Winter jujube rapid freeze-drying device

Abstract

The utility model discloses a kind of winter jujube quick freeze-drying devices, belong to freeze-drying equipment technical field, to solve the problem of airflow distribution uneven, cold and hot airflow interference and poor vacuum stability when multilayer winter jujube static freeze-drying. Adopt the horizontal baffle inside box and divide drying storehouse and containing storehouse, vertical rotating rod in drying storehouse is fixed multilayer placing plate, each placing plate can be detachably formed into a pair of tray, rotating rod is equipped with rotating pipe of fan baffle;Containing storehouse is connected with multilayer cold gas branch pipe in drying storehouse by refrigerating plant through cold gas main pipe, hot air fan is connected with hot gas branch pipe that is parallelly misaligned arrangement with cold gas branch pipe by hot gas main pipe, vacuum pump is connected with drying storehouse by connecting pipe.The utility model realizes winter jujube efficient uniform freeze-drying by rotating tray combined with layered directional air supply and airflow guide.

Description

Technical Field

[0001] This utility model relates to the field of freeze-drying equipment technology, specifically to a rapid freeze-drying device for winter jujubes. Background Technology

[0002] In the freeze-drying processing of fruits and vegetables such as jujubes, existing freeze-drying equipment often faces the following technical limitations: Freeze-drying of jujubes is becoming increasingly popular because it preserves the flavor and nutrition of fresh fruit. However, in actual production, existing freeze-drying equipment generally suffers from uneven drying when processing multiple layers of materials, directly affecting product quality and efficiency. Specifically, jujubes need to be laid flat on multiple trays for freeze-drying. In existing equipment, these trays are usually stationary. When the refrigeration unit or hot air blower introduces cold or hot air into the drying chamber, the airflow mainly relies on its own diffusion and vacuum suction to flow within the chamber. Due to the physical obstruction of the multiple trays and the materials on them, the airflow is difficult to penetrate and cover each layer evenly, especially the tray areas in the middle and lower layers. This leads to a significant problem: jujubes located upstream in the airflow path (such as near the air inlet or upper layer) can come into contact with the cold / hot airflow earlier and more fully, resulting in faster freezing or drying. Jujubes located downstream (such as far from the air inlet or lower layer) are in a relatively sluggish "low-velocity zone," freezing more slowly than the upper layer and receiving significantly less heat during sublimation drying. As a result, at the end of freeze-drying in the same batch, some jujubes (especially those in the lower layer) are often not completely dried, with residual moisture or ice crystals in the core, leading to excessive moisture content, poor rehydration, and even easy spoilage. Meanwhile, the upper layer material may suffer from quality degradation due to overheating.

[0003] To ensure all materials, especially those in the lower layers, meet drying standards, operators are often forced to extend the overall freeze-drying time. This not only reduces equipment turnover and capacity but also increases energy costs. The core reason for this problem is that the static stacking structure of the materials restricts the effective and uniform distribution of airflow within the multi-layered space and its sufficient contact with the materials, failing to meet the stringent requirements of uniform heat and mass transfer in freeze-drying processes. Overcoming the airflow distribution bottleneck under multi-layered static structures is a key challenge that urgently needs to be addressed to achieve efficient and uniform freeze-drying. Utility Model Content

[0004] This utility model provides a rapid freeze-drying device for winter jujubes, aiming to solve the problem of uneven airflow distribution caused by static stacking of materials during multi-layer freeze-drying of winter jujubes. It also addresses the problem of swaying at the free ends of multi-layer cold / hot air distribution pipes due to airflow impact or equipment vibration. Furthermore, it resolves the issues of tray horizontal offset or tilting on the placement plate, accidental slippage or detachment of trays in the loading and unloading direction, easy loosening and detachment of vertical limit rods, unreliable power transmission in the multi-layer rotating system, and the risk of equipment damage due to abnormal pressure rise in the drying chamber.

[0005] To achieve these and other advantages according to the present invention, a rapid freeze-drying device for jujubes is provided, comprising:

[0006] The box body is internally divided into a drying chamber and a receiving chamber by a fixed horizontal partition. A vertical rotating rod is rotatably installed in the drying chamber. Multiple horizontal placement plates are fixedly fitted on the rotating rod from top to bottom. Each placement plate is detachably fitted with a pair of trays. The rotating rod is located between the pairs of trays. Multiple horizontal support rods are installed on the rotating rod. Rotating tubes are rotatably fitted on the support rods. At least two fan plates parallel to the rotating tube are installed on the side wall of the rotating tube. The fan plates are located above their corresponding trays.

[0007] A refrigeration device is installed in the receiving chamber and connected to the drying chamber through a main cold air pipe that passes through the partition. The main cold air pipe in the drying chamber is connected to multiple horizontal cold air branches. Each cold air branch is located above each pair of trays and is higher than the corresponding fan plate. Multiple cold air holes that spray cold air toward the corresponding tray are evenly arranged on the lower side wall of each cold air branch.

[0008] A hot air blower is installed inside the receiving chamber. The air inlet of the hot air blower is connected to the outside of the chamber through an air inlet pipe. The air outlet of the hot air blower is connected to the drying chamber through a hot air main pipe that passes through the partition. The hot air main pipe located in the drying chamber is connected to multiple horizontal hot air branch pipes. Each hot air branch pipe is located above each pair of trays and is higher than the corresponding fan plate and is parallel and staggered with each cold air branch pipe. Multiple hot air holes that spray hot air toward the corresponding tray are evenly arranged on the lower side wall of each hot air branch pipe.

