A pulp mixing device

Abstract

This utility model discloses a pulping and mixing device, belonging to the technical field of pulping and mixing equipment. It includes a mixing tank containing a first and second mixing shaft arranged in parallel. The plane containing the central axes of the two mixing shafts forms an angle with the bottom surface of the mixing tank. The first and second mixing shafts rotate in opposite directions. Mixing blades arranged at intervals along the same helical direction are mounted on both shafts. In this design, the helically arranged blades on the first and second mixing shafts provide axial propulsion to the slurry, while the spaced blades also provide mixing. A radial shear flow field is formed. The intersecting plane of the first and second mixing shafts divides the mixing area into an asymmetric space, resulting in three-dimensional turbulence in the slurry during mixing. This effectively eliminates dead zones and improves the mixing effect within the mixing tank.

Description

Technical Field

[0001] This utility model relates to a pulping and stirring structure, and more specifically, to a pulping and stirring device. Background Technology

[0002] In the construction of subway tunnels and other projects, shield tunneling excavated soil can be recycled and used as a raw material for synchronous grouting. However, existing mixing equipment generally uses a single mixing shaft for mixing, which can easily lead to uneven mixing of mortar in the mixing tank, resulting in density defects and affecting construction quality. For some larger mixing tanks, the mixing equipment uses a dual-shaft system. This not only increases the number of mixing shafts, but may also lead to some dead zones in the mixing tank due to unreasonable arrangement of the mixing shafts, which may result in problems such as foam layers at the top and sediment layers at the bottom.

[0003] For example, Chinese Patent Publication No. CN217514229U, published on September 30, 2022, describes a utility model entitled "Premixed Horizontal Mixer for Steel Fiber Reinforced Concrete Preparation." The mixer includes a frame, a top frame fixed to the top of the frame, and a mixing chamber fixed to the top of the top frame via multiple box-shaped columns. Inside the mixing chamber are parallel-arranged first and second mixing shafts. A first mixing paddle is mounted on the first mixing shaft and located within the mixing chamber; a second mixing paddle is mounted on the second mixing shaft and located within the mixing chamber. The first mixing shaft is connected to a mixing power mechanism for driving its rotation. A gear transmission mechanism is installed between the first and second mixing shafts to drive their synchronous rotation. This mixer, employing a horizontal structure specifically designed for the dry premixing of steel fibers and aggregates, ensures uniform mixing, guarantees mixing quality, and improves mixing efficiency, thereby ensuring the structural strength and quality of the subsequently prepared steel fiber reinforced concrete. However, this scheme uses a traditional parallel arrangement of the mixing shaft, which can only mix the slurry at the same horizontal level as the mixing shaft. The mixing effect at the bottom or top is small, which may also lead to uneven mixing of the slurry. Utility Model Content

[0004] This invention overcomes the problem of uneven mixing of slurry in existing dual-shaft mixing equipment and provides a slurry mixing device. In this solution, the axial planes of the two mixing shafts are arranged at an angle to the bottom of the mixing tank, and the two mixing shafts are staggered at different heights, which can achieve a better mixing effect on the slurry in the mixing tank.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a pulping and mixing device, including a mixing tank, in which a first mixing shaft and a second mixing shaft are arranged in parallel. The plane containing the central axes of the two mixing shafts is arranged at an angle to the bottom surface of the mixing tank. The rotation directions of the first mixing shaft and the second mixing shaft are opposite. Mixing blades arranged at intervals along the same helical direction are provided on the first and second mixing shafts. In this solution, the helically arranged blades on the first and second mixing shafts can provide an axial propulsion effect on the slurry, and the spaced distribution of the mixing blades can also provide a mixing effect on the slurry, forming a shear flow field in the radial direction. The staggered plane formed by the first and second mixing shafts divides the mixing area into an asymmetric space. During the mixing process, the slurry forms a three-dimensional turbulent flow, which can effectively eliminate the mixing dead zone and improve the mixing effect of the slurry in the mixing tank.

[0006] Preferably, the stirring blade is fan-shaped, and its thickness gradually decreases radially from the axis to the outer edge. The outer edge of the stirring blade is edged with a hard alloy. The greater thickness near the axis enhances the structural strength of the stirring blade, while the smaller thickness at the edge reduces rotational resistance, achieving a balance between energy saving and durability. Simultaneously, the edged structure also protects the stirring blade, extending its service life.

