Superheated steam cyclone sterilization system and method of system operation

Abstract

The application provides a superheated steam cyclone sterilization system and a system operation method, and belongs to the technical field of sterilization. The system comprises, in sequence, a feed preheating bin, a feeder, a superheated steam cyclone sterilization bed, a cyclone collector, a filter cartridge collector and a finished product cooling bin, wherein the cyclone collector is also directly connected to the finished product cooling bin; a superheated steam pipeline is connected to the filter cartridge collector, a steam heat exchanger, a circulating fan, a first heater and the superheated steam cyclone sterilization bed in sequence; and a low-pressure saturated steam pipeline is connected to the filter cartridge collector, the cyclone collector and the steam heat exchanger. The material is sterilized in an oxygen-free environment throughout the process, oxidation and deterioration are avoided, the quality is improved, and the superheated steam has a high circulation speed.

Description

Technical Field

[0001] This invention belongs to the field of sterilization technology, specifically relating to a superheated steam cyclone sterilization system and a system operation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Powdered and granular materials such as food additives, flavorings, pharmaceutical excipients, and additives, used in food and high-end pharmaceutical excipients and drugs, must strictly adhere to GMP and pharmacopoeia standards, with high requirements for microbial limits, physicochemical stability, and production compliance. The core requirements are mainly as follows: Product characteristic requirements: After sterilization, key indicators such as viscosity, whiteness, color, pH value, and solubility should not deteriorate, with a viscosity retention rate ≥98%; Microbial control requirements: Total bacterial count ≤100 CFU / g, no pathogenic bacteria, sterilization rate ≥99.99%; Production process requirements: Continuous aseptic operation, high degree of automation, and reduced manual intervention; Compliance management requirements: Full-process data traceability and verification, meeting pharmacopoeia standards, and a complete set of validation documents; Cost control requirements: Reduced energy consumption and consumable costs, shortened production cycles, and reduced batch losses.

[0004] Common sterilization processes include ethylene oxide sterilization, radiation sterilization (gamma rays / electron beams), dry heat sterilization, microwave sterilization, and superheated steam sterilization. Superheated steam sterilization refers to further heating saturated steam to a superheated state. Under high temperature, normal pressure, or slightly positive pressure conditions above saturation temperature, the high-temperature phase change heat effect, high specific heat capacity, and penetrating power of superheated steam cause denaturation of microbial proteins and inactivation of enzymes, thereby achieving rapid sterilization. Superheated steam sterilization leaves no chemical residue, has good penetration, and high sterilization efficiency. However, in the past, there were problems with the precise control of superheated steam sterilization temperature, sterilization time, continuous sterilization of materials, and uniformity. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a superheated steam cyclone sterilization system and system operation method. By ensuring stable temperature and precise time control during hot steam sterilization, materials can be sterilized continuously or intermittently and uniformly, meeting the process requirements of high-temperature short-time sterilization, zero residue, and viscosity maintenance for powdered food and pharmaceuticals.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, a superheated steam cyclone sterilization system includes a feed preheating chamber, a feeder, a superheated steam cyclone sterilization bed, a cyclone collector, a filter cartridge collector, and a finished product cooling chamber connected in sequence, wherein the cyclone collector is also directly connected to the finished product cooling chamber; a superheated steam pipeline is connected in sequence to the filter cartridge collector, a steam heat exchanger, a circulating fan, a first heater, and the superheated steam cyclone sterilization bed; and a low-pressure saturated steam pipeline is connected to the filter cartridge collector, the cyclone collector, and the steam heat exchanger respectively. The superheated steam cyclone sterilization bed includes a superheated steam inlet chamber and a bed body that are connected. A guide vane and a dispersant are provided between the superheated steam inlet chamber and the bed body. Several material homogenization structure groups are provided in the bed body. The material homogenization structure includes a swirl generator, a second guide vane, and a classifying ring arranged sequentially along the airflow direction. The swirl generator is a double cone coaxial with the bed body and spaced a predetermined distance from the inner wall of the bed body. A first guide vane is provided on the surface of the double cone near the superheated steam inlet chamber. The second guide vane is provided on the inner wall of the bed body. The classifying ring is a cone coaxial with the bed body. The large end of the cone is connected to the inner wall of the bed body, and the small end of the cone has a through hole facing the swirl generator. A feed inlet is provided between the disperser and the cyclone generator, and a discharge outlet is provided at the end of the bed away from the superheated steam inlet chamber.

[0007] Secondly, the operation method of the above-mentioned superheated steam cyclone sterilization system includes the following processes: After drying and dehydration, the powder is preheated in the feeding preheating chamber and then output. It is then conveyed to the superheated steam cyclone sterilization bed by the feeder for superheated steam sterilization. The mixture of sterilized powder and superheated steam is separated into gas and solid by the cyclone collector. The separated powder enters the finished product cooling chamber, and the remaining mixture is separated into gas and solid by the filter cartridge collector. The separated powder enters the finished product cooling chamber. After entering the filter cartridge receiver, the superheated steam is mixed with the superheated steam obtained from gas-solid separation. After being raised to the set temperature by the steam heat exchanger and the first heater, it enters the superheated steam cyclone sterilization bed.

