Smelting device, smelting system and metal powder forming system

Abstract

The invention belongs to the technical field of metal powder processing, and discloses a smelting device, a smelting system and a metal powder forming system. A flow guide pipe is arranged at the bottom of the crucible, a flow guide channel communicated with the interior of the crucible is arranged in the flow guide pipe, a nozzle is arranged at an outlet of the flow guide channel, a flow channel is arranged in the nozzle, and the flow channel comprises a transition section and a drainage section which are sequentially arranged; a heating unit; the switch control unit comprises a stopper rod which penetrates through the crucible and is inserted into the flow guide channel, a switch valve assembly is arranged at the end of the stopper rod, and the switch valve assembly comprises a plug valve matched with the transition section and a needle valve matched with the drainage section. According to the centrifugal atomization device, the flowing stability of copper liquid flow, the consistency of the liquid flow direction and the specification size, the uniformity of the liquid flow, the constancy of the liquid flow temperature and the consistency of the temperature can be well guaranteed, and therefore the quality of metal powder prepared through centrifugal atomization is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal powder processing, and in particular relates to a smelting device, a smelting system and a metal powder forming system for preparing metal powder. Background Art

[0002] With the development of laser printing technology and electron beam 3D printing technology, the 3D printing of copper and its alloys is becoming more and more widely used in industry. Foreign companies such as NASA have entered the experimental stage of 3D printing of copper alloy thrust chamber components. Domestic companies have also carried out research on 3D printing technology of copper alloy tail nozzles. At the same time, the application of copper and its alloys in electric vehicle parts has promoted the rapid development of 3D printing technology of copper and its alloys.

[0003] Copper and copper alloy powders, as important raw materials for 3D printing, are showing a rapid growth trend. However, the traditional aerosol preparation process is difficult to prepare copper and copper alloy powders that meet SLM application indicators, and the product stability is poor, making the preparation of copper and copper alloy powders an important link restricting the industrial application of copper and copper alloy 3D printing technology. Summary of the invention

[0004] The purpose of the present invention is to provide a smelting device, a smelting system and a metal powder forming system to solve the problem that the existing gas atomization metal powder preparation device cannot meet the industrial production and application needs of copper powder, and is particularly suitable for the industrial preparation and forming of metal powder for additive manufacturing.

[0005] The present invention is achieved through the following technical solutions: The smelting device comprises: A crucible, wherein a flow guide tube is arranged at the bottom of the crucible, wherein a flow guide channel communicating with the interior of the crucible is arranged in the flow guide tube, wherein a nozzle is arranged at the outlet of the flow guide channel, wherein a flow channel is arranged in the nozzle, wherein the flow channel comprises a transition section and a flow guide section arranged in sequence, wherein the transition section is a conical structure whose diameter gradually decreases from the inlet to the outlet, and the flow guide section is a through hole having the same diameter as the outlet of the transition section; A heating unit, the heating unit comprising a first induction coil for heating the crucible and a second induction coil for heating the flow guide tube; A switch control unit, the switch control unit includes a stopper rod passing through the crucible and inserted into the guide channel, a switch valve assembly is arranged at the end of the stopper rod, the switch valve assembly includes a stopper valve matched with the transition section and a needle valve matched with the drainage section, and when the switch valve assembly is in a closed state, the needle valve is inserted through the drainage section.

[0006] In some embodiments, the inlet end surface of the transition section is configured as a continuously transitioned arc surface.

[0007] In some embodiments, the ratio of the diameter of the inlet end of the transition section to the diameter of the outlet end thereof is not less than 10, and the diameter of the drainage section is not greater than 3 mm.

[0008] In some embodiments, the nozzle end is located at the flow channel outlet, and a boss is protruding outward. The drainage section passes through the boss along the axis of the boss, and the circumferential dimension of the boss at one end of the drainage section outlet is set to be equivalent to the diameter of the drainage section.

