A medium frequency hydrogen preheating and dispersing device

Abstract

The utility model discloses a kind of intermediate frequency hydrogen preheating and dispersion device, including including zirconia ceramic tube, tungsten main pipe and two groups of mirror image distribution's branch pipe assembly, characterized in that, each group of branch pipe assembly is sequentially connected by tungsten branch pipe one, tungsten branch pipe two and tungsten branch pipe three, and the upper end of zirconia ceramic tube is fixedly connected with the lower end of tungsten main pipe;The upper end of tungsten main pipe is sealed mouth, and the both sides of tungsten main pipe are respectively equipped with internal thread mouth, and one end of tungsten branch pipe one is equipped with the external thread of adaptation with the internal thread mouth of tungsten main pipe;The device solves the problem of poor gas dispersion and preheating effect of the existing intermediate frequency hydrogen inlet device, and the hydrogen flow rate is greatly different in each region during sintering process of intermediate frequency furnace. The high-risk coefficient of using external hydrogen preheating equipment is not only can evenly disperse hydrogen entering the intermediate frequency furnace into each region, but also fully utilizes the heat of intermediate frequency furnace to realize the preheating of hydrogen.

Description

Technical Field

[0001] This utility model relates to the field of medium-frequency sintering forming technology of refractory alloy rods and plates, specifically a medium-frequency hydrogen preheating and dispersion device. Background Technology

[0002] Medium-frequency induction sintering is used for the production of elemental and alloy rods and plates of refractory metals (such as molybdenum, tungsten, and rhenium). With continuous improvements in the processing capabilities of rolling and forging equipment, sintered rods and plates are becoming thicker, heavier, and more robust. This significantly reduces sintering costs and allows for more uniform and denser microstructures in products with greater deformation, resulting in better material properties. However, as dimensions increase, the volatilization of impurities and the uniformity of the medium-frequency temperature field become crucial. Specific solutions focus on optimizing the hydrogen content within the medium-frequency furnace. To address issues such as gas flow rate, eliminating cold hydrogen, and temperature field differences caused by gas flow, the current industry practice involves adding a bottom hydrogen inlet and using a bottom-layer non-porous or perforated tungsten plate for gas dispersion. While this effectively increases the hydrogen flow rate to some extent, a large amount of hydrogen still overflows from both sides, resulting in poor actual dispersion. At the same time, the hydrogen is not adequately preheated, leading to a significant temperature difference along the hydrogen flow direction. This causes differences in crystallization between the sintered rods and plates, which in turn affects the material's subsequent processing performance and makes it prone to defects such as cracks and poor microstructure uniformity. Therefore, improvements to the existing technology are necessary. Utility Model Content

[0003] The purpose of this invention is to provide a medium-frequency hydrogen preheating and dispersion device to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a medium-frequency hydrogen preheating and diffusion device, comprising a zirconia ceramic tube, a tungsten main tube, and two sets of mirror-distributed branch tube assemblies, characterized in that each set of branch tube assemblies is composed of a first tungsten branch tube, a second tungsten branch tube, and a third tungsten branch tube connected sequentially; the upper end of the zirconia ceramic tube is fixedly connected to the lower end of the tungsten main tube; the upper end of the tungsten main tube is a sealing port, and internal threaded openings are provided on both sides of the tungsten main tube. One end of the tungsten branch pipe is provided with an external thread that matches the internal thread of the tungsten main pipe, and the other end of the tungsten branch pipe is provided with an internal thread. Both ends of the tungsten branch pipe are provided with external threads, and one end is adapted to connect with the internal thread of the tungsten branch pipe. One end of the tungsten branch pipe is provided with an internal thread that matches the external thread of the tungsten branch pipe. The other end of the tungsten branch pipe is a closed opening. The bottom end of the zirconia ceramic tube is equipped with a connecting pipe, and the bottom end of the connecting pipe is equipped with a transition pipe.

