Aluminum alloy vacuum and rotor high-efficiency composite degassing equipment and degassing process thereof

Abstract

The application relates to an aluminum alloy vacuum and rotor high-efficiency composite degassing equipment and a degassing process thereof, and belongs to the field of aluminum alloy smelting and refining. The equipment comprises a crucible furnace, a sealing cover which is combined above the crucible furnace and surrounds the crucible furnace to form a closed degassing chamber, a gas suction port and a rotor mounting hole which are arranged on the sealing cover, a vacuum pump which is connected with the gas suction port through a vacuum pipeline, a rotating shaft which is mounted in the rotor mounting hole through a high-temperature sealing bearing, a driving motor which is connected with the rotating shaft at the upper end and connected with a rotating degassing rotor at the lower end, the rotating degassing rotor which is inserted into the aluminum liquid below the liquid surface of the crucible furnace, a heating system which is arranged on the furnace wall of the crucible furnace, and a control system which is electrically connected with the driving motor, the vacuum pump and the heating system respectively. The application solves the technical problems of long degassing process time and high gas content in the prior art, has the advantages of high degassing efficiency, low energy consumption and simple operation, and can be widely applied to aluminum alloy casting production.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy smelting and refining technology, specifically to an aluminum alloy vacuum and rotor high-efficiency composite degassing device and its degassing process. Background Technology

[0002] Aluminum alloys readily absorb hydrogen during the smelting process. The dissolved hydrogen precipitates out during solidification, forming pores that severely reduce the density, mechanical properties, and pressure resistance of the castings. Therefore, degassing of molten aluminum is one of the core processes in aluminum alloy smelting.

[0003] Currently, the commonly used methods for purifying molten aluminum in the aluminum alloy casting industry mainly fall into two categories: rotary blowing and vacuum degassing. Rotary blowing involves blowing inert gas (argon or nitrogen) into the molten aluminum using a graphite rotor with vent holes. Simultaneously, the high-speed rotation of the rotor breaks the gas into tiny bubbles. These bubbles adsorb hydrogen and inclusions as they rise, thus purifying the molten aluminum. This method has good degassing effects, but it suffers from problems such as severe surface turbulence, damage to the oxide film leading to secondary oxidation, and the addition of new inclusions. The refining time is typically 8–15 minutes, and the gas content is generally controlled between 0.12–0.15 ml / 100gAl.

[0004] Vacuum degassing involves drawing the melting chamber into a vacuum state, using negative pressure to reduce the solubility of hydrogen in the molten aluminum and promote gas escape. This method avoids violent churning of the molten aluminum surface, but when used alone, the pumping speed is slow, the degassing efficiency is low, and the degassing effect on deep molten aluminum is not ideal.

[0005] In recent years, some technologies have attempted to combine vacuum degassing with rotary jet blowing. For example, the Qinghai Salt Lake Institute of the Chinese Academy of Sciences disclosed a high-efficiency degassing device combining vacuum and rotary jet blowing for aluminum alloy refining. This device combines vacuum degassing with rotary jet blowing for degassing, reducing refining time by more than 30% compared to traditional refining equipment, and achieving a gas content of less than 0.08 ml / 100g. Another example is the device disclosed by Xi'an University of Technology for composite degassing and grain refinement of cast aluminum alloy melts. This device combines rotary degassing and vacuum degassing, and refines the grains using ultrasonic waves.

[0006] However, the existing technologies still have the following shortcomings: First, the coordination between the slag-removing agent and the degassing process is insufficient; the oxide film and slag on the surface of the molten aluminum are not pre-treated, affecting the subsequent degassing effect. Second, the timing of vacuum degassing and rotor degassing lacks scientific basis, and the combined use of the two degassing methods results in a still relatively long total refining time. Third, the process parameters (rotor speed, gas flow rate, vacuum degree, etc.) at different degassing stages lack targeted stage-specific control. Therefore, developing a composite degassing equipment and process with shorter degassing time and lower gas content has significant industrial application value. Summary of the Invention

