Lance device

Abstract

Provided in the present application is a lance device for immersing an optical cored wire in a molten metal bath. The lance device includes: an outer tube comprising a first end and an opposite second end; an inner tube extending into the outer tube, wherein the optical cored wire is to be inserted into the inner tube and is freely movable in an axial direction of the inner tube; and a gas supply tube connected to the second end of the outer tube and in fluid communication with a space between the inner tube and the outer tube, wherein at least one through-hole is provided in a section of the outer tube close to the gas supply tube; and a first gas path formed by a tube cavity of the inner tube, a second gas path formed between the outer tube and the inner tube, and a third gas path extending outside the outer tube are present in the lance device.

Description

[0001] LANCE DEVICE

[0002] TECHNICAL FIELD

[0003] The present invention relates to the technical field of temperature measurement, and relates in particular to a lance device for immersing an optical cored wire (a cored optical fiber) in a molten metal bath.

[0004] BACKGROUND

[0005] One of the approaches for measuring the temperature of a molten metal bath (specifically, a molten metal bath of iron or steel in the melting environment of an electric arc furnace (EAF)) involves immersing an optical fiber surrounded by a metal tube in a molten metal. The optical fiber surrounded by the metal tube is also usually referred to as an optical cored wire. The optical fiber receives thermal radiation and transmits the thermal radiation from the molten metal to a detector. A suitable instrument can be associated with the detector for determining the temperature of the molten metal bath.

[0006] To measure the temperature of the molten metal bath, the optical cord wire is fed into the molten metal bath where the optical cord wire may be consumed within a predetermined time interval. The front end of the optical cord wire is immersed in a metallurgical container so that the optical fiber, on its way towards the molten metal bath, encounters a hot atmosphere first, followed by a slag layer, and then the molten metal bath. The immersed portion of the optical cord wire will melt in the molten metal bath. Once the temperature measurement has been completed, the tip of the optical cord wire can be partially retracted from the molten metal bath. Then, the tip of the retracted optical cord wire serves as a new front end for the next round of temperature measurement.

[0007] The optical cord wire may be introduced into a furnace through a lance device. Compressed air is blown by means of the lance device to ensure that an inlet through which the optical cord wire enters the electric arc furnace remains open. However, for a currently used lance device, when the slag layer is thick, it is difficult to prevent clogging of the front end port of the lance, and a layer of molten metal and slag will easily adhere to the front tip of the optical cord wire, such that the optical cord wire is blocked in the inner tube and unable to freely move forward and backwards, thereby shortening the maintenance cycle of the lance device. SUMMARY

[0008] The objective of the present invention is to solve one or more of the above-mentioned problems and other problems. A lance device is provided, in which a plurality of gas passages are arranged such that the front end port of the lance device can be effectively prevented from being clogged with slag. Furthermore molten metal or slag can be prevented from entering an inner tube of the lance so that the optical cord wire is prevented from being blocked in the inner tube which hinders a free movement .

[0009] Hence, the present invention provides a lance device for immersing an optical cored wire in a molten metal bath, wherein the lance device comprises: an outer tube comprising a first end and an opposite second end; an inner tube extending into the outer tube, wherein the optical cored wire is to be inserted into the inner tube and is freely movable in an axial direction of the inner tube; and a gas supply tube connected to the second end of the outer tube and in fluid communication with a space between the inner tube and the outer tube; wherein at least one through-hole is provided in a section of the outer tube close to the gas supply tube; wherein a first gas path formed by a tube cavity of the inner tube, a second gas path formed between the outer tube and the inner tube, and a third gas path extending outside the outer tube are present in the lance device.

