Hot isostatic pressing composite copper tube water cooling module with complex water cooling channel and manufacturing method thereof

Abstract

This invention relates to a complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module and its manufacturing method. It includes a cast module body and a cast steel pipe embedded within the module body, with both ends of the cast steel pipe located outside the module body. It also includes a copper pipe inserted into the cast steel pipe after casting. The copper pipe expands under high temperature and pressure and then adheres to the inner wall of the cast steel pipe. This invention eliminates the coating thermal barrier and air gap thermal barrier of traditional water-cooled module piping. The piping in the water-cooled module achieves metallurgical bonding with the module body, and the copper pipe achieves metallurgical bonding with the cast steel pipe in the module. This significantly improves the heat exchange capacity of the water-cooled channel, making the overall thermal conductivity of the complex water-cooled channel hot isostatic pressure composite deoxidized copper tube water-cooled module approach that of the module body material. This greatly extends the service life of the water-cooled module and ensures the safe, efficient, and long-term operation of high-temperature furnaces.

Description

Technical Field

[0001] This invention relates to the field of cast water-cooled modules, specifically to a complex water-cooled channel hot isostatic pressure composite copper tube water-cooled module and its manufacturing method. Background Technology

[0002] Cast water-cooled modules are widely used in high-temperature furnaces and kilns such as electric arc furnaces, submerged arc furnaces, hydrogen reduction furnaces, and blast furnaces. Their main function is to resist the high heat, wear, and corrosion inside the high-temperature furnace and kiln, and to maintain the strength and rigidity of the furnace shape and shell. Existing cast water-cooled modules are made by casting low-carbon steel pipes into a cast steel or cast iron matrix. During the module casting process, the steel pipes must withstand the long-term scouring and corrosion of high-temperature molten steel / iron. To prevent the low-carbon steel pipes from carburizing and being melted by the high-temperature molten steel / iron, a high-temperature resistant coating of about 0.3 mm thickness needs to be brushed onto the outer surface of the steel pipes. The coating is generally composed of silicon dioxide, alumina powder, etc., and has a low thermal conductivity. This creates a coating thermal barrier between the water pipe and the matrix, as well as an air gap thermal barrier between the matrix and the water pipe. These two thermal barriers reduce the overall thermal conductivity of the cast steel or cast iron water-cooled module to about one-tenth of the body's thermal conductivity. When used in high-temperature environments, water-cooled modules with low cooling capacity will inevitably experience high module temperatures due to their poor thermal conductivity. This will cause a sharp decline in the overall mechanical properties of the module, significantly reducing its functionality and lifespan, and endangering the safe production of high-temperature furnaces.

[0003] Patent application number 201810297874.6 discloses a high-efficiency, long-life pre-inserted cast iron cooling wall and its manufacturing process. This application involves pre-inserting steel, copper, or aluminum tubes into the steel pipes to be cast into the cooling wall before casting in a blast furnace. The inserted tubes are then expanded to ensure a tight bond with the steel pipes, and after bending and shot blasting, they are assembled into a mold. However, because the pre-inserted copper or aluminum tubes are cast along with the main body, if an inert cryogenic fluid is not introduced into the pre-inserted tubes during the casting process, the high-temperature steel / iron, far exceeding the melting point of copper or aluminum, will inevitably cause the copper / aluminum tubes to melt. Conversely, if a large flow of cryogenic inert fluid is introduced into the pre-inserted tubes, under strong cooling conditions, a large gap will inevitably form between the outer wall of the steel tube and the main body, completely negating the purpose of pre-inserting the copper / aluminum tubes. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a complex water-cooling channel hot isostatic pressure composite copper tube water-cooling module and its manufacturing method.

[0005] This invention is achieved through the following technical solution: a method for manufacturing a complex water-cooling channel hot isostatic composite copper tube water-cooling module, comprising the following steps:

[0006] a. Construct a water-cooled module model containing cast-in-steel pipes;

[0007] b. Select a copper pipe with an outer diameter of 1 / 4 to 1 / 3 of the inner diameter of the cast steel pipe, perform high-temperature softening annealing on the copper pipe, and then perform pickling, oxide scale removal and passivation treatment.

[0008] c. Seal one end of the copper pipe and rotate the copper pipe into the cast steel pipe;

[0009] d. Seal the other end of the copper tube but leave an air inlet. Inject high-pressure inert gas into the copper tube through the air inlet and then seal the air inlet.

[0010] e. Place the water-cooled module into the annealing furnace, heat it to 850-890℃ and keep it at that temperature. The inert gas inside the copper tube expands in volume at high temperature. At the same time, the high-pressure gas inside the copper tube expands at high temperature, causing the copper tube to expand evenly. The diameter of the copper tube continuously increases until it is constrained by the inner wall of the cast steel tube, so that the copper tube fits tightly against the inner wall of the cast steel tube.

[0011] As an optimization, in step d, the other end of the copper tube is sealed by an expansion sealing mechanism. Before sealing, the copper tube opening is tightened to the inner wall of the cast steel tube using a hole-expanding device. The expansion sealing mechanism includes a sealing cap that is fixed to the opening of the cast steel tube, a plug plate located inside the copper tube, and a bolt connecting the plug plate and the sealing cap. A ceramic powder plug is installed between the plug plate and the sealing cap, and the air inlet is opened on the bolt.