[0007] Preferably, the mixing tank includes a feed end and a discharge end. The pitch of the mixing blades on the side of the first mixing shaft near the feed end is greater than the pitch of the mixing blades on the side near the discharge end, and the pitch of the mixing blades on the side of the second mixing shaft near the feed end is greater than the pitch of the mixing blades on the side near the discharge end. The larger pitch of the mixing blades on the first and second mixing shafts can effectively improve the propulsion of the slurry, while the smaller pitch of the mixing blades can improve the shearing and mixing effect of the mixing blades on the slurry.

[0008] Preferably, the bottom of the mixing tank has rounded sides in the width direction, and a wear-resistant layer is laminated on the bottom of the mixing tank. The rounded shape of the bottom of the mixing tank in the width direction effectively eliminates dead zones at the corners, improving the mixing effect. The wear-resistant layer at the bottom of the mixing tank reduces wear and extends the service life of the mixing tank.

[0009] Preferably, the mixing tank has a discharge port at the bottom and near the discharge end, and the discharge port is equipped with a discharge component. The discharge port can export the mixed slurry in the mixing tank and transport it to the next process. The discharge component provides power to the slurry at the discharge port, so that the slurry is transported out.

[0010] Preferably, the discharge assembly includes a discharge pipe inclinedly arranged at the bottom of the discharge port and a transfer pipe perpendicular to the direction of the discharge pipe, wherein the discharge pipe connects the discharge port and the transfer pipe.

[0011] Preferably, the feed pipe is equipped with a feed screw inside and a support outside the feed pipe. The feed screw can output the slurry in the feed pipe to the slurry bin, and the support provides support for the feed pipe.

[0012] Preferably, a first driving device is provided at the end of the feed pipe away from the discharge pipe, and the first driving device is connected to the feed screw. The first driving device is used to drive the feed screw to rotate and output the slurry.

[0013] Preferably, a second driving device is provided on the side of the mixing tank near the feed end. The second driving device includes a gearbox and a drive motor. The drive motor is connected to the gearbox, and the gearbox is connected to the first and second mixing shafts via a coupling. The second driving device is used to drive the first and second mixing shafts to rotate. The gearbox, as a transmission structure between the drive motor and the two mixing shafts, can drive the first and second mixing shafts to rotate in opposite directions.

[0014] Compared with the prior art, the beneficial effects of this utility model are: (1) the slurry forms a three-dimensional turbulence during the stirring process, which can effectively eliminate the stirring dead zone and improve the stirring effect of the slurry in the stirring tank; (2) the double stirring shafts intersect to form an angled plane, which divides the stirring area into an asymmetrical space. The arrangement is simple and can maximize the layout in the stirring tank, making the layout more reasonable; (3) the stirring blades have high structural strength, good stability, and low rotational resistance, which effectively improves the service life of the equipment. Attached Figure Description

[0015] Figure 1 This is an isometric view of the present invention.

[0016] Figure 2 This is the front view of the present invention.

[0017] Figure 3 This is a cross-sectional view of the present invention.

[0018] Figure 4 This is a schematic diagram of the first stirring shaft of this utility model.

[0019] Figure 5 This is a top view of the present invention.

[0020] In the figure: 1. Mixing tank, 2. First mixing shaft, 3. Second mixing shaft, 4. Mixing blade, 5. Feeding end, 6. Discharge end, 7. Wear-resistant layer, 8. Discharge port, 9. Discharge pipe, 10. Transfer pipe, 11. Support, 12. First drive device, 13. First gearbox, 14. Drive motor, 15. Second gearbox, 16. Conveyor belt. Detailed Implementation

[0021] The technical solution of this utility model will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0022] Example 1: As Figures 1 to 5 The illustrated pulping and mixing device includes a mixing tank 1, which is a rectangular open-top tank structure. Two sets of mixing shafts, namely a first mixing shaft 2 and a second mixing shaft 3, are arranged along the length of the mixing tank 1. The first mixing shaft 2 and the second mixing shaft 3 are arranged in parallel, and the plane of the first mixing shaft 2 and the second mixing shaft 3 forms an angle (acute angle) with the bottom plane of the mixing tank 1, so that the two mixing shafts are staggered with one high and one low. A number of mixing blades 4 are arranged on the first mixing shaft 2 and the second mixing shaft 3. The mixing blades 4 are spirally distributed on the first mixing shaft 2 and the second mixing shaft 3, and each mixing blade 4 is spaced apart. The mixing blades 4 have a certain spiral angle on the first mixing shaft 2 and the second mixing shaft 3, and the arrangement and spiral direction of the mixing blades 4 on the first mixing shaft 2 and the second mixing shaft 3 are the same.

