A multi-stage screening device and method for tobacco material

Abstract

This invention discloses a multi-stage screening device and method for tobacco shreds, comprising a first screening device, a tobacco homogenizer, a second screening device, and a flavoring machine connected in sequence. The first screening device includes a first screening vibrating trough, a material discharge flap, and a first recovery channel. The second screening device includes a second screening vibrating trough, a dual material discharge pipe, a pneumatic conveying pipe, and a second recovery pipe. The second screening vibrating trough is equipped with a perforated mesh plate. The dual material discharge pipe is installed at the bottom of the second screening vibrating trough. The pneumatic conveying pipe and the second recovery pipe are respectively connected to the dual material discharge pipe. A switching flap is movably installed inside the dual material discharge pipe. Through the action of the switching flap, the material enters either the pneumatic conveying pipe or the second recovery pipe. Without affecting the original main structure of the equipment, this invention achieves graded processing of tobacco shreds, increasing the production capacity to produce multiple grades of tobacco shreds, from producing one type of tobacco shred to producing three types.

Description

TECHNICAL FIELD

[0001] The present application relates to a multi-stage screening device and screening method of tobacco material, and belongs to the technical field of tobacco material screening. BACKGROUND

[0002] In order to meet the needs of consumers, the updating speed of tobacco product types is continuously improved, and higher requirements are put forward for the tobacco processing technology. In order to achieve product diversification and improve the quality of tobacco, the tobacco can be classified and screened in the tobacco processing process, so that different grades of tobacco can be obtained, which can provide rich selection materials for the development of new products, and thus meet the updating trend of the consumer market.

[0003] At present, in the blending and flavoring processing section, only one screening treatment is carried out on the blended material at the vibrating trough before the flavoring machine, and the screened material in the tobacco is collected and treated. Therefore, the existing equipment cannot realize multi-stage screening of the material, and cannot screen the material to obtain different grades of tobacco. The equipment in the blending and flavoring section does not have the ability to produce multiple types of tobacco.

[0004] Through the query of the prior art, there is no function of producing multiple types of tobacco in the blending and flavoring section in the process description of the tobacco industry. In order to achieve fine control of tobacco products, increase the diversity of products, and improve the quality of products, a multi-stage screening method of tobacco material is needed. On the basis of not changing the layout of the production line, the related equipment in the blending and flavoring section is upgraded and modified to realize multi-stage screening of the material and obtain different grades of tobacco.

[0005] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general context in which the present application can be practiced. It is not admitted that any of the information provided in this section is prior art. SUMMARY

[0006] The purpose of the present application is to overcome the deficiencies in the prior art, provide a multi-stage screening device and screening method of tobacco material, realize the classification treatment of tobacco material on the basis of not affecting the main structure of the original equipment, increase the function of producing multiple grades of tobacco, and improve the original production of one type of tobacco to three types of tobacco.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0008] On the one hand, the present application discloses a multi-stage screening device of tobacco material, which comprises a first screening device, a uniform tobacco machine, a second screening device and a flavoring machine which are sequentially connected,

[0009] The first screening device comprises a first screening vibration groove, a material falling flap and a first recycling channel, the first screening vibration groove is provided with a fish scale screen plate, the material falling flap is movably installed at the bottom of the first screening vibration groove, and the first recycling channel is installed below the material falling flap.

[0010] The second screening device comprises a second screening vibration groove, a material falling double pipeline, a pneumatic conveying pipeline and a second recycling pipeline, the second screening vibration groove is provided with a round hole screen plate, the material falling double pipeline is installed at the bottom of the second screening vibration groove, the pneumatic conveying pipeline and the second recycling pipeline are connected with the material falling double pipeline respectively, and a conversion flap is movably installed in the material falling double pipeline.

[0011] Further, the fish scale screen plate is uniformly provided with a plurality of fish scale holes, and the thickness of the fish scale screen plate ranges from 0.6 mm to 1 mm.

[0012] The horizontal aperture of the fish scale hole ranges from 1.3 mm to 1.7 mm, and the vertical aperture of the fish scale hole ranges from 2.8 mm to 3.2 mm.

[0013] The distance between the centers of two adjacent horizontal fish scale holes ranges from 7 mm to 9 mm.

[0014] The distance between the centers of two adjacent vertical fish scale holes ranges from 3.5 mm to 4.5 mm.

[0015] Further, the round hole screen plate is uniformly provided with a plurality of round holes, the diameter of the round hole ranges from 0.8 mm to 1.2 mm, and the distance between the centers of two adjacent round holes ranges from 1.8 mm to 2.2 mm.

[0016] Further, the bottom of the first screening vibration groove is provided with a first material falling port, the material falling flap is movably connected with the bottom of the first screening vibration groove through a first air cylinder, and the material falling flap has a screening position away from the first material falling port and a non-screening position for blocking the first material falling port by controlling the operation of the first air cylinder.

[0017] Further, the bottom of the second screening vibration groove is provided with a second material falling port, and the material falling double pipeline is communicated with the second material falling port.

[0018] The conversion flap is movably arranged in the material falling double pipeline through a second air cylinder, and the conversion flap has a first position for conveying material to the pneumatic conveying pipeline and a second position for conveying material to the second recycling pipeline by controlling the operation of the second air cylinder.

[0019] Further, the second screening device further comprises a material recycling dust cover, a cyclone dust collector and a dust removal pipeline.

[0020] The input end of the cyclone dust collector is communicated with the pneumatic conveying pipe, and the output end of the cyclone dust collector is respectively communicated with the back material dustproof cover and the dust removal pipe.

[0021] The back material dustproof cover is installed above the second screening vibration chute and is used for returning the material to the second screening vibration chute.

[0022] Further, the first screening device, the uniformizing machine, the second screening device and the flavoring machine are sequentially communicated through the conveying channels.

[0023] In another aspect, the application discloses a multi-stage screening method of the multi-stage screening device of tobacco material, and the method comprises the following steps:

[0024] When the first grade of tobacco is produced, the original material is screened once when passing through the first screening device, the screened material is recycled through the first recycling channel, the remaining material enters the uniformizing machine to obtain uniformized material, the uniformized material is screened twice when passing through the second screening device, the screened material is recycled through the second recycling channel, and the remaining material enters the flavoring machine for processing.

[0025] When the second grade of tobacco is produced, the original material does not need to be screened when passing through the first screening device, and directly enters the uniformizing machine to obtain uniformized material, the uniformized material is screened twice when passing through the second screening device, the screened material is recycled through the second recycling channel, and the remaining material enters the flavoring machine for processing.

[0026] When the third grade of tobacco is produced, the original material is screened once when passing through the first screening device, the screened material is recycled through the first recycling channel, the remaining material enters the uniformizing machine to obtain uniformized material, and the uniformized material does not need to be screened twice when passing through the second screening device, and directly enters the flavoring machine for processing.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] The multi-stage screening device and the screening method of the tobacco material can realize the grading treatment of the tobacco material without affecting the main structure of the original equipment, increase the function of producing multiple grades of tobacco, and improve the production of three types of tobacco from the original production of one type of tobacco.

[0029] The multi-stage screening device of the tobacco material is simple to reform, the original vibration chute is used for reforming, no additional equipment space is needed, the production rhythm of the original production line is not affected, and the production capacity of the production line is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structural schematic view of a multi-stage screening device of tobacco material.

[0031] Figure 2 is a structural schematic view of the first screening device;

[0032] Figure 3 is a front view of the fish scale screen plate;

[0033] Figure 4 is a top view of the fish scale screen plate;

[0034] Figure 5 is a structural schematic view of the second screening device;

[0035] Figure 6 is a structural schematic view of the blanking double pipeline;

[0036] Figure 7 is a structural schematic view of the round hole screen plate;

[0037] Figure 8 is a structural schematic view of the blending perfuming section device;

[0038] In the figure: 1, first screening device; 2, yarn distributor; 3, second screening device; 4, perfuming machine; 5, box turning machine module; 6, blending module; 7, yarn distributor module; 8, perfuming module; 9, storage cabinet module; 10, boxing module; 11, first screening vibrating trough; 12, blanking turning plate; 13, first recycling channel; 14, fish scale screen plate; 15, first air cylinder; 21, second screening vibrating trough; 22, blanking double pipeline; 221, conversion turning plate; 222, second air cylinder; 223, turning plate rocker arm; 23, pneumatic conveying pipeline; 24, second recycling pipeline; 25, round hole screen plate; 26, dust removal pipe; 27, recycling dustproof cover; 28, cyclone dust collector. DETAILED DESCRIPTION

[0039] The application will be further described below in conjunction with the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application.

[0040] Example 1.

[0041] The example 1 provides a multi-stage screening device for tobacco material, which comprises a first screening device 1, a yarn distributor 2, a second screening device 3 and a perfuming machine 4 connected in sequence,

[0042] The first screening device 1 comprises a first screening vibrating trough 11, a blanking turning plate 12 and a first recycling channel 13, the first screening vibrating trough 11 is provided with a fish scale screen plate 14, the blanking turning plate 12 is movably installed at the bottom of the first screening vibrating trough 11, and the first recycling channel 13 is installed below the blanking turning plate 12;

[0043] The second screening device 3 comprises a second screening vibration chute 21, a blanking double pipeline 22, a pneumatic conveying pipeline 23 and a second recovery pipeline 24, the second screening vibration chute 21 is provided with a round-hole screen plate 25, the blanking double pipeline 22 is installed at the bottom of the second screening vibration chute 21, the pneumatic conveying pipeline 23 and the second recovery pipeline 24 are connected with the blanking double pipeline 22 respectively, and the blanking double pipeline 22 is movably provided with a conversion flap 221, through the action of the conversion flap 221, the material enters the pneumatic conveying pipeline 23 or the second recovery pipeline 24.

[0044] The technical concept of the present application is that, on the basis of not affecting the original equipment main structure, through the first screening device 1 and the second screening device 3, the classification processing of the tobacco material is realized, the function of producing multiple grades of tobacco is increased, and the production of one type of tobacco is improved to three types of tobacco.

[0045] As shown in Figure 8 The blending and flavoring section equipment mainly comprises a box turning machine module 5, a blending module 6, a uniformizing module 7, a flavoring module 8, a storage cabinet module 9 and a boxing module 10.

[0046] The present application is based on the blending and flavoring section equipment, without changing the layout and production rhythm of the section equipment, part of the equipment is reformed and upgraded, two screening devices are arranged after blending and before flavoring, and the screening devices can realize controllable adjustment of material screening and non-screening, different grades of tobacco can be produced on the basis of ensuring the unchanged production process. It is determined that two screening positions are arranged in the blending and flavoring section, the degree of screening material is different, and according to the scheme, four grades of tobacco can be obtained in theory from the same tobacco. According to the existing production process requirements, the tobacco needs to be screened to reduce the amount of tobacco powder, so that the existing equipment can produce three grades of tobacco.

[0047] The key point of the present application is the two screening processes. In order not to affect the production process of the original equipment, and considering the realization of the screening function, the screening task is attached to the vibration chute equipment, the vibration chute before the uniformizing machine 2 and the vibration chute at the inlet of the flavoring machine 4 are reformed, and through the first screening device 1 and the second screening device 3, the screening function of the tobacco is realized. Figure 1 As shown in

[0048] As shown in Figure 2 The bottom of the first screening vibration chute 11 is provided with a first blanking port, a blanking flap 12 is movably connected to the bottom of the first screening vibration chute 11 through a first air cylinder 15, and through the control of the operation of the first air cylinder 15, the blanking flap 12 has a screening position away from the first blanking port and a non-screening position blocking the first blanking port.