[0008] The beneficial effects of this invention are as follows: This invention provides a superheated steam cyclone sterilization system. Within the system, superheated steam carries materials through various devices. The system is filled with superheated steam, and sterilization is performed entirely in an anaerobic environment, preventing oxidation and deterioration, improving quality, and providing high sterilization intensity. The high superheated steam circulation speed increases sterilization efficiency by 3-5 times (sterilization time at 130℃ is reduced to 1 / 3 of traditional dry heat methods). In the superheated steam cyclone sterilization bed, tangentially flowing superheated steam is delivered into the bed through the superheated steam inlet chamber, forming a cyclone state. This cyclone mixes with the materials stirred by the disperser, and the mixed superheated steam flows upwards in a rotating motion. During this process, the flow is regulated by a cyclone generator and a classifying ring, and the materials are output after meeting the set residence time within the bed. It provides a complete set of process technology and equipment for sterilization and drying of a wide-temperature-range closed-loop superheated steam cyclone bed that can operate continuously. By adjusting the operating pressure (vacuum degree -0.2-1.6Mpa absolute pressure) and operating temperature (applicable to the range of 55-230℃) in the sterilization bed, and with an indirect rapid cooling module, it can achieve aseptic operation throughout the process, closed negative pressure conveying throughout the process, no dust leakage, and meet the production specifications of clean areas; the residence time is adjustable across scales from 3s to 3h; the product particle size is adjustable across scales from 3cm to 30μm. Attached Figure Description

[0009] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0010] Figure 1 The following is a schematic diagram of the superheated steam cyclone sterilization bed in Example 1: (a) is a schematic diagram of the overall structure, (b) is a schematic diagram of the connection relationship of the guide vanes, and (c) is a top view of the overall structure.

[0011] Figure 2 The image shows a top view of the air guide vane in Example 1, where (a) is a structural schematic diagram of the first type of air guide vane and (b) is a structural schematic diagram of the second type of air guide vane.

[0012] Figure 3 The diagram shows the structure of the vortex generator in Example 1, where (a) is a structural diagram from a first perspective and (b) is a structural diagram from a second perspective.

[0013] Figure 4 The diagram below is a schematic diagram of the structure of the dispersant in Example 1, wherein (a) is a schematic diagram of the overall structure of the dispersant, (b) is a top view of the dispersant, (c) is a schematic diagram of the structure of the dispersing blades at the top of the dispersant, (d) is a schematic diagram of the structure of the dispersing blades in the middle of the dispersant, (e) is an isometric view of the dispersing blades at the bottom of the dispersant, and (f) is a front view of the dispersing blades at the bottom of the dispersant.

[0014] Figure 5 The diagram shows the structure of the second guide vane in Example 1, where (a) is a structural diagram of the first type of second guide vane, (b) is a structural diagram of the first type of second guide vane from another perspective, (c) is a structural diagram of the second type of second guide vane, and (d) is a structural diagram of the second type of second guide vane from another perspective.

[0015] Figure 6 This is a schematic diagram of a superheated steam cyclone sterilization system in Example 3.

[0016] The components include: 1. Feed preheating chamber; 2. Feeder; 3. Superheated steam cyclone sterilization bed; 4. Cyclone collector; 5. Filter cartridge collector; 6. Finished product cooling chamber; 7. Circulating fan; 8. Steam heat exchanger; 9. First heater; 10. Hot air replacement chamber; 11. Superheated steam inlet chamber; 111. Air inlet; 12. Bed body; 13. Guide vane; 131. Annular guide vane; 132. Cone cap; 14. Disperser; 141. Rotating shaft; 15. Cyclone generator; 151. First guide vane; 16. Grading ring; 17. Feed inlet; 18. Discharge outlet; 19. Second guide vane; 191. Angle adjustment shaft; 20. Heat tracing pipe; 21. Particle discharge outlet; 22. Sensor; 23. Automatic steam valve; 24. Second heater; 25. Third heater. Detailed Implementation

[0017] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] One or more embodiments of the present invention provide a superheated steam cyclone sterilization system, comprising a feed preheating chamber, a feeder, a superheated steam cyclone sterilization bed, a cyclone collector, a filter cartridge collector, and a finished product cooling chamber connected in sequence, wherein the cyclone collector is also directly connected to the finished product cooling chamber; a superheated steam pipeline is connected in sequence to the filter cartridge collector, a steam heat exchanger, a circulating fan, a first heater, and the superheated steam cyclone sterilization bed; and a low-pressure saturated steam pipeline is connected to the filter cartridge collector, the cyclone collector, and the steam heat exchanger respectively. The superheated steam cyclone sterilization bed includes a superheated steam inlet chamber and a bed body that are connected. A guide vane and a dispersant are provided between the superheated steam inlet chamber and the bed body. Several material homogenization structure groups are provided in the bed body. The material homogenization structure includes a swirl generator, a second guide vane, and a classifying ring arranged sequentially along the airflow direction. The swirl generator is a double cone coaxial with the bed body and spaced a predetermined distance from the inner wall of the bed body. A first guide vane is provided on the surface of the double cone near the superheated steam inlet chamber. The second guide vane is provided on the inner wall of the bed body. The classifying ring is a cone coaxial with the bed body. The large end of the cone is connected to the inner wall of the bed body, and the small end of the cone has a through hole facing the swirl generator. A feed inlet is provided between the disperser and the cyclone generator, and a discharge outlet is provided at the end of the bed away from the superheated steam inlet chamber.

