TW201330952A - Gas purging plug for metal casting vessel comprising anti-clogging system and method for the production thereof - Google Patents

Abstract

The present invention concerns a device (1), for example a gas purging plug, for blowing gas into a metallurgical vessel comprising (a) a body (2) extending along a central axis (X1) comprising, (b) at least one gas flow channel (3) fluidly connecting a gas inlet (3a) located at one end of said body to a gas outlet (3b), located at the opposite end along said axis, said channel (3) being in the shape of a slit defined by a first and second opposed surfaces. The device (1) according to the invention is characterized in that, c the at least one gas channel (3) comprises a series of continuous concave bridges (4) connecting the first and second opposing surfaces defining the channel, with their concave side (4a) oriented towards the gas outlet (3b), wherein said concave bridges (4) are disposed in a staggered arrangement, such that any first shortest line running from the gas outlet (3b) to the gas inlet (3a) of the channel necessarily intercepts the concave side (4a) of at least one first bridge (41). The device (1) according to the invention permits to prevent clogging of device by infiltrated molten metal or slag.

Description

Gas purification plug body for metal casting container containing anti-clogging system and manufacturing method thereof

The present invention relates to apparatus commonly used to blow a gas into a metallurgical vessel, such as a refractory plug body, a duct nozzle, a diffuser, a foaming stop or pad, or the like. This is particularly relevant in this regard to prevent the plug from being blocked by countercurrent infiltration of molten metal or slag. For the sake of simplicity, the description will be made with respect to the purification plug body, but it should be clearly understood that the invention is not limited thereto.

In the metal forming process, the molten metal is transferred from a metallurgical vessel to another metallurgical vessel or mold. For example, a bucket is filled with molten metal from the furnace and transferred to a feed tank. This metal melt can then be cast from the feed tank into a mold for forming a large slab, a billet or a billet. Alternatively, the ingot can be poured directly from the bucket. In most cases, it is preferred to blow a gas into the molten metal contained in such a metallurgical vessel. This may help to accelerate the homogenization of the temperature and bath components to bring the non-metallic inclusions present in the large bath up to the slag top layer to create favorable conditions within the molten metal, and the like. The gas is typically blown into the molten metal by a plurality of purge plugs disposed at the bottom or sides of a metallurgical vessel such as a bucket or feed tank.

The plug system is shaped into a refractory block that generally extends along a longitudinal axis. At one end of the block, a gas inlet connected to a source of pressurized gas is fluidly coupled to a gas outlet at the opposite end of the block. The gas inlet and the gas outlet can be opened The mesh of the holes is interconnected by one or more channels (e.g., in the shape of a slit or having a circular cross section), or a combination of the two. An open mesh is sometimes said to produce "indirect permeability", while a channel is said to produce "direct permeability." It is generally accepted that indirect osmotic plug systems are more efficient than direct osmosis plugs, both in terms of open cell ratio and agitation (due to bubble size and effective area). One disadvantage of the porous plug body (indirect) is that the material is generally poor (smaller heat and cold crush strength and faster corrosion at higher flow rates).

As shown in Figure 5, a purge plug (1) is typically embedded in the wall and liner of a metallurgical vessel such that the gas inlet faces the outside of the metallurgical vessel and the gas outlet faces the vessel The inner side in contact with the molten metal. The "gas inlet" and "gas outlet" are defined relative to the flow direction (11) of the gas injected into the metallurgical vessel. A major problem associated with gas purge plugs is that if the pressure drops when the flow is stopped, the molten metal may seep into the passages and/or pores of the plug body by gravity through the gas outlet. This not only increases security concerns but also creates operational problems. More specifically, when the molten metal in the channels or the pores freezes, the plug body is at least partially blocked. The blocked plug can only be unblocked by blowing high pressure gas into the channels or pores or by passing oxygen through the upper surface of the plug when the metallurgical vessel is empty, but these techniques are time consuming. Not always suitable, thus causing severe corrosion of the refractory material and not always successfully opening the plug body. In order to reduce the risk of infiltration, the diameter or width of a channel is usually limited to no more than 1 mm so that the capillary can be used to provide effective control of penetration. However, this measure is not conducive to the efficacy of purifying the plug body because it The flow rate of gas through this plug is strongly limited.

