High-shear anti-agglomeration helical ribbon mixer

Abstract

The utility model relates to the field of reconstituted tobacco production equipment, and provides a high-shear anti-agglomeration helical ribbon mixer, a mixing mechanism of the helical ribbon mixer is driven by a power mechanism to stir low-mesh powder in a cavity, the mixing mechanism is provided with a main shaft, and an inner helical ribbon group and an outer helical ribbon group on the main shaft are opposite in rotation direction; the inner helical ribbon group front section, the outer helical ribbon group front section, the inner helical ribbon group rear section and the outer helical ribbon group rear section are symmetrically distributed; the inner helical ribbon set and the outer helical ribbon set are arranged in a gradually-changing type screw pitch mode, the front section of the main shaft is provided with a small screw pitch, the middle section of the main shaft is provided with a large screw pitch, and the rear section of the main shaft is provided with a small screw pitch, so that strong convection can be formed, and powder is evenly mixed. Fractures exist between the adjacent stirring blades, shearing force generated by different fracture included angles is different, a shearing area, a transition area and a convection area are divided according to the fracture included angles, and powder is fed from different feeding ports according to the properties of the powder, so that low-mesh fiber powder is fully crushed in the shearing area and then mixed, and the mixing uniformity is improved.

Description

Technical Field

[0001] This patent relates to the field of reconstituted tobacco production equipment, specifically to a high-shear anti-agglomeration ribbon mixer. Background Technology

[0002] To address the various problems encountered when wet-adding fibers during the preparation of roll-pressed sheets, the latest roll-pressing method employs dry-addition of fibers. This involves first pulverizing the fibers into a powder of a specific mesh size (currently 60-100 mesh), then mixing it with dry powders such as tobacco powder while it is dry. However, when the fiber powder has a lower mesh size (≤60 mesh), its tendency to agglomerate is significantly greater than when it has a higher mesh size (≥80 mesh). This characteristic not only affects the appearance quality of the finished sheet but also leads to uneven distribution of mechanical properties, thus impacting subsequent processes. Therefore, when using 60-mesh fiber powder for dry-addition, it is crucial to ensure good dispersion of the fiber powder during mixing; improper mixing can result in "white spots" on the finished sheet.

[0003] Current mixing equipment mainly uses high-speed rotating blades to disperse materials. These devices include double-blade mixers, inclined mixers, plow mixers with added blades, and ribbon mixers with added blades. For example... Figure 1a As shown, the double-blade mixer uses a rotating cylinder to alternately break up the material inside the cylinder with blades at both ends. The alternation frequency is determined by the cylinder's rotation speed. The curved cylinder wall has a feed inlet and a discharge outlet at relative positions. During feeding, the feed inlet is rotated to face upwards; during discharging, the discharge outlet is rotated to face downwards. Figure 1b As shown, the inclined mixer uses vertical blades on the main shaft to stir materials within an inclined cylinder. The cylinder rotates in the opposite direction as the blades rotate. For feeding and discharging operations, the main shaft must be raised first; during operation, the main shaft must be lowered to be flush with the cylinder opening. For example... Figure 1c As shown, the plow mixer achieves its dispersing function by adding two flying knives to the bottom of the cylinder. Inside the cylinder is a horizontal main shaft, on which plow blades at different angles are mounted. Figure 1d As shown, the ribbon mixer can achieve both mixing and dispersing functions when equipped with a flying knife. It mainly uses the rotation of the internal horizontal main shaft to drive the ribbon, causing the material to reciprocate.

[0004] However, among the current equipment used for mixing low-mesh fiber powder, the double-blade mixer requires external force to discharge materials from the cylinder due to the material inlet and outlet rotating with the cylinder, coupled with the poor flowability of fiber powder. This makes continuous feeding and discharging difficult and unsuitable for industrial production. The effective working radius of the blades in the inclined mixer limits the cylinder volume, resulting in insufficient production capacity. The plow mixer uses two blades at the bottom of the cylinder to achieve dispersion, but the plow's function is primarily radial shearing of the powder, with poor axial mixing effect, making it unsuitable for powder mixing.

