mass transfer in a model ladle and explained this correlation with turbulence theory.…”

Numerical Study on Flow, Temperature, and Concentration Distribution Features of Combined Gas and Bottom-Electromagnetic Stirring in a Ladle

“…(1) The molten steel is an incompressible continuous fluid, and the bubbles are a discrete phase fluid with a constant diameter of 4 mm, the average bubble diameter was evaluated from empirical equation proposed by Davidson and Schuler [19]; (2) The break-up and coalescence of gas bubbles are neglected; (3) The ladle is filled with molten steel and the effect of the slag layer on the fluid flow is ignored; (4) The buoyant force and electromagnetic force (EMF) are mainly responsible for the fluid flow and the movement of bubbles; (5) The effect of temperature on the physical properties is ignored and the parameter of materials is regarded as a constant; (6) The displacement current is negligible.…”

“…However, the standard k-ε turbulence model proposed by Launder and Spalding [23] has been successfully employed to study the two-phase flow in many studies [19,24]. Therefore, this model was adopted in the present research.…”

Modeling of Gas-Steel-Slag Three-Phase Flow in Ladle Metallurgy: Part II. Multi-scale Mathematical Model

“…5,7) On the other side, Johansen and Boysan, 8) Guo et al 9) and Madan et al 10) early proposed a Lagrangian form of Newton's second law for solution of bubbles in liquid, which is referred to as the discrete phase model (DPM). Recently, Liu et al 11) and Cloete et al 12) coupled the VOF and DPM respectively for the immiscible continuous phases and bubbles with the standard k-ε turbulence model. For some other processes, also using the Lagrangian DPM for bubbles, Cho et al 13) investigated the transient fluid flow during continuous casting of steel slabs, Ling et al 14) investigated the effect of nozzle number on recirculation rate and mixing time in the RH process.…”