[0009] In some embodiments, the circumferential dimension of the boss gradually decreases in a direction away from the nozzle, and the circumferential dimension of the boss at one end of the outlet of the drainage section is the same as the diameter of the drainage section.

[0010] In some embodiments, the boss is a truncated cone structure.

[0011] In some embodiments, the nozzle and the flow guide tube are split structures, and the nozzle and the flow guide tube are connected by a conical surface fit.

[0012] In some embodiments, the flow guide tube and the crucible are an integrated structure.

[0013] On the other hand, the present invention also provides a smelting system, comprising: Enclosed melting chamber; And the smelting device is arranged in the smelting chamber, and the flow channel outlet of the nozzle is connected to the outside of the smelting chamber.

[0014] In some embodiments, the smelting chamber includes a first smelting chamber and a second smelting chamber; The crucible is arranged in the first smelting chamber, the guide tube is extended into the second smelting chamber, and a sealing member is arranged between the first smelting chamber and the crucible and the guide tube to isolate the first smelting chamber and the second smelting chamber into two independent chambers.

[0015] In another aspect, the present invention further provides a metal powder forming system, comprising: Atomization chamber; A centrifugal rotating disk is arranged in the atomization chamber; And the smelting device, when the smelting device is arranged on the atomizing chamber, the flow channel outlet of the nozzle in the smelting device is arranged in the atomizing chamber and close to the centrifugal rotating disk.

[0016] In another aspect, the present invention further provides a metal powder forming system, comprising: Atomization chamber; A centrifugal rotating disk is arranged in the atomization chamber; And the smelting system, the smelting chamber is connected to the atomizing chamber, and the flow channel outlet of the nozzle in the smelting device is arranged in the atomizing chamber and close to the centrifugal rotating disk.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: The smelting device adopts a flow guide tube arranged at the bottom of the crucible, and an induction coil for heating the flow guide tube is arranged. At the same time, the structure of the nozzle is arranged, and the flow channel of the nozzle is arranged as a transition section and a drainage section with a gradual structure. By setting the taper of the transition section, when the copper liquid in the crucible passes through the flow guide channel, the transition section, and the drainage section in sequence and flows out from the outlet of the drainage section, the stability of the flow of the copper liquid, the consistency of the flow direction and the specifications and dimensions of the liquid flow beam, the uniformity of the liquid flow, the constancy of the liquid flow temperature and the consistency of the temperature can be well guaranteed, thereby ensuring the quality of the metal powder prepared by centrifugal atomization.

[0018] Through the design of the structure and parameters of the transition section, when the molten metal flows from the nozzle into the inert atmosphere in the atomization chamber, the molten metal can be converted into a columnar beam in a very short time and flow stably toward the rotating disk, which effectively solves the problem of unstable flow morphology of high-temperature metal micro-beam and ensures the molding quality of metal powder.

[0019] Combined with the structure adopted by the switch valve assembly, when the switch valve assembly is opened, the plug valve with conical surface sealing can be opened first, and the flow channel of the nozzle is shut off by the needle valve at this time, so that the copper liquid can gradually fill the transition section and slowly fill the space inside the transition section until the needle valve is completely drawn out of the drainage section, and the switch valve assembly is fully opened, so that the liquid flows vertically from the outlet of the drainage section to the centrifugal rotating disk; in this process, the flow of the copper liquid is more stable, which can well avoid the problems that when the traditional switch method is turned on instantly, the molten liquid forms an impact at the outlet of the flow channel, causing the molten liquid flow at the outlet of the flow channel to be turbulent, resulting in uneven liquid flow, unstable flow beam and other problems, ensuring the molding quality of the metal powder, and reducing the erosion that the copper liquid may cause to the flow channel, ensuring the service life of the device. In addition, when the switch valve assembly is turned off, the flow channel can be quickly shut off by the cooperation between the needle valve and the drainage section.

