Online impurity and gas removal device for molten aluminum

Abstract

The invention belongs to the technical field of aluminum processing, and particularly relates to a molten aluminum online impurity and gas removal device which comprises a box body, the box body is provided with a treatment cavity, a vacuumizing structure communicated with the treatment cavity is arranged on one side of the box body, a molten aluminum inlet and a molten aluminum outlet are formed in one side of the box body, and the treatment cavity comprises a front treatment cavity and a rear treatment cavity which are separated by a partition plate; the pre-treatment cavity is communicated with the molten aluminum inlet, the post-treatment cavity is communicated with the molten aluminum outlet, the pre-treatment cavity and the post-treatment cavity are communicated at the top, and a pre-treatment rotor and a post-treatment rotor are respectively arranged at the cavity bottom of the pre-treatment cavity and the cavity bottom of the post-treatment cavity. The two treatment cavities are arranged, the rotors are arranged, the degassing and impurity removal effect on molten aluminum is better, the device is particularly suitable for treatment of regenerated aluminum melt, meanwhile, the molten aluminum can be treated online, and the treatment efficiency is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum processing, and in particular relates to an online impurity removal and degassing device for aluminum liquid. Background Art

[0002] The hydrogen content and non-metallic inclusions of the molten aluminum alloy in the casting workshop will seriously affect the quality of the castings. Usually during the condensation process, as the solubility of hydrogen decreases, hydrogen does not have time to escape from the solution, and non-metallic inclusions do not have time to float to the liquid surface before entering the crystallizer. In the subsequent rolling process, it will cause an increase in white spots and pinholes on the surface of the plates and foils, a decrease in the mechanical properties of the materials, and ultimately lead to product scrapping. Therefore, the aluminum alloy melt must be degassed and purified.

[0003] Existing online rotary blowing devices, such as a molten aluminum degasser disclosed in CN106119564A, use one cavity and two rotors for degassing, which is complete and efficient.

[0004] Although the above-mentioned degassing machine improves the degassing efficiency to a certain extent, it has low efficiency in removing impurities, especially for the melt processing of recycled aluminum. When the amount of scrap aluminum added is large, for example, greater than 30%, the ideal impurity removal and degassing effect cannot be achieved, resulting in unqualified product quality. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned defects of the existing degassing machine and provide an online impurity removal and degassing device for molten aluminum, which has a more excellent impurity removal and degassing effect and is particularly suitable for the melt treatment of recycled aluminum with a large amount of scrap aluminum added.

[0006] The present invention adopts the following technical solution: An online impurity removal and degassing device for molten aluminum comprises a box body, the box body has a processing chamber, a vacuum pumping structure connected to the processing chamber is arranged on one side of the box body, an aluminum liquid inlet and an aluminum liquid outlet are opened on one side of the box body, the processing chamber comprises a pre-processing chamber and a post-processing chamber separated by a partition, the pre-processing chamber is connected to the aluminum liquid inlet, the post-processing chamber is connected to the aluminum liquid outlet, and the pre-processing chamber and the post-processing chamber are connected at the top, and a pre-processing rotor and a post-processing rotor are respectively arranged at the bottom of the pre-processing chamber and the bottom of the post-processing chamber.

[0007] In the above scheme, inert gas is introduced through the graphite rotor. The inert gas does not react chemically with aluminum liquid at the casting temperature and is not dissolved in the aluminum melt. The inert gas is sprayed into the aluminum liquid through the high-speed rotating graphite rotor to form a large number of continuous fine bubbles. When the inert gas bubbles rise from the bottom of the melting chamber, the hydrogen in the melt continuously diffuses into the bubbles because the hydrogen partial pressure in these bubbles is zero. When the bubbles encounter non-metallic inclusions during the floating process, the inclusions adhere to the surface of the bubbles due to the effect of surface tension. These inclusions are removed as the bubbles float up, so that the aluminum liquid can be thoroughly purified.

