Metallurgical furnace cooling plates

Abstract

The present invention relates to a cooling plate (1) for a metallurgical furnace, the cooling plate (1) comprising: a cooling plate body (10) having a front surface (11) facing the interior of the metallurgical furnace, an opposite rear surface (12), and at least one coolant flow channel (17) therein, the coolant flow channel (17) communicating with a rear opening (13) in the rear surface (12); and a connecting pipe (20) connected to the cooling plate body (10), the pipe flow channel (21) of the connecting pipe (20) communicating with the coolant flow channel (17), the connecting pipe (20) adapted to carry a coolant fluid to or from the coolant flow channel (17). The cooling plate body (10) has receiving holes (14) extending in the bore direction (B) from the rear opening (13) to the coolant channels (17), which are spaced apart in the bore direction (B) from the rear face (12) by a cover thickness (C) of the cover part (11.3) and extend in the bore direction (B) across a width (W). To provide a means for preventing leakage in the cooling system of the metallurgical furnace, the present invention provides that the ends (23) of the connecting pipes (20) extend in the bore direction (B) beyond the cover thickness (C) into the receiving holes (14) and are form-fitted within the receiving holes (14) along at least a portion of the width (W) of the coolant channels (17). This form-fit prevents movement perpendicular to the bore direction (B) relative to the cooling plate body (10).

Description

[Technical Field]

[0001] The present invention relates to a cooling plate for a metallurgical furnace and to a method for manufacturing such a cooling plate. [Background technology]

[0002] Cooling plates, also called cooling staves, are used in metallurgical furnaces, e.g., blast furnaces, as part of the blast furnace's cooling system. They are located inside the blast furnace's outer shell, and their surfaces facing the interior of the blast furnace can be lined with refractory material. The cooling plates have internal coolant channels connected to other parts of the cooling system by connecting pipes that supply coolant, e.g., water. The connecting pipes are guided through drilled holes in the furnace's outer steel shell. According to one design, the cooling staves and connecting pipes are made of copper (or a copper alloy).

[0003] Currently, the connection between the copper tube and the copper stave body is made by preparing the weld seam and by pre-applying a small countersunk section on the copper stave body. This countersunk section serves to position the connecting tube and provide a flat support surface for it. The weld preparation is made so that an HV weld (a square groove weld) can be created between the cooling tube and the copper stave body. However, this welded joint has a weak point. Due to wear and thermal stress during operation, the copper stave body deforms, for example into a bent or "banana" shape. This deformation changes the position and angle of the cooling tube relative to the outer shell of the blast furnace.

[0004] To absorb a certain portion of this deformation and close the holes in the blast furnace shell airtight, it is known to weld so-called compensators between the shell and the cooling pipes, as disclosed, for example, in Patent Document 1. These compensators, which form a kind of annular element around the connecting pipe, can only absorb a certain amount of deformation. If this deformation is exceeded, the compensators form a fixed point on the connecting pipe. During blast furnace operation, the stave body often undergoes further deformation, placing a load on the connecting pipe. This load is transferred from the fixed point to the connection between the stave body and the connecting pipe and thus to the weld. This can lead to cracks in the weld, leading to leaks and thus water entering the blast furnace. Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide a means for preventing water leakage in the cooling system of a metallurgical furnace. This object is solved by a cooling plate according to claim 1 and a method according to claim 17. [Means for solving the problem]

[0006] The present invention provides a cooling plate for a metallurgical furnace, which may be a vertical furnace, in particular a blast furnace, and it is understood that when installed in the metallurgical furnace, the cooling plate serves to cool the outer shell of the furnace.

[0007] The cooling plate has a front surface facing the inside of the metallurgical furnace, an opposite rear surface, and at least one coolant channel inside the cooling plate body, which coolant channel communicates with a rear opening in the rear surface. The cooling plate, which may also be called a cooling panel or cooling stave, is typically intended to be installed inside the outer shell of a metallurgical furnace. In an assembled state, the cooling plate can be arranged parallel to or concentric with the outer shell. The cooling plate body can be made from a single metal part, for example, by casting. Although the present invention is not limited thereto, the cooling plate body is preferably made of a copper-containing metal, i.e., copper or a copper alloy. The cooling plate has a front surface facing the inside of the metallurgical furnace, i.e., in an assembled state, this front surface faces the inside of the blast furnace. To increase the surface area of the front surface, the front surface can be provided with multiple ribs, and two consecutive ribs are separated by a groove. The cooling plate body further has a rear surface arranged opposite the front surface, i.e., this rear surface faces the outside of the metallurgical furnace. When the cooling plate is installed inside the shell of a blast furnace, its rear surface faces the shell. Typically, the cooling system of a metallurgical furnace comprises multiple cooling plates, which provide some degree of protection for the entire shell from excessive heat. If necessary, at least one surface of the cooling plate may be provided with a refractory lining to protect the surface from excessive heat and / or mechanical wear. At least one coolant channel is arranged inside the cooling plate body. The coolant channel is an elongated cavity inside the cooling plate body, and is usually linear. In particular, the coolant channel may have a circular or oval cross section. It is understood that the coolant channel is designed to contain and guide a coolant, for example, water.

