Refractory gas purge plug and method for controlling conduction of gas to refractory gas purge plug

Abstract

The invention relates to a refractory gas purge plug and to a method for controlling the conduction of gas to a refractory gas purge plug.

Description

Technical Field

[0001] The present invention relates to a refractory gas purge plug and a method for controlling the conduction of gas to a refractory gas purge plug. Background Art

[0002] Gas purge plugs are used for metallurgical treatment of molten metal. They are arranged in the bottom region of a metallurgical vessel, for example in a ladle for secondary metallurgical treatment of molten steel. The refractory gas purge plug comprises a body of refractory ceramic material through which gas can pass. The body extends from a first end of the body to an opposite second end of the body. Gas can be introduced into the body at the first end. The gas introduced into the body flows through the body and leaves the body at the opposite second end of the body. When the gas purge plug is arranged in the bottom region of the metallurgical vessel, the first end is regularly arranged at the bottom and the second end is regularly arranged at the top. The second end is in direct contact with the molten metal in the metallurgical vessel.

[0003] Gas can thus be introduced into the molten metal through the gas purge plug, thereby creating a flow in the molten metal that circulates the molten metal. This flow can remove harmful gases from the molten metal, transport oxide inclusions to the slag, and homogenize the composition and temperature in the molten metal.

[0004] Various techniques are known to allow gas to pass through the body of refractory ceramic material in such gas purge plugs. According to one technique, the body comprises a porous, permeable refractory ceramic material through which the gas can pass. Because this natural gas permeability is generated by the random, disordered arrangement of the pore structure in the refractory ceramic material, the structure is also referred to as "random" porosity.

[0005] According to another technique, it is known to arrange gas channels of defined geometry in the body of a refractory ceramic material. These gas channels are usually produced by first arranging a combustible material in the refractory ceramic material and then burning out and thus removing the combustible material. The burned-out hollow area then forms a gas channel. For example, a ribbon or filament of a combustible material (such as plastic or cellulose) can be arranged in the ceramic material and then burned out. These gas channels with defined geometry are also referred to as "directional" porous structures.

[0006] For example, in EP 1 101 825 A1 a refractory ceramic gas purge plug is disclosed which has both such a non-oriented porous structure and such an oriented porous structure (ie in the form of slit-shaped gas channels).

[0007] The porous, permeable refractory ceramic material on the one hand (i.e., non-oriented porous structure) and the gas channels on the other hand (i.e., oriented porous structure) complement each other. Thus, depending on the flow rate of gas flowing through the gas purge plug, it may be desirable for a higher proportion of the gas to flow through only one of the two porous structures in each case.

[0008] In this regard, for example, a high flow of gas through a gas purge plug is desirable for homogenization of the molten metal, which can be best achieved through the gas channel. On the other hand, oxide inclusions and harmful gases in the molten metal are preferably removed by many small bubbles, and such bubbles are best achieved at a low flow of gas through a porous, permeable refractory ceramic material. In this regard, it is generally desirable that the gas preferentially passes through the porous, permeable refractory ceramic material at a low flow rate, and preferentially passes through the gas channel at a higher flow rate. In addition, the conduction of the gas through the gas channel at a higher flow rate may also be particularly desirable, because the porous, permeable refractory ceramic material may be damaged by a higher flow rate, particularly a high mass flow rate of the gas. In this sense, at a higher flow rate, it is preferably desirable to guide the gas through the gas channel. This conduction of the gas through the gas channel may also cause the porous, permeable refractory ceramic material to be cleared of the infiltrated molten metal again.

[0009] In order to be able to conduct the gas supplied to the refractory gas purge plug to both the porous refractory material and the gas passages, the prior art gas purge plugs typically have a gas distribution chamber or a porous insert to which the gas is first conducted. The gas supplied to the gas purge plug then flows from the gas distribution chamber or the porous insert into the porous, permeable refractory ceramic material or the gas passages.

[0010] According to the invention, it has been found that only with the aid of such gas distribution chambers or porous inserts, the gas cannot always be optimally conducted through the gas purge plug. In particular, with the gas purge plugs of the prior art it is not always possible to achieve a conduction of the gas through the gas purge plug that is suitable for the flow behavior of the gas. Summary of the invention

[0011] It is an object of the present invention to provide a refractory gas purge plug by means of which gas can be conducted through the gas purge plug in an improved manner compared to using gas purge plugs known from the prior art. In particular, it is an object of the present invention to provide a refractory gas purge plug by means of which gas can be conducted through the gas purge plug in a manner adapted to the flow behavior of the gas.

[0012] To achieve these objectives, according to the present invention, there is provided a refractory gas purge plug comprising the following features: A body of refractory ceramic material; the body extending from a first end of the body at which gas can be introduced into the body to a second end of the body opposite the first end of the body and at which gas can be exhausted from the body; The body includes a first portion made of a porous, permeable refractory ceramic material, the first portion extending from a first end of the body to a second end of the body; the body including a second portion made of a refractory ceramic material, the second portion extending from a first end of the body to a second end of the body, the second portion including a gas passage extending through the second portion from the first end of the body to the second end of the body; a gas supply device from which gas can be conducted to the first part and the second part; wherein The gas supply means comprises a control means by which conduction of gas from the gas supply means to the first part and the second part is controllable.

[0013] The invention is based on the finding that the gas can be better conducted through the refractory gas purge plug if the gas purge plug comprises a gas supply device, via which the gas can be conducted to the porous, permeable refractory ceramic material and the gas channels, and if these gas supply devices comprise control devices, by which the conduction of the gas via the gas supply device is controllable. This is because, with the aid of such control devices, it is in particular also possible to achieve a conduction of the gas through the gas purge plug that is adapted to the flow behavior of the gas. In particular, these control devices allow a targeted conduction of the gas to the porous, permeable refractory ceramic material or the gas channels, depending on the flow behavior of the gas. For example, these control devices allow, on the one hand, preferentially guiding the gas through the porous, permeable refractory ceramic material at a low flow rate, and on the other hand preferentially conducting the gas through the gas channels at a higher flow rate, depending on the flow behavior of the gas. In this way, depending on the flow behavior of the gas, it is possible in each case to achieve an optimal conduction of the gas through the gas purge plug.

[0014] The controllability of the conduction of the gas to the first portion (i.e. to the porous, permeable refractory ceramic material) or to the second portion (i.e. to the gas passage) also has the particular advantage that the amount of gas conducted to the first portion or the second portion can be defined or adjusted. In particular, this has the advantage that the amount of gas that can be directed to the first portion or the second portion is controllably adjustable to achieve a desired purging result of the gas purging plug.

[0015] The control device can be, for example, a valve by which the conduction of gas to the first part and / or the second part can be controlled. Preferably, the control device can be designed in the manner of a directional control valve. By designing the control device in the manner of such a directional control valve, the conduction of gas to the first part and to the second part can be controlled very simply and effectively. Advantageously, such a directional control valve can also be provided in a very robust and simple manner.

[0016] According to a preferred embodiment, the conduction of gas from the gas supply device to the first portion and the second portion is controllable by the control device depending on the flow behavior of the gas.

