CN111511090B - Microwave plasma reactor - Google Patents
Microwave plasma reactor Download PDFInfo
- Publication number
- CN111511090B CN111511090B CN202010285786.1A CN202010285786A CN111511090B CN 111511090 B CN111511090 B CN 111511090B CN 202010285786 A CN202010285786 A CN 202010285786A CN 111511090 B CN111511090 B CN 111511090B
- Authority
- CN
- China
- Prior art keywords
- microwave
- resonant cavity
- ignition structure
- ignition
- microwave resonant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/46—Generating plasma using applied electromagnetic fields, e.g. high frequency or microwave energy
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/46—Generating plasma using applied electromagnetic fields, e.g. high frequency or microwave energy
- H05H1/461—Microwave discharges
Abstract
The invention relates to the technical field of microwave reaction devices, and discloses a microwave plasma reactor which comprises a multi-channel microwave transmission reaction body, a self-triggering ignition device and at least one layer of microwave source component, wherein a microwave resonant cavity is arranged in the multi-channel microwave transmission reaction body; each layer of microwave source component comprises a plurality of microwave transmission excitation sources which are distributed along the circumferential direction of the multichannel microwave transmission reaction body; the frequency of the microwave transmission excitation source is equal to the resonant frequency of the working mode in the microwave resonant cavity; the self-triggering ignition device comprises a conical ignition structure arranged at the end part of the multi-channel microwave transmission reaction body, and the tip part of the conical ignition structure faces to the inside of the microwave resonant cavity; an air flow channel is arranged in the conical ignition structure and penetrates through the tip of the conical ignition structure. The microwave plasma reactor can effectively enhance the energy density of plasma and enlarge the range of a plasma region in the microwave reactor, and is beneficial to expanding the application field of the microwave plasma.
Description
Technical Field
The invention relates to the technical field of microwave devices, in particular to a microwave plasma reactor.
Background
The plasma may be generated by dc discharge, rf discharge, microwave discharge, or the like. The defects of direct current discharge are electrode discharge, low density, low ionization degree and high operating pressure; although the density and the ionization degree of the radio frequency discharge are improved, the application range is limited; compared with other technologies, the microwave discharge technology has a series of advantages of high energy conversion efficiency, no electrode pollution, wide pressure range and the like, and is widely applied to the industrial field.
The working modes of a conventional microwave reactor in a microwave resonant cavity can be divided into a single-mode microwave resonant cavity and a multi-mode microwave resonant cavity, wherein the single-mode microwave resonant cavity refers to that only one working mode exists in the microwave resonant cavity, and the multi-mode microwave resonant cavity refers to that multiple working modes exist in the microwave resonant cavity. The single-mode microwave resonant cavity has the advantages that electric field concentration causes large electric field intensity and large energy storage, and has the defects of small volume and uneven field intensity distribution in the cavity, a plurality of electric field modes coexist in the multi-mode microwave resonant cavity, and the electric fields of all the modes are mutually superposed, so that electromagnetic energy distribution which is more uniform than that of the single-mode microwave resonant cavity can be formed in the cavity, but the electric field intensity is not large. For the chemical reaction to be carried out, it is desirable that the field intensity distribution in the reactor be large and uniform, and that the field intensity have a large value in a partial region to excite the plasma.
For the existing microwave reactor, the energy density of the excited plasma in the reactor is not large enough, the area range of the plasma is small, the plasma distribution is not uniform, and the chemical reaction is not facilitated. In addition, the current microwave resonance has a field strength of up to MV/m only rarely, and the relatively large field strength has a small area and an uneven electric field distribution inside the reactor.
Disclosure of Invention
The embodiment of the invention provides a microwave plasma reactor, which is used for solving the problems of nonuniform electric field distribution and insufficient energy density of the conventional microwave reactor.
The embodiment of the invention provides a microwave plasma reactor, which comprises a multi-channel microwave transmission reaction body, a self-triggering ignition device and at least one layer of microwave source component, wherein a microwave resonant cavity is arranged in the multi-channel microwave transmission reaction body;
each layer of microwave source component comprises a plurality of microwave transmission excitation sources, and the plurality of microwave transmission excitation sources are distributed on the side wall of the multichannel microwave transmission reaction body along the circumferential direction of the multichannel microwave transmission reaction body; the frequency of the microwave transmission excitation source is equal to the resonant frequency of the working mode of the microwave resonant cavity;
the self-triggering ignition device comprises a conical ignition structure arranged at the end part of the multi-channel microwave transmission reaction body, and the tip part of the conical ignition structure faces to the inside of the microwave resonant cavity; an airflow channel is arranged in the conical ignition structure and penetrates through the tip of the conical ignition structure.
