A scraper assembly and a scraper device for a spray dryer

Abstract

This utility model discloses a scraper assembly and a scraper device for a spray dryer. The scraper assembly includes a non-magnetic scraper support, one end of which has a connection port, and the other end is detachably equipped with a scraper blade via an adjustment component. The scraper device for the spray dryer includes a magnetic levitation assembly and a scraper assembly. The magnetic levitation assembly includes a magnetic levitation rotor ring installed inside the drying chamber of the spray dryer, a magnetic levitation stator ring installed on the outer wall of the spray dryer, and a displacement sensor installed on the magnetic levitation stator ring. Multiple sets of permanent magnets are equidistantly embedded on the magnetic levitation rotor ring, and multiple scraper assemblies are detachably installed on the outer periphery of the magnetic levitation rotor ring for scraping off materials adhering to the inner wall of the spray dryer. A central control unit includes a controller and a sensor group. The sensor group is installed on the spray dryer and connects wirelessly to the controller to achieve data interaction. The controller controls the magnetic levitation stator ring and the scraper assembly respectively.

Description

Technical Field

[0001] This utility model relates to the pharmaceutical field, specifically to a scraper assembly and a scraper device for a spray dryer. Background Technology

[0002] Spray drying is a process in which liquid material is sprayed into hot air through an atomizing device, causing the droplets to dry rapidly into powder. During the spray drying process, due to the influence of material characteristics and process conditions, some adhering material will stick to the inner wall of the drying chamber, which not only reduces the product yield but also affects product quality and equipment operating efficiency. To solve this problem, spray dryers usually need to be equipped with a scraper device to remove the adhering material on the chamber wall.

[0003] Currently, there are two main types of scraper devices for spray dryers: mechanical and pneumatic.

[0004] Mechanical scrapers are usually driven by an electric motor, which drives the scraper blades to move on the inner wall of the drying chamber through a transmission mechanism. For example, a spray dryer disclosed in CN220404843U includes a dryer main frame, and a cleaning structure is set inside the dryer main frame. The motor drives the rotating shaft to rotate, so that the scraper blades clean and scrape off the adhering material particles on the inner wall of the dryer main frame.

[0005] Pneumatic scrapers use airflow impact or vibration to remove adhering materials. They are easy to operate but have limited cleaning effect.

[0006] With the development of magnetic levitation technology, some innovative scraper devices have begun to apply the principle of magnetic drive. For example, CN204648904U discloses a scraping device for removing adhering materials from the walls of a centrifugal spray dryer, which includes a power supply, an electromagnet, and a permanent magnet. The electromagnet is electrically connected to the power supply, and the electromagnet and the permanent magnet are slidably connected to the outer wall and inner wall of the drying chamber of the centrifugal spray dryer, respectively. The permanent magnet is driven by the electromagnet to rotate and slide up and down along the circumference of the drying chamber, thereby scraping off the adhering materials at different locations.

[0007] Magnetic levitation technology also has wide applications in other fields. For example, CN119483022A discloses a magnetic levitation motor and a submersible stirrer, which includes a ring rotor and a stator assembly. The two ring rotors are coaxial and arranged vertically. The stator assembly drives the two ring rotors to levitate and rotate through magnetic force. CN107465364A discloses a magnetic levitation device, which includes a first magnet, an electromagnet, a levitation body, a sensor, and a control circuit. The control circuit changes the magnitude or direction of the current of the electromagnet according to the signal fed back by the sensor, so that the levitation body is stably levitated.

[0008] However, existing spray dryer scraper technology still has the following problems:

[0009] First, traditional mechanical scrapers need to be in direct contact with the inner wall of the drying chamber. Long-term operation causes mechanical wear, resulting in frequent blade replacements and increased maintenance costs. Contact scraping easily creates scratches on the chamber wall, exacerbating the adhesion of materials and creating a vicious cycle.

[0010] Secondly, existing technologies rely on the linkage of multiple components such as motors, lead screws, and cylinders, resulting in a large space-consuming transmission system and delayed operation response. Furthermore, the mechanical structure struggles to cover the curved surfaces of the drying chamber, leading to insufficient cleaning coverage.

[0011] Third, a sealing device is required at the connection between the mechanical shaft and the drying chamber. Long-term use can easily lead to wear and leakage, and the sealing structure has dead corners that are difficult to clean thoroughly.

[0012] Fourth, the existing scraper pressure is fixed and cannot be automatically adjusted according to the adhesion of the material, lacking adaptability to materials of different viscosities.