[0007] In view of this, the present invention aims to propose an efficient composite degassing device for aluminum alloy vacuum and rotor and its degassing process, which can solve the problems of long degassing time, high gas content, and disconnect between slag cleaning and degassing processes in the prior art, and achieve the goal of reducing the total degassing time by more than 50% and reducing the gas content of the refined aluminum liquid to below 0.07 ml / 100g.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0009] A high-efficiency composite degassing device for aluminum alloy vacuum and rotor includes a crucible furnace, a sealing cover covering the crucible furnace and forming a sealed degassing chamber, an exhaust port and a rotor mounting hole on the sealing cover, a vacuum pump connected to the exhaust port via a vacuum pipe, a rotating shaft mounted in the rotor mounting hole via a high-temperature sealed bearing, a drive motor whose upper end is connected to the rotating shaft and whose lower end is connected to the rotating degassing rotor, a rotating degassing rotor extending below the surface of the molten aluminum in the crucible furnace, a heating system installed on the furnace wall, and a control system electrically connected to the drive motor, the vacuum pump and the heating system respectively.

[0010] In some embodiments, the rotary degassing rotor is made of high-purity graphite, with a rotor diameter of 80–120 mm, an outlet diameter of 1–3 mm, and 12–24 outlets, which are evenly distributed in a multi-layered spiral shape on the bottom and sides of the rotor.

[0011] In some embodiments, the inert gas is high-purity argon or high-purity nitrogen, with a purity of ≥99.99% and a flow rate of 5–25 L / min.

[0012] In some embodiments, the vacuum pump is a two-stage rotary vane vacuum pump with an ultimate vacuum of ≤10Pa and a pumping speed of 10-30L / s.

[0013] A high-efficiency combined vacuum and rotor degassing process for aluminum alloys, employing the aforementioned degassing equipment, includes the following steps:

[0014] Step 1: Evenly spread the slag remover on the surface of the molten aluminum and let it stand;

[0015] Step 2: Start the drive motor, control the rotating degassing rotor to rotate and introduce inert gas to degas the rotor;

[0016] Step 3: After the rotor degassing is completed, turn off the drive motor, keep the inert gas flowing, and start the vacuum pump to evacuate the degassing chamber for vacuum degassing.

[0017] Step 4: After vacuum degassing is completed, turn off the vacuum pump, restore normal pressure, let stand, and then remove the slag.

[0018] In some embodiments, in step one, the temperature of the molten aluminum is 700–740°C, the amount of slag remover added is 0.5–1.5 kg per ton of molten aluminum, and the settling time is 2–3 minutes; in step two, the rotation speed of the degassing rotor is 300–500 r / min, the flow rate of the inert gas is 10–20 L / min, and the rotor degassing time is 2–4 minutes; in step three, the flow rate of the inert gas is 3–8 L / min, the vacuum degree of the degassing chamber is 50–500 Pa, and the vacuum degassing time is 1–3 minutes.

[0019] In some embodiments, the rotor degassing time in step two is 3 minutes, and the vacuum degassing time in step three is 2 minutes.

[0020] In some embodiments, the amount of slag remover added in step one is 1 kg / ton of molten aluminum.

[0021] In some embodiments, the total time for the rotor degassing stage and the vacuum degassing stage is 4 to 7 minutes.

[0022] In some embodiments, the gas content of the refined molten aluminum is reduced to below 0.07 ml / 100gAl. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of an aluminum alloy vacuum and rotor high-efficiency composite degassing device according to the present invention.

[0025] Figure 2 This is a schematic diagram of the degassing state of an aluminum alloy vacuum and rotor high-efficiency composite degassing device according to the present invention.

[0026] Figure 3 This is a schematic diagram of the vacuum state of an aluminum alloy vacuum and rotor high-efficiency composite degassing device according to the present invention.

[0027] Figure 4 This is a flowchart of a high-efficiency composite degassing process for aluminum alloy using vacuum and rotor technology according to the present invention.

[0028] Explanation of reference numerals in the attached figures

[0029] 1. Base plate; 2. Vacuum tank; 3. Vacuum pump; 4. Metal tube one; 5. Control panel; 6. Telescopic hose; 7. Degasser column; 8. Degasser beam; 9. Drive motor; 10. Sealing cover fixing rod; 11. Sealing cover; 12. Degasser rotating rod; 13. Graphite rotor; 14. Metal tube two; 15. High-temperature resistant sealing ring; 16. Mechanical seal; 17. Crucible furnace; 18. Graphite crucible; 19. Electric heating coil; 20. Refractory brick; 21. Crucible furnace pressure plate. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The following is for reference. Figures 1 to 4 The embodiments of the present invention are described in conjunction with examples of the aluminum alloy vacuum and rotor high-efficiency composite degassing equipment and its degassing process.

