High-power double-source double-frequency microwave heating device

Abstract

The invention discloses a high-power double-source double-frequency microwave heating device, and relates to the technical field of microwave heating equipment. Comprising a first microwave generation source and a second microwave generation source, the first microwave generation source is connected with a first coaxial antenna through a waveguide tube, the second microwave generation source is connected with a second coaxial antenna through a waveguide tube, and the first coaxial antenna and the second coaxial antenna are vertically arranged on a top cover of the microwave reaction cavity; a material conveying device is arranged below the microwave reaction cavity top cover, a microwave reaction cavity is movably arranged above the material conveying device, a lifting device is arranged at the end part of the material conveying device, and after the microwave reaction cavity moves to the lifting device, the lifting device rises to enable the microwave reaction cavity to be in sealed contact with the microwave reaction cavity top cover. High-power output is achieved through double-source double-frequency microwaves, uniformity and high efficiency of the heating process are guaranteed, energy consumption is remarkably reduced, energy conservation and environmental protection are achieved, and the requirements for high-quality treatment and efficient heating of different materials and technologies are met.

Description

Technical Field

[0001] This invention relates to the field of microwave heating equipment technology, specifically to a high-power dual-source dual-frequency microwave heating device. Background Technology

[0002] In modern industry and materials science, the importance of high-temperature processing technology is increasingly prominent. In ceramic sintering, uniform and precise temperature control directly determines the final product quality; in metal smelting, efficient heating methods can significantly improve production efficiency. Among traditional heating technologies, resistance heating is inefficient, gas heating poses safety hazards and environmental pollution problems, and electromagnetic induction heating is unsuitable for non-metallic materials. Microwave heating technology, because it can achieve the same heating effect as traditional heating in a short time, is increasingly widely used in applications requiring rapid heating and temperature control. Microwaves are electromagnetic waves with frequencies in the 300MHz-300GHz range. They are the result of a superposition of electric and magnetic fields, offering advantages such as rapid and uniform heating, high efficiency and energy saving, selective heating, and environmental friendliness. Lower-frequency microwaves have greater penetration depth, enabling them to deeply and uniformly heat large-volume or high-density materials, while higher-frequency microwaves offer higher heating efficiency and are suitable for applications requiring rapid temperature increases. Although microwave heating technology has many advantages, in practical applications, single-frequency microwave heating often cannot meet the needs of large-volume or high-density materials.

[0003] Therefore, in order to overcome the limitations of single-frequency microwave heating, it is urgent to develop a high-power dual-source dual-frequency microwave heating device to meet the needs of rapid and uniform heating of large-volume or high-density materials. Summary of the Invention

[0004] The purpose of this invention is to provide a high-power dual-source dual-frequency microwave heating device to solve the problem that existing single-frequency microwave heating often cannot meet the needs of large-volume or high-density materials.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a high-power dual-source dual-frequency microwave heating device, characterized in that: it includes a first microwave source and a second microwave source, the first microwave source is connected to a first coaxial antenna through a waveguide, the second microwave source is connected to a second coaxial antenna through a waveguide, the first coaxial antenna and the second coaxial antenna are vertically arranged on the top cover of the microwave reaction cavity; a material conveying device is arranged below the top cover of the microwave reaction cavity, the microwave reaction cavity is movably arranged above the material conveying device, a lifting device is arranged at the end of the material conveying device, after the microwave reaction cavity moves to the lifting device, the lifting device rises so that the microwave reaction cavity and the top cover of the microwave reaction cavity are in sealed contact.

[0006] A further technical solution is that the microwave reaction cavity includes a coaxially arranged inner reaction cavity and an outer reaction cavity, both of which are filled with heat-insulating material, and a sealing ring is provided on the top of the microwave reaction cavity.

[0007] A further technical solution is that the material transport device includes a support frame, a U-shaped slide rail is arranged parallel to the top of the support frame, and rollers adapted to the U-shaped slide rail are arranged at the bottom of the microwave reaction cavity.

[0008] A further technical solution is that the lifting device includes an automatic lifting frame, a supporting top plate is provided on the top of the automatic lifting frame, a U-shaped slide rail is provided parallel on the supporting top plate, a snap-fit ​​limiting component is provided on one side of the supporting top plate, and a protrusion adapted to the snap-fit ​​limiting component is provided on one side of the microwave reaction cavity.

