Lactose coating and granulating equipment

Abstract

The invention relates to the technical field of lactose production, and particularly discloses lactose coating granulation equipment which comprises a granulation chamber, a coating material liquid spraying channel, a particle spraying channel, a drying conveying air channel, a surrounding air channel and a discharging channel. Lactose particles are sprayed out from the particle spraying channel, coating material liquid is sprayed out from the coating material liquid spraying channel, the particles make contact with the coating material liquid, under the high-temperature effect of dry conveying air, moisture of the coating material liquid is volatilized, tiny lactose crystals are separated out, the sunken defect of the particles is overcome, and spherical lactose coated particles are formed; the lactose coated particles can be rapidly formed at high temperature, the particle size distribution range of the lactose coated particles is narrow, the fluidity of the lactose coated particles is excellent, the lactose coated particles can be directly put into a high-speed tablet press for tabletting, and the weight error of final tablets is small.

Description

Technical Field

[0001] The present invention relates to the technical field of lactose production, and more specifically, to a lactose coating granulation device. Background Art

[0002] Lactose is a natural sugar widely used in the food and medical industries. It is mainly extracted from milk and can be used as a seasoning, nutritional supplement, drug carrier, etc. It can be widely used in the medical field.

[0003] Medicinal lactose generally exists in the form of monohydrate. In conventional technology, lactose monohydrate is usually crystallized in a supersaturated solution, but the lactose crystallization process is uncontrollable, and lactose monohydrate crystals are usually irregular shapes with multiple edges and corners, and their fluidity is poor. Lactose monohydrate crystals are stable in nature and do not react chemically with most drugs. They are tablet fillers with great development potential. The material is directly pressed into tablets by a high-speed tablet press, but due to the poor fluidity of lactose, it cannot be evenly filled into the compression mold. Therefore, how to make lactose particles have better fluidity is a problem that needs to be solved in this field. Summary of the invention

[0004] In order to solve the problem of poor fluidity of lactose crystals, the present application provides a lactose coating granulation equipment, which makes the lactose particles present regular spherical shape and can be directly put into a high-speed tablet press for use. The particle size distribution range of the lactose particles is narrow and the weight deviation of the pressed tablets is low.

[0005] The present application provides a lactose coating granulation device, which adopts the following technical solution: A lactose coating granulation device, comprising: a granulation chamber; A coating liquid spraying channel is installed at the bottom of the granulation chamber; A particle ejection channel is installed on the top of the granulation chamber, the particle ejection channel is arranged opposite to the coating liquid ejection channel, a coating space is formed between the ejection end of the particle ejection channel and the ejection end of the coating liquid ejection channel, and the jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel have the following relationship: V2=(6-8)×D2 / D1×V1, D1 is the diameter of the granulation chamber, and D2 is the diameter of the coating space in the height direction; A drying and conveying air channel is provided at one end of the granulating chamber, the axis of the drying and conveying air channel passes through the covering space, and the air supply temperature of the drying and conveying air channel is 60-85° C.; A surrounding air channel, wherein the surrounding air channel is arranged along the periphery of the particle ejection channel, and the air supply volume of the surrounding air channel is 1 / 8 to 1 / 5 of the air supply volume of the drying and conveying air channel; The material discharging channel is opened at one end of the granulating chamber away from the drying and conveying air channel.

[0006] By adopting the above technical scheme, the coating liquid is sprayed from the coating liquid spray channel, and the lactose monohydrate is sprayed through the particle spray channel. Since the axis of the particle spray channel coincides with the axis of the coating liquid spray channel, the lactose particles and the coating liquid are evenly dispersed in the coating space. The jet velocity of the lactose particles is adjusted with the height of the coating space. The higher the height of the coating space, the faster the jet velocity of the lactose particles, so that the lactose particles can reach the bottom of the coating space. The setting of the surrounding wind can prevent the coating liquid from carrying particles and adhering to the outer peripheral wall of the particle spray channel on the one hand. On the other hand, the surrounding wind forms a vortex airflow in the coating space, and the coating liquid adheres to the surface of the lactose particles in the vortex airflow to fill the depression of the lactose particles. The air supply temperature of the drying conveying air channel is controlled at 60-85°C, so that the moisture can evaporate quickly during the coating process, and the lactose particles form spherical particles. At the same time, the air supply volume of the drying and conveying air channel is controlled, which can, on the one hand, dry the spherical coated lactose particles more fully, and on the other hand, blow the spherical coated lactose particles to the discharge channel.

[0007] By adjusting the jet speed of lactose particles and coating liquid and adjusting the air volume of surround wind and drying conveying wind, the lactose particles and coating liquid are evenly dispersed in the coating space, and the two can come into contact multiple times under the action of vortex airflow, so that lactose coated particles with high sphericity and narrow particle size distribution range can be obtained. The particle size of lactose coated particles is uniform, the friction between particles is smaller, and the fluidity of lactose coated particles is higher, which is beneficial to improve the tableting rate of high-speed tableting in the later stage and reduce the tablet weight difference.

[0008] Furthermore, an arc-shaped blowing air channel is provided at the bottom of one end of the granulation chamber, and the arc-shaped blowing air channel and the discharge channel are located on the same side.

[0009] Furthermore, the blowing airflow of the arc-shaped blowing air channel forms an upward angle θ with the inner wall of the granulating chamber, and the angle θ is 2-5°.

[0010] Furthermore, a plurality of arc-shaped air blowing channels are provided, and each of the arc-shaped air blowing channels forms an angle of 120°.

[0011] Furthermore, the total air supply volume of the arc-shaped blowing air channel is 1 / 15 to 1 / 10 of the air supply volume of the drying and conveying air channel.

[0012] By adopting the above technical scheme, the arc-shaped blowing air channel is close to the bottom of the granulation chamber, and the wind of the arc-shaped blowing air channel covers the bottom of the granulation chamber. On the one hand, the probability of lactose coated particles colliding with the inner wall of the bottom of the granulation chamber can be reduced, and the lactose coated particles remain intact, so that the lactose coated particles maintain a high sphericity in the process of moving to the discharge channel; on the other hand, the size of the angle and the air supply volume are controlled, so that the arc-shaped blowing air and the drying and conveying air form a small convection, which can further dry the lactose coated particles and reduce the moisture in the lactose coated particles without affecting the conveying of the lactose coated particles.

[0013] Furthermore, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 2-1 / 3.

[0014] By adopting the above technical solution, the ratio of the diameter of the coating space to the diameter of the granulation chamber is controlled. The larger the diameter of the coating space, the larger the coating space, the faster the jet speed of the particles. Since the outlet area of ​​the particle injection channel is constant, the particle feed increases, the air flow in the coating space increases, the vortex airflow coverage of the coating space increases, the number of contacts between the particles and the coating liquid increases, and the sphericity of the lactose coated particles is higher. Below this ratio range, the coating space coverage is small, the number of contacts between the particles and the coating liquid decreases, resulting in a decrease in the sphericity of the lactose coated particles. Above this ratio range, the lactose coated particles are prone to swirl upwards, and the lactose coated particles are prone to contact the top of the granulation chamber in the early stage of forming, resulting in irregular shapes of the lactose coated particles after final drying.

[0015] Furthermore, the water content in the coating liquid in the coating liquid spraying channel is 25-45% of the total weight.

[0016] By adopting the above technical solution, the amount of water added to the coating liquid is controlled. When the water content in the coating liquid is too high, the water volatilization rate of the lactose coated particles is slow, the particle size distribution range of the lactose coated particles becomes wider, and the fluidity of the lactose coated particles decreases. When the water content in the coating liquid is too low, the coating liquid evaporates quickly, resulting in a large amount of lactose precipitating before the coating liquid contacts the particles, and there are still a large number of concave defects on the surface of the lactose coated particles.

[0017] Furthermore, the distance between the drying and conveying air channel and the coating space is smaller than the distance between the coating space and the discharge channel.

[0018] Furthermore, the distance between the drying and conveying air channel and the coating space is 1 / 4 to 1 / 3 of the distance between the coating space and the discharge channel.

[0019] By adopting the above technical scheme, the distance between the drying conveying air channel and the coating space is small, which can be beneficial to retaining the high temperature in the front stage, promoting rapid drying of the early lactose coated particles, and narrowing the particle size range of the lactose coated particles. At the same time, it helps to extend the drying time of the later lactose coated particles and reduce the moisture in the lactose coated particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of the cross-sectional structure of a lactose coating granulation device disclosed in the embodiment.

[0021] Figure 2 for Figure 1 Section view along the AA direction.

[0022] Figure 3 for Figure 1 Cross-sectional view along the BB direction.

[0023] Figure 4 The morphology of the lactose-coated particles produced according to the relevant parameters of Example 1.

[0024] Markings in the accompanying drawings: 1. Granulation chamber; 2. Fixed seat; 3. Coating liquid spraying channel; 4. Particle spraying channel; 5. Coating space; 6. Surrounding air channel; 7. Drying and conveying air channel; 8. Discharging channel; 9. Main channel; 10. Auxiliary channel; 11. Arc blowing air channel. DETAILED DESCRIPTION

[0025] Example Figure 1 The cross-sectional structure diagram of a lactose coating granulation device disclosed in the embodiment. Figure 1A lactose coating granulation device comprises a granulation chamber 1, a fixing seat 2 is installed at the bottom of the granulation chamber 1, a coating liquid spraying channel 3 is penetrated in the fixing seat 2, the coating liquid is sprayed through the coating liquid spraying channel 3, and lactose is used as the solute of the coating liquid. A particle spraying channel 4 is installed at the top of the granulation chamber 1, and the particles are lactose monohydrate crystals, and the lactose monohydrate crystals are sprayed with the airflow. Since the coating liquid spraying channel 3 and the particle spraying channel 4 are arranged opposite to each other, the space between the spraying end of the coating liquid spraying channel 3 and the spraying end of the particle spraying channel 4 becomes a coating space 5, and the coating liquid contacts the particles in the coating space 5 after being sprayed. A surrounding wind channel 6 is arranged on the peripheral wall of the particle spraying channel 4, and the surrounding wind channel 6 sprays airflow toward the coating space 5, and a vortex airflow is generated in the coating space 5, which increases the number of contacts between the coating liquid and the particles and improves the sphericity of the lactose coated particles. A drying and conveying air channel 7 is provided at one end of the granulation chamber 1, and the axis of the drying and conveying air channel 7 passes through the coating space 5. The drying and conveying air can be blown into the coating space 5. The temperature of the drying and conveying air is controlled at 60-85°C. The moisture of the lactose coated particles evaporates quickly, and the particle size distribution range of the lactose coated particles is narrow and the sphericity is high. A discharge channel 8 is provided at the other end of the granulation chamber 1, and the lactose coated particles are blown into the discharge channel 8 by the drying and conveying air and leave. Since the lactose coated particles have high sphericity and narrow particle size distribution range, they can be directly connected to a high-speed tablet press for tableting.

[0026] See also Figure 1 The coating liquid is prepared from lactose and water, and the weight percentage of lactose in the coating liquid is controlled to be 55-75wt%, and the weight percentage of water is 25-45wt%. The coating liquid is a supersaturated solution of lactose. The supersaturated solution state helps the lactose coated particles to form quickly, the lactose crystals in the coating liquid contact with the particles, and the lactose dissolved in the coating liquid precipitates under the high temperature of the drying conveying wind to fill the surface of the lactose particles, as well as the concave defects between the lactose particles, so that the sphericity of the lactose coated particles is improved. In this application, atomization technology is used to make the coating liquid spray evenly upward at 360°, and the coating liquid can fully contact with the particles.

[0027] Figure 2 for Figure 1 Section view in the AA direction. Figure 1 and Figure 2, the particle ejection channel 4 includes a main channel 9 and a plurality of side channels 10, and the plurality of side channels 10 are evenly distributed around the main channel 9. In order to increase the output of lactose coated particles, each side channel 10 is provided with a corresponding coating liquid ejection channel 3. In the present application, the injection flow rate V2 of the particles and the injection flow rate V1 of the coating liquid have the following relationship: V2=(6-8)×D2 / D1×V1, D1 is the diameter of the granulation chamber 1, and D2 is the diameter in the height direction of the coating space 5. When the diameter of the coating space 5 is larger, that is, the larger D2 is, the contact distance between the particles and the coating liquid is larger, and the particle flow rate needs to be increased so that it can reach the bottom of the coating space 5 and contact the coating liquid; after research, it was found that according to this relationship, the contact position between the particles and the coating liquid is close to about 1 / 4 of the bottom of the coating space 5.

[0028] See also Figure 1 , the ratio of the diameter D2 of the coating space 5 to the diameter D1 of the granulation chamber 1 is controlled to be D2 / D1=1 / 2~1 / 3. Within this ratio range, the jet velocity of the particles is moderate. Since the outlet area of ​​the particle ejection channel 4 is constant and the feed amount of the particles is moderate, it can not only increase the output of the lactose coated particles, but also appropriately increase the air flow rate in the coating space 5, thereby increasing the coverage range of the vortex airflow in the coating space 5, increasing the number of contacts between the coating liquid and the particles, and the sphericity of the lactose coated particles is higher.

[0029] See also Figure 1 , there are several surrounding wind channels 6, and the number of surrounding wind channels 6 is consistent with the number of sub-channels 10. The surrounding wind channel 6 can be opened on the outer peripheral wall of the sub-channel 10, and the surrounding wind can prevent the coating liquid from adhering to the outer peripheral wall of the sub-channel 10. The total air supply volume of the surrounding wind channel 6 is 1 / 8 to 1 / 5 of the air supply volume of the drying and conveying air channel 7. The total air supply volume of the surrounding wind channel 6 is controlled within this range. When the surrounding wind supply volume is too high, it is easy to cause insufficient diffusion range of the particles when approaching the coating liquid, and the contact effect between the particles and the coating liquid is not good. When the surrounding wind volume is too small, the particles diffuse prematurely, and the particle diffusion range is large, resulting in a reduction in the number of contacts between some particles and the coating liquid, a decrease in the sphericity of the lactose coated particles, and a widening of the particle size range.

[0030] Figure 3 for Figure 1 Section view in the AA direction. Figure 1 and Figure 3, a plurality of arc-shaped blowing air channels 11 are provided at one end of the granulation chamber 1, each arc-shaped blowing air channel 11 is located on the same side of the discharge channel 8, and each arc-shaped blowing air channel 11 is located at the bottom of the granulation chamber 1, and the axes of the two arc-shaped blowing air channels 11 that are farthest apart form an angle of 120°. The total air supply of the arc-shaped blowing air channel 11 is 1 / 15 to 1 / 10 of the air supply of the drying and conveying air channel 7, and the blowing port of the arc-shaped blowing air channel 11 is inclined upward, and the arc-shaped blowing air channel 11 forms an angle θ with the inner wall of the granulation chamber 1, and the angle θ is 2 to 5°. The arc-shaped blowing air can not only cover the inner wall of the granulation chamber 1, reducing the possibility of lactose coated particles sticking to the wall, but also form a small convection with the drying and conveying air, further drying the lactose coated particles and reducing the moisture in the lactose coated particles. Since the arc-shaped blowing air slightly lifts the lactose-coated particles upward, the lactose-coated particles can still leave from the discharge channel 8 .

[0031] See also Figure 1 The distance between the drying and conveying air channel 7 and the coating space 5 is 1 / 4 to 1 / 3 of the distance between the coating space 5 and the discharge channel 8. The small distance between the drying and conveying air channel 7 and the coating space 5 can help to retain the high temperature in the front stage, promote the rapid drying of the lactose coated particles in the early stage, and narrow the particle size range of the lactose coated particles. At the same time, it helps to extend the drying time of the lactose coated particles in the later stage and reduce the moisture in the lactose coated particles.

[0032] Examples 1-3 and Comparative Examples 1-2 were both produced using the lactose coating granulation equipment described in the above examples, with the only difference being that the parameters in the lactose coating granulation equipment were different, as follows: In Example 1, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 3; The jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel are: V2=8 / 3×V1; the water content in the coating liquid is 30wt%; The air supply temperature of the drying conveying air channel is 75°C; The distance between the drying and conveying air channel and the coating space is 1 / 4 of the distance between the coating space and the discharge channel; The total air supply volume of the surrounding air channel is 1 / 6 of the air supply volume of the drying conveying air channel; There are 4 arc-shaped blowing air channels, and the upward angle θ formed by the blowing airflow of the arc-shaped blowing air channel and the inner wall of the granulation chamber is 3°; the total air supply volume of the arc-shaped blowing air channel is 1 / 10 of the air supply volume of the drying and conveying air channel; Figure 4 The morphology of the lactose coated particles produced by the relevant parameters of Example 1 is shown in Figure 4The sphericity of the lactose-coated particles was as high as 93.1%, the particle size distribution was between 50 and 150 μm, and the angle of repose was 18.5°; using 950 g of lactose-coated particles, 35 g of hydroxypropyl methylcellulose and 15 g of magnesium stearate as raw materials, 5,000 tablets were produced, and the average tablet weight difference was controlled at 3.0%.

[0033] In Example 2, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 2; The jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel are: V2=3×V1; the water content in the coating liquid is 45wt%; The air supply temperature of the drying conveying air channel is 85°C; The distance between the drying and conveying air channel and the coating space is 1 / 3 of the distance between the coating space and the discharge channel; The total air supply volume of the surrounding air channel is 1 / 5 of the air supply volume of the drying conveying air channel; There are 4 arc-shaped blowing air channels, and the upward angle θ formed by the blowing airflow of the arc-shaped blowing air channel and the inner wall of the granulation chamber is 5°; the total air supply volume of the arc-shaped blowing air channel is 1 / 15 of the air supply volume of the drying and conveying air channel; The sphericity of the lactose-coated particles is as high as 82.5%, the particle size distribution is 5-450 μm, and the angle of repose is 22.0°; using 950 g of lactose-coated particles, 35 g of hydroxypropyl methylcellulose and 15 g of magnesium stearate as raw materials, 5,000 tablets are produced, and the average tablet weight difference is controlled at 5.8%.

[0034] In Example 3, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 3; The jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel are: V2=2×V1; the water content in the coating liquid is 25wt%; The air supply temperature of the drying conveying air channel is 60℃; The distance between the drying and conveying air channel and the coating space is 1 / 4 of the distance between the coating space and the discharge channel; The total air supply volume of the surrounding air channel is 1 / 8 of the air supply volume of the drying conveying air channel; There are 4 arc-shaped blowing air channels, and the upward angle θ formed by the blowing airflow of the arc-shaped blowing air channel and the inner wall of the granulation chamber is 2°; the total air supply volume of the arc-shaped blowing air channel is 1 / 10 of the air supply volume of the drying and conveying air channel; The sphericity of the lactose-coated particles is as high as 88.6%, the particle size distribution is between 25 and 400 μm, and the angle of repose is 20.5°; using 950 g of lactose-coated particles, 35 g of hydroxypropyl methylcellulose and 15 g of magnesium stearate as raw materials, 5,000 tablets were produced, and the average tablet weight difference was controlled at 4.6%.

[0035] In Comparative Example 1, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 3; The jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel are: V2=V1; the water content in the coating liquid is 30wt%; The air supply temperature of the drying conveying air channel is 50°C; The distance between the drying and conveying air channel and the coating space is 1 / 4 of the distance between the coating space and the discharge channel; The total air supply volume of the surrounding air channel is 1 / 10 of the air supply volume of the drying conveying air channel; There are 4 arc-shaped blowing air channels, and the upward angle θ formed by the blowing airflow of the arc-shaped blowing air channel and the inner wall of the granulation chamber is 3°; the total air supply volume of the arc-shaped blowing air channel is 1 / 10 of the air supply volume of the drying and conveying air channel; The sphericity of the lactose-coated granules is 47.5%, the particle size distribution is between 1 and 1500 μm, and the angle of repose is 32°; using 950 g of lactose-coated granules, 35 g of hydroxypropyl methylcellulose and 15 g of magnesium stearate as raw materials, 5000 tablets are produced, and the average tablet weight difference is controlled at 9.2%.

[0036] The difference between Comparative Example 1 and Example 1 is that the jet velocity of the particles is relatively small, the air intake of the surrounding wind is low, and the temperature of the drying conveying wind is relatively low, which leads to a significant reduction in the number of contacts between the particles and the coating liquid in the coating space, insufficient coating of the particles, and a significant reduction in the sphericity of the lactose-coated particles, poor fluidity, and a high average tablet weight difference.

[0037] In Comparative Example 2, the ratio of the diameter D2 of the coating space to the diameter D1 of the granulation chamber is D2 / D1=1 / 3; The jet velocity V2 of the particle ejection channel and the jet velocity V1 of the coating liquid ejection channel are: V2=4V1; the water content in the coating liquid is 30wt%; The air supply temperature of the drying conveying air channel is 100°C; The distance between the drying and conveying air channel and the coating space is 1 / 4 of the distance between the coating space and the discharge channel; The total air supply volume of the surrounding air channel is 1 / 2 of the air supply volume of the drying conveying air channel; There are 4 arc-shaped blowing air channels, and the upward angle θ formed by the blowing airflow of the arc-shaped blowing air channel and the inner wall of the granulation chamber is 3°; the total air supply volume of the arc-shaped blowing air channel is 1 / 10 of the air supply volume of the drying and conveying air channel; The sphericity of the lactose-coated granules is 35.8%, the particle size distribution is between 0.1 and 800 μm, and the angle of repose is 42°; using 950 g of lactose-coated granules, 35 g of hydroxypropyl methylcellulose and 15 g of magnesium stearate as raw materials, 5,000 tablets are produced, and the average tablet weight difference is controlled at 13.3%.

[0038] The difference between Comparative Example 2 and Example 1 is that the jet velocity of the particles is relatively large, the air intake of the surrounding wind is high, and the temperature of the drying conveying wind is relatively high, which causes the water in the coating liquid to evaporate too quickly before contacting the particles, causing the coating liquid to lose its coating effect and the particles to be insufficiently coated, resulting in a significant decrease in the sphericity of the lactose-coated particles, poor fluidity, and a high average tablet weight difference.

[0039] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] Moreover, the above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A lactose coating granulation device, comprising: Granulation chamber (1); A coating liquid spraying channel (3) is installed at the bottom of the granulation chamber (1); A particle ejection channel (4) is installed on the top of the granulation chamber (1), the particle ejection channel (4) and the coating liquid ejection channel (3) are arranged opposite to each other, a coating space (5) is formed between the ejection end of the particle ejection channel (4) and the ejection end of the coating liquid ejection channel (3), and the jet velocity V2 of the particle ejection channel (4) and the jet velocity V1 of the coating liquid ejection channel (3) are related as follows: V2=(6-8)×D2 / D1×V1, D1 is the diameter of the granulation chamber (1), and D2 is the diameter of the coating space (5) in the height direction; A drying and conveying air channel (7) is provided at one end of the granulating chamber (1), the axis of the drying and conveying air channel (7) passes through the covering space (5), and the air supply temperature of the drying and conveying air channel (7) is 60-85°C; A surrounding air channel (6), wherein the surrounding air channel (6) is arranged along the periphery of the particle ejection channel (4), and the air supply volume of the surrounding air channel (6) is 1 / 8 to 1 / 5 of the air supply volume of the drying and conveying air channel (7); A discharge channel (8) is provided at one end of the granulation chamber (1) away from the drying and conveying air channel (7).

2. A lactose coating granulation equipment as claimed in claim 1, characterized in that: An arc-shaped blowing air channel (11) is provided at the bottom of one end of the granulation chamber (1), and the arc-shaped blowing air channel (11) and the discharge channel (8) are located on the same side.

3. A lactose coating granulation equipment as claimed in claim 2, characterized in that: The blowing airflow of the arc-shaped blowing air channel (11) forms an upward angle θ with the inner wall of the granulating chamber (1), and the size of the angle θ is 2 to 5°.

4. A lactose coating granulation equipment as claimed in claim 2, characterized in that: A plurality of arc-shaped air blowing channels (11) are provided, and each arc-shaped air blowing channel (11) forms an angle of 120°.

5. A lactose coating granulation equipment as claimed in claim 2, characterized in that: The total air supply volume of the arc-shaped blowing air channel (11) is 1 / 15 to 1 / 10 of the air supply volume of the drying and conveying air channel (7).

6. A lactose coating granulation equipment as claimed in claim 1, characterized in that: The ratio of the diameter D2 of the coating space (5) to the diameter D1 of the granulation chamber (1) is D2 / D1=1 / 2 to 1 / 3.

7. A lactose coating granulation equipment as claimed in claim 1, characterized in that: The water content of the coating liquid in the coating liquid spraying channel (3) is 25-45% of the total weight.

8. A lactose coating granulation equipment as claimed in claim 1, characterized in that: The distance between the drying and conveying air channel (7) and the covering space (5) is smaller than the distance between the covering space (5) and the discharge channel (8).

9. A lactose coating granulation equipment as claimed in claim 8, characterized in that: The distance between the drying and conveying air channel (7) and the coating space (5) is 1 / 4 to 1 / 3 of the distance between the coating space (5) and the discharge channel (8).

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