Plasma processing device

Abstract

The utility model discloses a plasma processing device which comprises a cavity and a coaxial electrode assembly, a reaction chamber is arranged in the cavity, and the cavity is connected with a gas input assembly and a vacuumizing unit. The coaxial electrode assembly comprises a tubular high-voltage electrode and a grounding electrode, the high-voltage electrode is connected with a high-frequency power supply, and the grounding electrode coaxially sleeves the high-voltage electrode to form a discharge gap; the high-voltage electrode is a hollow pipe body, micropores are formed in the side wall, and the gas input assembly conveys process gas to the discharge gap through the hollow pipe body and the micropores. According to the structure, the high-voltage electrode adopts the hollow pipe body structure design, the side wall of the hollow pipe body is provided with the micropores, and process gas is directly conveyed to the discharge gap through the hollow pipe body and the micropores, so that uniform gas distribution is ensured, and the plasma generation efficiency is improved; and meanwhile, powder uniform fluidization and efficient plasma treatment are achieved. And through the rotatable design of the cavity, the powder agglomeration is further broken, and the surface treatment uniformity of the plasma on the powder is improved.

Description

A plasma processing device Technical Field

[0001] This utility model relates to the field of plasma equipment technology, and in particular to a plasma processing device. Background Technology

[0002] Existing plasma surface treatment devices for powder materials typically employ static processing methods. Powders are prone to agglomeration within the reaction chamber, particularly at the bottom due to gravity, leading to uneven plasma treatment and affecting modification efficiency. Furthermore, traditional devices usually inject process gases along the chamber sidewalls. These gases rely on natural convection within the chamber for diffusion and must reach the discharge gap to ionize, resulting in a significant portion of the gas failing to participate in the discharge and low plasma generation efficiency. Moreover, in traditional devices, powder diffusion is slow in a vacuum environment, easily creating airflow dead zones. This insufficient airflow penetration means only the powder surface is disturbed, with much of the powder lacking effective dynamic fluidization and forming agglomerates. Consequently, the contact area between the powder and plasma is insufficient, resulting in low reaction efficiency.

[0003] Therefore, there is an urgent need to develop a plasma processing device that can achieve dynamic fluidization of powder, uniform excitation of plasma, and efficient delivery of process gas, thereby improving the uniformity and reaction efficiency of powder surface treatment. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this utility model provides a plasma processing device.

[0005] The technical solution of this utility model is as follows: it includes a cavity and a coaxial electrode assembly, wherein a reaction chamber is provided inside the cavity; a gas input assembly and a vacuum unit are provided on the cavity.

[0006] The coaxial electrode assembly includes a tubular high-voltage electrode and a tubular grounding electrode. The high-voltage electrode is connected to a high-frequency power supply, and the grounding electrode is coaxially sleeved outside the high-voltage electrode to form a discharge gap.

[0007] The high-voltage electrode is a hollow tube with several micropores distributed on its sidewall. The gas input component delivers process gas to the discharge gap through the hollow tube and micropores of the high-voltage electrode.

[0008] A further technical solution is that a number of plasma diffusion holes are arranged on the side wall of the grounding electrode, and the generated plasma diffuses radially along the reaction chamber through the plasma diffusion holes.

[0009] A further technical solution is that the inner peripheral wall of the reaction chamber is provided with a radially extending array of protrusions, which are used to generate a three-dimensional perturbation field when the chamber rotates.

[0010] A further technical solution is that the gas input component includes an air inlet hole disposed on the cavity, and the air inlet hole is connected to the hollow tube of the high-voltage electrode.

[0011] A further technical solution is as follows: the coaxial electrode assembly is provided in multiple sets, and the high voltage electrode and the grounding electrode are respectively provided with an inner electrode fixing plate and an outer electrode fixing plate at both ends along the axial direction; the inner electrode fixing plate is used to fix multiple high voltage electrodes, and the outer electrode fixing plate is used to fix multiple grounding electrodes.

[0012] A further technical solution is as follows: one end of the high-voltage electrode is axially inserted into the cavity and fixedly connected to the inner electrode fixing plate; the inner electrode fixing plate is sealed to the end of the cavity, and an air intake shielding plate is provided on the side away from the cavity; a gas flow channel is formed between the air intake shielding plate and the inner electrode fixing plate, the gas flow channel is connected to the air intake port on the air intake shielding plate, and is connected to each air intake through hole respectively.

