Lances for use in metal manufacturing and foundry equipment

Abstract

Lances for use in metal manufacturing and foundry equipment The present invention relates to a lance consisting of a top lance (1t) and a sublance (2) connected to the top lance (1t) and forming a shoulder (1s) between the top lance and the sublance (2). The sublance (2) of the invention is provided with a protective element (3) having a connecting end (2c) opening into a cavity (2v), the protective element (3) being in an initial configuration when at rest, characterized by a maximum outer diameter (D3o), D3o being at most 10% greater than the diameter (D2) of the sublance (2) (D3o≦1.1D2). When the sublance (2) is connected to the lance, the protective element (3) contacts the shoulder (1s) and deforms into a deformed configuration, forming a surface extending over the entire area of ​​the shoulder (1s) that is impervious to molten metal and slag.

Description

[Technical Field]

[0001] The present invention relates to a lance for immersing a probe in molten metal contained in a metallurgical vessel, such as a steelmaking converter. The lance is of a type that includes a reusable top lance that does not contact the molten metal, and a sublance that is connected to the top lance and holds at its free end a probe for measuring parameters of the molten metal and / or a sampling device for taking samples of the molten metal. The sublance is used while partially immersed in the molten metal and is disposable. When the top lance and the sublance are connected, a shoulder is defined because the top lance has a larger diameter than the sublance. If the molten metal splashes onto the shoulder of the top lance, the connection of the new sublance to the top lance may become unstable once the metal solidifies. The present invention proposes a sublance with a protective component that prevents molten metal or slag from splashing onto the shoulder area of ​​the top lance. To facilitate storage of the sublance in an existing rack and to allow the sublance to be operated by a robot without changing the robot's programming, the protective parts stored in the rack have a diameter similar to that of the sublance. [Background technology]

[0002] Metal manufacturing processes are carried out at high temperatures within metallurgical vessels, often undergoing chemical or physical reactions or transferring between vessels of molten metal and / or slag during residence times, whether desired or undesired. Because the properties of the final metal product produced in this way are highly dependent on process conditions, including temperature and pH, and the occurrence of chemical or physical reactions, whether desired or undesired, it is important to measure such parameters and also to take samples in situ for further characterization. This operation is typically performed with a lance comprising a top lance, which remains separate from the molten metal or slag, and a sublance, which is coupled to the top lance and has a probe and / or sampler at its free end. The top lance is typically made of metal or polymer and is reusable. The sublance, on the other hand, is typically made of thick cardboard and is disposable.

[0003] For example, steel can be produced from carbon-rich molten pig iron by a basic oxygen furnace process, in which oxygen is blown through the molten pig iron with a lance (12) to reduce the carbon content of the alloy and convert it to low-carbon steel (compare FIG. 1). During this process, samples are taken and melt parameters are measured with different sublances, at least during oxygen blowing (sometimes referred to as an internal blowing sublance) and after oxygen blowing (sometimes referred to as an end blowing sublance), to ensure the desired quality of steel is obtained. The internal blowing sublance is typically equipped with sensors capable of measuring the temperature and liquidus of the molten metal and a sampler for collecting metal samples. The end blowing sublance is typically equipped with sensors for measuring the temperature and oxygen content of the molten metal and a sampler for collecting metal samples.

[0004] A new sublance is inserted onto the coupling of the top lance until it reaches the shoulder formed by the gripping portion of the top lance, which has a larger diameter than the sublance. Vibrations during use can cause the sublance to dislodge from the shoulder, creating a small gap. Molten metal (11) or slag floating on the surface, either due to vessel movement or, in the case of a steel converter, oxygen sparging, can be agitated and create splashes (11s) that can reach the top of the sublance and even the shoulder, or create a gap between the shoulder and the top of the sublance. The metal or slag splash solidifies and forms deposits on the surface of the shoulder and / or coupling at the height of the gap. When the current sublance is retrieved from the top lance and discarded, it is important to scrape any solid metal deposits from the surface of the shoulder and the coupling of the top lance to prevent the next sublance from being unable to properly couple to the top lance.

[0005] U.S. Pat. No. 4,566,343 and European Patent No. EP 3,588,052 describe solutions for preventing the formation of metal deposits in the gap between the sublance and the shoulder. U.S. Pat. No. 4,566,343 describes an elastic ring seal between the submerged end of the shoulder of the top lance and the top of the sublance to reduce the deposition of frozen metal at the joint between the top lance and the sublance. European Patent No. EP 3,588,052 describes a similar solution using two ring seals arranged circumferentially on top of each other at the end portion of the sublance to seal the space between the connecting tap and the end portion of the sublance. These solutions prevent metal or slag splash from reaching the gap between the sublance and the shoulder. As mentioned above, a gap does not necessarily occur, and these solutions do not protect against metal splash at the shoulder.

[0006] Korean Patent No. KR101597688 proposes a solution for protecting the shoulder of a top lance from metal splash. The upper end of the sublance is provided with an anti-sticking cover formed by an inner ring with an inner channel suitable for engaging with the coupling portion of the top lance, and an outer ring coaxial with but separate from the inner ring, the outer ring having a larger diameter than the inner ring, which matches the diameter of the shoulder and protects it from metal splash. The problem with this solution is that the outer ring has a diameter substantially larger than that of the sublance. As a result, racks previously used to store potential new sublances are no longer usable without modifying the dimensions of the receiving means to match the dimensions of the anti-sticking cover. Furthermore, changing the shape of the upper end of the sublance by attaching an anti-sticking cover may require changing the programming of the robot used to manipulate the sublances and attach them to or retrieve them from the top lance.

[0007] The present invention proposes a solution for protecting the shoulder of the top lance, as well as any gap between the shoulder and the sublance, and maintaining the shape of the upper part of the sublance, which is not significantly improved. This solution has the advantage that it can be implemented by replacing an existing sublance one-to-one, without any design changes to the existing rack used to store the sublance or changes to the programming of the robot used to operate the sublance. This solution has the advantage that the adaptation of the protective element to the surface of the top lance and the adaptation of the sublance to the surface of the top lance are the result of deformation of the entire device, not deformation of the surface of an elastic material. This solution has the advantage that the radially expandable protective element expands only after the top lance and sublance are axially joined, thus reducing the possibility of damage during operation and assembly. These and other advantages of the present invention will be presented in due course. [Prior art documents] [Patent documents]

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0009] The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. The present invention relates particularly to a lance for dipping a probe into molten metal, the lance comprising (A) a top lance comprising · a gripping part extending along a longitudinal axis (X) and including a distal end of a cross-section perpendicular to the longitudinal axis (X) of diameter (D1), and provided at the distal end with · a coupling part extending coaxially with the longitudinal axis (X) and having a maximum diameter (d1) with D1>d1, and (B) a sub-lance formed by an elongated tube having a cavity configured to just receive the coupling part and extending along the longitudinal axis (X), the cavity extending along the longitudinal axis (X) from an immersion end provided with a probe and / or a sampler to a proximal end coupled to a protective part having a coupling end opening into the cavity, being substantially cylindrical in diameter (d2) with d1≦d2, o the elongated tube having a cross-section of outer diameter (D2) with d1<d2<D2<D1, o the protective part being deformable when a force is applied thereto along the longitudinal axis (X), o the coupling part being inserted into the cavity of the sub-lance by the protective part contacting a shoulder, · the protective part having an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most up to 10% larger than D2 (D3o≦1.1 D2), preferably at most up to 5% larger than D2 (D3o≦1.05 D2), more preferably D3o = D2, When the sublance is coupled to the lance by insertion into the cavity of the coupling part, the protective part contacts the shoulder and is deformed into a deformed configuration, forming a surface impervious to molten metal and slag extending over an area inscribed in a circle perpendicular to the longitudinal axis (X) of diameter (D3d), where D3d ≥ D1, and covering the entire area of ​​the shoulder.

