A sieve and sieving method for separating branch stems from tobacco shreds.

Abstract

This invention relates to a screen and screening method for separating branch stems and stalks from tobacco shreds, belonging to the field of tobacco shred screening and impurity removal technology. It includes a wavy guiding and sorting zone and a screen aperture zone, which are arranged in a staggered manner to form a "louvered" type screen. This invention uses a wavy guiding plate and a feeding plate to form a "louvered" type screen, which suspends the bridging material between the tobacco shreds and branch stems and stalks, effectively preventing shreds from getting stuck or clumped on the screen. It achieves good screening effect for branch stems and stalks, high screening efficiency, and high purity of the screened tobacco shreds, effectively ensuring cigarette quality. It also avoids tobacco shreds being pressed down by branch stems and stalks and being carried through the screen apertures, thus preventing waste. This invention avoids the problems of traditional irregularly shaped vibrating screens, which struggle to separate bridging material and straighten branch stems and stalks.

Description

Technical Field

[0001] This invention relates to a sieve and sieving method for separating branch stems from tobacco shreds, belonging to the field of tobacco shred sieving and impurity removal technology. Background Technology

[0002] In the cigarette manufacturing process, tobacco leaves undergo processing steps such as threshing, re-drying, shredding, and drying to form a mixture of shredded tobacco and stems / veins. Shredded tobacco mainly comes from the leaf parts of the tobacco leaves and is often in the form of curled sheets or strips. Stems / veins mainly come from the stems or leaf stalks of the tobacco leaves and are mostly in the form of short cylinders. If the content of stems / veins in the shredded tobacco is too high, it will affect the quality of the cigarette, especially its appearance, physical properties, and sensory quality, seriously affecting the consumer's smoking experience. Therefore, it is necessary to separate the stems / veins from the shredded tobacco during the manufacturing process to obtain pure shredded tobacco.

[0003] Because the length of the stems and ribs is shorter than that of tobacco shreds, traditional tobacco processing mainly uses rectangular or round-hole screens to screen the mixture of tobacco shreds and stems and ribs, separating tobacco shreds and stems of different particle sizes. However, due to the curled shape of the tobacco shreds after drying and the temperature and humidity of the tobacco itself, the tobacco shreds are prone to entangle with the stems and ribs during the screening process, forming bridging materials, resulting in shreds getting stuck and screens becoming clogged. Alternatively, the tobacco shreds may be directly hooked onto the metal mesh of the screen, causing the stems and ribs to fall off the screen and not fall normally into the screen holes. This leads to the screen becoming clogged after a certain period of continuous material feeding, making it easy for the stems and ribs to not be fully screened out of the tobacco shreds. As a result, there are still many stems and ribs in the screened tobacco shreds, leading to poor screening effect and difficulty in ensuring the quality of cigarettes.

[0004] In the prior art, there are also irregularly shaped vibrating screens specifically designed for screening mixtures of tobacco shreds and stems. For example, Chinese Patent Publication No. CN108523208A discloses an irregularly shaped vibrating screen for separating stems from tobacco shreds. This screen includes a flow guiding and sorting zone and a screen hole zone arranged in multiple alternating rows in the front-to-back direction. The screen hole zone contains multiple rectangular screen holes, and the flow guiding and sorting zone contains multiple forward- and upward-inclined flow guiding ramps. These ramps suspend the mixture of tobacco shreds and stems, breaking up the bridging material and thus achieving separation of the tobacco shreds and stems. However, the flow guiding of this irregularly shaped vibrating screen... The ramp is relatively wide. When the length of the branch stem stick is only slightly greater than the width of the ramp and the rectangular screen, if the branch stem stick slides directly on the ramp, it will not be able to be supported by the ramp or dismantle the bridging material. The branch stem stick will be difficult to straighten and enter the rectangular screen, causing it to mix with tobacco. In particular, when multiple branch stem sticks of this length pass through the same ramp at the same time, it is easy for multiple branch stem sticks and their wrapped tobacco to enter the rectangular screen at the same time, causing the screen to become blocked and the branch stem stick to mix with tobacco. Or the tobacco may be carried through the rectangular screen by the branch stem stick, resulting in waste of tobacco. Summary of the Invention

[0005] To overcome the problems existing in the background technology, the present invention proposes a screen and screening method for separating branch stems and stalks from tobacco shreds. A "louvered" type screen is formed by a guide plate with a corrugated structure and a feeding plate, creating a flow-guiding and sorting area and a screen hole area. The corrugated guide plate suspends the bridging material between the tobacco shreds and branch stems and stalks, effectively separating them. This effectively avoids the phenomenon of tobacco stalks getting stuck and the screen becoming clumpy. It provides good screening effect for branch stems and stalks, high screening efficiency, and high purity of the screened tobacco shreds, effectively ensuring cigarette quality. It also prevents tobacco shreds from being pressed down by branch stems and stalks and being carried through the screen holes, thus avoiding waste. This also avoids the problems of traditional irregularly shaped vibrating screens, which struggle to separate bridging material and straighten branch stems and stalks.

[0006] To solve the above problems, the present invention is achieved through the following technical solution:

[0007] A sieve for separating branch stems from tobacco shreds includes a wavy flow guiding and sorting zone and a sieve hole zone. The wavy flow guiding and sorting zone and the sieve hole zone are arranged alternately to form a "louvered" type sieve. The wavy flow guiding and sorting zone is composed of multiple wavy flow guiding plates, and the length direction of the flow guiding plates is parallel to the forward direction of the tobacco shreds. Several feed plates are installed in an inclined array perpendicular to the flow guiding plates in the sieve hole zone, and a sieve hole is formed between every two adjacent flow guiding plates and every two adjacent feed plates.

[0008] Preferably, the feeding plate is arranged with the front lower than the back relative to the screen plane.

[0009] Preferably, the thickness of the guide plate is 1mm-2mm, the peak height is 10mm-15mm, the trough height is 5.5mm-7.5mm, the horizontal distance between two adjacent guide plates is 20mm-25mm, and the peaks and troughs of two adjacent guide plates are alternately arranged.

[0010] Preferably, the projection of the sieve holes on the sieve plane is rectangular, and the opening length of the sieve holes is greater than the length of the branch stems and less than the length of the tobacco shreds, with a sieve hole diameter of 18.8mm*4.8mm.

[0011] Preferably, the guide vanes can also be arranged radially, with a wider front and narrower rear.

[0012] A sieving method for separating branch stems from tobacco shreds, employing the sieve described in any one of the preceding claims, wherein the sieving method for separating branch stems from tobacco shreds includes at least the following steps:

[0013] S1: Start the vibrating screen with the screen installed, so that the screen vibrates back and forth in the front and back direction in the screen plane. The feeding end of the screen is defined as the rear end and the direction of tobacco shreds forward is defined as the front end. The front end of the screen is arranged at a downward angle.

[0014] S2: A mixture of tobacco shreds and branch stems is continuously added from the feed end of the screen. During the reciprocating vibration of the screen, when the screen moves forward each time, the tobacco shreds and branch stems are simultaneously pushed towards the front end of the screen in a wave-like manner, entering the wave-shaped flow guiding and sorting zone and the screen hole zone.

[0015] S3: During the reciprocating vibration of the screen, the branch stems lean against the guide plate. Under the action of the wave-shaped guide plate, the bridging material between the tobacco and the branch stems is suspended and dismantled. At the same time, the branch stems leaning against the guide plate are straightened into a state pointing in the direction of tobacco movement.

[0016] S4: Subsequently, the branch stems fall onto the feeding plate under the action of gravity. Each time the screen moves backward, the branch stems on the feeding plate pass through the screen holes and are thrown backward away from the screen. The tobacco cannot pass through the screen holes and is pushed towards the front of the screen each time the screen moves forward.

[0017] S5: During the reciprocating vibration of the screen, the mixture of tobacco and stems enters the subsequent wave-shaped flow guiding and sorting zone and the screen hole zone in sequence, and repeats the above steps S2 to S4 until all stems pass through the screen holes to achieve separation from the tobacco.

[0018] The beneficial effects of this invention are as follows:

[0019] This invention utilizes a "louvered" type screen composed of a flow-guiding and sorting zone formed by a wave-shaped guide plate and a feeding plate, along with a screen hole zone. The wave-shaped guide plate suspends the bridging material between the tobacco shreds and the stems, effectively separating the tobacco shreds and stems. This effectively prevents the screen from getting clumped or stuck, resulting in good screening effect, high screening efficiency, and high purity of the screened tobacco shreds. This effectively ensures the quality of cigarettes and prevents tobacco shreds from being pressed down and trapped through the screen holes by the stems, thus avoiding waste. It also avoids the problems of traditional irregularly shaped vibrating screens, which have difficulty in separating bridging material and straightening stems. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the flow guide plate and the material feeding plate of the present invention.

[0022] Explanation of reference numerals in the attached diagram: 1-Wave-shaped flow guiding and sorting area, 2-Sieve hole area, 3-Flow guide plate, 4-Discharge plate, 5-Sieve hole. Detailed Implementation

[0023] To make the objectives, technical solutions, and effects of this invention clear and easy to understand, the preferred embodiments of this invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can understand them.

[0024] It should be noted that, in the description of this invention, unless otherwise specified and limited, the terms "installation", "connection", "linking", "interconnection", etc., should be interpreted broadly, that is, they can be fixed connections or detachable connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium.

[0025] In this invention, such as Figure 1-2 As shown, a sieve for separating tobacco stems from shredded tobacco includes a wavy flow-guiding and sorting zone 1 and a sieve hole zone 2. The wavy flow-guiding and sorting zone 1 and the sieve hole zone 2 are arranged in a crisscross pattern to form a "louvered" type sieve. The wavy flow-guiding and sorting zone 1 is composed of multiple wavy-structured guide plates 3, and the length direction of the guide plates 3 is parallel to the forward direction of the tobacco shreds. Figure 1The direction indicated by the middle arrow is the forward direction of the tobacco shreds. Several feed plates 4 are installed in an inclined array perpendicular to the guide plates 3 within the screen area 2. Screen holes 5 are formed between every two adjacent guide plates 3 and every two adjacent feed plates 4. Specifically, the feeding end of the screen is defined as the rear end, and the forward direction of the tobacco shreds is defined as the front end. The feed plates 4 are arranged with a lower front and higher rear relative to the screen plane. This arrangement facilitates the back-inclined feed plates 4 during the reciprocating vibration of the screen, allowing the branch stems and twigs falling onto the feed plates 4 to be thrown backward through the screen holes 5 and removed from the screen. Simultaneously, it effectively prevents the tobacco shreds from being pressed down and trapped by the branch stems and twigs, thus avoiding waste. The mixture of tobacco shreds and branch stems is propelled towards the front end of the screen in a wave-like manner during the reciprocating vibration of the screen, and screening is completed during this process.

[0026] In this embodiment, the projection of the sieve hole 5 on the sieve plane is rectangular, and the opening length of the sieve hole 5 is greater than the length of the branch stem stick and less than the length of the tobacco shreds, so as to ensure that the branch stem stick can be smoothly discharged from the sieve hole 5 while avoiding the tobacco shreds passing through the sieve hole 5 and causing tobacco waste; in this embodiment, the preferred sieve hole 5 diameter is 18.8mm*4.8mm.

[0027] In this embodiment, a wave-shaped flow guiding and sorting zone 1 is formed by using a flow guide plate 3 with undulating high and low wave-shaped structure. During the reciprocating vibration of the screen, the flow guide plate 3 can suspend the bridging material formed by the entanglement of tobacco shreds and branch stems. The reciprocating flow guiding action of the wave-shaped structure of the flow guide plate 3 can disintegrate the bridging material, thereby untangling the tobacco shreds and branch stems. At the same time, the branch stems resting on the flow guide plate 3 are straightened and fall into the feed plate 4 in the direction of tobacco movement, and then fall out through the screen holes 5, thus separating the branch stems from the tobacco shreds. Because the length of the tobacco shreds exceeds the opening length of the screen holes 5, they are discharged from the screen outlet during the reciprocating vibration of the screen. The wave-shaped guide plate 3 suspends the bridging material between the tobacco shreds and the stems, thus separating them. Simultaneously, the feed plate 4, with its certain width, prevents curled tobacco shreds from getting caught on the screen, effectively avoiding shred snagging and screen clogging. This results in good screening effect for the stems, high screening efficiency, and high purity of the screened tobacco shreds, effectively ensuring cigarette quality. By using the guide plate 3 to suspend the bridging material between the tobacco shreds and the stems, stems of any length can be suspended and combed into the screen holes 5, avoiding the problems of traditional irregular-shaped vibrating screens that struggle to separate bridging material and straighten stems.

[0028] In some embodiments, the specifications of the guide plate 3 can be adaptively adjusted according to the different lengths of tobacco shreds and stems of different brands. Specifically, the thickness of the guide plate 3 can be 1mm-2mm, the peak height can be 10mm-15mm, the trough height can be 5.5mm-7.5mm, and the horizontal distance between two adjacent guide plates 3 can be 20mm-25mm, so as to select a suitable guide plate 3 according to the tobacco brand, so that the screening effect of the screen on the tobacco shreds and stems matches the tobacco brand. In this embodiment, the thickness of the guide plate 3 is preferably 1mm, the peak height is 10mm, the trough height is 5.5mm, and the horizontal distance between two adjacent guide plates 3 can be 20mm. Preferably, the peaks and troughs of two adjacent guide plates 3 are alternately set, which can effectively improve the disintegration effect of the guide plate 3 on the bridging material of tobacco shreds and stems, thereby improving the screening effect of the screen on tobacco shreds and stems.

[0029] In some embodiments, the guide plates 3 can also be arranged radially in a form that is wider at the front and narrower at the back, so that the screen mesh has a structure in which the width of the screen holes 5 gradually increases from the feeding end to the discharging end. This reduces the passage of longer branch stems near the feeding end of the screen mesh, thereby screening shorter branch stems near the feeding end of the screen mesh and screening longer branch stems near the discharging end of the screen mesh. This can effectively reduce the screening load of the screen mesh at the feeding end and improve screening efficiency. Specifically, the distance between two adjacent guide plates 3 at the front end of the screen mesh should be less than the length of the tobacco shreds, so as to avoid the tobacco shreds passing through the screen holes 5 at the front end of the screen mesh and causing tobacco waste.

[0030] A sieving method for separating branch stems from tobacco shreds, using the aforementioned sieve, comprising the following steps:

[0031] S1: Start the vibrating screen with the screen installed, so that the screen vibrates back and forth in the front and back direction in the screen plane. The feeding end of the screen is defined as the rear end and the direction of tobacco shreds forward is defined as the front end. The front end of the screen is arranged at a downward angle.

[0032] S2: A mixture of tobacco shreds and branch stems is continuously added from the feed end of the screen. During the reciprocating vibration of the screen, when the screen moves forward each time, the tobacco shreds and branch stems are simultaneously pushed towards the front end of the screen in a wave-like manner, entering the wave-shaped flow-guiding and sorting zone 1 and the screen hole zone 2.

[0033] S3: During the reciprocating vibration of the screen, the branch stems lean against the guide plate 3. Under the action of the wave-shaped guide plate 3, the bridging material between the tobacco and the branch stems is suspended and dismantled. At the same time, the branch stems leaning against the guide plate 3 are straightened into a state pointing in the direction of tobacco movement.

[0034] S4: Subsequently, the branch stems fall onto the feed plate 4 under the action of gravity. Each time the screen moves backward, the branch stems on the feed plate 4 pass through the screen hole 5 along the feed plate 4 and are thrown backward away from the screen. The tobacco cannot pass through the screen hole 5 and is pushed towards the front end of the screen each time the screen moves forward.

[0035] S5: During the reciprocating vibration of the screen, the mixture of tobacco and stems enters the subsequent wave-shaped flow guiding and sorting zone 1 and the screen hole zone 2 in sequence, and repeats the above steps S2 to S4 until all stems pass through the screen holes 5 to achieve separation from the tobacco.

