Microwave vacuum plasma equipment

Abstract

This invention provides a microwave vacuum plasma device. The microwave vacuum plasma device includes a vacuum cavity, a microwave source, and a microwave focusing element. The vacuum cavity is configured to contain packaged or unpackaged materials and a working gas. The microwave source is positioned above the vacuum cavity and configured to supply microwaves. The microwave focusing element is positioned between the microwave source and the vacuum cavity and configured to focus and concentrate the microwaves within the vacuum cavity, thereby generating plasma by ionizing the working gas with microwaves. Compared with existing technologies, the microwave vacuum plasma device provided by this invention features a simple structure, low manufacturing cost, low energy consumption, and improved microwave energy conversion to plasma efficiency.

Description

Microwave vacuum plasma equipment Technical Field

[0001] This invention relates to the field of plasma technology, and more specifically, to a microwave vacuum plasma device. Prior Technology

[0002] Commercial sterilization methods for heat-sensitive foods or drugs mainly include heat treatment, radiation treatment, and chemical disinfectants or sterilizing agents. These methods can effectively reduce the microbial content in food or drugs, but each also has certain drawbacks. For example, heat treatment may lead to the deterioration of the product's color, aroma, and nutritional components, and may even reduce the quality and content of active ingredients in drugs. In addition, heat treatment may sometimes increase the moisture content of food or drugs, thereby shortening their shelf life. Radiation treatment is a non-thermal sterilization technology. The European Union has authorized the use of gamma rays to treat food and drugs, with a maximum average dose of 10 to 25 kGy, and the sensory characteristics and antioxidant capacity of the finished product are only slightly affected. However, consumer acceptance of radiation treatment is generally low, and such treatment usually needs to be carried out by professional agencies that comply with local regulations, resulting in additional costs and logistical complexity. As for chemical disinfectants or sterilizing agents, short-term exposure may cause physical discomfort, while long-term exposure may damage the nervous system and even increase the risk of cancer.

[0003] In addition, some foods and medicines often use high-barrier packaging such as aluminum foil bags, glass bottles and jars, and metal cans to prevent the penetration of gases and moisture, thereby maintaining the freshness and original flavor of the food or preventing the medicine from getting damp. However, considering environmental protection and sustainable development, it is extremely important to develop new packaging materials that eliminate aluminum foil. The sterilization treatment of foods or medicines using new packaging materials requires physical non-thermal treatment equipment (such as plasma equipment).

[0004] However, existing plasma devices are complex in structure, have high manufacturing costs and high energy consumption, and have low energy conversion efficiency.

[0005] Therefore, it is necessary to improve the plasma equipment in the existing technology to solve the above-mentioned problems. Summary of the Invention

[0006] The purpose of this invention is to provide a microwave vacuum plasma device to solve the technical problems of existing plasma devices, such as complex structure, high manufacturing cost, high energy consumption, and low energy conversion plasma efficiency.

[0007] According to one embodiment of the present invention, a microwave vacuum plasma device includes a vacuum cavity, a microwave source, and a microwave focusing element. The vacuum cavity is configured to contain packaged or unpackaged materials and a working gas. The microwave source is disposed above the vacuum cavity and configured to supply microwaves. The microwave focusing element is disposed between the microwave source and the vacuum cavity and configured to focus and concentrate the microwaves within the vacuum cavity to generate plasma by ionizing the working gas with microwaves.

[0008] Compared with the prior art, the microwave vacuum plasma equipment provided by this invention has the advantages of simple structure, low manufacturing cost and low energy consumption. It can also focus microwaves into the vacuum cavity through microwave focusing elements to improve the microwave energy conversion plasma efficiency. Simple Explanation of the Diagram

[0009] When read in conjunction with the accompanying drawings, some embodiments of the present invention will become readily apparent from the following detailed description. It should be noted that the various structures may not be drawn to scale, and the dimensions of the various structures may be arbitrarily increased or decreased for clarity of explanation.

