Drying device and method suitable for medicinal povidone
By using a cylindrical rotating drying device and an annular heating chamber design, the problems of adhesion and degradation of pharmaceutical povidone during the drying process are solved, achieving uniform heating and efficient drying, thus improving drug quality and mixing uniformity.
Patent Information
- Application Number
- CN202511359818.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-23
- Publication Date
- 2025-12-09
AI Technical Summary
Pharmaceutical-grade povidone easily absorbs moisture from the environment during the drying process, causing it to adhere to the inner wall of the equipment, reducing drying efficiency, affecting particle flowability and drug quality, and easily leading to drug degradation.
The device employs a cylinder-turning drying system, which rotates the cylinder between 0 and 180 degrees. Combined with an annular heating chamber and scraper design, it utilizes kinetic potential energy to break down weak bonding forces, increasing the contact area. Temperature control and breathable vent design ensure uniform heating.
It improves the drying quality and efficiency of pharmaceutical povidone, prevents it from adhering to the inner wall of the equipment, ensures uniform heating of the drug, and enhances mixing uniformity and drug stability.
Smart Images
Figure CN121089409A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pharmaceutical raw material drying technology, specifically to a drying apparatus and method suitable for pharmaceutical-grade povidone. Background Technology
[0002] Pharmaceutical-grade povidone (PVP) is a synthetic, water-soluble polymer compound with wide applications in the pharmaceutical field. It is generally a white to off-white, odorless or almost odorless powder with hygroscopic properties; it is readily soluble in water and many organic solvents. As a very important pharmaceutical excipient, povidone can be used as a tablet binder, effectively binding drug powders together to ensure tablet formation and integrity. Drying pharmaceutical-grade povidone (PVP) is a critical step in the preparation process, directly affecting its quality and application performance.
[0003] Povidone is highly hygroscopic, readily absorbing moisture from the environment during the drying process. This increases the water content of pharmaceutical-grade povidone, causing it to adhere to the inner walls of drying equipment, reducing drying efficiency and potentially interrupting the drying process. More importantly, the adhesion between damp pharmaceutical-grade povidone particles leads to decreased flowability, making subsequent formulation processing (such as mixing, filling, and tableting) difficult. This not only prolongs drying time but may also increase production costs and cleaning complexity. Furthermore, the absorption of large amounts of moisture from the air can cause changes in particle size. Moisture is a catalyst for the degradation of many drugs; the absorbed moisture may promote hydrolysis, oxidation, and other degradation reactions in the drug, leading to a decrease in the content of active ingredients and reduced efficacy. Summary of the Invention
[0004] The purpose of this invention is to provide a drying apparatus and method suitable for pharmaceutical-grade povidone, in order to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a drying device suitable for pharmaceutical povidone, comprising a frame, wherein vertically distributed and self-rotating cylindrical bodies are mounted on the frame, and the cylindrical bodies have drying chambers to provide a drying environment for pharmaceutical povidone; The drying chamber has enlarged cavities at both ends and a cylindrical constricted cavity in the middle, with the cylindrical constricted cavity connecting the two enlarged cavities. The cylinder rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. The pharmaceutical povidone falls from one of the expanding cavities through the cylindrical shrinking cavity into another expanding cavity. The kinetic potential energy generated is converted into impact force, which breaks the weak bonding force between the bonded pharmaceutical povidone. At the same time, the impact process scatters the pharmaceutical povidone in all directions, changing the position of pharmaceutical povidone at different heights. The middle section of the cylinder also has an annular heating cavity located outside the cylindrical shrinking cavity. The annular heating cavity is located between the two expanding cavities. The side wall between the annular heating cavity and the drying cavity is a heat transfer medium, providing a heat source for the drying cavity.
[0006] In a further embodiment, an opening communicating with the annular heating cavity is provided on the side wall of the cylindrical shrinking cavity, and a breathable sheet is provided between the upper and lower side walls inside the opening. Hot air from the annular heating chamber enters the cylindrical shrinking chamber through the vent plate, and then enters the two enlarged chambers through the openings at both ends of the cylindrical shrinking chamber, where it comes into thermal contact with the pharmaceutical povidone.
