A modified atmosphere sterilizer and sterilization method for longan storage

Abstract

This invention discloses a modified atmosphere packaging (MAP) sterilizer and sterilization method for longan storage, relating to the field of longan storage sterilization technology. The invention includes an air inlet pipe connected to a sterilization chamber at its bottom. Plasma-treated gas enters the sterilization chamber through the air inlet pipe, creating a plasma-filled sterilization environment to eliminate bacteria on the longan skin. A vacuum treatment chamber is fixed to the bottom of the sterilization chamber, comprising an outer chamber and an inner chamber with a top opening. The top of the inner chamber is equipped with a sealing mechanism for sealing the longan in a preservation box. This invention creates a plasma-filled sterilization environment within the sealing chamber, and utilizes the preservation box sealing mechanism to perform a heat-sealing operation within this gas environment. This simplifies the structural design of the preservation box sealing mechanism, enabling the invention to meet existing sterilization requirements while simultaneously reducing the sealing cost for longan storage.

Description

Technical Field

[0001] This invention relates to the field of longan storage and sterilization technology, specifically to a modified atmosphere sterilizer and sterilization method for longan storage. Background Technology

[0002] Modified atmosphere packaging (MAP) is a food preservation method that combines modified atmosphere packaging technology with plasma sterilization technology. MAP technology inhibits microbial growth by altering the gas composition (such as the ratio of oxygen, carbon dioxide, and nitrogen) within the packaging, thereby extending the shelf life of food. Plasma sterilization technology, on the other hand, uses high-voltage, high-frequency pulsed discharge to create an asymmetric plasma electric field. This causes a series of collisions between numerous plasma particles in the gas, generating electrochemical reactions. Under high-voltage electric field conditions, the medium gas is highly ionized, forming various active groups and particles that react with microorganisms, leading to cell structure destruction and ultimately death. This method effectively kills viruses, bacteria, odors, smoke, and dust without producing any toxic or harmful substances.

[0003] This technology is now widely used in the storage and packaging of various fresh foods, especially fruits and vegetables. To extend the shelf life of fruits, longan merchants have also applied this technology to longan storage. In practice, modified atmosphere packaging (MAP) technology typically involves the following steps: placing longans in a storage container → covering the container with a film → evacuating the inside of the container → injecting plasma-treated gas into the container. These processes require evacuating each container individually and injecting gas into each container separately. This necessitates that each autoclaving device has a dedicated vacuum and inflation mechanism, resulting in complex equipment structure, increased design precision requirements, and ultimately, increased fruit storage costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a modified atmosphere sterilizer and sterilization method for longan storage. By creating a sterilization environment filled with plasma gas in a sealed box, the food storage box sealing mechanism completes the heat-sealing operation in this gas environment, simplifying the structural design of the food storage box sealing mechanism. This invention can reduce the sealing cost of longan storage while meeting existing sterilization requirements.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a modified atmosphere sterilizer for longan storage, comprising an air inlet pipe, the bottom end of which is connected to a sterilization chamber. Gas treated with plasma enters the sterilization chamber through the air inlet pipe to create a sterilization environment filled with plasma gas inside the sterilization chamber, thereby eliminating bacteria on the surface of the longan in the sterilization chamber. The gas is a mixture of nitrogen, oxygen, and carbon dioxide, which, after plasma treatment, can form a variety of active groups and particles, destroying the cell structure of microorganisms and achieving the sterilization effect.

[0006] The sterilization box has a vacuum treatment box fixed at the bottom. The vacuum treatment box includes an outer box and an inner box with a top opening fixed inside the outer box. The top of the inner box is provided with a food preservation box sealing mechanism for sealing longan in a food preservation box. The outer casing is equipped with a vacuum pump at the rear to create a vacuum inside the inner casing. The front of the outer casing and the front of the inner casing are connected to each other, and the outer casing and the inner casing are connected to each other ...

[0007] Preferably, the food storage container sealing mechanism includes a support frame installed on the top of the inner box, a sealing plate that can move up and down is installed inside the support frame, a sealing platform for holding the food storage container is provided at the bottom of the sealing plate, the sealing platform is provided with two workstations, which can simultaneously complete the heat-sealing work of two food storage containers, sealing platform supports are provided on both sides of the sealing platform, the two sealing platform supports are mirrored, and the sealing platform is driven by the sealing platform lifting component to move the food storage container up and down between the inner box and the sterilization box; A roll of plastic sealing film is rotatably connected to one side of the top of the support frame. Guide rollers for guiding the plastic sealing film are installed on both sides below the support frame. A take-up shaft for winding the plastic sealing film is rotatably connected to the other side of the top plate of the support frame. The plastic sealing film passes around the two guide rollers in sequence and is located on the top of the sealing platform. Then, the sealing plate moves down to heat-press the plastic sealing film onto the opening of the food storage box to seal the longan in the food storage box. After heat-pressing and sealing, the excess plastic sealing film is wound up by the take-up shaft.

[0008] Preferably, the sealing platform lifting assembly includes two hydraulic cylinders a installed at the bottom of the sealing platform. The hydraulic cylinders a drive the sealing platform to move up and down. A C-shaped bracket is fixed to the outer end of the hydraulic cylinder a. A threaded rod a is threadedly connected to the C-shaped bracket. The threaded rod a passes through the C-shaped bracket and drives the C-shaped bracket to move the hydraulic cylinders a up and down.

