Aerodynamic rotating arc plasma generator

Abstract

The application relates to a kind of gas dynamic rotating arc plasma generators, comprising: cathode, insulating layer, connecting section, rotating anode and base from top to bottom are coaxially arranged in sequence, the cathode, insulating layer and base are fixedly connected by stud, the connecting section and rotating anode are pressed between the insulating layer and base, the cathode and rotating anode are cooled by cooling medium;The rotating anode includes inner layer and outer layer, and the inner layer can rotate around the axis. The rotating anode inner layer can rotate the anode arc root relative to the anode surface, avoid the anode arc root to adhere to a certain fixed position for a long time, so as to increase the time average attachment area of anode arc root;At the same time, the rotation of rotating anode enhances the convection heat transfer of cooling medium, and strengthens the cooling effect of cooling medium on rotating anode, so as to reduce anode ablation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of arc plasma generator, in particular to a kind of aerodynamic rotary arc plasma generator capable of reducing anode ablation. BACKGROUND

[0002] Arc plasma generator is a device that generates high-temperature plasma by discharge between cathode and anode, and is widely used in many industrial fields such as metal surface treatment, material preparation, waste treatment, etc. Currently, there are two major problems in the application of arc plasma generator: first, the plasma parameters generated by the arc jumping along the axial direction are unstable, which affects the production process; second, the anode ablation caused by the arc root of arc plasma adhering to the surface of anode not only affects the production process, but also determines the service life of the generator. Therefore, it is necessary to study the principle of anode ablation inside the arc plasma generator, so as to propose a new scheme to reduce anode ablation, which is of great significance to improve the production process and service life of arc plasma generator.

[0003] In the plasma generator, local long-time high-temperature overheating is the main factor causing anode ablation, and the main reason for generating local long-time high temperature is the large amount of Joule heat generated when the arc current passes through the anode arc root into the anode. The anode arc root adheres to a fixed position on the surface of the anode for a long time, causing the accumulation of Joule heat at this position. Joule heat is proportional to the square of current, so under the condition of certain power of arc plasma generator, the working current can be reduced by lengthening the arc and increasing the voltage, thereby reducing the ablation. The widely used method to increase the voltage is to increase the intermediate section between the cathode and the anode, to blow and pull the arc by multi-stage gas, and to use segmented anode. Another method to reduce anode ablation is to make the arc rotate in the circumferential direction of the anode surface, thereby increasing the time-averaged heating area of the anode and avoiding the long-term effect of the arc on a fixed area on the surface of the anode. The main method to make the arc rotate in the circumferential direction of the anode surface is to increase the power solenoid outside the arc plasma generator, and the tangential Lorentz force generated by the arc under the action of the axial magnetic field of the power solenoid drives the arc to rotate at high speed along the circumferential direction of the anode, i.e. magnetic rotation. This method not only needs to use a relatively heavy solenoid, but also needs to apply a direct current to the solenoid to generate an axial magnetic field, i.e. a direct current power supply system for the solenoid needs to be added. If the required magnetic field strength is large, a larger current needs to be applied to the solenoid, and a water cooling device needs to be added to the solenoid. It can be seen that the method of making the anode arc root rotate at high speed on the surface of the anode to increase the time-averaged heating area and reduce the anode ablation increases the complexity and reliability of the generator system to some extent. SUMMARY

[0004] The present application aims to provide a kind of gas dynamic rotating arc plasma generator that can effectively reduce anode ablation without increasing additional devices.

[0005] The technical scheme of the present application is: a kind of gas dynamic rotating arc plasma generator, comprising: cathode, insulating layer, connecting section, rotating anode and base are sequentially coaxially arranged from top to bottom, the cathode, insulating layer and base are fixedly connected by stud, the connecting section and rotating anode are compressed between the insulating layer and base, the cathode and rotating anode are cooled by cooling medium;The rotating anode includes inner layer and outer layer, and the inner layer can rotate around the axis.

[0006] Further, the cathode includes: upper base plate, cathode middle part and lower pointed part;4 through holes are arranged on the upper base plate, and the 4 through holes are connected with cathode cooling water inlet, cathode cooling water outlet and two working medium gas inlets respectively;Cathode cooling water cavity is arranged in the cathode middle part, and the cathode cooling water inlet and the cathode cooling water outlet are communicated with the cathode cooling water cavity;The upper base plate and one end of the cathode middle part are fixedly connected, and the lower pointed part is clamped at the other end of the cathode middle part (12).