[0010] In the first embodiment, the protective component includes: an inner tube that is deformable when a compressive force is applied thereto along a longitudinal axis (X) and that forms an inner passageway of diameter (D3i), where D3i ≧ d1, extending along the longitudinal axis (X), the inner layer comprising a plurality of internal slits that are separated from one another and that are disposed around the circumference of the inner tube; an outer tube that is deformable when a compressive force is applied to it along a longitudinal axis (X) and that just surrounds the inner tube, the outer tube having a plurality of outer slits that are separated from one another and that are arranged around the circumference of the outer tube; optionally, one or more peripheral tubes that are deformable when a compressive force is applied thereto along the longitudinal axis (X), inserted into one another and surrounding the outer tube (3o), each of the one or more peripheral tubes being separated from one another and each comprising a plurality of peripheral slits arranged around the circumference of the one or more peripheral tubes, the peripheral slits (3i) of two adjacent peripheral tubes not overlapping each other at any point, and the outer slits (3o) not overlapping at any point the peripheral slits of the peripheral tube adjacent to the outer tube, The inner slit (3i) and the outer slit (3o) do not overlap each other at any point.

[0011] The internal and external slits preferably extend parallel to the longitudinal axis (X). In an alternative embodiment, the internal and external slits extend obliquely, but not perpendicularly, to the longitudinal axis (X), forming an angle with the longitudinal axis of preferably 10 to 50°, more preferably 25 to 45°. The internal and external tubes can be made of an elastomeric material or a plastically deformable metal, or can be in the form of a woven or nonwoven fabric made of ceramic, polymeric, or metal fibers. To enhance the reproducibility of the deformation of the protective element, the internal and / or external tubes can be provided with folds to control the deformation of the protective element (3) so that it folds in a reproducible manner. The internal and external tubes can have different heights, measured along the longitudinal axis (X).

[0012] In a second embodiment, the protective component may comprise a tubular component that is deformable when a compressive force is applied thereto along a longitudinal axis (X). The tubular component extends along the longitudinal axis (X) and defines an inner passageway of diameter (D3i), where D3i ≥ d1. The tubular component comprises a plurality of slits that are separated from one another and arranged around the circumference of the tubular component. In a preferred embodiment, the slits may be arranged in two sets: an upper set extending from adjacent the joining end to adjacent half the height of the tubular component as measured along the longitudinal axis (X); a lower set extending from a position adjacent the fixed end opposite the coupling end to a position adjacent halfway up the height of the tubular component, The upper set of slits are offset relative to the lower set of slits.

[0013] The protective components of the first and second embodiments described above may be cylindrical or may comprise one or more cylindrical portions and one or more tapered or curved portions arranged along a longitudinal axis (X).

[0014] In a third embodiment, the protective component includes: a support ring coupled to the proximal end of the elongated tube; a plurality of rotatably mounted L-shaped plates, each including an outer portion joined to an inner portion at a corner of the L, the L-shaped plates being disposed about the periphery of the support ring by hinges at or adjacent the corners of the L-shaped plates; In the initial configuration of the protective element, each L-shaped plate is biased to rotate so that its inner portion extends radially inward and generally perpendicular to the longitudinal axis (X) to at least partially block the cavity, and its outer portion rests against the outer surface of the sublance; o The L-shaped plate is configured to pivot about the hinge (3h) from an initial configuration to a deformed configuration when the coupling part (1c) is inserted into the cavity to connect the sub-lance to the top lance, and in the deformed configuration, the inner part is aligned parallel to the longitudinal axis (X) and the outer part extends radially and generally perpendicular to the longitudinal axis (X), and the L-shaped plates overlap each other to form a continuous screen against splash when the protective part is contacted with the shoulder.

[0015] Preferably, each outer portion has a free edge, measured perpendicular to the longitudinal axis (X), that is larger than the corners, and each outer portion is curved with a curvature that matches the outer diameter (D2) of the coupling end so that when the protective element is in its initial configuration, each outer portion connects to the outer surface of the sublance.

[0016] Similarly, it is preferred that each inner portion has a free edge, measured perpendicular to the longitudinal axis (X), that is shorter than the corners, and that each inner portion is curved with a curvature that corresponds to the maximum diameter (d1) of the coupling portion so that when the coupling portion is inserted into the cavity and the L-shaped plates are pivoted on their hinges, the inner portion is pressed against the wall of the cavity and forms an inner passage of diameter (D3i), where D3i ≧ d1, allowing the coupling portion to be inserted.

[0017] The L-shaped plates are preferably sufficiently rigid so as not to deform substantially during normal use of the device, and are preferably made from metal, preferably steel or aluminium, or from a ceramic material, or from a polymeric material.

[0018] The present invention also relates to a sublance for coupling to the coupling portion of the lance. The sublance is formed by an elongated tube that extends along a longitudinal axis (X) and has a cavity configured to just receive the coupling portion, the cavity extending along the longitudinal axis (X) from an immersion end provided with a probe and / or a sampler to a proximal end that is coupled to a protective part (3) having a coupling end (2c) that opens into the cavity (2v), and is substantially cylindrical with a diameter (d2) such that d1 ≦ d2. The sublance is characterized as follows: · The elongated tube has a cross-section with an outer diameter (D2) such that d1 < d2 < D2 < D1, · The protective part is deformable when a force is applied thereto along the longitudinal axis (X), · The coupling portion is inserted into the cavity of the sublance by a protective part that contacts the shoulder, · The protective part has an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most 10% larger than D2 (D3o ≦ 1.1 D2), preferably at most 5% larger than D2 (D3o ≦ 1.05 D2), more preferably D3o = D2, · When the sublance is coupled to the lance by insertion into the cavity of the coupling portion, the protective part contacts the shoulder and is deformed into a deformed configuration, forming a surface that is impermeable to molten metal and slag, which extends over an area that circumscribes a circle with a diameter (D3d) such that D3d ≧ D1, covers the entire area of the shoulder, and extends orthogonally to the longitudinal axis (X) over a distance that is at least equal to 1 / 2 D1 from the longitudinal axis (X).

[0019] The protective part is preferably defined in the first, second, or third embodiment as described above.