[0009] Preferably, the inner box is provided with a feeding mechanism on one side for moving the food storage box containing longan into the sealing platform; The feeding mechanism includes a feeding platform at the same height as the lowered sealing platform. The bottom of the feeding platform is provided with a baffle that can move up and down. A push plate is provided on one side of the top of the feeding platform. A push bracket is provided on one side of the push plate for driving the push plate to move. One end of the push bracket is threadedly connected to a threaded rod b. The rotating threaded rod b drives the push bracket to move the push plate on the top of the feeding platform, which is used to push the food storage box that has moved to the top of the feeding platform into the sealing platform.

[0010] Preferably, the inner box is equipped with a food storage box lifting mechanism for discharging the sealed food storage box; The food storage container lifting mechanism includes two lifting heads located at the bottom of the sealing platform. The lifting heads are driven to move up and down by lifting cylinders at the bottom. A belt conveyor is provided on one side of the discharge port in the inner box. The top of the belt conveyor is flush with the top of the lowered sealing platform. The lower part of the discharge port in the inner box is machined into an inclined surface. The upward-moving lifting heads push the sealed food storage container embedded in the sealing platform to move upward. Then, the push plate pushes the unsealed food storage container towards the sealing platform. At the same time, the unsealed food storage container pushes the sealed food storage container to the top of the belt conveyor. Finally, the belt conveyor transports the sealed food storage container to the discharge port so that it moves down the inclined surface in the discharge port and goes out.

[0011] Preferably, the opening sealing mechanism includes two sealing plates a that seal the top opening of the inner box. The two sealing plates a are arranged in a mirror image. An iron plate is fixed to the far end of each sealing plate a. An electromagnet is embedded in the top of the inner box at the contact position. When the electromagnet is energized, it attracts the iron plate to fix the position of the sealing plate a. A plurality of springs a in a stretched state are fixed to the side of the iron plate away from the sealing plate a. When the electromagnet is de-energized, the springs a pull the sealing plate a out of the top opening of the inner box. The feed inlet sealing mechanism includes a sealing plate b inserted inside the inner box, and the sealing plate b is driven to move up and down by a hydraulic cylinder b at the bottom. The discharge port sealing mechanism includes a sealing plate c inserted into the inner box, a triangular bracket fixed to the bottom of the sealing plate c, and a hydraulic cylinder c that drives the sealing plate c to move up and down fixed to the bottom of the triangular bracket.

[0012] Preferably, an arc-shaped groove is provided on the side of the two sealing plates a that are close to each other. An arc-shaped sealing ring is fixed in the arc-shaped groove. The sealing ring is tightly fitted to the outside of the moving end of the hydraulic cylinder a. Two short plates are inserted inside one of the sealing plates a. Multiple springs b are fixed to one end of the short plates. When the moving end of the hydraulic cylinder a retracts, the springs b push the short plates to seal the arc-shaped groove between the two sealing plates a. The opening sealing mechanism, the sealing plate b, and the sealing plate c are all wrapped with sealing strips to seal the gaps between the opening sealing mechanism, the inlet sealing mechanism, the outlet sealing mechanism, and the inner box.

[0013] Preferably, a feeding conveyor is provided on the front side of the outer casing, and the feeding conveyor is located below the feeding port; A discharge conveyor is provided on one side of the outer casing. The discharge conveyor is located below the discharge port, and the width of the discharge conveyor is twice the width of the infeed conveyor.

[0014] Preferably, the sterilization box includes a sealed box, a sealed door is installed on one of the outer walls of the sealed box, and transparent observation windows are installed on the remaining outer walls of the sealed door; Pressure gauges are installed on both the front of the sealed box and the rear of the outer box. The pressure gauge installed on the sealed box is used to monitor the air pressure inside the sealed box, and the pressure gauge installed on the rear of the outer box is used to monitor the air pressure inside the inner box. The top side of the sealed box is equipped with a strobe alarm light for alarm purposes, and the front side of the sealed box is equipped with a control box for receiving monitoring data from the pressure gauge. The strobe alarm light, the feeding conveyor, and the discharging conveyor are all controlled by the control box.

[0015] The present invention also includes a sterilization method using the above-mentioned modified atmosphere sterilizer for longan storage, the specific steps of which are as follows: S1. The sealing plate b is lowered by the hydraulic cylinder b to open the feed port in the inner box. Then, the staff put the food storage boxes containing longan on the top of the feeding conveyor and the feeding conveyor transports them through the feed port to the inner box. S2. When one food storage container moves to the top side of the loading platform, the baffle rises, and then the other food storage container moves to the side of the baffle. At this time, the sealing plate b moves up to block the inlet. Then the push plate is driven by the rotating threaded rod b to move on the top of the loading platform, and at the same time pushes the two food storage containers located on its side to the two workstations on the sealing platform respectively. S3. The vacuum pump is started by the control box to extract the air from the inner box and make the inner box a vacuum environment. S4. The two electromagnets are de-energized by the control box, so that the sealing plate a is pulled out from the top opening of the inner box by the spring a. Then the sealing platform lifting assembly drives the sealing platform to move up and through the top opening of the inner box to move into the inner box. Then the electromagnets are energized again, and the adsorption iron plate drives the sealing plate a to be inserted back into the top opening of the inner box to seal the top opening of the inner box. S5. The gas after plasma treatment is injected into the sterilization chamber through the air inlet pipe to create a sterilization environment in the sterilization chamber. Then, the sealing plate is activated to seal the food storage box containing longan, and at the same time, the plasma gas is sealed in the food storage box. S6. The two electromagnets are de-energized again by the control box, so that the sealing plate a is pulled out from the top opening of the inner box by the spring a. Then the sealing table lifting assembly drives the sealing table to move the sealed food container down until it moves into the inner box. Then the electromagnets are energized again, and the adsorption iron plate drives the sealing plate a back into the top opening of the inner box to reseal the top opening of the inner box. S7. The lifting head is driven to move upward by the lifting cylinder, pushing the two sealed food storage boxes embedded in the sealing platform to move upward. Then, repeat step S1 above to transport the two new unsealed food storage boxes to the top of the loading platform. The pusher plate pushes them toward the sealing platform so that the unsealed food storage boxes can push the sealed food storage boxes to the top of the belt conveyor. The belt conveyor moves the sealed food storage boxes to the discharge port, so that they move down the inclined surface at the bottom of the discharge port to the top of the discharge conveyor for output.

