A continuous feeding device for a vacuum melting furnace

Abstract

The present application relates to the technical field of vacuum melting furnaces, and specifically to a continuous feeding device for vacuum melting furnaces, comprising: a three-stage vacuum transition chamber, comprising a pre-evacuation chamber, a buffer chamber, and a vertically arranged main furnace connecting chamber, each with a decreasing vacuum degree and arranged horizontally; a spiral rod coaxial with a guide tube inside the main furnace chamber is vertically arranged inside the main furnace connecting chamber, the bottom end of the guide tube is located above the crucible, and its side wall is provided with an annularly distributed argon gas nozzle to form an argon gas curtain; adjacent chambers in the three-stage vacuum transition chamber, the main furnace connecting chamber, and the main furnace chamber are isolated by plug valves. This achieves seamless connection of multiple batches, shortens the feeding cycle, eliminates the need to repeatedly destroy vacuum conditions, and improves production efficiency; the feeding process suppresses splashing and isolates oxygen to prevent oxidation.

Description

Technical Field

[0001] The present application relates to the technical field of vacuum melting furnaces, and in particular to a continuous feeding device for a vacuum melting furnace. Background Art

[0002] Vacuum melting refers to a specialized melting technique performed under vacuum conditions, widely used in the melting of metals and their alloys. Traditional vacuum melting furnaces require repeated disruption of the chamber's vacuum during charging. Frequent opening and closing of the furnace door introduces oxygen and moisture, increasing the oxygen content of the melt (>50 ppm). This leads to significant vacuum fluctuations within the chamber, impacting the properties of nickel-based alloys. This impacts product quality, while requiring frequent vacuum pumping, which is extremely inconvenient. Furthermore, the secondary charging process causes molten metal in the crucible to splash, allowing the metal to come into contact with the interior of the main furnace chamber, posing a safety hazard.

[0003] The manual feeding cycle is long, making it difficult to adapt to continuous production needs and reducing work efficiency.

[0004] In view of this, this application is filed. Summary of the Invention

[0005] The object of the present invention is to provide a continuous feeding device for a vacuum melting furnace. By setting up a three-stage vacuum transition cabin with an L-shaped structure, the vacuum degree of each cabin is gradually reduced. When the vacuum degree of the main furnace connecting cabin is consistent with that of the main furnace chamber, the feeding is started. The guide tube is connected to the crucible in a contact manner to prevent the splashing of molten metal during the feeding process.

[0006] In order to solve the above technical problems, the present invention adopts the following solutions:

[0007] A continuous feeding device for a vacuum melting furnace comprises: a three-stage vacuum transition chamber, comprising a pre-evacuation chamber, a buffer chamber and a vertically arranged main furnace connecting chamber with successively decreasing vacuum degrees and arranged horizontally; a spiral rod coaxial with a guide tube inside the main furnace chamber is vertically arranged inside the main furnace connecting chamber, the bottom end of the guide tube is located above the crucible, and the side wall of the guide tube is provided with annularly distributed argon spray holes to form an argon gas curtain; plug-in valves are respectively provided for isolation between adjacent chambers in the three-stage vacuum transition chamber, the main furnace connecting chamber and the main furnace chamber.

[0008] Furthermore, a movable seat is provided in the pre-evacuation chamber, and symmetrical support frames and rollers located between the two support frames are provided above the movable seat, and a conveyor belt for conveying materials is provided between the rollers.

[0009] Furthermore, it includes a base located at the bottom of the pre-evacuation cabin and an electric push rod on the side. The bottom of the movable seat is located above multiple rollers in the sliding groove on the surface of the base. The output end of the electric push rod is fixedly connected to one end of the movable seat and drives the movable seat into the interior of the buffer cabin.

[0010] Furthermore, the buffer cabin is provided with a rotating shaft located on the cabin wall, a loading plate connected to the rotating shaft, a tray and a fixing rod respectively located above and below the loading plate, and a buffer pad is provided at the bottom end of the fixing rod.

[0011] Furthermore, a collecting hopper for receiving the pallet material is provided below the rotating shaft, and the collecting hopper is communicated with the discharge port of the buffer cabin.

[0012] Furthermore, the vacuum degree of the main furnace connecting cabin is consistent with the vacuum degree of the main furnace chamber. A fixing ring, a bearing and a connecting rod are respectively provided at the top and bottom of the main furnace connecting cabin. The connecting rod is distributed in a ring shape between the fixing ring and the bearing, and the top and bottom ends of the spiral rod are respectively located in the bearing.

[0013] Furthermore, a bevel gear 1 is provided at the top end of the spiral rod, and the outer periphery of the bevel gear 1 is meshed with a bevel gear 2 connected to the output rod of the drive motor.