[0020] The preheating chamber is used to preheat the material before it enters the sterilization equipment, which can reduce the temperature fluctuation of superheated steam sterilization caused by the heat absorption of the material during heating, and help maintain a stable sterilization temperature. The feeder is used to transport the material output from the preheating chamber to the superheated steam cyclone sterilization bed. The cyclone collector is used for gas-solid separation, separating the powder from the steam and transporting the powder to the finished product cooling chamber. The powder that has not been separated enters the filter cartridge collector for further gas-solid separation. The finished product cooling chamber is used to collect the powder separated from the cyclone collector and the filter cartridge collector. The superheated steam pipeline of the filter cartridge receiver is sequentially connected to the filter cartridge receiver, the circulating fan, the steam heat exchanger, the first heater, and the superheated steam cyclone sterilization bed. The superheated steam entering the cyclone sterilization bed mixes with the powder and then passes through the cyclone receiver and the filter cartridge receiver in sequence, where gas-solid separation occurs, realizing the circulation of superheated steam between the filter cartridge receiver and the superheated steam cyclone sterilization bed. The circulating fan provides the power to transport the superheated steam. The steam heat exchanger and the first heater use low-pressure saturated steam and an electric heater, respectively, as heat sources to heat the steam in the superheated steam pipeline, so that it reaches the temperature range required for superheated steam sterilization. The low-pressure saturated steam pipeline connects the filter cartridge receiver and the cyclone receiver, serving as a heat tracing and insulation function. The medium (mainly superheated steam) in the filter cartridge receiver and the cyclone receiver is always in a superheated state, with a temperature higher than the boiling point of water but lower than the superheated steam sterilization temperature. It is heated by external low-pressure saturated steam to prevent the superheated steam temperature from dropping and condensing, thus maintaining the temperature of the superheated steam and reducing the heat loss of the equipment.

[0021] In the superheated steam vortex sterilization bed, the superheated steam inlet chamber is used to receive external superheated steam. The superheated steam that is tangentially transported into the superheated steam inlet chamber forms a preliminary vortex state. The guide vane is used to adjust the superheated steam into a vortex state and transport it into the bed. The disperser is used to disperse the material to be sterilized and mix it with the superheated steam, so that the material can be transported along the bed in a vortex state with the superheated steam to complete the sterilization process. To overcome the problem of uneven residence time of materials in the cyclone bed, a material homogenization structure is set up, including a cyclone generator, a second guide vane, and a classifying ring. The double-cone cyclone generator is set on the central axis of the bed to disperse the airflow and material at the central axis position, which is then guided to the periphery by the first guide vane. The second guide vane is set on the inner wall of the bed and downstream of the cyclone generator. It can receive the material conveyed by the first guide vane and promote the cyclone state of the material and airflow through its own set angle, further conveying it downstream to the classifying ring position. The classifying ring is used to block the material near the inner wall and guide it to the area between the cyclone generator and the second guide vane to increase the residence time of the material. Through the above settings, the airflow and material conveying state at the central axis position and near the inner wall of the bed are effectively adjusted, so that the material in different areas of the bed is fully mixed and undergoes a consistent heating time, thereby outputting material with uniform properties and ensuring material quality.

[0022] Optionally, the bed body is provided with a particle discharge port, which is located on the outside of the cone cap; the particle discharge port is connected to the hot air replacement chamber; the function of the hot air replacement chamber is to use hot air to replace the superheated steam mixed in the output material of the superheated steam cyclone sterilization bed, so that the particle material is in a dry hot air environment before being cooled, avoiding large fluctuations in the moisture content of the material or agglomeration due to steam condensation.

[0023] Optionally, a sensor is installed on the superheated steam pipeline between the steam heat exchanger and the superheated steam swirl sterilization bed. The sensor is used to detect the content of superheated steam in the circulation pipeline. The sensor is connected to an automatic steam valve through a controller. When the content of superheated steam in the circulation pipeline drops to a set value, steam can be added to the pipeline through the automatic steam valve.

[0024] Optionally, the guide vane includes a cone cap coaxially arranged with the bed and an annular guide vane around the cone cap. The top of the cone cap is away from the superheated steam inlet chamber. The annular guide vane is a flat plate and perpendicular to the central axis of the bed. The annular guide vane is provided with a through hole in the same direction as the swirling flow, so that the superheated steam is transported to the bed in a swirling state through the through hole.

[0025] Optionally, a through hole along the swirling direction is provided in the designated annular cone region inside the boundary of the cone cap; this through hole is also used to guide the superheated steam in the hot steam inlet chamber into the bed. Since the circumferential velocity of the gas at the central axis position is small in the swirling airflow, no through hole is provided at the center of the cone cap to prevent the gas with a small flow velocity at the center position from entering the bed. The through hole provided at the edge of the cone cap can increase the amount of superheated steam passing through, thereby increasing the amount of superheated steam input into the bed.

[0026] Optionally, a dispersant is provided in the bed body away from the superheated steam inlet chamber. The dispersant includes a rotating shaft and multiple dispersing blades arranged on the rotating shaft. The dispersing blades are distributed at multiple heights, and the bottom dispersing blades are in contact with the upper surface of the cone cap. The dispersant is used to disperse materials that may clump together, promote the mixing of materials with superheated steam to form a rotating state, and convey them towards the discharge port against gravity with the superheated steam.

[0027] Optionally, the dispersing blades located at the top of the rotating shaft are propeller-shaped, which can promote the swirling state of the material and the superheated steam mixture.

[0028] Optionally, the bottom dispersing blades are set on the rotating shaft at a set tilt angle, which makes the dispersing blades fit against the cone cap to prevent material from accumulating on the upper surface of the cone cap. The bottom dispersing blades are provided with a branch structure, which is perpendicular to the rotating shaft and can disperse the material on the upper surface of the cone cap and mix it with superheated steam.

[0029] Optionally, the feed inlet is tangentially connected to the hot steam inlet chamber, and the powder outlet is tangentially connected to the bed body, so that the sterilized powder is output through the powder outlet at the top of the bed body.

[0030] Optionally, multiple material homogenization structure groups are provided. Due to the inclusion of a grading ring in the material homogenization structure group, the material can only move upward through the opening at the small end of the cone to the powder outlet. The material swirling to the area where the large end of the cone and the inner wall of the bed form an angle will lose kinetic energy and fall, and then rise again with the airflow until it passes through the opening at the small end of the cone. Therefore, the material can be prevented from rising, thus prolonging the sterilization time of the material in the bed. Since the swirling state of the material in the bed is gradually weakened at locations far from the superheated steam inlet, multiple material homogenization structure groups are provided. The first and second guide vanes in these groups enhance the swirling state, thereby controlling the sterilization time of the superheated steam.