[0020] The present invention also relates to a protective part for protecting against splashing occurring on a shoulder formed between the distal end of a gripping part and the sublance of a lance. The protective part is an inner tube that is deformable when a compressive force is applied thereto along a longitudinal axis (X) and that forms an inner passageway of diameter (D3i), where D3i ≧ d1, extending along the longitudinal axis (X), the inner layer comprising a plurality of internal slits that are separated from one another and that are disposed around the circumference of the inner tube; an outer tube that is deformable when a compressive force is applied to it along a longitudinal axis (X) and that just surrounds the inner tube, the outer tube having a plurality of outer slits that are separated from one another and that are arranged around the circumference of the outer tube; optionally, one or more peripheral tubes that are deformable when a force is applied thereto along the longitudinal axis (X), inserted into one another and immediately surrounding the outer tube, each of the one or more peripheral tubes being separated from one another and comprising a plurality of peripheral slits arranged around the circumference of each of the one or more peripheral tubes, the peripheral slits (3i) of two adjacent peripheral tubes not overlapping each other at any point, and the outer slits not overlapping at any point the peripheral slits of the peripheral tube adjacent to the outer tube, The inner and outer slits do not overlap each other at any point.

[0021] The protective component is preferably as defined in the first, second or third embodiment as described above. [Brief explanation of the drawings]

[0022] For a more complete understanding of the nature of the present invention, reference should now be made to the following detailed description taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 shows an oxygen lance and a steel converter equipped with a lance according to the invention. [Figure 2(a)] Figure 2(a) shows the gripping part and separate coupling part of a lance according to the invention. [Figure 2(b)] FIG. 2(b) shows a top lance of the present invention formed by the gripping portion and coupling portion of FIG. 1(a) joined together. [Figure 2(c)] FIG. 2(c) shows a sublance according to the present invention. [Figure 2(d)]FIG. 2(d) shows a lance according to the present invention formed by the sub-lance of FIG. 2(c) coupled to the top lance of FIG. 2(b). [Figure 2(e)] FIG. 2(e) shows a sublance according to the present invention. [Figure 3(a)] FIG. 3(a) shows an exploded view of an embodiment of a protective component according to the present invention. [Figure 3(b)] FIG. 3(b) shows the protective component of FIG. 3(a) in assembled form. [Figure 3(c)] 3(c) to 3(f) show alternative embodiments of the protection component according to the present invention. [Figure 3(d)] Same as above. [Figure 3(e)] Same as above. [Figure 3(f)] Same as above. [Figure 4(a)] FIG. 4(a) shows details of joining the coupling portion to the gripping portion to form the top lance of the present invention. [Figure 4(b)] Figure 4(b) shows a detail of the top lance of Figure 4(a) assembled on a sublance provided with protective components of the type shown in Figures 3(a) to 3(f). [Figure 4(c)] FIG. 4(c) shows the sublance of FIG. 4(b) partially inserted onto the coupling portion of the top lance of FIG. 4(b), with the upper surface of the protective part contacting the shoulder in the initial configuration but remaining undeformed. [Figure 4(d)] FIG. 4(d) shows the sub-lance of FIG. 4(c) fully inserted over the coupling portion of the top lance of FIG. 4(c) with one embodiment of the protective element deformed in a deformed configuration to provide splash protection to the shoulder. [Figure 4(e)] Figure 4(e) shows a partially deformed protective element of the type shown in Figures 3(a) to 3(f). [Figure 5(a)] FIG. 5(a) shows an exploded view of a second embodiment of the protection component of the present invention. [Figure 5(b)] Figure 5(b) shows a side view of a second embodiment of the protective element of Figure 5(a) in assembled form. [Figure 5(c)]FIG. 5(c) shows a second embodiment of the protection component of FIG. 5(b) in an initial configuration. [Figure 5(d)] FIG. 5(d) shows a second embodiment of the protection component of FIG. 5(b) in a modified configuration. [Figure 5(e)] FIG. 5(e) shows a sublance according to the present invention equipped with the protection component of the second embodiment of FIG. 5(a). [Figure 6(a)] FIG. 6(a) shows details of joining the coupling portion to the gripping portion to form the top lance of the present invention. [Figure 6(b)] Figure 6(b) shows a detail of the top lance of Figure 6(a) assembled on a sublance equipped with a protective component of the type shown in Figures 5(a) to 5(e). [Figure 6(c)] Figure 6(c) shows the sub-lance of Figure 6(b) with the upper surface of the second embodiment of the protective part remaining separated from the shoulder and partially inserted onto the coupling part of the top lance of Figure 6(b) already at least partially deformed by the introduction of the coupling part. [Figure 6(d)] Figure 6(d) shows the sub-lance of Figure 6(c) fully inserted onto the coupling part of the top lance of Figure 6(c) with the second embodiment of the protective part deformed in a deformed configuration to protect the shoulder from splashing. [Figure 7(a)] Figures 7(a) and 7(b) show an alternative embodiment of a protective component according to the present invention. [Figure 7(b)] Same as above. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention relates to a lance for immersing a probe in molten metal, the lance comprising a top lance (1t) and a disposable sub-lance (2) that holds the probe and is connected to the top lance (1t).

[0024] The top lance (1t) comprises a reusable gripping portion (1h) and a coupling portion (1c) coupled to the distal end of the gripping portion (1h) and at least partially integrated. The gripping portion (1h) extends along a longitudinal axis (X) and has a distal end with a generally substantially circular cross-section orthogonal to the longitudinal axis (X) of diameter (D1). The distal end extends coaxially with the longitudinal axis (X) and is provided with a coupling portion (1c) having a maximum diameter (d1) where D1>d1. The coupling portion generally · a fixing element (1f) that is fixed or integrated to the distal end of the gripping portion (1h) and defines an exposed area of the distal end forming a shoulder (1s); · is formed by a probe holder (1p) that extends along the longitudinal axis (X) and has a proximal end reversibly coupled to the fixing element (1f).

[0025] The specified probe holder is reusable a plurality of times without replacement, but due to the severe usage conditions it undergoes, its quality rapidly deteriorates, and unlike the gripping portion (1h) and the fixing element (1f), the probe holder requires replacement at regular intervals.

[0026] The sub-lance (2) is disposable and is formed by an elongated tube (2t) that extends along the longitudinal axis (X) and has a cavity (2v) configured to just receive the coupling portion (1c). The cavity extends along the longitudinal axis (X) from an immersion end provided with a probe (2p) and / or a sampler to a proximal end coupled to a protective component (3) having a coupling end (2c) that opens into the cavity (2v), and is generally cylindrical with a diameter (d2) where d1<d2. The elongated tube (2t) has a generally circular cross-section with an outer diameter (D2) where d1<d2<D2<D1. The protective component (3) is deformable when a force is applied thereto along the longitudinal axis (X). The sub-lance (2) is reversibly coupled to the top lance (1t) to form a lance. Coupling the sub-lance (2) to the top lance (1t) to form the lance of the present invention is achieved by inserting the coupling portion (1c) of the top lance (1t) into the cavity (2v) of the sub-lance (2) at the coupling end (2c) of the protective component (3) that contacts the shoulder (1s).