[0013] Finally, although there is a magnetically driven scraper device, its magnet arrangement and scraper structure design are not optimized enough, making it difficult to achieve precise control of scraper pressure while ensuring scraping effect.

[0014] Therefore, there is an urgent need for a spray dryer scraper device that can solve the above problems, effectively remove materials adhering to the chamber wall, avoid mechanical wear, and have adjustable pressure to improve equipment operating efficiency and product quality. Utility Model Content

[0015] The technical problem this invention aims to solve is the defects in existing spray dryer scraper technology, such as mechanical friction leading to equipment wear, complex transmission structure limiting efficiency, contradiction between energy consumption and cleaning effect, insufficient intelligence, easy leakage of sealing structure, and existence of sanitary dead corners. This invention provides a scraper assembly and a scraper device for spray dryers, which can achieve technical effects such as non-contact cleaning, complete sealing, improved product yield, energy saving and consumption reduction, and intelligent adjustment, thereby solving the defects caused by the existing technology.

[0016] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0017] In a first aspect, a scraper assembly includes a non-magnetic scraper holder, one end of which has a connection port, and the other end of which a scraper blade is detachably mounted via an adjustment component. The scraper blade is made of pharmaceutical-grade PEEK (polyether ether ketone) material, which has excellent temperature resistance, wear resistance, and chemical corrosion resistance, and meets FDA certification standards. The scraper holder is made of high-strength carbon fiber composite material, which is lightweight and high-strength.

[0018] In the aforementioned scraper assembly, the adjusting component includes a pressure adjusting mechanism, an elastic slide, a pressure sensor, and a controller;

[0019] The pressure regulating mechanism is installed at the end of the scraper bracket that does not have the connection port. The two ends of the elastic sliding component are respectively connected to the pressure regulating mechanism and the scraper blade. The pressure sensor is installed on the elastic sliding component.

[0020] The controller wirelessly establishes connections with the pressure sensor and the pressure regulating mechanism to achieve data interaction. The pressure sensor is mounted on the scraper bracket to monitor the actual resistance between the scraper blade and the adhesive.

[0021] The adjustment component is a precision adjustment device integrated on each of the scraper supports. After the pressure sensor transmits the signal to the control unit, the control unit generates a feedback adjustment signal and transmits it to the pressure adjustment mechanism. The pressure adjustment mechanism slides along the guide rail inside the scraper support according to the feedback adjustment signal, compressing or stretching the elastic sliding component to achieve fine adjustment of the position of the scraper blade within the range of 0-10mm, thereby precisely controlling the gap or contact pressure between the scraper blade and the area to be scraped.

[0022] In the aforementioned scraper assembly, the elastic sliding component is connected to the scraper blade via a T-shaped slot, facilitating quick replacement and cleaning.

[0023] In the aforementioned scraper assembly, the scraper blade has dimensions of 40mm × 20mm × 3mm, a cutting edge design with a back tilt angle of approximately 15°, and is processed to form a micro-rounded corner, which facilitates the peeling of adhered materials without damaging the cavity wall.

[0024] In a second aspect, a scraper device for a spray dryer includes a magnetic levitation assembly and a scraper assembly from the first aspect. The magnetic levitation assembly includes a magnetic levitation rotor ring installed in the drying chamber inside the spray dryer, a magnetic levitation stator ring installed on the outer wall of the spray dryer, and a displacement sensor installed on the magnetic levitation stator ring.

[0025] Multiple sets of permanent magnets are equidistantly embedded on the magnetic levitation rotor ring. The permanent magnets are N52 neodymium iron boron permanent magnets. Multiple scraper assemblies, as described in the first aspect, are detachably installed on the outer periphery of the magnetic levitation rotor ring for scraping off the material adhering to the inner wall of the spray dryer. The scraper bracket is detachably connected to the magnetic levitation rotor ring through the connection port. Each scraper bracket is equipped with the pressure sensor and the pressure adjustment mechanism, which can independently adjust the gap and contact pressure between the scraper blade and the inner wall of the spray dryer. The scraper bracket is made of high-strength carbon fiber composite material, which is lightweight and high-strength, and can significantly reduce the load on the magnetic levitation system.

[0026] An electromagnetic drive assembly is installed on the outer wall of the spray dryer to drive the magnetically levitated stator ring. By controlling the electromagnetic field distribution of the magnetically levitated stator ring, the magnetically levitated rotor ring is made to rotate, thereby driving the scraper blades to remove the adhering material on the inner wall of the drying chamber.