The present invention provides a method for extending the service life of a purge plug, even after the passages have been partially penetrated by the molten metal. The invention can also be operated in conjunction with a channel having a diameter that is close to or even greater than 1 mm, since partial penetration does not compromise the use of the purge plug.

The invention is defined by the scope of the appended claims. The individual items define a number of preferred embodiments. In particular, the invention relates to a gas purification plug for blowing a gas into a metallurgical vessel, as defined in claim 1 of the scope of the patent application.

A "shortest line extending from the gas outlet of the passage to the gas inlet" generally corresponds to the molten metal in the theoretical direction of the flow, provided that the molten metal penetrates into a slit-shaped passage, especially by gravity. In a preferred embodiment, any second shortest line extending from either side of the first bridge that is intercepted by the first shortest line to the gas inlet of the passage will necessarily intercept at least one The concave side of the second bridge body. Preferably, the same case is for a third shortest line that intercepts the concave side of at least one third bridge body, and so on, any of which is intercepted by a shortest line of (i-1) (i-1) The i-th shortest line extending from either side of the bridge body to the gas inlet of the passage must be intercepted to the concave side of at least one i-th bridge body until there is no between the Nth bridge body and the gas inlet Any bridge body. The value of N is preferably at least equal to 3, more preferably at least equal to 5, and most preferably at least equal to 10.

Many different configurations of one or more slit-like channels are possible. In a first embodiment, at least one channel surrounds the longitudinal axis (X1), thus A core portion is defined that is separated from a surrounding layer by a slit forming the channel. In a second embodiment, at least one of the slits extends substantially along a plane. This plane preferably extends radially from the longitudinal axis (X1) of the purification plug body. In still another preferred embodiment, a plurality of slits (connected or phase separated) extend along a plurality of planes, and the planes are included and radially distributed adjacent the longitudinal axis (X1) of the purification plug body . The phrase "extending substantially along a plane" is intended to include embodiments in which the slit channel is undulated relative to a plane.

The concave bridges are formed as a plurality of containers adapted to receive and retain metal, and the flow front of the metal intercepts the containers. The bridges can have many different geometries. Particularly preferably, the concave bridge bodies have one of the following geometric shapes: U-shaped, V-shaped, preferably circular or elliptical curved, open rectangular or square box, a parabola, and the like. The shape. The shape of the slit and thus the thickness of the concave bridge body preferably does not exceed 2.0 mm, more preferably does not exceed 1.5 mm, more preferably does not exceed 1.0 mm, and optimally does not exceed 0.5 mm, depending on The viscosity of the molten metal used and the fluid tension. In summary, excellent results can be obtained using slit-shaped channels having a thickness between 0.25 mm and 0.5 mm.

The body of the purge plug of the present invention can be made entirely of dense refractory material, thereby collectively defining a direct permeable system in conjunction with at least one slit-like passage. In an alternative embodiment, at least a portion of the purge plug (eg, the wrap layer) is formed from a porous refractory material, thereby collectively defining a hybrid direct and indirect together with the slit-like passage(s) Permeable system. For example, the plug body may include a large amount of difficult fire material The core portion is formed by an annular slit-shaped passage from a surrounding porous refractory layer.

The invention also relates to a metallurgical vessel comprising a purge plug body as described above, wherein the gas outlet is in fluid communication with the interior of the vessel; and a method for making such a purge plug body. The method for manufacturing a purge plug as described above comprises the steps of: (a) providing a tool having a chamber defining a volume of the elongated body extending the cleaning plug body along a central longitudinal axis (X1); (b) at least one foil is placed at a position corresponding to the desired position of the channel slit in one of the tools, which may be removed during the heating step (d) of the method; the foil is on its surface Having a plurality of apertures and defining a continuous path between the apertures from a first end thereof corresponding to the passage gas inlet to a second opposite end thereof corresponding to the gas outlet; (c) having The foil tool casts a castable component; (d) heats a purge plug at a temperature sufficient to harden the refractory material and eliminate the foil. The method according to the invention is characterized in that the holes have a concave geometry such that their concave sides are positioned towards a first foil portion corresponding to the gas outlet of the passage and are configured in a staggered configuration. The shortest line at any of the opposing second foil portions extending from the first foil portion to a channel gas inlet of the passage necessarily intercepts the concave side of at least one of the holes.

