Powder feeding device for plasma spheroidizing powder
By designing a conical structure for the powder feeding pipe and combining it with a gas guide groove, along with a water-cooling mechanism, the problem of powder being difficult to accurately enter the plasma center was solved, thereby increasing the yield of spherical powder and the service life of the device.
Patent Information
- Application Number
- CN202520006027.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2035-01-02
AI Technical Summary
Existing DC plasma generation devices have difficulty ensuring that all powder enters the plasma center region precisely during powder delivery, resulting in poor spheroidization and limited production.
A powder feeding device including a powder feeding pipe and a water cooling mechanism was designed. The inner wall of the powder outlet section of the powder feeding pipe has a conical structure and is equipped with an air guide groove and a water cooling mechanism. The combination of the conical structure and the air guide groove improves the powder flow rate and rotation effect, and the water cooling ensures that the powder enters the plasma region.
It improves the efficiency of powder entering the plasma region, increases the yield of spherical powder, extends the service life of the device, and solves the problem of powder being difficult to accurately deliver to the center of the plasma.
Smart Images
Figure CN223645835U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of plasma technology, specifically relating to a powder feeding device for plasma spheroidizing powder. Background Technology
[0002] Spherical powders, with their excellent flowability, extremely low stress state, and outstanding bulk density, have demonstrated broad application potential in numerous high-tech fields. These properties make spherical powders an indispensable component of additive manufacturing, precision integrated circuit manufacturing, high-efficiency thermal management materials, and new energy technologies. In particular, spherical powders prepared through advanced plasma spheroidization methods combine the advantages of uniform powder dispersion, high purity, and near-perfect sphericity, further solidifying their leading position in the field of spherical powder preparation.
[0003] Regarding the core plasma generation device in powder spheroidization technology, there are currently three main types: radio frequency (RF) plasma generation devices, microwave plasma generation devices, and direct current (DC) plasma generation devices. Although RF and microwave plasma generation devices can technically provide a high-quality plasma environment, their high equipment cost and relatively low output limit their application in large-scale production. In contrast, DC plasma generation devices, with their low cost, high efficiency, and wide applicability, have become the ideal choice for the large-scale production of spherical powders.
[0004] The plasma generated by the DC plasma generator not only has high energy concentration and density, but also possesses a significant temperature gradient, which provides ideal conditions for the rapid spheroidization of powders. Specifically, irregularly shaped powder particles undergo rapid heating until they melt as they pass through the plasma region, and then rapidly cool and solidify under the influence of the extremely high temperature gradient, eventually transforming into smooth-surfaced, regularly shaped spherical powders.
[0005] However, in practice, DC plasma generators also face a series of challenges. In particular, while the temperature in the central plasma region is extremely high, this high-temperature zone is relatively narrow, complicating the effective handling of powder. Traditional straight-tube powder feeding devices experience a gradual expansion of the powder area after leaving the device, making it difficult to ensure that all powder to be processed is accurately fed into the central plasma region. While this problem can be addressed by reducing the size of the feeding device and decreasing the powder feed rate, this undoubtedly sacrifices production efficiency. Furthermore, the high temperature gradient and resulting stiffness of the plasma region mean that some powder, even if seemingly close to the plasma region, may not actually enter due to insufficient energy and instead be carried away by the plasma's turbulence. These problems not only severely weaken the spherical effect of the plasma but also greatly limit the potential of DC plasma technology in increasing the yield of spherical powders. Utility Model Content
[0006] This application provides a powder feeding device for plasma spheroidizing powder, which solves the problem in the prior art that straight tube powder feeding devices cannot ensure that all powder to be processed can be accurately fed into the plasma center region when conveying powder.
