Copper-aluminum composite casting system with low gas content

Abstract

The invention relates to a low-gas-content copper-aluminum composite casting system which comprises a copper melting furnace, a copper heat preservation furnace, a deoxidizing device, a copper-aluminum composite furnace, an aluminum melting furnace, an aluminum heat preservation furnace and a hydrogen removing device. The deoxidizing device is used for blowing inert gas into copper liquid of the copper heat preservation furnace, and the copper heat preservation furnace is communicated with the copper-aluminum composite furnace through a channel. The aluminum melting furnace is communicated with the aluminum heat preservation furnace, the dehydrogenation device is arranged in the aluminum heat preservation furnace and used for blowing inert gas into molten aluminum of the aluminum heat preservation furnace, and the aluminum heat preservation furnace is communicated with the copper-aluminum composite furnace through a second conveying channel. The inert gas is introduced into the copper liquid and the aluminum liquid respectively, the inert gas enables the copper liquid and the aluminum liquid to roll over, the deoxidizing and dehydrogenating effects are achieved, the purity of the copper liquid and the aluminum liquid is improved, the casting quality is improved, and continuous and large-scale production of the copper-aluminum compound system is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of casting systems, and in particular to a copper-aluminum composite casting system with low gas content. Background Art

[0002] At present, copper-aluminum composite materials are used as an energy-saving conductor material. They have the electrical conductivity of copper and the low density of aluminum. The length of a copper-aluminum composite bar of the same cross-sectional area is about twice that of a copper bar. This can effectively save copper resources and has become an alternative to pure copper bars in the electrical and electrical field.

[0003] Since the gas content of molten copper and molten aluminum is very important for product quality, when the gas content is high, the casting is more likely to have pores and oxide impurities, affecting the casting quality of the product. In addition, the molten copper will continuously slag during the smelting process. Part of the slag floats to the surface of the molten copper, and the other part adheres to the inner wall of the furnace. The slag continues to accumulate on the inner wall of the furnace, affecting the heat transfer performance of the furnace, thereby affecting the smelting effect of the molten copper. Summary of the invention

[0004] The invention aims at solving the existing technical problems and provides a copper-aluminum composite casting system with low gas content.

[0005] The technical solution of the present invention for solving the above technical problems is as follows: a copper-aluminum composite casting system with low gas content, comprising a copper melting furnace, a copper holding furnace, a deoxidizing device, a copper-aluminum composite furnace, an aluminum melting furnace, an aluminum holding furnace and a dehydrogenating device, wherein the copper melting furnace is connected to the copper holding furnace through a first conveying channel, the deoxidizing device is used to blow inert gas into the copper liquid in the copper holding furnace, and the copper holding furnace is connected to the copper-aluminum composite furnace through a channel; the aluminum melting furnace is connected to the aluminum holding furnace, the dehydrogenating device is arranged in the aluminum holding furnace, the dehydrogenating device is used to blow inert gas into the aluminum liquid in the aluminum holding furnace, and the aluminum holding furnace is connected to the copper-aluminum composite furnace through a second conveying channel.

[0006] Preferably, the deoxygenation device is arranged at the bottom of the copper insulation furnace, and the deoxygenation device includes a connected air inlet pipe and an air inlet cavity, the top wall of the air inlet cavity is a honeycomb air-permeable brick, and a plurality of air-permeable brick holes are provided on the top wall of the air inlet cavity.

[0007] Preferably, the first conveying channel is arranged obliquely, and the first conveying channel is inclined downward from the copper melting furnace to the copper holding furnace.

[0008] Preferably, the inclination angle δ of the first conveying channel is 20° to 30°.

[0009] Preferably, the first conveying channel comprises a copper liquid through hole, and the outer side of the copper liquid through hole is sequentially provided with a high temperature resistant protective coating and a refractory sintering layer.

[0010] Preferably, the material of the high temperature resistant protective coating is boron nitride and / or silicon nitride, and the refractory sintered layer is a refractory clay sintered layer.

[0011] Preferably, the dehydrogenation device is arranged at the bottom of the aluminum insulation furnace, and the dehydrogenation device comprises a connected blowing pipe and a blowing cavity, and the top wall of the blowing cavity is provided with a plurality of capillary blowing holes.

[0012] Preferably, the second conveying channel comprises an aluminum liquid through hole, and an inner casting layer, a heating layer, a heat-insulating layer and an outer shell are sequentially arranged on the outer side of the aluminum liquid through hole.

[0013] Preferably, the inner casting layer is made of aluminum silicate refractory castable, the insulation layer is made of ceramic fiber high temperature resistant insulation wool, the heating layer is made of heating wire, and the outer shell is made of metal.