[0007] In a further embodiment, the annular heating cavity is provided with a hollow protruding cover that connects with the opening, and an air inlet is provided on the side wall of the hollow protruding cover away from the opening. The space inside the hollow convex cover serves as a buffer space, which allows for air circulation and, in the event of a ruptured breathable sheet, prevents the path of pharmaceutical povidone from accidentally entering the opening and the annular heating chamber.
[0008] In a further embodiment, a temperature sensor is embedded in the inner wall of one of the hollow protrusions, the temperature sensor being used to monitor the temperature of hot air in real time.
[0009] In a further embodiment, the device also includes multiple scrapers located within the drying chamber. Each scraper has a conical fitting portion that rotates and fits against the radial sidewalls of the cylindrical shrinking chamber, the upper and lower sidewalls of the expanding chamber, and the radial sidewalls, thereby sliding and adhering to the pharmaceutical povidone.
[0010] In a further embodiment, the material hardness of the tapered fitting portion gradually softens near its end position.
[0011] In a further embodiment, a drive shaft is fixed between multiple scrapers. The drive shaft extends into one of the expansion cavities along the axial direction of the cylindrical shrinking cavity. The drive shaft is adjustable in height along the axial direction. The scrapers are adjusted in height synchronously with the drive shaft. The end of the scraper selectively fits against the side wall of one of the expansion cavities away from the cylindrical shrinking cavity.
[0012] In a further embodiment, a material-pushing component is also included at one end of the cylindrical shrinking cavity. One end of the scraper has a slanted rod located in the expanding cavity. The slanted rod is used to agitate the material-pushing component to provide a propelling force for the pharmaceutical povidone located at one end of the cylindrical shrinking cavity.
[0013] In a further embodiment, the feeding component has a spherical block rotatably embedded in the side wall of the end of the transmission shaft, an elastic rod fixedly connected to the outer wall of the spherical block, and a counterweight ball fixed to the other end of the elastic rod. The top wall of the counterweight ball is fixed with an L-shaped stop bar, and the outer wall of the counterweight ball is provided with a plurality of feeding rods extending into the cylindrical shrinking cavity. The height of the end of the inclined rod is lower than the height of the end of the stop rod. The inclined rod follows the scraper in a circular motion within the enlarged cavity. When it passes the horizontal plane where the end of the stop rod is located, it provides a lateral force to push the stop rod.
[0014] Preferably, the drying method for pharmaceutical-grade povidone described above includes the following steps: A1. The cylinder rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. The pharmaceutical povidone is scattered from one of the expanding cavities through the cylindrical shrinking cavity to the other expanding cavity. This process is repeated continuously. The pharmaceutical povidone circulates back and forth between the two expanding cavities, changing the position of the pharmaceutical povidone at different heights, increasing the contact area and reducing the heat transfer resistance. During this process, the high potential energy is converted into kinetic potential energy, and the generated kinetic potential energy is converted into impact force, which destroys the weak bonding force between the bonded pharmaceutical povidone. A2. The scraper is adjusted to move up and down synchronously with the drive shaft. The end of the scraper selectively adheres to the side wall of one of the expanded cavities, away from the cylindrical shrinking cavity. The conical part rotates and slides to stick the pharmaceutical povidone to the inner wall of the drying cavity, thus preventing the pharmaceutical povidone from adhering to the inner wall of the drying cavity for a long time.
[0015] Compared with the prior art, the beneficial effects of the present invention are: The cylindrical body of this invention provides a sealed drying chamber for pharmaceutical povidone. The cylinder is rotated in both directions from 0 to 180 degrees, and paused at 0 and 180 degrees to ensure that the pharmaceutical povidone has sufficient time to disperse from one of the expanding chambers through the cylindrical shrinking chamber into the other expanding chamber. The resulting kinetic energy is converted into impact force, which breaks the weak bonding force between the pharmaceutical povidone particles. At the same time, the impact process disperses the pharmaceutical povidone particles in all directions, changing the position of pharmaceutical povidone particles of different heights, increasing the contact area, reducing heat transfer resistance, ensuring that the pharmaceutical povidone particles are heated evenly throughout the drying process, and improving the drying quality. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a schematic diagram of the cylindrical structure of the present invention; Figure 3 This is a partial cross-sectional view of the cylindrical structure of the present invention; Figure 4This is a cross-sectional view of the internal structure of the cylinder of the present invention; Figure 5 This is a schematic diagram of the scraper structure of the present invention; Figure 6 This is a partial sectional view of the scraper structure from the side of the present invention; Figure 7 A cross-sectional view of the further improved internal structure of the cylinder of the present invention; Figure 8 For the present invention Figure 7 Enlarged view of the structure at point A in the middle; Figure 9 This is an inverted sectional view of the internal structure of the cylinder of the present invention, which is further modified. Figure 10 This is another improved sectional view of the internal structure of the cylinder of the present invention; Figure 11 This is a schematic diagram of the deformation structure of the material feeding component of the present invention.