[0007] To achieve the above objectives, this utility model provides a powder feeding device for plasma spheroidizing powder, including a powder feeding pipe and a water cooling mechanism;
[0008] The powder feeding pipe includes a powder feeding section and a powder discharging section. The inner wall of the powder discharging section has a conical structure. The large end of the powder discharging section is connected to the outlet of the powder feeding section. Multiple air guide grooves are evenly distributed around the inner wall of the powder discharging section. The air guide grooves are spirally arranged along the axis of the powder discharging section.
[0009] The water-cooling mechanism is fitted onto the powder feeding pipe.
[0010] In one possible implementation, the projected length of the air guide groove along the axis of the powder outlet section is 1 / 4 to 1 / 2 of the length of the powder outlet section.
[0011] In one possible implementation, the cone half-angle of the inner wall of the powder outlet section is 5° to 60°.
[0012] In one possible implementation, the rotation angle of the air guide groove is 3° to 15°.
[0013] In one possible implementation, the water cooling mechanism includes an inlet pipe, an outlet pipe, and an end cap;
[0014] The water inlet pipe is coaxially fitted onto the powder delivery pipe, and the rear end of the water inlet pipe is sealed to the outer wall of the powder delivery pipe through a first plugging ring; a cooling water inlet connector is provided at the rear of the water inlet pipe.
[0015] The return water pipe is coaxially fitted onto the inlet water pipe. The rear end of the return water pipe is sealed to the outer wall of the inlet water pipe through a second plug ring. A cooling water outlet connector is provided at the rear of the return water pipe. The front end of the return water pipe is sealed to the outlet end of the powder delivery pipe through an end cap. The front end of the inlet water pipe and the end cap are spaced apart.
[0016] In one possible implementation, the powder feeding section and the powder discharging section are connected by threads, and a powder feeding sealing ring is provided between the mating surfaces of the powder feeding section and the powder discharging section.
[0017] In one possible implementation, the end cap includes a connected annular body and an annular surface, the annular body being a cylindrical structure, and the cross-sections of the annular body and the annular surface being L-shaped; the end of the annular body is threadedly connected to the front end of the return water pipe, and a water-cooled outer sealing ring is provided between the mating surfaces of the annular body and the return water pipe;
[0018] A water-cooled inner sealing ring is provided between the mating surface of the annular surface and the powder feeding section.
[0019] In one possible implementation, a connector is installed on the return water pipe, and the connector is provided with a mounting hole.
[0020] One or more technical solutions provided in the embodiments of this utility model have at least the following technical effects or advantages:
[0021] This utility model provides a powder feeding device for plasma spheroidizing powder. In use, the powder is fed into a powder feeding pipe, and then transported along the feeding section of the pipe in a linear trajectory. Subsequently, the powder enters the discharge section of the powder feeding pipe. During the powder discharge section's transport, the inner wall cross-section of the discharge section continuously decreases, increasing the powder's flow velocity. After the powder exits from the discharge section's outlet, it forms a confluence, and the cross-sectional area of the powder-generated airflow increases, but the cross-sectional area of the airflow is smaller than that of the plasma region. During the movement of the powder feeding pipe, a water-cooling mechanism cools the powder feeding pipe. During the powder conveying process in the powder outlet section, the cross-section of the outlet section continuously decreases. According to Bernoulli's principle, the powder flow velocity increases, and the powder forms a confluence. Therefore, the powder airflow exiting the outlet section is characterized by high energy and high velocity, making the cross-sectional area of the powder airflow exiting the outlet section relatively small compared to existing powder airflows. That is, although the cross-sectional area of the airflow formed by the powder after exiting the outlet section increases, it is much smaller than the cross-sectional area in the prior art, thus fully meeting the receiving range of the plasma region. The powder airflow exiting the outlet section is characterized by high energy and high velocity, making the outlet section more prone to ablation problems compared to existing technologies. This invention solves this problem effectively by using a water-cooling mechanism to cool the powder feeding pipe, thereby improving the service life of the device. This invention ensures that all powder enters the plasma region, preventing it from being carried away by plasma turbulence, thus ensuring the spheroidization effect of the plasma and greatly increasing the yield of spherical powder produced by DC plasma. The outer layer of the powder gas flow rotates under the action of the gas guide groove, which reduces the increase in the cross-sectional area of the gas flow formed by the powder after it exits the powder outlet section. This rotation of the outer layer of the powder gas flow makes it less likely for the cross-sectional area of the powder gas flow exiting the powder outlet section to increase compared to existing powder gas flows. This allows the powder gas flow to overcome the rigidity of the plasma region and smoothly reach it. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a schematic diagram of the powder feeding device for plasma spheroidizing powder provided in Embodiment 1 of this utility model.