[0010] By providing the lance device with such a configuration, a purge gas that prevents the optical cored wire from being fused with the inner tube to cause conveyance failure of the optical cored can be injected along the first gas path, and a purge gas that prevents the front end of the lance device from being clogged with slag can be injected along the second gas path, thereby improving the durability of the lance device. It is further advantageous to provide a through-hole in the outer tube, so that compressed air from the second gas path can flow along the third gas path outside the outer tube, further preventing the front end of the lance device from being clogged. A section of the outer tube close to the gas supply tube is to be understood as a section within the first third of the length of the outer tube in the direction from the opposite second end the first end. Preferably, the at least one through-hole is provided in a section of the outer tube close which is positioned in the first 20 % of the length of the outer tube in the direction from the opposite second end the first end of the outer tube.

[0011] According to a preferred embodiment of the present invention, the lance device is mounted, by means of a mounting mechanism, to a container containing a molten metal bath, wherein the mounting mechanism comprises a mounting sleeve, and the mounting sleeve has an inner diameter larger than an outer diameter of the outer tube; and when the lance device is mounted at the container, the outer tube extends through the mounting sleeve, and is movable within the mounting sleeve, and the inner diameter of the mounting sleeve is larger than the outer diameter of the outer tube, so that the third gas path is formed between the mounting sleeve and the outer tube, wherein the third gas path is in fluid communication with the second gas path via the at least one through-hole.

[0012] It may be advantageous that the through-hole is configured to extend obliquely from an inner circumferential surface of the outer tube towards an outer circumferential surface of the outer tube and towards the first end. Also, if a plurality of through-holes are provided, the through-holes are preferably arranged uniformly along a circumferential direction of the outer tube.

[0013] Preferably, the gas supply tube comprises a connecting tube section and a gas intake tube section extending obliquely with respect to the connecting tube section, the connecting tube section is fixedly connected to the second end of the outer tube, and the connecting tube section and the outer tube are coaxial.

[0014] Preferably, the lance device further comprises a coupling member, the inner tube being fixedly connected to the outer tube or the connecting tube section of the gas supply tube by means of the coupling member, wherein the connecting tube section has a first connecting end and a second connecting end.

[0015] The coupling member may have a stepped hole extending in an axial direction thereof, wherein the stepped hole has a first hole section and a second hole section, a diameter of the first hole section is smaller than a diameter of the second hole section and is the same as an outer diameter of the inner tube, a rear end of the inner tube is fixedly connected to one end of the coupling member at the first hole section, the other end of the coupling member is fixedly connected to the first connecting end of the connecting tube section, and the second connecting end of the connecting tube section is fixedly connected to the second end of the outer tube, wherein the coupling member, the inner tube, and the outer tube are coaxial.

[0016] It can be preferred, that the outer tube comprises at least a first outer tube component and a second outer tube component fixedly connected to the first outer tube component, wherein the second outer tube component is fixedly connected to the gas supply tube and has a constant first inner diameter, and a part of the first outer tube component has a second inner diameter, the second inner diameter being smaller than the first inner diameter. The first outer tube component may be fixedly connected to the second outer tube component by means of welding, for example.

[0017] Preferably, the first outer tube component defines a first tube cavity section, a second tube cavity section, a third tube cavity section and a fourth tube cavity section connected in sequence, wherein the first tube cavity section has a diameter equal to the first inner diameter, the third tube cavity section has a diameter equal to the second inner diameter, and the fourth tube cavity section has a diameter gradually increasing from the third tube cavity section toward the first end of the outer tube, wherein the first tube cavity section is closest to the first outer tube component, and an end of the second outer tube component close to the first outer tube component is provided with a plurality of radial through-holes (such as three radial through- holes) uniformly arranged in a circumferential direction thereof; and each of the radial through- holes is provided with a positioning pin extending into the first tube cavity section and abutting against the inner tube to fixedly retain the inner tube in the outer tube.

