Multistage hot air circulation microcapsule rapid drying box

Abstract

The utility model discloses a kind of multi-stage hot air circulation's microcapsule rapid drying oven, it is related to microcapsule rapid drying oven, comprising: first drive belt, second conveyor belt and third conveyor belt are sequentially staggered distribution in vertical direction, and resistance wire plate screen belt are fixedly arranged in the center in above three groups of conveyor belt;Silicon-molybdenum rod ceramic heating plate and exhaust fan group are arranged above the first drive belt, still including circulation pipe, one end is located in the air inlet distribution of the exhaust fan group, the other end is located between the distribution of the second conveyor belt and third conveyor belt;Feeding conveyor belt, it is used to receive the third conveyor belt conveying blanking. The utility model combines dynamically flips, evenly distributes material, partitions temperature control and high-efficiency sealing perfectly, constructs a highly optimized, controllability extremely strong rapid drying system, especially suitable for drying uniformity and product quality have extremely high requirement's microcapsule drying scene.

Description

Technical Field

[0001] This utility model relates to a microcapsule rapid drying box, specifically a multi-stage hot air circulation microcapsule rapid drying box. Background Technology

[0002] Microencapsulation technology, as an effective encapsulation and controlled release method, has been widely used in pharmaceuticals, food, cosmetics, pesticides, and advanced materials. In its preparation process, drying is a crucial post-processing step for obtaining stable solid products. The drying process not only needs to remove moisture or solvents but also needs to maximize the preservation of the microcapsule's morphological integrity, encapsulation efficiency, and the stability of the core active ingredient. However, existing microcapsule drying technologies have several bottlenecks, making it difficult to simultaneously meet the requirements of high efficiency, high quality, mildness, and low energy consumption.

[0003] Spray drying, as a continuous drying technology, offers rapid drying speeds. However, during the process, microcapsules undergo instantaneous impact, high-speed shearing, and rapid dehydration from the high-temperature airflow. For microcapsules with weak wall strength or containing volatile / heat-sensitive core materials, this can easily lead to capsule wall rupture, core material loss, or activity degradation. Furthermore, the equipment is bulky, energy-intensive, and prone to wall adhesion for high-solids-content or viscous microcapsule suspensions. Utility Model Content

[0004] The purpose of this invention is to provide a multi-stage hot air circulation microcapsule rapid drying box to address the aforementioned shortcomings in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a multi-stage hot air circulation microcapsule rapid drying box, comprising:

[0006] The first transmission belt, the second transmission belt, and the third transmission belt are staggered in sequence along the vertical direction, and a resistance wire plate mesh belt is fixedly installed in the center of each of the three sets of transmission belts.

[0007] The silicon molybdenum rod ceramic heating plate and the heat exhaust fan group arranged above the first transmission belt also include a circulation pipe, one end of which is distributed at the air inlet of the heat exhaust fan group, and the other end is distributed between the second and third transmission belts.

[0008] A feeding conveyor belt is used to receive the material being transported by the third conveyor belt.

[0009] Preferably, the device also includes an insulation shell, in which the first transmission belt, the second transmission belt, the third transmission belt, the resistance wire plate mesh belt, the silicon molybdenum rod ceramic heating plate, the heat dissipation fan group, the circulation pipe, and the feeding conveyor belt are all installed.

[0010] Preferably, the top of the insulation shell is the feed inlet, which is located at the beginning of the first transmission belt conveying direction.

[0011] Preferably, the maximum operating power of the resistance wire mesh belt located on the first transmission belt is less than the maximum operating power of the resistance wire mesh belt located on the second transmission belt, but greater than the maximum operating power of the resistance wire mesh belt located on the third transmission belt.

[0012] Preferably, at least two three-dimensional rectangular grids located at the material transfer points of the first and second conveyor belts and the third conveyor belt are fixedly installed inside the insulation shell.

[0013] The three-dimensional rectangular grid contains densely packed, crisscrossing heating resistance wires.

[0014] Preferably, the three-dimensional rectangular grid is made of high-temperature resistant aluminum alloy.

