A kind of PTC thermosensitive ceramic heating sheet production uses spray granulator

Abstract

The application relates to a spraying granulating device for PTC thermosensitive ceramic heating sheet production, which comprises a granulating bin, a feeding pipe and an air inlet pipe are arranged at the top of the granulating bin, a discharging pipe is arranged at the bottom of the granulating bin, the air inlet pipe is connected with a preheating bin through a first air blower, an air outlet pipe is further arranged at the top of the granulating bin, one end of the air outlet pipe is connected with a wheel disc, the inner cavity of the wheel disc is communicated with the air outlet pipe, and the communication position deviates from the central axis of the wheel disc; a rotating wheel is arranged in the inner cavity of the wheel disc, a plurality of mounting cavities are uniformly arranged on the rotating wheel in the circumferential direction, a filter screen module is slidably arranged in each mounting cavity; a driving mechanism is further arranged on the granulating bin, when the filter screen module communicated with the air outlet pipe is blocked to cause the pressure difference on both sides to increase, the driving mechanism can drive the rotating wheel to rotate, so that the adjacent filter screen module is switched to the position communicated with the air outlet pipe. Through the synergistic effect of the above components, the problem that the air outlet pipe is easily blocked in the granulating process of the existing spraying granulating device and the production continuity is affected is effectively solved.

Description

Technical Field

[0001] This application relates to the technical field of PTC thermistor ceramic heating element processing, and in particular to a spray granulation device for the production of PTC thermistor ceramic heating elements. Background Technology

[0002] A spray granulation dryer is a drying device that produces a product by treating materials through fluidization, dust removal, atomization, and solidification to achieve the required particle size. The process generally involves air being heated by a heater and entering the bottom of a fluidized bed. It then passes through a distribution plate and contacts the material, causing it to fluidize. Mother liquor or binder is pressurized by a pressure pump and delivered to the atomizing nozzles. After atomization, it coats the surface of the fluidized particles or causes the particles to adhere to each other. Through continuous fluidization, coating, and drying, the particles gradually grow larger and, once they reach the required particle size, are discharged from the fluidized bed outlet. It is widely used in the chemical, pharmaceutical, and food industries.

[0003] When producing PTC thermistor ceramic heating elements, the slurry generated by stirring needs to be spray-granulated using a spray granulator. However, the existing spray granulators produce particles of random size and inconsistent particle uniformity, which affects the subsequent production and processing of PTC thermistor ceramic heating elements. In addition, non-compliant powder is generated during the granulation process. If this powder is directly output to subsequent production, it will also affect the quality of the final product.

[0004] Chinese patent application CN201821773262.1 discloses a spray granulation device for producing PTC thermistor ceramic heating elements. The device includes a granulation chamber with a guide plate fixed to the top surface, dividing the chamber into two interconnected lower regions. A feed pipe and an air inlet pipe are located at the top of the granulation chamber, corresponding to the regions on either side of the guide plate. A rotating mesh plate, composed of multiple evenly distributed metal mesh plates on a rotating shaft driven by a motor, is located in the granulation chamber's internal region below the feed pipe. This structure ensures uniform granulation, resulting in more consistent particle sizes. Furthermore, it allows for the recycling of powder produced during particle output for secondary granulation, preventing powder from mixing with the particles and affecting subsequent production.

[0005] The aforementioned technologies have the following drawbacks: During the granulation process, the gas discharged from the granulation chamber of the spray granulation device contains not only water vapor but also a large amount of fine powder. This powder easily adheres to and accumulates in the bends of the pipes, causing blockages and severely affecting the continuous and stable operation of the system. In particular, heat exchange pipes used for heat recovery suffer from complex structures, requiring heavy cleaning and maintenance work and frequent shutdowns, significantly reducing equipment utilization and production efficiency. Utility Model Content

[0006] To address the problem of easy blockage of the air outlet pipe during the granulation process of existing spray granulation devices, which affects the continuity of production, this application provides a spray granulation device for the production of PTC thermistor ceramic heating elements.