[0009] A vacuum pump is located at the top of the chamber and its inlet is connected to the interior of the drying chamber via a connecting pipe.

[0010] Preferably, in the rapid freeze-drying device for jujubes described in this utility model, the free ends of each cold air branch pipe are connected to the same first support pipe, and the free ends of each hot air branch pipe are connected to the same second support pipe. A fixing ring is fitted around the outer periphery of the cold air main pipe, the first support pipe, the hot air main pipe, and the second support pipe, and the fixing ring is fixedly connected to the inner wall of the drying chamber.

[0011] Preferably, in the aforementioned jujube rapid freeze-drying device, one end of the support rod is fixedly connected to the rotating rod, and the other end is provided with a first limiting hole. A first limiting rod is detachably provided in the first limiting hole, and a vertical first baffle is provided at the end of the first limiting rod located outside the first limiting hole. The rotating tube is located between the first baffle and the rotating rod.

[0012] Preferably, in the aforementioned rapid freeze-drying device for jujubes, the first limiting hole is a threaded hole, and the first limiting rod is a screw.

[0013] Preferably, in the aforementioned jujube rapid freeze-drying device, the bottom of the tray is provided with a limiting groove parallel to its loading and unloading movement direction, and the placement plate is provided with a long strip-shaped limiting protrusion corresponding to the limiting groove, the limiting protrusion being inserted into its corresponding limiting groove.

[0014] Preferably, in the aforementioned jujube rapid freeze-drying device, a second baffle is fixedly provided at one end of the limiting protrusion, and a vertical second limiting hole is provided at the other end of the limiting protrusion. A second limiting rod is inserted into the second limiting hole, and the tray is located between the second baffle and the second limiting rod.

[0015] Preferably, in the aforementioned jujube rapid freeze-drying device, the second limiting hole is a cone shape that is wider at the top and narrower at the bottom, and the second limiting rod is a cone shape that matches the second limiting hole.

[0016] Preferably, in the aforementioned rapid freeze-drying device for jujubes, the bottom end of the rotating rod is rotatably mounted on the partition plate, and the top end of the rotating rod penetrates the top wall of the box and is connected to the output shaft of the motor located at the top of the box, and is driven to rotate by the motor.

[0017] Preferably, in the aforementioned rapid freeze-drying device for jujubes, a pressure relief hole is provided on the side wall of the drying chamber, and a pressure relief valve is installed at the pressure relief hole.

[0018] This utility model has at least the following beneficial effects:

[0019] 1. The rotating rod drives the multi-layer placement plate and tray to rotate: This dynamically breaks the static stacking state of materials, allowing all trays (especially the lower layer) to be periodically exposed to the main airflow path. This fundamentally solves the problem of "low flow rate zone" caused by the fixed position of multi-layer materials, ensuring that each layer of materials (including the lower layer) is in uniform contact with the airflow, and eliminating uneven freezing and drying.

[0020] 2. A rotatable fan plate is installed above the tray: It dynamically guides and agitates the airflow above the tray, enhances the ability of the airflow to penetrate the material layer and the surface heat exchange efficiency, further optimizes the uniformity of airflow distribution, and improves the freezing and drying speed and uniformity.

[0021] 3. Each tray is equipped with an independent cold air distribution pipe and downward cold air vents: This enables "layered, precise, and uniform supply" of cold air, directly covering the corresponding tray materials, completely eliminating insufficient cooling of lower-layer materials due to shared air intake or positional differences, and ensuring synchronous and uniform freezing of multiple layers of materials.

[0022] 4. Each tray has an independent hot air distribution pipe and downward hot air vents above it, which are parallel and staggered with the cold air distribution pipes: This achieves "layered, precise, and uniform supply" of hot air, ensuring the sublimation heat requirements of each layer. The staggered arrangement effectively isolates the hot and cold pipes, minimizing the mixing and interference of hot and cold airflows before injection, significantly improving cooling and heating efficiency, and reducing energy consumption.

[0023] 5. The vacuum pump is connected to the drying chamber through the top connecting pipe: It quickly establishes and maintains a uniform and stable low-pressure environment in the dynamic layered structure, providing a basic guarantee for the uniform and efficient sublimation of ice crystals and reducing quality problems caused by vacuum fluctuations.

[0024] 6. This utility model systematically overcomes the core problems of uneven airflow distribution, low drying efficiency, and unstable quality in the existing technology of multi-layer freeze-drying of winter jujubes by using a synergistic design of dynamic material rotation, independent and precise air supply (cold and hot isolation) for each layer, local airflow guidance, and stable vacuum. It achieves a high-efficiency, uniform, and low-energy-consumption freeze-drying process.