[0008] The cooling plate further comprises a connecting pipe connected to the cooling plate, the pipe flow path of the connecting pipe being in communication with the coolant flow path, and the connecting pipe is adapted to exchange cooling fluid with the coolant flow path. The connecting pipe is typically made of a single metal and has a predetermined length. The connecting pipe may be of various lengths, generally selected to be long enough to extend from the back side of the cooling plate body through the outer shell and protrude to the outside of the blast furnace body for connection to the cooling system. Like the cooling plate body, the connecting pipe is preferably made of a copper-containing metal, i.e., copper or a copper alloy. Although the present invention is not limited thereto, the connecting pipe preferably has a circular cross section. The connecting pipe has a tube flow path, i.e., an inner duct, which is typically also of circular cross section. The tube flow path is bounded by the tube wall of the connecting pipe from the outside. The connecting pipe is connected to the cooling plate body so that the tube flow path is in communication with the coolant flow path. Here and hereinafter, "in communication" refers to a configuration that allows exchange of coolant. In other words, the coolant flow channels and the tube flow channels are connected such that coolant can flow from the coolant flow channels to the tube flow channels and vice versa, i.e., the connecting tubes are adapted to carry coolant (i.e., cooling fluid) to or from the coolant flow channels.

[0009] The cooling plate further includes a receiving hole extending from the rear opening into the coolant channel in the hole direction. Adjacent to at least a first side of the receiving hole, the coolant channel extends across a width in the hole direction, spaced apart from the rear surface by the cover thickness of the cover. The term "receiving hole" should not be construed as requiring drilling or drilling, although drilling or drilling is a preferred method for forming the receiving hole. The receiving hole extends in the hole direction, and this hole direction also corresponds to the axis of symmetry of the receiving hole. The receiving hole extends from the rear opening into the coolant channel and may extend beyond the coolant channel. The shape of the receiving hole is not limited, but preferably has a circular cross section. In this regard, the width of the coolant channel is its dimension measured along the hole direction. Since the hole direction is typically perpendicular to the axis of the coolant channel, in the case of a circular cross section, the width of the coolant channel corresponds to its diameter. In the hole direction, the coolant channel is also spaced apart from the rear surface by the cover thickness of the cover. In other words, the coolant channels are separated from the rear surface by a cover portion of the cooling plate body, which has a thickness (in the hole direction) referred to as the cover thickness. Often, the coolant channels are parallel to the rear surface such that the cover thickness is constant along the entire length of the coolant channels, and this also applies to the width of the coolant channels. When the cover thickness and / or width are not constant, these terms refer specifically to the cover thickness and width of the coolant channels adjacent to and on a first side of the receiving hole. As explained below, in some embodiments, the cover portion may not be present on the second side of the receiving hole (opposite the first side). In other embodiments, the cover portion is present on both sides of the receiving hole, and the cover thickness is typically the same on both sides.

[0010] The ends of the connecting tubes extend into the receiving holes in the hole direction beyond the cover thickness and are received in the receiving holes with a form fit along at least a portion of the width of the coolant channels. The fit advantageously prevents movement perpendicular to the hole direction relative to the cooling plate body. The tube channels are straight at the ends. Naturally, this form fit refers to at least one direction perpendicular to the hole direction, and preferably to any direction perpendicular to the hole direction. The inner dimensions of the receiving holes and the outer dimensions of the ends are adapted so that the ends cannot move perpendicular to the hole direction (or only move to a negligible extent). Typically, the cross section of the receiving holes corresponds approximately to the cross section of the connecting tubes. For example, if the connecting tubes have a circular cross section, the same applies to the receiving holes.

[0011] More specifically, the end portion extends beyond the cover thickness into the receiving hole and is form-fitted along at least a portion of the width of the coolant flow passage in the hole direction. It is understood that the receiving hole extends through the cover portion along at least a portion of the width of the coolant flow passage. Because the form-fit connection exists not only locally but also along at least a portion of the width of the coolant flow passage, the connection can receive or transmit not only forces perpendicular to the hole direction but also torque around an axis perpendicular to the hole direction. Furthermore, force transmission between the end portion of the connecting tube and the coolant plate does not occur locally but along a specific length or region. Therefore, local pressure and stress are significantly reduced. In contrast to the prior art, force transmission is not concentrated at a single one-dimensional weld seam. Therefore, the connection between the connecting tube and the cooling plate body can be maintained even if the cooling plate body (and / or the connecting tube) undergoes significant deformation during operation of the cooling plate. The connecting tubes are inserted deep into the receiving holes (i.e., through the cover separating the coolant channels from the rear face and beyond the cover thickness), and a form-fit connection is established at least partially within the area of the coolant channels (i.e., along their width). This allows a secure connection to be established without the need to extend the cooling plate body, for example, by providing an annular part or the like on the rear face. Instead, the rear face can have a simple, flat shape, which facilitates the manufacturing process and reduces manufacturing costs. It is also beneficial for the tube channels to be straight at their ends, i.e., without bends or other features that could complicate the manufacture of the ends and, in some cases, the insertion of the ends into the receiving holes. In at least some embodiments, the tube channels are straight along their entire length. Furthermore, the tube channels typically have end openings along their axial length, corresponding to open-ended tubes.