[0005] As a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, an annular groove is provided at the upper end of the inner wall of the transfer pipe, a sealing plate is installed inside the annular groove, a sealing gasket is provided on the outer wall of the sealing plate, a driving groove is provided on the side wall of the transfer pipe, an adjusting plate is inserted into the driving groove, and the adjusting plate is connected to the sealing plate.

[0006] As a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, the outer wall of the transfer pipe is provided with an electric push rod, and the drive end of the electric push rod is connected to an adjustment plate.

[0007] As a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, the sealing gasket has a filling cavity inside, and an arched elastic plate is installed inside the filling cavity.

[0008] As a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, the outer wall of the connecting pipe is provided with an external thread, and the upper end of the inner wall of the adapter pipe is provided with an internal thread, wherein the internal thread and the external thread are engaged.

[0009] In a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, the end of the connecting pipe is fitted with rubber ring a and rubber ring b inside the transfer pipe, and a rubber block is installed between rubber ring a and rubber ring b.

[0010] As a preferred embodiment of the medium-frequency hydrogen preheating and diffusion device of this utility model, each of the three tungsten branch pipes has two symmetrically arranged air holes drilled in the middle of its body. The zirconia ceramic tube is arranged corresponding to the hydrogen inlet at the bottom of the medium-frequency furnace, and the hydrogen is sequentially diverted to the two sets of branch pipe assemblies through the zirconia ceramic tube and the tungsten main tube.

[0011] Compared with the prior art, the beneficial effects of this utility model are: the structure of this medium-frequency hydrogen preheating and diffusion device is reasonably designed;

[0012] This device solves the problems of gas dispersion and poor preheating effect of existing medium-frequency hydrogen inlet devices. During the sintering process of the medium-frequency furnace, the hydrogen flow rate varies greatly in different areas. Using external hydrogen preheating has a high risk factor. This device can not only evenly disperse the hydrogen entering the medium-frequency furnace into various areas, but also make full use of the heat of the medium-frequency furnace itself to preheat the hydrogen, so that the temperature of the upper and lower temperature zones can be reduced to within 10°C. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the transfer tube of this utility model;

[0015] Figure 3This is a schematic diagram of the connecting pipe and the adapter pipe of this utility model;

[0016] Figure 4 This is a schematic diagram of the sealing gasket of this utility model.

[0017] In the diagram: 1. Zirconia ceramic tube; 2. Tungsten main pipe; 3. Tungsten branch pipe one; 4. Tungsten branch pipe two; 5. Tungsten branch pipe three; 6. Vent; 7. Adaptor pipe; 8. Connecting pipe; 10. External thread; 11. Internal thread; 12. Rubber ring a; 13. Rubber block; 14. Rubber ring; 15. Annular groove; 16. Sealing plate; 17. Electric push rod; 18. Adjusting plate; 19. Drive groove; 20. Sealing gasket; 21. Arched elastic plate; 22. Filling cavity. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-4 This utility model provides a technical solution:

[0020] In this technical solution, a medium-frequency hydrogen preheating and diffusion device includes a zirconia ceramic tube 1, a tungsten main tube 2, and two sets of mirror-distributed branch pipe assemblies. Each set of branch pipe assemblies is composed of a first tungsten branch pipe 3, a second tungsten branch pipe 4, and a third tungsten branch pipe 5 connected sequentially. The upper end of the zirconia ceramic tube 1 is fixedly connected to the lower end of the tungsten main tube 2. The upper end of the tungsten main tube 2 is a sealing port, and internal threaded openings are provided on both sides of the tungsten main tube 2. One end of the first tungsten branch pipe 3... The tungsten main pipe 2 is provided with an external thread that matches the internal thread of the tungsten main pipe 2. The other end of the tungsten branch pipe 3 is provided with an internal thread. Both ends of the tungsten branch pipe 4 are provided with external threads, and one end is connected to the internal thread of the tungsten branch pipe 3. One end of the tungsten branch pipe 5 is provided with an internal thread that matches the external thread of the tungsten branch pipe 4. The other end of the tungsten branch pipe 5 is a closed opening. The bottom end of the zirconia ceramic pipe 1 is equipped with a connecting pipe 8, and the bottom end of the connecting pipe 8 is equipped with a transfer pipe 7.