[0031] Optionally, the central axis of the double cone of the cyclone generator coincides with the central axis of the bed. The first guide vane is a blade that protrudes outward from the surface of the cone and is spirally arranged on the surface of the cone. The spiral direction is consistent with the direction of superheated steam swirl in the bed. This structure is used to block the material near the central axis of the bed and guide it by the first guide vane, thereby reducing the axial velocity and increasing the circumferential velocity, and continuing to maintain the swirling state to rise gradually. This prevents the material from rising directly along the central axis of the bed, which would result in insufficient sterilization time. The double cone structure can also prevent the formation of dead air zones and avoid the accumulation of material falling from the grading ring.

[0032] Optionally, the second guide vane is spiral-shaped, with the spiral direction consistent with the direction of superheated steam swirl within the bed. The second guide vane is fixed to the inner wall of the bed at a set angle, or the second guide vane is connected to the inner wall of the bed via an angle adjustment shaft that can adjust the angle of the second guide vane, so that the angle of the second guide vane can be adjusted. The second guide vane is used to adjust the swirling state of the material and airflow near the inner surface of the bed. By adjusting the angle of the second guide vane through the angle adjustment shaft, the rotational upward angle of the airflow is adjusted to maintain the swirling state and to promote the transfer of material towards the central axis of the bed, preventing excessive accumulation of material on the inner surface and affecting the swirling state.

[0033] Optionally, a heat tracing pipe is provided on the side wall of the bed, and the heat tracing pipe is connected to a low-pressure saturated steam pipeline; used to heat the bed and maintain the temperature of the superheated steam used for sterilization inside.

[0034] Optionally, the bed is provided with a particle outlet, which is located on the bed outside the guide vane. When particle material is fed into the inlet, the particle material is dispersed by the disperser and comes into contact with the superheated steam fed through the guide vane. Since the particle material is large and difficult to rise with the superheated steam, a particle material outlet is provided on the outside of the cone cap to output the particle material after the sterilization time reaches the set requirements.

[0035] One or more embodiments of the present invention provide an operating method for the above-described superheated steam cyclone sterilization system, comprising the following processes: After drying and dehydration, the powder is preheated in the feeding preheating chamber and then output. It is then conveyed to the superheated steam cyclone sterilization bed by the feeder for superheated steam sterilization. The mixture of sterilized powder and superheated steam is separated into gas and solid by the cyclone collector. The separated powder enters the finished product cooling chamber, and the remaining mixture is separated into gas and solid by the filter cartridge collector. The separated powder enters the finished product cooling chamber. After entering the filter cartridge receiver, the superheated steam is mixed with the superheated steam obtained from gas-solid separation. After being raised to the set temperature by the steam heat exchanger and the first heater, it enters the superheated steam cyclone sterilization bed. Low-pressure saturated steam is fed into the feed preheating chamber, the superheated steam cyclone sterilization bed, the cyclone collector, and the filter cartridge collector, respectively, to provide heat tracing and insulation. The low-pressure saturated steam does not come into contact with the materials in the equipment, thus maintaining the internal temperature of the device.

[0036] Optionally, the material to be sterilized is fed into the superheated steam cyclone sterilization bed through the feed inlet. After being dispersed and stirred by the disperser, it is mixed with the superheated steam conveyed by the superheated steam inlet chamber and driven by the superheated steam to form a cyclone that moves upward along the bed. Under the action of the material homogenization structure group, after staying in the bed for a set time, the powder material that has completed cyclone sterilization is output from the discharge port.

[0037] Optionally, when the sensor between the steam heat exchanger and the superheated steam swirl sterilization bed detects that the content of superheated steam in the superheated steam pipeline has decreased to a set value, the controller controls the automatic steam valve upstream of the circulating fan on the superheated steam pipeline to replenish steam.

[0038] Optionally, after the dried and dehydrated granules are preheated in the feeding preheating chamber, they are conveyed to the superheated steam cyclone sterilization bed for superheated steam sterilization via a feeder. The sterilized granules then enter the finished product cooling chamber through the hot air replacement chamber.

[0039] The present invention will be further described below with reference to specific embodiments.

[0040] Example 1 In traditional cyclone beds, the airflow state is inconsistent at different locations. At the central axis of the cyclone bed, the airflow has a weak swirling effect, meaning the axial velocity is high and the circumferential velocity is low, making it easy to rise rapidly along the central axis and be discharged. As the airflow moves away from the central axis, the axial velocity decreases while the circumferential velocity increases. Near the inner wall, which is far from the central axis, the airflow easily loses its swirling state due to the resistance of the inner wall. Therefore, the airflow state is uneven at different locations in the cyclone bed. If this airflow is used to drive the material, the residence time of the material at the central axis is short while that near the inner wall is long, resulting in inconsistent heating times for the material at different locations and causing uneven material properties.

[0041] This embodiment provides a superheated steam cyclone sterilization bed, such as Figure 1 As shown in (a), it includes a superheated steam inlet chamber 11 and a bed 12 arranged sequentially from bottom to top. The internal space of the bed 12 is cylindrical. A guide vane 13 and a disperser 14 are arranged between the superheated steam inlet chamber 11 and the bed 12. Two material homogenization structure groups are arranged in the bed 12 from bottom to top. The material homogenization structure includes a swirl generator 15, a second guide vane 19, and a classifying ring 16 arranged sequentially along the airflow direction; the swirl generator 15 is a double cone coaxial with the bed 12 and spaced a predetermined distance from the inner wall of the bed 12, such as... Figure 3As shown, a first guide vane 151 is provided on the surface of the double cone near the superheated steam inlet chamber 11; a second guide vane 19 is provided on the inner wall of the bed body 12; the grading ring 16 is a cone coaxially arranged with the bed body 12, the large end of the cone is connected to the inner wall of the bed body 12, and the small end of the cone has a through hole facing the vortex generator 15.