[0027] The central control unit includes the controller and the sensor group. The sensor group is installed on the spray dryer and interacts with the controller wirelessly. The controller controls the magnetic levitation stator ring, the electromagnetic drive assembly, and the scraper assembly respectively.

[0028] The magnetically levitated rotor ring can be stably suspended within the drying chamber of the spray dryer and can rotate.

[0029] The magnetic levitation rotor ring is the core component of the ring structure, made of titanium alloy with a cross-sectional dimension of 50mm × 40mm. The diameter of the magnetic levitation rotor ring is 900mm. It remains stably suspended within the 1000mm diameter drying chamber, surrounding the inner circumference of the drying chamber of the spray dryer, maintaining a concentric gap of approximately 50mm with the chamber wall, so as not to interfere with the airflow distribution and droplet movement trajectory during the spray drying process. Multiple sets of N52 neodymium iron boron permanent magnets are uniformly embedded on the magnetic levitation rotor ring to form a circumferentially uniformly distributed magnetic pole array. The outer circumference of the magnetic levitation rotor ring is provided with 12 quick-connect slots for installing the detachable scraper bracket.

[0030] The aforementioned scraper device for a spray dryer includes 12 scraper assemblies equidistantly mounted on the outer circumference of the magnetic levitation rotor ring. Each scraper assembly comprises a non-magnetic scraper bracket, an adjustment component, and scraper blades. The scraper brackets are installed using a quick-connect method for easy disassembly, cleaning, or replacement. The number of scraper brackets can be flexibly configured according to cleaning requirements. The scraper brackets are made of lightweight, high-strength materials (such as titanium alloys or carbon fiber composites) to reduce the load and rotational inertia of the levitation system. The scraper blades are installed at the end of each scraper bracket and are designed to be high-temperature resistant (meeting the temperature requirements of the drying chamber), corrosion resistant (meeting the chemical corrosion requirements of adhering materials and organic solvents), wear resistant (meeting the requirements of possible physical friction with the drying chamber), and meet pharmaceutical-grade hygiene standards. Optional materials include polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), ultra-high molecular weight polyethylene (UHMWPE), special grade stainless steel (such as 316L), or ceramic materials.

[0031] The pressure regulating mechanism is installed on each of the scraper supports, and can individually adjust the gap or contact pressure between the scraper blade and the inner wall of the drying chamber of the spray dryer, as well as the scraping angle.

[0032] This modular and adjustable design allows the scraper device to adapt more flexibly to different adhesion conditions or slight changes in the shape of the cavity wall in different areas. The shape of the scraper blade should be designed to fit well with the inner wall contour of the spray drying cavity. For example, an arc-shaped scraper or a single scraper with a certain degree of elasticity can be used. The scraping edge can be designed with a specific angle (such as wedge, rounded corner or obtuse angle) to facilitate the peeling of the adhered material from the wall rather than hard cutting, thereby further reducing damage to the cavity wall in the light contact mode.

[0033] The above-mentioned scraper device for a spray dryer, wherein the magnetic levitation stator ring includes an annular bracket installed on the outer wall of the spray dryer and a rotary drive electromagnet group, a radial stator electromagnet group, and an axial stator electromagnet installed on the annular bracket, and the ring surrounds the spray dryer to form a complete annular structure;

[0034] The magnetically levitated stator ring comprises three types of electromagnet arrays:

[0035] The radial stator electromagnet group includes 24 groups of radial electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring. Each group includes a pair of coils installed opposite each other, which are used to control the stable levitation of the magnetic levitation rotor ring in the radial direction, ensuring that the magnetic levitation rotor ring remains concentric with the inner wall of the drying chamber and maintains an appropriate gap.

[0036] The axial stator electromagnet assembly includes 16 sets of axial electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring, used to control the levitation position and stability of the magnetic levitation rotor ring in the axial (height direction), and the levitation height of the magnetic levitation rotor ring can be changed by adjusting the axial magnetic force.

[0037] The rotary drive electromagnet assembly includes eight specially designed drive electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring. The central control unit precisely controls the energizing sequence and current magnitude of the rotary drive electromagnet assembly to generate a rotating magnetic field, which interacts with the permanent magnets on the magnetic levitation rotor ring to generate a tangential driving torque, enabling the magnetic levitation rotor ring to rotate controllably.

