RU2480696C2 - Manufacturing method of cooling plate of metallurgical furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method involves the stages, at which plate stock (11) of metallic material is provided, which has front surface (14), opposite rear surface (16) and four side end faces, in plate stock (11) there formed is at least one cooling channel (30) by drilling in it of at least one blind hole (40) that is made from the first end face (22) in the direction to the second opposite end face (24). Plate stock (11) is deformed so that its first end area (46) is such that it is at least partially bent in the direction to rear surface (16) of plate stock and excess material is removed by machining from front and rear surfaces (14, 16) of plate stock (11) for obtaining cooling plate (10) having the main panel-shaped part (12), on the rear surface (16) of which a hole for inlet of cooling channel (30) is located.

EFFECT: increasing service life of the cooling plate.

11 cl, 4 dwg

Description

Technical field

The invention generally relates to a method for manufacturing a cooling plate of a metallurgical furnace.

State of the art

In the prior art, such cooling plates, also called refrigerators, are widely known. They are used to cover the inner wall of the outer casing of a metallurgical furnace, such as, for example, a blast furnace or an electric arc furnace, to create: (1) a heat-shielding screen between the interior of the furnace and the outer casing of the furnace; and (2) fixing means for securing the refractory brick lining, the refractory shotcrete layer, or the build-up formed by the overlay layer inside the furnace. Initially, the cooling plates were cast iron with cooling pipes poured into them. As an alternative to cast-iron refrigerators, copper refrigerators have been proposed. Currently, most of the cooling plates of a metallurgical furnace are made of copper, a copper alloy, and most recently, steel.

Various methods have been proposed for the manufacture of copper plate refrigerators. Initially, attempts were made to cast copper refrigerators in foundry molds and to form internal cooling channels with sand rods inserted into these molds. However, this method has not proved its effectiveness in practice, since the main parts of cast copper plates often had shells and porosity, which had an extremely negative effect on the service life of the main part of the plate. Foundry sand is difficult to remove from the channels, and the channels themselves often did not have the desired shape.

A cooling plate made of forged or rolled copper sheet billet is known from DE 2907511 C2. The cooling channels are blind holes made by deep drilling in a rolled copper sheet billet. Blind holes are closed by welding the plugs. Then, the connecting channels are drilled from the back surface of the main part of the plate into blind holes. Then in these connecting channels enter the connecting pipes for supplying or removing the cooler and weld them to the main part of the refrigerator. Such cooling plates avoid the aforementioned drawbacks inherent in cast structures. In particular, the formation of shells and porosity in the main part of the plate is actually prevented. However, the presented manufacturing method requires a relatively high cost, both in terms of complexity and material consumption. In addition, due to the significant mechanical and thermal loads acting on the plate refrigerator, various welded joints are critical in terms of tightness for the cooling medium. In addition, since the channels are made together with the main part of the refrigerator, there is only one level of separation between the cooler and the interior of the furnace, that is, in the event of a crack in the main part of the refrigerator, the cooler will leak. However, leakage of the cooling medium into the furnace poses a significant risk of explosion, and its occurrence must be avoided at all costs.

Technical problem

The aim of the present invention is to provide an improved method of manufacturing a cooling plate of a metallurgical furnace, free from the above disadvantages. This goal is achieved in the method according to claim 1 of the claims.

Disclosure of invention

In accordance with the present invention, a method for manufacturing a cooling plate of a metallurgical furnace, the implementation of which provide a sheet metal workpiece having a front surface, an opposite rear surface and four side ends; and forming at least one cooling channel in the sheet blank by drilling at least one blind hole therein, which is produced from the first end in the direction of the opposite second end. In accordance with an important aspect of the present invention, when performing the method, in addition, the workpiece is deformed so that its first end region is at least partially curved towards the rear surface of the sheet stock; and machining removes excess material from the front and rear surfaces of the sheet stock to obtain a cooling plate having a panel-like main part, on the rear surface of which there is an opening for entering the cooling channel.