[0015] Preferably, it also includes a spiral conveyor shaft assembly, which is arranged on the belt surface of the second and third conveyor belts, and its two ends extend into the transmission chambers fixedly provided on both sides of the heat insulation shell so that the driven motor is driven by the belt drive assembly.

[0016] The two ends of the spiral conveyor shaft assembly are located at the beginning and end of the conveyor belt.

[0017] Preferably, the spiral conveyor shaft assembly consists of at least four spiral conveyor shafts.

[0018] Preferably, a heat insulation plate is fixedly installed inside the heat insulation shell and is arranged at the end of the third conveyor belt.

[0019] The inner walls of the material feeding channel and the feed inlet on opposite sides of the heat insulation plate are respectively provided with inclined plates, and thin high-temperature resistant plastic plates with their ends in contact with each other are fixedly provided at the ends of the two inclined plates.

[0020] In the above technical solution, the multi-stage hot air circulation microcapsule rapid drying box provided by this utility model has the following beneficial effects: Through the coordinated design of vertically staggered multi-layer conveyor belts and a composite heating circulation system, a compact structure and continuous operation are achieved. During the top-down conveying process, the material is constantly tumbled due to natural falling between layers, effectively breaking the humidity and thermal resistance gradient formed by static drying, ensuring the uniformity and thoroughness of drying. The top uses a silicon molybdenum rod ceramic heating plate combined with a heat exhaust fan group to provide a high-efficiency radiant heat source, and the upper hot air is directionally guided to the middle and lower areas through the circulation pipe, constructing a top-down directional circulating airflow that conforms to thermodynamic laws. This not only greatly improves the thermal energy utilization efficiency, but also significantly improves the uniformity and stability of the temperature field inside the box. At the same time, the resistance wire plate mesh belt integrated into each layer of the conveyor belt provides stable bottom contact conduction heating, which, together with the top radiant heat and the middle convective heat, constitutes a three-dimensional composite heating mode, enabling the microcapsules to be heated and dehydrated quickly and uniformly. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 A schematic diagram of the overall structure provided for an embodiment of this utility model;

[0023] Figure 2 A schematic diagram of the structure of the three-dimensional rectangular grid provided in the embodiment of this utility model;

[0024] Figure 3 This is a schematic diagram of the internal structure of the heat-insulating shell provided in an embodiment of the present utility model;

[0025] Figure 4 Provided for the embodiments of this utility model Figure 3 A plan view;

[0026] Figure 5 Provided for the embodiments of this utility model Figure 4 A magnified schematic diagram of the internal structure.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. First transmission belt; 2. Second transmission belt; 3. Third transmission belt; 4. Resistance wire plate mesh belt; 5. Silicon molybdenum rod ceramic heating plate; 6. Exhaust fan assembly; 7. Circulation pipe; 8. Feeding conveyor belt; 9. Three-dimensional rectangular grid; 10. Spiral conveyor shaft assembly; 100. Insulation shell; 101. Feed inlet; 102. Transmission chamber; 103. Heat insulation plate; 104. Inclined plate; 105. Thin high-temperature resistant plastic sheet. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides a multi-stage hot air circulation microcapsule rapid drying box, which constructs a vertical, three-dimensional, stepped tumbling and composite heating drying environment. The main structure includes a first conveyor belt 1, a second conveyor belt 2, and a third conveyor belt 3 arranged vertically from top to bottom in a staggered manner. The so-called "staggered arrangement" means that the discharge end of the upper conveyor belt is not aligned horizontally with the feed end of the lower conveyor belt directly below it, but has a horizontal offset. This layout allows the material falling from the upper conveyor belt to fall naturally into the starting area of ​​the lower conveyor belt. All three conveyor belts adopt a mesh belt structure, and a resistance wire plate mesh belt 4 is fixedly embedded in the center below the bearing surface of each mesh belt. The resistance wire plate mesh belt 4 is composed of a high-temperature resistant metal mesh substrate and embedded resistance heating wires. After being energized, it can both carry and transport materials as part of the conveyor belt and directly conduct heat to the bottom of the materials in contact with it.

