COOLING PLATE FOR A METALLURGICAL FURNACE

Abstract

A metallurgical furnace cooling plate includes a cooling plate body with front and rear faces and at least one coolant channel inside the body, which communicates with a rear opening on the rear face; and a connection pipe connected to the body so that a pipe channel of the connection pipe communicates with the coolant channel, the connection pipe adapted for carrying coolant fluid to or from the channel.

The body includes a receiving bore extending in a bore direction from the rear opening into the coolant channel, the channel being spaced in the bore direction from the rear face by a cover thickness of a cover portion and extends in the bore direction over a width. A connection pipe end portion extends into the receiving bore beyond the cover thickness and is form-fittingly received in the receiving bore along at least a portion of a width of the channel.

Claims

1. A cooling plate for a metallurgical furnace, comprising a cooling plate body having with a front face for facing the inside of the metallurgical furnace, an opposite rear face and at least one coolant channel inside the cooling plate body, wherein the coolant channel communicates with a rear opening on the rear face; and a connection pipe connected to the cooling plate body so that a pipe channel of the connection pipe communicates with the coolant channel, said connection pipe being adapted for carrying coolant fluid to or from said coolant channel; wherein the cooling plate body comprises a receiving bore that extends in a bore direction from the rear opening into the coolant channel, wherein, at least adjacent the receiving bore on a first side of the receiving bore, the coolant channel is spaced in the bore direction from the rear face by a cover thickness of a cover portion and extends in the bore direction over a width, wherein an end portion of the connection pipe extends into the receiving bore in the bore direction beyond the cover thickness and is form-fittingly received in the receiving bore along at least a portion of the width of the coolant channel, which form fit prevents movement perpendicular to the bore direction with respect to the cooling plate body, wherein the pipe channel is straight in the end portion.

2. The cooling plate according to claim 1, wherein the end portion is press fitted into the receiving bore.

3. The cooling plate according to claim 1, wherein the end portion is form-fittingly received in the receiving bore along at least 50% of the width of the coolant channel.

4. The cooling plate according to claim 3, wherein the end portion is form-fittingly received in the receiving bore along the entire width of the coolant channel.

5. The cooling plate according to claim 4, wherein the receiving bore and the end portion extend in the bore direction beyond the coolant channel.

6. The cooling plate according to claim 1, wherein the connection pipe is connected to the cooling plate body by a welding connection proximate to the rear opening; and the cooling plate body comprises a countersink circumferentially disposed around the rear opening, wherein the welding connection is disposed inside the countersink.

7. The cooling plate according to claim 1, wherein a pipe wall of the connection pipe comprises at least one lateral opening through which the pipe channel communicates with the coolant channel.

8. The cooling plate according to claim 6, wherein a cross-section of the at least one lateral opening corresponds to a cross-section of the coolant channel and the at least one lateral opening is aligned with the coolant channel.

9. The cooling plate according to claim 7, wherein the pipe wall comprises two lateral openings arranged on opposite sides of the pipe channel.

10. The cooling plate according to claim 6, wherein the coolant channel and the at least one lateral opening are formed by a single drill hole.

11. The cooling plate according to claim 6, wherein the coolant channel comprises an end opening communicating with the outside of the cooling plate body, wherein the pipe wall sealingly closes the coolant channel between the at least one lateral opening and the end opening.

12. The cooling plate according to claim 1, wherein the end portion of the connection pipe has a first outer dimension perpendicular to the bore direction that is larger than a second outer dimension of an external portion of the connection pipe that is disposed outside the receiving bore.

13. The cooling plate according to claim 1, wherein the cooling plate body has a general slab shape and comprises a plurality of coolant channels extending in a longitudinal direction of the cooling plate body, two of said receiving bores being provided for each coolant channel at opposite extremities thereof, a connection pipe being form fittingly received by its end portion in a respective receiving bore.

14. The cooling plate according to claim 6, wherein on a second side of the receiving bore opposite the at least one lateral opening, the coolant channel is open towards the rear face and the connection pipe is welded to the cooling plate body at least partially away from the rear face.

15. The cooling plate according to claim 1, wherein a first central axis the coolant channel and a second central axis of the pipe channel intersect.

