Atmosphere control method and device for smelting system
By setting up an argon injection device in the metal smelting furnace, argon gas is uniformly injected along the circumference of the observation hole on the top of the inner lining of the smelting furnace and the center of the furnace cover, the problem of uncontrolled atmosphere during the metal smelting process is solved, and the entire process is realized Atmosphere control improves the quality of the ingot and reduces costs.
Patent Information
- Application Number
- CN202411910909.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-02-07
AI Technical Summary
During the metal smelting process, the atmosphere is uncontrolled and will cause oxidation burning and inhalation, affecting the quality and cost of the ingot. The existing technology such as vacuum, cover agent and inert gas protection methods have limitations and cannot achieve the precise atmosphere of the entire process. control.
By setting up a furnace air outlet device and a furnace cover air outlet device in the smelting furnace, argon gas is uniformly injected into the center of the smelting furnace along the circumference of the observation hole on the top of the smelting furnace lining and the center of the furnace cover, controlling the argon flow rate to achieve precise control of the atmosphere.
The atmosphere control during the entire smelting process is achieved, the oxidation loss of the smelting raw materials and melts is reduced, the quality of the ingot is improved, the waste and cost of argon gas is reduced, and safety is ensured.
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Figure CN119394048A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of metal smelting technology, and in particular to a method for controlling the atmosphere of a smelting system. In addition, the present application also relates to a control device for implementing the above control method. Background Art
[0002] During the metal smelting process, if the atmosphere is not controlled, oxidation burning and air absorption will occur, seriously affecting the quality and cost of the ingot. For the atmosphere protection during the smelting of aluminum-lithium alloys, the industry currently uses vacuum, covering agent and inert gas protection methods.
[0003] Vacuum melting is the melting operation under a certain vacuum degree. Because the metal does not come into contact with oxygen, it can avoid oxidation and also has the function of degassing. Generally, in the production process of aluminum alloy ingots, only the melting process is a vacuum atmosphere, which is not suitable for casting. In addition, the vacuum melting furnace equipment is complex, difficult to maintain and expensive.
[0004] Covering agent protection is to add covering agent to the melt to block the melt surface from the outside world, so it can reduce oxidation burning and air absorption. However, covering agent protection can only be used after refining and slag removal, and protection cannot be achieved in the whole process. At the same time, there are strict requirements on the sodium content and dryness of the covering agent.
[0005] Inert gas protection usually adopts argon protection, which is the method used in this patent. Argon protection smelting means that the aluminum melt is in an argon atmosphere during the entire production process of smelting, online processing and casting. The metal can avoid oxidation because it does not contact oxygen. At the same time, because the partial pressure of gases such as H2, O2, N2, CO in argon is small, the degassing effect can be achieved. However, for argon protection, there is no specific understanding of the gas inlet position and gas flow, which leads to the inability to achieve sufficient protection and the waste of argon. At the same time as argon protection, it is generally necessary to perform operations such as feeding, refining and degassing, slag removal and sampling that require unsealing, which will carry air into the furnace, resulting in increased oxidation loss of smelting raw materials and melt.
[0006] Therefore, in response to the above technical problems, how to achieve precise control of the atmosphere in the smelting system and reduce the oxidation loss of smelting raw materials and melt is a technical problem that technical personnel in this field need to solve. Summary of the invention
[0007] The purpose of the present application is to provide a method for controlling the atmosphere of a smelting system, which can achieve precise control of the atmosphere in the smelting furnace, reduce the air brought into the furnace when other objects enter the furnace, reduce the oxidation loss of smelting raw materials and melts, thereby reducing impurities, improving the purity of the melt and reducing losses, improving the quality of the ingot and reducing the amount of processing removal, reducing the waste of argon and also reducing costs, and the lack of oxygen can avoid unexpected combustion and ensure safety.
[0008] To achieve the above object, the present application provides a method for controlling the atmosphere of a smelting system. When the atmosphere control is started, argon gas is uniformly injected into the center of the smelting furnace along the top of the inner lining of the smelting furnace, and is uniformly injected into the center of the smelting furnace along the observation hole in the center of the furnace cover;
[0009] During the argon holding stage, argon is uniformly injected into the center of the smelting furnace only along the observation hole in the center of the furnace cover, and the minimum argon injection flow rate is 19Nm 3 / h;
[0010] When the observation hole is opened to insert the object, argon is uniformly injected into the center of the smelting furnace along the circumference of the top of the lining of the smelting furnace, and uniformly injected into the center of the smelting furnace along the circumference of the observation hole, and the minimum flow rate of argon injection at the two locations is 11Nm 3 / h.
