A wet granulation drying system for azithromycin suspensions

Abstract

The application provides an azithromycin suspension wet granulation drying system, and belongs to the technical field of medicine granulation production, which comprises a wet granulator body, the wet granulator body is connected with a discharging pipe, one side of the wet granulator body is provided with a cover plate and a drying cylinder, and the application further comprises: a blowing assembly, which is used for drying free-flowing particles; a primary drying assembly, which is used for completing air drying treatment of granulated particles in cooperation with the blowing assembly; and a secondary drying assembly, which further promotes the drying of particles; the application has the beneficial effects that: the motor makes the fan blade produce airflow and blow towards the bottom of the material receiving plate, and rotates through the spiral bearing piece to increase the contact area of the particles and air, the drying efficiency can be further improved in cooperation with the free falling of the particles, the time of the free falling of the particles is delayed through the partition plate, the caked particles are dispersed, and the uniformity of the drying of the particles can be ensured through the filtering of the drying gas by the absorption plate.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical granulation production technology, and more specifically, to a wet granulation and drying system for azithromycin suspension. Background Technology

[0002] Granules are dry, granular preparations made by mixing active pharmaceutical ingredients (APIs) with suitable excipients to form a specific particle size. Granules are a commonly used oral solid dosage form for medicines, especially traditional Chinese medicine. Some antibiotics are unstable in water and can be made into granules, which are dissolved or suspended in water before use. Examples include amoxicillin granules, azithromycin suspension, and cephalexin granules. Azithromycin, a commonly used macrolide antibiotic, plays an important role in clinical applications with its suspension. Wet granulation and drying are key steps in the preparation of azithromycin suspension, directly affecting the product's quality and efficacy.

[0003] Most granules in the current technology are produced using wet granulation machines. After granulation, the granules need to be dried. The existing drying method involves collecting the granules produced by the wet granulation machine and then placing them in a drying chamber for drying. During the drying process, the airflow cannot fully contact the surface of the wet granules. The airflow trajectory is set so that the airflow can only follow a fixed path, resulting in a small area covered by the airflow. As a result, some wet granules cannot be fully dried, causing some granules to clump together. Furthermore, the evaporation of moisture on the surface of the granules increases the attraction between the granules, making them prone to agglomeration. For some granules containing sticky components, such as certain drug granules and food granules, the sticky components are exposed during drying, which exacerbates the agglomeration of the granules. On the other hand, if the drying speed is too fast, the surface moisture of the granules will evaporate rapidly, forming a hard shell. The internal moisture cannot escape in time, which will increase the internal pressure of the granules, causing them to break or agglomerate. How to invent a wet granulation and drying system for azithromycin suspension to solve these problems has become an urgent problem for those skilled in the art. Summary of the Invention

[0004] To overcome the above deficiencies, this invention provides a wet granulation and drying system for azithromycin suspension, which aims to solve the problem that the wind cannot fully contact the surface of the wet particles, causing some particles to stick together and clump together. Furthermore, the evaporation of moisture from the particle surface increases the attraction between particles, making them prone to agglomeration.

[0005] This invention is implemented as follows: This invention provides a wet granulation and drying system for azithromycin suspension, comprising a wet granulator body connected to a feed pipe, a cover plate and a drying cylinder on one side of the wet granulator body, and further comprising: A blowing assembly, which is connected to a drying cylinder, is used to dry free-flowing particles; A primary drying component is located inside the drying cylinder and is used in conjunction with the blowing component to complete the air drying process of the granulated particles. A secondary drying assembly, located inside the drying cylinder, further promotes the drying of the particles.

[0006] Preferably, the cover plate and the drying cylinder are detachably connected, one end of the cover plate is fixedly connected to the feed pipe, and an inner cover is fixedly connected inside the cover plate. Both the cover plate and the inner cover are funnel-shaped, and the side wall of the inner cover has a plurality of circumferentially arrayed guide holes.

