On-line separation and classification device for large and medium redried tobacco slices

Abstract

The utility model discloses an on-line separation and classification device for large and medium redried tobacco sheets. The separation and classification device comprises a conveyor (1), a first-stage vibrating screen (4), a conveying plate (5), a first-stage discharge hopper (6), a second-stage vibrating screen (9), a second-stage discharge hopper (10) and a third-stage discharge hopper (11), the first-stage vibrating screen (4) and the second-stage vibrating screen (9) respectively comprise a first-stage screen plate (2) and a second-stage screen plate (7), the surface screening surfaces of the first-stage screen plate (2) and the second-stage screen plate (7) are arranged to be wave-shaped surfaces, and the wave-shaped surfaces are space curved surfaces formed by orthogonality of curved surfaces formed by moving along a first track and curved surfaces formed by moving along a second track; the loose conveying and screening effects are better, large tobacco flakes and medium tobacco flakes can be loosened and screened, for the tobacco shred making and cigarette rolling process, the medium tobacco flake rate is increased, the filament rate of tobacco shred making is controlled, the tobacco shred structure of medium and thin cigarettes is improved, and the cigarette quality is improved.

Description

Technical Field

[0001] The utility model belongs to the field of tobacco, relates to cigarette production technology, and specifically relates to an online separation and classification device for large and medium redried tobacco sheets on a redrying production line. Background Art

[0002] Leaf beating and redrying are the basis of cigarette raw material production. There is a key process in the leaf beating and redrying production line, in which the leaf beating machine completes the separation of stems and leaves. Since it is difficult to separate stems and leaves, multi-stage leaf beating and multi-stage wind separation are adopted, such as "five beatings and eighteen points". Therefore, it is particularly important to control the size of the tobacco leaves after beating, and roller beating and frame fence control are generally used. As for the leaf beating and redrying process, the higher the rate of large and medium pieces in the tobacco leaves, the lower the fragments and crushed powder, which means the better the effect. The best process method is to increase the rate of large pieces (for example, tobacco leaves larger than 25.4mm square) and reduce the rate of medium pieces (for example, tobacco leaves larger than 12.5mm and less than or equal to 25.4mm square), which is referred to as "increasing large and reducing medium".

[0003] However, research and application have shown that for the silk-making process and cigarette-rolling process, if the medium-sized flake rate can be increased in the re-baking process, or "increasing the medium and reducing the large", the long-filament rate in the silk-making process can be effectively controlled, and the tobacco structure of medium and thin cigarettes will be greatly improved, which is conducive to improving the quality of cigarettes. Obviously, it is difficult to achieve good results by controlling the size of the flakes after threshing. A large and medium-sized flake screening process should be designed to improve the size consistency and avoid large and medium-sized flakes from being broken into pieces (for example, less than 6 mm square) during the second threshing, that is, to reduce the broken tobacco rate.

[0004] In terms of improving the accuracy of tobacco leaf classification, it is not easy to finely screen the fragments and debris in the redried tobacco leaves, let alone effectively distinguish between large and medium-sized tobacco leaves. The core of this challenge lies in the unique physical properties of redried tobacco leaves, such as its strong plasticity, variability in size, light weight and insignificant differences. In addition, the clamping, wrapping or adsorption phenomena that are easy to occur between tobacco leaves, especially the common adhesion, accumulation and even agglomeration problems of materials at the exit of the leaf beating unit, make it quite difficult to simply achieve loose handling of large and medium-sized tobacco leaves, not to mention the subsequent accurate classification. What is particularly tricky is that there are many huge leaves of more than 100 mm square in large and medium-sized tobacco leaves, and even occasional smaller but complete leaves (or whole leaves), which makes it difficult to achieve smaller size differences or higher consistency when classifying by size. After all, in an assembly line operation environment, it is almost an impossible task to achieve the accuracy of tobacco leaf size classification to the level of metrology testing.

[0005] In view of the above technical bottlenecks, the core of the separation and classification technology for large and medium-sized tobacco flakes in redried tobacco leaves focuses on how to efficiently achieve the loose treatment of tobacco flakes and subsequent precise size screening. The linear planar vibrating screen in the current technology is limited by its single planar elastic force and is difficult to fully demonstrate the ideal effect of tobacco flake loosening. Coupled with the relatively fast material transmission speed of the planar vibrating screen, it further exacerbates the improvement of screening difficulty. From the perspective of optimizing the production line layout, in order to ensure that the cut tobacco material can be thoroughly screened, it is also impossible to infinitely extend the length of the screening line, which undoubtedly puts forward a more urgent need for technological innovation.