[0005] While ribbon mixers can perform both mixing and dispersing functions with the addition of flying knives, existing ribbon mixers suffer from several drawbacks. The flying knives interfere with the ribbon within the drum. To avoid this interference, the ribbon is typically broken to create working space for the flying knives, significantly increasing the mixing dead zone. For materials with good flowability, this dead zone has little impact on flow within the drum. However, for materials with poor flowability, such as tobacco powder and fiber powder, the dead zone reduces flow efficiency, thus affecting the mixing effect. Therefore, a mixer suitable for low-mesh powders, especially fiber powders, is needed that can provide high shear strength to prevent agglomeration and achieve thorough and uniform mixing. Utility Model Content

[0006] To reduce the large mixing dead zones generated by low-mesh powder in the ribbon mixer and improve production efficiency, this patent provides the following technical solution to ensure thorough and uniform mixing of low-mesh powder under high shear:

[0007] First aspect: A high-shear anti-agglomeration ribbon mixer is provided. The ribbon mixer includes a cylinder, a mixing mechanism and a power mechanism. The cylinder includes a chamber. The mixing mechanism is placed in the chamber and stirs the powder under the drive of the power mechanism. The mixing mechanism includes a main shaft, an inner ribbon group and an outer ribbon group. The inner ribbon group and the outer ribbon group are distributed on the main shaft with opposite rotation directions and symmetrical variable pitch.

[0008] Furthermore, the main shaft includes a left half-shaft and a right half-shaft, the inner threaded assembly includes a front section and a rear section of the inner threaded assembly, and the outer threaded assembly includes a front section and a rear section of the outer threaded assembly. The front section of the inner threaded assembly and the front section of the outer threaded assembly are disposed on the left half-shaft, and the rear section of the inner threaded assembly and the rear section of the outer threaded assembly are disposed on the right half-shaft.

[0009] Furthermore, the spindle has a spindle point P along its axial direction, located at the junction of the left and right half-shafts; the contact point between the front and rear sections of the inner helical ribbon assembly is the inner coincident point H; the contact point between the front and rear sections of the outer helical ribbon assembly is the outer coincident point D; the extensions of the spindle point P, the inner coincident point H, and the outer coincident point D along the radial direction converge on the same straight line, which is the extension line PHD.

[0010] Furthermore, the front section of the inner spiral ribbon group and the front section of the outer spiral ribbon group are symmetrically distributed along the axial direction of the main axis with the extension line PHD as the axis of symmetry.

[0011] Furthermore, the front section of the inner spiral ribbon assembly, the rear section of the inner spiral ribbon assembly, the front section of the outer spiral ribbon assembly, and the rear section of the outer spiral ribbon assembly include fan-shaped stirring blades, with the stirring blades having a gradually changing pitch distribution along the left and right half-axis; the pitch is 4–24 mm, 24–44 mm, or 44–64 mm.

[0012] Furthermore, a fracture is formed between adjacent stirring blades of the inner and outer spiral ribbon groups; the angle formed by the projection of the fracture with the axis of the main shaft along the axial direction is the fracture angle.

[0013] Furthermore, based on the fracture angle, there are convection zone, transition zone and shear zone; the first fracture angle α of the shear zone is 5-10°, 10-15°, 15-20°; the third fracture angle γ of the convection zone is 40-45°, 45-50°, 50-55°; the second fracture angle β of the transition zone is 20-25°, 25-30°, 30-35°, 35-40°.

[0014] Furthermore, the cylinder also includes a top cover, baffle, side plates, bottom plate and feet. The bottom plate is arc-shaped, and the top cover, baffle, side plates and bottom plate form a cavity. The bottom plate is provided with a discharge port, and the top cover is provided with a first inlet, a second inlet and a third inlet according to the properties of the powder.

[0015] Furthermore, the spindle speed is 10-25 rpm, 25-40 rpm, 40-55 rpm, or 55-60 rpm; the mixing mechanism also includes an inner support rod and an outer support rod, the inner support rod connecting the inner helical ribbon assembly and the spindle in the radial direction, and the outer support rod connecting the outer helical ribbon assembly and the spindle in the radial direction.

[0016] Furthermore, the powder includes tobacco powder, fiber powder, and additives; the fiber powder is low-mesh fiber powder, with mesh sizes of 30-40 mesh, 40-50 mesh, and 50-60 mesh.