[0007] Preferably, the upper end of the drying cylinder is provided with a movable frame, the interior of the movable frame is provided with a detachably connected absorption plate, the movable frame is fixedly connected with an electric heating frame, and a plurality of circumferentially arrayed return springs are fixedly connected to the side wall of the movable frame. One end of the return spring is fixedly connected to the inner wall of the drying cylinder, and a displacement sensor is fixedly connected to the side wall of the movable frame.

[0008] Preferably, a discharge pipe is fixedly connected to the side wall of the drying cylinder, and a plurality of air inlets and exhaust holes are respectively opened at the bottom end of the drying cylinder in a circumferential array. The air inlets are located inside the exhaust holes. A support plate and an air collecting hood are provided inside the drying cylinder. The support plate and the air collecting hood are fixedly connected, and the air collecting hood is rotatably connected to the bottom wall of the drying cylinder.

[0009] Preferably, the primary drying assembly includes a receiving cylinder, one end of which is rotatably connected to the inner wall of the cover plate, and the other end of which is fixedly connected to a plurality of support rods arranged in a circumferential array, with a column fixedly connected to the end of each support rod away from the receiving cylinder.

[0010] Preferably, a fixing rod is fixedly connected to the outer wall of the receiving cylinder, and a spiral bearing plate is fixedly connected to the end of the fixing rod away from the receiving cylinder, and a discharge frame is fixedly connected to the upper end of the spiral bearing plate.

[0011] Preferably, the secondary drying assembly includes a shroud, the inner wall of which is slidably connected to the end of the spiral support plate away from the receiving cylinder, the outer wall of which is fixedly connected to a plurality of circumferentially arrayed partition plates, the partition plates being corrugated, the inner wall of which is fixedly connected to a receiving plate, the side wall of which is rotatably connected to a column, and the lower end of which is rotatably connected to an air collecting shroud.

[0012] Preferably, the secondary drying assembly further includes a separator cylinder, one end of which is fixedly connected to the bottom wall of the drying cylinder. The separator cylinder is located outside the cover cylinder. The inner wall of the separator cylinder is fixedly connected to the end of the separator plate away from the cover cylinder. The side wall of the separator cylinder has through holes arranged in a circumferential array. A baffle is fixedly connected to the side wall of the separator cylinder, and the baffle is located below the separator plate. The separator cylinder is fixedly connected to the discharge pipe, and the baffle is located on one side of the discharge pipe. The inner wall of the separator cylinder is slidably connected to the support plate. The baffle is arranged in a trapezoidal shape, and one end of the baffle is slidably connected to the side wall of the support plate and the air collecting hood, respectively.

[0013] Preferably, the blowing assembly includes a motor and a rotating shaft. The motor is fixedly connected to the lower end of the drying cylinder. One end of the motor passes through the side wall of the drying cylinder and is fixedly connected to the rotating shaft. A drive gear is fixedly connected to the outer wall of the rotating shaft. A fixing plate is fixedly connected to the outer wall of the rotating shaft. The end of the fixing plate away from the rotating shaft is fixedly connected to the inner wall of the air collecting hood. The end of the rotating shaft away from the motor is fixedly connected to the column base.

[0014] Preferably, the blowing assembly further includes a rotating column located inside the air collecting hood. Several rotating columns are arranged in a circumferential array about the central axis of the rotating shaft. One end of the rotating column is rotatably connected to the inner wall of the drying cylinder. A fan blade and a driven gear are fixedly connected to the outer wall of the rotating column. The driven gear is meshed with the driving gear, and the fan blade is located above the driven gear.

