Double-roller different-tooth screening device and screening method using same

Abstract

The invention provides a tobacco shred screening device which solves the problem that according to a traditional tobacco shred screening device, in the screening tooth arrangement mode, during rotation, part of tobacco shreds are pressed by screening teeth, and screening leakage is caused. A plurality of screening teeth are arranged in the circumferential direction of each screening disc, the screening teeth at the screening discs at the adjacent screening rollers are mutually staggered to form a screening surface, each screening roller is in transmission connection with a driving device through a traditional device and rotates, and the screening device comprises a structure that the screening teeth of the screening discs at one screening roller are longer, the screening teeth of the screening discs at the other screening roller are shorter, and the screening teeth of the adjacent screening rollers are different in length. According to the technical scheme, the arrangement mode of the screen teeth breaks through the arrangement mode of the traditional screen teeth, the staggered distribution mode of the screen teeth with the long roller shafts and the screen teeth with the short roller shafts is adopted, and the screening device is different from an existing screening device. When the long screen teeth deflect to scrape and press tobacco shreds, the long screen teeth make contact with the short screen teeth of the adjacent screen rollers within a small deflection angle, namely, the short screen teeth pick up and convey the tobacco shreds about to be scraped and pressed at the moment, and the number of the tobacco shreds leaking from the screen due to the fact that the tobacco shreds are pressed downwards by the long screen teeth is reduced.

Description

Technical Field

[0001] The invention relates to a screening structure, in particular to a double-roller hetero-tooth screening device and a screening method using the device. Background Art

[0002] The tobacco processing involves grading, transportation, screening and other operations. As a characteristic of tobacco, due to the large amount of oily substances on the surface of tobacco, tobacco clumping is a common phenomenon. In order to ensure the grading and screening effects of tobacco, the tobacco must be loosened.

[0003] Ordinary flat screens have very limited screening effects due to the clumping and stacking of tobacco, and there are problems such as poor screening and blocking of the screen holes. Under normal circumstances, tobacco is generally 0.8-1.0mm wide and about 0.16mm thick. Tobacco with a length of more than 15mm accounts for about 20-30% of all tobacco, and the length of more than 5mm is curved. If the length exceeds 15mm (before rolling), it will sag naturally and will deform with a slight external force, making it very easy to clumping.

[0004] In order to break through the limitations of traditional plane screening devices, in the field of tobacco screening, special screening equipment for tobacco screening has been formed by introducing and digesting screening devices such as roller screens. The original roller screen has multiple disc-shaped screens on the roller shaft, relying on the irregular outer contour of the screen to achieve the movement and vibration of the screened materials, so as to facilitate the screening operation. The traditional roller screen is mainly used to screen hard materials such as mineral materials, and is obviously not suitable for flexible and agglomerated materials. Therefore, on the basis of the above, a screen plate with a screen tooth structure has been developed. During transportation and screening, the screen teeth loosen the contacted materials. The looser the tobacco material is, the more conducive it is to subsequent screening. As a common perception in the industry, it is generally believed that the easier it is to insert the screen teeth into the agglomerated tobacco, the easier it is to loosen the tobacco. Therefore, in the design of the screen tooth structure, the screen teeth are generally required to be slender or set with a tip while retaining a longer tooth length structure. Therefore, in recent years, the field of tobacco screening has been pursuing the setting of screen plates and screen teeth, but due to the consideration of screening effect, the design structure of the screen teeth has not been broken through.

[0005] The sieve holes of traditional tobacco screens are formed by the gaps between the screen plates and the adjacent screen roller profiles, which are formed on the plane orthographic projection holes. The disc-shaped structure on the screen roller makes the screened material jump, which is suitable for screening granular and blocky hard materials. The sieve plate with screen teeth has different sieve holes from the traditional roller screen, just like Figure 1As shown, for the convenience of expression, the top of the screen teeth is called the tooth peak, and the bottom is called the tooth valley. As an inevitable phenomenon, when the screen teeth rotate from the top point, there is always a part of the agglomerated tobacco in the tooth valley, which is scraped and pressed down by the adjacent screen teeth. At the same time, the screen teeth on both sides of the rotating screen teeth on the adjacent tooth rollers rotate in the same direction, picking up a part of the tobacco and moving it to the next position. The downward rotating screen teeth inevitably continue to scrape and press the part of the tobacco in the tooth valley to continue to move downward, that is, this part of the tobacco is not loosened by the screen teeth and is pressed down by the lower rotating screen teeth, and is forced to pass through the screen hole, that is, the leakage phenomenon occurs. This is also the vast majority of the reasons for the leakage of the current double-roller different-tooth screening device with screen tooth structure.

