Cut tobacco scrap stem sliver separation and cut tobacco recovery device in cigarette making process

Abstract

The utility model provides a stem separating and tobacco shred recycling device for tobacco shred chippings in a cigarette making process, the tobacco shred chippings are input into a first-stage vibrating screen by a hoister, and hard puncture stems are captured by an orthogonal curved screen plate and dot matrix alternating cylindrical screening holes, so that tobacco powder and stems with the diameter smaller than d1 are separated. The excess materials are input into a second-stage vibrating screen, hard slivers with the length larger than the length d2 and poor plasticity are controlled and separated through a curve flow guide strip, a size control screen plate, screening holes, separation holes, a separation curved surface and the like, and tobacco shreds with good flexibility sequentially pass through the screening holes, the separation holes, the separation curved surface and the like and are finally input into a tobacco shred collecting box. The tobacco shred separating device has high loosening force and screening efficiency on tobacco shred chippings, is low in breakage rate, has more accurate separating capacity on stem slivers in the tobacco shred chippings, and improves the tobacco shred recovery rate and the tobacco shred recovery quality.

Description

Technical Field

[0001] The utility model relates to the technical field of cigarette production, is applied to the separation of stems and sticks from tobacco scraps and the recovery of tobacco scraps, and specifically relates to a device for separating stems and sticks from tobacco scraps and recovering tobacco scraps in a cigarette making process. Background Art

[0002] In the tobacco processing industry, "stem sticks" is a very important term, and its research has been accompanied by the development of cigarette technology. Generally speaking, "stem sticks" refer to "tobacco stems" in tobacco that are similar in shape to toothpicks, have not expanded or the expansion effect does not meet the requirements of the cigarette making process, or their poor physical characteristics such as size, hardness or shape have a negative impact on the cigarette making process or cigarette quality. For example, if the "stem stick" content in tobacco is too high or the "stem stick" characteristics are poor, it will lead to uneven burning of tobacco in the cigarette, uneven burning end faces and "blooming"; or in the process of rolling and joining cigarettes, hard stem sticks will pierce and crack the cigarette paper, directly affecting the quality of cigarettes such as sensory suction, etc.

[0003] "Stem sticks" come from the fact that it is impossible to completely remove the stems from tobacco leaves during leaf threshing and re-baking, that is, the leaves contain stems, which inevitably leads to the appearance of "stem sticks" in tobacco leaves during tobacco production. In addition, in the process of using tobacco stems to produce "stem shreds", "stem shreds" that do not meet technical requirements are mixed into the finished tobacco shreds to form "stem sticks". Therefore, the purpose of "stem stick" separation is to qualitatively separate the "stem shreds" that have a negative impact on the quality of cigarettes. Therefore, from the perspective of describing the properties of "stem sticks", "stem stick" separation is a difficult subject.

[0004] At present, in the pre-process of rolling cigarettes in cigarette making machines, a stem separation process is set up. Its basic principle is to separate harmful stems and other impurities through wind selection technology. The impurities of stems and impurities selected by wind are collectively referred to as "tobacco debris". Large cigarette companies produce about 4 to 5 tons of "tobacco debris" containing "stems" every day. Because the weight difference and suspension speed difference between some tobacco and stems are not obvious, the "tobacco debris" contains not only stems, but also a large amount of tobacco. It is difficult to have an accurate parameter for the proportion of tobacco in "tobacco debris", but it is probably more than 50% to 60%, so it is very necessary to recycle these tobacco.

[0005] In view of the above problems, the inventor of the present invention finally obtained the present invention after a long period of research and practice. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides a device for separating stems and tobacco scraps and recovering tobacco scraps in the cigarette making process, which improves the accuracy of stem separation in tobacco scraps, tobacco quality and recovery rate, saves expensive tobacco costs, and improves cigarette production quality.

[0007] The technical solution adopted by the utility model is:

[0008] Provided is a device for separating stems and tobacco scraps and recovering tobacco in a cigarette making process, comprising: a primary vibrating screen and a secondary vibrating screen; a curved screen plate is provided in the primary vibrating screen, and a size-controlling screen plate is provided in the secondary vibrating screen;

[0009] The upper surface of the curved screen plate is a spatial surface constructed by orthogonal sinusoidal basis functions. Assuming that the length L direction of the directional movement of the material is the x-axis, the width B direction perpendicular to the x-axis is the z-axis, the direction perpendicular to the xz plane is the y-axis, and the spatial surface is y=f(x,z), then in the x-axis section at the origin of the coordinate system, the curve equation on the spatial surface y=f(x,z) is: y=cos(x), and the coordinates of any point on the spatial surface y=f(x,z) meet: x=sin(z) and y=cos(x), then the standard spatial surface equation of y=f(x,z) is y=f(x,z)=cos(x-sin(z)); a plurality of first sieve holes are formed on the curved sieve plate, the first sieve holes are cylindrical holes processed on the spatial surface y=f(x,z) perpendicular to the xz plane, the intersection of the hole and the spatial surface is a continuous three-dimensional spatial curve C, and the first sieve holes are distributed on the spatial surface y=f(x,z) in an equidistant manner on each wavelength λ;