[0024] Figure 2Schematic diagram of the powder outlet section provided in the embodiment of this utility model Figure 1 .
[0025] Figure 3 Schematic diagram of the powder outlet section provided in the embodiment of this utility model Figure 2 .
[0026] Figure 4 This is a schematic diagram of the powder feeding device for plasma spheroidizing powder provided in Embodiment 2 of this utility model.
[0027] Figure 5 This is a schematic diagram showing the separation state of the end cap of the powder feeding device for plasma spheroidizing powder provided in Embodiment 2 of this utility model.
[0028] Reference numerals in the attached drawings: 1-Powder feeding pipe; 2-Powder feeding section; 3-Powder outlet section; 4-Air guide groove; 5-Water inlet pipe; 6-Water return pipe; 7-End cap; 8-First plugging ring; 9-Cooling water inlet connector; 10-Second plugging ring; 11-Cooling water outlet connector; 12-Powder feeding sealing ring; 13-Circular ring; 14-Circular ring surface; 15-Water-cooled outer sealing ring; 16-Water-cooled inner sealing ring; 17-Connecting seat; 18-Mating groove; 19-Groove bottom sealing ring; 20-Mating ring; 21-Inner water-cooling cavity; 22-Outer water-cooling cavity. Detailed Implementation
[0029] 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, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.
[0030] In the description of the embodiments of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the embodiments of this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.
[0031] like Figures 1 to 5 As shown, the powder feeding device for plasma spheroidizing powder provided in this embodiment of the present invention includes a powder feeding pipe 1 and a water cooling mechanism.
[0032] The powder feeding pipe 1 includes a powder feeding section 2 and a powder discharging section 3. The inner wall of the powder discharging section 3 is a conical structure. The large end of the powder discharging section 3 is connected to the outlet of the powder feeding section 2. Multiple air guide grooves 4 are evenly distributed around the inner wall of the powder discharging section 3. The air guide grooves 4 are spirally arranged along the axis of the powder discharging section 3.
[0033] A water-cooling mechanism is installed on the powder delivery pipe 1.
[0034] It should be noted that during the use of this device, after the powder is fed into the powder feeding pipe 1, the powder is conveyed along the powder feeding section 2 of the powder feeding pipe 1 in a linear trajectory. Subsequently, the powder enters the powder outlet section 3 of the powder feeding pipe 1. During the conveying process in the powder outlet section 3, the cross-sectional area of the inner wall of the powder outlet section 3 continuously decreases, resulting in an increase in the powder flow velocity. After the powder is output from the outlet of the powder outlet section 3, the powder forms a confluence, and the cross-sectional area of the airflow formed by the powder increases, but the cross-sectional area of the airflow formed by the powder is smaller than that of the plasma region. During the movement of the powder in the powder feeding pipe 1, the powder feeding pipe 1 is cooled by a water cooling mechanism.