[0023] During the mixing process, the first stirring shaft 2 and the second stirring shaft 3 rotate in opposite directions, creating two different mixing effects on the slurry in the mixing tank 1. Since the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 are spirally distributed, during their rotation, the stirring blades 4 not only mix the slurry but also propel it axially, allowing the slurry to flow along the mixing tank 1. Furthermore, because the first stirring shaft 2 and the second stirring shaft 3 rotate in opposite directions, the axial flow of the slurry at their locations is also opposite. This means the slurry can circulate within the mixing tank 1, reducing dead zones and achieving a better mixing effect.

[0024] The stirring blades 4 propel the slurry axially, forming an axial flow field. The inclined arrangement of the first stirring shaft 2 and the second stirring shaft 3 allows the stirring blades 4 to generate a radial secondary vortex in addition to the main axial propulsion force, thus creating a shearing and stirring effect and effectively improving the suspension capacity of the particles. At the same time, the friction between the slurry and the stirring blades 4 also enables the slurry to form a circumferential flow field under the action of centrifugal force, thereby forming a three-dimensional turbulence and eliminating the stirring dead zone.

[0025] Specifically, the angle between the plane formed by the center of the first stirring shaft 2 and the second stirring shaft 3 and the bottom plane of the stirring tank 1 is preferably 35 to 40 degrees. In this embodiment, the angle is 38 degrees, and the first stirring shaft 2 is located below and the second stirring shaft 3 is located above. This arrangement can disrupt the low-speed zone at the four corners of the stirring tank 1, allowing the slurry to circulate along the diagonal direction of the stirring tank 1, which can effectively reduce the amount of sediment at the bottom of the stirring tank 1.

[0026] The stirring blade 4 has a fan-shaped structure, and its thickness gradually decreases from the axis of the stirring shaft to the outer edge. Specifically, the thickness of the stirring blade 4 decreases radially from 12mm to 8mm from the center to the outer edge. The thicker thickness near the center of the stirring blade 4 enhances its structural strength, while the thinner thickness at the edges reduces rotational resistance, achieving a balance between energy saving and durability. Furthermore, a 5mm thick hard alloy edging is provided at the edges of the stirring blade 4. This edging protects the edges of the stirring blade 4, preventing excessive wear during stirring and extending its service life.

[0027] Furthermore, the pitch of the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 is unequal. Specifically, taking the midpoint of the first stirring shaft 2 and the midpoint of the second stirring shaft 3 as the boundary, the pitch of the stirring blades 4 at one end of the first stirring shaft 2 and the second stirring shaft 3 is 300mm, and the pitch of the stirring blades 4 at the other end of the first stirring shaft 2 and the second stirring shaft 3 is 200mm. The larger pitch of the stirring blades 4 can effectively improve the propulsion of the slurry, while the smaller pitch of the stirring blades 4 can improve the shearing and mixing effect of the stirring blades 4 on the slurry. The larger pitch ends of the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 are both located at the feed end of the mixing tank 1, and the smaller pitch ends are both located at the discharge end 6 of the mixing tank 1, so that the slurry can be fully mixed and discharged from the discharge end 6.

[0028] The bottom of the mixing tank 1 is U-shaped, meaning that the two sides of the mixing tank 1 in the width direction are rounded to prevent the bottom of the mixing tank 1 from forming a right angle structure and reduce the formation of dead zones in the mixing. A wear-resistant layer 7 is also provided at the bottom of the mixing tank 1 to reduce wear on the bottom of the mixing tank 1 and improve the service life of the equipment.

[0029] A second drive device is provided on one side of the feed end 5 of the mixing tank 1. The second drive device consists of a drive motor 14 and two gearboxes, namely a first gearbox 13 and a second gearbox 15. The first gearbox 13 is connected to the drive motor 14 via a conveyor belt 16. The first gearbox 13 has multiple sets of meshing gears to form a reducer structure. One set of gears in the first gearbox 13 is coaxially connected to one set of gears in the second gearbox 15, thereby forming a transmission with the gears in the second gearbox 15. The gears in the second gearbox 15 are directly connected to the first stirring shaft 2 and the second stirring shaft 3. Thus, when the drive motor 14 is started, it can drive the gears in the first gearbox 13 to rotate, thereby driving the gears in the second gearbox 15 to rotate, ultimately enabling the first stirring shaft 2 and the second stirring shaft 3 to rotate synchronously.