[0033] Example 1

[0034] like Figures 1 to 3 As shown, the high-efficiency composite degassing equipment for aluminum alloy vacuum and rotor in this embodiment includes: a base plate 1, a vacuum tank 2 mounted on the base plate 1, and a degassing machine column 7. A crucible furnace 17 is installed inside the vacuum tank 2. Refractory bricks 20 and a crucible furnace pressure plate 21 are sequentially arranged at the bottom of the crucible furnace 17. A graphite crucible 18 is installed inside the crucible furnace 17, and an electric heating coil 19 is installed inside the furnace wall of the crucible furnace 17 for heating and maintaining the temperature of the molten aluminum. A sealing cover 11 is placed on top of the vacuum tank 2, and the sealing cover 11 is connected to the degassing machine crossbeam 8 via a sealing cover fixing rod 10. The sealing cover 11 and the crucible furnace 17 enclose a sealed degassing chamber.

[0035] The sealing cover 11 has an air extraction port and a rotor mounting hole. The air extraction port is connected to the vacuum pump 3 through metal pipe 2 14, flexible hose 6 and metal pipe 1 4, and is used to evacuate the degassing chamber. The vacuum pump 3 is a two-stage rotary vane vacuum pump with an ultimate vacuum of ≤10Pa and a pumping speed of 10~30L / s.

[0036] A rotating shaft, known as the degassing machine rotor 12, is installed inside the rotor mounting hole via a mechanical seal 16 and a high-temperature resistant sealing ring 15. The degassing machine rotor 12 has an internal gas channel, and its upper end is connected to a drive motor 9 via a belt. The drive motor 9 is mounted on the degassing machine crossbeam 8. A graphite rotor 13 is connected to the lower end of the degassing machine rotor 12. The graphite rotor 13 extends below the surface of the molten aluminum in the crucible furnace 17. It has an internal gas channel that communicates with the gas channel of the degassing machine rotor 12. The graphite rotor 13 has multiple gas outlets on its bottom and sides, with diameters ranging from 1 to 3 mm and a number ranging from 12 to 24, evenly distributed in a multi-layered spiral pattern on the bottom and sides of the rotor. The graphite rotor 13 has a diameter of 80 to 120 mm and operates at a speed of 200 to 600 r / min. The equipment also includes an inert gas supply system (not shown in the figure), which supplies gas to the graphite rotor 13 through the gas channel in the degasser rotor 12. The inert gas used is high-purity argon or high-purity nitrogen with a purity of ≥99.99% and a gas flow rate of 5 to 25 L / min.

[0037] The equipment also includes a control system, whose control panel 5 is mounted on the degasser column 7. The control system is electrically connected to the drive motor 9, vacuum pump 3, and electric heating coil 19, and is used to control the start / stop and operating parameters of each actuator according to a preset degassing process sequence. The control system is a PLC programmable logic controller with a built-in degassing process parameter preset module and a timing control module.

[0038] Figures 1 to 3 The equipment status is shown when the degasser beam 8 is in different working positions: Figure 1 For the location of adding slag remover and removing slag, Figure 2 For refining and degassing, Figure 3 This is the vacuum degassing location.

[0039] This embodiment uses the above-mentioned equipment to implement a high-efficiency composite degassing process for aluminum alloy vacuum and rotor, including the following steps:

[0040] Step 1: Melting and Adding Slag Remover: Add 800 kg of aluminum alloy raw material (A356 aluminum alloy in this example) to crucible furnace 17 and heat it to melt using electric heating coil 19. After the aluminum liquid temperature rises to 700-740℃ (720℃ in this example) and it is completely melted, evenly sprinkle granular slag remover onto the surface of the aluminum liquid. The amount of slag remover added is 0.5-1.5 kg per ton of aluminum liquid (1 kg / ton of aluminum liquid in this example, i.e., 0.8 kg), and let it stand for 2-3 minutes (2 minutes in this example). This slag remover is made by mixing chloride and fluoride in a certain proportion and extruding them into granules with a particle size of 2-6 mm. At this time, the degasser beam 8 is located at... Figure 1 The location shown.