[0036] This invention utilizes a "louvered" type screen composed of a flow-guiding and sorting zone formed by a wave-shaped guide plate and a feeding plate, along with a screen hole zone. The wave-shaped guide plate suspends the bridging material between the tobacco shreds and the stems, effectively separating the tobacco shreds and stems. This effectively prevents the screen from getting clumped or stuck, resulting in good screening effect, high screening efficiency, and high purity of the screened tobacco shreds. This effectively ensures the quality of cigarettes and prevents tobacco shreds from being pressed down and trapped through the screen holes by the stems, thus avoiding waste. It also avoids the problems of traditional irregularly shaped vibrating screens, which have difficulty in separating bridging material and straightening stems.

[0037] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A sieve for separating branch stems from tobacco shreds, characterized in that: The screen used to separate the branch stems from the tobacco includes a wave-shaped flow guiding and sorting area (1) and a screen hole area (2). The wave-shaped flow guiding and sorting area (1) and the screen hole area (2) are arranged in a cross pattern to form a "louvered" screen. The wave-shaped flow guiding and sorting area (1) is composed of multiple wave-shaped flow guiding plates (3), and the length direction of the flow guiding plate (3) is parallel to the forward direction of the tobacco. Several feed plates (4) are installed in an inclined array perpendicular to the flow guiding plate (3) in the screen hole area (2). A screen hole (5) is formed between every two adjacent flow guiding plates (3) and every two adjacent feed plates (4). The peaks and troughs of adjacent two flow guiding plates (3) are alternately arranged. The flow guiding plates (3) are arranged radially in a form that is wider at the front and narrower at the back.

2. A sieve for separating branch stems from tobacco shreds according to claim 1, characterized in that: The feed plate (4) is arranged with the front lower than the back relative to the screen plane.

3. A sieve for separating branch stems from tobacco shreds according to claim 1 or 2, characterized in that: The thickness of the guide plate (3) is 1mm-2mm, the peak height is 10mm-15mm, the trough height is 5.5mm-7.5mm, and the horizontal distance between two adjacent guide plates (3) is 20mm-25mm.

4. A sieve for separating branch stems from tobacco shreds according to claim 3, characterized in that: The projection of the sieve hole (5) on the sieve plane is rectangular, and the opening length of the sieve hole (5) is greater than the length of the branch stem and less than the length of the tobacco shreds. The sieve hole (5) has a diameter of 18.8mm*4.8mm.

5. A sieving method for separating branch stems from tobacco shreds, characterized in that: Using the sieve described in any one of the preceding claims, the sieving method for separating branch stems from tobacco shreds includes at least the following steps: S1: Start the vibrating screen with the screen installed, so that the screen vibrates back and forth in the front and back direction in the screen plane. The feeding end of the screen is defined as the rear end and the direction of tobacco shreds forward is defined as the front end. The front end of the screen is arranged at a downward angle. S2: A mixture of tobacco shreds and branch stems is continuously added from the feed end of the screen. During the reciprocating vibration of the screen, when the screen moves forward each time, the tobacco shreds and branch stems are simultaneously pushed towards the front end of the screen in a wave-like manner, entering the wave-shaped flow guiding and sorting zone (1) and the screen hole zone (2). S3: During the reciprocating vibration of the screen, the branch stem sticks rest on the guide plate (3). Under the action of the wave-shaped guide plate (3), the bridging material between the tobacco and the branch stem sticks is suspended and dismantled. At the same time, the branch stem sticks resting on the guide plate (3) are straightened into a state pointing towards the direction of tobacco movement. S4: Subsequently, the branch stems fall onto the feed plate (4) under the action of gravity. Each time the screen moves backward, the branch stems on the feed plate (4) pass through the screen hole (5) along the feed plate (4) and are thrown backward away from the screen. The tobacco cannot pass through the screen hole (5) and is pushed towards the front end of the screen each time the screen moves forward. S5: During the reciprocating vibration of the screen, the mixture of tobacco and branch stems enters the subsequent wave-shaped flow guiding and sorting zone (1) and the screen hole zone (2) in sequence, and repeats the above steps S2 to S4 until all branch stems pass through the screen holes (5) to achieve separation from the tobacco.

Images