Tobacco stem screening device

Abstract

The application provides a tobacco stem screening device, which comprises a box body, a first vibrating screen and a second vibrating screen. The top of the box body is provided with an inlet. The first vibrating screen and the second vibrating screen are located in the box body and are connected to opposite side walls of the box body. Along the height direction of the box body, the first vibrating screen is located on the side of the second vibrating screen close to the inlet. The first vibrating screen is arranged obliquely, and the bottom end thereof along the oblique direction is provided with a long stem outlet. The first vibrating screen is provided with a plurality of first screen holes for the medium stem outlet and the short stem outlet. The second vibrating screen is provided with a plurality of second screen holes for the short stem outlet after the screening of the fine powder. The diameter of the first screen hole is larger than that of the second screen hole. The application can complete the length classification and thickness selection of the tobacco stem, improve the separation effect, and solve the problems of single function and complex process of the traditional equipment.

Description

Technical Field

[0001] This application relates to the field of tobacco stem screening and production technology, and in particular to a tobacco stem screening device. Background Technology

[0002] In the tobacco processing industry, the screening of tobacco stems is a key pre-processing step in cigarette production. Tobacco stems need to be classified according to length (long stems, medium stems, short stems) and diameter (thick stems, thin stems) to meet the requirements of different cigarette products for combustibility, taste and processing technology.

[0003] Traditional tobacco stem screening often relies on a single vibrating screen or simple airflow separation. However, vibrating screens rely solely on the size of the screen openings, which can easily clog irregularly shaped tobacco stems and make it difficult to distinguish tobacco stems of similar diameters. Conventional airflow separation does not take into account the differences in tobacco stem length and thickness. Due to differences in quality and airflow area, long stems are poorly separated from short stems, and thick stems are poorly separated from thin stems. This results in a mixture of tobacco stem specifications after screening, which affects subsequent tobacco processing and rolling processes. Utility Model Content

[0004] This application provides a tobacco stem screening device that can complete the classification of tobacco stems by length and the separation of coarseness by a single machine, thereby improving the separation effect and solving the problems of single function and complex process of traditional equipment.

[0005] This application provides a tobacco stem screening device, including: a box body, a first vibrating screen and a second vibrating screen, wherein the top of the box body is provided with a feed inlet;

[0006] The first vibrating screen and the second vibrating screen are located in the box and are respectively connected to the opposite side walls of the box. Along the height direction of the box, the first vibrating screen is located on the side of the second vibrating screen closer to the feed inlet. The first vibrating screen is inclined and has a long stem outlet at its bottom end along its inclined direction.

[0007] The first vibrating screen has multiple first screen holes, which are used for the outlet of medium stems and the outlet of short stems. The second vibrating screen has multiple second screen holes, which are used for the outlet of short stems after the shavings are removed.

[0008] The aperture of the first sieve hole is larger than the aperture of the second sieve hole.

[0009] In one embodiment, the first vibrating screen includes an upper vibrating screen and a lower vibrating screen arranged along the height direction of the housing, wherein the upper vibrating screen is located on the side of the lower vibrating screen closer to the feed inlet;

[0010] The long stem outlet is located at the bottom end of the upper vibrating screen along its inclined direction, a middle stem collection chamber is formed between the upper vibrating screen and the lower vibrating screen, and a short stem collection chamber is formed between the lower vibrating screen and the second vibrating screen.

[0011] The upper vibrating screen has multiple upper screen holes, and the lower vibrating screen has multiple lower screen holes. The diameter of the upper screen holes is larger than the diameter of the lower screen holes, and the diameter of the lower screen holes is larger than the diameter of the second screen hole.

[0012] In one embodiment, the upper vibrating screen is further provided with a long stem collection bin at its bottom end along its inclined direction, and a vertical airflow separation chamber is connected between the long stem collection bin and the long stem outlet, and the long stem outlet and the long stem collection bin are connected through the vertical airflow separation chamber.

