Coaxial radiator, heating method and system

Abstract

The invention belongs to the field of radiators, and particularly relates to a coaxial radiator and a heating method and system.The coaxial radiator comprises an inner conductor, a dielectric material and an outer conductor, the inner conductor is arranged in the outer conductor and located in the middle area of the outer conductor, the cross section of the inner conductor is circular, and the dielectric material is arranged in the outer conductor. A dielectric material is arranged between the inner conductor and the outer conductor; the inner conductor comprises a heating end used for heating, the diameter of the heating end is gradually and uniformly increased towards the tail end direction of the heating end, a step structure is further arranged on the end face of the tail end of the heating end, and the step structure comprises at least two steps. The invention provides a coaxial radiator, a heating method and a heating system, and aims to solve the problem that in the prior art, a microwave heating device needs to depend on a closed cavity, so that the use of microwave heating is limited.

Description

Technical Field

[0001] This invention belongs to the field of radiators, specifically relating to a coaxial radiator, a heating method, and a system. Background Technology

[0002] Microwaves, as electromagnetic waves with frequencies between 300MHz and 300GHz, have become a highly promising and efficient clean energy source in modern industry due to their high energy density, low transmission loss, and environmental friendliness. They have achieved large-scale application and deep penetration in many key industries such as chemical synthesis, metallurgical refining, electronic manufacturing, and materials processing. As a typical representative of emerging heating technologies, microwave heating breaks through the inherent limitations of traditional heating modes. Its core advantages are not only reflected in its high energy utilization efficiency, strong selective heating capability, and low operating cost, but also in its unique heating mechanism. It achieves a three-dimensional heating mode "from the inside out" by exciting the high-frequency vibration (billions of times per second) of polar molecules inside the material, causing intermolecular friction and collision to generate internal heat.

[0003] Traditional microwave heating devices employ a closed-loop structure. This design is the mainstream solution for applying microwave energy to industrial heating and laboratory sample processing. Its core design logic revolves around confining microwave energy within a sealed space to the heated object, ensuring heating efficiency and operational safety. Specifically, the core components of such devices include a sealed cavity, a microwave generator, a waveguide transmission assembly, a sealed door, and a safety protection system. The sealed cavity typically uses a composite structure made of metal (such as stainless steel) or lined with microwave-reflective materials. The cavity shape is often rectangular, cylindrical, or other regular geometric forms. The microwave reflection characteristics of the metal walls create a resonant field within the cavity, maximizing microwave energy utilization. The microwave energy generated by the microwave generator is directionally transmitted to the interior of the sealed cavity via a waveguide. A microwave leakage protection device (such as a metal shielding mesh or a choke structure) must be installed at the junction of the cavity and the door to ensure that microwave leakage meets international safety standards.

[0004] However, existing technologies for microwave heating rely on enclosed cavities, which severely limit the size and shape of the objects being processed. Furthermore, the entire microwave heating system is often bulky, expensive to manufacture, and its energy decays exponentially within the cavity, resulting in low utilization.

[0005] Therefore, there is an urgent need in the existing technology for a device that can perform microwave heating without the need for a closed cavity. Summary of the Invention This invention provides a coaxial radiator, a heating method, and a system, the purpose of which is to solve the problem that microwave heating devices in the prior art need to rely on a closed cavity, which leads to limitations in the use of microwave heating.

[0006] To achieve the above objectives, the present invention provides a coaxial radiator, comprising an inner conductor, a dielectric material, and an outer conductor, wherein the inner conductor is disposed inside the outer conductor and is located in the middle region of the outer conductor, and the dielectric material is disposed between the inner conductor and the outer conductor, wherein the dielectric material separates the inner conductor and the outer conductor from each other; The inner conductor includes a heating end for heating, the diameter of which gradually increases uniformly towards the end of the heating end, and a stepped structure is provided on the end face of the heating end. The stepped structure includes at least two steps, each of which is cylindrical, and the upper step has a smaller diameter than the lower step. All steps are coaxial with the axis of the inner conductor.

[0007] This solution proposes a coaxial radiator that can be connected to a microwave source to heat objects in an open environment, thus overcoming the limitation of existing microwave heating devices that must be heated in a closed cavity. Furthermore, by gradually increasing the diameter of the heating end of the inner conductor to form a frustum shape, impedance matching is achieved, and the electric field is increased. Then, by setting a stepped structure, the electric field is focused into a small area, resulting in better heating performance.