[0035] It should be noted that during the powder conveying process in powder outlet section 3, the cross-section of powder outlet section 3 continuously decreases. According to Bernoulli's principle, the powder flow velocity increases, and the powder forms a confluence. Therefore, the powder airflow exiting from the outlet of powder outlet section 3 has the characteristics of high energy and high velocity, making the cross-sectional area of the powder airflow exiting from the outlet of powder outlet section 3 less likely to increase compared to existing powder airflows. That is, although the cross-sectional area of the airflow formed by the powder after exiting from the outlet of powder outlet section 3 will increase, it is much smaller than the cross-sectional area in the prior art, thus fully meeting the receiving range of the plasma region. The powder airflow exiting from the outlet of powder outlet section 3 has the characteristics of high energy and high velocity, so the outlet of powder outlet section 3 is more prone to ablation problems compared to the prior art. However, this utility model solves this problem well by cooling the powder feeding pipe 1 with a water cooling mechanism, thereby improving the service life of the device. This utility model can ensure that all powder enters the plasma region and prevents it from being carried away by plasma turbulence, thereby ensuring the spheroidization effect of the plasma and greatly improving the yield of spherical powder produced by DC plasma.
[0036] The outer layer of the powder gas flow rotates under the action of the gas guide groove 4, which reduces the increase in the cross-sectional area of the gas flow formed by the powder after it exits from the powder outlet section 3. By rotating the outer layer of the powder gas flow under the action of the gas guide groove 4, the cross-sectional area of the powder gas flow exiting from the powder outlet section 3 is less likely to increase compared to existing powder gas flows. This allows the powder gas flow to overcome the rigidity of the plasma region and smoothly reach the plasma region.
[0037] Before use, a sealing test is performed on the device. First, connect the water source through the cooling water inlet connector 9 and the cooling water outlet connector 11 respectively. Then, introduce cooling water at a pressure of 0.4MPa to 0.6MPa and maintain it for 30 minutes. If there is no cooling water leakage, disconnect the cooling water supply and drain the cooling water from the pipeline. Finally, install the device onto the equipment through the connector 17. If cooling water leakage occurs due to burning during pressure testing or use, first remove the device from the equipment through the connector 17, then check whether each sealing ring is faulty. If it is faulty, replace the sealing ring. Check whether the powder delivery pipe 1 and the end cap 7 are severely burned. If they affect normal use, replace them.
[0038] In this embodiment, the projected length of the air guide groove 4 on the axis of the powder outlet section 3 is 1 / 4 to 1 / 2 of the length of the powder outlet section 3.
[0039] It should be noted that during the powder conveying process in the powder outlet section 3, the cross-sectional area of the inner wall of the powder outlet section 3 continuously decreases, the powder flow rate increases, and after the powder has moved 1 / 2 to 3 / 4 of the length of the powder outlet section 3, the powder rotates under the action of the air guide groove 4.
[0040] The air guide groove 4 reduces the energy of the powder airflow, meaning its velocity decreases. Therefore, the length of the air guide groove 4 further reduces velocity loss. If the air guide groove 4 is located at the inlet of the powder outlet section 3, the axial force of the airflow will be converted into rotational force prematurely. Combined with the converging effect of the conical inner wall of the powder outlet section 3, the airflow may converge at some point in the middle of the powder outlet section 3 before reaching its outlet. This results in greater velocity loss and could even cause blockage within the powder outlet section 3. The length of the air guide groove 4 also reduces processing difficulty.
[0041] In this embodiment, the cone half-angle of the inner wall of the powder outlet section 3 is 5° to 60°.
[0042] It should be noted that the flow rate of the powder airflow is adjusted by adjusting the angle between the inner wall of the powder outlet section 3 and the axis of the powder outlet section 3, thereby changing the powder confluence effect.
[0043] The cone half-angle of the inner wall of the powder outlet section 3 is preferably 15°. This size can make the transition of powder airflow more stable. If the cone half-angle of the inner wall of the powder outlet section 3 is too large, the powder airflow speed will increase, causing powder to accumulate at the powder outlet and block the powder delivery pipe 1. If the cone half-angle of the inner wall of the powder outlet section 3 is too small, the converging effect will also be limited.
[0044] In this embodiment, the rotation angle of the air guide groove 4 is 3° to 15°.
[0045] It should be noted that the rotational force and axial force of the powder are adjusted by adjusting the rotation angle of the air guide groove 4, so that the powder airflow can enter the plasma region completely.