[0010] A plurality of second screening holes are arranged on the upper surface of the size-controlling screen plate, and separation holes with the same aperture as the second screening holes are connected directly below the second screening holes; a plurality of parallel and equally spaced blanking troughs are formed on the lower surface of the size-controlling screen plate; a separation space connected to the blanking trough is directly below the separation holes, one side of the separation space is closed by a separation curved surface, and the other side is open and connected to the adjacent blanking trough; the length L1 direction of the size-controlling screen plate is the directional movement direction of the material, the width B1 direction is perpendicular to the length L1 direction, and the second screening holes are distributed along a sinusoidal curve function on the length L1; a plurality of curved guide strips extending along the L1 direction are installed on the upper surface of the size-controlling screen plate, and the curved guide strips are located between two adjacent second screening holes in the width B1 direction.

[0011] Furthermore, the diameter of the separation hole is d2, and an arc with a radius equal to d2 and an arbitrary point on the circumference of the separation hole as the center is on the separation surface, and the separation surface is a rotational surface.

[0012] Furthermore, the second sieve holes are distributed on the length L1 according to a sinusoidal function, and the center of each sieve hole is on the sinusoidal curve. The equation is: The wavelength is λ=2π; the second sieve holes on the sine curve in the width B1 direction are translated in sequence.

[0013] Furthermore, the curved guide strip is designed according to a sine curve, and the equation is: The wavelength is λ=2π.

[0014] Furthermore, the diameter of the first sieve hole is d1, d1 is smaller than d2, the height h of the first sieve hole is not less than 3 mm, and the minimum h value appears at the trough.

[0015] Furthermore, the blanking groove is an open through groove passing through the circumference of the separation hole and tangent to the separation curved surface, and the minimum distance from the tangent surface to the center of the separation hole is x, and the range of x is:

[0016] Furthermore, the length L1 of the size-controlled sieve plate is designed as an integer multiple of the wavelength λ and can be manufactured in sections; the designed length L1 of the size-controlled sieve plate is within 25 wavelengths λ.

[0017] Furthermore, the opening of the three-dimensional space curve C of the first screening hole on the curved surface of the curved screen plate and the edge of the outlet of the blanking chute on the size-controlled screen plate are manually trimmed, barbed or chamfered to prevent the tobacco from being broken or jammed.

[0018] Furthermore, the stem stick separation and tobacco shred recovery device also includes an elevator, a conveying plate, a stem stick collection box, a stem stick discharge trough, a tobacco shred discharge trough, a tobacco shred collection box, a tobacco end stem stick collection tube and a tobacco end discharge trough; the elevator is connected to the front end of the first-level vibrating screen, and the end of the first-level vibrating screen and the front end of the second-level vibrating screen are connected through the conveying plate; the tobacco end discharge trough is arranged below the curved screen plate, and the tobacco end stem stick collection tube is arranged below the outlet of the curved screen plate; the tobacco shred discharge trough is arranged below the size control screen plate, and the tobacco shred collection box is arranged below the outlet of the tobacco shred discharge trough; the end of the second-level vibrating screen is connected to the stem stick discharge trough, and the stem stick collection box is arranged below the outlet of the stem stick discharge trough.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] From the perspective of cigarette making technology, stem sticks have the potential to puncture and crack cigarette paper; from the perspective of cigarette quality, the content and physical form of "stem sticks" affect cigarette quality, such as sensory suction. In order to address the problem of stem sticks puncturing and cracking cigarette paper, the utility model uses cylindrical screening holes, whose openings are continuous closed three-dimensional space curves, and the opening surfaces are located at the crests, troughs and wave surfaces, forming a three-dimensional space with a dot matrix distribution. The center position of the screening hole on the wave surface is the only orthogonal point on the chord curve y=cos(x), and its normal vector forms an optimal ejection angle of 45° with the bottom surface of the curved screen plate. Therefore, the screening holes have the best material capture and ejection effects. If the screening holes are Make the diameter The following stalks can enter the cylindrical sieve hole by their own momentum (impulse) Similar to "borrowing arrows from a straw boat", it is basically determined that it has the potential problem of puncturing and cracking cigarette paper. Due to the good plasticity and flexibility of tobacco, it is difficult to enter the cylindrical screening hole if it exceeds a certain length. , thereby achieving separation.

[0021] In the existing mature technology of stem separation and tobacco recovery production line, steam, rollers, vibration troughs, etc. are used to solve the problems of clumping and loose tobacco. The orthogonal screening of the utility model itself has a high-efficiency loosening effect, because the curved surface of the curved screen plate is a sinusoidal surface. From the perspective of physics and mathematics, its elastic force is alternating. Therefore, it has an extremely low material breakage rate. At the same time, in addition to the harmonic effect of the sinusoidal surface, the screening area is significantly expanded and the performance is improved, which is beneficial to the development of tobacco machinery.