[0025] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the internal structure of the rapid freeze-drying device for winter jujubes in one of the technical solutions of this utility model;

[0027] Among them, 1-motor, 2-vacuum pump, 3-connecting pipe, 4-first baffle, 5-first limiting rod, 6-tray, 7-main cold air pipe, 8-placement plate, 9-box body, 10-fixing ring, 11-fan plate, 12-rotating pipe, 13-pressure relief hole, 14-horizontal partition, 15-refrigeration device, 16-hot air blower, 17-accommodation chamber, 18-limiting protrusion, 19-first support pipe, 20-cold air branch pipe, 21-drying chamber, 22-rotating rod, 23-main hot air pipe. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0029] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0030] like Figure 1 As shown, this utility model provides a rapid freeze-drying device for winter jujubes, comprising:

[0031] The box 9 has a horizontal partition 14 fixedly installed inside, which divides it into a drying chamber 21 and a receiving chamber 17 distributed vertically. A vertical rotating rod 22 is rotatably installed inside the drying chamber 21. Multiple horizontal placement plates 8 are fixedly sleeved on the rotating rod 22 from top to bottom. A pair of trays 6 can be detachably installed on each placement plate 8. The rotating rod 22 is located between the pairs of trays 6. Multiple horizontal support rods are installed on the rotating rod 22. A rotating tube 12 is rotatably sleeved on the support rod. At least two fan plates 11 parallel to the rotating tube 12 are installed on the side wall of the rotating tube 12. The fan plates 11 are located above their corresponding trays 6.

[0032] A refrigeration device 15 is installed in the receiving chamber 17 and connected to the drying chamber 21 through a cold air main pipe 7 that passes through the partition 14. The cold air main pipe 7 located in the drying chamber 21 is connected to a plurality of horizontal cold air branch pipes 20. Each cold air branch pipe 20 is located above each pair of trays 6 and is higher than the corresponding fan plate 11. A plurality of cold air holes that spray cold air toward the corresponding tray 6 are evenly arranged on the lower side wall of the cold air branch pipe 20.

[0033] A hot air blower 16 is installed inside the receiving chamber 17. The air inlet of the hot air blower 16 is connected to the outside of the box 9 through an air inlet pipe. The air outlet of the hot air blower 16 is connected to the drying chamber 21 through a hot air main pipe 23 that passes through the partition 14. The hot air main pipe 23 located in the drying chamber 21 is connected to multiple horizontal hot air branch pipes. Each hot air branch pipe is located above each pair of trays 6 and is higher than the corresponding fan plate 11 and is parallel and offset from each cold air branch pipe 20. Multiple hot air holes that spray hot air toward the corresponding tray 6 are evenly arranged on the lower side wall of the hot air branch pipe.

[0034] Vacuum pump 2 is located at the top of the housing 9 and its inlet is connected to the interior of the drying chamber 21 via a connecting pipe 3.

[0035] In this technical solution, a horizontal partition 14 is fixedly installed inside the housing 9, dividing the housing 9 into an upper drying chamber 21 and a lower receiving chamber 17. The upper drying chamber 21 is used for material dehydration, and the lower receiving chamber 17 is used to install refrigeration and heating equipment. The partition 14 can be made of 10-15mm thick 304 stainless steel plate to ensure load-bearing capacity and sealing. The inner wall of the drying chamber 21 can be coated with a food-grade epoxy resin coating to prevent corrosion from condensation. Observation windows are opened on the side wall of the housing 9 to monitor the material status. A vertical rotating rod 22 passes through the center of the drying chamber 21 and is supported by bearings at both ends. The top of the rotating rod 22 is connected to the output shaft of the motor 1. The motor 1 can be a 750W three-phase asynchronous motor with a speed set to 5-15rpm. Multiple horizontal placement plates 8 are welded onto the rotating rod 22, with a spacing of 200-300mm between adjacent placement plates 8. A pair of rectangular trays 6, made of food-grade PP plastic, are symmetrically installed on each layer of placement plates 8. The trays 6 and placement plates 8 are connected by a detachable structure for easy loading and unloading of materials. Multiple horizontal support rods are radially welded to the rotating rod 22. A rotatable rotating tube 12 is fitted onto each support rod, and at least two fan blades 11 are fixed to the outer wall of the rotating tube 12; there can be 2-4 fan blades 11. The length of the fan blades 11 can cover the width of the tray 6, and they are located 50-80mm directly above the tray 6. By adjusting the angle of the fan blades 11, the direction of the airflow impacting the material can be controlled. The refrigeration unit 15 is located in the receiving chamber 17 and uses a compressor refrigeration system. The refrigeration unit 15 is connected to the drying chamber 21 via a main cold air pipe 7. The main cold air pipe 7 passes through the partition 14 and connects to multiple horizontally arranged cold air branch pipes 20. Each cold air branch pipe 20 is located 100-150mm above the corresponding tray 6, and its installation height is higher than the upper edge of the fan blades 11. Multiple cold air holes are opened on the bottom side wall of the cold air branch pipe 20, with a hole diameter of 1.5-2mm and a hole spacing of 15-20mm, spraying cold air vertically downwards. A hot air blower 16 is installed in the receiving chamber 17, and its air inlet is connected to an external filter. The air outlet of the hot air blower 16 is connected to the drying chamber 21 via a hot air main pipe 23 that passes through the partition 14. The hot air main pipe 23 passes through the partition 14 and connects to multiple horizontally arranged hot air branch pipes. Each hot air branch pipe is located above each pair of trays 6 and is higher than the corresponding fan plate 11. Each hot air branch pipe is arranged parallel to and staggered with its corresponding cold air branch pipe 20. Multiple hot air holes are opened on the bottom sidewall of the hot air branch pipes, with the spray direction vertically downward. The hot air holes are staggered with the cold air holes to avoid airflow collision. A vacuum pump 2 is installed on the top of the chamber 9, with a pumping rate of 20 m³ / h. The inlet of the vacuum pump 2 is connected to the inside of the drying chamber 21 via a connecting pipe 3. The inlet of the connecting pipe 3 can extend to the center of the top of the drying chamber 21 to ensure uniform vacuuming. The working vacuum is maintained at 50-100 Pa during the freezing stage and adjusted to 80-120 Pa during the sublimation drying stage.