[0016] Compared with the prior art, the present invention provides a modified atmosphere sterilizer and sterilization method for longan storage, which has the following beneficial effects: 1. In contrast to the existing technology that processes each food storage container individually, this invention proposes for the first time to create a sterilization environment filled with plasma gas in a sealed box, and use the food storage container sealing mechanism to complete the heat-sealing operation in this gas environment. This simplifies the structural design of the food storage container sealing mechanism, enabling this invention to reduce the sealing cost of longan storage while meeting existing sterilization requirements.

[0017] 2. This invention extracts the gas from the inside of the inner box and the sealed box before hot-press sealing. On the one hand, it can avoid the influence of microorganisms in the external gas on the longan storage. On the other hand, it can directly place the preservation box in a vacuum environment, eliminating the need for the separate vacuuming operation of the preservation box in the prior art, further simplifying the structural design and reducing the cost of longan storage. Attached Figure Description

[0018] Figure 1 This is a first view of the overall structure of the present invention; Figure 2 This is a second view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the sealing mechanism and inner box of the food storage container of the present invention; Figure 4 This is a schematic diagram of the outer and inner boxes of the present invention; Figure 5 This is a schematic diagram of the internal structure of the inner box of the present invention; Figure 6 This is a schematic diagram of the sealing platform of the present invention at the top of the inner box; Figure 7 This is a schematic diagram of the sealing platform of the present invention inside the inner box; Figure 8 This is a schematic diagram of the sealing plate a and the short plate of the present invention; Figure 9 This is a schematic diagram of the feeding mechanism of the present invention; Figure 10 This is a schematic diagram of the feeding mechanism and the food storage container lifting mechanism of the present invention; In the picture: 1. Air inlet pipe, 2. Sterilization chamber, 3. Vacuum treatment chamber, 4. Feed inlet, 5. Feed conveyor, 6. Discharge outlet, 7. Discharge conveyor, 8. Pressure gauge, 9. Strobe alarm light, 10. Control box, 11. Vacuum pump; 21 Sealed box, 22 Sealed door, 23 Observation window; 31 Outer box, 32 Inner box, 33 Food storage container sealing mechanism, 34 Sealing platform lifting assembly, 35 Feeding mechanism, 36 Food storage container lifting mechanism, 37 Opening sealing mechanism, 38 Inlet sealing mechanism, 39 Outlet sealing mechanism; 331 Support frame, 332 Sealing plate, 333 Sealing platform, 334 Plastic sealing film, 335 Guide roller, 336 Take-up shaft, 337 Sealing platform support; 341 Hydraulic cylinder a, 342 C-type bracket, 343 Threaded rod a; 351 Loading platform, 352 Baffle, 353 Push plate, 354 Push bracket, 355 Threaded rod b; 361 Lifting head, 362 Lifting cylinder, 363 Belt conveyor; 371 sealing plate a, 372 iron plate, 373 spring a, 374 sealing ring, 375 short plate, 376 spring b, 377 electromagnet; 381 sealing plate b, 382 hydraulic cylinder b; 391 sealing plate c, 392 triangular bracket, 393 hydraulic cylinder c. Detailed Implementation

[0019] The preferred embodiments of the present invention are described in detail below, and a clear and complete description is provided in conjunction with the accompanying drawings.