[0017] The advantage of such controllability of the conduction of the gas depending on the flow behavior of the gas is, in particular, that no additional or external control of the conduction of the gas is required. Instead, the conduction of the gas line can be self-regulated depending on the flow behavior of the gas. This has the particular advantage that in each case the proportion of gas conducted to the first part or to the second part can be determined depending on the flow behavior of the gas. In this embodiment, the flow behavior of the gas itself can control what proportion of the gas flows to the first part or to the second part. In this sense, the flow behavior of the gas can preferably be the flow behavior of the gas in the gas supply device, in particular in the area of ​​the control device.

[0018] Such controllability of the conduction of the gas by means of the flow behavior can be achieved very simply and effectively, for example again with the aid of a control device designed in the manner of a directional control valve, wherein the directional control valve can be actuated by gas (i.e. pneumatically) via a valve having an actuator (in particular a piston or a valve core) which can be moved into different switching positions of the valve depending on the flow behavior of the gas.

[0019] According to a particularly preferred embodiment, this flow behavior of the gas is the mass flow rate of the gas. In this embodiment, the conduction of the gas from the gas supply device to the first portion and to the second portion is therefore controllable by the control device depending on the mass flow rate of the gas. As is known, the mass flow rate is defined as the mass of a medium moving through a cross section per unit time. Therefore, in this case, the mass flow rate of the gas is the mass of gas moving through the cross section per unit time. The cross section can preferably be a defined cross section of the gas supply device, in particular in the region of the control device. According to the invention, it has been found that the conduction of the gas to the first portion and the second portion can be controlled particularly easily and effectively depending on the mass flow rate of the gas.

[0020] According to a preferred embodiment, it can be provided that the conduction of the gas is controllable by the control device, so that the gas can be conducted to the first part or the second part via the gas supply device. Therefore, the first part (i.e. the porous, permeable refractory ceramic material) and the second part (i.e. the gas duct) are not supplied with gas at the same time.

[0021] According to a particularly preferred embodiment, it can be provided that the conduction of gas from the gas supply device to the first part and the second part is controllable by the control device, so that the gas can be conducted to the first part but not to the second part or to the second part but not to the first part.

[0022] According to one embodiment, provision is made that the conduction of gas via the gas supply device to the first portion and the second portion is controllable by means of the control device depending on at least one range or value range of the mass flow rate of the gas, respectively. For example, the controllability may depend on whether the mass flow rate of the gas is within such range or value range of the mass flow rate of the gas or outside such range or value range. The value of the mass flow rate of the gas is preferably defined.

[0023] According to one embodiment, it is provided that conduction of gas from the gas supply device to the first part and the second part is controllable by the control device depending on the mass flow rate of the gas in such a way that, when the mass flow rate is within a first range, the gas can be conducted to the first part, and when the mass flow rate is within a second range, the gas can be conducted to the second part.

[0024] According to a further embodiment of the inventive concept, it may be provided that the first range is lower than the second range.

[0025] According to a further embodiment of the present invention, it may be provided that conduction of gas from the gas supply device to the first part and the second part is controllable by the control device depending on the mass flow rate of the gas in such a way that when the mass flow rate is within a first range, the gas can be conducted to the first part but not to the second part, and when the mass flow rate is within a second range, the gas can be conducted to the second part but not to the first part, wherein the first range is preferably lower than the second range.

[0026] By means of the foregoing embodiments of the invention, it is achieved that at a lower mass flow rate of gas, the gas is conducted to the porous permeable refractory ceramic material, whereas at a higher mass flow rate of gas, the gas is conducted to the gas channel. Thus, by means of the gas purge plug according to the invention, a particularly advantageous conduction of gas through the gas purge plug can be achieved.

[0027] According to a further development of the inventive concept, it can be provided that the conduction of gas from the gas supply device to the first part and the second part can be further controlled by the control device according to the mass flow rate of the gas in such a way that the gas can be conducted to the first part and the second part when the mass flow rate is within a third range, wherein the third range is higher than the first range and lower than the second range.

[0028] By this measure, an advantageous conduction of the gas through the first section and the second section simultaneously can be achieved, in particular at moderate gas flow rates.

[0029] According to one embodiment, it can be provided that the control device comprises an actuator, in particular a piston or a valve core. Preferably, the actuator can assume different positions. Preferably, the actuator can assume different positions depending on the flow behavior of the gas. According to a preferred embodiment, it can be provided that the conduction of the gas to the first part and the second part is controllable depending on the position of the actuator. In this respect, the actuator can be designed in the manner of a control piston or a valve core in a directional control valve, wherein the position of the actuator releases or blocks the gas path.

[0030] Preferably, it may be provided that the actuator may assume at least a first position and a second position. It may also be provided that when the mass flow rate of the gas is within the aforementioned first range, the actuator may assume the first position, and when the mass flow rate of the gas is within the aforementioned second range, the actuator may assume the second position. According to a further embodiment, it may also be provided that the gas cannot be directed to the second portion in the first position, and cannot be directed to the first portion in the second position.

[0031] According to a further embodiment of the invention, provision can be made that the actuator assumes a third position when the mass flow of the gas lies in a third range, and wherein, in the third position, the gas can be conducted to the first portion and to the second portion.

[0032] Therefore, when the mass flow rate of the gas is between the first range (i.e., a lower mass flow rate of the gas) and the second range (i.e., a higher mass flow rate of the gas), the actuator assumes this third position, and in this position, the actuator can control the conduction of the gas to the first part and the second part so that the gas can be conducted to both the first part and the second part.

[0033] In general, the gas supply device may be any device by which gas can be conducted to the first part and the second part. Preferably, the gas supply device is arranged in the region of the first end of the body of the refractory ceramic material of the gas purge plug. Preferably, as is also known from the prior art, the gas supply device is designed in the form of a nozzle or a cap, respectively, which is arranged at the first end of the body of the refractory ceramic material, i.e. at the gas inlet side of the gas purge plug. Preferably, the gas supply device is formed from metal. Preferably, the control device is arranged in the gas supply device, i.e., for example, in the gas supply device formed as a nozzle or a cap.

[0034] The gas supply device preferably has a gas connection to which a gas line can be connected. The gas line can in turn be connected to a gas source. Thus, gas can be conducted from the gas source via the gas line into the gas supply device, and the gas is then conducted via the gas supply device to the first and second parts of the body of the refractory ceramic material of the gas purge plug.

[0035] As is known from the prior art, the gas purge plug may preferably comprise one or more gas distribution chambers via which gas may be introduced into the first part and the second part.

[0036] Preferably, a gas distribution chamber is arranged at the first end of the body of refractory ceramic material, as known from the prior art, so that gas from the gas distribution chamber can be introduced directly into the gas channels of the first and second part.

[0037] According to a preferred embodiment, the refractory gas purge plug also includes: a first gas distribution chamber, which is arranged at the first end of the body; a second gas distribution chamber, which is arranged at the first end of the body; wherein the gas can be introduced into the first part via the first gas distribution chamber; and the gas can be introduced into the second part via the second gas distribution chamber.

