A multi-stage impurity removing system for cut stem

Abstract

The application discloses a stem shred multi-stage impurity removing processing system and relates to the technical field of tobacco processing. The system comprises a three-layer vibrating screen, a winnowing assembly, a filament breaking device and a dust removal assembly. In the application, the three-layer vibrating screen separates sheet-shaped stem shreds from filament-shaped stem shreds and tobacco ash and tobacco dregs through two layers of punched screen plates, further screens the filament-shaped stem shreds from the tobacco ash and the tobacco dregs, and makes the tobacco ash and the tobacco dregs fall into the bottom layer of the bottom plate and flow into the dust removal assembly through the dust removal port. The filament breaking device receives the top layer of sheet-shaped stem shreds, rolls and cuts the sheet-shaped stem shreds into filament-shaped stem shreds, returns the filament-shaped stem shreds to the three-layer vibrating screen through a circulating loop for re-screening, ensures that no sheet-shaped stem shreds are missed, and collects the newly generated dust, ash and dregs produced by rolling through the matched dust removal assembly. The middle layer of filament-shaped stem shreds is sent to the next process through the winnowing assembly, and the separated ash, dregs and impurities are also connected to the dust removal assembly. Finally, the ash and the dregs are removed through the centralized collection of impurities in the whole process, the purity of stem shreds in the subsequent process is improved, and the quality of the final tobacco product is ensured.

Description

Technical Field

[0001] This application relates to the field of tobacco processing technology, specifically a multi-stage stem removal system. Background Technology

[0002] Tobacco stems, a common blending ingredient in cigarettes, offer advantages such as high filling capacity, good combustibility, and relatively low tar content and harm in the smoke. Furthermore, their use in cigarettes can effectively reduce raw material costs. Removing impurities from tobacco stems is a crucial step in the tobacco processing industry. The core objective is to remove ash, dust, and other impurities mixed into the shredded stems, preventing them from affecting the taste, safety, and appearance consistency of the final tobacco product.

[0003] Chinese patent CN219069438U discloses a device for screening and cutting sheet-like stems into filamentous stems. It uses a two-layer vibrating screen to separate sheet-like stems from filamentous stems. Then, it uses a roller pressing method to process the sheet-like stems into filamentous stems by passing them through a set of cooperating rollers. After completion, the filamentous stems are combined with the original filamentous stems, thus completing the screening and reuse of sheet-like stems.

[0004] During the process of conceiving and implementing the above application, the inventors discovered that, in actual use, although the two-layer vibrating screen can complete the screening and reuse of sheet-like tobacco stems, the ash and dust in the original tobacco stems cannot be completely removed, resulting in insufficient purity of the tobacco stems mixed into subsequent processes, which affects the quality of the final tobacco products. Utility Model Content

[0005] The main purpose of this application is to provide a multi-stage stem removal system, which aims to solve the technical problem that although the traditional two-layer vibrating screen can complete the screening and reuse of sheet-like stems, it cannot completely remove the ash and dust in the original stems, resulting in insufficient purity of the stems mixed into subsequent processes and affecting the quality of the final tobacco products.

[0006] To achieve the above objectives, this application provides the following technical solution: A multi-stage stem removal system includes: The three-layer vibrating screen is used to separate flaky stems, filamentous stems, soot and soot by vibrating and collecting them in the top, middle and bottom layers respectively. The middle layer discharge end is equipped with an air separation component. The wire breaking device is located at the top discharge end of the three-layer vibrating screen, and the discharge end of the wire breaking device returns to the top feed end of the three-layer vibrating screen to form a circulation loop. The three-layer vibrating screen, the wire breaking device, and the air separation component all have dust removal ports, and the dust removal ports are connected to the dust removal components.

[0007] Optionally, the wind separation component includes: The primary air classifier has its feed end connected to the middle discharge end of the three-layer vibrating screen via a first conveyor belt, and its discharge end connected to a secondary air classifier via a second conveyor belt. A camera is installed between the secondary air classifier and the primary air classifier.