[0012] Thus, to ensure a sufficiently stable connection between the connecting tube and the cooling plate body, a form fit is sufficient, but the end is preferably press-fit into the receiving hole. In other words, the outer dimensions of the connecting tube are selected to be slightly larger than the inner dimensions of the receiving hole. For example, if both the receiving hole and the connecting tube have circular cross sections, the outer radius of the connecting tube is selected to be slightly (e.g., by a few tenths of a millimeter or a few millimeters) larger than the inner radius of the receiving hole. Therefore, in order to insert the end of the connecting tube, the connecting tube and / or the cooling plate body around the receiving hole must be deformed. This press fit not only increases the stability of the mechanical connection, but also improves the sealing of the connection against the coolant.

[0013] It is understood that by increasing the length of the end portion received within the receiving hole, the reliability of the connection between the cooling plate body and the connecting tube can be increased. According to a preferred embodiment, the end portion is form-fitted within the receiving hole along at least 50% of the width of the coolant channel. In this embodiment, it can be said that the receiving hole and the end portion extend through the coolant channel at least to its middle portion. More preferably, the end portion can be form-fitted within the receiving hole along the entire width of the coolant channel.

[0014] In particular, the receiving holes and ends can extend beyond the coolant passages in the bore direction, or can be said to extend through the coolant passages or extend beyond the cover thickness and the width of the coolant passages. The receiving holes can have flat end faces against which the ends of the connecting tubes abut.

[0015] Although the mechanical stability of the connection between the connecting tube and the cooling plate body is primarily established by a form-fit, especially when the connecting tube is press-fit into the receiving hole, it is generally desirable to complement this connection, especially to ensure liquid-tightness against the coolant. Therefore, the connecting tube is preferably connected to the cooling plate body by a welded connection adjacent to the rear opening. This welded connection may include, in particular, a sealed annular weld seam around the rear opening. On the one hand, the welded connection strengthens the mechanical connection between the cooling plate body and the connecting tube. However, the most important function of the welded connection is usually to provide a fluid-tight seal. It should be noted that, since any mechanical stress is largely absorbed by the form-fit connection, the stress of the welded connection is significantly reduced compared to the prior art. Other options for improving the seal and strength of the connection at the interface between the connecting tube and the cooling plate body (or the respective receiving hole) include gluing or threading.

[0016] Preferably, the cooling plate body has a countersunk portion arranged circumferentially around the rear opening, and the weld connection is arranged inside the countersunk portion. This countersunk portion is usually annular. Its outer diameter decreases in the direction toward the front surface, so that a V-shaped cross section of the countersunk portion is formed between the wall of the connecting pipe and the cooling plate body. Again, the weld connection preferably includes a sealed annular weld seam. Specifically, this weld can be an HV weld (HV groove weld).

[0017] Depending on how far the connecting pipe is inserted into the cooling plate body, its pipe wall can be circular all the way around the end. However, if the connecting pipe is inserted deeper into the cooling plate body, its pipe wall can potentially block a significant portion of the cross section of the coolant flow path, which is generally undesirable. To avoid this, the connecting pipe wall preferably has at least one lateral opening through which the pipe flow path communicates with the coolant flow path. This lateral opening can be a recess near the edge of the end. In particular, it can be a through-hole that traverses the pipe wall.

[0018] To minimize disturbance to the coolant flow, it is preferable that the cross section of at least one lateral opening corresponds to the cross section of a coolant channel and that at least one lateral opening is aligned with the coolant channel. In other words, each lateral opening has the same cross section as the coolant channel and is aligned with it, so that it can be considered a continuation of the coolant channel. If the cross section of the lateral opening is slightly smaller (e.g., 10% smaller) than the cross section of the coolant channel, the effect on the coolant flow is minimal and still satisfactory performance can be achieved. The cross section of the lateral opening can also be larger than the cross section of the coolant channel. The shape of the lateral opening can be adapted to the shape of the cross section of the coolant channel. For example, even if the cross section of the tube channel is circular, the lateral opening can have an oval cross section corresponding to the oval cross section of the coolant channel.

[0019] Where the connecting tube is located immediately adjacent the end of the coolant flow passage, a single lateral opening is generally sufficient, however, it is preferred to provide two lateral openings in the tube wall, located on either side of the tube flow passage, particularly where the coolant flow passage continues beyond the location of the connecting tube.

[0020] The coolant channels are typically formed by a drilling process or direct casting, i.e., drilled or molded into the cooling plate body. Similarly, the at least one lateral opening is typically drilled into the tube wall. These drilling processes can be combined in a preferred embodiment, in which the coolant channels and the at least one lateral opening are formed by a single drilled hole. In other words, a single drilled hole or drill path is formed in the cooling plate body and also crosses the tube wall. This means that the connecting tubes are inserted into the receiving holes before the coolant channels are formed, or at least before they are completely formed. The coolant channels, or at least portions near the receiving holes, are then formed by a drilling process that also forms at least one lateral opening. It will be appreciated that this embodiment ensures that the at least one lateral opening has the same cross section as the coolant channels and is aligned with them.

[0021] According to one embodiment, the coolant channels include end openings communicating with the outside of the cooling plate body, and the tube walls hermetically close the coolant channels between the at least one lateral opening and the end opening. As described above, the coolant channels are typically created by drilling holes in the cooling plate body. The drilling operation creates end openings at one end of the coolant channels, i.e., where a drill is inserted into the cooling plate body. End openings can also result from casting processes. According to the prior art, such end openings are often closed by dedicated plugs. These dedicated plugs must be manufactured according to the size of the end opening, inserted into the end opening, and secured, typically by welding. In this embodiment, such plugs are not required because the tube walls hermetically close the coolant channels relative to the end openings. At least one lateral opening is located opposite the end opening to allow fluid communication between the tube channels and the coolant channels. It will be appreciated that eliminating the need for dedicated plugs significantly reduces the manufacturing costs of the cooling plate.