The microwave tuning device and the conical ignition structure are respectively arranged at two ends of the multichannel microwave transmission reaction body; the microwave tuning device comprises a reaction substrate arranged in the microwave resonant cavity, and the surface of the reaction substrate faces the tip part of the conical ignition structure; the reaction substrate is connected to the multi-channel microwave transmission reaction body and can move along the axial direction of the microwave resonant cavity.
The self-triggering ignition device further comprises a probe ignition structure arranged on the side wall of the multichannel microwave transmission reaction body, and an ignition end of the probe ignition structure extends into the microwave resonant cavity; at least one probe ignition structure is correspondingly arranged on each microwave source component, the axis of each probe ignition structure and the axis of each microwave source component are located in the same plane, and the axis of each probe ignition structure and the axis of each microwave transmission excitation source are focused on the central axis of the microwave resonant cavity.
The probe ignition structure is connected to the side wall of the multichannel microwave transmission reaction body and can move along the axial direction of the probe ignition structure so as to adjust the length of the ignition end of the probe ignition structure extending into the microwave resonant cavity.
Wherein, the microwave source components are distributed at intervals along the axial direction of the microwave resonant cavity.
Wherein the working mode type of the microwave resonant cavity is TMmn0And (5) molding.
The microwave resonant cavity is a cylindrical microwave resonant cavity, and the size of the cylindrical microwave resonant cavity satisfies the following expression:
wherein the content of the first and second substances,f mnp at the resonant frequency of the operating mode of the microwave resonant cavity,cin order to be the speed of light,ais the radius of the cylindrical microwave resonant cavity,lthe height of the cylindrical microwave resonant cavity along the longitudinal direction,mthe number of the whole standing waves with the field quantity distributed along the circumference of the cylindrical microwave resonant cavity,nthe number of the half standing waves with the field quantity distributed along the radius of the cylindrical microwave resonant cavity,pthe number of the half standing waves with the field quantity distributed along the longitudinal direction of the cylindrical microwave resonant cavity,υ mn is TMmn0Modulo the corresponding bezier function value.
The microwave resonant cavity is a cuboid microwave resonant cavity, and the dimensions of the cuboid microwave resonant cavity satisfy the following expression:
wherein the content of the first and second substances,f mnp at the resonant frequency of the operating mode of the microwave resonant cavity,cin order to be the speed of light,ais the length of the cuboid type microwave resonant cavity,bis the width of the cuboid type microwave resonant cavity,his the height of the cuboid microwave resonant cavity,mthe number of the half standing waves with the field quantity distributed along the length direction of the cuboid type microwave resonant cavity,nthe number of the half standing waves with the field quantity distributed along the width direction of the cuboid type microwave resonant cavity,pthe number of the half standing waves with the field quantity distributed along the height direction of the cuboid type microwave resonant cavity.
The microwave transmission excitation source comprises a rectangular waveguide and a microwave feed source, one end of the rectangular waveguide is communicated with the microwave resonant cavity, the other end of the rectangular waveguide is connected with the microwave feed source, and the rectangular waveguide is used for guiding microwaves generated by the microwave feed source into the microwave resonant cavity.
The side face where the wide side of the rectangular waveguide is located is parallel to the end face of the microwave resonant cavity, and the rectangular waveguides are distributed at equal intervals along the circumferential direction of the microwave resonant cavity.