[0021] In this technical solution, the medium-frequency hydrogen preheating and diffusion device takes zirconia ceramic tube 1, tungsten main tube 2 and two sets of mirror branch tubes as the core functional units. On the basis of the original bottom air intake structure, a connecting pipe 8 and a transfer pipe 7 are added to form a bottom air intake channel connection structure of "transfer pipe 7-connecting pipe 8-zirconia ceramic tube 1". Among them, the connecting pipe 8 serves as a transitional connection between the zirconia ceramic tube 1 and the transfer pipe 7. Its top end is fixed to the bottom end of the zirconia ceramic tube 1 by high-temperature welding, and the welding surface is filled with high-temperature resistant nickel-based alloy solder to ensure the connection sealing and structural stability under the high-temperature conditions of the medium-frequency furnace (the furnace temperature is usually 800-1200℃). The transfer pipe 7 serves as the docking unit between the device and the external hydrogen transmission pipeline. Its bottom end is reserved with a flange interface adapted to the external pipeline. The reliable connection with the external hydrogen source is achieved by bolt tightening, so that the hydrogen can enter the zirconia ceramic tube 1 through the transfer pipe 7 and the connecting pipe 8 in sequence, and then enter the subsequent preheating and diffusion channels. This solves the problem of poor compatibility between the bottom gas inlet of the original device and the external pipeline and the inconvenience of disassembly and assembly.

[0022] In some technical solutions, an annular groove 15 is provided on the upper end of the inner wall of the transfer pipe 7, a sealing plate 16 is installed inside the annular groove 15, a sealing gasket 20 is provided on the outer wall of the sealing plate 16, a drive groove 19 is provided on the side wall of the transfer pipe 7, an adjusting plate 18 is inserted into the drive groove 19, and the adjusting plate 18 is connected to the sealing plate 16.

[0023] In this technical solution, to achieve a detachable connection and reliable sealing between the transfer pipe 7 and the connecting pipe 8, an external thread 10 is machined on the outer wall of the connecting pipe 8, and a corresponding internal thread 11 is machined on the upper end of the inner wall of the transfer pipe 7. The pitch and tooth profile of the internal thread 11 are perfectly matched with those of the external thread 10 (preferably M40×2mm fine thread). The thread engagement enables quick assembly and disassembly of the two components, facilitating the replacement of internal parts during equipment maintenance. Simultaneously, the threaded connection structure has a certain preload adjustment capability. By controlling the engagement depth (engagement depth not less than 15mm), the connection strength can be ensured, preventing loosening of the connection due to vibration during the operation of the induction furnace, and providing structural protection for the stability of the air intake channel.

[0024] In some technical solutions, an electric push rod 17 is provided on the outer wall of the transfer pipe 7, and the drive end of the electric push rod 17 is connected to the adjustment plate 18.