[0022] The diameter of the stem is larger than For example, if it is larger than 3.2mm, and the length of the stem is larger than d2 (6-10mm), such as larger than 6mm or 10mm, the utility model provides a two-stage vibration screen controlled size measurement and separation technology, namely, a size control screen plate, which integrates metrology, geometry and physics features. It can measure or determine the size value of the stem within a certain spatial angle range. The separation surface is a spatial rotation surface. The normal of any point on the surface points to the separation hole or the circumference of the screening hole. Mechanically speaking, stems larger than d2 will be ejected by the vibration screen. Tobacco shreds or "stem shreds" are plastic and flexible, and their natural size is variable. As long as they enter the separation hole, they will most likely enter the blanking chute, thereby achieving stem separation. Theoretically, the size control screen plate once again measures the physical hardness of the stems.

[0023] Separation holes or screening holes and curved guide strips all use sine functions Design, because its amplitude is less than 1, the tobacco debris on the vibrating screen is smooth and even, the curved guide strip balances the material rate, unlike the flat screen like a "frog jump", while the sine lengthens the path of the screening material. Therefore, the size control screen plate is effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1The overall structural diagram of the stem and tobacco separation and shredded tobacco recovery device according to the embodiment of the utility model is shown;

[0026] Figure 2 A schematic structural diagram of a primary vibrating screen according to an embodiment of the utility model is shown;

[0027] Figure 3 A schematic diagram showing the curve equation identification of the curved sieve plate of the embodiment of the utility model in a three-dimensional space coordinate system;

[0028] Figure 4 Three design views of the curved sieve plate of the embodiment of the utility model are shown;

[0029] Figure 5 The front view and side view of the curved screen plate and the first screening hole of the embodiment of the utility model are shown;

[0030] Figure 6 Shows Figure 5 Schematic diagram of the BB section in;

[0031] Figure 7 A schematic structural diagram of a two-stage vibrating screen according to an embodiment of the present utility model is shown;

[0032] Figure 8 A schematic diagram showing the design of the second screening hole, the separation hole, the separation curved surface, and the blanking chute on the size-controlled screen plate according to an embodiment of the utility model is shown;

[0033] Fig. 9 A schematic diagram showing the size design of the second sieve hole in an embodiment of the utility model is shown;

[0034] Fig.10 Shows Fig. 9 Schematic diagram of the AA section in;

[0035] Fig.11 A schematic diagram of a plane design of a size-controlled sieve plate according to an embodiment of the utility model is shown;

[0036] Fig.12 A schematic diagram of the three-dimensional structure of a curved guide strip according to an embodiment of the utility model is shown;

[0037] Fig.13 A schematic plan view of a curved guide strip according to an embodiment of the present utility model is shown;

[0038] Fig.14 Shows Fig.13 Schematic diagram of the BB section in;

[0039] Fig.15 A schematic diagram showing the structure of a stem discharging trough according to an embodiment of the utility model is shown;

[0040] Fig.16 The schematic diagram of the structure of the shredded tobacco discharging chute and the smoke powder discharging chute of the embodiment of the utility model is shown. DETAILED DESCRIPTION

[0041] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] The separation of stems and tobacco recycling from tobacco debris has always been one of the most critical technologies in the tobacco industry, and the difficulty lies in the determination of its morphology and separation technology. According to research, in the rolling process, the stems that puncture and crack the cigarette paper of the cigarette are hard and have puncture ability. Stems longer than 6 to 10 mm can affect the quality of cigarettes; the clumping and entanglement of tobacco in tobacco debris can be better solved by using a sine-structured vibration trough screen. From the material observation and analysis of tobacco debris, it is rare for the geometric diameter of the stems to be greater than 3 mm, and it is common for the length to be greater than 6 to 10 mm. Based on the above-mentioned utility model, the person using the geometric characteristics of "tobacco debris" designs related size control and separation technologies, which better solves the problems of stem separation and tobacco recycling.

[0046] like Figure 1 As shown, the utility model provides a tobacco stem separation and tobacco recovery device for tobacco shreds in a cigarette making process, comprising an elevator 2, a primary vibrating screen 3, a curved screen plate 4, a first screening hole 4-1, a conveying plate 5, a secondary vibrating screen 6, a curved guide strip 7, a size control screen plate 8, a second screening hole 8-1, a separation hole 8-7, a separation curved surface 8-8, a material drop trough 8-9, a stem collection box 9, a stem discharge trough 10, a tobacco discharge trough 11, a tobacco collection box 12, a tobacco end stem collection cylinder 13, a tobacco end discharge trough 14, etc. The diameter of the first screening hole 4-1 is d1, the diameter of the second screening hole 8-1 is d2, and the diameter of the separation hole is d2. The tobacco scraps are fed into the primary vibrating screen 3 through the elevator 2 and the conveyor belt 1 thereon. The protective plate 4-2 of the primary vibrating screen 3 is provided with a curved screen plate 4. The curved screen plate 4 and the first screening hole 4-1 complete the separation of tobacco dust and stems with a diameter size less than d1, and the tobacco dust and stems are fed into the tobacco dust and stems collecting cylinder 13 through the tobacco dust discharge trough 14. The residual material is fed into the secondary vibrating screen 6 through the conveying plate 5. The protective plate 8-2 of the secondary vibrating screen 6 is provided with a size control screen plate 8. The curved guide strip 7, the size control screen plate 8, the second screening hole 8-1, the separation hole 8-7, the separation curved surface 8-8, and the drop trough 8-9 jointly complete the separation of stems with a length size greater than d2. The stems pass through the conveying plate 8-5 and enter the stem discharge trough 10. The stems are fed into the stem collection box 9 through the stem discharge trough 10, and the tobacco is fed into the tobacco collection box 12 through the tobacco discharge trough 11.