[0015] The beneficial effects of this invention are: During the granulation and drying process, the motor can be started to drive the rotating shaft, active gear disc, and driven gear disc to rotate, causing the fan blades to generate a vertically upward airflow. This airflow is then evenly blown towards the bottom of the receiving plate through the air collector. The rotating receiving cylinder, in conjunction with the column and receiving plate structure, allows the granules to freely disperse and flow. Meanwhile, the rotating spiral support plate lifts the granules, increasing the contact area with the air. At the same time, the falling of granules on the spiral support plate and the airflow contact between the receiving cylinder and the spiral support plate further improve drying efficiency. Compared with traditional methods, the drying time is significantly shortened. Furthermore, during the free flow and movement of the granules, the column... The design of the platform and receiving plate avoids central accumulation. The separator plate slows down the falling time of the particles and promotes the dispersion of agglomerated particles. The dry gas filtered by the absorption plate is blown onto the particles through the through holes of the separator cylinder to achieve secondary drying, ensuring drying uniformity, effectively reducing particle agglomeration and breakage, improving particle quality, and increasing the yield. At the same time, the fixed plate drives the air collecting hood synchronously and actively, so that the particles on the surface of the bearing plate are quickly discharged from the discharge pipe under the combined action of centrifugal force and baffles, which greatly improves the working efficiency of the entire drying system and ensures the efficient and stable operation of the granulation and drying process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the drying cylinder of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the drying cylinder of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 4 This invention provides a wet granulation and drying system for azithromycin suspension. Figure 3 Enlarged schematic diagram of the structure at point A in the middle; Figure 5 This is a schematic diagram of the primary drying component and secondary drying component of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the primary drying component structure of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the support plate and blowing assembly structure of an azithromycin suspension wet granulation and drying system provided by an embodiment of the present invention; Figure 8 This is a schematic diagram of the separator cylinder structure of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the absorption plate structure of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the air collection hood structure of an azithromycin suspension wet granulation and drying system provided in an embodiment of the present invention.

[0018] In the diagram: 1. Wet granulation machine body; 2. Feed pipe; 3. Cover plate; 31. Inner cover; 32. Guide hole; 4. Drying cylinder; 41. Air inlet; 42. Air outlet; 43. Movable frame; 44. Displacement sensor; 45. Return spring; 46. Electric heating frame; 47. Absorption plate; 5. Discharge pipe; 6. Blowing assembly; 61. Motor; 62. Rotating shaft; 63. Fan blades; 64. Drive gear plate; 6 5. Fixed plate; 66. Rotating column; 67. Driven gear plate; 7. Primary drying assembly; 71. Receiving cylinder; 72. Spiral bearing plate; 73. Discharge frame; 74. Fixed rod; 75. Support rod; 76. Column base; 8. Secondary drying assembly; 81. Divider plate; 82. Cover cylinder; 821. Receiving plate; 83. Divider cylinder; 831. Through hole; 832. Baffle; 9. Air collecting hood; 91. Bearing plate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0020] Example 1, refer to Figures 1-10 An azithromycin suspension wet granulation and drying system includes a wet granulator body 1, a feed pipe 2 connected to the wet granulator body 1, a cover plate 3 and a drying cylinder 4 on one side of the wet granulator body 1, and further includes: The blowing assembly 6 is connected to the drying cylinder 4 and is used to dry free-flowing particles. Primary drying component 7 is located inside the drying cylinder 4. Primary drying component 7 is used in conjunction with the blowing component 6 to complete the air drying process of the granulated particles. Secondary drying component 8, located inside drying cylinder 4, further promotes the drying of particles.