[0025] In this technical solution, an annular groove 15 is formed at the upper end of the inner wall of the adapter pipe 7. The groove depth is 8-10mm, and the groove width is adapted to the thickness of the sealing plate 16 (the thickness of the sealing plate 16 is 5mm). The sealing plate 16 is made of 316L stainless steel that is resistant to hydrogen corrosion and can slide radially within the annular groove 15. A sealing gasket 20 (made of fluororubber, with a temperature resistance range of -20-200℃) is attached to the outer wall of the sealing plate 16. The sealing gasket 20 fits tightly against the inner wall of the adapter pipe 7 to form a radial seal. A drive groove 19 is radially opened on the side wall of the adapter pipe 7 (the groove width is 0.5mm larger than the thickness of the adjusting plate 18 to ensure smooth sliding of the adjusting plate 18). One end of the adjusting plate 18 is welded and fixed to the side wall of the sealing plate 16, and the other end extends out of the drive groove 19. By pushing the adjusting plate 18 to slide in the drive groove 19, the sealing plate 16 can be moved along the annular groove 15, thereby adjusting the contact pressure between the sealing gasket 20 and the inner wall of the adapter pipe 7, realizing dynamic adjustment of the sealing degree. It is suitable for sealing requirements under different hydrogen pressure conditions (usually 0.1-0.3MPa). In order to realize the automated control of sealing adjustment, an electric push rod 17 (preferably a small DC electric push rod with a rated thrust of 500N and a stroke of 20mm) is fixedly installed on the outer wall of the adapter pipe 7 by a bracket. The drive end of the electric push rod 17 is hinged to the extended end of the adjusting plate 18 by a pin. By controlling the extension and retraction of the electric push rod 17 through an external control system (such as a PLC), the adjustment plate 18 can be precisely driven to move, thereby controlling the position of the sealing plate 16, avoiding errors caused by manual adjustment. At the same time, the sealing pressure can be automatically adjusted according to the real-time pressure data fed back by the hydrogen pressure sensor, ensuring the reliability of the seal while preventing excessive compression that could damage the sealing gasket 20 and extending the service life of the sealing components.

[0026] In some technical solutions, the sealing gasket 20 has a filling cavity 22 inside, and an arched elastic plate 21 is installed inside the filling cavity 22.

[0027] In this technical solution, a filling cavity 22 (rectangular cross-section, 3mm wide and 2mm high) is formed circumferentially inside the sealing gasket 20. Arched elastic plates 21 (made of spring steel, arch height 1.5mm) are installed at intervals within the filling cavity 22, with a spacing of 10mm between adjacent arched elastic plates 21. When the sealing gasket 20 is compressed, the arched elastic plates 21 undergo elastic deformation. This provides a counter-elastic force to the sealing gasket 20, enhancing the tightness of the fit between the sealing gasket and the inner wall of the transfer pipe 7. Furthermore, it prevents permanent deformation of the sealing gasket 20 due to excessive compression, ensuring stable sealing performance after long-term use. This is particularly suitable for scenarios where slight deformation of the transfer pipe 7 occurs due to temperature fluctuations during the operation of an induction furnace. The deformation compensation of the arched elastic plates 21 maintains the sealing effect.

[0028] In some technical solutions, the outer wall of the connecting pipe 8 is provided with an external thread 10, and the upper end of the inner wall of the adapter pipe 7 is provided with an internal thread 11, which is matched with the external thread 10.

[0029] In this technical solution, to further improve the sealing performance of the connection between the connecting pipe 8 and the adapter pipe 7, rubber rings a12 and b14 (both made of silicone rubber with a Shore hardness of 60±5HA) are sequentially fitted at the end of the connecting pipe 8 (the part located inside the adapter pipe 7). The inner diameters of rubber rings a12 and b14 are interference-fitted with the outer diameter of the connecting pipe 8 (interference amount 0.5-1mm) to ensure a tight fit with the outer wall of the connecting pipe 8. Rubber blocks 13 (circular cross-section, 5mm in diameter, made of the same material as the rubber rings) are evenly distributed between rubber rings a12 and b14, and the rubber blocks 13 are bonded and fixed to rubber rings a12 and b14 respectively. When the connecting pipe 8 and the adapter pipe 7 are screwed together, rubber rings a12 and b14 are compressed and deformed, tightly fitting the inner wall of the adapter pipe 7 to form the first radial seal. During the compression process, rubber block 13 fills the gap between rubber rings a12 and b14, and further enhances the sealing pressure through its own deformation, forming the second seal. This double-seal structure effectively prevents hydrogen leakage at the connection point, meeting the sealing requirements of the hydrogen atmosphere in the medium-frequency furnace (leakage rate ≤ 1×10⁻). 5 Pa・m³ / s).

