Tunnel type microwave vacuum ultralow-temperature drying equipment

Abstract

The utility model provides tunnel type microwave vacuum ultralow-temperature drying equipment which is used for drying materials and comprises main machine equipment, the main machine equipment comprises a cavity and a plurality of microwave generators, the cavity is of a cylindrical structure, the inner section of the cavity is in the shape of a regular polygon, and the microwave generators are arranged in the cavity. The plurality of microwave generators are respectively arranged on the outer wall surface of the cavity and are sequentially arranged at least along the length direction of the cavity; a vacuum port of the vacuum unit is communicated with the cavity through a pipeline; a cooling water pipe of the water chilling unit is communicated with the microwave generator, and the water chilling unit is used for cooling the microwave generator. By utilizing the characteristic of oscillation heating of microwave polar molecules and assisting with the vacuum unit to vacuumize the cavity, the water-containing material in the cavity is quickly evaporated at low temperature in a vacuum environment to realize drying, the drying efficiency is high, and in addition, the material can be prevented from being damaged due to over-high temperature.

Description

Technical Field

[0001] The utility model relates to the field of microwave drying, in particular to tunnel type microwave vacuum ultra-low temperature drying equipment. Background Art

[0002] Drying equipment is a large category of mechanical equipment. The heat sources of traditional drying equipment are mainly steam, hot water, thermal oil, hot air, electric heating, infrared rays, etc. These heat sources are suitable for drying most wet materials, but some types of wet materials are not easy to dry with traditional drying equipment, and the drying time is long, the energy consumption is high, and even the physical state of the material is destroyed, which has become a bottleneck restricting some industries.

[0003] Microwaves as a drying heat source are very different from the above heat sources. They do not require a heat transfer medium and directly act on wet materials. They have high thermal efficiency and strong penetration ability. Using this feature of microwaves, a type of drying equipment has also been developed and applied to many industries, mainly chemical, food, pharmaceutical, paper products, packaging and other industries.

[0004] At present, most microwave drying equipment is of normal pressure rectangular tunnel structure, or single-layer or multi-layer belt type, or small vacuum equipment. The application scope of microwave drying equipment with these structures is limited. Normal pressure equipment is not suitable for drying flammable, explosive and heat-sensitive materials, and affects product quality. Small vacuum equipment is not suitable for mass production, which restricts its promotion. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a tunnel type microwave vacuum ultra-low temperature drying equipment.

[0006] The utility model solves the above technical problems through the following technical solutions:

[0007] A tunnel type microwave vacuum ultra-low temperature drying device, which is used for drying materials, and the tunnel type microwave vacuum ultra-low temperature drying device comprises:

[0008] A host device, the host device comprising a cavity and a plurality of microwave generators, wherein the cavity is a cylindrical structure, the inner cross-section of the cavity is a regular polygon, and the plurality of microwave generators are respectively arranged on the outer wall surface of the cavity and are arranged in sequence at least along the length direction of the cavity;

[0009] A vacuum unit, wherein the vacuum port of the vacuum unit is connected to the cavity through a pipeline;

[0010] A water chiller, wherein a cooling water pipe of the water chiller is connected to the microwave generator, and the water chiller is used to cool the microwave generator and the microwave power supply.

[0011] The tunnel-type microwave vacuum ultra-low temperature drying equipment utilizes the characteristic of microwave polar molecular oscillation and heating, and uses a vacuum unit to evacuate the cavity, so that the water-containing material in the cavity is quickly evaporated at ultra-low temperature in a vacuum environment to achieve drying. It has high drying efficiency and can also prevent the material from being damaged by excessive temperature.

[0012] Among them, because the inner wall of the cavity adopts a closed regular polygon structure, it can withstand a high vacuum pressure, and it is also conducive to the refraction of microwaves, so that microwaves can act better on the material, achieving low-temperature evaporation of water and material drying. In addition, by setting up a chiller to cool the microwave generator and other components, it ensures that the microwave generator and other components operate at a reasonable temperature, and the durability of use is further improved.

[0013] Preferably, the cavity comprises multiple sections of cylinders and flanges, and each section of the cylinders is connected by flanges; and / or,

[0014] The inner cross-sectional shape of the cavity is a regular 24-gon; and / or,

[0015] The cavity is made of mirror-finished stainless steel; and / or,

[0016] An electric heating tube is arranged at the bottom of the cavity.

[0017] By setting flanges to connect the cylinder sections, such a structural setting can strengthen the structure of the entire cavity and ensure the consistency of the overall dimensional parameters.

[0018] Preferably, the microwave generators are respectively located on the left and right sides of the cavity, and the arrangement positions of the microwave generators on the cavity correspond to the edges of the cross-sectional shape of the cavity.

[0019] This layout is conducive to a wider wavelength range, deeper radiation depth, and more uniform material drying.

[0020] Preferably, the microwave generator comprises a power supply, a waveguide, a mounting flange and a magnetron. The waveguide is mounted on the outer wall of the cavity through a distributed mounting flange. The waveguide and the magnetron are installed in coordination. The magnetron is powered by the power supply. The magnetron is controlled to start and emit microwaves into the cavity of the waveguide, and then the microwaves are reflected into the cavity by the cavity wall of the waveguide.

[0021] Preferably, quartz glass is provided at the connection between the cavity and the microwave generator.

[0022] Preferably, the waveguide is one of a hard waveguide, a soft waveguide, a rectangular waveguide and an elliptical waveguide.

[0023] Preferably, a cylinder vacuum tube is provided on the cavity, the vacuum port of the vacuum unit is connected to the cylinder vacuum tube through a pipeline, a vacuum pressure relief valve is provided on the cavity, and the vacuum pressure relief valve, the cylinder vacuum tube and the microwave generator are staggered on the surface of the cavity;

[0024] Preferably, the vacuum unit includes one of the following three pump bodies:

[0025] (1) A combination of an oil-free screw vacuum pump and a Roots vacuum pump; (2) a water ring vacuum pump; (3) an oil pump.

[0026] Preferably, the tunnel-type microwave vacuum ultra-low temperature drying equipment also includes an ultra-low temperature water capture system, which includes a refrigeration unit, a heat exchanger, an evaporator and a condenser. The vacuum port of the vacuum unit is connected to the cavity through the condenser and evaporator of the ultra-low temperature water capture system.

[0027] By setting up an ultra-low temperature water capture system, the water vapor extracted from the cavity is condensed into water and then processed centrally, so as to avoid excessive humidity in the vacuum pump and ensure that the performance of the vacuum pump is not disturbed.

[0028] Preferably, there are two sets of ultra-low temperature water capture systems, and the vacuum port is connected to the cavity via a condenser of one of the ultra-low temperature water capture systems by means of pipeline switching.