Due to the bending of the sheet stock in the direction of the rear surface and subsequent removal by machining of excess material from the front and rear surfaces of the sheet stock, the opening of the inlet to the cooling channel is located on the rear surface. Compared with the method known in the prior art, such as, for example, as described in patent DE 2907511 C2, there is no need for sealing by welding a plug to the opening of the inlet to the cooling channel at the first end. There is also no need to drill a connecting channel between the rear surface and the cooling channel in order to reach the latter in the first end region. Removing these process steps reduces both labor and material costs.

However, more importantly, the absence of a plug provides additional reliability to the cooling plate. Indeed, the cooling plate is subject to significant mechanical and thermal stresses, in particular its end regions, and the plug should be considered as a weak point. If the plug seam is broken, the tightness of the cooling channel for the cooling medium can no longer be guaranteed, and the cooler can flow out of the cooling channel into the furnace. Such leakage of the cooling medium into the furnace must be avoided at all costs, as it can lead to a significant risk of explosion. Since no plug is welded to the cooling plate made according to the method of the present invention, the risk of leakage associated with the presence of such a plug is eliminated. In addition, the cooling plate made according to the method of the present invention has a greater thickness at the front surface in the first end region than the cooling plates made according to methods known in the prior art. The increased material thickness also contributes to an increase in the life of the cooling plate.

Preferably, after the machining removes the excess material from the front and back surfaces of the sheet stock, the method includes an additional step of forming grooves and multiple parallel ribs lying between them on the front surface of the panel-like main body, which are designed to fix the refractory brick lining.

To ensure good fixing properties of the structure with multiple parallel ribs and grooves on the front surface of the cooling plate and good thermal stability of the cooling plate, the grooves are preferably shaped with a width that is smaller at the entrance of the groove than at its base. The grooves can be made, for example, with a cross section in the form of a dovetail.

Preferably, when performing the method, a connecting pipe is further provided for each cooling channel formed in the panel-like main body; combine one end of each connecting pipe with an inlet in a corresponding cooling channel located on the rear surface of the panel-like main part; and fastening the connecting pipe to the rear surface of the panel-like main body so as to create a downstream communication between each connecting pipe and a corresponding cooling channel.

An adapter having the shape of a hollow truncated cone can be used between the panel-shaped main part and the connecting pipe. The smaller base of the adapter may have a diameter adapted for articulation with the connecting pipe. The larger base of the adapter is sized to cover the entire opening of the cooling channel on the rear surface. Indeed, due to the bending of the cooling channel and subsequent machining of the rear surface, the cooling channel may have an elongated inlet at the rear surface. The enlarged base of the adapter ensures that there are no leaks on the back of the cooling plate.

Preferably, the rear surface of the panel-like main body, the connecting pipe and the adapter, if used, are fastened to each other by soldering or welding.

According to a first embodiment of the invention, when performing the method, a first cooling channel is formed in the sheet blank by drilling a first blind hole therein, which is produced from the first end face towards the second end face; and form in the sheet blank a second cooling channel by drilling a second blind hole in it, which is produced from the first end face towards the second end face. The first and second cooling channels are positioned so that their ends in the second end region intersect with each other and create a flow message between the first and second cooling channels.

The first and second blind holes are drilled from the first end in the direction to the second end at an angle to each other so that their ends intersect in the second end region. Thus, the first and second cooling channels as a result form a combined V-shaped cooling channel in which the cooler flows through one cooling channel to the second end region and then through the other cooling channel back to the first end region. Such a V-shaped cooling channel makes it possible to place both the input connecting pipe and the output connecting pipe in the first end region.

According to a second embodiment of the invention, when performing the method, a first cooling channel is formed in the sheet blank by drilling a first blind hole therein, which is produced from the first end toward the second end; and form in the sheet blank a second cooling channel by drilling a second blind hole in it, which is produced from the second end in the direction of the first end. The first and second cooling channels are arranged so that their ends intersect with each other and create a flow message between the first and second cooling channels.