[0030] In some technical solutions, the end of the connecting pipe 8 is fitted with a rubber ring a12 and a rubber ring b14 inside the adapter pipe 7, and a rubber block 13 is installed between the rubber ring a12 and the rubber ring b14.

[0031] In some technical solutions, two symmetrically arranged air holes 6 are drilled in the middle of the tube bodies of tungsten branch pipe 1 3, tungsten branch pipe 2 4, and tungsten branch pipe 3 5. Zirconia ceramic tube 1 is set to correspond to the hydrogen inlet at the bottom of the medium frequency furnace. Hydrogen is sequentially diverted to the two sets of branch pipe assemblies through zirconia ceramic tube 1 and tungsten main tube 2.

[0032] In this technical solution, two symmetrically arranged vent holes 6 (vent hole diameter not less than 4mm, hole wall roughness Ra≤1.6μm) are drilled radially in the middle of the tungsten branch pipe 3, tungsten branch pipe 4, and tungsten branch pipe 5. The axis of the vent holes 6 is parallel to the bottom surface of the medium-frequency furnace to ensure that the hydrogen discharge direction conforms to the airflow distribution requirements inside the furnace. The top end of the zirconia ceramic tube 1 and the bottom end of the tungsten main tube 2 are connected by an interference fit, with a wire diameter difference of less than 0.1mm. The connection surface is coated with high-temperature sealant (temperature resistance ≥1200℃) to prevent hydrogen leakage at the joint. When hydrogen gas enters the zirconia ceramic tube 1 through the transfer pipe 7 and connecting pipe 8, the zirconia ceramic tube 1 has excellent thermal insulation properties (thermal conductivity ≤2W / (m・K)), which can isolate the high temperature inside the furnace from the influence of the bottom gas inlet channel. Subsequently, the hydrogen gas enters the tungsten main pipe 2. The tungsten main pipe 2 and the branch pipe assembly (tungsten branch pipes 1-3, 2-4, and 3-5) are all made of pure tungsten material (melting point 3410℃, specific heat capacity 130J / (kg・K)), and more than 90% of them are exposed inside the medium-frequency furnace. Under the thermal radiation of the medium-frequency crucible and its own magnetic induction cutting effect, the temperature can be raised to the same level as the temperature inside the furnace (temperature difference ≤ 50℃). The hydrogen gas fully absorbs heat and preheats when flowing through the tungsten pipe. Finally, the hydrogen gas is split into two sets of mirror branch pipe assemblies through the tungsten main pipe 2 and discharged evenly from 12 gas holes 6. The gas outlet coverage extends from the center of the medium-frequency furnace to the edge of the crucible, realizing uniform dispersion and high-temperature preheating of hydrogen gas, and avoiding the entry of cold hydrogen that would cause excessive temperature difference between the top and bottom of the furnace (temperature difference can be controlled within 30℃).

[0033] Working principle: The device is located at the bottom hydrogen inlet of the medium-frequency furnace. Hydrogen enters from the 1# zirconia ceramic sleeve, then enters the 2# tungsten main pipe, and is split into the two mirror-shaped diffused branch pipes composed of 3 / 4 / 5 on both sides. The hydrogen will be slowly discharged through the gas holes parallel to the bottom surface of the furnace in each branch pipe. On the one hand, the hydrogen is diverted by the bend of the pipe, and the gas flow rate decreases. It is discharged from a total of 12 gas holes, covering the entire area from the center of the medium-frequency furnace to the edge of the crucible. Hydrogen can be evenly and slowly introduced into the furnace from the entire bottom area.