[0018] It can be preferred, that the mounting mechanism further comprises a spherical adjustment member and a mounting fixture, the spherical adjustment member is fixedly connected to the sleeve or integrally formed with the sleeve, and the mounting fixture comprises a first mounting plate having a first aperture, a second mounting plate having a second aperture, and a plurality of threaded fasteners, wherein when the first mounting plate and the second mounting plate are connected to each other, the first aperture and the second aperture constitute a mounting hole adapted to receive the spherical adjustment member, and the spherical adjustment member is rotatable within the mounting hole during assembly, so as to adjust a mounting orientation of the lance device. According to a preferred embodiment, the lance device further comprises a coupling unit, and the coupling unit comprises a sensing device and a coupling fixture for coupling a guide tube to the inner tube, the sensing device being a pressure sensor and / or an inductive sensor.

[0019] Brief Description of the Drawings

[0020] The drawings, which form a part of the present application, are used to enable further understanding of the present invention, and the exemplary embodiments of the invention and the description thereof are used to explain the invention, and do not constitute an improper limitation on the invention. In the drawings:

[0021] FIG. 1 is a perspective view of a combination of an embodiment of a lance device for immersing an optical cored wire into a molten metal bath and a mounting mechanism according to the present invention, the mounting mechanism being used for mounting the lance device at a container of the molten metal bath;

[0022] FIG. 2 is a cross-sectional view of the lance device shown in FIG. 1;

[0023] FIG. 3 is a cross-sectional view of a combination of the lance device of FIG. 2 and a mounting mechanism, showing an optical cored wire extending through an inner tube;

[0024] FIG. 4 is a cross-sectional view showing the configuration of a mounting mechanism according to the present invention;

[0025] FIG. 4a shows a perspective view of an embodiment of a first mounting plate according to the present invention;

[0026] FIG. 4b shows a perspective view of an embodiment of a second mounting plate according to the present invention;

[0027] FIG. 5a is a perspective view of an embodiment of an outer tube according to the present invention;

[0028] FIG. 5b is a cross-sectional view of the outer tube of FIG. 5a;

[0029] FIG. 6 is a perspective view of another embodiment of the outer tube according to the present invention;

[0030] FIG. 7a is a perspective view of an embodiment of a first outer tube component of an outer tube according to the present invention; FIG. 7b is a cross-sectional view of the first outer tube component in FIG. 7a;

[0031] FIG. 8a is a perspective view of an inner tube and a coupling member assembled together;

[0032] FIG. 8b is a cross-sectional view of the inner tube and the coupling member assembled together as shown in FIG. 8a;

[0033] FIG. 8c is a perspective view of the coupling member of FIG. 8a;

[0034] FIG. 8d is a cross-sectional view of the coupling member of FIG. 8a; and

[0035] FIG. 9 is a schematic view of slag being pushed away by a gas flow injected from between an outer tube of a lance device and a mounting mechanism according to the present invention.

[0036] The drawings are merely schematic and are not necessarily drawn to scale. The drawings show only the parts necessary for clarifying the present invention, and other parts may be omitted or simply mentioned only. The present invention may further include other components in addition to the components shown in the drawings.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] A lance device according to an exemplary embodiment of the present invention is described below with reference to the drawings. In the following description, numerous specific details are set forth in order to enable those skilled in the art to understand the present invention more thoroughly. It will be apparent, however, to those skilled in the art that the present invention may be implemented without some of these specific details. Furthermore, it should be understood that the present invention is not limited to the particular embodiments introduced. Instead, the present invention may be implemented using any combination of the following features and elements, no matter whether they relate to different embodiments. Therefore, the following features, embodiments, and advantages are illustrative only, and should not be construed as elements or limitations of the claims unless expressly recited in the claims.

[0039] As used herein, the term “molten metal bath” is used to describe a melt in a furnace, particularly in a container, and there is no particular limitation on the molten metal of the molten metal bath, which may be, for example, molten steel. The term “molten metal bath” does not exclude the presence of any solid or gaseous parts, including, for example, non-molten parts of the corresponding metal. The molten metal bath may be covered by a slag layer. The term “slag” refers to non-steel by-products and additions typically generated in steelmaking furnaces and is typically present as molten material floating on top of the molten metal. The temperature of a metal melt varies, and generally depends on the composition of the metal and the stage of the melting process. For example, the temperature of the molten metal bath may be from 1500°C to 1800°C, more preferably from 1500°C to 1700°C.

