Dual-mode multi-stage molten aluminum filtering and purifying method

Abstract

The invention relates to a dual-mode multi-stage molten aluminum filtering and purifying method which comprises a fixed launder, two sides of the fixed launder are respectively provided with a first mounting position and a second mounting position, the first mounting position and the second mounting position are sequentially arranged along the flowing direction of molten aluminum in the fixed launder, and the first mounting position is provided with a first-stage deep bed filter connected with the fixed launder; the second mounting position is used for mounting a secondary deep bed filter or a tubular filter which is linearly preheated; an aluminum inlet A, an aluminum inlet B and an aluminum outlet are formed in the side, close to the second mounting position, of the fixed launder, outlet launder bodies of the secondary deep bed filter and the tubular filter are both connected with the aluminum outlet, an inlet launder body of the secondary deep bed filter is used for being connected with the aluminum inlet A, and an inlet launder body of the tubular filter is used for being connected with the aluminum inlet B. According to the invention, the dual-mode free switching filtering mode of'primary deep bed filtering + secondary deep bed filtering 'and'primary deep bed filtering + tubular filtering' is realized through equipment transformation, so that the requirements of different products and different customers are met.

Description

Technical Field

[0001] This invention belongs to the field of online filtration technology for aluminum alloy solutions, and particularly relates to a dual-mode, multi-stage aluminum liquid filtration and purification method. Background Technology

[0002] In the field of online filtration of molten aluminum, tubular filters and deep-bed filters each have their own application scenarios. Deep-bed filters utilize a certain thickness of alumina balls, gravel, or other filter media. When the molten aluminum passes through a tortuous path and has a large surface area, large particles in the melt undergo physical interception and chemical adsorption with the media. Tubular filters employ a solid-liquid separation method. Under immense pressure, the molten aluminum passes through the porous filter media on the outer wall of the tubing and enters the inner wall of the tubing. Suspended particles larger than the pores are intercepted, and the filtration accuracy depends on the size of the pores in the tubing.

[0003] Currently, different processing companies in the aluminum processing industry have different understandings of different filtration methods, and different products have different requirements for filtration effects. There are also cases where some customers specify a certain filtration method.

[0004] Currently, in the application of tubular filters, in order to avoid breakage and damage to the tubular assembly caused by shaking and vibration during hoisting and installation after installation and preheating, tubular filters are mostly installed, preheated, and filled with molten aluminum online before use. This process takes at least 6 days and is limited by online space, making it impossible to accommodate multiple tubular filters or deep bed filters online. Therefore, the tubular assembly installation and preheating process of deep bed filters and tubular filters cannot be used, and only some products with low requirements for melt quality can be produced, which greatly affects the production output of high-quality products. Summary of the Invention

[0005] The present invention addresses the problems existing in the prior art, namely, the technical problem to be solved by the present invention is to provide a dual-mode multi-stage aluminum liquid filtration and purification method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a dual-mode multi-stage aluminum liquid filtration and purification method, comprising a fixed flow channel connected at one end to a degassing furnace, a first installation position and a second installation position respectively provided on both sides of the fixed flow channel, the first installation position and the second installation position being arranged sequentially along the flow direction of the aluminum liquid in the fixed flow channel, the first installation position being provided with a primary deep bed filter connected to the fixed flow channel; the second installation position being used to install a secondary deep bed filter or a tubular filter; the fixed flow channel near the second installation position is provided with an aluminum inlet A, an aluminum inlet B and an aluminum outlet, the outlet flow channels of the secondary deep bed filter and the tubular filter are both connected to the aluminum outlet, the inlet flow channel of the secondary deep bed filter is used to connect to the aluminum inlet A, and the inlet flow channel of the tubular filter is used to connect to the aluminum inlet B; the method includes the following steps: Step (1): Preheat the tubular filter or the two-stage deep bed filter offline; Step (2): Remove the existing filter from the site at the second installation position; level the bottom of the second installation position according to the different elevation requirements of tubular filters and two-stage deep bed filters; Step (3): Attach fiber felt to the bottom of the fixed flow channel; Step (4): Preheat the tubular filter or the secondary deep bed filter line and disconnect the power. Hoist the tubular filter or the secondary deep bed filter to the second installation position. Step (5): Connect the power cord at the output end of the control cabinet to the power cord at the input end of the tubular filter or the secondary deep bed filter, and select the corresponding temperature parameter; Step (6): After confirming that the temperature has reached the target temperature, fill the tubular filter or the secondary deep bed filter with molten aluminum. Step (7): After the aluminum molten material is filled, the aluminum molten material is filtered by a primary deep bed filter, a tubular filter, or a secondary deep bed filter.