[0017] This patent has the following beneficial effects:

[0018] 1. This patent relates to the field of reconstituted tobacco production equipment, and provides a high-shear anti-agglomeration ribbon mixer. The mixing mechanism of the ribbon mixer is driven by a power mechanism to stir low-mesh powder in the cavity. The mixing mechanism is provided with a main shaft, on which the inner ribbon group and the outer ribbon group rotate in opposite directions. The front section of the inner ribbon group and the front section of the outer ribbon group are symmetrically distributed with the rear section of the inner ribbon group and the rear section of the outer ribbon group.

[0019] 2. In this patent, the symmetrically distributed inner and outer spiral ribbon groups adopt a gradually changing pitch setting, with a small pitch at the front of the main shaft, a large pitch in the middle of the main shaft, and a small pitch at the rear of the main shaft. This pitch setting can form strong convection, making the powder mix evenly.

[0020] 3. There are breaks between adjacent stirring blades in this patent. Different break angles produce different shear forces. Based on the break angle, there are shearing zones, transition zones and convection zones. Furthermore, the powder is fed from different feed ports according to its properties, so that the low-mesh fiber powder is fully crushed and mixed in the shearing zone, thereby improving the uniformity of mixing. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this patent, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this patent and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0022] Figure 1a This is a three-dimensional schematic diagram of a double-blade mixer in actual production.

[0023] Figure 1b This is a three-dimensional schematic diagram of an inclined mixer in actual production.

[0024] Figure 1c This is a three-dimensional schematic diagram of a plow mixer in actual production.

[0025] Figure 1d This is a three-dimensional schematic diagram of a ribbon mixer in actual production.

[0026] Figure 2 This is a three-dimensional schematic diagram of the ribbon mixer of this patent;

[0027] Figure 3 This is a cross-sectional view of the ribbon mixer of this patent;

[0028] Figure 4 This is a three-dimensional schematic diagram of the hybrid mechanism of this patent;

[0029] Figure 5 This is a front view of the hybrid mechanism of this patent;

[0030] Figure 6 This is a schematic diagram of the first fracture angle α of this patent;

[0031] Figure 7 This is a schematic diagram of the second fracture angle β of this patent;

[0032] Figure 8 This is a schematic diagram of the included angle γ of the third fracture surface in this patent.

[0033] Figure 9 This is a schematic diagram showing the location of the fracture surface in this patent.

[0034] Figure 10 This is a three-dimensional schematic diagram of the ribbon mixer of this patent from another perspective.

[0035] The reference numerals in the attached figures are explained as follows:

[0036] 100: Cylinder body;

[0037] 110: Top cover;

[0038] 111: First feed inlet;

[0039] 112: Second feed inlet;

[0040] 113: Third feed inlet;

[0041] 120: Baffle;

[0042] 121: First baffle;

[0043] 122: Second baffle;

[0044] 130: Side panel;

[0045] 131: First side panel;

[0046] 132: Second side panel;

[0047] 140: Base plate;

[0048] 141: Discharge port;

[0049] 150: Feet;

[0050] 160: Chamber;

[0051] 200: Hybrid mechanism;

[0052] 210: Spindle;

[0053] 211: Left half-shaft;

[0054] 212: Right half-shaft;

[0055] 220: Front section of the internal threaded assembly;

[0056] 221: First inner front stirring blade;

[0057] 222: Second inner front stirring blade;

[0058] 223: Third inner front stirring blade;

[0059] 224: Fourth inner front stirring blade;

[0060] 225: Fifth inner front stirring blade;

[0061] 226: Sixth inner front stirring blade;

[0062] 230: Rear section of the internal threaded band assembly;

[0063] 240: Front section of the external helical ribbon assembly;

[0064] 241: First outer front stirring blade;

[0065] 242: Second outer front stirring blade;

[0066] 243: Third outer front stirring blade;

[0067] 244: Fourth outer front stirring blade;

[0068] 245: Fifth outer front stirring blade;

[0069] 246: Sixth outer front stirring blade;

[0070] 250: Rear section of the external helical ribbon assembly;

[0071] 260: Fracture group;

[0072] 261: First fracture point;

[0073] 262: Second fracture point;

[0074] 263: Third fracture point;

[0075] 270: Inner support rod;