[0040] The molten metal bath of which a temperature measurement is desired is located in a container, particularly a container of an electric arc furnace. The lance device according to the present invention is a part of a measuring apparatus (not shown) for measuring the temperature of the molten metal bath, and is used to guide an optical cored wire (i.e., an optical fiber coated with a metal jacket), which is also a part of the lance device of the measuring apparatus, into the molten metal bath while supplying a purge gas through a plurality of gas paths which the lance device itself has, so as to prevent the front end of the lance device from being clogged. In the present application, the purge gas may be compressed air and / or an oxygen-containing gas, an inert gas such as argon gas and nitrogen gas, or air.

[0041] The lance device may, for example, be mounted on a furnace wall of an electric arc furnace containing a molten metal bath. The lance device has a front end to extend into the electric arc furnace and a rear end located outside the electric arc furnace. The lance device is not immersed in the molten metal bath. Moreover, the front end is located at 0.3 m to 2.5 m above the molten metal, and the optical cored wire is inserted from the rear end and extends beyond the front end. To prevent clogging of the lance device, gas needs to be supplied into the lance device using a gas supply assembly / an external gas source (not shown). One end of the optical cored wire inserted into the lance device is fed into the molten metal bath by an optical fiber feeding assembly (not shown), the optical fiber feeding assembly including a guide tube for guiding the optical cored wire fiber into a nozzle assembly.

[0042] FIG. 1 shows a preferred embodiment of a lance device for guiding and immersing an optical cored wire into a molten metal bath and a mounting mechanism according to the present invention, and FIG. 2 is a cross-sectional view of the lance device shown in FIG. 1. As can be seen in the figures, a lance device 100 includes an outer tube 1, an inner tube 2 extending into the outer tube 1, and a gas supply tube 3 connected, in fluid communication, to the outer tube. The lance device 100 is fixedly mounted, by means of a mounting mechanism 4, at a furnace wall (not shown) of an electric arc furnace containing a molten metal bath. Optionally, the lance device 100 may further include a coupling unit 6 for fixedly connecting the guide tube of the optical fiber feeding assembly to the lance device 100. For example, the coupling unit 6 may include a sensing device 61, and a coupling fixture 62 for coupling the guide tube to the inner tube 2 of the lance device 100. The sensing device may include an inductive sensor for detecting the presence and position of an optical cored wire in the inner tube. Optionally, the sensing device may further include a pressure sensor.

[0043] With reference to FIGS. 2 and 3 in particular, in the embodiment described above, the outer tube 1 includes a first end 11 (i.e. a front end) and an opposite second end 12, the inner tube 2 extends at least partially into the outer tube 1, and a front end 2a of the inner tube 2 may be flush with the first end 11 of the outer tube 1 or retracted inwardly by a certain distance relative to the first end 11. When the front end 2a of the inner tube 2 is flush with the first end 11 of the outer tube 1, the first end of the outer tube and the front end of the inner tube constitute the front end of the lance device 100; otherwise, only the first end 11 of the outer tube 1 constitutes the front end of the lance device. The front end of the lance device, i.e. the first end 11 of the outer tube 1, is not in contact with the molten metal bath, and may be arranged 0.3 m to 2.5 m above the molten metal bath. The front end of the lance device may be concentrated by splashing objects, such as splashing molten steel and slag.

[0044] Referring to FIG. 3, it is advantageous that the inner diameter of the inner tube 2 is selected to be larger than the outer diameter of an optical cored wire 10 so that the optical cored wire 10 can move freely within the inner tube. A first gas path extends between the inner tube 2 and the optical cored wire 10 along the length direction of the inner tube. It should be understood that the term “gas path” refers to a virtual structure in which a gas flow is present when a gas is supplied, or a path of a gas flow when a gas is supplied. The first gas path may be in fluid communication with a guide tube (not shown) for guiding the optical cored wire 10 into the inner tube, and the guide tube may be in fluid communication with a gas source provided in the optical fiber feeding assembly. A gas from the gas source may be injected from the front end of the lance device via the first gas path, and the pressure of the conveyed gas may be in the range of 3- 8 bar, for example. Preferably, the inner tube may also be directly in fluid communication with the gas source in fluid communication with the coupling unit 6.