The first and second blind holes are drilled from opposite ends towards the center of the sheet blank so that their ends intersect in the central region. Thus, the resulting cooling channels form a combined cooling channel extending from the first end to the second end. This mainly matters when it is necessary to produce a cooling plate with a particularly significant height. Indeed, blind holes can only be drilled to a certain depth. If the length of the cooling channel exceeds this depth, then a second blind hole is drilled mainly from the opposite side. In this embodiment, both the first end region and the second end region are bent towards the rear surface before removing excess material from the sheet blank. Thereby, two openings of the cooling channels are formed on the rear surface without the need for inserting plugs at each end of the cooling channels.

According to a third embodiment of the invention, when performing the method, a first cooling channel is formed in the sheet blank by drilling a first blind hole in it, which is produced from the first end in the direction of the second end, wherein the end of the first blind hole is located in the second end region of the sheet blank; and in the second end region, a connecting channel is drilled extending from the rear surface of the sheet blank to the end of the first blind hole and a flow message is created between the first cooling channel and the connecting channel.

In the first end region, the sheet blank is bent toward the rear surface and thereby an opening in the entrance to the cooling channel is formed in the rear surface. On the other hand, in the second end region, a connecting channel is formed, creating a second opening for entering the cooling channel. The formation of this second opening of the inlet to the cooling channel basically corresponds to the method used in the methods known from the prior art. In this embodiment, it is provided for attaching an inlet connecting pipe in a first end region and attaching an outlet connecting pipe in a second end region.

Preferably, the cooling plate is made of at least one of the following materials: copper, copper alloy or steel.

Brief Description of the Drawings

The invention is further described in more detail with reference to the accompanying drawings, which schematically shows:

figure 1 is a cross section of a sheet billet in accordance with the first step proposed in the present invention a method of manufacturing a cooling plate;

figure 2 is a cross section of a sheet stock in accordance with the second step;

figure 3 is a cross section of a sheet stock in accordance with the third step;

figure 4 is a cross section of a sheet stock in accordance with the fourth step;

Preferred Embodiments

Cooling plates are used to cover the inner wall of the outer casing of a metallurgical furnace, such as a blast furnace or an electric arc furnace. The purpose of using such stoves is to create: (1) a protective shield to prevent heat leakage between the interior of the furnace and the outer casing of the furnace; (2) fixing means for lining of refractory bricks, a refractory shotcrete layer or a build-up formed by a layer of sheathing inside the furnace.

Turning to the drawings, it can be noted that the cooling plate 10 is formed from a sheet blank 11, consisting, for example, of a forged or cast body of copper, a copper alloy or steel, and turned into a panel-shaped main part 12. This panel-shaped main part 12, more described in detail with reference to figure 4, has a front surface 14, also called a hot surface, which will face the interior of the furnace, and a rear surface 16, also called a cold surface, which will face the inner surface of the casing of the furnace. Figure 4 shows that the panel-shaped main part 12 is generally quadrangular in shape with a pair of long ends (not shown) and a pair of short first and second ends 22, 24. Most modern cooling plates have a width ranging from 600 to 1300 mm, and a height lying in the range from 1000 to 4200 mm. However, it must be understood that the height and width of the cooling plate can be adapted, inter alia, to the structural features of the metallurgical furnace and to the limitations resulting from the manufacturing process.

The cooling plate 10 also includes connecting pipes 26, 28 for the passage of the cooling medium, mainly water. These connecting pipes 26, 28 are connected at the rear surface of the panel-shaped main part 12 with cooling channels 30 formed in this main part. As can be seen in FIG. 4, these cooling channels 30 pass through a panel-like main body 12 near the rear surface 16. In accordance with the proposed manufacturing method, which will be described in more detail below, such cooling channels 30 are drilled. Each cooling channel 30 is usually provided with a corresponding inlet connecting pipe 26 through which cooling medium enters into it and (or) an output connecting pipe 28 through which the cooling medium exits the cooling channel 30.