The microwave plasma reactor provided by the embodiment of the invention comprises a multi-channel microwave transmission reaction body, a self-triggering ignition device and at least one layer of microwave source component, wherein a microwave resonant cavity is arranged in the multi-channel microwave transmission reaction body, each layer of microwave source component comprises a plurality of microwave transmission excitation sources distributed along the circumferential direction, so that a plurality of microwave beams in different directions can be simultaneously coupled into the reactor, a plurality of microwave beams in the same working mode are superposed in the microwave reactor, and the electric field intensity, the uniformity and the area of a high field intensity area in the microwave reactor can be increased; meanwhile, the conical ignition structure is arranged at the end part of the multi-channel microwave transmission reaction body, so that the microwaves in the microwave resonant cavity can generate a high-intensity electromagnetic field in the tip part area of the conical ignition structure, and the gas flowing through the area is punctured to generate plasma. The microwave plasma reactor can effectively enhance the energy density of plasma and enlarge the range of a plasma region existing in the microwave reactor, and is beneficial to expanding the application field of the microwave plasma.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a longitudinal sectional view of a microwave plasma reactor in an embodiment of the present invention;
FIG. 2 is a transverse cross-sectional view of the microwave plasma reactor of FIG. 1;
FIG. 3 is a schematic illustration of the electric field distribution within the microwave plasma reactor of FIG. 1;
FIG. 4 is a graphical representation of the relationship between the number of microwave feeds in a single microwave source assembly and the electric field strength in a microwave plasma reactor in accordance with an embodiment of the present invention;
fig. 5 is a schematic diagram of electric field distribution in a microwave plasma reactor of different numbers of microwave feed sources in a single-layer microwave source assembly in an embodiment of the present invention, where fig. a is a schematic diagram of electric field distribution under one microwave feed source, fig. b is a schematic diagram of electric field distribution under two microwave feed sources, fig. c is a schematic diagram of electric field distribution under three microwave feed sources, fig. d is a schematic diagram of electric field distribution under four microwave feed sources, fig. e is a schematic diagram of electric field distribution under five microwave feed sources, and fig. f is a schematic diagram of electric field distribution under six microwave feed sources;
FIG. 6 is a longitudinal sectional view of another microwave plasma reactor in an embodiment of the present invention;
FIG. 7 is a TEM image of nanoparticles prepared using one of the microwave plasma reactors in an example of the present invention;
FIG. 8 shows an operating mode TM in a microwave plasma reactor in an embodiment of the present inventionmn0Of mould and cylindrical microwave resonant cavityThe dimensional relationship is shown schematically.
Description of reference numerals:
1. a multi-channel microwave transmission reaction body; 11. A microwave resonant cavity;
2. a conical ignition structure; 21. An air flow channel; 3. A microwave transmission excitation source;
31. a rectangular waveguide; 32. A microwave feed source; 4. A probe firing structure;
5. a reaction substrate; 51. Adjusting a rod; 52. And (7) an exhaust port.
Detailed Description
In order to make the objects, 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute position of a described object is changed, the relative positional relationships may also be changed accordingly. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations.
It is to be understood that, unless otherwise expressly specified or limited, the term "coupled" is used broadly, and may, for example, refer to directly coupled devices or indirectly coupled devices through intervening media. Specific meanings of the above terms in the embodiments of the invention will be understood to those of ordinary skill in the art in specific cases.
As shown in fig. 1 to 7, a microwave plasma reactor according to an embodiment of the present invention includes a multi-channel microwave transmission reaction body 1, a self-triggering ignition device, and at least one layer of microwave source assembly, where a microwave resonant cavity 11 is disposed in the multi-channel microwave transmission reaction body 1.
Each layer of microwave source component comprises a plurality of microwave transmission excitation sources 3, and the plurality of microwave transmission excitation sources 3 are distributed on the side wall of the multichannel microwave transmission reactant 1 along the circumferential direction of the multichannel microwave transmission reactant 1. The frequency of the microwave transmission excitation source 3 is equal to the resonant frequency of the operating mode of the microwave cavity 11.
The self-triggering ignition device comprises a conical ignition structure 2 arranged at the end part of the multi-channel microwave transmission reaction body 1, and the tip part of the conical ignition structure 2 faces the inside of the microwave resonant cavity 11; an air flow channel 21 is arranged in the conical ignition structure 2, and the air flow channel 21 penetrates through to the tip part of the conical ignition structure 2.
Specifically, the axes of the microwave transmission excitation sources 3 of each microwave source component layer are located on the same plane, and can be vertical to and focused at the focal point of the axis of the microwave resonant cavity 11. As shown in fig. 2, in a specific embodiment, a plurality of microwave transmission excitation sources 3 are uniformly distributed on the sidewall of the multichannel microwave transmission reaction body 1 along the circumferential direction of the multichannel microwave transmission reaction body 1, so as to be capable of coupling a plurality of microwaves in different directions into the microwave resonant cavity 11 simultaneously. The frequency of the microwave transmission excitation source 3 may be any one of 433MHz, 915MHz, 2450MHz, 5800MHz, and 22125MHz, or may be other frequencies. Fig. 4 and 5 show the relationship curve between the number of the microwave transmission excitation sources 3 and the electric field intensity in the microwave cavity 11 and the variation of the electric field distribution, and it can be seen from fig. 4 and 5 that the number of the microwave transmission excitation sources 3 has a positive correlation with the electric field intensity, and the increase of the number of the microwave transmission excitation sources 3 increases the high electric field area and the electric field distribution is uniform. With the increase of the number of the microwave transmission excitation sources 3, the superposition of the electric field intensity and the electric field distribution can be realized through the superposition of the working modes, so that the microwave plasma reactor has high electric field intensity, large-area high-field intensity regions and uniform electric field distribution.
