Composite connecting piece for aluminum alloy scrap recovery aluminum melting furnace

Abstract

The invention discloses a composite connecting piece for an aluminum alloy scrap recovery aluminum melting furnace, and relates to the technical field of aluminum alloy recovery equipment. The graphite impeller is of a multi-layer composite structure and comprises an inner layer which is made of high-strength metal and connected between the graphite impeller and the vortex device. The outer layer is made of an inorganic non-metal material and is used for ensuring molten aluminum corrosion and abrasion resistance; the transition layer is filled between the inner layer and the outer layer and is used for enhancing the binding force between the inner layer and the outer layer; the top end sealing structure is made of high-temperature-resistant castable and used for sealing the metal portion where the inner layer and the graphite impeller are assembled and preventing molten aluminum from leaking and corroding. The manufacturing method comprises the steps of inner layer processing, composite assembling, port sealing and air drying. The product has the advantages of high strength and low cost, the service life is greatly prolonged, the manufacturing cost is lower than that of a silicon nitride integrated piece, and the product can adapt to the scene of recovering 90% or above of aluminum alloy scraps.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy recycling equipment technology, and in particular to a composite connector for an aluminum alloy scrap recycling furnace. Background Technology

[0002] With the rapid development of the automotive industry and increasingly stringent environmental requirements, lightweighting has become one of the core development directions in the automotive manufacturing sector. Aluminum alloys, due to their combination of high strength and lightweight properties, are widely used in the manufacture of automotive steering brackets, chassis components, wheel hubs, engine housings, and body parts. To reduce production costs and implement the concept of low-carbon development, the recycling of aluminum shavings and waste generated during aluminum product processing has become an indispensable production step.

[0003] The aluminum scrap melting furnace is a key piece of equipment for aluminum scrap recycling, with its internal vortex device being the core component. A 440mm diameter graphite impeller is installed at the lower end of the vortex device. The impeller and the vortex device are connected and immersed together in the molten aluminum, driven to rotate by the vortex device. Because it needs to be immersed in molten aluminum for extended periods without affecting the chemical composition of the aluminum, existing technologies generally use graphite materials for the connectors between the graphite impeller and the vortex device. However, existing graphite connectors have the following significant drawbacks: poor corrosion resistance; under normal use, their service life is only about one week when continuously used in molten aluminum at 700℃; frequent replacement by operators in a high-temperature environment after wear, resulting in high labor intensity; and equipment downtime during replacement, severely impacting production efficiency.

[0004] Therefore, developing a composite connector for aluminum alloy scrap recycling furnaces that combines corrosion resistance, high strength, and controllable cost has become a pressing technical problem for the aluminum alloy scrap recycling industry. Summary of the Invention

[0005] In view of this, the purpose of this invention is to overcome the shortcomings of the prior art and provide a composite connector for aluminum alloy scrap recycling furnaces and its manufacturing method, achieving a balance of resistance to aluminum melt corrosion, wear resistance, high strength and low cost.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A composite connector for an aluminum alloy scrap recycling furnace includes an inner layer, an outer layer, a middle transition layer, and a top sealing structure. The inner layer is made of high-strength metal and connects the graphite impeller and the vortex device to bear the main load torque. The outer layer is made of inorganic non-metallic material to ensure resistance to aluminum melt corrosion and wear. The middle transition layer fills the space between the inner and outer layers to enhance the bonding force between them. The top sealing structure is made of high-temperature resistant castable to seal the metal parts where the inner layer and the graphite impeller are assembled, preventing aluminum melt leakage and corrosion.

[0007] Preferably, the high-strength metal is H13 mold steel.

[0008] Preferably, the inorganic non-metallic material is silicon nitride.

[0009] Preferably, the intermediate transition layer is high-temperature resistant insulation cotton.

[0010] Preferably, the intermediate transition layer is a lightweight, high-temperature resistant insulation cotton, and the inner and outer layers are compositely connected by filling.

[0011] Preferably, the high-temperature resistant castable with the top-closed structure retains a flat end after molding.

