阅读说明：本技术 一种微波真空干燥设备 (Microwave vacuum drying equipment ) 是由 王顺 周明干 毕广龙 屠奇 刘迪 蒋齐翻 于 2020-05-15 设计创作，主要内容包括：本发明实施例中涉及一种微波真空干燥设备,该设备包括第一真空罐；第二真空罐；用于将第一真空罐上部和第二真空罐上部连通的第一真空管道；用于将第一真空罐下部和第二真空罐下部连通的第二真空管道；第一真空管道的内腔、第二真空管道的内腔、第一真空罐的内腔、第二真空罐的内腔连通共同形成一环形腔室；还包括载料循环装置,载料循环装置被配置为可承载被干燥物料并使物料沿环形腔室的环形轨迹循环运动；若干个微波发生器,微波发生器被配置为用于微波处理物料；真空排气装置,真空排气装置被配置为用于对环形腔室内的环境气体进行排气。该设备可有效减小干燥设备的体积,提高设备的空间利用率和产能。(The embodiment of the invention relates to microwave vacuum drying equipment, which comprises a first vacuum tank; a second vacuum tank; a first vacuum pipeline for communicating the upper part of the first vacuum tank with the upper part of the second vacuum tank; a second vacuum pipeline for communicating the lower part of the first vacuum tank with the lower part of the second vacuum tank; the inner cavity of the first vacuum pipeline, the inner cavity of the second vacuum pipeline, the inner cavity of the first vacuum tank and the inner cavity of the second vacuum tank are communicated to form an annular chamber; the material loading circulating device is configured to load the dried material and make the material circularly move along the circular track of the annular chamber; a number of microwave generators configured for microwave processing of the material; a vacuum exhaust configured to exhaust ambient gas within the annular chamber. The equipment can effectively reduce the volume of the drying equipment and improve the space utilization rate and the capacity of the equipment.)

1. A microwave vacuum drying apparatus, characterized in that the apparatus comprises:

a first vacuum tank;

a second vacuum tank;

the first vacuum pipeline is positioned on the upper layer and is used for communicating the upper part of the first vacuum tank with the upper part of the second vacuum tank; and

the second vacuum pipeline is positioned at the lower layer and is used for communicating the lower part of the first vacuum tank with the lower part of the second vacuum tank; the first vacuum pipeline and the second vacuum pipeline are arranged in parallel;

the inner cavity of the first vacuum pipeline, the inner cavity of the second vacuum pipeline, the inner cavity of the first vacuum tank and the inner cavity of the second vacuum tank are communicated to form an annular chamber;

the apparatus further comprises:

the material loading circulating device is positioned in the annular chamber and is configured to load the dried materials and enable the materials to circularly move along the annular track of the annular chamber;

a plurality of microwave generators disposed on an outer surface of the first vacuum conduit and/or the second vacuum conduit, the microwave generators configured for microwave treatment of material carried on the load circulation device;

a vacuum exhaust configured to exhaust ambient gas within the annular chamber.

2. A microwave vacuum drying apparatus according to claim 1, wherein the apparatus comprises condensing means configured to condense ambient gas within the annular chamber.

3. Microwave vacuum drying apparatus according to claim 1,

an inclined angle is formed between the central axis of the first vacuum pipeline and the horizontal plane;

an inclined angle exists between the central axis of the second vacuum pipeline and the horizontal plane.

4. Microwave vacuum drying apparatus according to claim 1,

the height of the end part of the first vacuum tank connected with the first vacuum pipeline is lower than that of the end part of the second vacuum tank connected with the first vacuum pipeline;

the height of the end part of the first vacuum tank connected with the second vacuum pipeline is lower than that of the end part of the second vacuum tank connected with the second vacuum pipeline.

5. Microwave vacuum drying apparatus according to claim 1,

the number of the microwave generators on the outer surface of the first vacuum pipeline is decreased progressively along the direction from the material input end to the material output end of the first vacuum pipeline;

and the number of the microwave generators on the outer surface of the second vacuum pipeline is decreased progressively along the direction from the material input end to the material output end of the second vacuum pipeline.