[0029] Preferably, a cooling water pipe is fixedly installed at the external interface of the chiller, and the interface end of the cooling water pipe is fixedly installed and sealedly connected with the power supply of the microwave generator and the cooling interface end of the magnetron;

[0030] Preferably, the tunnel-type microwave vacuum ultra-low temperature drying equipment further comprises a cooling water tower, which is connected to the chiller and is used to provide cooling to the chiller.

[0031] Preferably, the host device further comprises a sealing door and a sealing door moving mechanism, wherein the sealing door is arranged at the end of the cavity, and the sealing door moving mechanism is connected to the sealing door and is used to drive the sealing door to switch between closing and opening relative to the end of the cavity;

[0032] When the sealing door is switched to be closed relative to the end of the cavity, the sealing door is sealed and connected to the end of the cavity;

[0033] When the sealing door is switched to open at the end of the cavity, the end of the cavity is open to the outside. Preferably, the tunnel-type microwave vacuum ultra-low temperature drying equipment further includes a feeding conveyor and a discharging conveyor, the feeding conveyor is correspondingly arranged at the feeding end of the cavity, and the discharging conveyor is correspondingly arranged at the feeding end of the cavity;

[0034] The host device also includes an in-tunnel conveyor, which is arranged in the cavity, and two ends of the in-tunnel conveyor extend to the feeding conveyor and the discharging conveyor respectively.

[0035] Preferably, the host device further comprises a material pressing mechanism, which is disposed in the cavity and located above the conveyor in the tunnel, and is used to fix the material on the conveyor in the tunnel.

[0036] Preferably, the tunnel-type microwave vacuum ultra-low temperature drying equipment also includes auxiliary equipment, the vacuum unit and the chiller are both arranged in the auxiliary equipment, the auxiliary equipment and the main equipment are arranged separately, the vacuum unit located in the auxiliary equipment is connected to the cavity in the main equipment through a vacuum tube, and the chiller located in the auxiliary equipment is connected to the microwave generator in the main equipment through a cooling water pipe.

[0037] Preferably, the tunnel-type microwave vacuum ultra-low temperature drying equipment further comprises an electrical control module, and the electrical control module is arranged near the host device.

[0038] The positive and progressive effects of the utility model are:

[0039] 1. This tunnel-type microwave vacuum ultra-low temperature drying equipment utilizes the characteristics of microwave polar molecular oscillation and heating, and uses a vacuum unit to evacuate the cavity, so that the water-containing material in the cavity evaporates quickly at low temperature in a vacuum environment to achieve drying. It has high drying efficiency and can also prevent the material from being damaged by excessive temperature.

[0040] 2. The inner wall of the cavity of this tunnel-type microwave vacuum ultra-low temperature drying equipment adopts a closed regular polygonal structure, which can withstand higher vacuum pressure and is also conducive to the refraction of microwaves, so that microwaves can better act on the material, achieving low-temperature evaporation of water and drying of the material.

[0041] 3. Tunnel-type microwave vacuum ultra-low temperature drying equipment cools the microwave generator and other components by installing a chiller to ensure that the microwave generator and other components operate at a reasonable temperature, further improving the durability of use.

[0042] Fourth, an ultra-low temperature water capture system is set up to condense the water vapor extracted from the cavity into water and then centrally process it to avoid excessive humidity in the vacuum pump and ensure that the performance of the vacuum pump is not disturbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a schematic structural diagram of a tunnel-type microwave vacuum ultra-low temperature drying device according to an embodiment of the present invention.

[0044] Figure 2 It is a structural schematic diagram of a host device according to an embodiment of the utility model.

[0045] Figure 3 This is a schematic structural diagram of a host device according to an embodiment of the utility model, wherein the cavity and the sealing door are hidden.

[0046] Figure 4 It is a schematic structural diagram of a cavity according to an embodiment of the utility model.

[0047] Figure 5 It is a schematic diagram of the partial structure of a cavity according to an embodiment of the utility model.

[0048] Figure 6 It is a front view of the partial structure of the cavity of one embodiment of the utility model.

[0049] Figure 7 The structure diagram of a microwave generator according to an embodiment of the utility model is shown in FIG.

[0050] Figure 8 The figure is a schematic structural diagram of a door sealing moving mechanism according to an embodiment of the present utility model.

[0051] Fig. 9 This is a schematic diagram of the connection relationship of a tunnel-type microwave vacuum ultra-low temperature drying equipment according to an embodiment of the present utility model.

[0052] Fig.10 This is a schematic structural diagram of an auxiliary device according to an embodiment of the utility model.

[0053] Fig.11 The utility model is a schematic structural diagram of a vacuum unit and an ultra-low temperature water capture system according to an embodiment of the present invention.

[0054] Fig.12 This is a schematic diagram of the partial structure of a tunnel-type microwave vacuum ultra-low temperature drying equipment according to an embodiment of the present utility model.

[0055] Fig.13 The present invention is a schematic flow chart of a material drying process of a tunnel-type microwave vacuum ultra-low temperature drying device according to an embodiment of the present invention.

[0056] Description of reference numerals:

[0057] Host device 1

[0058] Cavity 101

[0059] Frame 102

[0060] Close the door 103

[0061] Microwave generator 104, power supply 1045, waveguide 1042, mounting flange 1041, magnetron 1043, water injection port 1044

[0062] Power cooling water pipe 107

[0063] Vacuum relief valve 108

[0064] Pressing mechanism 109, pressing cylinder 1091, pressing plate 1092

[0065] Tunnel conveyor 111

[0066] Vacuum tube 112

[0067] Feed conveyor 2

[0068] Outfeed conveyor 3

[0069] Vacuum unit 4

[0070] Chiller 5

[0071] Cold water tank 6

[0072] Cooling tower 7

[0073] Vacuum pipe 8

[0074] Cooling water pipe 9

[0075] Ultra-low temperature water capture system 10

[0076] Evaporator 1001, condenser 1002, refrigeration unit 1003

[0077] Auxiliary equipment 11

[0078] Door sealing moving mechanism 12, driving motor 129, positioning guide shaft 125, transmission shaft 128, chain 123, safety lock 126, cylinder 124, safety lock hole column 122, power sprocket 121

[0079] Water collection system14 DETAILED DESCRIPTION

[0080] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0081] like Figures 1 to 8As shown, the utility model provides a technical solution: a tunnel-type microwave vacuum ultra-low temperature drying equipment, including a main device 1, the main device 1 also includes a cavity 101, a frame 102 and a sealing door 103, the cavity 101 is arranged on the frame 102, specifically a cylindrical tube structure, the cavity 101 is arranged horizontally, and its interior is used to accommodate materials for low-temperature drying, the sealing door 103 is used to close the barrel mouth of the cavity 101, and the barrel mouth relative to the cavity 101 can be switched between an open state and a closed state, so that the material can enter the cavity 101 by opening the sealing door 103, and a closed environment is formed inside the cavity 101 by closing the sealing door 103.