[0022] In another embodiment, the end of the connecting pipe has a first outer dimension perpendicular to the hole direction that is larger than a second outer dimension of the outer portion of the connecting pipe located outside the receiving hole. The (first / second) outer dimension, i.e., outer dimension, can be, for example, the diameter of the respective portion. In both cases, it is a dimension perpendicular to the hole direction. More specifically, it can be a dimension perpendicular to the hole direction and perpendicular to the direction of the coolant channel (or its central axis, as described below). In this embodiment, the end is thicker and / or wider with respect to the outer portion located outside the receiving hole, i.e., outside the cooling plate body. This embodiment can be particularly employed when one dimension of the coolant channel is larger than the dimension of the tube channel. In such a case, the dimension of the lateral opening is preferably adapted to the dimension of the coolant channel. For example, the coolant channel can be oval with a dimension larger than the diameter of the circular tube channel. In this case, the widened end of the connecting pipe can include a lateral opening, also oval, with a dimension corresponding to the coolant channel.

[0023] In some embodiments, the connecting tube can have an end portion with a larger diameter (and thicker tube wall) than the rest of the connecting tube, which strengthens the connection and makes it easier to seal.

[0024] Preferably, the cooling plate body has a general slab shape and includes a plurality of coolant channels extending longitudinally of the cooling plate body. Each coolant channel is provided with two receiving holes at its opposite ends, and a connecting tube is form-fitted into each receiving hole by its end. In such an embodiment, the connecting tube corresponds to the inlet and outlet of the cooling channel. The slab shape of the cooling plate body can be manufactured in a single casting operation. The coolant channels can be provided in the casting operation or can be drilled later.

[0025] As described above, the cover portion separates the coolant flow passage from the rear surface at least on a first side of the receiving hole. In some embodiments, no cover portion is present on another side of the receiving hole. According to such embodiments, on a second side of the receiving hole opposite the at least one lateral opening, the coolant flow passage is open toward the rear surface, and the connecting tube is welded to the cooling plate body at least partially away from the rear surface. This second side is typically located opposite the first side relative to the receiving hole. The cover portion is absent here and can be removed after the coolant flow passage is formed (e.g., before or after drilling the receiving hole, but preferably before inserting the connecting tube). Because the coolant flow passage is open toward the rear surface on this second side, a significant portion of the end is accessible from the outside. This portion is used for making welded connections, for example, within the coolant flow passage, not only near the rear surface but also at least partially away from the rear surface.

[0026] Typically, the coolant flow passages and the tube flow passages are symmetrical, each having its own central axis. Typically, the flow of coolant between the coolant flow passages and the tube flow passages can be optimized when a first central axis of the coolant flow passage and a second central axis of the tube flow passage intersect. Therefore, the first and second central axes are arranged in a single geometric plane. In other words, the coolant flow passages and the tube flow passages are naturally arranged at an angle, for example, a right angle, but they are not offset relative to each other. Even if the two passages are offset so that their respective central axes do not intersect, the flow of coolant can still be quite good, especially if the offset is not large.

[0027] In some cases, the connecting tubes do not only establish a connection with a single coolant channel. For example, in cooling panels known as "two-hole" panels, the coolant channels are paired, drilled adjacent to each other and communicating with the same connecting tube at each end.

[0028] In one such embodiment, the cooling plate body includes two coolant channels. At least one coolant channel is adjacent to the receiving hole on at least a first side thereof, spaced apart from the rear surface by the cover thickness of the cover portion and extending across the width of the receiving hole. The receiving hole extends from the rear opening to both coolant channels, and the tube channels of the connecting tube communicate with both coolant channels. Typically, both channels are spaced apart from the rear surface by the same cover thickness and extend across the same width. Typically, they are adjacent to each other with a dividing wall between them and extend parallel. The connecting tube connects both coolant channels. It should be apparent that the dimensions (e.g., diameter) of the tube channel are typically significantly larger than the dimensions (e.g., diameter) of the individual coolant channels. For example, the cross-sectional area of the tube channel generally corresponds to the combined cross-sectional area of both coolant channels. In practice, the cooling panel includes multiple pairs of coolant channels, each pair communicating with one connecting tube at each end.

[0029] The present invention further provides a method for manufacturing a cooling plate for a metallurgical furnace. The method includes providing a cooling plate body having a front surface and an opposite rear surface, and providing a connecting tube having a straight tube flow path at an end thereof. In another step of the method, the cooling plate body is provided with a receiving hole extending from a rear opening in the rear surface toward the front surface. The receiving hole can be provided, specifically, by drilling the cooling plate body. It should be noted that the receiving hole can be provided before or after the connecting tube is provided. In yet another step, an end of the connecting tube is inserted through the rear opening to connect the connecting tube to the cooling plate by receiving the end of the connecting tube in a form-fit within the receiving hole. Specifically, the connecting tube can be press-fit into the receiving hole.