[0036] The working process of this technical solution is as follows: The jujubes to be processed are evenly laid on tray 6, which is installed on the placement plate 8 via a detachable structure. Pairs of trays 6 are symmetrically distributed on both sides of the rotating rod 22 to ensure rotational balance. The sealing door of the box 9 is then closed.

[0037] The refrigeration unit 15 is activated, generating cold air at -40℃ to -30℃. This cold air passes through the main cold air pipe 7, horizontal partition 14, and enters the drying chamber 21, then is distributed to individual cold air distribution pipes 20. Each cold air distribution pipe 20 is located directly above the paired trays 6, with its bottom cold air holes spraying cold air vertically downwards. The temperature of the jujubes is lowered to below -30℃ (usually requiring 1-2 hours), at which point the refrigeration unit 15 is turned off. Simultaneously, the motor 1 is activated, driving the rotating rod 22 to rotate at a uniform speed of 5-10 rpm, causing the multi-layer placement plates 8 and trays 6 to rotate synchronously. At this time, the cold air continuously sprays onto the surface of the material in the trays 6, causing the jujubes to freeze quickly. The support rod rotates with the rotating rod 22, causing the rotating pipe 12 and the fan plate 11 to revolve synchronously. The fan plate 11, under the influence of the airflow, passively rotates around the rotating pipe 12, changing the direction of the cold airflow and creating turbulence, breaking up the stagnant layer on the material surface. This results in faster and more uniform freezing of the jujubes.

[0038] Then start vacuum pump 2 to draw air from drying chamber 21 through connecting pipe 3, reducing the pressure inside the chamber to 50-80 Pa.

[0039] The hot air blower 16 is then restarted. Outside air, filtered through the intake pipe, is heated to 40℃-60℃ by the hot air blower 16. The hot air flows through the main hot air pipe 23, passes through the partition 14, and is distributed to each individual hot air branch pipe. Hot air is sprayed vertically downwards from the hot air holes at the bottom of each branch pipe. The hot air is agitated by the fan plate 11 and simultaneously flows to all the jujubes, heating them evenly. Meanwhile, the vacuum pump 2 continuously discharges water vapor, maintaining a low-pressure (80-120℃) environment.

[0040] This technical solution includes at least the following technical effects:

[0041] 1. A vertical rotating rod 22 is rotatably installed inside the drying chamber 21. Multiple horizontal placement plates 8 are fixedly mounted on the rotating rod 22 from top to bottom. Each placement plate 8 can be detachably mounted with a pair of trays 6. The rotating rod 22 is located between the pairs of trays 6. This structure drives the multi-layer placement plates 8 and the trays 6 on them to rotate by setting the rotatable rotating rod 22, which dynamically breaks the static stacking state of the materials. This significantly alleviates the problem of the "low flow rate zone" of airflow caused by the traditional multi-layer static tray 6 structure, so that materials at different heights (especially the lower layer) can be periodically exposed to the main airflow path. This greatly promotes the uniform contact between cold / hot airflow and all materials (including the lower layer), and solves the core problem of slow freezing, delayed drying and uneven quality of lower layer materials caused by static stacking in the prior art.

[0042] 2. Multiple horizontal support rods are provided on the rotating rod 22, and a rotating tube 12 is rotatably sleeved on the support rod. At least two fan plates 11 parallel to the rotating tube 12 are provided on the side wall of the rotating tube 12, and the fan plates 11 are located above their corresponding trays 6. This structure provides a rotatable fan plate 11 above each tray 6. When the rotating rod 22 drives the tray 6 to rotate, the airflow acts on the fan plate 11. The fan plate 11 is impacted by the airflow and rotates freely around the axis of the rotating tube 12. Under the impact of the airflow, it automatically adjusts its angle and guides the airflow. This not only disturbs the local airflow boundary layer above the tray 6 and enhances the convective heat transfer efficiency between the airflow and the material surface, but more importantly, it guides the airflow that might have originally swept across the tray 6 parallel to the surface of the tray 6 to blow it towards the surface of the tray 6. This significantly enhances the penetration and coverage effect of the airflow on the material, further solves the problem of uneven airflow distribution, and improves the uniformity and speed of freezing and drying.

[0043] 3. The main cold air pipe 7 located in the drying chamber 21 is connected to multiple horizontal cold air branch pipes 20. Each cold air branch pipe 20 is located above each pair of trays 6 and is higher than the corresponding fan plate 11. Multiple cold air holes are evenly arranged on the lower side wall of the cold air branch pipe 20 to spray cold air towards the corresponding tray 6. This structure achieves "layered, precise and uniform supply" of cold air by independently setting up cold air branch pipes 20 for each pair of trays 6 (each layer) and evenly opening cold air holes below the branch pipes to spray cold air downwards. This ensures that each layer of material can receive direct and uniform cold air flow coverage, avoiding the problem of insufficient cold air volume of the lower layer of material due to shared or single air intake in the existing technology, and significantly improving the uniformity and speed of freezing of multi-layer materials.