6. A microwave vacuum drying apparatus according to claim 1 wherein a microwave generator is provided around the outer surface of the first vacuum conduit and/or second vacuum conduit.

7. A microwave vacuum drying apparatus according to claim 1, wherein the charge circulating means comprises two oppositely disposed rails located within the annular chamber and a charge tray disposed between the two oppositely disposed rails.

8. The microwave vacuum drying apparatus according to claim 1, wherein the vacuum exhaust device comprises a vacuum pump, a buffer tank;

the vacuum pump is respectively communicated with the first vacuum pipeline and the second vacuum pipeline through exhaust pipelines, and the buffer tank is positioned on the exhaust pipelines.

9. The microwave vacuum drying equipment as claimed in claim 2, wherein the condensing device comprises a plurality of condensing pipes arranged on the inner wall of the first vacuum pipeline and/or the second vacuum pipeline and a water chiller communicated with the condensing pipes, and the water chiller is configured to provide cold water and circulating power for the condensing pipes.

10. A microwave vacuum drying apparatus according to claim 1, wherein the apparatus includes a monitoring illumination device, the monitoring illumination device including an illumination lamp for illuminating the interior of the apparatus and a plurality of sensors for real-time monitoring of the temperature of the material in the apparatus, the vacuum level and the humidity in the annular chamber.

11. Microwave vacuum drying apparatus according to claim 1,

the microwave generator comprises a magnetron and an excitation cavity, one end of the excitation cavity is communicated with the magnetron, and the other end of the excitation cavity is fixedly connected with the first vacuum pipeline and/or the second vacuum pipeline;

the microwave generated by the magnetron is fed into the inner cavity of the first vacuum pipeline and/or the inner cavity of the second vacuum pipeline through the excitation cavity.

Technical Field

The invention relates to the technical field of microwave vacuum. And more particularly, to a microwave vacuum drying apparatus.

Background

Microwave refers to electromagnetic wave with frequency in the range of 300 MHz-300 GHz, and is used in military radar and communication field at first; later, it was found that the microwave has a thermal effect on the polar molecular material, that is, the material with polar molecules is repeatedly and rapidly oriented and rotated under the action of the microwave high-frequency electric field to generate heat by friction, and the microwave also has penetrability, that is, the microwave can be deep into the material when irradiating the polar material, and the inside and the outside are heated simultaneously, so that the heating speed is high and the efficiency is high. The vacuum drying is a drying mode of putting the material under a vacuum negative pressure condition to reduce the boiling point of water, properly heating to reach the boiling point under a negative pressure state or cooling to solidify the material and then drying the material through the melting point, and the drying method is applicable to the drying process of the heat-sensitive material. The microwave vacuum drying technology integrates the advantages of microwave drying and vacuum drying, and combines the rapid and efficient performance of microwave drying and the characteristic of moisture low-temperature evaporation under a vacuum condition, thereby realizing the low-temperature rapid drying of materials.

Disclosure of Invention

The invention aims to provide microwave vacuum drying equipment which has the advantages of high capacity, high space utilization rate, high vacuum degree in the equipment, low processing and manufacturing difficulty and convenience for large-scale production.

To achieve at least one of the above objects, there is provided a microwave vacuum drying apparatus, comprising: a first vacuum tank; a second vacuum tank; the first vacuum pipeline is positioned on the upper layer and is used for communicating the upper part of the first vacuum tank with the upper part of the second vacuum tank; the second vacuum pipeline is positioned at the lower layer and is used for communicating the lower part of the first vacuum tank with the lower part of the second vacuum tank; the first vacuum pipeline and the second vacuum pipeline are arranged in parallel; the inner cavity of the first vacuum pipeline, the inner cavity of the second vacuum pipeline, the inner cavity of the first vacuum tank and the inner cavity of the second vacuum tank are communicated to form an annular chamber; the equipment also comprises a material loading circulating device positioned in the annular chamber, wherein the material loading circulating device is configured to load the dried material and make the material circularly move along the annular track of the annular chamber; a plurality of microwave generators disposed on an outer surface of the first vacuum conduit and/or the second vacuum conduit, the microwave generators configured for microwave treatment of material carried on the load circulation device; a vacuum exhaust configured to exhaust ambient gas within the annular chamber.