[0012] Another object of the present invention is to provide a method for manufacturing the composite connector for an aluminum alloy scrap recycling furnace, comprising the following steps: Step S1: Process the inner metal layer by machining internal and external threads at both ends to ensure assembly dimensional accuracy; Step S2: Place the inner layer treated in step S1 at the center of the outer inorganic non-metallic sleeve, and fill the space between the inner layer and the outer inorganic non-metallic sleeve with high-temperature resistant insulation cotton to form an intermediate transition layer, so that the inner layer and the outer layer are compositely bonded. Step S3: Use high-temperature resistant castable to seal the top of the composite structure to ensure the port is flat; Step S4: The finished product processed in step S3 is air-dried to obtain the composite connector.

[0013] Preferably, the inner metal in step S1 is H13 mold steel, which ensures the compatibility of the threaded connection after processing.

[0014] Preferably, the outer inorganic non-metallic sleeve in step S2 is a silicon nitride sleeve.

[0015] Preferably, the high-temperature resistant insulation cotton in step S2 is lightweight insulation cotton, and during the filling process, it is ensured that there are no gaps between the inner layer and the outer inorganic non-metallic sleeve.

[0016] The beneficial effects of adopting the above technical solution are as follows: 1. The composite connector for aluminum alloy scrap recycling furnace provided by the present invention has an inner layer made of H13 mold steel, which can effectively withstand the main load torque during operation and ensure the stability and reliability of the connection between the graphite impeller and the vortex device.

[0017] 2. The composite connector for aluminum alloy scrap recycling furnace provided by the present invention has an outer layer made of silicon nitride composite material. This material is almost not corroded in molten aluminum at 700°C and has significantly better wear resistance than traditional graphite materials, which greatly extends the service life of the connector and reduces the frequency of replacement.

[0018] 3. The composite connector for aluminum alloy scrap recycling furnace provided by the present invention has a high-temperature resistant insulation cotton filling in the middle transition layer, which not only enhances the bonding force between the inner and outer layers, but also buffers the thermal stress caused by temperature changes and avoids structural separation.

[0019] 4. The composite connector for aluminum alloy scrap recycling furnace provided by the present invention has a high-temperature resistant castable sealing structure at the top, which effectively blocks the leakage and corrosion of the inner metal by the aluminum liquid, and further extends the service life. 5. The composite connector for aluminum alloy scrap recycling furnace provided by the present invention adopts a multi-layer composite structure, which avoids the high cost problem caused by using pure silicon nitride monolithic material. By rationally selecting materials and simplifying the process, the manufacturing cost is much lower than that of silicon nitride monolithic parts, while taking into account both performance and economy.

[0020] 6. The composite connector for aluminum alloy scrap recycling furnaces provided by this invention can be adapted to the connection requirements of eddy current devices and graphite impellers in more than 90% of aluminum alloy scrap recycling furnaces at home and abroad, and has strong versatility. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the composite connector for an aluminum alloy scrap recycling furnace, as per the present invention. In this diagram, 1 represents the inner layer; 2 represents the outer layer; 3 represents the intermediate transition layer; and 4 represents the top closed structure. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of the present invention and to make the above-mentioned features, objectives, and advantages of the present invention clearer and easier to understand, the present invention will be further described below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Example 1

[0023] This embodiment provides a composite connector for an aluminum alloy scrap recycling furnace, the structure of which is as follows: Figure 1 As shown, it includes: Inner layer: H13 mold steel is selected as the base material. This material has high strength and high temperature resistance, meeting the requirements for bearing load torque. The inner layer is machined into a cylindrical structure, with the diameter designed according to the connection interface size between the vortex device and the graphite impeller. M30 internal and external threads are machined at both ends to ensure the tightness of the connection during assembly. Outer layer: A silicon nitride ceramic sleeve is used, with its inner diameter slightly larger than the outer diameter of the inner H13 mold steel. The wall thickness is designed to be 15mm to ensure sufficient structural strength and corrosion resistance. Intermediate transition layer: Lightweight, high-temperature resistant insulation cotton with a thickness of 5mm is used to fill between the inner and outer layers. During the filling process, compaction is carried out to ensure no gaps and to achieve a tight bond between the inner and outer layers. Top-sealed structure: High-temperature resistant castable (model AL-70) is used with a casting thickness of 10mm. After molding, mechanical grinding is used to ensure that the flatness error of the end does not exceed ±0.2mm.