[0044] 4. The main hot air pipe 23 located in the drying chamber 21 is connected to multiple horizontal hot air branches. Each hot air branch is located above each pair of trays 6 and is higher than the corresponding fan plate 11 and parallel and staggered with each cold air branch 20. Multiple hot air holes are evenly arranged on the lower side wall of the hot air branch, spraying hot air towards the corresponding tray 6. This structure also independently sets up hot air branches and hot air holes for each layer, realizing the "layered, precise and uniform supply" of hot air, ensuring the uniform supply of heat required for the sublimation of materials in each layer. In particular, the hot air branch and the cold air branch 20 are arranged in a "parallel staggered" manner, which effectively avoids the hot and cold air pipelines being too close or overlapping in space, and minimizes the premature mixing and interference of hot and cold air before entering the area of ​​tray 6. This solves the problem of mutual weakening efficiency of hot and cold air in the prior art and significantly improves the energy utilization efficiency of the refrigeration and heating stages.

[0045] 5. Vacuum pump 2, which is located at the top of the chamber 9 and whose inlet is connected to the inside of the drying chamber 21 through the connecting pipe 3; This structure with vacuum pump 2 and direct connection to the drying chamber 21 through the top connecting pipe 3 is conducive to quickly establishing and maintaining a uniform and stable low-pressure environment in the rotating, layered drying chamber 21 structure. Stable vacuum is a prerequisite for efficient and uniform sublimation of ice crystals, which provides a basic guarantee for the entire freeze-drying process (especially uniform sublimation) and reduces product quality problems (such as crust formation) caused by vacuum fluctuations.

[0046] 6. This technical solution, through the dynamic rotation of multiple trays 6 combined with an independent and precise cold / hot air jetting system for each layer and a fan plate 11 to guide airflow, fundamentally solves the core problems of uneven airflow distribution, low drying efficiency, and unstable quality in existing multi-layer static freeze-drying of winter jujubes, achieving efficient and uniform freeze-drying of winter jujubes. At the same time, the staggered arrangement of the cold and hot air pipes effectively reduces energy waste.

[0047] In another technical solution, such as Figure 1 As shown, in the rapid freeze-drying device for winter jujubes, the free ends of each cold air branch pipe 20 are connected to the same first support pipe 19, and the free ends of each hot air branch pipe are connected to the same second support pipe. The outer periphery of the cold air main pipe 7, the first support pipe 19, the hot air main pipe 23, and the second support pipe are all fitted with fixing rings 10, and the fixing rings 10 are fixedly connected to the inner wall of the drying chamber 21.

[0048] In this technical solution, one end of each cold air branch pipe 20 is connected to the main cold air pipe 7, and the other end (free end) is connected to the same first support pipe 19. The first support pipe 19 extends horizontally and can be a stainless steel pipe. The outlet end of each cold air branch pipe 20 is connected to the side wall of the first support pipe 19 by welding or flange connection, allowing cold air from the main cold air pipe 7 to be distributed to each cold air branch pipe 20. Similarly, one end of each hot air branch pipe is connected to the main hot air pipe, and the other end (free end) is connected to the same second support pipe. This second support pipe is also horizontally arranged and can be made of the same material and with the same connection method as the first support pipe 19. The outlet end of each hot air branch pipe is connected to the side wall of the second support pipe, allowing hot air from the main hot air pipe 23 to be distributed to each hot air branch pipe.

[0049] A retaining ring 10 is fitted around the outer periphery of the main cooling air pipe 7. The inner diameter of the retaining ring 10 is slightly larger than the outer diameter of the main cooling air pipe 7, and the two are fitted with a clearance fit. A retaining ring 10 is also fitted around the outer periphery of the first support pipe 19, and its installation method is the same as that of the main cooling air pipe 7. Retaining rings 10 are also fitted around the outer periphery of the main hot air pipe 23 and the second support pipe, respectively, with the inner wall of the retaining ring 10 maintaining a clearance fit with the outer wall of the corresponding pipe. The outer circumference of all retaining rings 10 is securely fixed to the inner wall of the drying chamber 21 by welding or bolting.

[0050] During equipment operation, the cold air generated by the refrigeration unit 15 is transported through the main cold air pipe 7. Part of it directly enters each cold air branch pipe 20, while the other part enters the first support pipe 19 and is then distributed to each cold air branch pipe 20. The hot air generated by the hot air blower 16 is transported through the main hot air pipe 23. Part of it directly enters each hot air branch pipe, while the other part is distributed to each hot air branch pipe via the second support pipe. When the cold or hot air flows through the pipes or when equipment vibration causes slight pipe swaying, the overall position of the piping system is constrained because the main cold air pipe 7, the first support pipe 19, the main hot air pipe 23, and the second support pipe are all rigidly connected to the drying chamber 21 through their respective fixing rings 10. The fixing rings 10 transmit any possible pipe displacement to the robust walls of the drying chamber 21, effectively suppressing the swaying amplitude of the free ends of the cold and hot air branch pipes 20 and reducing the risk of positional displacement of the cold and hot branch pipes due to pipe swaying.