[0020] A boss is provided at the end of the nozzle, and the size of the boss end is set to be equivalent to the diameter of the drainage section, that is, close to or equal to the diameter of the drainage section, so that when the liquid flows out of the drainage section, the liquid flow can always fall vertically on the centrifugal rotating disk in a direction consistent with the drainage section, thereby ensuring the consistency of the landing point position when the liquid flow falls on the centrifugal rotating disk, thereby ensuring the molding quality of the copper powder.

[0021] In the smelting system, a smelting chamber having a first smelting chamber and a second smelting chamber is provided. When the crucible is set in the smelting chamber, the first smelting chamber, the second smelting chamber and the atomizing chamber can be isolated into independent spaces in combination with the structural characteristics of the crucible and the functions to be achieved by the smelting unit. While providing molten copper to the atomizing chamber, the first smelting chamber and the atomizing chamber can form an independent vacuum space, thereby ensuring the vacuum environment required for smelting and the inert gas atmosphere required for centrifugal forming, which plays an important role in realizing the industrial preparation of copper powder and the industrial application of the centrifugal forming system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a schematic diagram of the structure of a smelting device in an embodiment of the present invention.

[0024] Figure 2 for Figure 1 Partial schematic diagram at point A in the middle.

[0025] Figure 3 Schematic diagram of the nozzle structure in an embodiment of the present invention.

[0026] Figure 4 Schematic diagram of CFD simulation analysis of copper solution flowing out of the nozzle in an embodiment of the present invention.

[0027] Figure 5 Schematic diagram of the structure of the smelting system in an embodiment of the present invention.

[0028] Figure 6 Schematic diagram of the structure of a metal powder forming system in an embodiment of the present invention.

[0029] in: 20. Centrifugal rotating disc; 30. Atomization chamber; 40. Smelting device, 401. Crucible, 402. Guide tube, 403. Guide channel, 404. Nozzle, 441. Transition section, 442. Guide section, 443. Boss, 444. Transition section inlet end face, 405. First induction coil, 406. Second induction coil, 407. Stopper rod, 408. Plug valve, 409. Needle valve, 410. Matching cone surface; 41. Smelting chamber, 411. First smelting chamber, 412. Second smelting chamber, 413. Sealing member. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0031] The centrifugal atomization molding method is to melt the copper and let the copper liquid flow onto a high-speed rotating disk. Under the centrifugal effect of the rotating disk, the copper liquid droplets move from the center to the edge of the rotating disk, and are broken into tiny droplets and thrown out. Under the action of surface tension, the tiny droplets cool and solidify into spherical powder in the atomization chamber. Usually, the particle size of metal powder required by different 3D printing processes is also different, including 0-25μm, 15-53μm, and 20-45μm.

[0032] In this forming method, the smelting device needs to melt the copper into liquid state, and then drip the molten copper flow onto the rotating disk in sequence. The temperature of the molten copper flow when it drips onto the rotating disk, the position of the molten copper flow on the rotating disk, the stability of the dripping, etc., have an important influence on the centrifugal separation forming quality of the rotating disk for the molten copper droplets, such as sphericity, particle size, etc., and even the service life of the rotating disk.

[0033] For the above problems, refer to Figure 1 , Figure 2 and Figure 3 In some embodiments, a smelting device for preparing metal powder includes: Crucible 401, a flow guide tube 402 is arranged at the bottom of crucible 401, a flow guide channel 403 connected to the inside of the crucible is arranged in the flow guide tube 402, a nozzle 404 is arranged at the outlet of the flow guide channel, a flow channel is arranged in the nozzle 404, and the flow channel includes a transition section 441 and a flow guide section 442 arranged in sequence, the transition section 441 is a conical structure with a diameter gradually decreasing from the inlet to the outlet, and the flow guide section 442 is a through hole with the same diameter as the transition section outlet. The molten metal in the crucible flows out through the flow guide channel, the transition section and the flow guide section in sequence, which well ensures the stability of the copper liquid flow, the consistency of the flow direction and the specifications and dimensions of the liquid flow beam, and the uniformity of the liquid flow.