In a preferred embodiment, a portion of the tool becomes part of the purge plug body as a metal casting covering the surrounding surface of the refractory material. More than one such foil is required to make a clean plug, depending on The desired geometry of the slits. The foil(s) may be removed by melting, incineration, or sublimation during the heating step (d). The heating step (d) may comprise a step of drying the plug body. For example, the drying step can include: a step of gradually increasing the temperature; a step of stopping the station (for example, at a temperature between 300 ° C and 650 ° C for 3 to 10 hours) so that the free removal can be substantially removed from the refractory material. Water, and burn off a plastic foil; and a step of cooling down. Alternatively, the heating step (d) may comprise a simultaneous fire step. For example, the igniting step may include: a step of gradually increasing the temperature; and a step of stopping the station (for example, at a temperature between 1200 ° C and 1700 ° C for 3 to 10 hours) so that a ceramic bond can be formed in the refractory material. And burn off a plastic foil; and a step of cooling down.

In another embodiment of the method, an outer layer defining an interior space may be formed first. A foil is then inserted into the interior space of the outer layer in step (b), and a core is then cast in step (c) into the remainder of the interior space defined by the foil. A foil may be wrapped around the core in step (b), and an outer layer is then cast in step (c) between the chamber and the foil wrapped around the core. In the volume. By virtue of this technique, a purified plug body can be produced which includes a core having a porosity different from that of the sheath, and the core is separated from the sheath by an annular slit.

As can be seen in Figure 1, a purification plug body (1) according to the invention comprises a body extending along a longitudinal axis (X1) to a gas inlet at a first end of one of the bodies (3a) between a gas outlet (3b) at one end opposite one of the bodies; along the longitudinal axis The line, gas inlet (3a) is in fluid communication with the gas outlet (3b) via at least one slit in the shape of a channel (3). The slit-shaped passage is defined by the first passage surface and the opposite second passage surface, and the distance between the two surfaces defines the opening width W of the passage slit (3). The opening length L of this passage is a distance which, when integrated with the opening width W, produces a slit region perpendicular to the longitudinal axis (X1) (see Figure 4c). In the case of the annular slit as shown in Fig. 1, the opening length L of the slit is the circumference of the annular slit. In the case of a planar slit as shown in Fig. 4c, the opening length L of the slit is its length. A slit-shaped passage is defined as a passage having an opening width W which is much smaller than the opening length L of the passage. Specifically, one channel is regarded as a slit shape, and if the length to width ratio is L/W ≧ 3, preferably L/W ≧ 5, more preferably L/W ≧ 10 and even L/W ≧ 50 . The geometry and configuration of the channel slits in the body of the purge plug is not critical to the invention, as long as it is a channel shape.

The present invention must not completely prevent the molten metal from inadvertently penetrating into the channels, but it can strongly limit the depth of such penetration; in particular, it allows the plug to operate despite partial depth. This is accomplished by the use of a series of continuous concave bridges (4) that define a first surface and a second opposing surface defining the passage such that its concave side (4a) can face the gas outlet (3b). Each concave bridge can thus act as a small retaining groove that can replenish and retain a certain amount of molten metal that has penetrated into the passage. The concave bridges (4) are spaced apart from each other and arranged in a staggered configuration such that either of the passages extends from the gas outlet (3b) to the first shortest line of the gas inlet (3a) The strip will necessarily intercept the concave side (4a) of at least one of the first bridge bodies (41). One of the channels "the shortest line extending from the gas outlet to the gas inlet" will follow the direction of flow of the molten metal, provided that the molten metal driven by gravity penetrates into a slit-like passage that does not have a concave bridge. Since the shortest line will inevitably intercept at least one first bridge body (41), the flow of molten metal (10) will be blocked by the at least one bridge body until the container formed by the concave side of at least one of the bridge bodies is filled Full of metal. The concave bridges are separated from each other to provide a continuous gas path whereby pressurized gas can flow from the gas inlet (3a) to the gas outlet (3b). The gap between any two adjacent bridges may be filled with a bridge located downstream of the two bridges, wherein the term "downstream" is used herein to refer to the direction of flow of the molten metal (which is opposite to the gas) The direction of flow) is defined.