[0011] Preferably, when the oxygen content in the smelting furnace is less than or equal to 0.2%, the argon holding stage is entered, and the oxygen content in the smelting furnace is maintained less than or equal to 0.2%.
[0012] Preferably, when injecting gas circumferentially along the observation hole, argon gas is injected obliquely downward into the center of the internal space of the smelting furnace, and an argon gas layer is formed at the observation hole to block air from entering the interior of the smelting furnace.
[0013] A control device for implementing any of the above-mentioned smelting system atmosphere control methods, comprising a smelting furnace and a furnace cover matched with the smelting furnace, wherein a furnace gas outlet device is arranged at the top of the inner lining of the smelting furnace, and the furnace gas outlet device is arranged along the circumference of the inner wall of the inner lining, and uniformly injects argon gas from the outer periphery of the top of the smelting furnace obliquely downward into the center of the inner space of the smelting furnace;
[0014] An observation hole is opened in the center of the furnace cover, and a furnace cover gas outlet device is arranged at the top of the inner wall of the observation hole. The furnace cover gas outlet device is arranged circumferentially along the inner wall of the observation hole, and evenly injects argon gas from the middle of the furnace cover top downwardly into the center of the internal space of the smelting furnace.
[0015] Preferably, the in-furnace gas outlet device and the furnace cover gas outlet device are both annular tubes, and the annular tubes are provided with a plurality of evenly distributed gas outlet holes, and the opening directions of the gas outlet holes are all obliquely downward and toward the center of the internal space of the smelting furnace.
[0016] Preferably, an observation hole cover cooperating with the observation hole is arranged on the furnace cover, and the observation hole cover is sealed when it is closed with the observation hole cover.
[0017] Preferably, an oxygen analyzer detection tube having one end extending into the interior of the smelting furnace is provided on the furnace cover, and the oxygen analyzer detection tube is arranged close to the observation hole.
[0018] Preferably, an outlet is provided on the furnace wall of the smelting furnace, and one end of the outlet extending outside the smelting furnace is a closed space.
[0019] Compared with the above background technology, when starting the atmosphere control, the present application injects argon into the smelting furnace through two ways, namely, one is to inject uniformly along the top of the inner lining of the smelting furnace into the center of the smelting furnace, and the other is to inject uniformly along the observation hole in the center of the furnace cover. The argon flow rate can be controlled by the flow control valve and can be adjusted separately. When the oxygen content is less than or equal to 0.2%, it can be considered that there is no oxygen in the furnace; and in the argon holding stage, when argon is only injected uniformly circumferentially through the observation hole in the center of the furnace cover, the total amount of argon flow required is the smallest. Therefore, in this stage, the best atmosphere protection effect can be achieved by injecting argon only in this way. In addition, in order to keep the argon concentration up to standard in this stage, the minimum argon flow rate injected in this way is 19Nm 3 / h. When the observation hole needs to be opened to insert objects, in order to prevent air from entering the furnace through the observation hole and to keep the argon content in the furnace up to standard, so as to achieve atmosphere control during the entire smelting process, argon needs to be uniformly injected into the center of the smelting furnace along the top of the lining of the smelting furnace and along the observation hole. At this time, the minimum flow rate of argon injection at the two locations is 11Nm 3 / h. Through the above control method, the atmosphere control in the whole smelting process can be realized, and in the argon holding stage, argon can be uniformly injected circumferentially only by relying on the observation hole, which greatly reduces the waste of argon and reduces the use cost while achieving atmosphere protection. At the same time, when the observation hole is opened, the argon injected in a ring shape at the observation hole can be used to block the external air from entering the furnace, reducing the oxidation loss of smelting raw materials and melt. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0021] FIG1 is a schematic diagram of the structure of a control device provided in an embodiment of the present application.
[0022] In the figure: 1, inner lining 2, gas outlet device in furnace 3, furnace cover 4, observation hole cover 5, observation hole 6, gas outlet device of furnace cover 7, oxygen analyzer detection tube 8, outlet. DETAILED DESCRIPTION
[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0024] It should be noted that in this embodiment, the directions or positional relationships indicated by "upper", "lower", "front", "back", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0025] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0026] As shown in FIG1 , in this embodiment, a smelting system atmosphere control device is provided, which includes a smelting furnace and a furnace cover 3 matched with the smelting furnace. The smelting furnace can be an induction furnace, and the internal space of the furnace is a cylinder. The induction furnace has an inner lining 1, and an in-furnace gas outlet device 2 is arranged on the top of the inner lining 1. The in-furnace gas outlet device 2 is arranged along the circumference of the inner wall of the lining 1, and uniformly injects argon gas from the outer periphery of the top of the smelting furnace to the center of the internal space of the smelting furnace at an angle downward.