[0006] To sum up, in order to achieve the classification of large and medium-sized tobacco flakes in redried tobacco leaves and complete the three-stage screening of tobacco flakes, such as separating and classifying large tobacco flakes with a side length greater than 25.4 mm, medium-sized tobacco flakes with a side length greater than 12.5 mm and less than 25.4 mm, and fragments and powdery substances with a side length less than 6 mm, it is of great significance to the redrying process and has broad application prospects for the cut tobacco process, cigarette rolling process and improving cigarette quality.

[0007] To solve the above problems, the present utility model is proposed. Content of the Utility Model

[0008] In view of the deficiencies of the prior art, the present utility model provides an on-line separation and classification device for large and medium-sized tobacco flakes in redried tobacco leaves and a three-stage screening method for tobacco flakes. In view of the simple harmonic vibration physical characteristics of the planar vibrating screen, the present utility model adopts a sine basis function and designs a conveying and screening plate by using two sine curves in an "orthogonal" manner. The sine wave surface can provide the most efficient loosening effect on tobacco flakes. In this way, by using sine wave conveying and screening, large tobacco flakes can be conveyed in a floating manner along the wave crest or between two wave surfaces, and small-sized tobacco flakes or broken tobacco can complete the conveying and screening in the wave trough, so that the material has good fluidity and loose uniformity. The sine wave surface also has characteristics such as low breakage of materials and balanced material rate. Therefore, the application of the waveform curved surface screening plate of the present utility model will improve the screening efficiency and the performance of the vibrating screen. The surface of the screening plate of the present utility model is a waveform surface, which is constructed by using the sine basis functions y = acos(ω1x) and y = bcos(ω2z). The z-axis direction is the forward direction of the material, and the x-direction is the width direction of the screening plate; the screening holes are all manufactured on the wave trough line; the present utility model has a high loosening effect and screening efficiency for the separation and classification of large and medium-sized tobacco flakes and broken tobacco in redried tobacco leaves, with low breakage, and can be connected to the threshing and redrying production line on-line.

[0009] The present utility model provides an on-line separation and classification device for large and medium-sized tobacco flakes in redried tobacco leaves, which includes a feeder 1, a primary vibrating screen 4, a conveying plate 5, a primary discharge hopper 6, a secondary vibrating screen 9, a secondary discharge hopper 10 and a tertiary discharge hopper 11;

[0010] The first-stage vibrating screen 4 and the second-stage vibrating screen 9 respectively include a first-stage sieve plate 2 and a second-stage sieve plate 7. The first-stage sieve plate 2 is provided with first-stage screening holes 3, and the second-stage sieve plate 7 is provided with second-stage screening holes 8;

[0011] The first-stage vibrating screen 4 and the second-stage vibrating screen 9 are respectively in material communication with the first-stage discharge hopper 6 and the second-stage discharge hopper 10 through the conveying plate 5. Below the second-stage vibrating screen 9 is the third-stage discharge hopper 11;

[0012] The surface screening surfaces of the first-stage sieve plate 2 and the second-stage sieve plate 7 are set as corrugated surfaces. The corrugated surface is a spatial surface formed by the orthogonal intersection of a surface formed by moving along a first trajectory and a surface formed by moving along a second trajectory. The first trajectory is a cosine curve in a first vertical plane, and the tangents at the wave peaks and valleys of the first trajectory are parallel to the width direction of the sieve plate. The second trajectory is a cosine curve in a second vertical plane, and the tangents at the wave peaks and valleys of the second trajectory are parallel to the length direction of the sieve plate. The first vertical plane and the second vertical plane are perpendicular and orthogonal to each other;

[0013] The length direction of the first-stage sieve plate 2 and the second-stage sieve plate 7 is the conveying direction of the tobacco sheet material.

[0014] Preferably, the first-stage discharge hopper 6 is a large-piece discharge hopper, referring to large tobacco sheets with a size greater than 25.4 mm;

[0015] The second-stage discharge hopper 10 is a medium-piece discharge hopper, referring to medium tobacco sheets with a size greater than 12.5 mm and less than or equal to 25.4 mm;

[0016] The third-stage discharge hopper 11 is a fragment discharge hopper, referring to shredded tobacco with a size less than or equal to 12.5 mm. Shredded tobacco includes shredded tobacco dust, tobacco stems, etc.

[0017] Preferably, in the spatial coordinate system constructed by the first vertical plane and the second vertical plane, the equation of the first trajectory is y = a cos(ω1x), with a wavelength of λ1, and the equation of the second trajectory is y = b cos(ω2z), with a wavelength of λ2. Preferably, a = 1, b = 1, ω1 = 1, and ω2 < 1.