[0082] In order to heat the material in the cavity 101 to speed up the drying speed, a plurality of microwave generators 104 are arranged on the outside of the cavity 101 according to a specific rule. The microwave generator 104 specifically includes a power supply 1045, a waveguide 1042, a mounting flange 1041 and a magnetron 1043. The waveguide 1042 is mounted on the outer wall of the cavity 101 through the mounting flange 1041, and the waveguide 1042 is installed in cooperation with the magnetron 1043. The power supply 1045 supplies power to the magnetron 1043, and the magnetron 1043 is controlled to start and emit microwaves into the cavity of the waveguide 1042, and then the microwaves are reflected by the cavity wall of the waveguide 1042 into the cavity 101, and act on the material in the cavity 101, and the material is subjected to microwave drying treatment. A water injection port 1044 is installed on the outside of the magnetron 1043, which is used to inject cooling water and cool the waveguide 1042 and the magnetron 1043, so that the microwave generator can continue to work normally. In addition, a light-transmitting barrier structure is provided at the connection between the cavity of the waveguide 1042 and the outer wall of the cavity 101, specifically quartz glass. By setting the quartz glass to block the waveguide 1042 and the cavity 101, firstly, the energy concentration of the microwave entering the cavity 101 can be increased, which is conducive to the concentration and diffusion of the microwave; at the same time, it can effectively prevent the waveguide 1042 from being contaminated, and ensure the cleanliness of the magnetron 1043.

[0083] In this embodiment, there are many types of waveguides 1042 that can be used, which can be one of hard waveguides, soft waveguides, rectangular waveguides and elliptical waveguides. Each type of waveguide has different national implementation standards and is widely used. In the field of industrial applications, the unique functions and characteristics of the waveguide can be brought into play according to the structural characteristics of the waveguide and the results of the waveguide's operation.

[0084] like Figure 5As shown, the inner surface of the cavity 101 is formed by bending a stainless steel mirror plate 1011 into a regular polygon, and the setting direction of the stainless steel mirror plate 1011 is that the mirror surface faces inward, which is conducive to microwave refraction. Since the long-length annular regular polygon stainless steel mirror plate 1011 is difficult to process and manufacture, the stainless steel mirror plate 1011 of the entire cavity 101 is divided into multiple sections of cylinders along the length direction, and the multiple sections of cylinders are respectively formed by bending the stainless steel mirror plate 1011. Flanges 1012 are welded between the multiple sections of cylinders, so that the sections of the cylinders are welded together with the flanges 1012 to form a sealed tunnel cavity. In addition, the arrangement of the flange 1012 can strengthen the structure of the entire cavity 101 to ensure the consistency of the overall dimensional parameters. Specifically, the cavity 101 is fixedly installed in the frame 102, and door sealing frames 105 are installed at both ends of the frame 102. The sealing doors 103 are arranged at both ends of the host device 1, specifically at the front and rear ends of the cavity 101. The host device 1 implements the drying process for the material by closing and opening the sealing doors 103, and the sealing doors 103 are specifically installed in the door sealing frames 105.

[0085] Among them, by using the stainless steel mirror plate 1011 to be bent into a regular polygon to form the cavity 101, the specific panel angle is set according to the microwave radiation angle. The panel angle setting of this regular polygon is conducive to further refraction of microwaves, so as to better act on the material to accelerate the drying progress. Specifically in this embodiment, the stainless steel mirror plate 1011 constituting the cavity 101 is a regular 24-gon, and each microwave generator 104 is respectively set to the shape side of the regular 24-gon. Of course, in other embodiments, regular polygons with other numbers of sides can also achieve the purpose of improving microwave refraction. It is also possible to use a cavity equivalent to a circle that is not limited to the number of shape sides to achieve microwave refraction.

[0086] In order to further heat the material disposed in the cavity 101 to speed up the drying speed, a cylinder vacuum tube 112 is disposed on the upper side of the cavity 101. The cylinder vacuum tube 112 is sealed and connected to the interior of the cavity 101, and is used to evacuate and generate a vacuum inside the cavity 101. At the same time, a vacuum pressure relief valve 108 is installed directly above the cavity 101 to release the vacuum inside the cavity 101.

[0087] By setting the cylinder vacuum tube 112, a high vacuum environment is constructed inside the cavity 101, and the characteristic of lowering the boiling point of water under vacuum is utilized, and the penetration and thermal effect of the microwaves generated by the microwave generator 104 are used to achieve low-temperature drying of the material under a vacuum environment. Specifically, inside the cavity 101 which is a sealed tunnel structure in a regular polygon and can withstand vacuum pressure, the microwaves generated by the microwave generator 104 are used as a heat source, and the wet material is heated under the vacuum environment constructed by the cylinder vacuum tube 112, so that the moisture in the material can be evaporated at a low temperature to meet the demand for drying the material.

[0088] In order to improve the drying effect and uniformity of the microwave generator 104 on the material, multiple microwave generators 104 are evenly arranged on the left and right sides of the cavity 101. These microwave generators 104 are staggered and arranged in a row on the side wall of the cavity 101 to achieve the purpose of uniform irradiation to the material. At the same time, each microwave generator 104 is arranged on the left and right sides of the cavity 101, and the cylinder vacuum tube 112 is arranged on the upper side of the cavity 101, and the vacuum relief valve 108 is arranged directly above the cavity 101. The components do not affect each other, and it is beneficial to provide sufficient operating space for the line connection and pipeline connection of each component.

[0089] Specifically, the tunnel-type microwave vacuum ultra-low temperature drying equipment in this embodiment is also provided with a vacuum unit 4 for generating a vacuum. A vacuum pipe 8 is fixedly installed at the external end of the vacuum unit 4. The interface end of the vacuum pipe 8 is fixedly installed and sealedly connected with the interface end of the cylinder vacuum tube 112, so that the vacuum unit 4 evacuates the inner cavity of the cavity 101 via the vacuum pipe 8 and the cylinder vacuum tube 112, so that after reaching a certain vacuum degree, the microwave generator 104 is started to start low-temperature drying treatment of the material.

[0090] In this embodiment, in order to further improve the vacuum degree to reduce the boiling point of water, the vacuum unit 4 adopts a combination of multiple vacuum pumps, mainly a vacuum unit 4 composed of an oil-free screw vacuum pump and a Roots vacuum pump. Its purpose is to extract the water vapor evaporated in the cavity 101 of the main machine, ensure the vacuum degree in the cavity, and facilitate the microwave drying of the material under vacuum and low temperature conditions. Of course, in other embodiments, in order to ensure that the vacuum unit 4 can effectively reduce the vacuum degree of the cavity 101, thereby reducing the boiling point of water and achieving the purpose of ultra-low temperature drying, the vacuum unit 4 can also use a water ring vacuum pump for vacuuming, or use an oil pump for vacuuming to achieve it.

