Aluminum alloy sealed continuous casting system and continuous casting method

Abstract

The invention discloses an aluminum alloy sealed continuous casting system and a continuous casting method, and relates to the technical field of aluminum alloy continuous casting, the aluminum alloy sealed continuous casting system comprises a first launder, an online degassing device, a second launder, a filtering standing box, an aluminum liquid casting ladle and a crystallization wheel, the online degassing equipment, the second launder, the filtering and standing box and the molten aluminum casting ladle are sequentially communicated to form a sealed circulation path for separating molten aluminum from air, an inlet of the sealed circulation path is communicated with the heat preservation furnace through the first launder, and an outlet of the sealed circulation path is communicated with the crystallization wheel; by means of the sealed circulation path, molten aluminum flowing in from the first flow groove does not make contact with air any more in the sealed circulation path, secondary pollution is avoided, the system flow is integrally optimized, the total length of the flow is shortened, temperature loss is reduced, the molten aluminum does not need to be heated to the high temperature to compensate for large temperature loss, and the energy consumption is reduced. Therefore, the purposes of simplifying the continuous casting process and improving the product quality are achieved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy continuous casting technology, and in particular to an aluminum alloy sealed continuous casting system and continuous casting method. Background Technology

[0002] Continuous casting technology for aluminum alloys is essential for the production of aluminum alloys, enabling continuous production of aluminum alloy products. In a known existing continuous casting system, the applicant mainly includes an online degassing device, a filtration mechanism, a pouring pipe, a lever ladle, and a crystallizing wheel. The online degassing device is connected to the furnace eye of the holding furnace via an open flow channel, and to the filtration mechanism via an open flow channel. The filtration mechanism is then connected to the pouring pipe via an open flow channel and an open boat-shaped flow channel. The pouring pipe is connected to the crystallizing wheel via a lever ladle. While this system can achieve the transportation of molten aluminum and the continuous casting of aluminum alloy products, it suffers from a long overall system length, large space requirements, and significant temperature loss, necessitating a furnace temperature increase to 770℃, which exacerbates Mg oxidation. Furthermore, multiple open nodes lead to secondary contamination, originating from the contact between molten aluminum and air. Prefil testing (an international standard method for determining the cleanliness of molten aluminum through pressure filtration) shows that the number of oxide films is >50 / kg. Therefore, the applicant's known continuous casting system for aluminum alloys suffers from poor product quality.

[0003] Therefore, there is an urgent need for a sealed continuous casting system and method for aluminum alloys that simplifies the continuous casting process and improves product quality. Summary of the Invention

[0004] The purpose of this invention is to provide an aluminum alloy sealed continuous casting system and method to solve the problems existing in the prior art. By designing a sealed flow path, the continuous casting process is simplified and product quality is improved.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides an aluminum alloy sealed continuous casting system, including a first flow channel, an online degassing device, a second flow channel, a filter settling box, an aluminum liquid ladle, and a crystallizing wheel. The online degassing device, the second flow channel, the filter settling box, and the aluminum liquid ladle are sequentially connected to form a sealed flow path that separates the aluminum liquid from the air. The inlet of the sealed flow path is connected to a holding furnace through the first flow channel, and the outlet of the sealed flow path is connected to the crystallizing wheel.

[0006] Preferably, the end of the first flow channel near the heat preservation furnace is higher than the end of the first flow channel near the online degassing device.

[0007] Preferably, the end of the second flow channel near the online degassing device is higher than the end of the second flow channel near the filter settling box.

[0008] Preferably, the filter settling box includes a box body and a filter layer. The box body is provided with a filter cavity and a settling cavity, and the filter cavity and the settling cavity are connected through the filter layer.

[0009] Preferably, the housing is provided with multiple filter chambers, and the filter chambers are connected to each other and to the settling chamber through the filter layer.

[0010] Preferably, the settling chamber is provided with an overflow port at the pure aluminum liquid layer after the aluminum liquid has settled and separated, and the overflow port is connected to the aluminum liquid ladle.

[0011] Preferably, an electric heater is provided at the bottom of the settling chamber.

[0012] Preferably, a liquid level sensor for monitoring the liquid level is provided in the settling chamber.

[0013] Preferably, a temperature sensor is installed inside the settling chamber, an emergency discharge port is installed on the settling chamber, and a solenoid valve is installed at the emergency discharge port. The solenoid valve is electrically connected to the temperature sensor and the control system.