[0007] Furthermore, the second installation position is lowered by 320mm based on the original height of the deep bed installation position; in step (2), when the second installation position is used to install a secondary deep bed filter, a 320mm thick support platform is added to the bottom of the second installation position; when the second installation position is used to install a tubular filter, a 30mm thick aluminum silicate blanket is laid at the bottom of the second installation position.

[0008] Furthermore, in step (1), both the secondary deep bed filter and the tubular filter are preheated to 750°C.

[0009] Furthermore, in steps (2) and (4), a crane and a lifting device are used for hoisting. The lifting device includes a rectangular hoisting frame. A hoisting chain is connected to the bottom of the hoisting frame near the four corners. A hoisting hook is provided at the lower end of the hoisting chain. A connecting chain is connected to the top of the hoisting frame near the four corners. The upper ends of the four connecting chains are connected to a lifting ring. The lifting ring is connected to the hook of the crane.

[0010] Furthermore, in step (4), when hoisting the tubular filter or the secondary deep bed filter, stop when the tubular filter or the secondary deep bed filter is hoisted above the second installation position and 200mm away from the bottom of the second installation position. Adjust the crane so that the outlet flow channel and the inlet flow channel of the tubular filter or the secondary deep bed filter are aligned with the aluminum outlet port and aluminum inlet port A or aluminum inlet port B on the fixed flow channel, respectively. Then, place a 30mm layer of aluminum silicate blanket between the inclined openings of the flow channels. The tubular filter or the secondary deep bed filter is slowly lowered. After confirming that the aluminum silicate blanket below is pressed tightly, cut off the aluminum silicate blanket in the flow channel. Confirm that the flow channels are aligned again. Repair the flow channel joints with refractory mortar and boron nitride. Finally, lock the housing of the tubular filter or the secondary deep bed filter to the steel structure shell at the inclined opening of the fixed flow channel with buckles.

[0011] Furthermore, in step (3), the thickness of the fiber felt is 0.3 mm.

[0012] Furthermore, in step (5), the secondary deep bed filter and the tubular filter share a control cabinet. Two quick-connect aviation connectors are led out from the output end of the control cabinet. One of them is connected to the energy input end of the heating component of the secondary deep bed filter, and the other is connected to the energy input end of the heating component of the tubular filter.

[0013] Compared with the prior art, the present invention has the following advantages: The present invention adopts a two-stage filtration method, and through equipment modification, it can freely switch between two filtration modes: "first-stage deep bed filtration + second-stage deep bed filtration" and "first-stage deep bed filtration + tubular filtration", to meet the needs of different products and different customers; at the same time, it uses limited online space to achieve offline preheating and online use, and continuously produce products that require high filtration accuracy. Attached Figure Description

[0014] Figure 1 This is a top view of the structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the second mounting position for installing a secondary deep bed filter in an embodiment of the present invention; Figure 3 This is a schematic diagram of the second mounting position for installing a tubular filter in an embodiment of the present invention; Figure 4 This is a three-dimensional structural diagram of the lifting device in an embodiment of the present invention; Figure 5 This is a schematic diagram of the usage state of the lifting device in an embodiment of the present invention.