[0091] It should be specifically explained that the tunnel-type microwave vacuum ultra-low temperature drying equipment provided by this scheme, its "low temperature" and "ultra-low temperature" concepts refer to that when the vacuum unit 4 is continuously working, the vacuum degree of the cavity 101 is in a low state, so as to reduce the boiling point of water, make water molecules easier to evaporate, and ensure the stability of the physical state of the material. Specifically, as the vacuum degree increases, the boiling point of water will gradually decrease. When the boiling point of water drops below 50°C, drying by the operation of the microwave generator is considered to be a low-temperature drying state. When the boiling point of water drops to close to 0°, drying by the operation of the microwave generator is considered to be an ultra-low temperature drying state.

[0092] In this solution, the vacuum unit 4 is provided to continuously evacuate the cavity 101 so that the boiling point of water can be maintained below 0°C, thereby achieving the purpose of ultra-low temperature drying of materials and avoiding the physical state of the materials being affected by excessively high drying temperatures.

[0093] In order to ensure the ambient temperature of the cavity 101, a reverse auxiliary heating system is further provided in the present scheme. In the present embodiment, the reverse auxiliary heating system is specifically an electric heating tube arranged at the bottom d of the cavity 101. By turning on the electric heating tube, it is used to perform auxiliary heating on the cavity 101, so that when the temperature of the cavity 101 is low, the ambient temperature inside the cavity 101 is kept within a reasonable range by electric heating. At the same time, it is also beneficial to the evaporation of water vapor on the inner wall of the cavity 101, so that the water vapor in the cavity 101 is further evaporated and extracted from the cavity 101, so as to construct a more drying environment in the cavity 101. Furthermore, the outer peripheral side surface of the cavity 101 is also covered with a heat-insulating material to reduce the temperature conduction inside and outside the cavity 101 and reduce energy consumption.

[0094] In order to collect the water vapor in the gas extracted from the chamber 101 by the vacuum unit 4, Figure 10-12 As shown, the vacuum unit 4 provided in this embodiment is further provided with an ultra-low temperature water collection system 10 to achieve the purpose of water vapor collection. Fig. 9As shown, the ultra-low temperature water capture system 10 includes a refrigeration unit 1003, a heat exchanger, an evaporator 1001 and a condenser 1002. The refrigeration unit 1003 and the heat exchanger work together to provide cooling to the evaporator 1001 and the condenser 1002. The low-pressure steam extracted from the cavity 101 by the cylinder vacuum tube 112 is sequentially passed into the evaporator 1001 and the condenser 1002, and the water vapor in the low-pressure steam is condensed into liquid water by phase change, and the water droplets are condensed by rapid cooling, so as to achieve the purpose of freezing and capturing water vapor in the low-pressure steam, and effectively prevent these water vapors from further entering the vacuum pump of the vacuum unit 4 and affecting the normal operation of the vacuum pump. The water droplets collected and formed in the evaporator 1001 and the condenser 1002 can be further collected in the water collection system 14 for subsequent use. Specifically, the vacuum unit 4 is connected to the cylindrical vacuum tube 112 on the cavity 101 through the evaporator. The extracted water vapor is condensed into water under the condensation treatment of the ultra-low temperature water capture system 10 and then processed centrally. This ensures that the performance of the vacuum unit 4 is not disturbed, ensures that the equipment can continue to dry materials under ultra-low temperature conditions, and avoids the generated water vapor affecting the vacuum unit 4.

[0095] Among them, the working temperature of the evaporator 1001 for water replenishment is relatively low, and the water droplets condensed from the water vapor may be further frozen into ice. In order to solve the problem of how to thaw and how to collect these low-temperature water / ice, in this embodiment, Fig.12 As shown, the ultra-low temperature water capture system 10 is mainly composed of two sets of refrigeration units 1003, two sets of plate heat exchangers and two sets of evaporators 1001. Among them, the refrigeration unit used is composed of a refrigeration compressor, an oil separator, a water separator, a liquid storage pipe, a filter, a temperature return device, an expansion valve connecting pipeline and an installation base plate bracket, so that the refrigeration unit is double-acting and can choose to operate in cooling mode or heating mode. By setting up two relatively independent ultra-low temperature water capture systems 10, when ice forms in the cylinder of the evaporator 1001 of one ultra-low temperature water capture system 10, the low-temperature steam can be transported to the cylinder of the evaporator 1001 of another ultra-low temperature water capture system 10 through pipeline switching to capture water. At the same time, the refrigeration unit of the first ultra-low temperature water capture system is switched to the heating mode, and the heat output thaws the ice in the cylinder of the evaporator 1001 into water. Switching between the two ultra-low temperature water capture systems in this way can solve the problem of difficulty in collecting frozen captured water.

[0096] The plate heat exchanger uses cooling water from an external cooling tower to exchange heat with the refrigerant of the refrigeration unit. The temperature of the refrigerant is reduced after passing through the expansion valve and enters the evaporator 1001. In this embodiment, Fig.12As shown, the two sets of ultra-low temperature water capture system evaporators 1001 are double-linked structures, and the special heat exchange plate group in the evaporator 1001 is installed in a horizontal cylinder. The evaporator 1001 double-linked cylinder has a total of four inlets and outlets, including two inlets 10011 for connecting to the vacuum pipe 8, and two outlets 10012 for connecting to the vacuum unit 4. Butterfly valves are respectively provided on the inlet 10011 and the outlet 10012. The two cylinders of the evaporator 1001 are respectively connected to the low-pressure steam extracted from the cavity 101 through the butterfly valve switching, and the first cylinder and the second cylinder are switched. The two sets of refrigeration units and the evaporator 1001 of the double-linked cylinder are switched at the same time to realize the alternating freezing water capture-heating and defrosting mode of the refrigeration unit 1003 and the corresponding evaporator 1001, so that the whole is in a continuous working state. Among them, the liquid water after heating and defrosting can be collected by the water collection tank and automatic drainage device connected to the evaporator 1001, and automatically discharged.

[0097] In addition, the tunnel type microwave vacuum ultra-low temperature drying equipment also includes a water chiller 5 and a water cooling tower 7, wherein the water chiller not only provides cooling capacity for the condensation and water capture of the evaporated low-pressure steam, but also provides cooling capacity for the cooling of the microwave system, ensuring the smooth progress of the process of low-temperature drying of the material. The water cooling tower 7 is used to cooperate with the water chiller 5, the external interface of the water chiller 5 is fixedly installed with a cooling water pipe 9, and the outer support of the frame 102 is fixedly installed with a power cooling water pipe 107, the interface end of the cooling water pipe 9 is fixedly installed and sealed with the interface end of the power cooling water pipe 107, and the other interface end of the power cooling water pipe 107 is connected to the water injection port 1044 to transport cooling water to the magnetron 1043 and its power supply, and the microwave generator and its power supply 1045 are water-cooled by the water chiller 5 to maintain the normal operation of the microwave generator and ensure the service life of the magnetron 1043. Among them, the power cooling water pipe 107 is fixed by the outer support structure of the frame 102, and the structural consistency of the entire host device 1 is high.