[0006] To solve the problem of missed screening in the roller-shaped screening device with screen teeth structure, this problem must be solved, that is, to reduce the amount of tobacco scraped and pressed by the screen teeth. However, at present, everyone's research direction is focused on improving the loosening efficiency of the screen teeth on the tobacco. In fact, longer screen teeth will increase the amount of scraping and pressing on the tobacco, which will affect the missed screening rate. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to propose a double-roller uneven-tooth screening device to solve the problem that in traditional tobacco screening devices, when the screen teeth are set in a way that some tobacco will be pressed down by the screen teeth during rotation, resulting in leakage.

[0008] The technical solution is to include a screen frame for mounting and fixing a plurality of parallel arranged screen rollers, each of the screen rollers being provided with a plurality of screen plates axially spaced to prevent rotation, each of the screen plates being provided with a plurality of screen teeth circumferentially, the screen teeth at the screen plates at adjacent screen rollers being staggered to form a screen surface, forming a structure for loosening, transporting and screening tobacco, and also including a driving device and a transmission mechanism, each of the screen rollers being connected to the driving device and rotating via a traditional transmission device, including a structure in which the screen teeth at each screen plate at one screen roller are longer, the screen teeth at each screen plate at another adjacent screen roller are shorter, and the screen teeth of adjacent screen rollers are different in length.

[0009] In the above or some embodiments, the sieve plates at the same sieve roller are of uniform shape and structure, and each sieve plate includes a base plate and the sieve teeth evenly arranged at the periphery of the base plate; the sieve teeth of each sieve roller have the same outer diameter, forming a structure in which the sieve teeth of one sieve roller are longer and the sieve teeth of another adjacent sieve roller are shorter in diameter.

[0010] In the above or some embodiments, each of the toothed discs is connected to the roller shaft via a key to form the non-rotating connection.

[0011] In the above or some embodiments, a sprocket is fixedly connected to the end of each roller shaft, and each roller shaft is connected for synchronous rotation via the sprocket and the transmission chain.

[0012] In the above or some embodiments, the ends of each roller shaft are respectively connected to the motor via a coupling to form a synchronous rotation structure driven by the motor.

[0013] In the above or some embodiments, the screen surface includes zone I and zone II, wherein zone I includes two groups of screen rollers with different screen tooth lengths arranged in a staggered manner, and zone II includes several uniformly arranged screen rollers.

[0014] In the above or some embodiments, the sieve teeth at each sieve roller in zone II are short sieve teeth, and the number of sieve teeth at each sieve roller in zone II is less than the number of short sieve teeth at the sieve roller in zone I.

[0015] The present invention also proposes a tobacco screening method to solve the problem that in a traditional tobacco screening device, when the screen teeth are set in a rotating manner, part of the tobacco will be pressed down by the screen teeth and will be missed.

[0016] The setting of the screen teeth in this technical solution breaks through the traditional setting method of screen teeth, that is, the structure of uniform screen surface with the same length of each screen tooth. This solution adopts a staggered distribution method of one roller with longer screen teeth and one roller with shorter screen teeth, which constitutes a screening device different from the previous one. In order to prevent the tobacco from being bent by the long teeth and sliding between the two short teeth, when the longer screen teeth are deflected to scrape and press the tobacco, they will contact the shorter screen teeth of the adjacent screen roller within a smaller deflection angle. That is, at this time, the tobacco to be scraped and pressed is picked up and transported away by the shorter screen teeth, which reduces the amount of tobacco that is missed due to the downward pressure of the longer screen teeth, and the effect is obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural principle diagram of the present invention.

[0018] Figure 2 for Figure 1 Enlarged schematic diagram of part A.

[0019] Figure 3 It is a schematic diagram of the main structure of the present invention.

[0020] Figure 4 It is a top view of the present invention.

[0021] Figure 5 It is a side view of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure including the screen surfaces in zones I and II. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of the present invention, "plurality" means two or more than two, unless otherwise clearly and specifically defined.