[0027] An observation hole 5 is provided in the center of the furnace cover 3, and a furnace cover gas outlet device 6 is provided at the top of the inner wall of the observation hole 5. The furnace cover gas outlet device 6 is arranged circumferentially along the inner wall of the observation hole 5, and uniformly injects argon gas from the middle of the top of the furnace cover 3 downwardly into the center of the internal space of the smelting furnace.
[0028] It should be noted that two configurations of injecting argon are provided above, namely, one is to uniformly inject argon into the center of the smelting furnace along the top of the inner lining 1 of the smelting furnace, and the other is to uniformly inject argon into the center of the smelting furnace along the observation hole 5 in the center of the furnace cover 3. Argon can be injected in both configurations at the same time, or in only one of the configurations.
[0029] On this basis, the present application provides a method for controlling the atmosphere of a smelting system, which further refines the process of inert gas protection based on the inert gas protection method in the background technology. Specifically, when the atmosphere control is started, argon is uniformly injected into the center of the smelting furnace along the top of the lining 1 of the smelting furnace, and uniformly injected into the center of the smelting furnace along the observation hole 5 in the center of the furnace cover 3. At this time, argon is injected simultaneously in two ways, and as for the argon injection flow rate, there are no excessive restrictions here, and it is sufficient to ensure that the injection speed of argon is greater than the overflow speed of air. And under normal operation, the air replaced by argon is discharged from the gap between the furnace cover 3 and the furnace body.
[0030] When the oxygen content in the smelting furnace is less than or equal to 0.2%, it can be considered that there is no oxygen in the furnace. The oxygen content value can be observed during the operation to keep the oxygen content less than or equal to 0.2%. At this time, the argon holding stage begins. In this stage, argon is only uniformly injected into the center of the smelting furnace along the observation hole 5 in the center of the furnace cover 3, and the minimum argon injection flow rate is 19Nm 3 / h. Since the other injection path is closed, it is necessary to increase the flow rate of argon injected in a single path to ensure that the argon content is qualified and achieve full atmosphere protection in the furnace.
[0031] When it is necessary to open the observation hole 5 to insert the object, in order to maintain the argon atmosphere protection in the furnace, it is necessary to open two ways of injecting argon at the same time, that is, argon is uniformly injected into the center of the smelting furnace along the top of the lining 1 of the smelting furnace, and argon is uniformly injected into the center of the smelting furnace along the observation hole 5, and the minimum flow rate of argon injection at the two places is 11Nm 3 / h, thereby maintaining the oxygen content in the furnace below 0.2%.
[0032] In summary of the above embodiments, when the atmosphere control is started in the control method of the present application, argon is injected into the smelting furnace through two paths, namely, one is to be uniformly injected into the center of the smelting furnace along the top of the lining 1 of the smelting furnace, and the other is to be uniformly injected into the center of the smelting furnace along the observation hole 5 in the center of the furnace cover 3, and the argon flow rate can be controlled by the flow control valve and can be adjusted separately. When the oxygen content is less than or equal to 0.2%, it can be considered that there is no oxygen in the furnace; and in the argon holding stage, when argon is only uniformly injected circumferentially through the observation hole 5 in the center of the furnace cover 3, the total amount of argon flow required is the smallest. Therefore, in this stage, the best atmosphere protection effect can be achieved by injecting argon only in this way, and in order to keep the argon concentration up to standard in this stage, the minimum argon flow rate injected in this way is 19Nm 3 / h. When it is necessary to open the observation hole 5 to insert an object, in order to prevent air from entering the furnace through the observation hole 5 and to keep the argon content in the furnace up to standard so as to achieve atmosphere control during the entire smelting process, it is necessary to uniformly inject argon into the center of the smelting furnace along the top of the lining 1 of the smelting furnace and uniformly inject argon into the center of the smelting furnace along the observation hole 5. At this time, the minimum flow rate of argon injection at the two locations is 11Nm 3 Through the above control method, the atmosphere control in the whole smelting process can be realized, and in the argon holding stage, argon can be uniformly injected circumferentially only by relying on the observation hole 5, which greatly reduces the waste of argon and reduces the use cost while achieving atmosphere protection.
[0033] At the same time, since argon gas is injected circumferentially along the observation hole 5, the argon gas is injected obliquely downward into the center of the internal space of the smelting furnace. When the observation hole 5 is opened, an argon gas layer is formed at the observation hole 5 to block the air from entering the interior of the smelting furnace. The argon gas injected in a ring shape at the observation hole 5 can be used to block external air from entering the furnace, thereby reducing the oxidation loss of smelting raw materials and melt.