[0045] In an example, the inner tube 2 may, for example, be configured to have an inner diameter of 10 mm, an outer diameter of 14 mm, and a wall thickness of 2 mm, and the optical cored wire 10 may, for example, have an outer diameter of 6 mm. It should be understood that the dimensional values herein are merely exemplary, and other suitable dimensions may be selected as required. Here, for example, compressed air is caused to flow through the inner tube 2, that is, to flow out of the front end of the lance device along the first gas path between the inner tube 2 and the optical cored wire 10, so that the optical cored wire can be prevented from being fused with the inner tube and being clogged in the inner tube and unable to freely move forward and backwards. In addition, when the optical cored wire is retracted, a layer of molten metal and slag is easily attached to the front end of the optical cored wire, and gas purging inside the inner tube can prevent the molten metal / slag layer from entering the inner tube and can suppress burning at the front end of the optical cored wire.

[0046] In addition, the inner diameter of the outer tube 1 is preferably selected to be larger than the outer diameter of the inner tube 2, so that a second gas path extending in the axial direction of the outer tube 1 is formed between the outer tube and the inner tube. The second gas path is in fluid communication with the gas supply tube 3, and the gas supply tube 3 may be in fluid communication with an external gas source (not shown) for providing a purge gas. The pressure of the conveyed gas may be in the range of 3-8 bar, for example. In the embodiment shown in FIG. 3, the gas supply tube 3 may be configured to include a connecting tube section 31 and a gas intake tube section 32 extending obliquely with respect to the connecting tube section. The connecting tube section is fixedly connected to the second end 12 of the outer tube, for example, by means of screwing. That is, an external thread is provided at the second end of the outer tube 12, an internal thread is provided in the connecting tube section, and the connecting tube section and the outer tube are coaxial.

[0047] In an embodiment, the outer tube 1 may, for example, be configured to have an inner diameter of 28 mm, an outer diameter of 34 mm, and a wall thickness of 3 mm. It should be understood that the dimensional values herein are merely exemplary, and other suitable dimensions may be selected as required. More advantageously, a purge gas such as compressed air is caused to flow out of the front end of the lance device from the second gas path between the inner tube and the outer tube, so that the lance device feeding the optical cored wire into the molten metal bath can be prevented from being clogged.

[0048] Referring again to FIG. 3, the mounting mechanism 4 includes a sleeve 41, a spherical adjustment member 42, and a mounting fixture 43. The sleeve 41 surrounds the outer tube 1 and is arranged close to the gas supply tube 3, that is, mounted at the second end 12 of the outer tube 1. In the embodiment shown in FIG. 2, the spherical adjustment member 42 may be integrally formed with the sleeve 41. The inner diameter of the sleeve 41 is selected to be larger than the outer diameter of the outer tube 1, so that a gap is created between the sleeve 41 and the outer tube 1. One end of the sleeve 41 abuts against the gas supply tube 3 at the second end 12 of the outer tube 1, and the other end extends towards the first end 11 of the outer tube 2 but is retracted by a certain distance relative to the first end, that is, not extending beyond the first end.