[0098] Furthermore, the tunnel type microwave vacuum ultra-low temperature drying equipment further comprises a cold water tank 6. The cold energy generated by the water chiller 5 is replaced with low temperature cold water by water filled with antifreeze in the cold water tank 6, and then transported to the magnetron 1043 and the power supply 1045 via the cold water system 61. The cold water tank 6 is specially designed to ensure that the heat exchange with the water chiller and each heat exchange system using cold water can extract low temperature cold water. Through the cooperation of the cold water tank 6 and the cold water tower 7, the water chiller 5 can work normally and continuously output cold energy.

[0099] In this embodiment, Figure 1 As shown, the tunnel type microwave vacuum ultra-low temperature drying equipment includes auxiliary equipment 11 in addition to the main equipment 1, and the vacuum unit 4 and the chiller 5 are both arranged inside the equipment frame of the auxiliary equipment 11. Fig.10It can be seen that the equipment frame of the auxiliary equipment 11 is completely independent of the frame 102 of the main equipment 1, so that the entire tunnel-type microwave vacuum ultra-low temperature drying equipment is arranged in modules. Specifically, the main equipment 1 can be arranged inside the factory building, specifically in an area with high cleanliness, and the auxiliary equipment 11 can be arranged outside the factory building to avoid the operation of the vacuum unit 4 and the chiller 5 arranged inside affecting the cleanliness inside the factory building, and at the same time, the space required inside the factory building is relatively smaller. Among them, the vacuum unit 4 extends horizontally from the top of the auxiliary equipment 11 to the top of the cavity 101 in the main equipment 1 through a pipeline, and is connected to the vacuum tube 112. At the same time, the cooling water pipe 9 of the chiller 5 also extends horizontally from the top of the auxiliary equipment 11 to the main equipment 1, which is used to cool the various components in the main equipment 1.

[0100] This layout scheme of separately setting up the main equipment 1 and the auxiliary equipment 11 can effectively reduce the volume of each component in the tunnel-type microwave vacuum ultra-low temperature drying equipment and meet the plant layout requirements of different factory areas. Figure 1 As shown, the vacuum unit 4 and the chiller 5 in the auxiliary equipment 11 are also located in two different equipment frames, so as to further realize the modular layout.

[0101] The specific structural setting scheme and control principle of each component in the host device 1 are introduced in detail below.

[0102] like Figure 8 As shown, the sealing door 103 of the device can be a lifting sealing door, a translation sealing door, a scissor-type sealing door, a smooth sealing door, etc. In this embodiment, a lifting sealing door is specifically used. The sealing door moving mechanism 12 is arranged on the frame 102, and is a component for controlling the lifting and lowering movement of the sealing door 103 located at the front and rear ends of the cavity 101, and has a power mechanism for opening or closing the sealing door 103. When the sealing door moves down and seals the cavity 101, the drying equipment can perform operations such as vacuum, drying and cooling materials. The sealing door moving mechanism 12 specifically includes a driving motor 129, a positioning guide shaft 125, a transmission shaft 128, a chain 123, a safety lock 126, a detection switch, a cylinder 124 and other components. The driving motor 129 drives the transmission shaft 128 to drive the chain 123 to transmit, thereby driving the sealing door 103 connected to the chain 123 to move up and down. When the sealing door 103 descends to the closed cavity 101, a horizontal thrust is applied to the sealing door 103 through the cylinder, so that the sealing door 103 is pressed against the cavity 101 to ensure that the sealing degree meets the requirements.

[0103] Among them, the positioning guide shaft 125 is installed on the left and right sides of the sealing door 103. The role of the positioning guide shaft 125 is to fix the moving direction of the sealing door 103 to avoid deviation. The transmission shaft 128 is installed on both sides of the motor. Its role is to connect the transmission of the motor and the power sprocket 121. The power sprocket 121 drives the chain 123 to provide power for the up and down movement of the sealing door 103. The safety lock 126 is installed on both sides of the sealing door 103. The supporting two side frames are equipped with safety lock hole columns 122. The sealing door mechanism is equipped with a detection switch. When the sealing door moves to a certain position or an unexpected situation occurs, the safety lock device will be triggered, and its cylinder 124 will push the safety lock column into the safety lock hole column 122 for emergency braking, ensuring the safe operation of the equipment.

[0104] Regarding how the materials are transported to the cavity 101 and how the dried materials are sent out from the cavity 101, the tunnel-type microwave vacuum ultra-low temperature drying equipment is provided with three conveyor lines, namely, a feed conveyor line, a discharge conveyor line and a tunnel internal conveyor line. Among them, the feed conveyor line is a feed conveyor 2, and the discharge conveyor line is a discharge conveyor 3. The structures of the two are roughly the same, and they are respectively arranged at the entrance and exit ends of the cavity 101, specifically including a conveyor line support frame, a roller conveyor, and an over-retractable lifting and transplanting line. The main parts of the feed conveyor line and the discharge conveyor line are made of stainless steel to meet the cleanliness requirements during material transportation. Both the feed conveyor line and the discharge conveyor line are equipped with transitional telescopic, lifting, and transfer functions. The power used is a cylinder and a motor to realize the telescopic, lifting, and transfer functions, so that when the sealing door 103 is opened and closed, the feed conveyor 2 and the discharge conveyor 3 close to the cavity 101 can avoid the sealing door 103 to avoid collision between the two. Specifically, the feed conveyor 2 and the discharge conveyor 3 are respectively connected to the inlet and outlet of the host device 1 , and the material enters the cavity 101 of the host device 1 through the feed conveyor 2 , and the processed material is then sent out from the discharge conveyor 3 through the cavity 101 .

[0105] Of course, in other embodiments, the cavity 101 may be closed at one end and open at the other end, and only one entrance and exit may be provided, so that the material enters and exits the cavity 101 through the same entrance and exit. In this case, it is only necessary to provide a sealing door 103 at the entrance and exit to open or close the entrance and exit. At the same time, the feed conveyor line and the discharge conveyor line are combined into one, and the material is conveyed into or out of the cavity 101 through a single conveyor line. In this case, it is preferred to provide a transplanting mechanism on the conveyor line to further optimize the flow of the material to be dried and the dried material on the conveyor line.

[0106] The tunnel conveyor line is installed in the cavity 101, specifically the tunnel conveyor 111. Due to the sealed environment inside the cavity 101, the driving shaft that provides power to the tunnel conveyor 111 extends to the outside of the cylinder wall of the cavity 101 through a sealed transmission device and is connected to the motor located outside. The function of the tunnel conveyor 111 is to realize the automatic entry and exit of materials in the cavity. At the same time, in order to improve the drying effect, when the microwave generator 104 is turned on to heat and dry the material, the tunnel conveyor 111 can also be driven to drive the material to move back and forth in the cavity 101 to improve the uniformity of heating. The reciprocating movement amplitude is usually set at about 200mm.