[0024] The manufacturing method of the above-mentioned composite connector includes the following specific steps: Inner layer machining: Select H13 mold steel round bar with specifications of Φ50×200mm, and machine it to Φ40×180mm by CNC lathe. Then, machine M30 internal and external threads at both ends with a thread length of 20mm. After machining, use go and no-go gauges to check the thread accuracy to ensure that it meets the assembly requirements. Composite assembly: Place the qualified inner steel part in the center of the silicon nitride ceramic sleeve (Φ50×180mm), adjust the coaxiality error to not exceed 0.5mm, and then evenly fill the space between the two with lightweight high-temperature resistant insulation cotton. During the filling process, use special tools to compact the insulation cotton to ensure that the insulation cotton is tightly attached to the inner and outer layers. Top sealing: Fix the composite semi-finished product in a special tooling, pour AL-70 high temperature resistant castable into the top, the pouring height is 10mm, and after the castable has initially solidified (about 2 hours), use a scraper to trim the end to ensure flatness; Air drying and curing: Place the semi-finished product in a ventilated and dry environment to air dry naturally for no less than 24 hours. After the casting material has completely cured, conduct appearance inspection and dimension verification. If it passes the inspection, it is considered a finished product.

[0025] The composite connector manufactured in this embodiment, after actual testing, has a service life of more than 3 months when continuously used in molten aluminum at 700℃, far exceeding the one-week service life of traditional graphite connectors; the replacement frequency is reduced by more than 80%, effectively reducing equipment downtime; and the manufacturing cost is only 60% of that of pure silicon nitride integrated connectors, significantly reducing production costs. Furthermore, this connector is easy to install, has good compatibility with existing aluminum melting furnace vortex devices and graphite impellers, and can directly replace existing graphite connectors.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A composite connector for an aluminum alloy scrap recycling and melting furnace, characterized in that, It includes an inner layer, an outer layer, an intermediate transition layer, and a top sealing structure. The inner layer is made of high-strength metal and connects the graphite impeller and the vortex device to bear the main load torque. The outer layer is made of inorganic non-metallic material to ensure resistance to aluminum liquid corrosion and wear. The intermediate transition layer fills the space between the inner and outer layers to enhance the bonding force between them. The top sealing structure is made of high-temperature resistant castable to seal the metal parts where the inner layer is assembled with the graphite impeller, preventing aluminum liquid leakage and corrosion.

2. The composite connector for an aluminum alloy scrap recycling furnace according to claim 1, characterized in that, The high-strength metal is H13 mold steel.

3. The composite connector for an aluminum alloy scrap recycling furnace according to claim 1, characterized in that, The inorganic non-metallic material is silicon nitride.

4. The composite connector for an aluminum alloy scrap recycling furnace according to claim 1, characterized in that, The intermediate transition layer is high-temperature resistant insulation cotton.

5. The composite connector for an aluminum alloy scrap recycling furnace according to claim 1, characterized in that, The intermediate transition layer is made of lightweight, high-temperature resistant insulation cotton, and the inner and outer layers are connected by filling.

6. The composite connector for an aluminum alloy scrap recycling furnace according to claim 1, characterized in that, The high-temperature resistant castable with the top closed structure remains flat at the end after molding.

7. A method for manufacturing a composite connector for an aluminum alloy scrap recycling furnace according to any one of claims 1-6, characterized in that, Includes the following steps: Step S1: Process the inner metal layer by machining internal and external threads at both ends to ensure assembly dimensional accuracy; Step S2: Place the inner layer treated in step S1 at the center of the outer inorganic non-metallic sleeve, and fill the space between the inner layer and the outer inorganic non-metallic sleeve with high-temperature resistant insulation cotton to form an intermediate transition layer, so that the inner layer and the outer layer are compositely bonded. Step S3: Use high-temperature resistant castable to seal the top of the composite structure to ensure the port is flat; Step S4: The finished product processed in step S3 is air-dried to obtain the composite connector.

8. The method for manufacturing the composite connector for an aluminum alloy scrap recycling furnace according to claim 7, characterized in that, The inner metal in step S1 is H13 mold steel, which ensures the compatibility of the threaded connection after processing.

9. The method for manufacturing the composite connector for an aluminum alloy scrap recycling furnace according to claim 7, characterized in that, The outer inorganic non-metallic sleeve mentioned in step S2 is a silicon nitride sleeve.

10. The method for manufacturing the composite connector for an aluminum alloy scrap recycling furnace according to claim 7, characterized in that, The high-temperature resistant insulation cotton mentioned in step S2 is lightweight insulation cotton, and during the filling process, it is ensured that there are no gaps between the inner layer and the outer inorganic non-metallic sleeve.

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