[0014] On the basis of the above technical solution, the present invention can also be improved as follows:

[0015] The beneficial effects of the present invention are as follows: by introducing inert gas into the copper holding furnace, the inert gas causes the copper liquid to roll, which has the effect of deoxidation, and reduces the turbulence and vortex of the copper liquid, so that the copper liquid can stably flow into the copper-aluminum composite furnace, and the tiny bubbles can carry non-metallic inclusions (such as oxides, sulfides, etc.) in the copper liquid to float to the surface, which helps to purify the copper liquid and improve the quality of the castings. By introducing inert gas into the aluminum liquid, the rolling and slag formation of the aluminum liquid can be accelerated, the purity of the aluminum liquid can be improved, the hydrogen content in the aluminum liquid can be reduced, the quality of the castings can be further improved, and the continuous and large-scale production of the copper-aluminum composite system can be realized. The copper liquid in the copper melting furnace is transported to the copper holding furnace through the first conveying channel arranged obliquely, so that the slag in the copper liquid gathers in the copper holding furnace, which is convenient for cleaning the slag, solves the problem that the furnace gathers on the inner wall of the copper melting furnace and affects the copper melting effect, and improves the heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the copper-aluminum composite casting system of the present invention;

[0017] Figure 2 It is a partial cross-sectional schematic diagram of the deoxygenation device of the present invention;

[0018] Figure 3 It is a schematic diagram of the air-permeable brick holes of the deaerator of the present invention;

[0019] Figure 4 It is a partial cross-sectional schematic diagram of the first conveying channel of the present invention;

[0020] Figure 5 It is a partial cross-sectional schematic diagram of the hydrogen removal device of the present invention;

[0021] Figure 6 Schematic diagram of the capillary blowing hole of the present invention;

[0022] Figure 7 It is a partial cross-sectional schematic diagram of the second delivery channel of the present invention.

[0023] The accompanying drawings are marked as follows: 1. Copper melting furnace; 2. First conveying channel; 2.1. High temperature resistant protective coating; 2.2. Refractory sintering layer; 3. Copper insulation furnace; 4. Deoxidation device; 4.1. Air inlet pipe; 4.2. Air inlet cavity; 4.3. Breathable brick hole; 5. Copper-aluminum composite furnace; 6. Aluminum melting furnace; 7. Aluminum insulation furnace; 8. Dehydrogenation device; 8.1. Blowing pipe; 8.2. Blowing cavity; 8.3. Capillary blowing hole; 9. Second conveying channel; 9.1. Inner casting layer; 9.2. Heating layer; 9.3. Insulation layer; 9.4. Outer shell. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] like Figures 1 to 7As shown, the present invention discloses a copper-aluminum composite casting system with low gas content, comprising a copper melting furnace 1, a copper holding furnace 3, a deoxidizing device 4, a copper-aluminum composite furnace 5, an aluminum melting furnace 6, an aluminum holding furnace 7 and a dehydrogenating device 8, wherein the copper melting furnace 1 is connected to the copper holding furnace 3 through a first conveying channel 2, the deoxidizing device 4 is used to blow an inert gas into the copper liquid in the copper holding furnace 3, and the inert gas is argon gas, and the copper holding furnace 3 is connected to the copper-aluminum composite furnace 5 through a channel to realize the flow of the copper liquid into the copper-aluminum composite furnace 5. Oxide inclusions and excessive dissolved oxygen can cause defects such as holes and cracks inside the casting, reducing the mechanical properties and corrosion resistance of the casting. By introducing inert gas into the copper liquid, after the inert gas enters the copper liquid in the form of tiny bubbles, these bubbles will absorb and carry dissolved gases including oxygen to float to the surface, and finally escape from the copper liquid, thereby reducing the dissolved oxygen content in the copper liquid, purifying the copper liquid, and ensuring the quality of the castings. In addition, the inert gas can improve the fluidity of the copper liquid, so that the copper liquid can flow more evenly into the copper-aluminum composite furnace 5. The aluminum melting furnace 6 is connected to the aluminum insulation furnace 7 through the aluminum liquid channel. The aluminum insulation furnace 7 is provided with the dehydrogenation device 8, which is used to blow inert gas into the aluminum liquid of the aluminum insulation furnace 7. The inert gas is argon. The aluminum insulation furnace 7 is connected to the copper-aluminum composite furnace 5 through the second conveying channel 9. Further, the second conveying channel 9 is set at 90 degrees to buffer the direct flow of aluminum liquid, avoid the influence of flow rate fluctuation on copper-aluminum composite casting, and improve the casting quality. The solubility of hydrogen in aluminum liquid decreases significantly with the decrease of temperature. When the aluminum liquid cools and solidifies, supersaturated hydrogen will precipitate to form bubbles. If these bubbles cannot escape in time, they will remain inside the casting to form pores. By blowing inert gas into the aluminum liquid, the hydrogen dissolved in the aluminum liquid can be effectively brought to the surface in the form of tiny bubbles, thereby greatly reducing the number of pores in the casting and further ensuring the quality of the copper-aluminum composite casting. Among them, the specific structures and heating temperature parameters of the copper melting furnace 1, the copper holding furnace 3, the copper-aluminum composite furnace 5, the aluminum melting furnace 6 and the aluminum holding furnace 7 adopt the existing technology and will not be repeated here.