[0018] Preferably, the diameter of the first-stage screening holes 3 is The diameter of the second-stage screening holes 8 is Both the first-stage screening holes 3 and the second-stage screening holes 8 are manufactured on the wave trough lines, and The function curve of the wave trough line is: y = b cos(ω2z), x = nπ, where n is a positive integer representing the wave trough line number;

[0019] The first-stage screening holes 3 are manufactured by using the normal vector drilling method at the center position of the screening holes on the wave trough line.

[0020] Preferably, for the classification of large pieces of tobacco, the aperture of the primary screening holes 3 is preferably For the waveform surface, the equation of the first trajectory is y = 10cos(x / 10), the wavelength λ1 = 62.832 mm, and the equation of the second trajectory is y = 10cos(z / 20), the wavelength λ2 = 125.664 mm.

[0021] Preferably, on the wave trough line within one λ2 of the wavelength, 5 of the primary screening holes 3 are processed using the average interpolation method, and the aperture is processed along the normal vector direction of the wave trough line according to the coordinate positions of each hole, and the coordinate positions of each hole;

[0022]

[0023] In the formula, x0 and z0 represent the position of the starting hole 0;

[0024] n represents the wave trough number of y = 10cos(x / 10), and k represents the hole number on the curve of y = 10cos(z / 20).

[0025] Preferably, for the classification of medium pieces of tobacco, the aperture of the secondary screening holes 8 is preferably For the waveform surface, the equation of the first trajectory is y = 5cos(x / 5), the wavelength λ1 = 31.416 mm, and the equation of the second trajectory is y = 5cos(z / 10), the wavelength λ2 = 62.832 mm;

[0026] On the wave trough line within one λ2 of the wavelength, 5 of the secondary screening holes 8 are processed using the average interpolation method, and are processed along the direction perpendicular to the XOZ horizontal plane according to the coordinate positions of each hole, and the coordinate positions of each hole:

[0027]

[0028] In the formula, x0 and z0 represent the position of the starting hole 0;

[0029] n represents the wave trough number of y = 5cos(x / 5), and k represents the hole number on the curve of y = 5cos(z / 10).

[0030] Preferably, the lengths L and widths B of the primary sieve plate 2 and the secondary sieve plate 7 are designed and rounded according to the golden ratio of 0.618.

[0031] Preferably, the length L of the primary sieve plate 2 is 1319.472 mm, and it contains a total of 10.5λ2 (λ2 = 125.664 mm), the width B is 816.816 mm, and it contains a total of 13λ1 (λ1 = 62.832 mm), and the material moves along the length L of the primary sieve plate 2 or the z-axis direction;

[0032] The length L of the secondary sieve plate 7 is 1319.472 mm, which contains a total of 21λ2 (λ2 = 62.832 mm), and the width B is 816.816 mm, which contains a total of 26λ1 (λ1 = 31.416 mm). The material moves along the length L of the secondary sieve plate 7 or the z-axis direction.

[0033] Using the online separation and classification device for large and medium-sized tobacco flakes of the present utility model, the three-stage screening method for large and medium-sized tobacco flakes of the re-dried tobacco flakes includes the following steps: The re-dried tobacco flakes are input from the feeder 1 to the first-stage vibrating sieve 4, and the separation of large tobacco flakes (large tobacco size) is completed by the first-stage sieve plate 2 and the first-stage screening holes 3. The large tobacco flakes are output by the conveying plate 5 and the first-stage discharge hopper 6; the remaining material is input into the second-stage vibrating sieve 9 again, and the separation of medium-sized tobacco flakes (medium-sized tobacco size) and broken tobacco is completed by the second-stage sieve plate 7 and the second-stage screening holes 8. The medium-sized tobacco flakes are output by the conveying plate 5 and the second-stage discharge hopper 10, and the broken tobacco is output by the third-stage discharge hopper 11; the first-stage sieve plate 2 and the second-stage sieve plate 7 are used for the loose conveying and screening of the tobacco flake material.

[0034] Compared with the prior art, the present utility model has the following beneficial effects:

[0035] 1. In the threshing and redrying production line, multi-stage threshing and multi-stage pneumatic separation are used to complete the separation of tobacco stems and leaves, and the control of the size of cut tobacco by the threshing roller and the frame is a key process in the redrying process. Therefore, classifying cut tobacco by size is a key common technology, and the screening device of the present utility model can realize the separation and classification of cut tobacco in multiple sizes.

