Pneumatic conveying device for improving tobacco material conveying efficiency

Abstract

The utility model relates to the technical field of tobacco processing, in particular to a pneumatic conveying device capable of improving tobacco material conveying efficiency, which comprises a feeding pipe, a material conveying pipe and an adjustable air pipe which are arranged in a T shape and communicated with one another, and the feeding pipe is perpendicular to the material conveying pipe and the adjustable air pipe. An air volume adjusting plate assembly and a constant-speed spiral air hole plate are sequentially arranged at an inlet of the adjustable air pipe from outside to inside. The air volume adjusting plate assembly is used for controlling the air volume entering the adjustable air pipe. The constant-speed spiral air hole plate is a circular plate, the outer diameter of the constant-speed spiral air hole plate is matched with the inner diameter of the adjustable air pipe, a plurality of through holes are formed in the circular plate and distributed according to a constant-speed spiral, and the consistent inclination angle is formed between the axis of each through hole and the tangent line of the circle center of the circular plate. According to the utility model, the conveying fluency of tobacco materials can be obviously improved, and meanwhile, the breakage rate of fragile materials such as tobacco flakes can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of tobacco processing technology, specifically to a pneumatic conveying device for improving the efficiency of tobacco material conveying. Background Technology

[0002] In the tobacco industry, the use of adjustable ducts for pneumatic conveying of tobacco sheets, tobacco leaves, and tobacco stems is common. The principle of pneumatic conveying is to use the pressure difference between the adjustable duct and the external atmospheric pressure to propel the material flow. Pneumatic conveying offers advantages such as compact duct layout, high conveying efficiency, and labor savings, thus it is widely used in tobacco production. However, existing pneumatic conveying technology still has many problems in practical applications. For example, in tobacco material conveying, especially at bends or right-angle turns in the pipes (currently, bends or right-angle turns are generally "L" shaped), material accumulation or impaired flow can easily occur, leading to pipe blockage. This is particularly true when conveying heavy materials like tobacco sheets that contain tobacco stems and have a complex structure; blockages often occur at the beginning of the conveying process because the material has low kinetic energy upon entry and easily accumulates at the pipe's starting point, causing blockages. Furthermore, during pneumatic conveying, the material is frequently subjected to direct impact from high-speed airflow, which can easily cause damage and breakage of the tobacco leaves. After prolonged conveying, the integrity of the material will significantly decrease, affecting product quality and subsequent processing.

[0003] To address these issues and improve material conveying smoothness, existing technologies often employ adjusting differential pressure and / or adjustable duct diameter to regulate material flow. Generally, differential pressure is directly proportional to air velocity; a higher differential pressure results in higher air velocity and faster, smoother material flow within the duct. A larger adjustable duct diameter also improves flow. However, while these methods are effective in the short term, they incur high production costs and have limited effectiveness when handling complex materials, particularly for materials with complex physical structures like sheet metal, where these methods fail to effectively solve clogging problems. Furthermore, excessively increasing differential pressure can increase the breakage rate of sheet metal.

[0004] Existing technologies have been studied to improve the smoothness of material transportation or reduce the breakage rate of tobacco flakes, but no technical solutions have been reported to simultaneously improve the smoothness of material transportation and reduce the breakage rate of tobacco flakes.

[0005] To address the aforementioned problems, this utility model is proposed. Utility Model Content

[0006] To address the problems of material accumulation and poor flow at pipe bends or right-angle turns in existing technologies, especially the tendency for heavy, hard materials like tobacco stems of varying lengths to clog at the beginning of the conveying process, and the issue of fragile materials (such as tobacco sheets) being easily broken by the impact of high-speed airflow during pneumatic conveying, this invention proposes a pneumatic conveying device and method to improve the efficiency of tobacco material conveying. The aim is to significantly improve the smoothness of tobacco material conveying and reduce the breakage rate of fragile materials such as tobacco sheets.