[0008] In this solution, first, two processing chambers are set, including a front processing chamber and a rear processing chamber. The front processing chamber is connected to the aluminum liquid inlet, and the rear processing chamber is connected to the aluminum liquid outlet. The aluminum liquid to be processed passes through the front and rear processing chambers in sequence and is discharged after being processed. Compared with the processing equipment in the prior art, this prolongs the processing path, so that the inert gas can fully contact with the aluminum liquid, and the impurities can be fully adsorbed on the bubbles, and the degassing and impurity removal effects are significantly improved.

[0009] Furthermore, under the premise of setting up two processing chambers, this solution sets a graphite rotor in each processing chamber to increase the degree of jetting and stirring, further ensure that the inert gas can fully contact with the aluminum liquid, and further improve the processing effect.

[0010] Thirdly, on the basis of the above two, the present scheme sets the graphite rotor in each processing chamber at the bottom of the corresponding processing chamber, and the aluminum liquid inlet and aluminum liquid outlet are also set at the lower part of the side wall of the box body, so as to ensure that the aluminum liquid to be processed entering the pre-processing chamber will always pass through the gas distribution area of ​​the graphite rotor first, and then go up, and then in the post-processing chamber, the bubbles generated at the bottom float up and pass through the aluminum liquid coming from the pre-processing chamber. The small bubbles continuously absorb hydrogen, and impurities are fully adsorbed on the surface of the bubbles in the process. The treated aluminum liquid then flows out from the aluminum liquid treatment, further improving the treatment effect.

[0011] It may be further preferred that the aluminum liquid inlet does not exceed the lowest gas outlet of the pre-treatment rotor in the height direction, which is more conducive to sufficient contact between the inert gas and the aluminum liquid.

[0012] Preferably, a flow channel is provided on one side of the box body, the side wall of the flow channel is close to the outer wall of the box body, and a front notch aligned with the aluminum liquid inlet and a rear notch aligned with the aluminum liquid outlet are opened on the side wall of the flow channel close to the box body.

[0013] Preferably, a front baffle plate located between the front notch and the rear notch and a rear baffle plate located behind the rear notch are provided on the flow channel along the flow direction of the aluminum liquid.

[0014] Preferably, the height of the pre-processing rotor does not exceed half of the height of the pre-processing chamber.

[0015] Preferably, the height of the post-processing rotor does not exceed half of the height of the post-processing chamber.

[0016] Preferably, a guide plate is provided at the upper part of the post-processing chamber, on one side of the partition, and a fluid channel for the aluminum liquid to flow from the front-processing chamber to the post-processing chamber is formed between the guide plate, the partition and the inner wall of the box body, and the outlet of the fluid channel and the aluminum liquid outlet are located on different sides of the box body.

[0017] Preferably, a mixed flow area is provided in the middle or upper part of the pre-treatment chamber, and the inner diameter of the mixed flow area is larger than the inner diameter of other areas of the pre-treatment chamber.

[0018] Preferably, the mixed flow region starts at the top of the pre-treatment rotor in the vertical direction.

[0019] By implementing the above technical solution, the present invention has the following beneficial effects: The present invention provides two processing chambers and arranges rotors respectively, so as to achieve better degassing and impurity removal effects on molten aluminum, and is particularly suitable for the treatment of recycled aluminum melt. Meanwhile, the arrangement of the present invention can process the molten aluminum online, thus greatly improving the treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the online impurity removal and degassing device for molten aluminum shown in Example 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of the processing chamber of the online impurity removal and degassing device for molten aluminum shown in Example 1 of the present invention.

[0022] Figure 3 This is a schematic plan view of the internal structure of the processing chamber of the online impurity removal and degassing device for molten aluminum shown in Example 1 of the present invention.

[0023] Figure 4 This is a schematic diagram of the internal structure of the processing chamber of the online aluminum liquid impurity removal and degassing device shown in Example 2 of the present invention.

[0024] Figure 5 This is a schematic diagram of the internal structure of the processing chamber of the online aluminum liquid impurity removal and degassing device shown in Example 3 of the present invention.