[0036] Furthermore, at the cut tobacco discharge point in the threshing and redrying production line, cut tobacco of various specifications often accumulates, is clamped or wrapped with each other, or agglomerates, etc., and there is also a large flow rate. The sieve plate of the screening device of the present utility model is set as a corrugated surface, and the corrugated surface is a space surface formed by the orthogonal intersection of the surface formed by moving along the first trajectory and the surface formed by moving along the second trajectory. Its loose conveying and screening effect is better, and it can realize the loosening and screening of large tobacco flakes and medium-sized tobacco flakes. For the processes of cut tobacco processing and cigarette rolling, the medium-sized tobacco rate can be increased to control the long filament rate of cut tobacco processing, which will improve the cut tobacco structure of medium and fine filter cigarettes and is beneficial to improving the cigarette quality. At the same time, screening medium-sized tobacco flakes online can also reduce the broken tobacco rate and improve the redrying process level.

[0037] 2. Since there are orthogonal sine curve surfaces on the screening surfaces of the two-stage screening plates, their wave crests, wave troughs and wave surfaces provide alternating changes and arrayed elastic forces. Therefore, the loosening and even distribution effects on cut tobacco are the best, and based on its surface characteristics, the breakage of cut tobacco is also the lowest. In addition, the screening holes on the two-stage screening plates All are designed on the wave trough line. For the tobacco flakes with a size smaller than the wavelength λ, screening and conveying will be completed within the wave trough, while for those larger than the wavelength λ, they will be smoothly conveyed along the vibration direction of the vibrating screen along the wave surface or wave crest. Therefore, the screening efficiency and the thorough screening rate are the highest.

[0038] 3. Further preferably, the screening holes of the primary sieve plate of the screening device of the present invention are 25.4 mm, and can also be adjusted according to the specific process. Holes are punched using the normal vector on the curved surface. Therefore, for the manufacturing of the screening holes on the wave surface, the size control of the screened tobacco flakes is more accurate. The screening holes of the secondary sieve plate are designed on the wave trough line according to 6 mm, and this wave trough line is a cosine curve. Therefore, when screening the broken tobacco, the screening holes will probably capture the "stem sticks" in the tobacco flakes if any and complete their separation.

[0039] 4. The sieve plate of the screening device of the present invention is set as a corrugated surface, and this corrugated surface is constructed by using orthogonal sine basis functions. More specifically, the present invention is constructed by y = acos(ω1x) and y = bcos(ω2z). Compared with the construction by y = acos(ω1x) and x = bcos(ω2z), the corrugated surface formed orthogonally in the present invention has the characteristic of amplitude superposition. Therefore, it provides higher efficient loosening and screening efficiency, which is particularly crucial for the conveying and screening of materials such as re-dried cut tobacco with serious adhesion and agglomeration.

[0040] 5. Since the screening technology is important and crucial in the tobacco processing industry, the key theories in this technical solution, such as the construction of orthogonal sine wave surfaces and the wave trough line screening method, have a promoting significance for the development of the tobacco machinery equipment technology in the tobacco industry. Similarly, it also has promotional value in other industrial application fields such as food, medicine, and mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to better understand the above and other objects, features, advantages and functions of the present invention, the embodiments shown in the drawings can be referred to. The same reference numerals in the drawings refer to the same components. Those skilled in the art should understand that the drawings are intended to schematically illustrate the preferred embodiments of the present invention and have no restrictive effect on the scope of the present invention. The components in the drawings are not drawn to scale.

[0042] In the drawings:

[0043] Figure 1 is the structural schematic diagram of the on-line separation and classification device for large and medium-sized flakes of re-dried cut tobacco of the present invention;

[0044] Figure 2 The schematic diagram of the annotation of the primary sieve plate in the three-dimensional coordinate system in the embodiment of the present invention;

[0045] Figure 3 It is a schematic diagram of the screening hole design of the primary sieve plate in the embodiment of the present utility model;

[0046] Figure 4 It is a schematic diagram of the annotation of the secondary sieve plate in the three-dimensional coordinate system in the embodiment of the present utility model;

[0047] Figure 5 It is a schematic diagram of the screening hole design of the secondary sieve plate in the embodiment of the present utility model;

[0048] Figure 6 It is a schematic diagram for analyzing the drilling position of the normal line on the cosine curve of the wave trough line of the primary sieve plate in the embodiment of the present utility model.

[0049] The names corresponding to the reference numerals in the drawings are: feeder 1, primary sieve plate 2, primary screening hole 3, primary vibrating screen 4, conveying plate 5, primary discharge hopper 6, secondary sieve plate 7, secondary screening hole 8, secondary vibrating screen 9, secondary discharge hopper 10, and tertiary discharge hopper 11. Detailed implementation manners

[0050] The present utility model will be further described in detail below in conjunction with the embodiments.