[0009] A further technical solution is that the inner cavity top cover is equipped with thermocouples, with 9 thermocouples in total. Five of them are evenly distributed along the same diameter length direction, and the remaining 4 are symmetrically distributed on both sides of the first coaxial antenna and the second coaxial antenna, with the length of the thermocouples increasing sequentially.

[0010] A further technical solution is that the automatic lifting frame is driven to lift by a motor.

[0011] A further technical solution is that the parameters of the first microwave source are 0-15kW / 2450MHz; and the parameters of the second microwave source are 0-30kW / 915MHz.

[0012] A further technical solution is to provide a coaxial converter on the top of the first and second coaxial antennas, which converts the rectangular waveguide into a coaxial waveguide.

[0013] A further technical solution is that an air inlet is provided on one side of the top of the microwave reaction cavity cover, and the air inlet is connected to the protective atmosphere; an exhaust port is provided on the other side of the top of the microwave reaction cavity cover, and the exhaust port is connected to the gas purification and separation system through a pipe.

[0014] Compared with the prior art, the beneficial effects of the present invention are: it provides a high-power dual-source dual-frequency microwave high-temperature device, which combines the large microwave penetration depth at 915MHz frequency and the high-efficiency microwave heating characteristics at 2450MHz frequency to achieve high power output, ensure the uniformity and efficiency of the heating process, significantly reduce energy consumption, achieve energy saving and environmental protection, and meet the needs of high-quality processing and high-efficiency heating of different materials and processes.

[0015] The microwave reaction cavity containing the reactants is moved horizontally by a material transport device and moved vertically by a lifting device to assemble with the top cover of the microwave reaction cavity equipped with a coaxial antenna, and to quickly complete the heating process. After completion, the microwave reaction cavity is lowered by the lifting device to facilitate the loading and unloading of the reactants. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a front structural diagram of the present invention.

[0018] Figure 3 This is a schematic diagram of the material transport device and lifting device in this invention.

[0019] Figure 4 This is a schematic diagram of the structure of the microwave reaction cavity in this invention.

[0020] Figure 5 This is a schematic diagram showing the usage state of the first coaxial antenna in this invention.

[0021] Figure 6 This is a schematic diagram of the microwave reaction cavity in use in this invention.

[0022] Figure 7 This is a schematic diagram of the assembly of the microwave reaction cavity in this invention.

[0023] Figure 8 This is a schematic diagram of the thermocouple assembly in this invention.

[0024] Figure 9 This is a diagram showing the distribution of thermocouples in this invention.

[0025] Figure 10 This is a temperature distribution diagram monitored by thermocouples.

[0026] In the figure, 1-first microwave generator, 2-second microwave generator, 3-first coaxial antenna, 4-second coaxial antenna, 5-top cover of microwave reaction cavity, 6-material transport device, 601-U-shaped slide rail, 7-microwave reaction cavity, 701-reaction inner cavity, 704-protrusion, 8-lifting device, 801-automatic lifting frame, 802-supporting top plate, 803-clamping limiting component, 9-thermocouple, 12-waveguide, 13-microwave circulator, 14-coaxial converter. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative of the invention and are not intended to limit the invention.

[0028] Figure 1 , 2 A high-power dual-source dual-frequency microwave heating device is shown, including a first microwave source 1 and a second microwave source 2, such as... Figure 5 The first microwave generator 1 is connected to the microwave circulator 13 via a waveguide 12, and then to the coaxial converter 14 via the waveguide. The coaxial converter 14 is then connected to the first coaxial antenna 3, converting the rectangular waveguide into a coaxial waveguide. Similarly, the second microwave generator 2 on the other side is connected to the corresponding microwave circulator 13, coaxial converter 14, and second coaxial antenna 4 via a waveguide on the other side. The first coaxial antenna 3 and the second coaxial antenna 4 are vertically mounted on the top cover 5 of the microwave reaction cavity. An air inlet is provided on one side of the top of the top cover 5 of the microwave reaction cavity, which is connected to the protective atmosphere. An exhaust port is provided on the other side of the top of the top of the top cover 5 of the microwave reaction cavity, which is connected to the gas purification and separation system via a pipe. The top cover 5 of the microwave reaction cavity is fixed to the top of the mounting frame, which has a through hole for the microwave reaction cavity 7 to pass through. The bottom of the mounting frame is suspended and equipped with a lifting device 8.