[0020] like Figure 1 and 2 As shown, the present invention provides a modified atmosphere sterilizer for longan storage, including an air inlet pipe 1, the bottom end of which is connected to a sterilization chamber 2. The gas treated by plasma enters the sterilization chamber 2 through the air inlet pipe 1 to create a sterilization environment filled with plasma gas inside the sterilization chamber 2, so as to kill bacteria on the surface of longan in the sterilization chamber 2. Furthermore, a vacuum treatment box 3 is fixed at the bottom of the sterilization box 2. The vacuum treatment box 3 includes an outer box 31, an inner box 32 with a top opening is fixed inside the outer box 31, an opening sealing mechanism 37 for sealing the top opening of the inner box 32 is installed on the top of the inner box 32, and a vacuum pump 11 for drawing a vacuum inside the inner box 32 is provided on the rear side of the outer box 31. like Figure 5-8As shown, the opening sealing mechanism 37 includes two sealing plates a371 that seal the top opening of the inner box 32. The sealing plates a371 are wrapped with sealing strips around their perimeter to seal the gap between the sealing plates a371 and the inner box 32. The two sealing plates a371 are arranged in a mirror image. An iron plate 372 is fixed to the ends of the two sealing plates a371 that are far apart from each other. An electromagnet 377 is embedded in the top of the inner box 32 where it contacts 317. When the electromagnet 377 is energized, it attracts the iron plate 372 to fix the position of the sealing plate a371. A plurality of springs a373 in a stretched state are fixed to the side of the iron plate 372 away from the sealing plate a371. When the electromagnet 377 is de-energized, the springs a373 pull the sealing plate a371 out of the top opening of the inner box 32. By removing the sealing plate a371 from the top opening of the inner box 32, the interior of the sterilization chamber 2 is connected to the interior of the inner box 32. Then, the air inside the sterilization chamber 2 and the inner box 32 can be extracted in advance by the vacuum pump 11 to maintain a vacuum environment inside the sterilization chamber 2. Then, the sealing plate a371 is inserted into the top opening of the inner box 32, which can separate the interior of the sterilization chamber 2 and the interior of the inner box 32 into two independent spaces. Plasma gas is then introduced into the sterilization chamber 2 through the air inlet pipe 1, thereby creating a sterilization atmosphere filled with plasma gas in the sterilization chamber 2 and eliminating the influence of microorganisms present in the original air inside the sterilization chamber 2 on the preservation of longan.

[0021] like Figure 2 As shown, the sterilization box 2 in this invention includes a sealed box 21. A sealed door 22 is installed on one of the outer walls of the sealed box 21. The remaining outer walls of the sealed door 22 are equipped with transparent observation windows 23 to facilitate the staff to observe the processing inside the sealed box 21. Furthermore, pressure gauges 8 are installed on the front of the sealed box 21 and the rear of the outer box 31. The pressure gauge 8 installed on the sealed box 21 is used to monitor the air pressure inside the sealed box 21, and the pressure gauge 8 installed on the rear of the outer box 31 is used to monitor the air pressure inside the inner box 32. A flashing alarm light 9 is provided on one side of the top of the sealed box 21 for alarm purposes. The flashing alarm light 9 can sound an alarm when there are abnormal changes in the air pressure inside the sealed box 21 and the inner box 32, reminding the staff to check and eliminate the danger in time.

[0022] A control box 10 for receiving monitoring data from the pressure gauge 8 is provided on the front side of the sealed box 21. The control box 10 can be used to control all electrical components in this invention, so as to realize centralized control and facilitate operation by staff.

[0023] The top of the inner box 32 of the present invention is provided with a food preservation box sealing mechanism 33 for sealing longan in the food preservation box. The food preservation box sealing mechanism 33 is installed inside the sealing box 21, so that the present invention can complete the hot pressing work of the longan food preservation box in a sterilization environment filled with plasma gas. Specific examples Figure 4-7 As shown in Figure 9, the food storage container sealing mechanism 33 includes a support frame 331 installed on the top of the inner box 32. A sealing plate 332 that can move up and down is installed inside the support frame 331. A sealing platform 333 for holding the food storage container is provided at the bottom of the sealing plate 332. The sealing platform 333 has two workstations that can simultaneously complete the heat-sealing work of two food storage containers. Sealing platform supports 337 are provided on both sides of the sealing platform 333. The two sealing platform supports 337 are mirror images of each other. A rolled plastic sealing film 334 is rotatably connected to one side of the top of the support frame 331. Guide rollers 335 for guiding the plastic sealing film 334 are installed on both sides below the support frame 331. A winding shaft 336 for winding the plastic sealing film 334 is rotatably connected to the other side of the top plate of the support frame 331. When sealing a food storage container containing longan, the plastic sealing film 334 should be passed around the two guide rollers 335 in sequence and positioned on top of the sealing platform 333. Then, the sealing plate 332 is activated, and the sealing plate 332 moves down to heat-press the plastic sealing film 334 onto the opening of the food storage container, thereby sealing the longan in the food storage container. Then, the winding shaft 336 is driven to rotate and the remaining scraps of the plastic sealing film 334 after heat-pressing and sealing are rolled up.

[0024] Furthermore, the sealing platform 333 is driven by the sealing platform lifting assembly 34, which moves the food storage container up and down between the inner box 32 and the sterilization box 2. Figure 6 As shown, the sealing table lifting assembly 34 includes two hydraulic cylinders a341 installed at the bottom of the sealing table 333. The hydraulic cylinders a341 drive the sealing table 333 to move up and down. A C-shaped bracket 342 is fixed to the outer end of the hydraulic cylinders a341. A threaded rod a343 is threadedly connected to the C-shaped bracket 342. The threaded rod a343 passes through the C-shaped bracket 342 and drives the C-shaped bracket 342 to drive the hydraulic cylinders a341 to move up and down. The threaded rod a343 is driven to rotate by a positive and negative motor. This technology is a mature existing technology, so it will not be described in detail in this invention. Rotation of the threaded rod a343 causes the C-shaped bracket 342 and hydraulic cylinder a341 to move upwards. The extension of the moving end of hydraulic cylinder a341 then pushes the sealing platform 333 below the sealing plate 332. At this point, the moving end of hydraulic cylinder a341 passes between the two sealing plates a371. Figure 6 and 9 As shown, in order to ensure the sealing effect of the two sealing plates a371 on the top opening of the inner box 32, an arc-shaped groove is provided on the side of the two sealing plates a371 that are close to each other. An arc-shaped sealing ring 374 is fixed in the arc-shaped groove, and the sealing ring 374 is tightly fitted to the outside of the moving end of the hydraulic cylinder a341. When lowering the sealing platform 333, the retraction of the moving end of the hydraulic cylinder a341 is first used to drive the sealing platform 333 to initially move downward. At this time, the positional relationship between the sealing plate a371 and the hydraulic cylinder a341 is as follows: Figure 7 As shown, to ensure the sealing effect of the two sealing plates a371 on the top opening of the inner box 32, two short plates 375 are inserted inside one of the sealing plates a371. Multiple springs b376 are fixed to one end of each short plate 375. When the moving end of the hydraulic cylinder a341 retracts, the springs b376 push the short plates 375 to seal the arc-shaped groove between the two sealing plates a371. Then, the rotation of the threaded rod a343 further moves the sealing platform 333 down to... Figure 7 The location shown.