Optionally, the apparatus comprises a condensing means configured to condense ambient gas within the annular chamber.

Optionally, an inclined angle exists between the central axis of the first vacuum pipeline and the horizontal plane; an inclined angle exists between the central axis of the second vacuum pipeline and the horizontal plane.

Optionally, the height of the end of the first vacuum tank connected with the first vacuum pipe is lower than the height of the end of the second vacuum tank connected with the first vacuum pipe;

the height of the end part of the first vacuum tank connected with the second vacuum pipeline is lower than that of the end part of the second vacuum tank connected with the second vacuum pipeline.

Optionally, the number of microwave generators on the outer surface of the first vacuum pipe decreases in the direction from the material input end to the material output end of the first vacuum pipe;

and the number of the microwave generators on the outer surface of the second vacuum pipeline is decreased progressively along the direction from the material input end to the material output end of the second vacuum pipeline.

Optionally, a microwave generator is disposed around an outer surface of the first vacuum conduit and/or the second vacuum conduit.

Optionally, the material loading circulation device includes two oppositely disposed rails located in the annular chamber and a material loading tray disposed between the two oppositely disposed rails.

Optionally, the vacuum exhaust device comprises a vacuum pump and a buffer tank;

the vacuum pump is respectively communicated with the first vacuum pipeline and the second vacuum pipeline through exhaust pipelines, and the buffer tank is positioned on the exhaust pipelines.

Optionally, the condensing device includes a plurality of condenser pipes disposed on an inner wall of the first vacuum pipe and/or the second vacuum pipe, and a water chiller in communication with the condenser pipes, the water chiller being configured to provide chilled water and circulating power for the condenser pipes.

Optionally, the apparatus includes a monitoring illumination device, and the monitoring illumination device includes an illumination lamp for providing illumination to the inside of the apparatus and a plurality of sensors for monitoring the temperature of the material in the apparatus and the vacuum degree and humidity in the annular chamber in real time.

Optionally, the microwave generator includes a magnetron and an excitation cavity having one end communicated with the magnetron, and the other end of the excitation cavity is fixedly connected with the first vacuum pipe and/or the second vacuum pipe;

the microwave generated by the magnetron is fed into the inner cavity of the first vacuum pipeline and/or the inner cavity of the second vacuum pipeline through the excitation cavity.

The invention has the following beneficial effects:

the microwave vacuum drying equipment provided by the invention can reduce the volume and the wall thickness of the equipment, reduce the processing and manufacturing difficulty of the equipment, reduce the manufacturing cost, improve the space utilization rate and the capacity of the equipment, enhance the effects of microwave treatment and steam condensation in the equipment and ensure that the vacuum degree in the equipment is not reduced in the long-time operation process of the microwave vacuum drying equipment; moreover, the first vacuum pipeline and the second vacuum pipeline can be assembled by connecting a plurality of vacuum pipeline sections in series, so that the microwave vacuum drying equipment can be applied to different industrial environments in a large scale, and the application range of the equipment is widened.

In addition, the number of the microwave generators on the outer surface of the first vacuum pipeline is decreased progressively along the direction from the material input end to the material output end of the first vacuum pipeline; the number of the microwave generators on the outer surface of the second vacuum pipeline is decreased progressively along the direction from the material input end to the material output end of the second vacuum pipeline, so that the material can be heated rapidly as soon as entering the vacuum pipeline, and meanwhile, the number of the microwave generators is decreased progressively along the direction to the material output end, so that the temperature of the material can be kept within a certain temperature range.

Moreover, this equipment is through setting up the microwave generator that the material circulating device that carries in first vacuum pipeline and second vacuum pipeline and the surface setting of encircleing first vacuum pipeline and second vacuum pipeline for this equipment can carry out microwave heating to the material simultaneously from a plurality of directions, enlarges the area of action of material and microwave, improves microwave heating's homogeneity, further strengthens the effect of the inside microwave treatment of equipment.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 shows a structural side view of a microwave vacuum drying apparatus according to an embodiment of the present invention.