[0013] A further technical solution is that the air inlet is connected to an external air source through an air inlet pipe for conveying process gas to the gas flow channel.

[0014] A further technical solution is as follows: the vacuum pumping unit includes a vacuum pump group, which is connected to the reaction chamber through a vacuum connection pipeline, and a vacuum sensor and a powder interception component are installed on the vacuum pipeline.

[0015] A further technical solution is that it also includes a fixed housing, and the cavity is rotatably housed within the housing.

[0016] A further technical solution is as follows: the cavity rotates under the drive of a drive unit, the drive unit including a servo motor and a rotating shaft, the output shaft of the servo motor being coaxially connected to the rotating shaft via a coupling; the end of the cavity is provided with an axially extending tubular rotating drive port, the axis of the rotating drive port being collinear with the rotation axis of the cavity; the free end of the rotating shaft is sealed to the rotating drive port via a dynamic sealing flange assembly.

[0017] The beneficial technical effects of this invention are as follows: In this structure, the process gas is axially and uniformly distributed through the hollow tube of the high-voltage electrode, and then diffuses radially through the micropores in the sidewall, forming a porous medium permeation flow that fluidizes the powder throughout its thickness. Simultaneously, the process gas is directly ionized within the discharge gap, resulting in high plasma generation efficiency and high surface treatment efficiency of the plasma on the powder. The drive unit drives the cavity to rotate around its axis of rotation, and in conjunction with the array of protrusions on the inner wall of the reaction chamber, generates a three-dimensional disturbance field, further breaking up powder agglomerations, enhancing the powder fluidization effect, ensuring full contact between the powder and the plasma, and improving the uniformity of the plasma surface treatment of the powder. This makes it more suitable for surface modification treatment of various high-end powder materials. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 is a cross-sectional view along direction AA in Figure 1 of this utility model;

[0020] Figure 3 is a schematic diagram of the internal structure of the reaction chamber of this utility model;

[0021] Figure 4 is an exploded structural diagram of the coaxial electrode assembly of this utility model;

[0022] Among them: 100, shell;

[0023] 1. Cavity; 11. Reaction Chamber; 12. Rotary Drive Port; 13. Protrusion Array; 2. Coaxial Electrode Assembly; 21. High Voltage Electrode; 211. Micropore; 22. Grounding Electrode; 221. Plasma Diffusion Hole; 23. Inner Electrode Fixing Plate; 24. Outer Electrode Fixing Plate; 25. Inlet Shielding Plate; 3. Gas Input Assembly; 31. Inlet Through Hole; 32. Inlet Port; 33. Gas Flow Channel; 4. Vacuum Unit; 41. Vacuum Pump Assembly; 42. Vacuum Connection Pipeline; 43. Vacuum Sensor; 44. Powder Interception Assembly; 5. Drive Unit; 51. Servo Motor; 52. Coupling; 53. Rotating Shaft; 54. Dynamic Sealing Flange Assembly; 6. Electric Slip Ring; 7. Gas Slip Ring. Detailed Implementation

[0024] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0025] As shown in Figures 1 and 2, the plasma processing device of this invention includes a cavity 1 and multiple sets of coaxial electrode assemblies 2. The cavity 1 contains a reaction chamber 11 for plasma processing, which is pre-filled with powder to be processed. The cavity 1 is equipped with a gas input assembly 3 and a vacuum pumping unit 4, both communicating with the reaction chamber 11. The gas input assembly 3 injects process gas into the reaction chamber 11; the vacuum pumping unit 4 establishes and maintains the required vacuum level within the reaction chamber 11. The coaxial electrode assemblies 2 are used to excite the process gas to generate plasma.

[0026] Specifically, as shown in Figure 3, each coaxial electrode assembly 2 includes a high-voltage electrode 21 and a grounding electrode 22, both of which are tubular structures. The high-voltage electrode 21 extends axially through the reaction chamber 11, and its axial end is connected to a high-frequency power supply. The grounding electrode 22 is used to achieve grounding. The grounding electrode 22 is coaxially sleeved outside the high-voltage electrode 21, forming a discharge gap between the grounding electrode 22 and the high-voltage electrode 21. Under high voltage, a strong radial electric field is formed between the grounding electrode 22 and the high-voltage electrode 21, and the process gas located in the discharge gap is ionized to generate plasma.