[0051] The above and other technical features and advantages of the present utility model will be described in more detail below in conjunction with the drawings. In the description of the present utility model, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present utility model, the meaning of "a plurality" is at least two, unless otherwise specifically defined.

[0052] In the present utility model, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] In the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0054] As Figure 1 shown, this embodiment provides an online separation and classification device for large and medium-sized reconstituted tobacco leaves and a three-stage screening method for tobacco leaves. The online separation and classification device for large and medium-sized reconstituted tobacco leaves includes a feeder 1, a first-stage vibrating screen 4, a conveying plate 5, a first-stage discharge hopper 6, a second-stage vibrating screen 9, a second-stage discharge hopper 10 and a third-stage discharge hopper 11;

[0055] The first-stage vibrating screen 4 and the second-stage vibrating screen 9 respectively include a first-stage screen plate 2 and a second-stage screen plate 7. The first-stage screen plate 2 is provided with first-stage screening holes 3, and the second-stage screen plate 7 is provided with second-stage screening holes 8;

[0056] The first-stage vibrating screen 4 and the second-stage vibrating screen 9 are respectively in material communication with the first-stage discharge hopper 6 and the second-stage discharge hopper 10 through the conveying plate 5. The third-stage discharge hopper 11 is located below the second-stage vibrating screen 9.

[0057] As Figures 2 to 5 shown, the surface screening surfaces of the first-stage screen plate 2 and the second-stage screen plate 7 are set as corrugated surfaces. The corrugated surface is a space surface formed by the orthogonal intersection of a surface formed by moving along a first trajectory and a surface formed by moving along a second trajectory. The first trajectory is a cosine curve in a first vertical plane, and the tangents at the wave peaks and wave valleys of the first trajectory are parallel to the width direction of the screening plate. The second trajectory is a cosine curve in a second vertical plane, and the tangents at the wave peaks and wave valleys of the second trajectory are parallel to the length direction of the screening plate. The first vertical plane and the second vertical plane are perpendicular and orthogonal to each other;

[0058] The length directions of the first-stage screen plate 2 and the second-stage screen plate 7 are the conveying directions of the tobacco leaf materials.

[0059] The three-stage screening method for large and medium-sized reconstituted tobacco leaves using the above device includes the following steps: The reconstituted tobacco leaves are input from the feeder 1 into the first-stage vibrating screen 4, and the separation of large tobacco leaves (large tobacco leaf size) is completed by the first-stage screen plate 2 and the first-stage screening holes 3. The large tobacco leaves are output through the conveying plate 5 and the first-stage discharge hopper 6; The remaining materials are input into the second-stage vibrating screen 9 again, and the separation of medium-sized tobacco leaves (medium-sized tobacco Separation of (size) and broken tobacco, medium-sized tobacco flakes are output by the conveying plate 5 and the secondary discharge hopper 10, and broken tobacco is output by the tertiary discharge hopper 11; the primary sieve plate 2 and the secondary sieve plate 7 are used for loose conveying and screening of the tobacco flake material.

[0060] In this embodiment Figure 1 , when it comes to the threshing and redrying production line, the feeder 1 is the on-line output port of the tobacco flakes on the threshing and redrying line, and the primary discharge hopper 6, the secondary discharge hopper 10 and the tertiary discharge hopper 11 can be connected to the transmission device on the redrying production line.

[0061] In this embodiment, the primary discharge hopper 6 is a large flake discharge hopper, referring to large tobacco flakes with a size greater than 25.4 mm;

[0062] The secondary discharge hopper 10 is a medium flake discharge hopper, referring to medium tobacco flakes with a size greater than 12.5 mm and less than or equal to 25.4 mm;

[0063] The tertiary discharge hopper 11 is a fragment discharge hopper, referring to broken tobacco with a size less than or equal to 12.5 mm.

[0064] Specifically, as Figure 2 , 4 described, in the space coordinate system constructed by the first vertical plane and the second vertical plane, the equation of the first trajectory is y = acos(ω1x), with a wavelength of λ1, and the equation of the second trajectory is y = bcos(ω2z), with a wavelength of λ2. Preferably, a = 1, b = 1, ω1 = 1, and ω2 < 1.

[0065] In this embodiment, a three-dimensional coordinate system YXZ is established, and the waveform surface of the sieve plate is designed. The surface function equation is y = f(x,z), where y = acos(ω1x) and y = bcos(ω2z). The z direction is the material conveying direction, that is, the length direction L of the sieve plate, and the x direction is the width direction B.

[0066] That is to say, in the three-dimensional coordinate system, the waveform surface formed by the extension of the y = acos(ω1x) curve in the z-axis direction according to the law of the y = bcos(ω2z) curve is the transmission surface. Given a y value, there are corresponding x and z coordinate values corresponding to it.

[0067]

[0068] Here, k1 and k2 are integers.

[0069] This embodiment is designed according to a = 1, b = 1, ω1 = 1, and ω2 < 1. Among them, a = 1 and ω1 = 1 have two positive intersection points within any period of the sine curve, which has a better loosening force on the material; b = 1 and ω2 < 1 have a faster or smoother conveying effect on the material. Specifically, in this embodiment, ω2 = 0.5 is taken.

[0070] Then the above equation is:

[0071] x = arccos(y) + 2k1π

[0072] z = 2(arccos(y) + 2k2π)

[0073] Furthermore, the diameter of the first - stage screening holes 3 is The diameter of the second - stage screening holes 8 is Both the first - stage screening holes 3 and the second - stage screening holes 8 are manufactured on the trough line, The functional curve of this trough line is: y = bcos(ω2z), x = nπ, where n is a positive integer representing the serial number of the trough line.

[0074] Furthermore, the first - stage screening holes 3 are manufactured by using the normal vector punching method at the center position of the screening holes on the trough line.

[0075] The above two sieve plates are both given by the same mathematical equation and can be selected according to process parameters. Specifically, in this embodiment, as follows:

[0076] For the classification of large - piece tobacco, the aperture of the first - stage sieve plate 2 is preferably The equation of the first trajectory of the corrugated surface is y = 10cos(x / 10), the wavelength λ1 = 62.832 mm, and the equation of the second trajectory is y = 10cos(z / 20), the wavelength λ2 = 125.664 mm.

[0077] The is in inches of holes, and the relevant parameters can also be modified according to specific applications.

[0078] On the trough line within one λ2 of the wavelength, 5 first - stage screening holes 3 are processed by using the average interpolation method, and the aperture is processed along the normal vector direction of the trough line according to the coordinate positions of each hole. The coordinate positions of each hole:

[0079]

[0080] In the formula, x0 and z0 represent the position of the starting hole 0;

[0081] n represents the trough serial number of y = 10cos(x / 10), and k represents the hole serial number on the curve of y = 10cos(z / 20).

[0082] Refer to the embodiment Figure 2 In it: the position of the starting hole 0, x0 = λ1 / 2 = 62.832 / 2 = 31.416 mm, z0 = λ2 / 4 = 125.664 / 4 = 31.416 mm.

[0083] If calculating the 5th trough line of x-axis towards y = 10cos(x / 10) and the position of the 11th hole on the curve of y = 10cos(z / 20), the coordinates are:

[0084]

[0085] The embodiment of its projection plane Figure 3 As described. The analysis of normal vector punching on the trough line is as Figure 6 described.

[0086] In three-dimensional space, the first-stage screening holes 3 on the trough line are punched with normal vectors. Since the trough line curve y = 10cos(z / 20) is in the coordinate system YOZ, the component of this normal vector on the X-axis is 0. The following is calculated in the coordinate system YOZ:

[0087] The first derivative of y = 10cos(z / 20) is:

[0088]

[0089] That is the slope of the tangent line P of the curve passing through the coordinate z point, and the slope of the normal line N at the coordinate z point is:

[0090] N = -1 / y = 2 / sin(z / 20)

[0091] Since the normal line N and the z-axis form an angle α, and N = tanα, therefore, the vector of the normal line N can be obtained.

[0092] Calculating the normal vector (or direction cosine) of a certain point on the curved surface is a basic technology for NC machine tool manufacturing or precision testing technology. In CNC numerical control, the movement direction of the tool or the probe can be controlled.

[0093] As Figures 4 to 5 described, for the classification of medium flue-cured tobacco, the aperture of the secondary sieve plate 7 is preferably The equation of the first trajectory of the waveform surface is y = 5cos(x / 5), the wavelength λ1 = 31.416mm, and the equation of the second trajectory is y = 5cos(z / 10), the wavelength λ2 = 62.832mm.

[0094] On the trough line within one wavelength of λ2, 5 secondary screening holes 8 are processed by the average interpolation method. They are processed along the direction perpendicular to the horizontal plane of the coordinate system XOZ according to the coordinate positions of each hole, and the aperture The coordinate positions of each hole:

[0095]

[0096] In the formula, x0 and z0 represent the position of the starting hole 0;

[0097] n represents the trough sequence number of y = 5cos(x / 5), and k represents the hole sequence number on the curve of y = 5cos(z / 10).