[0038] The aforementioned scraper device for a spray dryer, wherein the sensor group includes an angle / speed sensor, a gap sensor, a position sensor (including eddy current, Hall effect, optical, capacitive and other sensors that play a role in realizing ring suspension control) and an attitude sensor mounted on the spray dryer;

[0039] The angle / speed sensor consists of eight evenly distributed Hall sensors, used to detect the rotation angle, direction and speed of the magnetic levitation rotor ring. The gap sensor is used to detect the distance between the scraper blade and the inner wall of the spray dryer. Multiple position sensors are evenly distributed along the circumference of the magnetic levitation rotor ring, used to detect the position information of the magnetic levitation rotor ring. The attitude sensor is used to detect the attitude information of the magnetic levitation rotor ring.

[0040] The data from these sensors is transmitted to the controller to ensure that the magnetically levitated rotor ring remains stably suspended and rotated.

[0041] The controller can change the magnetic field distribution acting on the magnetic levitation rotor ring by precisely adjusting the current distribution of the axial stator electromagnet and the radial stator electromagnet, thereby adjusting the levitation height and radial position of the entire device.

[0042] In the radial direction, by increasing or decreasing the current of the radial electromagnet, the concentricity between the magnetically levitated rotor ring and the cavity wall can be finely adjusted to ensure that all the scraper blades maintain a uniform gap with the inner wall.

[0043] In the axial direction, by controlling the current of the axial electromagnet, the levitation height of the magnetically levitated rotor ring can be adjusted, thereby synchronously changing the contact position between all the scraper blades and the inner wall.

[0044] The aforementioned scraper device for a spray dryer has the following improvements:

[0045] 1. Non-contact operation, reducing wear and contamination: Magnetic levitation technology ensures a constant, minute gap between the scraper assembly and the inner wall of the drying chamber, eliminating physical contact. This fundamentally eliminates the wear problem caused by friction in traditional mechanical scrapers, preventing secondary contamination of the product by wear debris, and extending the service life of both the drying chamber and the scraper assembly. The non-contact design is one of the core advantages of this technology.

[0046] 2. Adjustable scraping pressure or gap: The system can accurately and dynamically adjust the gap (adjustment range: 0.5mm to 5mm) between the scraper and the drying chamber, or the scraping pressure, based on the viscosity of the adhered material, the thickness of the adhesion layer, and other process requirements. This adapts to different adhesion conditions, whether dealing with easily removable loose powders, viscous semi-dry adhered materials requiring a certain amount of force, or initially formed thin crusts. It effectively removes adhered materials while avoiding impact on the drying chamber or certain heat-sensitive adhered materials.

[0047] 3. Adaptable to different wall adhesion situations: For situations where the material adhering to the tower wall is unevenly distributed or only severely adheres to the wall in specific areas, this technical solution can control the scraper to focus on cleaning these areas. For drying chambers of different diameters or conical structures, the scraper blades can maintain an effective scraping state by adjusting the radial suspension force and attitude, thereby improving cleaning efficiency, reducing energy consumption, and reducing unnecessary work on non-adhering areas.

[0048] 4. High scraping efficiency and stable operation: The electromagnetic drive can achieve smooth, high-speed and continuous scraping. The scraping path covers the entire inner wall, which significantly improves scraping efficiency and uniformity. The magnetic levitation system has a certain anti-interference ability and can adapt to the air volume and atomized airflow during the operation of the drying chamber.

[0049] 5. High degree of automation and low maintenance cost: The entire scraping process is automatically controlled by the central control unit, reducing manual intervention. Since there are no mechanical contact and wear parts (such as bearings and seals), the maintenance requirements of the equipment are significantly reduced, thereby reducing the overall cost.

[0050] 6. Structural advantages without a central suspension shaft: Compared with the general design using a central suspension shaft, the annular magnetic levitation scraper device completely avoids the central area of ​​the drying chamber, and will not affect the airflow distribution and droplet movement during the spray drying process. This design avoids the central suspension shaft itself becoming another component that needs cleaning and maintenance, simplifies the system structure, and improves the overall operating efficiency. The annular structure can also cover the drying chamber wall more evenly and reduce cleaning dead corners.

[0051] 7. Convenient modular design: The annular magnetic levitation scraper device adopts a modular design (such as a detachable scraper bracket), which greatly improves the ease of equipment maintenance. When individual scraper blades need to be replaced or cleaned, it is not necessary to disassemble the entire system. Only the corresponding bracket module needs to be replaced. This design adapts to different production needs and facilitates the quick replacement of the appropriate scraper type according to the characteristics of different adhering materials. It also makes troubleshooting simpler and more efficient.