[0021] Further; the primary drying assembly 7 includes a receiving cylinder 71, one end of which is rotatably connected to the inner wall of the cover plate 3, and the other end of which is fixedly connected to a plurality of circumferentially arrayed support rods 75. A column base 76 is fixedly connected to the end of each support rod 75 away from the receiving cylinder 71; a fixing rod 74 is fixedly connected to the outer wall of the receiving cylinder 71, and a spiral bearing plate 72 is fixedly connected to the end of the fixing rod 74 away from the receiving cylinder 71. A discharge frame 73 is fixedly connected to the upper end of the spiral bearing plate 72; the blowing assembly 6 includes a motor 61 and a rotating shaft 62. The motor 61 is fixedly connected to the lower end of the drying cylinder 4, and one end of the motor 61 penetrates the side wall of the drying cylinder 4 and is fixedly connected to the rotating shaft 62. An active gear disk 64 is fixedly connected to the outer wall, and a fixed plate 65 is fixedly connected to the outer wall of the rotating shaft 62. The end of the fixed plate 65 away from the rotating shaft 62 is fixedly connected to the inner wall of the air collecting hood 9, and the end of the rotating shaft 62 away from the motor 61 is fixedly connected to the column base 76. The blowing assembly 6 also includes a rotating column 66, which is located inside the air collecting hood 9. Several rotating columns 66 are provided, and the several rotating columns 66 are arranged in a circular array about the central axis of the rotating shaft 62. One end of the rotating column 66 is rotatably connected to the inner wall of the drying cylinder 4. A fan blade 63 and a driven gear disk 67 are fixedly connected to the outer wall of the rotating column 66. The driven gear disk 67 is meshed with the active gear disk 64, and the fan blade 63 is located above the driven gear disk 67.

[0022] The drying cylinder 4 performs the initial drying of the granules: After the wet granulator body 1 produces the required granules, the granules are discharged into the drying cylinder 4 through the connection between the feed pipe 2 and the cover plate 3. The cover plate 3 and the feed pipe 2 are fixedly connected by multiple bolts, which can be easily disassembled. During the feeding process of the granules, the motor 61 can be started to drive the rotating shaft 62 and the active gear plate 64 to rotate. In turn, the meshing connection between the active gear plate 64 and the driven gear plate 67 can drive the rotating column 66 to rotate. The transmission ratio of the active gear plate 64 and the driven gear plate 67 is precisely designed to ensure that the rotating shaft 62 and the fan blade 63 achieve stable differential rotation, so that the fan blade 63 generates a vertical upward airflow. The airflow can be evenly blown to the bottom of the receiving plate 821 through the air collecting hood 9 to improve the drying efficiency. The receiving plate 821 is made of breathable material to ensure the flow of air and prevent the granules from falling into the interior of the air collecting hood 9. Meanwhile, the upper end of the receiving cylinder 71 is rotatably connected to the cover plate 3, and the discharged particles fall from the inside of the receiving cylinder 71 into the inside of the cover cylinder 82. During the falling process, the frustum-shaped setting of the column 76 and the protruding setting in the middle of the receiving plate 821 allow the falling particles to diffuse to the outside of the receiving plate 821, avoiding accumulation in the center and facilitating subsequent drying. Therefore, during the rotation of the rotating shaft 62, due to the fixed connection with the column 76, the receiving cylinder 71 can be driven to rotate, which facilitates the rotational discharge of granules and avoids accumulation. Simultaneously, the fixed rod 74 drives the spiral bearing plate 72 to rotate, further... The granulation material around the receiving plate 821 is gradually lifted into the discharge frame 73. The spiral support plate 72 is also made of breathable material, which facilitates airflow. This increases the contact area between the granules and the air, thereby improving drying efficiency. In addition, during the rotation of the spiral support plate 72, excess granules on its surface may fall off one side of the spiral support plate 72 during the lifting process, allowing them to flow freely. These fallen granules can then come into contact with the airflow in the gap between the receiving cylinder 71 and the spiral support plate 72, further increasing the drying area and effect of the granules and improving drying efficiency.