[0017] In the diagram: 1. Base plate; 11. Support frame; 2. Cylinder; 21. Rotating shaft; 22. Annular heating chamber; 23. Expanding chamber; 24. Cylindrical shrinking chamber; 25. Sealing plug; 26. Hollow protruding cover; 261. Air inlet; 262. Breathable plate; 27. Slanted rod; 3. Scraper; 31. Drive shaft; 32. Rectangular insert; 4. Temperature sensor; 5. Counterweight ball; 51. Stop bar; 52. Material feeding rod; 53. Elastic rod; 54. Spherical block. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] This embodiment provides a drying device suitable for pharmaceutical-grade povidone, such as... Figure 1 As shown, the device includes a frame on which vertically distributed, self-rotating and tumbling cylinders 2 are mounted. The frame has a base plate 1 and support frames 11 symmetrically mounted on both sides of the upper surface of the base plate 1. Rotating shafts 21 are fixed on opposite side walls of the cylinder 2. The opposite side walls of the two support frames 11 are provided with insertion holes for rotatable insertion into the rotating shafts 21. One of the support frames 11 has a motor built in it. The output end of the motor is connected to a flange between it and the corresponding rotating shaft 21 to achieve power connection. The rotating shaft 21 is located in the middle section of the cylinder 2. The motor provides the tumbling power for the rotation of the cylinder 2.
[0020] Cylinder 2 has a drying chamber, providing a drying environment for pharmaceutical-grade povidone. More specifically, such as... Figure 2As shown, the upper end of cylinder 2 is equipped with a feed inlet. Pharmaceutical povidone, having already been wet-granulated, is evenly spread into cylinder 2 through the feed inlet, with the loading not exceeding 60% of the cylinder's volume to allow sufficient space for agitation. The feed inlet is fitted with a cover, and a limiting plate with a notch is provided on the side of the cover. A threaded rod is provided on the side wall of the feed inlet, capable of engaging the notch. A pressure ring is threaded onto the threaded rod and presses down on the limiting plate. Rotating the pressure ring presses it down on the limiting plate, ensuring the cover is installed at the feed inlet. The bottom end of cylinder 2 is equipped with a discharge outlet, threaded with a sealing plug 25 to seal the outlet. Thus, cylinder 2 is in a temporarily enclosed space, ensuring that moisture-containing air is minimized during the drying process, reducing oxygen contact and guaranteeing product quality. The entire cylinder 2 maintains good sealing during the drying process, making it suitable for drying volatile or toxic pharmaceutical povidone.
[0021] like Figure 3 and Figure 4 As shown, the drying chamber has two expanding chambers 23 at both ends and a cylindrical shrinking chamber 24 in the middle, which connects to the two expanding chambers 23. It is important to note that the rotation range of the cylinder 2 is 0 degrees to 180 degrees. When the cylinder 2 is at the 0-degree position, as... Figure 1 and 4 The state shown is as follows. When the motor drives the cylinder 2 to rotate 180 degrees around the rotating shaft 21, the upper and lower ends of the cylinder 2 change positions, as shown in the figure. Figure 9 The state shown is as follows. It should be noted that the motor is a servo motor. When the cylinder 2 is in the 0-degree position and the 180-degree position, the motor will stop and stay for 2-3 minutes, or for another 2 minutes, to ensure that when the cylinder 2 is in the 0-degree position or the 180-degree position, the pharmaceutical povidone to be dried has enough time to fall from one of the expansion chambers 23 through the cylindrical shrinkage chamber 24 into the other expansion chamber 23.
