Degassing device for low-pressure pouring of aluminum alloy

Abstract

The aluminum alloy low-pressure pouring degassing device comprises a quantitative furnace, a gas guide pipe is arranged in the quantitative furnace and is longitudinally arranged, a fireproof layer is arranged on the peripheral face of the gas guide pipe, a gas guide hole is formed in the bottom of the gas guide pipe, and the gas guide hole is close to the inner bottom of the quantitative furnace; the upper part of the gas guide pipe penetrates out of the quantitative furnace and is communicated with one end of a heat-resistant gas pipe through a flange; the other end of the heat-resistant gas pipe is communicated with an argon bottle. According to the method, after the aluminum alloy melt enters the quantitative furnace, the argon bottle is opened, argon enters the gas guide pipe through the heat-resistant gas pipe, the connector and the connecting pipe in sequence, then is discharged through the gas guide hole and enters the aluminum alloy melt, the argon forms bubbles and rises after entering the melt, and hydrogen is gradually separated out of the melt and attached to the surfaces of the argon bubbles; along with the rising of argon bubbles, molten aluminum alloy is brought out, and the hydrogen content is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of metal processing, in particular to a degassing device for low-pressure pouring of aluminum alloy. Background Art

[0002] Aluminum alloys have been widely used in many industries such as automobiles, aviation, and construction due to their good physical properties, chemical stability, and low cost. However, in the production process of aluminum alloys, the control of melt quality is an extremely important task, especially the control of hydrogen content. Hydrogen is one of the most common gas impurities in aluminum alloys. It will precipitate during the cooling and solidification process to form bubbles, resulting in pores inside the casting, which in turn affects the mechanical properties and surface quality of the casting.

[0003] During the smelting and pouring of aluminum alloys, the melt is very easy to absorb hydrogen, especially in the process of introducing the molten aluminum alloy from the smelting furnace into the transfer ladle and from the transfer ladle into the dosing furnace. Due to exposure to the atmosphere, the melt will quickly absorb moisture in the air and precipitate hydrogen. Usually, after the aluminum alloy is melted, the molten aluminum is introduced into the transfer ladle, and after degassing, it is introduced from the transfer ladle into the dosing furnace for pouring production. However, in the process of introducing the transfer ladle into the dosing furnace, the molten aluminum is circulated again, and air entrainment and splashing will occur in the middle. Therefore, after being introduced into the dosing furnace, the hydrogen content of the molten aluminum will increase again and may exceed the standard value, and the existing degassing methods are often difficult to eliminate the hydrogen introduced at this stage. Therefore, even if effective degassing treatment has been carried out during the smelting process, if the hydrogen content cannot be reduced again after circulation, it will still cause defects such as pores in the final cast product, seriously affecting the quality and service life of the casting. To this end, we propose a degassing device for low-pressure pouring of aluminum alloys. Summary of the invention

[0004] The purpose of the present invention is to provide a degassing device for low-pressure pouring of aluminum alloy. By arranging an air guide pipe in a quantitative furnace, an inert gas connected outside the furnace is introduced into the aluminum liquid in the furnace, and the hydrogen in the aluminum liquid is brought out by the inert gas, so as to reduce the hydrogen content in the aluminum liquid, thereby improving product performance and solving the problems in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A degassing device for low-pressure pouring of aluminum alloy comprises a dosing furnace, wherein an air guide pipe is arranged inside the dosing furnace, the air guide pipe is arranged longitudinally, a refractory layer is arranged on the outer peripheral surface of the air guide pipe, an air guide hole is opened at the bottom of the air guide pipe, the air guide hole is close to the inner bottom of the dosing furnace, the upper part of the air guide pipe passes through the dosing furnace and is connected to one end of a heat-resistant air pipe through a flange, and the other end of the heat-resistant air pipe is connected to an argon gas bottle.

[0007] Preferably, a float flowmeter is provided on the heat-resistant air pipe.

[0008] Preferably, the connecting end of the heat-resistant air pipe and the air guide pipe is provided with a joint, and the joint is a bent pipe structure.

[0009] Preferably, the flange comprises an upper flange and a lower flange, a connecting pipe is provided on the top of the upper flange, and the connecting pipe is connected to the joint.