[0012] As an optimization, the sealing cap is connected to the end of the cast steel pipe via threads.

[0013] As an optimization, between steps a and c, the inner wall of the cast steel pipe is subjected to pickling, rust removal, passivation, and drying.

[0014] As an optimization, the pressure of the high-pressure inert gas in step d is 130-160 MPa.

[0015] As an optimization, the heat preservation time in step e is calculated based on 1 hour of heat preservation for every 25mm of water-cooled module thickness.

[0016] A complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module includes a cast module body and a cast steel pipe cast into the module body. Both ends of the cast steel pipe are located outside the module body. The module also includes a copper pipe that is cast and inserted into the cast steel pipe. The copper pipe is bonded to the inner wall of the cast steel pipe after being expanded under high temperature and high pressure.

[0017] The beneficial effects of this invention are as follows: The complex water-cooled channel hot isostatic pressure composite copper tube water-cooled module and its manufacturing method of this invention eliminate the coating thermal barrier and air gap thermal barrier of traditional water-cooled module pipelines. The pipelines (water-cooled channels) in the water-cooled module are metallurgically bonded to the matrix, and the copper tubes are metallurgically bonded to the cast steel tubes (water-cooled channels) in the module. This greatly improves the heat exchange capacity of the water-cooled channel, and makes the comprehensive thermal conductivity of the complex water-cooled channel hot isostatic pressure composite deoxidized copper tube water-cooled module close to the thermal conductivity of the matrix material.

[0018] Taking traditional cast iron water-cooled modules as an example, their original comprehensive thermal conductivity is about 10W / mk. After being processed by hot isostatic pressing composite copper tubes, their comprehensive thermal conductivity is increased to about 30W / mk, which greatly extends the service life of the water-cooled modules and ensures the safe, efficient and long-term operation of high-temperature furnaces. Attached Figure Description

[0019] Figure 1 This is a front view of the water-cooling module of the present invention;

[0020] Figure 2 This is a side sectional view of the present invention;

[0021] Figure 3 This is a cross-sectional view of the expansion sealing mechanism of the present invention;

[0022] As shown in the figure:

[0023] 1. Module body, 2. Cast steel pipe, 3. Copper pipe, 4. Bolt, 5. Sealing cap, 6. Air inlet, 7. Plug, 8. Ceramic powder plug. Detailed Implementation

[0024] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0025] like Figures 1-3 As shown,

[0026] A complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module includes a cast module body 1 and a cast steel pipe 2 cast into the module body 1. The module body 1 is made of cast iron or cast steel, and the cast steel pipe 2 is arranged in a curved state inside the module body 1.

[0027] Both ends of the cast steel pipe 2 are located outside the module body 1, which facilitates the connection of water inlet and outlet.

[0028] It also includes a copper pipe 3 that is inserted into the cast steel pipe 2 after being cast and formed. The copper pipe 3 is then expanded under high temperature and high pressure and then fits against the inner wall of the cast steel pipe 2.

[0029] A method for manufacturing a complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module includes the following steps:

[0030] a. Construct a water-cooled module model containing the cast-in-steel pipe 2; the water-cooled module model includes the module body 1 and the cast-in-steel pipe 2;

[0031] When the matrix 1 is made of cast iron, the casting temperature of the water-cooled module is 1340-1360℃; when the matrix 1 is made of cast steel, the casting temperature of the water-cooled module is 1530-1560℃, and after casting, it is cooled to below 350℃ and then cleaned and ground.

[0032] The inner wall of the cast steel pipe 2 is subjected to pickling, rust removal, passivation, and drying.

[0033] b. Select a copper pipe 3 with an outer diameter of 1 / 4 to 1 / 3 of the inner diameter of the cast steel pipe 2. Perform high-temperature softening annealing on the copper pipe 3, and then perform pickling, oxide scale removal and passivation treatment.

[0034] c. Seal one end of the copper pipe 3 with clamps, rotate the copper pipe 3 and insert it into the cast steel pipe 2. After insertion, cut off the excess copper pipe exposed at the screw-in end.

[0035] d. Seal the other end of the copper pipe 3 and leave an air inlet 6. In this embodiment, the other end of the copper pipe 3 is sealed by an expansion sealing mechanism. Before sealing, the opening of the copper pipe 3 is tightened into the inner wall of the cast steel pipe 2 by a hole expansion device.

[0036] like Figure 3 As shown, the expansion sealing mechanism includes a sealing cap 5 fixedly attached to the opening of the cast steel pipe 2, a plug plate 7 located inside the copper pipe 3, and a bolt 4 connecting the plug plate 7 and the sealing cap 5. The air inlet 6 is opened on the bolt 4. The sealing cap 5 is connected to the opening of the cast steel pipe 2 by threads, thereby facilitating the removal of the sealing cap 5.