[0046] The rotation angle of the air guide groove 4 is the angle between the line connecting the two ends of the air guide groove 4 and the axis of the powder outlet section 3. The rotation angle of the air guide groove 4 is preferably 7°. The air guide groove 4 can convert the axial force of the powder airflow into a circumferential rotational force. This dimension is derived from a comprehensive analysis based on the cone half angle and the required rotational force of the powder airflow. If the rotation angle of the air guide groove 4 is too large, it will be difficult to process. If the rotational force of the powder airflow is too large, it will reduce the axial force, making it difficult for the powder airflow to reach the plasma region. If the rotational force of the powder airflow is too small, it will not be effective.
[0047] In this embodiment, the rotation angle of the air guide groove 4 is 7°, and the included angle between the inner wall of the powder outlet section 3 and the axis of the powder outlet section 3 is 15°.
[0048] In this embodiment, the water cooling mechanism includes an inlet pipe 5, a return pipe 6, and an end cap 7.
[0049] The water inlet pipe 5 is coaxially mounted on the powder delivery pipe 1, and the rear end of the water inlet pipe 5 is sealed to the outer wall of the powder delivery pipe 1 through the first plug ring 8. A cooling water inlet connector 9 is provided at the rear of the water inlet pipe 5.
[0050] The return water pipe 6 is coaxially fitted onto the inlet water pipe 5. The rear end of the return water pipe 6 is sealed to the outer wall of the inlet water pipe 5 through the second plug ring 10. A cooling water outlet connector 11 is provided at the rear of the return water pipe 6. The front end of the return water pipe 6 is sealed to the outlet end of the powder delivery pipe 1 through the end cap 7. The front end of the inlet water pipe 5 and the end cap 7 are spaced apart.
[0051] It should be noted that both the first sealing ring 8 and the second sealing ring 10 are connected by welding. The end cap 7 experiences high temperatures and is therefore prone to damage; an independent design not only reduces processing costs but also facilitates replacement. The water-cooling mechanism forms the heat exchange space shown in the diagram, with one side of the heat exchange space having an n-shaped cross-section. The cooling water inlet connector 9 is tangent to the inner wall of the inlet pipe 5, allowing the cooling water to rotate around the powder delivery pipe 1 after entering the inlet pipe 5, thereby improving heat exchange efficiency. The water-cooling mechanism forms the outer water-cooling cavity 22 and the inner water-cooling cavity 21 shown in the diagram.
[0052] In this embodiment, cooling water at a set pressure is injected into the inner water-cooling cavity 21 of the cylindrical structure. The cooling water is injected along the tangential direction of the inner water-cooling cavity 21, so that the cooling water forms a turbulent flow state until it moves to the intersection of the outer water-cooling cavity 22 and the inner water-cooling cavity 21. During this process, the cooling water cools the powder delivery pipe 1.
[0053] The external water cooling cavity 22 has a cylindrical structure and is fitted onto the internal water cooling cavity 21. Cooling water enters the external water cooling cavity 22 from the junction of the external water cooling cavity 22 and the internal water cooling cavity 21 until the cooling water is discharged from the outlet at the end of the external water cooling cavity 22. During this process, the cooling water cools the cooling water in the internal water cooling cavity 21.
[0054] It should be noted that the cooling water is injected tangentially into the inner water-cooling cavity 21, creating a turbulent flow. The water in the outer water-cooling cavity 22 is also in a turbulent flow state. Compared to the existing technology that directly injects cooling water to create a laminar flow state, the convective heat transfer coefficient of turbulent flow is higher than that of laminar flow, thereby improving the heat transfer efficiency.
[0055] In this first embodiment, the powder feeding section 2 and the powder discharging section 3 are connected by threads, and a powder feeding sealing ring 12 is provided between the mating surfaces of the powder feeding section 2 and the powder discharging section 3.