[0041] Step Two: Rotor Degassing: Start the drive motor 9 to control the graphite rotor 13 to rotate at a speed of 300-500 r / min (400 r / min in this embodiment). Simultaneously, high-purity argon gas is introduced into the molten aluminum through the inert gas supply system at a flow rate of 10-20 L / min (15 L / min in this embodiment). During rotation, the graphite rotor 13 shears and breaks the inert gas into microbubbles. These bubbles are evenly dispersed inside the molten aluminum, adsorbing hydrogen and inclusions before floating to the surface. The rotor degassing time in this stage is 2-4 minutes (3 minutes in this embodiment). At this time, the degassing machine beam 8 is located at... Figure 2 The location shown.

[0042] Step 3: Vacuum Degassing: After the rotor degassing is completed, turn off the drive motor 9 and stop the graphite rotor 13 from rotating. Maintain a low flow rate of inert gas (3-8 L / min, 4 L / min in this embodiment) to keep the positive pressure in place and prevent backflow. Start the vacuum pump 3 to evacuate the degassing chamber to a vacuum level of 50-500 Pa (100 Pa in this embodiment), and maintain the vacuum degassing for 1-3 minutes (2 minutes in this embodiment). Under the negative vacuum pressure, the residual dissolved hydrogen in the molten aluminum further diffuses out, while the slag and oxide film on the surface of the molten aluminum become loose and easy to remove under negative pressure. At this time, the degassing machine beam 8 is located... Figure 3 The location is shown. The total time for the rotor degassing stage and the vacuum degassing stage is 4 to 7 minutes (5 minutes in this embodiment).

[0043] Step Four: Settling and Slag Removal: After vacuum degassing, turn off vacuum pump 3, open the vent valve to restore the chamber to normal pressure, and let it stand for 2-5 minutes (3 minutes in this embodiment) to allow the fine bubbles in the molten aluminum to continue to rise and the slag phase to fully rise and aggregate. Then, perform slag removal to remove the surface slag and obtain refined molten aluminum for casting. At this time, the degassing machine beam 8 is located at... Figure 1 The location shown.

[0044] After refining by the above process, the aluminum liquid was tested by the reduced pressure density equivalent method, and its gas content was reduced to below 0.07 ml / 100gAl (0.058 ml / 100gAl in this example), and the pinhole degree of the casting reached level 1.

[0045] Example 2

[0046] This embodiment uses the same equipment as in Embodiment 1 to process ADC12 aluminum alloy molten aluminum, with a processing capacity of 800 kg.

[0047] The process steps are as follows: (1) Control the temperature of the aluminum liquid at 710℃, evenly sprinkle 0.8kg of granular slag remover on the surface of the aluminum liquid, and let it stand for 3 minutes. (2) Rotor degassing: Start the drive motor 9, control the graphite rotor 13 to rotate at 350r / min, introduce high-purity argon gas at a flow rate of 12L / min, and degassing time of 4 minutes. (3) Vacuum degassing: Turn off the drive motor 9, stop the rotation of the graphite rotor 13, keep the argon gas continuously introduced at a flow rate of 4L / min, start the vacuum pump 3 to evacuate the degassing chamber to a vacuum degree of 80Pa, and maintain the vacuum degassing time for 2 minutes. (4) Turn off the vacuum pump 3, open the vent valve to restore normal pressure, let it stand for 5 minutes, and then remove the slag.

[0048] Results: The total degassing time was 6 minutes, and the gas content of the refined aluminum liquid was 0.055 ml / 100 g Al.

[0049] Comparative Example 1 (Traditional rotary jet degassing)

[0050] A conventional rotary jet degassing device (without vacuum function) was used to process A356 aluminum alloy molten aluminum of the same grade and weight as in Example 1.

[0051] Process steps: The aluminum liquid temperature is 720℃. After sprinkling 0.8kg of slag remover on the surface of the aluminum liquid, the degassing rotor is rotated at a speed of 400r / min. Argon gas is introduced at a flow rate of 15L / min for 8 minutes. After standing for 5 minutes, the slag is removed.

[0052] Results: The total degassing time was 8 minutes, and the gas content of the refined aluminum liquid was 0.13 ml / 100gAl.

