DEVICE FOR PREVENTING SLAG OUTFLOW AND HIGH PRESSURE GAS INJECTION LANCE USED THEREIN

Abstract

 The present invention relates to a slag outflow prevention apparatus and a high-pressure gas shooting lance used therein, and more particularly, a slag outflow prevention apparatus in which a high-pressure inert gas is shot into a vortex region formed in an upper portion of a tap hole to push slag from the tap hole, thereby more easily efficiently prevent the slag from flowing out and a high-pressure shooting lance used therein. The high-pressure gas shooting lance for preventing slag outflow includes a pipe structure provided as a cylindrical body including twofold inner and outer walls with a front end closed, wherein a space limited by the inner wall define a high-pressure gas path, and a cylindrical partition wall having a front end spaced apart from the closed front end of the inner wall and the outer wall is disposed in a space between the inner wall and the outer wall to define a cooling water circulation path, a nozzle assembly 158 shooting the high-pressure gas downward, and an adaptor connecting the shooting pipe structure to the nozzle assembly to switch a shooting direction of the high-pressure gas.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a slag outflow prevention apparatus and a high-pressure gas shooting lance used therein, and more particularly, a slag outflow prevention apparatus in which a high-pressure inert gas is shot into a vortex region formed in an upper portion of a tap hole to push slag from the tap hole, thereby more easily efficiently prevent the slag from flowing out and a high-pressure shooting lance used therein.

Description of the Related Art

[0002] In general, in an integrated steel mill in which molten iron produced by a blast furnace is transferred to a converter to perform a refining process such as oxygen shooting and other alloying treatments, thereby tapping the molten steel into a receiving ladle seated on a receiving vehicle as well as the mini mill in which steel sources such as scrap steel are melted in the electric arc furnace converter by arc heat to perform refining and alloying treatment, thereby tapping the molten iron into a receiving ladle, as illustrated in FIG. 1, when molten steel M is tapped into a receiving ladle 110 from a converter 10, it may be necessary to perform a process for separating slag S, which is generated in the refining process to exist on a top surface of the molten steel M due to a difference in specific gravity, from the molten steel M.

[0003] That is, in case where the molten steel M is tapped into the receiving ladle 110 through a tap hole 102 in a state where the converter 100 is in a tilted-down state, it is required that the slag S having a specific gravity less than that of the molten steel M and produced during the refining process for the molten steel M is not mixed into the receiving ladle 110 to prevent a component of the molten steel M from changing after the refining process. As a result, the tapping efficiency of the molten steel M may depend on how to minimize an amount of slag S having the less specific gravity and mixed into the receiving ladle.

[0004] For this, according to the related art, a slag dart 120 including a head having a funnel-like shape with a filled inner space and a sleeve extending downward from the head and inserted into the tap hole 102 is inserted into the tap hole 102 by using a dart throwing apparatus (not shown) to prevent the slag S from flowing out.

[0005] A conventional slag dart 120 is required to have a specific gravity of about 3 to about 6 that is an intermediate range of a specific gravity of about 2.3 of slag and a specific gravity of about 7.8 of molten steel. When the specific gravity of the slag dart 120 is not adequate, the slag dart 120 closes the tap hole 102 too early or too lately so that that the molten steel M may not be tapped perfectly, or the slag outflow may occur.

[0006] In addition, since the molten steel M is discharged with a vortex in the tap hole 102, the slag outflow may be effectively prevented by accurately throwing the slag dart 120 into the vortex region. However, according to the related art, it is necessary to use another mechanical device so as to accurately throw the slag dart 120 into the vortex region.

[0007] (Patent Document 1) Korean Patent Registration No. 0862819 (announced on Oct. 13, 2008), Title: SLAG DART

[0008] (Patent Document 2) Korean Patent Registration No. 1058394 (announced on Aug. 24, 2011), Title: SLAG CUTTING DART CONTAINING RECYCLED MAGNESIA-CHROMIUM REFRACTORY AND MANUFACTURING METHOD THEREOF

DISCLOSURE OF THE INVENTION

TECHNICAL PROBLEM

[0009] Accordingly, the present invention is directed to a slag outflow prevention apparatus in which a high-pressure inert gas is shot into a vortex region formed in an upper portion of a tap hole to push slag from the tap hole, thereby more easily efficiently prevent the slag from flowing out and a high-pressure shooting lance used therein.