[0107] In addition, a pressing mechanism 109 is also provided in the cavity 101. The pressing mechanism 109 is installed on both sides of the top of the cavity 101 and is located directly above the conveyor 111 in the tunnel. The pressing mechanism 109 specifically includes a pressing cylinder 1091. The pressing cylinder 1091 seals through the cavity 101 from the outside of the cavity 101 and extends to the inside of the cavity 101. A pressing plate 1092 is fixedly installed at the end of the telescopic end of the pressing cylinder 1091. When the material enters the cavity 101 under the transportation of the conveyor 111 in the tunnel, the pressing cylinder 1091 pushes the pressing plate 1092 downward to cover the top of the material to fix the material and prevent the material from scattering. Among them, if the conveyor in the tunnel needs to move the material back and forth to improve the uniformity of heating when the microwave generator 104 is turned on to heat and dry the material, then the pressing cylinder 1091 needs to drive the pressing plate 1092 to move upward so that the material can move back and forth on the conveyor in the tunnel.

[0108] In this embodiment, the feed conveyor line and the discharge conveyor line are also connected to the frame 102. The frame 102 of the host device 1 is an integral frame. The frame 102 is used to support and install all systems in the host device 1. The outer surface of the frame 102 is covered with a host outer cover plate (not shown in the figure) to make the overall appearance more beautiful. In other embodiments, the feed conveyor line, the discharge conveyor line and the conveyor line inside the tunnel can also be transported by other existing technical structures other than conveyors, such as conveyor belts, push rods, etc.

[0109] In addition, the tunnel type microwave vacuum ultra-low temperature drying equipment also includes an electrical control system, and the relevant electrical control modules are mainly set in the electrical cabinet located near the host equipment. The system architecture of the electrical control system is divided into several parts: conveying system, door opening and closing system, heating system, vacuum system, refrigeration system, ultra-low temperature water capture system, microwave system, heat dissipation system, drainage system, formulation system, detection system, cooling system, alarm system, communication control system, monitoring system, surveillance system, and remote monitoring system.

[0110] In terms of equipment operation, the tunnel type microwave vacuum ultra-low temperature drying equipment is mainly started and operated by the equipment on-site operator or the equipment main control room personnel with one button to start the full automatic operation, or can choose manual self-control operation. After the equipment is turned on, the electrical control system will work according to the set operation mode, thereby realizing unmanned automatic production.

[0111] The following is a brief introduction to the functions of each subsystem of the electrical control system:

[0112] (1) Material conveying system: After the electrical control system is in operation, it first detects whether the material conditions on each conveyor meet the preset values. Specifically, the material parameters can be detected by sensors arranged on each conveyor, especially the material parameters on the feed conveyor 2. The sensors that can be used include in-place sensors, temperature sensors, humidity sensors, etc. At the same time, the tunnel conveyor 111 in the cavity 101 is detected to see whether there is material to be dried or dried material, and whether there is material accumulation at the outlet of the cavity 101. After the system automatically determines that the material is transported into the cavity 101 or directly implements the next step.

[0113] (2) Door opening and closing system: When the conveying material detection device has completed the detection to confirm that the material to be dried is already in the chamber 101, the electrical control system drives the door closing moving mechanism 12 to close the door 103, operates the door closing 103 in place detection device, and transmits the door 103 closing completion signal back to the electrical control system, and the door closing step is completed. The detection of whether the door 103 is closed can be achieved by setting an in place sensor on the chamber 101 to detect the position of the door 103.

[0114] (3) Heating system: Based on the temperature of the cavity 101, the electric heating tube is turned on for heating. The temperature of the cavity 101 is obtained based on the temperature sensor arranged in the cavity 101. Heating is divided into startup heating and heating following the system operation process. After setting the temperature parameters and selecting the heating mode, the heating device (electric heating tube) is started.

[0115] (4) Vacuum system: The vacuum system mainly controls the multiple vacuum units of the vacuum unit 4 to start in sequence to evacuate the cavity 101. Specifically, after the sealing door 103 is closed, the oil-free screw vacuum pump and the Roots vacuum pump group are started in sequence to evacuate the vacuum degree in the cavity 101 where the material is located to -100Kpa in the shortest time.

[0116] (5) Refrigeration system: The refrigeration system controls the chiller 5 to operate synchronously with other components such as the vacuum unit 4. After setting the temperature parameters of the low-temperature cold water, the chiller 5 operates at a constant temperature according to the set temperature to meet the cooling capacity of the entire equipment and avoid excessive temperatures of various components.

[0117] (6) Ultra-low temperature water capture system: The ultra-low temperature water capture system is also started with the vacuum system and the refrigeration system. After the vacuum unit 4 starts to operate, the compressor of one of the refrigeration units in the ultra-low temperature water capture system starts and operates at full load or according to the set temperature. The compressor of the other refrigeration unit automatically determines whether it is necessary to turn on the heating mode for defrosting. The two compressors operate alternately based on time to achieve the purpose of water capture and defrosting, and remove the low-pressure steam extracted from the cavity 101 by the vacuum unit 4.

[0118] (7) Microwave system: When the vacuum degree in the cavity 101 reaches the set pressure under the continuous operation of the vacuum unit 4, the power supply 1045 and the magnetron 1043 are controlled to operate. The microwave system automatically controls the output power of the magnetron 1043 according to the formula setting value to achieve the required process requirements and effectively dry the material.

[0119] (8) Heat dissipation system: The heat dissipation system is composed of multiple devices installed in various places of the tunnel-type microwave vacuum ultra-low temperature drying equipment, including external circulation water heat dissipation, magnetron cooling water heat dissipation, microwave power cooling water heat dissipation, ultra-low temperature water capture system plate heat exchanger heat dissipation, etc., to dissipate heat for various important components in the tunnel-type microwave vacuum ultra-low temperature drying equipment to avoid excessive temperature during the operation of the equipment and affect the stability of the equipment operation. Among them, the heat dissipation system operates according to the preset heat dissipation temperature. By comparing the preset heat dissipation temperature with the temperature sensor parameters arranged on the object to be cooled, when the actual temperature measured by the sensor exceeds the set value, the heat dissipation system is started, and the cooling water is transported to the object to be cooled by opening the solenoid valve connecting the pipeline to reduce the target problem. If the actual temperature measured by the sensor is lower than the set value, the battery valve of the corresponding pipeline is closed. Such a closed-loop heat dissipation control scheme with active detection and active control can not only ensure the heat dissipation effect, but also reduce the continuous working time of the heat dissipation system, thereby reducing energy consumption.

[0120] (9) Drainage system: After the system is running, a large amount of water vapor will be generated. Through the control of pneumatic components, the water vapor will be concentrated in the water tank. Through the detection of sensors, when the water tank exceeds a certain capacity or height, the system will switch the pneumatic valve and discharge the water vapor to the designated area under vacuum.