[0052] 8. Improve batch-to-batch variability of spray-dried products: By timely and effectively removing the adhering material from the inner wall, the surface of the drying chamber can be kept clean and smooth, thereby maintaining the stability and uniformity of temperature and airflow distribution within the chamber. This helps to avoid fluctuations in drying conditions caused by the wall-adhering layer, indirectly ensuring the quality of the final product (such as particle size distribution, residual solvent, and active ingredient content). Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structure of a scraper assembly according to the present invention;

[0054] Figure 2 This is a schematic diagram of the working structure of the scraper blade in a scraper assembly according to the present invention;

[0055] Figure 3 This is a schematic diagram of the scraper device for a spray dryer according to the present invention;

[0056] Figure 4 This is a top view schematic diagram of the magnetic levitation rotor ring and magnetic levitation stator ring in a scraper device for a spray dryer according to the present invention.

[0057] Figure 5 This is a schematic cross-sectional view of the magnetic levitation rotor ring and magnetic levitation stator ring in a scraper device for a spray dryer according to the present invention.

[0058] The reference numerals in the attached figures are as follows:

[0059] Scraper bracket 100, scraper blade 200, magnetic levitation rotor ring 300, magnetic levitation stator ring 400, displacement sensor 500, spray dryer 600, central control unit 700, adhesive material 800, connection port 101, pressure adjustment mechanism 102, elastic sliding assembly 103, pressure sensor 104, T-slot 201, permanent magnet 301, ring bracket 401, rotary drive electromagnet assembly 402, radial stator electromagnet assembly 403, axial stator electromagnet 404, display screen 701, angle / speed sensor 702. Detailed Implementation

[0060] In order to make the technical means, inventive features, objectives and effects of the utility model easy to understand, the technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to specific illustrations. Obviously, the described embodiments are some embodiments of the utility model, but not all embodiments.

[0061] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0062] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0063] Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0064] like Figure 1-2 As shown in the first embodiment, a scraper assembly includes a non-magnetic scraper holder 100. One end of the scraper holder 100 is provided with a connection port 101, and the other end is detachably mounted with a scraper blade 200 via an adjustment component. The scraper blade 200 is made of pharmaceutical-grade PEEK (polyether ether ketone) material, which has excellent temperature resistance, wear resistance, and chemical corrosion resistance, and meets FDA certification standards. The scraper holder 100 is made of high-strength carbon fiber composite material, which has the characteristics of being lightweight and high-strength.

[0065] The adjustment component includes a pressure adjustment mechanism 102, an elastic slide, a pressure sensor 104, and a controller.

[0066] The pressure regulating mechanism 102 is installed at the end of the scraper bracket 100 without the connection port 101. The two ends of the elastic sliding component 103 are respectively connected to the pressure regulating mechanism 102 and the scraper blade 200. The pressure sensor 104 is installed on the elastic sliding component 103.

[0067] The controller wirelessly establishes a connection with the pressure sensor 104 and the pressure regulating mechanism 102 to achieve data interaction. The pressure sensor is installed on the scraper bracket 100 to monitor the actual resistance between the scraper blade 200 and the adhesive.

[0068] The adjustment component is a precision adjustment device integrated on each scraper holder 100. After the pressure sensor transmits the signal to the control unit, the control unit generates a feedback adjustment signal and transmits it to the pressure adjustment mechanism 102. The pressure adjustment mechanism 102 slides along the guide rail inside the scraper holder 100 according to the feedback adjustment signal, compressing or stretching the elastic sliding component 103 to achieve fine adjustment of the position of the scraper blade 200 within the range of 0-10mm, thereby precisely controlling the gap or contact pressure between the scraper blade 200 and the area to be scraped.

[0069] The elastic sliding component 103 is connected to the scraper blade 200 via a T-shaped slot 201, which facilitates quick replacement and cleaning.

[0070] The scraper blade 200 measures 40mm × 20mm × 3mm, with a cutting edge designed at an angle of approximately 15° and rounded corners, which facilitates the peeling of the adhered material 800 without damaging the cavity wall.

[0071] like Figure 3-5 As shown in the second embodiment, a scraper device for a spray dryer is characterized by comprising a magnetic levitation assembly and a scraper assembly from the first aspect. The magnetic levitation assembly includes a magnetic levitation rotor ring 300 installed inside the drying chamber of the spray dryer 600, a magnetic levitation stator ring 400 installed on the outer wall of the spray dryer 600, and a displacement sensor 500 installed on the magnetic levitation stator ring 400. The displacement sensor 500 employs a Hall effect sensor, a laser displacement sensor, etc. The displacement sensor 500 non-contactly and in real-time monitors the accurate position (i.e., suspension gap) of the magnetic levitation rotor ring 300 relative to the magnetic levitation stator ring 400 (indirectly relative to the inner wall of the drying chamber) in each control axis. The displacement sensors 500 are uniformly distributed circumferentially along the magnetic levitation rotor ring 300 to ensure that the motion state of the magnetic levitation rotor ring 300 can be captured.