[0026] In this embodiment, the deoxidation device 4 is arranged at the bottom of the copper holding furnace 3 to increase the flow path of the inert gas, improve the deoxidation effect, and further improve the fluidity of the copper liquid so that it flows evenly into the copper-aluminum composite furnace 5, thereby reducing casting defects. The deoxidation device 4 includes a connected air intake pipe 4.1 and an air intake cavity 4.2. The gap between the air intake pipe 4.1 and the bottom wall of the copper insulation furnace 3 is sealed with graphite wool to prevent the copper liquid from flowing out. Specifically, the inner diameter of the air intake pipe 4.1 is φ13mm-φ15mm to ensure sufficient air intake. The top wall of the air intake cavity 4.2 is a honeycomb air-permeable brick. The top wall of the air intake cavity 4.2 is provided with a plurality of air-permeable brick holes 4.3. The inert gas in the air intake cavity 4.2 is diverted through the plurality of air-permeable brick holes 4.3 and blown into the copper liquid to improve the uniformity of the distribution of the inert gas in the copper liquid, improve the deoxidation effect, and ensure that the oxygen content in the copper liquid does not exceed 5ppm. The oxygen content of the copper liquid solidification sample can be detected by a hydrogen-oxygen tester. The air-permeable brick holes 4.3 allow inert gases such as argon and nitrogen to pass through, and can prevent the penetration of molten copper liquid at the same time. Therefore, inert gas can be introduced into the molten copper liquid during the casting process. The honeycomb structure allows the inert gas to be evenly dispersed in the molten copper liquid, forming small and evenly distributed bubbles, reducing casting defects such as shrinkage cavities and shrinkage, and helping to improve the quality of castings. At the same time, by continuously introducing inert gas into the copper holding furnace 3, the inert gas forms a protective atmosphere inside the copper holding furnace 3, isolating oxygen in the air, thereby reducing the possibility of oxidation on the surface of the copper liquid, avoiding the formation of an oxide film, and ensuring the surface quality of the casting.

[0027] Furthermore, the honeycomb air-permeable bricks of the deoxygenation device 4 are laid flat in the copper insulation furnace 3 and / or the honeycomb air-permeable bricks are arranged on the inner wall of the copper insulation furnace 3, so as to further improve the uniformity of the distribution of the inert gas in the copper insulation furnace 3, realize uniform deoxygenation, and improve the deoxygenation effect and the uniformity of the copper liquid flow.

[0028] The first conveying channel 2 is arranged between the copper melting furnace 1 and the copper holding furnace 3. The first conveying channel 2 is arranged at an angle. The first conveying channel 2 is inclined downward from the copper melting furnace 1 to the copper holding furnace 3. By arranging the first conveying channel 2 at an angle, the flow effect of the copper liquid can be improved, and the slag can flow into the copper holding furnace 3 through the first conveying channel 2. Since the function of the copper holding furnace 3 is to stabilize the copper liquid within a certain temperature range, the slag has good fluidity, making it easier for the slag to be removed by the slag removal tool, thereby solving the problem that the slag accumulates on the inner wall of the copper melting furnace 1 and affects its smelting effect.

[0029] Furthermore, the first conveying channel 2 is inclined at an angle δ of 20° to 30°, and the length of the first conveying channel 2 is 280mm-350mm. In the present embodiment, the first conveying channel 2 is inclined at an angle of 25°. When the inclination angle is greater than 30°, the opening height of the first conveying channel 2 in the copper melting furnace 1 is relatively high, resulting in that a large amount of copper solution in the copper melting furnace 1 cannot flow normally into the copper insulation furnace 3, wasting copper solution, and slag is easily accumulated in the space below the opening of the first conveying channel 2 of the copper melting furnace 1, affecting the heating effect of the copper melting furnace 1; when the inclination angle is less than 20°, the inclination angle is too small, affecting the flow rate of the copper solution and the amount of slag flowing into the copper insulation furnace 3, thereby affecting the copper-aluminum casting quality and the cleaning effect of the slag.