[0015] In the picture: 1-Fixed flow channel; 2-Degassing furnace; 3-First installation position; 4-Second installation position; 5-First-stage deep bed filter; 6-Second-stage deep bed filter; 7-Tube filter; 8-Aluminum inlet A; 9-Aluminum inlet B; 10-Aluminum outlet; 11-Inlet flow channel; 12-Outlet flow channel; 13-Support platform; 14-Alumina silicate blanket; 15-Lifting frame; 16-Lifting chain; 17-Lifting hook; 18-Connecting chain; 19-Lifting ring; 20-Crane hook. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0018] like Figures 1-5As shown, this invention discloses a dual-mode, multi-stage aluminum liquid filtration and purification method. It aims to achieve offline preheating and online use, enabling continuous production of products requiring high filtration accuracy by utilizing limited online space. Specifically, it includes a linear fixed flow channel 1 connected at one end to a degassing furnace 2. A first mounting position 3 and a second mounting position 4 are respectively provided on both sides of the fixed flow channel 1, arranged sequentially along the flow direction of the aluminum liquid within the fixed flow channel 1. The first mounting position 3 is equipped with a primary deep-bed filter 5 connected to the fixed flow channel 1. The second mounting position 4 is used to install a secondary deep-bed filter 6 or a tubular filter 7, which can be switched as needed. When the secondary deep-bed filter 6 is installed at the second mounting position 4, the primary and secondary deep-bed filters form a dual-stage filtration system. When the tubular filter 7 is installed at the second mounting position 4, the primary deep-bed filter 5 and the tubular filter 7 form a dual-stage filtration system. To accommodate the different inlet and outlet spacings of the secondary deep bed filter and the tubular filter, the fixed flow channel 1 is equipped with an aluminum inlet A8, an aluminum inlet B9, and an aluminum outlet 10 on the side near the second mounting position 4. The outlet flow channels 12 of both the secondary deep bed filter 6 and the tubular filter 7 are connected to the aluminum outlet 10; that is, the secondary deep bed filter 6 and the tubular filter 7 share a single aluminum outlet 10. The inlet flow channel 11 of the secondary deep bed filter 6 is used to connect to the aluminum inlet A8, and the inlet flow channel 11 of the tubular filter 7 is used to connect to the aluminum inlet B9. By adding an aluminum inlet to the fixed flow channel, the deep bed filter and the tubular filter use the same aluminum outlet but different aluminum inlets. When using either the deep bed or tubular filter, a silicon nitride gate and silicate cotton are used to block the corresponding aluminum inlet to prevent aluminum leakage.

[0019] The method includes the following steps: Step (1): Preheat the tubular filter 7 or the secondary deep bed filter 6 offline. Generally, the secondary deep bed filter is ≥600℃ and the tubular filter is ≥720℃. Step (2): Remove the original filter from the site at the second installation position 4 and clean the second installation position 4; level the bottom of the second installation position 4 according to the different elevation requirements of the tubular filter 7 and the secondary deep bed filter 6; for example, if the original filter at the second installation position 4 is the secondary deep bed filter 6, first remove the secondary deep bed filter 6 and then install the tubular filter 7 at the second installation position 4. Step (3): Attach a 0.3mm thick fiber felt to the bottom of the fixed flow channel 1; Step (4): Preheat the tubular filter 6 or the secondary deep bed filter 7 offline and disconnect the power. Hoist the tubular filter 7 or the secondary deep bed filter 6 to the second installation position 4. Step (5): Connect the power cord at the output end of the control cabinet to the power cord at the input end of the tubular filter 7 or the secondary deep bed filter 9, and select the corresponding temperature parameter; Step (6): After confirming that the temperature has reached the target temperature, fill the tubular filter 7 or the secondary deep bed filter 6 with molten aluminum. Step (7): After the aluminum molten material is filled, the aluminum molten material is filtered by the primary deep bed filter 5, the tubular filter 7, or the secondary deep bed filter 6.

[0020] In this embodiment, in step (1), both the secondary deep bed filter 6 and the tubular filter 7 are preheated to 750°C.

[0021] In this embodiment, because the tubular filter 7 and the secondary deep bed filter 6 require different inlet pressures and have different housing elevations, the second installation position 4 is 320mm lower than the original deep bed installation position. Therefore, when using the secondary deep bed filter, a special platform is needed to raise it so that the inlet and outlet flow channels of the deep bed filter are consistent with the fixed flow channel.

[0022] In this embodiment, in step (2), when the secondary deep bed filter 6 is installed at the second mounting position 4, a 320mm thick support platform 13 is added to the bottom of the second mounting position 4, such as... Figure 2 As shown; when the tubular filter 7 is installed at the second mounting position 4, a 30mm thick aluminum silicate blanket 14 is laid at the bottom of the second mounting position 4, as shown. Figure 3 As shown.

[0023] In this embodiment, a crane and a lifting device are used for lifting in steps (2) and (4), such as Figure 4 , 5 As shown, the lifting device includes a rectangular lifting frame 15. A lifting chain 16 is connected to each of the four corners of the bottom of the lifting frame 15. A lifting hook 17 is provided at the lower end of each lifting chain 16 for hooking the secondary deep bed filter or tubular filter. A connecting chain 18 is connected to each of the four corners of the top of the lifting frame 15. The upper ends of the four connecting chains 18 are connected to a lifting ring 19, which is connected to the hook 20 of the crane. By using this lifting device, the swaying during lifting can be greatly reduced, and the rigid contact between the tubular filter housing and the ground / installation platform during lifting and lowering can be minimized. Simultaneously, a 30mm thick aluminum silicate blanket is laid at the second installation position to increase the cushioning when the filter housing lands, preventing the internal wedges from loosening due to vibration, which could cause displacement, damage, or breakage of the tubular components and affect the filtration effect.