[0013] In one embodiment, the long stem collection chamber includes a coarse stem collection chamber and a fine stem collection chamber;

[0014] The coarse stem collection chamber is located at the bottom of the vertical airflow sorting chamber, and the coarse stem collection chamber is used to collect the coarse stems in the long stems under the action of gravity;

[0015] The fine stem collection chamber is located on the side of the vertical airflow sorting chamber. On the other side of the vertical airflow sorting chamber opposite to the fine stem collection chamber, a first fan is provided. The first fan is configured to blow the fine stems from the long stems into the fine stem collection chamber.

[0016] In one embodiment, the upper vibrating screen is an inclined vibrating screen with an inclination angle of A, wherein A is between 0° and 20°.

[0017] And / or, the lower vibrating screen is an inclined vibrating screen with an inclination angle of B, wherein B is between 0° and 20°.

[0018] And / or, the second vibrating screen is a horizontal vibrating screen.

[0019] In one embodiment, a guide plate is provided inside the box, and along the height direction of the box, the guide plate is located on the side of the second vibrating screen away from the first vibrating screen;

[0020] The guide plate is an inclined plate, and a coarse stem collection groove is provided at the bottom end of the guide plate along the inclined extension direction of the guide plate. The coarse stem collection groove is used to collect the coarse stems in the short stems.

[0021] In one embodiment, a second fan is provided at the top of the guide plate along the inclined extension direction of the guide plate, and a fine stem collection groove is provided on the side of the guide plate. The second fan is configured to blow fine stems from the short stems into the fine stem collection groove.

[0022] In one embodiment, the tilt angle of the guide plate is C, where C is between 10° and 40°; and / or, the guide plate is made of stainless steel and is coated with a polytetrafluoroethylene coating.

[0023] In one embodiment, the aperture of the upper vibrating screen is D1, and D1 satisfies the condition: 13mm < D1 < 17mm;

[0024] And / or, the aperture of the lower vibrating screen is D2, and D2 satisfies the condition: 6mm < D2 < 10mm;

[0025] And / or, the aperture of the second vibrating screen is D3, wherein D3 satisfies the condition: 0mm < D2 < 4mm.

[0026] In one embodiment, the first vibrating screen and / or the second vibrating screen are elastic polyurethane components;

[0027] And / or, the bottom of the first vibrating screen and the second vibrating screen are respectively provided with airflow nozzles.

[0028] The tobacco stem screening device provided in this application embodiment achieves precise grading of tobacco stems through the layered collaboration of two vibrating screens: the first vibrating screen first completes the separation of long stems with a large-diameter screen hole (sliding out of the long stem outlet along the inclined structure), while the screen holes allow medium and short stems to fall; the second vibrating screen uses a small-diameter screen hole to screen the falling material a second time, removing debris and separating short stems. With the help of the layered screening of screen holes of different diameters, tobacco stems are efficiently classified according to length and debris, providing precise raw materials for the differentiated processing of tobacco stems in subsequent cigarette production, improving the efficiency and accuracy of tobacco stem screening, and can complete the classification of tobacco stems by length and coarseness by a single machine, improving the separation effect and solving the problems of single function and complex process of traditional equipment. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the tobacco stem screening device provided in the embodiments of this application;

[0031] Figure 2 This is a schematic diagram showing the dimensions of the tobacco stem screening device provided in the embodiments of this application.

[0032] Figure label:

[0033] 100. Tobacco stem screening device;

[0034] 110. Housing; 111. Feed inlet; 112. Long stem outlet; 113. Long stem collection bin; 1131. Coarse stem collection bin; 1132. Fine stem collection bin; 114. Vertical airflow sorting chamber; 115. First fan;

[0035] 120. First vibrating screen; 121. Upper vibrating screen; 1211. Upper screen aperture; 122. Lower vibrating screen; 1221. Lower screen aperture;

[0036] 130. Second vibrating screen; 131. Second screen aperture;

[0037] 140. Flow deflector; 141. Fine stem collection trough; 142. Coarse stem collection trough;

[0038] 150. Second fan;

[0039] 160. Mid-stalk collection chamber;

[0040] 170. Short stem collection bin. Detailed Implementation

[0041] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0042] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0045] In some related technologies, multiple layers of screens are used to gradually separate tobacco stems by aperture size. However, these screens are easily clogged by tobacco stems and can only achieve single-dimensional (length) sorting. Coarse / fine stems mixed in with short stems cannot be further classified and require secondary processing. The single sorting dimension makes precise sieving difficult when short stems are mixed with debris, and high-moisture tobacco stems easily stick to the screens, leading to increased downtime for cleaning. In some embodiments, the difference in airflow buoyancy is used to separate coarse / fine stems, but this requires additional independent equipment connected in series with a vibrating screen. The tobacco stem length range needs to be preset before coarse / fine sorting, resulting in a complex process, high energy consumption, large footprint, and high material transport losses.

[0046] To address the aforementioned issues, this application provides a tobacco stem screening device that achieves precise grading of tobacco stems through the synergistic effect of two vibrating screens: the first vibrating screen uses large-aperture screens to separate long stems (sliding out of the long stem outlet along the inclined structure), while simultaneously allowing medium and short stems to fall through the screen holes; the second vibrating screen uses small-aperture screens to perform secondary screening of the falling material, removing debris and separating short stems. By utilizing the tiered screening with different aperture screens, tobacco stems are efficiently classified by length and debris, providing precise raw materials for the differentiated processing of tobacco stems in subsequent cigarette production, improving the efficiency and accuracy of tobacco stem screening, and enabling a single machine to complete the classification of tobacco stems by length and coarseness, improving the separation effect and solving the problems of traditional equipment having limited functionality and complex processes.

[0047] The following will combine Figure 1 and Figure 2 The specific structure of the tobacco stem screening device provided in the embodiments of this application will be described.

[0048] Reference Figure 1 and Figure 2As shown in the figure, this application provides a tobacco stem screening device 100, including: a box 110, a first vibrating screen 120 and a second vibrating screen 130, and a feed inlet 111 is provided on the top of the box 110.

[0049] The first vibrating screen 120 and the second vibrating screen 130 are located in the housing 110 and are respectively connected to the opposite side walls of the housing 110. Along the height direction of the housing 110, the first vibrating screen 120 is located on the side of the second vibrating screen 130 near the feed inlet 111. The first vibrating screen 120 is inclined and has a long stem outlet 112 at its bottom end along its inclined direction.

[0050] The first vibrating screen 120 has multiple first screen holes for medium stem outlet and short stem outlet. The second vibrating screen 130 has multiple second screen holes 131 for short stem outlet after sieving out the broken parts. The diameter of the first screen holes is larger than the diameter of the second screen holes 131.

[0051] It should be noted that the tobacco stems in this embodiment are divided into long stems, medium stems and short stems, and the tobacco stems are further divided into coarse stems and fine stems. The screening device in this embodiment is mainly used to separate and screen the long stems, medium stems and short stems, and to screen out the coarse stems and fine stems among the tobacco stems.

[0052] Understandably, the feed inlet 111 at the top of the housing 110 provides an inlet for the tobacco stems, which first enter the inclined first vibrating screen 120. The first vibrating screen 120 has multiple large-diameter first screen holes. Under vibration, long stems, being longer than the first screen hole diameter, cannot pass through and slide along the inclined direction to the long stem outlet 112 at the bottom for separation. Medium and short stems, being shorter than the first screen hole diameter, fall through the screen holes to the lower second vibrating screen 130. The second vibrating screen 130 has multiple smaller-diameter second screen holes 131, used for further screening of the falling medium and short stems: fragments in the short stems, being smaller than the second screen hole diameter 131, are removed through the screen holes.

[0053] For example, refer to Figure 1 As shown, the flow direction of the long stem can be as follows: Figure 1 As indicated by the middle arrow 'a', the flow direction of the middle stem can be entered. Figure 1 As indicated by the middle arrow b, the flow direction of the short stem can be as follows: Figure 1 The direction indicated by the middle arrow c.

[0054] It should be noted that the long stem outlet 112 is located at the bottom end of the first vibrating screen 120 along its inclined direction. Since the long stem cannot pass through the first screen hole, it mainly slides to the bottom end by gravity and is discharged through the long stem outlet 112.

[0055] Therefore, in this embodiment, by utilizing the difference in aperture size between the first vibrating screen 120 and the second vibrating screen 130 (first screen aperture > second screen aperture 131) and their hierarchical layout, long stems, medium stems, short stems, and fragments are separated in stages within the same housing 110. This avoids the limitations of traditional single-screen functionality and reduces process redundancy in multi-device series connection. The inclined first vibrating screen 120 utilizes the combined effect of gravity and vibration to ensure that long stems slide out in a directional manner, reducing the mixing of long stems with medium and short stems. The fine aperture design of the second screen aperture 131 precisely removes fragments, providing short stem raw materials of uniform specifications for subsequent processing.

[0056] Reference Figure 1 and Figure 2 As shown, in one embodiment, the first vibrating screen 120 may include an upper vibrating screen 121 and a lower vibrating screen 122 arranged along the height direction of the housing 110, with the upper vibrating screen 121 located on the side of the lower vibrating screen 122 near the feed inlet 111.

[0057] The long stem outlet 112 is located at the bottom end of the upper vibrating screen 121 along its inclined direction. A middle stem collection chamber 160 is formed between the upper vibrating screen 121 and the lower vibrating screen 122, and a short stem collection chamber 170 is formed between the lower vibrating screen 122 and the second vibrating screen 130. The upper vibrating screen 121 has multiple upper screen holes 1211, and the lower vibrating screen 122 has multiple lower screen holes 1221. The diameter of the upper screen holes 1211 is larger than the diameter of the lower screen holes 1221, and the diameter of the lower screen holes 1221 is larger than the diameter of the second screen holes 131.

[0058] The upper vibrating screen 121 is inclined and has the largest upper screen hole 1211 (e.g., 15mm). After the tobacco stems enter from the feed inlet 111, they first fall on the upper vibrating screen 121. Long stems (length > upper screen hole diameter) cannot pass through the screen hole and slide along the inclined direction to the long stem outlet 112 at the bottom to complete the separation. Medium stems (length between the upper and lower screen hole diameters) and short stems (length < lower screen hole diameter) fall through the upper screen hole 1211 to the lower vibrating screen 122.

[0059] The lower vibrating screen 122 is inclined and has lower screen holes 1221 (e.g., 8mm) with a smaller diameter than the upper screen holes 1211. Middle stems, whose length is greater than the diameter of the lower screen holes 1221, are intercepted on the lower vibrating screen 122 and eventually fall into the middle stem collection chamber 160 between the upper and lower vibrating screens 122. Short stems (length less than the diameter of the lower screen holes) pass through the lower screen holes 1221 and enter the short stem collection chamber 170 between the lower vibrating screen 122 and the second vibrating screen 130.

[0060] The second vibrating screen 130 is located at the bottom and has a second screen hole 131 with the smallest diameter (e.g., 2mm). After the short stems in the short stem collection bin 170 fall to the second vibrating screen 130, the fragments (size <2mm) are screened out through the second screen hole 131, and the short stems that meet the specifications (size >2mm) are discharged from the short stem outlet.

[0061] Therefore, through the above-mentioned pore size gradient design, it is possible to achieve the stepwise separation of long stems, medium stems, short stems and fragments.

[0062] Reference Figure 1 and Figure 2 As shown, in one embodiment, the upper vibrating screen 121 is also provided with a long stem collection chamber 113 at its bottom end along its inclined direction. A vertical airflow separation chamber 114 is connected between the long stem collection chamber 113 and the long stem outlet 112. The long stem outlet 112 and the long stem collection chamber 113 are connected through the vertical airflow separation chamber 114.

[0063] It should be noted that the vertical airflow sorting chamber 114 is a vertical channel structure connecting the long stem outlet 112 and the long stem collection chamber 113. After the long stems discharged from the long stem outlet 112 of the upper vibrating screen 121 enter this chamber, the coarse stems (diameter > 1.2 mm) fall vertically along the chamber to the coarse stem collection chamber 1131 because of their greater weight and the inability of the airflow to counteract their downward trend. The fine stems (diameter ≤ 1.2 mm) are pushed by the horizontally upward airflow and blown along a parabolic trajectory to the fine stem collection chamber 1132 on the side of the chamber, thus completing the coarse and fine sorting simultaneously based on the length of the long stems.

[0064] Reference Figure 1 and Figure 2 As shown, in one embodiment, the coarse stem collection chamber 1131 is located at the bottom of the vertical airflow sorting chamber 114, and the coarse stem collection chamber 1131 is used to collect coarse stems from long stems under the action of gravity.

[0065] The fine stem collection chamber 1132 is located on the side of the vertical airflow sorting chamber 114. On the other side of the vertical airflow sorting chamber 114 opposite to the fine stem collection chamber 1132, a first fan 115 is provided. The first fan 115 is configured to blow the fine stems in the long stems into the fine stem collection chamber 1132.

[0066] Among them, the design realizes the immediate coarse and fine sorting of long stems after length sorting by subdividing the long stem collection bin 113 into a coarse stem collection bin 1131 and a fine stem collection bin 1132, and cooperating with the vertical air flow sorting chamber 114 and the first fan 115: the coarse stems naturally fall to the bottom coarse stem collection bin 1131 relying on their own gravity, and the fine stems are precisely blown into the side fine stem collection bin 1132 by the directional air flow generated by the first fan 115. This structure completes the double classification of "length - thickness" of long stems within a single machine, without the need for additional coarse and fine sorting equipment, reducing the floor area and energy consumption caused by equipment series connection; at the same time, the synergistic effect of gravity and air flow improves the accuracy of long stem coarse and fine sorting.

[0067] Referring to Figure 2 As shown, in one embodiment, the upper vibrating screen 121 is an inclined vibrating screen with an inclination angle A, where A is between: 0° < A < 20°; the lower vibrating screen 122 is an inclined vibrating screen with an inclination angle B, where B is between: 0° < B < 20°; the second vibrating screen 130 is a horizontal vibrating screen.

[0068] Exemplarily, the inclination angle A of the upper vibrating screen 121 can be 5°, 10°, 15°, 20° or any value between 0 - 20°. In this embodiment, the inclination angle A of the upper vibrating screen 121 is taken as 10° for illustration. Similarly, the inclination angle B of the lower vibrating screen 122 is taken as 20° for illustration.

[0069] The upper vibrating screen 121 and the lower vibrating screen 122 adopt an inclination angle design of 0° < A < 20°, 0° < B < 20°, combined with the horizontal setting of the second vibrating screen 130, to form a stepped screening path: the inclination angle enables the tobacco stems to slide directionally along the screen surface under the vibration action, avoiding accumulation and blockage, and at the same time adapting to the different sliding speeds of long stems and medium stems through the angle difference to improve the grading efficiency; the horizontal second vibrating screen 130 provides a stable support for the fine screening of short stems and fines, reducing the screening deviation of fines caused by inclination. This angle design not only ensures the smooth separation of long stems and medium stems (the inclination helps directional transportation), but also improves the screening accuracy of short stem fines through the horizontal screen surface.

[0070] Referring to Figure 1 and Figure 2 As shown, in one embodiment, a guide plate 140 is provided inside the box body 110. Along the height direction of the box body 110, the guide plate 140 is located on the side of the second vibrating screen 130 away from the first vibrating screen 120; the guide plate 140 is an inclined plate, and along the inclined extension direction of the guide plate 140, a coarse stem collection groove 142 is provided at the bottom end of the guide plate 140, and the coarse stem collection groove 142 is used to collect the coarse stems in the short stems.

[0071] Understandably, the short stems, after being sieved by the second vibrating screen 130 to remove debris, will fall onto the inclined guide plate 140. The inclined design of the guide plate 140 allows the short stems to slide naturally down the plate surface. At the same time, the difference in buoyancy is used to separate the short stems into coarse and fine ones. The coarse short stems, due to their greater weight, have a gravity greater than the buoyancy of the airflow and slide down the inclined guide plate 140 to the coarse stem collection trough 142 at the bottom. The fine short stems, due to their lighter weight, are blown away from the surface of the guide plate 140 by the airflow and enter the corresponding fine stem collection area.

[0072] In one embodiment, a second fan 150 is provided at the top of the guide plate 140 along the inclined extension direction of the guide plate 140, and a fine stem collection groove 141 is provided on the side of the guide plate 140. The second fan 150 is configured to blow the fine stems in the short stems into the fine stem collection groove 141.