[0014] The present invention also provides a continuous casting method using the above-mentioned aluminum alloy sealed continuous casting system, comprising the following steps: S1: The molten aluminum flows from the furnace opening of the holding furnace through the first flow channel into the online degassing equipment for purification; S2: After being purified by the online degassing equipment, the aluminum liquid enters the filter settling box through the second flow channel. The aluminum liquid first passes through the filter layer and then enters the settling chamber. S3: When a certain amount of molten aluminum is stored in the settling chamber, the delivery of molten aluminum is stopped and the mixture is allowed to settle and separate into layers. S4: After the static layering is completed, open the overflow port. The pure aluminum liquid in the pure aluminum liquid layer enters the aluminum liquid ladle from the overflow port through the overflow pipe, and flows from the aluminum liquid ladle to the crystallizing wheel.

[0015] The present invention achieves the following main technical effects compared to the prior art: By sequentially connecting the online degassing equipment, the second flow channel, the filter settling box, and the aluminum liquid ladle, a sealed flow path is formed that isolates the aluminum liquid from the air. This ensures that the aluminum liquid flowing in from the first flow channel no longer comes into contact with the air within the sealed flow path, avoiding secondary contamination. Furthermore, the overall system process is optimized, which helps to shorten the total process length and reduce temperature loss. This eliminates the need to heat the aluminum liquid to a high temperature to compensate for the large temperature loss, thereby simplifying the continuous casting process and improving product quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the aluminum alloy sealed continuous casting system in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the filter settling box in an embodiment of the present invention; Figure 3 This is a top view of the filter settling box in an embodiment of the present invention; Among them, 1. Furnace opening; 2. Molten aluminum; 3. First flow channel; 4. Online degassing equipment; 5. Second flow channel; 6. Filter settling box; 61. Filter chamber; 62. Filter layer; 63. Settling chamber; 64. Overflow port; 65. Stopper rod; 7. Molten aluminum ladle; 8. Pour nozzle; 9. Top receiving area of ​​crystallizing wheel; 10. Crystallizing wheel. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0019] The purpose of this invention is to provide an aluminum alloy sealed continuous casting system and method to solve the problems existing in the prior art. By designing a sealed flow path, the continuous casting process is simplified and product quality is improved.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Please refer to the following: Figures 1-3As shown, an aluminum alloy sealed continuous casting system is provided, including a first flow channel 3, an online degassing device 4, a second flow channel 5, a filter settling box 6, an aluminum liquid ladle 7, and a crystallizing wheel 10. The online degassing device 4, the second flow channel 5, the filter settling box 6, and the aluminum liquid ladle 7 are sequentially connected to form a sealed flow path that isolates the aluminum liquid 2 from the air. Except for the inlet and outlet, the online degassing device 4, the second flow channel 5, the filter settling box 6, and the aluminum liquid ladle 7 are all closed structures. The inlet of the sealed flow path is connected to the furnace eye 1 of the holding furnace through the first flow channel 3, and the outlet of the sealed flow path ( The nozzle 8 of the aluminum ladle 7 is connected to the receiving area 9 at the top of the crystallizing wheel 10. This system uses the online degassing device 4, the second flow channel 5, the filter settling box 6, and the aluminum ladle 7 to form a sealed flow path that separates the aluminum liquid 2 from the air. This ensures that the aluminum liquid 2 flowing in from the first flow channel 3 no longer comes into contact with the air in the sealed flow path, avoiding secondary pollution. Moreover, the overall system process is optimized, which helps to shorten the total process length and reduce temperature loss. This eliminates the need to heat the aluminum liquid 2 to a higher temperature to compensate for the large temperature loss, thereby simplifying the continuous casting process and improving product quality.

[0022] To further prevent air from coming into contact with the molten aluminum 2, an argon gas protection port can be installed inside the online degassing device 4 to introduce argon gas into the device and form an inert protective gas layer.

[0023] The connections between the first flow tank 3, the online degassing equipment 4, the second flow tank 5, the filter settling box 6, and the aluminum liquid casting ladle 7 are all made using flange sealing connections to ensure disassembly while improving sealing performance. The flange seals are made of high-temperature resistant graphite gaskets.

[0024] The end of the first flow channel 3 near the holding furnace is higher than the end of the first flow channel 3 near the online degassing device 4, with a specific height difference of 5-7cm. This facilitates the flow of molten aluminum 2 within the first flow channel 3 and reduces the aluminum dross generated when the molten aluminum 2 fluctuates up and down during its flow and comes into contact with air. This reduces the aluminum dross content in the molten aluminum 2 before entering the online degassing device 4, thereby reducing the load on the online degassing device 4.