[0025] Before hot pressing, the container containing longan needs to be transferred into the inner box 32, such as... Figure 1 and 2 As shown, the front sides of the outer casing 31 and the inner casing 32 are provided with interconnected feed inlets 4, and, as Figure 6 As shown, an inlet sealing mechanism 38 for sealing the inlet 4 is installed inside the inner box 32. The inlet sealing mechanism 38 includes a sealing plate b381 inserted into the inner box 32. The sealing plate b381 is surrounded by a sealing strip, which can seal the gap between the sealing plate b381 and the inner box 32. The sealing plate b381 is driven to move up and down by the hydraulic cylinder b382 at the bottom. The outer box 31 is provided with a feeding conveyor 5. The feeding conveyor 5 is located below the inlet 4. The operator first controls the hydraulic cylinder b382 to move the sealing plate b381 down to open the inlet 4. Then, the food storage box containing longan is placed on top of the feeding conveyor 5 and driven by the feeding conveyor 5 to pass through the inlet 4 and move into the inner box 32. Next, in order to move the food storage container containing longan to the designated location, such as... Figure 7 The image shows one side of the lowered sealing platform 333, as shown. Figure 5 and 7 As shown, the inner box 32 has a feeding mechanism 35 on one side for moving the food storage box containing longan into the sealing platform 333. Specifically, the feeding mechanism 35 includes a feeding platform 351 at the same height as the lowered sealing platform 333. The bottom of the feeding platform 351 is provided with a baffle 352 that can move up and down. A push plate 353 is provided on one side of the top of the feeding platform 351. A push bracket 354 for driving the push plate 353 to move is provided on one side of the push plate 353. A threaded rod b355 is threaded to one end of the push bracket 354. The rotating threaded rod b355 drives the push bracket 354 to move the push plate 353 on the top of the feeding platform 351. In this invention, the rotation of the threaded rod b355 is also driven by a positive and negative motor. This technology is a mature existing technology, so it will not be described in detail in this invention. During the conveying process, the feeding conveyor 5 will move multiple boxes containing longan to the top of the feeding platform 351. When one box moves to one side of the top of the feeding platform 351, the baffle 352 will rise. Then another box moves to the side of the baffle 352. At this time, the sealing plate b381 moves up to block the inlet 4. Then the push plate 353 is driven by the rotating threaded rod b355 to move on the top of the feeding platform 351, and at the same time pushes the two boxes on one side to the two stations on the sealing platform 333 to complete the feeding.

[0026] Next, the vacuum pump 11 is started by the control box 10 to extract the air inside the inner box 32, so that the inside of the inner box 32 is in a vacuum environment. At the same time, the food storage box is also in a vacuum environment, so that there is no need to perform vacuuming operation on each food storage box separately, which helps to reduce the difficulty of operation. At this time, the sealing plate a371 seals the top opening of the inner box 32 and the sealing plate b381 seals the feed port 4. Then, the control box 10 controls the two electromagnets 377 to be de-energized, causing the sealing plate a371 to be pulled out from the top opening of the inner box 32 by the spring a373. Then, the sealing platform lifting assembly 34 drives the sealing platform 333 to move upward, so that it passes through the top opening of the inner box 32 and moves into the sealed box 21. Then, the electromagnets 377 are energized again, and the adsorption iron plate 372 drives the sealing plate a371 to be reinserted into the top opening of the inner box 32, sealing the top opening of the inner box 32. At this time, the gas after plasma treatment is filled into the sealed box 21 through the air inlet pipe 1, creating a sterilization environment in the sealed box 21, which helps to kill microorganisms on the surface of the longan. Then, the sealing plate 332 is activated to seal the food storage box containing the longan, which can encapsulate the plasma gas in the food storage box to kill the microorganisms attached to the surface of the longan again. At the same time, the plasma gas in the food storage box also helps to inhibit the growth of microorganisms during the daily storage of longan. Compared with existing technologies, this invention does not require filling each food storage container with plasma gas separately, which helps to further reduce the difficulty of operation.