[0030] In another step of the method, at least one coolant channel is provided in the cooling plate body. The coolant channel is adjacent to the receiving hole at least on a first side thereof, spaced apart from the rear surface in the hole direction by the cover thickness of the cover, and extending across its width in the hole direction. The coolant channel communicates with the rear opening, and the receiving hole extends from the rear opening to the coolant channel. When the end of the connecting tube is received in the receiving hole, the end extends into the receiving hole beyond the cover thickness in the hole direction and is received in a form-fit along at least a portion of the width of the coolant channel. The fit prevents movement of the connecting tube perpendicular to the hole direction relative to the cooling plate body. Preferably, the coolant channel is formed by drilling. It should be noted that the coolant channel can be provided before or after inserting the connecting tube into the receiving hole.

[0031] The preferred embodiment of the inventive method corresponds to the embodiment of the inventive cooling plate and will generally not be described again here.

[0032] According to one embodiment, the ends of the connecting tubes are inserted into the coolant channels after the coolant channels have been formed, e.g., drilled, although it is preferred to drill the coolant channels in the cooling plate body after the ends are inserted into the receiving holes.

[0033] Preferably, the at least one lateral opening in the pipe wall of the connecting pipe is drilled together with the coolant passage in a single drilling operation, in other words, a single drilling operation is performed to form a single perforation that extends through the cooling plate body (as the coolant passage) and through the pipe wall (as the at least one lateral opening).

[0034] According to a preferred embodiment of the method, the tube wall of the connecting tube has at least one lateral opening, and the coolant channel is drilled into the cooling plate body before the end of the connecting tube is inserted into the receiving hole. The tube channel is thereby in communication with the coolant channel through the at least one lateral opening, and the tube wall hermetically closes the coolant channel between the at least one lateral opening and the end opening of the coolant channel, which communicates with the outside of the cooling plate body. This end opening has already been described in relation to the cooling plate. In this embodiment, the cooling channel with the end opening is provided before the connecting tube is inserted into the receiving hole. When the connecting tube is inserted, the tube wall closes the end opening of the cooling channel, eliminating the need for a dedicated plug.

[0035] In a preferred embodiment of the method, the connecting tubes are welded to the cooling plate body. If the coolant channels are drilled after the ends of the connecting tubes are inserted into the receiving holes, the welding can be performed either before or after the coolant channels are drilled. A preferred type of weld connection has been described above in connection with the cooling plate of the present invention. Preferably, before welding, a countersunk portion is formed around the receiving holes, and the weld connection is located inside this countersunk portion.

[0036] According to one embodiment, before the connecting tube is welded to the cooling plate body at the second side of the receiving hole, the cover is removed in a removal area on the second side of the receiving hole opposite the at least one lateral opening, and welding is performed at least partially away from the rear face. In this case, the cover is left intact on the first side of the receiving hole, but the cover is removed, for example, by machining, on the second side opposite the at least one lateral opening (usually also opposite the first side). The area from which the cover is removed is referred to herein as the removal area. Here, the coolant channels are open toward the rear face on this second side, so that a significant portion of the end of the connecting tube is accessible from the outside even after it is inserted into the receiving hole. Therefore, the welding process can be performed not only near the rear face but also away from the rear face, for example, within the coolant channels. It will be understood that such a welded connection increases the stability of the connection between the connecting tube and the cooling plate body. [Brief explanation of the drawings]

[0037] Preferred embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: [Figure 1] 1 is a cross-sectional view of a first embodiment of a cooling plate having a cooling plate body and a connecting tube assembly according to the present invention; [Figure 2] 2 is a perspective cross-sectional view of Detail A of FIG. 1 showing the assembly of the connecting tube to the cooling plate body. [Figure 3] FIG. 3 is a cross-sectional view of a cooling plate body corresponding to FIG. 2. [Figure 4] FIG. 3 is a side view of the connecting pipe of FIG. 2. [Figure 5] FIG. 5 is a side view taken along the direction IV in FIG. [Figure 6] 2 is a cross-sectional view showing a first stage of a method for manufacturing the cooling plate of FIG. 1. FIG. [Figure 7] FIG. 4 is a cross-sectional view showing a second stage of the method for manufacturing a cooling plate. [Figure 8] FIG. 10 is a cross-sectional view showing a third stage of the method for manufacturing a cooling plate. [Figure 9] FIG. 10 is a cross-sectional view showing a fourth stage in the method for manufacturing a cooling plate. [Figure 10] FIG. 4 is a cross-sectional view of a second embodiment of the cooling plate of the present invention. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 11 is a cutaway view of the cooling plate of FIG. [Figure 14] FIG. 11 is a perspective view of the cooling plate in FIG. [Figure 15] FIG. 10 is a cutaway view of a third embodiment of a cooling plate of the present invention. [Figure 16] FIG. 16 is a cross-sectional view of the cooling plate of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0038] 1 shows an embodiment of a cooling plate 1 of the invention in a longitudinal cross section through its thickness. The cooling plate is a metallic cooling plate body 10, typically formed from a slab, for example cast or forged, of copper or a copper alloy.

[0039] The cooling plate body 10 has a front surface, also referred to as the hot surface, generally designated 11, directed towards the interior of the furnace, and an opposite rear surface 12, also referred to as the cold surface, which faces the inner surface of the furnace shell in use.