[0010] Figure 1 shows a schematic diagram of a microwave vacuum plasma device according to some embodiments of the present invention.

[0011] Figure 2 shows a side view of a microwave vacuum plasma device according to some embodiments of the present invention.

[0012] Figure 3 shows a cross-sectional schematic diagram of the vacuum cavity and material conveying unit of some embodiments of the present invention.

[0013] Figure 4 shows a schematic diagram of the operation of the material conveying unit in some embodiments of the present invention. Implementation

[0014] Figure 1 shows a schematic diagram of a microwave vacuum plasma device 1 according to some embodiments of the present invention. Figure 2 shows a side view of a microwave vacuum plasma device 1 according to some embodiments of the present invention. Referring to Figures 1 and 2, the microwave vacuum plasma device 1 of the present invention includes a vacuum chamber 10, a microwave source 20, a microwave focusing element 30, a waveguide 21, a circulator 40, a microwave power monitoring unit 50, a quartz barrier plate 60, a pressure control unit 61, an image recognition unit 62, a material conveying unit 70, and a plurality of gas migration barrier structures 80.

[0015] The vacuum chamber 10 can be configured to contain packaged material 90 or unpackaged material and a working gas. In some embodiments of this invention, the packaged material 90 may include, for example, packaged food or packaged pharmaceuticals. The unpackaged material may include, for example, unpackaged food or unpackaged pharmaceuticals. The working gas may include, but is not limited to, air or argon.

[0016] Figure 3 shows a cross-sectional schematic diagram of the vacuum chamber 10 and the material conveying unit 70 in some embodiments of the present invention. In some embodiments of the present invention, as shown in Figures 2 and 3, the vacuum chamber 10 may have an inlet end 10A, an outlet end 10B, a top surface 11, a side surface 12, an inner wall surface 13, an internal accommodating groove 14, an air inlet 15, an air extraction port 16, and a shelf 17. The side surface 12 may have an observation window (not shown), and a conductive or magnetic mesh structure may be provided on the observation window to prevent microwave leakage. The internal accommodating groove 14 may extend outward from the inner wall surface 13. The working gas may enter the vacuum chamber 10 through the air inlet 15 and then be extracted from the vacuum chamber 10 through the air extraction port 16. The shelf 17 can be used to place packaged materials 90 or unpackaged materials.

[0017] The microwave source 20 can be placed above the vacuum cavity 10 and configured to supply microwaves M.

[0018] A microwave focusing element 30 may be disposed between the microwave source 20 and the vacuum cavity 10. In some embodiments of this invention, the microwave focusing element 30 may contact the top surface 11 of the vacuum cavity 10. The microwave focusing element 30 may be configured to focus microwaves M into the vacuum cavity 10 to generate plasma P by ionizing the working gas through the microwaves M. In some embodiments of this invention, the plasma P may be used to sterilize packaged materials 90 or unpackaged materials.

[0019] In some embodiments of this invention, as shown in Figures 1 and 2, the microwave focusing element 30 may include a straight cylindrical portion 31 and a tapered portion 32. The straight cylindrical portion 31 may contact the top surface 11 of the vacuum cavity 10. The tapered portion 32 may connect to the straight cylindrical portion 31. In some embodiments of this invention, the width of the tapered portion 32 may gradually increase toward the straight cylindrical portion 31.

[0020] Waveguide 21 can be disposed between microwave source 20 and microwave focusing element 30. Waveguide 21 can also be configured to transmit microwave M.

[0021] The circulator 40 can be disposed between the waveguide 21 and the microwave source 20. In some embodiments of this invention, a water-loaded structure may be provided within the circulator 40. The water-loaded structure may be configured to absorb reflected microwaves M to prevent damage to the microwave source 20 from reflected microwaves M.

[0022] The microwave power monitoring unit 50 can be located on one side of the waveguide 21 and configured to monitor the power changes of the microwave M in real time to ensure the stability of the energy provided when the plasma P is generated.

