A microwave vacuum drying equipment

Abstract

The present invention relates to a microwave vacuum drying device, which includes a shell with a receiving cavity formed inside; a material-carrying rotating device located in the receiving cavity, the material-carrying rotating device includes a rotating shaft and at least one layer of a carrier plate configured around the rotating shaft for carrying the dried material, the rotating shaft can drive the carrier plate to rotate around the axis of the rotating shaft; a plurality of microwave generators located on the outer surface of the shell, the microwave generator at least includes a waveguide penetrating the shell and extending into the receiving cavity along the radial direction of the rotating shaft, the waveguide is located at a corresponding position above the material on the carrier plate; the microwave generator is configured to microwave the material on the carrier plate; a vacuum exhaust device, the vacuum exhaust device is configured to exhaust the ambient gas in the receiving cavity. The device can effectively reduce the floor space of the device, improve the space utilization rate and production capacity of the device, and at the same time, the microwave generator is located on the outer surface of the shell, which is convenient for the maintenance and replacement of the device.

Description

Technical Field

[0001] The present invention relates to the field of microwave vacuum technology, and more specifically, to a microwave vacuum drying device. Background Art

[0002] Microwaves refer to electromagnetic waves with frequencies in the range of 300MHz to 300GHz. They were first used in military radar and communications. Later, people discovered that irradiating objects with microwave radiation would produce a thermal effect, causing the temperature of the irradiated objects to rise rapidly. Based on this characteristic of microwaves, microwave vacuum drying equipment is currently widely used for drying.

[0003] The microwave vacuum drying equipment in the prior art mostly adopts a cylindrical tank placed horizontally, with a central axis and a material tray located on the central axis arranged inside the tank, and the central axis rotates to drive the material tray to do uniform circular motion. However, the microwave vacuum drying equipment with this structure has a low space utilization rate and occupies a large area, thereby increasing the construction cost of the plant.

[0004] Therefore, in order to overcome the defects of the prior art, it is necessary to provide a novel microwave vacuum drying equipment. Summary of the invention

[0005] The object of the present invention is to provide a microwave vacuum drying device with high equipment capacity, high space utilization and small footprint.

[0006] In order to achieve the above-mentioned purpose, a microwave vacuum drying device is provided, which includes a shell with a containing cavity formed inside; a material-carrying rotating device located in the containing cavity, the material-carrying rotating device includes a rotating shaft and at least one layer of a carrier plate arranged around the rotating shaft and used for carrying the dried material, the rotating shaft can drive the carrier plate to rotate around the axis of the rotating shaft; the device also includes a plurality of microwave generators located on the outer surface of the shell, the microwave generator at least includes a waveguide penetrating the shell and extending into the containing cavity along the radial direction of the rotating shaft, the waveguide is located at a corresponding position above the material on the carrier plate; the microwave generator is configured to be used for microwave processing of the material on the carrier plate; the device also includes a vacuum exhaust device, the vacuum exhaust device is configured to exhaust the ambient gas in the containing cavity.

[0007] Optionally, a microwave feed port is provided on the bottom surface of one end of the waveguide away from the shell.

[0008] Optionally, a plurality of microwave generators are arranged around the outer surface of the shell corresponding to the carrying plate.

[0009] Optionally, the waveguides of the plurality of microwave generators have different lengths extending in the radial direction of the rotation axis.

[0010] Optionally, the material-carrying rotating device comprises a plurality of layers of carrying plates, and the device comprises a plurality of microwave generators located at corresponding positions above the materials on each layer of the carrying plates.

[0011] Optionally, the material loading rotating device includes a frame body sleeved on a rotating shaft; the frame body includes a sleeve portion fixedly combined with the rotating shaft and a plurality of extension portions extending from the sleeve portion to both sides; one end of the extension portion away from the sleeve portion extends upward to both sides to form a rib; an opening is formed between adjacent ribs; the supporting plate includes a supporting portion and a folded edge extending downwardly from the edge of the supporting portion, the folded edge includes a side portion and an edge portion, the side portion is used to be combined and fixed with the extension portion adjacent to the frame body, and a notch is formed on the edge portion corresponding to the opening.

[0012] Optionally, the equipment includes a monitoring device, which includes a lighting lamp for providing lighting in the containing chamber and a plurality of sensors for real-time monitoring of the humidity of the material in the containing chamber, the heating temperature, and the vacuum degree in the containing chamber.