[0027] After sealing the food storage container containing longan, it needs to be removed from inner box 32, such as... Figure 1 and 2As shown, a discharge port 6 is connected to the outer box 31 and the inner box 32. A discharge conveyor 7 is provided on the outer box 31. The discharge conveyor 7 is located below the discharge port 6. The width of the discharge conveyor 7 is twice the width of the feed conveyor 5. The inner box 32 is equipped with a feed port blocking mechanism 38 for blocking the feed port 4 and a discharge port blocking mechanism 39 for blocking the discharge port 6. The discharge port blocking mechanism 39 includes a blocking plate c391 inserted into the inner box 32. The blocking plate c391 is surrounded by a sealing strip for sealing the gap between it and the inner box 32. A triangular bracket 392 is fixed at the bottom of the blocking plate c391. A hydraulic cylinder c393 is fixed at the bottom of the triangular bracket 392 to drive the blocking plate c391 to move up and down. When the vacuum pump 11 is used to evacuate the inner box 32 and the sealed box 21, the blocking plate c391 is in the blocking state of the discharge port 6. To achieve the purpose of outputting a sealed food storage box, the food storage box in the sealed box 21 needs to be moved into the inner box 32 first. At this time, the control box 10 can control the two electromagnets 377 to be de-energized, so that the sealing plate a371 is pulled out from the top opening of the inner box 32 under the pull of the spring a373. Then, the sealing table lifting assembly 34 drives the sealing table 333 to move the sealed food storage box down until it moves into the inner box 32. Then, the electromagnets 377 are energized again, and the adsorption iron plate 372 drives the sealing plate a371 to be reinserted into the top opening of the inner box 32, and the top opening of the inner box 32 is resealed to prevent the outside gas from entering the sealed box 21 through the top opening of the inner box 32 after the sealing plate c391 moves down. Inside the inner box 32 is a food storage container lifting mechanism 36 for discharging the sealed food storage container. Specifically, as shown in the image... Figure 10 As shown, the food storage container lifting mechanism 36 includes two lifting heads 361 located at the bottom of the sealing platform 333. The lifting heads 361 are driven to move up and down by the lifting cylinder 362 at the bottom. A belt conveyor 363 is provided on one side of the discharge port 6 in the inner box 32. The top of the belt conveyor 363 is flush with the top of the lowered sealing platform 333. The lower part of the discharge port 6 in the inner box 32 is processed into a slope. The lifting head 361 is driven to move upward by the lifting cylinder 362. The upward lifting head 361 pushes the sealed food storage box embedded in the sealing platform 333 to move upward. At this time, the push plate 353 pushes the unsealed food storage box towards the sealing platform 333. Then, the unsealed food storage box pushes the sealed food storage box to the top of the belt conveyor 363. Finally, the belt conveyor 363 transports the sealed food storage box to the discharge port 6, so that it can move down the inclined surface in the discharge port 6 to the top of the discharge conveyor 7. The discharge conveyor 7 outputs the sealed and sterilized food storage box.

[0028] The specific operation process of this invention is as follows: S1. The sealing plate b381 is moved down by the hydraulic cylinder b382 to open the feed port 4 in the inner box 32. Then the staff put the food preservation box containing longan on the top of the feeding conveyor 5 in sequence. The feeding conveyor 5 transports the food preservation box through the feed port 4 and moves it into the inner box 32. S2. When one food storage container moves to the top side of the loading platform 351, the baffle 352 rises, and then the other food storage container moves to the side of the baffle 352. At this time, the sealing plate b381 moves up to block the inlet 4. Then the push plate 353 is driven by the rotating threaded rod b355 to move on the top of the loading platform 351, and at the same time pushes the two food storage containers on one side to the two workstations on the sealing platform 333 respectively. S3. The vacuum pump 11 is started by the control box 10 to extract the air inside the inner box 32, so that the inside of the inner box 32 is in a vacuum environment. S4. The control box 10 controls the two electromagnets 377 to de-energize, so that the sealing plate a371 is pulled out from the top opening of the inner box 32 by the spring a373. Then, the sealing table lifting assembly 34 drives the sealing table 333 to move up, pass through the top opening of the inner box 32 and move into the inner box 32. Then, the electromagnets 377 are energized again, and the adsorption iron plate 372 drives the sealing plate a371 to be reinserted into the top opening of the inner box 32 to seal the top opening of the inner box 32. S5. The gas after plasma treatment is injected into the sterilization chamber 2 through the air inlet pipe 1, creating a sterilization environment in the sterilization chamber 2. Then, the sealing plate 332 is activated to seal the food storage box containing longan, while simultaneously encapsulating the plasma gas in the food storage box. S6. The two electromagnets 377 are de-energized again by the control box 10, so that the sealing plate a371 is pulled out from the top opening of the inner box 32 by the spring a373. Then the sealing table lifting assembly 34 drives the sealing table 333 to move the sealed food container down until it moves into the inner box 32. Then the electromagnets 377 are energized again, and the adsorption iron plate 372 drives the sealing plate a371 to be reinserted into the top opening of the inner box 32, and the top opening of the inner box 32 is resealed. S7. The lifting head 361 is driven to move upward by the lifting cylinder 362, pushing the two sealed food storage boxes embedded in the sealing platform 333 upward. Then, the above step S1 is repeated to transport the two new unsealed food storage boxes to the top of the loading platform 351. The push plate 353 pushes them toward the sealing platform 333, so that the unsealed food storage boxes can push the sealed food storage boxes to the top of the belt conveyor 363. The belt conveyor 363 moves the sealed food storage boxes to the discharge port 6, so that they move down the inclined surface at the bottom of the discharge port 6 to the top of the discharge conveyor 7 for output.

[0029] Based on the above description and accompanying drawings, those skilled in the art can understand and implement this invention. Furthermore, any non-creative modifications made to this invention by those skilled in the art without inventive effort are still within the scope of protection of this invention.