TECHNICAL SOLUTION

[0010] According to an aspect of the present invention, there is provided a high-pressure gas shooting lance for preventing slag outflow, the high-pressure gas shooting lance including: a pipe structure provided as a cylindrical body including twofold inner and outer walls with a front end closed, wherein a space limited by the inner wall define a high-pressure gas path, and a cylindrical partition wall having a front end spaced apart from the closed front end of the inner wall and the outer wall is disposed in a space between the inner wall and the outer wall to define a cooling water circulation path; a nozzle assembly shooting the high-pressure gas downward; and an adaptor connecting the shooting pipe structure to the nozzle assembly to switch a shooting direction of the high-pressure gas.

[0011] A spiral guide projection may be disposed on at least an outer circumferential surface of the inner wall or the partition wall.

[0012] The nozzle assembly may include a hollow nozzle body and a needle valve inserted into the nozzle body to shoot the high-pressure gas at a high speed through a front end of the nozzle body, and the nozzle body may realize an expanding nozzle together with the needle valve.

[0013] The high-pressure gas shooting lance may further include an elevation unit for elevating the needle valve with respect to the nozzle body, wherein the needle valve may have a double-headed drum shape with a narrow cross-section in the middle thereof and is provided as a hollow cylindrical body having a closed front end and a through-hole passing through a wall thereof to adjust a shooting angle of the high-pressure gas by elevating the needle valve with the nozzle body.

[0014] The adaptor may include: a hollow fitting member communicating with the pipe structure in one side thereof; and a box structure including a female screw screw-coupled to a male screw, which is disposed on the nozzle body, in a bottom surface thereof and a connection part communicating with the other side of the fitting member in one side surface thereof, the box structure having an upper portion shielded by an openable cover.

[0015] According to another aspect of the present invention, there is provided a slag outflow prevention apparatus including: the shooting lance according to one of the foregoing features; a high-pressure shooting unit shooting a high-pressure gas through the shooting lance; a lance tilt angle adjustment unit adjusting a tilt angle of the shooting lance; a lance forward/backward driving unit allowing the shooting lance to move forward or backward; a cooling water circulation unit circulating cooling water into the shooting lance; and a control unit which controls overall operations of the high-pressure shooting unit, the lance tilt angle adjustment unit 210, the lance forward/backward driving unit 220, and the cooling water circulation unit.

[0016] The slag outflow prevention apparatus may further include a communication unit receiving converter information with respect to tapping of molten iron from converter control equipment through a wired/wireless communication network, wherein the control unit may control the overall operations of the high-pressure gas shooting unit, the lance tilt angle adjustment unit, the lance forward/backward driving unit, and the cooling water circulation unit on the basis of the converter information received through the communication unit.

EFFECTS OF OF THE INVENTION

[0017] In the slag outflow prevention apparatus and the high-pressure gas shooting lance used therein according to the present invention, the high-pressure inert gas may be shot into the vortex region formed in the upper portion of the tap hole to push the slag from the tap hole, thereby more easily and efficiently prevent the slag from leaking.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 

FIG. 1 is a view illustrating limitations of a slag outflow prevention apparatus according to a related art.

FIG. 2 is a system diagram illustrating a concept of a slag outflow prevention apparatus according to the present invention.

FIG. 3 is an electrical block diagram of the slag outflow prevention apparatus according to the present invention.

FIG. 4A and FIG. 4B are longitudinal cross-section view of the high-pressure gas shooting lance in FIG. 2 and a cross-section view taken along line A-A in FIG. 4A, respectively.

FIG. 5 is an exploded cross-sectional view illustrating a structure of a front end of the high-pressure shooting lance in the slag outflow prevention apparatus according to the present invention.

FIG. 6 is an cross-sectional view illustrating an assembled structure of the front end of the high-pressure shooting lance in the slag outflow prevention apparatus according to the present invention.

FIG. 7A and FIG. 7B are cross-sectional views illustrating a state in which a needle valve of a nozzle assembly ascends or descends in FIG. 6.

FIG. 8 is a flowchart illustrating an operation process of the slag outflow prevention apparatus according to the present invention.

FIGS. 9A to 9F are views illustrating states of the high-pressure gas shooting lance and a converter depending on an operation process for each stage in the slag outflow prevention apparatus according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, exemplary embodiments of a slag outflow prevention apparatus and a high-pressure gas shooting lance used therein according to the present invention will be described in detail with reference to the accompanying drawings.