[0007] The spray granulation device for producing PTC thermistor ceramic heating elements provided in this application adopts the following technical solution: A spray granulation device for producing PTC thermistor ceramic heating elements includes a granulation chamber. The top of the granulation chamber is provided with a feed pipe and an air inlet pipe, and the bottom is provided with a discharge pipe. The air inlet pipe is connected to a preheating chamber through a first blower. The top of the granulation chamber is also provided with an air outlet pipe communicating with the preheating chamber. One end of the air outlet pipe near the granulation chamber is connected to a wheel. The inner cavity of the wheel is connected to the air outlet pipe, and the connection position is offset from the central axis of the wheel. A rotating wheel is rotatably arranged in the inner cavity of the wheel. Multiple mounting cavities are evenly opened on the rotating wheel along its circumference. A filter module is slidably arranged in each mounting cavity along its depth direction. The granulation chamber is also equipped with a drive mechanism. When the filter module connected to the air outlet pipe becomes blocked, causing an increase in the pressure difference on both sides, the drive mechanism can drive the rotating wheel to rotate, so that the adjacent filter module switches to the position connected to the air outlet pipe.

[0008] Furthermore, the driving mechanism includes a drive motor fixedly mounted on the granulation bin, the rotating wheel is rotatably connected to the wheel disk through rotating shafts at both ends, and the output end of the drive motor is drively connected to one of the rotating shafts; The rotating wheel is also equipped with a drive component, which can trigger the drive motor to start when the filter module is clogged.

[0009] Furthermore, the drive assembly includes an elastic element and a tactile switch disposed at the bottom of each of the mounting cavities; when the pressure difference between the two sides increases, the filter module can compress the elastic element and slide towards the tactile switch.

[0010] Furthermore, a bearing is provided at the connection between the rotating shaft and the wheel.

[0011] Furthermore, a maintenance window is provided on the side of the wheel near the granulation chamber, and a slide rail is provided on the wheel at the position of the maintenance window. A sliding door is slidably mounted on the slide rail; limit blocks are provided at both ends of the slide rail.

[0012] Furthermore, a handle is fixedly connected to the sliding door, and damping pads are provided at both ends of the wheel and the maintenance window.

[0013] Furthermore, the sliding door is made of a transparent material.

[0014] In summary, the beneficial technical effects of this application are as follows: 1. This device, by setting up a rotating wheel with multiple filter modules and an automatic switching mechanism driven by differential pressure, can instantly and automatically switch to the backup filter module when the working filter is clogged, ensuring that the spray granulation process can continue without interruption, effectively overcoming the production efficiency loss caused by downtime for cleaning; 2. A differential pressure sensor is formed by the cooperation of an elastic element and a tactile switch. When the filter module is blocked and the differential pressure exceeds the threshold, the drive motor is automatically triggered to rotate. After the filter module is switched, it is automatically reset, realizing the full automation of the "sensing-triggering-switching" process. 3. The design of the maintenance window and sliding door makes cleaning and replacing the filter module convenient, greatly reducing maintenance time and difficulty; the transparent sliding door allows for non-invasive real-time observation, while the damping pad and other structures enhance sealing and prevent accidental opening, improving operational safety. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a top view of an embodiment of this application; Figure 3 It is along Figure 2 Schematic diagram of the cross-sectional structure along line AA; Figure 4 This is a schematic diagram of the structure of the sliding door on the wheel in an embodiment of this application when it is opened.

[0016] Explanation of reference numerals in the attached figures: 1. Granulation bin; 11. Feed pipe; 12. Air inlet pipe; 13. Discharge pipe; 14. First blower; 15. Preheating bin; 16. Air outlet pipe; 17. Drive motor; 2. Wheel; 21. Bearing; 22. Maintenance window; 23. Slide rail; 231. Limit block; 24. Sliding door; 241. Handle; 25. Damping pad; 3. Rotary wheel; 31. Mounting cavity; 311. Filter module; 312. Elastic element; 313. Tactile switch; 32. Rotary shaft. Detailed Implementation