[0053] Comparative Example 2 (vacuum-assisted rotary degassing)

[0054] A composite degassing device that operates simultaneously with a vacuum chamber and a rotary degassing unit was used to process A356 aluminum alloy molten aluminum of the same grade and weight as in Example 1.

[0055] Process steps: The aluminum liquid temperature is 720℃. After sprinkling 0.8kg of slag remover onto the surface of the aluminum liquid, start the vacuum pump to evacuate to 100Pa. At the same time, start the rotor to rotate at 400r / min and introduce argon gas at 15L / min. The total degassing time is 5 minutes. After standing for 3 minutes, remove the slag.

[0056] Results: The total degassing time was 5 minutes, and the gas content of the refined aluminum liquid was 0.095 ml / 100gAl, which was higher than that in Example 1. The reason for this was that the tumbling and disturbance of the aluminum liquid surface during rotor rotation disrupted the sealing stability of the vacuum chamber, and the eddies generated by the rotation caused some aluminum liquid to splash onto the inner wall of the furnace cover, forming oxide scale, which in turn introduced new inclusions.

[0057] The results of the examples and comparative examples are compared as follows:

[0058]

[0059] Compared with traditional processes, the time is shortened by 37.5%-37.5%; the gas content is reduced by 55.4%-26.9% compared with traditional processes.

[0060] Experimental data show that the present invention, through the time-division composite degassing process of "rotor first, vacuum later", reduces the total degassing time by 37.5%, while reducing the gas content by 55.4% compared with traditional rotor degassing and by 38.9% compared with synchronous composite degassing, achieving significant technological progress.

[0061] In summary, this invention utilizes a three-stage composite process of "first applying a slag-removing agent—rapid rotor degassing—deep vacuum degassing," fully leveraging the synergistic effect of each stage: the slag-removing agent pre-breaks the surface oxide film and creates conditions for subsequent degassing; the rotor degassing stage removes over 80% of the hydrogen in the molten aluminum in a short time through high-speed rotation and bubble shearing; and the vacuum degassing stage utilizes a negative pressure environment to deeply remove residual hydrogen. The total degassing time is only 5-6 minutes, more than 50% shorter than traditional rotary jet degassing (8-15 minutes). The gas content of the refined molten aluminum can be stably reduced to below 0.07 ml / 100gAl. It boasts advantages such as high degassing efficiency, low energy consumption, and simple operation, and can be widely applied in aluminum alloy casting production.

[0062] Compared with existing technologies, the aluminum alloy vacuum and rotor high-efficiency composite degassing equipment and its degassing process of the present invention have the following advantages:

[0063] First, the degassing efficiency is significantly improved, and the total time is significantly shortened. Through a three-stage composite process of "first applying a slag-removing agent—rapid rotor degassing—deep vacuum degassing," the advantages of each stage are fully utilized: the slag-removing agent pre-breaks the surface oxide film and creates conditions for subsequent degassing; the rotor degassing stage removes more than 80% of the hydrogen in the molten aluminum in a short time through high-speed rotation and bubble shearing; the vacuum degassing stage utilizes a negative pressure environment to deeply remove residual hydrogen. The total degassing time is only 5-6 minutes (3 minutes for rotor + 2 minutes for vacuum), which is more than 50% shorter than traditional rotary jet degassing (8-15 minutes).

[0064] Secondly, the degassing effect is excellent, achieving an ultra-low gas content. This invention employs a "rotor-first, vacuum-later" process sequence, avoiding the problem of rotor rotation damaging the vacuum chamber's seal in the traditional "vacuum-while-rotating" approach, and also preventing additional oxidation caused by aluminum molten surface tumbling during the rotor degassing stage. The three processes work synergistically, resulting in a stable gas content in the refined aluminum molten material below 0.07 ml / 100gAl, far lower than the 0.12–0.15 ml / 100gAl levels of traditional processes.

[0065] Third, energy consumption is reduced, and production costs decrease. The significant reduction in degassing time directly reduces equipment operating energy consumption, while also reducing inert gas consumption. Calculated at a reduction of 5 minutes in degassing time per furnace cycle, a single unit can save tens of thousands of yuan in electricity and gas costs annually, demonstrating significant economic benefits.

[0066] Fourth, it is easy to operate and highly automated. The equipment of this invention has a compact structure. Through the PLC control system, process parameters can be preset and each stage sequence can be executed automatically. The operator only needs to press the start button to complete the entire degassing process, which reduces human operation error and ensures process stability and consistency.