[0020] FIG. 2 is a system diagram illustrating a concept of a slag outflow prevention apparatus according to the present invention and FIG. 3 is an electrical block diagram of the slag outflow prevention apparatus according to the present invention. As illustrated in FIGS. 2 and 3, in a slag outflow prevention apparatus according to the present invention, a high-pressure gas is shot into a vortex generation point of a tap hole 102 to push away slag S to the outside of a converter tap hole 102 in a state where a high-pressure gas shooting lance 150 (hereinafter, referred to as a "shooting lance") is thrown into a converter through an inlet of the converter when the converter is tilted, thereby pushing slag S toward the outside of the converter tap hole 102 and preventing the slag S from being discharged through the tap hole 102.

[0021] For this, the slag outflow prevention apparatus according to the present invention may include a shooting lance 150, a lance tilt angle adjustment unit 210 adjusting a tilt angle of the shooting lance 150, a lance forward/backward driving unit 220 moving the shooting lance 150 forward or backward with respect to a converter throwing hole, a high-pressure gas shooting unit 230 shooting a high-pressure gas through the shooting lance 150, a cooling water circulation unit 240 circulating cooling water into the shooting lance 150 to cool the shooting lance 150, a communication unit 250 which communicates with converter control equipment (not shown) through a wired/wireless communication network to receive various information about tapping (hereinafter, referred to as "converter information"), for example, a tilting angle or tapping degree of the converter from the converter control equipment in real-time, and a control unit 200 which adequately controls the lance tilt angle adjustment unit 210, the lance forward/backward driving unit 220, the high-pressure gas shooting unit 230, and the cooling water circulation unit 240 on the basis of the converter information.

[0022] In the constitutions described above, the shooting lance 150 may be disposed in the vicinity of the converter 100 in a working area where the converter 100 is installed. Reference numeral 130 represents a fixed support disposed on a ceiling of the working area, and reference numeral 134 represents a shooting lance support movably supporting the shooting lance 150. For example, a rear end (hereinafter, a direction toward the converter is defined as a forward direction) of the shooting lance support 134 may be rotatably hinge-coupled to an H-beam 136 vertically extending downward from the fixed support 130. A front end of the shooting lance support 134 may be elevated by a hoist wire 132 which is wound or unwound by a hoist motor 133 installed on the fixed support 130.

[0023] As a result, when the hoist wire 132 is wound, a front end of the shooting lance 150 may face an upper side. On the other hand, when the hoist wire 132 is unwound, the front end of the shooting lance 150 may face a lower side. Reference numeral 138 represents a shooting lance carrier which moves forward/backward on the shooting lance 150 in the state where the shooting lance carrier supports the shooting lance 150. Reference numeral 139 represent a power generation unit, for example, a motor which allows the shooting lance carrier 138 to move forward/backward.

[0024] The lance tilt angle adjustment unit 210 may be realized by the hoist motor 133 and the hoist wire 132 as described above or by an electric motor and additional mechanisms which reciprocate a piston of a hydraulic or pneumatic cylinder. If needed, a sensor for detecting the tilt angle may be additionally provided.

[0025] The lance forward/backward driving unit 220 may be realized by an electric motor 139 which allows the shooting lance carrier 138 to move forward/backward, by a compression pump (motor) which compresses a hydraulic or pneumatic fluid and a solenoid valve, or by a linear motor. If needed, a sensor for detecting a position or distance of a forward/backward motion may be additionally provided.

[0026] The high-pressure gas shooting unit 230 may be realized by a compression pump (motor) which compresses an inert gas, for example, argon (Ar), nitrogen, and the like and a solenoid valve.

[0027] The cooling water circulation unit 240 may be realized by a circulation pump (motor). The communication unit 250 may be realized by a serial communication interface such as RS-232 or RS-485 or by a local area network such as Ethernet. Finally, the control unit 200 may be realized by a hardware or software manner.

[0028] FIG. 4A and FIG. 4B are longitudinal cross-section view of the high-pressure gas shooting lance in FIG. 2 and a cross-section view taken along line A-A in FIG. 4A, respectively. As illustrated in FIG. 4, the shooting lance 150 applied to the slag outflow prevention apparatus according to the present invention may include a pipe structure having a high-pressure gas path 155a in a central area thereof and an inside/outside twofold wall with a front end closed, i.e., an inner wall 154 and an outer wall 151, a nozzle assembly 158 shooting a high-pressure gas downward, and adaptors 156 and 157 connecting the shooting pipe structure to the nozzle assembly 158 to switch the shooting direction of the high-pressure gas.