[0025] The end of the second flow channel 5 near the online degassing device 4 is higher than the end of the second flow channel 5 near the filter settling box 6. The specific tilt angle can be 5°-10°, which can play a role in preventing turbulence.

[0026] In this embodiment, the length of the first flow channel 3 is no more than 4m, the length of the second flow channel 5 is no more than 0.3m, and the total length of the entire process is controlled to be no more than 8m.

[0027] In one embodiment, the filter settling box 6 includes a box body and a filter layer 62. The box body is provided with a filter chamber 61 and a settling chamber 63. The filter chamber 61 and the settling chamber 63 are connected through the filter layer 62. The filter layer 62 can be used to filter the aluminum liquid 2 and remove some aluminum dross.

[0028] Multiple filter chambers 61 can be set inside the chamber. Adjacent filter chambers 61 and filter chambers 61 and settling chambers 63 are connected by filter layers 62. For example, two filter chambers 61 can be set. A 30ppi / 50ppi ceramic foam layer is set between the two filter chambers 61 as filter layer 62. A deep bed particle bed is set between the rear filter chamber 61 and settling chamber 63 as filter layer 62. Through the design of multiple filter layers 62, the filtration effect of aluminum liquid 2 can be further improved.

[0029] An overflow port 64 is provided in the settling chamber 63 corresponding to the pure aluminum liquid layer after the aluminum liquid has settled and separated. The height of the overflow port 64 is set at 30%-70% (preferably 40%-50%) of the effective liquid level height. The overflow port 64 is connected to the aluminum liquid ladle. The aluminum liquid 2 can be left in the settling chamber 63 for settling and separation. After separation, it includes a surface oxide film, a middle pure aluminum liquid and a bottom slag. After settling, the pure aluminum liquid in the pure aluminum liquid layer can be directly transported to the aluminum liquid ladle 7 through the overflow port 64, which is beneficial to improving product quality.

[0030] Taking two filter chambers 61 as an example, the specific arrangement of the internal cavities of the box can be as follows: two filter chambers 61 and a settling chamber 63 are arranged in sequence along the horizontal direction. The depth of the three cavities increases sequentially along the flow direction of the aluminum liquid 2. A filter layer 62 is provided at the bottom of the front cavity, and a connecting path is provided at the bottom of the filter layer 62 to connect with the rear cavity. The overflow port 64 of the settling chamber 63 can be set at an angle upward. Compared with the horizontally set overflow port 64, it can reduce the impact force of the aluminum liquid 2 being discharged and facilitate the control of the flow rate of the aluminum liquid 2. A stopper 65 is provided at the overflow port 64 to block the overflow port 64 during the settling and stratification process.

[0031] The settling chamber 63 can be connected to the negative pressure suction port, and a vacuum of -0.05MPa can be provided by a vacuum pump to force the volatile gas to be discharged. The volatile gas refers to the gas in the aluminum liquid 2.

[0032] An electric heater is installed at the bottom of the settling chamber 63 to keep the aluminum liquid 2 in the settling chamber 63 warm and prevent it from cooling down too much. The heating temperature of the electric heater can be controlled by the control system.

[0033] A liquid level sensor is installed in the settling chamber 63 to monitor the liquid level, so that when the aluminum liquid 2 reaches a certain capacity in the settling chamber 63, the liquid level sensor and the control system will stop the delivery of the aluminum liquid 2 and wait for the settling to be completed; the liquid level sensor can be a eddy current liquid level sensor.

[0034] In order to effectively deal with emergencies when the temperature rises significantly, a temperature sensor is installed in the settling chamber 63. An emergency discharge port is installed on the settling chamber 63, and a solenoid valve is installed at the emergency discharge port. The solenoid valve is electrically connected to the temperature sensor and the control system. When the temperature sensor detects that the temperature inside the settling chamber 63 is greater than the safe value (750℃), the control system opens the solenoid valve to realize the emergency discharge of the internal aluminum liquid 2.

[0035] The bottom of the settling chamber 63 can be inverted cone shape. The lowest point of the bottom of the settling chamber 63 is connected to the slag discharge port. The slag discharge port is equipped with a slag discharge valve to facilitate the discharge of the surface oxide film and bottom slag remaining after the pure aluminum liquid is transported.

[0036] The stopper rod 65 can be controlled by the stopper rod control system to precisely control the flow rate of molten aluminum 2 from the molten aluminum ladle 7 into the crystallizing wheel 10.

[0037] The filtration and settling can also be designed as separate units, with the filter settling box consisting of a filter box and a settling box, which are connected by a flange seal.