[0098] Figure 4 In implementation, x0 = λ1 / 2 = 31.416 / 2 = 15.708 mm, z0 = λ2 / 2 = 62.832 / 2 = 31.416 mm, which is located at the lowest point of the trough line.

[0099] The lengths L and widths B of the first-stage sieve plate 2 and the second-stage sieve plate 7 are designed and rounded according to the golden ratio of 0.618. Because the golden ratio coefficient (about 0.618) is used to design the first-stage sieve plate 2 and the second-stage sieve plate 7, mainly considering that the trough line screening method on the orthogonal surface of the present utility model has higher material screening and loosening efficiency, and has a beautiful appearance and a compact screening line design.

[0100] The length L of the first-stage sieve plate 2 is 1319.472 mm, which contains a total of 10.5λ2 (λ2 = 125.664 mm), and the width B is 816.816 mm, which contains a total of 13λ1 (λ1 = 62.832 mm). The material moves along the length L or the z-axis direction of the first-stage sieve plate 2, as Figure 3 described.

[0101] The length L of the second-stage sieve plate 7 is 1319.472 mm, which contains a total of 21λ2 (λ2 = 62.832 mm), and the width B is 816.816 mm, which contains a total of 26λ1 (λ1 = 31.416 mm). The material moves along the length L or the z-axis direction of the second-stage sieve plate 7, as Figure 5 described.

[0102] In this embodiment, Figure 2 、 4 , a three-dimensional coordinate system YXZ is established, and the waveform surface of the sieve plate is designed. The surface function equation is y = f(x,z), y = acos(ω1x), y = bcos(ω2z). The z direction is the material conveying direction, that is, the length direction L of the conveying sieve plate 1, and the x direction is the width direction B.

[0103] Obviously, the waveform surface is a space surface formed by the orthogonality of two cosine curves. Due to the alternating array of wave peaks and troughs on the waveform surface, when no sieve holes are designed, the conveying sieve plate 1 can be used for the loose conveying and uniform distribution of tobacco materials such as tobacco leaves on the tobacco leaf redrying production line and cut tobacco on the cut tobacco production line, etc., to solve the problems of material agglomeration and adhesion online and improve the process effect.

[0104] In addition, since on both sides of any trough, the positive and cosine surfaces smoothly change to the wave peak, and the wave peak has a high effect on loosening the material, so that small-sized materials are gathered and conveyed in the trough. Therefore, the sieve holes designed in this technical solution have the best screening effect on the trough line.

[0105] The screening methods for large and medium-sized tobacco flakes and broken tobacco in reconstituted tobacco leaves are introduced above by way of examples. This wave trough line screening method has significant advantages. In combination with the simple harmonic vibration of a better vibration trough, appropriate amplitude and frequency, it ensures the directional movement of tobacco materials on the orthogonal sine wave surface of the screening plate, improving its loose conveying effect and screening efficiency.

[0106] Since this technical solution designs the conveying curved surface using the sine basis function in the orthogonal system, according to the curve area integral theory, the effective area of the screening surface of the conveying and screening plate is much larger than that of a flat plate with the same length and width dimensions. According to physical mechanics theory, this orthogonal sine wave surface has high efficiency in loosening materials and low characteristics of causing breakage. Therefore, this technical solution is of great significance for improving the conveying and screening performance of the production line or shortening the production length.

[0107] Based on the development of current manufacturing technologies, especially the progress of CAD / CAM modeling technology and multi-dimensional processing technology, there is no technical difficulty in manufacturing the orthogonal sine wave surface, but the manufacturing cost is much higher than that of manufacturing a flat conveying and screening plate.

[0108] Finally, it is noted that in this embodiment, the screening hole is 25.4 mm (one inch), and the 25.4 mm size is the size standard for distinguishing large and medium-sized reconstituted tobacco flakes in the tobacco industry; the screening hole d = 6 mm is the process execution standard for screening "broken tobacco" from tobacco flakes.