[0029] In the constitutions described above, the pipe structure further includes a cylindrical partition wall 153 that is disposed in a space between the inner wall 154 and the outer wall 151 to extend in parallel with the inner wall 154 and the outer wall 151, thereby equally dividing the inside of the pipe structure. A front end of the partition wall 153 is spaced apart from that of the pipe structure. Accordingly, cooling water for cooling the inside of the pipe structure, i.e., cooling water introduced into a cooling water inflow path 155b defined as a space between the inner wall 154 and the partition wall 153 may be discharged into a cooling water discharge path 155c defined as a space between the partitioning wall 153 and the outer wall 151 through the spaced gap to realize the circulation of the cooling water. Of course, a space outside the partition wall 153 may serve as the cooling water inflow path, and a space inside the partition wall 153 may serve as the cooling water discharge path.

[0030] When the cooling water is not sufficiently supplied through the cooling water inflow path 155b, or the shooting lance 150 is tilted, it may be difficult to uniformly cool the inside of the shooting lance 150 because the cooling water flows only downward due to a self-weight thereof. To prevent this phenomenon, the cooling water inflow path 155b and the cooling water discharge path 155c may further include spiral guide projections 154a and 153a, respectively, for example, spiral guide projections each of which has a triangular cross-section. That is, the spiral guide projection 154a having a height corresponding to about 1/2 or more of the shortest distance between the inner wall 154 and the partition wall 153 may be disposed on an outer circumferential surface of the inner wall 154 of the pipe structure. Also, the spiral guide projection 154a each of which has a height corresponding to about 1/2 or more of the shortest distance between the outer wall 151 and the partition wall 153 may be disposed on an outer circumferential surface of the partition wall 153. Thus, even though the introduced cooling water is leak, or the shooting lance is tilted, the concentration phenomenon of the cooling water in one direction may be prevented by the spiral guide projections 154a and 153a.

[0031] FIG. 5 is an exploded cross-sectional view illustrating a structure of the front end of the high-pressure shooting lance in the slag outflow prevention apparatus according to the present invention, and FIG. 6 is an cross-sectional view illustrating an assembled structure of the front end of the high-pressure shooting lance in the slag outflow prevention apparatus according to the present invention. FIG. 7A and FIG. 7B are cross-sectional views illustrating a state in which the needle valve of the nozzle assembly ascends or descends in FIG. 6.

[0032] As illustrated in FIGS. 5 to 7, since the high-pressure gas path 155a of the shooting lance is disposed horizontally in the slag outflow prevention apparatus according to the present invention, a direction switching unit for switching the shooting direction of the high-pressure gas downward is required. In the drawings, reference numeral 156 represents a fitting member that is a portion of an adaptor for connecting a box structure 157 to the pipe structure. A high-pressure gas path 156a is defined horizontally in the fitting member 156.

[0033] A horizontal extension part 156b inserted into the high-pressure gas path 155a of the pipe structure is disposed on a rear portion of the fitting member 156. A male screw 156c screw-coupled to a female screw (not shown) disposed on an inner circumferential surface of the high-pressure path 155a of the pipe structure may be disposed on an outer circumferential surface of a front end of the horizontal extension part 156b. A male screw 156e screw-coupled to a nut 157f in a state where the male screw 156e is inserted into the box structure 157 through a coupling through-hole 157a defined in one side surface of the box structure 157 may be disposed on a front side of the fitting member 156. In the drawings, reference numeral 156d represents a flange contacting a front end of the pipe structure when the box structure 157 is coupled to the fitting member 156. At least one annular-shaped projection 156f functioning as an O-ring for preventing the high-pressure gas from leaking is disposed on a front surface of the flange 156d.

[0034] Next, the box structure 157 has a hollow box-shape having the above-described coupling through-hole 157a in one side surface thereof and a communication hole 157b communicating with the nozzle assembly 158 in a bottom surface thereof. Here, a female screw 157c is disposed on a main wall of the communication hole 157b. A cover 157d for allowing an access into the box structure 157 when opened is disposed on an upper portion of the box structure 157. The cover 157d may seal the upper portion of the box structure 157 by a bolt in a normal state. Reference numeral 157e represents a packing member for sealing, and reference numeral 157g represents an annular-shaped concave groove defined in a rear wall of the box structure 157 and engaged with the annular-shaped projection 156f of the fitting member 156.

[0035] Next, the nozzle assembly 158 may include a hollow nozzle body 158a and a needle valve 158b inserted into the nozzle body 158a to shoot the high-pressure gas through a front end of the nozzle body 158a. The nozzle body 158a may have an expanding nozzle shape functioning in pair with the needle valve 158b, i.e., a shape in which a central portion of the nozzle becomes narrow and then becomes wide again. For this, a free end (front end) of the nozzle body 158a has a cross-section of which the inside is widened in a fan-shape. Reference numeral 158a1 represents a neck portion of the nozzle body 158a. In the drawings, reference numeral 158a2 represents a male screw disposed on an outer circumferential surface of an upper end of the nozzle body 158a and screw-coupled to the female 157c disposed on the bottom surface of the nozzle body 158a.

[0036] The needle valve 158b is provided as a hollow cylindrical body with a front end closed. At least one through-hole 158b2 passing through a wall of the cylindrical body in a portion adjacent to the closed front end 158b3. The closed front end 158b3 of the needle valve 158b has a double-headed drum shape with a narrow waist in the middle thereof. Thus, as the needle valve 158b is elevated within the nozzle body 158a, the shooting angle of the high-pressure gas becomes wide and narrow.

[0037] A female screw 158a3 is disposed in position on an inner circumferential surface of the nozzle body 158a, and a male screw 158b5 screw-coupled to the female screw 158a3 is disposed on a portion corresponding to an outer circumferential surface of the needle valve 158b. Further, a manipulating head part 158b4 capable of being fastened and released, for example, by a hand or a tool such as a wrench is disposed on a rear end of the needle valve 158b. The needle valve 158b may be elevated within the nozzle body 158a by turning the manipulating head part 158b4 to a left or right side. As a result, the shooting angle of the high-pressure gas may be adjusted adequately. In this case, for an access toward the manipulating head portion 158b4, the cover 157d of the box structure 157 has to be opened. Also, the nozzle assembly 158 may be easily replaced from the shooting lance due to the above-described structure.

[0038] That is, as illustrated in FIG. 7a, when the needle valve 158b is retreated towards the inside of the nozzle body 158a, a gap between an outlet of the nozzle body 158a and the needle valve 158b may be widened to increase the shooting angle of the high-pressure gas. On the other hand, when the needle valve 158b moves forward to the outside of the nozzle body 158a, the gap between the outlet of the nozzle body 158a and the needle valve 158b may be narrowed to decrease the shooting angle of the high-pressure gas.

[0039] FIG. 8 is a flowchart illustrating an operation process of the slag outflow prevention apparatus according to the present invention. Here, the operation of the slag outflow prevention apparatus may be performed by the control unit 200. FIGS. 9A to 9F are views illustrating states of the high-pressure gas shooting lance and the converter depending on an operation process for each stage in the slag outflow prevention apparatus according to the present invention. As illustrated in FIG. 9a, before the tapping starts, the converter 100 is maintained to an upright state, and also the shooting lance 150 is maintained to a horizontal and retreat state.

[0040] In this state, when a preparation for the tapping is finished, a converter control apparatus (not shown) may tilt the converter 100 to start the tapping as illustrated in FIG. 9B. Simultaneously with the tilting, in operation S10, a tapping start signal that is a kind of converter information is received from the converter control apparatus through the communications unit 250. In operation S20, as illustrated in FIG. 9B and 9C, the shooting lance 150 is tilted and moves forward toward the inlet of the converter 100 so that the front end of the shooting lance 150, that is, the nozzle assembly 158 is positioned at the vortex region defined in the upper portion of the tap hole 102.

[0041] Next, in operation S30, as illustrated in FIG. 9c, the high-pressure gas is shot into the vortex region so that the slag S floating on the molten steel S is pushed away from the vortex region, thereby preventing the slag S from being discharged through the tap hole 102.

[0042] In operation S40, the converter information including the converter angle and tapping degree may be received in real-time from the converter control apparatus through the communication unit 250 to shoot the high-pressure gas while adequately controlling the tilt angle of the shooting lance 150 as illustrating in FIG. 9D and 9E. Next, just as soon as the tapping is completed, the converter control apparatus allows the converter to return to its position, that is, allows the inlet of the converter to return such that the inlet faces an upper side. In operation S50, on the basis of the converter information received from the converter control apparatus, it is determined whether the tapping is completed. According to the determined result in the operation S50, if the tapping is not completed, the process returns to the operation S30. On the other hand, if the tapping is completed, the process proceeds to operation 60 to retreat the shooting lance 150 and adjust the tilt angle of the shooting lance 150, thereby maintaining the horizontal state as illustrating in FIG. 9F.

[0043] Finally, in operation S70, the shooting of the high-pressure gas is stopped. This operation S70 may be performed before the operation S60 described above.