[0025] The invention comprises a screen frame 100 for installing and fixing a plurality of parallel arranged screen rollers, the screen frame 100 is composed of plate-shaped fixed plates 101 opposite to each other on both sides, a fixed beam between the two fixed plates 101, a mounting hole for installing the bearing seat of the roller shaft 300 is arranged at the fixed plate 101, each roller shaft 300 is located between the fixed plates 101, and each roller shaft 300 is exposed at the end of the fixed frame. Each roller shaft 300 can be driven by a motor through a chain and a sprocket, or can be synchronously driven by an independent motor. When the chain is driven, the end of each roller shaft 300 is fixedly connected with a sprocket, and each roller shaft 300 is connected to a synchronous rotation through the sprocket and the transmission chain. When each screen roller is driven independently, the end of each roller shaft 300 is connected to a motor, such as a stepping motor, through a coupling, to form a synchronous rotation structure driven by a motor.

[0026] Each of the sieve roller shafts 300 is provided with a plurality of sieve plates 200 for anti-rotation at intervals, and each of the sieve plates 200 is provided with a plurality of sieve teeth 201 in the circumferential direction. The anti-rotation installation includes that each sieve plate and the sieve roller are detachably fixedly connected by keyways and keys, and the anti-rotation means that the sieve plate does not rotate relative to the sieve roller. Each sieve plate 200 at the same sieve roller is of uniform shape and structure, that is, the sieve plates have the same diameter, sieve teeth length and structure. Each sieve plate 200 includes a base plate 202, and the sieve teeth 201 evenly arranged at the periphery of the base plate 202. The pair of rollers with different teeth, two adjacent sieve rollers constitute the pair of rollers, wherein the sieve teeth 201 of one of the sieve rollers are longer, and the sieve teeth 201 of the other adjacent sieve rollers are shorter, constituting the different tooth structure. The base plate 202 and the sieve teeth 201 are an integral structure or a split structure, and when it is a split structure, it can be fixed by fasteners such as bolts.

[0027] In the above or some embodiments, each of the toothed discs is connected to the roller shaft 300 via a key to form the anti-rotation connection.

[0028] The longer screen teeth 201 and the screen roller constitute a longer-tooth screen roller group, and the shorter screen teeth 201 and the screen roller constitute a shorter-tooth screen roller group. The longer-tooth screen roller group and the shorter-tooth screen roller group are installed adjacent to each other, and the screen teeth 201 at each screen plate 200 at adjacent screen rollers are staggered to form a screen surface. The screen teeth 201 of adjacent screen rollers have different lengths, forming a structure for loosening, transporting, and screening tobacco. Preferably, the length of the longer screen teeth 201 is 50mm-80mm, the length of the shorter screen teeth 201 is 5mm-8mm, the number of the longer screen teeth 201 is 9-16, and the number of the shorter screen teeth 201 is 36-48, so that when the longer screen teeth 201 are deflected 15°-35° from the vertical state, the adjacent tooth valley immediately contacts the tooth valley of the shorter teeth, forming a structure in which the tobacco to be pressed is lifted and transported when it is pressed down at a smaller angle.

[0029] The shape structure of the screen teeth can be set to a trapezoidal structure with a smaller outer end and a wider tooth valley. Of course, in order to better loosen the tobacco, a tip with a sudden change in width can be set at the top of the screen teeth, that is, a structure with a sudden change in width at the tip.

[0030] In order to better achieve the screening of tobacco shreds and reduce the screening pressure in the same area, in the above or some embodiments, the screen surface includes zone I and zone II, the zone I includes two groups of screen rollers with different lengths of screen teeth 201 arranged in a staggered manner, and the zone II includes several uniformly arranged screen rollers.

[0031] In the above or some embodiments, the sieve teeth 201 at each sieve roller in zone II are short sieve teeth 201, and the number of sieve teeth 201 at each sieve roller in zone II is less than the number of short sieve teeth 201 at the sieve roller in zone I. Preferably, the number of sieve teeth 201 there is 16 teeth, and the number of sieve rollers there is three groups.

[0032] The present invention also proposes a method for screening shredded tobacco, in which the shredded tobacco is pre-screened and then passed through the double-roller different-tooth screening device to screen the passed shredded tobacco; the method comprises a structure in which the sieve teeth 201 of each sieve plate 200 at one sieve roller are longer, the sieve teeth 201 of each sieve plate 200 at another sieve roller are shorter, and the sieve teeth 201 of adjacent sieve rollers have different lengths; when the longer sieve teeth 201 are deflected 15°-35° from the vertical state, the adjacent tooth valleys thereof immediately contact the tooth valleys of the shorter teeth, forming a structure in which the shredded tobacco to be pressed is picked up and transported when it is pressed down at a smaller angle.