[0027] The gist of the present invention is to provide a protective component, which comprises, on the one hand: The shape of the connecting end (2c) of the separate (unconnected) sublance is not significantly changed in order to use the existing rack for storing the sublances and to use the robot without changing its programming, while The entire area of ​​the shoulder and any gap formed between the shoulder (1s) and the sublance (2) is covered and protected from splash when the sublance is coupled to the shoulder.

[0028] This is achieved by designing protective components, which the protective element (3) is in an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most 10% greater than D2 (D3o≦1.1 D2), preferably at most 5% greater than D2 (D3o≦1.05 D2), more preferably D3o=D2; When the sublance (2) is coupled to the lance by insertion into the cavity (2v) of the coupling part (1c), the protective part (3) contacts the shoulder part (1s) and is deformed into a deformed configuration, forming a surface impervious to molten metal and slag extending over an area inscribed in a circle perpendicular to the longitudinal axis (X) and having a diameter (D3d) and where D3d ≥ D1, and in the deformed configuration, the protective part (3) covers the entire area of ​​the shoulder part (1s) and extends perpendicular to the longitudinal axis (X) for a distance at least equal to 1 / 2D1 from the longitudinal axis (X). Top Lance (1t)

[0029] The top lance (1t) is a hollow rod long enough to be inserted into a metallurgical vessel, as shown in Figure 1. For example, for a steel converter, the top lance (1t) is 10-20 m long and can be even longer depending on the dimensions of the metallurgical installation. The top lance is operated by a robot configured to pull the lance downward into and upward from the vessel. The top lance is formed by a gripper (1h) and a coupling (1c).

[0030] The gripping portion (1h) extends along a longitudinal axis (X) and has a distal end that is generally circular in cross section perpendicular to the longitudinal axis (X) with a diameter (D1). In the vast majority of cases, the cross section of the distal end is circular, but if it is not circular, the cross section may similarly be characterized by a hydraulic diameter (Dh1) (not shown) rather than a diameter (D1), where Dh1 = A1 / P1, where A1 and P1 are the area and perimeter of the cross section of the distal end perpendicular to the longitudinal axis (X). The circularity of the cross section of the gripping portion's distal end is not required by the present invention. However, in practice, the cross section will generally be circular.

[0031] The gripper (1h) may be made of metal or polymer, or fiber-reinforced polymer composite material. The gripper is designed to withstand a significant service time without replacement. The gripper may be considered an integral part of the metallurgical equipment.

[0032] As shown in Figure 2(b), coupling portion (1c) extends coaxially with longitudinal axis (X) and has a maximum diameter (d1), where D1 > d1. A shoulder (1s) of width (1 / 2 (D1 - d1)) is thus formed by the distal end of gripping portion (1h) and coupling portion (1c).

[0033] As shown in FIG. 2(a), the coupling portion (1c) is generally a fixation element (1f) fixed to or integral with the distal end of the gripping portion (1h) and defining an exposed area at the distal end forming a shoulder (1s); a probe holder (1p) extending along a longitudinal axis (X) and having a proximal end reversibly connected to a fixation element (1f).

[0034] Like the gripping portion, the coupling portion is generally hollow to define a path for accommodating any wiring required by the probe (2p) positioned at the free end of the sublance (2). The coupling portion (1c), and in particular the free end of the probe holder (1p), may be provided with an electrical connection (1e) (e.g., a male plug or female socket) for coupling to a corresponding electrical connection (2e) of any wiring on the probe (2b) when the sublance (2) is coupled to the top lance (1t), thus forming a conductive continuous communication extending from the probe (2p) along a path passing through the top lance to any control device for recording measurements made by the probe (2p). Since the electrical connections (1e) of the probe holder (1p) can be damaged by repeated connections / disconnections with new sublances (2) and the harsh operating conditions in a metallurgical vessel, which is often very close to molten metal at very high temperatures and exposed to vibrations, the probe holder (1p) must be replaced at regular intervals to ensure good connections of any wiring.

[0035] The probe holder (1p) can be reversibly coupled to the fixing element (1f) to form a coupling part (1c) by mechanical means such as a screw thread, a bayonet pin, a snap fit, etc. as shown in Figures 4(a) and 6(a). Sublance (2)

[0036] The sublance (2) extends along a longitudinal axis (X) and comprises a cavity (2v) adapted to receive the coupling part (1c). The sublance (2) comprises at least: an elongated tube (2t) including an immersed end and a proximal end; The probe (2p) and / or metal or slag sampler is connected to the immersion end of the elongated tube (2t); A protective element (3) is coupled to the proximal end of the elongated tube (2t).

[0037] The cavity is generally of a substantially cylindrical shape with a diameter (d2) such that d1 ≦ d2, and extends along the longitudinal axis (X) from the immersion end, which is at least partially closed by the probe (2p), to the coupling end (2c) of the protective component (3) that opens to receive the coupling part (1c) of the top lance (1t). The coupling part (1c) of the top lance (1t) can be in contact with the wall of the cavity (2v) and can include gripping means for frictionally fixing the sub-lance (2). The sub-lance (2) can also be fixed to the coupling part by mechanical means such as threads, insertion pins, snap fits, etc.

[0038] The electrical connection (2e) that connects to the electrical connection (1e) of the coupling part (1c) of the top lance can be fixed at a corresponding position within the cavity (2v) such that when the sub-lance (2) is coupled to the top lance (1t), electrical communication is formed by connecting the electrical connectors (1e, 2e) of the top lance (1t) and the sub-lance (2). Thus, the probe (2b) can be electrically coupled to an external control device (not shown).

[0039] The elongated tube (2t) is generally made of cardboard and is closed by the probe at its immersion end. The coupling end (2c) of the elongated tube (2t) of the sub-lance (2) generally has a substantially circular cross-section with an outer diameter (D2) such that d1 < d2 < D2 < D1. If any one of the cross-sections of the coupling part (1t), the cavity (2v) of the sub-lance (2), the coupling end (2c), or the distal end of the gripping part (1h) is not circular, the cross-section can be defined by the corresponding hydraulic diameter such that dh1 < dh2 < Dh2 < Dh1, and the hydraulic diameter is defined as the ratio of the perimeter to the area of the corresponding cross-section (Dh = A / P).

[0040] The gist of the present invention involves the provision of a fixed protective element (3) at the coupling end of the sublance (2). The protective element has an initial configuration at rest that does not significantly change the external geometry of the sublance. The protective element (3) is deformable to a deformed configuration when a force is applied thereto parallel to the longitudinal axis (X). The force that deforms the protective element (3) should not significantly exceed the force normally applied to couple the sublance (2) to the top lance (1t), and the protective element should be deformed from the initial configuration to the deformed configuration upon insertion of the coupling portion (1c) of the top lance (1t) into the cavity (2v) as the coupling portion (1c) is inserted deeper into the cavity (2v), in some embodiments until the free end of the protective element (3) contacts the shoulder (1s) of the top lance (1t).