[0044] Heretofore, although the slag outflow prevention apparatus and the high-pressure shooting lance used therein are described in detail with reference to the accompanying drawings, this is intended to be illustrative, and those with ordinary skill in the technical field of the present invention pertains will be understood that the present invention can be carried out in other specific forms without changing the technical idea or essential features. Hence, the real protective scope of the present invention shall be determined by the technical scope of the accompanying claims. For example, the system diagram in FIG. 2 is only a schematic diagram to easily explain the ideas of the present invention, thus specific configuration thereof can be modified in any degree. For example, a lance left/right tilting angle adjustment unit for adjusting a left/right tilt angle of the shooting lance may be additionally provided. Here, the lance left/right tilting angle adjustment unit may operate by using the electric motor.

DESCRIPTION OF THE SYMBOLS IN MAIN PORTIONS OF THE DRAWINGS

[0045] 

100: Converter, 102: Tap hole

110: Receiving ladle, 120: Slag dart

130: Fixed support, 132: Hoist wire

133: Hoist motor, 134: Shooting lance support

136: H-beam, 138: Shooting lance carrier

139: Electric motor, 150: Shooting lance

151: Outer wall, 153: Partition wall

153a: Spiral guide projection, 154: Inner wall

154a: Spiral guide projection, 155a: High-pressure gas path

155b: Cooling water inflow path, 155c: Cooling water discharge path

156: Fitting member, 157: Box structure

158: Nozzle assembly, 158a: Nozzle body

158b: Needle valve, 200: Control unit

210: Lance tilt angle adjustment unit, 220: Lance forward/backward driving unit

230: High-pressure gas shooting unit, 240: Cooling water circulation unit

250: Communication unit

M: Molten steel, S: Slag

Claims

1. A high-pressure gas shooting lance for preventing slag outflow, the high-pressure gas shooting lance comprising:

a pipe structure provided as a cylindrical body comprising twofold inner and outer walls with a front end closed, wherein a space limited by the inner wall define a high-pressure gas path, and a cylindrical partition wall having a front end spaced apart from the closed front end of the inner wall and the outer wall is disposed in a space between the inner wall and the outer wall to define a cooling water circulation path;

a nozzle assembly shooting the high-pressure gas downward; and

an adaptor connecting the shooting pipe structure to the nozzle assembly to switch a shooting direction of the high-pressure gas.

2. The high-pressure gas shooting lance of claim 1, wherein a spiral guide projection is disposed on at least an outer circumferential surface of the inner wall or the partition wall.

3. The high-pressure gas shooting lance of claim 1, wherein the nozzle assembly comprises a hollow nozzle body and a needle valve inserted into the nozzle body to shoot the high-pressure gas at a high speed through a front end of the nozzle body, and
the nozzle body realizes an expanding nozzle together with the needle valve.

4. The high-pressure gas shooting lance of claim 3, further comprising an elevation unit for elevating the needle valve with respect to the nozzle body,
wherein the needle valve has a double-headed drum shape with a narrow cross-section in the middle thereof and is provided as a hollow cylindrical body having a closed front end and a through-hole passing through a wall thereof to adjust a shooting angle of the high-pressure gas by elevating the needle valve within the nozzle body.

5. The high-pressure gas shooting lance of claim 3, wherein the adaptor comprises:

a hollow fitting member having one side that communicates with the pipe structure; and

a box structure comprising a female screw screw-coupled to a male screw, which is disposed on the nozzle body, in a bottom surface thereof and a connection part communicating with the other side of the fitting member in one side surface thereof, the box structure having an upper portion shielded by an openable cover.

6. A slag outflow prevention apparatus comprising:

the shooting lance of any one of claims 1 to 5;

a high-pressure shooting unit shooting a high-pressure gas through the shooting lance;

a lance tilt angle adjustment unit adjusting a tilt angle of the shooting lance;

a lance forward/backward driving unit allowing the shooting lance to move forward or backward;

a cooling water circulation unit circulating cooling water into the shooting lance; and

a control unit which controls overall operations of the high-pressure shooting unit, the lance tilt angle adjustment unit 210, the lance forward/backward driving unit 220, and the cooling water circulation unit.

7. The slag outflow prevention apparatus of claim 6, further comprises a communication unit receiving converter information from converter control equipment through a wired/wireless communication network,
wherein the control unit controls the overall operations of the high-pressure gas shooting unit, the lance tilt angle adjustment unit, the lance forward/backward driving unit, and the cooling water circulation unit on the basis of the converter information received through the communication unit.

Drawing