[0032] Above the first conveyor belt 1, a silicon molybdenum rod ceramic heating plate 5 and an exhaust fan assembly 6 are arranged in parallel. The silicon molybdenum rod ceramic heating plate 5 serves as the main high-temperature heat radiation source, capable of rapid heating and providing a stable high-temperature field. The exhaust fan assembly 6 is located near the heating plate 5; its function is not traditional exhaust, but rather to actively extract the hot air generated by the heating of the silicon molybdenum rod and accumulated in the upper part of the chamber. In addition, this device includes a circulation pipe 7. One end of the circulation pipe 7 (connected in series with an air dryer to dry the humid gas in the circulation) (air inlet) is connected to the air inlet side of the exhaust fan assembly 6 to receive the extracted hot air; its other end (air outlet) extends downwards and opens into the space between the second conveyor belt 2 and the third conveyor belt 3. Thus, the exhaust fan assembly 6 and the circulation pipe 7 together form a forced hot air circulation channel, directionally transporting the hot air from the top to the middle and lower drying area.

[0033] Below the discharge end of the third conveyor belt 3, there is a horizontal feeding conveyor belt 8, which is used to receive the dried microcapsule finished products that fall from the end of the third conveyor belt 3 and transport them to the next process or collection device.

[0034] Work process:

[0035] The wet microcapsules are fed in from the top and evenly spread on the first conveyor belt 1, moving slowly along it. During this process, the material simultaneously receives radiant heating from the upper silicon molybdenum rod ceramic heating plate 5 and conductive heating from the lower resistance wire plate mesh belt 4 (50℃~70℃). The exhaust fan group 6 at the top pumps some hot air to the middle and lower part through the circulation pipe 7. This hot air merges with the heat generated by the second and third layers of resistance wire plate mesh belts 4, forming a strong convection drying zone in the lower part of the chamber. The material is fully agitated as it falls between the layers, and the hot air penetrates through the gaps between the materials, achieving efficient heat and mass transfer. Finally, the dried microcapsules fall onto the feeding conveyor belt 8 via the third conveyor belt 3 for output.

[0036] Example 2

[0037] like Figure 4 As shown, in this embodiment, all working components are integrated and installed within an insulated housing 100. This insulated housing 100 is constructed of an outer steel plate and an inner lining of insulation material (such as ceramic fiber cotton), which greatly reduces heat loss, improves thermal efficiency, and enhances the working environment. A feed inlet 101 is provided at the top of the insulated housing 100, located directly above the starting section of the first conveyor belt 1 in the conveying direction, facilitating the continuous and controllable addition of wet materials via a feeder (such as a vibrating feeder or a screw feeder).

[0038] A key improvement in this embodiment lies in the differentiated design of the heating power of the resistance wire mesh belt 4 on the three conveyor belts. Specifically, the maximum operating power of the resistance wire mesh belt 4 located on the first conveyor belt 1 is set to be less than the maximum operating power of the resistance wire mesh belt 4 located on the second conveyor belt 2, but greater than the maximum operating power of the resistance wire mesh belt 4 located on the third conveyor belt 3. That is:

[0039] First conveyor belt (preheating zone):

[0040] The resistance wire mesh belt in this layer is set to operate at medium to low power. Combined with the radiant heating from the top silicon molybdenum rod ceramic heating plate and the initial hot air introduced through the circulation pipe, this area aims to achieve gentle and uniform preheating of the material. At this power, the surface temperature of the mesh belt can typically be controlled within the range of 50°C to 70°C, allowing the surface temperature of the wet microcapsules to rise gradually to approximately 40°C to 50°C. The main purpose of this stage is to evaporate some of the surface free water, while avoiding the formation of a hard shell on the surface of the microcapsule wall material due to excessively rapid heating or surface dehydration, which would hinder the subsequent diffusion of internal moisture.

[0041] Second conveyor belt (main drying area):

[0042] The resistance wire mesh belt in this layer operates at maximum power. At this point, the material has been preheated, and its internal moisture migration activity is enhanced. The high power input allows the mesh belt surface temperature to rise to 80℃~100℃ or higher (adjusted according to the material's tolerance). Combined with powerful circulating hot air, the air temperature in this area can be maintained at 60℃~80℃. Under these conditions, the material temperature can reach 55℃~70℃, enabling efficient and rapid vaporization and removal of most of the free water and some bound water from the microcapsules. This is the core drying stage with the fastest dehydration rate.