[0049] Referring to FIG. 4, another embodiment of the mounting mechanism 4 is shown, which differs from the mounting mechanism shown in FIG. 3 only in that the spherical adjustment member 42 is fixedly connected to the sleeve 41 such as by means of welding, rather than being integrally formed with the sleeve. In the embodiment described above, the mounting fixture 43 includes a first mounting plate 431 having a first aperture 4310 (see FIG. 4b), a second mounting plate 432 having a second aperture 4320 (see FIG. 4a), and a plurality of threaded fasteners 433, wherein when the first mounting plate and the second mounting plate are connected together, the first aperture fits with the second aperture to form a mounting hole 434 adapted to receive the spherical adjustment member 42, and during an assembly process in which the lance device 100 is mounted on the furnace wall, the spherical adjustment member 42 is rotatable within the mounting hole, so as to adjust the mounting orientation of the lance device, thereby adjusting the position of the front end of the optical cored wire 10 in the molten metal bath. In addition, the first mounting plate 431 is provided with a plurality of threaded holes 4311, and the second mounting plate 432 is provided with a plurality of threaded holes 4321. These threaded holes cooperate with the threaded fasteners to fixedly connect the first mounting plate and the second mounting plate together.

[0050] Referring to FIGS. 5a and 5b, it is advantageous that the second end 12 of the outer tube 1, i.e. the section close to the gas supply tube 3, is provided with a plurality of through-holes 13a, so that a gas from the second gas path can purge the outside of the outer tube 2, that is, a third gas path is formed outside the outer tube 1. The plurality of through-holes 13a may be uniformly distributed in the circumferential direction of the outer tube 1, and it is preferable that the through-holes extend obliquely from the inner circumferential surface of the outer tube 1 to the outer circumferential surface of the outer tube 1 and toward the first end 11, and the inclination angle of the through-holes may be, for example, 30° to 45°. The number of the through-holes 13a may be appropriately selected according to the circumferential size of the outer tube. In addition, the inclination angle of the through-holes is not limited to the example given above.

[0051] When the lance device 100 is mounted on the furnace wall of an electric arc furnace by means of the mounting mechanism 4, the outer tube extends through the mounting sleeve 41 and is movable within the mounting sleeve, wherein the third gas path is formed between the mounting sleeve and the outer tube and extends in the axial direction of the mounting sleeve (as indicated by the arrow in FIG. 9). Since the third gas path is in fluid communication with the second gas path via the plurality of apertures 13a, the purge gas from the gas supply tube 3 can purge the outer wall of the outer tube 1 along the third gas path and then be ejected in a fan shape from the front end of the sleeve 41.

[0052] Referring again to FIGS. 3 and 9, the third gas path is provided so that a gas (such as compressed air) from the gas supply tube can flow through the outer circumferential surface of the outer tube 1 and be injected in a fan shape at the front end of the sleeve 41; in this way, slag S can be pushed away to a certain extent, so as to further prevent the front end of the lance device from being clogged.

[0053] In the embodiment shown in FIGS. 5a and 5b, the outer tube 1 may include a first outer tube component 13 and a second outer tube component 14 fixedly connected to the first outer tube component such as by means of welding. The second outer tube component 14 has a constant first inner diameter, and the free end thereof (which constitutes the second end 12 of the outer tube) may be provided with an external thread. Correspondingly, an internal thread is provided at a second connecting end 312 of the connecting tube section 31 of the gas supply tube 3. The outer tube 1 is fixedly connected to the gas supply tube 3 by means of threaded connection. The free end of the first outer tube component 13 constitutes the first end 11 of the outer tube 1. It is advantageous that a part of the first outer tube component 13 has a second inner diameter smaller than the first inner diameter, so that the inner chamber of the first outer tube component 13 has a thickened part, thereby increasing the speed at which the gas flowing through the second gas path flows out from the front end of the inner tube 2, and further enhancing the ability to remove slag.