[0013] Optionally, the vacuum exhaust device includes a vacuum pump and a buffer tank; the vacuum pump is connected to the accommodating chamber through an exhaust pipe, and the buffer tank is located on the exhaust pipe.

[0014] Optionally, the microwave generator includes a magnetron and an excitation cavity having one end connected to the magnetron, and the other end of the excitation cavity is connected and fixed to the waveguide; the microwave generated by the magnetron is transmitted to the waveguide through the excitation cavity, and the waveguide feeds the microwave into the accommodating cavity.

[0015] The beneficial effects of the present invention are as follows:

[0016] The microwave drying equipment provided by the present invention can greatly improve the space utilization rate and production capacity of the equipment, reduce the floor space of the equipment, and thus save the construction cost of the plant; and by improving the space utilization rate of the equipment, the electricity cost required for exhausting the vacuum exhaust device during the operation of the equipment can be effectively reduced; at the same time, the microwave generator is arranged on the outer surface of the shell, and the microwave generator can be directly installed and replaced from the outer surface of the shell, which is convenient for the inspection and replacement of the microwave vacuum drying equipment.

[0017] In addition, the waveguides of several microwave generators extend to different lengths in the radial direction of the rotating shaft, so that the microwave feed ports of the waveguides can cover various positions of the carrier plate as much as possible, so that the microwaves generated by the microwave generators can perform microwave heating on the material on the carrier plate from different positions, solving the problem of uneven microwave heating caused by insufficient microwave penetration depth, ensuring the uniformity of heating of the material on the carrier plate, and improving the effect of microwave processing inside the equipment.

[0018] In addition, by providing openings and gaps, it is convenient for loading and unloading vehicles to insert into the loading and unloading carrier plate, thereby improving the work efficiency of loading and unloading materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0020] Figure 1 A structural cross-sectional view showing a microwave vacuum drying apparatus according to an embodiment of the present invention.

[0021] Figure 2 A schematic structural diagram of a microwave generator according to an embodiment of the present invention is shown.

[0022] Figure 3 A cross-sectional view showing the structure of a microwave generator according to an embodiment of the present invention.

[0023] Figure 4 A schematic structural diagram of a material circulation device according to an embodiment of the present invention is shown.

[0024] Figure 5 A schematic structural diagram of a frame according to an embodiment of the present invention is shown.

[0025] Figure 6 A schematic structural diagram of a carrier plate according to an embodiment of the present invention is shown.

[0026] Figure 7 A structural top view of a microwave vacuum drying device according to an embodiment of the present invention is shown.

[0027] Figure 8 A structural front view showing a microwave vacuum drying apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0029] To achieve the above object, a microwave vacuum drying device is provided in one embodiment of the present invention, such as Figure 1-8As shown, the device includes a shell 10 with a accommodating cavity formed therein; in a specific embodiment, the shell 10 includes a first shell 11 and a sliding door 12 arranged on one side of the first shell 11, and the sliding door 12 and the first shell 11 can be assembled to form an accommodating cavity, and materials can be loaded and unloaded into the accommodating cavity through the sliding door 12. In a further embodiment, a microwave shielding net and a sealing strip are provided on the sliding door 12, which can achieve double-layer isolation between the accommodating cavity and external microwaves and ambient gases. The sealing strip can be, for example, a D-type conductive silicone sealing strip. Figure 1 As shown, the equipment also includes a material-carrying rotating device 20 located in the accommodating chamber, and the material-carrying rotating device 20 includes a rotating shaft 21 and at least one layer of a carrier plate 22 arranged around the rotating shaft 21 and used to carry the dried material. The rotating shaft 21 can drive the carrier plate 22 to rotate around the axis of the rotating shaft 21; in a specific embodiment, the rotating shaft 21 passes through the top surface of the shell 10 and is connected to the reduction motor outside the shell 10. The rotating shaft 21 is driven to rotate by the reduction motor, thereby driving the carrier plate 22 to rotate. It is understandable that the rotating shaft can also be driven to rotate by other technical means commonly used in the field, such as gears. As Figure 1 , 7 As shown in Figure 8, the device further includes a plurality of microwave generators 30 located on the outer surface of the housing 10, the microwave generator 30 at least includes a waveguide 31 that penetrates the housing 10 and extends to the accommodating cavity along the radial direction of the rotating shaft 21, the waveguide 31 is located at a position corresponding to the material above the carrier plate 22, and the waveguide 31 is used to feed microwaves into the accommodating cavity to perform microwave heating on the material below the waveguide 31. The microwave generator is configured to process the material on the carrier plate with microwaves; the device further includes a vacuum exhaust device 40, which is configured to exhaust the ambient gas in the accommodating cavity.