[0037] A ceramic powder plug 8 is installed between the plug plate 7 and the sealing cap 5. During use, the ceramic powder plug 8 expands radially under axial pressure. The greater the gas pressure inside the pipe, the greater the radial expansion force of the ceramic powder plug 8 and the greater the friction with the pipe wall, thus playing a reliable sealing role under ultra-high gas pressure.

[0038] High-pressure inert gas is injected into the copper tube 3 through the air inlet 6. The pressure of the high-pressure inert gas is 130-160 MPa. Then the air inlet 6 is sealed.

[0039] e. Place the water-cooled module into the annealing furnace. In this embodiment, the annealing furnace is a vacuum annealing furnace or a reducing atmosphere annealing furnace. Heat the furnace to 850-890℃ and hold it at that temperature. The holding time is calculated based on the thickness of the water-cooled module, which is 1 hour per 25mm.

[0040] Under heating conditions, the inert gas inside the copper tube 3 is heated to 850-890℃ along with the module body 1. The volume of the inert gas inside the copper tube 3 expands by about 30 times at high temperature, and the gas pressure increases sharply. As a result, thermal isostatic pressure conditions are automatically established inside the copper tube 3. At such high temperatures, the tensile strength of deoxidized copper is only less than 10% of the original strength. The expansion of the high-pressure gas inside the copper tube 3 causes the copper tube 3 to expand uniformly under isostatic pressure conditions. The diameter of the copper tube 3 continuously increases until it is constrained by the inner wall of the cast steel tube 2, so that the copper tube 3 fits tightly against the inner wall of the cast steel tube 2. At this time, the pressure inside the copper tube 3 is still maintained above 30MPa.

[0041] Under the aforementioned high temperature, high pressure, and sufficiently long duration conditions, stable and reliable conditions were created for the metallurgical bonding of copper tube 3 and cast steel tube 2. The establishment of hot isostatic pressing conditions for copper tube 3 was completed during the homogenization annealing of cast steel water-cooling modules or the graphitization annealing of cast iron water-cooling modules, without increasing additional costs, greatly improving the cost-effectiveness of hot isostatic pressing composite copper tube water-cooling modules with complex water-cooling channels.

[0042] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A method for manufacturing a complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module, characterized in that, The complex water-cooled channel hot isostatic pressure composite copper tube water-cooling module includes a cast module body (1) and a cast steel pipe (2) cast into the module body (1). Both ends of the cast steel pipe (2) are located outside the module body (1). It also includes a copper pipe (3) that is cast and inserted into the cast steel pipe (2). The copper pipe (3) is bonded to the inner wall of the cast steel pipe (2) after being expanded by high temperature and high pressure. The manufacturing method includes the following steps: a. Construct a water-cooled module model containing cast steel pipe (2); b. Select a copper pipe (3) with an outer diameter of 1 / 4-1 / 3 of the inner diameter of the cast steel pipe (2), and perform high-temperature softening annealing on the copper pipe (3), followed by pickling, oxide scale removal and passivation treatment. c. Seal one end of the copper pipe (3) and rotate the copper pipe (3) into the cast steel pipe (2); d. Seal the other end of the copper pipe (3) and leave an air inlet (6). Inject high-pressure inert gas into the copper pipe (3) through the air inlet (6) and seal the air inlet (6). The other end of the copper pipe (3) is sealed by an expansion sealing mechanism. Before sealing, the copper pipe (3) is tightened to the inner wall of the cast steel pipe (2) by an expansion device. The expansion sealing mechanism includes a sealing cap (5) that is sealed and fixed on the pipe opening of the cast steel pipe (2), a plug plate (7) located in the copper pipe (3), and a bolt (4) connecting the plug plate (7) and the sealing cap (5). A ceramic powder plug (8) is installed between the plug plate (7) and the sealing cap (5). The air inlet (6) is opened on the bolt (4). e. Place the water-cooled module into the annealing furnace, heat it to 850-890℃ and keep it warm. The inert gas in the copper tube (3) expands in volume at high temperature. At the same time, the high-pressure gas in the copper tube (3) expands at high temperature, causing the copper tube (3) to expand evenly. The diameter of the copper tube (3) becomes thicker until it is constrained by the inner wall of the steel tube (2), so that the copper tube (3) fits tightly against the inner wall of the steel tube (2).

2. The manufacturing method of the complex water-cooled channel hot isostatic pressing composite copper tube water-cooling module according to claim 1, characterized in that: The sealing cap (5) is connected to the opening of the cast steel pipe (2) by threads.

3. The manufacturing method of the complex water-cooled channel hot isostatic pressing composite copper tube water-cooling module according to claim 1, characterized in that: Between steps a and c, the inner wall of the cast steel pipe (2) is pickled, derusted, passivated and dried.

4. The manufacturing method of the complex water-cooled channel hot isostatic pressing composite copper tube water-cooling module according to claim 1, characterized in that: In step d, the pressure of the high-pressure inert gas is 130-160 MPa.

5. The manufacturing method of the complex water-cooled channel hot isostatic pressing composite copper tube water-cooling module according to claim 1, characterized in that: The heat preservation time in step e is calculated based on 1 hour of heat preservation for every 25mm of water-cooled module thickness.

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