[0007] Further, the connecting section is provided with a ring-shaped water tank for cooling near the bottom position, a plurality of through holes are opened around the ring-shaped water tank and communicated with the ring-shaped water tank, and each through hole is connected with a cooling water outlet.

[0008] Further, the rotating anode includes: upper rotating part, lower rotating part, rotating anode inner layer and rotating anode outer layer, and the rotating anode inner layer and the rotating anode outer layer are arranged between the upper rotating part and the lower rotating part.

[0009] Further, the upper rotating part and the lower rotating part include inner and outer layers, and the inner layer and the outer layer can rotate relative to each other;The outer layer of the upper rotating part is fixedly connected with the connecting section, and the inner layer of the upper rotating part is sealingly connected with the connecting section and can rotate relative to each other;The outer layer of the lower rotating part is fixedly connected with the base, and the inner layer of the lower rotating part is sealingly connected with the base and can rotate relative to each other.

[0010] Further, the upper and lower ends of the rotating anode inner layer are fixedly connected with the inner layers of the upper rotating part and the lower rotating part respectively;The upper and lower ends of the rotating anode outer layer are fixedly connected with the outer layers of the upper rotating part and the lower rotating part respectively.

[0011] Further, the space between the rotating anode inner layer and the rotating anode outer layer is an anode cooling water cavity.

[0012] Further, the internal passage of the rotating anode inner layer is a plasma flow passage, and the plasma flow passage is divided into expansion section and contraction section, and the guide vane of the aerodynamic blade structure is arranged in the contraction section.

[0013] Further, the base is provided with a through hole in the middle for the outflow channel of the arc plasma, and is provided with a ring-shaped water tank for cooling near the upper part, and is provided with a plurality of through holes communicating with the ring-shaped water tank, and each through hole is connected with a cooling water inlet.

[0014] Further, the cathode is communicated with the channel formed by the insulation layer and the connecting section and the inner channel of the inner layer of the rotating anode.

[0015] The present application has the following advantages:

[0016] (1) The structure is simple, and no additional device such as a solenoid is introduced compared with a magnetic rotating plasma generator;

[0017] (2) The high-temperature and high-speed gas generated by the generator itself is fully utilized to make the anode rotate in the working process;

[0018] (3) The rotation of the anode relative to the anode arc root increases the time-averaged heating area of the anode;

[0019] (4) The rotation of the anode relative to the cooling medium strengthens the cooling of the anode;

[0020] (5) By increasing the time-averaged heating area of the anode and strengthening the cooling of the anode, the ablation problem of the anode is effectively alleviated. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the assembly schematic diagram of the pneumatic rotating arc plasma generator of the present application.

[0022] Figure 2 is the top view of the pneumatic rotating arc plasma generator of the present application.

[0023] Figure 3 is the A-A sectional view of the pneumatic rotating arc plasma generator of the present application.

[0024] Figure 4 is the B-B sectional view of the pneumatic rotating arc plasma generator of the present application.

[0025] Figure 5 is the top view of the rotating anode of the pneumatic rotating arc plasma generator of the present application.

[0026] Figure 6 is the C-C sectional view of the rotating anode of the pneumatic rotating arc plasma generator of the present application.

[0027] Among the above drawings, the following reference signs are included:

[0028] 10-Cathode; 20-Insulating layer; 30-Connecting section; 40-Rotating anode; 50-Base; 60-Stud; 70-Cathode cooling water chamber; 80-Anode cooling water chamber; 90-Plasma flow channel; 11-Upper substrate; 12-Cathode center; 13-Lower tip; 14-Cathode water cooling inlet; 15-Cathode water cooling outlet; 16-Working gas inlet; 31-Connecting section body; 32-Cooling water outlet; 41-Upper rotating component; 42-Lower rotating component; 43-Rotating anode inner layer; 44-Rotating anode outer layer; 45-Guide vane; 51-Base; 52-Cooling water inlet. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] like Figure 1 As shown, a pneumatic rotating arc plasma generator includes: a cathode 10, an insulating layer 20, a connecting section 30, a rotating anode 40, and a base 50 arranged coaxially from top to bottom. The cathode 10, the insulating layer 20, and the base 50 are fixedly connected by studs 60. The connecting section 30 and the rotating anode 40 are pressed between the insulating layer 20 and the base 50. The cathode 10 and the rotating anode 40 are cooled by a cooling medium. The rotating anode 40 includes an inner layer and an outer layer, and the inner layer can rotate around a central axis.