[0014] Furthermore, the guide tube is a three-layer composite structure, the inner layer is a stainless steel mesh with a graphite coating, the middle layer is a ceramic fiber insulation layer, and the outer layer is a stainless steel sheath. A connecting ring is provided on the outer periphery of the top end of the vertical part of the guide tube and is connected to the top of the main furnace chamber by bolts, and a graphite sealing ring is provided between the connecting ring and the main furnace chamber.

[0015] Furthermore, the outer periphery of the bucket-shaped portion of the guide tube is fixedly connected to an annular gas pipe connected to the argon gas pipeline at the top of the main furnace chamber, and the multiple argon gas nozzles are respectively connected to the annular gas pipe.

[0016] Furthermore, the axis of the argon gas nozzle and the axis of the guide tube have an inclination angle of 30° to 45°.

[0017] The beneficial effects of the present invention are as follows: by providing a three-stage vacuum transition chamber connected to the main furnace chamber, each chamber is independently evacuated, resulting in a gradual decrease in the vacuum level of each chamber. At the same time, the vacuum level of the main furnace connecting chamber is kept consistent with that of the main furnace chamber. This allows the pre-evacuated chamber to load the next batch of materials while the current batch enters the main furnace connecting chamber, achieving seamless transitions between multiple batches, shortening the feeding cycle, eliminating the need for repeated vacuum conditions, and improving production efficiency. Furthermore, a guide tube and argon gas nozzles located on the sidewalls of the guide tube's bucket-shaped portion are provided to transport argon gas, forming an annular argon gas curtain and creating a centripetal airflow that suppresses splashing, isolates oxygen, and prevents oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 It is a partial structural diagram of the main furnace connecting cabin and the main furnace chamber in the present invention;

[0020] Figure 3 It is a bottom view structural schematic diagram of the guide tube in the present invention.

[0021] Reference numerals: 1-three-stage vacuum transition chamber, 2-pre-evacuation chamber, 20-feeding port, 21-conveyor belt, 22-roller, 23-support frame, 24-electric push rod, 25-base, 26-moving seat, 27-roller shaft, 3-buffer chamber, 30-rotating shaft, 31-tray, 32-fixed rod, 320-buffer pad, 33-collecting hopper, 34-loading plate, 4-main furnace connecting chamber, 40-screw rod, 400 -Bevel gear 1, 41-fixed ring, 410-connecting rod, 411-bearing, 42-drive motor, 420-output rod, 421-Bevel gear 2, 5-main furnace chamber, 50-crucible, 51-guide tube, 510-stainless steel mesh, 511-ceramic fiber insulation layer, 512-stainless steel sheath, 52-connecting ring, 520-graphite sealing ring, 53-annular air pipe, 54-argon nozzle, 6-gate valve. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Unless otherwise specifically stated, the relative arrangement of components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.

[0024] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0025] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0026] Technologies, methods and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods and equipment should be considered part of the authorization specification.

[0027] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0028] Example 1

[0029] A continuous feeding device for a vacuum melting furnace comprises: a three-stage vacuum transition chamber 1, comprising a pre-evacuation chamber 2, a buffer chamber 3 and a vertically arranged main furnace connecting chamber 4 with successively decreasing vacuum degrees and arranged horizontally; a spiral rod 40 is vertically arranged inside the main furnace connecting chamber 4 and is coaxial with a guide tube 51 inside the main furnace chamber 5, the bottom end of the guide tube 51 is located above the crucible 50, and its side wall is provided with annularly distributed argon nozzles 54 to form an argon gas curtain; adjacent chambers in the three-stage vacuum transition chamber 1, the main furnace connecting chamber 4 and the main furnace chamber 5 are respectively isolated by gate valves 6.

[0030] Reference Figure 1 and Figure 2 The present application mainly sets up a three-stage vacuum transition cabin 1 connected to the main furnace chamber 5. Each cabin is evacuated independently, so that the vacuum degree of each cabin is reduced step by step. At the same time, the vacuum degree of the main furnace connecting cabin 4 is kept consistent with the vacuum degree of the main furnace chamber 5, realizing step-by-step vacuum isolation during feeding, enhancing oxygen isolation, and reducing the risk of contamination of the main furnace chamber 5; at the same time, continuous feeding of metal or alloy materials is realized, allowing the pre-evacuation cabin 2 to load the next batch of materials while the current batch enters the main furnace connecting cabin 4, realizing seamless connection of multiple batches, shortening the feeding cycle, and eliminating the need to repeatedly destroy the vacuum conditions, thereby improving production efficiency.