[0027] As shown in Figure 4, a number of plasma diffusion holes 221 are arranged on the circumferential sidewall of the grounding electrode 22, and the generated plasma diffuses uniformly along the radial direction of the reaction chamber 11 through the plasma diffusion holes 221.

[0028] The gas input component 3 includes a plurality of air inlet holes 31 disposed on the cavity 1. In this embodiment, the high-voltage electrode 21 is a hollow tube, and the circumferential sidewall of the high-voltage electrode 21 is provided with uniformly distributed micropores 211; each air inlet hole 31 is connected to the micropore 211 through a corresponding hollow tube. During operation, the process gas is uniformly delivered to the discharge gap through the hollow tube and micropores 211 of the high-voltage electrode 21.

[0029] Since the powder to be processed is pre-filled in the reaction chamber 11, part of it enters the discharge gap through the plasma diffusion hole 221. After the process gas is radially injected from the micropore 211 of the high voltage electrode 21 and ionized, the generated plasma directly contacts the powder. The process gas is in a strong electric field region throughout the process, and the plasma generation efficiency is high. A porous medium permeation flow is formed through the micropore 211, and a stable gas concentration gradient is established in the discharge gap. At the same time, a multi-directional airflow is formed, which penetrates the powder accumulation layer and destroys the interaction force between powder particles, realizing full-thickness fluidization of the powder to better prevent powder agglomeration and improve plasma processing efficiency.

[0030] Furthermore, an inner electrode fixing plate 23 and an outer electrode fixing plate 24 are respectively provided at both ends of the high voltage electrode 21 and the grounding electrode 22 along the axial direction. One end of the multiple high voltage electrodes 21 is axially inserted through the cavity 1 and fixedly connected to the inner electrode fixing plate 23, and one end of the multiple grounding electrodes 22 is axially inserted through the cavity 1 and fixedly connected to the outer electrode fixing plate 24, so as to ensure the spacing and coaxiality between each high voltage electrode 21 and each grounding electrode 22.

[0031] In this embodiment, the inner electrode fixing plate 23 is sealed to the end of the cavity 1. An air intake shielding plate 25 is provided on the side of the inner electrode fixing plate 23 away from the cavity 1. The air intake shielding plate 25 and the inner electrode fixing plate 23 are tightly stacked and sealed together by fasteners. A gas flow channel 33 is formed between the two and communicates with the air intake port 32 on the air intake shielding plate 25. The gas flow channel 33 is connected to each air intake hole 31 respectively, and the air intake port 32 is connected to an external air source through an air intake pipe.

[0032] The vacuum pumping unit 4 includes a vacuum pump group 41, which is connected to the reaction chamber 11 via a vacuum connection pipe 42. A vacuum sensor 43 and a powder interception component 44 are installed on the vacuum connection pipe. The vacuum sensor 43 is used to monitor and provide feedback on the pressure of the reaction chamber 11 in real time. The powder interception component 44 is located at the end of the vacuum connection pipe 42 near the reaction chamber 11 to prevent powder from entering the vacuum connection pipe 42 and affecting the pumping efficiency.

[0033] Since some of the powder to be processed, which is pre-filled in the reaction chamber 11, is deposited at the bottom of the reaction chamber 11 due to gravity, in order to solve the problems of uneven static processing and powder agglomeration in plasma powder processing, this utility model sets up a driving unit 5 to realize the rotation of the chamber 1, thereby further enhancing the dynamic fluidization of the powder.

[0034] Specifically, the drive unit 5 includes a servo motor 51 and a rotating shaft 53 coaxially connected to the output shaft of the servo motor 51 via a coupling 52. The end of the cavity 1 is provided with a rotating drive port 12 extending outward along the axial direction. The rotating drive port 12 has a tubular structure. The powder to be processed can be pre-filled into the reaction chamber 11 through the rotating drive port 12. The axis of the rotating drive port 12 is collinear with the rotation axis of the cavity 1. The free end of the rotating shaft 53 achieves torque transmission and vacuum sealing with the rotating drive port 12 through a dynamic sealing flange assembly 54.

[0035] An electric slip ring 6 and a gas slip ring 7 are sequentially provided on the rotating shaft 53. The electric slip ring 6 is used to continuously supply power to the high-voltage electrode 21, and the gas slip ring 7 is used to realize the uninterrupted delivery of process gas.