[0038] The advantage of such first and second gas distribution chambers is in particular that gas can be selectively introduced into the first part and thus into the porous, permeable refractory ceramic material via the first gas distribution chamber and into the second part and thus into the gas channel via the second gas distribution chamber.

[0039] According to one embodiment, it can be provided that the first gas distribution chamber and the second gas distribution chamber are separated from each other, for example, by a wall. According to a further embodiment of the invention, it can be provided that the first gas distribution chamber and the second gas distribution chamber are fluidically separated from each other. This has the particular advantage that the gas in the first gas distribution chamber and the gas in the second gas distribution chamber do not mix with each other, so that the gas can be directed in particular into the first part via the first gas distribution chamber and in particular into the second part via the second gas distribution chamber.

[0040] In case the gas purge plug comprises gas distribution chambers, gas may be conducted from the gas supply first into the gas distribution chambers and via these into the first part and into the second part, more specifically into the gas channels of the second part.

[0041] According to one embodiment, it is provided that the gas can be conducted by the gas supply device via a first gas distribution chamber to the first portion, and wherein the gas can be conducted by the gas supply device via a second gas distribution chamber to the second portion.

[0042] According to one embodiment, it is provided that gas cannot be introduced into the second part via the first gas distribution chamber.

[0043] According to one embodiment, it is provided that gas cannot be introduced into the first portion via the second gas distribution chamber.

[0044] The above-described embodiments can ensure in a special way that gas can be introduced into the first part via the first gas distribution chamber and gas can be introduced into the second part via the second gas distribution chamber. In this way, a targeted conduction of the gas either to the porous, permeable refractory ceramic material or to the gas channel can be achieved in a particularly advantageous manner depending on the flow behavior of the gas.

[0045] As is known from the prior art, a "gas distribution chamber" in the sense of the present invention is a space enclosed or defined, respectively, by a wall. The gas distribution chamber does not need to be completely enclosed by the wall. Instead, the wall enclosing the gas distribution chamber may, for example, have openings, for example to guide gas into the gas distribution chamber.

[0046] According to a preferred embodiment, it is provided that the space defined by the first gas distribution chamber is partially defined by the first portion. In other words, the first portion constitutes a portion of a wall defining the space enclosed by the first gas distribution chamber. This feature is particularly easy to implement due to the fact that the first gas distribution chamber is arranged at the first end of the body of the refractory ceramic material of the gas purge plug according to the invention. In particular, a particular advantage of this feature is that, when the first portion constitutes a portion of the wall of the first gas distribution chamber, the gas can be conducted to the first portion particularly easily through the first gas distribution chamber.

[0047] According to one embodiment, it is provided that the space defined by the second gas distribution chamber is partially defined by the second part. In other words, the second part constitutes a part of the wall defining the space enclosed by the second gas distribution chamber. Since the second gas distribution chamber is arranged at the first end of the body of the refractory ceramic material of the gas purge plug according to the invention, this feature is particularly easy to implement. A particular advantage of this feature is that, in particular, if the second part constitutes a part of the wall of the second gas distribution chamber, the gas can be conducted particularly easily through the second gas distribution chamber to the second part or to the gas channel formed in the second part.

[0048] Preferably, further parts of the walls of the first and second gas distribution chambers which are not defined by the first and second parts may be formed from a metal such as is known from the prior art. It may be provided that parts of the walls of the first and second gas distribution chambers may be part of the gas supply device via which gas may be conducted to the first and second parts.

[0049] In order to conduct the gas into the first gas distribution chamber, it can be provided that the first gas distribution chamber has at least one first gas supply opening, via which the gas can be introduced into the first gas distribution chamber.

[0050] In order to conduct gas into the first gas distribution chamber, it can be provided that the second gas distribution chamber has at least one second gas supply opening, via which gas can be introduced into the second gas distribution chamber.

[0051] Preferably, gas may be introduced into the first gas distribution chamber by the gas supply device via the first opening. Similarly, gas may preferably be introduced into the second gas distribution chamber by the gas supply device via the second gas supply opening.

[0052] As stated above and according to the common nomenclature in the field of refractory gas purge plugs, "gas channels" according to the invention are understood to be channels with a defined geometry, which in the prior art are also understood in particular as "oriented" porous structures. As explained above, these gas channels in this respect are in contrast to porous, permeable refractory ceramic materials, in which the natural gas permeability results from the random, disordered arrangement of the pore structure in the refractory ceramic material, which is therefore also referred to as a "non-oriented" porous structure.

[0053] As set out above, preferably the gas channel may have been produced by burning out a combustible material in order to provide a gas channel having a defined geometry.

[0054] According to one embodiment, it can be provided that the gas channels extending through the second part form at least one web.

[0055] According to one embodiment, it can be provided that the first part provides a surface and wherein the at least one web extends at least partially directly on the surface of the first part.

[0056] According to the invention, it has been found that the network formed by the gas channels makes it possible to achieve a particularly advantageous homogenization of the molten metal. The invention is based on the further finding that with the gas purge plug according to the invention it is possible, in particular at high mass flows, for the gas channels to be cleared again of infiltrating molten metal. The invention is based on the further finding that with the gas purge plug according to the invention it is possible for the metal infiltrants to be removed very carefully without damaging the sensitive porous, permeable refractory ceramic material.

[0057] The inventors assume that the flow of gas through the different porous structures, which depends on the flow rate, is due to the fact that firstly, there is a certain amount of gas exchange between the porous, permeable refractory ceramic material and the gas channel, and secondly, at low flow rates, the gas preferentially passes through the porous, permeable refractory ceramic material, and at higher flow rates, the gas preferentially passes through the gas channel. The inventors assume that this effect may be based on the fact that at low flow rates, the gas channel is blocked by the infiltrating melt, while at high flow rates, the metal infiltrates in the channel can be blown out or removed from the first part very carefully, respectively, without damaging the sensitive porous, permeable refractory ceramic material. Therefore, at high flow rates, the gas flowing through the porous, permeable refractory ceramic material enters the gas channel to a certain extent, blows out the metal infiltrates from the gas channel, and then flows through the gas channel. At the same time, when the gas enters the gas channel from the porous, permeable refractory ceramic material at high flow rates, the sensitive porous, permeable refractory ceramic material is not damaged.

[0058] According to the invention, it has also been found that a gas purge plug can be provided very easily in terms of manufacturing technology if the gas channel forms at least one such mesh. This is because, for this purpose, as explained in further detail below, the mesh-like combustible material can first be arranged very simply on the first part, for example by simply sliding the combustible mesh onto the first part and then surrounding the first part with refractory material.

[0059] The gas channels form a "net" in the sense of the present invention as long as the gas channels have a net-like structure or extend in a net-like manner.

[0060] According to one embodiment, the gas channels form at least one network consisting of groups of gas channels, each group of gas channels extending parallel to each other and crossing each other. This results in a symmetrical structure of the network, which again results in a uniform injection of the gas in the steel melt, thereby reducing inconsistent wear of the plug.

[0061] According to one embodiment, the gas channels form at least one symmetrical network.

[0062] According to the invention, it has been found that such a symmetrical network formed by the gas channels makes it possible to achieve a particularly advantageous homogenization of the molten metal. Furthermore, it has been found that, through such a symmetrical network, the gas can be diffused particularly uniformly into the first portion, so that the first portion can be particularly carefully cleaned of any metal infiltrations.