[0047] According to the cigarette making process and quality requirements, the diameter size d1 of the first sieve hole 4-1 on the curved sieve plate 4 is selected, preferably 2-3.2 mm; and the stem length size d2 of the diameter of the second sieve hole 8-1 on the size-controlled sieve plate 8 is selected, preferably 6-10 mm.

[0048] In a preferred embodiment, the diameter of the first sieve hole 4-1 of the curved sieve plate 4 is selected to be The diameter of the second sieve hole 8-1 on the size-controlled sieve plate 8 is selected as

[0049] like Figures 2 to 5 As shown, the upper surface of the curved screen plate 4 is a spatial surface constructed by orthogonal sinusoidal basis functions. Assume that the length L direction of the directional movement of the material is the x-axis, the width B direction perpendicular to the length L direction of the x-axis is the z-axis, the direction perpendicular to the xz plane is the y-axis, and the spatial surface is y=f(x,z). Then, in the x-axis section at the origin of the coordinate system, the curve equation on the spatial surface y=f(x,z) is: y=cos(x), and the coordinates of any point on the spatial surface y=f(x,z) meet: x=sin(z) and y=cos(x), then the standard spatial surface equation of y=f(x,z) is y=f(x,z)=cos(x-sin(z)).

[0050] See also Figure 3 , cite the sine basis functions x = αsin (ω1z) and y = b cos (ω2x) to establish a coordinate system on the orthogonal plane to construct a space surface and design an orthogonal surface; in the coordinate system, z, y and x have the same number of units and units of measurement, x = αsin (ω1z) The minimum positive period of the wavelength λ1 = 2π / ω1, ω1 = 2π / λ1; y = b The wavelength of the minimum positive period of cos(ω2x) is λ2=2π / ω2, ω2=2π / λ2, where α, b, ω1, and ω2 can all be selected as preferred. In a preferred embodiment, ω1=1, λ1=2π, α=1, ω2=1, λ2=2π, b=1, ω1x and ω2x can be converted by wavelengths λ1 and λ2, and in radians, the following are obtained: x=sin(z) and y=cos(x); or in length, the following are obtained: x=sin(2π / λ×z) and y=cos(2π / λ×x).

[0051] Introduce the sine basis function on the orthogonal plane to generate the space curve surface, introduce the parameter t on the z-axis and the parameter t1 that reflects the change of the y-coordinate value, and the parametric equation of the space curve is as follows:

[0052]

[0053] In the space curve surface established by the above equation, given a parameter t value, there is a cosine curve that changes with the parameter t1, and given a parameter t1 value, there is a sine curve that changes with the parameter t. They are respectively simplified to the space surface equation in the standardized form of y=f(x,z) on the orthogonal planes that establish the three-dimensional coordinate system:

[0054] y=f(x,z)=cos(x-sin(z))

[0055] y=±1, maximum value condition: x-sin(z)=kπ→x=kπ+sin(z)

[0056] x = sin(z) (k = 0 peak line)

[0057] x=π+sin(z)(k=1 trough line)

[0058] …

[0059] like Figure 3 In the figure, the wavelength λ has been introduced to replace the length meter.

[0060] The spatial surface can be designed, modeled and manufactured in CAD / CAM according to the above equation, or manufactured using an NC machine tool according to the formula or by introducing a CNC system, or manufactured using a customized sine tool that executes the sine function equation.

[0061] The sine basis function wave height 2α is set to 10 mm, the wavelength λ is set to 31.4159 mm, and the thickness H of the curved sieve plate 4 is not less than 13 mm.

[0062] like Figure 5 , Figure 6 As shown, the diameter of the first sieve hole 4-1 is It is a cylindrical hole machined on the spatial surface y=f(x,z) perpendicular to the xz plane. The height h of the cylindrical hole is not less than 3mm. The intersection line of the cylindrical hole and the spatial surface is a continuous three-dimensional spatial curve C.

[0063] The first sieve holes 4-1 are distributed on the space surface y=f(x,z) in an equidistant manner on each wavelength λ, and the equidistant value is λ / 4, that is, 5 first sieve holes 4-1 are processed on each wavelength, and the coordinates of the first reference hole are located at (0, 0, 0), and are distributed according to x=cos(z) on the x-axis (length L direction), and z=sin(x) on the z-axis (width B direction). Specifically:

[0064] The mesh holes processed on the curved screen plate 4 according to the sine and cosine curves are numbered M in the z-axis direction and N in the x-axis direction. Five first screening holes 4-1 are processed on each wavelength λ (minimum period). The coordinate positions are as follows:

[0065]

[0066] M=1, N=1 means the first hole is processed at the origin of the coordinate system, and the total number of holes is: M×N, and the above formula is in radians. In a preferred embodiment, the length of the first screening hole 4-1 in the cross section in the x direction is 305, and the width in the z direction is 97.