[0038] The present invention also provides a continuous casting method using the above-mentioned aluminum alloy sealed continuous casting system, comprising the following steps: S1: The aluminum liquid 2 flows from the furnace eye 1 of the holding furnace into the online degassing equipment 4 through the first flow channel 3 for purification. The purification principle is as follows: the inert gas argon is evenly dispersed into tiny bubbles after rotating through the gas holes on the graphite rotor impeller. Since the density of the tiny bubbles is lower than that of the aluminum liquid 2, the bubbles can adsorb hydrogen and oxide inclusion impurities during the rising process, thereby reducing the hydrogen content and finally achieving the purification of the aluminum liquid 2. S2: After being purified by the online degassing equipment 4, the aluminum liquid 2 enters the filter settling box 6 through the second flow channel 5. The aluminum liquid 2 first passes through the filter layer 62 and then enters the settling chamber 63. S3: When the aluminum liquid 2 has stored a certain amount in the settling chamber 63, stop the delivery of aluminum liquid 2 and set it for settling and stratification. The settling time shall not be less than 8 minutes. S4: After the static layering is completed, open the overflow port 64. The pure aluminum liquid in the pure aluminum liquid layer enters the aluminum liquid ladle 7 through the overflow pipe from the overflow port 64, and flows from the aluminum liquid ladle 7 to the crystallizing wheel 10.

[0039] The products prepared using this system and continuous casting method are compared with the prior art mentioned in the background (TIC refers to total inclusion content: the total area of ​​non-metallic inclusions in a unit of molten aluminum (mm²)). 2 / kg): Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0040] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0041] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An aluminum alloy sealed continuous casting system, characterized by, The system comprises a first flow channel, an online degassing device, a second flow channel, a filtering and standing tank, a molten aluminum ladle and a crystallization wheel, the online degassing device, the second flow channel, the filtering and standing tank and the molten aluminum ladle are sequentially communicated to form a sealed flow path which separates the molten aluminum from air, an inlet of the sealed flow path is communicated with a holding furnace through the first flow channel, and an outlet of the sealed flow path is communicated with the crystallization wheel.

2. The aluminum alloy sealed continuous casting system of claim 1, wherein, An end of the first flow channel close to the holding furnace is higher than an end of the first flow channel close to the online degassing device.

3. The aluminum alloy sealed continuous casting system of claim 1, wherein, An end of the second flow channel close to the online degassing device is higher than an end of the second flow channel close to the filtering and standing tank.

4. The aluminum alloy sealed continuous casting system of claim 1, wherein, The filtering and standing tank comprises a tank body and a filtering layer, the tank body is provided with a filtering cavity and a standing cavity, and the filtering cavity and the standing cavity are communicated through the filtering layer.

5. The aluminum alloy sealed continuous casting system of claim 4, wherein, The tank body is provided with a plurality of filtering cavities, and the filtering cavities are communicated through the filtering layer.

6. The aluminum alloy sealed continuous casting system of claim 4, wherein, The standing cavity is provided with an overflow port corresponding to a pure molten aluminum layer after the molten aluminum is standing and stratified, and the overflow port is communicated with the molten aluminum ladle.

7. The aluminum alloy sealed continuous casting system of claim 6, wherein, The standing cavity is provided with an electric heater at the bottom.

8. The aluminum alloy sealed continuous casting system of claim 6, wherein, The standing cavity is provided with a liquid level sensor for monitoring the liquid level.

9. The aluminum alloy sealed continuous casting system of claim 6, wherein, The standing cavity is provided with a temperature sensor, and an emergency discharge port is arranged on the standing cavity, an electromagnetic valve is arranged at the emergency discharge port, and the electromagnetic valve and the temperature sensor are electrically connected with a control system.

10. A continuous casting method characterized by, The application of the aluminum alloy sealed continuous casting system according to any one of claims 6-9 comprises the following steps: S1: the molten aluminum flows from a furnace eye of a holding furnace into an online degassing device through a first flow channel for purification; S2: the molten aluminum purified by the online degassing device flows into a filtering and standing tank through a second flow channel, and the molten aluminum enters a standing cavity after being filtered by a filtering layer; S3: when the molten aluminum is stored in the standing cavity for a certain amount, the molten aluminum is stopped and stratified; S4: after the stratification is completed, the overflow port is opened, the pure molten aluminum in the pure molten aluminum layer flows into the molten aluminum ladle through an overflow pipeline from the overflow port, and then flows from the molten aluminum ladle to the crystallization wheel.

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