[0076] 280: External support rod;

[0077] 300: Power mechanism;

[0078] P: Principal axis point;

[0079] D: External coincidence point;

[0080] H: Internal coincidence point;

[0081] PHD: Extension line;

[0082] α: Angle of the first fracture surface;

[0083] β: Angle of the second fracture surface;

[0084] γ: Angle of the third fracture. Detailed Implementation

[0085] The detailed features and advantages of this patent are described below in the specific embodiments. The content is sufficient to enable any person skilled in the art to understand the technical content of this patent and implement it accordingly. Based on the specification, claims and drawings disclosed in this specification, a person skilled in the art can easily understand the related objectives and advantages of this patent.

[0086] To make the objectives, technical solutions, and advantages of this patent clearer, the embodiments of this patent will be described in further detail below with reference to the accompanying drawings.

[0087] like Figure 2 , 3 As shown in Figures 1 and 10, a high-shear anti-agglomeration ribbon mixer includes a cylinder 100, a mixing mechanism 200, and a power mechanism. The mixing mechanism 200 is disposed inside the cylinder 100, and the power mechanism 300 is disposed on one side of the cylinder 100.

[0088] Specifically, the cylinder 100 includes a top cover 110, a baffle 120, a side plate 130, a bottom plate 140, and a foot 150. The top cover 110 is located on the top of the cylinder 100. The top cover 110 is a rectangular thin-shell structure. Three holes are equally spaced on the thin-shell structure. The holes extend outward to form a hollow cylinder, thereby forming a first feed inlet 111, a second feed inlet 112, and a third feed inlet 113.

[0089] Specifically, the three feed ports correspond to different powders according to the characteristics of the powders being fed. In this embodiment, the first feed port 111 is used to feed fiber powder, the second feed port 112 is used to feed tobacco powder, and the third feed port 113 is used to feed additives.

[0090] In this embodiment, the additives used may be sodium alginate, chitosan, guar gum, or cellulose acetate.

[0091] The side plate 130 includes a first side plate 131 and a second side plate 132, which are respectively disposed on both sides of the cylinder 100. The side plate 130 is square at the top and semi-circular at the bottom. The first side plate 131 and the second side plate 132 are connected to the main shaft 210. The baffle 120 includes a first baffle 121 and a second baffle 122. The first baffle 121 and the second baffle 122 are respectively connected to the upper cover 110 and the bottom plate 140. The bottom plate 140 has a hole in the center, which extends outward to form a hollow cylinder to form a discharge port 141. The foot 150 is disposed at the intersection of the side plate 130 and the bottom plate 140 to support the ribbon mixer.

[0092] Specifically, the top cover 110, baffle 120, side plate 130, and bottom plate 140 form a chamber 160, which is used to accommodate the mixing mechanism 200. The large volume of the chamber 160 provides ample space for the powder to mix evenly and prevent agglomeration.

[0093] like Figures 4-5 As shown, the mixing mechanism 200 includes a main shaft 210, an inner spiral ribbon group, an outer spiral ribbon group, a break group 260, a pitch group, and a support rod. The inner and outer spiral ribbon groups are distributed along the axial direction of the main shaft 210. The break group 260 is the discontinuity between adjacent stirring blades of the inner spiral ribbon group and adjacent stirring blades of the outer spiral ribbon group. The support rod is distributed along the radial direction of the main shaft 210 to support the inner and outer spiral ribbon groups. The stirring blades of the inner and outer spiral ribbon groups intersect with the main shaft 210 along the axial direction, and a pitch is formed between two adjacent intersections. In this patent, the inner and outer spiral ribbon groups have a symmetrically gradually changing pitch distribution along the axial direction of the main shaft 210.

[0094] Specifically, the main shaft 210 includes a left half shaft 211 and a right half shaft 212. The left half shaft 211 is fixed to the first side plate 131, and the right half shaft 212 extends from the second side plate 132 and is connected to the connecting block. The connecting block is driven to rotate by the power mechanism 300, and the connecting block drives the main shaft 210 to rotate. At this time, the mixing mechanism 200 rotates as a whole under the drive of the main shaft 210.