[0022] Meanwhile, the middle section of the cylinder 2 also has an annular heating chamber 22 located outside the cylindrical shrinking cavity 24. The annular heating chamber 22 is located between the two expanding cavities 23. The sidewall between the annular heating chamber 22 and the drying cavity serves as a heat transfer medium, providing a heat source for the heating chamber. Specifically, such as... Figure 4As shown, another rotating shaft 21 has a hollow structure and is connected to the annular heating chamber 22. A hot air blower is built into another support frame 11, and the air outlet of the hot air blower is connected to the hollow rotating shaft 21 via a flange. The hot air blower operates to provide a heat source for the annular heating chamber 22. The sidewall between the annular heating chamber 22 and the drying chamber serves as a heat transfer medium. The sidewall material can be alumina ceramic fiberboard, which has a low thermal conductivity and can effectively slow down heat transfer. After the temperature inside the annular heating chamber 22 rises, heat is transferred through the sidewall to preheat the drying chamber, preventing the temperature from rising rapidly in a short time and causing the pharmaceutical povidone near the inner wall of the drying chamber to become too high, leading to povidone degradation. This is suitable for heat-sensitive pharmaceutical povidone. The above process is the pretreatment stage.
[0023] The cylinder 2 rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. Pharmaceutical povidone flows from one of the expanding cavities 23 through the cylindrical shrinking cavity 24 into the other expanding cavity 23. A key detail here is that the sidewall of the expanding cavity 23 near the cylindrical shrinking cavity 24 is inclined, allowing the pharmaceutical povidone to slide along the inclined sidewall into the cylindrical shrinking cavity 24. This process is repeated continuously, with the pharmaceutical povidone circulating back and forth between the two expanding cavities 23. During this process, high potential energy is converted into kinetic potential energy. The generated kinetic potential energy is converted into impact force, breaking the weak bonding force between the bonded pharmaceutical povidone particles. This weak bonding force refers to the physical cross-linking of the povidone molecular chains during the drying process due to solvent evaporation, where the molecules form physical cross-links through van der Waals forces, hydrogen bonds, etc., causing the particles to clump together. This bonding force is mainly non-covalent and relatively weak, falling into the category of "weak bonding force." At the same time, the impact process disperses the pharmaceutical povidone in all directions, changing the position of pharmaceutical povidone at different heights, increasing the contact area, and reducing heat transfer resistance; it also prevents excessive accumulation of pharmaceutical povidone in some areas, which would lead to excessively high local temperatures in these areas while other areas are not dry enough.
[0024] Impact dispersion of pharmaceutical povidone ensures its uniform distribution within the enlarged cavity 23, preventing localized overheating and guaranteeing even heating throughout the drying process, thus improving drying quality. The impact-dispersed povidone particles are finer and more uniformly distributed, facilitating easier and more thorough contact and mixing with other excipients, improving mixing uniformity and efficiency. For example, in tablet manufacturing, where pharmaceutical povidone serves as a binder or filler, uniform mixing with other raw materials is a key factor in ensuring tablet quality.
[0025] Meanwhile, this embodiment also discloses multiple scrapers 3 located within the drying chamber, used to rotate and slide scrapers to remove pharmaceutical-grade povidone adhering to the inner wall of the drying chamber. Specifically, as... Figure 4 and Figure 5 As shown, the scraper 3 has a conical fitting part, which rotates and fits against the radial sidewall of the cylindrical shrinking cavity 24, the upper and lower sidewalls of the expanding cavity 23, and the radial sidewall, and slides to adhere the pharmaceutical povidone. A drive shaft 31 is fixed between multiple scrapers 3. The drive shaft 31 extends along the axial direction of the cylindrical shrinking cavity 24 and enters one of the expanding cavities 23. The drive shaft 31 is adjustable in height along the axial direction, and the scrapers 3 move up and down synchronously with the drive shaft 31. The end of the scraper 3 selectively fits against the sidewall of one of the expanding cavities 23 away from the cylindrical shrinking cavity 24. A motor is also installed on the bottom wall of the sealing plug 25. The output end of the motor rotates through the sealing plug 25 and is connected to a rectangular insert 32. The bottom wall of the drive shaft 31 has a rectangular groove for slidingly inserting into the rectangular insert 32. During installation, first align the rectangular insert 32 with the rectangular slot and insert it. Then push the sealing plug 25 upward and rotate the sealing plug 25 to connect it to the discharge port threadedly. The motor provides power, and the rectangular insert 32 and the drive shaft 31 serve as the transmission medium to provide power for the rotation of multiple scrapers 3.