[0051] This technical solution enhances the structural stability of the multi-layered piping system. The first support pipe 19 integrates the end of the cold air branch pipe 20, and the second support pipe integrates the end of the hot air branch pipe. Combined with multi-point distributed fixing rings 10, the main pipelines are rigidly fixed to the inner wall of the drying chamber 21, significantly reducing pipeline vibration caused by airflow impact or vibration during equipment operation. This helps maintain the pre-set parallel staggered layout between the cold air branch pipe 20 and the hot air branch pipe, preventing accidental overlap of cold and hot air jet areas due to pipeline displacement, thus ensuring the independence of the cold and hot air delivery paths. Simultaneously, reducing pipeline vibration also helps extend the lifespan of seals at pipeline connections and reduces the risk of leakage.

[0052] In another technical solution, such as Figure 1 As shown, in the rapid freeze-drying device for winter jujubes, one end of the support rod is fixedly connected to the rotating rod 22, and the other end is provided with a first limiting hole. A first limiting rod 5 is detachably provided in the first limiting hole. A vertical first baffle 4 is provided at the end of the first limiting rod 5 located outside the first limiting hole. The rotating tube 12 is located between the first baffle 4 and the rotating rod 22.

[0053] In this technical solution, one end of the support rod is fixedly connected to the rotating rod 22, and this connection can be achieved by welding or bolt fastening. The other end of the support rod is machined with a first limiting hole. The first limiting hole can be a through hole or a blind hole. A first limiting rod 5 is detachably installed inside the first limiting hole. A vertical first baffle 4 is fixedly connected to the end of the first limiting rod 5 located outside the first limiting hole. The rotating tube 12 is rotatably sleeved on the support rod and located between the first baffle 4 and the rotating rod 22. When impacted by airflow, the rotating tube 12 can rotate freely around the support rod. The inner diameter of the rotating tube 12 is slightly larger than the outer diameter of the support rod, and the two are clearance-fitted, allowing the rotating tube 12 to rotate freely around the axis of the support rod.

[0054] During equipment operation, when airflow enters the drying chamber 21, the airflow acts on the fan blades 11, generating torque. At this time, the rotating tube 12 can rotate freely on the support rod. Under the action of the airflow, the fan blades 11 automatically rotate to an angle that adapts to the direction of the airflow. This angle depends on the airflow speed and direction, and is usually made so that the surface of the fan blades 11 is parallel to the airflow to obtain less resistance. This free rotation state helps the fan blades 11 to follow the airflow, reduce wind resistance, and disturb the airflow above the tray 6 during rotation, enhancing the contact between the airflow and the material.

[0055] The fan plate 11 in this technical solution can adapt to the airflow direction. The free-rotating design reduces airflow resistance and lowers energy consumption. Simultaneously, the fan plate 11 continuously disturbs the airflow around it during rotation, helping to break the airflow boundary layer and promote more even coverage of the material surface of the tray 6 below with cold or hot air, thus improving heat and mass transfer efficiency. The main functions of the first limiting rod 5 and the first baffle 4 are to prevent the rotating tube 12 from accidentally axially detaching from the support rod, ensuring structural safety while allowing the rotating tube 12 to rotate freely.

[0056] In another technical solution, such as Figure 1 As shown, in the aforementioned rapid freeze-drying device for jujubes, the first limiting hole is a threaded hole, and the first limiting rod 5 is a screw.

[0057] In this technical solution, the first limiting hole is machined into a threaded hole with internal threads. The specification of this internal thread can be a metric thread, such as M6 or M8, and the specific size is selected according to the strength and stress requirements of the support rod. The first limiting rod 5 is machined into an external thread that matches the internal thread of the first limiting hole, i.e., a screw rod. This screw rod can be made of stainless steel. A vertical first baffle 4 is fixedly connected to one end of the screw rod outside the first limiting hole. The first baffle 4 can be welded and fixed to this end of the screw rod.

[0058] When the angle of the fan plate 11 needs to be fixed, the operator rotates the first limiting rod 5 (screw). Since the external thread of the screw engages with the internal thread of the first limiting hole, the rotation will drive the screw to move linearly along its axis within the first limiting hole. When the operator rotates the screw clockwise, the screw screws into the first limiting hole, causing the first baffle 4 at its end to move towards the rotating rod 22. The operator continues to rotate the screw until the first baffle 4 and the rotating rod 22 together firmly clamp the rotating tube 12 onto the support rod. At this point, the rotating tube 12 is completely restricted and can no longer rotate around the support rod, thus fixing the angle between the fan plate 11 and the horizontal plane. In this state, the airflow will mainly flow along the surface of the fixed fan plate 11, for example, blowing vertically towards the tray 6 or forming an inclined airflow at a specific angle to meet specific process requirements.

[0059] When it is necessary to restore the free rotation of the fan blade 11, the operator rotates the first limiting rod 5 (screw) counterclockwise. The screw unscrews out of the first limiting hole, causing the first baffle 4 to move away from the rotating rod 22, thereby releasing the clamping constraint on the rotating tube 12. The rotating tube 12 then regains its free rotation capability.

[0060] This technical solution provides a simple, reliable, and precisely adjustable angle locking mechanism for the fan blade 11. The threaded drive converts rotational motion into precise linear displacement, allowing the operator to fine-tune the position of the first baffle 4 by controlling the number of rotations of the screw, thereby achieving precise control of the clamping force on the rotating tube 12 and ensuring reliable clamping. The detachable design of the screw also facilitates maintenance or component replacement.