Claims

1. An online separation and classification device for large and medium-sized redried tobacco sheets, characterized in that: It comprises a feeder (1), a first-stage vibrating screen (4), a conveying plate (5), a first-stage discharging hopper (6), a second-stage vibrating screen (9), a second-stage discharging hopper (10) and a third-stage discharging hopper (11); The primary vibrating screen (4) and the secondary vibrating screen (9) respectively comprise a primary sieve plate (2) and a secondary sieve plate (7), the primary sieve plate (2) having primary sieve holes (3), and the secondary sieve plate (7) having secondary sieve holes (8); The first-stage vibrating screen (4) and the second-stage vibrating screen (9) are respectively connected to the first-stage discharge hopper (6) and the second-stage discharge hopper (10) through the conveying plate (5), and the third-stage discharge hopper (11) is located below the second-stage vibrating screen (9); The surface screening surfaces of the primary screen plate (2) and the secondary screen plate (7) are set as corrugated surfaces, the corrugated surfaces are spatial curved surfaces formed by orthogonal intersection of a curved surface formed by moving along a first trajectory and a curved surface formed by moving along a second trajectory, the first trajectory is a cosine curve in a first vertical plane, and the tangents of the first trajectory at the crests and troughs are parallel to the width direction of the screen plate, the second trajectory is a cosine curve in a second vertical plane, and the tangents of the second trajectory at the crests and troughs are parallel to the length direction of the screen plate, and the first vertical plane and the second vertical plane are perpendicular to each other; The length direction of the primary sieve plate (2) and the secondary sieve plate (7) is the direction in which the tobacco sheet material is conveyed.

2. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1 is characterized in that: The first-stage discharge hopper (6) is a large-sheet discharge hopper, which refers to large sheets of tobacco with a size greater than 25.4 mm; The secondary discharge hopper (10) is a medium-sized tobacco sheet discharge hopper, which refers to medium-sized tobacco sheets with a size greater than 12.5 mm and less than or equal to 25.4 mm; The third-level discharge hopper (11) is a debris discharge hopper, which refers to the debris with a size less than or equal to 12.5 mm.

3. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1 is characterized in that: In the spatial coordinate system constructed by the first vertical plane and the second vertical plane, the equation of the first trajectory is y=acos(ω1x), wavelength λ1, and the equation of the second trajectory is y=bcos(ω2z), wavelength λ2, a=1, b=1, ω1=1, ω2<1.

4. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1, characterized in that: The diameter of the primary sieve hole (3) is The diameter of the secondary sieve hole (8) is The primary sieve holes (3) and the secondary sieve holes (8) are both manufactured on the trough line, and The function curve of the trough line is: y = bcos (ω2z), x = nπ, n is a positive integer, indicating the trough line number; The primary screening holes (3) are manufactured by using a normal vector punching method at the center of the screening holes on the trough line.

5. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1, characterized in that: For the classification of large pieces of smoke, the aperture of the first-level screening hole (3) is The equation of the first trajectory of the waveform surface is y=10cos(x / 10), and the wavelength λ1=62.832mm. The equation of the second trajectory is y=10cos(z / 20), and the wavelength λ2=125.664mm.

6. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1, characterized in that: On the trough line within a wavelength of 1 λ2, five first-level screening holes (3) are processed by average interpolation method, and the aperture Processing is carried out along the normal vector direction of the trough line according to the coordinate position of each hole; In the formula, x0 and z0 represent the position of the starting hole 0; n represents the trough number of y=10cos(x / 10), and k represents the hole number on the y=10cos(z / 20) curve.

7. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1 is characterized in that: For the classification of medium-sized tobacco, the aperture of the secondary screening hole (8) is The equation of the first track of the waveform surface is y=5cos(x / 5), the wavelength λ1=31.416mm, and the equation of the second track is y=5cos(z / 10), the wavelength λ2=62.832mm; On the trough line within a wavelength of 1 λ2, the five secondary screening holes (8) are processed by the average interpolation method, and the coordinate position of each hole is processed along a direction perpendicular to the horizontal plane of the coordinate system XOZ. The coordinate position of each hole is: In the formula, x0 and z0 represent the position of the starting hole 0; n represents the trough number of y=5cos(x / 5), and k represents the hole number on the y=5cos(z / 10) curve.

8. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 1 is characterized in that: The length L and width B of the primary sieve plate (2) and the secondary sieve plate (7) are designed to be rounded off according to the golden ratio of 0.

618.

9. The online separation and classification device for large and medium-sized redried tobacco sheets according to claim 8, characterized in that: The length L of the primary sieve plate (2) is 1319.472 mm, including 10.5λ2, λ2=125.664 mm, and the width B is 816.816 mm, including 13λ1, λ1=62.832 mm, and the material flows along the length L or z-axis direction of the primary sieve plate (2); The length L of the secondary sieve plate (7) is 1319.472 mm, containing 21λ2 in total, λ2=62.832 mm, and the width B is 816.816 mm, containing 26λ1 in total, λ1=31.416 mm. The material flows along the length L or z-axis direction of the secondary sieve plate (7).

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