[0023] Reference Figure 2 , Figure 3 , Figure 4 , Figure 7 and Figure 9 Furthermore, the cover plate 3 and the drying cylinder 4 are detachably connected. One end of the cover plate 3 is fixedly connected to the feed pipe 2. An inner cover 31 is fixedly connected inside the cover plate 3. Both the cover plate 3 and the inner cover 31 are funnel-shaped. The side wall of the inner cover 31 has several circumferentially arrayed guide holes 32. The upper end of the drying cylinder 4 is provided with a movable frame 43. The inside of the movable frame 43 is provided with a detachably connected absorption plate 47. The movable frame 43 is fixedly connected with an electric heating frame 46. The side wall of the movable frame 43 is fixedly connected with several circumferentially arrayed guide holes 32. The return spring 45 of the cloth is fixedly connected to the inner wall of the drying cylinder 4 at one end. The displacement sensor 44 is fixedly connected to the side wall of the movable frame 43. The discharge pipe 5 is fixedly connected to the side wall of the drying cylinder 4. Several air inlets 41 and air outlets 42 are respectively opened at the bottom of the drying cylinder 4 in a circular array. The air inlets 41 are located inside the air outlets 42. The interior of the drying cylinder 4 is provided with a support plate 91 and an air collecting hood 9. The support plate 91 and the air collecting hood 9 are fixedly connected. The air collecting hood 9 is rotatably connected to the bottom wall of the drying cylinder 4.

[0024] Absorption plate 47 absorbs moisture from the gas after primary drying: After the airflow passes through the primary drying component 7, most of the gas will be blown towards the inner cover 31 due to the flow, and then flow into the space between the inner cover 31 and the cover plate 3 through the guide hole 32. The funnel-shaped design of the cover plate 3 guides the flow velocity of the airflow. At this time, the airflow will contain moisture after primary drying. Before the secondary drying of the particles, the moisture in the airflow can be absorbed by the absorption plate 47 to ensure the effect of secondary drying. The absorption plate 47 can be made of activated carbon fiber composite material. Activated carbon fiber has a rich microporous structure, which can not only adsorb moisture, but also adsorb odors, organic impurities and small particles in the air, improve the air quality in the drying system, ensure the purity of azithromycin suspension, and the fiber structure provides good air permeability channels, allowing air to flow smoothly, which is conducive to heat exchange during the drying process. In addition, the airflow is insufficient to reset the position. Spring 45 undergoes significant deformation. When the absorption plate 47 absorbs a large amount of moisture, its weight increases. When the weight increases to a certain level, it causes the movable frame 43 to move downwards and compresses the return spring 45, causing it to deform significantly. The displacement sensor 44 is electrically connected to the electric heating frame 46. When the displacement sensor 44 generates a predetermined value, it triggers the electric heating frame 46 to work, drying the absorption plate 47. The absorption plate 47 can be recycled after heating, restoring its adsorption performance, thereby reducing usage costs and ensuring the subsequent drying process. As the weight of the absorption plate 47 decreases, the movable frame 43 gradually returns to its original position through the elastic recovery of the return spring 45. At this time, the displacement sensor 44 can stop the electric heating frame 46 from working, and the electric heating frame 46 can use its own residual heat to dry the absorption plate 47, thereby improving heat utilization.

[0025] Example 2, refer to Figure 3 , Figure 5 and Figure 8Furthermore, the secondary drying assembly 8 includes a shroud 82, the inner wall of which is slidably connected to the end of the spiral support plate 72 away from the receiving cylinder 71. A plurality of circumferentially arrayed partition plates 81 are fixedly connected to the outer wall of the shroud 82, the partition plates 81 being corrugated. A receiving plate 821 is fixedly connected to the inner wall of the shroud 82, the side wall of the receiving plate 821 being rotatably connected to the column base 76. The lower end of the shroud 82 is rotatably connected to the air collecting hood 9. The secondary drying assembly 8 also includes a partition cylinder 83, one end of which is fixedly connected to the bottom wall of the drying cylinder 4. Located outside the cover cylinder 82, the inner wall of the separator cylinder 83 is fixedly connected to the end of the separator plate 81 away from the cover cylinder 82. The side wall of the separator cylinder 83 has through holes 831 distributed in a circumferential array. A baffle 832 is fixedly connected to the side wall of the separator cylinder 83. The baffle 832 is located below the separator plate 81. The separator cylinder 83 is fixedly connected to the discharge pipe 5. The baffle 832 is located on one side of the discharge pipe 5. The inner wall of the separator cylinder 83 is slidably connected to the support plate 91. The baffle 832 is set in a trapezoidal shape. One end of the baffle 832 is slidably connected to the support plate 91 and the side wall of the air collecting cover 9.