[0030] When the microwave vacuum drying equipment is working, first, move the sliding door 12, place the material on the carrier plate 22, close the sliding door 12, then start the material rotating device 20 and the vacuum exhaust device 40, and the rotating shaft 21 drives the material on the carrier plate 22 to rotate around the axis of the rotating shaft 21. Then start the microwave generator 30, and the microwave generated by the microwave generator 30 is fed into the containing cavity through the waveguide 31, and the material under the waveguide 31 is heated and dried by microwaves. When the heating and drying of the material is completed, the ambient gas in the containing cavity is exhausted through the vacuum exhaust device 40, so that the air pressure of the containing cavity is consistent with that of the outside. Open the sliding door 12, take out the carrier plate 22, and take out the dried material.

[0031] The microwave vacuum drying equipment provided in this embodiment uses a loading rotating device to divide the material into multiple layers in a three-dimensional space, thereby greatly improving the space utilization and processing capacity of the equipment, thereby improving the production capacity of the equipment, reducing the floor space of the equipment, and thus saving the construction cost of the factory building; and by improving the space utilization of the equipment, the electricity cost required for the exhaust of the vacuum exhaust device during the operation of the equipment can be effectively reduced; at the same time, the microwave generator is arranged on the outer surface of the shell, and the microwave generator can be directly installed and replaced from the outer surface of the shell, which is convenient for the inspection and replacement of the microwave drying equipment.

[0032] In a specific embodiment, a microwave feed port 32 is disposed on the bottom surface of the end of the waveguide 31 away from the housing 10. Figure 2-3 As shown, the microwave feed port 32 is used to directly heat and dry the material below the waveguide 31 with microwaves generated by the microwave generator 30 through the microwave feed port 32. In another embodiment, a plurality of microwave generators 30 are arranged around the outer surface of the housing 10 corresponding to the carrier plate 22, such as Figure 7 As shown, the end of the waveguide 31 covers different positions of the carrier plate 22. The structure of this embodiment can ensure that the microwaves generated by the microwave generator directly act on the materials at different positions on the carrier plate, thereby improving the microwave processing effect of the equipment.

[0033] In a specific embodiment, the waveguides 31 of the plurality of microwave generators 30 extend in the radial direction of the rotating shaft 21 to different lengths. Figure 7 As shown, the microwave openings 32 of different waveguide tubes 31 are located at different positions on the carrier plate 22, and adjacent waveguide tubes 31 will not interfere with each other, so that the microwave feed port of the waveguide tube can cover various positions of the carrier plate as much as possible, so that the microwaves generated by the microwave generator can perform microwave treatment on the material on the carrier plate from different angles and different positions, thereby solving the problem of uneven microwave heating caused by insufficient microwave penetration depth, ensuring the uniformity of heating of the material on the carrier plate, and improving the effect of microwave treatment inside the equipment. In a more specific embodiment, the length of the waveband tube 31 is in the range of 200-900mm, which can be selected according to actual operating needs and the specifications and dimensions of the equipment. In another specific embodiment, the material loading rotating device 20 includes a plurality of layers of carrier plates 22, and the equipment includes a plurality of microwave generators 30 located at corresponding positions above the material on each layer of the carrier plate 22, such as Figure 1As shown, the equipment of this embodiment can further improve the processing capacity of the equipment, thereby improving the production capacity of the equipment. At the same time, a number of corresponding microwave generators are arranged at corresponding positions above the materials on each layer of the carrier plate, which can ensure that the materials on each layer of the carrier plate are evenly heated and dried, further improving the microwave processing effect of the equipment. In a specific embodiment, a number of carrier plates 22 are fixed on the rotating shaft 21 at equal intervals.