[0008] Preferably, in order to connect the coaxial radiator to the microwave source, this solution further includes a connector located at the ends of the inner conductor and the outer conductor, and the connector is adapted to connect to both the inner conductor and the outer conductor. The connector is used to connect to the microwave source.

[0009] This solution uses a connector that can be connected to a microwave source to ensure a sufficient microwave supply to the coaxial radiator.

[0010] Preferably, since the coaxial radiator is connected to an external microwave source via a connector, the external microwaves are easily affected when they enter through the connector. Because of this issue, the inner conductor in this solution includes a connecting end that is adapted to the connector, and the diameter of the connecting end gradually decreases towards its end.

[0011] In this scheme, the connection end of the inner conductor is connected to the connector. Then, by reducing the diameter of the connection end to form a frustum shape, the impedance between the inner conductor and the connector is matched. Compared with the case where the diameter is unchanged, the heating effect of the coaxial radiator is better.

[0012] Meanwhile, the preferred connector in this solution is the L29 connector.

[0013] Preferably, since the coaxial radiator is connected to an external microwave source via a connector, the external microwaves are easily affected when they enter through the connector. To solve the above problem, the outer conductor of this solution includes a connector end for fitting and connecting with the connector, the diameter of which gradually decreases towards the end of the connector end.

[0014] In this scheme, the connector end of the outer conductor is connected to the connector, and then the diameter of the connector end is reduced to form a frustum shape. The impedance between the inner conductor and the connector is matched, and the heating effect of the coaxial radiator is better than when the diameter is unchanged.

[0015] Preferably, to further focus the electric field and achieve a better heating effect, the outer conductor in this solution includes a working end for heating, and the working end is constructed with an annular port. This solution further focuses the electric field by setting the annular port, thereby achieving a better heating effect.

[0016] In this design, the cross-section of the outer conductor is preferably annular.

[0017] Preferably, in order to form a ring port, the ring port in this embodiment is formed by extending the outer conductor.

[0018] The preferred embodiment of this design is that the annular port is circular.

[0019] Preferably, the inner conductor does not protrude from the annular port in this design.

[0020] In order to heat the object to be heated, a second aspect of the present invention discloses a heating method using the above-mentioned coaxial radiator, specifically including the following steps: S1: The microwave absorbing medium is set in conjunction with the object to be heated; S2: Use a coaxial radiator to heat the absorbing medium; S3: The temperature of the absorbing medium increases, which heats the object to be heated.

[0021] This scheme involves setting up an absorbing medium in conjunction with the object to be heated. When a coaxial radiator is used to heat the absorbing medium, its temperature rises. Because the absorbing medium is in contact with the object to be heated, the object is also heated, thus achieving the desired heating effect.

[0022] Preferably, in order to achieve a better heating effect, in S1 of this solution, the absorbing medium is placed between the two objects to be heated.

[0023] Alternatively, to achieve a better heating effect, in S1 of this solution, the absorbing medium is mixed with the object to be heated.

[0024] Preferably, the absorbing medium in this solution is carbon black or CNTs.

[0025] The absorbing medium is in powder or film form.

[0026] A third aspect of this invention discloses a system for heating using the aforementioned coaxial radiator, comprising a coaxial radiator and a microwave source, wherein the microwave source is connected to the coaxial radiator. By connecting the coaxial radiator to the microwave source, the normal operation of the coaxial radiator is ensured.

[0027] The beneficial effects of this invention are as follows: This solution proposes a coaxial radiator that can be connected to a microwave source, enabling heating of objects in an open environment, thus overcoming the deficiency of existing microwave heating devices that must be heated in a closed cavity. Simultaneously, by gradually increasing the diameter of the heating end of the inner conductor to form a frustum shape, impedance matching is achieved, and the electric field is increased. Furthermore, by setting a stepped structure, the electric field is focused within a small area, resulting in better heating performance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the coaxial radiator in Example 1.

[0029] Figure 2 This is a cross-sectional view of the coaxial radiator in Example 1.

[0030] Figure 3 This is a schematic diagram of the inner conductor in Example 1.

[0031] Figure 4 This is a temperature diagram of the coaxial radiator in Example 1.

[0032] Figure 5 The diagram shows a comparison of the electric field when the heating end diameter remains unchanged and no stepped structure is set, and when the heating end diameter changes and a stepped structure is set.

[0033] Figure 6 This is a schematic diagram of the heating system in Example 3.