[0042] A feed inlet 17 is provided between the disperser 14 and the cyclone generator 15, and a discharge outlet 18 is provided at the end of the bed 12 away from the superheated steam inlet chamber 11.

[0043] air deflector 13 Figure 2 As shown in (a), the device includes a cone cap 132 coaxially arranged with the bed body 12 and an annular guide vane 131 surrounding the cone cap 132. The top of the cone cap 132 is far from the superheated steam inlet chamber 11. The annular guide vane 131 is a flat plate perpendicular to the central axis of the bed body 12, and has through holes aligned with the swirling direction. Figure 2 As shown in (a), the annular gap guide vane 131 is provided with through holes arranged along the swirling direction, so that the superheated steam blown out from the through holes is in a swirling state.

[0044] A diffuser 14 is provided in the bed body 12 in a direction away from the superheated steam inlet chamber 11. The diffuser 14 is as follows: Figure 4 As shown, it includes a rotating shaft 141 and multiple dispersing blades disposed on the rotating shaft 141. The dispersing blades are distributed at multiple heights, such as... Figure 4 As shown in (e), the bottom dispersing blades are in contact with the upper surface of the cone cap 132. The disperser 14 is used to break up agglomerated materials and promote the mixing of materials with superheated steam to form a rotating state.

[0045] Each material homogenization structure group includes a cyclone generator 15, a second guide vane 19, and a classifying ring 16 arranged sequentially along the airflow direction; a feed inlet 17 communicating with the outside is provided between the disperser 14 and the nearest cyclone generator 15, and a discharge outlet 18 is provided at the end of the bed body 12 away from the superheated steam inlet chamber 11; such as Figure 1 As shown in (c), the air inlet 111 is tangentially connected to the hot steam inlet chamber 11 to initially form a swirling state, and the discharge port 18 is tangentially connected to the bed body 12, so that the material / superheated steam mixture in the swirling state can be tangentially conveyed to the discharge port 18.

[0046] like Figure 4 As shown in (a), the agitator 14 includes a rotating shaft 141 and a plurality of agitating blades disposed on the rotating shaft 141. Figure 4 As shown in (c), the dispersing blades located at the top of the rotating shaft 141 are propeller-shaped, which can promote the swirling state of the material and superheated steam mixture. Figure 4As shown in (b), the rotating shaft 141 is coaxially arranged with the cone cap 132 and is connected downward to the drive device through the through hole in the center of the cone cap 132. Figure 4 As shown in (e), the dispersing blades near the bottom of the cone cap 132 are positioned on the rotating shaft at a set tilt angle. This tilt angle ensures that the dispersing blades fit snugly against the cone cap 132, preventing material accumulation on the upper surface of the cone cap 132. Figure 4 As shown in (f), the bottom dispersing blades are equipped with a branched structure, which is perpendicular to the rotation axis and can disperse the material on the upper surface of the cone cap 132 and mix it with superheated steam. The dispersing blades in the middle of the disperser 14 are as follows: Figure 4 As shown in (d), the blade has a large cross-sectional size, providing a greater dispersing force to break up clumps of material.

[0047] like Figure 3 As shown in (a), the cyclone generator 15 has a double-cone structure, with the central axis of the double cones coinciding with the central axis of the bed 12. The first guide vane 151 is a blade protruding outward from the surface of the cone, and the first guide vane 151 is spirally arranged on the surface of the cone, with the spiral direction consistent with the direction of the superheated steam cyclone within the bed 12. The double-cone structure can also prevent the formation of dead airflow angles and avoid material accumulation. Figure 3 (b) shows the vortex generator 15 from another perspective.

[0048] like Figure 5 As shown in (a) and (b), the second guide vane 19 is spiral-shaped, with the spiral direction consistent with the direction of the superheated steam swirl within the bed 12. The second guide vane 19 is fixed to the inner wall of the bed 12 at a set angle; or as shown in (a) and (b) in (b). Figure 5 As shown in (c) and (d), the second guide vane 19 is provided with an angle adjustment shaft 191, as... Figure 1 As shown in (a), the second guide vane 19 is connected to the inner wall of the bed 12 via an angle adjustment shaft 191 that can adjust the angle, so that the angle of the second guide vane 19 can be adjusted by the angle adjustment shaft 191. The operator can adjust the tilt angle of the second guide vane 19 by adjusting the angle adjustment shaft 191 on the outside of the bed 12.

[0049] A heat tracing pipe 20 is provided on the side wall of the bed body 12, and the heat tracing pipe 20 is connected to a low-pressure saturated steam pipeline; it is used to heat the bed body 12 and maintain the temperature of the superheated steam used for sterilization inside.

[0050] Alternatively, the air deflector 13, as shown Figure 2As shown in (b), not only are through holes evenly distributed on the annular guide vane 131, but through holes are also provided in the set annular cone region inside the boundary between the cone cap 132 and the annular guide vane 131, along the swirling direction. These through holes are also used to guide the superheated steam in the hot steam inlet chamber into the bed body 12. No through holes are provided at the center of the cone cap 132 to prevent the gas with a low flow velocity at the center from entering the bed body 12. The through holes provided at the edge of the cone cap 132 can increase the amount of superheated steam passing through, thereby increasing the amount of superheated steam input into the bed body 12.