[0023] A quartz barrier plate 60 can be disposed between the waveguide 21 and the microwave focusing element 30. The quartz barrier plate 60 isolates the microwave generating components (including, for example, the microwave source 20, the circulator 40, and the waveguide 21) from the vacuum chamber 10 to maintain the vacuum level of the vacuum chamber 10. Furthermore, utilizing the material properties of the quartz barrier plate 60 itself, energy loss during microwave M transmission can be reduced. In some embodiments of this invention, the quartz barrier plate 60 can be combined with a sealing element (not shown) to further prevent working gas leakage, thereby improving the barrier effect.

[0024] A pressure control unit 61 may be disposed on the top surface 11 of the vacuum chamber 10 and configured to control the internal pressure of the vacuum chamber 10. In some embodiments of the present invention, the pressure control unit 61 may use parameters obtained from a pressure gauge to control the operation of a vacuum pump and maintain the internal pressure of the vacuum chamber 10 according to a set value.

[0025] The image recognition unit 62 can be disposed on the side 12 of the vacuum chamber 10 and configured to recognize the characteristics (including, for example, type, size, or color) of the packaged material 90 or unpackaged material. In addition, during the vacuuming process, the image recognition unit 62 can detect the deformation of the packaging and control the system operating parameters through image recognition.

[0026] Figure 4 shows a schematic diagram of the operation of a material conveying unit 70 according to some embodiments of the present invention. Referring to Figures 3 and 4, the material conveying unit 70 can be configured to convey packaged materials 90 or unpackaged materials. The material conveying unit 70 may include a magnetic tray 71, an internal magnet 72, and an external electromagnet 73.

[0027] The magnetic tray 71 can be disposed within the vacuum chamber 10 and configured to hold packaged materials 90 or unpackaged materials. In some embodiments of this invention, the magnetic tray 71 can be disposed on a shelf 17.

[0028] An internal magnet 72 may be disposed within the vacuum chamber 10 and located on at least one side of the magnetic tray 71. In some embodiments of the present invention, as shown in Figures 3 and 4, the internal magnet 72 may be located on both sides of the magnetic tray 71. In some embodiments of the present invention, the internal magnet 72 may be disposed in the internal receiving groove 14 of the vacuum chamber 10. In some embodiments of the present invention, the internal receiving groove 14 of the vacuum chamber 10 may extend from the inner wall surface 13 toward the external electromagnet 73.

[0029] An external electromagnet 73 may be disposed outside the vacuum cavity 10 and adjacent to the internal magnet 72. In some embodiments of this invention, the external electromagnet 73 may define a direction of movement R, and the direction of movement R may be parallel to the length direction of the vacuum cavity 10. In some embodiments of this invention, the external electromagnet 73 may be energized to magnetically attract and fix the magnetic tray 71 inside the vacuum cavity 10; the external electromagnet 73 may be movable to pull or drag the magnetic tray 71 to achieve the effect of conveying packaged materials 90 or unpackaged materials; the external electromagnet 73 may be de-energized to release the magnetic attraction and fixation of the magnetic tray 71.

[0030] Referring again to Figure 1, a plurality of gas migration barrier structures 80 can be spaced apart between the feed end 10A and the discharge end 10B of the vacuum chamber 10, and configured to define a plurality of vacuum chambers 10' within the vacuum chamber 10. In some embodiments of this invention, a gas migration barrier structure 80 can be provided on each side of each vacuum chamber 10'. In some embodiments of this invention, the gas migration barrier structure 80 may include, but is not limited to, a gate, and the gate may have a microwave leakage prevention design, for example, by providing a conductive or magnetic mesh structure on the gate. In some embodiments of this invention, a pneumatic element can be used to drive the opening and closing of the valve. In some embodiments of this invention, a plurality of vacuum chambers 10' can be connected in series as needed.