[0025] In the figure, 10-box, 20-vacuum pumping structure, 101a-pre-treatment chamber, 102b-post-treatment chamber, 102-aluminum liquid inlet, 103-aluminum liquid outlet, 104-power chamber, 105-mixed flow area, 30-partition, 401-pre-treatment rotor, 402-post-treatment rotor, 50-flow trough, 501-front slot, 502-rear slot, 601-front baffle, 602-rear baffle, 70-guide plate 701-fluid channel, 702-outlet. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and specific implementation examples.

[0027] It should be noted that the following implementation cases are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention is described in detail with reference to the following implementation cases, those skilled in the art should understand that they can still modify the technical solutions recorded in the implementation cases, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation cases of the present invention.

[0028] Example 1 This embodiment provides an online impurity removal and degassing device for aluminum liquid, which removes hydrogen and some non-metallic impurities in aluminum liquid online. Figure 1 As shown, the device includes a box body 10, and a processing chamber is provided inside the box body 10. The processing chamber is relatively sealed. One of the side walls of the box body 10 can be opened and is directly hinged to the adjacent side wall. After closing, the box body 10 is sealed to the adjacent side wall.

[0029] A vacuum pumping structure 20 connected to the processing chamber is provided on one side of the box 10 to evacuate the box 10 and continuously remove gas during the degassing and impurity removal process to ensure the stable online impurity and degassing. The vacuum pumping structure 20 uses an existing vacuum pumping machine, which generally includes a pipeline connected to the box 10 and a vacuum pump.

[0030] An aluminum liquid inlet 102 and an aluminum liquid outlet 103 are provided at the lower part of one side of the box body 10, and the processing chamber includes a pre-processing chamber 101a and a post-processing chamber 101b separated by a partition 30, the pre-processing chamber 101a is connected to the aluminum liquid inlet 102, the post-processing chamber 101b is connected to the aluminum liquid outlet 103, and the pre-processing chamber 101a and the post-processing chamber 101b are connected at the top, and a pre-processing rotor 401 and a post-processing rotor 402 are respectively provided at the bottom of the pre-processing chamber 101a and the bottom of the post-processing chamber 101b. Both the pre-processing rotor 401 and the post-processing rotor 402 are graphite rotors, and a power chamber 104 is provided at the bottom of the box body 10, and two driving parts are arranged in the power chamber 104 to provide power for the corresponding graphite rotors. The graphite rotor is also connected to an inert gas through an air pipe. While the graphite rotor rotates, an inert gas is continuously introduced into the processing box of the box body 10. For the structure inside the box body 10, see Figure 2 After entering the continuous online impurity removal and degassing, the aluminum liquid to be treated enters the pre-treatment chamber 101a from the aluminum liquid inlet 102, and then flows out from the aluminum liquid outlet 103 after passing through the post-treatment chamber 101b, completing the online impurity removal and degassing.

[0031] In this embodiment, the height of the pre-processing rotor 401 is lower than half of the height of the pre-processing chamber 101a, and the height of the post-processing rotor 402 is lower than half of the height of the post-processing chamber 101b. Since in this embodiment, the pre-processing rotor 401 and the post-processing rotor 402 are both arranged at the bottom of the corresponding chamber, the aluminum liquid inlet 102 does not exceed the lowest gas outlet of the pre-processing rotor 401 in the height direction. In this case, the aluminum liquid flowing in from the aluminum liquid inlet 102 will first pass through the outlet position of the pre-processing rotor 401 and make full contact with the inert gas during the process of flowing upward into the post-processing chamber 101b. After the contact, it will ascend to the upper end of the pre-processing rotor 401. At this time, the aluminum liquid is remixed with the help of the disturbance of the aluminum liquid flow driven by the rotation of the pre-processing rotor 401. Compared with the direct stirring of the pre-processing rotor 401 or the inert gas, this is more conducive to the adhesion of non-metallic impurities on the surface of the bubble. When the bubble floats to the top position of the partition 30, the aluminum liquid enters the post-processing chamber 101b, and the bubble is sucked away by the vacuum structure, and the impurities adsorbed on the surface are taken away at the same time, so that the removal effect of non-metallic impurities is better. Subsequently, the aluminum liquid enters the post-processing chamber 101b to continue the secondary degassing and impurity removal treatment.