[0051] The bed body 12 is also provided with a particle discharge port 21, which is located on the outside of the cone cap 132. When particle material is fed into the feed port 17, the particle material is dispersed by the disperser 14 and comes into contact with the superheated steam fed through the guide air plate 13. Since the particle material has a large mass and is difficult to rise with the superheated steam, a particle discharge port 21 is provided on the outside of the cone cap 132 to output the particle material after the sterilization time reaches the set requirements. Therefore, the superheated steam cyclone sterilization bed provided in this embodiment can be used for both powder materials and particle materials.

[0052] The sterilization method of the superheated steam cyclone sterilization bed based on this embodiment includes: the material to be sterilized is fed into the bed body 12 through the feed inlet 17, dispersed and stirred by the disperser 14, mixed with the superheated steam conveyed by the superheated steam inlet chamber 11, and driven by the superheated steam to form a cyclone that moves upward along the bed body 12. Under the action of the material homogenization structure group, after staying in the bed body 12 for a set time, the powder material that has completed cyclone sterilization is output from the discharge port 18. During the process, under the action of the cyclone generator 15, the second guide vane 19 and the grading ring 16, the materials in different areas are fully mixed and can maintain a consistent residence time in the bed body 12 and undergo the same heating process.

[0053] When the material to be sterilized is granules, it is fed into the bed 12 through the feed inlet 17, dispersed and stirred by the disperser 14, and mixed with the superheated steam conveyed by the superheated steam inlet 11. The granules sterilized by superheated steam are then output from the granule outlet 21.

[0054] Example 2 A superheated steam cyclone sterilization bed, the difference between this embodiment and embodiment 1 is that the bed body 12 is not provided with a particle discharge port 21, and is only used for sterilizing powder materials.

[0055] Example 3 A superheated steam cyclone sterilization system, such as Figure 6 As shown, it includes a feeding preheating chamber 1, a feeder 2, a superheated steam cyclone sterilization bed 3 as shown in Example 1, a cyclone collector 4, a filter cartridge collector 5, and a finished product cooling chamber 6 connected in sequence. The cyclone collector 4 is also directly connected to the finished product cooling chamber 6. The superheated steam pipeline is sequentially connected to the filter cartridge receiver 5, the circulating fan 7, the steam heat exchanger 8, the first heater 9, and the superheated steam cyclone sterilization bed 3. External superheated steam at 0.3~0.8MPa is input into the filter cartridge receiver 5 for backflushing the filter cartridges to prevent clogging. Then, the superheated steam enters the circulating fan 7 to supplement the conveying power. After being heated to the set temperature by the steam heat exchanger 8 and the first heater 9, it enters the superheated steam cyclone sterilization bed 3 to achieve superheated steam sterilization. Afterward, the mixture of superheated steam and material sequentially enters the cyclone receiver 4 and the filter cartridge receiver 5. The superheated steam after gas-solid separation merges with the superheated steam used for backflushing in the filter cartridge receiver 5 and re-enters the circulating fan 7 to achieve the recycling of superheated steam.

[0056] The low-pressure saturated steam pipeline is connected to the feed preheating chamber 1, the filter cartridge collector 5, the cyclone collector 4 and the steam heat exchanger 8 respectively, and plays the role of heat tracing and heat preservation; when it enters the superheated steam cyclone sterilization bed 3, it is used to heat the heat tracing pipe 20 on the side wall of the bed body 12.

[0057] The feeding preheating chamber 1 is used to preheat the material before it enters the sterilization equipment to maintain a stable sterilization temperature; the feeder 2 is used to transport the material output from the feeding preheating chamber 1 to the superheated steam cyclone sterilization bed 3; the cyclone collector 4 is used for gas-solid separation to separate the powder from the steam; the filter cartridge collector 5 is used to further separate the gas output from the cyclone collector 4; the finished product cooling chamber 6 is used to collect the powder separated from the filter cartridge collector 5 and the cyclone collector 4.

[0058] In the flow path of the superheated steam, externally sourced superheated steam at 0.3~0.8MPa enters the filter cartridge receiver 5 for backflushing the filter cartridges and replenishing the superheated steam in the circulation pipeline. The temperature of the superheated steam here is higher than the boiling point of water but lower than the temperature required for sterilization, which can prevent condensation from forming in the filter cartridge receiver 5 and prevent the material from being overheated. Using superheated steam to backflush the filter cartridges can better maintain the stability of the gas composition in the superheated steam circulation pipeline compared to using hot dry air for backflushing, preventing the sterilization effect from decreasing due to an increase in the proportion of air. The circulating fan 7 is used to provide the conveying power for the superheated steam. The steam heat exchanger 8 and the first heater 9 use low-pressure saturated steam and an electric heater, respectively, as heat sources to heat the steam in the superheated steam pipeline to reach the temperature range required for superheated steam sterilization.

[0059] The superheated steam cyclone sterilization bed 3 is connected to the hot air replacement chamber 10. When the superheated steam cyclone sterilization bed 3 sterilizes the granular material, the granular material is difficult to be discharged from the top of the superheated steam cyclone sterilization bed 3 with the cyclone steam. Therefore, it is difficult to adjust the sterilization time through devices such as the grading ring. After the granular material is discharged from the granular discharge port 21 of the superheated steam cyclone sterilization bed 3, it enters the hot air replacement chamber 10. The hot air replacement chamber 10 is used to replace the superheated steam in the granular material with dry hot air at a temperature of 100°C or higher to achieve cooling, thereby strictly controlling the contact time between the granular material and the superheated steam and preventing moisture condensation from causing the material to clump.

[0060] A sensor 22 is installed on the superheated steam pipeline between the steam heat exchanger 8 and the superheated steam cyclone sterilization bed 3. The sensor 22 is used to detect the content of superheated steam in the superheated steam pipeline. The sensor 22 is connected to the automatic steam valve 23 through the controller. The automatic steam valve 23 is located upstream of the circulating fan 7 of the superheated steam pipeline. It is used to transport the low-pressure saturated steam in the low-pressure saturated steam pipeline into the superheated steam pipeline. After being heated by the steam heat exchanger 8 and the first heater 9, it meets the superheated steam sterilization requirements and is then transported into the superheated steam cyclone sterilization bed 3.