[0034] The reference numerals in the attached figures include: inner conductor 1, heating end 11, connecting end 12, stepped structure 13, outer conductor 2, ring port 21, connector 3, and microwave source 4. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0036] Example 1 The basic implementation examples are as follows: Figure 1 To be continued Figure 5As shown, a coaxial radiator includes an inner conductor 1, a dielectric material, and an outer conductor 2. The inner conductor 1 has a cylindrical cross-section, while the outer conductor 2 has an annular cross-section. The inner conductor 1 is housed inside the outer conductor 2, and is located in the central region of the outer conductor 2. The inner conductor 1 and the outer conductor 2 are coaxially aligned. The dielectric material is specifically disposed between the inner conductor 1 and the outer conductor 2, and is preferably FR4. The dielectric material separates the inner conductor 1 and the outer conductor 2 from each other. In this embodiment, the dominant mode of the guided wave in the coaxial radiator is the TEM mode, which has low radiation loss and is not easily affected by external signals.

[0037] like Figure 3 As shown, in this embodiment, the inner conductor 1 has a heating end 11 and a connecting end 12 at its two ends, which are arranged opposite to each other. The connecting end 12 is in a mating connection with the connector 3, while the heating end 11 is used to heat the external object to be heated. To solve the problem of poor heating effect due to the inability of the electric field to be focused in a small area, in this embodiment, the diameter of the heating end 11 of the inner conductor 1 gradually increases towards its end, so that the end of the heating end 11 forms a frustum-shaped matching structure. The top of the frustum-shaped matching structure is connected to the middle of the inner conductor 1, and the diameter of the top of the frustum-shaped structure is the same as the diameter of the middle of the inner conductor 1. The main purpose of forming the frustum-shaped heating end 11 is to achieve a smooth transition region for impedance matching. The characteristic impedance of the heating end 11 changes slowly with its length by continuously changing the radial dimension of the inner / outer conductor 2 (i.e., the diameter of the heating end 11 of the inner conductor 1 gradually increases, while the inner diameter of the outer conductor 2 remains unchanged). The frustum-shaped heating end 11 is a linear matching structure. Through continuous changes in its geometry, the boundary conditions of the electromagnetic field can be gradually altered, achieving impedance matching. Then, a stepped structure 13 is placed on the end face of the heating end 11, as shown below. Figure 3 As shown. The stepped structure 13 includes at least two levels of steps. In specific implementations, the steps can be set to 2, 3, 4, 5, 6, or 7 levels, but 5 or 6 levels are more preferred. Each step in this embodiment is cylindrical, with the upper step having a smaller diameter than the lower step. All steps overlap, with no gaps between them, and all steps are coaxially arranged with each other and with the inner conductor. By setting the stepped structure 13, the electric field is concentrated at the steps, achieving an electric field focusing effect and resulting in better heating. Figure 4 and Figure 5 As shown, the electric field strength increases significantly after the stepped structure and matching structure are set.

[0038] like Figure 1 and Figure 2As shown, in this embodiment, the working end of the outer conductor 2 extends outward, and the end of the working end of the outer conductor 2 extends towards the end of the dielectric material, so that the end of the coaxial radiator forms a circular port. Through the circular port, the electric field can be further focused, thereby improving the heating effect of the coaxial radiator.

[0039] To achieve connection with microwave source 4, the coaxial radiator in this design is equipped with connector 3. Connector 3 is preferably an L29 connector, which is adapted to connect with the inner conductor 1 and the outer conductor 2. When a microwave signal is fed into the coaxial radiator through connector 3, reflection will occur due to the impedance mismatch between the inner conductor 1 and connector 3, resulting in energy loss. Therefore, in this embodiment, the diameter of the connecting end 12 of the inner conductor gradually decreases towards its end, forming a frustum shape. The end of the connecting end 12 connects to connector 3, gradually transitioning the impedance at connector 3 to the impedance of the inner conductor 1, reducing energy loss. Similarly, to achieve impedance matching for the outer conductor 2, in this embodiment, the end of the outer conductor 2 connected to connector 3 is called the connector end. The diameter of the connector end of the outer conductor 2 gradually decreases towards its end, gradually transitioning the impedance at connector 3 to the impedance of the outer conductor 2, reducing energy loss and achieving better heating effect.

[0040] The specific working process is described below: When heating is required, the microwave source 4 is connected to the connector 3. The microwave source 4 feeds in microwave signals, and the coaxial radiator heats the object in an open environment using microwaves, overcoming the shortcomings of existing technologies. Simultaneously, when the coaxial radiator is working, because the diameter of the heating end 11 of the inner conductor 1 gradually increases, and the end face of the heating end 11 has a stepped structure, the electric field can be more concentrated, resulting in better heating.