[0063] Preferably, the gas channel extends linearly (ie along a straight line). This allows a particularly uniform, in particular laminar flow to be generated in the gas channel, whereby the gas can be injected particularly uniformly into the molten metal and diffused into the first portion, which again can prevent inconsistent wear of the plug.

[0064] According to one embodiment, it is provided that the net comprises a mesh surrounded by a gas channel, and wherein the mesh has a mesh size in the range of 1 to 10 mm, more preferably in the range of 2 to 8 mm and even more preferably in the range of 3 to 5 mm. This allows easy production and prevents errors in the channel structure. "Mesh" within the meaning of the present invention means an area surrounded by a gas channel.

[0065] Preferably, the gas channel at least predominantly has a constant cross-sectional area. In this sense, the cross-sectional area is the cross-section of the gas channel perpendicular to its longitudinal extension. The constant cross-sectional area prevents wear compared to an area with a non-constant cross-section. According to a preferred embodiment, the gas channel has a constant cross-sectional area beyond the nodes of the mesh of the gas channels. The "nodes" of the mesh of the gas channels are the points of the mesh where the gas channels intersect.

[0066] Preferably, the gas channel has a circular cross-sectional area. This is particularly preferred when a plurality of adjacent webs of gas channels are provided, since the contact surfaces of the webs of gas channels are minimized and gas permeation between the webs of gas channels is limited.

[0067] Preferably, the gas channel has a diameter in the range of 0.1 to 2.0 mm, more preferably in the range of 0.1 to 1.0 mm, even more preferably in the range of 0.2 to 0.9 mm. In this sense, the diameter is the diameter of the gas channel perpendicular to the longitudinal extension of the gas channel. In the case where the gas channel does not have a circular cross-sectional area, the diameter is the maximum distance between the channel walls perpendicular to the longitudinal extension of the gas channel.

[0068] According to the invention, it has been found that with a gas channel having such a diameter, gas can be injected into the molten metal through the gas channel in a particularly advantageous manner, in particular also at a high mass flow rate of gas, whereby a good homogenization of the molten metal can be achieved, but at the same time penetration of the molten metal into the gas channel can be completely or largely prevented.

[0069] According to one embodiment, it is provided that the refractory ceramic material of the second portion has a lower permeability than the refractory ceramic material of the first portion.

[0070] According to one embodiment, it can also be provided that the refractory ceramic material of the second portion is impermeable to gases, in particular to gases at the gas pressures prevailing in the refractory gas purge plug. According to one embodiment, it can be provided that the refractory ceramic material of the second portion can have a permeability of <2 nPerm, preferably <0.05 nPerm.

[0071] According to one embodiment, it is provided that the first region has a permeability in the range of 50-400 nPerm, preferably 60-250 nPerm.

[0072] The permeability values ​​given herein are determined according to standard ISO 8841: 1991-09.

[0073] According to the invention, it has been found that with such a permeability of the first portion, in particular at a low mass flow rate of gas through the first portion, the gas can pass through the first portion so that the gas flowing into the molten metal through the first portion generates a number of small bubbles in the molten metal, through which harmful gases and oxide inclusions can be advantageously removed from the molten metal. Furthermore, it has been found that with such a permeability of the first portion, the gas can diffuse particularly well from the gas channel into the first portion and the first portion can be cleared of metal infiltrants, as previously explained.

[0074] According to a preferred embodiment, provision is made that the second portion surrounds the first portion.

[0075] According to the invention, it has been found that the second part can be cleaned of metal permeants particularly advantageously through the gas passage of the first part when the second part surrounds the first part.

[0076] In general, the first portion may have any shape. For example, the first portion may have a circular cross-section, a polygonal cross-section, or a combination of such cross-sections. The polygonal cross-section may, for example, be a rectangular cross-section. For example, the first portion may include at least one section having a circular cross-section and at least one section having a polygonal cross-section.

[0077] In the case of a circular cross section of the first part, the first part may have, for example, a cylindrical shape, wherein the longitudinal axis of the cylinder extends from the first end of the body to the second end of the body. Alternatively, provision may be made that, in the case of a circular cross section of the first part, the first part has a frustoconical shape, wherein its longitudinal axis extends from the first end of the body to the second end of the body and it tapers in this direction.

[0078] In the case of a first portion having a polygonal cross section, the first portion may have, for example, a cuboid, prism or wedge shape, wherein the longitudinal axis of these shapes extends from the first end of the body to the second end of the body. According to one embodiment, it may be provided that the area of ​​the cross section tapers in the direction from the first end of the body to the second end of the body.

[0079] According to one embodiment, it can be provided that the first part is one-piece, in particular consists of a single piece with homogeneous properties.

[0080] According to a preferred embodiment, the first part comprises a first section and a second section, wherein the sections have different properties. Preferably, the first section and the second section differ in at least one of the following properties: shape or porous structure. A significant advantage of having a first part with different sections with different properties is in particular that each section can be optimized with respect to certain properties.

[0081] According to one embodiment, the first portion comprises a first section disposed proximate to a first end of the body of refractory ceramic material and a second section disposed proximate to a second end of the body of refractory ceramic material. In other words, the first section forms a portion of the first end of the body and the second section forms a portion of the second end of the body.

[0082] In the case where the shapes of the first section and the second section are different, it is preferred that the first section has a polygonal cross section as set out above and the second section has a circular cross section as set out above. A significant advantage of this embodiment is that the first section and the second section are visually different from each other and the first section can therefore also be used as a wear indicator. A further advantage is that only the second section adjacent to the second end of the body can be formed with a circular cross section. However, it must be taken into account in this regard that if the porous permeable refractory material has a circular cross section, it is advantageous for the gas to enter the melt from the material, but such a circular cross section is more difficult to achieve than a polygonal cross section in terms of manufacturing technology.

[0083] Preferably, provision is made that the first section may have the function of a wear indicator as known in the prior art.As is known, after removal of molten metal from the melting vessel, the first section may be visually identifiable and thereby indicate a gradual wear of the gas purge plug.

[0084] In the case where the porous structure of the first section and the second section is different, it is preferably provided that the first section comprises a porous permeable refractory ceramic material having a first permeability and the second section comprises a porous permeable refractory ceramic material having a second permeability, wherein the first permeability and the second permeability are different. Particularly preferably, it is provided that the first permeability is greater than the second permeability. According to a preferred embodiment, it is provided that the first permeability is in the range of 50-400nPerm, preferably 60-250nPerm, and the second permeability is in the range of 50-400nPerm, preferably 60-250nPerm. Preferably, the first permeability and the second permeability are the same. The advantage of such an embodiment also lies in particular in the fact that a larger amount of gas can pass through the first section than through the second section. As a result, the gas can be conducted from the first section to the second section and to the gas channel directly adjacent to the second section, as further described below. Concurrently conducting a smaller amount of gas through the second section produces the self-regulating effect described above, whereby at low gas flow rates the gas flows through the porous permeable refractory material and at higher flow rates the gas flows through the gas channels.