[0121] (10) Drainage system: During the operation of the equipment, especially after the microwave generator 104 is turned on to heat the material, a large amount of water vapor will be generated in the cavity 101. Through the continuous operation of the vacuum unit 4 and the ultra-low temperature water capture system, the water vapor is extracted and collected from the cavity 101. Afterwards, the drainage system controls the pneumatic components to concentrate the liquid water produced by the condenser into the water collection tank. The liquid level of the water collection tank is continuously monitored by the liquid level sensor set in the water collection tank. When the water collection tank exceeds a certain capacity or height, the drainage system will switch the pipeline through the pneumatic valve to discharge the water stored in the water collection tank to the designated area when the entire pipeline is in a vacuum.

[0122] (11) Recipe system: The recipe is the core part of the entire electrical control system. During the drying process, the operation mode of the entire microwave generator 104 is operated according to the set parameters in the recipe system, such as temperature, pressure, microwave operation time, etc., and these parameters can be detected by the temperature sensor and pressure sensor set in the cavity 101 to ensure the smooth operation of the entire system. Among them, the specific setting of the recipe parameters of the drying material should be set according to the actual material requirements to meet the drying effect of different materials. The specific drying parameter setting belongs to the scope of the prior art and will not be repeated here. The recipe number of each recipe parameter entered into the recipe system can be freely set as needed to facilitate real-time storage and call.

[0123] (12) Detection system: The detection system is also composed of a plurality of sensors with different functions, which are respectively arranged at various parts of the tunnel-type microwave vacuum ultra-low temperature drying equipment to detect whether various parameters meet the requirements of the drying process. For example, in this embodiment, the temperature of the material in the cavity 101 is detected by an infrared sensor, which mainly detects the temperature of different positions of the material in real time in a non-contact manner to directly control the output power of the magnetron 1043. For another example, the vacuum degree in the cavity 101 is detected by a vacuum degree sensor. By setting the vacuum degree sensor in the cavity 101 to detect the actual pressure value of the vacuum degree in the cavity 101, the material is ensured to be dried under absolute vacuum. For another example, the temperature sensor detects the temperature of the temperature-controlled object in real time to help the detection system determine whether the temperature-controlled object needs to be cooled or heated to achieve the purpose of precise control. Finally, for example, a water flow detector can be set in each cooling water pipeline to detect whether each water supply pipeline is in a normal operating state. Proximity sensors, magnetic sensors, etc. can be arranged at the end of the cavity 101 to detect the open or closed state of the sealing door 103. They can also be set in the cavity 101 to detect whether the material is transported into the cavity 101 to determine the working state of the conveyor line.

[0124] (13) Cooling system: When the microwave system completes its work as required, the cooling system starts, the microwave system is turned off, and the microwave generator 104 stops working. Then the vacuum unit 4 is controlled to draw vacuum from the cavity 101 at full load, further reducing the ambient temperature and material temperature in the cavity 101. After the cooling system is completed, the vacuum relief valve 108 will be opened to evacuate the vacuum degree in the cavity 101 until the vacuum degree reaches the vacuum value that allows the door to be opened, and then the sealing door 103 will be opened.

[0125] (14) Alarm system: After the entire electrical control system starts to operate, the alarm system will perform a self-check. If there is a fault during operation, the alarm device installed on the main equipment 1 and the auxiliary equipment will be controlled to issue an audible and visual alarm prompt, and the fault point and troubleshooting method will be displayed on the monitoring system. After the fault is eliminated, the fault alarm can be reset to allow the alarm system to continue to operate. When the alarm system detects that a serious fault has occurred in the entire tunnel-type microwave vacuum ultra-low temperature drying equipment, the entire electrical control system should be controlled to shut down. After the fault is repaired, the system will be allowed to resume operation.

[0126] (15) Communication system: The main control machine of the electrical control system will communicate interactively with the microwave power supply 1045. Through communication, the working status of the microwave generator 104 can be checked in real time, and the working power of the microwave can be controlled. The external system can exchange data with the main control machine through the communication system according to requirements and cooperate with each other.

[0127] (16) Monitoring system: The monitoring system is a visual monitoring system such as HMI or SCADA, which can view and control the operation of the entire electrical control system, and allow the modification of the allowable parameters of the electrical control system, change the system operation mode, view data records, etc.

[0128] (17) Monitoring system: The monitoring system is mainly used for monitoring materials, conveyor lines, production conditions, etc. The monitoring system mainly serves the unmanned production mode. During the automatic operation of the entire electrical control system based on the preset parameters of the recipe system, the on-duty personnel can view the status of the entire equipment assembly line through the display at the production site or the main control room. In this embodiment, the monitoring system is composed of multiple cameras to conduct real-time video monitoring of the site, and store the video images in a dedicated device, so that historical videos can be viewed at any time. At the same time, the monitoring system also allows remote login to view the on-site operation status based on the video.

[0129] (18) Remote monitoring system: The remote monitoring system allows users to view the operation status of the entire tunnel-type microwave vacuum ultra-low temperature drying equipment in real time through the network, or control the operation of the tunnel-type microwave vacuum ultra-low temperature drying equipment, modify parameters, and view the equipment operation history data, etc., locally or remotely.

[0130] The electrical control system of the tunnel-type microwave vacuum ultra-low temperature drying equipment operates in an orderly manner under the unified coordination of the above-mentioned multiple systems, completes the drying process of the materials with a high level of automated operation, effectively saves labor costs, and has high production efficiency.

[0131] like Fig.13 As shown, under the control of the electrical control system, the material drying process of the tunnel type microwave vacuum ultra-low temperature drying equipment is roughly as follows:

[0132] S1. The material enters the cavity 101 of the host device 1 through the feed conveyor 2. After the material is transported into the cavity 101 through the tunnel conveyor 111, the pressing cylinder 1091 of the pressing mechanism 109 pushes the pressing plate 1092 to press on the material to fix the material and prevent it from scattering.

[0133] S2. The sealing doors 103 of the host device 1 located at both ends of the cavity 101 are closed respectively.

[0134] S3, the vacuum unit 4 performs vacuum treatment on the interior of the cavity 101 through the vacuum pipe 8.

[0135] S4. After the required vacuum degree is reached inside the cavity 101, the microwave generator 104 starts and releases microwave energy to the material, and the material absorbs the microwave and evaporates water from the inside out. During the implementation of the drying step, in order to ensure that the equipment is in normal operation, the vacuum unit 4, the ultra-low temperature water capture system and the chiller 5 must continue to work: the vacuum unit 4 quickly extracts the water evaporated from the cavity 101 to ensure that the cavity 101 is in a high vacuum state and the water is in a low boiling point state; the ultra-low temperature water capture system cools the extracted water to make the gaseous water phase change into liquid water and further concentrate it; the chiller 5 cools the magnetron 1043 and the power supply with water to maintain the normal operation of the microwave generator 104, wherein the cold water tank 6 and the cold water tower 7 cooperate with the chiller 5 to work.