[0024] In this embodiment, in step (4), when hoisting the tubular filter 7 or the secondary deep bed filter 6, the hoisting stops when the tubular filter 7 or the secondary deep bed filter 6 is hoisted above the second installation position 4 and 200mm away from the bottom of the second installation position 4. The crane is adjusted so that the outlet flow channel 12 and the inlet flow channel 11 of the tubular filter 7 or the secondary deep bed filter 6 are aligned with the aluminum outlet 10, aluminum inlet A8 or aluminum inlet B9 on the fixed flow channel 1, respectively. The aluminum outlet, aluminum inlet A and aluminum inlet B of the fixed flow channel are all downward sloping, and the outlet and inlet flow channels of the secondary deep bed filter and the tubular filter are all upward sloping. Then, a 30m layer is placed between the sloping openings of the flow channels. The aluminum silicate blanket, tubular filter, or two-stage deep bed filter is slowly lowered. During the descent, the aluminum inlet and outlet sides of the filter housing can be slightly tilted upwards to ensure that the bottom bevel is tightly pressed together after descent, preventing aluminum leakage. After confirming that the aluminum silicate blanket is pressed tightly, the aluminum silicate blanket in the flow channel is cut off. The flow channels are then reconfirmed to be aligned (the installation standard is that the aluminum inlet and outlet of the fixed flow channel are flush with the bottom and sides of the inner substrate of the outlet flow channel of the filter housing, the misalignment of the left and right sides of the inlet and outlet flow channels is ≤5mm, and the bottom drop of the docking flow channels is ≤4mm). The joints of the flow channels are repaired with refractory mortar and boron nitride. Finally, the housing of the tubular filter or two-stage deep bed filter is locked to the steel outer shell at the bevel of the fixed flow channel with clips.

[0025] In this embodiment, in step (5), the secondary deep bed filter and the tubular filter share a control cabinet, and one system controls the two different filters. Because the effective aluminum content inside the tubular filter and the secondary deep bed filter is different, the power of the secondary deep bed filter is about half that of the tubular filter. At the same time, the secondary deep bed filter has a mini heater at the bottom for heating. The control adopts a dual-stage heating mode, and the operation interface offers different selectable modes, one for tubular filtration and one for deep bed filtration. Two quick-connect aviation connectors are led out from the output end of the control cabinet, namely output 1 and output 2; the energy input end of the secondary deep bed heater is equipped with one aviation quick-connect connector as input 1, and the energy input end of the tubular filter heater is designed with two aviation quick-connect connectors (input 1 and input 2 respectively). When using a tubular filter, the human-machine interface control terminal of the control cabinet is set to tubular filtration mode. Output 1 of the control cabinet is connected to input 1 of the tubular filter's energy input terminal, and output 2 of the control cabinet is connected to input 2 of the tubular filter's energy input terminal. When using a two-stage deep bed filter, the human-machine interface control terminal is set to deep bed filtration mode. Output 1 of the control cabinet is connected to input 1 of the two-stage deep bed filter's energy input terminal, and a quick connector for the deep bed mini heater is also connected. Output 2 is automatically de-energized and idle.

[0026] In this embodiment, the aluminum liquid filling method for the two-stage deep bed filter and the tubular filter is as follows: After offline preheating, the filter is hoisted to the line. For the two-stage deep bed filter, the inlet is first blocked with a silicon nitride gate plate and silicate cotton felt. Then, aluminum liquid (temperature above 720°C) is filled from the outlet. Filling stops when the aluminum liquid completely submerges the top layer of alumina balls and the liquid level is close to the bottom of the inlet and outlet channels. Finally, the silicon nitride gate plate and silicate cotton felt are tightened to prevent cross-contamination between the inlet and outlet. For the tubular filter, the inlet and outlet channels are directly tightened to ensure the internal temperature reaches 750°C. Then, aluminum liquid enters directly from the inlet until the tubular filter housing is full and overflows from the outlet.

[0027] This invention achieves seamless switching between two filtration modes—"deep bed filtration + deep bed filtration" and "deep bed filtration + tubular filtration"—through equipment modification, meeting the needs of different products and customers. The alternation between secondary deep bed filtration and tubular filtration is achieved by increasing the opening of the fixed flow channel, lowering the height of the second installation position, and adding a platform. Both the secondary deep bed filter and the tubular filter are preheated offline to their usable temperature before being hoisted to the online installation position using specialized lifting equipment for installation and filling. This invention aims to achieve offline preheating and online use, enabling continuous production of products requiring high filtration accuracy, by utilizing limited online space.