[0041] Example 2 This embodiment discloses a heating method, which specifically includes the following steps: S1: The microwave absorbing medium is set in conjunction with the object to be heated. The microwave absorbing medium can be CNTs or carbon black.

[0042] For example, when a coaxial radiator is needed to heat two plate-shaped objects, the absorbing medium can be placed between the two objects to achieve heating; when a coaxial radiator is needed to heat metal powder, the absorbing medium can be mixed with the metal powder to achieve heating.

[0043] S2: Move the coaxial radiator to a position aligned with the absorbing medium, and use the coaxial radiator to heat the absorbing medium.

[0044] During implementation, the coaxial radiator can be moved directly above or below the absorbing medium. The coaxial radiator operates, the absorbing medium absorbs waves, and the absorbing medium is heated. The coaxial radiator is 1 mm away from the absorbing medium.

[0045] S3: The temperature of the absorbing medium rises under the action of the coaxial radiator, which passively drives the temperature of the object placed in conjunction with the absorbing medium to rise as well, and the object to be heated is heated.

[0046] The heating method disclosed in this solution uses a coaxial radiator, which can focus heating on a local area in an open environment, thereby achieving a better heating effect.

[0047] Example 3 This embodiment discloses a heating system, such as Figure 6 As shown, the device includes a coaxial radiator as described in Embodiment 1 and a microwave source 4. The microwave source 4 can be a conventional microwave source 4 device, used to provide microwaves. The coaxial radiator and the microwave source 4 are connected via a connector 3 to ensure the normal operation of the coaxial radiator.

[0048] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A coaxial radiator, characterized in that: It includes an inner conductor (1), a dielectric material and an outer conductor (2), wherein the inner conductor (1) is disposed inside the outer conductor (2) and the inner conductor (1) is located in the middle region of the outer conductor (2), and the dielectric material is disposed between the inner conductor (1) and the outer conductor (2) to separate the inner conductor (1) and the outer conductor (2) from each other; The inner conductor (1) includes a heating end (11) for heating. The diameter of the heating end (11) gradually increases uniformly towards its end. A stepped structure (13) is also provided on the end face of the heating end (11). The stepped structure (13) includes at least two steps. Each step is cylindrical. The upper step has a smaller diameter than the lower step. All steps are coaxial with the axis of the inner conductor (1).

2. The coaxial radiator according to claim 1, characterized in that: It also includes a connector (3) located at the ends of the inner conductor (1) and the outer conductor (2), and the connector (3) is adapted to connect with both the inner conductor (1) and the outer conductor (2), and the connector (3) is used to connect with a microwave source (4).

3. The coaxial radiator according to claim 2, characterized in that: The inner conductor (1) includes a connecting end (12), which is adapted to be connected to the connector (3), and the diameter of the connecting end (12) gradually decreases towards the end of the connecting end (12); and / or; The connector (3) is an L29 connector.

4. The coaxial radiator according to claim 2, characterized in that: The outer conductor (2) includes a connector (3) end for adapting to the connector (3), the diameter of which gradually decreases toward the end of the connector (3).

5. The coaxial radiator according to claim 1, characterized in that: The outer conductor (2) includes a working end for heating, the working end being configured with an annular port (21); And / or, the cross-section of the outer conductor (2) is annular.

6. The coaxial radiator according to claim 5, characterized in that: The annular port (21) is formed by extending the outer conductor (2); And / or, the annular port (21) is circular; And / or, the inner conductor (1) does not protrude from the annular port (21).

7. A heating method using the coaxial radiator according to any one of claims 1 to 6, characterized in that: Includes the following steps, S1: The microwave absorbing medium is set in conjunction with the object to be heated; S2: Use a coaxial radiator to heat the absorbing medium; S3: The temperature of the absorbing medium increases, which heats the object to be heated.

8. The heating method according to claim 7, characterized in that: In step S1, the absorbing medium is disposed between the two objects to be heated; Alternatively, in S1, the absorbing medium is mixed with the object to be heated.

9. The heating method according to claim 7 or 8, characterized in that: The absorbing medium is carbon black or CNTs; And / or, the absorbing medium is in powder or film form.

10. A heating system using the coaxial radiator according to any one of claims 1 to 6, characterized in that: It includes a coaxial radiator and a microwave source (4), wherein the microwave source (4) is connected to the coaxial radiator.

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