[0072] Multiple sets of permanent magnets 301 are equidistantly embedded on the magnetic levitation rotor ring. The permanent magnets 301 are N52 neodymium iron boron permanent magnets 301. Multiple scraper assemblies, as described in the first aspect, are detachably installed on the outer periphery of the magnetic levitation rotor ring 300. These are used to scrape off the material adhering to the inner wall of the spray dryer 600. The scraper bracket 100 is detachably connected to the magnetic levitation rotor ring 300 through the connection port 101. Each scraper bracket 100 is equipped with a pressure sensor 104 and a pressure adjustment mechanism 102, which can independently adjust the gap and contact pressure between the scraper blade 200 and the inner wall of the spray dryer 600. The scraper bracket 100 is made of high-strength carbon fiber composite material, which is lightweight and high-strength, and can significantly reduce the load on the magnetic levitation system.

[0073] An electromagnetic drive assembly, installed on the outer wall of the spray dryer 600, is used to drive the magnetically levitated stator ring 400. By controlling the electromagnetic field distribution of the magnetically levitated stator ring 400, the magnetically levitated rotor ring 300 is made to rotate, thereby driving the scraper blade 200 to remove the adhering material 800 from the inner wall of the drying chamber. The electromagnetic drive assembly consists of multiple sets of magnetic conductors with wound coils, distributed along the circumference and axial direction of the spray dryer 600. Depending on the specific design, the circumferential drive control coil set can be integrated with the axial drive coil set, or it can be used as an independent set of coils (similar to the stator of a rotary motor) to drive the scraper blade 200 to rotate circumferentially. By controlling the direction and magnitude of the current, a rotating magnetic field is generated, which interacts with the permanent magnet 301 on the magnetically levitated rotor ring 300 to generate a tangential driving torque, pushing the magnetically levitated rotor ring 300 to rotate. This design is similar to the working principle of a large brushless DC motor.

[0074] The central control unit 700 includes a controller, a sensor group, and a display screen 701. The sensor group is installed on the spray dryer 600 and connects to the controller wirelessly to achieve data interaction. The controller controls the magnetic levitation stator ring 400, the electromagnetic drive assembly, the scraper assembly, and the display screen 701 respectively.

[0075] The magnetically levitated rotor ring 300 can be stably suspended within the drying chamber of the spray dryer 600 and can rotate.

[0076] The magnetic levitation rotor ring is the core component of the ring structure. It is made of titanium alloy with a cross-sectional dimension of 50mm×40mm. The diameter of the magnetic levitation rotor ring 300 is 900mm. It is stably suspended in the drying chamber with a diameter of 1000mm and surrounds the inner circumference of the drying chamber of the spray dryer 600. It maintains a concentric gap of about 50mm with the chamber wall of the drying chamber, so as not to interfere with the airflow distribution and droplet movement trajectory during the spray drying process. Multiple sets of N52 neodymium iron boron permanent magnets 301 are uniformly embedded on the magnetic levitation rotor ring to form a circumferentially uniformly distributed magnetic pole array. The outer circumference of the magnetic levitation rotor ring is provided with 12 quick connection slots for installing the detachable scraper bracket 100.

[0077] The magnetic levitation rotor ring 300 has 12 scraper assemblies equidistantly installed on its outer circumference. Each scraper assembly includes a non-magnetic scraper bracket 100, an adjustment component, and scraper blades 200. The scraper bracket 100 is installed using a quick-connect method, which facilitates disassembly, cleaning, or replacement. The number of scraper brackets 100 can be flexibly configured according to cleaning needs. The scraper brackets 100 are made of lightweight, high-strength materials (such as titanium alloys, carbon fiber composites, etc.) to reduce the load and rotational inertia of the levitation system. The scraper blades 200 are installed at the end of each scraper bracket 100. The materials are designed to be high-temperature resistant (meeting the temperature of the drying chamber), corrosion resistant (meeting the chemical corrosion of the adhering material 800 and organic solvents), wear resistant (meeting the physical friction that may occur with the drying chamber), and meet the requirements of pharmaceutical-grade hygiene standards. Optional materials include polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), ultra-high molecular weight polyethylene (UHMWPE), special grade stainless steel (such as 316L), or ceramic materials.