[0036] Preferably, the inner peripheral wall of the cavity 1 is provided with a radially extending array of protrusions 13. When the cavity 1 rotates, the array of protrusions 13 generates a three-dimensional disturbance field, which further breaks up powder agglomeration, improves the uniformity of powder processing, and enhances the reaction efficiency with plasma.

[0037] It also includes a fixed housing 100, the cavity 1 is rotatably housed in the housing 100, the servo motor 51 is fixedly installed on one side of the housing 100 along the axial direction, and the rotating shaft 53 is rotatably connected to the housing 100 through a bearing assembly.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A plasma processing device, comprising a cavity (1) and a coaxial electrode assembly (2), wherein a reaction chamber (11) is provided inside the cavity (1); a gas input assembly (3) and a vacuum pumping unit (4) are provided on the cavity (1); characterized in that: The coaxial electrode assembly (2) includes a tubular high-voltage electrode (21) and a tubular grounding electrode (22). The high-voltage electrode (21) is connected to a high-frequency power supply. The grounding electrode (22) is coaxially sleeved outside the high-voltage electrode (21) and forms a discharge gap. The high-voltage electrode (21) is a hollow tube with several micropores (211) distributed on its sidewall. The gas input assembly (3) delivers process gas to the discharge gap through the hollow tube and micropores (211) of the high-voltage electrode (21).

2. The plasma processing apparatus according to claim 1, characterized in that: A number of plasma diffusion holes (221) are arranged on the side wall of the grounding electrode (22), and the generated plasma diffuses radially along the reaction chamber (11) through the plasma diffusion holes (221).

3. The plasma processing apparatus according to claim 1, characterized in that: The inner peripheral wall of the reaction chamber (11) is provided with a radially extending array of protrusions (13) for generating a three-dimensional perturbation field when the chamber (1) rotates.

4. The plasma processing apparatus according to claim 1, characterized in that: The gas input component (3) includes an air inlet (31) disposed on the cavity (1), and the air inlet (31) is connected to the hollow tube of the high voltage electrode (21).

5. A plasma processing apparatus according to claim 4, characterized in that: The coaxial electrode assembly (2) is provided with multiple sets. The high voltage electrode (21) and the grounding electrode (22) are respectively provided with an inner electrode fixing plate (23) and an outer electrode fixing plate (24) at both ends along the axial direction. The inner electrode fixing plate (23) is used to fix multiple high voltage electrodes (21), and the outer electrode fixing plate (24) is used to fix multiple grounding electrodes (22).

6. A plasma processing apparatus according to claim 5, characterized in that: One end of the high-voltage electrode (21) is axially inserted into the cavity (1) and fixedly connected to the inner electrode fixing plate (23); the inner electrode fixing plate (23) is sealed to the end of the cavity (1), and an air intake shield plate (25) is provided on the side away from the cavity (1); a gas flow channel (33) is formed between the air intake shield plate (25) and the inner electrode fixing plate (23), the gas flow channel (33) is connected to the air inlet (32) on the air intake shield plate (25), and is connected to each air intake through hole (31) respectively.

7. A plasma processing apparatus according to claim 6, characterized in that: The air inlet (32) is connected to an external air source through an air inlet pipe and is used to deliver process gas to the gas flow channel (33).

8. The plasma processing apparatus according to claim 1, characterized in that: The vacuum pumping unit (4) includes a vacuum pump group (41), which is connected to the reaction chamber (11) through a vacuum connection pipeline (42). A vacuum sensor (43) and a powder interception component (44) are installed on the vacuum pipeline.

9. A plasma processing apparatus according to claim 1, characterized in that: It also includes a fixed housing (100), in which the cavity (1) is rotatably housed.

10. A plasma processing apparatus according to claim 9, characterized in that: The cavity (1) rotates under the drive of the drive unit (5), which includes a servo motor (51) and a rotating shaft (53). The output shaft of the servo motor (51) is coaxially connected to the rotating shaft (53) through a coupling (52). The end of the cavity (1) is provided with an axially extending tubular rotating drive port (12), and the axis of the rotating drive port (12) is collinear with the rotation axis of the cavity (1). The free end of the rotating shaft (53) is sealed to the rotating drive port (12) through a dynamic sealing flange assembly (54).

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