[0041] The coupling of the various components of the lance 1 according to this embodiment of the invention may include coupling the probe holder 1p to the fixed element 1f to form the coupling portion 1c. The probe holder 1p can be secured to the fixed element 1f by a screw thread, a bayonet, a snap fit, or the like. The coupling portion 1c of the top lance 1t can then be coaxially inserted into the cavity 2v of the sublance 2, like sheathing a sword, until the protective element 3 in its initial configuration contacts the shoulder 2h. When a force is applied to the protective element 3 along the longitudinal axis X, the protective element reaches a deformed configuration. It is essential to the invention that the protective element 3 reaches the deformed configuration when the coupling between the sublance 2 and the top lance 1t is complete.

[0042] As shown in Figures 2(d), 4(d), and 6(d), when the sublance (2) is coupled to the top lance (1t), the protective element (3) is in a deformed configuration with its free end in contact with the shoulder (1s), extending radially over an area that inscribes a circle perpendicular to the longitudinal axis (X) of diameter (D3d), where D3d ≥ D1, and thus encompasses the entire area of ​​the shoulder (1s). In the deformed configuration, the shoulder (1s) is protected by the protective element (3) from any molten metal splash (11s), and no scrubbing is required to remove any solidified metal from the surface of the shoulder (1s). Such cleaning operations must be performed manually and can be very tedious. Protective Parts (3) - Double Pipe

[0043] In the preferred embodiment shown in Figures 3(a) to 3(e), the protective component (3) is an inner tube (3i) that is deformable when a compressive force is applied to it along a longitudinal axis (X) and that forms an inner passageway of diameter (D3i), where D3i≧d1, extending along the longitudinal axis (X), the inner layer (3i) comprising a plurality of internal slits (3si) that are separated from one another and that are arranged around the circumference of the inner tube (3i); an outer tube (3o) that is deformable when a compressive force is applied to it along a longitudinal axis (X) and that exactly surrounds the inner tube (3i), the outer tube (3o) having a plurality of external slits (3so) that are separated from one another and that are arranged around the circumference of the outer tube (3o); The inner slit (3si) and the outer slit (3so) do not overlap each other at any point.

[0044] The protective part (3) optionally comprises one or more peripheral tubes which are deformable when a compressive force is applied along the vertical axis (X), are inserted into each other, and just surround the outer tube (3o), and each of the one or more peripheral tubes is separated from each other and comprises a plurality of peripheral slits arranged around the periphery of each of the one or more peripheral tubes, and the peripheral slits of two adjacent peripheral tubes do not overlap each other at any point, and the external slit (3so) does not overlap with the peripheral slit of the peripheral tube adjacent to the outer tube at any point, and comprises one or more peripheral tubes.

[0045] As shown in FIG. 4(e), the non-overlapping internal and external slits (3si, 3so) are essential in the present invention for the following reasons. In the initial configuration, the protective part is formed by a plurality of stripes of a material having a stripe width measured in the tangential direction (i.e., orthogonal to the vertical axis (X) and the radial direction) defined between two adjacent slits of the initial slit width, resulting in a maximum outer diameter (D3o) with a circumference Pi = π×D3o. In the deformed configuration, the protective part (3) forms a surface that expands into a region that circumscribes a circle of diameter (D3d) where D3o < D3d, resulting in a circumference Pd = π×D3d > Pi. Since the stripe width remains constant when bending the stripes of the material, Pd can accordingly be made larger than Pi only by increasing the slit width. The problem with locally wide slits (3si, 3so) is that such openings prevent the surface thus formed from being impermeable to the splash (11s) of molten metal and slag. For this reason, both the inner tube (3i) and the outer tube (3o) are required to have internal slits (3si) and external slits (3so) that do not overlap each other at any point, so that any locally wide slit in the inner tube or the outer tube is always covered by the stripes of the material of the inner tube or the outer tube respectively, thus defining a surface that is impermeable to the splash (11s) of metal or slag.

[0046] As shown in Figures 3(a) to 3(e), the internal slits (3si) and the external slits (3so) can extend parallel to the longitudinal axis (X). Alternatively, as shown in Figure 3(f), the internal slits (3si) and the external slits (3so) can extend obliquely, but not perpendicularly, to the longitudinal axis. In this embodiment, the internal slits (3si) and the external slits (3so) can form an angle with the longitudinal axis comprised between 10 and 50°, preferably between 25 and 45°.

[0047] Figure 3(c) shows an embodiment in which the inner tube (3i) and / or the outer tube (3o) are provided with fold lines (3f) to control deformation of the protective element (3) for folding in a reproducible manner. The fold lines ensure that the tubular elements deform preferentially along the fold lines (3f). The fold lines (3f) can be formed by point-like perforations in the tubular elements due to locally thinner wall thicknesses of the inner and / or outer tubes, and the fold lines are thus defined by corresponding grooves. Since the protective element (3) is connected at one end to the proximal end of the elongated tube (2t) and at the connecting end (2c) to the coupling part of the top lance (1t), the fold lines (3f) can run adjacent to and parallel to the connecting end (2c) of the protective element (3). The fold line (3f) may also be circumferentially formed at approximately the mid-height of the protective element (3), ensuring that the protective element (3) extends across the entire shoulder area in the deformed configuration. Preferred locations for the fold line (3f) are shown in Figures 3(c) and 4(e).

[0048] As shown in FIG. 3(d), the inner tube (3i) and the outer tube (3o) can have different heights, measured along the longitudinal axis (X). In the embodiment of FIG. 3(d), the outer tube (3o) is approximately half the height of the inner tube (3i). In the embodiment of FIG. 3(d), the outer tube's external slit (3so) opens at the free edge of the outer tube (3o) located closest to the joining end (2c). An external slit (3so) opening at the free edge of the outer tube (3o) located closest to the joining end (2c) can also be added to any outer tube (3o) having a height ranging from 50% to 100% of the height of the inner tube (3i). With this configuration, the inner tube is folded in half, unfolding the free stripe of material of the outer tube like a petal. The space between two adjacent stripes (=petals) of the outer tube is protected by a stripe of material of the inner tube (3i) that is offset relative to the stripe of material of the outer tube.

[0049] The protective element (3) may be cylindrical, as shown in Figures 3(a)-3(d) and 3(f), or the protective element may comprise one or more cylindrical portions and one or more tapered or curved portions arranged along a longitudinal axis (X), an embodiment of which is shown in Figure 3(e).

[0050] The inner tube (3i) and the outer tube (3o) can be made of an elastomeric material, or a plastically deformable metal, or can be in the form of a woven or non-woven fabric made of ceramic, polymeric or metallic fibers.