[0073] By setting a second fan 150 at the top of the guide plate 140 and a thin stem collection groove 141 on the side, when the short stem slides down the inclined guide plate 140, the second fan 150 generates a directional airflow. By utilizing the force difference between the short thick stem (gravity-dominated) and the short thin stem (buoyancy-dominated), the short thin stem is accurately blown into the side thin stem collection groove 141, while the short thick stem naturally slides down to the bottom thick stem collection groove 142.

[0074] Reference Figure 2 As shown, in one embodiment, the tilt angle of the deflector 140 is C, where C is between 10° and 40°. For example, the tilt angle C of the deflector 140 can be 10°, 15°, 20°, 25°, 30°, 35°, 40°, or any value between 10° and 40°.

[0075] The inclined angle design of the guide plate 140 not only provides downward momentum for the short stems by moderately tilting to avoid accumulation, but also reserves a reasonable working distance for the second fan 150 to separate the short and fine stems, so that the separation efficiency of the short stems is stable at over 95%, while the pulse anti-clogging design reduces the clogging rate.

[0076] The guide plate 140 is made of stainless steel and may be coated with a polytetrafluoroethylene (PTEE) coating. The low coefficient of friction of this coating reduces the resistance of short stems as they slide down the guide plate 140, ensuring smooth material flow and preventing accumulation and blockage caused by excessive friction.

[0077] Reference Figure 2As shown, in one embodiment, the aperture of the upper vibrating screen 121 can be D1, and D1 can satisfy the condition: 13mm < D1 < 17mm; the aperture of the lower vibrating screen 122 can be D2, and D2 can satisfy the condition: 6mm < D2 < 10mm; the aperture of the second vibrating screen 130 can be D3, and D3 can satisfy the condition: 0mm < D2 < 4mm.

[0078] For example, the aperture D1 of the upper vibrating screen 121 can be 13mm, 14mm, 15mm, 16mm, 17mm or any value between 13mm and 17mm. In this embodiment, the aperture D1 of the upper vibrating screen 121 is 15mm as an example for illustration.

[0079] For example, the aperture D2 of the lower vibrating screen 122 can be 6mm, 7mm, 8mm, 10mm or any value between 6mm and 10mm. In this embodiment, the aperture D1 of the upper vibrating screen 121 is 8mm as an example for illustration.

[0080] For example, the aperture D3 of the second vibrating screen 130 can be 1mm, 2mm, 3mm, 4mm or any value between 0mm and 4mm. In this embodiment, the aperture D3 of the upper vibrating screen 121 is 2mm as an example for illustration.

[0081] The above design helps to improve the separation effect and reduce sieve clogging.

[0082] In one embodiment, the first vibrating screen 120 and the second vibrating screen 130 can be made of elastic polyurethane components; wherein, the elastic polyurethane components have good elasticity and wear resistance, and can undergo slight deformation with vibration, reducing the hard collision between the tobacco stems and the screen mesh. In some embodiments, the bottom of the first vibrating screen 120 and the second vibrating screen 130 can be respectively equipped with airflow nozzles, which can intermittently spray pulsed airflow to assist in clearing blockages in the screen holes through the impact force of the airflow.

[0083] This embodiment provides a tobacco stem screening device that achieves precise grading of tobacco stems through the synergistic effect of two vibrating screens: the first vibrating screen uses large-diameter screen holes to first separate long stems (sliding out of the long stem outlet along the inclined structure), while the screen holes allow medium and short stems to fall; the second vibrating screen uses small-diameter screen holes to screen the falling material a second time, removing debris and separating short stems. By using the tiered screening with different screen hole diameters, tobacco stems are efficiently classified by length and debris, providing precise raw materials for the differentiated processing of tobacco stems in subsequent cigarette production, improving the efficiency and accuracy of tobacco stem screening, and enabling a single machine to complete the classification of tobacco stems by length and coarseness, improving the separation effect and solving the problems of single function and complex process of traditional equipment.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0085] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A tobacco stem sieving device, characterized in that, include: The box body, the first vibrating screen and the second vibrating screen, with a feed inlet at the top of the box body; The first vibrating screen and the second vibrating screen are located in the box and are respectively connected to the opposite side walls of the box. Along the height direction of the box, the first vibrating screen is located on the side of the second vibrating screen closer to the feed inlet. The first vibrating screen is inclined and has a long stem outlet at its bottom end along its inclined direction. The first vibrating screen has multiple first screen holes, which are used for the outlet of medium stems and the outlet of short stems. The second vibrating screen has multiple second screen holes, which are used for the outlet of short stems after the shavings are removed. The aperture of the first sieve hole is larger than the aperture of the second sieve hole.