[0034] Using zirconia ceramic sleeves can isolate the temperature and protect other components at the furnace bottom. More than 90% of the tungsten branch pipes are exposed inside the induction furnace. They are heated by the thermal radiation from the induction crucible and by the magnetic induction cutting of the pipes themselves, and can be kept at a temperature basically the same as the furnace. Therefore, hydrogen can exchange heat in the tungsten branch pipes. Tungsten has a high specific heat capacity, and the long-distance, small-pore pipe design can ensure sufficient preheating time for hydrogen, so that the hydrogen is preheated to a high temperature before entering the furnace, thereby minimizing or eliminating the temperature difference between the top and bottom of the induction furnace caused by the entry of cold hydrogen.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0036] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A medium-frequency hydrogen preheating and diffusion device, comprising a zirconia ceramic tube (1), a tungsten main tube (2), and two sets of mirror-distributed branch pipe assemblies, characterized in that, Each branch pipe assembly consists of tungsten branch pipe one (3), tungsten branch pipe two (4) and tungsten branch pipe three (5) connected in sequence, with the upper end of the zirconium oxide ceramic pipe (1) fixedly connected to the lower end of the tungsten main pipe (2). The upper end of the tungsten main pipe (2) is a sealed opening. The two sides of the tungsten main pipe (2) are respectively provided with internal threaded openings. One end of the tungsten branch pipe (3) is provided with external threaded openings that are compatible with the internal threaded openings of the tungsten main pipe (2). The other end of the tungsten branch pipe (3) is provided with internal threaded openings. Both ends of the tungsten branch pipe (4) are provided with external threaded openings, and one end is compatible with the internal threaded opening of the tungsten branch pipe (3). One end of the tungsten branch pipe (5) is provided with an internal threaded opening that is compatible with the external threaded opening of the tungsten branch pipe (4). The other end of the tungsten branch pipe (5) is a closed opening. The bottom end of the zirconia ceramic pipe (1) is equipped with a connecting pipe (8). The bottom end of the connecting pipe (8) is equipped with a transfer pipe (7).

2. The medium-frequency hydrogen preheating and dispersion device according to claim 1, characterized in that, The upper end of the inner wall of the adapter pipe (7) is provided with an annular groove (15), a sealing plate (16) is installed inside the annular groove (15), a sealing gasket (20) is provided on the outer wall of the sealing plate (16), a drive groove (19) is provided on the side wall of the adapter pipe (7), an adjustment plate (18) is inserted into the drive groove (19), and the adjustment plate (18) is connected to the sealing plate (16).

3. The medium-frequency hydrogen preheating and dispersion device according to claim 2, characterized in that, The outer wall of the transfer pipe (7) is provided with an electric push rod (17), and the drive end of the electric push rod (17) is connected to an adjustment plate (18).

4. The medium-frequency hydrogen preheating and dispersion device according to claim 2, characterized in that, The sealing gasket (20) has a filling cavity (22) inside, and an arched elastic plate (21) is installed inside the filling cavity (22).

5. The medium-frequency hydrogen preheating and dispersion device according to claim 1, characterized in that, The outer wall of the connecting pipe (8) is provided with an external thread (10), and the upper end of the inner wall of the adapter pipe (7) is provided with an internal thread (11). The internal thread (11) and the external thread (10) are matched.

6. The medium-frequency hydrogen preheating and dispersion device according to claim 5, characterized in that, The end of the connecting pipe (8) is fitted with a rubber ring a (12) and a rubber ring b (14) inside the adapter pipe (7), and a rubber block (13) is installed between the rubber ring a (12) and the rubber ring b (14).

7. The medium-frequency hydrogen preheating and dispersion device according to claim 1, characterized in that, Two symmetrically arranged air holes (6) are drilled in the middle of the tube bodies of the tungsten branch pipe one (3), tungsten branch pipe two (4), and tungsten branch pipe three (5). The zirconia ceramic tube (1) is set in correspondence with the hydrogen inlet at the bottom of the medium frequency furnace. The hydrogen is sequentially diverted to the two sets of branch pipe assemblies through the zirconia ceramic tube (1) and the tungsten main tube (2).

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