[0136] S5. After the drying of the material is completed, the microwave generator 104 is turned off and the cooling system is started, and the vacuum unit 4 is controlled to fully vacuum the cavity 101 to reduce the ambient temperature and material temperature in the cavity 101.

[0137] S6. After the cooling system is finished running, the vacuum relief valve 108 is opened to exhaust the vacuum degree in the cavity 101 until the vacuum degree reaches the vacuum value that allows the door to be opened.

[0138] S7, after the material processing is completed, the sealing doors 103 at both ends of the cavity 101 are opened, and at the same time, the pressing mechanism 109 is raised, and the processed material is transported out through the discharge conveyor 3.

[0139] The tunnel-type microwave vacuum ultra-low temperature drying equipment utilizes the characteristics of microwave polar molecular oscillation and heating, and is supplemented by vacuum and water cooling functions, so that the water-containing material in the cavity 101 is quickly evaporated at low temperature in a vacuum environment to achieve drying. This makes up for the defects of infrared auxiliary heating, air cooling, spray drying and other forms of drying on the market. At the same time, the electrical control system is supplemented by the equipment for reliable operation to cope with the drying of various different types of wet materials, and is especially suitable for the drying of special types of flammable, explosive and heat-sensitive materials.

[0140] Compared with other drying equipment currently available, this equipment has a fast drying speed for materials. The efficiency of the microwave generator in evaporating water is about 1kg / kw / h. It has high production capacity, uniform material drying, low energy consumption and is environmentally friendly and pollution-free.

[0141] Although the specific implementations of the utility model are described above, those skilled in the art should understand that this is only an example, and the protection scope of the utility model is defined by the attached claims. Those skilled in the art can make various changes or modifications to these implementations without departing from the principle and essence of the utility model, but these changes and modifications fall within the protection scope of the utility model.

Claims

1. A tunnel type microwave vacuum ultra-low temperature drying equipment, which is used for drying materials, characterized in that: The tunnel type microwave vacuum ultra-low temperature drying equipment comprises: A host device, the host device comprising a cavity and a plurality of microwave generators, wherein the cavity is a cylindrical structure, the inner cross-section of the cavity is a regular polygon, and the plurality of microwave generators are respectively arranged on the outer wall surface of the cavity and are arranged in sequence at least along the length direction of the cavity; A vacuum unit, wherein a vacuum port of the vacuum unit is connected to the cavity through a pipeline; A water chiller, wherein a cooling water pipe of the water chiller is connected to the microwave generator, and the water chiller is used to cool the microwave generator and the microwave power supply.

2. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: The cavity comprises a plurality of cylinder sections and flanges, and each cylinder section is connected by the flanges; and / or, The inner cross-sectional shape of the cavity is a regular 24-gon; and / or, The cavity is made of mirror-finished stainless steel; and / or, An electric heating tube is arranged at the bottom of the cavity.

3. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: The microwave generators are respectively disposed on the left and right sides of the cavity, and the arrangement positions of the microwave generators on the cavity correspond to the edges of the cross-sectional shape of the cavity; and / or, The microwave generator comprises a power supply, a waveguide, a mounting flange and a magnetron. The waveguide is mounted on the outer wall of the cavity through a distributed mounting flange. The waveguide is installed in coordination with the magnetron. The magnetron is powered by the power supply. The magnetron is controlled to start and emit microwaves into the cavity of the waveguide, and then the microwaves are reflected into the cavity by the cavity wall of the waveguide; and / or, Quartz glass is provided at the connection between the cavity and the microwave generator.

4. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 3, characterized in that: The waveguide adopts one of a hard waveguide, a soft waveguide, a rectangular waveguide and an elliptical waveguide.

5. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: A cylinder vacuum tube is provided on the cavity, a vacuum port of the vacuum unit is connected to the cylinder vacuum tube through a pipeline, a vacuum pressure relief valve is provided on the cavity, and the vacuum pressure relief valve, the cylinder vacuum tube and the microwave generator are staggered on the surface of the cavity; and / or, The vacuum unit includes one of the following three types of pump bodies: (1) Combination of oil-free screw vacuum pump and Roots vacuum pump; (2) Water ring vacuum pump; (3) Oil pump.

6. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: The tunnel-type microwave vacuum ultra-low temperature drying equipment also includes an ultra-low temperature water capture system, which includes a refrigeration unit, a heat exchanger, an evaporator and a condenser. The vacuum port of the vacuum unit is connected to the cavity after passing through the condenser and evaporator of the ultra-low temperature water capture system.

7. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 6, characterized in that: There are two sets of ultra-low temperature water capture systems, and the vacuum port is connected to the cavity via a condenser of one of the ultra-low temperature water capture systems by pipeline switching.

8. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: A cooling water pipe is fixedly installed at the external interface of the chiller, and the interface end of the cooling water pipe is fixedly installed and sealedly connected with the power supply of the microwave generator and the cooling interface end of the magnetron; and / or, The tunnel type microwave vacuum ultra-low temperature drying equipment also includes a cooling water tower, which is connected to the water chiller and is used to provide cooling capacity to the water chiller.

9. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: The host device further comprises a sealing door and a sealing door moving mechanism, wherein the sealing door is arranged at the end of the cavity, and the sealing door moving mechanism is connected to the sealing door and is used to drive the sealing door to switch between closing and opening relative to the end of the cavity; When the sealing door is switched to be closed relative to the end of the cavity, the sealing door is sealed and connected to the end of the cavity; When the sealing door is switched to open at the end of the cavity, the end of the cavity is opened outward.

10. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 9, characterized in that: The tunnel type microwave vacuum ultra-low temperature drying equipment further comprises a feeding conveyor and a discharging conveyor, wherein the feeding conveyor is correspondingly arranged at the feeding end of the cavity, and the discharging conveyor is correspondingly arranged at the feeding end of the cavity; The host device also includes an in-tunnel conveyor, which is arranged in the cavity, and two ends of the in-tunnel conveyor extend to the feeding conveyor and the discharging conveyor respectively.

11. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 10, characterized in that: The host device also includes a material pressing mechanism, which is arranged in the cavity and located above the conveyor in the tunnel. The material pressing mechanism is used to fix the material on the conveyor in the tunnel.

12. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 1, characterized in that: The tunnel-type microwave vacuum ultra-low temperature drying equipment also includes auxiliary equipment, in which the vacuum unit and the chiller are both arranged. The auxiliary equipment and the main equipment are arranged separately. The vacuum unit located in the auxiliary equipment is connected to the cavity in the main equipment through a vacuum tube, and the chiller located in the auxiliary equipment is connected to the microwave generator in the main equipment through a cooling water pipe.

13. The tunnel type microwave vacuum ultra-low temperature drying equipment according to claim 12, characterized in that: The tunnel-type microwave vacuum ultra-low temperature drying equipment also includes an electrical control module, and the electrical control module is arranged near the host device.

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