[0030] Example 2: As Figures 1 to 5 The illustrated pulping and mixing device includes a mixing tank 1, which is a rectangular open-top tank structure. Two sets of mixing shafts, namely a first mixing shaft 2 and a second mixing shaft 3, are arranged along the length of the mixing tank 1. The first mixing shaft 2 and the second mixing shaft 3 are arranged in parallel, and the plane of the first mixing shaft 2 and the second mixing shaft 3 forms an angle (acute angle) with the bottom plane of the mixing tank 1, so that the two mixing shafts are staggered with one high and one low. A number of mixing blades 4 are arranged on the first mixing shaft 2 and the second mixing shaft 3. The mixing blades 4 are spirally distributed on the first mixing shaft 2 and the second mixing shaft 3, and each mixing blade 4 is spaced apart. The mixing blades 4 have a certain spiral angle on the first mixing shaft 2 and the second mixing shaft 3, and the arrangement and spiral direction of the mixing blades 4 on the first mixing shaft 2 and the second mixing shaft 3 are the same.

[0031] During the mixing process, the first stirring shaft 2 and the second stirring shaft 3 rotate in opposite directions, creating two different mixing effects on the slurry in the mixing tank 1. Since the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 are spirally distributed, during their rotation, the stirring blades 4 not only mix the slurry but also propel it axially, allowing the slurry to flow along the mixing tank 1. Furthermore, because the first stirring shaft 2 and the second stirring shaft 3 rotate in opposite directions, the axial flow of the slurry at their locations is also opposite. This means the slurry can circulate within the mixing tank 1, reducing dead zones and achieving a better mixing effect.

[0032] The stirring blades 4 propel the slurry axially, forming an axial flow field. The inclined arrangement of the first stirring shaft 2 and the second stirring shaft 3 allows the stirring blades 4 to generate a radial secondary vortex in addition to the main axial propulsion force, thus creating a shearing and stirring effect and effectively improving the suspension capacity of the particles. At the same time, the friction between the slurry and the stirring blades 4 also enables the slurry to form a circumferential flow field under the action of centrifugal force, thereby forming a three-dimensional turbulence and eliminating the stirring dead zone.

[0033] Specifically, the angle between the plane formed by the center of the first stirring shaft 2 and the second stirring shaft 3 and the bottom plane of the stirring tank 1 is preferably 35 to 40 degrees. In this embodiment, the angle is 38 degrees, and the first stirring shaft 2 is located below and the second stirring shaft 3 is located above. This arrangement can disrupt the low-speed zone at the four corners of the stirring tank 1, allowing the slurry to circulate along the diagonal direction of the stirring tank 1, which can effectively reduce the amount of sediment at the bottom of the stirring tank 1.

[0034] The stirring blade 4 has a fan-shaped structure, and its thickness gradually decreases from the axis of the stirring shaft to the outer edge. Specifically, the thickness of the stirring blade 4 decreases radially from 12mm to 8mm from the center to the outer edge. The thicker thickness near the center of the stirring blade 4 enhances its structural strength, while the thinner thickness at the edges reduces rotational resistance, achieving a balance between energy saving and durability. Furthermore, a 5mm thick hard alloy edging is provided at the edges of the stirring blade 4. This edging protects the edges of the stirring blade 4, preventing excessive wear during stirring and extending its service life.

[0035] Furthermore, the pitch of the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 is unequal. Specifically, taking the midpoint of the first stirring shaft 2 and the midpoint of the second stirring shaft 3 as the boundary, the pitch of the stirring blades 4 at one end of the first stirring shaft 2 and the second stirring shaft 3 is 300mm, and the pitch of the stirring blades 4 at the other end of the first stirring shaft 2 and the second stirring shaft 3 is 200mm. The larger pitch of the stirring blades 4 can effectively improve the propulsion of the slurry, while the smaller pitch of the stirring blades 4 can improve the shearing and mixing effect of the stirring blades 4 on the slurry. The larger pitch ends of the stirring blades 4 on the first stirring shaft 2 and the second stirring shaft 3 are both located at the feed end of the mixing tank 1, and the smaller pitch ends are both located at the discharge end 6 of the mixing tank 1, so that the slurry can be fully mixed and discharged from the discharge end 6.