[0032] The aluminum liquid enters the post-processing chamber 101b from the top of the post-processing chamber 101b and flows out from the aluminum liquid outlet 103 at the bottom of the post-processing chamber 101b. If the post-processing rotor 402 is too high, the aluminum liquid will contact the inert gas too early to form bubbles, and then the bubbles will float up and be sucked away, which is not conducive to the adsorption of non-metallic impurities on the bubble surface. In this embodiment, the height of the post-processing rotor 402 is lower than half the height of the post-processing chamber 101b. The aluminum liquid will fully contact the inert gas only when it reaches the middle and lower part of the post-processing chamber 101b, forming a large number of bubbles. The bubbles float up and the aluminum liquid goes down. In this process, the bubble surface can fully adsorb impurities in the aluminum liquid.

[0033] In this embodiment, a flow slot is provided on one side of the box 10, and the side wall of the flow slot is close to the outer wall of the box 10. A front notch 501 aligned with the aluminum liquid inlet 102 and a rear notch 502 aligned with the aluminum liquid outlet 103 are provided on the side wall of the flow slot close to the box 10. The flow slot receives the aluminum liquid to be processed in the previous process, and the aluminum liquid passes through the front notch 501 and enters the pre-processing chamber 101a from the aluminum liquid inlet 102, and then enters the post-processing chamber 101b from the pre-processing chamber 101a. After the graphite rotor in the pre-processing chamber 101b, it flows into the flow slot from the aluminum liquid outlet 103 through the rear notch 502, that is, the impurity removal and degassing treatment is completed, and enters the subsequent process. This method can realize the continuous online treatment of aluminum liquid, which greatly improves the processing efficiency.

[0034] In another specific embodiment, a front baffle 601 is provided on the flow trough along the flow direction of the aluminum liquid, between the front notch 501 and the rear notch 502, to block the flow of the aluminum liquid between the front notch 501 and the rear notch 502 in the flow trough, and the front baffle 601 can be lifted to open the flow channel as needed. In this embodiment, a rear baffle 602 is also provided behind the rear notch 502, and similarly, the rear baffle 602 can also be lifted. When it is necessary to block the flow channel behind the rear notch 502, the rear baffle 602 is placed, for example, at the beginning, the aluminum liquid in the box 10 is filled, the front baffle 601 can be opened, and the rear baffle 602 can be placed. Or when it is necessary to degas and remove impurities for some liquids that need to be degassed for a long time, the rear baffle 602 can be placed to extend the retention time of the liquid in the box 10.

[0035] Example 2 The embodiment provides an online impurity removal and degassing device for aluminum liquid, which is an optimization and improvement based on the embodiment 1. The difference from the embodiment 1 is that in the embodiment, a guide plate 70 is provided at the upper part of the post-processing chamber 101b and on one side of the partition 30, and a fluid channel 701 is formed between the guide plate 70, the partition 30 and the inner wall of the box 10 so that the aluminum liquid flows from the front processing chamber 101a to the post-processing chamber 101b, and the outlet 702 of the fluid channel 701 and the aluminum liquid outlet 103 are located on different sides of the box 10. Figure 2 If the arrangement is as shown in , the aluminum liquid near the aluminum liquid outlet 103 may flow down along the inner wall of the box 10 and flow out of the aluminum liquid outlet 103, making the treatment effect of this part of the aluminum liquid poor, thereby affecting the overall treatment effect. Figure 3 , a guide plate is provided to guide the aluminum liquid from the pre-treatment chamber 101a to the opposite side of the aluminum liquid outlet 103, so as to ensure that the aluminum liquid is fully stirred by the graphite rotor and fully contacts with the inert gas before flowing out of the aluminum liquid outlet 103. The guide plate forms the fluid channel and the outlet, and also reduces the passage from the pre-treatment chamber 101a to the post-treatment chamber 101b, so that the bubbles coming out of the post-treatment chamber 101b under the action of the vacuum pumping structure 20 can have more sufficient contact with the aluminum liquid, which is more conducive to the adsorption of impurities.