[0008] Optionally, the feed end of the wire breaking device is connected to the top discharge end of the three-layer vibrating screen via a third conveyor belt. An airflow drying machine is provided on one side of the wire breaking device. A fourth conveyor belt is provided at the discharge end of the wire breaking device and the airflow drying machine. The discharge end of the fourth conveyor belt extends to the top feed end of the three-layer vibrating screen.

[0009] Optionally, the bottom layer of the three-layer vibrating screen has a dust collection port, and the dust collection assembly includes: The first dust collector has an air inlet connected to a dust collection port of a three-layer vibrating screen via a first air duct, and an air outlet connected to the air inlet of a second dust collector via a second air duct. The air inlet of the second dust collector is also connected to the dust collection ports of a wire breaking device, a primary air separator, and a secondary air separator via a third air duct.

[0010] Optionally, the wire-cutting device is a double-roller wire cutter.

[0011] Optionally, the first dust collector is a cyclone dust collector, and the second dust collector is a water curtain dust collector.

[0012] Optionally, the camera is an industrial CCD camera.

[0013] The technical solution provided in this application can include the following beneficial effects: In this application, the three-layer vibrating screen first separates the sheet-like stems from the filamentous stems and tobacco ash through two layers of perforated mesh plates with progressively smaller mesh sizes. Then, it further screens the filamentous stems and tobacco ash, causing the tobacco ash to fall into the bottom plate and flow into the dust removal component through the dust removal port. The filament-breaking device receives the top layer of sheet-like stems and rolls them into filamentous stems, which are then returned to the three-layer vibrating screen for re-screening via a circulation loop. This ensures that no sheet-like stems are missed, while the matching dust removal component can collect the additional dust, tobacco ash, and tobacco dust generated by the rolling process. The filamentous stems after the middle layer screening are sent to the next process through the air separation component. The separated tobacco ash and tobacco dust impurities are also connected to the dust removal component. Finally, the removal of tobacco ash and tobacco dust is achieved through centralized collection of impurities throughout the entire process, improving the purity of stems in subsequent processes and ensuring the quality of the final tobacco products. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the 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.

[0015] Figure 1 This is a schematic diagram of the multi-stage stem removal system; Figure 2 This is a process flow diagram of the multi-stage stem and filament removal system; Figure 3 This is a schematic diagram of the three-dimensional structure of a three-layer vibrating screen; Figure 4 This is a three-dimensional structural diagram of the wire-breaking device.

[0016] Reference numerals: 1. Three-layer vibrating screen; 2. Air classifier assembly; 3. Wire breaking device; 4. Dust removal assembly; 5. Primary air classifier; 6. First conveyor belt; 7. Second conveyor belt; 8. Secondary air classifier; 9. Camera; 10. Third conveyor belt; 11. Airflow drying machine; 12. Fourth conveyor belt; 13. First dust collector; 14. First air duct; 15. Second air duct; 16. Second dust collector; 17. Third air duct. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0018] Example 1: See Figures 1 to 2 A multi-level stem removal system, comprising: The three-layer vibrating screen 1 is used to separate flaky stems, filamentous stems, soot and soot by vibrating and collecting them in the top, middle and bottom layers respectively. The middle layer discharge end is equipped with an air separation component 2. The wire breaking device 3 is located at the top discharge end of the three-layer vibrating screen 1, and the discharge end of the wire breaking device 3 returns to the top feed end of the three-layer vibrating screen 1 to form a circulation loop. Among them, the three-layer vibrating screen 1, the wire breaking device 3 and the air separation component 2 all have dust removal ports, and the dust removal ports are connected to the dust removal component 4.