The conical ignition structures 2 are arranged at the ends of the multi-channel microwave transmission reaction body 1, and the number of the conical ignition structures 2 can be one or two. As shown in fig. 1 to fig. 3, the present embodiment is described by taking two conical ignition structures 2 respectively disposed at two ends of a multi-channel microwave transmission reaction body 1 as an example. The diameter of the conical ignition structure 2 is gradually reduced from the end part of the microwave resonant cavity 11 to the inside of the microwave resonant cavity 11, and a tip part is formed in the microwave resonant cavity 11, a gas flow channel 21 is arranged in the conical ignition structure 2, the gas flow channel 21 penetrates through the tip part of the conical ignition structure 2, so that external reaction gas flows in from the tip part of the conical ignition structure 2, or internal reaction product gas flows out from the tip part of the conical ignition structure 2, fig. 7 shows a TEM image of nanoparticles prepared by using the microwave plasma reactor, and as can be seen from fig. 7, nanoparticles can be prepared by using the device. Fig. 3 shows a schematic diagram of the electric field distribution in the microwave plasma reactor, and it can be derived from fig. 3 that the electric field intensity is the largest in the tip regions (i.e. the double-tip structure) of the upper and lower conical ignition structures 2, and the electric field distribution region is mainly concentrated between the two tips, which is beneficial to breakdown the gas flowing through the region to generate plasma, so as to form continuous plasma, and further enable the chemical reaction to completely proceed. More specifically, the conical ignition structure 2 may be a solid structure, the air flow channel 21 is a through pipe, and the diameter of the pipe may be designed according to requirements; the conical ignition structure 2 may also be a hollow structure, funnel-shaped.
The microwave plasma reactor provided by the embodiment comprises a multi-channel microwave transmission reaction body 1, a self-triggering ignition device and at least one layer of microwave source component, wherein a microwave resonant cavity 11 is arranged in the multi-channel microwave transmission reaction body 1, each layer of microwave source component comprises a plurality of microwave transmission excitation sources 3 distributed along the circumferential direction, a plurality of microwave beams in different directions can be simultaneously coupled into the reactor, a plurality of same working modes are superposed in the microwave reactor, and the electric field intensity, the uniformity and the area of a high field intensity area in the microwave reactor can be increased; meanwhile, the conical ignition structure 2 is arranged at the end part of the multi-channel microwave transmission reaction body 1, so that microwaves in the microwave resonant cavity 11 can generate a high-intensity electromagnetic field in the tip part area of the conical ignition structure 2, and gas flowing through the area is broken down to generate plasma. The microwave plasma reactor can effectively enhance the energy density of plasma and enlarge the range of a plasma region existing in the microwave reactor, and is beneficial to expanding the application field of the microwave plasma.
Further, as shown in fig. 6, the microwave tuning device and the conical ignition structure 2 are respectively disposed at two ends of the multi-channel microwave transmission reaction body 1. The microwave tuning device comprises a reaction substrate 5 arranged in a microwave resonant cavity 11, wherein the surface of the reaction substrate 5 faces the tip part of the conical ignition structure 2. The reaction substrate 5 is connected to the multi-channel microwave transmission reaction body 1, and the reaction substrate 5 can move along the axial direction of the microwave resonant cavity 11, and the reaction substrate 5 has the function of a short-circuit piston, and can also be used as a reaction base, for example, a plasma thin film deposition base, for forming a thin film material. The gas flow channel 21 in the conical ignition structure 2 forms an inlet for injecting the reaction gas into the microwave cavity 11, and then forming plasma to deposit on the reaction substrate 5, and the rest of the reaction gas can be exhausted through the exhaust port 52.
Specifically, the reaction substrate 5 may be a metal substrate, a plate surface of the reaction substrate 5 may be perpendicular to an axial direction of the microwave resonant cavity 11, the reaction substrate 5 may be connected to a bottom end of the multichannel microwave transmission reaction body 1 through an adjusting rod 51, for example, the adjusting rod 51 may be connected to the multichannel microwave transmission reaction body 1 in a threaded manner, and a height of the reaction substrate 5 in the microwave resonant cavity 11 may be changed by rotating the adjusting rod 51; the adjustment rod 51 may be a telescopic mechanism such as an electric push rod or other elevating mechanism as long as it can elevate the reaction substrate 5, and is not limited herein. The position of the microwave tuning device is adjusted to be beneficial to matching the impedance of the microwave plasma reactor, so that the damage of the reflection of electromagnetic waves to the microwave transmission excitation source 3 is reduced. Meanwhile, the coherence of electromagnetic waves can be changed, and the superposition of electric fields is realized, so that high field intensity is obtained in a plasma region, the plasma is favorably excited, and the range of a plasma reaction region can be adjusted.