[0010] Preferably, the upper ends of the air guide pipe and the refractory layer penetrate into the lower flange and are fixed to the lower flange, and the upper flange and the lower flange are connected by bolts.

[0011] Preferably, a cover plate is fixed to the bottom surface of the lower flange, the lower flange is installed on the quantitative furnace through the cover plate, and a refractory cotton layer is provided on the contact surface between the cover plate and the quantitative furnace.

[0012] Preferably, a plurality of the air guide holes are arranged and surround the periphery of the air guide tube.

[0013] Preferably, a pouring port is provided on one side of the quantitative furnace, and a material inlet and outlet is provided on a side of the quantitative furnace away from the pouring port.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. In the present invention, after the aluminum alloy melt enters the quantitative furnace, the argon bottle is opened to allow the argon gas to enter the gas guide pipe through the heat-resistant gas pipe, the joint and the connecting pipe in sequence, and then be discharged from the gas guide hole and enter the aluminum alloy melt. After the argon gas enters the melt, it forms bubbles and rises. The argon bubbles cause the local pressure in the aluminum alloy melt to drop, so that hydrogen is gradually precipitated from the melt and attached to the surface of the argon bubbles, and finally is taken out of the aluminum alloy melt as the argon bubbles rise, thereby reducing the hydrogen content.

[0016] 2. The refractory layer provided on the outer peripheral surface of the air guide tube of the present invention can isolate the aluminum alloy melt from contacting the air guide tube, thereby preventing the precipitation of iron elements from contaminating the aluminum alloy melt; the float flowmeter can accurately control the flow rate of the introduced gas; and the refractory cotton layer is provided on the contact surface between the cover plate and the quantitative furnace to reduce heat loss and prevent condensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 It is an axonometric view of the refractory layer of the present invention;

[0019] Figure 3 It is a partial structural disassembly diagram of the present invention;

[0020] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle.

[0021] In the figure: 1. Argon gas cylinder; 2. Float flowmeter; 3. Heat-resistant gas pipe; 4. Joint; 5. Flange; 6. Cover plate; 7. Gas guide pipe; 8. Refractory layer; 9. Gas guide hole; 10. Pouring nozzle; 11. Dosing furnace; 12. Material inlet and outlet; 13. Upper flange; 14. Lower flange; 15. Connecting pipe; 16. Refractory cotton layer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to solve the problem in the prior art that after the aluminum alloy melt is poured into the dosing furnace, the hydrogen content of the melt increases, but the degassing operation cannot be performed again in the dosing furnace, the following technical solution is provided, please refer to Figure 1-4 ;

[0024] A degassing device for low-pressure pouring of aluminum alloy comprises a quantitative furnace 11, a pouring port 10 is arranged on one side of the quantitative furnace 11, a material inlet and outlet 12 is arranged on the side of the quantitative furnace 11 away from the pouring port 10, an air guide pipe 7 is arranged inside the quantitative furnace 11, the air guide pipe 7 is arranged longitudinally, the air guide pipe 7 is made of refractory steel, and a refractory layer 8 is also arranged on the outer peripheral surface of the air guide pipe 7, which can isolate the aluminum alloy melt from contacting the air guide pipe 7 to avoid the precipitation of Fe elements and polluting the aluminum alloy melt; an air guide hole 9 is opened at the bottom of the air guide pipe 7, the air guide hole 9 is close to the inner bottom of the quantitative furnace 11, and a plurality of air guide holes 9 are arranged and surrounded by the outer periphery of the air guide pipe 7; the upper part of the air guide pipe 7 passes through the quantitative furnace 11 and is connected to one end of a heat-resistant air pipe 3 through a flange 5, and the other end of the heat-resistant air pipe 3 is connected to an argon gas bottle 1; a float flowmeter 2 is arranged on the heat-resistant air pipe 3 to control the flow of the introduced gas, which is equivalent to the function of a flow switch.