[0040] As is known in the art, the front surface 11 of the cooling plate body 10 can advantageously have a structured surface, in particular having alternating ribs 11.1 and grooves 11.2, the grooves 11.2 and layered ribs 11.1 generally arranged horizontally to provide a fastening means for a refractory brick lining (not shown) when the cooling plate 1 is mounted in a furnace.

[0041] Reference numeral 17 designates a coolant channel extending longitudinally within the body. Typically, the cooling plate body 10 includes a plurality of coolant channels 17 drilled therein, extending parallel to one another and distributed along the width of the body. The coolant channels 17 are drilled longitudinally through the molded cooling plate body 10 from one end to the other, thereby forming end openings 18 that communicate with the outside of the cooling plate body 10. One end of the coolant channel 17 (the upper end in FIG. 9 ) is not through-hole, and the end opening 18 at the drilled end is closed by a plug 19. In this embodiment, the coolant channel 17 is linear and has a circular cross section. It is also symmetrical about the first central axis A1. The drilling of the coolant channels 17 will also be described further below.

[0042] Each coolant channel 17 is provided with top and bottom access holes in its rear face, typically by drilling. These access holes will hereafter be referred to as receiving holes 14. A metal connecting tube 20 fits into each receiving hole 14 to provide fluid communication between the coolant channel and the blast furnace cooling system. Typically, coolant fluid enters the coolant channel 17 through one of the receiving holes 14 and the associated connecting tube 20, and exits the coolant channel 17 through the other receiving hole.

[0043] Reference is now made to FIG. 2, which shows Detail A of FIG. 1. As can be seen, the receiving holes 14 extend in a hole direction B from the rear opening 13 of the rear face 12 to the coolant channels 17. They also extend slightly beyond the coolant channels, terminating in a flat end face 16. The receiving holes 14 have a circular cross section, which may be larger than the cross section of the coolant channels 17. A countersink 15 is formed circumferentially around the rear opening 13. The coolant channels 17 are separated from the rear face 12 at a first side 26 and a second side 27 of the receiving holes 14 by a cover portion 10.1 of the cooling plate body 10. In the hole direction B, the cover portion 10.1 has a cover thickness C that defines the separation.

[0044] The cooling plate 1 also includes a connecting pipe 20, which also has a circular cross section and a pipe wall 22 surrounding the pipe flow passage 21. The connecting pipe 20 can be made of the same material as the cooling plate body 10. An end 23 of the connecting pipe 20 is press-fit into the receiving hole 14 so as to abut the end face 16. By press-fitting the end 23 into the receiving hole 14, it is received within the receiving hole 14 with a form fit along the entire width W of the coolant flow passage 17. This W is the dimension of the coolant flow passage 17 in the hole direction B. In this case, since the hole direction B is perpendicular to the first central axis A1, the width W corresponds to the diameter of the coolant flow passage 17. The connecting pipe 20 is symmetrical about a second central axis A2 that intersects the first central axis A1 at a right angle.

[0045] The form-fit connection between the cooling plate body 10 and the connecting tube 20 is reinforced by a press fit, ensuring that forces and torques acting between these two components can be transmitted without excessive pressure or stress during operation of the cooling plate 1. This connection is complemented, primarily for sealing purposes, by a welded seam 30 applied to the countersunk portion 15. In the illustrated embodiment, the welded seam 30 corresponds to an HV weld (square groove weld). To provide optimal coolant flow between the coolant channels 17 and the tube channels 21, the tube wall 22 has two lateral openings 24 (also visible in FIGS. 4 and 5, which show the connecting tube 20 separately). These are located on opposite sides of the tube channels 21 and face the first and second sides 26 and 27 of the receiving bore 14, respectively. Each lateral opening 24 has the same cross section as the coolant channel 17 and is aligned with it.

[0046] 6-9 illustrate a method for manufacturing the cooling plate 1. FIG. 6 shows the first stage of this method, in which the cooling plate body 10 is provided with the receiving holes 14 and countersunk portions 15. These can be produced by drilling or machining the copper material of the cooling plate body 10. The coolant channels 17 have not yet been drilled. FIG. 7 shows a new step in which the connecting tubes 20 are inserted into the receiving holes 14 through the rear openings 13 by press-fitting. For the press-fit process, the outer radius of the tube walls 22 must be slightly (e.g., a few millimeters or a few tenths of a millimeter) larger than the inner radius of the receiving holes 14. The countersunk portions 15 form an annular V-groove around the rear openings 13. In the next stage of the method, as shown in FIG. 8, the coolant channels 17 and the lateral openings 24 are drilled in a single drilling operation. This automatically ensures that the lateral openings 24 have the same cross-section as the coolant channels 17 and are aligned with them. In the final step of the method, shown diagrammatically in FIG. 9, an annular weld seam 30 is applied to provide a fluid-tight seal between the connecting tube 20 and the cooling plate body 10 .

[0047] 10 to 14 show a second embodiment of the cooling plate 1 of the present invention. This is similar to the first embodiment, and to that extent will not be described again. The difference is that the coolant channels 17 here have an oval shape, so that the width W is significantly smaller than the diameter of the tube channels 21 (see FIG. 10), while the dimensions of the coolant channels 17 perpendicular to the width W are significantly larger (see FIG. 12). Therefore, the lateral openings 24 of the connecting tubes 20 widen toward the coolant channels 17. Furthermore, in order to provide a seal corresponding to the dimensions inside the coolant channels 17, the ends 23 of the connecting tubes 20 have a first diameter D1 that is larger than the second diameter D2 of the outer portions 25 located outside the receiving holes 14. This increased thickness further strengthens the connection.