Further, as shown in fig. 1 to 2 and 6, the self-triggering ignition device further includes a probe ignition structure 4 mounted on a sidewall of the multi-channel microwave transmission reaction body 1, and an ignition end of the probe ignition structure 4 extends into the microwave cavity 11. Each layer of microwave source assembly is correspondingly provided with at least one probe ignition structure 4, the axis of the probe ignition structure 4 and the microwave source assembly are located in the same plane, and the axes of the probe ignition structure 4 and the microwave transmission excitation source 3 are focused on the focus on the central axis of the microwave resonant cavity 11. Specifically, the probe ignition structure 4 may be located at a middle position of two adjacent microwave transmission excitation sources 3, an axis of the probe ignition structure 4 and an axis of the microwave transmission excitation source 3 are in the same plane, and extension lines of the axes of the probe ignition structure 4 and the microwave transmission excitation source 3 may converge to the same focal point on the central axis of the microwave resonant cavity 11. The probe ignition structure 4 can also improve the electric field intensity in a local area, and is beneficial to the excitation of microwave plasma.
Furthermore, the probe ignition structure 4 is connected to the side wall of the multi-channel microwave transmission reaction body 1, and the probe ignition structure 4 can move along the axial direction of the probe ignition structure 4 to adjust the length of the ignition end of the probe ignition structure 4 extending into the microwave resonant cavity 11. Specifically, the probe ignition structure 4 can be screwed to the side wall of the multi-channel microwave transmission reaction body 1 through a mounting sleeve.
Further, as shown in fig. 1 and 6, the plurality of microwave source assemblies are spaced along the axial direction of the microwave cavity 11. The specific number of layers may be determined according to the height of the microwave resonant cavity 11, and the specific size of the layer interval may also be determined according to actual requirements, and may be equal intervals or unequal intervals, which is not limited herein. Fig. 3 shows a schematic diagram of electric field distribution of two layers of microwave source components, which is beneficial to realize excitation of plasma at multiple positions in a microwave plasma reactor by simultaneously arranging a plurality of conical ignition structures 2 and probe ignition structures 4 in the reactor, thereby increasing the area of a plasma existing region.
On the basis of the above embodiment, the operation mode type of the microwave resonant cavity 11 is TMmn0And (5) molding. By using TMmn0The mode is beneficial to enabling the microwave fed into the microwave resonant cavity 11 by the microwave transmission excitation source 3 to generate resonance, so that the energy coupling efficiency is improved, and the requirement on the processing precision can be reduced by the working mode.
Further, when the microwave cavity 11 is a cylindrical type microwave cavity, the size of the cylindrical type microwave cavity satisfies the following expression:
wherein the content of the first and second substances,f mnp is the resonant frequency of the operating mode of the microwave resonant cavity,cit is the speed of the light that is,ais the radius of the cylindrical microwave resonant cavity,lis the height of the cylindrical microwave resonant cavity along the longitudinal direction,mthe number of the whole standing waves with the field quantity distributed along the circumference of the cylindrical microwave resonant cavity,nthe number of the half standing waves with the field quantity distributed along the radius of the cylindrical microwave resonant cavity,pthe number of the half standing waves with the field quantity distributed along the longitudinal direction of the cylindrical microwave resonant cavity,υ mn is TMmn0Modulo the corresponding bezier function value. FIG. 8 shows the operating mode TM in a microwave reactormn0The dimension relationship between the mode and the cylindrical microwave resonant cavity is schematically shown, and the ordinate of the coordinate axis is (2af mnp /c) 2 On the abscissa of(2a/l) 2 . As can be seen from FIG. 8, when the operation mode type is TMmn0In the mode, the number of layers of the microwave source assembly axially increased in the cylindrical microwave resonant cavity does not change the resonance change of the corresponding resonant frequency, so that the microwave energy coupling efficiency is not reduced, and the effective reaction zone length of the microwave plasma can be increased by increasing the number of layers of the microwave source assembly axially in the microwave resonant cavity 11. Under the same working frequency, different working modes have different radiuses of the multichannel microwave transmission reaction body 1 (namely, the microwave resonant cavity 11), so that a proper working mode can be selected according to different microwave reaction requirements to obtain the radius of the multichannel microwave transmission reaction body 1 which is most matched, and the length of the effective reaction area of the plasma is increased by increasing the axial length of the microwave resonant cavity 11 and increasing the number of layers of microwave source components.