[0067] The above formula shows that: the mesh holes are processed according to the sinusoidal change law in the vertical direction, and the mesh holes are positioned and processed at the geometric midpoints of the wave surface between the wave crests, the wave troughs and the wave crests and troughs.

[0068] The length and width L of the curved sieve plate 4 are designed as integer multiples of the wavelength λ, the length L does not exceed 80λ, and the width B does not exceed 30λ. The curved sieve plate 4 can be manufactured and spliced ​​in sections.

[0069] like Figure 4 As shown, in this embodiment, the length L is 76λ, that is, 2387.667 mm, and the width B is 24λ, that is, 754.008 mm.

[0070] In addition, regarding the eigenfunction y=f(x)=sin(x) curve, its first-order derivative is: If we take any two points x1 and x2 on the f(x) curve, the condition for the tangent equations through the two points x1 and x2 to be perpendicular is:

[0071] cos(x1)·cos(x2)=-1

[0072] Since -1≤cos(x1)≤1, -1≤cos(x2)≤1, the condition that satisfies the equation is, |cos(x1)|=|cos(x2)|=1, and cos(x1) and cos(x2) have opposite signs. So, for example, if x1=kπ, x2=kπ+π, k is an integer, then the two points x1 and x2 are on the coordinate axis, respectively, on either side of the inflection point of the equation y=f(x)=sin(x), and the derivatives are alternately 1 and -1, respectively, and the angles between the tangents through the points x1 and x2 and the positive x-axis are: (i.e. 45°, 135°), so, for the y=sin(x) curve, any curve passing through x k+1 、x k+2 The normal vectors of the points are mutually orthogonal in the plane. That is: "On a sine and cosine curve with an amplitude equal to 1, there is a unique orthogonal point between any adjacent crests and troughs or between troughs and crests, and it is located at the geometric midpoint between the crests and troughs of the sine and cosine curves. The normal vectors at adjacent orthogonal points are mutually orthogonal and on the wave surface." This is of great significance in physics, because the angle between the normal vectors x1 and x2 at this point and the x-axis is (i.e. 45°), the material ejected from this point has the longest distance in parabolic motion. It balances the conveying, distribution and loosening performance of the vibrating screen screening material. For y=f(x,z), the geometric midpoint between the crest and trough of the sine and cosine curves actually passes through points x1 and x2 and is on a plane parallel to plane XOZ. This is also the key reason why the utility model selects an amplitude of 1.

[0073] y=f(x,z) is an orthogonal surface, which has excellent loosening force and screening efficiency for tobacco debris. For example, if (x0, z0) is set on the spatial surface y=f(x,z)=cos(x-sin(z)), the vector characteristics on the surface can be analyzed:

[0074] 1) Partial derivative with respect to z

[0075] The tangent vector is: S1(0, sin(x0-sin(z))·cos(z), 1)

[0076] f z (x0,z0)=sin(x0-sin(z))·cos(z)

[0077] 2) Partial derivative with respect to x

[0078] The tangent vector is: S2(1, -sin(x-sin(z0)), 0)

[0079] f x (x0,z0)=-sin(x-sin(z0))

[0080] 3) Normal vector N

[0081] Set the equation of the normal vector N of (x0, z0) on the space surface y=f(x,z):

[0082] N=S1×S2=(f x (x0,z0), -1, f z (x0,z0))

[0083] That is:

[0084] Right now:

[0085] N=(-sin(x-sin(z0)),-1,sin(x0-sin(z))·cos(z))

[0086] 4) Direction cosines of normal vector N

[0087] If α, β, and γ are used to represent the angles between the normal and the positive directions of the x, y, and z coordinate axes, respectively, then the normal direction cosine of the normal vector N corresponding to the point (x0, z0) is determined by the surface characteristics such as top and bottom, left and right, and front and back, respectively:

[0088]

[0089]

[0090]

[0091] So, by calculating:

[0092] a) If cosβ = ±1, it means that the direction of the space normal vector N and the Y axis have an angle of 0. The following conditions are met:

[0093] k is an integer

[0094] The condition that satisfies the above mentioned is y=±1, which is the peak and trough line.

[0095] b) If cosγ = 0, it means that the direction of the space normal vector N is at an angle of 90° with the Z axis. Taking the corresponding point (x0, z0) as the watershed, the space normal vector N on both sides of the Z coordinate value of the Z axis is symmetrically distributed and changes.

[0096] The conditions are:

[0097] That is, the change law of y=f(x,z) that meets the above conditions is a sine curve, and the loosening force on the material is relatively high.

[0098] like Figure 7-14 As shown, the size control screen plate 8 includes: a second screening hole 8-1, a separation hole 8-7, a separation curved surface 8-8, and a blanking trough 8-9. The second screening hole 8-1 on the surface of the size control screen plate 8 is connected to a separation hole 8-7 and a blanking trough 8-9 with the same aperture d2 as the second screening hole 8-1. The center distance between the second screening hole 8-1 and the separation hole 8-7 is h, and h is 2mm. The second screening hole 8-1 is chamfered by 1×45°. The separation curved surface 8-8 and the blanking trough 8-9 are connected and are respectively located directly below and to the right of the separation hole 8-7. The tobacco debris reaches the second screening hole 8-1, the separation hole 8-7 and the separation curved surface 8-8 from right to left in turn, and the length dimension d2 of the stems is controlled and separated by the circumference of the separation hole 8-7 and the separation curved surface 8-8. The ones smaller than d2 are excluded by the blanking chute 8-9, and the ones larger than d2 are ejected by the secondary vibration groove (8-3), and then pass through the size control sieve plate 8 in turn to enter the next second screening hole 8-1, completing the control and separation of the length dimension d2 of the stems, and so on; among them, due to the plasticity of the tobacco, even if its natural length is larger than d2, it will most likely be excluded by the blanking chute 8-9.

[0099] The length L1 direction of the size-controlling screen plate 8 is the directional moving direction of the tobacco scraps, and the width B1 direction is perpendicular to the length L1 direction.

[0100] The sieve holes (8-1) are distributed over the length L1 according to a sinusoidal function, and the equation is: The wavelength is λ=2π; the curved guide strip (7) is designed according to a sine curve, and the equation is: The wavelength is λ=2π; let its wave height 2α=20mm, and the wavelength λ=125.6637mm.

[0101] In a preferred embodiment, d2 = 10 mm, the diameter of the second sieve hole 8-1 The thickness of the size-controlled sieve plate 8 is H=11.5 mm. Nine second sieve holes 8-1 are evenly distributed on a wavelength λ. The distance between two adjacent holes on the wavelength λ is λ / 8=15.708 mm.

[0102] like Fig.10 , Fig.11 As shown, the distance from any point on the circular curve of the separation hole 8-7 to any point on the separation surface 8-8 is less than or equal to d2, and the condition for being equal to d2 is: an arc with any point on the circular curve of the separation hole 8-7 as the center and a radius equal to d2 is on the separation surface 8-8, and the separation surface 8-8 is a spatial rotation surface.

[0103] The diameters of the second sieve holes 8-1 and the separation holes 8-7 are h is 2mm, or the thickness of the screening surface, and then chamfering the screening hole 8-1 by 1×45° is beneficial to improving the screening process. Taking two points AD on the circumference of the separation hole 8-7 as an example, the arc AB with point D as the center and R10mm as the radius is on the separation surface 8-7, and the arc BC with point A as the center and R10mm as the radius is also on the separation surface 8-8. Obviously, the line connecting point B and the center of the screening hole 8-1 is perpendicular to the screening surface and is the rotation axis of the spatial rotation surface.

[0104] The blanking groove 8-9 is an open through groove passing through the circumference of the separation hole 8-7 and tangent to the separation curved surface 8-8. The minimum distance from the tangent surface to the center of the separation hole 8-7 is x. x affects the accuracy or efficiency of separating and classifying stem labels. The preferred range of x is: d2=10mm, the preferred range of x is: 0≤x≤2.071mm.

[0105] In a preferred embodiment, x=2.071 mm, the central angle of arc BC is 15°, then it can be proved by geometry that: The blanking grooves 8-9 are designed as open through grooves, and the groove width is designed to be 7.5 mm.

[0106] The diameter d2 of the second sieve hole 8-1 is a sinusoidal function The center of each second sieve hole 8-1 is on the sine curve. Nine second sieve holes 8-1 are evenly distributed in a minimum period or a wavelength of λ=125.6637 mm, and the distance between adjacent second sieve holes 8-1 on the wavelength is λ / 8=15.709 mm.

[0107] Each second screening hole 8 - 1 on the sine curve is translated in sequence in the width B1 direction, and the translation distance is t, t=22 mm.

[0108] like Fig.11As shown, L1=20λ=2513.274mm, the number of the second sieve holes 8-1 distributed on L1 is: 8×20+1=161, that is, the number distributed on a sine curve. 36 sine curves are designed on the size-controlled sieve plate 8, then the number of the second sieve holes 8-1 is: 161×36+3×20×2=5916.

[0109] like Figure 12-14 As shown, the curved guide strip 7 is installed between the second screening holes 8-1 in the direction of the width B1 of the surface of the size-controlled sieve plate 8, the translation distance between adjacent curved guide strips 7 is t (t=22 mm) or an integer multiple of t, the mounting hole 8-6 on the second screening hole 8-1 and the threaded hole 7-1 on the curved guide strip 7 are made in pairs, and the size-controlled sieve plate 8 and the curved guide strip 7 are fixed with screws.

[0110] The stem size d2 is the diameter of the The size of the sphere.