[0034] In a specific embodiment, Figure 4-7 As shown, the loading rotating device 20 includes a frame 23 which is sleeved on the rotating shaft 21; the frame 23 includes a sleeve portion 231 which is fixedly combined with the rotating shaft 21 and a plurality of extension portions 232 extending from the sleeve portion 231 to both sides; one end of the extension portion 232 away from the sleeve portion 231 extends upward to both sides to form a rib 233; an opening 234 is formed between adjacent ribs 233; in a specific embodiment, the sleeve portion 231 is a cylindrical sleeve, and the upper and lower surfaces of the sleeve are through-through for cooperating and fixing with the rotating shaft 21, and the frame 23 includes four extension portions 232, the extension portion 232 is a reinforcing frame for enhancing the rigidity of the frame, and the rib 233 is an annular frame, which can further enhance the rigidity of the frame on the one hand, and can fix a carrying plate on the frame on the other hand, so as to block the carrying plate and prevent the carrying plate from sliding outward due to the centrifugal force during rotation. In addition, the carrier plate 22 includes a carrier portion 221 and a folded edge 222 extending downward from the edge of the carrier portion 221, the folded edge 222 includes a side portion 223 and an edge portion 224, the side portion 223 is used to be combined and fixed with the extension portion 232 adjacent to the frame 23, that is, the carrier plate 22 is arranged between the extension portions 232 adjacent to the frame 23. A notch 225 corresponding to the opening 234 is formed on the edge portion 224. In a specific embodiment, the carrier plate 22 is a 1 / 4 circle fan-shaped structure, that is, four carrier plates 22 can be placed on the frame 23 at the same time. The frame 23 includes four extensions 232 and four openings 234. By placing the carrying plate 22 on the frame 23, the notches 225 of the four carrying plates 22 are aligned with the four openings 234 on the frame 23, respectively, thereby forming an entrance for the loading and unloading vehicle to insert. The loading and unloading vehicle can be inserted from the entrance between the frame and the carrying plate, lift the carrying plate upward and then pull it out, thereby realizing rapid loading and unloading of the carrying plate.

[0035] In a specific embodiment, Figure 2-3As shown, the microwave generator 30 includes a magnetron 33 and an excitation cavity 34 connected to the magnetron 33 at one end, and the other end of the excitation cavity 34 is connected and fixed to the waveguide 31; the microwave generated by the magnetron 33 is transmitted to the waveguide 31 through the excitation cavity 34, and the waveguide 31 feeds the microwave into the accommodation cavity. It is understandable that the microwave generator 30 also includes a switching power supply (not shown in the figure) for providing high voltage electricity to the magnetron 33 so that the magnetron 33 generates microwaves. In a specific embodiment, the excitation cavity 34 and the waveguide 31 are bolted together through a flange 35. Further, both sides of the flange 35 are provided with sealing grooves 36 for installing sealing strips, and the gas sealing of the flange can be achieved by setting the sealing strips. At the same time, the microwave generator 30 also includes a sealing sheet (not shown in the figure) arranged between the waveguide 31 and the excitation cavity 34. In a specific embodiment, the sealing sheet is made of polytetrafluoroethylene, and the sealing sheet can be used to achieve gas isolation between the excitation cavity and the accommodation cavity.

[0036] In a specific embodiment, the device includes a monitoring device, which includes a lighting lamp for providing lighting in the receiving cavity and several sensors for real-time monitoring of the humidity, heating temperature and vacuum degree of the material in the receiving cavity. In an embodiment, the monitoring device includes a humidity probe, a temperature probe, a pressure sensor, a camera, etc. Through the cooperation of the monitoring device and the microwave generator, the monitoring device can monitor the vacuum degree in the receiving cavity during the rotation of the rotating shaft 21. When the vacuum degree in the receiving cavity reaches the requirement, the microwave generator 30 is started to perform microwave heating on the material on the carrier plate 22. In addition, during the process of microwave heating and drying the material in the receiving cavity by the microwave generator 30, the monitoring device monitors the temperature of the material in the receiving cavity in real time. When the monitoring device senses that the temperature of the material reaches the upper limit of the set value, the microwave generator 30 is turned off; when the monitoring device senses that the temperature of the material drops to the lower limit of the set value, the microwave generator 30 is started again to perform microwave heating and drying on the material. The material is heated by microwaves in a temperature-controlled heating method realized by the synergistic effect of the monitoring device and the microwave generator, so that high-quality drying of the material can be achieved.