Fig. 2 illustrates a front view of a structure of a microwave vacuum drying apparatus according to an embodiment of the present invention.

Fig. 3 shows a schematic view of the internal structure of a vacuum pipe according to an embodiment of the present invention.

Fig. 4 shows a schematic configuration of a microwave generator according to an embodiment of the present invention.

Fig. 5 shows a schematic structural diagram of a material loading circulation device according to an embodiment of the invention.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below with reference to preferred embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

In order to achieve the above objects, a microwave vacuum drying apparatus according to an embodiment of the present invention, as shown in fig. 1 to 5, includes a first vacuum tank 11 and a second vacuum tank 12, and a first vacuum pipe 13 at an upper level for communicating an upper portion of the first vacuum tank 11 with an upper portion of the second vacuum tank 12, and a second vacuum pipe 14 at a lower level for communicating a lower portion of the first vacuum tank 11 with a lower portion of the second vacuum tank 12. The first vacuum pipeline 13 and the second vacuum pipeline 14 are arranged in parallel, and it can be understood that the first vacuum pipeline 13 and the second vacuum pipeline 14 can be respectively formed by connecting a plurality of vacuum pipeline sections in series, so that a user can design the length of the vacuum pipeline according to actual industrial conditions. In a specific embodiment, the first vacuum tank 11 is fixedly connected to the first vacuum pipe 13 and the second vacuum pipe 14 through the connecting flange 15, and the second vacuum tank 12 is fixedly connected to the first vacuum pipe 13 and the second vacuum pipe 14 through the connecting flange 15. The inner cavity of the first vacuum pipeline 13, the inner cavity of the second vacuum pipeline 14, the inner cavity of the first vacuum tank 11 and the inner cavity of the second vacuum tank 12 are communicated to form an annular chamber, namely a closed annular space. The microwave vacuum drying apparatus further comprises a material carrying circulation device 20 located in the annular chamber, the material carrying circulation device being configured to carry the material to be dried, such as vegetables, fruits or meats, and the material carrying circulation device being configured to circulate the material along the circular path of the annular chamber, i.e. clockwise or counterclockwise. Also included are a plurality of microwave generators 30 disposed on the outer surface of the first vacuum line 13 and/or the second vacuum line 14, the microwave generators being configured for microwave treatment of the material carried on the load circulation device, and in one embodiment, for heat drying the material in the load circulation device. The microwave vacuum drying apparatus further comprises a vacuum exhaust 40 configured to exhaust ambient gas within the annular chamber and to exhaust gas within the annular chamber out of the annular chamber.

When the microwave vacuum drying equipment works, firstly, the material loading circulating device 20 circularly moves the loaded material to be dried along the annular track of the annular chamber, and the microwave generator 30 feeds microwaves into the annular chamber to heat and dry the material on the material loading circulating device. At the same time, the vacuum exhaust device 40 exhausts the ambient gas in the annular chamber, so that the annular chamber is maintained at a low pressure. The boiling temperature of the water in the material on the material-carrying circulation device 20 is reduced under the low-pressure state, so that the low-temperature drying of the material can be realized, the nutrient content of the material is kept, and meanwhile, the microwave heating characteristic from inside to outside also enables the material to generate the puffing effect, and water vapor is evaporated. And the water vapor evaporated from the material is exhausted to the outside of the annular chamber by the vacuum exhaust means 40. Compared with the microwave vacuum drying equipment with the cylindrical tank body in the prior art, the microwave vacuum drying equipment provided by the embodiment can effectively reduce the volume of the equipment, and meets the requirement of the microwave vacuum drying equipment with small volume in the current industrial application; meanwhile, the space utilization rate and the one-time microwave processing capacity of the equipment are improved, and the capacity of the equipment is improved. The equipment can ensure high space utilization rate and high yield of the equipment, can also keep smaller equipment volume, and further reduce the wall thickness of the pipeline of the equipment by reducing the diameter of the pipeline, thereby reducing the processing and welding difficulty of the equipment, and reducing the manufacturing cost of the equipment and the electric power cost required by the exhaust of a vacuum air exhaust device in the running process of the equipment; compared with the microwave drying equipment with a single pipeline and a material loading circulating device in the prior art, the diameter of the vacuum pipeline of the equipment can be smaller, in a specific embodiment, the vacuum pipeline of the equipment is a standard pipeline with the diameter of 600-800mm, and the pipeline diameter of the microwave drying equipment with the single pipeline in the prior art is usually 2-3 meters. Compared with the microwave drying equipment with a single pipeline in the prior art, the equipment can also shorten the diameter of the vacuum pipeline, effectively reduce the volume of the equipment and reduce the manufacturing cost of the equipment; meanwhile, the equipment can improve the space utilization rate and the primary material handling capacity, and improve the capacity of the equipment. The equipment can enlarge the action area of materials and microwaves, improve the uniformity of microwave heating and enhance the effects of microwave treatment and steam condensation in the equipment through the material carrying circulating devices arranged in the first vacuum pipeline and the second vacuum pipeline; the vacuum exhaust device is used for pumping out water vapor evaporated by air or materials in the annular cavity in time to keep low humidity in the annular cavity, so that the vacuum degree in the microwave drying equipment is ensured not to be reduced in the long-time running process; furthermore, first vacuum pipeline and second vacuum pipeline accessible a plurality of vacuum pipeline sections equipment form, can be according to different industrial environment and operation interval, carry out the series connection equipment to the vacuum pipeline section as required for this microwave vacuum drying equipment can be applied to different industrial environment on a large scale, improves the range of application of this equipment.