2. The tobacco stem screening device according to claim 1, characterized in that, The first vibrating screen includes an upper vibrating screen and a lower vibrating screen arranged along the height direction of the box body, wherein the upper vibrating screen is located on the side of the lower vibrating screen closer to the feed inlet; The long stem outlet is located at the bottom end of the upper vibrating screen along its inclined direction, a middle stem collection chamber is formed between the upper vibrating screen and the lower vibrating screen, and a short stem collection chamber is formed between the lower vibrating screen and the second vibrating screen. The upper vibrating screen has multiple upper screen holes, and the lower vibrating screen has multiple lower screen holes. The diameter of the upper screen holes is larger than the diameter of the lower screen holes, and the diameter of the lower screen holes is larger than the diameter of the second screen hole.

3. The tobacco stem screening device according to claim 2, characterized in that, The upper vibrating screen is also provided with a long stem collection bin at its bottom along its inclined direction. A vertical airflow separation chamber is connected between the long stem collection bin and the long stem outlet. The long stem outlet and the long stem collection bin are connected through the vertical airflow separation chamber.

4. The tobacco stem screening device according to claim 3, characterized in that, The long stem collection chamber includes a coarse stem collection chamber and a fine stem collection chamber; The coarse stem collection chamber is located at the bottom of the vertical airflow sorting chamber, and the coarse stem collection chamber is used to collect the coarse stems in the long stems under the action of gravity; The fine stem collection chamber is located on the side of the vertical airflow sorting chamber. On the other side of the vertical airflow sorting chamber opposite to the fine stem collection chamber, a first fan is provided. The first fan is configured to blow the fine stems from the long stems into the fine stem collection chamber.

5. The tobacco stem screening device according to any one of claims 2-4, characterized in that, The upper vibrating screen is an inclined vibrating screen with an inclination angle of A, where A is between 0° and 20°. And / or, the lower vibrating screen is an inclined vibrating screen with an inclination angle of B, wherein B is between 0° and 20°. And / or, the second vibrating screen is a horizontal vibrating screen.

6. The tobacco stem screening device according to any one of claims 1-4, characterized in that, A guide plate is provided inside the box, and along the height direction of the box, the guide plate is located on the side of the second vibrating screen away from the first vibrating screen; The guide plate is an inclined plate, and a coarse stem collection groove is provided at the bottom end of the guide plate along the inclined extension direction of the guide plate. The coarse stem collection groove is used to collect the coarse stems in the short stems under the action of gravity.

7. The tobacco stem screening device according to claim 6, characterized in that, Along the inclined extension direction of the guide plate, a second fan is provided at the top of the guide plate, and a fine stem collection groove is provided on the side of the guide plate. The second fan is configured to blow the fine stems from the short stems into the fine stem collection groove.

8. The tobacco stem screening device according to claim 7, characterized in that, The tilt angle of the guide plate is C, where C is between 10° < C < 40°; And / or, the deflector is made of stainless steel and is coated with a polytetrafluoroethylene coating.

9. The tobacco stem screening device according to any one of claims 2-4, characterized in that, The aperture of the upper vibrating screen is D1, and D1 satisfies the condition: 13mm < D1 < 17mm; And / or, the aperture of the lower vibrating screen is D2, and D2 satisfies the condition: 6mm < D2 < 10mm; And / or, the aperture of the second vibrating screen is D3, wherein D3 satisfies the condition: 0mm < D2 < 4mm.

10. The tobacco stem screening device according to any one of claims 1-4, characterized in that, The first vibrating screen and / or the second vibrating screen are respectively elastic polyurethane components; And / or, the bottom of the first vibrating screen and the second vibrating screen are respectively provided with airflow nozzles.

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