[0029] like Figure 3 As shown, the lifting device 8 includes an automatic lifting frame 801, which is driven to lift by a motor. A supporting top plate 802 is provided on the top of the automatic lifting frame 801, and a U-shaped slide rail 601 is arranged parallel to it. A locking and limiting member 803 is provided on one side of the supporting top plate 802. The locking and limiting member 803 has an L-shaped structure, with a slot on the side facing the microwave reaction cavity 7, and a protrusion 704 adapted to the locking and limiting member 803 on the side of the microwave reaction cavity 7.

[0030] like Figure 6 , 7 As shown, the material conveying device 6 includes a support frame, with a U-shaped slide rail 601 arranged parallel to the top of the support frame, and rollers adapted to the U-shaped slide rail 601 arranged at the bottom of the microwave reaction cavity 7. The U-shaped slide rail 601 on the material conveying device 6 is positioned opposite to the U-shaped slide rail 601 on the support top plate 802. After the microwave reaction cavity 7 is filled with material on the material conveying device 6, it is pushed forward, and the rollers at the bottom of the microwave reaction cavity 7 move forward along the U-shaped slide rail 601 until the protrusion 704 at the end of the microwave reaction cavity 7 is engaged and fixed in place by the locking and limiting member 803.

[0031] like Figure 4As shown, the microwave reaction chamber 7 includes a coaxially arranged inner reaction chamber 701 and an outer reaction chamber, both filled with insulating material. A sealing ring is provided on the top of the microwave reaction chamber 7, which is compatible with the top cover 5 of the microwave reaction chamber. After the microwave reaction chamber 7 is fixed to the lifting device 8, the motor drives the automatic lifting frame 801 to rise, and the microwave reaction chamber 7 makes sealing contact with the top cover 5 of the microwave reaction chamber. This sealing contact can be achieved by the sealing ring on the top of the microwave reaction chamber 7, plus the lifting force of the automatic lifting frame 801 driven by the motor, which is basically sufficient for use. If this is insufficient, bolt holes can be further provided on the top cover 5 of the microwave reaction chamber and the microwave reaction chamber 7 for further fixation with fasteners. After the reaction is completed, the automatic lifting frame 801 descends. After cooling, the microwave reaction chamber 7 is manually pulled. After the protrusion 704 disengages from the locking limit member 803, the microwave reaction chamber 7 is then pulled to the material transport device 6, whereby the reactant can be removed or a new microwave reaction chamber 7 can be replaced.

[0032] To ensure an oxygen-free or low-oxygen environment within the microwave reaction cavity 7 during the reaction process, an air inlet is provided on one side of the top of the microwave reaction cavity cover 5. The air inlet is connected to a protective atmosphere nitrogen tank, and nitrogen is introduced to maintain a protective atmosphere and a slight negative pressure within the reaction cavity. To facilitate gas discharge, the inner cavity cover 702 is flat, while the microwave reaction cavity cover 5 is dome-shaped. The inner cavity cover 702 is also provided with an exhaust port.

[0033] To facilitate monitoring the heating of the reactants within the microwave reaction cavity 7, thermocouples 9 are distributed on the inner cavity top cover 702. Nine thermocouples 9 are provided, five of which are evenly distributed along the same diameter, and the remaining four are symmetrically distributed on both sides of the first coaxial antenna 3 and the second coaxial antenna 4, with the length of the thermocouples 9 increasing sequentially. Specifically, as follows... Figure 8 , 9 As shown, the measured temperature is as follows Figure 10 As shown, by setting different positions and heights to achieve multi-position temperature measurement, the results show that the temperature at each position is basically uniform. This also shows that dual-source dual-frequency microwave heating can achieve both rapid heating and uniform heating at each position.

[0034] The coaxial antenna is input into the microwave reaction cavity 7 via probe coupling. From the inside out, it consists of a central conductor, an insulating layer, and an outer sheath. The central conductor is made of copper, silver, aluminum, or their alloys, and is wrapped with an insulating layer of aluminum silicate cotton. The outer sheath is made of materials such as polytetrafluoroethylene, polypropylene, ceramic, or quartz glass. The coaxial antenna is connected to the coaxial converter via a threaded connection, and the central conductor is fixed to the waveguide via a threaded connection. The coaxial converter consists of three layers of stainless steel metal walls. The inner and middle walls form a gas cooling channel, while the middle and outer walls form a circulating water cooling channel, meeting the requirements for high-power, high-temperature operation of the device and extending its service life through water and gas cooling.