[0078] The pressure regulating mechanism 102 is installed on each scraper support 100, and can individually adjust the gap or contact pressure between the scraper blade 200 and the inner wall of the drying chamber of the spray dryer 600, as well as the scraping angle.

[0079] This modular and adjustable design allows the scraper device to adapt more flexibly to different adhesion conditions or slight changes in the shape of the cavity wall in different areas. The shape of the scraper blade 200 should fit well with the inner wall contour of the spray drying cavity. For example, an arc-shaped scraper or a single scraper with a certain degree of elasticity can be used. The scraping edge can be designed with a specific angle (such as wedge, rounded corner or obtuse angle) to facilitate the peeling of the adhered material 800 from the wall surface rather than hard cutting, thereby further reducing damage to the cavity wall in the light contact mode.

[0080] The magnetic levitation stator ring 400 includes an annular support 401 installed on the outer wall of the spray dryer 600, and a rotary drive electromagnet assembly 402, a radial stator electromagnet assembly 403, and an axial stator electromagnet 404 installed on the annular support 401. The ring forms a complete annular structure around the spray dryer 600.

[0081] The magnetic levitation stator ring 400 contains three types of electromagnet arrays:

[0082] The radial stator electromagnet group 403 includes 24 groups of radial electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring 300. Each group includes a pair of coils installed opposite each other to control the stable levitation of the magnetic levitation rotor ring 300 in the radial direction, ensuring that the magnetic levitation rotor ring 300 remains concentric with the inner wall of the drying chamber and maintains an appropriate gap. Its arrangement can also be segmented along the axial direction to match the axial position of the scraper blade 200.

[0083] The axial stator electromagnet group 404 includes 16 axial electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring 300. It is used to control the levitation position and stability of the magnetic levitation rotor ring 300 in the axial (height direction). The levitation height of the magnetic levitation rotor ring 300 can be changed by adjusting the axial magnetic force. Specifically, by controlling the timing and amplitude of the current supplied to these coils, a controllable axial thrust / pull force is generated by interacting with the permanent magnet 301, which drives the scraper blade 200 to move up and down along the tower wall. The magnetic levitation rotor ring 300 is a magnetic ring. The main body is made of lightweight materials such as high-strength aluminum alloy. It is embedded with permanent magnet 301 (such as neodymium iron boron material) or high permeability iron core material. It interacts with the magnetic field generated by the stator electromagnet to generate levitation force and rotational driving force.

[0084] The rotary drive electromagnet assembly 402 includes eight specially designed drive electromagnets evenly distributed along the circumference of the magnetic levitation rotor ring 300. The energizing sequence and current magnitude of the rotary drive electromagnet assembly 402 are precisely controlled by the central control unit 700 to generate a rotating magnetic field, which interacts with the permanent magnet 301 on the magnetic levitation rotor ring 300 to generate a tangential driving torque, enabling the magnetic levitation rotor ring 300 to achieve controllable rotation.

[0085] As needed, more complex scraping paths can be designed by adjusting the current of the three sets of coils: the radial stator electromagnet group 403, the axial stator electromagnet group 404, and the circumferential drive electromagnet group. These can include complex motion modes such as fixed-point reciprocating scraping (rapid reciprocating scraping within a specific angle range, targeting stubborn local adhesion areas), area-specific focused scraping (the control system can set the scraping speed, number of scrapings, and dwell time of the scraper in different areas), or adjusting the scraping posture according to the geometry of the tower wall.

[0086] For example, gap sensors (such as laser displacement sensors) can be arranged along the circumference and axis of the scraper assembly to accurately obtain the three-dimensional coordinates of the scraper assembly and its pitch, roll, and deviation attitudes within the tower. The controller is a data processing system that needs to have computing power and feedback adjustment capabilities (such as a PC-based real-time motion controller) and be able to plan and execute various motion trajectories according to different scenarios.

[0087] The sensor group includes an angle / speed sensor 702, a gap sensor, a position sensor, and an attitude sensor installed on the spray dryer 600.

[0088] The angle / speed sensor 702 consists of eight evenly distributed Hall sensors used to detect the rotation angle, direction and speed of the magnetic levitation rotor ring 300. The gap sensor is used to detect the distance between the scraper blade 200 and the inner wall of the spray dryer 600. Multiple position sensors are evenly distributed along the circumference of the magnetic levitation rotor ring to detect the position information of the magnetic levitation rotor ring 300. The attitude sensor is used to detect the attitude information of the magnetic levitation rotor ring 300.