[0056] It should be noted that the powder feeding sealing ring 12 is used to ensure the sealing between the powder feeding section 2 and the powder discharging section 3. The powder feeding section 2 adopts an independent design, which not only reduces processing costs but also makes it easy to replace.
[0057] In this first embodiment, the end cap 7 includes a connected annular body 13 and an annular surface 14. The annular body 13 has a cylindrical structure, and the cross-sections of the annular body 13 and the annular surface 14 are L-shaped. The end of the annular body 13 is threadedly connected to the front end of the return water pipe 6, and a water-cooled outer sealing ring 15 is provided between the mating surfaces of the annular body 13 and the return water pipe 6.
[0058] A water-cooled inner sealing ring 16 is provided between the mating surfaces of the annular surface 14 and the powder feeding section 2.
[0059] It should be noted that steps are provided at the joints of the annular surface 14 and the powder feeding section 2, the joints of the powder feeding section 2 and the powder outlet section 3, and the joints of the annular body 13 and the return water pipe 6. The steps improve the sealing effect and also allow for a smooth transition at the joints. The annular surface 14 and the powder feeding section 2 are connected by a threaded connection between the annular body 13 and the return water pipe 6, forming an abutting connection. The water-cooled inner sealing ring 16 is compressed, achieving a sealing effect.
[0060] The powder feeding section 2 can be made of stainless steel, aluminum alloy, copper alloy, or titanium alloy; in this embodiment, stainless steel is preferred. The powder discharging section 3 can be made of stainless steel, aluminum alloy, copper alloy, tungsten alloy, or titanium alloy; in this embodiment, copper alloy is preferred. Copper alloy has high thermal conductivity and good heat transfer effect, therefore the powder feeding pipe 1 can be easily cooled by a water cooling mechanism.
[0061] In this embodiment, a connector 17 is installed on the return water pipe 6, and the connector 17 is provided with an installation hole.
[0062] It should be noted that the device is installed on the plasma spheroidizing equipment or plasma spheroidizing chamber via the connector 17.
[0063] In this second embodiment, an annular docking groove 18 is provided circumferentially on the end face of the powder feeding section 2. The cross-section of the docking groove 18 is a conical structure, and a groove bottom sealing ring 19 is provided at the bottom of the docking groove 18.
[0064] The end cap 7 includes an annular body 13, an annular surface 14, and a mating ring 20. The annular body 13 is a cylindrical structure. The rear end of the annular body 13 is threadedly connected to the front end of the return water pipe 6. A water-cooled outer sealing ring 15 is provided between the mating surfaces of the annular body 13 and the return water pipe 6.
[0065] The outer ring of the annular surface 14 is connected to the front end of the annular body 13. The inner ring of the annular surface 14 is provided with a mating ring 20. The side wall of the mating ring 20 has a tapered cross-section. The mating ring 20 is inserted into the mating groove 18, and the end of the mating ring 20 abuts against the sealing ring 19 at the bottom of the groove.
[0066] In this second embodiment, the outer wall of the docking ring 20 is provided with a water-cooled inner sealing ring 16, and the inner wall of the docking groove 18 abuts against the water-cooled inner sealing ring 16.
[0067] It should be noted that in this embodiment, the powder feeding section 2 and the powder discharging section 3 are an integral structure, thus eliminating concerns about sealing between them. The outlet of the powder discharging section 3 is sealed to the end cap 7 using a conical mating ring 20. The conical sealing surface forms a tighter contact surface as the mating ring 20 gradually moves into the mating groove 18. Simultaneously, the sealing effect is greatly improved by the bottom sealing ring 19 and the water-cooled outer sealing ring 15, thereby preventing cooling water leakage and powder contamination. Even if the bottom sealing ring 19 and the water-cooled outer sealing ring 15 fail due to ablation during use, the sealing structure of this embodiment will not experience significant cooling water leakage.
[0068] In this embodiment, various sealing rings can be made of fluororubber or silicone rubber.