[0085] Preferably, the first section has a surface extending at a distance from the first end of the body. Thus, this surface of the first section extends "inside" the body. Preferably, this surface extends parallel to the first end of the body.

[0086] According to a particularly preferred embodiment, it is provided that the first section has a first contact surface and the second section has a second contact surface, the first contact surface and the second contact surface being adjacent to each other. Thus, the first section and the second section are directly adjacent to each other. In particular, this also has the advantage that the gas flowing through the first section can flow directly from the first section into the second section. Particularly preferably, the first contact surface and the second contact surface extend at a distance from the first end and the second end of the body, i.e. "inside" the body. According to one embodiment, the first contact surface and the second contact surface extend parallel to the first end of the body.

[0087] A gas channel forming at least one net extending at least partially directly on the surface of the first part extends through the second part. In principle, the gas channel can extend through the second part to any distance between the first end of the body and the second end of the body. Preferably, the gas channel extends to the second end of the body. This has the advantage that gas can be released from the body into the molten metal via the gas channel at the second end of the body.

[0088] It may be provided that the gas channel extends to the first end of the body. This allows gas to be introduced into the body via the gas channel at the first end of the body. According to a further embodiment of this embodiment, as explained above, the gas channel simultaneously extends to the second end of the body. In this respect, the gas channel extends from the first end of the body to the second end of the body. This allows gas to pass through the body via the gas channel from the first end of the body to the second end of the body.

[0089] According to an alternative preferred embodiment, the gas channel is arranged to extend through the second portion at a distance from the first end of the body.Thus, in this embodiment, the gas channel does not extend to the first end, but terminates at a distance from the first end of the body.

[0090] In the case of an embodiment in which the first part is a single piece, and wherein the gas passage is arranged to extend through the second part at a distance from the first end of the body, the gas passage terminates in a region of the first part between the first and second ends of the body at a location spaced apart from the first end of the body.

[0091] In the case of an embodiment in which the first part comprises a first section and a second section, as set out herein, and in which the gas channel is arranged to extend through the second part at a distance from the first end of the body, the gas is preferably supplied into the gas channel via the first part made of a porous, permeable refractory ceramic material by introducing the gas into the first part, and the gas is conducted from the first part into the gas channel via a gas exchange between the first part and the gas channel, as explained above. Given that the first section has a first contact surface, at which the first section abuts against the second section, as set out above, according to a further embodiment, provision is made for the gas channel to extend from the contact surface through the second part in a direction towards the second end. In this embodiment, the gas channel is thus arranged with a distance towards the first end corresponding to the distance of the first contact surface towards the first end. Preferably, in this embodiment, the gas channel is in contact with the first contact surface. This allows the gas flowing through the first section to flow directly from the first section into the gas channel.

[0092] According to the invention, it has been found that the second portion and therefore the gas channel can be cleaned of infiltrating metal particularly advantageously, in particular when the second portion surrounds the first portion.

[0093] In general, the first part can be made of any porous, permeable refractory ceramic material. In particular, the first part can be made of any porous, permeable refractory ceramic material, which is known as a porous, permeable refractory ceramic material for a gas purge plug. Preferably, the first part is made of a sintered porous permeable refractory ceramic material. Preferably, the first part can be made based on at least one of the following refractory ceramic materials, in particular materials sintered together: magnesia, alumina, spinel, mullite and refractory clay.

[0094] The second part can be made of any refractory material, in particular a refractory ceramic material with low permeability. In this respect, refractory materials known from the prior art can be used. Preferably, the refractory ceramic material of the second part is in the form of a refractory cement or a ceramic block, i.e. an unformed refractory ceramic product. Preferably, the second part can be made based on at least one of the following refractory ceramic materials: magnesia, alumina, spinel, mullite and refractory clay.

[0095] In order to provide a gas passage in the second part, techniques known in the prior art for producing a gas passage in a refractory gas purge plug may be used. Preferably, the gas passage may be produced by first embedding a combustible material into a refractory ceramic material, then heating the refractory ceramic material so that the combustible material burns out and subsequently forms the gas passage. Preferably, such combustible material has the shape of one or more nets preferably arranged on the surface of the first part. For example, at least one net made of combustible material may be drawn onto the surface of the first part.

[0096] The combustible material may be an organic, preferably woven material, such as cotton, cellulose or a plastic, such as one of the following plastics: soft polyethylene, soft polypropylene or polyethersulfone.

[0097] According to one embodiment of the invention, it can be provided that the gas channel replaces the burnt-out material.

[0098] As is known in the art, a gas purge plug may include a metal shell or sleeve surrounding a body of refractory ceramic material.

[0099] The body of refractory ceramic material may be produced by a method comprising the following steps: An element of refractory ceramic material is provided; wherein the element extends from a first end of the element to a second end of the element opposite the first end of the element; the element comprises a first section made of a first refractory material, the first section extending from the first end of the element to the second end of the element; and the element comprises a second section made of a second refractory material, the second section extending from the first end of the element to the second end of the element, the second section comprising a combustible material embedded in the second refractory material and extending through the second section from the first end of the element to the second end of the element; and Heating element.

[0100] Preferably, the combustible material forms at least one web. Further preferably, the at least one web extends at least partially directly over the surface of the first section.

[0101] For example, the combustible material may be drawn over the first portion so that it extends at least partially directly over the surface of the first section before the second section is applied around the combustible material.

[0102] After the heating step, the element of refractory ceramic material forms the body of refractory ceramic material of the gas purge plug of the present invention.

[0103] The combustible material may be embedded in the second refractory material by applying the combustible material, preferably forming at least one web, preferably at least partially directly on the surface of the first section and subsequently applying the second section around the combustible material.

[0104] The method for producing a refractory gas purge plug may further comprise the step of applying a strip of combustible material on the surface of the first section from the first end of the element to the second end of the element prior to providing the second section.

[0105] After heating, the first section of the first refractory material forms the first part of the body made of porous, permeable refractory ceramic material. The first section made of refractory material is preferably a shaped body. As mentioned above, the first part is preferably in the form of a sintered body. Therefore, the first section can be in the form of a sintered body. Alternatively, the first section is a shaped green body, wherein the heating is preferably carried out so that the first refractory material is sintered by heating to form a porous, permeable refractory ceramic material. The first refractory material is preferably based on at least one of the following refractory ceramic materials: magnesium oxide, aluminum oxide, spinel, mullite and refractory clay. Preferably, the first section is in the form of a shaped product, in particular a pressed product, in particular in the form of a green body.