In addition, the microwave cavity 11 may also be a rectangular parallelepiped microwave cavity, and the dimensions of the rectangular parallelepiped microwave cavity satisfy the following expression:
wherein the content of the first and second substances,f mnp is the resonant frequency of the operating mode of the microwave resonant cavity,cin order to be the speed of light,ais the length of the cuboid microwave resonant cavity,bis the width of the cuboid-shaped microwave resonant cavity,his the height of the cuboid microwave resonant cavity,mthe number of the half standing waves of which the field quantity is distributed along the length direction of the cuboid type microwave resonant cavity,nthe number of the half standing waves whose field quantities are distributed along the width direction of the cuboid type microwave resonant cavity,pthe number of the half standing waves of which the field quantities are distributed along the height direction of the cuboid microwave resonant cavity.
Further, as shown in fig. 1, the microwave transmission excitation source 3 includes a rectangular waveguide 31 and a microwave feed source 32, one end of the rectangular waveguide 31 is communicated with the microwave resonant cavity 11, the other end of the rectangular waveguide 31 is connected to the microwave feed source 32, and the rectangular waveguide 31 is used for guiding the microwaves generated by the microwave feed source 32 into the microwave resonant cavity 11. Specifically, the microwave feed 32 may employ a magnetron.
Further, the side surface where the wide side of the rectangular waveguide 31 is located is parallel to the end surface of the microwave cavity 11, and the plurality of rectangular waveguides 31 are distributed at equal intervals along the circumferential direction of the microwave cavity 11.
On the basis of determining the working mode of the cylindrical microwave resonant cavity, the working mode and the transmission mode of the rectangular waveguide 31 need to meet the odd-even forbidden rule, that is, the electric field or magnetic field distribution of the working mode of the cylindrical microwave resonant cavity and the transmission mode of the rectangular waveguide 31 has the same odd-even mode property, and the electric field and the magnetic field only need to meet one of the odd-even mode property and the even-even mode property.
The rectangular waveguides 31 are circumferentially distributed in the cylindrical microwave resonant cavity, and the wide sides of the rectangular waveguides 31 are parallel to the cylindrical end surface of the cylindrical microwave resonant cavity. The rectangular waveguide 31 has a transmission mode of TE10The mode of operation in the mode cylindrical microwave resonant cavity is TMmn0Mode, observing two modes in the same space coordinate system to obtain electromagnetic field divisionCondition by comparison of TE10Mode and TMmn0The field distribution of the modes determines that the same parity mode property is present. Wherein TE is in the rectangular waveguide 3110The field simplified distribution of modes, as in equation (1) below:
cylindrical microwave resonant cavity TMmn0The field-simplified distribution of the modes, as in the following equation (2):
w in the formula (1) is the wide side of the rectangular waveguide 31, a in the formula (2) is the radius of the cylindrical microwave resonant cavity, and according to the above, the parity property of the two modes can be judged only by one of the electric field and the magnetic field, and by observing the formulas (1) and (2), the judgment of the parity of the two working modes by using the direction of the electric field is relatively easy, and the TE in the rectangular waveguide 31 is relatively easy10The electric field of the mode exists only in the y-direction, while the cylindrical microwave cavity TMmn0The electric field of the mode exists only in the z direction, which shows that the electric field directions of the mode and the mode are parallel to the yz plane, and for the parity forbidden rule, the same parity modes can be mutually excited, the parity of the modes is related to a reference plane, and the reference plane is a geometric symmetry plane of a boundary surface of a system connection. The direction of the electric field (or the direction of the magnetic field) is parallel to the reference surface, and the mode is an odd mode; perpendicular to the reference plane, it is in even mode. According to the formulas (1) and (2), the directions of the two modes are parallel to the yz plane, and when the rectangular waveguide 31 is circumferentially distributed in the cylindrical microwave resonant cavity and the wide side of the rectangular waveguide is parallel to the cylindrical end surface of the cylindrical microwave resonant cavity, the two modes have the same parity property relative to the reference plane.