[0026] The secondary drying component 8 further dries the particles: As the spiral support plate 72 continues to rotate, the particles entering the discharge frame 73 are gradually discharged between the hood 82 and the separator 83, and fall through the corrugated separator 81. This design makes the trajectory of the particles complex and variable as they fall freely, greatly slowing down the falling time. During the falling process, the particles constantly collide with adjacent separators 81. This moderate impact force can effectively disperse agglomerated particles. In this process, the drying gas filtered by the absorption plate 47 is blown at a stable flow rate between the separator 83 and the hood 82 through the circumferentially distributed through holes 831 on the side wall of the separator 83. The flow rate of the gas can be controlled by setting the size of the through holes 831 to ensure that the drying gas is in full contact with the falling particles, while preventing the particles from being blown away due to excessive flow rate. This achieves a secondary drying process while the particles are falling. Furthermore, it increases the contact area between the particles and the air, ensuring uniform drying. During this process, some gas may rise and circulate through the cover plate 3, but most of the gas enters the space between the air collecting hood 9 and the separator cylinder 83 through the well-permeable support plate 91, and is finally discharged from the exhaust hole 42. The particles after secondary drying will fall to the top of the support plate 91. However, while the rotating shaft 62 rotates, the air collecting hood 9 can be driven synchronously by the fixed plate 65. The advantage of this is that when the air collecting hood 9 rotates, it will drive the support plate 91 to rotate together, so that the particles on the surface of the support plate 91 are quickly discharged from the discharge pipe 5 under the combined action of centrifugal force and baffle 832. The baffle 832 is set in a trapezoidal shape. This design can effectively guide the particles to the discharge pipe 5, avoid the dried particles from accumulating inside the drying cylinder 4, greatly improve the working efficiency of the entire drying system, and ensure the efficient and stable operation of the wet granulation and drying process of azithromycin suspension.

[0027] It should be noted that the specific model and specifications of the motor need to be selected and determined based on the actual specifications of the device. The specific selection and calculation method adopts the existing technology in this field, so it will not be described in detail here.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. An azithromycin suspension wet granulation and drying system, comprising a wet granulator body (1), wherein the wet granulator body (1) is connected to a feed pipe (2), and a cover plate (3) and a drying cylinder (4) are provided on one side of the wet granulator body (1), characterized in that, Also includes: A blowing assembly (6) is connected to a drying cylinder (4) and is used to dry free-flowing particles; Primary drying component (7), which is located inside the drying cylinder (4), is used in conjunction with the blowing component (6) to complete the air drying process of the granulated particles; Secondary drying assembly (8), located inside the drying cylinder (4), further promotes the drying of particles.

2. The wet granulation and drying system for azithromycin suspension according to claim 1, characterized in that, The cover plate (3) and the drying cylinder (4) are detachably connected. One end of the cover plate (3) is fixedly connected to the feed pipe (2). An inner cover (31) is fixedly connected inside the cover plate (3). Both the cover plate (3) and the inner cover (31) are funnel-shaped. The side wall of the inner cover (31) is provided with several circumferentially arrayed guide holes (32).

3. The wet granulation and drying system for azithromycin suspension according to claim 1, characterized in that, The upper end of the drying cylinder (4) is provided with a movable frame (43), and the interior of the movable frame (43) is provided with a detachable absorption plate (47). The movable frame (43) is fixedly connected with an electric heating frame (46). The side wall of the movable frame (43) is fixedly connected with a number of circumferentially arrayed reset springs (45). One end of the reset springs (45) is fixedly connected to the inner wall of the drying cylinder (4). The side wall of the movable frame (43) is fixedly connected with a displacement sensor (44).