[0049] As shown in Figures 3-4 The fish scale screen plate 14 is uniformly distributed with a plurality of fish scale holes, and the thickness of the fish scale screen plate 14 ranges from 0.6 mm to 1 mm; the transverse aperture of the fish scale hole ranges from 1.3 mm to 1.7 mm, and the vertical aperture of the fish scale hole ranges from 2.8 mm to 3.2 mm; the distance between the centers of two adjacent transverse fish scale holes ranges from 7 mm to 9 mm; and the distance between the centers of two adjacent vertical fish scale holes ranges from 3.5 mm to 4.5 mm.

[0050] Preferably, as shown in the following table, the thickness T of the fish scale screen plate 14 ranges from 0.8 mm; the transverse aperture of the fish scale hole is 1.5 mm, and the vertical aperture W of the fish scale hole is 3 mm; the distance A between the centers of two adjacent transverse fish scale holes is 8 mm; and the distance B between the centers of two adjacent vertical fish scale holes is 4 mm.

[0051] Table 1 Fish scale screen plate parameters

[0052]

[0053] The area of the fish scale screen plate 14 is determined according to the actual flow of the production line, and the first screening vibration chute 11 is customized with the original size without affecting the speed of the production line. The controllable ability of the material screening is realized by the material falling flap 12 added below the screen.

[0054] When the material falling flap 12 is in the closed state, i.e. in the non-screening position away from the first material falling port, the material is screened, and the screened material enters the groove below the fish scale screen plate 14 and then enters the uniform yarn vibration chute. When the material falling flap 12 is in the open state, i.e. in the screening position close to the first material falling port, the material is screened once, and then enters the first recycling pipeline for reprocessing and utilization of the once-screened material.

[0055] As shown in Figures 5-6 The bottom of the second screening vibration chute 21 is provided with a second material falling port, and the material falling double pipeline 22 is connected to the second material falling port. The conversion flap 221 is movably arranged in the interior of the material falling double pipeline 22 by the second air cylinder 222. By controlling the operation of the second air cylinder 222, the conversion flap 221 has a first position for conveying the material to the pneumatic conveying pipeline 23 and a second position for conveying the material to the second recycling pipeline 24.

[0056] The second screening device 3 further comprises a material returning dust cover 27, a cyclone dust collector 28 and a dust removal pipeline 26. The input end of the cyclone dust collector 28 is connected to the pneumatic conveying pipeline 23, and the output end of the cyclone dust collector 28 is connected to the material returning dust cover 27 and the dust removal pipeline 26, respectively. The material returning dust cover 27 is installed above the second screening vibration chute 21 and is used to return the material to the second screening vibration chute 21.

[0057] As shown in Figure 7 ​As shown, the round-hole screen plate 25 is uniformly provided with a plurality of round holes, the diameter of the round holes ranges from 0.8mm to 1.2mm, and the distance between the centers of two adjacent round holes ranges from 1.8mm to 2.2mm.

[0058] Preferably, as shown in the following table, the diameter D0 of the round holes is 1mm, and the distance A1, A2, A3 between the centers of two adjacent round holes is 2mm.

[0059] Table 2: Parameters of the round-hole screen plate

[0060]

[0061] The second screening device 3 in this embodiment adopts a blanking double-pipe 22, a second cylinder 222 is connected to a conversion flap 221 through a flap rocker arm 223, and by controlling the operation of the second cylinder 222, the position of the conversion flap 221 is switched to deliver the material to the pneumatic conveying pipe 23 or the second recycling pipe 24. The input end of the blanking double-pipe 22 is connected to the second blanking port, one output end is the second recycling pipe 24 for recycling, and the other output end is connected to the pneumatic conveying pipe 23, which is driven by the air pressure in the pneumatic conveying pipe 23, the cyclone dust collector 28 is a gas-material separation device, and the recycling and processing of the material are realized.

[0062] The air pressure of the pneumatic conveying channel can ensure the lifting and recycling of the screened material; the working capacity of the cyclone dust collector 28 can meet the gas-material separation task of the screened material and the air volume of the pneumatic conveying; the dust removal pipe 26 can absorb the dust and air volume in the cyclone dust collector 28 and keep the air pressure in the cyclone dust collector 28 and the recycling dust cover 27 at a negative pressure state; the recycling dust cover 27 can ensure the smooth falling of the screened material, and the inside of the cover is at a negative pressure state without tobacco dust overflow.