Referring to FIG. 4, it can be seen that the front surface 14 is divided by grooves 32 into multiple parallel ribs 34. Grooves 32 laterally defining multiple parallel ribs 34 can be milled on the front surface 13 of the main panel-like portion 12. Multiple ribs 34 extend in parallel the first and second ends 22, 24 from the first long end (not shown) to the second long end (not shown) of the main panel-shaped part 12. They are perpendicular to the cooling channels 30 passing in the main panel-shaped part 12. P and installing the cooling panel 10 in the furnace grooves 32 and multiple parallel ribs 34 are arranged horizontally. They form a fastening means for a lining of refractory bricks, a refractory shotcrete layer or a build-up formed by a layer of sheathing on the front surface 14.

It should be noted that, in order to ensure good fixing of the refractory brick lining, the refractory shotcrete layer or the growth formed by the layer of sheathing on the front surface 14, the grooves 32 are made with a dovetail section, that is, the internal width of the groove 32 is less than the width of it grounds. Preferably, the average width of the parallel rib 34 is less than the average width of the groove 32. Typically, the mean width of the groove 32 lies, for example, in the range from 40 mm to 100 mm. Typically, the mean widths of the parallel rib 34 are, for example, in the range of 20 mm to 40 mm. The height of multiple parallel ribs 34, corresponding to the depth of the grooves 32, is generally from 20% to 40% of the total thickness of the main panel-shaped part 12.

Next, a method for manufacturing cooling plates 10 is described in more detail with reference to Figures 1-4, which show cooling panels 10 at different basic steps of the manufacturing method. In the first step, shown in figure 1, provide a sheet blank 11 made, for example, of cast or forged main part of copper, copper alloy or steel. Such a sheet blank generally has a quadrangular shape with a front surface 14, a rear surface 15, a pair of long ends (not shown) and a pair of short first and second ends 22, 24. It should be noted that the dimensions of the sheet blank exceed the specified dimensions of the main panel-shaped part 12 A blind hole 40 is drilled from the first end 22 in the sheet blank 11 extending to the second end region 42. The blind hole 40 has an end 44 lying in the second end region 42. In the next step of the method shown in FIG. 2, the sheet the billet 11 is deformed so that the first end region 46 is bent toward the rear surface 16 of the sheet billet 11. This results in a corresponding bending of the blind hole 40. The bending angle α between the central axis 50 of the bent blind hole 40 and the central axis 52 of the bent blind hole 40 at the first end 22 may be from 30 to 45 degrees. This value of the bending angle α should not be construed as limiting. The bending angle α can, for example, vary significantly depending on the thickness of the sheet stock 11 or the diameter of the blind hole 40.

After deformation of the sheet stock 11, excess material is removed from it along the cut lines shown by dashed lines 55 in FIG. 2. As a result, the main panel-shaped part 12 shown in FIG. 3 again acquires a generally rectangular shape with a front surface 14, a rear surface 16, a pair of long ends (not shown) and a pair of short first and second ends 22, 24. The cooling channel 30 formed by a blind hole 40, is performed in the main panel-shaped part 12 generally parallel to the rear surface 16. In the first end region 46, the cooling channel 30 bends and opens through the rear surface 16.

In accordance with one embodiment of the present invention, the main panel-shaped portion 12 may be provided in the second end region with a channel 60 extending from the cooling channel 30 to the rear surface 16.

After the excess material is removed from the sheet metal 11 by machining, the resulting main panel-shaped part 12 is then subjected to a milling operation in which grooves 32 and parallel multiple ribs 34 passing between them are formed on the front surface 14 of the main panel-shaped part 12. As explained above, these grooves 32 and the ribs 34 form a fixing means for fixing the lining of refractory bricks, refractory shotcrete layer or growth, formed by a layer of sheathing inside the furnace.

Finally, connecting pipes 26, 28 are fastened to the rear surface of the main panel-like portion 12. The inlet connecting pipe 26 is in fluid communication with the mouth of the cooling channel 30 in the first end region 46 for supplying cooling medium to the cooling channel 30. The output connecting pipe 28 is in communication with channel 60 in the second end region 42 for draining the cooling medium from the cooling channel 30.

Explanation of reference signs:

10 - cooling plate;

11 - sheet blank;

12 - the main panel-shaped part (panel type);

14 - front surface;

16 - back surface;

22 - the first end;

24 - the second end;

26 - input connecting pipe;

28 - output connecting pipe;

30 - cooling channel;

32 - groove;

34 - rib;

40 - blind hole;

42 - the second end region;

44 - the end;

46 - the first end region;

α is the bending angle;

50 - the Central axis of the unbent blind channel;

52 - the Central axis of the blind channel in the first end region;

55 - cut line;

60 - channel.

Claims (11)

1. A method of manufacturing a cooling plate of a metallurgical furnace, comprising the steps of: providing a sheet metal blank having a front surface, an opposite rear surface and four side ends, and forming at least one cooling channel in the sheet blank by drilling at least one a blind hole, which is produced from the first end in the direction to the opposite second end, characterized in that the sheet is deformed in such a way that its first the end face region is at least partially curved towards the rear surface of the sheet stock, and excess metal is removed by machining from the front and rear surfaces of the sheet stock to obtain a cooling plate having a panel-like main part, on the rear surface of which there is an opening for entering the cooling channel . 2. The method according to claim 1, in which, after machining the excess material from the front and rear surfaces of the sheet blank, the grooves and parallel ribs lying between them are additionally formed on the front surface of the panel-shaped body, for fixing the refractory brick lining. 3. The method according to claim 2, in which the grooves are formed with a width that is less at the entrance of the groove than at the base of the groove. 4. The method according to claim 3, in which the grooves are formed with a cross section in the form of a dovetail. 5. The method according to claim 1, in which additionally provide a connecting pipe for each cooling channel formed in the panel-shaped main part, combine one end of each connecting pipe with an inlet in the corresponding cooling channel located on the rear surface of the panel-shaped main part, and fasten the connecting pipes with a rear surface of the panel-like main body so as to create a downstream communication between each connecting pipe and a corresponding cooling channel. 6. The method according to claim 5, in which between the panel-shaped main part and the connecting pipe is placed an adapter having the shape of a hollow truncated cone. 7. The method according to claim 5, in which the back surface of the panel-shaped main part, the connecting pipe and the adapter when using it are fastened to each other by soldering or welding. 8. The method according to any one of claims 1 to 7, in which the first cooling channel is formed in the sheet blank by drilling a first blind hole in it, which is produced from the first end towards the second end, the second cooling channel is formed in the sheet blank by drilling a second a blind hole, which is produced from the first end towards the second end, the first and second cooling channels being arranged so that their ends in the second end region intersect and create a flow message between first and second cooling channels. 9. The method according to any one of claims 1 to 7, in which the first cooling channel is formed in the sheet blank by drilling a first blind hole in it, which is produced from the first end towards the second end, the second cooling channel is formed in the sheet blank by drilling a second a blind hole, which is produced from the second end towards the first end, the first and second cooling channels being positioned so that their ends intersect and create a flow message between the first and second cooling and channels. 10. The method according to any one of claims 1 to 7, in which a first cooling channel is formed in the sheet blank by drilling a first blind hole in it, which is produced from the first end towards the second end, wherein the end of the first blind hole is located in the second end region of a sheet blank, a connecting channel is drilled in the second end region extending from the rear surface of the sheet blank to the end of the first blind hole, and a flow message is generated between the first cooling channel and the connector independent channels. 11. The method according to claim 1, in which the cooling plate is made of at least one material selected from copper, copper alloy or steel.

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