[0034] The heating unit includes a first induction coil 405 for heating the crucible and a second induction coil 406 for heating the flow guide tube. Figure 1As shown, the first induction coil 405 is completely wrapped around the outer circumference of the crucible to heat the metal in the crucible, which can well ensure the consistency of the heating temperature in the crucible; similarly, the second induction coil 406 is completely wrapped around the outer circumference of the guide tube to heat the guide channel inside the guide tube to ensure the consistency of the heating temperature at various locations inside the guide channel, thereby well ensuring the constant temperature of the molten metal droplets.

[0035] The switch control unit is used to control the flow and shutoff of the molten metal in the smelting device. The switch control unit includes a stopper rod 407 that passes through the crucible and is inserted into the diversion channel. The diameter of the stopper rod 407 is smaller than the diameter of the diversion channel. A switch valve assembly is provided at the end of the stopper rod 407. The switch valve assembly includes a plug valve 408 that matches the transition section and a needle valve 409 that matches the diversion section. When the switch valve assembly is in the closed state, the needle valve 409 is inserted through the diversion section 442.

[0036] The plug valve adopts a truncated cone structure with the same taper and matching size as the transition section. The nozzle can be shut off through the cooperation between the plug valve and the transition section. The needle valve adopts a cylindrical structure with the same diameter as the drainage section. When the needle valve is inserted into the drainage section, the nozzle can be shut off.

[0037] When the switch valve assembly is opened, as the stopper moves, the stopper valve is separated from the transition section and the stopper valve is opened. Since the needle valve is inserted through the drainage section, the movement distance of the stopper rod is not enough to completely pull the needle valve out of the drainage section, and part of the needle valve remains in the drainage section. The needle valve still shuts off the flow channel of the nozzle at this time. In this process, as the stopper valve moves, the copper liquid can be gradually filled into the transition section and fill the space inside the transition section until the needle valve is completely pulled out of the drainage section. The flow channel of the nozzle is opened, so that the molten metal can drip from the flow channel outlet onto the centrifugal rotating disk. The opening method based on this structure solves the problem that when the traditional method is opened instantly, the molten metal will form an impact at the flow channel outlet, causing the molten metal flow at the flow channel outlet to be turbulent, resulting in unstable liquid flow, thereby ensuring the molding quality of the metal powder. In the case of solving the impact of the molten metal at the flow channel outlet, the erosion of the flow channel caused by the copper liquid can be reduced, effectively ensuring the service life of the device.

[0038] When the switch valve assembly is turned off, based on the structural characteristics of the switch valve, the needle valve can shut off the flow channel at the moment of inserting the drainage section, which can quickly shut off the flow of the molten metal. Similarly, due to the small aperture of the drainage section, the disturbance to the flow of the molten metal during the shut-off process and at the moment of shut-off is small, which can also well ensure the molding quality of the metal powder in the process.

[0039] In some embodiments, reference Figure 3The inlet end face 444 of the transition section is set as a continuously transitioned arc surface to improve the stability of the high-temperature beam when the molten liquid flows out of the nozzle.

[0040] In some embodiments, the ratio of the diameter of the inlet end of the transition section to the diameter of the outlet end thereof is not less than 10, and the diameter of the drainage section is not greater than 3 mm, for example, it is set to a size of 1 mm, 2 mm, etc.; ensuring that the specifications of the liquid flow beam can meet the requirements of centrifugal forming, so that the fine liquid flow formed by the molten liquid in the crucible flowing out of the nozzle can always maintain a stable beam shape.

[0041] In some embodiments, Figure 3 The end of the nozzle 404 is located at the location of the flow channel outlet, and a boss 443 is protruding outward. The drainage section is arranged along the axis of the boss and penetrates the boss, and the circumferential dimension of the boss at the outlet of the drainage section is set to be equivalent to the diameter of the drainage section. Here, the circumferential dimension is equivalent to the diameter of the drainage section, which means that the circumferential dimension (such as the diameter of the outer contour) is close to the diameter of the drainage section, for example, the circumferential dimension is slightly larger than the diameter of the drainage section, such as 0.1mm-1mm larger than the diameter of the drainage section.