[0034] In the control device, the furnace gas outlet device 2 and the furnace cover gas outlet device 6 are both annular tubes, and a plurality of evenly distributed gas outlet holes are opened on the annular tubes, and the opening directions of the gas outlet holes are all obliquely downward and toward the center of the internal space of the smelting furnace. For a non-cylindrical furnace body, the furnace gas outlet device 2 can also be set according to the actual structure of the furnace space, ensuring that it can be set in close contact with the lining 1.
[0035] Please refer to Figure 1, the furnace cover 3 is provided with an observation hole cover 4 that matches the observation hole 5, and the observation hole cover 4 is sealed when it is covered with the observation hole 5, so as to prevent the argon gas in the furnace from leaking through the hole. The observation hole 5 can be used to observe the furnace situation without opening the furnace cover 3, and can also be used to add smelting raw materials, refine and degas, and take samples through the observation hole 5.
[0036] In addition, an oxygen analyzer detection tube 7 with one end extending into the interior of the smelting furnace is provided on the furnace cover 3. The oxygen concentration is confirmed to determine whether the atmosphere meets the requirements. The detection port of the oxygen analyzer detection tube 7 is arranged at a position close to the observation hole 5. This is because the density of argon is greater than that of air. At the same time, the air replaced by argon under normal operation is discharged from the gap between the furnace cover 3 and the furnace body. The air brought in when an object is added or inserted through the observation hole 5 will first reach the detection port of the oxygen analyzer detection tube 7. Therefore, it is most reasonable to set the detection port here, and the oxygen content detection accuracy is the highest.
[0037] An outlet 8 is provided on the furnace wall of the smelting furnace, and one end of the outlet 8 extending outside the smelting furnace is a closed space, so that the smelting furnace is in a good sealing state when working normally; the details can be referred to the existing technology, which will not be described in detail here.
[0038] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.
[0039] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.
Claims
1. A method for controlling the atmosphere of a smelting system, characterized in that: When the atmosphere control is started, argon gas is uniformly injected into the center of the smelting furnace along the top of the inner lining of the smelting furnace, and is uniformly injected into the center of the smelting furnace along the observation hole in the center of the furnace cover; During the argon holding stage, argon is uniformly injected into the center of the smelting furnace only along the observation hole in the center of the furnace cover, and the minimum argon injection flow rate is 19Nm 3 / h; When the observation hole is opened to insert the object, argon is uniformly injected into the center of the smelting furnace along the circumference of the top of the lining of the smelting furnace, and uniformly injected into the center of the smelting furnace along the circumference of the observation hole, and the minimum flow rate of argon injection at the two locations is 11Nm 3 / h.
2. The smelting system atmosphere control method according to claim 1, characterized in that: When the oxygen content in the smelting furnace is less than or equal to 0.2%, the argon gas maintenance stage is entered, and the oxygen content in the smelting furnace is maintained less than or equal to 0.2%.
3. The smelting system atmosphere control method according to claim 1, characterized in that: When gas is injected circumferentially along the observation hole, argon gas is injected obliquely downward into the center of the internal space of the smelting furnace, and an argon gas layer is formed at the observation hole to block air from entering the interior of the smelting furnace.
4. A control device for implementing the smelting system atmosphere control method according to any one of claims 1 to 3, comprising a smelting furnace and a furnace cover matched with the smelting furnace, characterized in that: The top of the lining of the smelting furnace is provided with a furnace gas outlet device, which is arranged along the circumference of the inner wall of the lining and uniformly injects argon gas from the periphery of the top of the smelting furnace obliquely downward into the center of the internal space of the smelting furnace; An observation hole is opened in the center of the furnace cover, and a furnace cover gas outlet device is arranged at the top of the inner wall of the observation hole. The furnace cover gas outlet device is arranged circumferentially along the inner wall of the observation hole, and evenly injects argon gas from the middle of the furnace cover top downwardly into the center of the internal space of the smelting furnace.
5. The control device according to claim 4, characterized in that: The in-furnace gas outlet device and the furnace cover gas outlet device are both annular tubes, and the annular tubes are provided with a plurality of evenly distributed gas outlet holes, and the opening directions of the gas outlet holes are all obliquely downward and toward the center of the internal space of the smelting furnace.
6. The control device according to claim 4, characterized in that: The furnace cover is provided with an observation hole cover matched with the observation hole, and the observation hole cover is sealed when it is closed with the observation hole cover.
7. The control device according to claim 4, characterized in that: The furnace cover is provided with an oxygen analyzer detection tube with one end extending into the interior of the smelting furnace, and the oxygen analyzer detection tube is arranged close to the observation hole.
8. The control device according to claim 4, characterized in that: An outlet is arranged on the furnace wall of the smelting furnace, and one end of the outlet extending outside the smelting furnace is a closed space.