[0043] Third conveyor belt (slow-down drying / warming and setting zone):

[0044] The resistance wire mesh belt in this layer operates at a lower power. After the main drying process, the material's moisture content has been significantly reduced, and the drying process enters a slowdown phase. At this point, the lower power maintains the mesh belt surface temperature at 60℃~80℃, and the ambient air temperature is adjusted to 50℃~65℃. The material temperature at this stage is approximately 45℃~55℃. This mild thermal environment facilitates the slow evaporation of remaining bound water, reduces stress cracking in the product caused by rapid drying, and also acts as a "resilience" or heat treatment, contributing to the final shaping and structural relaxation of the microcapsule wall material, improving product stability, and especially protecting the heat-sensitive core material.

[0045] This power configuration strategy creates a temperature gradient consistent with drying kinetics: the first layer (preheating zone) uses low to medium power, primarily to gently and uniformly raise the temperature of the wet material, preventing rapid surface crusting; the second layer (main drying zone) uses the highest power, where the material temperature has already risen and internal moisture diffusion is accelerated, allowing for rapid vaporization and removal of a large amount of moisture—a crucial stage for dehydration; the third layer (low-temperature drying / warming zone) uses lower power, aiming to further remove residual bound water at lower temperatures and provide gentle heat treatment to the microcapsules, aiding in morphological shaping and reducing thermal stress, particularly beneficial for protecting the heat-sensitive core material. This gradient power design, combined with top silicon molybdenum rod heating and circulating hot air, enables precise simulation and control of the drying process curve.

[0046] Example 3

[0047] like Figures 3 to 5As shown, inside the insulation shell 100 of this embodiment, at least two three-dimensional rectangular grids 9 are fixedly installed in the falling trajectory area where materials fall from the upper conveyor belt to the lower conveyor belt. Specifically, one is located at the material transfer point between the first conveyor belt 1 and the second conveyor belt 2, and the other is located at the material transfer point between the second conveyor belt 2 and the third conveyor belt 3. The three-dimensional rectangular grid 9 is preferably made of high-temperature resistant aluminum alloy, and its interior is densely embedded with heating resistance wires in a crisscross pattern. When the microcapsule particles tumble and disperse as they fall between the layers, they pass through this heated grid 9. The heat generated by the heating resistance wires directly provides secondary impact heating to the falling particles and further heats the air passing through the gaps, forming a dynamic and uniform high-temperature "air curtain" in the falling area. This ensures the immediacy and uniformity of heat replenishment during the material's tumbling process and eliminates cold spots during tumbling.

[0048] To further optimize the distribution and movement of materials on the conveyor belts, a spiral conveyor shaft assembly 10 is arranged in parallel above the belt surfaces of the second conveyor belt 2 and the third conveyor belt 3. This spiral conveyor shaft assembly 10 consists of at least four parallel shafts with spiral blades on their surfaces. The bearing seats at both ends extend into the transmission chambers 102 fixedly installed on both sides of the insulation shell 100, and are synchronously driven by a drive motor via a belt drive assembly. The spiral conveyor shaft assembly 10 is arranged such that its starting end (spiral feed end) corresponds to the starting end of the conveyor belt, and its ending end (spiral discharge end) corresponds to the ending end of the conveyor belt. When the material layer on the conveyor belt may become uneven due to various reasons, the rotating spiral blades can actively flatten, stir, and propel it forward, ensuring a consistent thickness of material in the belt width direction and a stable conveying speed, thereby ensuring uniform heating and drying.

[0049] Inside the insulated housing 100, a heat insulation plate 103 is fixedly installed at the end of the third conveyor belt 3 (i.e., the position where the material is about to fall onto the feeding conveyor belt 8). A material discharge channel is provided on the heat insulation plate 103. Inclined plates 104 are respectively provided on opposite sides of the inner walls of the material discharge channel and the top inlet 101. A thin high-temperature resistant plastic sheet 105 (such as a polyimide PI sheet) extends and is fixedly installed at the end of each pair of inclined plates 104, with the ends of the two sheets 105 in flexible contact with each other. This structure forms an adaptive "soft curtain." On the one hand, it can effectively block the free exchange of gas between drying zones and between the inside and outside of the chamber, reducing temperature fluctuations and heat loss; on the other hand, its flexible contact allows the material to pass smoothly and plays a certain role in hindering and guiding the falling material, allowing the material to enter the next area or complete the discharge in a more dispersed state.