Claims

1. A modified atmosphere sterilizer for longan storage, characterized in that: Includes an air inlet pipe (1), the bottom end of which is connected to a sterilization box (2). The gas treated by plasma enters the sterilization box (2) through the air inlet pipe (1) to create a sterilization environment filled with plasma gas inside the sterilization box (2) to eliminate bacteria on the longan skin in the sterilization box (2). The sterilization box (2) has a vacuum treatment box (3) fixed at the bottom. The vacuum treatment box (3) includes an outer box (31). An inner box (32) with a top opening is fixed inside the outer box (31). The top of the inner box (32) is provided with a food preservation box sealing mechanism (33) for sealing longan in a food preservation box. The outer box (31) is provided with a vacuum pump (11) for evacuating the interior of the inner box (32) into a vacuum. The front of the outer box (31) and the front of the inner box (32) are provided with a connected feed inlet (4). The outer box (31) and the inner box (32) are provided with a connected discharge outlet (6). The top of the inner box (32) is provided with an opening sealing mechanism (37) for sealing the top opening of the inner box (32). The inner box (32) is provided with an inlet sealing mechanism (38) for sealing the feed inlet (4) and an outlet sealing mechanism (39) for sealing the outlet (6). The food storage container sealing mechanism (33) includes a support frame (331) installed on the top of the inner box (32). The support frame (331) has a sealing plate (332) that can move up and down inside. The bottom of the sealing plate (332) is provided with a sealing platform (333) for holding the food storage container. The sealing platform (333) has sealing platform supports (337) on both sides. The two sealing platform supports (337) are mirror images of each other. The sealing platform (333) is driven by the sealing platform lifting assembly (34) to move the food storage container up and down between the inner box (32) and the sterilization box (2). The inner box (32) has a feeding mechanism (35) on one side for moving the food storage box containing longan into the sealing platform (333). The feeding mechanism (35) includes a feeding platform (351) of the same height as the lowered sealing platform (333). The bottom of the feeding platform (351) is provided with a baffle (352) that can move up and down. A push plate (353) is provided on one side of the top of the feeding platform (351). A push bracket (354) for driving the push plate (353) to move is provided on one side of the push plate (353). One end of the push bracket (354) is threadedly connected to a threaded rod b (355). The rotating threaded rod b (355) drives the push bracket (354) to move the push plate (353) on the top of the feeding platform (351) to push the food storage box that has moved to the top of the feeding platform (351) into the sealing platform (333). The opening sealing mechanism (37) includes two sealing plates a (371) that seal the top opening of the inner box (32). The two sealing plates a (371) are mirror images of each other. Iron plates (372) are fixed at the ends of the two sealing plates a (371) that are far apart from each other. Electromagnets (377) are embedded at the top of the inner box (32) that are in contact with (317). When the electromagnets (377) are energized, they attract the iron plates (372) to fix the position of the sealing plates a (371). Multiple springs a (373) in a stretched state are fixed on the side of the iron plate (372) that is far away from the sealing plates a (371). When the electromagnets (377) are de-energized, the springs a (373) pull the sealing plates a (371) out of the top opening of the inner box (32). Two sealing plates a (371) are provided with arc-shaped grooves on their adjacent sides. Arc-shaped sealing rings (374) are fixed in the arc-shaped grooves. The sealing rings (374) are tightly fitted to the outside of the moving end of the hydraulic cylinder a (341). Two short plates (375) are inserted inside one of the sealing plates a (371). Multiple springs b (376) are fixed to one end of the short plates (375). When the moving end of the hydraulic cylinder a (341) retracts, the springs b (376) push the short plates (375) to seal the arc-shaped groove between the two sealing plates a (371).

2. The modified atmosphere sterilizer for longan storage according to claim 1, characterized in that: A roll of plastic sealing film (334) is rotatably connected to one side of the top of the support frame (331). Guide rollers (335) for guiding the plastic sealing film (334) are installed on both sides below the support frame (331). A winding shaft (336) for winding the plastic sealing film (334) is rotatably connected to the other side of the top plate of the support frame (331). The plastic sealing film (334) passes around the two guide rollers (335) in sequence and is located on the top of the sealing table (333). Then, the sealing plate (332) moves down to heat-press the plastic sealing film (334) onto the opening of the food storage box to seal the longan in the food storage box. After heat-pressing and sealing, the excess plastic sealing film (334) is wound up by the winding shaft (336).

3. A modified atmosphere sterilizer for longan storage according to claim 2, characterized in that: The sealing platform lifting assembly (34) includes two hydraulic cylinders a (341) installed at the bottom of the sealing platform (333). The hydraulic cylinders a (341) drive the sealing platform (333) to move up and down. A C-shaped bracket (342) is fixed to the outer end of the hydraulic cylinders a (341). A threaded rod a (343) is threadedly connected in the C-shaped bracket (342). The threaded rod a (343) passes through the C-shaped bracket (342) and drives the C-shaped bracket (342) to drive the hydraulic cylinders a (341) to move up and down.

4. A modified atmosphere sterilizer for longan storage according to claim 2, characterized in that: The inner box (32) is equipped with a food storage box lifting mechanism (36) for outputting the sealed food storage box. The food storage container lifting mechanism (36) includes two lifting heads (361) located at the bottom of the sealing platform (333). The lifting heads (361) are driven to move up and down by the lifting cylinder (362) at the bottom. A belt conveyor (363) is provided on one side of the discharge port (6) in the inner box (32). The top of the belt conveyor (363) is flush with the top of the lowered sealing platform (333). The lower part of the discharge port (6) in the inner box (32) is reinforced with a belt conveyor. The inclined plane is formed, and the upward lifting head (361) pushes the sealed food container embedded in the sealing table (333) to move upward. Then the push plate (353) pushes the unsealed food container toward the sealing table (333). At the same time, the unsealed food container pushes the sealed food container to the top of the belt conveyor (363). Finally, the belt conveyor (363) transports the sealed food container to the discharge port (6) so that it moves down the inclined plane in the discharge port (6) and goes out.