In a specific embodiment, as shown in fig. 1, a sealing door 16 for taking and placing materials is provided at one side of the first vacuum tank 11 and/or the second vacuum tank 12, and an observation window 17 for observing the internal condition of the annular chamber is provided in the middle of the sealing door 16.

In a specific embodiment, as shown in fig. 1 to 3, the apparatus further comprises a condensing device configured to condense the ambient gas in the annular chamber, i.e. the water vapor evaporated from the material during the microwave heating process is condensed into droplets by the condensing device 50, and the droplets are collected and discharged out of the annular chamber to ensure the vacuum degree in the annular chamber. In a specific embodiment, the condensing units are installed and fixed on both side walls of the first vacuum duct 13 and the second vacuum duct 14 in parallel. Through setting up condensing equipment, can further form the liquid drop in time and discharge annular chamber with the gaseous ring chamber, further ensure that this microwave drying equipment can not descend at the inside vacuum of long-time operation in-process equipment.

In a further embodiment, the condensing device includes a plurality of condensing pipes 51 disposed on the inner wall of the first vacuum pipe 13 and/or the second vacuum pipe 14, and a water chiller (not shown) connected to the condensing pipes 51 through pipes, the water chiller being located outside the apparatus, the water chiller being configured to provide chilled water and circulating power to the condensing pipes. It can be understood that the condensing device further comprises a drain pipe 52 arranged at the lower part of the first vacuum pipe 13 and the second vacuum pipe 14. In a specific embodiment, during the operation of the microwave drying device, part of the steam evaporated from the material is cooled to form droplets by encountering the condensation pipe 51, flows downwards along the inner wall of the first vacuum pipe 13 and/or the second vacuum pipe 14, and is discharged through the discharge pipe 52 or from the discharge port 18 of the first vacuum tank 11 or the second vacuum tank 12.

In a specific embodiment, an inclined angle exists between the central axis of the first vacuum pipeline 13 and the horizontal plane, and an inclined angle exists between the central axis of the second vacuum pipeline 14 and the horizontal plane, that is, the first vacuum pipeline 13 and the second vacuum pipeline 14 are inclined, so that after the water vapor of the material forms droplets on the inner side wall of the vacuum pipeline in the microwave drying process, or in an embodiment including a condensing device, after the material is cooled into droplets by a condensing pipe, the droplets can flow downwards along the inner wall of the first vacuum pipeline 13 or the second vacuum pipeline 14 and are discharged from the liquid outlet 18 at the bottom of the first vacuum tank 11 or the second vacuum tank 12, so that the low humidity in the annular chamber is ensured, and the vacuum degree in the annular chamber is further improved.