[0061] The compressed air pipeline is connected to the feed preheating chamber 1 through the second heater 24, which serves to loosen the material and replace the humid gas in the silo, thus facilitating material discharge.

[0062] The compressed air pipeline is also connected to the finished product cooling chamber 6 and the hot air replacement chamber 10 respectively. During the process, the compressed air pipeline passes through the refrigerated dryer, the primary filter and the sterile filter in sequence before connecting to the finished product cooling chamber 6 to ensure a sterile state. This is used to quickly cool the materials for subsequent packaging processes and to avoid contamination of the sterilized materials. The compressed air is further heated to above 100°C by the third heater 25 before entering the hot air replacement chamber 10. This is used to replace the superheated steam mixed in with the materials in the hot air replacement chamber 10, to prevent steam condensation and facilitate the next packaging step.

[0063] In this embodiment, an external low-pressure saturated superheated steam pipeline is connected to replenish the required steam in the pipeline; an external compressed air pipeline is connected to the superheated steam pipeline to replace the steam buffered in the system during shutdown, thereby discharging the steam in the system and preventing condensation after shutdown.

[0064] The principle of superheated steam generation includes: using heat exchangers / heaters to indirectly or directly heat the steam in the pipeline to a superheated state, thereby creating a superheated steam environment.

[0065] The filter cartridge receiver 5 is connected to the vent / air replacement venting pipeline. The vent / air replacement venting pipeline is equipped with a normally closed venting valve, which is used when the system is started or stopped to replace the circulating gas inside the system.

[0066] The operation method of the superheated steam cyclone sterilization system in this embodiment includes: After being dried and dehydrated, the powder is preheated in the feeding preheating chamber 1 and then conveyed to the superheated steam cyclone sterilization bed 3 through the feeder 2 for superheated steam sterilization. The mixture of sterilized powder and superheated steam is separated into gas and solid by the cyclone collector 4. The separated powder enters the finished product cooling chamber 6, and the remaining mixture is separated into gas and solid by the filter cartridge collector 5. The separated powder enters the finished product cooling chamber 6. External superheated steam enters the system through the filter cartridge receiver 5. First, the filter cartridge of the filter cartridge receiver 5 is backflushed. Then, it is mixed with the superheated steam obtained by gas-solid separation and enters the superheated steam circulation pipeline. After being raised to the set temperature required for sterilization by the steam heat exchanger 8 and the first heater 9, it enters the superheated steam cyclone sterilization bed 3. Low-pressure saturated steam is fed into the feed preheating chamber 1, the superheated steam cyclone sterilization bed 3, the cyclone collector 4, and the filter cartridge collector 5 respectively, serving as a heat tracing and insulation function. The low-pressure saturated steam does not come into contact with the materials in the equipment, thus maintaining the internal temperature of the device.

[0067] When sensor 22 detects that the content of superheated steam in the superheated steam pipeline has decreased to the set value, the controller controls the automatic steam valve 23 upstream of the circulating fan 7 to replenish steam.

[0068] When processing granular materials, the dried and dehydrated granules are preheated in the feed preheating chamber 1 and then conveyed to the superheated steam cyclone sterilization bed 3 through the feeder 2 for superheated steam sterilization. After sterilization, the granules enter the finished product cooling chamber 6 through the hot air replacement chamber 10.

[0069] The temperature of the superheated steam entering the filter cartridge receiver 5 is lower than the superheated steam sterilization temperature. This temperature is used for backflushing the filter cartridges to prevent condensation in the system and pipelines and to prevent the material from overheating. The superheated steam is heated to the superheated steam sterilization temperature through the steam heat exchanger 8 and the first heater 9. Thus, the gas temperature in the entire system and pipelines is always higher than the boiling point of water, preventing the generation of condensate.

[0070] When the entire system starts up, superheated steam is continuously supplied to the superheated steam circulation pipeline and the vent valve is opened to discharge the air in the system through the vent pipeline, gradually replacing the air in the system with superheated steam. When the system stops, heated dry air is continuously supplied to the superheated steam circulation pipeline and the vent valve is opened to gradually discharge the superheated steam in the system through the vent pipeline, gradually replacing the superheated steam in the system with dry air, so as to fully remove the moisture in the system.

[0071] The required utilities and design parameters for the system are shown in Table 1. Fresh water is used for cleaning system equipment or pipelines.

[0072] Table 1

[0073] The material handling capacity, physical property data, and sterilization parameters of the system provided in this embodiment are shown in Table 2 (taking cellulose powder as an example). Here, material handling capacity refers to the upper limit of the material that this system can process; initial moisture content of raw materials refers to the moisture content of the raw materials fed into the preheating chamber 1; final moisture content of the product refers to the moisture content of the product output from the finished product cooling chamber 6 or the hot air replacement chamber 10; raw material bulk density refers to the bulk density of the raw materials fed into the preheating chamber 1; and sterilization time and sterilization temperature refer to the process parameters of the sterilization process in the superheated steam cyclone sterilization bed 3, which can be flexibly adjusted within a range.

[0074] Table 2

[0075] The system used in this embodiment is employed for superheated steam sterilization of cellulose powder. The viscosity of cellulose powder is a key material indicator, primarily affected by sterilization process parameters. Inappropriate parameters can decrease viscosity and negatively impact quality. Table 3 shows the sterilization effects of cellulose powder at different temperatures and times.