[0048] In this embodiment, the sealing function is particularly important because the coolant channels 17 have end openings 18 that open toward the outside of the cooling plate body. In the first embodiment, these end openings 18 are closed with dedicated plugs 19. This plug would need to be manufactured, inserted, and fixed inside the cooling plate body 10, resulting in unnecessary manufacturing costs. However, in this embodiment, the tube wall 22 hermetically closes the coolant channels 17 between the transverse openings 24 and the end openings 18. This prevents coolant from leaking from the tube channels 21 and the coolant channels 17 to the end openings 18. Furthermore, the cover part 10.1 has been removed, for example, by machining, at a removal area 10.2 on the second side 27 of the receiving hole 14, as shown by the dotted line in FIG. 10 . Therefore, the end 23 is accessible from the outside. In addition to the weld seam 31 on the first side surface 26 adjacent to the rear opening 31, another weld seam 32 is applied on the second side surface 27 extending away from the rear side surface 12 towards the front side surface 11. The application of this weld seam 32 is facilitated or made possible by removing the cover part 10.1 in the removal area 10.2. It should be noted that, compared to the previous embodiment, the connecting pipe 20 only has one end opening 24 directed towards the first side surface 26, i.e. for receiving the coolant flow from the flow channel 17.

[0049] 15 and 16 show a third embodiment of the cooling plate 1 of the present invention, which is nearly identical to the second embodiment. However, in this case, the coolant channels are drilled in adjacent pairs. As can be seen, the cooling plate body 10 includes two parallel coolant channels 17, separated by a dividing wall 10.3. The tube channel 21 communicates with both coolant channels 17 through a single lateral opening 24. Alternatively, there may be two lateral openings 24, one for each coolant channel 17. The receiving holes 14 extend from the rear opening 13 into both coolant channels 17 and beyond to the flat end face 16.

[0050] In this embodiment, the coolant channels 17 are formed by drilling, but they may alternatively be formed by casting. Similarly, the rear opening 13 and the receiving holes 14 may be formed by casting together with the cooling plate body 10. With regard to materials, copper (and copper alloys) are commonly used for the cooling plate body 10, but other suitable materials may also be used, such as cast iron. [Explanation of symbols]

[0051] 1 cooling plate 10 Cooling plate body 10.1 Cover 10.2 Removal area 10.3 Dividing wall 11 Front 11.1 Rib 11.2 Groove 12 Rear 13 Rear opening 14 Receptacle 15 Plate kneading section 16 End face 17 Coolant flow path 18 End opening 19 Plug 20 Connecting pipe 21 Pipe flow path 22 Pipe wall 23 End 24 Lateral opening 25 Outer part 26,27 Side 30, 31, 32 Welded seams A1,A2 center axis B hole direction C Cover Thickness D1,D2 diameter W width [Prior art documents] [Patent documents]

[0052] [Patent Document 1] European Patent No. 1466989

Claims

1. A cooling plate (1) for a metallurgical furnace, comprising: a cooling plate body (10) having a front surface (11) facing the interior of the metallurgical furnace, an opposite rear surface (12), and at least one coolant flow channel (17) inside the cooling plate body (10), the coolant flow channel (17) communicating with a rear opening (13) in the rear surface (12); a connecting pipe (20) connected to the cooling plate body (10), the pipe flow path (21) of which is connected to communicate with the coolant flow path (17) and adapted to carry a coolant fluid to or from the coolant flow path (17); The cooling plate body (10) has receiving holes (14) extending in a hole direction (B) from the rear opening (13) into the coolant flow passages (17), the coolant flow passages (17) being adjacent to the receiving holes (14) at least at a first side (26) of the receiving holes (14) and spaced apart in the hole direction (B) from the rear surface (12) by a cover thickness (C) of the cover part (10.1) and extending in the hole direction (B) over a width (W), and an end (23) of the connecting pipe (20) is spaced apart from the rear surface (12) in the hole direction (B) by a cover thickness (C) of the cover part (10.1). and the tube flow passages (21) extend into the receiving holes (14) in the hole direction (B) and are received in the receiving holes (14) in a fitted state along the entire width (W) of the coolant flow passages (17), the inner diameter of the receiving holes (14) and the outer diameter of the ends (23) are adapted so that the ends (23) cannot move in a direction perpendicular to the hole direction (B), and this fitting prevents movement perpendicular to the hole direction (B) relative to the cooling plate body (10), and the tube flow passages (21) are straight at the ends (23).

2. The cooling plate of claim 1 , wherein the end (23) is press-fit into the receiving hole (14).

3. 3. A cooling plate according to claim 1 or 2, characterized in that the receiving holes (14) and the ends (23) extend beyond the coolant channels (17) in the hole direction (B).

4. 4. The cooling plate according to claim 1, wherein the connecting pipe (20) is connected to the cooling plate body (10) by a welded connection (30, 31, 32) adjacent to the rear opening (13).