[0025] A joint 4 is provided at the connecting end of the heat-resistant gas pipe 3 and the gas guide pipe 7, and the joint 4 is a bent pipe structure; the flange 5 includes an upper flange 13 and a lower flange 14, and a connecting pipe 15 is provided on the top of the upper flange 13, and the connecting pipe 15 is connected to the joint 4; the upper ends of the gas guide pipe 7 and the refractory layer 8 penetrate into the lower flange 14 and are fixed to the lower flange 14, and the upper flange 13 and the lower flange 14 are connected by bolts; a cover plate 6 is fixed to the bottom surface of the lower flange 14, and the lower flange 14 is installed on the quantitative furnace 11 through the cover plate 6, and the refractory cotton layer 16 arranged on the contact surface between the cover plate 6 and the quantitative furnace 11 can reduce heat loss.

[0026] Specifically, after degassing, the aluminum alloy melt enters the quantitative furnace 11 from the material inlet and outlet 12. At this time, the argon bottle 1 is opened to allow the argon gas to enter the float flowmeter 2 from the heat-resistant gas pipe 3. The introduced gas flow is controlled by the float flowmeter 2. The argon gas passes through the joint 4 and the connecting pipe 15 in turn and enters the gas guide pipe 7, and then is discharged from the gas guide hole 9 and enters the aluminum alloy melt to bring out hydrogen.

[0027] Working principle: After the aluminum alloy melt enters the quantitative furnace 11, the argon bottle 1 is opened to allow the argon gas to pass through the heat-resistant gas pipe 3, the joint 4 and the connecting pipe 15 in turn and then enter the gas guide pipe 7, and then be discharged from the gas guide hole 9 and enter the aluminum alloy melt. After the argon gas enters the melt, it forms bubbles and rises. The argon bubbles cause the local pressure in the aluminum alloy melt to drop, so that hydrogen gradually precipitates from the melt and adheres to the surface of the argon bubbles, and is finally taken out of the aluminum alloy melt as the argon bubbles rise, thereby reducing the hydrogen content.

[0028] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0029] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A degassing device for low-pressure pouring of aluminum alloy, comprising a dosing furnace (11), characterized in that: An air guide pipe (7) is provided inside the quantitative furnace (11), the air guide pipe (7) is arranged in a longitudinal direction, a refractory layer (8) is provided on the outer peripheral surface of the air guide pipe (7), an air guide hole (9) is provided at the bottom of the air guide pipe (7), the air guide hole (9) is close to the inner bottom of the quantitative furnace (11), the upper part of the air guide pipe (7) passes through the quantitative furnace (11) and is connected to one end of the heat-resistant air pipe (3) through a flange (5), and the other end of the heat-resistant air pipe (3) is connected to an argon gas bottle (1).

2. A degassing device for low-pressure pouring of aluminum alloy according to claim 1, characterized in that: The heat-resistant gas pipe (3) is provided with a float flowmeter (2).

3. A degassing device for low-pressure pouring of aluminum alloy according to claim 2, characterized in that: A joint (4) is provided at the connection end between the heat-resistant air pipe (3) and the air guide pipe (7), and the joint (4) is in a bent pipe structure.

4. A degassing device for low-pressure pouring of aluminum alloy according to claim 3, characterized in that: The flange (5) comprises an upper flange (13) and a lower flange (14). A connecting pipe (15) is provided at the top of the upper flange (13), and the connecting pipe (15) is connected to the joint (4).

5. A degassing device for low-pressure pouring of aluminum alloy according to claim 4, characterized in that: The upper ends of the air guide pipe (7) and the fireproof layer (8) penetrate into the lower flange (14) and are fixed to the lower flange (14), and the upper flange (13) and the lower flange (14) are connected by bolts.

6. A degassing device for low-pressure pouring of aluminum alloy according to claim 5, characterized in that: A cover plate (6) is fixed to the bottom surface of the lower flange (14), and the lower flange (14) is installed on the quantitative furnace (11) through the cover plate (6). A fire-resistant cotton layer (16) is provided on the contact surface between the cover plate (6) and the quantitative furnace (11).

7. A degassing device for low-pressure pouring of aluminum alloy according to claim 6, characterized in that: A plurality of the air guide holes (9) are arranged in an arranged manner and surround the outer periphery of the air guide pipe (7).

8. A degassing device for low-pressure pouring of aluminum alloy according to claim 7, characterized in that: A pouring port (10) is provided on one side of the dosing furnace (11), and a material inlet and outlet (12) is provided on a side of the dosing furnace (11) away from the pouring port (10).

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