[0076] Table 3

[0077] By comparing the experimental results of various samples under different experimental conditions, it was found that the optimal sterilization effect on the cellulose sample was achieved under superheated steam at 130℃ for 20 seconds, while having minimal impact on the viscosity and whiteness of the material. Therefore, this method optimizes the above sterilization parameters: superheated steam temperature of 130℃ and sterilization time of 20 seconds.

[0078] Example 4 A superheated steam cyclone sterilization system differs from Example 3 in that it uses the superheated steam cyclone sterilization bed from Example 2, and therefore does not include a hot air replacement chamber 10.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A superheated steam cyclone sterilization system, characterized in that, The system includes a preheating chamber, a feeder, a superheated steam cyclone sterilization bed, a cyclone collector, a filter cartridge collector, and a finished product cooling chamber, all connected in sequence. The cyclone collector is also directly connected to the finished product cooling chamber. A superheated steam pipeline is connected in sequence to the filter cartridge collector, a steam heat exchanger, a circulating fan, a first heater, and the superheated steam cyclone sterilization bed. Low-pressure saturated steam pipelines are connected to the filter cartridge collector, the cyclone collector, and the steam heat exchanger, respectively. The superheated steam cyclone sterilization bed includes a connected superheated steam inlet chamber and a bed body. A guide vane and a dispersant are arranged between the superheated steam inlet chamber and the bed body. Several material homogenization structure groups are arranged in the bed body. Each material homogenization structure group includes a cyclone generator, a second guide vane, and a grading ring arranged sequentially along the airflow direction. The cyclone generator is a double cone coaxial with the bed body and spaced a certain distance from the inner wall of the bed body. A first guide vane is arranged on the surface of the double cone near the superheated steam inlet chamber. The second guide vane is arranged on the inner wall of the bed body. The grading ring is a cone coaxial with the bed body. The large end of the cone is connected to the inner wall of the bed body, and the small end of the cone has a through hole facing the cyclone generator. A feed inlet is arranged between the dispersant and the cyclone generator, and a discharge outlet is arranged at the end of the bed body away from the superheated steam inlet chamber.

2. The superheated steam cyclone sterilization system as described in claim 1, characterized in that, A sensor is installed on the superheated steam pipeline between the steam heat exchanger and the superheated steam swirl sterilization bed. The sensor is used to detect the content of superheated steam in the circulation pipeline. The sensor is connected to the automatic steam valve through a controller.

3. The superheated steam cyclone sterilization system as described in claim 1, characterized in that, The air guide vane includes a cone cap coaxially arranged with the bed body and an annular air guide vane around the cone cap. The top of the cone cap is far away from the superheated steam inlet chamber, and the annular air guide vane is a flat plate and perpendicular to the central axis of the bed body. The annular gap guide vane is provided with through holes aligned with the swirling direction.

4. The superheated steam cyclone sterilization system as described in claim 3, characterized in that, The bed is provided with a particle discharge port, which is located on the outside of the cone cap; the particle discharge port is connected to the hot air replacement chamber. A through hole along the swirling direction is provided within a defined annular cone region inside the boundary of the cone cap. The feed inlet is tangentially connected to the hot steam inlet chamber, and the powder outlet is tangentially connected to the bed body.

5. The superheated steam cyclone sterilization system as described in claim 1, characterized in that, A dispersant is provided in the bed body away from the superheated steam inlet chamber. The dispersant includes a rotating shaft and multiple dispersing blades arranged on the rotating shaft. The dispersing blades are distributed at multiple heights, with the bottom dispersing blades in contact with the upper surface of the cone cap; the dispersing blades located at the top of the rotating shaft are propeller-shaped.

6. The superheated steam cyclone sterilization system as described in claim 1, characterized in that, The central axis of the double cone of the vortex generator coincides with the central axis of the bed. The first guide vane is a blade that protrudes outward from the surface of the cone and is spirally arranged on the surface of the cone. The spiral direction is consistent with the direction of superheated steam vortex in the bed.

7. The superheated steam cyclone sterilization system as described in claim 1, characterized in that, The second guide vane is spiral-shaped, and the spiral direction is consistent with the direction of superheated steam swirl in the bed. The second guide vane is fixed to the inner wall of the bed at a set angle; or, the second guide vane is connected to the inner wall of the bed through an angle adjustment shaft that can adjust the angle.

8. A method for operating a superheated steam cyclone sterilization system as described in any one of claims 1-7, characterized in that, Includes the following processes: After drying and dehydration, the powder is preheated in the feeding preheating chamber and then output. It is then conveyed to the superheated steam cyclone sterilization bed by the feeder for superheated steam sterilization. The mixture of sterilized powder and superheated steam is separated into gas and solid by the cyclone collector. The separated powder enters the finished product cooling chamber, and the remaining mixture is separated into gas and solid by the filter cartridge collector. The separated powder enters the finished product cooling chamber. After entering the filter cartridge receiver, the superheated steam is mixed with the superheated steam obtained from gas-solid separation. After being raised to the set temperature by the steam heat exchanger and the first heater, it enters the superheated steam cyclone sterilization bed.

9. The method of operating the superheated steam cyclone sterilization system as described in claim 8, characterized in that, When the sensor between the steam heat exchanger and the superheated steam swirl sterilization bed detects that the content of superheated steam in the hot steam pipeline has decreased to a set value, the controller controls the automatic steam valve upstream of the circulating fan on the superheated steam pipeline to replenish steam.

10. The method of operating the superheated steam cyclone sterilization system as described in claim 8, characterized in that, The material to be sterilized is fed into the superheated steam cyclone sterilization bed through the feed inlet. After being dispersed and stirred by the disperser, it is mixed with the superheated steam conveyed by the superheated steam inlet chamber and driven by the superheated steam to form a cyclone that moves upward along the bed. Under the action of the material homogenization structure group, after staying in the bed for a set time, the powder material that has completed the cyclone sterilization is output from the discharge port.

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