[0031] In some embodiments of this novel invention, the vacuum level of a plurality of vacuum chambers 10' can be adjusted in segments (for example, starting with the vacuum chamber 10' adjacent to the feed end 10A, the vacuum level can be -600 Torr, -750 Torr, -756 Torr, -600 Torr, 0 Torr in sequence) to achieve segmented vacuum, so that the vacuum level of the vacuum chamber 10 can be maintained within a certain range, thereby reducing the time and energy consumption for depressurization and vacuuming each time material is fed or discharged.

[0032] In the embodiments shown in Figures 1 to 4, the microwave vacuum plasma device 1 can focus microwaves M into the vacuum cavity 10 through the microwave focusing element 30 to improve the microwave energy conversion plasma efficiency. Furthermore, the microwave power monitoring unit 50 monitors the power changes of microwaves M in real time, ensuring the stability of the energy provided during plasma P generation. In addition, the magnetic attraction design of the material conveying unit 70 (including a magnetic tray 71, an internal magnet 72, and an external electromagnet 73) allows for the conveying of packaged materials 90 or unpackaged materials without disrupting the vacuum level of the vacuum cavity 10, and prevents microwave M leakage. Besides the above-mentioned technical effects, the microwave vacuum plasma device 1 provided by this invention also features a simple structure, low manufacturing cost, and low energy consumption compared to existing technologies.

[0033] The novel microwave focused plasma generation method can be implemented using the vacuum cavity 10, microwave source 20, microwave focusing element 30 shown in Figures 1 and 2, and material conveying unit 70 shown in Figures 3 and 4. As shown in Figures 1 and 2, the novel microwave focused plasma generation method may include providing a vacuum cavity 10 and a microwave source 20. The vacuum cavity 10 can be configured to contain packaged material 90 or unpackaged material and working gas. The microwave source 20 can be configured to supply microwave M.

[0034] The microwave-focused plasma generation method may further include focusing microwaves M into a vacuum cavity 10 using a microwave focusing element 30, so as to generate plasma P by ionizing the working gas through the microwaves M. In some embodiments of this invention, the plasma P can be used to sterilize packaged materials 90 or unpackaged materials.

[0035] The microwave focusing plasma generation method may further include real-time monitoring of power changes in the microwave M.

[0036] As shown in Figures 3 and 4, the microwave focusing plasma generation method may further include conveying packaged material 90 or unpackaged material through a material conveying unit 70 (including a magnetic tray 71, an internal magnet 72, and an external electromagnet 73). In some embodiments of this invention, the above steps may include: energizing the external electromagnet 73 and transmitting magnetic force to the magnetic tray 71 through the internal magnet 72 to magnetically attract the magnetic tray 71; moving the external electromagnet 73 along the moving direction R to pull or drag the magnetic tray 71 to achieve the effect of conveying packaged material 90 or unpackaged material; de-energizing the external electromagnet 73 to release the magnetic attraction of the magnetic tray 71.

[0037] [Example]

[0038] The surface of whole black peppercorns is inoculated with 6 log CFU / g Enterococcus faecium. The novel microwave vacuum plasma device 1, with a power of 500-700W and working gas (e.g., air), sterilizes for 10-15 minutes, reducing the bacterial count by 2-4 log CFU / g.

[0039] The novel microwave vacuum plasma equipment 1, with a power of 500-700W and working gas (e.g., air), sterilizes for 10-15 minutes and can reduce the surface spores of black pepper products by 1-2 log CFU / g.

[0040] The above embodiments are merely illustrative of the principles and effects of this invention, and are not intended to limit the scope of the invention. Modifications and variations made to the above embodiments by those skilled in the art will not depart from the spirit of this invention. The scope of the invention should be as set forth in the following patent application claims.