[0106] After heating, the second section of the second refractory material forms the second part of the body of the refractory ceramic material of the gas purge plug according to the present invention. The second refractory material is preferably based on at least one of the following refractory ceramic materials: magnesium oxide, aluminum oxide, spinel, mullite and refractory clay. In order to form a gas channel in the second section during heating, there is a combustible material embedded in the second refractory material. During heating, the combustible material burns out so that the gas channel replaces the burned-out material after heating. According to a particularly preferred embodiment, in order to embed the combustible material in the second refractory material, the combustible material is first arranged on the surface of the first section and then embedded in the second material. For embedding, the second refractory material can, for example, be subsequently placed, in particular poured onto the combustible material arranged on the first refractory material. For this purpose, the first section on which the combustible material is arranged can be arranged, for example, in a mold or template. Preferably, the second refractory material can be in the form of a refractory cement or in the form of a ceramic block (i.e., an unformed refractory ceramic material) or applied for this purpose. Preferably, the first section used for this purpose is in the form of a shaped product, as explained above, so that the first section provides a surface on which the combustible material can be arranged particularly easily. As described above, the combustible material thus forms, after heating, a gas channel preferably in the form of at least one net, which preferably extends at least partially directly on the surface of the first part. A particular advantage of using at least one such net as the combustible material is also that such a net can be arranged particularly easily on the surface of the first part by simply pulling it onto the first part. In general, the combustible material can be any material that burns out by heating, such as paper, cardboard or any synthetic material, in particular plastic. Preferably, the combustible material is present as a plastic, particularly preferably in the form of at least one of the following plastic materials: soft polyethylene, soft polypropylene or polyethersulfone.

[0107] Preferably, the heating is performed at a temperature at which the combustible material burns out or incinerates, respectively. Preferably, the heating is performed at a temperature in the range from 200° C. to 600° C., in particular in the range from 400° C. to 600° C., thereby preferably solidifying the second refractory material. Within this range, the aforementioned combustible material can burn out or incinerate, respectively.

[0108] Preferably, the method is performed such that the second section surrounds the first section.

[0109] To produce the gas purge plug according to the invention, after heating or firing, a gas supply device can subsequently be arranged on the body obtained.

[0110] Furthermore, a first and a second gas distribution chamber may be arranged on the obtained body.

[0111] Furthermore, after firing, the shell or sleeve may be arranged on the body such that it surrounds the body of refractory ceramic material, as set forth above.

[0112] In general, the refractory gas purge plug according to the invention can be used for arrangement in the bottom region of a metallurgical vessel. In particular, provision can be made for the use of the refractory gas purge plug according to the invention in the bottom region of a vessel for receiving molten metal, in particular molten steel. Particularly preferably, provision is made for the use of the gas purge plug according to the invention arranged in the bottom region of a ladle, in particular in a continuous casting plant for processing molten steel.

[0113] A further subject matter of the present invention is to provide a metallurgical vessel having a gas purge plug according to the invention arranged in the bottom region of the metallurgical vessel.The metallurgical vessel may in particular be a metallurgical vessel as described above.

[0114] A further subject of the present invention is to provide a method for controlling the conduction of gas to a refractory gas purge plug, the method comprising the steps of: Providing a refractory gas purge plug according to the present invention; The conduction of gas to the first portion and the second portion is controlled by a gas supply device.

[0115] Thereby, control of conduction of gas to the first portion and the second portion by the gas supply may be performed as set out herein.

[0116] Further features of the present invention will be apparent from the claims, the drawings and the accompanying description of the drawings.

[0117] All features of the invention can be combined with one another individually or in combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] Exemplary embodiments of the invention are shown schematically in the drawings and are explained in more detail by the description.

[0119] In the accompanying drawings, it is shown as follows: Figure 1 is a perspective view from below of an embodiment of a gas purge plug according to the present invention; Figure 2 is based on Figure 1 A cross-sectional view of a gas purge plug; Figure 3 is based on Figure 1 Detailed view of the gas passages in the gas purge plug; Figure 4 is in the region of the gas supply of the gas purge plug in the first switching position of the control device according to Figure 2 Detailed view of a cross-section of; Figure 5 is in the second switching position of the control device according to Figure 4 Detailed view of Figure 6 is in the third switching position of the control device according to Figure 4 Detailed view of Figure 7 is a perspective view from above of a portion from which a gas purge plug should be produced during a manufacturing step of the gas purge plug; Figure 8 yes Figure 7 A portion of the web shown in ; and Fig. 9 is a cross-sectional view of a gas purge plug according to an alternative embodiment of a gas purge plug of the present invention. DETAILED DESCRIPTION

[0120] according to Figures 1 to 8 Example of a gas purge plug: In general, according to Figures 1 to 8 A refractory gas purge plug of an embodiment of the invention is identified by reference numeral 1 in the drawings.

[0121] The refractory gas purge plug 1 comprises a body 2 of refractory ceramic material extending from a first end 3 of the body 2 to a second end 4 of the body 2 opposite to the first end 3 of the body 2, at which gas can be introduced into the body 2 and at the second end 4 from which gas can be discharged.

[0122] The body 2 has an overall frustoconical outer contour which tapers from a first end 3 to a second end 4 along a longitudinal axis 5 of the body 2. At its radial outer contour, the body 2 is completely covered by a metal sleeve 6. Figure 1 As clearly shown, the gas purge plug 1 thus has a generally frustoconical outer profile which tapers from the first end 3 to the second end 4 along the longitudinal axis 5 of the body 2 .

[0123] The body 2 comprises a first part 7 made of a porous, permeable refractory ceramic material, which extends from the first end 3 of the body 2 to the second end 4 of the body 2. The first part 7 consists of two sections: a first section 7.1 and a second section 7.2. The first section 7.1 extends from the first end 3 in the direction of the second end 4 to an upper end 8; the second section 7.2 directly adjoins the first section 7.1 and extends to the second end 4. The upper end 8 serves as a first contact surface for contacting the second section 7.2. In the embodiment shown, the first section 7.1 has the shape of a truncated cone, while the second section 7.2 has the shape of a cuboid with a rectangular cross section. Thus, the first section 7.1 also has the function of a wear indicator. In the region of the first section 7.1, the first end 3 of the body 2 is defined by the gas inlet-side region 3.1 of the first section 7.1. The first section 7.1 and the second section 7.2 are each made of a sintered porous, permeable refractory ceramic material based on alumina and magnesium spinel. The first section 7.1 has a first permeability of 200 nPerm, and the second section 7.2 also has a second permeability of 200 nPerm.

[0124] The first section 7.1 is covered on its side facing the first end 3 by a metal cap 17. The metal cap 17 has a substantially can-like shape with a side wall 17.1 and a bottom 17.2. The side wall 17.1 surrounds the lower radial edge of the first section 7.1. The bottom 17.2 extends at a distance from the gas inlet-side region 3.1 of the first section 7.1, so that a first gas distribution chamber 18 is formed between the metal cap 17 and the first section 7.1. The space defined by the first gas distribution chamber 18 is thus defined by the metal cap 17 and the first part 7, i.e. the section 7.1 of the first part 7. The bottom 17.2 has a central through-opening 19.

[0125] The body 2 further comprises a second portion 9 made of a refractory ceramic material, which extends from the first end 3 of the body 2 to the second end 4 of the body 2 and completely and symmetrically surrounds the first portion 7. The second portion 9 has a frustoconical outer contour, which, as described above, is covered on the radially outer surface by a metal sleeve 6. In the region of the second portion 9, the first end 3 of the body 2 is defined by a gas inlet-side region 3.2 of the second portion 9. The refractory material of the second portion 9 comprises a refractory ceramic material in the form of a solidified refractory ceramic material based on alumina and magnesium spinel and has almost no gas permeability, having a permeability of <0.05 nPerm. The second portion 9 comprises a gas channel 10 in the form of a mesh 11 and extending through the second portion 9 from the first end 3 of the body 2 to the second end 4 of the body 2. In this regard, the first portion 7 provides a surface 12, and wherein the mesh 11 extends partially directly on the surface 12 of the first portion 7.