In one embodiment as shown in fig. 2, the end of the first vacuum tank 11 connected to the first vacuum line 13 has a lower height than the end of the second vacuum tank 12 connected to the first vacuum line 13; the height of the end part of the first vacuum tank 11 connected with the second vacuum pipeline 14 is lower than that of the end part of the second vacuum tank 12 connected with the second vacuum pipeline 14, so that after water vapor of the material is condensed into liquid drops on the vacuum pipeline and the inner wall of the vacuum tank in the microwave drying process, the liquid drops flow to the first vacuum tank 11 along the extending direction of the first vacuum pipeline 13 or the second vacuum pipeline 14 and finally reach the liquid discharge port 18 of the first vacuum tank bottom 11 and are discharged from the liquid discharge port 18, and the low humidity in the annular chamber is kept. It will be appreciated that in another embodiment, the end of the first vacuum tank connected to the first vacuum line has a greater height than the end of the second vacuum tank connected to the first vacuum line; when the height of the end part of the first vacuum tank connected with the second vacuum pipeline is higher than that of the end part of the second vacuum tank connected with the second vacuum pipeline, the condensed liquid drops are discharged through a liquid outlet at the bottom of the second vacuum tank.

In one embodiment, to ensure a continuous uniform heating of the material in the annular chamber, the number of microwave generators 30 on the outer surface of the first vacuum line 13 decreases in the direction from the material input end to the material output end of the first vacuum line 13; the number of microwave generators 30 on the outer surface of the second vacuum pipe 14 decreases in the direction from the material input end to the material output end of the second vacuum pipe 14. In the implementation mode that the material loading disc circularly moves clockwise along the annular track of the annular chamber, the material input end of the first vacuum pipeline is the end part of the first vacuum pipeline communicated with the first vacuum tank, and the material output end of the first vacuum pipeline is the end part of the first vacuum pipeline connected with the second vacuum tank; the material input end of the second vacuum pipeline is the end part of the second vacuum pipeline connected with the second vacuum tank, and the material output end of the second vacuum pipeline is the end part of the second vacuum pipeline connected with the first vacuum tank. It can be understood that when the loading tray circularly moves along the circular track of the annular chamber anticlockwise, the material input ends and the material output ends of the first vacuum pipeline and the second vacuum pipeline are correspondingly changed.

The embodiment mainly considers that when the material moves in the inner cavity of the vacuum tank, no microwave generator heats the material, the temperature of the material drops quickly, the number of the microwave generators arranged on the outer surface of the material input end of the first vacuum pipeline is more than that of the microwave generators arranged on the outer surface of the material output end of the first vacuum pipeline, and the number of the microwave generators arranged on the outer surface of the material input end of the second vacuum pipeline is more than that of the microwave generators arranged on the outer surface of the material output end of the second vacuum pipeline, so that the material can be heated quickly once entering the vacuum pipeline, and meanwhile, the number of the microwave generators is decreased progressively along the direction of the movement track of the material, so that the temperature of the material can be kept in a certain temperature range.

In a specific embodiment, the microwave generator 30 is disposed around the outer surface of the first vacuum pipe 13 and/or the second vacuum pipe 14, and as shown in fig. 1 to 3, the microwave generator 30 is disposed on the outer surface of each of the upper and lower sides of the first vacuum pipe 13 and the second vacuum pipe 14. In a specific embodiment, the microwave generators 30 are spaced along the circumferential direction of the outer surfaces of the first vacuum pipe 13 and the second vacuum pipe 14. The equipment of the specific embodiment can simultaneously carry out microwave heating on the material from multiple directions through the synergistic effect of the material carrying circulating device arranged in the first vacuum pipeline and the second vacuum pipeline and the microwave generator arranged around the outer surfaces of the first vacuum pipeline and the second vacuum pipeline, so that the acting area of the material and the microwave is enlarged, the uniformity of the microwave heating is improved, and the effect of the microwave treatment in the equipment is further enhanced.