[0051] Figures 4(a)-4(d) show various steps for installing a lance according to this embodiment of the invention, highlighting the deformation of the protective element 3 when connecting the sublance 2 to the top lance 1t. Figure 4(a) shows how the probe holder 1p is connected to the fixed element 1f to form the coupling portion 1c of the top lance 1t. Figure 4(a) shows the threads for connecting the probe holder 1p to the fixed element 1f. As mentioned above, other connecting means, such as a bayonet or a snap fit, can be used without affecting the invention. As shown in Figures 4(b) and 4(c), the coupling portion 1c of the top lance 1t is inserted into the cavity 2v of the sublance 2, like sheathing a sword, until the connecting end 2c of the protective element contacts the shoulder 1s without deformation of the protective element, which remains in its initial configuration. The protective element (3) shown in Figures 4(b)-4(e) is of the type shown in Figure 3(b) or 3(c), but the same principles apply to any one of the embodiments shown in Figures 3(b)-3(f). At this stage, shown in Figure 4(c), the sublance (2) is not yet fully coupled to the top lance (1t). To complete the coupling, the coupling part (1c) must penetrate further and deeper into the cavity, and a compressive force is applied along the longitudinal axis (X) on the protective element (3), which is deformed to reach a deformed configuration. Comparing Figures 4(d) and 4(e) clearly shows that upon application of the compressive force along the longitudinal axis (X), the double-tube, generally cylindrical protective element clamps together at its mid-height (measured along the longitudinal axis (X)), forming a shape resembling two inverted funnels joined together at their wide ends. The diameter (D3d) of the stripe of material at the fold height must be at least equal to the diameter (D2) of the distal end of the top lance (D3d ≥ D2). Consequently, the height of the protective element (3) measured along the longitudinal axis (X) must be greater than twice the radial width (= 1 / 2 (D1 - D2c)) of the shoulder (1s) formed between the top lance (1t) and the sublance (2), where D2c is the diameter of the connecting end (2c) of the protective element (3). Protective Part (3) - Single Tube

[0052] In an alternative preferred embodiment shown in Figures 7(a) and 7(b), the protective element (3) comprises a single tube that is deformable when a compressive force is applied to it along a longitudinal axis (X). The tubular element (3i) extends along the longitudinal axis (X) and defines an inner passageway of diameter (D3i), where D3i ≥ d1. The tubular element (3i) comprises a plurality of slits (3s) that are separated from one another and distributed around the circumference of the tubular element.

[0053] In the embodiment shown in Figure 7(a), the slit extends over at least 70%, preferably at least 80%, more preferably at least 90% of the height of the tubular component measured along the longitudinal axis (X).

[0054] In the embodiment shown in FIG. 7(b), the slits (3s) are arranged in two sets: an upper set extending from adjacent the joining end (2c) to adjacent half the height of the tubular component measured along the longitudinal axis (X); a lower set extending from a position adjacent to the fixed end opposite the connecting end (2c) to a position adjacent to half the height of the tubular part, The upper set of slits (3s) are offset relative to the lower set of slits (3s).

[0055] The slits (3s) may extend parallel to the longitudinal axis (X), or alternatively, their extension may be oblique, but not perpendicular to the longitudinal axis (X). In the latter embodiment, the slits (3s) form an angle with the longitudinal axis preferably comprised between 10 and 50°, more preferably between 25 and 45°. In all cases, the slits are preferably parallel to one another, or at least never intersect one another.

[0056] As shown in Figures 7(a) and 7(b), the tubular part is preferably provided with fold lines (3f) to control the deformation of the protective part (3) for folding in a reproducible manner. For example, the fold lines (3f) may extend circumferentially for half the height of the tubular part.

[0057] The tubular component can be cylindrical or can comprise one or more cylindrical portions and one or more tapered or curved portions arranged along the longitudinal axis (X). The tubular component is preferably made of an elastomeric material, or a plastically deformable metal, or is in the form of a woven or non-woven fabric made of ceramic, polymer or metal fibers. Protective component (3) - flower of the basket

[0058] In a preferred alternative embodiment shown in FIGS. 5(a) to 5(e), the protective component (3) comprises · a support ring (3r) coupled to the coupling end (2c) of the sublance (2), and · a plurality of L-shaped plates (3p), each including an outer portion (3po) joined to an inner portion (3pi) at the corner of the L, as compared to FIG. 5(a).

[0059] As shown in FIG. 5(b), the L-shaped plates are rotatably mounted and arranged around the support ring by hinges (3h) at or adjacent to the corners of the L-shaped plates such that the protective component (3) can be changed between an initial configuration and a deformed configuration by rotation of the L-shaped plates (3p) about their respective hinges (3h).

[0060] In the initial configuration of the protective component (3) shown in FIG. 5(c), each L-shaped plate is biased to rotate such that the inner portion (3pi) extends radially inward and substantially orthogonally to the longitudinal axis (X), at least partially closing the cavity (2v), and the outer portion (3po) abuts against the outer surface of the sublance (2). In the initial configuration, the inner portion (3pi) forms an inner path with a diameter (D3i) where D3i < d1. The bias can be created by a spring that pushes the L-shaped plates into the initial configuration as described above. However, the bias can be very simply created by moving the center of gravity of the L-shaped plates such that the L-shaped plates rotate naturally under gravity and reach the configuration described above. Note that since the sublance is generally stored, operated, and used with the longitudinal axis (X) being substantially vertical, the influence of gravity can be easily controlled.

[0061] As shown in Figure 5(b), the L-shaped plate is configured to pivot about hinge (3h) from an initial configuration shown in Figure 5(c) to a deformed configuration shown in Figure 5(d) when coupling part (1c) is inserted into cavity (2v) to couple sublance (2) to top lance (1t). In the deformed configuration shown in Figure 5(d), inner parts (3pi) are aligned parallel to longitudinal axis (X) and outer parts (3po) extend radially generally perpendicular to longitudinal axis (X) and overlap each other to form a continuous screen against metal splash when protective part (3) contacts shoulder (1s).

[0062] As can be seen in Figures 5(a) and 5(d), each outer portion (3po) preferably has a free edge, measured tangentially (i.e. radially perpendicular to the longitudinal axis (X)), that is larger than the corners. In this way, when the L-shaped plates (3p) pivot about their hinges to reach a deformed configuration (like a blooming lotus flower), every L-shaped plate comes into contact with the adjacent L-shaped plate positioned on one side of it, thus forming a continuous screen that protects the shoulders (1s) from splashes.

[0063] Each outer portion (3po) is preferably curved with a curvature that matches the outer diameter (D2) of the coupling end (2c) so that when the protective element (3) is in its initial configuration, each outer portion (3po) connects to the outer surface of the sublance (2), as shown in Figures 5(c) and 5(e), and does not exceed the maximum diameter (D3o) of the protective element (3) by more than 10% (D3o ≤ 1.1 D2).

[0064] In a preferred embodiment, each inner portion (3pi) has a free edge, measured perpendicular to the longitudinal axis (X), that is shorter than the corners, as is evident from Figures 5(a) to 5(c). Thus, when the protective element (3) is in its initial configuration and the inner portions (3pi) extend radially inward, the inner portions do not overlap each other. In the initial configuration, the inner portions do not need to form a continuous screen when not in use, since the sublance is not connected to the top lance. When the L-shaped plates pivot to reach the deformed configuration, the L-shaped plates contact the cavity wall and preferably should not overlap each other in order to maximize the cavity opening to allow the coupling portion (1c) with diameter (d1) to pass through the cavity (2v).