[0063] Embodiment 2.

[0064] This embodiment 2 also provides a multi-stage screening method of the multi-stage screening device of the tobacco material, which includes the following steps:

[0065] When producing the first grade of tobacco, the original material is screened once when passing through the first screening device 1, the screened material is recycled through the first recycling channel 13, and the remaining material is processed in the uniformizing machine 2 to obtain uniformized material; the uniformized material is screened twice when passing through the second screening device 3, the screened material is recycled through the second recycling pipe 24, and the remaining material is processed in the flavoring machine 4;

[0066] When producing the second grade of tobacco, the raw material is directly fed into the uniformity machine 2 after passing through the first screening device 1 without screening, and the screened material is fed into the flavoring machine 4 after passing through the second screening device 3 without secondary screening.

[0067] When producing the third grade of tobacco, the raw material is screened once after passing through the first screening device 1, and the screened material is recycled through the first recycling channel 13, and the remaining material is fed into the uniformity machine 2 to obtain the screened material, which is directly fed into the flavoring machine 4 without secondary screening after passing through the second screening device 3.

[0068] Specifically, taking the production of the first grade of tobacco as an example, the various tobaccos are mixed on a conveying channel by proportional blending, and then enter the first screening point, the first screening device 1 before the uniformity machine 2, which adopts a fish scale screen plate 14 with a horizontal aperture of 1.5 mm as shown in the drawing, and the screened tobacco shreds pass through the lower layer of the screen plate and enter the first recycling channel 13 to complete the first screening of the tobacco. Figures 3-4

[0069] Then, the other unscreened tobaccos normally pass through the uniformity machine 2, the feeder and the electronic belt scale to enter the second screening point, the second screening device 3 before the flavoring machine 4, which adopts a round hole screen plate 25 with a diameter of 1 mm as shown in the drawing, and the screened tobacco shreds pass through the lower layer of the screen plate and enter the dropping double pipeline 22 to be recycled, thereby completing the secondary screening of the tobacco. Figure 7

[0070] It is emphasized that the device of the present application is based on the prior art, and on the one hand, the first screening device 1 is added to realize the screening and recycling functions, and on the other hand, the second screening device 3 is improved based on the existing domestic Zhangjiakou vibrating trough, which is provided with a dropping double pipeline 22 connected with the pneumatic conveying pipeline 23 and the second recycling pipeline 24 to realize the screening and recycling functions. On the other hand, the double screening point improvement is first tried in the industry. According to the actual processing requirements, the appropriate processing route is selected, the appropriate processing method is determined, and the corresponding processing parameters are changed to quickly respond to changes, convert product specifications, organize production scheduling, meet brand development and flexible production and manufacturing.

[0071] ​​In conclusion, the application can improve the processing capacity of tobacco on the basis of the original production capacity, from producing one grade of tobacco to producing three grades of tobacco. From the product point of view, the product reclassification processing is performed on the first class of tobacco, the structure of the tobacco product is improved, the quality of the tobacco is improved, and the product competitiveness is improved. The modification process is simple, the original vibrating trough is used for modification, and no additional equipment space is added. At the same time, the production rhythm of the original production line is not affected, and the production capacity of the production line is ensured.