[0030] Furthermore, the opening of the first conveying channel 2 in the copper insulation furnace 3 is adjacent to the bottom wall of the copper insulation furnace 3. In order to achieve the maximum cross-sectional flow rate, the cross-sectional shape of the first conveying channel 2 adopts a rectangular shape to ensure the smooth flow of the molten copper and facilitate the gathering of slag in the copper insulation furnace 3 to facilitate the cleaning of the slag.

[0031] Specifically, the first conveying channel 2 includes a copper liquid through hole, the diameter of the copper liquid through hole is φ160mm-φ180mm, and the outer side of the copper liquid through hole is sequentially provided with a high-temperature resistant protective coating 2.1 and a refractory sintered layer 2.2. Specifically, the material of the high-temperature resistant protective coating 2.1 is boron nitride and / or silicon nitride, and the thickness of the high-temperature resistant protective coating 2.1 is 2mm-3.5mm, and has good corrosion resistance and thermal stability, ensuring the normal flow of copper liquid and the service life of the first conveying channel 2. The refractory sintered layer 2.2 is a refractory mud sintered layer, specifically, refractory mud of aluminum silicate material, which has high mechanical strength and thermal stability, and has a heat-insulating effect to ensure the temperature of the copper liquid.

[0032] In this embodiment, the dehydrogenation device 8 is arranged at the bottom of the aluminum insulation furnace 7 to increase the flow path of the inert gas, improve the dehydrogenation effect, further improve the fluidity of the aluminum liquid, make it flow evenly into the copper-aluminum composite furnace 5, reduce the casting defects of the copper-aluminum composite ingot, and ensure the casting quality. Specifically, the dehydrogenation device 8 includes a connected blowing pipe 8.1 and a blowing cavity 8.2, and the top wall of the blowing cavity 8.2 is provided with a plurality of capillary blowing holes 8.3, and the plurality of capillary blowing holes 8.3 are arranged in a matrix to achieve uniform blowing into the aluminum insulation furnace 7. The diameter of the blowing pipe 8.1 is φ18mm-φ20mm, and the diameter of the capillary blowing hole 8.3 is φ0.5mm-φ1mm. Before the aluminum liquid flows to the aluminum holding furnace 7, the dehydrogenation device 8 is turned on to continuously blow air, so that the blowing pressure of the inert gas is controlled at 5Kpa to prevent the aluminum liquid from blocking the capillary blowing holes 8.3, so that the inert gas can be evenly dispersed into the aluminum liquid through the capillary blowing holes 8.3 to form fine bubbles, thereby more effectively capturing and removing hydrogen, accelerating the rolling and slag formation of the aluminum liquid, and improving the purity of the aluminum liquid to form an aluminum liquid with a hydrogen content not higher than 3ppm. Among them, the hydrogen content of the aluminum liquid solidification sample can be tested by a hydrogen and oxygen tester.

[0033] The second conveying channel 9 is located at the lower side of the aluminum melting furnace 6 and the aluminum holding furnace 7, and relies on the static liquid level difference pressure of the aluminum liquid to flow. The aluminum liquid is transmitted through the closed second conveying channel 9 to achieve continuous conveying of the aluminum liquid, improve the aluminum liquid conveying efficiency, reduce the contact between the aluminum liquid and the air, significantly reduce the inclusion of oxides, ensure the quality of the casting, and can reduce heat loss and ensure the stability of the aluminum liquid temperature.

[0034] The second conveying channel 9 includes an aluminum liquid through hole, the diameter of the aluminum liquid through hole is φ200mm-φ220mm, and the outer side of the aluminum liquid through hole is provided with an inner casting layer 9.1, a heating layer 9.2, an insulation layer 9.3 and an outer shell 9.4 from the inside to the outside. Specifically, the inner casting layer 9.1 adopts an aluminum silicate refractory castable with a thickness of 12mm-18mm, has high temperature stability and corrosion resistance, and can prevent aluminum liquid from penetrating, thereby ensuring the integrity of the second conveying channel 9. The heating layer 9.2 adopts a heating wire. When the casting flow rate is slow, the second conveying channel 9 is a high-risk area for aluminum liquid temperature drop. The heating wire is arranged on the second conveying channel 9 to avoid the aluminum liquid from solidifying due to too fast a temperature drop, thereby ensuring that the copper-aluminum composite casting can be cast normally. The material of the thermal insulation layer 9.3 is ceramic fiber high temperature resistant insulation cotton, and the thickness of the thermal insulation layer 9.3 is 4mm-10mm, which prevents the heat loss of the aluminum liquid, ensures the quality of the casting, and reduces the risk of solidification of the aluminum liquid. The material of the outer shell 9.4 is metal, preferably an iron shell, which ensures the overall mechanical strength of the second conveying channel 9 and has a certain thermal expansion compensation effect to ensure the service life of the second conveying channel 9.