[0050] It should be noted that the transmission of the first conveyor belt 1, the second conveyor belt 2, the third conveyor belt 3, and the spiral conveyor shaft assembly mentioned above are all common knowledge in the art, and therefore are not disclosed in detail herein. Furthermore, the temperature control mentioned above is achieved by detecting temperature sensors located near the first conveyor belt 1, the second conveyor belt 2, and the third conveyor belt 3, and adjusting the temperature based on the detected temperature. The relevant temperature control procedure is also common knowledge in the art, and therefore will not be elaborated upon further.

[0051] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A multi-stage hot air circulating microcapsule rapid drying oven, characterized in that, include: The first transmission belt (1), the second transmission belt (2) and the third transmission belt (3) are staggered in the vertical direction, and a resistance wire plate mesh belt (4) is fixedly installed in the center of each of the three sets of transmission belts. The silicon molybdenum rod ceramic heating plate (5) and the heat exhaust fan group (6) arranged above the first transmission belt (1) also include a circulation pipe (7), one end of which is distributed at the air inlet of the heat exhaust fan group (6), and the other end is distributed between the second transmission belt (2) and the third transmission belt (3). The feeding conveyor belt (8) is used to receive the material being transported by the third conveyor belt (3).

2. The multi-stage hot air circulation microcapsule rapid drying box according to claim 1, characterized in that, It also includes an insulation shell (100), in which the first transmission belt (1), the second transmission belt (2), the third transmission belt (3), the resistance wire plate mesh belt (4), the silicon molybdenum rod ceramic heating plate (5), the heat dissipation fan group (6), the circulation pipe (7), and the feeding conveyor belt (8) are all installed.

3. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 2, characterized in that, The top of the heat-insulating shell (100) is the feed inlet (101), which is located at the beginning of the conveying direction of the first transmission belt (1).

4. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 3, characterized in that, The maximum operating power of the resistance wire mesh belt (4) located on the first transmission belt (1) is less than the maximum operating power of the resistance wire mesh belt (4) located on the second transmission belt (2), and greater than the maximum operating power of the resistance wire mesh belt (4) located on the third transmission belt (3).

5. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 3, characterized in that, At least two three-dimensional rectangular grid meshes (9) located on the material transmission of the first transmission belt (1) and the second transmission belt (2), the second transmission belt (2) and the third transmission belt (3) are fixedly installed inside the heat insulation shell (100); The three-dimensional rectangular grid (9) contains densely packed heating resistance wires arranged in a crisscross pattern.

6. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 5, characterized in that, The three-dimensional rectangular grid (9) is made of high-temperature resistant aluminum alloy.

7. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 6, characterized in that, It also includes a spiral conveyor shaft assembly (10), which is arranged on the belt surface of the second conveyor belt (2) and the third conveyor belt (3), and its two ends extend into the transmission chambers (102) fixedly provided on both sides of the heat insulation shell (100) so that the driven motor is driven by the belt drive assembly. The two ends of the spiral conveyor shaft assembly (10) are located at the beginning and end of the conveyor belt.

8. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 7, characterized in that, The spiral conveyor shaft assembly (10) consists of at least four spiral conveyor shafts.

9. A multi-stage hot air circulating microcapsule rapid drying oven according to claim 8, characterized in that, A heat insulation plate (103) is fixedly installed inside the heat insulation shell (100), and it is arranged at the end of the third conveyor belt (3). Inclined plates (104) are respectively provided on the inner walls of the material feeding channel and the feed inlet (101) on opposite sides of the heat insulation plate (103), and thin high-temperature resistant plastic plates (105) with their ends in contact with each other are fixedly provided at the ends of the two inclined plates (104).

Images