[0072] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0073] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0074] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A multi-stage screening apparatus for tobacco material, characterised in that, The first screening device (1), the yarn equalizer (2), the second screening device (3) and the perfuming machine (4) are sequentially connected, The first screening device (1) comprises a first screening vibrating trough (11), a material dropping flap (12) and a first recycling channel (13), the first screening vibrating trough (11) is provided with a fish scale screen (14), the material dropping flap (12) is movably installed at the bottom of the first screening vibrating trough (11), and the first recycling channel (13) is installed below the material dropping flap (12). The second screening device (3) comprises a second screening vibrating trough (21), a material dropping double pipeline (22), a pneumatic conveying pipeline (23) and a second recycling pipeline (24), the second screening vibrating trough (21) is provided with a round-hole screen (25), the material dropping double pipeline (22) is installed at the bottom of the second screening vibrating trough (21), the pneumatic conveying pipeline (23) and the second recycling pipeline (24) are connected with the material dropping double pipeline (22) respectively, and the material dropping double pipeline (22) is movably provided with a switching flap (221), through the action of the switching flap (221), the material is allowed to enter the pneumatic conveying pipeline (23) or the second recycling pipeline (24). The fish scale screen (14) is uniformly provided with a plurality of fish scale holes, and the thickness of the fish scale screen (14) ranges from 0.6 mm to 1 mm. The transverse aperture of the fish scale hole ranges from 1.3 mm to 1.7 mm, and the vertical aperture of the fish scale hole ranges from 2.8 mm to 3.2 mm. The distance between the centers of two adjacent transverse fish scale holes ranges from 7 mm to 9 mm. The distance between the centers of two adjacent vertical fish scale holes ranges from 3.5 mm to 4.5 mm. The second screening device (3) further comprises a material returning dust cover (27), a cyclone dust collector (28) and a dust removal pipeline (26), The input end of the cyclone dust collector (28) is communicated with the pneumatic conveying pipeline (23), and the output end of the cyclone dust collector (28) is communicated with the material returning dust cover (27) and the dust removal pipeline (26) respectively. The material returning dust cover (27) is installed above the second screening vibrating trough (21) and is used for returning the material to the second screening vibrating trough (21).

2. A multi-stage tobacco material screening device according to claim 1, characterised in that, The round-hole screen (25) is uniformly provided with a plurality of round holes, the diameter of the round hole ranges from 0.8 mm to 1.2 mm, and the distance between the centers of two adjacent round holes ranges from 1.8 mm to 2.2 mm.

3. A multi-stage tobacco material screening apparatus according to claim 1, characterised in that, The bottom of the first screening vibrating trough (11) is provided with a first material dropping port, the material dropping flap (12) is movably connected to the bottom of the first screening vibrating trough (11) through a first air cylinder (15), and the material dropping flap (12) has a screening position away from the first material dropping port and a non-screening position for blocking the first material dropping port by controlling the operation of the first air cylinder (15).

4. A multi-stage tobacco material screening apparatus according to claim 1, characterised in that, The bottom of the second screening vibrating trough (21) is provided with a second material dropping port, and the material dropping double pipeline (22) is communicated with the second material dropping port. The conversion flap (221) is movably arranged in the inside of the blanking double pipeline (22) by the second cylinder (222), and the conversion flap (221) has a first position for conveying material to the pneumatic conveying pipeline (23) and a second position for conveying material to the second recycling pipeline (24) by controlling the operation of the second cylinder (222).

5. A multi-stage tobacco material screening apparatus according to claim 1, characterised in that, The first screening device (1), the uniformity machine (2), the second screening device (3) and the flavoring machine (4) are sequentially communicated through the conveying channels.

6. A multi-stage screening method of tobacco material according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: When producing the first grade of tobacco, the raw material is screened once by the first screening device (1), and the screened material is recycled through the first recycling channel (13), and the remaining material is processed by the uniformity machine (2) to obtain uniform material; the uniform material is screened twice by the second screening device (3), and the screened material is recycled through the second recycling pipeline (24), and the remaining material is processed by the flavoring machine (4); When producing the second grade of tobacco, the raw material is not screened by the first screening device (1), and is directly processed by the uniformity machine (2) to obtain uniform material; the uniform material is screened twice by the second screening device (3), and the screened material is recycled through the second recycling pipeline (24), and the remaining material is processed by the flavoring machine (4); When producing the third grade of tobacco, the raw material is screened once by the first screening device (1), and the screened material is recycled through the first recycling channel (13), and the remaining material is processed by the uniformity machine (2) to obtain uniform material; the uniform material is not screened twice by the second screening device (3), and is directly processed by the flavoring machine (4).

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