[0019] Specifically, the three-layer vibrating screen 1 has two layers of perforated screen plates with progressively smaller mesh sizes arranged from top to bottom within its screen body. The bottom layer is made of stainless steel. Vibration separates the mixed materials, and the aperture can be adjusted by replacing the perforated screen plates. The large-aperture perforated screen plate is located at the top layer of the three-layer vibrating screen 1. By reasonably adjusting its aperture size, the material can be screened into flaky strands and other materials. The flaky strands remain on the top perforated screen plate, while other materials, including filamentous strands, soot, and dust, fall through the large-aperture mesh to the middle perforated screen plate. Under the action of the small-aperture perforated screen plate in the middle layer, other materials can be screened into filamentous strands, soot, and dust. The filamentous strands remain on the middle perforated screen plate, while the soot and dust fall into the bottom bottom plate. The three-layer vibrating screen 1 has a dust collection port located below and connected to the bottom plate. This port is connected to the dust collection assembly 4, allowing soot and dust falling onto the bottom plate to be collected and centrally processed. Furthermore, the three-dimensional structure of the three-layer vibrating screen 1 is as follows: Figure 3 As shown.

[0020] An air separation component 2 is installed at the discharge end of the middle layer perforated mesh plate, and the discharge end of the air separation component 2 connects to the next process. The air separation component 2 uses the principle of airflow separation to separate light impurities such as soot and dust from qualified filamentous stems on the middle layer perforated mesh plate. The qualified filamentous stems, due to their higher density, are discharged along the discharge end of the air separation component 2 and conveyed to the subsequent process. The separated light impurities such as soot and dust are collected centrally by the dust removal port of the air separation component 2 into the system dust removal component 4. At the same time, the airflow disturbance breaks up the clumps of filamentous stems, ensuring that the filamentous stems are output in a dispersed state, providing qualified raw materials with higher purity and more uniform shape for subsequent processing, further reducing the risk of impurity residue in the final cigarette product, and ensuring the stability and compliance of stem blending.

[0021] The wire breaking device 3 receives the sheet-like stems from the top discharge end of the three-layer vibrating screen 1, converts them into filamentous stems that meet the process requirements, and then returns them to the top feed end of the three-layer vibrating screen 1 through a circulation loop. This allows the incompletely processed sheet-like stems to re-participate in the screening process, achieving a closed-loop process of sheet-like stems-conversion-re-screening. This ensures that the sheet-like stems can be fully converted into filamentous stems, avoiding raw material waste and improving the comprehensive utilization rate of stems. It also allows the converted filamentous stems to enter the subsequent middle-layer screening and air-classification purification stages through the circulation loop, further removing impurities and ensuring the consistency and purity of the final output stems.

[0022] Furthermore, the wire-cutting device 3 uses a set of rollers with grooves of a specific width to convert sheet-like filaments into filaments. Its core working principle is as follows: the two rollers maintain relative rotation, forming a stable roller-pressing and cutting area; the sheet-like filaments, after being screened by the top layer of the three-layer vibrating screen 1, are conveyed from the top discharge end to the wire-cutting device 3, and then fall freely into the working area between the two rollers. At this time, the rotating rollers generate inward roller pressure, while the grooves of a specific width on the roller surface act as positioning and limiting mechanisms, locking the sheet-like filaments into the grooves. Under the combined action of roller pressure and shearing, the sheet-like filaments are precisely cut into filaments of a specified width matching the groove width. The filament thickness is already determined at the filament cutting machine; this device is only responsible for fixed-width cutting, ensuring that the final filament specifications meet the process requirements.

[0023] During the aforementioned roller pressing and slitting process, the filaments are inevitably broken up due to mechanical compression and shearing, resulting in dust and impurities such as soot and dust particles. To avoid roller jamming and wear caused by the accumulation of such impurities and to ensure stable operation of the device, this system is equipped with a dual dust removal and protection structure: First, a dust cover is installed outside the filament breaking device 3 to completely enclose the roller pressing working area, effectively preventing soot and dust particles from spreading into the workshop environment and preventing impurities from drifting into the subsequent conveying links and contaminating materials; second, a dust removal component 4 is configured simultaneously. The filament breaking device 3 is connected to the dust removal component 4 through a dust removal port to accurately capture the soot and dust particles generated by roller pressing. The dust removal component 4 quickly collects the dust, preventing it from accumulating on the roller surface and in the groove gaps. Finally, the impurities collected by the dust removal component 4 are discharged through a dedicated channel. In this way, both the long-term stable operation of the filament breaking device 3 and the conversion of the filaments into filaments without carrying additional dust and impurities are ensured.