[0054] FIG. 6 shows another embodiment of the outer tube 1 which differs from the previous embodiment in that three outer tube components are included, that is, the second tube component includes two parts which are fixedly connected by means of internal and external threads. Referring to FIGS. 7a and 7b, an embodiment of the first outer tube component 13 is shown, wherein the first outer tube component 13 defines a first tube cavity section 131, a second tube cavity section 132, a third tube cavity section 133 and a fourth tube cavity section 134 connected in sequence. The first tube cavity section 131 has a diameter equal to the first inner diameter, the third tube cavity section 133 has a diameter equal to the second inner diameter, and the fourth tube cavity section 134 has a diameter gradually increasing from the third tube cavity section 133 towards the first end of the outer tube. The first tube cavity section 131 is closest to the second outer tube component 14, and an end of the first outer tube component close to the second outer tube component is provided with a plurality of radial through-holes 135 (such as three radial through-holes) uniformly arranged in the circumferential direction thereof. Each radial through-hole is provided with a positioning pin 130, and the positioning pin extends into the first tube cavity section and abuts against the inner tube 2, thereby positioning, i.e. fixedly retaining, the front end of the inner tube 2.

[0055] Referring to FIGS. 8a and 8b and referring again to FIG. 3, in a preferred embodiment, the lance device 100 further includes a coupling member 5, the inner tube 2 being fixedly connected to the connecting tube section 31 of the gas supply tube 3 by means of the coupling member 5, wherein the connecting tube section 31 has a first connecting end 311 and a second connecting end 312. It should be understood that the inner tube 2 may also be fixedly connected to the first end of the outer tube 1 by means of the coupling member 5.

[0056] In an embodiment shown in FIGS. 8c and 8d, the coupling member 5 has a first end 5a, a second end 5b, and a stepped hole 50 extending in an axial direction thereof. The stepped hole has a first hole section 51 close to the first end 5a and a second hole section 52 close to the second end 5b. The diameter of the first hole section is smaller than the diameter of the second hole section, and the diameter of the first hole section is the same as the outer diameter of the inner tube 2. The rear end of the inner tube 2 is fixedly connected to the first end 5a of the coupling member at the first hole section, the second end 5b of the coupling member is fixedly connected, such as by means of threaded connection, to the first connecting end 311 of the connecting tube section 31, and the second connecting end 312 of the connecting tube section 31 is fixedly connected, such as by means of threaded connection, to the second end 12 of the outer tube 1 (see FIG. 3), wherein the coupling member, the inner tube, and the outer tube are coaxial. By means of the lance device according to the present invention, a purge gas that prevents the optical cored wire from being fused with the inner tube to cause conveyance failure of the optical cored wire can be injected from the first gas path, and a purge gas that prevents the front end of the lance device from being clogged with slag can be injected from the second gas path, thereby improving the durability of the lance device. The third gas path is provided so that a gas (such as compressed air) from the gas supply tube can flow through the outer circumferential surface of the outer tube, and can push away slag to a certain extent, so as to further prevent the front end of the lance device from being clogged.

[0057] Although the present invention is disclosed above in the preferred embodiments, the present invention is not limited thereto. Various changes or modifications made by those skilled in the art without departing from the spirit and scope of the invention should all fall within the scope of protection of the present application, and therefore the scope of protection of the present application should be defined by the scope of the claims.

Claims

CLAIMS1. A lance device for immersing an optical cored wire (10) in a molten metal bath, the lance device (100) comprising: an outer tube (1) comprising a first end (11) and an opposite second end (12); an inner tube (2) extending into the outer tube, wherein the optical cored wire is to be inserted into the inner tube and is freely movable in an axial direction of the inner tube; and a gas supply tube (3) connected to the second end (12) of the outer tube and in fluid communication with a space between the inner tube and the outer tube; characterized in that: at least one through-hole (13a) is provided in a section of the outer tube close to the gas supply tube (3); and a first gas path formed by a tube cavity of the inner tube (2), a second gas path formed between the outer tube and the inner tube, and a third gas path extending outside the outer tube are present in the lance device.