[0067] Fifth, the integrated design of slag removal and degassing ensures smooth process transitions. The addition of the slag removal agent, as a pre-process, seamlessly connects with the subsequent degassing process, avoiding the secondary oxidation and temperature drop issues of molten aluminum caused by separate slag removal and degassing operations in traditional processes. This results in a more compact and efficient overall process flow.

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0070] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency composite degassing device combining aluminum alloy vacuum and rotor, characterized in that, The system includes a crucible furnace (17), a sealing cover (11) that covers the crucible furnace (17) and encloses the crucible furnace (17) to form a sealed degassing chamber, an exhaust port and a rotor mounting hole provided on the sealing cover (11), a vacuum pump (3) connected to the exhaust port through a vacuum pipe, a rotating shaft installed in the rotor mounting hole through a high-temperature sealed bearing (16), a drive motor (9) whose upper end is connected to the rotating shaft and whose lower end is connected to the rotating degassing rotor, the rotating degassing rotor extending into the crucible furnace (17) below the surface of the molten aluminum, a heating system provided on the furnace wall of the crucible furnace (17), and a control system (5) electrically connected to the drive motor (9), the vacuum pump (3) and the heating system respectively.

2. The aluminum alloy vacuum and rotor high-efficiency composite degassing equipment according to claim 1, characterized in that, The rotary degassing rotor is made of high-purity graphite, with a rotor diameter of 80-120 mm, an outlet diameter of 1-3 mm, and 12-24 outlets, which are evenly distributed in a multi-layered spiral shape on the bottom and sides of the rotor.

3. The aluminum alloy vacuum and rotor high-efficiency composite degassing equipment according to claim 1, characterized in that, The inert gas is high-purity argon or high-purity nitrogen, with a purity of ≥99.99% and a flow rate of 5–25 L / min.

4. The aluminum alloy vacuum and rotor high-efficiency composite degassing equipment according to claim 1, characterized in that, The vacuum pump (3) is a two-stage rotary vane vacuum pump with an ultimate vacuum of ≤10Pa and a pumping speed of 10~30L / s.

5. A high-efficiency composite degassing process for aluminum alloy vacuum and rotor, employing the degassing equipment described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Evenly spread the slag remover on the surface of the molten aluminum and let it stand; Step 2: Start the drive motor (9), control the rotating degassing rotor to rotate and introduce inert gas to degas the rotor; Step 3: After the rotor degassing is completed, turn off the drive motor (9), keep the inert gas in the air, and start the vacuum pump (3) to evacuate the degassing chamber for vacuum degassing; Step 4: After vacuum degassing is completed, turn off the vacuum pump (3), restore normal pressure, and remove the slag after standing.

6. The high-efficiency composite degassing process for aluminum alloy vacuum and rotor as described in claim 5, characterized in that, In step (1), the temperature of the molten aluminum is 700-740℃, the amount of slag remover added is 0.5-1.5kg per ton of molten aluminum, and the settling time is 2-3 minutes; in step (2), the rotation speed of the rotary degassing rotor is 300-500r / min, the flow rate of the inert gas is 10-20L / min, and the rotor degassing time is 2-4 minutes; in step (3), the flow rate of the inert gas is 3-8L / min, the vacuum degree of the degassing chamber is 50-500Pa, and the vacuum degassing time is 1-3 minutes.

7. The high-efficiency composite degassing process for aluminum alloy vacuum and rotor according to claim 6, characterized in that, In step (2), the rotor degassing time is 3 minutes, and in step (3), the vacuum degassing time is 2 minutes.

8. The high-efficiency composite degassing process for aluminum alloy vacuum and rotor according to claim 6, characterized in that, In step (1), the amount of slag remover added is 1 kg / ton of aluminum liquid.

9. The high-efficiency composite degassing process for aluminum alloy vacuum and rotor according to claim 5, characterized in that, The total time for the rotor degassing stage and the vacuum degassing stage is 4 to 7 minutes.

10. The high-efficiency composite degassing process for aluminum alloy vacuum and rotor according to claim 5, characterized in that, After refining, the gas content of the molten aluminum is reduced to below 0.07 ml / 100gAl.

Images