[0126] like Figure 3 As shown in , each of the nets 11 formed by the gas channels 10 is a symmetrical net 11, wherein the gas channels 10 in these nets 11 extend linearly. The mesh 13 surrounded by the gas channels 10 has a mesh size of 4.0 mm. The gas channels 10 have a constant circular cross-sectional area with a diameter of 0.50 mm.

[0127] The second part 9 is covered on its side facing the first end 3 by a metal cover 15. The cover 15 is welded at the edge along a weld 16 to the lower edge of the metal sleeve 6. The cover 15 covers the gas inlet side 3.1 of the second part 9 of the body 2 and the metal cap 17, leaving space for the second gas distribution chamber 20. Thus, the space defined by the second gas distribution chamber 20 is defined by the metal cap 17, the cover 15 and the second part 9. The cover 15 has a central through opening 21.

[0128] Therefore, the first gas distribution chamber 18 and the second gas distribution chamber 20 are separated from each other by the wall, ie the metal cap 17 .

[0129] The central through opening 21 of the cap 15 and the central through opening 19 of the bottom 17 . 2 of the metal cap 17 are aligned with each other, wherein the longitudinal axis 5 of the body 2 passes centrally through the through opening 21 and the central through opening 19 .

[0130] The gas purge plug 1 further comprises a gas supply device 13 from which gas can be conducted to the first part 7 and the second part 9. The gas supply device 13 comprises a control device 14 by which the conduction of gas via the gas supply device 13 to the first part 7 and the second part 9 is controllable.

[0131] The gas supply device 13 is arranged in the region of the first end 3 of the body 2 and is Figures 4 to 6 Shown in detail in.

[0132] The gas supply device 13 is substantially tubular in shape and has a tubular portion 22 which passes through a central through opening 21 of the cover 15 and a central through opening 19 of the bottom 17 . 2 of the metal cap 17 and opens into the first gas distribution chamber 18 .

[0133] In the region of the second gas distribution chamber 20 between the bottom 17.2 and the cover 15, the tubular section 22 has a radially outwardly projecting collar 23, by means of which the tubular section 22 is sealingly supported against the bottom 17.2 and the cover 15 and is simultaneously fixed in a form-fitting manner between the metal cap 17 and the cover 15. The tubular section 22 comprises an inner bore 24 extending axially through the tubular section 22. A bore 25 is formed in the collar 23 to fluidically connect the bore 24 to the second gas distribution chamber 20.

[0134] A tubular body 26 of the gas supply device 13 is arranged in the tubular section 22, in which the control device 14 is arranged. The tubular body 26 has an inner axial hole 27, through which the gas can be conducted from the inlet side 28 of the tubular body 26 into the first gas distribution chamber 18 and into the second gas distribution chamber 20. The gas can be conducted from the first gas distribution chamber 18 directly into the first section 7.1 of the first part 7. In addition, the gas can be conducted from the second gas distribution chamber 20 directly into the gas channel 10 formed in the second part 9.

[0135] The tubular body 26 is configured to be inserted into the tubular section 22 in the axial direction. Figure 1 , the tubular body 26 is shown removed from the tubular section 22.

[0136] The conduction of gas via the gas supply 13 to the first part 7 and the second part 9 is controllable by means of a control device 14 formed in the tubular body 26. Thereby, the control device 14 is formed in the manner of a directional control valve. The control device 14 has an actuator 29 in the form of a piston which can be moved into different positions (i.e. pneumatically) by gas flowing from the inlet side 28 and through the tubular body 26 depending on the mass flow of the gas.

[0137] Specifically, the actuator 29 can move to three positions depending on the mass flow rate of the gas: if the gas flows through the tubular body 26 at a mass flow rate within a first range, the actuator 29 assumes a Figure 4 , in which the actuator 29 clears only one gas path through the tubular body 26 into the first gas distribution chamber 18 and blocks the gas path into the second gas distribution chamber 20. When the gas flows through the tubular body 26 at a mass flow rate in a second range higher than the first range, the actuator 29 exhibits Figure 5 , in which the actuator 29 only clears one gas path through the tubular body 26 and the hole 25 into the second gas distribution chamber 20 and blocks the gas path into the first gas distribution chamber 18. In addition, when the gas flows through the tubular body 26 at a mass flow rate within a third range that is higher than the first range and lower than the second range, the actuator 29 exhibits Figure 6 , in which the actuator 29 clears the gas path through the tubular body 26 into the first gas distribution chamber 18 and the gas path through the tubular body 26 and the aperture 25 into the second gas distribution chamber 20. Figures 4 to 6 , the gas paths are indicated by arrows.

[0138] Therefore, the gas can be conducted by the gas supply device 13 to the first part 7 via the first gas distribution chamber 18 and to the second part 9 via the second gas distribution chamber 20. At the same time, the gas cannot be introduced into the second part 9 via the first gas distribution chamber 18, and cannot be introduced into the first part 7 via the second gas distribution chamber 20.

[0139] Furthermore, it is achievable that at a lower mass flow rate of gas, the gas is conducted to the porous permeable refractory ceramic material of the first portion 7, and at a higher mass flow rate of gas, the gas is conducted to the gas channel 10 of the second portion 9, while at a medium mass flow rate of gas, the gas can be conducted through both the first portion 7 and the second portion 9 simultaneously.

[0140] At the inlet end 28, the gas supply device 13 has a gas connection to which a gas line (not shown) can be connected. The gas line can in turn be connected to a gas source (not shown). Thus, gas can be conducted from the gas source via the gas line into the gas supply device 13, and the gas is then conducted via the gas supply device 13 to the first part 7 and the second part 9 of the body 2.

[0141] Of course, the gas channels 10 forming at least one network 11 may also be provided without the aforementioned gas supply device 13 .

[0142] To produce the body 2 of refractory ceramic material, firstly, two components 107.1, 107.2 are provided as sintered bodies from a first refractory material in the form of an alumina-spinel low-cement castable. The two components 107.1, 107.2 are then Figure 7 1 and 2. The refractory gas purge plug 1 is shown assembled together to form a first section 107. The first section 107 has the shape of the first portion 7 and will form the first part 7 of the refractory gas purge plug 1. The first section 107 provides an outer radial surface.

[0143] Furthermore, a plastic mesh is provided which is made of soft polyethylene and has the dimensions of the mesh 11 of the gas channel 10. Thus, as Figure 8 As illustrated in FIG. 1 , a portion of such a net 111 is shown, each of the nets 111 formed by plastic fibers 110 is a symmetrical net 111 in which the fibers 110 extend linearly. The mesh 113 surrounded by the fibers 110 has a mesh size of about 4.0 mm. The fibers 110 have a constant circular cross-sectional area with a diameter of 0.5 mm. Since these nets 111 are made of plastic, they are flammable and elastic.

[0144] Several of these elastic nets 111 are pulled onto the first section 107 , so that some of the nets 111 partially extend directly on the surface of the first section 107 .