[0069] In this embodiment, when the end cap 7 of the water-cooling mechanism is installed, the conical docking ring 20 on the end cap 7 rotates and moves laterally into the conical docking groove 18 on the end face of the powder delivery pipe 1, forming a conical sealing surface between the docking groove 18 and the docking ring 20. The water-cooled outer sealing ring 15 between the side walls of the docking groove 18 and the docking ring 20, as well as the groove bottom sealing ring 19 of the docking groove 18, can achieve a double sealing structure, thereby reducing the probability of water leakage from the water-cooling cavity through the sealing surface between the end cap 7 and the powder delivery pipe 1.
[0070] In this embodiment, it will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all changes falling within the meaning and scope of the equivalents of the claims be included within the present invention.
Claims
1. A powder feeding device for plasma spheroidizing powder, characterized in that: Includes powder feeding pipe (1) and water cooling mechanism; The powder feeding pipe (1) includes a powder feeding section (2) and a powder discharging section (3). The inner wall of the powder discharging section (3) is a conical structure. The large end of the powder discharging section (3) is connected to the outlet of the powder feeding section (2). Multiple air guide grooves (4) are evenly distributed around the inner wall of the powder discharging section (3). The air guide grooves (4) are spirally arranged along the axis of the powder discharging section (3). The powder feeding pipe (1) is fitted with the water cooling mechanism.
2. The powder feeding device for plasma spheroidizing powder according to claim 1, characterized in that: The projection length of the air guide groove (4) on the axis of the powder outlet section (3) is 1 / 4 to 1 / 2 of the length of the powder outlet section (3).
3. The powder feeding device for plasma spheroidizing powder according to claim 1, characterized in that: The cone half-angle of the inner wall of the powder outlet section (3) is 5° to 60°.
4. The powder feeding device for plasma spheroidizing powder according to claim 1, characterized in that: The rotation angle of the air guide groove (4) is 3° to 15°.
5. The powder feeding device for plasma spheroidizing powder according to claim 1, characterized in that: The water cooling mechanism includes an inlet pipe (5), a return pipe (6), and an end cap (7); The water inlet pipe (5) is coaxially mounted on the powder delivery pipe (1), and the rear end of the water inlet pipe (5) is sealed to the outer wall of the powder delivery pipe (1) through the first plug ring (8); a cooling water inlet connector (9) is provided at the rear of the water inlet pipe (5); The return water pipe (6) is coaxially fitted onto the inlet water pipe (5). The rear end of the return water pipe (6) is sealed to the outer wall of the inlet water pipe (5) through a second plug ring (10). A cooling water outlet connector (11) is provided at the rear of the return water pipe (6). The front end of the return water pipe (6) is sealed to the outlet end of the powder delivery pipe (1) through an end cap (7). The front end of the inlet water pipe (5) and the end cap (7) are spaced apart.
6. The powder feeding device for plasma spheroidizing powder according to claim 5, characterized in that: The powder feeding section (2) and the powder discharging section (3) are connected by threads, and a powder feeding sealing ring (12) is provided between the mating surfaces of the powder feeding section (2) and the powder discharging section (3).
7. The powder feeding device for plasma spheroidizing powder according to claim 6, characterized in that: The end cap (7) includes a connected annular body (13) and an annular surface (14). The annular body (13) is a cylindrical structure, and the cross-sections of the annular body (13) and the annular surface (14) are L-shaped. The end of the annular body (13) is threadedly connected to the front end of the return water pipe (6), and a water-cooled outer sealing ring (15) is provided between the mating surfaces of the annular body (13) and the return water pipe (6). A water-cooled inner sealing ring (16) is provided between the mating surfaces of the annular surface (14) and the powder feeding section (2).
8. The powder feeding device for plasma spheroidizing powder according to claim 5, characterized in that: A connector (17) is installed on the return water pipe (6), and the connector (17) is provided with an installation hole.