[0035] The working process of the copper-aluminum composite casting system of the present invention is:

[0036] The copper liquid enters the copper holding furnace 3 from the copper melting furnace 1, and under the joint action of the first conveying channel 2 and the deoxidizing device 4, the copper liquid with an oxygen content not higher than 5 PPm is formed; the aluminum liquid enters the aluminum holding furnace 7 through the aluminum melting furnace 6, and forms the aluminum liquid with a hydrogen content not higher than 3 PPm through the dehydrogenating device 8. The two metal liquids are collected and enter the copper-aluminum composite furnace 5 to complete the composite casting process. The present invention is a systematic composite casting system for copper and aluminum with low gas content, which realizes the continuous and large-scale production of copper liquid and aluminum liquid bimetallic composite continuous casting to the maximum extent, and improves production efficiency and casting quality.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A copper-aluminum composite casting system with low gas content, characterized in that: The invention comprises a copper melting furnace (1), a copper insulation furnace (3), a deoxidizing device (4), a copper-aluminum composite furnace (5), an aluminum melting furnace (6), an aluminum insulation furnace (7) and a dehydrogenating device (8), wherein the copper melting furnace (1) is connected to the copper insulation furnace (3) via a first conveying channel (2), the deoxidizing device (4) is used for blowing inert gas into the copper liquid in the copper insulation furnace (3), and the copper insulation furnace (3) is connected to the copper-aluminum composite furnace (5) via a channel; the aluminum melting furnace (6) is connected to the aluminum insulation furnace (7), the aluminum insulation furnace (7) is provided with the dehydrogenating device (8), and the dehydrogenating device (8) is used for blowing inert gas into the aluminum liquid in the aluminum insulation furnace (7), and the aluminum insulation furnace (7) is connected to the copper-aluminum composite furnace (5) via a second conveying channel (9).

2. The low-gas content copper-aluminum composite casting system according to claim 1, characterized in that: The deoxidizing device (4) is arranged at the bottom of the copper insulation furnace (3), and comprises an air inlet pipe (4.1) and an air inlet cavity (4.2) which are connected. The top wall of the air inlet cavity (4.2) is a honeycomb air-permeable brick, and a plurality of air-permeable brick holes (4.3) are arranged on the top wall of the air inlet cavity (4.2).

3. The copper-aluminum composite casting system with low gas content according to claim 1 or 2, characterized in that: The first conveying channel (2) is arranged at an angle, and the first conveying channel (2) is inclined downward from the copper melting furnace (1) to the copper holding furnace (3).

4. The low-gas content copper-aluminum composite casting system according to claim 3 is characterized in that: The first conveying channel (2) has an inclination angle δ of 20° to 30°.

5. The copper-aluminum composite casting system with low gas content according to claim 4, characterized in that: The first conveying channel (2) comprises a copper liquid through hole, and the outer side of the copper liquid through hole is provided with a high temperature resistant protective coating (2.1) and a refractory sintering layer (2.2) in sequence.

6. The copper-aluminum composite casting system with low gas content according to claim 5, characterized in that: The material of the high temperature resistant protective coating (2.1) is boron nitride and / or silicon nitride, and the refractory sintered layer (2.2) is a refractory clay sintered layer.

7. The low gas content copper-aluminum composite casting system according to claim 1, characterized in that: The dehydrogenation device (8) is arranged at the bottom of the aluminum insulation furnace (7), and comprises a connected blowing pipe (8.1) and a blowing cavity (8.2), and the top wall of the blowing cavity (8.2) is provided with a plurality of capillary blowing holes (8.3).

8. The copper-aluminum composite casting system with low gas content according to claim 1 or 7, characterized in that: The second conveying channel (9) comprises an aluminum liquid through hole, and the outer side of the aluminum liquid through hole is provided with an inner casting layer (9.1), a heating layer (9.2), a heat insulation layer (9.3) and an outer shell (9.4) in sequence.

9. The copper-aluminum composite casting system with low gas content according to claim 8, characterized in that: The inner casting layer (9.1) is made of aluminum silicate refractory castable, the insulation layer (9.3) is made of ceramic fiber high temperature resistant insulation cotton, the heating layer (9.2) is made of heating wire, and the outer shell (9.4) is made of metal.

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