[0007] The technical solution adopted in this utility model is:

[0008] The first aspect of this utility model provides a pneumatic conveying device for improving the conveying efficiency of tobacco materials. The pneumatic conveying device includes a feed pipe 1, a material transmission pipe 2 and an adjustable air duct 3, which are arranged in a "T" shape and are interconnected. The feed pipe 1 is perpendicular to the material transmission pipe 2 and the adjustable air duct 3.

[0009] The adjustable air duct 3 is provided with an air volume regulating plate assembly 31 and a constant velocity spiral air vent plate 32 arranged sequentially from the outside to the inside at the inlet of the air volume regulating plate assembly 31.

[0010] The air volume regulating plate assembly 31 is used to control the air volume entering the adjustable air duct 3;

[0011] The constant velocity spiral vent plate 32 is a circular plate with an outer diameter that matches the inner diameter of the adjustable air duct 3. The circular plate has several through holes 321 arranged in a constant velocity spiral pattern, and the axis of each through hole 321 has a consistent inclination angle with the tangent of the center of the constant velocity spiral vent plate.

[0012] The ventilation area of ​​the feed pipe 1 is S2, and the ventilation area of ​​all through holes 321 on the constant velocity spiral vent plate 32 is S1, where S1 > S2 and S1 / S2 > 1.

[0013] Preferably, the pneumatic conveying device further includes a waste discharge pipe 4, which is connected to the feed pipe 1 at a relative position, and the feed pipe 1, the material conveying pipe 2, the adjustable air duct 3 and the waste discharge pipe 4 are arranged in a cross-shaped layout that is interconnected with each other.

[0014] An airlock can be added to the top of the feed pipe 1 to facilitate the adjustment of the air intake and effectively manage the materials.

[0015] Preferably, the plurality of through holes 321 provided on the constant velocity spiral vent plate 32 have their two end faces centered on the constant velocity spiral on the surface of the constant velocity spiral vent plate 32.

[0016] A coordinate system is established with the center of the constant velocity spiral vent plate 32 as the origin of the coordinate system. The parametric equations of the constant velocity spiral are x=c+b·t·cos(2πt) and y=c+b·t·sin(2πt).

[0017] Where: x and y are the coordinates of the center of the through hole;

[0018] c is the radius offset value of the starting point, which ranges from [0, R / 2], where R is the radius of the circular plate;

[0019] b is the pitch parameter, with a value range of 10-50mm;

[0020] t is a parameter that determines the distribution density of through holes. It takes discrete values ​​within a positive range, and the maximum value of t is determined by the radius of the circular plate.

[0021] As a preferred embodiment, the thickness of the constant velocity spiral perforated plate 32 is greater than or equal to the maximum diameter of the cross-section of the through hole 321.

[0022] Preferably, in the parametric equation of the constant velocity spiral, c = 0, b = 30 mm, and the parametric equation of the constant velocity spiral is x = 30·t·cos(2πt) and y = 30·t·sin(2πt).

[0023] Preferably, the angle between the axis of the through hole 321 and the tangent to the center of the constant velocity spiral vent plate 32 is 30°≤β≤50°, and most preferably 45°.

[0024] Preferably, the cross-section of the through hole 321 can be circular.

[0025] Preferably, the arc length distance between any two adjacent through holes 321 is equal to S, where S is the arc length calculated based on the center of the through hole 321 along the spiral direction on the surface of the constant velocity spiral vent plate 32; the maximum diameter of the cross-section of each through hole 321 is D, and S and D satisfy D <S<3D。

[0026] Preferably, the airflow regulating plate assembly 31 includes an airflow regulating plate 311 and a connecting shaft 312. The airflow regulating plate 311 is a circular structure matching the inner diameter of the adjustable duct 3, arranged inside the adjustable duct 3 and coaxially arranged with the central axis of the adjustable duct 3. One end of the connecting shaft 312 is located outside the adjustable duct 3, and the other end passes through the side wall of the adjustable duct 3 and is connected to the airflow regulating plate 311. The connecting shaft 312 is rotatably connected to the adjustable duct 3 through a bearing structure. Rotating the connecting shaft 312 can drive the airflow regulating plate 311 to rotate about the straight line where the connecting shaft 312 is located, so as to adjust the airflow entering the adjustable duct 3. Preferably, the end of the connecting shaft 312 located outside the adjustable duct 3 is also provided with an airflow regulating plate adjusting handle 3121.

[0027] In addition, the air volume regulating plate adjustment handle 3121 can also be designed as an automatic control structure. For example, the adjustment handle 3121 can be connected to the output end of the motor. At the same time, an air volume detection mechanism is added in the adjustable air duct (3), and the motor air volume detection mechanism is connected to the control main board, so as to realize the automatic control of air volume.

[0028] Preferably, the lower end of the waste collection tube 4 is further provided with an "L"-shaped spring plate 41 and a valve 42. The valve 42 is located at the opening at the lower end of the waste collection tube 4. One end of the "L"-shaped spring plate 41 is connected to the lower side wall of the waste collection tube 4, and the other end is connected to the outer surface of the valve 42. When the "L"-shaped spring plate 41 is in a non-deformed state, the valve 42 covers the opening at the lower end of the waste collection tube 4. When the "L"-shaped spring plate 41 is in a deformed state, the valve 42 is at least partially away from the opening at the lower end of the waste collection tube 4. The deformation value of the "L"-shaped spring plate 41 can be determined according to actual production to ensure that a certain amount of long stems are accumulated before opening the valve 42, which facilitates cleaning and overall collection of long stems.

[0029] The second aspect of this utility model provides a method for pneumatic conveying using the pneumatic conveying device described in the first aspect, the method being:

[0030] Adjust the ventilation volume of the adjustable air duct 3 by holding the adjustment handle 3121 and rotating the connecting shaft 312, so that the air volume adjustment plate 311 is rotated to a suitable angle;

[0031] Next, the smoke sheet enters the pneumatic conveying device from the feed pipe 1, and air is simultaneously introduced into the feed pipe 1 and the adjustable air duct 3. The gas introduced into the adjustable air duct 3 forms a vortex airflow under the guidance of the constant velocity spiral air vent plate 32, which guides the smoke sheet or smoke sheet to flow and be conveyed along the material transfer pipe 2 in a spiral conveying trajectory at the junction of the feed pipe 1 and the adjustable air duct 3 until it reaches the destination.

[0032] The third aspect of this utility model provides a method for pneumatic conveying using the pneumatic conveying device described in the first aspect. The method involves adjusting the ventilation volume of the adjustable air duct 3. Specifically, by holding the adjusting handle 3121 and rotating the connecting shaft 312, the air volume adjusting plate 311 is rotated to a suitable angle.

[0033] Next, the tobacco sheet enters the pneumatic conveying device through the feed pipe 1, and air is simultaneously introduced into the feed pipe 1 and the adjustable air duct 3. Impurities such as stones and metals in the tobacco sheet will fall from the waste pipe 4 under the action of gravity and accumulate on the inner surface of the valve 42. When the long stalks on the inner surface of the valve 42 accumulate to the deformation value of the "L"-shaped spring plate 41, the "L"-shaped spring plate 41 deforms, the valve 42 opens, and the impurities will be released from the waste pipe 4. The gas introduced into the adjustable air duct 3 at the same time forms a vortex airflow under the guidance of the constant velocity spiral air vent plate 32, which will guide the tobacco sheet to flow and be conveyed along the material transfer pipe 2 in a spiral conveying trajectory at the junction of the feed pipe 1 and the adjustable air duct 3.

[0034] The beneficial effects of this utility model are:

[0035] 1. In actual production, the tobacco stems to be transported are stems of varying lengths. Due to the large fluctuations in the quantity and size of the stems fed into the feed pipe 1, and the fact that tobacco stems are relatively heavy compared to tobacco sheets, they are prone to clogging. In particular, the blockages are almost always located at the bends of the adjustable air duct or right-angle bends. This utility model innovatively adds an adjustable air duct 3 to the raw material transmission pipe 2 at a relative position, and adds a waste pipe 4 to the original feed pipe 1 at a relative position. The four are arranged in a cross-shaped layout. Furthermore, by controlling the airflow of the feed pipe 1 and the waste pipe 4, the tobacco stems that are relatively heavy, i.e., relatively long, can be first air-separated and allowed to fall into the waste pipe 4.

[0036] 2. As a preferred embodiment, this utility model also provides an air volume regulating plate assembly 31 at the inlet of the adjustable air duct 3 to adjust the air volume in real time according to the conveying of tobacco stems; and innovatively, a constant velocity spiral air hole plate 32 is installed downstream of the air volume regulating plate assembly 31, so that the final action on the tobacco stems is a vortex airflow. This vortex airflow will ultimately make the material be conveyed in the center of the adjustable air duct, reducing material breakage and improving the smoothness of conveying.

[0037] 3. As a preferred embodiment, when the present invention is transporting flake tobacco or other fragile materials, the waste pipe 4 is not provided. Under the guidance of the airflow by the constant velocity spiral vent plate 32, the final airflow acting on the tobacco stem is a vortex-type airflow. This vortex-type airflow will ultimately cause the material to be transported in the center of the adjustable duct. Because of the vortex-type airflow, the direct impact of high-speed airflow on the material is avoided, which will significantly reduce the breakage of the material. Moreover, because the material is concentrated in the center of the adjustable duct, the smoothness of the conveying will be significantly improved.

[0038] 4. This utility model requires that the ventilation area of ​​all through holes 321 on the constant velocity spiral vent plate 32 be greater than the ventilation area S2 of the feed pipe 1 and that S1 / S2 > 1. This is because repeated verification and research have found that when S1 / S2 ≤ 1, the breakage rate of the vortex airflow on the smoke sheet will be significantly greater than when S1 / S2 > 1. At the same time, for materials like smoke sheets with complex structures and large areas, the smoothness can be significantly improved when S1 / S2 > 1 is selected.

[0039] 5. As a preferred solution, although the present invention has designed a constant velocity spiral air plate 32, which enables the material to be transported to advance in a high-speed vortex in the material transmission pipe 2, effectively improving the smoothness of the tobacco material transport in the pipe, the present invention fully considers the problem of large differences in the physical characteristics of tobacco stems, and innovatively designs a cross-shaped layout in which the feed pipe 1, material transmission pipe 2, adjustable air pipe 3 and debris discharge pipe 4 are interconnected, first removing long stems and heavy debris, significantly improving the reliability of the present invention. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 A schematic diagram of the pneumatic conveying device of the first structure in a specific embodiment of this utility model;

[0042] Figure 2 This is a perspective view of the pneumatic conveying device structure of the first type in a specific embodiment of this utility model;

[0043] Figure 3 This is a schematic diagram of the installation of the constant velocity spiral vent plate in the first structure of this utility model in a specific embodiment;

[0044] Figure 4 This is a schematic diagram of the constant velocity spiral perforated plate structure in a specific embodiment of this utility model;

[0045] Figure 5 A schematic diagram of the pneumatic conveying device with the second structure in a specific embodiment of this utility model;

[0046] Figure 6 This is a perspective view of the pneumatic conveying device structure of the second type in a specific embodiment of this utility model;

[0047] Reference numerals: 1. Feed pipe; 2. Material transfer pipe; 3. Adjustable air duct; 31. Air volume regulating plate assembly; 311. Air volume regulating plate; 312. Connecting shaft; 3121. Adjusting handle; 32. Constant velocity spiral vent plate; 321. Through hole; 4. Waste discharge pipe; 41. "L" shaped spring plate; 42. Valve. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to embodiments, but this is not intended to limit the present invention. Any modifications or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the field or in accordance with the product manual.

[0049] Example 1

[0050] like Figure 1-3 As shown, this embodiment provides a pneumatic conveying device for improving the conveying efficiency of tobacco materials. The pneumatic conveying device includes a feed pipe 1, a material transfer pipe 2, an adjustable air duct 3, and a waste discharge pipe 4, which are arranged in a cross-shaped layout. The feed pipe 1 and the waste discharge pipe 4 are arranged opposite each other, and the material transfer pipe 2 and the adjustable air duct 3 are arranged opposite each other. The feed pipe 1 and the waste discharge pipe 4 are perpendicular to the material transfer pipe 2 and the adjustable air duct 3.

[0051] The adjustable air duct 3 is provided with an air volume regulating plate assembly 31 and a constant velocity spiral vent plate 32 arranged sequentially from the outside to the inside at its inlet.

[0052] The air volume regulating plate assembly 31 is used to control the air volume entering the adjustable air duct 3;

[0053] The constant velocity spiral vent plate 32 is a circular plate with an outer diameter equal to the inner diameter of the adjustable air duct 3. The circular plate has a plurality of through holes 321 arranged in a constant velocity spiral pattern, and the axis of each through hole 321 has a consistent tilt angle with the normal of the circular plate.

[0054] like Figure 4 As shown, a plurality of through holes 321 are provided on the constant velocity spiral vent plate 32, the centers of which are located on the constant velocity spiral on the surface of the constant velocity spiral vent plate 32.

[0055] A coordinate system is established with the center of the constant velocity spiral vent plate 32 as the origin. The parametric equations of the constant velocity spiral are x = c + b·t·cos(2πt) and y = c + b·t·sin(2πt). A Cartesian coordinate system is established with c = 0 and b = 30 mm. In this embodiment, the parametric equations of the constant velocity spiral are x = 30·t·cos(2πt) and y = 30·t·sin(2πt).

[0056] The thickness of the constant velocity spiral perforated plate 32 is equal to the maximum diameter of the cross-section of the through hole 321.

[0057] An angle β is formed between the axis of the through hole 321 and the tangent to the center of the constant velocity spiral vent plate 32, and the angle β is selected as 45°.

[0058] The arc length distance between any two adjacent through holes 321 is equal to S. The arc length distance S is calculated based on the center of the through hole 321 along the spiral direction on the surface of the constant velocity spiral vent plate 32. The maximum diameter of the cross-section of each through hole 321 is D. The relationship between S and D is that S and D satisfy D... <S<3D。

[0059] The airflow regulating plate assembly 31 includes an airflow regulating plate 311 and a connecting shaft 312. The airflow regulating plate 311 is a circular structure that matches the inner diameter of the adjustable air duct 3. It is arranged inside the adjustable air duct 3 and is coaxially arranged with the central axis of the adjustable air duct 3. One end of the connecting shaft 312 is located outside the adjustable air duct 3, and the other end passes through the side wall of the adjustable air duct 3 and is connected to the airflow regulating plate 311. The connecting shaft 312 is rotatably connected to the adjustable air duct 3 through a bearing structure. Rotating the connecting shaft 312 can drive the airflow regulating plate 311 to rotate around the straight line where the connecting shaft 312 is located, so as to adjust the airflow entering the adjustable air duct 3.

[0060] The connecting shaft 312 is also provided with an air volume adjustment plate and adjustment handle 3121 at one end located outside the adjustable air duct 3.

[0061] The lower end of the waste collection tube 4 is also equipped with an "L"-shaped spring plate 41 and a valve 42. The valve 42 is located at the opening at the lower end of the waste collection tube 4. One end of the "L"-shaped spring plate 41 is connected to the lower side wall of the waste collection tube 4, and the other end is connected to the outer surface of the valve 42. When the "L"-shaped spring plate 41 is in a non-deformed state, the valve 42 covers the opening at the lower end of the waste collection tube 4. When the "L"-shaped spring plate 41 is in a deformed state, the valve 42 is at least partially away from the opening at the lower end of the waste collection tube 4. The deformation value of the "L"-shaped spring plate 41 can be determined according to actual production to ensure that a certain amount of long stems are accumulated before opening the valve 42, which facilitates cleaning and overall collection of long stems.

[0062] The ventilation area of ​​the feed pipe 1 is S2, and the ventilation area of ​​all through holes 321 on the constant velocity spiral vent plate 32 is S1, where S1 > S2 and S1 / S2 > 1.

[0063] The method of using the device of this embodiment for pneumatic conveying is to adjust the ventilation volume of the adjustable air duct 3. Specifically, hold the adjustment handle 3121 and rotate the connecting shaft 312 so that the air volume adjustment plate 311 is rotated to a suitable angle.

[0064] Next, the tobacco sheet enters the pneumatic conveying device through the feed pipe 1, and air is simultaneously introduced into the feed pipe 1 and the adjustable air duct 3. Impurities such as stones and metals in the tobacco sheet will fall from the waste pipe 4 under the action of gravity and accumulate on the inner surface of the valve 42. When the long stalks on the inner surface of the valve 42 accumulate to the deformation value of the "L"-shaped spring plate 41, the "L"-shaped spring plate 41 deforms, the valve 42 opens, and the impurities will be released from the waste pipe 4. The gas introduced into the adjustable air duct 3 at the same time forms a vortex airflow under the guidance of the constant velocity spiral air vent plate 32, which will guide the tobacco sheet to flow and be conveyed along the material transfer pipe 2 in a spiral conveying trajectory at the junction of the feed pipe 1 and the adjustable air duct 3.

[0065] Example 2

[0066] like Figure 5 , 6 As shown, the difference between this embodiment and embodiment 1 is that the structural design of the debris discharge pipe 4, the "L"-shaped spring plate 41 and the valve 42 is omitted in this embodiment.

[0067] The ventilation volume of the adjustable air duct 3 is adjusted by using the pneumatic conveying method of the device in this embodiment. Specifically, the connecting shaft 312 is rotated by holding the adjustment handle 3121, so that the air volume adjustment plate 311 is rotated to a suitable angle.

[0068] Next, the smoke sheet enters the pneumatic conveying device from the feed pipe 1, and air is simultaneously introduced into the feed pipe 1 and the adjustable air duct 3. The gas introduced into the adjustable air duct 3 forms a vortex airflow under the guidance of the constant velocity spiral air vent plate 32, which guides the smoke sheet or smoke sheet to flow and be conveyed along the material transfer pipe 2 in a spiral conveying trajectory at the junction of the feed pipe 1 and the adjustable air duct 3 until it reaches the destination.

[0069] When it is confirmed that the tobacco sheet does not contain impurities such as metal or stones, the structural design of the impurity discharge pipe 4, the "L"-shaped spring plate 41, and the valve 42 can be omitted, and direct pneumatic conveying can be performed. Therefore, in order to enhance the applicability of the pneumatic conveying device of this utility model, the impurity discharge pipe 4 can be designed as a detachable structure with respect to the feed pipe 1, the material transfer pipe 2, and the adjustable air pipe 3. However, when impurity removal is not required, it is only necessary to disassemble the impurity discharge pipe 4 and seal the corresponding openings.

[0070] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this application; the dimensions described in the drawings and embodiments are not related to the specific physical object and are not used to limit the protection scope of this application. The physical dimensions can be selected and changed according to actual needs.

Claims

1. A pneumatic conveying device for improving the efficiency of tobacco material conveying, characterized in that, The pneumatic conveying device includes a feed pipe (1), a material transfer pipe (2) and an adjustable air duct (3), which are arranged in a "T" shape and are interconnected. The feed pipe (1) is perpendicular to the material transfer pipe (2) and the adjustable air duct (3). The adjustable air duct (3) is provided with an air volume regulating plate assembly (31) and a constant velocity spiral air vent plate (32) from the outside to the inside at the inlet. The air volume regulating plate assembly (31) is used to control the air volume entering the adjustable air duct (3); The constant velocity spiral vent plate (32) is a circular plate with an outer diameter that matches the inner diameter of the adjustable air duct (3). The circular plate has several through holes (321) arranged in a constant velocity spiral pattern, and the axis of each through hole (321) has a consistent inclination angle with the tangent of the center of the constant velocity spiral vent plate. The ventilation area of ​​the feed pipe (1) is S2, and the ventilation area of ​​all through holes (321) on the constant velocity spiral vent plate (32) is S1, where S1 > S2 and S1 / S2 > 1.

2. The pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 1, characterized in that, The pneumatic conveying device also includes a waste discharge pipe (4), which is connected to the feed pipe (1) at a relative position. The feed pipe (1), the material conveying pipe (2), the adjustable air duct (3) and the waste discharge pipe (4) are arranged in a cross shape that is interconnected with each other.

3. The pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 1, characterized in that, The constant velocity spiral vent plate (32) is provided with a plurality of through holes (321), the centers of which are located on the constant velocity spiral on the surface of the constant velocity spiral vent plate (32). A coordinate system is established with the center of the constant velocity spiral vent plate (32) as the origin of the coordinate system. The parametric equations of the constant velocity spiral are x=c+b·t·cos(2πt) and y=c+b·t·sin(2πt). Where: x and y are the coordinates of the center of the through hole; c is the radius offset value of the starting point, which ranges from [0, R / 2], where R is the radius of the circular plate; b is the pitch parameter, with a value range of 10-50mm; t is a parameter that determines the distribution density of through holes. It takes discrete values ​​within a positive range, and the maximum value of t is determined by the radius of the circular plate.

4. The pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 3, characterized in that, In the parametric equation of the constant velocity spiral, c = 0 and b = 30 mm.

5. A pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 3, characterized in that, The angle between the axis of the through hole (321) and the tangent to the center of the constant velocity spiral vent plate (32) is 30°-50°.

6. A pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 3, characterized in that, The arc length distance between any two adjacent through holes (321) is equal to S. The arc length distance S is the arc length calculated based on the center of the through hole (321) along the spiral direction on the surface of the constant velocity spiral vent plate (32). The maximum diameter of the cross-section of each through hole (321) is D, and S and D satisfy D. <S<3D。 7. A pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 1, characterized in that, The air volume regulating plate assembly (31) includes an air volume regulating plate (311) and a connecting shaft (312). The air volume regulating plate (311) is a circular structure that matches the inner diameter of the adjustable air duct (3). It is arranged inside the adjustable air duct (3) and is coaxial with the central axis of the adjustable air duct (3). One end of the connecting shaft (312) is located outside the adjustable air duct (3), and the other end passes through the side wall of the adjustable air duct (3) and is connected to the air volume regulating plate (311). The connecting shaft (312) is rotatably connected to the adjustable air duct (3) through a bearing structure. Rotating the connecting shaft (312) can drive the air volume regulating plate (311) to rotate around the straight line where the connecting shaft (312) is located, so as to adjust the air volume entering the adjustable air duct (3). The connecting shaft (312) is also provided with an air volume adjustment plate adjustment handle (3121) at one end located outside the adjustable air duct (3).

8. A pneumatic conveying device for improving the conveying efficiency of tobacco materials according to claim 2, characterized in that, The lower end of the waste collection tube (4) is also provided with an "L"-shaped spring plate (41) and a valve (42). The valve (42) is located at the opening at the lower end of the waste collection tube (4). One end of the "L"-shaped spring plate (41) is connected to the side wall at the lower end of the waste collection tube (4), and the other end is connected to the outer surface of the valve (42). When the "L"-shaped spring plate (41) is in a non-deformed state, the valve (42) covers the opening at the lower end of the waste collection tube (4). When the "L"-shaped spring plate (41) is in a deformed state, the valve (42) is at least partially away from the opening at the lower end of the waste collection tube (4).

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