[0031] Furthermore, a guide tube 51 is installed above the crucible 50 in the main furnace chamber 5. The bottom of the guide tube 51 contacts the top of the crucible 50. An argon gas curtain is installed on the sidewall of the guide tube 51. The incoming argon gas forms a centripetal argon barrier within the guide tube 51, offsetting the lateral kinetic energy of the falling material and reducing flyaway particles. Simultaneously, the argon gas flows downward, covering the surface of the molten metal, preventing reactive gases like oxygen and water vapor from contacting the molten metal and reducing its oxygen content. As the argon gas sweeps the edges of the crucible 50, it removes low-melting-point impurity vapors (such as sulfur and phosphorus), improving the purity of the material.

[0032] It should be noted that a gate valve 6 is provided between each compartment and between the main furnace connecting chamber and the main furnace chamber 5, which is used to open or close the conveying channel between the two. The gate valve 6 is an existing technology and ensures the sealing performance of the two chambers when closed. It will not be elaborated here.

[0033] In some preferred embodiments, a movable seat 26 is provided in the pre-evacuation chamber 2. A pair of symmetrical support frames 23 and rollers 22 are provided above the movable seat 26. A conveyor belt 21 for conveying materials is provided between the rollers 22. The movable seat 26 comprises a base 25 at the bottom of the pre-evacuation chamber 2 and an electric push rod 24 on the side. The bottom of the movable seat 26 is located above a plurality of rollers 27 in a sliding groove on the surface of the base 25. The output end of the electric push rod 24 is fixedly connected to one end of the movable seat 26, and drives the movable seat 26 into the interior of the buffer chamber 3.

[0034] Specifically, the material enters through the feed port 20 above the conveyor belt 21, and the feed port 20 is located near the buffer chamber 3. When the required material is transferred to the top of the conveyor belt 21 through the feed port 20, the feed port 20 is closed, and the atmospheric pressure in the pre-vacuum chamber 2 is reduced to the first vacuum preset value to remove water and oxygen adsorbed on the surface of the material, thereby avoiding direct transmission of the material to the main furnace chamber 5 and reducing the risk of contamination of the main furnace chamber 5.

[0035] In some preferred embodiments, the buffer chamber 3 is provided with a rotating shaft 30 located on the cabin wall, a material loading plate 34 connected to the rotating shaft 30, a tray 31 located above and below the material loading plate 34, and a fixed rod 32. A buffer pad 320 is provided at the bottom end of the fixed rod 32. When the gate valve 6 between the pre-evacuation chamber 2 and the buffer chamber 3 is opened, the electrically driven movable seat 26 inside the pre-evacuation chamber 2 moves above the sliding groove to the inside of the buffer chamber 3. When it moves above one end of the tray 31, it stops moving and starts the roller 22 to move the material on the conveyor belt 21 to the right end and drop it into the inside of the tray 31 to transfer the material. After completion, the gate valve 6 between the two chambers is closed, and the buffer chamber 3 is evacuated to a second preset vacuum value to further remove the gas (such as H2, CO) remaining in the micropores of the material. At the same time, the buffer cabin 3 serves as a transition cabin between the pre-vacuum cabin 2 and the main furnace connecting cabin 4, so that the material can establish a transitional vacuum environment before entering the main furnace chamber 5, further purify the material and maintain the high vacuum stability of the main furnace chamber 5, thereby avoiding the main furnace chamber 5 from being exposed to a low vacuum environment due to frequent material addition, and reducing oxygen and nitrogen impurity pollution.

[0036] Furthermore, a collection hopper 33 for receiving material from tray 31 is located below the rotating shaft 30 and communicates with the discharge port of the buffer chamber 3. The material within the buffer chamber 3 is primarily transferred by the rotating shaft 30, which drives the loading plate 34, the loading tray 31, and the fixing rod 32 to rotate 90 degrees, thereby transferring the material on the tray 31 into the collection hopper and simultaneously returning all components to their original positions. A cushion 320 protects the fixing rod 32 from contact with the buffer chamber 3, and its specific material is determined based on actual needs.

[0037] Furthermore, the vacuum degree of the main furnace connecting cabin 4 is consistent with the vacuum degree of the main furnace chamber 5. A fixing ring 41, a bearing 411 and a connecting rod 410 are respectively provided at the top and bottom of the main furnace connecting cabin 4. The connecting rod 410 is distributed in a ring shape between the fixing ring 41 and the bearing 411, and the top and bottom ends of the spiral rod 40 are respectively located in the bearing 411.