[0061] In another technical solution, such as Figure 1 As shown, in the rapid freeze-drying device for winter jujubes, the bottom of the tray 6 is provided with a limiting groove parallel to its loading and unloading movement direction, and the placement plate 8 is provided with a long strip-shaped limiting protrusion 18 corresponding to the limiting groove, and the limiting protrusion 18 is inserted into its corresponding limiting groove.

[0062] In this technical solution, a limiting groove is machined on the bottom of the pallet 6 along its loading and unloading movement direction (usually a horizontal push-pull direction). This limiting groove can be rectangular or dovetail-shaped, extending through both ends of the bottom of the pallet 6. A long strip-shaped limiting protrusion 18 is fixedly provided on the upper surface of the placement plate 8. The shape of the limiting protrusion 18 matches the limiting groove, for example, a rectangular protrusion, a cylindrical protrusion, or a dovetail tenon. When installing the pallet 6, the operator aligns the limiting groove on the bottom of the pallet 6 with the limiting protrusion 18 on the placement plate 8 and pushes it in horizontally until the limiting protrusion 18 is fully inserted into the limiting groove.

[0063] The structure of this technical solution, through the interlocking of the limiting protrusion 18 and the limiting groove, restricts the pallet 6 to move horizontally on the placement plate 8 only in the loading and unloading direction, preventing the pallet 6 from shifting laterally or tilting during equipment operation or rotation, thus ensuring the stability of the pallet 6's positioning.

[0064] In another technical solution, in the rapid freeze-drying device for jujubes, a second baffle is fixedly provided at one end of the limiting protrusion, and a vertical second limiting hole is provided at the other end of the limiting protrusion. A second limiting rod is inserted into the second limiting hole, and the tray is located between the second baffle and the second limiting rod.

[0065] In this technical solution, a vertical second baffle is fixedly welded to one end of the limiting protrusion. The height of the second baffle can be slightly higher than the limiting protrusion. A vertical second limiting hole is machined at the other end of the limiting protrusion. This second limiting hole can be a through hole. A second limiting rod is detachably inserted into the second limiting hole. The length of the second limiting rod is such that its upper end is higher than the surface of the limiting protrusion after insertion.

[0066] When installing the pallet, first push the pallet's limiting groove along the limiting protrusion until one end of the pallet abuts against the second baffle. At this point, the other end of the pallet corresponds to the position of the second limiting hole. The operator then vertically inserts the second limiting rod into the second limiting hole. After insertion, the pallet is firmly fixed to the limiting protrusion between the second baffle and the second limiting rod, preventing it from moving or coming out in the loading / unloading direction.

[0067] The structure of this technical solution reliably locks the horizontal position of the pallet on the placement plate through the bidirectional blocking of the second baffle and the second limiting rod, preventing the pallet from accidentally slipping under rotation or airflow impact.

[0068] In another technical solution, in the rapid freeze-drying device for jujubes, the second limiting hole is a cone shape that is wider at the top and narrower at the bottom, and the second limiting rod is a cone shape that matches the second limiting hole.

[0069] In this technical solution, the second limiting hole is machined into a tapered hole with a large opening at the upper end and a small opening at the lower end. The second limiting rod is machined into a tapered rod with the same taper as the second limiting hole. The outer surface of the tapered second limiting rod and the inner surface of the tapered second limiting hole are in surface contact fit.

[0070] When the second limiting rod is inserted, the conical rod can slide down the conical hole wall and automatically center itself by its own weight or slight downward pressure. Due to the wedge-tightening effect of the conical surface, the second limiting rod is not easy to wobble after insertion, and it has self-locking properties in the vertical direction, making it difficult to accidentally come loose from the hole.

[0071] The structure of this technical solution utilizes the self-centering and self-locking characteristics of the conical surface fit to improve the stability of the second limiting rod in the limiting hole, reduce the risk of loosening, and facilitate quick insertion and removal operations.

[0072] In another technical solution, such as Figure 1 As shown, in the rapid freeze-drying device for winter jujubes, the bottom end of the rotating rod 22 is rotatably mounted on the partition plate 14, and the top end of the rotating rod 22 penetrates the top wall of the box 9 and is connected to the output shaft of the motor 1 located at the top of the box 9, and is driven to rotate by the motor 1.

[0073] In this technical solution, the bottom end of the rotating rod 22 is rotatably mounted on the horizontal partition 14 via a bearing. This bearing can be a deep groove ball bearing, with its outer ring interference-fitted with the bearing housing on the partition 14, and its inner ring interference-fitted with the bottom end of the rotating rod 22. The top end of the rotating rod 22 extends upwards through the top wall of the housing 9. A rotary seal is provided at the penetration point to prevent gas leakage from the drying chamber 21. The top end of the rotating rod 22 is coaxially connected to the output shaft of the motor 1 via a coupling. The motor 1 is fixedly mounted on the outer side of the top of the housing 9 via a bracket.

[0074] When the equipment is running, motor 1 is started, and the output shaft of motor 1 drives the rotating rod 22 to rotate around its vertical axis via a coupling. The rotating rod 22 drives all the placement plates 8, trays 6, support rods, and fan plates 11 fixed on it to rotate synchronously. This structure provides stable and reliable rotational power for the multi-layer tray 6 system, realizing dynamic material handling.