[0017] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] This application discloses a spray granulation apparatus for the production of PTC thermistor ceramic heating elements. (Refer to...) Figures 1 to 3 The granulation chamber includes a granulation bin 1. The top of the granulation bin 1 is equipped with a feed pipe 11 and an air inlet pipe 12, and the bottom is equipped with a discharge pipe 13. The air inlet pipe 12 is connected to a preheating bin 15 via a first blower 14. The top of the granulation bin 1 is also equipped with an air outlet pipe 16 communicating with the preheating bin 15. A wheel 2 is connected to one end of the air outlet pipe 16 near the granulation bin 1. The wheel 3 is made of a corrosion-resistant alloy. The inner cavity of the wheel 2 communicates with the air outlet pipe 16, and the communication position is offset from the central axis of the wheel 2. A wheel 3 is rotatably mounted in the inner cavity of the wheel 2. Multiple mounting cavities 31 are evenly formed along the circumference of the wheel 3. A filter module 311 is slidably mounted in each mounting cavity 31 along its depth direction. The filter module 311 can be, but is not limited to, a sintered metal mesh, a ceramic filter element, or a composite material filter element, with the appropriate material selected according to the actual filtration accuracy and temperature resistance requirements.

[0019] The granulation chamber 1 is also equipped with a drive mechanism. When the filter module 311 connected to the air outlet pipe 16 is blocked, causing the pressure difference on both sides to increase, the drive mechanism can drive the rotating wheel 3 to rotate so that the adjacent filter module 311 can switch to the position connected to the air outlet pipe 16.

[0020] In the initial operation phase of this device, one filter module 311 on the rotor 3 is connected to the exhaust pipe 16, filtering the waste gas generated in the granulation chamber 1. This effectively intercepts tiny particles and dust carried in the waste gas, ensuring the cleanliness of the gas entering the preheating chamber 15 or subsequent processing stages, which is beneficial for stable system operation. As the operating time progresses, the impurities attached to the surface of the filter module 311 in the working position gradually increase, increasing the flow resistance and causing a pressure difference between its upstream and downstream sides. When this pressure difference reaches the trigger value set by the drive mechanism, the drive mechanism actuates, driving the rotor 3 to rotate. This design achieves automatic switching of the filtration working position. Through the rotation of the rotor 3, the clogged filter module 311 is moved out of the main flow channel and "offline," while a spare, clean filter module 311 is switched to the working position to continue the filtration task. This design allows the cleaning or replacement of the clogged filter module 311 to be carried out without affecting the continuous operation of the granulation chamber 1. This granulation device achieves continuous and automated exhaust gas filtration by setting up multiple cyclically switchable filter modules 311 and an automatic switching mechanism driven by differential pressure. It effectively improves the problem of easy clogging of the exhaust pipe 16 during the granulation process of the existing spray granulation device, which affects the continuity of production.

[0021] Specifically, refer to Figures 1 to 3The drive mechanism includes a drive motor 17 fixedly mounted on the granulation chamber 1. The rotating wheel 3 is rotatably connected to the wheel disk 2 via rotating shafts 32 at both ends. The output end of the drive motor 17 is drive-connected to one of the rotating shafts 32. The drive connection method includes, but is not limited to, gear drive, belt drive, or direct connection via coupling. Through the above design, the drive motor 17 can accurately transmit rotational power to the rotating shaft 32, thereby driving the rotating wheel 3 to rotate. The rotating wheel 3 is also equipped with a drive assembly. When the filter module 311 is clogged, the drive assembly can trigger the drive motor 17 to start.

[0022] Furthermore, referring to Figures 1 to 3 The drive assembly includes an elastic element 312 and a tactile switch 313 disposed at the bottom of each mounting cavity 31. The elastic element 312 is a coil spring or other elastic element with good elasticity and restoring ability, which is fixedly mounted at the bottom of the mounting cavity 31. The tactile switch 313 is also disposed at the bottom of the mounting cavity 31, and its position corresponds to that of the elastic element 312. When the pressure difference between the two sides of the filter module 311 increases, it can compress the elastic element 312 and slide towards the tactile switch 313.

[0023] When the filter module 311 is not clogged, exhaust gas can flow smoothly through it, resulting in a small pressure difference across it. At this time, the gas pressure on the filter module 311 is insufficient to compress the elastic element 312, which remains naturally extended. The filter module 311 is in its initial position within the mounting cavity 31, not in contact with the tactile switch 313, which is in the off state, and the drive motor 17 does not start. As operating time increases, more impurities adhere to the surface of the filter module 311, increasing airflow resistance and causing a rise in the pressure difference between its upstream and downstream sides. When the pressure difference reaches a set threshold, the filter module 311, under the action of gas pressure, overcomes the elastic force of the elastic element 312 and slides down the mounting cavity 31, compressing the elastic element 312. When the filter module 311 slides to contact the tactile switch 313 and triggers it, the tactile switch 313 generates an electrical signal, which is transmitted to the control system of the drive motor 17.