[0038] After opening the gate valve 6 between the buffer cabin 3 and the main furnace connecting cabin 4, the material in the collecting hopper 33 enters the interior of the screw rod 40 through the passage of the two cabins, and then close the gate valve 6 between the two to make the vacuum degree of the main furnace connecting cabin 4 and the main furnace chamber 5 consistent, and then start the gate valve 6 of the main furnace connecting cabin 4 and the main furnace chamber 5, and at the same time start the screw rod 40 to drive the material to fall into the crucible 50. Due to the provision of the guide tube 51, when the material contacts the molten metal in the crucible 50, the molten metal is prevented from splashing onto the inner wall of the main furnace chamber 5, thereby preventing damage to the main furnace chamber 5.

[0039] Among them, the bearing 411, the fixing ring 41 and the connecting rod 410 all provide conditions for the assembly of the spiral rod 40, and can be made of ceramic material with high temperature resistance, low thermal expansion coefficient, high hardness and good wear resistance.

[0040] It should be noted that bevel gear 1 400 is disposed at the top of the screw 40. The outer periphery of bevel gear 1 400 engages with bevel gear 2 421 connected to the output rod 420 of the drive motor 42. The screw 40 is driven primarily by the drive motor 42, which causes the output rod 420 to rotate bevel gear 2 421, thereby causing bevel gear 1 400 to rotate the entire screw 40 between the bearings 411, ultimately achieving the entire material feeding operation into the crucible 50 in the main furnace chamber 5.

[0041] The main furnace connecting chamber 4 serves as a transitional chamber between the buffer chamber 3 and the main furnace chamber 5. Its vacuum level is synchronized with that of the main furnace chamber 5, preventing contamination of the main furnace chamber 5 by directly receiving low-vacuum materials. A gate valve 6 physically separates the main furnace connecting chamber 4 from the main furnace chamber 5. During material addition, the valve opens, allowing the material to enter the crucible 50 through a guide tube 51. Once material addition is complete, the valve closes, ensuring a stable vacuum in the main furnace chamber 5.

[0042] Example 2

[0043] This embodiment 2 is implemented on the basis of embodiment 1. The guide tube 51 is a three-layer composite structure, the inner layer is a stainless steel mesh 510 with a graphite coating, the middle layer is a ceramic fiber insulation layer 511, and the outer layer is a stainless steel sheath 512. A connecting ring 52 is provided on the outer periphery of the top end of the vertical part of the guide tube 51 and is connected to the top of the main furnace chamber 5 by bolts, and a graphite sealing ring 520 is provided between the connecting ring 52 and the main furnace chamber 5.

[0044] Specifically, guide tube 51 is secured to the passage between main furnace connection compartment 4 and main furnace chamber 5 via connecting ring 52, making it removable and easy to replace. A graphite sealing ring 520 also enhances sealing performance. The bottom of guide tube 51 is a bucket-shaped portion that covers the surface of crucible 50, shielding it from the impact of insulated materials during charging and preventing molten metal from splashing onto the inner wall of main furnace chamber 5. Its three-layer composite structure improves its high-temperature resistance during operation in the vacuum melting furnace, providing corrosion resistance and a long service life. The smooth graphite coating on the surface of stainless steel mesh 510 reduces material adhesion.

[0045] In some preferred embodiments, the outer periphery of the bucket-shaped portion of the guide tube 51 is fixedly connected to an annular gas pipe 53 that is connected to the argon gas pipeline at the top of the main furnace chamber 5. A plurality of argon gas nozzles 54 are respectively connected to the annular gas pipe 53. The axes of the argon gas nozzles 54 are inclined at an angle of 30° to 45° with the axis of the guide tube 51.

[0046] Argon nozzles 54 are arranged in an annular arrangement in the bucket-shaped portion of the guide tube 51 and are connected to an argon source via an annular air pipe 53. During the feeding process, argon is simultaneously transported through the annular air pipe 53 and the argon nozzles 54 to form an annular argon gas curtain, which creates a centripetal airflow, suppresses splashing, isolates oxygen, prevents oxidation, and ensures the purity of the melt. At the same time, the 30° to 45° inclination angle guides the material to fall into the center of the molten metal in the crucible 50, reducing component segregation.

[0047] The working principle of this application is as follows: when in use, the material is fed into the pre-evacuation cabin 2 to remove the water and oxygen adsorbed on the surface of the material, so as to avoid the material being directly transferred to the main furnace chamber 5; then the material enters the buffer cabin 3 to further remove the residual gas in the micropores of the material; the main furnace connecting cabin 4 serves as a transition cabin between the buffer cabin 3 and the main furnace chamber 5, and synchronizes its vacuum degree to the level of the main furnace chamber 5 to avoid the main furnace chamber 5 from being contaminated by directly receiving low-vacuum materials; at the same time, when the material is transferred to the inside of the crucible 50, argon is delivered to the argon nozzle 54 to form an annular argon gas curtain, forming a centripetal airflow, suppressing splashing and isolating oxygen to prevent oxidation. In addition, each cabin is independently evacuated, allowing the pre-evacuation cabin 2 to load the next batch of materials while the current batch enters the main furnace connecting cabin 4, realizing seamless connection of multiple batches and shortening the feeding cycle.