[0111] like Figure 7 As shown, there are 11 curved guide strips 7, and the adjacent distance is a translation distance of 66 mm. Figure 12-14 As shown, the width of the curved guide strip 7 is designed to be 8 mm, the height is designed to be 44 mm, the top is rounded, and the threaded hole 7-1 on the curved guide strip 7 and the mounting hole 8-6 on the size-controlled sieve plate 8 are matched.

[0112] Under the action of the curved guide strip 7, the flow rate of the tobacco debris is balanced, making the separation and classification more accurate. Therefore, the sinusoidal hole arrangement and curved guide are more excellent.

[0113] Based on the range of the machine tool manufacturing workbench, the length L1 of the size-controlled sieve plate 8 is designed as an integer multiple of the wavelength λ=125.6637 mm and can be manufactured in sections.

[0114] The following uses differentials to give the integral analysis of the y=αsin(x) curve and surface:

[0115] The curve integral about y = αsin(x), α≤1 is Legendre's second kind elliptic integral, which is expanded by Taylor series method and according to Wallace's definite integral formula After sorting out and listing the calculations in an EXCEL table, the integral value of a period of 2π (a wavelength λ) is given below.

[0116] When y=si n(x): S1=7.63919.

[0117] When y=1 / 2×sin(x): S1=6.65917.

[0118] 1) The λ of the curved screen plate 4 is 31.416mm, and the wave height is 2α=10mm. The definite integral on one wavelength λ corresponding to one cycle is 38.196mm, that is, the curve length. The length L of the curved screen plate 4 is designed to be 76λ, about 2387.667mm, and the length of the sine curve is 2902.892mm, with a difference of 515.225mm; the width B is designed to be 24λ, that is, 754.008mm, and the length of the sine curve is 916.704mm, with a difference of 162.704mm. It can be seen that the introduction of the sine basis function to design the spatial curved surface y=f(x,z) significantly improves the screening area of ​​tobacco debris, and the efficient loosening and screening efficiency brought by the sine wave are not taken into account here. If necessary, the surface integral can also be introduced to more accurately calculate the screening area for evaluation. For example, through the surface integral of the spatial surface S: y=f(x,z)=cos(x-sin z), the surface area of ​​S is precisely:

[0119]

[0120] Here (x,z)∈D xz , respectively, partial differentials can be calculated by period without value units, L direction x: 76λ = 76 × 2π = 477.52168; B direction y: 24λ = 24 × 2π = 150.796, y[0,2]. Then the value range or integration length of this embodiment is: x[0,2387.667], z[0,754.008], y[0,10]. Due to the symmetry and array of the sinusoidal curve surface, the above formula can be completed within 1 / 4 period.

[0121] 2) The λ of the controlled-size sieve plate 8 is 125.6637 mm, the wave height is 2α=20 mm, and the definite integral on one wavelength λ corresponding to one cycle is 133.183 mm, that is, the length of the curve. The controlled-size sieve plate (8) is designed to be 20λ, about 2513.274 mm, and the length of the sine curve is 2663.660 mm. The difference between the two is 150.386 mm. This is the theoretical difference in the distance of the movement trajectory of tobacco debris on the vibrating screen when using the sine curve and not using the sine curve. Of course, the effect of the sine curve guiding the material to balance the rate is not taken into account here.

[0122] In summary: In theory, "stem sticks" are not quantitatively defined in terms of geometric dimensions and physical and chemical indicators, but are based on their effects and characteristics. Therefore, the stem stick separation technology of the utility model is based on application effects. And the length dimension is less than d2 and cannot be separated. Therefore, according to the cigarette making process and quality requirements, the diameter d1 value is preferably 2-3.2mm; the length d2 value of the stem is preferably controlled, such as 6-10mm, which is very critical. Therefore, the utility model has high loosening force, screening efficiency and low crushing rate for tobacco debris, and has a more accurate separation ability for stems in tobacco debris, which can improve the recovery rate and quality of tobacco.

[0123] Finally, at the three-dimensional curved hole C of the first screening hole on the curved surface of the curved screen plate 4 and at the edge of the outlet of the blanking trough 8-9 on the size-controlled screen plate 8, the mechanical manufacturing industry specifications are followed, and the hair trimming, barbing or chamfering are manually processed to prevent the tobacco from being broken or jammed. The hair trimming, barbing or chamfering process is a basic benchwork operation in the mechanical manufacturing industry, but as a vibrating screen screening hole, the smoothness of the screening hole is crucial, and it is a key part for jamming tobacco and depositing tobacco oil. Therefore, the hair trimming, barbing or chamfering process affects the vibrating screen performance.

[0124] like Fig.15 , 16 As shown, preferably, the discharge inclination angle of the stem discharge chute 10 is 6°, and the discharge inclination angles of the shredded tobacco discharge chute 11 and the tobacco end discharge chute 14 are 15°.

[0125] The above are only preferred embodiments of the present invention, which are only illustrative and not restrictive. The structures and connection modes of the components in the present invention can be changed, and any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A device for separating stems from tobacco debris and recovering tobacco in a cigarette making process, characterized in that: include: A primary vibrating screen (3) and a secondary vibrating screen (6); the primary vibrating screen (3) is provided with a curved screen plate (4), and the secondary vibrating screen (6) is provided with a size-controlling screen plate (8); The upper surface of the curved screen plate (4) is a spatial curved surface constructed by orthogonal sinusoidal basis functions. Assuming that the length L direction of the directional movement of the material is the x-axis, the width B direction perpendicular to the x-axis is the z-axis, the direction perpendicular to the xz plane is the y-axis, and the spatial curved surface is y=f(x,z), then in the x-axis section at the origin of the coordinate system, the curve equation on the spatial curved surface y=f(x,z) is: y=cos(x), and the coordinates of any point on the spatial curved surface y=f(x,z) meet the following conditions: x=sin(z) and y=cos(x ), then the standard spatial surface equation of y=f(x,z) is y=f(x,z)=cos(x-sin(z)); a plurality of first sieve holes (4-1) are formed on the curved sieve plate (4), the first sieve holes (4-1) are cylindrical holes processed on the spatial surface y=f(x,z) perpendicular to the xz plane, the intersection of the hole and the spatial surface is a continuous three-dimensional spatial curve C, and the first sieve holes (4-1) are distributed on the spatial surface y=f(x,z) in an equidistant manner on each wavelength λ; A plurality of second screening holes (8-1) are arranged on the upper surface of the size-controlling screen plate (8), and a separation hole (8-7) having the same aperture as the second screening hole (8-1) is connected directly below the second screening hole (8-1); a plurality of parallel and equally spaced material drop grooves (8-9) are formed on the lower surface of the size-controlling screen plate (8); a separation space connected thereto is directly below the separation hole (8-7), one side of the separation space is closed by a separation curved surface (8-8), and the other side is open and connected to the adjacent material drop groove (8-9); the length L1 direction of the size-controlling screen plate (8) is the directional movement direction of the material, the width B1 direction is perpendicular to the length L1 direction, and the second screening holes (8-1) are distributed along a sine curve function on the length L1; a plurality of curved guide strips (7) extending along the L1 direction are installed on the upper surface of the size-controlling screen plate (8), and the curved guide strips (7) are located between two adjacent second screening holes (8-1) in the width B1 direction.

2. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 1, characterized in that: The diameter of the separation hole (8-7) is d2, and an arc with a radius equal to d2 is formed with any point on the circumference of the separation hole (8-7) as the center. The arc is on the separation curved surface (8-8), and the separation curved surface (8-8) is a rotational curved surface.

3. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 2, characterized in that: The second sieve holes (8-1) are distributed along the length L1 according to a sinusoidal function, and the center of each sieve hole (8-1) is on the sinusoidal curve. The equation is: The wavelength is λ=2π; each second sieve hole (8-1) on the sine curve in the width B1 direction is translated in sequence.

4. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 1, characterized in that: The curved guide strip (7) is designed according to a sine curve, and the equation is: The wavelength is λ=2π.

5. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 3, characterized in that: The diameter of the first sieve hole (4-1) is d1, d1 is smaller than d2, the height h of the first sieve hole (4-1) is not less than 3 mm, and the minimum h value appears at the trough.

6. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 5, characterized in that: The blanking groove (8-9) is an open through groove passing through the circumference of the separation hole (8-7) and tangent to the separation curved surface (8-8), and the minimum distance from the tangent surface to the center of the separation hole (8-7) is x, and the range of x is:

7. A device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 6, characterized in that: The length L1 of the size-controlling sieve plate (8) is designed as an integer multiple of the wavelength λ and can be manufactured in sections; the designed length L1 of the size-controlling sieve plate (8) is within 25 wavelengths λ.

8. The device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 7, characterized in that: The opening of the three-dimensional space curve C of the first screening hole (4-1) on the curved surface of the curved screen plate (4) and the edge of the outlet of the blanking trough (8-9) on the size-control screen plate (8) are manually trimmed, barbed or chamfered to prevent the tobacco from being broken or jammed.

9. A device for separating stems from tobacco scraps and recovering tobacco in a cigarette making process according to claim 8, characterized in that: The invention also comprises an elevator (2), a conveying plate (5), a stem collection box (9), a stem discharge trough (10), a tobacco discharge trough (11), a tobacco collection box (12), a tobacco stem collection cylinder (13) and a tobacco discharge trough (14); the elevator (2) is connected to the front end of the primary vibration screen (3), and the end of the primary vibration screen (3) and the front end of the secondary vibration screen (6) are connected through the conveying plate (5); the tobacco discharge trough (14) is arranged on the upper surface of the secondary vibration screen (6). Below the curved sieve plate (4), the tobacco end and stem collection cylinder (13) is arranged below the outlet of the curved sieve plate (4); the tobacco discharge trough (11) is arranged below the size control sieve plate (8), and the tobacco collection box (12) is arranged below the outlet of the tobacco discharge trough (11); the end of the secondary vibrating screen (6) is connected to the stem discharge trough (10), and the stem collection box (9) is arranged below the outlet of the stem discharge trough (10).

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