The entire set of concave bridges that are so staggered such that any shortest line extending from the gas outlet (3b) to the gas inlet (3a) can indeed intercept a concave bridge will define a "complement level", N = 1. Theoretically, and depending on the amount of liquid metal that each concave bridge can contain, a purge plug comprising a complement level N = 1 will be sufficient to at least partially retain the metal flow. In practice, it is preferred to increase the number of complement levels to a higher value in order to reduce the risk of leakage. The total number of complement levels extended from the gas outlet (3b) to the gas inlet (3a) defines "replenishment N". Once at least one of the bridges (41) intercepting the flow of molten metal is filled with metal, the molten metal will overflow over either side of the bridge and further follow the shortest route to the gas inlet (3a). As discussed above, a purge plug having a degree of complementation of 1 (N = 1) may be sufficient to completely block the flow of molten metal in order to control the extent of penetration in the case of a small flow of molten metal, but in the event of a conduction In the event of a large infiltration of the bridge body (41) overflow, there will be no additional retaining means to slow and stop this flow from downstream of the bridge. For this reason, the purification plug body of the present invention preferably includes a degree of complementation (N≧1) greater than 1, preferably at least 2 (N≧2), preferably at least 3 (N≧3), more Preferably at least 5 (N≧5), optimally at least 10 (N≧10).

As shown in Fig. 3, a degree of complementation N greater than one may be obtained in a staggered configuration in which any gas extending from either side of the first bridge (41) intercepted by the first shortest line to the channel The second shortest line of the entrance (3a) necessarily intercepts the concave side (4a) of at least one second bridge (42) and so on, any of which is intercepted by a shortest line of (i-1) I-1) The i-th shortest line extending from either side of the bridge body (4(i-1)) to the gas inlet (3a) of the channel necessarily intercepts the concave side of at least one i-th bridge body (4i) (4a) until there is no bridge between the Nth bridge and the gas inlet (3a).

The concave bridge body can have a variety of shapes, sizes, and distributions as long as: (a) the bridge body is adapted to retain a given amount of molten metal in its recess and thereby form a full width across the slit and across a full-length impermeable wall between the ends thereof, (b) the staggered arrangement of the bridges does not allow a shortest free-flowing line to extend from the gas outlet (3b) to the gas inlet (3a), and (c) The distribution of the bridge body defines a gas flow path from the gas inlet (3a) to the gas outlet (3b) and produces an acceptable pressure drop.

Figure 2 shows a possible embodiment of a plurality of geometric shapes suitable for use with the concave bridge of the present invention. For example, the bridge body can be a U-shape, a V-shape, a curved shape, preferably a circle or an ellipse, an open rectangular or square box, A shape such as a parabola. This geometry is not necessarily "rule" as long as it includes a concave side (4a) that defines a retaining groove. An identical purification plug body may include a plurality of bridge bodies having different geometries and/or sizes and distributed over the slit passages thereof, and the distribution thereof may also be in the slit of the same plug body. Or change between the two slits.

The slit channels (3) can have a plurality of geometric shapes. For example, Figure 4 shows an embodiment of a plurality of purge plugs comprising a plurality of slits that are differently disposed in a plane perpendicular to the longitudinal axis (X1). Figures 4(a) and (b) show two embodiments in which one and two channels individually surround the longitudinal axis (X1), thus defining a slit to form the channel (3) with a surrounding layer (2b) ) separated by the heart (2a). More than two surround channels can be used, and obviously they need not be circular as shown in Figures 4(a) and (b), but can have any shape, curve or polygon shape, which forms A closed loop is not a star designer as shown in Figure 4(e). Figures 4(c) and (d) show two embodiments in which the slit does not form a closed loop. In the illustrated embodiments, the slits are linear and are configured to extend radially from the center of the cross-section (see Figure 4(c)) or extend parallel to each other (see paragraph 4(d) Figure). Further, when the linear slits are displayed in the fourth (c) and (d) drawings, it is apparent that they may be curved and/or sawtooth shapes as shown in Fig. 4(e).

The slit channels extend from the gas inlet (3a) along the longitudinal axis (X1) to the gas outlet (3b) at the opposite ends. The channels may extend substantially parallel or non-parallel to the longitudinal axis (X1). In the embodiment shown in Figure 1, the channel (3) is not parallel to the longitudinal axis and follows the direction of the busbar of a cone which shares a phase with the outer body of the purification plug body The same vertex. In the case where the channel configuration is as shown in Figures 4(c) and (d), it is not mandatory but it is more suitable to extend the channel parallel to the longitudinal axis (X1). The passage may extend linearly between the gas inlet and outlet or may be curved. The latter embodiment can be expected or can be the result of a job under poor control wherein the foil (23) used to form the channel (3) will deform or wrinkle during operation.