5. A cooling plate as described in claim 4, wherein the cooling plate body (10) has a countersunk portion (15) arranged circumferentially around the rear opening (14), and the welded connection portions (30, 31, 32) are arranged inside the countersunk portion (15).

6. 6. The cooling plate according to claim 1, wherein the tube wall (22) of the connecting tube (20) comprises at least one lateral opening (24) through which the tube flow passage (21) communicates with the coolant flow passage (17).

7. 7. The cooling plate of claim 6, wherein a cross section of the at least one lateral opening (24) corresponds to a cross section of the coolant channel (17), and the at least one lateral opening (24) is aligned with the coolant channel (17).

8. 8. Cooling plate according to claim 7, characterized in that the tube wall (22) comprises two lateral openings (24) arranged on either side of the tube flow passage (21).

9. 7. The cooling plate of claim 6, wherein the coolant channel (17) and the at least one lateral opening (24) are formed by a single drilled hole.

10. 7. The cooling plate according to claim 6, wherein the coolant channels (17) comprise end openings (18) communicating with the outside of the cooling plate body (10), and the tube walls (22) hermetically close the coolant channels (17) between the at least one lateral opening (24) and the end openings (18).

11. 11. A cooling plate according to claim 1, wherein the end (23) of the connecting pipe (20) has a first outer dimension (D1) perpendicular to the hole direction (B) that is greater than a second outer dimension (D2) at an outer portion (25) of the connecting pipe (20) arranged outside the receiving hole (14).

12. 7. The cooling plate according to claim 6, wherein the coolant flow passages (17) are open towards the rear face (12) at a second side (27) of the receiving hole (14) opposite the at least one lateral opening (24), and the connecting pipe (20) is welded to the cooling plate body (10) at least partially away from the rear face (12).

13. 13. The cooling plate according to claim 1, wherein the first central axes (A1) of the coolant channels (17) and the second central axes (A2) of the tube channels (21) intersect.

14. 14. The cooling plate according to claim 1, wherein the cooling plate body (10) comprises two coolant channels (17), at least one coolant channel (17) adjacent to the receiving hole (14) on a first side (26) of the receiving hole (14) being spaced apart from the rear face (12) in the hole direction (B) by a cover thickness (C) of the cover part (10.1) and extending in the hole direction (B) across the width (W), the receiving hole (14) extending from the rear opening (13) into both coolant channels (17), and the tube channels (21) of the connecting tube (20) communicating with both coolant channels (17).

15. A method for manufacturing a cooling plate (1) for a metallurgical furnace, comprising the steps of: providing a cooling plate body (10) having a front surface (11) and an opposite rear surface (12); providing a connecting pipe (20) having a straight pipe flow path (21) at an end (23); providing a receiving hole (14) in the cooling plate body (10) extending from a rear opening (13) of the rear surface (12) toward the front surface (11) in a hole direction (B); inserting the end (23) of the connecting pipe (20) through the rear opening (13) so as to be received in the receiving hole (14) in a mating state, thereby connecting the connecting pipe (20) to the cooling plate body (10); At least one coolant flow channel (17) is provided inside the cooling plate body (10), at least adjacent to the receiving hole (14) on a first side (26) of the receiving hole (14), the coolant flow channel (17) is spaced from the rear surface (12) in the hole direction (B) by a cover thickness (C) of the cover part (10.1) and extends in the hole direction (B) over a width (W), the coolant flow channel (17) communicates with the rear opening (13), and the receiving hole (14) is connected from the rear opening (13) to the coolant flow channel (17). the end (23) extends across the entire width (W) of the coolant flow passage (17), and when received in the receiving hole (14), the end (23) extends beyond the cover thickness (C) into the receiving hole (14) in the hole direction (B) and is received in a fitted state along the entire width (W) of the coolant flow passage (17), and the inner diameter of the receiving hole (14) and the outer diameter of the end (23) are adapted to prevent the end (23) from moving in a direction perpendicular to the hole direction (B), and this fitting prevents movement perpendicular to the hole direction (B) relative to the cooling plate body (10).

16. 16. The method of claim 15, wherein the coolant channels (17) are drilled in the cooling plate body (10) after the ends (23) are inserted into the receiving holes (14).

17. A method as described in claim 16, wherein at least one lateral opening (24) in the pipe wall (22) of the connecting pipe (20) is drilled together with the coolant flow path (17) in a single drilling operation.

18. 16. The method according to claim 15, wherein the pipe wall (22) of the connecting pipe (20) comprises at least one lateral opening (24), the pipe flow path (21) communicates with the coolant flow path (17) via the at least one lateral opening (24), and the coolant flow path (17) is drilled in the cooling plate body (10) before the end (23) is inserted into the receiving hole (14) so that the pipe wall (22) hermetically closes the coolant flow path (17) between the at least one lateral opening (24) and an end opening (18) of the coolant flow path (17) that communicates with the outside of the cooling plate body (10).

19. 19. Method according to any one of claims 15 to 18, characterized in that the connecting pipe (20) is welded to the cooling plate body (10).

20. 19. The method according to claim 18, characterized in that before the connecting pipe (20) is welded to the cooling plate body (10) on the second side (27) of the receiving hole (14), the cover part (10.2) is removed in a removal area (10.2) on the second side (27) of the receiving hole (14) opposite the at least one lateral opening (24), and the welding is performed at least partially away from the rear face (12).

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