16. The cooling plate according to claim 1, wherein the cooling plate body comprises two coolant channels, wherein, at least adjacent the receiving bore on a first side thereof, at least one coolant channel is spaced in the bore direction from the rear face by a cover thickness of a cover portion and extends in the bore direction over the width, the receiving bore extends from the rear opening into both coolant channels, and the pipe channel of the connection pipe communicates with both coolant channels.

17. A method for manufacturing a cooling plate for a metallurgical furnace, the method including the following steps: providing a cooling plate body having a front face and an opposite rear face; providing a connection pipe having a pipe channel that is straight in an end portion of the connection pipe; providing a receiving bore in the cooling plate body that extends in a bore direction from a rear opening on the rear face towards the front face; and inserting the end portion of the connection pipe through the rear opening so that it is form-fittingly received in the receiving bore, thereby connecting the connection pipe to the cooling plate body, wherein at least one coolant channel is provided inside the cooling plate body, so that at least adjacent the receiving bore on a first side thereof, the coolant channel is spaced in the bore direction from the rear face by a cover thickness of a cover portion and extends in the bore direction over a width, the coolant channel communicates with the rear opening and the receiving bore extends from the rear opening into the coolant channel, and when the end portion is received in the receiving bore, it extends into the receiving bore in the bore direction beyond the cover thickness and is form-fittingly received along at least a portion of the width of the coolant channel, which form fit prevents movement perpendicular to the bore direction with respect to the cooling plate body.

18. The method according to claim 17, wherein the coolant channel is drilled into the cooling plate body after the end portion is inserted into the receiving bore; and at least one lateral opening in a pipe wall of the connection pipe is drilled along with the coolant channel in a single drilling operation.

19. The method according to claim 17, wherein a pipe wall of the connection pipe comprises at least one lateral opening, and the coolant channel is drilled into the cooling plate body before the end portion is inserted into the receiving bore so that the pipe channel communicates with the coolant channel through the at least one lateral opening and the pipe wall sealingly closes the coolant channel between the at least one lateral opening and an end opening of the coolant channel that communicates with the outside of the cooling plate body.

20. The method according to claim 17, wherein the connection pipe is welded to the cooling plate body.

21. The method according to claim 19, wherein the cover portion is removed in a removal region on a second side of the receiving bore opposite the at least one lateral opening before the connection pipe is welded to the cooling plate body on the second side of the receiving bore, which welding is at least partially performed away from the rear face.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Preferred embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:

[0038] FIG. 1 is a sectional view illustrating a first embodiment of a cooling plate with an assembly of cooling plate body and a connection pipe according to the disclosure;

[0039] FIG. 2 is a perspective sectional view of detail A of FIG. 1, illustrating the assembly of the connection pipe to the cooling plate body;

[0040] FIG. 3 is a sectional view of the cooling plate body corresponding to FIG. 2;

[0041] FIG. 4 is a side view of the connection pipe from FIG. 2;

[0042] FIG. 5 is side view along the direction IV in FIG. 4;

[0043] FIG. 6 is a sectional view illustrating a first stage of a method for producing the cooling plate from FIG. 1;

[0044] FIG. 7 is a sectional view illustrating a second stage of the method for producing the cooling plate;

[0045] FIG. 8 is a sectional view illustrating a third stage of the method for producing the cooling plate;

[0046] FIG. 9 is a sectional view illustrating a fourth stage of the method for producing the cooling plate;

[0047] FIG. 10 is a sectional view of second embodiment of an inventive cooling plate;

[0048] FIG. 11 is a sectional view along the line XI-XI in FIG. 10;

[0049] FIG. 12 is a sectional view along the line XII-XII in FIG. 11;

[0050] FIG. 13 is a cutaway view of the cooling plate from FIG. 10;

[0051] FIG. 14 is a perspective view of the cooling plate from FIG. 10;

[0052] FIG. 15 is a cutaway view of a third embodiment of an inventive cooling plate; and

[0053] FIG. 16 is a sectional view of the cooling plate from FIG. 15.

DETAILED DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 shows an embodiment of the present cooling plate 1, in a longitudinal cross-section view in the thickness direction. The cooling plate has a metallic cooling plate body 10 that is typically formed from a slab e.g. a cast or forged body of metal, in particular copper or copper alloy.

[0055] The cooling plate body 10 has a front face generally indicated 11, also referred to as hot face, which is turned towards the furnace interior, and an opposite rear face 12, also referred to as cold face, which in use faces the inner surface of the furnace shell.

[0056] As is known in the art, the front face 11 of the cooling plate body 10 may advantageously have a structured surface, in particular with alternating ribs 11.1 and grooves 11.2. When the cooling plate 1 is mounted in the furnace, the grooves 11.2 and lamellar ribs 11.1 are generally arranged horizontally in order to provide an anchoring means for a refractory brick lining (not shown).

[0057] Reference sign 17 designates a coolant channel extending longitudinally in the body. Typically the cooling plate body 10 comprises a plurality of coolant channels 17 drilled in the body that run parallel to one another and are distributed along the width of the body. The coolant channels 17 are drilled through the shaped cooling plate body 10 from one longitudinal end to the other, whereby an end opening 18 is created that communicates with an outside of the cooling plate body 10. One end of the coolant channel 17 is blind (top end in FIG. 9) whereas end opening 18 at the drilling end is closed by a plug 19. In this embodiment, the coolant channel 17 is straight and has a circular cross-section. It is symmetric with respect to a first central axis Al. Drilling of the coolant channel 17 will also be discussed further below.

[0058] For each coolant channel 17, a top and bottom access hole is provided in the rear face, generally by drilling. In the following, these access holes are referred to as receiving bores 14. A metallic connection pipe 20 is fitted in each receiving bore 14 allowing fluid communication between the coolant channel and the cooling system of the blast furnace. Typically, the coolant fluid enters the coolant channel 17 via one of the receiving bores 14 and the associated connection pipe 20, and exits the coolant channel 17 though the other.

[0059] Let us now refer to FIG. 2, which shows detail A of FIG. 1. As can be seen, the receiving bore 14 extends in a bore direction B from a rear opening 13 on the rear face 12 into the coolant channel 17. It even extends somewhat beyond the coolant channel and ends in a plain end surface 16. The receiving bore 14 has a circular cross-section that may be greater than the cross-section of the coolant channel 17. A countersink 15 is formed circumferentially about the rear opening 13. The coolant channel 17 is spaced from the rear face 12 by a cover portion 10.1 of the cooling plate body 10 on a first side 26 and a second side 27 of the receiving bore 14. In the bore direction B, the cover portion 10.1 has a cover thickness C that defines the spacing.

[0060] The cooling plate 1 also comprises a connection pipe 20 that also has a circular cross-section and comprises a pipe wall 22 that surrounds a pipe channel 21. The connection pipe 20 can be made of the same material as the cooling plate body 10. An end portion 23 of the connection pipe 20 has been inserted by press-fitting into the receiving bore 14 so that it abuts the end surface 16. By press fitting the end portion 23 into the receiving bore 14, it is form fittingly received in the receiving bore 14 along the entire width W of the coolant channel 17, which with W is the dimension of the coolant channel 17 in the bore direction B. Since in this case, the bore direction B is perpendicular to the first central axis A1, the width W corresponds to the diameter of the coolant channel 17. In the connection pipe 20 is symmetrical about a second central axis A2, which intersects the first central axis A1 at a right angle.

[0061] The form fitting connection between the cooling plate body 10 and the connection pipe 20, which is enhanced by press-fitting, guarantees that any forces and torques acting between these two elements during operation of the cooling plate 1 can be transferred without leading to excessive pressure or stress. Mainly for sealing purposes, the connection is supplemented by a welding seam 30 that is applied in the countersink 15. In the embodiment shown, the welding seam 30 corresponds to an HV weld (single bevel groove weld). In order to provide an optimum coolant flow between the coolant channel 17 and the pipe channel 21, the pipe wall 22 comprises two lateral openings 24 (also visible in in FIGS. 4 and 5, which show the connection pipe 20 individually) that are arranged on opposite sides of the pipe channel 21, and face the first side 26 and the second side 27, respectively, of the receiving bore 14. Each lateral opening 24 has the same cross-section as the coolant channel 17 and is aligned with the coolant channel 17.

[0062] FIGS. 6 to 9 illustrate a method for producing the cooling plate 1. FIG. 6 illustrates a first stage of the method, in which the cooling plate body 10 is provided with the receiving bore 14 and the countersink 15. These can be produced by drilling or machining into the copper material of the cooling plate body 10. The coolant channel 17 has not yet been drilled. FIG. 7 illustrates another step, in which the connection pipe 20 is inserted by press fitting through the rear opening 13 into the receiving bore 14. For the press-fitting process, the outer diameter of the pipe wall 22 has to be somewhat greater (e.g. by a few millimetres or tenths of a millimetre) than the inner diameter of the receiving bore 14. The countersink 15 forms an annular, V-shaped groove around the rear opening 13. In a next stage of the method, as shown in FIG. 8, the coolant channel 17 and the lateral openings 24 are drilled with a single drilling process. This automatically guarantees that the lateral openings 24 have the same cross-section as the coolant channel 17 and are aligned with it. In a final stage of the method, which is illustrated in FIG. 9, the annular welding seam 30 is applied to provide a fluid-tight seal between the connection pipe 20 and the cooling plate body 10.

[0063] FIGS. 10 to 14 show a second embodiment of an inventive cooling plate 1, which is similar to the first embodiment and will insofar not be described again. One difference is that the coolant channel 17 here has an oblong shape, wherefore the width W is considerably smaller than the diameter of the pipe channel 21 (see FIG. 10), while a dimension of the coolant channel 17 perpendicular to the width W is considerably larger (see FIG. 12). Accordingly, the lateral opening 24 of the connecting pipe 20 widens towards the coolant channel 17. Also, in order to provide a seal inside the coolant channel 17 corresponding to its dimensions, the end portion 23 of the connecting pipe 20 has a first diameter D1 that is greater than a second diameter D2 of an external portion 25 that is disposed outside of the receiving bore 14. This increased thickness further reinforces the connection.

[0064] In this embodiment, the sealing function is particularly important, since the coolant channel 17 has an end opening 18 that is open toward the outside of the cooling plate body. In the first embodiment, such an end opening 18 is closed with a dedicated plug 19, which needs to be manufactured, inserted and secured inside the cooling plate body 10, leading to undesirable production costs. In this embodiment, however, the pipe wall 22 sealingly closes the coolant channel 17 between the lateral opening 24 and the end opening 18. Thus, coolant is prevented from flowing from the pipe channel 21 or the coolant channel 17 to the end opening 18. Also, the cover portion 10.1 has been removed, e.g. by machining, in a removal region 10.2 on the second side 27 of the receiving bore 14, as is indicated by the dotted lines in FIG. 10. Thus, the end portion 23 is accessible from the outside. In addition to a welding seam 31 on the first side 26 adjacent the rear opening 31, another welding seam 32 is applied on the second side 27 extending away from the rear face 12 towards the front face 11. Application of this welding seam 32 is facilitated or made possible by the removal of the cover portion 10.1 in the removal region 10.2. Compared to the previous embodiment, it may be noted that connection pipe 20 has only one end opening 24, which is turned towards the first side 26, i.e. to receive the flow of coolant from channel 17.

[0065] FIGS. 15 and 16 show a third embodiment of an inventive cooling plate 1, which is mostly identical to the second embodiment. However, in this case, the coolant channels are drilled as adjacent pairs. As seen in the figures, cooling plate body 10 comprise two parallel coolant channels 17 that are thus spaced by a separating wall 10.3 in between. The pipe channel 21 communicates with both coolant channels 17 through a single lateral opening 24. Alternatively, there could be two lateral openings 24, one for each coolant channel 17. The receiving bore 14 extends from the rear opening 13 into both coolant channels 17 and beyond them up to a plain end surface 16.

[0066] Although in the present embodiment the coolant channels 17 are formed by drilling, they may alternatively by obtained by casting. Similarly, the rear opening 13 and receiving bore 14 could be formed by casting together with the cooling plate body 10. In terms of materials, although copper (and copper alloys) is widely used for cooling plate bodies 10, other appropriate materials may be used, e.g. cast iron.