The opening width W of a slit channel (3) can vary in the longitudinal direction and along the length L of the opening, but a simpler fabrication is a slit channel (3) having a constant width W, which will be hereinafter Know. By virtue of the geometry proposed in the present invention, the slit channel can have a greater degree of safety than would normally be considered as a safety shield for eliminating the risk of severe damage to the plug body due to molten metal infiltration. Width W. In particular, slit channels having a width of up to 2 mm can operate in conjunction with the present invention. However, the width of the passage is preferably no greater than 1.5 mm, more preferably no greater than 1.0 mm, and most preferably no greater than 0.5 mm.

The refractory material used to make the body of the purge plug is preferably at least partially made of a material that has a relatively low permeability to the gas. A refractory material is considered to have a relatively low permeability to gases if its permeability is less than 4 μm ² (equivalent to 40 nPm). If the system for purifying the plug body is made entirely of a refractory material having a relatively low permeability to the gas, the purge plug body defines a "direct permeability" system as previously defined. A mixed "direct/indirect permeability" system can be obtained by using a refractory material having a gas permeability higher than that of the bulk portion of 4 μm ² . For example, in the core/sheath geometry shown in Figures 1 and 4(a) and (b), the core may be made of a refractory material having a first permeability and surrounding the sheath. It is made of a refractory material having a second permeability which is higher or lower than the permeability of the core. For example, refractory materials such as alumina, aluminum carbon or spinel, and the like can be used (if available, for materials that are permeable and non-permeable (or have a relatively low gas permeability)).

Although the purge plug shown in the figures is frustoconical, the invention is of course not limited to such a geometry, which may vary depending on the design of the metallurgical line. The peripheral surface of the core portion made of refractory material as described above is often covered with a metal casing to mechanically strengthen the structure. In some embodiments, the metal housing can be used as part of a mold cast from a refractory material during the manufacture of the purge plug. In an alternative embodiment, the metal casing is joined to a fully fabricated refractory body via an adhesive or cement.

A cleaning plug body according to the invention can be produced very simply by a method comprising the steps of: (a) providing a tool (21), the chamber (22) defining a cleaning plug body along a The volume of the elongate body (2) extending along the central longitudinal axis (X1). In a preferred embodiment, a portion of the tool is formed from a metal housing that can be used to mechanically reinforce the structure, which will be part of the final purified plug body; (b) as in item 6 (a) As shown in the figure, at least one foil (23) is placed at a position corresponding to the desired position of the channel slit (3), which is removable during the heating step (d) of the method. The foil has a plurality of holes (24) on its surface and defines a first end (23a) from the holes corresponding to the channel gas inlet (3a) a continuous path to the second opposite end portion (23b) corresponding to the gas outlet (3b); the foil may be made of paper, cardboard, wax or a polymer material such as PVC, PE or PP, and Sufficiently rigid to avoid bending, wrinkling or wavy itself during operation; (c) casting a castable component (25) in the tool having the foil (see Figure 6(b)); d) heating a clean plug body at a temperature sufficient to harden the refractory material and eliminate the foil (see Figure 6(c)); typically a temperature greater than 300 ° C is required to harden the refractory material; for example, one between 400 ° C and 650 The temperature between ° C, preferably between 450 ° C and 550 ° C, is generally sufficient to harden most of the refractory material and is sufficient to burn or at least melt the foil, and the elimination of the foil will produce a staggered concave shape comprising the above A slit-like passage of the bridge body.

The method of the invention is characterized in that the holes (24) have a concave geometry such that their concave sides (24a) are positioned towards a second foil portion (23b) corresponding to the passage gas outlet (3b) And configured to be staggered so that any shortest line extending from the second foil portion (23b) to a opposing first foil portion (23a) corresponding to the channel gas inlet (3a) is bound to The concave side (24a) of at least one hole (24) is intercepted.

The thickness of the foil (24) defines a width W of the slit channel formed when the foil is removed. When the castable refractory (25) fills the holes and thus joins the refractory material on either side of the foil (23), the holes (24) in the foil (23) are available to form across Concave bridges (4) of the width W of the slit channels. After the foil is removed, a plurality of bridges (4) made of refractory material are immediately formed, which have the same holes as the foils. Profile, and has the same width W as this foil.