5. A modified atmosphere sterilizer for longan storage according to claim 1, characterized in that: The feed inlet sealing mechanism (38) includes a sealing plate b (381) inserted into the inner box (32), and the sealing plate b (381) is driven to move up and down by a hydraulic cylinder b (382) at the bottom; The outlet sealing mechanism (39) includes a sealing plate c (391) inserted into the inner box (32), a triangular bracket (392) fixed at the bottom of the sealing plate c (391), and a hydraulic cylinder c (393) for driving the sealing plate c (391) to move up and down fixed at the bottom of the triangular bracket (392).

6. A modified atmosphere sterilizer for longan storage according to claim 5, characterized in that: The opening sealing mechanism (37), the sealing plate b (381) and the sealing plate c (391) are all wrapped with sealing strips to seal the gaps between the opening sealing mechanism (37), the inlet sealing mechanism (38), the outlet sealing mechanism (39) and the inner box (32).

7. A modified atmosphere sterilizer for longan storage according to claim 1, characterized in that: The outer casing (31) is equipped with a feeding conveyor (5) on the front side, and the feeding conveyor (5) is located below the feeding port (4); The outer casing (31) is provided with a discharge conveyor (7) on one side. The discharge conveyor (7) is located below the discharge port (6). The width of the discharge conveyor (7) is twice the width of the feed conveyor (5).

8. A modified atmosphere sterilizer for longan storage according to claim 7, characterized in that: The sterilization box (2) includes a sealed box (21), a sealed door (22) is installed on one of the outer walls of the sealed box (21), and transparent observation windows (23) are installed on the remaining outer walls of the sealed door (22). Pressure gauges (8) are installed on the front side of the sealed box (21) and the rear side of the outer box (31). The pressure gauges (8) installed on the sealed box (21) are used to monitor the air pressure inside the sealed box (21), and the pressure gauges (8) installed on the rear side of the outer box (31) are used to monitor the air pressure inside the inner box (32). The top side of the sealed box (21) is provided with a strobe alarm light (9) for alarm purposes. The front side of the sealed box (21) is provided with a control box (10) for receiving monitoring data from the pressure gauge (8). The strobe alarm light (9), the feeding conveyor (5) and the discharging conveyor (7) are all controlled by the control box (10).

9. A method for sterilizing longan using the modified atmosphere sterilizer according to any one of claims 1-8, characterized in that: Includes the following steps: S1. The sealing plate b (381) is controlled by the hydraulic cylinder b (382) to move down and open the feed port (4) in the inner box (32). Then the staff put the food preservation box containing longan on the top of the feeding conveyor (5) in sequence. The feeding conveyor (5) transports the food preservation box through the feed port (4) and moves it into the inner box (32). S2. When one food container moves to the top side of the loading platform (351), the baffle (352) rises, and then the other food container moves to the side of the baffle (352). At this time, the sealing plate b (381) moves up to seal the inlet (4). Then the push plate (353) is driven by the rotating threaded rod b (355) to move on the top of the loading platform (351), and at the same time pushes the two food containers located on one side to the two workstations on the sealing platform (333). S3. The vacuum pump (11) is started by the control box (10) to extract the air inside the inner box (32) and make the inner box (32) a vacuum environment. S4. The control box (10) controls the two electromagnets (377) to be de-energized, so that the sealing plate a (371) is pulled out from the top opening of the inner box (32) by the spring a (373). Then the sealing platform lifting assembly (34) drives the sealing platform (333) to move up and through the top opening of the inner box (32) to move into the inner box (32). Then the electromagnet (377) is energized again, and the adsorption iron plate (372) drives the sealing plate a (371) to be reinserted into the top opening of the inner box (32) to seal the top opening of the inner box (32). S5. The gas after plasma treatment is filled into the sterilization box (2) through the air inlet pipe (1) to create a sterilization environment in the sterilization box (2). Then the sealing plate (332) is activated to seal the food storage box containing longan, and the plasma gas is sealed in the food storage box at the same time. S6. The two electromagnets (377) are de-energized again by the control box (10), so that the sealing plate a (371) is pulled out from the top opening of the inner box (32) by the spring a (373). Then the sealing table lifting assembly (34) drives the sealing table (333) to move the sealed food container down until it moves into the inner box (32). Then the electromagnet (377) is energized again, and the adsorption iron plate (372) drives the sealing plate a (371) to be inserted back into the top opening of the inner box (32) to re-seal the top opening of the inner box (32). S7. The lifting head (361) is driven to move upward by the lifting cylinder (362), pushing the two sealed food containers embedded in the sealing table (333) to move upward. Then repeat S1 to transport the two new unsealed food containers to the top of the loading table (351). The push plate (353) pushes them toward the sealing table (333) so that the unsealed food containers can push the sealed food containers to the top of the belt conveyor (363). The belt conveyor (363) moves the sealed food containers to the discharge port (6) so that they move down the inclined surface at the bottom of the discharge port (6) to the top of the discharge conveyor (7) for output.

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