2. The lance device according to claim 1, wherein the lance device is mounted, by means of a mounting mechanism (4), to a container containing a molten metal bath, wherein the mounting mechanism comprises a mounting sleeve (41), and the mounting sleeve has an inner diameter larger than an outer diameter of the outer tube (1); and when the lance device is mounted to the container, the outer tube extends through the mounting sleeve (41) and is movable within the mounting sleeve, wherein the inner diameter of the mounting sleeve is larger than the outer diameter of the outer tube, so that the third gas path is formed between the mounting sleeve and the outer tube, wherein the third gas path is in fluid communication with the second gas path via the at least one through-hole (13a).

3. The lance device according to claim 2, wherein the through-hole is configured to extend obliquely from an inner circumferential surface of the outer tube toward an outer circumferential surface of the outer tube and toward the first end.

4. The lance device according to any one of claims 1 to 3, wherein the gas supply tube (3) comprises a connecting tube section (31) and a gas intake tube section (32) extending obliquely with respect to the connecting tube section, the connecting tube section is fixedly connected to the second end (12) of the outer tube, and the connecting tube section and the outer tube are coaxial.

5. The lance device according to claim 4, wherein the lance device further comprises a coupling member (5), the inner tube (2) being fixedly connected to the outer tube or the connecting tube section (31) of the gas supply tube (3) by means of the coupling member, wherein the connecting tube section has a first connecting end (311) and a second connecting end (312).

6. The lance device according to claim 5, wherein the coupling member (5) has a stepped hole (50) extending in an axial direction thereof, the stepped hole has a first hole section (51) and a second hole section (52), a diameter of the first hole section is smaller than a diameter of the second hole section and is the same as an outer diameter of the inner tube (2), a rear end of the inner tube (2) is fixedly connected to one end of the coupling member at the first hole section, the other end of the coupling member is fixedly connected to the first connecting end (311) of the connecting tube section, and the second connecting end (312) of the connecting tube section is fixedly connected to the second end (12) of the outer tube, wherein the coupling member, the inner tube, and the outer tube are coaxial.

7. The lance device according to claim 4, wherein the outer tube (1) comprises at least a first outer tube component (13) and a second outer tube component (14) fixedly connected to the first outer tube component, wherein the second outer tube component (14) is fixedly connected to the gas supply tube (3) and has a constant first inner diameter, and a part of the first outer tube component (13) has a second inner diameter, the second inner diameter being smaller than the first inner diameter.

8. The lance device according to claim 7, wherein the first outer tube component (13) defines a first tube cavity section (131), a second tube cavity section (132), a third tube cavity section (133) and a fourth tube cavity section (134) connected in sequence, wherein the first tube cavity section (131) has a diameter equal to the first inner diameter, the third tube cavity section (133) has a diameter equal to the second inner diameter, and the fourth tube cavity section (134) has a diameter gradually increasing from the third tube cavity section (133) toward the first end of the outer tube, wherein the first tube cavity section (131) is closest to the first outer tube component, and an end of the second outer tube component close to the first outer tube component is provided with a plurality of radial through-holes (135) uniformly arranged in a circumferential direction thereof; and each of the radial through-holes is provided with a positioning pin (130) extending into the first tube cavity section and abutting against the inner tube (2).

9. The lance device according to claim 2 or 3, wherein the mounting mechanism further comprises a spherical adjustment member (42) and a mounting fixture (43), the spherical adjustment member is fixedly connected to the sleeve (41) or integrally formed with the sleeve, and the mounting fixture (43) comprises a first mounting plate (431) having a first aperture, a second mounting plate (432) having a second aperture, and a plurality of threaded fasteners (433), wherein when the first mounting plate and the second mounting plate are connected together, the first aperture fits with the second aperture to form a mounting hole (434) adapted to receive the spherical adjustment member (42), and the spherical adjustment member is rotatable within the mounting hole during assembly, so as to adjust a mounting orientation of the lance device.

10. The lance device according to any one of claims 1 to 3, wherein the lance device (100) further comprises a coupling unit (6), and the coupling unit (6) comprises a sensing device (61), and a coupling fixture (62) for coupling the guide tube to the inner tube (2), the sensing device being a pressure sensor and / or an inductive sensor.

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