4. The azithromycin suspension wet granulation and drying system according to claim 1, characterized in that, The drying cylinder (4) is fixedly connected to the side wall of the discharge pipe (5). The bottom end of the drying cylinder (4) is provided with a number of circumferentially distributed air inlet holes (41) and air outlet holes (42). The air inlet holes (41) are located inside the air outlet holes (42). The drying cylinder (4) is provided with a support plate (91) and an air collecting hood (9). The support plate (91) and the air collecting hood (9) are fixedly connected. The air collecting hood (9) is rotatably connected to the bottom wall of the drying cylinder (4).

5. The wet granulation and drying system for azithromycin suspension according to claim 4, characterized in that, The primary drying assembly (7) includes a receiving cylinder (71), one end of which is rotatably connected to the inner wall of the cover plate (3), and the other end of which is fixedly connected to a plurality of support rods (75) arranged in a circular array. A column base (76) is fixedly connected to the end of the support rod (75) away from the receiving cylinder (71).

6. The wet granulation and drying system for azithromycin suspension according to claim 5, characterized in that, A fixing rod (74) is fixedly connected to the outer wall of the receiving cylinder (71). A spiral bearing plate (72) is fixedly connected to the end of the fixing rod (74) away from the receiving cylinder (71). A discharge frame (73) is fixedly connected to the upper end of the spiral bearing plate (72).

7. The wet granulation and drying system for azithromycin suspension according to claim 6, characterized in that, The secondary drying assembly (8) includes a shroud (82), the inner wall of which is slidably connected to the end of the spiral support plate (72) away from the receiving cylinder (71), the outer wall of which is fixedly connected to a plurality of circumferentially arrayed partition plates (81), the partition plates (81) being corrugated, the inner wall of which is fixedly connected to a receiving plate (821), the side wall of which is rotatably connected to the column (76), and the lower end of which is rotatably connected to the air collecting shroud (9).

8. The wet granulation and drying system for azithromycin suspension according to claim 7, characterized in that, The secondary drying assembly (8) also includes a separator cylinder (83), one end of which is fixedly connected to the bottom wall of the drying cylinder (4). The separator cylinder (83) is located outside the cover cylinder (82). The inner wall of the separator cylinder (83) is fixedly connected to the end of the separator plate (81) away from the cover cylinder (82). The side wall of the separator cylinder (83) is provided with through holes (831) arranged in a circumferential array. The side wall of the separator cylinder (83) is fixedly connected to a baffle plate (832), which is located below the separator plate (81). The separator cylinder (83) is fixedly connected to the discharge pipe (5). The baffle plate (832) is located on one side of the discharge pipe (5). The inner wall of the separator cylinder (83) is slidably connected to the support plate (91). The baffle plate (832) is arranged in a trapezoidal shape. One end of the baffle plate (832) is slidably connected to the side wall of the support plate (91) and the air collecting hood (9).

9. The wet granulation and drying system for azithromycin suspension according to claim 1, characterized in that, The blowing assembly (6) includes a motor (61) and a rotating shaft (62). The motor (61) is fixedly connected to the lower end of the drying cylinder (4). One end of the motor (61) passes through the side wall of the drying cylinder (4) and is fixedly connected to the rotating shaft (62). An active gear disc (64) is fixedly connected to the outer wall of the rotating shaft (62). A fixing plate (65) is fixedly connected to the outer wall of the rotating shaft (62). The end of the fixing plate (65) away from the rotating shaft (62) is fixedly connected to the inner wall of the air collecting hood (9). The end of the rotating shaft (62) away from the motor (61) is fixedly connected to the column base (76).

10. The wet granulation and drying system for azithromycin suspension according to claim 9, characterized in that, The blowing assembly (6) also includes a rotating column (66), which is located inside the air collecting hood (9). There are several rotating columns (66), which are arranged in a circular array about the central axis of the rotating shaft (62). One end of the rotating column (66) is rotatably connected to the inner wall of the drying cylinder (4). The outer wall of the rotating column (66) is fixedly connected to a fan blade (63) and a driven gear disk (67). The driven gear disk (67) is meshed with the driving gear disk (64). The fan blade (63) is located above the driven gear disk (67).

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