[0048] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A continuous feeding device for a vacuum melting furnace, characterized in that: include: A three-stage vacuum transition chamber (1) comprises a pre-evacuation chamber (2), a buffer chamber (3) and a vertically arranged main furnace connection chamber (4) with successively decreasing vacuum degrees and arranged horizontally; a spiral rod (40) coaxial with a guide tube (51) inside a main furnace chamber (5) is vertically arranged inside the main furnace connection chamber (4); the bottom end of the guide tube (51) is located above the crucible (50), and the side wall thereof is provided with annularly distributed argon spray holes (54) to form an argon gas curtain; adjacent chambers in the three-stage vacuum transition chamber (1), the main furnace connection chamber (4) and the main furnace chamber (5) are respectively isolated by a plug valve (6).

2. A continuous feeding device for a vacuum melting furnace according to claim 1, characterized in that: A movable seat (26) is provided in the pre-evacuation chamber (2), and symmetrical support frames (23) and rollers (22) located between the two support frames (23) are provided above the movable seat (26), and a conveyor belt (21) for conveying materials is provided between the rollers (22).

3. A continuous feeding device for a vacuum melting furnace according to claim 2, characterized in that: It comprises a base (25) located at the bottom of the pre-evacuation chamber (2) and an electric push rod (24) on the side, the bottom of the movable seat (26) is located above a plurality of rollers (27) in a sliding groove on the surface of the base (25), the output end of the electric push rod (24) is fixedly connected to one end of the movable seat (26), and drives the movable seat (26) to enter the interior of the buffer chamber (3).

4. A continuous feeding device for a vacuum melting furnace according to claim 2, characterized in that: The buffer cabin (3) is provided with a rotating shaft (30) located on the cabin wall, a loading plate (34) connected to the rotating shaft (30), a tray (31) and a fixing rod (32) respectively located above and below the loading plate (34), and a buffer pad (320) is provided at the bottom end of the fixing rod (32).

5. A continuous feeding device for a vacuum melting furnace according to claim 4, characterized in that: A collecting hopper (33) for receiving materials from the tray (31) is provided below the rotating shaft (30), and the collecting hopper (33) is communicated with the discharge port of the buffer cabin (3).

6. A continuous feeding device for a vacuum melting furnace according to claim 4, characterized in that: The vacuum degree of the main furnace connecting cabin (4) is consistent with the vacuum degree of the main furnace chamber (5). A fixing ring (41), a bearing (411), and a connecting rod (410) are respectively provided at the top and bottom of the main furnace connecting cabin (4). The connecting rod (410) is annularly distributed between the fixing ring (41) and the bearing (411). The top and bottom ends of the spiral rod (40) are respectively located in the bearing (411).

7. A continuous feeding device for a vacuum melting furnace according to claim 6, characterized in that: A bevel gear 1 (400) is provided at the top end of the spiral rod (40), and the outer periphery of the bevel gear 1 (400) is meshed with a bevel gear 2 (421) connected to an output rod (420) of the drive motor (42).

8. The continuous feeding device for a vacuum melting furnace according to claim 6, characterized in that: The guide tube (51) is a three-layer composite structure, wherein the inner layer is a stainless steel mesh (510) with a graphite coating, the middle layer is a ceramic fiber heat insulation layer (511), and the outer layer is a stainless steel sheath (512). A connecting ring (52) is provided on the outer periphery of the top end of the vertical portion of the guide tube (51) and is connected to the top of the main furnace chamber (5) by bolts, and a graphite sealing ring (520) is provided between the connecting ring (52) and the main furnace chamber (5).

9. The continuous feeding device for a vacuum melting furnace according to claim 6, characterized in that: The outer periphery of the bucket-shaped portion of the guide tube (51) is fixedly connected to an annular gas pipe (53) that is in communication with the argon gas pipeline at the top of the main furnace chamber (5), and a plurality of argon gas injection holes (54) are respectively in communication with the annular gas pipe (53).

10. The continuous feeding device for a vacuum melting furnace according to claim 6, characterized in that: The axis of the argon gas injection hole (54) and the axis of the guide tube (51) are inclined at an angle of 30° to 45°.

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