[0026] like Figure 4 As shown, there are two scrapers 3, symmetrically distributed in the drying chamber with the drive shaft 31 as the center. The structure of the scraper 3 is as follows: Figure 5 As shown, the conical fitting part rotates and fits into the radial sidewall of the cylindrical shrinking cavity 24, the upper and lower sidewalls of the expanding cavity 23, and the radial sidewall. In this way, the scraper 3 makes a circular motion trajectory in the drying cavity, and uses the rotating sliding spatula of the conical fitting part to stick the pharmaceutical povidone to the inner wall of the drying cavity, so as to avoid the pharmaceutical povidone adhering to the inner wall of the drying cavity for a long time during the drying process, which would cause over-drying due to the high temperature of the inner wall of the drying cavity.
[0027] Scraper 3 rotates one revolution, allowing it to slide along the inner wall of the drying chamber. For example... Figure 4 As shown, at this time, the feed inlet of the cylinder 2 is located on the upper side and the discharge outlet is located on the lower side. The pharmaceutical povidone in the upper expansion cavity 23 falls into the lower expansion cavity 23, while the pharmaceutical povidone in the upper expansion cavity 23 will accumulate near the cylindrical shrinking cavity 24. The pharmaceutical povidone will not contact the side wall of the expansion cavity 23 near the feed inlet. As the scraper 3 rotates continuously at the end near the feed inlet, there will be no more pharmaceutical povidone adhering to the side wall of the expansion cavity 23 near the feed inlet, resulting in continuous empty scraping and unnecessary power loss.
[0028] Therefore, the length of the part of the scraper 3 located in the cylindrical shrinking cavity 24 is set to be longer than the axial length of the cylindrical shrinking cavity 24 by L. At the same time, the longitudinal height of the side wall of the end of the rectangular insert 32 from the top wall of the rectangular slot is greater than L. So when the scraper 3 is in a vertical state, it will fall due to its own weight, and the difference in falling height is L. The rectangular insert 32 will not affect the free fall adjustment height of the scraper 3. In this way, the upper end of the scraper 3 will not contact the side wall of the expansion cavity 23 near the feed inlet. At the same time, the end of the scraper 3 located on the bottom wall of the upper expansion cavity 23 is in contact with the bottom wall of the upper expansion cavity 23. On the one hand, this avoids the side wall near the feed inlet from being empty for a long time. On the other hand, the other side walls in the drying cavity are still within the scraping range and are not affected.
[0029] Conversely, when the feed inlet of cylinder 2 is located on the upper side and the discharge outlet is located on the lower side, such as Figure 9 As shown, when the scraper 3 is in a vertical position, it will fall due to its own weight, and the difference in falling height is L. In this way, the upper end of the scraper 3 will not contact the side wall of the expansion cavity 23 near the discharge port, thus avoiding long-term empty scraping.
[0030] The purpose of this design is to reduce the rotational resistance caused by empty scraping, and to avoid prolonged empty scraping, thereby reducing unnecessary wear on the scraper 3 against the side wall of the feed inlet or discharge outlet.
[0031] At the same time, here is like Figure 6 As shown, the material hardness of the conical fitting part gradually softens towards its end. This design allows for better adhesion to the inner wall of the drying chamber, ensuring that the adhering pharmaceutical povidone is completely lifted when the sliding spatula is rotated.
[0032] In this embodiment, in order to further improve drying efficiency, such as Figure 7 and Figure 8 As shown, the cylindrical shrinking cavity 24 has an opening on its side wall that communicates with the annular heating cavity 22. A permeable sheet 262 is provided between the upper and lower side walls of the opening; the permeable sheet 262 can be made of canvas with mesh. Hot air from the annular heating cavity 22 enters the cylindrical shrinking cavity 24 through the permeable sheet 262, and then enters the two enlarged cavities 23 through the openings at both ends of the cylindrical shrinking cavity 24, coming into thermal contact with the pharmaceutical povidone. The permeable sheet 262 does not impede the flow of hot air, while simultaneously preventing pharmaceutical povidone from accidentally entering the annular heating cavity 22 during the drying process.