[0024] Upon receiving the signal, the drive motor 17 starts immediately, driving the rotating shaft 32 and the rotating wheel 3 to rotate at a certain angle (e.g., the angle between adjacent filter modules 311) via a transmission connection. At this time, the clogged filter module 311 moves out of its working position, and the adjacent clean filter module 311 switches to the position connected to the air outlet pipe 16 to continue filtration. After the clogged filter module 311 leaves its working position, the pressure difference on both sides disappears, the elastic element 312 resumes its extension, pushing the filter module 311 to reset, the tactile switch 313 disconnects, and the drive motor 17 stops running. Through the coordinated design of the elastic element 312 and the tactile switch 313, the entire process of pressure difference sensing, electrical signal triggering, motor driving, and filter switching is fully automated. This enables the spray granulation device to automatically and promptly switch filter modules 311 when they become clogged, ensuring continuous and stable operation of the device without shutdown, and providing a reliable guarantee for the production of PTC thermistor ceramic heating elements.

[0025] Furthermore, referring to Figures 1 to 3 A bearing 21 is provided at the connection between the rotating shaft 32 and the wheel 2. The bearing 21 changes the relative motion between the rotating shaft 32 and the wheel 2 from sliding friction to rolling friction, significantly reducing frictional resistance and thus improving transmission efficiency. In addition, the stable rotational environment provided by the bearing 21 also helps to reduce the impact and vibration experienced by the filter module 311 during switching.

[0026] Furthermore, referring to Figure 4 A maintenance window 22 is provided on the side of the wheel 2 closest to the granulation chamber 1. The maintenance window 22 is a through structure on the wall of the wheel 2, and its shape and size are designed to facilitate observation and operation of the internal components of the wheel 2 by the staff. A slide rail 23 is provided on the wheel 2 at the location of the maintenance window 22. The slide rail 23 is fixedly installed on the outer wall of the wheel 2 on both sides of the maintenance window 22 by fasteners. A sliding door 24 is slidably installed on the slide rail 23, and the sliding door 24 is slidably connected to the slide rail 23 by pulleys or sliders. Limit blocks 231 are provided at both ends of the slide rail 23. The limit blocks 231 are protrusions or baffle structures fixed at both ends of the slide rail 23. The size of the maintenance window 22 is larger than the maximum external size of the filter module 311 to facilitate the removal and insertion of the filter module 311. The slide rail 23 is preferably made of corrosion-resistant metal material and is fixed to the outer wall of the wheel 2 by bolts or welding.

[0027] When maintenance is required, the operator pushes the sliding door 24, causing it to slide to one side along the slide rail 23, thereby opening the maintenance window 22 and creating an operating passage to the interior of the wheel 2. When the sliding door 24 slides to one end of the slide rail 23, it contacts the limiting block 231 at that end, preventing the sliding door 24 from sliding further and thus preventing it from falling off the slide rail 23. After maintenance is completed, the sliding door 24 is slid back to its original position along the slide rail 23, closing the maintenance window 22. At this time, the sliding door 24 forms a sealed fit with the outer wall of the wheel 2. Through the cooperation of the maintenance window 22 and the sliding door 24, the operator can quickly and conveniently enter the interior of the wheel 2 to clean, replace, or perform other maintenance and repair work on the filter module 311 without disassembling a large number of device parts, significantly shortening maintenance time and improving maintenance efficiency.

[0028] At the same time, refer to Figure 4 A handle 241 is fixedly connected to the sliding door 24, and the handle 241 is fixed to the outer surface of the sliding door 24 by welding, bolting, or integral molding. Damping pads 25 are provided at both ends of the wheel 2 at the maintenance window 22. The damping pads 25 are made of materials with elasticity and cushioning properties, including but not limited to polymer materials such as rubber, silicone, or polyurethane. The damping pads 25 are embedded or bonded to the wheel 2 structure at the edge of the opening of the maintenance window 22, and their position matches the contact surface of the sliding door 24 when it is fully closed or fully open. The thickness of the damping pads 25 is slightly larger than the design gap between the sliding door 24 and the wheel 2 to ensure that an appropriate amount of compression is generated when the sliding door 24 is closed.

[0029] The handle 241 provides an easy-to-grip and force-applying part for the operator. When opening or closing the sliding door 24, the operator can effectively transfer their force to the sliding door 24 by gripping the handle 241. When the sliding door 24 is closed, the damping pad 25 is compressed and deformed, filling the assembly gap between the sliding door 24 and the wheel 2 frame, forming an effective sealing barrier. This sealing structure can prevent external dust, impurities, and fine dust generated during the granulation process from entering the interior of the wheel 2, maintaining a clean working environment for key components such as the rotor 3 and the filter module 311. Furthermore, the friction between the damping pad 25 and the sliding door 24 provides appropriate resistance, which can effectively overcome external forces caused by equipment vibration or minor collisions, preventing the sliding door 24 from accidentally opening when not in operation, thus enhancing the safety of equipment operation.

[0030] Additionally, refer to Figure 4The sliding door 24 is made of a transparent material. This transparent material can be tempered glass or plexiglass, or other transparent polymer or composite materials with high light transmittance, high mechanical strength, and good chemical corrosion resistance. This allows staff to directly observe the internal working status of the wheel 2 through the transparent sliding door 24 without opening it, such as the rotation of the wheel 3, the position of the filter module 311, and the degree of buildup of deposits on its surface. This non-invasive real-time monitoring helps to promptly detect abnormalities such as clogging of the filter module 311 and whether the wheel 3 is stuck, providing a clear basis for preventative maintenance.

[0031] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A spray granulation device for producing PTC thermistor ceramic heating elements, comprising a granulation chamber (1), wherein the top of the granulation chamber (1) is provided with a feed pipe (11) and an air inlet pipe (12), and the bottom is provided with a discharge pipe (13), wherein the air inlet pipe (12) is connected to a preheating chamber (15) via a first blower (14), and the top of the granulation chamber (1) is also provided with an air outlet pipe (16) communicating with the preheating chamber (15), characterized in that, The air outlet pipe (16) is connected to a wheel (2) at one end near the granulation chamber (1). The inner cavity of the wheel (2) is connected to the air outlet pipe (16), and the connection position is offset from the central axis of the wheel (2). A rotating wheel (3) is rotatably arranged in the inner cavity of the wheel (2). Multiple mounting cavities (31) are evenly opened on the rotating wheel (3) along its circumference. A filter module (311) is slidably arranged in each mounting cavity (31) along its depth direction. The granulation chamber (1) is also equipped with a drive mechanism. When the filter module (311) connected to the air outlet pipe (16) is blocked, causing the pressure difference on both sides to increase, the drive mechanism can drive the rotating wheel (3) to rotate so that the adjacent filter module (311) can switch to the position connected to the air outlet pipe (16).

2. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 1, characterized in that, The driving mechanism includes a drive motor (17) fixedly mounted on the granulation bin (1), the wheel (3) is rotatably connected to the wheel disk (2) through the rotating shafts (32) at both ends, and the output end of the drive motor (17) is connected to one of the rotating shafts (32) in a transmission connection. The rotating wheel (3) is also equipped with a drive component. When the filter module (311) is blocked, the drive component can trigger the drive motor (17) to start.

3. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 2, characterized in that, The drive assembly includes an elastic element (312) and a tactile switch (313) disposed at the bottom of each of the mounting cavities (31); the filter module (311) can compress the elastic element (312) and slide towards the tactile switch (313) when the pressure difference between the two sides increases.

4. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 2, characterized in that, A bearing (21) is provided at the connection between the rotating shaft (32) and the wheel (2).

5. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 1, characterized in that, The wheel (2) has a maintenance window (22) on the side near the granulation chamber (1). The wheel (2) has a slide rail (23) at the position of the maintenance window (22). A sliding door (24) is slidably installed on the slide rail (23). Limit blocks (231) are provided at both ends of the slide rail (23).

6. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 5, characterized in that, A handle (241) is fixedly connected to the sliding door (24), and damping pads (25) are provided at both ends of the wheel (2) and the maintenance window (22).

7. The spray granulation device for producing PTC thermistor ceramic heating elements according to claim 5, characterized in that, The sliding door (24) is made of transparent material.

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