[0089] The data from these sensors is transmitted to the controller to ensure that the magnetic levitation rotor ring 300 remains stably suspended and rotated;

[0090] The controller can change the magnetic field distribution acting on the magnetic levitation rotor ring 300 by precisely adjusting the current distribution of the axial stator electromagnet 404 and the radial stator electromagnet, thereby adjusting the levitation height and radial position of the entire device.

[0091] In the radial direction, by increasing or decreasing the current of the radial electromagnet, the concentricity between the magnetic levitation rotor ring 300 and the cavity wall can be finely adjusted to ensure that all scraper blades 200 maintain a uniform gap with the inner wall.

[0092] In the axial direction, by controlling the current of the axial electromagnet, the levitation height of the magnetic levitation rotor ring 300 can be adjusted, thereby synchronously changing the contact position between all scraper blades 200 and the inner wall.

[0093] In summary, the scraper assembly and scraper device for spray dryers of this utility model can achieve technical effects such as contactless cleaning, complete sealing, improved product yield, energy saving and consumption reduction, and intelligent adjustment.

[0094] The specific embodiments of the utility model have been described above. It should be understood that the utility model is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a manner common to the art; those skilled in the art can make various modifications or alterations within the scope of the claims, and make several simple deductions, modifications or substitutions, which do not affect the substantive content of the utility model.

Claims

1. A scraper assembly, characterized in that, It includes a non-magnetic scraper holder, one end of which has a connection port, and the other end is detachably fitted with a scraper blade via an adjustment component.

2. The scraper assembly as described in claim 1, characterized in that, The adjustment assembly includes a pressure adjustment mechanism, an elastic sliding component, a pressure sensor, and a controller; The pressure regulating mechanism is installed at the end of the scraper bracket that does not have the connection port. The two ends of the elastic sliding component are respectively connected to the pressure regulating mechanism and the scraper blade. The pressure sensor is installed on the elastic sliding component. The controller wirelessly establishes connections with the pressure sensor and the pressure regulating mechanism to achieve data interaction.

3. A scraper assembly as described in claim 2, characterized in that, The elastic sliding component is connected to the scraper blade via a T-shaped slot.

4. A scraper assembly as described in claim 1, characterized in that, The scraper blade measures 40mm × 20mm × 3mm, with a 15° back tilt angle and a slightly rounded corner.

5. A scraper device for a spray dryer, characterized in that, The device includes a magnetic levitation assembly and a scraper assembly as described in any one of claims 1-4. The magnetic levitation assembly includes a magnetic levitation rotor ring installed in the drying chamber inside the spray dryer, a magnetic levitation stator ring installed on the outer wall of the spray dryer, and a displacement sensor installed on the magnetic levitation stator ring. Multiple sets of permanent magnets are equidistantly embedded on the magnetic levitation rotor ring, and multiple scraper assemblies are detachably installed on the outer periphery of the magnetic levitation rotor ring for scraping off the adhering material on the inner wall of the spray dryer. The central control unit includes the controller and the sensor group. The sensor group is installed on the spray dryer and interacts with the controller wirelessly. The controller controls the magnetic levitation stator ring and the scraper assembly respectively.

6. A scraper device for a spray dryer as described in claim 5, characterized in that, The magnetic levitation rotor ring has 12 scraper assemblies installed at equal intervals on its outer circumference.

7. A scraper device for a spray dryer as described in claim 5, characterized in that, The magnetic levitation stator ring includes an annular bracket mounted on the outer wall of the spray dryer, and a rotary drive electromagnet assembly, a radial stator electromagnet assembly, and an axial stator electromagnet mounted on the annular bracket.

8. A scraper device for a spray dryer as described in claim 5, characterized in that, The sensor group includes an angle / speed sensor, a gap sensor, a position sensor, and an attitude sensor installed on the spray dryer; The angle / speed sensor is used to detect the rotation angle, direction and speed of the magnetic levitation rotor ring; the gap sensor is used to detect the distance between the scraper blade and the inner wall of the spray dryer; the position sensor is used to detect the position information of the magnetic levitation rotor ring; and the attitude sensor is used to detect the attitude information of the magnetic levitation rotor ring.

9. A scraper device for a spray dryer as described in claim 5, characterized in that, It also includes an electromagnetic drive assembly, which is installed on the outer wall of the spray dryer and is used to drive the magnetically levitated stator ring. The controller controls the electromagnetic drive assembly.

10. A scraper device for a spray dryer as described in claim 5, characterized in that, The permanent magnet is an N52 neodymium iron boron permanent magnet.

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