As shown in Fig. 7, in another embodiment, a core portion (2a) is formed before step (b) (refer to Fig. 7(b)), and the foil (23) is wrapped around it (refer to Figures 7(c) and (d)). In step (c), an outer layer is then cast into a volume defined between the chamber (21) and the foil (23) wrapped around the core (2a) (see Figure 7(e) ). After heating, the purge plug can be removed from the tool. This embodiment is suitable for use in the manufacture of a hybrid "direct/indirect permeability" plug body in which the refractory material forming the core and surrounding the body sheath has a different composition and/or porosity.

The purge plug (1) is particularly suitable for injecting gas into a bucket, a feed tank, and other similar metallurgical vessels. This plug body can be placed at the bottom floor of the metallurgical vessel as shown in Figure 5, where it is most sensitive to the infiltration of molten metal. Fortunately, an array of a plurality of retaining concave bridges (4) forming a barrier to the depth of the gas passage (3) allows the service life of the purge plug to be substantially compared with the existing purge plug body. The land has increased. In addition, wider channels will be safer to use than conventional ones, as less penetration of molten metal will not result in a substantial drop in plug performance compared to conventional purge plugs. Indeed, in hardening, in addition to controlling the infiltrated area and depth to a limited number of metal-filled bridges, although the metal still fills the concave side of some of the bridges, the metal that connects the bridge to the next downstream bridge The tabs are often broken, so that the gas can even flow between the two metal-filled bridges.

1‧‧‧ Purified plug body

2‧‧‧ Ontology

2a‧‧‧heart

2b‧‧‧ wrapping layer

3‧‧‧ channel

3a‧‧‧ gas inlet

3b‧‧‧ gas export

4‧‧‧ Bridge body

4a‧‧‧ concave side

10‧‧‧ molten metal

11‧‧‧ Gas direction

21‧‧‧ Tools

22‧‧‧ chamber

23‧‧‧Foil

23a‧‧‧First end

23a‧‧‧First foil section

23b‧‧‧second end

23b‧‧‧Second foil section

24‧‧‧ hole

24a‧‧‧ concave side

41‧‧‧First Bridge

L‧‧‧ length

W‧‧‧Width

X1‧‧‧ longitudinal axis

Various embodiments of the invention are shown in the following In the drawings: Figure 1 shows a perspective view of a cleaning plug body according to the invention having a partially cut-away area for displaying concave bridges; Figure 2 shows a plurality of concave shapes according to the invention. Various embodiments of the geometry of the bridge; Figure 3 shows a bridge array implemented in accordance with the present invention showing a flow path of molten metal and a plurality of gas inlets connected to the gas outlet or to an nth bridge The shortest line in the body; Figure 4 shows a variety of cross sections perpendicular to the longitudinal axis (X1) showing different slit channel shapes; Figure 5 shows a cleaning plug mounted on the bottom floor of a metallurgical vessel body.

Figure 6 is a schematic illustration of a plurality of different steps for fabricating a first embodiment of a purge plug body implemented in accordance with the present invention; and Figure 7 is a schematic representation of a purge plug body for use in the manufacture of a purification plug body according to the present invention. A number of different steps of the second embodiment.

The invention is not limited to the embodiments shown in the figures. Therefore, it is to be understood that the features of the appended claims are to be Used to limit the scope of patent applications.

1‧‧‧ Purified plug body

2‧‧‧ Ontology

2a‧‧‧heart

2b‧‧‧ wrapping layer

3‧‧‧ channel

3a‧‧‧ gas inlet

3b‧‧‧ gas export

4‧‧‧ Bridge body

11‧‧‧ Gas direction

W‧‧‧Width

X1‧‧‧ longitudinal axis

Claims (15)