[0033] It should be noted that while the hot air blows hot air through the vent 262 into the cylindrical shrinking cavity 24, a high-pressure air pump is connected externally inside the annular heating cavity 22 to increase the blowing force of the hot air. This helps to blow away the pharmaceutical povidone adhering to the surface of the vent 262. At the same time, the surface of the vent 262 is flush with the radial sidewall of the cylindrical shrinking cavity 24. With the help of the rotating scraper 3, a large amount of pharmaceutical povidone is prevented from adhering to the surface of the vent 262, thus avoiding obstruction of hot air flow.
[0034] Meanwhile, a hollow protruding cover 26 that connects to the opening is provided inside the annular heating cavity 22, and an air inlet 261 is provided on the side wall of the hollow protruding cover 26 away from the opening; such as Figure 8 As shown, the space inside the hollow protrusion hood 26 serves as a buffer space for air circulation. At the same time, in the event of accidental damage to the breathable sheet 262 after prolonged use, it blocks the passage for medicinal povidone to accidentally enter the opening and into the annular heating chamber 22.
[0035] In this embodiment, furthermore, povidone is temperature-sensitive and prone to molecular chain breakage or cross-linking reactions under high-temperature drying conditions. Excessively high temperatures may cause povidone to decompose or change color, resulting in a wider molecular weight distribution or decreased viscosity. This not only reduces the purity and consistency of the product but may also affect its function in formulations (such as its performance as an adhesive or film-forming agent).
[0036] Therefore, a temperature sensor 4 is embedded in the inner wall of one of the hollow protruding covers 26, such as... Figure 7 and Figure 8 As shown, temperature sensor 4 is used to monitor the hot air temperature in real time and convert the temperature data into an electrical signal (such as an analog or digital signal) for output. A controller and relay are installed inside the frame, and a desired constant temperature value (such as 60°C, not exceeding 80°C) is preset in the controller. The controller receives the signal from temperature sensor 4 and compares it with the preset constant temperature value. Based on the comparison result, the controller outputs a corresponding control signal. The relay is connected to the hot air blower circuit and receives the signal from the controller to control the power supply to the hot air blower, thereby realizing the start and stop control of the hot air blower. If the real-time temperature is lower than or equal to the constant temperature value, the controller keeps the hot air blower running and continues heating. If the real-time temperature is higher than the constant temperature value, the controller triggers the hot air blower to stop, ensuring that the temperature inside the entire cylinder 2 is maintained at 60°C in real time. This ensures that povidone is dried under constant low-temperature conditions. The low-temperature drying process helps maintain the molecular structure and activity of povidone, ensuring its stable performance as a pharmaceutical excipient.
[0037] Because the channel at the junction of the cylindrical shrinking cavity 24 and the expanding cavity 23 is narrower, if the pharmaceutical-grade povidone has a high humidity, it is prone to agglomerate at the junction, blocking the channel. Figure 10 and Figure 11As shown, it also includes a material-pushing component located at one end of the cylindrical shrinking cavity 24. One end of the scraper 3 has a slanted rod 27 located in the expanding cavity 23 on its side wall. The slanted rod 27 is used to agitate the material-pushing component to provide a pushing force for the pharmaceutical povidone located at one end of the cylindrical shrinking cavity 24. Specifically, the material-pushing component has a spherical block 54 rotatably embedded in the side wall of the end of the drive shaft 31, an elastic rod 53 fixedly connected to the outer wall of the spherical block 54, and a counterweight ball 5 fixed to the other end of the elastic rod 53. The top wall of the counterweight ball 5 is fixed with an L-shaped stop bar 51, and the outer wall of the counterweight ball 5 is provided with multiple material-pushing thin rods 52 extending into the cylindrical shrinking cavity 24.