[0035] To facilitate rapid heating of large-volume or high-density materials, the microwave circulator is adapted to 915MHz / 30kW and 2450MHz / 15kW microwave sources, respectively. The rectangular waveguides are BJ9 and BJ22 waveguides. Combining the large microwave penetration depth at 915MHz and the efficient heating characteristics of microwaves at 2450MHz, high-power output is achieved. The compressed coal is loaded into the microwave reaction chamber 7, a thermocouple is inserted, and the inner chamber top cover 702 is closed. The material is then raised using the lifting device 8 until it is in sealed contact with the microwave reaction chamber top cover 5. After sealing, N2 is introduced, and a slight positive pressure is created inside the chamber using a vacuum pump. The microwave source is then activated, and the material is heated via a coaxial antenna. By adjusting the microwave frequency, microwave power, and holding time, the thermal effect of the coal under microwave action is studied. Microwaves are transmitted from a rectangular waveguide to the coaxial antenna via probe coupling, achieving heat source transmission and efficient selective heating of the coal. The material temperature can reach 800~1000℃ after heating for 30 minutes. The exhaust gas generated during this process is pumped into a gas purification and separation system, where it is recovered after condensation, alkaline washing, and drying.

[0036] Although the invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope of this disclosure. More specifically, various modifications and improvements can be made to the components or layouts within the scope of this disclosure, the drawings, and the claims. Besides modifications and improvements to the components or layouts, other uses will be apparent to those skilled in the art.

Claims

1. A high-power dual-source dual-frequency microwave heating device, characterized in that: The system includes a first microwave source (1) and a second microwave source (2). The first microwave source (1) is connected to a first coaxial antenna (3) via a waveguide, and the second microwave source (2) is connected to a second coaxial antenna (4) via a waveguide. The first coaxial antenna (3) and the second coaxial antenna (4) are vertically mounted on the top cover (5) of the microwave reaction cavity. A material transport device (6) is provided below the top cover (5) of the microwave reaction cavity. A microwave reaction cavity (7) is moved above the material transport device (6). A lifting device (8) is provided at the end of the material transport device (6). After the microwave reaction cavity (7) moves to the lifting device (8), the lifting device (8) rises so that the microwave reaction cavity (7) and the top cover (5) of the microwave reaction cavity are in sealed contact.

2. The high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The microwave reaction cavity (7) includes a reaction inner cavity (701) and a reaction outer cavity arranged coaxially. The reaction inner cavity (701) and the reaction outer cavity are filled with heat-insulating material, and a sealing ring is provided on the top of the microwave reaction cavity (7).

3. The high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The material transport device (6) includes a support frame, with a U-shaped slide rail (601) arranged parallel to the top of the support frame, and rollers adapted to the U-shaped slide rail (601) arranged at the bottom of the microwave reaction cavity (7).

4. A high-power dual-source dual-frequency microwave heating device according to claim 3, characterized in that: The lifting device (8) includes an automatic lifting frame (801), a support top plate (802) is provided on the top of the automatic lifting frame (801), a U-shaped slide rail (601) is provided parallel on the support top plate (802), a snap-fit ​​limiting member (803) is provided on one side of the support top plate (802), and a protrusion (704) adapted to the snap-fit ​​limiting member (803) is provided on one side of the microwave reaction cavity (7).

5. A high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The microwave reaction cavity top cover (5) is equipped with thermocouples (9). There are 9 thermocouples (9), 5 of which are evenly distributed along the same diameter length direction, and the remaining 4 are symmetrically distributed on both sides of the first coaxial antenna (3) and the second coaxial antenna (4). The length of the thermocouples (9) increases sequentially.

6. A high-power dual-source dual-frequency microwave heating device according to claim 4, characterized in that: The automatic lifting frame (801) is driven to lift by a motor.

7. A high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The parameters of the first microwave source (1) are 0-15kW / 2450MHz; the parameters of the second microwave source (2) are 0-30kW / 915MHz.

8. A high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The first coaxial antenna (3) and the second coaxial antenna (4) are provided with a coaxial converter at the top to convert the rectangular waveguide into a coaxial waveguide.

9. A high-power dual-source dual-frequency microwave heating device according to claim 1, characterized in that: The top of the microwave reaction chamber cover (5) is provided with an air inlet on one side, which is connected to the protective atmosphere; the top of the microwave reaction chamber cover (5) is provided with an exhaust hole on the other side, which is connected to the gas purification and separation system through a pipe.

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