A device (1) for blowing a gas into a metallurgical vessel, comprising: (a) a body (2) extending along a central axis (X1) comprising: (b) at least one gas flow channel ( 3) which is in fluid communication with a gas inlet (3a) at one end of the body and a gas outlet (3b) at an opposite end along the axis, the channel (3) being a slit shape defined by the first and second opposing surfaces, characterized in that: (c) the at least one gas flow channel (3) comprises a series of continuous concave bridge bodies (4) connected to define the channel First and second opposing surfaces, the concave bridges (4) having concave sides (4a) positioned toward the gas outlet (3b), wherein the concave bridges (4) are arranged in a staggered manner Arranged such that any first shortest line extending from the gas outlet (3b) of the passage to the gas inlet (3a) necessarily intercepts the concave side (4a) of at least one first bridge (41). The device (1) of claim 1, wherein the device is a gas purification plug body and wherein the body (2) is elongated and the shaft (X1) is a longitudinal axis. A gas purifying plug body according to claim 2, wherein any one of the first bridge body (41) intercepted by the first shortest line extends to the gas inlet (3a) of the passage The second shortest line necessarily intercepts the concave side (4a) of at least one second bridge (42) and so on, any of which is intercepted by an (i-1) shortest line (i-1) The i-th shortest line extending from either side of the bridge body (4(i-1)) to the gas inlet (3a) of the passage necessarily intercepts at least one i-th The concave side (4a) of the bridge body (4i) until there is no bridge body between the Nth bridge body (4N) and the gas inlet (3a). A gas purifying apparatus according to claim 3, wherein N is at least equal to 3, preferably N is at least equal to 5, and more preferably N is at least equal to 10. A gas purifying device according to any one of claims 2 to 4, wherein the at least one passage (3) surrounds the longitudinal axis (X1), thereby defining a core portion (2a) by forming the passage The slit of (3) is spaced apart from a surrounding layer (2b). The gas purifying device of claim 3 or 4, wherein the at least one passage (3) is substantially planar, and preferably radially from and along a body including the plug body (1) The plane of the longitudinal axis (X1) extends. A gas purifying device according to any one of claims 2 to 6, wherein the concave bridge (4) has one of the following geometric shapes: U-shaped, V-shaped, preferably circular or elliptical A rectangular or square box with a curved open shape and a parabola. The gas purifying device of any one of claims 2 to 7, wherein a distance between the first surface defining the slit channel (3) and the second surface is separated by no more than 2.0 mm, It preferably does not exceed 1.5 mm, more preferably does not exceed 1.0 mm, and most preferably does not exceed 0.5 mm. A gas purifying apparatus according to any one of claims 2 to 8, wherein the system is at least partially made of a pair of refractories having a gas having a relatively low permeability. One includes as described in any one of claims 2 to 9 of the patent application. The metallurgical vessel (31) of the gas purification plug body, wherein the gas outlet (3b) is in fluid communication with the interior of the vessel. A method for producing a gas purifying plug for blowing a gas into a metallurgical vessel according to any one of claims 2 to 9, which comprises the steps of: (a) providing a tool ( 21), the chamber (22) defining the volume of the elongated body (2) extending along the central longitudinal axis (X1) of the purification plug body; (b) one of the tools and the channel slit (3) Providing at least one foil (23) at a position corresponding to the desired position, which is removable during the heating step (d) of the method; the foil having a plurality of holes (24) on its surface And defining a continuous flow between the holes from a first end portion (23a) corresponding to the channel gas inlet (3a) to a second opposite end portion (23b) corresponding to the gas outlet (3b) a path; (c) casting a refractory material (25) in the tool equipped with the foil; (d) heating a purification plug body at a temperature sufficient to harden the refractory material and eliminate the foil; The holes (24) have a concave geometry with their concave sides (24a) oriented toward a second foil portion (23b) corresponding to the passage gas outlet (3b), Arranged in a staggered arrangement such that any shortest line extending from the second foil portion (23b) to an opposing first foil portion (23a) corresponding to the gas inlet (3a) of the passage is necessarily intercepted To the concave side (24a) of at least one hole (24). The method of claim 11, wherein before the step (b) is performed, an outer layer (2b) defining an inner space is first formed, the foil The sheet is then inserted in step (b) along the walls defining the interior space of the outer layer (2b), and a core is then cast in step (c) to the interior defined by the foil (23) In the rest of the space. The method of claim 12, wherein before the step (b) is performed, a core portion (2a) is first formed, and the foil (23) is wrapped around the core portion in the step (b), an outer layer It is then cast in step (c) in a volume defined between the chamber (21) and the foil (23) wrapped around the core (2a). The method of any one of claims 11 to 13, wherein a plurality of foils (23) are disposed in the tool. The method of any one of claims 11 to 14, wherein the foil is removed by melting, incineration or sublimation during the heating step (d).