[0036] Example 3 This embodiment provides an aluminum liquid online impurity removal and degassing device, which is an optimization and improvement based on the embodiment 1. The difference from the embodiment 1 is that, see Figure 4In this embodiment, a mixed flow area 105 is provided in the middle of the pre-treatment chamber 101a, and the inner diameter of the mixed flow area 105 is larger than the inner diameter of other areas of the pre-treatment chamber 101a. The mixed flow area 105 starts from the top of the pre-treatment rotor 401 in the vertical direction. By setting the mixed flow area 105, the disturbance direction of the upward aluminum liquid flow is changed, which is conducive to more sufficient contact between the bubbles and the aluminum liquid during the upward process, which is particularly conducive to the adsorption of impurities on the bubble surface, thereby further improving the treatment effect of the aluminum liquid.

Claims

1. An online impurity removal and degassing device for aluminum liquid, comprising a box body, the box body having a processing chamber, a vacuum pumping structure connected to the processing chamber is arranged on one side of the box body, and an aluminum liquid inlet and an aluminum liquid outlet are opened on one side of the box body, characterized in that: The processing chamber includes a front processing chamber and a post processing chamber separated by a partition, the front processing chamber is connected with an aluminum liquid inlet, the post processing chamber is connected with an aluminum liquid outlet, and the front processing chamber and the post processing chamber are connected at the top, and a front processing rotor and a post processing rotor are respectively arranged at the bottom of the front processing chamber and the bottom of the post processing chamber.

2. The on-line impurity removal and degassing device for aluminum liquid according to claim 1 is characterized in that: The aluminum liquid inlet does not exceed the lowest air outlet of the pre-processing rotor in the height direction.

3. The on-line impurity removal and degassing device for aluminum liquid according to claim 1 is characterized in that: A flow channel is arranged on one side of the box body, and the side wall of the flow channel is close to the outer wall of the box body. A front notch aligned with the aluminum liquid inlet and a rear notch aligned with the aluminum liquid outlet are opened on the side wall of the flow channel close to the box body.

4. The on-line impurity removal and degassing device for aluminum liquid according to claim 3 is characterized in that: A front baffle is provided on the flow trough along the flow direction of the aluminum liquid, located between the front notch and the rear notch.

5. The on-line impurity removal and degassing device for aluminum liquid according to claim 4 is characterized in that: A rear baffle is also provided on the flow trough and along the flow direction of the aluminum liquid, and is located behind the rear notch.

6. The on-line impurity removal and degassing device for aluminum liquid according to claim 1 is characterized in that: The height of the pre-processing rotor does not exceed half of the height of the pre-processing chamber.

7. The device for online impurity removal and degassing of molten aluminum according to claim 6, characterized in that: The height of the post-processing rotor does not exceed half of the height of the post-processing chamber.

8. The on-line impurity removal and degassing device for aluminum liquid according to claim 1 is characterized in that: A guide plate is arranged at the upper part of the post-processing chamber and on one side of the partition, and a fluid channel for the aluminum liquid to flow from the front-processing chamber to the post-processing chamber is formed between the guide plate, the partition and the inner wall of the box body, and the outlet of the fluid channel and the aluminum liquid outlet are located on different sides of the box body.

9. The on-line impurity removal and degassing device for aluminum liquid according to claim 1 is characterized in that: A mixed flow area is arranged in the middle or upper part of the pre-treatment chamber, and the inner diameter of the mixed flow area is larger than the inner diameter of other areas of the pre-treatment chamber.

10. The on-line impurity removal and degassing device for aluminum liquid according to claim 9, characterized in that: The mixed flow area starts from the top of the pre-processing rotor in the vertical direction.

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