[0095] Specifically, the main shaft 210 has a main shaft point P along its axial direction, located at the intersection of the left half-shaft 211 and the right half-shaft 212; the contact point between the front section 220 and the rear section 230 of the inner helical ribbon assembly is the inner coincident point H; the contact point between the front section 240 and the rear section 250 of the outer helical ribbon assembly is the outer coincident point D; the extensions of the main shaft point P, the inner coincident point H, and the outer coincident point D along the radial direction converge on the same straight line, which is the extension line PHD. It is easy to understand that the inner and outer helical ribbon assemblies are symmetrically distributed along the axial direction of the main shaft 210 with the extension line PHD as the axis of symmetry.

[0096] Specifically, the inner and outer spiral ribbon groups are composed of multiple semi-circular ring-shaped stirring blades. The shapes of the individual stirring blades are not entirely the same, and the inner and outer spiral ribbon groups rotate in opposite directions. Based on their positional relationship on the main shaft 210, they are divided into front and rear sections. The inner spiral ribbon group includes a front section 220 and a rear section 230, while the outer spiral ribbon group includes a front section 240 and a rear section 250. The front sections 220 and 240 of the inner and outer spiral ribbon groups are located on the left half-shaft 211, while the rear sections 230 and 250 are located on the right half-shaft 212.

[0097] Specifically, the front segment 220 of the inner spiral group and the front segment 240 of the outer spiral group form a double helix structure resembling DNA on the left half-axis 211, and the rear segment 250 of the outer spiral group and the rear segment 230 of the inner spiral group form a double helix structure resembling DNA on the second loop; the extension lines PHD of the front segments 220 of the inner spiral group and the front segments 240 of the outer spiral group are symmetrically distributed along the axial direction of the main axis 210 with the extension line PHD as the axis of symmetry, and the rear segment 230 of the inner spiral group and the outer spiral group are symmetrically distributed along the axial direction of the main axis 210 with the extension line PHD as the axis of symmetry.

[0098] Specifically, the support rod includes an inner support rod 270 and an outer support rod 280. The length of the outer support rod 280 is greater than the length of the inner support rod 270, and the lengths of the outer support rod 280 are equal. The inner support rod 270 is of equal length and is used to support the stirring blades of the inner spiral ribbon group distributed along the main shaft 210. The outer support rod 280 is used to support the stirring blades of the outer spiral ribbon group distributed along the main shaft 210.

[0099] It is easy to understand that all inner support rods 270 have the same length, and all outer support rods 280 have the same length. That is, the lengths of the radial projections of the endpoints of the different shaped stirring blades of all inner spiral ribbon groups are the same, and the lengths of the radial projections of the endpoints of the different shaped stirring blades of all outer spiral ribbon groups are the same.

[0100] Specifically, the stirring blades of the front section 220 of the inner spiral ribbon assembly, from the front end of the left half-shaft 211 to the end of the left half-shaft 211 (main shaft point P), are distributed as follows: the first inner front stirring blade 221, the second inner front stirring blade 222, the third inner front stirring blade 223, the fourth inner front stirring blade 224, the fifth inner front stirring blade 225, and the sixth inner front stirring blade 226.

[0101] Specifically, the stirring blades of the front section 240 of the outer spiral ribbon assembly, from the front end of the left half-shaft 211 to the end of the left half-shaft 211 (main shaft point P), are distributed as follows: the first outer front stirring blade 241, the second outer front stirring blade 242, the third outer front stirring blade 243, the fourth outer front stirring blade 244, the fifth outer front stirring blade 245, and the sixth outer front stirring blade 246.

[0102] For example, taking the structure composed of the left half-shaft 211 and the front section 220 of the inner spiral ribbon group as an example, the structure composed of the left half-shaft 211 and the front section 240 of the outer spiral ribbon group is only different in the radial direction; the structures of the right half-shaft 212, the rear section 230 of the inner spiral ribbon group, and the rear section 250 of the outer spiral ribbon group are completely identical and symmetrically distributed. The first outer front stirring blade 241 begins to circle the left half-shaft 211 from its front end. The second outer front stirring blade 242 continues to circle the left half-shaft 211 after being separated from the first outer front stirring blade 241 by the distance of the first fracture 261. The third outer front stirring blade 243 continues to circle the left half-shaft 211 after being separated from the second outer front stirring blade 242 by the distance of the second fracture 262. The fourth outer front stirring blade 244 continues to circle the left half-shaft 211 after being separated from the third outer front stirring blade 243 by a fracture distance. The fifth outer front stirring blade 245 continues to circle the left half-shaft 211 after being separated from the third outer front stirring blade 243 by the distance of the third fracture 263. The sixth outer front stirring blade 246 stops at the inner coincidence point H. The first fracture 261, the second fracture 262, and the third fracture 263 form fracture group 260.

[0103] Specifically, such as Figures 6-8 As shown, the first outer front stirring blade 241 and the second outer front stirring blade 242 are projected along the axial direction of the main shaft 210 in the shape of a ring with a notch. The two sides of the notched ring form an angle with the center of the side of the left half-shaft 211. It is easy to understand that the notch is the projection of the first fracture 261 along the axial direction of the main shaft 210, and the angle is the first fracture angle α, α = 20°. The second outer front stirring blade 242 and the third outer front stirring blade 243 are projected along the axial direction of the main shaft 210 in the shape of a ring with a slightly larger notch. The notch is the projection of the second fracture 262 along the axial direction of the main shaft 210, and the angle is the second fracture angle β, β = 35°. The fourth outer front stirring blade 244 and the fifth and sixth outer front stirring blade 245 are projected along the axial direction of the main shaft 210 in the shape of a ring with a larger notch. The notch is the projection of the third fracture 263 along the axial direction of the main shaft 210, and the angle is the third fracture angle γ, γ = 45°.

[0104] Specifically, based on the fracture angle, there are convection zones, transition zones, and shear zones. There is only one convection zone, symmetrically distributed along the extended line PHD in the rear section of the left half-axis 211 and the rear section of the right half-axis 212. There are two transition zones, symmetrically distributed along the convection zone in the middle section of the left half-axis 211 and the middle section of the right half-axis 212. There are two shear zones, symmetrically distributed along the convection zone in the front section of the left half-axis 211 and the front section of the right half-axis 212. The fracture angle of the shear zone is 5–10°, 10–15°, 15–20°, or 20°; the fracture angle of the transition zone is 20–25°, 25–30°, 30–35°, 35–40°, or 40°; and the fracture angle of the convection zone is 40–45°, 45–50°, 50–55°, or 55°.

[0105] Specifically, the second inlet 112 and the outlet 141 are located in the convection zone, while the first inlet 111 and the third inlet 113 are located in the shearing zone.

[0106] Specifically, taking the structure composed of the left half-shaft 211, the front section 220 of the inner spiral ribbon group, and the front end of the outer spiral ribbon group as an example, the structures of the right half-shaft 212, the rear section 230 of the inner spiral ribbon group, and the rear section 250 of the outer spiral ribbon group are completely identical and symmetrically distributed. Looking from the first baffle 121 towards the second baffle 122, the left half-shaft 211 has multiple support rods along the axial direction, which, from this perspective, appear as points where the stirring blades intersect with the left half-shaft 211. From this perspective, the first outer front stirring blade 241 is connected to the left half-shaft 211 via the first support rod, the second inner front stirring blade 222 is connected to the left half-shaft 211 via the second support rod, the second outer front stirring blade 242 is connected to the left half-shaft 211 via the third support rod, the third inner front stirring blade 223 is connected to the left half-shaft 211 via the fourth support rod, the fourth outer front stirring blade 244 is connected to the left half-shaft 211 via the fifth support rod, the fifth inner front stirring blade 225 is connected to the left half-shaft 211 via the sixth support rod, and the sixth outer front stirring blade 246 is connected to the left half-shaft 211 via the seventh support rod.

[0107] Specifically, the axial distance between the first and second support rods is the first pitch; the axial distance between the second and third support rods is the second pitch; the axial distance between the third and fourth support rods is the third pitch; the axial distance between the fourth and fifth support rods is the fourth pitch; the axial distance between the fifth and sixth support rods is the fifth pitch; and the axial distance between the sixth and seventh support rods is the sixth pitch. It is easy to understand that the length of the first pitch < the length of the second pitch < the length of the third pitch < the length of the fourth pitch < the length of the fifth pitch < the length of the sixth pitch. Therefore, the pitch of the front section 220 of the inner spiral ribbon assembly and the front section 240 of the outer spiral ribbon assembly on the left half-shaft 211 exhibits a gradual distribution from small to large pitch. The pitch distribution of the rear section 230 of the inner spiral ribbon assembly and the rear section 250 of the outer spiral ribbon assembly is symmetrical to this distribution. This distribution avoids abrupt changes in flow resistance. Overall, the pitch distribution along the axial direction is from small pitch to large pitch to small pitch. This pitch distribution can form strong convection, making the powder mix evenly.

