KR20160071702A - Vacuum Treating Apparatus - Google Patents

Abstract

The present invention comprises: a container accommodating molten steel; and a refractory layer provided in an internal side of the container. An uneven portion is formed in a portion to form a path wherein the molten steel is moved in the refractory layer. Moreover, a rotational force is provided to the molten steel for a surface area exposed to the outside of the molten steel to be increased, thereby shortening a time for the molten steel to be treated.

Description

[0001] Vacuum Treating Apparatus [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus, and more particularly, to a vacuum processing apparatus capable of increasing the surface area exposed to the outside of molten steel by providing rotational force to molten steel and shortening the time for processing molten steel.

The RHE (Altitude) facility vacuum-depressurizes the interior of the vacuum vessel, then raises the ladle containing the molten steel, immerses the submerged tube, such as the riser tube and the downcomer tube, in the molten steel and blows gas through the submerged tube The molten steel is circulated inside the vacuum furnace. Accordingly, the molten steel is circulated in the vacuum furnace while being exposed to a vacuum atmosphere to perform degassing and decarburization processes of molten steel.

For example, when the reflux gas is supplied to the uprising pipe, the molten steel in the ladle flows into the uprising pipe by the suction of the vacuum tank in the vacuum state, and then the molten steel returning to the inside of the ladle is made through the downfalling pipe, Can be performed.

Conventionally, in order to accelerate the decarburization reaction, the size of the bottom tank of the submerged tube or the vessel is increased to induce the decarburization reaction by the increase of the reaction system area. However, due to the limitation of the size of the equipment, there is a limit in increasing the size of the needle tube.

KR 20-0278673 Y1

The present invention provides a vacuum processing apparatus capable of increasing the surface area exposed to the outside of molten steel.

The present invention provides a vacuum processing apparatus capable of quickly carrying out a treatment process on molten steel.

The present invention includes a container in which molten steel is circulated, a refractory layer is provided inside the container, and a concavity and convexity is formed in a portion of the refractory layer that forms the path through which the molten steel moves.

The refractory layer includes a heat insulating material, a permanent sheath, and a refractory softener in an inward direction from the outside, and the concave and convex portion is formed in the refractory softener.

Wherein the container includes a lower tank having an upper portion opened and an upper tank provided at an upper portion of the lower tank, wherein the lower tank has a downwardly extending downwardly extending tube, As shown in FIG.

Wherein the deposition pipe comprises: an uprising pipe for sucking the molten steel; And a downfalling pipe which is spaced apart from the uprising pipe and discharges the molten steel, wherein the unevenness is formed in at least one of the uprising pipe and the refractory pipe of the downfalling pipe.

The concave-convex portion has a curvature.

The concave-convex portion is formed in a corrugated pipe shape.

The concavo-convex portion is formed in a spiral shape along the inner circumference of the deposition tube.

The length of the protruding portion of the concavo-convex portion protruding toward the central portion of the immersion tube is 3 to 8 cm.

According to the embodiment of the present invention, the irregular portion is formed in the immersion tube in which the molten steel is sucked into the container, so that the molten steel can be sucked while rotating in the immersion tube. Thus, a rotating force that rises in the molten steel is generated, and a vibration wave can be formed in the molten steel passing through the immersion tube, and the elevation height of the molten steel can be increased. Therefore, since the surface area exposed to the outside of the molten steel is increased, the surface area reacted with the vacuum and the ferro-alloy or the like in the container is widened, so that the degasification, decarburization process and reaction of the alloy iron pipe can be performed quickly. Thus, the effect that the treatment process for molten steel is performed quickly and can be improved can also be improved.

1 schematically shows a vacuum processing apparatus according to an embodiment of the present invention.
2 is a view showing a concavo-convex portion in an embodiment of the present invention.
3 is a view schematically showing the operation of a vacuum processing apparatus according to an embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. To illustrate the invention in detail, the drawings may be exaggerated and the same reference numbers refer to the same elements in the figures.

FIG. 1 is a view schematically showing a vacuum processing apparatus according to an embodiment of the present invention. FIG. 2 is a view showing a concavo-convex portion according to an embodiment of the present invention, Fig.

Referring to FIG. 1, a vacuum processing apparatus 100 according to an embodiment of the present invention includes containers 110 and 120 through which molten steel is circulated, and a plurality of refractory layers 140 are provided inside the containers 110 and 120 And a concave / convex portion 143a is formed in a portion of the refractory layer 140 that forms a path through which the molten steel moves.

The vessels 110 and 120 form a space in which molten steel can be processed. The vessels 110 and 120 are disposed on the upper side of the ladle 200 containing molten steel and the molten steel in the ladle 200 can be refluxed into the vessels 110 and 120 to remove impurities or gas. The containers 110 and 120 may be formed by vertically coupling the upper tank 110 and the lower tank 120.

The upper tank 110 is provided at an upper portion of the lower tank 120. The upper tank 110 may be provided with a lance 150 for passing oxygen through one side of the upper tank 110 and an iron iron inlet for injecting ferroalloy through the side wall of the upper tank 110 .

The lower tank 120 is provided at a lower portion of the upper tank 110 and has a hollow shape with an open upper portion and a pair of dip pipes 121 at both lower portions thereof. The immersion tube 121 is extended in the downward direction. The deposition tube 121 may be disposed on the ladle 200 and may be immersed in the ladle 200 or in the ladle 200. One of the pair of deposition pipes 121 is an uprising pipe 121a for sucking the molten steel of the ladle 200 into the inner space of the vessels 110 and 120 and the other is disposed apart from the uprising pipe 121b, And a downfalling pipe 121b for discharging the molten steel sucked in the molten steel 121a to the ladle 200 again.

In order to prevent the container 200 from being broken by the high-temperature molten steel, the container 200 is made of a cylindrical iron sheet 100a and the refractory layer 140 is provided on the inner side. The refractory layer 140 may be composed of a heat insulating material 141, a permanent sheet 142, and a refractory ridge 143 inwardly from the crust 100a. The refractory is made of various materials having heat resistance capable of accommodating molten steel.

As the refractory, various refractory bricks can be used. For example, dolomite, magnesia refractory brick and the like can be used. The permanent field 142 may be formed in a cylindrical or polygonal shape with an inside hollow and an open end. The refractory ridge 143 is made of a material having heat resistance enough to accommodate molten steel and can be made of bricks of a material having high heat resistance. However, the present invention is not limited thereto, and various materials having heat resistance capable of accommodating molten steel can be used. However, the structure of the refractory layer 140 is not limited to this and may vary.

The vessels 110 and 120 are connected to a reflux gas supply line 130 for supplying reflux gas. Particularly, the reflux gas supply line 130 may be connected to a portion of the submerged pipe 121, which is provided below the lower submerged tank 120, to be deposited with molten steel. The deposition tube 121 is provided with a nozzle 121c for injecting a reflux gas. For example, when the molten steel stored in the ladle 200 is refluxed, the containers 110 and 120 are placed on the ladle 200, the deposit pipe 121 is immersed in the molten steel in the ladle 200, 110 and 120 to lower the inner pressure of the ladle 200 and suck the molten steel of the ladle 200 into the upper vessels 110 and 120. Then, the reflux gas is blown through the nozzle 121c provided in one of the submerged pipes 121. [

By reducing the apparent specific gravity of the molten steel, the difference in the molten steel height in the vessels 110 and 120 causes the molten steel to be sucked in the submerged pipe in which the reflux gas is injected, that is, the uprising pipe 121a, 121b, the molten steel can be refluxed while being discharged. As the reflux gas, argon (Ar) gas may be used. However, various inert gases may be used as the reflux gas without being limited thereto.

At this time, a concave / convex portion 143a is formed in the refractory layer 140, which is a part of the refractory layer 140 forming a path for moving the molten steel, for example, the refractory layer 140. That is, the uneven portion 143a is formed in the path through which the molten steel is sucked so that the flow of the molten steel moving along the submerged pipe 121 has a rotational property in addition to the straightness. As a result, a rotating force that rises in the molten steel is generated, so that the activated interface area of molten steel passing through the immersion pipe 121 can be widened. Further, since the elevation height of the molten steel is also increased by the rotational force in the upward direction, the surface area reacted with the vacuum and the ferro-alloy or the like in the vessels 110 and 120 is widened and the reaction of the degassing, decarburization, Lt; / RTI >

The concave and convex portions 143a are formed in the refractory layer 140 at the innermost portion of the refractory layer 140 in the vessels 110 and 120, that is, in the refractory frit 143 in direct contact with the molten steel. For example, the refractory ridge 143 is formed in a brick shape, and a concavo-convex portion is formed on a surface that forms a moving path of the molten steel of the refractory ridge 143. Therefore, since the refractory tearing wall 143 is formed in the shape of a brick, the refractory tearing wall 143 can be formed along the periphery of the deposition tube 121 inside the deposition tube 121, And the concave portion 143a may be formed in the moving path of the molten steel.

The uneven portion 143a may be formed in at least one of the uprising pipe 121a of the submerging pipe 121 or the refractory siphon 143 of the downfalling pipe 121b. For example, only the uprising pipe 121a of the pair of dip pipes 121 may be provided with the uneven portion 143a. That is, in order to rapidly process the molten steel, the surface area exposed to the outside of the molten steel sucked into the vessels 110 and 120, for example, the surface area contacting the inner space of the molten steel vessels 110 and 120, must be widened. That is, if the surface area of the molten steel in contact with the gas or the like is increased, the process of treating the molten steel can be performed quickly. Therefore, when the uprising portion 121a serving as a suction pipe for sucking molten steel is provided, the surface area of the molten steel sucked is formed to be exposed to the outside, so that only the uprising pipe 121a is provided with the uneven portion 143a And the downfalling pipe 121b may not be provided with the recessed portion 143a.

However, the roles of the uprising pipe 121a and the downfalling pipe 121b of the submerging pipe 121 may be changed. For example, when the vacuum processing apparatus 100 is used for a long period of time, the uprising pipe 121a may be used as a downfalling pipe due to aging of the equipment, and the downfalling pipe 121b may be used as an uprising pipe. Therefore, in order to prevent the role of the uprising pipe 121a and the downfalling pipe 121b from changing, the unevenness may be provided in both the uprising pipe 121a and the downfalling pipe 121b.

When both the uprising pipe 121a and the downfalling pipe 121b are provided with concavities and convexities, a rotating force is generated by the irregularities of the molten steel, so that the speed at which the molten steel rises into the vessels 110 and 120 through the uprising pipe 121a, The speed of descending to the ladle 200 through the first slider 121b can be increased. Thus, the reflux speed of the molten steel is increased, and the time of the molten steel treatment process can be shortened. Therefore, the concave / convex portion 143a may be provided only on the uprising pipe 121a or on both the uprising pipe 121a and the downfalling pipe 121b.

The concave-convex portion 143a may be formed to have a curvature. For example, referring to FIG. 2 (a), the concave and convex portions 143a may be formed so that the concave portion and the convex portion extend in the vertical direction. Accordingly, the molten steel sucked into the deposition pipe 121 rises into the vessels 110 and 120, and a rotational force may be generated as it contacts the concave portion of the concave / convex portion 143a and passes through the convex portion.

For example, the irregular portion may be formed in a spiral shape along the inner circumference of the deposition tube 121. That is, the recessed portion of the concave / convex portion 143a can form a path through which the molten steel moves in the form of a screw in the vertical direction. As the molten steel sucked into the deposition pipe 121 rises into the vessels 110 and 120, part of the molten steel moves along the spiral-shaped portion of the uneven portion 143a, and a rotating force such as a whirl is generated in the molten steel being sucked have. Therefore, a rotating force that rises in the molten steel is generated, so that a vibration wave can be formed in molten steel passing through the immersion pipe 121, and the elevation height of the molten steel can be increased. Since the surface area exposed to the outside of the molten steel is increased, the surface area of reacting with the vacuum and the ferro-alloy or the like in the vessels 110 and 120 is widened, so that the degasification, decarburization process and reaction of the alloy iron pipe can be performed quickly. Thus, the effect that the treatment process for molten steel is performed quickly and can be improved can also be improved.

The length W of the projecting portion 143a projecting toward the central portion of the deposition pipe 121 may be 3 to 8 cm. That is, if the length W of the protruding portion 143a is less than 3 cm, the concavoconvex portion 143a may not form a path of sufficient size to generate a rotational force on the molten steel.

On the other hand, the inner width of the immersion tube 121 may be generally about 84 cm. If the length W of the protruding portion 143a exceeds 8 cm, the internal width of the deposition pipe 121 becomes narrow, so that the molten steel can not easily be sucked, and the molten steel may not be refluxed smoothly. Therefore, the length W of the protruding portion 143a may be formed to be 3 to 8 cm, for example, such that the moving path of the molten steel is not narrowed while generating a rotational force in the molten steel sucked upward. However, the length of the projecting portion of the concave / convex portion 143a is not limited to this, and may vary.

The concavo-convex portion according to another embodiment will be described below.

Referring to FIG. 2 (b), the uneven portion 143b according to another embodiment may be formed as a corrugated tube along the inner circumference of the immersion tube 121. That is, the protruding portion and the inserted portion of the concave / convex portion 143b may be sharply formed and extend in the vertical direction along the circumference of the deposition pipe 121 in a spiral shape. Thus, a portion formed like the groove of the concave / convex portion 143b can form a path through which the molten steel moves. As the molten steel sucked into the submerged pipe 121 rises into the vessels 110 and 120, a part of the molten steel moves along the spiral portion of the uneven portion 143b, and a rotating force such as a whirlpool may be generated in the molten steel sucked have. However, the shape of the concave-convex portion 143b is not limited to this, but may be formed in various forms that generate a rotational force in molten steel rising.

Hereinafter, an operation method of a vacuum processing apparatus according to an embodiment of the present invention will be described.

Placing the vessels 110 and 120 above the ladle 200 housing the molten steel and depositing the deposition tube 121 into the ladle 200. The molten steel contained in the ladle 200 is supplied to the vessel through the settling pipe 121, that is, the uprising pipe 121a and the downfalling pipe 121b by lowering the pressure inside the vessels 110 and 120 with driving force of high temperature and high pressure, (110, 120). Then, when the reflux gas is blown through the nozzle 121c provided in the uprising pipe 121a, the apparent specific gravity of the molten steel is reduced to cause the height difference of the molten steel in the vessels 110 and 120 to reflux the molten steel.

The molten steel is refluxed to perform decarburization process for performing vacuum decarburization, deoxidation process for removing oxygen remaining in the decarburized molten steel, removal of deoxidation products generated during iron depletion and deoxidation for adjusting molten steel components after deoxidation A reflux process can be performed. The reflux process is to assist in the separation of a large amount of fine deoxidation product produced during the deoxidation process. The refining is terminated after refluxing the molten steel for 10 to 15 minutes.

At this time, the recessed pipe 121, which is the path through which the molten steel moves, may be provided with the recessed and protruded portions 143a spirally along the inner circumference of the deposition pipe 121. [ 3, when the molten steel sucked into the submerged pipe 121, particularly the uprising pipe 121a, rises to the inside of the vessels 110 and 120 while part of the molten steel moves along the spiral portion of the uneven portion, A rotational force such as a whirlwind may occur. The molten steel discharged through the downfalling pipe 121b moves along the concave and convex portion provided in the downfalling pipe 121b and generates a rotational force like a whirlwind so that the molten steel is lowered to the ladle 200 through the downfalling pipe 121b The speed can be increased. Thus, the reflux speed of the molten steel is increased, and the time of the molten steel treatment process can be shortened.

Further, a rotating force that rises in the molten steel is generated, so that a vibration wave can be formed in molten steel passing through the immersion pipe 121, and the elevation height of the molten steel can be increased. Therefore, since the surface area exposed to the outside of the molten steel is increased, the surface area reacted with the vacuum and the ferro-alloy or the like in the vessels 110 and 120 is widened, so that the degasification, decarburization process, and reaction of the alloy iron pipe can be performed quickly. Thus, the effect that the treatment process for molten steel is performed quickly and can be improved can also be improved.

Although the present invention has been described in detail with reference to the specific embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined by the appended claims, as well as the appended claims.

110: upper tank 120: lower tank
121: deposition tube 121a: riser tube
121b: downcomer 121c nozzle
140: refractory layer 143: refractory layer
143a:

Claims (8)

And a container in which molten steel is circulated,
A refractory layer is provided inside the vessel,
And a concavo-convex portion is formed in a portion of the refractory layer that forms a path through which the molten steel moves. The method according to claim 1,
Wherein the refractory layer includes a heat insulating material, a permanent sheet, and a refractory sheath in an inward to outward direction,
And the concavo-convex portion is formed in the refractory softener. The method of claim 2,
Wherein the container includes a lower tank having an upper portion opened and an upper tank provided at an upper portion of the lower tank, the lower tank having a downwardly extending submerged pipe,
Wherein the concavo-convex portion is formed in a refractory burr provided in the deposition pipe. The method of claim 3,
Wherein the deposition pipe comprises: an uprising pipe for sucking the molten steel; And a downfalling pipe for discharging the molten steel away from the uprising pipe,
And the concavo-convex portion is formed in at least one of the rising pipe and the refractory pipe of the downcomer. The method of claim 3,
The concavo-convex portion may be a vacuum processing apparatus having a curved shape, The method of claim 3,
Wherein the concavo-convex portion is formed in a corrugated pipe shape. The method according to claim 5 or 6,
Wherein the concavo-convex portion is formed in a spiral shape along an inner circumference of the deposition tube. The method according to any one of claims 3 to 6,
Wherein a length of a protruding portion of the concavo-convex portion toward the center of the immersion tube is 3 to 8 cm.

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