[0075] In another technical solution, such as Figure 1 As shown, in the aforementioned rapid freeze-drying device for winter jujubes, a pressure relief hole 13 is provided on the side wall of the drying chamber 21, and a pressure relief valve is installed at the pressure relief hole 13.

[0076] In this technical solution, a pressure relief hole 13 is provided on the side wall of the drying chamber 21. The pressure relief hole 13 can be a circular through hole. A pressure relief valve is fixedly installed at the pressure relief hole 13. This pressure relief valve can be a spring-loaded safety valve, and its opening pressure threshold can be set to 10 MPa (gauge pressure).

[0077] When the internal pressure of the drying chamber 21 exceeds the set safety threshold due to abnormal conditions (such as rapid evaporation of a large amount of moisture), the pressure relief valve automatically opens, allowing the gas inside the chamber to be quickly discharged to the outside through the pressure relief hole 13. When the internal pressure drops below the safety threshold, the pressure relief valve closes the pressure relief hole 13.

[0078] The structure of this technical solution provides a safety protection mechanism to prevent abnormal pressure rise inside the drying chamber 21 from causing equipment damage or seal failure, thus ensuring the safety of equipment operation.

[0079] The number of devices and processing scale described herein are for the purpose of simplifying the description of this utility model. Applications, modifications, and variations of this utility model will be readily apparent to those skilled in the art.

[0080] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A rapid freeze-drying device for winter jujubes, characterized in that, include: The box body is internally divided into a drying chamber and a receiving chamber by a fixed horizontal partition. A vertical rotating rod is rotatably installed in the drying chamber. Multiple horizontal placement plates are fixedly fitted on the rotating rod from top to bottom. Each placement plate is detachably fitted with a pair of trays. The rotating rod is located between the pairs of trays. Multiple horizontal support rods are installed on the rotating rod. Rotating tubes are rotatably fitted on the support rods. At least two fan plates parallel to the rotating tube are installed on the side wall of the rotating tube. The fan plates are located above their corresponding trays. A refrigeration device is installed in the receiving chamber and connected to the drying chamber through a main cold air pipe that passes through the partition. The main cold air pipe in the drying chamber is connected to multiple horizontal cold air branches. Each cold air branch is located above each pair of trays and is higher than the corresponding fan plate. Multiple cold air holes that spray cold air toward the corresponding tray are evenly arranged on the lower side wall of each cold air branch. A hot air blower is installed inside the receiving chamber. The air inlet of the hot air blower is connected to the outside of the chamber through an air inlet pipe. The air outlet of the hot air blower is connected to the drying chamber through a hot air main pipe that passes through the partition. The hot air main pipe located in the drying chamber is connected to multiple horizontal hot air branch pipes. Each hot air branch pipe is located above each pair of trays and is higher than the corresponding fan plate and is parallel and staggered with each cold air branch pipe. Multiple hot air holes that spray hot air toward the corresponding tray are evenly arranged on the lower side wall of each hot air branch pipe. A vacuum pump is located at the top of the chamber and its inlet is connected to the interior of the drying chamber via a connecting pipe.

2. The rapid freeze-drying device for winter jujubes as described in claim 1, characterized in that, Each cold air branch pipe has its free end connected to the same first support pipe, and each hot air branch pipe has its free end connected to the same second support pipe. The outer periphery of the cold air main pipe, the first support pipe, the hot air main pipe, and the second support pipe is fitted with a fixing ring, which is fixedly connected to the inner wall of the drying chamber.

3. The rapid freeze-drying device for jujubes as described in claim 1, characterized in that, One end of the support rod is fixedly connected to the rotating rod, and the other end is provided with a first limiting hole. A first limiting rod is detachably provided in the first limiting hole. A vertical first baffle is provided at the end of the first limiting rod located outside the first limiting hole. The rotating tube is located between the first baffle and the rotating rod.

4. The rapid freeze-drying device for jujubes as described in claim 3, characterized in that, The first limiting hole is a threaded hole, and the first limiting rod is a screw.

5. The rapid freeze-drying device for jujubes as described in claim 1, characterized in that, The bottom of the tray is provided with a limiting groove parallel to its loading and unloading movement direction, and the placement plate is provided with a long strip-shaped limiting protrusion corresponding to the limiting groove. The limiting protrusion is inserted into its corresponding limiting groove.

6. The rapid freeze-drying device for winter jujubes as described in claim 5, characterized in that, A second baffle is fixedly provided at one end of the limiting protrusion, and a vertical second limiting hole is provided at the other end of the limiting protrusion. A second limiting rod is inserted into the second limiting hole, and the tray is located between the second baffle and the second limiting rod.

7. The rapid freeze-drying device for winter jujubes as described in claim 6, characterized in that, The second limiting hole is a tapered shape that is wider at the top and narrower at the bottom, and the second limiting rod is a tapered shape that matches the second limiting hole.

8. The rapid freeze-drying device for winter jujubes as described in claim 1, characterized in that, The bottom end of the rotating rod is rotatably mounted on the partition plate, and the top end of the rotating rod passes through the top wall of the box and is connected to the output shaft of the motor located at the top of the box, and is driven to rotate by the motor.

9. The rapid freeze-drying device for winter jujubes as described in claim 1, characterized in that, The drying chamber has a pressure relief hole on its side wall, and a pressure relief valve is installed at the pressure relief hole.

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