It can be seen from the above embodiments that the microwave plasma reactor provided by the present invention comprises a multichannel microwave transmission reactor 1, a self-triggering ignition device and at least one layer of microwave source assembly, wherein a microwave resonant cavity 11 is arranged in the multichannel microwave transmission reactor 1, each layer of microwave source assembly comprises a plurality of microwave transmission excitation sources 3 distributed along the circumferential direction, so that a plurality of microwaves in different directions can be simultaneously coupled into the reactor, and the microwave reactor has a plurality of superposition of same working modes, so as to increase the electric field intensity, uniformity and area of high field intensity region in the microwave reactor; meanwhile, the conical ignition structure 2 is arranged at the end part of the multi-channel microwave transmission reaction body 1, so that microwaves in the microwave resonant cavity 11 can generate a high-intensity electromagnetic field in the tip part area of the conical ignition structure 2, and gas flowing through the area is broken down to generate plasma. The microwave plasma reactor can effectively enhance the energy density of plasma and enlarge the range of a plasma region existing in the microwave reactor, and is beneficial to expanding the application field of the microwave plasma.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A microwave plasma reactor is characterized by comprising a multi-channel microwave transmission reaction body, a self-triggering ignition device and at least one layer of microwave source component, wherein a microwave resonant cavity is arranged in the multi-channel microwave transmission reaction body;
each layer of microwave source component comprises a plurality of microwave transmission excitation sources, and the plurality of microwave transmission excitation sources are distributed on the side wall of the multichannel microwave transmission reaction body along the circumferential direction of the multichannel microwave transmission reaction body; the frequency of the microwave transmission excitation source is equal to the resonant frequency of the working mode in the microwave resonant cavity;
the self-triggering ignition device comprises a conical ignition structure arranged at the end part of the multi-channel microwave transmission reaction body, and the tip part of the conical ignition structure faces to the inside of the microwave resonant cavity; an airflow channel is arranged in the conical ignition structure and penetrates through the tip of the conical ignition structure.
2. A microwave plasma reactor according to claim 1, further comprising a microwave tuning device, wherein the microwave tuning device and the conical ignition structure are respectively disposed at two ends of the multi-channel microwave transmission reactor body; the microwave tuning device comprises a reaction substrate arranged in the microwave resonant cavity, and the surface of the reaction substrate faces the tip part of the conical ignition structure; the reaction substrate is connected to the multi-channel microwave transmission reaction body and can move along the axial direction of the microwave resonant cavity.
3. A microwave plasma reactor according to claim 1, wherein the self-triggering ignition device further comprises a probe ignition structure mounted to a sidewall of the multi-channel microwave transmission reactor body, an ignition end of the probe ignition structure extending into the microwave resonator; at least one probe ignition structure is correspondingly arranged on each microwave source component, the axis of each probe ignition structure and the axis of each microwave source component are located in the same plane, and the axis of each probe ignition structure and the axis of each microwave transmission excitation source are focused on the central axis of the microwave resonant cavity.
4. A microwave plasma reactor according to claim 3, wherein the probe ignition structure is connected to a sidewall of the multi-channel microwave transmission reaction body, and the probe ignition structure is movable in an axial direction of the probe ignition structure to adjust a length of the ignition end of the probe ignition structure extending into the microwave cavity.
5. A microwave plasma reactor according to claim 1, wherein a plurality of the microwave source assemblies are spaced apart along an axial direction of the microwave resonant cavity.
6. A microwave plasma reactor according to any one of claims 1 to 5, wherein the operating mode type of the microwave resonant cavity is TMmn0And (5) molding.
7. A microwave plasma reactor according to claim 6, wherein the microwave resonant cavity is a cylindrical microwave resonant cavity, and the dimensions of the cylindrical microwave resonant cavity satisfy the following expression:
wherein f ismnpFor the resonant frequency of the working mode of the microwave resonant cavity, c is the speed of light, a is the radius of the cylindrical microwave resonant cavity, l is the height of the cylindrical microwave resonant cavity along the longitudinal direction, m is the field quantity along the number of the whole standing waves distributed on the circumference of the cylindrical microwave resonant cavity, n is the field quantity along the number of the half standing waves distributed on the radius of the cylindrical microwave resonant cavity, p is the field quantity along the number of the half standing waves distributed on the longitudinal direction of the cylindrical microwave resonant cavity, upsilonmnIs TMmn0Modulo the corresponding bezier function value.
8. A microwave plasma reactor according to claim 6, wherein the microwave resonant cavity is a cuboid type microwave resonant cavity, the dimensions of which satisfy the following expression:
wherein f ismnpIs the resonant frequency of the working mode of the microwave resonant cavity, c is the speed of light, a is the length of the cuboid microwave resonant cavity, b is the width of the cuboid microwave resonant cavity, and h is the cuboid microwave resonant cavityThe method comprises the following steps that the height of a wave resonant cavity is obtained, m is the number of half standing waves with field quantities distributed along the length direction of the cuboid type microwave resonant cavity, n is the number of half standing waves with field quantities distributed along the width direction of the cuboid type microwave resonant cavity, and p is the number of half standing waves with field quantities distributed along the height direction of the cuboid type microwave resonant cavity.
9. A microwave plasma reactor according to claim 6, wherein the microwave transmission excitation source comprises a rectangular waveguide and a microwave feed source, one end of the rectangular waveguide is communicated with the microwave resonant cavity, the other end of the rectangular waveguide is connected to the microwave feed source, and the rectangular waveguide is configured to guide microwaves generated by the microwave feed source into the microwave resonant cavity.