[0042] At this time, the outlet end of the flow channel of the nozzle 404 is set to be equivalent to the diameter of the drainage section. When the fluid flows out from the outlet of the flow channel, due to the small end surface area of ​​the flow channel outlet end, the molten metal flow can always be maintained in the direction consistent with the drainage section and drip vertically onto the centrifugal rotating disk, thereby ensuring the consistency of the dripping position when the liquid flow falls on the centrifugal rotating disk and ensuring the molding quality of the copper powder.

[0043] In some embodiments, the circumferential dimension of the boss 443 gradually decreases in the direction away from the nozzle, and the circumferential dimension of the boss at the outlet end of the drainage section is the same as the diameter of the drainage section. This can reduce the influence of the nozzle outlet end on the flow stability of the melt and facilitate the processing and forming of the boss on the nozzle.

[0044] In some embodiments, the boss 443 may have a truncated cone structure.

[0045] A CFD simulation test was performed on the liquid flow performance of the nozzle in the above embodiment to simulate the liquid flow performance when the copper melt flows out of the nozzle of the smelting device in the above embodiment and flows into an argon inert atmosphere.

[0046] The simulation results are shown in the figure below. Figure 4 As shown in the figure, it can be seen that when the nozzle with the above structural design is turned on, the liquid flow forms droplets at the nozzle outlet, and after flowing for 0.14s, the copper solution flows out stably in the form of a columnar beam. (The red in the figure represents the molten liquid, and the red in the blue rectangular box represents the liquid flow formed by the molten liquid flowing out of the nozzle.) In some embodiments, the nozzle 404 and the guide tube 402 adopt a split structure, and the nozzle 404 is arranged at the outlet end of the guide channel 403 and is connected to the guide tube 402 through a matching cone surface 410. This makes it convenient to replace the nozzle and to process and form a complex flow channel structure that meets the requirements on the nozzle. The taper of the matching cone surface between the nozzle and the guide tube is set to 1:5-15. While achieving the connection between the nozzle and the guide tube, a good seal can be formed between the nozzle and the guide tube to ensure the sealing performance of the two at the connection position. At the same time, this connection method does not require a complex connection structure to be set on the nozzle and the guide tube, thereby facilitating the processing of the guide tube and the nozzle.

[0047] The nozzle can be made of SiC material.

[0048] In some embodiments, the flow guide tube 402 and the crucible 401 are of an integrated structure. The crucible and the flow guide tube may be made of Al2O3. The integrated structural design can avoid the problem of molten metal leakage in the smelting device, and can well ensure the uniformity of heating of the molten metal.

[0049] In some embodiments, the stopper rod 407 is made of ceramic material and can be a segmented combined structure. The needle valve 409 and the plug valve 408 are split structures. Figure 2 The plug valve 408 is connected between one end and the plug rod 407, and the needle valve 409 is set to pass through the through hole on the plug valve 408, so that one end is set between the plug valve and the end of the plug rod, and the needle valve is fixedly connected to the plug rod through the cooperation between the needle valve and the plug valve. The needle valve and the plug valve adopt a split structure, which can facilitate the processing and molding of the needle valve and the plug valve, and can well ensure the processing accuracy of the needle valve and the plug valve, so as to well meet the needs of the industrial production of metal powder.

[0050] Of course, in some embodiments, a sensor for detecting the temperature of the molten metal inside the crucible and the guide channel can be arranged. By obtaining the temperature of the molten metal, the heating of the first induction coil and the second induction coil can be controlled to ensure the consistency of the temperature of the molten metal and the stability of the temperature of the molten metal flowing out of the flow channel; for example, the temperature of the flowing copper liquid can be controlled at 1250°C.

[0051] On the other hand, the present invention also relates to a smelting system. In some embodiments, referring to Figure 4 , the smelting system includes: A closed smelting chamber 41; As well as the smelting device 40 in the above embodiment, the smelting device 40 is arranged in a smelting chamber 41, and the flow channel outlet of the nozzle is connected to the outside of the smelting chamber.

[0052] The smelting device is arranged in a closed smelting chamber, which can provide the required vacuum environment for smelting, avoid oxidation of the molten metal during the smelting process, and thus ensure the purity of the prepared copper powder.

[0053] In some embodiments, the smelting chamber 41 includes a first smelting chamber 411 and a second smelting chamber 412; the crucible 401 is disposed in the first smelting chamber 411, the flow guide tube 403 extends into the second smelting chamber 412, and a seal 413 is disposed between the first smelting chamber and the crucible and / or between the first smelting chamber and the flow guide tube, and the first smelting chamber and the second smelting chamber are isolated into two independent chambers by the setting of the seal. In this case, the crucible can be stably disposed in the smelting chamber, and a good closed space can be formed in the first smelting chamber.

[0054] Correspondingly, at this time, the first induction coil 405 is arranged in the first smelting chamber, and the second induction coil 406 is arranged in the second smelting chamber.

[0055] One end of the stopper rod 407 extends out of the smelting chamber to facilitate the operation of the switch control unit to control the opening and closing of the smelting device; the stopper rod adopts a split structure, so that the stopper rod can be extended out of the smelting chamber, and the liquid flow state can be controlled without repeatedly opening the smelting chamber during the molding process, thereby improving the molding efficiency and emergency handling capabilities. A sealing structure is provided between the stopper rod and the smelting chamber to seal the connection position between the stopper rod and the smelting chamber.

[0056] A water cooling jacket may be provided on the smelting chamber 41 to cool the interior of the smelting chamber during the production process.

[0057] On the other hand, the present invention also relates to a metal powder forming system for centrifugal atomization forming of metal powder such as copper powder; in some embodiments, referring to Figure 5 , metal powder forming system includes: Atomizing chamber 30; a closed chamber is formed in the atomizing chamber. During the production process, the atomizing chamber is first vacuumed and then replaced with an inert gas, so that there is a slight positive pressure in the atomizing chamber, which can prevent the prepared metal powder (such as copper powder) from being oxidized and ensure that the metal droplets can be fully cooled during the molding process.

[0058] A centrifugal rotating disk 20 is arranged in the atomizing chamber. The centrifugal rotating disk is arranged in the atomizing chamber and can rotate along its axis at a high speed. The speed of the centrifugal rotating disk can reach 100000 rpm. As well as the smelting device 40 in the above embodiment, when the smelting device 40 is arranged on the atomizing chamber, the flow channel outlet of the nozzle in the smelting device is arranged in the atomizing chamber and close to the centrifugal rotating disk.

[0059] In the smelting device, the molten metal in the crucible is heated to the set temperature, and after the temperature stabilizes, the operating switch control unit is turned on, and the copper liquid flows out through the flow channel of the nozzle and drips onto the centrifugal rotating disk. Under the centrifugal force of the high-speed rotating centrifugal rotating disk, the copper liquid droplets are decomposed into tiny droplets and thrown into the atomization chamber. During the flight, the tiny droplets cool and solidify to obtain spherical metal powder with a small particle size (15-53μm).

[0060] On the other hand, the present invention also relates to a metal powder forming system. In some embodiments, referring to Figure 5 , metal powder forming system includes: Atomization chamber 30; A centrifugal rotating disk 20 is arranged in the atomization chamber, and the centrifugal rotating disk is arranged in the atomization chamber and can rotate at high speed along its axis; And the smelting system in the above embodiment, the smelting chamber of the smelting system is connected to the atomization chamber, and the flow channel outlet of the nozzle in the smelting device is arranged in the atomization chamber and close to the centrifugal rotating disk.

[0061] Based on the smelting device, smelting system and metal powder forming system in the above embodiments of the present invention, the copper powder prepared is of high quality and good sphericity, with an oxygen content of less than 200 ppm and a bulk density of more than 4.9 g / cm 3 , fluidity is less than 60s / 50g, and the satellite hollow powder rate is less than 5‰; the system has a high degree of industrialization in preparing copper powder, with a production capacity of 100 tons / year, and a recovery rate of 15-53μm powder products of more than 90%. The copper powder prepared by the preparation can well meet the performance requirements of additive manufacturing.

[0062] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship commonly placed when the product of the invention is used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0063] In addition, if the terms "horizontal" or "vertical" appear in the description of the present invention, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0064] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A smelting device, characterized in that: include: A crucible, wherein a flow guide tube is arranged at the bottom of the crucible, wherein a flow guide channel communicating with the interior of the crucible is arranged in the flow guide tube, wherein a nozzle is arranged at the outlet of the flow guide channel, wherein a flow channel is arranged in the nozzle, wherein the flow channel comprises a transition section and a flow guide section arranged in sequence, wherein the transition section is a conical structure whose diameter gradually decreases from the inlet to the outlet, and the flow guide section is a through hole having the same diameter as the outlet of the transition section; A heating unit, the heating unit comprising a first induction coil for heating the crucible and a second induction coil for heating the flow guide tube; A switch control unit, the switch control unit includes a stopper rod passing through the crucible and inserted into the guide channel, a switch valve assembly is arranged at the end of the stopper rod, the switch valve assembly includes a stopper valve matched with the transition section and a needle valve matched with the drainage section, and when the switch valve assembly is in a closed state, the needle valve is inserted through the drainage section.

2. The smelting device according to claim 1, characterized in that: The inlet end surface of the transition section is arranged as a continuously transitioned arc surface.

3. The smelting device according to claim 1, characterized in that: The ratio of the diameter of the inlet end of the transition section to the diameter of the outlet end thereof is not less than 10, and the diameter of the drainage section is not greater than 3 mm.

4. The smelting device according to any one of claims 1, 2 or 3, characterized in that: The nozzle end is located at the flow channel outlet, and a boss is protruding outward. The drainage section passes through the boss along the axis of the boss, and the circumferential dimension of the boss at one end of the drainage section outlet is set to be equivalent to the diameter of the drainage section.

5. The smelting device according to claim 1, characterized in that: The nozzle and the flow guide tube are of separate structures, and the nozzle and the flow guide tube are connected through a conical surface fit.

6. The smelting device according to claim 1, characterized in that: The flow guide tube and the crucible are an integrated structure.

7. A smelting system, characterized in that: include: Enclosed melting chamber; And the smelting device according to any one of claims 1 to 6, wherein the smelting device is arranged in a smelting chamber, and the flow channel outlet of the nozzle is connected to the outside of the smelting chamber.

8. The smelting system according to claim 7, characterized in that: The smelting chamber includes a first smelting chamber and a second smelting chamber; The crucible is arranged in the first smelting chamber, the guide tube is extended into the second smelting chamber, and a sealing member is arranged between the first smelting chamber and the crucible and the guide tube to isolate the first smelting chamber and the second smelting chamber into two independent chambers.

9. A metal powder forming system, characterized in that: include: Atomization chamber; A centrifugal rotating disk is arranged in the atomization chamber; And the smelting device according to any one of claims 1 to 6, when the smelting device is set on the atomization chamber, the flow channel outlet of the nozzle in the smelting device is set in the atomization chamber and close to the centrifugal rotating disk.

10. A metal powder forming system, characterized in that: include: Atomization chamber; A centrifugal rotating disk is arranged in the atomization chamber; And the smelting system according to claim 7 or 8, wherein the smelting chamber is connected to the atomization chamber, and the flow channel outlet of the nozzle in the smelting device is arranged in the atomization chamber and close to the centrifugal rotating disk.

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