[0108] Looking at the mixing mechanism 200 from the first side to the second side, all the stirring blades of the inner spiral ribbon assembly overlap to form a ring with a notch. This notch is the axial projection of the first fracture 261, where the included angle α = 20°. If the included angle α is too large, the axial thrust will be reduced, causing the powder to be unable to move effectively to the discharge port 141.

[0109] Specifically, the spindle speed of 210 is 10-25 rpm, 25-40 rpm, 40-55 rpm, 55-60 rpm, or 60 rpm.

[0110] Specifically, the rotational speed of the main shaft 210 varies according to the feeding process: First, before feeding, the main shaft 210 idles at a low speed of 10-15 rpm in the chamber 160. Then, tobacco powder is gradually fed into the chamber 160 from the second feed port 112, while the main shaft 210 continues to agitate at 10-15 rpm until all tobacco powder is metered and enters the chamber 160. Next, fiber powder is fed into the chamber 160 from the first feed port 111 and additives are fed into the chamber 160 from the third feed port 113. During the feeding process, the rotational speed of the main shaft 210 is gradually increased and reaches a maximum speed of 60 rpm before the fiber powder is metered and all additives are fed. Finally, after all the powders are fed into the chamber 160, the main shaft 210 continues to rotate and mix at the maximum speed of 60 rpm.

[0111] Specifically, the area below the first feed inlet 111 is a shearing zone. After the fiber powder enters the chamber 160 through the first feed inlet 111, it falls into the shearing zone. The pitch and fracture angle of the shearing zone are small, which allows the fiber powder to be continuously subjected to high-intensity shearing during the feeding process. At the same time, turbulence is formed at the fracture point to prevent the fiber powder from accumulating and agglomerating. As the rotational speed of the main shaft 210 increases, the fiber powder is gradually moved from the front section of the left half shaft 211 to the rear section of the left half shaft 211 by the axial thrust of the front section 220 of the inner spiral ribbon group and the front section 240 of the outer spiral ribbon group. The fiber powder enters the convection zone from the shearing zone to the transition zone. At this time, the fiber powder, tobacco powder, and additives form a strong convective mixture in the convection zone.

[0112] Specifically, the gradual pitch distribution, from small to large and then back to small, enhances the shearing effect in two ways. First, in the narrow gap, the powder is forced to pass through the confined space at a higher speed. In the radial direction, the powder near the surface of the stirring blades has a lower speed due to friction, while the powder near the main shaft 210 has a higher speed, creating a larger speed difference and a significantly increased gradient speed, leading to increased shear force. Second, the gradual pitch, especially the pitch change in the shearing zone, requires the powder to frequently change direction as it moves axially. This exacerbates velocity fluctuations in laminar or turbulent flow. This complex motion pattern further increases the local velocity gradient, thereby improving the shearing effect.

[0113] Specifically, regarding the powder involved in this patent, its material properties result in poor flowability. Therefore, in the initial mixing stage at low speeds, the internal powder is mainly in laminar flow, gradually transitioning to turbulent flow as the speed increases. For mixed powders, it is generally believed that the powder is more easily and uniformly mixed when it reaches a disordered turbulent state.

[0114] The specification of this patent uses terms indicating direction, such as "front," "rear," "side," "top," and "bottom," to describe various example structural parts and components of this patent. However, the use of these terms is merely for illustrative purposes and is based on the orientation of the examples shown in the accompanying drawings. Since the embodiments disclosed in this patent can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations, and are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0115] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0116] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "left," "right," and similar expressions used herein are for illustrative purposes only and do not indicate the only possible implementation. The terms "upper," "lower," etc., indicating orientation or positional relationships are defined with reference to the coordinates of the accompanying drawings and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent. The terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0117] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this patent belongs. The terminology used herein in the specification of this patent is for the purpose of describing particular embodiments only and is not intended to be limiting of this patent. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0118] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this patent will not describe the various possible combinations separately.

[0119] Furthermore, various implementations of this patent can be combined in any way, and as long as they do not violate the spirit of this patent, they should also be regarded as the content disclosed in this patent.

Claims

1. A high-shear anti-agglomeration ribbon mixer, characterized in that, The ribbon mixer includes a cylinder, a mixing mechanism, and a power mechanism. The cylinder includes a chamber, and the mixing mechanism is placed in the chamber and stirs the powder under the drive of the power mechanism. The mixing mechanism includes a main shaft, an inner ribbon group, and an outer ribbon group. The inner ribbon group and the outer ribbon group are distributed on the main shaft with opposite rotation directions and symmetrical variable pitch.

2. The ribbon mixer according to claim 1, characterized in that, The main shaft includes a left half-shaft and a right half-shaft. The inner threaded ribbon assembly includes a front section and a rear section. The outer threaded ribbon assembly includes a front section and a rear section. The front section of the inner threaded ribbon assembly and the front section of the outer threaded ribbon assembly are disposed on the left half-shaft. The rear section of the inner threaded ribbon assembly and the rear section of the outer threaded ribbon assembly are disposed on the right half-shaft.

3. The ribbon mixer according to claim 2, characterized in that, The main shaft is provided with a main shaft point P along the axial direction, and the main shaft point P is located at the junction of the left half shaft and the right half shaft; The contact point between the front section and the rear section of the internal spiral ribbon assembly is the inner coincidence point H; The contact point between the front section and the rear section of the external spiral ribbon assembly is the external coincidence point D; The radial extensions of the principal axis point P, the inner coincident point H, and the outer coincident point D converge on the same straight line, which is the extension line PHD.

4. The ribbon mixer according to claim 3, characterized in that, The front section of the inner spiral ribbon group and the front section of the outer spiral ribbon group are symmetrically distributed with respect to the extension line PHD along the axial direction of the main shaft.

5. The ribbon mixer according to claim 2, characterized in that, The inner spiral ribbon group front section, the inner spiral ribbon group rear section, the outer spiral ribbon group front section and the outer spiral ribbon group rear section include fan-shaped stirring blades, and the stirring blades are distributed with a gradually changing pitch along the left half axis and the right half axis; The pitch is 4–24 mm, 24–44 mm, or 44–64 mm.

6. The ribbon mixer according to claim 5, characterized in that, A break is formed between the adjacent stirring blades of the inner spiral ribbon group and the outer spiral ribbon group; The angle formed by the projection of the fracture surface and the axis of the main shaft along the axial direction is the fracture angle.

7. The ribbon mixer according to claim 6, characterized in that, Based on the included angle of the fracture surface, a convection zone, a transition zone, and a shear zone are provided; The included angle α of the first fracture surface in the shear zone is 5–10°, 10–15°, or 15–20°. The included angle γ of the third fracture in the convection zone is 40–45°, 45–50°, or 50–55°. The included angle β of the second fracture in the transition zone is 20–25°, 25–30°, 30–35°, or 35–40°.

8. The ribbon mixer according to claim 1, characterized in that, The cylinder also includes a top cover, a baffle, side plates, a bottom plate, and feet. The bottom plate is arc-shaped. The top cover, the baffle, the side plates, and the bottom plate enclose the chamber. The bottom plate is provided with a discharge port, and the top cover is provided with a first inlet, a second inlet and a third inlet according to the properties of the powder.

9. The ribbon mixer according to claim 1, characterized in that, The spindle speed is 10-25 rpm, 25-40 rpm, 40-55 rpm, or 55-60 rpm; The mixing mechanism further includes an inner support rod and an outer support rod. The inner support rod connects the inner helical ribbon assembly and the main shaft in the radial direction, and the outer support rod connects the outer helical ribbon assembly and the main shaft in the radial direction.

10. The ribbon mixer according to claim 1, characterized in that, The powder includes tobacco powder, fiber powder, and additives; The fiber powder is a low-mesh fiber powder, with a mesh size of 30-40 mesh, 40-50 mesh, or 50-60 mesh.

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