In a specific embodiment, the material loading circulation device 20 comprises two rails 21 which are oppositely arranged and are positioned in the annular chamber, and a material loading tray 22 which is arranged between the two rails 21 which are oppositely arranged, and in a specific embodiment, the outer parts of the two rails 21 are fixed with a support frame in the first vacuum tank 11, the second vacuum tank 12, the first vacuum pipeline 13 and the second vacuum pipeline 14. It can be understood that the inner side walls of the two rails 21 are provided with moving parts, and the moving parts can drive the material loading tray 22 to circularly move along the extending direction of the rails 21. Wherein in one embodiment the moving part is a chain 23. Wherein, the outside of two tracks is the stainless steel material that can provide sufficient rigidity, and the inside lining is super high molecular polyethylene, can reduce the frictional force between track and the chain. The chain 23 is fixed to the tray 22. It will be appreciated that the material loading tray can be driven to move circularly along the circular track of the track by a motor, a chain wheel transmission or other means commonly used in the art. In the embodiment shown in fig. 3-5, the material loading and circulating device 20 includes a rotating shaft 24 disposed between two oppositely disposed rails 21 and a gear 25 disposed on the rotating shaft 24 and engaged with the chain 23, the rotating shaft 24 is connected to an external motor (not shown), the rotating shaft 24 and the gear 25 are driven by the external motor to rotate, and the gear 25 is engaged with the chain 22 to drive the chain 22 to move. In an alternative embodiment, a tensioner 26 is included adjacent the gear 25 and may be used to tension the chain.

In a specific embodiment, the vacuum exhaust device 40 includes a vacuum pump 41, a buffer tank 42; the vacuum pump 41 is respectively communicated with the vacuum flanges 19 on the first vacuum pipeline 13 and the second vacuum pipeline 14 through an exhaust pipeline 43, the buffer tank 42 is positioned on the exhaust pipeline 43, it can be understood that the vacuum exhaust device 40 further comprises a water tank 44 connected with the vacuum pump 41, as shown in fig. 1-2, one end of the buffer tank 42 is communicated with the vacuum pump 41, the other end of the buffer tank 42 is communicated with the exhaust pipeline 43, and the buffer tank can store certain vacuum pressure on one hand, and on the other hand, can prevent water in the vacuum pump from being sucked back into the vacuum pipeline in case of unexpected failure. In a specific embodiment, the exhaust pipe 43 is provided with a solenoid valve 45 for controlling the gas connection and disconnection between the exhaust pipe and the outside air. In view of the heating temperature of the vegetables and fruits and the required vacuum degree, in an alternative embodiment, the vacuum pump is a water ring vacuum pump.

In a specific embodiment, the apparatus further comprises a monitoring and lighting device, the monitoring and lighting device comprises a lighting lamp 60 for providing lighting to the inside of the apparatus, the lighting lamp 60 is disposed on the top surface of the first vacuum tank 11 or the second vacuum tank 12, and a plurality of sensors 70 for monitoring the temperature of the material in the apparatus, the vacuum degree and the humidity in the annular chamber in real time, the plurality of sensors may be, for example, infrared temperature sensors, humidity sensors, etc., it is understood that the monitoring and lighting device may further comprise a camera.

In a specific embodiment, as shown in fig. 4, the microwave generator 30 includes a magnetron 31 and an excitation cavity 32 having one end communicating with the magnetron 31, and the other end of the excitation cavity 32 is fixedly connected to a microwave source mounting flange 110 corresponding to the first vacuum pipe 13 and/or the second vacuum pipe 14 through a mounting cover plate 33; it will be appreciated that the microwave generator 30 further comprises a switching power supply (not shown) for supplying a high voltage to the magnetron 31 so that the magnetron 31 generates microwaves, and a sealing plate (not shown) disposed between the mounting cover 33 and the microwave source mounting flange 110 of the vacuum pipe, wherein the microwaves generated by the magnetron 31 are fed into the inner cavity of the first vacuum pipe 13 and/or the inner cavity of the second vacuum pipe 14 through the excitation cavity 32. When the microwave source is installed, the sealing sheet is firstly limited in the groove of the microwave source installation flange 110 of the vacuum pipeline by using the installation cover plate 33, then the excitation cavity 32 is fixed on the installation cover plate 33, and finally the magnetron 31 is fixed on the excitation cavity 32 through bolts.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.