10. A microwave plasma reactor according to claim 9, wherein the sides of the broad sides of the rectangular waveguides are parallel to the end face of the microwave resonant cavity, and a plurality of the rectangular waveguides are equally spaced along the circumference of the microwave resonant cavity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010285786.1A CN111511090B (en) | 2020-04-13 | 2020-04-13 | Microwave plasma reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010285786.1A CN111511090B (en) | 2020-04-13 | 2020-04-13 | Microwave plasma reactor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111511090A CN111511090A (en) | 2020-08-07 |
| CN111511090B true CN111511090B (en) | 2022-05-10 |
Family
ID=71877563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010285786.1A Active CN111511090B (en) | 2020-04-13 | 2020-04-13 | Microwave plasma reactor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111511090B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114136095A (en) * | 2021-11-25 | 2022-03-04 | 昆明理工大学 | Microwave ignition device of sintering machine |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63236791A (en) * | 1987-03-24 | 1988-10-03 | Matsushita Electric Ind Co Ltd | Production of diamond |
| JPS6424094A (en) * | 1987-07-21 | 1989-01-26 | Nat Inst Res Inorganic Mat | Synthesizing apparatus for diamond |
| JPH03111577A (en) * | 1989-09-26 | 1991-05-13 | Idemitsu Petrochem Co Ltd | Microwave plasma generator and production of diamond film by utilizing this generator |
| CN101829487A (en) * | 2010-06-11 | 2010-09-15 | 天津市环境保护科学研究院 | Microwave plasma decomposition Freon innocent treatment method |
| CN103636059B (en) * | 2011-06-24 | 2016-01-27 | 雷卡邦股份有限公司 | Microwave cavity |
| DE102011111884B3 (en) * | 2011-08-31 | 2012-08-30 | Martin Weisgerber | Device for generating thermodynamic cold plasma by microwaves, has resonance chambers distributed in evacuated, electrically conductive anode, where plasma is generated by microwaves under standard atmospheric conditions |
| CN102698300B (en) * | 2012-05-31 | 2014-04-09 | 电子科技大学 | Microwave resonator for sterilizing liquid substance at low temperature |
| GB201410703D0 (en) * | 2014-06-16 | 2014-07-30 | Element Six Technologies Ltd | A microwave plasma reactor for manufacturing synthetic diamond material |
| DE102018000401A1 (en) * | 2018-01-19 | 2019-07-25 | Ralf Spitzl | Microwave plasma device |
-
2020
- 2020-04-13 CN CN202010285786.1A patent/CN111511090B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111511090A (en) | 2020-08-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9818580B2 (en) | Transmission line RF applicator for plasma chamber | |
| US20040011465A1 (en) | Plasma Processing apparatus | |
| AU2014240387B2 (en) | Microwave plasma spectrometer using dielectric resonator | |
| KR101696198B1 (en) | Transmission line rf applicator for plasma chamber | |
| US20040011466A1 (en) | Plasma processing apparatus | |
| WO2007020810A1 (en) | Plasma processing apparatus | |
| JP2002280196A (en) | Plasma generating device using microwave | |
| JP3907087B2 (en) | Plasma processing equipment | |
| KR20090092720A (en) | Microwave plasma processing system and method for using microwave plasma processing system | |
| CN111511090B (en) | Microwave plasma reactor | |
| JPWO2013124906A1 (en) | Plasma processing apparatus and plasma processing method | |
| Liu et al. | A large-area planar helicon plasma source with a multi-ring antenna on Linear Experimental Advanced Device (LEAD) | |
| US9265138B2 (en) | Electromagnetic waveguide and plasma source | |
| CN212278529U (en) | Multi-feed source microwave plasma device | |
| WO2014192062A1 (en) | Microwave plasma emitter device cavity resonator | |
| JP5273759B1 (en) | Plasma processing apparatus and plasma processing method | |
| JP2007018819A (en) | Treatment device and treatment method | |
| JP2013175480A (en) | Plasma processing apparatus and plasma processing method | |
| CN212270234U (en) | Microwave plasma film deposition device | |
| CN110769585B (en) | Surface wave plasma device | |
| JP2004165551A (en) | Plasma processing apparatus | |
| CN218868424U (en) | Microwave resonant cavity | |
| EP4129504A1 (en) | High frequency reaction treatment device and high frequency reaction treatment system | |
| JP4305141B2 (en) | Microwave introduction apparatus and surface wave excitation plasma processing apparatus | |
| CN114976559A (en) | Microwave resonant cavity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |