A jujube concentrate juice freeze-drying device
Patent Information
- Application Number
- CN202522145820.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-09-08
- Estimated Expiration
- 2035-10-11
AI Technical Summary
若直接进行冷冻，会形成巨大、坚硬的冰晶块，导致后续升华干燥阶段传热传质效率极低，干燥周期非常漫长(往往需要24小时以上)，能耗巨大；干燥阶段：坚硬的固体冰晶块内部孔隙率低，水蒸气逸出的通道不畅，容易造成干燥不完全(外部已干焦，内部仍有湿心)或产品结构坍塌，影响最终产品的复水性
[0015] This application disperses highly viscous jujube concentrate into countless tiny droplets through an atomizing nozzle, which are then instantly frozen by a spiral quick-freezing coil. This significantly increases the specific surface area of the material, greatly enhancing the heat and mass transfer efficiency of the subsequent sublimation drying process. Combined with the low-frequency vibration generated by the vibration generator during the drying stage, the boundaries of the drying layer are effectively broken, promoting the escape of internal water vapor, thereby shortening the drying cycle and significantly reducing energy consumption.
Smart Images
Figure CN224730948U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of food processing equipment technology, and more specifically to a freeze-drying device for concentrated jujube juice. Background Technology
[0002] Red dates are rich in various vitamins, minerals, and cyclic adenosine monophosphate (cAMP), giving them extremely high nutritional and health benefits. Red date concentrate is an important product form of deep-processed red dates, but its high viscosity and sugar content make it extremely susceptible to moisture absorption, spoilage, and microbial growth during storage and transportation, and it is also very sensitive to heat.
[0003] Currently, jujube concentrate is often processed into solid-state products using hot air drying or spray drying. However, both methods have significant drawbacks. Hot air drying: The processing temperature is high (usually 60-80℃ or even higher), and prolonged heating leads to a significant loss of heat-sensitive nutrients in jujubes (such as vitamin C and cyclic adenosine monophosphate). It also easily causes Maillard reactions, resulting in browning of the product, deterioration of flavor, and severe quality degradation. Spray drying: Although the drying time is short, the inlet air temperature is extremely high (usually 160-200℃). The sugars in the jujube concentrate are prone to caramelization at high temperatures, adhering to the inner wall of the drying tower, resulting in low yield, high energy consumption, and frequent equipment cleaning. It also cannot prevent the degradation of heat-sensitive substances.
[0004] Freeze-drying technology (also known as vacuum freeze-drying) can directly sublimate the water in materials at low temperatures (usually <-40℃), preserving the color, aroma, flavor, and nutrients of the materials to the maximum extent, making it an ideal method for processing heat-sensitive materials. However, applying existing general-purpose freeze-drying equipment to jujube concentrate has encountered new technical challenges. Pre-freezing stage: Jujube concentrate has high viscosity and poor flowability in the tray, resulting in uneven thickness when spread. Direct freezing will form large, hard ice crystals, leading to extremely low heat and mass transfer efficiency in the subsequent sublimation drying stage, a very long drying cycle (often requiring more than 24 hours), and huge energy consumption. Drying stage: The hard solid ice crystals have low internal porosity, hindering the escape of water vapor and easily causing incomplete drying (the outside is charred, but the inside is still wet) or product structure collapse, affecting the rehydration properties of the final product.
[0005] Therefore, there is an urgent need in this field for a freeze-drying device specifically designed for jujube concentrate, which can optimize the pre-freezing process, significantly improve drying efficiency, shorten the production cycle, and ensure that the final product has excellent quality and a uniform porous structure. Utility Model Content
[0006] The purpose of this invention is to provide a freeze-drying device for concentrated jujube juice, which improves drying efficiency, shortens the production cycle, and ensures that the final product has excellent quality and a uniform porous structure.
[0007] To achieve the above objectives, the technical solution of this utility model is as follows:
[0008] A freeze-drying device for concentrated jujube juice includes a freeze-drying chamber and a refrigeration system. A mounting frame is placed at the bottom inner side of the freeze-drying chamber, and a vibration generator is mounted on the mounting frame. A flexible material tray is placed on the mounting frame, and an electric heating plate is embedded in the contact surface between the mounting frame and the flexible material tray. An atomizing nozzle is located at the top inner side of the freeze-drying chamber, facing the flexible material tray. The atomizing nozzle is connected to an external storage tank via a feed pipe, and a high-pressure feed pump is installed on the feed pipe. A spiral quick-freezing coil is provided between the atomizing nozzle and the flexible material tray. The inlet and outlet of the spiral quick-freezing coil pass through the freeze-drying chamber and are connected to the refrigeration system. A vacuum tube is connected to the top of the freeze-drying chamber, and a vacuum pump is installed on the vacuum tube. Multiple water-capturing components are provided on the inner wall of the freeze-drying chamber.
[0009] Furthermore, the water-catching assembly includes a water-catching plate vertically installed on the inner wall of the freeze-drying chamber. The water-catching plate has a flow channel inside, and the two ends of the flow channel are connected to the refrigeration system through an inlet pipe and an outlet pipe, respectively.
[0010] Furthermore, the surface of the water-catching plate is provided with thermally enhanced fins.
[0011] Furthermore, the flexible material tray is made of flexible aluminum alloy composite material.
[0012] Furthermore, the atomizing nozzle is a pressure-type or airflow-type atomizing nozzle, and the particle size of the sprayed droplets ranges from 50 to 150 μm.
[0013] Furthermore, the spiral quick-freezing coil is made of copper or stainless steel and its surface is coated with a low-temperature resistant and corrosion-resistant coating.
[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0015] This application disperses highly viscous jujube concentrate into countless tiny droplets through an atomizing nozzle, which are then instantly frozen by a spiral quick-freezing coil. This significantly increases the specific surface area of the material, greatly enhancing the heat and mass transfer efficiency of the subsequent sublimation drying process. Combined with the low-frequency vibration generated by the vibration generator during the drying stage, the boundaries of the drying layer are effectively broken, promoting the escape of internal water vapor, thereby shortening the drying cycle and significantly reducing energy consumption. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of this utility model.
[0017] 1. Freeze-drying oven; 2. Mounting frame; 3. Vibration generator; 4. Flexible material tray; 5. Electric heating plate; 6. Atomizing nozzle; 7. Feed pipe; 8. High-pressure feed pump; 9. Spiral quick-freezing coil; 10. Vacuum tube; 11. Vacuum pump; 12. Water trap; 13. Liquid inlet pipe; 14. Liquid outlet pipe. Detailed Implementation
[0018] like Figure 1 As shown, a freeze-drying device for concentrated jujube juice includes a freeze-drying chamber 1 and a refrigeration system. A mounting frame 2 is placed at the bottom inner side of the freeze-drying chamber 1, and a vibration generator 3 is mounted on the mounting frame 2. A flexible material tray 4 is placed on the mounting frame 2, and an electric heating plate 5 is embedded in the contact surface between the mounting frame 2 and the flexible material tray 4. An atomizing nozzle 6 is provided at the top inner side of the freeze-drying chamber 1, facing the flexible material tray 4. The atomizing nozzle 6 is connected to an external storage tank via a feed pipe 7, and a high-pressure feed pump 8 is installed on the feed pipe 7. A spiral quick-freezing coil 9 is provided between the atomizing nozzle 6 and the flexible material tray 4. The inlet and outlet of the spiral quick-freezing coil 9 pass through the freeze-drying chamber 1 and are connected to the refrigeration system. A vacuum tube 10 is connected to the top of the freeze-drying chamber 1, and a vacuum pump 11 is installed on the vacuum tube 10. Multiple water-capturing components are provided on the inner wall of the freeze-drying chamber 1.
[0019] The water-catching assembly includes a water-catching plate 12 vertically installed on the inner wall of the freeze-drying chamber 1. The water-catching plate 12 has a flow channel inside, and the two ends of the flow channel are connected to the refrigeration system through an inlet pipe 13 and an outlet pipe 14, respectively. This structure allows the water-catching plate 12 to independently maintain an extremely low surface temperature (such as below -60°C), forming a highly efficient cold trap that can quickly capture and condense a large amount of water vapor, ensuring that a high water vapor partial pressure difference is always maintained inside the drying chamber. This is one of the core driving forces for the rapid sublimation drying process.
[0020] The surface of the water-catching plate 12 is provided with thermally conductive enhanced fins; the thermally conductive enhanced fin structure (such as honeycomb or louvered) can significantly increase the effective surface area of the water-catching plate 12, thereby greatly improving its water-catching capacity and efficiency per unit time, further accelerating the drying rate, and is especially suitable for materials with high moisture content.
[0021] The flexible material tray 4 is made of flexible aluminum alloy composite material; this material has both good thermal conductivity and a certain degree of flexibility. Its excellent thermal conductivity ensures that the heat provided by the electric heating plate 5 can be efficiently and evenly transferred to the material; its flexibility ensures that it can effectively transmit the mechanical vibration generated by the vibration generator 3 without attenuating the vibration or causing breakage due to excessive rigidity.
[0022] The atomizing nozzle 6 is a pressure-type or airflow-type atomizing nozzle, and the droplet size range of the sprayed droplets is 50-150μm.
[0023] The spiral quick-freezing coil 9 is made of copper or stainless steel, and its surface is coated with a low-temperature resistant and corrosion-resistant coating. Copper or stainless steel has high thermal conductivity, which can quickly transfer cold energy to the air to form a stable ultra-low temperature field. The low-temperature resistant and corrosion-resistant coating on the surface can effectively prevent the coil from being corroded in a long-term high-humidity and low-temperature environment, extend the service life of the core components of the equipment, and ensure the stability and reliability of operation.
[0024] Working principle:
[0025] During operation, the refrigeration system is first activated, rapidly lowering the temperature of the spiral quick-freezing coil 9 to below -50°C, creating an ultra-low temperature zone below the atomizing nozzle 6. Then, the high-pressure feed pump 8 is activated, delivering concentrated jujube juice from the external storage tank to the atomizing nozzle 6 via the feed pipe 7. The concentrated juice is atomized into fine droplets of 50-150 μm. These droplets fall under gravity, passing through the ultra-low temperature zone formed by the spiral quick-freezing coil 9, where they are instantly frozen into small solid particles and evenly dispersed onto the flexible material tray 4 below.
[0026] After pre-freezing, the feeding system is shut down, and the vacuum pump 11 is started to evacuate the freeze-drying chamber 1 to a high vacuum state through the vacuum tube 10. Then, the electric heating plate 5 is activated to provide the heat required for sublimation of the material. Simultaneously, the vibration generator 3 is activated to generate low-frequency, small-amplitude mechanical vibrations of 5-25Hz. This vibration is transmitted through the mounting frame 2 to the flexible material tray 4 and the porous freeze-dried material layer on it. The ice crystals in the material absorb heat and sublimate, and the resulting water vapor diffuses into the chamber under the vacuum pressure difference, eventually being captured and condensed by the low-temperature water-catching components on the inner wall. The vibration effectively disturbs the material particles, disrupts the boundary layer of the water vapor escape channels, greatly enhances the mass transfer process, prevents the "wet core" phenomenon, and significantly shortens the drying time. After drying, the vacuum pump 11 and heating system are shut down, the vacuum is broken, and the chamber door is opened to obtain a loose, porous, high-quality freeze-dried jujube juice concentrate.
[0027] This invention successfully solves the industry-wide challenge of freeze-drying concentrated jujube juice by integrating atomized pre-freezing, vibration drying, and a high-efficiency water-capturing system. It atomizes the highly viscous juice and then instantly freezes it, forming fine ice crystal particles. Combined with low-frequency vibration during the drying stage, this greatly enhances the mass transfer process, shortens the drying cycle, and reduces energy consumption. Simultaneously, the entire process is performed at low temperatures, perfectly preserving heat-sensitive nutrients and natural color and flavor, resulting in a product with excellent rehydration properties. The equipment is highly automated, completely solving the problems of high-sugar materials sticking to the walls and uneven drying, making it particularly suitable for continuous industrial production.
[0028] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A jujube concentrate juice freeze-drying device, comprising a freeze-drying box (1) and a refrigeration system, characterized in that: A mounting frame (2) is placed on the bottom inner side of the freeze-drying chamber (1). A vibration generator (3) is installed on the mounting frame (2). A flexible material tray (4) is placed on the mounting frame (2). An electric heating plate (5) is embedded in the contact surface between the mounting frame (2) and the flexible material tray (4). An atomizing nozzle (6) is provided on the top inner side of the freeze-drying chamber (1). The atomizing nozzle (6) faces the flexible material tray (4). The atomizing nozzle (6) is connected to the feed pipe (7) by the feed pipe. The external storage tank is connected, and a high-pressure feed pump (8) is installed on the feed pipe (7). A spiral quick-freezing coil (9) is provided between the atomizing nozzle (6) and the flexible material tray (4). The inlet and outlet of the spiral quick-freezing coil (9) pass through the freeze-drying box (1) and are connected to the refrigeration system. A vacuum tube (10) is connected to the top of the freeze-drying box (1). A vacuum pump (11) is installed on the vacuum tube (10). Multiple water-catching components are provided on the inner wall of the freeze-drying box (1).
2. The freeze-drying equipment for concentrated jujube juice according to claim 1, characterized in that: The water-catching assembly includes a water-catching plate (12) vertically installed on the inner wall of the freeze-drying chamber (1). The water-catching plate (12) has a flow channel inside, and the two ends of the flow channel are connected to the refrigeration system through an inlet pipe (13) and an outlet pipe (14), respectively.
3. The freeze-drying equipment for concentrated jujube juice according to claim 2, characterized in that: The surface of the water-catching plate (12) is provided with thermally conductive enhanced fins.
4. The freeze-drying equipment for concentrated jujube juice according to claim 1, characterized in that: The flexible material tray (4) is made of flexible aluminum alloy composite material.
5. The freeze-drying equipment for concentrated jujube juice according to claim 1, characterized in that: The atomizing nozzle (6) is a pressure-type or airflow-type atomizing nozzle, and the droplet size range of the sprayed droplets is 50-150μm.
6. The freeze-drying apparatus for concentrated juice of red dates according to claim 1, characterized in that: The spiral quick-freezing coil (9) is made of copper or stainless steel and its surface is coated with a low-temperature resistant and corrosion-resistant coating.