[0033] like Figures 2-4 As shown, the cathode 10 includes: an upper substrate 11, a cathode middle portion 12, and a lower pointed portion 13; the upper substrate 11 is a circular plate structure, preferably made of copper, and has four through holes, which are respectively connected to the cathode cooling water inlet 14, the cathode cooling water outlet 15, and two working gas inlets 16. Multiple through holes are also evenly distributed along the edge for connection with studs 60, preferably four through holes; the cathode middle portion 12 is pencil-shaped, preferably made of copper, and has a cathode cooling water cavity 70 inside, with the cathode cooling water inlet 14 and the cathode cooling water outlet 15 communicating with the cathode cooling water cavity 70; the lower pointed portion 13 is a cone shape, made of a high-temperature resistant material, preferably tungsten, hafnium, etc.; one end of the upper substrate 11 and the cathode middle portion 12 are fixed together by welding, and the lower pointed portion 13 is clamped to the other end of the cathode middle portion 12 by an interference fit.

[0034] The insulating layer 20 is made of insulating material, such as polytetrafluoroethylene or ceramic. Its two ends are pressed and connected to the cathode 10 and the connecting section 30 respectively. Multiple through holes are evenly distributed on the edge for connecting the studs 60, preferably four through holes.

[0035] The connecting section 30 is a columnar structure, preferably made of copper. The outline of the internal through hole of the connecting section body 31 is the same as the outer outline of the cathode center 12. A ring-shaped water tank for cooling is provided near the bottom. Multiple through holes are opened around it to communicate with the ring-shaped cooling water tank. Each through hole is connected to the cooling water outlet 32.

[0036] like Figures 5-6 As shown, the rotating anode 40 includes: an upper rotating component 41, a lower rotating component 42, an inner rotating anode layer 43, and an outer rotating anode layer 44; the upper rotating component 41 and the lower rotating component 42 have the same structure, similar to a bearing structure, and are divided into inner and outer layers with spherical balls between them, allowing them to rotate relative to each other; the inner rotating anode layer 43 is an anode attached to the arc root, preferably made of copper, and the internal channel of the inner rotating anode layer 43 is a plasma flow channel 90, which is divided into an expansion section and a contraction section, with a guide vane 45 of a pneumatic blade structure in the contraction section; the outer rotating anode layer 44 has a tubular structure. The upper and lower ends of the rotating anode inner layer 43 are fixedly connected to the inner layers of the upper rotating component 41 and the lower rotating component 42, respectively; the upper and lower ends of the rotating anode outer layer 44 are fixedly connected to the outer layers of the upper rotating component 41 and the lower rotating component 42, respectively; the outer layer of the upper rotating component 41 is fixedly connected to the connecting section 30, and the inner layer of the upper rotating component 41 is sealed to the connecting section 30, allowing relative rotation; the outer layer of the lower rotating component 42 is fixedly connected to the base 50, and the inner layer of the lower rotating component 42 is sealed to the base 50, allowing relative rotation; the space between the rotating anode inner layer 43 and the rotating anode outer layer 44 is the anode cooling water chamber 80.

[0037] The channel formed by the cathode 10, the insulation layer 20 and the connecting section 30 is in communication with the internal channel of the inner layer 43 of the rotating anode.

[0038] The base 50 is in a columnar structure, preferably made of red copper, has a through hole in the middle for the outflow channel of the arc plasma, has a ring-shaped water groove for cooling near the upper part, has two through holes in communication with the ring-shaped cooling water groove around, connects the cooling water inlet 52, and has a plurality of stepped holes for the connection of the stud 60 around.

[0039] The stud 60 tightly connects the coaxially assembled base 50, rotating anode 40, connecting section 30, insulation layer 20 and cathode 10.

[0040] Further combination Figure 3 And Figure 4 The flow channels of the working gas and the cooling water are described as follows: the working gas enters from the two working gas inlets 16 on the cathode 10, passes through the channel formed by the cathode 10, the insulation layer 20 and the connecting section 30, enters the discharge area to form plasma, and then flows out through the base 50 after impacting the aerodynamic guide vane 45; the cathode cooling water enters the cathode cooling water cavity 70 through the cathode water cooling inlet 14 on the cathode 10, and then flows out through the cathode water cooling outlet 15; the anode cooling water flows into the anode cooling water cavity 80 through the anode cooling water inlet 52 on the base 50, and then flows out through the anode cooling water outlet 32 on the connecting section 30; the cathode and anode wires can be connected to the outside of the cathode 10 and the rotating anode 40, respectively.