[0145] Furthermore, the first section 107 on which the mesh 111 is arranged is placed into a mold (not shown), and a refractory ceramic block (not shown) based on an alumina-spinel low-cement castable is poured into the space between the first section 107 and the mold. Thereby, the mesh 111 is embedded in the second refractory material. The portion formed by the refractory ceramic block forms a second section having the shape of the second portion 9, and after combustion will form the second portion 9 of the refractory gas purge plug 1.

[0146] The first section 107 and the second section in combination form an element which, after combustion, will form the body 2 of the gas purge plug 1 .

[0147] In a further step, the element made of the first section 107 and the second section is heated in a furnace at a temperature of about 500° C., whereby the second refractory material solidifies. After heating, a body 5 is produced, wherein the first section 107 forms the first part 7 and the second section forms the second part 9. Furthermore, during heating, the plastic mesh 111 is burned out and the gas channel 110 replaces the burned out mesh 111.

[0148] Finally, to produce the gas-purged plug 1 , the metal sleeve 6 is arranged around the body 5 , and the gas supply 13 is arranged at the gas inlet side of the body 5 , as explained above.

[0149] The refractory gas purge plug 1 is intended to be arranged in the bottom region of a ladle in a continuous casting installation for processing molten steel.

[0150] according to Fig. 9 Example of a gas purge plug: according to Fig. 9 The gas purge plug 201 in the embodiment of Figures 1 to 8 The gas purge plug 1 is substantially the same. Fig. 9 The gas purge plug 201 is provided with components according to Figures 1 to 8 The elements of the gas purge plug 1 are identical and have the same reference numerals.

[0151] The gas purge plug 201 is relative to the Figures 1 to 8 An essential difference of the gas purge plug 1 is that the first part 7 is a single piece and therefore does not consist of a first section 7.1 and a second section 7.2. Instead, the first part 7 is a single piece having uniform chemical and physical properties (i.e., according to Figures 1 to 8 of section 7.2 of the physicochemical and physical properties) of a single piece.

Claims

1. A refractory gas purge plug (1) comprising the following features: 1.1 Body of refractory ceramic material (2); 1.2 The body (2) extends from a first end (3) of the body (2) to a second end (4) of the body (2) opposite to the first end (3) of the body (2), at which the gas can be introduced into the body (2), and at which the gas can be discharged from the body (2); 1.3 The body (2) comprises a first portion (7) made of a porous, permeable refractory ceramic material, wherein the first portion (7) extends from the first end (3) of the body (2) to the second end (4) of the body (2); 1.4 The body (2) comprises a second portion (9) made of a refractory ceramic material, the second portion (9) extending from the first end (3) of the body (2) to the second end (4) of the body (2), the second portion (9) comprising a gas passage (10) extending through the second portion (9) from the first end (3) of the body (2) to the second end (3) of the body (2); 1.5 a gas supply device (13), gas can be conducted from the gas supply device (13) to the first part (7) and the second part (9); wherein 1.6 The gas supply device (13) comprises a control device (14), and the conduction of gas from the gas supply device (13) to the first part (7) and the second part (9) can be controlled by the control device (14).

2. The refractory gas purge plug (1) according to claim 1, wherein: The conduction of the gas by the gas supply device (13) to the first portion (7) and the second portion (9) is controllable by the control device (14) depending on the flow behavior of the gas.

3. The refractory gas purge plug (1) according to claim 2, wherein: The flow behavior of the gas is the mass flow rate of the gas.

4. The refractory gas purge plug (1) according to claim 2, wherein: The conduction of the gas by the gas supply device (13) to the first portion (7) and the second portion (9) can be controlled by the control device (14) depending on the flow behavior of the gas in such a way that, depending on the flow behavior of the gas, the gas can be conducted to the first portion (7) but not to the second portion (9), or to the second portion (9) but not to the first portion (7).

5. The refractory gas purge plug (1) according to claim 3, wherein: The conduction of the gas by the gas supply device (13) to the first portion (7) and the second portion (9) is controllable by the control device (14) depending on the mass flow rate of the gas in such a way that, when the mass flow rate is within a first range, the gas can be conducted to the first portion (7) but not to the second portion (9), and when the mass flow rate is within a second range, the gas can be conducted to the second portion (9) but not to the first portion (7), wherein the first range is lower than the second range.

6. The refractory gas purge plug (1) according to claim 5, wherein: The conduction of the gas by the gas supply device (13) to the first part (7) and the second part (9) can also be controlled by the control device (14) depending on the mass flow rate of the gas in such a way that the gas can be conducted to the first part (7) and the second part (9) when the mass flow rate is within a third range, wherein the third range is higher than the first range and lower than the second range.

7. The refractory gas purge plug (1) according to claim 2, wherein: The control device (14) comprises an actuator (29) which can assume different positions depending on the flow behavior of the gas, wherein the conduction of the gas to the first portion (7) and the second portion (9) is controllable depending on the position of the actuator (29).

8. A refractory gas purge plug (1) according to claims 5 and 7, wherein: When the mass flow is within a first range, the actuator (29) assumes a first position, and wherein, when the mass flow is within the second range, the actuator (29) assumes a second position, and wherein, in the first position, the gas cannot be conducted to the second portion (9), and in the second position, the gas cannot be conducted to the first portion (7).

9. Refractory gas purge plug (1) according to claims 6 and 8, wherein: When the mass flow rate is within the third range, the actuator (29) assumes a third position, and wherein, in the third position, the gas can be conducted to the first portion (7) and the second portion (9).

10. The refractory gas purge plug (1) according to at least one of the preceding claims, further comprising: 10.1 a first gas distribution chamber (18), the first gas distribution chamber (18) being arranged at the first end (3) of the body (2); 10.2 A second gas distribution chamber (20), the second gas distribution chamber (20) being arranged at the first end (3) of the body (2); wherein 10.3 Gas can be introduced into the first portion (7) via the first gas distribution chamber (18); and 10.4 Gas can be introduced into the second portion (9) via the second gas distribution chamber (20).

11. The refractory gas purge plug (1) according to claim 10, wherein: Gas can be conducted from the gas supply device (13) via the first gas distribution chamber (18) to the first part (7), and wherein gas can be conducted from the gas supply device (13) via the second gas distribution chamber (20) to the second part (9).

12. Refractory gas purge plug (1) according to at least one of claims 10 to 11, wherein: The first gas distribution chamber (18) and the second gas distribution chamber (20) are fluidically separable from each other.

13. Refractory gas purge plug (1) according to at least one of the preceding claims, wherein: The gas passage (10) extending through the second portion (9) forms at least one web (11).

14. Refractory gas purge plug (1) according to at least one of the preceding claims, wherein: The first portion (7) provides a surface (12), and wherein the at least one web (11) extends at least partially directly on the surface (12) of the first portion (7).

15. A method for controlling the conduction of gas to a refractory gas purge plug (1), the method comprising the following features: A. Providing a refractory gas purge plug (1) according to at least one of the preceding claims; B. The conduction of gas to the first portion (7) and the second portion (9) is controlled by the gas supply device (13).

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