[0024] In traditional tobacco stem removal processes, a two-layer vibrating screen is typically used to screen and reuse the sheet-like tobacco stems. Although the two-layer vibrating screen can screen and reuse the sheet-like tobacco stems, it cannot completely remove the ash and dust from the original tobacco stems. This results in insufficient purity of the tobacco stems mixed into subsequent processes, affecting the quality of the final tobacco products. In this application, the three-layer vibrating screen 1 uses two layers of perforated mesh plates with progressively smaller mesh sizes to first separate sheet-like stems from filamentous stems and tobacco ash and dust. Then, it further separates the filamentous stems from the tobacco ash and dust, causing the tobacco ash and dust to fall into the bottom plate and flow into the dust removal component 4 through the dust removal port. The filament-breaking device 3 receives the top layer of sheet-like stems and rolls them into filamentous stems, which are then returned to the three-layer vibrating screen 1 for re-screening through a circulation loop. This ensures that no sheet-like stems are missed, while the dust removal component 4 collects any additional dust, tobacco ash, and tobacco dust generated during the rolling process. The filamentous stems after the middle layer screening are sent to the next process through the air separation component 2. The separated tobacco ash and tobacco dust impurities are also connected to the dust removal component 4. Finally, the removal of tobacco ash and tobacco dust is achieved through centralized collection of impurities throughout the entire process, improving the purity of stems in subsequent processes and ensuring the quality of the final tobacco products.

[0025] Example 2: See Figure 1 and 2 Based on Embodiment 1, optionally, the wind separator component 2 includes: The primary air classifier 5 has its feed end connected to the middle discharge end of the three-layer vibrating screen 1 via the first conveyor belt 6, and its discharge end connected to the secondary air classifier 8 via the second conveyor belt 7. A camera 9 is installed between the secondary air classifier 8 and the primary air classifier 5.

[0026] Specifically, both the primary air classifier 5 and the secondary air classifier 8 adopt the FS417A flexible air classifier. The primary classifier is a device that uses the conveying speed of the inlet and outlet conveyor belts and the drop between them, along with negative pressure suction perpendicular to the material flow direction, to remove light-weight ash and dust, as well as heavy-weight stems and clumps. The removal effect is often controlled by adjusting the opening of the negative pressure suction damper. The camera 9 analyzes the characteristics of the stems after primary air classification by taking pictures, and then adjusts the damper opening of the primary air classifier 5 based on feedback to optimize the removal effect, forming a closed-loop control. The secondary air classifier 8 conveys the material from bottom to top. Heavier stems and clumps are further separated from the qualified stems, while the remaining qualified stems are air-puffed to the blending and flavoring process for storage and later use.

[0027] Optionally, the feed end of the wire breaking device 3 is connected to the top discharge end of the three-layer vibrating screen 1 via a third conveyor belt 10. An airflow drying machine 11 is provided on one side of the wire breaking device 3. A fourth conveyor belt 12 is provided at the discharge end of the wire breaking device 3 and the airflow drying machine 11. The discharge end of the fourth conveyor belt 12 extends to the top feed end of the three-layer vibrating screen 1.

[0028] Specifically, the third conveyor belt 10 provides a stable material conveying channel for the top discharge end of the three-layer vibrating screen 1 and the feed end of the wire breaking device 3. It can accurately convey the sheet-like filaments separated by the three-layer vibrating screen 1 to the wire breaking device 3, ensuring continuous feeding and processing continuity of the sheet-like filaments. After receiving the sheet-like filaments and converting them into filaments, the wire breaking device 3 merges with the mixed filaments discharged from the airflow drying machine 11 and enters the fourth conveyor belt 12 together. With the conveying action of the fourth conveyor belt 12, the mixed material is transported back to the top feed end of the three-layer vibrating screen 1. This design not only helps to allow the filaments after wire breaking and conversion to participate in secondary screening together with the mixed filaments in the airflow drying machine 11, improving the processing fullness of various filaments, but also reduces the possibility of incompletely converted sheet-like filaments or impurities remaining through the circulation process. At the same time, it ensures the continuity and stability of material conveying, helps to improve the overall morphological consistency and screening adaptability of the filaments, and provides raw materials that better meet the process requirements for subsequent air classification and purification.

[0029] Furthermore, the airflow drying machine 11 fully contacts the mixed stems inside the machine with the heated clean airflow. On the one hand, it removes moisture from the stems through heat exchange to achieve humidity control. On the other hand, the high-speed airflow turbulence makes the stems suspend or tumble, avoiding local overheating, uneven drying, and breaking up slight clumps. The airflow temperature and flow rate can be adjusted according to process requirements to suit the characteristics of the stems. Its core function is to reduce the moisture of the stems through appropriate drying, prevent the stems from sticking and clumping, improve the grading and separation efficiency of the subsequent three-layer vibrating screen 1, and reduce the risk of screen blockage or impurity entrainment. At the same time, the dispersed stems are easier to separate impurities in the subsequent air classification stage, and the more fluid stems after drying can smoothly return to the three-layer vibrating screen 1 through the fourth conveyor belt 12, ensuring the continuous and stable circulation loop. It can also reduce the breakage loss in subsequent processing by adjusting the toughness and looseness of the stems, providing raw materials that are more in line with process requirements for air classification purification, blending and flavoring, etc., which helps to improve the system's impurity removal effect and the stability of the final cigarette quality. It should be noted that the airflow drying machine 11 is existing technology and will not be described in detail here.

[0030] Optionally, the bottom layer of the three-layer vibrating screen 1 has a dust collection port, and the dust collection assembly 4 includes: The first dust collector 13 has its air inlet connected to the dust collection port at the bottom of the three-layer vibrating screen 1 via the first air duct 14, and its air outlet connected to the air inlet of the second dust collector 16 via the second air duct 15. The air inlet of the second dust collector 16 is also connected to the dust collection ports of the wire breaking device 3, the primary air separator 5, and the secondary air separator 8 via the third air duct 17.

[0031] Specifically, the first dust collector 13 is connected to the bottom dust collection port of the three-layer vibrating screen 1 through the first air duct 14, which can perform preliminary filtration of the smoke ash and dust separated by the three-layer vibrating screen 1; the second dust collector 16 receives the airflow after preliminary treatment by the first dust collector 13 through the second air duct 15, and is simultaneously connected to the dust collection ports of the wire breaking device 3 (dust generated by roller crushing), the primary air classifier 5 (separated smoke ash and dust light impurities), and the secondary air classifier 8 (separated smoke ash and dust light impurities), so as to realize the centralized collection and treatment of impurities in each process of the whole system, and avoid the diffusion of smoke ash, dust, and other impurities into the workshop environment or accumulation inside the equipment.

[0032] Optionally, the wire cutting device 3 is a double-roller type wire cutter.

[0033] Specifically, in a roller-type stem cutting machine, when pairs of rollers with grooves of a specific width rotate relative to each other, the sheet-like stems can be cut to a fixed width through the combined action of roller pressure and shearing. The cutting accuracy is good, resulting in more uniform specifications of the converted filamentous stems, which meets the requirements of subsequent screening and air separation purification processes. Furthermore, the three-dimensional structure of the filament-breaking device 3 is as follows: Figure 4As shown (the feed end and discharge end are not shown in the figure).

[0034] Optionally, the first dust collector 13 is a cyclone dust collector, and the second dust collector 16 is a water curtain dust collector.