[0065] Each inner portion (3pi) is preferably curved with a curvature that corresponds to the maximum diameter (d1) of the coupling part (1c) so that when the coupling part (1c) is inserted into the cavity (2v) and the L-shaped plates (3) are pivoted on their hinges (3h), the inner portions (3pi) are pressed against the wall of the cavity (2v) and form an inner passage of diameter (D3i), where D3i ≥ d1, allowing the insertion of the coupling part (1c).

[0066] The L-shaped plate (3) is preferably sufficiently rigid so as not to deform significantly during normal use of the device. In particular, when the coupling part (1c) is introduced into the cavity (2v) and presses onto the inner part (3pi) of the L-shaped plate, the inner part must not bend (significantly) but must be sufficiently rigid to drive the rotation of the L-shaped plate in the absence of bending. The L-shaped plate is preferably made of metal, preferably steel or aluminum, or of a ceramic material, or of a polymer material, preferably not a rubbery polymer.

[0067] Figures 6(a)-6(d) show various steps for connecting the various components of a lance according to this embodiment of the invention, highlighting the deformation of the protective element 3 when connecting the sublance 2 to the top lance 1t. Figure 6(a) shows how the top lance 1t is formed by connecting the probe holder 1p to the fixed element 1f, forming the coupling portion 1c. In Figure 6(a), the threads for connecting the probe holder 1p to the fixed element 1f are shown. As mentioned above, other connecting means, such as a bayonet or a snap fit, can be used without affecting the invention. As shown in Figures 6(b) and 6(c), the coupling portion 1c of the top lance 1t is inserted into the cavity 2v of the sublance 2, like sheathing a sword. In the initial configuration, the inner portion (3pi) of the L-shaped plate (3p) extends radially inward, partially blocking the opening of the cavity (2v), leaving an opening with a diameter smaller than the diameter (d1) of the coupling part (1c). As a result, when the coupling part (1c) contacts the inner portion (3pi) of the L-shaped plate (3p), the coupling part exerts a force on the inner portion along the longitudinal axis (X), pushing the inner portion downward against the wall of the cavity (2v), thus driving the tilt of the L-shaped plate (3p) and simultaneously lifting the outer portion (3po) away from the outer wall of the sublance (2). At the stage shown in Figure 6(c), the protective element may or may not have reached the deformed configuration, depending on how far the inner portion (3pi) is pushed against the wall of the cavity (2v). At this stage, the sublance (2) is not yet fully coupled to the top lance (1t) because its coupling end (2c) does not contact the shoulder (1s). To complete this coupling, the coupling part (1c) must penetrate further and deeper into the cavity. It is essential in the present invention that the protective part (3) has reached the deformed configuration when the coupling between the sublance (2) and the top lance (1t) is completed.To fully open the "lotus flower" and align the outer portion (3po) to form a continuous screen, the coupling portion (1c) may be tapered so that the diameter of the coupling portion increases until it reaches a maximum diameter (d1) at its upper portion adjacent the gripping portion (1c) in order to fully press the inner portion against the wall of the cavity (2v). final thoughts

[0068] The various aspects of the present invention, including the top lance (1t), the sublance (2) and the protective element (3), have in common a protective element characterized as follows: the protective element (3) is in an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most 10% greater than D2 (D3o≦1.1 D2), preferably at most 5% greater than D2 (D3o≦1.05 D2), more preferably D3o=D2; When the sublance (2) is coupled to the lance by insertion into the cavity (2v) of the coupling part (1c), the protective part (3) contacts the shoulder part (1s) and is deformed into a deformed configuration, forming a surface impervious to molten metal and slag over an area inscribed in a circle of diameter (D3d), where D3d ≥ D1, covering the entire area of ​​the shoulder part (1s) and extending perpendicular to the longitudinal axis (X) for a distance from the longitudinal axis (X) at least equal to 1 / 2D1.

[0069] This apparently simple solution offers great advantages in terms of lance maintenance, since it is not necessary to scrape off any solidified metal or slag splashes that foul the shoulder (1s) of the top lance (1t). At the same time, the sublance of the prior art can be replaced by the sublance (2) of the present invention without changing anything in the process, neither the rack for storing spare sublances (2) nor the programming of the robot that operates the sublance. This is possible because, in its initial configuration, the protective part (3) does not significantly change the shape of the sublance. This solution is also quite economical to implement. [Table 1]

Claims

1. A lance (1) for immersing a probe in molten metal, comprising: (A) a gripping portion (1h) extending along a longitudinal axis (X) and having a distal end with a cross-section perpendicular to said longitudinal axis (X) of diameter (D1); a top lance (1t) including a coupling portion (1c) extending coaxially with said longitudinal axis (X) and having a maximum diameter (d1) such that D1>d1; (B) a sublance (2) formed by an elongated tube (2t) extending along said longitudinal axis (X) and having a cavity (2v) adapted to just receive said coupling part (1c); The cavity is generally cylindrical with a diameter (d2), where d1≦d2, extending along said longitudinal axis (X) from an immersion end provided with a probe (2p) and / or a sampler to a proximal end connected to a protective part (3) having a connection end (2c) opening into said cavity (2v); o the elongated tube (2t) has a cross section with an outer diameter (D2) such that d1<d2<D2<D1, o said protective part (3) is deformable upon application of a force along said longitudinal axis (X); The coupling portion (1c) is inserted into the cavity (2v) of the sublance (2), and at that time, the protective part (3) contacts the shoulder portion (1s), said protective part (3) is in an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most 10% greater than D2 (D3o≦1.1 D2); - A lance (1), characterized in that when the sub-lance (2) is coupled to the top lance by insertion into the cavity (2v) of the coupling part (1c), the protective part (3) contacts the shoulder portion (1s) and is deformed into a deformed configuration, extending over an area inscribed in a circle perpendicular to the longitudinal axis (X) of diameter (D3d) where D3d ≧ D1, forming a surface impermeable to molten metal and slag and covering the entire area of ​​the shoulder portion (1s).

2. The protective part (3) is an inner tube (3i) that is deformable when a compressive force is applied to it along said longitudinal axis (X) and that forms an inner passageway of diameter (D3i), where D3i ≧ d1, extending along said longitudinal axis (X), said inner tube (3i) comprising a plurality of internal slits (3si) separated from one another and arranged around the circumference of said inner tube (3i); an outer tube (3o) which is deformable when a compressive force is applied to it along said longitudinal axis (X) and which just surrounds said inner tube (3i), said outer tube (3o) comprising a number of external slits (3so) separated from one another and arranged around the circumference of said outer tube (3o); Optionally, one or more peripheral tubes that are deformable when a compressive force is applied thereto along said longitudinal axis (X), inserted into one another and just surrounding said outer tube (3o), each of said one or more peripheral tubes being separated from one another and each of said one or more peripheral tubes being provided with a plurality of peripheral slits arranged around the circumference of each of said one or more peripheral tubes, said peripheral slits of two adjacent peripheral tubes not overlapping each other at any point, and said outer slits (3so) not overlapping at any point with said peripheral slits of the peripheral tube adjacent to the outer tube, 2. The lance of claim 1, wherein the inner slit (3si) and the outer slit (3so) do not overlap each other at any point.

3. 3. The lance according to claim 2, wherein said internal slit (3si) and said external slit (3so) extend parallel to said longitudinal axis (X).

