Physical Modeling Evaluation on Refining Effects of Ladle with Different Purging Plug Designs

Abstract

Circular slits are introduced in purging plugs for alleviating the stress concentration to prolong their service life. Herein, the effects of slits with different geometries on the mixing time, inclusion removal rate, and slag eye area are studied by water model method. Experimental results show that the inclusion removal rate decreases with increasing slit angle for the gas flow rate of less than 6.02 NL min À1 . Moreover, with slit diameter increases, the mixing time and inclusion removal rate decrease when a gas flow rate is less than 5.26 NL min À1 . The slag eye area increases with increasing slit diameter, and the slit angle has a positive influence on the formation of the slag eye. Finally, the optimization of the mixing time and inclusion removal rate for less consumption of stirring energy and less slag entrapment indicates that the smaller the slag eye area is, the better the refining effect is.

Bubble generation in refractory porous plugs: The role of the ceramic surface composition

“…As the bubble spreads over the horizontal surface of the bubbler, the perimeter of its circumference base (C B ) is calculated by projecting R B on the horizontal plane, as stated by Equation (9). Although it would be straightforward to calculate the force due to the interfacial tension based on Equation (2), the literature often considers the projection of the interfacial tension (σ lg ) on the vertical axis by sinθ, resulting in Equation (10) to calculate F σ . 19,23,30 The implications of this assumption are further discussed,…”

“…9 Therefore, water models are broadly applied to test ceramic purging plugs. [10][11][12] For instance, Gotsis et al 13 have tested magnesia-spinel porous plugs in a water model obtaining bubble sizes within a 0.7-1.0 mm range. However, when the same plugs were evaluated in a 150 mm high crucible filled in with low-carbon steel, the bubble size was visually estimated between 2 and 5 mm on the surface of the molten bath.…”

Effect of the Location of Tracer Addition in a Ladle on the Mixing Time through Physical and Numerical Modeling

“…20) In most of the previously mentioned papers, the location of the tracer addition has minor importance within the analyzed variables and use a single addition location which, in most of the cases it is located in the slag eye opening. However, various works have been reported in literature with contrasting conclusions, such as the investigations carried out by Krishna Murthy and his colleagues [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] in which the authors conclude that the measurements obtained of the mixing time do not depend on the location neither on the tracer amount released with which the conductivity technique is performed. On the other hand, various authors conclude that not only the location of the sensors 22) affects the mixing time measurements but also the location of the tracer addition [23][24][25] is a variable that considerably affects the time required to reach a homogeneity degree of 95%.…”

“…The degree of mixing at 95% is usually accepted, although the degree of mixing at 99% has also been used, which is more rigorous. 3) The mixing phenomenon has been widely investigated and various works have been reported in literature on the main operation variables that considerably affects mixing time measurements, such as gas flow, [4][5][6][7][8][9][10][11][12][13][14] number and location of injections, [15][16][17][18] as well as properties 19) and thickness of slag. 20) In most of the previously mentioned papers, the location of the tracer addition has minor importance within the analyzed variables and use a single addition location which, in most of the cases it is located in the slag eye opening.…”

Numerical study of creep effect on purging plug performance under cyclic service

“…To satisfy the requirements of high-quality steel, secondary metallurgy is widely applied, which is often performed in a ladle furnace [1][2][3][4]. As a functional component of the ladle lining, the purging plug was used for stirring molten steel [5][6][7]. Thus, in service, the purging plug is periodically exposed to intense thermomechanical loads, which results from the collaborative impact of severe thermal shock due to blowing gas and molten steel, external mechanical constraints, and thermal expansion of its materials [8][9][10].…”