[0035] Specifically, the dust-laden airflow (mainly flue dust and soot) from the dust removal port of the three-layer vibrating screen 1 enters the dust collector cylinder through the first air duct 14 and rotates at high speed along the cylinder wall. The centrifugal force generated by the airflow rotation throws the dust particles (flue dust and soot) with a density greater than air towards the cylinder wall. Under the action of gravity, the particles settle down along the cylinder wall to the bottom ash hopper, completing the initial dust removal. The airflow after initial separation is then transported to the water curtain dust collector through the outlet and the second air duct 15. The water curtain dust collector, as a secondary deep purification unit, works based on the principle of gas-liquid contact adsorption: on the one hand, it receives the dust from the airflow through the second air duct 15. The pre-treated airflow from the cyclone dust collector, on the other hand, receives dust-laden airflow generated by the wire-breaking device 3, primary air classifier 5, and secondary air classifier 8 through various ducts. Multiple dust-laden airflows come into full contact with a continuous water curtain (or water mist) formed from top to bottom within the dust collector. Fine dust, residual soot, and other impurities in the airflow are adsorbed by the water curtain, forming dust-laden wastewater that is discharged along the bottom (for further treatment), while the purified clean airflow is discharged from the outlet. Simultaneously, the wetting effect of the water curtain effectively captures easily dispersed fine dust, further improving dust removal efficiency and preventing secondary diffusion of impurities. Optionally, the water curtain dust collector uses the D-33818 water curtain dust collector.

[0036] Optionally, the camera 9 is a CCD camera.

[0037] Specifically, the industrial CCD camera uses an LED industrial vision supplement light LB32038-A10C to provide a stable and uniform lighting environment for image acquisition, ensuring the accuracy of stem morphology detection. The industrial CCD camera uses a Keyence CA-HX200M industrial camera, which can acquire clear images of the stems after primary air classification. By analyzing the residual impurity content and clumping status of the stems, the opening of the damper of the primary air classifier 5 is adjusted accordingly. It should be noted that the conveyor belt models involved in this application are uniformly DPH-3312.1 series (the number of decimal places increases sequentially according to the connected scenario, such as the models of the first conveyor belt 6 and the second conveyor belt, which can be set as DPH-3312.1 and DPH-3312.2, respectively).

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A multi-stage stem and filament removal system, characterized in that, include: The three-layer vibrating screen (1) is used to separate flaky stems, filamentous stems, ash and dust by vibrating screen and collect them in the top, middle and bottom layers respectively, and the middle layer discharge end is equipped with an air separation component (2). The wire breaking device (3) is located at the top discharge end of the three-layer vibrating screen (1), and the discharge end of the wire breaking device (3) returns to the top feed end of the three-layer vibrating screen (1) to form a circulation loop. Among them, the three-layer vibrating screen (1), the wire breaking device (3) and the air separation component (2) all have dust removal ports, and the dust removal ports are connected to the dust removal component (4).

2. The multi-stage stem removal system according to claim 1, characterized in that, The wind separation component (2) includes: The primary air classifier (5) has its feed end connected to the middle discharge end of the three-layer vibrating screen (1) via the first conveyor belt (6), and its discharge end is connected to the secondary air classifier (8) via the second conveyor belt (7). A camera (9) is installed between the secondary air classifier (8) and the primary air classifier (5).

3. The multi-stage stem removal system according to claim 2, characterized in that, The feed end of the wire breaking device (3) is connected to the top discharge end of the three-layer vibrating screen (1) via a third conveyor belt (10). An airflow drying machine (11) is provided on one side of the wire breaking device (3). A fourth conveyor belt (12) is provided at the discharge end of the wire breaking device (3) and the airflow drying machine (11). The discharge end of the fourth conveyor belt (12) extends to the top feed end of the three-layer vibrating screen (1).

4. The multi-stage stem removal system according to claim 3, characterized in that, The bottom layer of the three-layer vibrating screen (1) has a dust removal port, and the dust removal assembly (4) includes: The first dust collector (13) has its air inlet connected to the dust collection port of the three-layer vibrating screen (1) through the first air duct (14), and its air outlet connected to the air inlet of the second dust collector (16) through the second air duct (15). The air inlet of the second dust collector (16) is also connected to the dust collection ports of the wire breaking device (3), the primary air separator (5), and the secondary air separator (8) through the third air duct (17).

5. The multi-stage stem removal system according to claim 1, characterized in that, The wire-cutting device (3) is a double-roller wire cutter.

6. The multi-stage stem removal system according to claim 4, characterized in that, The first dust collector (13) is a cyclone dust collector, and the second dust collector (16) is a water curtain dust collector.

7. The multi-stage stem removal system according to claim 2, characterized in that, The camera (9) is an industrial CCD camera.

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