[0041] 1: Microwave vacuum plasma equipment 10: Vacuum cavity 10': Vacuum chamber 11: Top surface 12: Side view 13:Inner wall surface 14: Internal receiving slot 15: Air Inlet 16: Air extraction port 17: Shelves 20: Microwave source 21: Waveguide 30: Microwave focusing element 31: Straight section 32: Conical part 40: Circulator 50: Microwave power monitoring unit 60: Quartz barrier plate 61: Pressure Control Unit 62: Image Recognition Unit 70: Material conveying unit 71: Magnetic Tray 72: Internal magnet 73: External electromagnet 80: Gas migration barrier structure 90: Packaging materials 10A: Feed end 10B: Discharge end M: Microwave P: Plasma [ ]

Claims

1. A microwave vacuum plasma device, comprising: A vacuum chamber configured to contain packaged or unpackaged materials and working gas; A microwave source is disposed above the vacuum cavity and configured to supply microwaves; And a microwave focusing element, which is disposed between the microwave source and the vacuum cavity, and configured to focus the microwaves into the vacuum cavity so as to generate plasma by ionizing the working gas through the microwaves.

2. The microwave vacuum plasma apparatus as claimed in claim 1, wherein the vacuum cavity has a top surface and the microwave focusing element contacts the top surface of the vacuum cavity.

3. The microwave vacuum plasma apparatus as claimed in claim 2, wherein the microwave focusing element comprises a straight cylindrical portion and a tapered portion, the straight cylindrical portion contacting the top surface of the vacuum cavity, the tapered portion connecting to the straight cylindrical portion, and the width of the tapered portion gradually increasing toward the straight cylindrical portion.

4. The microwave vacuum plasma apparatus as described in claim 2, further comprising: A pressure control unit is disposed on the top surface of the vacuum chamber and configured to control the internal pressure of the vacuum chamber.

5. The microwave vacuum plasma apparatus as described in claim 1, further comprising: A waveguide is disposed between the microwave source and the microwave focusing element and configured to transmit the microwaves; and a circulator, which is disposed between the waveguide and the microwave source.

6. The microwave vacuum plasma apparatus as claimed in claim 5, wherein the circulator is provided with a water load structure configured to absorb reflected microwaves.

7. The microwave vacuum plasma apparatus as described in claim 5, further comprising: A microwave power monitoring unit is disposed on one side of the waveguide and configured to monitor the power changes of the microwave in real time.

8. The microwave vacuum plasma apparatus as described in claim 5, further comprising: A quartz barrier plate is disposed between the waveguide and the microwave focusing element.

9. The microwave vacuum plasma apparatus as described in claim 1, further comprising: An image recognition unit is disposed on the side of the vacuum cavity and configured to recognize the features of the packaged material or the unpackaged material.

10. The microwave vacuum plasma apparatus as described in claim 1, further comprising: A material conveying unit configured to convey the packaged material or the unpackaged material, the material conveying unit comprising: a magnetic tray disposed within the vacuum chamber and configured to hold the packaged material or the unpackaged material; an internal magnet disposed within the vacuum chamber and located on at least one side of the magnetic tray; and an external electromagnet disposed outside the vacuum chamber and adjacent to the internal magnet.

11. The microwave vacuum plasma apparatus as claimed in claim 10, wherein the vacuum chamber has an inner wall surface and an internal receiving groove, the internal receiving groove extending from the inner wall surface toward the external electromagnet, and the internal magnet being disposed in the internal receiving groove.

12. The microwave vacuum plasma apparatus as claimed in claim 10, wherein the external electromagnet defines a direction of movement parallel to the length direction of the vacuum cavity.

13. The microwave vacuum plasma apparatus as described in claim 1, further comprising: A plurality of gas migration barrier structures are spaced apart between the feed end and the discharge end of the vacuum cavity and are configured to define the vacuum cavity into a plurality of vacuum chambers.

14. The microwave vacuum plasma apparatus as described in claim 13, wherein a gas migration barrier structure is provided on each side of each vacuum chamber.

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