[0041] The high-temperature and high-speed plasma generated by the normal operation of the aerodynamic rotating arc plasma generator expands in the expansion section of the rotating anode 40, enters the contraction section, flows through the guide vane 45, and then flows out from the outlet of the generator base 50 to form a plasma jet; the high-temperature and high-speed plasma interacts with the guide vane 45 in the plasma flow channel 90, generating a circumferential rotating force to rotate the inner layer 43 of the rotating anode; the rotation of the inner layer 43 of the rotating anode can rotate the anode arc root relative to the anode surface, avoiding the anode arc root from being attached to a fixed position for a long time, thereby increasing the time-averaged attachment area of the anode arc root; at the same time, the rotation of the rotating anode enhances the convective heat transfer of the cooling medium, thereby strengthening the cooling effect of the cooling medium on the rotating anode and reducing the anode ablation.

[0042] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement modes and shall be included in the protection scope of the present application.

Claims

1. A kind of aerodynamic rotating arc plasma generator, it is characterized by: Including: Cathode (10), insulating layer (20), connecting section (30), rotating anode (40) and base (50) are arranged coaxially in turn from top to bottom, the cathode (10), insulating layer (20) and base (50) are fixedly connected by stud (60), the connecting section (30) and rotating anode (40) are compressed between the insulating layer (20) and base (50), the cathode (10) and rotating anode (40) are cooled using cooling medium;The rotating anode (40) includes inner layer and outer layer, inner layer can rotate around axis;Rotating anode inner layer (43) internal passage is plasma flow channel (90), the plasma flow channel (90) is divided into expansion section and contraction section, there is guide vane (45) of aerodynamic blade structure in contraction section; The rotating anode (40) includes: upper rotating part (41), lower rotating part (42), rotating anode inner layer (43) and rotating anode outer layer (44), rotating anode inner layer (43) and rotating anode outer layer (44) are arranged between upper rotating part (41) and lower rotating part (42);The upper rotating part (41) and lower rotating part (42) include inner and outer two layers, inner layer and outer layer can be relatively rotated;The outer layer of upper rotating part (41) is fixedly connected with connecting section (30), the inner layer of upper rotating part (41) is sealingly connected with connecting section (30), and can be relatively rotated;The outer layer of lower rotating part (42) is fixedly connected with base (50), and the inner layer of lower rotating part (42) is sealingly connected with base (50) and can be relatively rotated;The upper and lower ends of the rotating anode inner layer (43) are fixedly connected with the inner layers of the upper rotating part (41) and the lower rotating part (42) respectively;The upper and lower ends of the rotating anode outer layer (44) are fixedly connected with the outer layers of the upper rotating part (41) and the lower rotating part (42) respectively.

2. A gasdynamic rotating arc plasma generator according to claim 1, characterized in that: The cathode (10) includes: upper base plate (11), cathode middle part (12) and lower pointed part (13);4 through holes are provided on the upper base plate (11), and the 4 through holes are respectively connected with the cathode cooling water inlet (14), the cathode cooling water outlet (15) and two working medium gas inlets (16);The cathode cooling water cavity (70) is arranged in the cathode middle part (12), and the cathode cooling water inlet (14) and the cathode cooling water outlet (15) are communicated with the cathode cooling water cavity (70);The upper base plate (11) and one end of the cathode middle part (12) are fixedly connected, and the lower pointed part (13) is clamped at the other end of the cathode middle part (12).

3. A gasdynamic rotating arc plasma generator according to claim 1, characterized in that: The connecting section (30) is provided with an annular water tank for cooling near the bottom position, a plurality of through holes are formed around the annular water tank and communicated with the annular water tank, and each through hole is connected with a cooling water outlet (32).

4. A gasdynamic rotating arc plasma generator according to claim 1, characterized in that: The space between the rotating anode inner layer (43) and the rotating anode outer layer (44) is an anode cooling water cavity (80).

5. A gasdynamic rotating arc plasma generator according to claim 1, characterized in that: The base (50) is provided with an annular water tank for cooling near the upper part, a plurality of through holes are formed around the annular water tank and communicated with the annular water tank, and each through hole is connected with a cooling water inlet (52).

6. A gasdynamic rotating arc plasma generator according to claim 1, characterized in that: The cathode (10) and the passage formed by the insulating layer (20) and the connecting section (30) are in communication with the internal passage of the rotating anode inner layer (43).

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