[0038] like Figure 10 As shown, the height of the end of the inclined rod 27 is lower than the height of the end of the stop rod 51. The inclined rod 27 follows the scraper 3 in a circular motion within the enlarged cavity 23. When it passes the horizontal plane where the end of the stop rod 51 is located, it provides a lateral force to push the stop rod 51. In order to prevent the entire feeding component from rotating synchronously with the scraper 3, the spherical block 54 is rotatably embedded in the side wall of the end of the transmission shaft 31. When the cylinder 2 is in a vertical state, the pharmaceutical povidone will concentrate and fall towards the position near the opening of the end of the cylindrical shrinking cavity 24, pressing on the edge of the elastic rod 53 and providing a lateral stabilizing force to the elastic rod 53. In this way, when the transmission shaft 31 drives the scraper 3 to rotate, it will not drive the spherical block 54 and the elastic rod 53 to rotate synchronously.
[0039] The elastic rod 53 can be a thin stainless steel sheet. When the stop rod 51 receives a lateral force, the elastic rod 53 bends in the same direction as the force, and the stop rod 51 tilts and rises and falls synchronously. At this time, the feeding rod 52 will also deviate from its initial position, expanding the feeding range. When the inclined rod 27 rotates past the stop rod 51, the elastic rod 53 will return to its original position due to its elasticity. The feeding rod 52 will move back to its initial position. As the inclined rod 27 continues to rotate and push the stop rod 51, the elastic rod 53 will also vibrate continuously. The feeding rod 52 will vibrate frequently near the opening of the cylindrical shrinking cavity 24, which helps to accelerate the flow and fall of pharmaceutical povidone.
[0040] This embodiment also discloses a drying method suitable for pharmaceutical-grade povidone, comprising the following steps: A1. The cylinder 2 rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. The pharmaceutical povidone is scattered from one of the expanding cavities 23 through the cylindrical shrinking cavity 24 into the other expanding cavity 23. This process is repeated continuously. The pharmaceutical povidone will circulate back and forth between the two expanding cavities 23, changing the position of the pharmaceutical povidone of different layer heights, increasing the contact area and reducing the heat transfer resistance. In this process, the high potential energy is converted into kinetic potential energy. The generated kinetic potential energy is converted into impact force, which destroys the weak bonding force between the bonded pharmaceutical povidone. A2. The scraper 3 moves up and down synchronously with the drive shaft 31. The end of the scraper 3 selectively adheres to the side wall of one of the enlarged cavities 23, away from the cylindrical shrinking cavity 24. The conical fitting part rotates and slides to stick the pharmaceutical povidone to the inner wall of the drying cavity, thus preventing the pharmaceutical povidone from adhering to the inner wall of the drying cavity for a long time.
[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A drying apparatus suitable for pharmaceutical-grade povidone, characterized in that, include: A frame on which vertically distributed and self-rotating cylinders (2) are mounted, the cylinders (2) having a drying chamber to provide a drying place for pharmaceutical povidone; The drying chamber has two enlarged chambers (23) at both ends and a cylindrical shrinking chamber (24) in the middle, and the cylindrical shrinking chamber (24) connects to the two enlarged chambers (23); The cylinder (2) rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. The pharmaceutical povidone falls from one of the enlarged cavities (23) through the cylindrical shrinking cavity (24) into the other enlarged cavity (23). The generated kinetic potential energy is converted into impact force, which destroys the weak bonding force between the bonded pharmaceutical povidone. At the same time, the impact process scatters the pharmaceutical povidone in all directions, changing the position of pharmaceutical povidone at different heights. The middle section of the cylinder (2) also has an annular heating cavity (22) located outside the cylindrical shrinking cavity (24) to provide a heat source for the drying cavity; It also includes multiple scrapers (3) located in the drying chamber, used to rotate and scrape the pharmaceutical povidone adhering to the inner wall of the drying chamber.
2. The drying apparatus for pharmaceutical-grade povidone according to claim 1, characterized in that, The cylindrical shrinking cavity (24) has an opening on its side wall that communicates with the annular heating cavity (22), and a breathable sheet (262) is provided between the upper and lower side walls inside the opening. Hot air in the annular heating chamber (22) enters the cylindrical shrinking chamber (24) through the vent plate (262), and then enters the two enlarged chambers (23) through the openings at both ends of the cylindrical shrinking chamber (24), and comes into thermal contact with the pharmaceutical povidone.
3. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 2, characterized in that, The annular heating cavity (22) is provided with a hollow protruding cover (26) that is connected to the opening. An air inlet (261) is provided on the side wall of the hollow protruding cover (26) away from the opening. The space inside the hollow bulge cover (26) is a buffer space. The buffer space is used for air circulation and, when the breathable sheet (262) is damaged, it blocks the passage of pharmaceutical povidone that accidentally enters the opening and enters the annular heating chamber (22).
4. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 3, characterized in that, One of the hollow protruding covers (26) has a temperature sensor (4) embedded in its inner wall, which is used to monitor the temperature of hot air in real time.
5. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 1, characterized in that, The scraper (3) has a conical fitting part, which rotates and fits with the radial sidewall inside the cylindrical shrinking cavity (24), the upper and lower sidewalls inside the enlarged cavity (23), and the radial sidewall, and the pharmaceutical povidone is adhered by the scraper.
6. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 5, characterized in that, The material hardness gradually decreases at the end of the tapered fitting portion.
7. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 5, characterized in that, A drive shaft (31) is fixed between multiple scrapers (3). The drive shaft (31) extends into one of the expansion chambers (23) along the axial direction of the cylindrical shrinking cavity (24). The drive shaft (31) can be adjusted up and down along the axial direction. The scrapers (3) are adjusted up and down synchronously with the drive shaft (31). The end of the scraper (3) is selectively attached to the side wall of one of the expansion chambers (23) away from the cylindrical shrinking cavity (24).
8. A drying apparatus suitable for pharmaceutical-grade povidone according to claim 7, characterized in that, It also includes a material-pulling component located at one end of the cylindrical shrinking cavity (24), and a slanted rod (27) located in the enlarged cavity (23) is provided on the side wall of one end of the scraper (3). The slanted rod (27) is used to poke the material-pulling component to vibrate and provide a poke force for the pharmaceutical povidone located at one end of the cylindrical shrinking cavity (24).
9. A drying apparatus for pharmaceutical-grade povidone according to claim 8, characterized in that, The feeding component has a spherical block (54) rotatably embedded in the side wall of the end of the transmission shaft (31), an elastic rod (53) fixedly connected to the outer wall of the spherical block (54), and a counterweight ball (5) fixed to the other end of the elastic rod (53). The top wall of the counterweight ball (5) is fixed with an L-shaped stop bar (51), and the outer wall of the counterweight ball (5) is provided with a plurality of feeding rods (52) extending into the cylindrical shrinking cavity (24). The height of the end of the inclined rod (27) is lower than the height of the end of the stop rod (51). The inclined rod (27) follows the scraper (3) in a circular motion trajectory within the enlarged cavity (23). When it passes the horizontal plane where the end of the stop rod (51) is located, it provides a lateral force to push the stop rod (51).
10. A drying method for pharmaceutical-grade povidone, employing a drying apparatus for pharmaceutical-grade povidone as described in any one of claims 1-9, characterized in that, Includes the following steps: A1. The cylinder (2) rotates from 0 degrees to 180 degrees on the frame and stops, then rotates in the opposite direction from 180 degrees to 0 degrees and stops. The pharmaceutical povidone is scattered from one of the expansion chambers (23) through the cylindrical shrinking chamber (24) into the other expansion chamber (23). The process is repeated continuously. The pharmaceutical povidone will circulate back and forth between the two expansion chambers (23), changing the position of the pharmaceutical povidone of different layer heights, increasing the contact area and reducing the heat transfer resistance. In this process, the high potential energy will be converted into kinetic potential energy. The generated kinetic potential energy is converted into impact force, which destroys the weak bonding force between the bonded pharmaceutical povidone. A2. The scraper (3) moves up and down synchronously with the drive shaft (31). The end of the scraper (3) selectively fits against the side wall of one of the enlarged cavities (23) away from the cylindrical shrinking cavity (24). The conical fitting part rotates and slides to stick the pharmaceutical povidone to the inner wall of the drying cavity, thus avoiding the pharmaceutical povidone from adhering to the inner wall of the drying cavity for a long time.