[0033] The setting of the screen teeth in this technical solution breaks through the traditional setting method of screen teeth and the structure of uniform screen surface with the same length of each screen tooth. This solution adopts a staggered distribution method of one roller with longer screen teeth and one roller with shorter screen teeth, which constitutes a screening device different from the previous one. When the longer screen teeth are deflected to scrape and press the tobacco, they will contact the shorter screen teeth of the adjacent screen roller within a smaller deflection angle, that is, at this time, the tobacco to be scraped and pressed is picked up and transported away by the shorter screen teeth, which reduces the amount of tobacco that is missed due to the pressure of the longer screen teeth, and the effect is obvious.

Claims

1. A roller-different-tooth screening device, comprising a screen frame (100) for mounting and fixing a plurality of parallel-arranged screen rollers, a plurality of screen plates (200) being axially spaced and non-rotatably mounted on each of the screen roller shafts (300), a plurality of screen teeth (201) being circumferentially arranged on each of the screen plates (200), the screen teeth (201) of each of the screen plates (200) at adjacent screen roller shafts being staggered to form a screen surface, forming a structure for loosening, transporting and screening tobacco shreds, and further comprising a driving device and a transmission mechanism, wherein each of the screen rollers is connected to the driving device via the transmission device and rotates, characterized in that: The invention comprises a structure in which the sieve teeth (201) of each sieve plate (200) at one sieve roller are longer, and the sieve teeth (201) of each sieve plate (200) at another adjacent sieve roller are shorter, thereby forming a structure in which the sieve teeth (201) on adjacent sieve rollers have different lengths.

2. The roller-different-tooth screening device according to claim 1 is characterized in that: The sieve plates (200) at the same sieve roller have a uniform shape and structure, and each sieve plate (200) comprises a base plate (202) and the sieve teeth (201) are evenly arranged at the periphery of the base plate (202); the sieve teeth (201) of each sieve roller have the same outer diameter, forming a structure in which the sieve (201) of one sieve roller is longer and the sieve teeth (201) of another adjacent sieve roller are shorter, and the maximum diameters are the same.

3. The roller-different-tooth screening device according to claim 2 is characterized in that: Each of the toothed discs is connected to the roller shaft (300) via a key to form the anti-rotation connection.

4. The roller-different-tooth screening device according to any one of claims 1 to 3, characterized in that: The end of each roller shaft (300) is fixedly connected with a sprocket, and each roller shaft (300) is connected to rotate synchronously via the sprocket and the transmission chain.

5. The roller-different-tooth screening device according to any one of claims 1 to 3, characterized in that: The ends of each roller shaft (300) are respectively connected to the motor via a coupling, forming a synchronous rotation structure driven by the motor.

6. The roller-different-tooth screening device according to claim 4 or 5, characterized in that: The screen surface comprises a zone I and a zone II, wherein the zone I comprises two groups of screen rollers having screen teeth (201) of different lengths arranged in a staggered manner, and the zone II comprises a plurality of screen rollers having uniform screen teeth arranged in a staggered manner.

7. The roller-different-tooth screening device according to claim 6 is characterized in that: The sieve teeth (201) at each sieve roller in zone II are short sieve teeth (201), and the number of sieve teeth (201) at each sieve roller in zone II is less than the number of short sieve teeth (201) at each sieve roller in zone I.

8. A method for screening shredded tobacco using the roller-different-tooth screening device according to claim 7, characterized in that: After being pre-screened, the tobacco shreds are passed through the roller-different-tooth screening device to screen the tobacco shreds that pass through; the device comprises a structure in which the sieve teeth (201) of each sieve plate (200) at one sieve roller are longer, the sieve teeth (201) of each sieve plate (200) at another sieve roller are shorter, and the sieve teeth (201) of adjacent sieve rollers are of different lengths; when the longer sieve teeth 201 are deflected by 15°-35° from a vertical state, the adjacent tooth valleys immediately contact the tooth valleys of the shorter teeth, forming a structure in which the tobacco shreds that are about to be pressed are lifted up and transported when they are pressed down at a smaller angle.

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