4. 3. The lance according to claim 2, wherein said internal slit (3si) and said external slit (3so) are oblique but not perpendicular in extension to said longitudinal axis (X).

5. A lance according to any one of claims 2 to 4, wherein the inner tube (3i) and the outer tube (3o) can be made of an elastomeric material, or of a plastically deformable metal, or are in the form of a woven or non-woven fabric made of ceramic, polymeric or metallic fibres.

6. A lance according to any one of claims 2 to 5, wherein the inner tube (3i) and / or the outer tube (3o) are provided with folds (3f) in order to control the deformation of the protective part (3) for folding in a reproducible manner.

7. A lance according to any one of claims 2 to 6, wherein the inner tube (3i) and the outer tube (3o) have different heights, measured along the longitudinal axis (X).

8. 2. The lance according to claim 1, wherein the protective part (3) comprises a tubular part which is deformable when a compressive force is applied to it along the longitudinal axis (X), the tubular part extending along the longitudinal axis (X) and defining an inner passage of a diameter (D3i), where D3i≧d1, the tubular part comprising a plurality of slits (3s) separated from one another and arranged around the circumference of the tubular part.

9. The slits (3s) are arranged in two sets as follows: an upper set extending from adjacent the joining end (2c) to adjacent half the height of the tubular component measured along the longitudinal axis (X); a lower set extending from a position adjacent to the fixed end opposite said connecting end (2c) to a position adjacent to half the height of the tubular part, 9. A lance as claimed in claim 8, wherein the slits (3s) of the upper set are offset relative to the slits (3s) of the lower set.

10. The protective part (3) is Cylindrical or - comprising multiple cylindrical sections, or A lance according to any one of claims 2 to 9, comprising one or more cylindrical portions and one or more tapered or curved portions arranged along said longitudinal axis (X).

11. The protective part (3) is a support ring (3r) coupled to the proximal end of the elongated tube (2t); a plurality of L-shaped plates (3p), each of which includes an outer portion (3po) joined to an inner portion (3pi) at a corner of the L, the L-shaped plates being rotatably mounted and arranged around the periphery of the support ring by hinges (3h) at or adjacent to the corners of the L-shaped plates; o in an initial configuration of the protective part (3), each L-shaped plate is biased to rotate so that its inner portion (3pi) extends radially inwards substantially perpendicular to the longitudinal axis (X) and at least partially blocks the cavity (2v) and its outer portion (3po) rests against an outer surface of the sublance (2); o The lance according to claim 1, wherein the L-shaped plates are configured to pivot about the hinges (3h) from the initial configuration to the deformed configuration upon insertion of the coupling part (1c) into the cavity (2v) in order to couple the sub-lance (2) to the top lance (1t), in which the inner parts (3pi) are aligned parallel to the longitudinal axis (X) and the outer parts (3po) extend radially, substantially perpendicular to the longitudinal axis (X) and overlap each other to form a continuous screen against splash when the protective part (3) contacts the shoulder (1s).

12. 12. A lance according to claim 11, wherein each outer portion (3po) has a free edge, measured orthogonally to the longitudinal axis (X), which is greater than the corners, and each outer portion (3po) is curved with a curvature which corresponds to the outer diameter (D2) of the connecting end (2c) so that, when the protective part (3) is in its initial configuration, each outer portion (3po) contacts the outer surface of the sublance (2).

13. 13. The lance according to claim 11 or 12, wherein each inner portion (3pi) has a free edge which, when measured orthogonally to the longitudinal axis (X), is shorter than the corners and wherein, when the coupling part (1c) is inserted into the cavity (2v) and the L-shaped plates (3) are pivoted on their hinges (3h), the inner portions (3pi) are pressed against the wall of the cavity (2v) and form an inner passage of diameter (D3i), where D3i≧d1, thereby allowing the insertion of the coupling part (1c).

14. A lance according to any one of claims 11 to 13, wherein the L-shaped plate (3) is sufficiently rigid so as not to deform substantially during normal use of the protection component.

15. A sublance (2) for coupling to the coupling part (1c) of the lance (1t) according to any one of claims 1 to 14, the sublance (2) being formed by an elongated tube (2t) extending along the longitudinal axis (X) and comprising a cavity (2v) adapted to just receive the coupling part (1c), the cavity being substantially cylindrical with a diameter (d2) where d1≦d2, and extending along the longitudinal axis (X) from an immersed end provided with a probe (2p) and / or a sampler to a proximal end coupled to a protective part (3) comprising a coupling end (2c) opening into the cavity (2v), the elongated tube (2t) has a cross section with an outer diameter (D2) such that d1<d2<D2<D1, said protective part (3) is deformable when a force is applied to it along said longitudinal axis (X); The coupling portion (1c) is inserted into the cavity (2v) of the sublance (2), and at that time, the protective part (3) contacts the shoulder portion (1s), said protective part (3) is in an initial configuration characterized by a maximum outer diameter (D3o) when at rest, D3o being at most 10% greater than D2 (D3o≦1.1 D2); - When the sublance (2) is coupled to the lance by insertion into the cavity (2v) of the coupling part (1c), the protective part (3) contacts the shoulder (1s), is deformed into a deformed configuration and forms a surface impermeable to molten metal and slag extending over an area inscribed in a circle of diameter (D3d), where D3d ≧ D1, covers the entire area of ​​the shoulder (1s) and extends perpendicular to the longitudinal axis (X) over a distance from the longitudinal axis (X) at least equal to 1 / 2D1.

16. The sublance (2) according to claim 15, wherein the protective part (3) is defined in any one of claims 2 to 7, claims 8 to 10, or claims 11 to 14.

17. A protective part (3) for protecting a front shoulder (1s) formed between the distal end of a front gripping part (1h) and the sublance (2) of the lance according to claim 1 against splashes, said protective part (3) comprising: an inner tube (3i) that is deformable when a compressive force is applied to it along said longitudinal axis (X) and that forms an inner passageway of diameter (D3i), D3i≧d1, extending along said longitudinal axis (X), the inner layer (3i) comprising a plurality of internal slits (3si) separated from one another and arranged around the circumference of said inner tube (3i); an outer tube (3o) which is deformable when a compressive force is applied to it along said longitudinal axis (X) and which just surrounds said inner tube (3i), said outer tube (3o) comprising a number of external slits (3so) separated from one another and arranged around the circumference of said outer tube (3o); optionally, one or more peripheral tubes, deformable when a force is applied thereto along said longitudinal axis (X), inserted into one another and just surrounding said outer tube (3o), each of said one or more peripheral tubes being separated from one another and each of said one or more peripheral tubes being provided with a plurality of peripheral slits arranged around the circumference of each of said one or more peripheral tubes, said peripheral slits of two adjacent peripheral tubes not overlapping each other at any point, and a front outer slit (3so) not overlapping at any point with said peripheral slit of the peripheral tube adjacent to the outer tube, The inner slit (3si) and the outer slit (3so) do not overlap each other at any point.

18. The protective component according to claim 17, as defined in any one of claims 2 to 7 and claim 10.

Images