[0037] In a specific embodiment, Figure 8 As shown, the vacuum exhaust device 40 includes a vacuum pump 41 and a buffer tank 42; the vacuum pump 41 is connected to the accommodating cavity through an exhaust pipe 43, and the buffer tank 42 is located on the exhaust pipe 43. It is understandable that Figure 8As shown, the vacuum exhaust device 40 also includes a water tank 44 connected to the vacuum pump 41, and the water tank 44 also includes a water inlet valve 45 and a drain valve 46. In addition, one end of the buffer tank 42 is connected to the vacuum pump 41, and the other end of the buffer tank 42 is connected to the exhaust pipe 43. On the one hand, the buffer tank can store a certain vacuum pressure, and on the other hand, it can prevent the water in the vacuum pump from being sucked back into the vacuum pipe in the event of an unexpected failure. In a specific embodiment, a one-way valve 47 and a vent valve 48 are provided on the exhaust pipe 43. The one-way valve 47 is used to control the gas connection and disconnection between the exhaust pipe 43 and the external air, and the vent valve 48 is used to timely release air so that the air pressure of the accommodating chamber is consistent with that of the outside world. Considering the heating temperature of vegetables and fruits and the required vacuum degree, in an optional embodiment, the vacuum pump 41 is a water ring vacuum pump.

[0038] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A microwave vacuum drying device, characterized in that: The device comprises: A shell body with a receiving cavity formed therein; A material-carrying rotating device is located in the accommodating chamber, the material-carrying rotating device comprises a rotating shaft and at least one layer of a carrier plate arranged around the rotating shaft for carrying the dried material, the rotating shaft drives the carrier plate to rotate around the axis of the rotating shaft; The device further comprises a plurality of microwave generators located on the outer surface of the shell, wherein the microwave generator at least comprises a waveguide penetrating the shell and extending into the containing cavity along the radial direction of the rotating shaft, and the waveguide is located at a position corresponding to the material on the carrier plate; The microwave generator is configured to process the material on the carrier plate with microwaves; The device further comprises a vacuum exhaust device, wherein the vacuum exhaust device is configured to exhaust the ambient gas in the containing chamber; The material-carrying rotating device comprises a frame body sleeved on a rotating shaft; The frame body includes a sleeve portion fixedly connected to the rotating shaft and a plurality of extension portions extending from the sleeve portion to both sides; one end of the extension portion away from the sleeve portion extends upward to both sides to form a rib; an opening is formed between adjacent ribs; The carrier plate includes a carrier portion and a folded edge extending downward from the edge of the carrier portion, the folded edge includes a side portion and an edge portion, the side portion is used to be combined and fixed with an extension portion adjacent to the frame, and a notch corresponding to the opening is formed on the edge portion; a plurality of microwave generators are arranged around the outer surface of the shell corresponding to the carrier plate; the waveguide tubes of the plurality of microwave generators extend at different lengths in the radial direction of the rotating shaft.

2. The microwave vacuum drying equipment according to claim 1, characterized in that: A microwave feed port is arranged on the bottom surface of one end of the waveguide away from the shell.

3. The microwave vacuum drying equipment according to claim 1, characterized in that: The material-carrying rotating device comprises a plurality of layers of carrying plates, and the equipment comprises a plurality of microwave generators located at corresponding positions above the materials on each layer of the carrying plates.

4. The microwave vacuum drying equipment according to claim 1, characterized in that: The equipment includes a monitoring device, which includes a lighting lamp for providing lighting in the containing cavity and a plurality of sensors for real-time monitoring of the humidity, heating temperature and vacuum degree of the material in the containing cavity.

5. The microwave vacuum drying equipment according to claim 1, characterized in that: The vacuum exhaust device includes a vacuum pump and a buffer tank; The vacuum pump is communicated with the accommodating chamber through an exhaust pipe, and the buffer tank is located on the exhaust pipe.

6. The microwave vacuum drying equipment according to claim 1, characterized in that: The microwave generator comprises a magnetron and an excitation cavity having one end connected to the magnetron, and the other end of the excitation cavity is connected and fixed to the waveguide; The microwaves generated by the magnetron are transmitted to the waveguide through the excitation cavity, and the waveguide feeds the microwaves into the accommodating cavity.

Images