[0028] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0029] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0030] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A dual-mode, multi-stage aluminum liquid filtration and purification method, characterized in that: The method includes a fixed flow channel connected at one end to a degassing furnace. A first mounting position and a second mounting position are respectively provided on both sides of the fixed flow channel, arranged sequentially along the flow direction of the molten aluminum within the fixed flow channel. A primary deep-bed filter connected to the fixed flow channel is installed at the first mounting position. A secondary deep-bed filter or a tubular filter is installed at the second mounting position. An aluminum inlet A, an aluminum inlet B, and an aluminum outlet are provided on the side of the fixed flow channel near the second mounting position. The outlet flow channels of both the secondary deep-bed filter and the tubular filter are connected to the aluminum outlet. The inlet flow channel of the secondary deep-bed filter is connected to the aluminum inlet A, and the inlet flow channel of the tubular filter is connected to the aluminum inlet B. The method includes the following steps: Step (1): Preheat the tubular filter or the two-stage deep bed filter offline; Step (2): Remove the existing filter from the site at the second installation position; level the bottom of the second installation position according to the different elevation requirements of tubular filters and two-stage deep bed filters; Step (3): Attach fiber felt to the bottom of the fixed flow channel; Step (4): Preheat the tubular filter or the secondary deep bed filter line and disconnect the power. Hoist the tubular filter or the secondary deep bed filter to the second installation position. Step (5): Connect the power cord at the output end of the control cabinet to the power cord at the input end of the tubular filter or the secondary deep bed filter, and select the corresponding temperature parameter; Step (6): After confirming that the temperature has reached the target temperature, fill the tubular filter or the secondary deep bed filter with molten aluminum. Step (7): After the aluminum molten material is filled, the aluminum molten material is filtered by a primary deep bed filter, a tubular filter, or a secondary deep bed filter.

2. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 1, characterized in that: The second installation position is lowered by 320mm from the original deep bed installation position; in step (2), when the second installation position is used to install a secondary deep bed filter, a 320mm thick support platform is added to the bottom of the second installation position; when the second installation position is used to install a tubular filter, a 30mm thick aluminum silicate blanket is laid at the bottom of the second installation position.

3. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 1, characterized in that: In step (1), both the secondary deep bed filter and the tubular filter are preheated to 750°C.

4. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 1, characterized in that: In steps (2) and (4), a crane and a lifting device are used for hoisting. The lifting device includes a rectangular hoisting frame. A hoisting chain is connected to the bottom of the hoisting frame near the four corners. A hoisting hook is provided at the lower end of the hoisting chain. A connecting chain is connected to the top of the hoisting frame near the four corners. The upper ends of the four connecting chains are connected to a lifting ring. The lifting ring is connected to the hook of the crane.

5. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 4, characterized in that: In step (4), when hoisting the tubular filter or the secondary deep bed filter, stop when the tubular filter or the secondary deep bed filter is hoisted above the second installation position and 200mm away from the bottom of the second installation position. Adjust the crane so that the outlet flow channel and the inlet flow channel of the tubular filter or the secondary deep bed filter are aligned with the aluminum outlet port and aluminum inlet port A or aluminum inlet port B on the fixed flow channel, respectively. Then, place a 30mm layer of aluminum silicate blanket between the inclined openings of the flow channels. The tubular filter or the secondary deep bed filter is slowly lowered. After confirming that the aluminum silicate blanket below is pressed tightly, cut off the aluminum silicate blanket in the flow channel. Confirm that the flow channels are aligned again. Repair the flow channel joints with refractory mortar and boron nitride. Finally, lock the housing of the tubular filter or the secondary deep bed filter to the steel structure shell at the inclined opening of the fixed flow channel with buckles.

6. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 1, characterized in that: In step (3), the thickness of the fiber felt is 0.3 mm.

7. The dual-mode multi-stage aluminum liquid filtration and purification method according to claim 1, characterized in that: In step (5), the secondary deep bed filter and the tubular filter share a control cabinet. Two quick-connect aviation connectors are led out from the output end of the control cabinet. One of them is connected to the energy input end of the heating component of the secondary deep bed filter, and the other is connected to the energy input end of the heating component of the tubular filter.

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