[0036] The bottom of the mixing tank 1 is U-shaped, meaning that the two sides of the mixing tank 1 in the width direction are rounded to prevent the bottom of the mixing tank 1 from forming a right angle structure and reduce the formation of dead zones in the mixing. A wear-resistant layer 7 is also provided at the bottom of the mixing tank 1 to reduce wear on the bottom of the mixing tank 1 and improve the service life of the equipment.

[0037] A discharge assembly is arranged at the discharge port 8 of the mixing tank 1. Specifically, the discharge assembly includes a discharge pipe 9, a conveying pipe 10, and a first driving device 12. The discharge pipe 9 is located at the bottom of the discharge port 8 and outside the mixing tank 1. The discharge pipe 9 is inclined relative to the bottom of the mixing tank 1, with the inclination direction facing away from the feed end of the mixing tank 1. The conveying pipe 10 is connected to the discharge pipe 9, and the discharge pipe 9 and the conveying pipe 10 are arranged perpendicularly. That is, the discharge pipe 9 is inclined downwards, and the conveying pipe 10 is inclined upwards. A conveying screw is provided inside the conveying pipe 10. The rod has a first driving device 12 at its top, which is connected to a conveying screw. The first driving device 12 is a rotary motor. When the first driving device 12 is started, the conveying screw can rotate inside the conveying pipe 10, thereby transporting the slurry at the bottom of the conveying pipe 10 upward. The upward conveying direction not only transports the slurry to a higher slurry storage port, but also ensures that the first driving device 12 at a higher position is not affected by the slurry. A conveying pipe is set at a lower position of the first driving device 12 and around the periphery of the conveying pipe 10 to output the slurry in the conveying pipe 10 to the slurry storage device. In order to ensure the stable arrangement of the conveying pipe 10, a bracket 11 is also set on the outside of the conveying pipe 10 to support the structure of the conveying pipe 10.

[0038] A second drive device is provided on one side of the feed end 5 of the mixing tank 1. The second drive device consists of a drive motor 14 and two gearboxes, namely a first gearbox 13 and a second gearbox 15. The first gearbox 13 is connected to the drive motor 14 via a conveyor belt 16. The first gearbox 13 has multiple sets of meshing gears to form a reducer structure. One set of gears in the first gearbox 13 is coaxially connected to one set of gears in the second gearbox 15, thereby forming a transmission with the gears in the second gearbox 15. The gears in the second gearbox 15 are directly connected to the first stirring shaft 2 and the second stirring shaft 3. Thus, when the drive motor 14 is started, it can drive the gears in the first gearbox 13 to rotate, thereby driving the gears in the second gearbox 15 to rotate, ultimately enabling the first stirring shaft 2 and the second stirring shaft 3 to rotate synchronously.

Claims

1. A pulping and mixing device, characterized in that, The system includes a mixing tank, in which a first mixing shaft and a second mixing shaft are arranged in parallel. The plane containing the central axes of the two mixing shafts forms an angle with the bottom surface of the mixing tank. The first mixing shaft and the second mixing shaft rotate in opposite directions. The first mixing shaft and the second mixing shaft are provided with mixing blades arranged at intervals along the same spiral direction. The mixing tank includes a feed end and a discharge end. The pitch of the mixing blades on the side of the first mixing shaft near the feed end is greater than the pitch of the mixing blades on the side near the discharge end. The pitch of the mixing blades on the side of the second mixing shaft near the feed end is greater than the pitch of the mixing blades on the side near the discharge end.

2. The pulping and mixing device according to claim 1, characterized in that, The stirring blade is fan-shaped, and the thickness of the stirring blade gradually decreases radially from the axis to the outer edge. The outer edge of the stirring blade is provided with a hard alloy edging.

3. The pulping and mixing device according to claim 1, characterized in that, The bottom of the mixing tank has two arc-shaped sides in the width direction, and the bottom of the mixing tank is coated with a wear-resistant layer.

4. The pulping and mixing device according to claim 1, characterized in that, The bottom of the mixing tank and the side near the discharge end are provided with a discharge port, and the discharge port is provided with a discharge component.

5. The pulping and mixing device according to claim 4, characterized in that, The discharge assembly includes a discharge pipe inclinedly arranged at the bottom of the discharge port and a transfer pipe perpendicular to the discharge pipe, the discharge pipe connecting the discharge port and the transfer pipe.

6. The pulping and mixing device according to claim 5, characterized in that, The material transfer tube is equipped with a material transfer screw inside, and a support is provided outside the material transfer tube.

7. The pulping and mixing device according to claim 6, characterized in that, The material transfer pipe is provided with a first driving device at the end away from the discharge pipe, and the first driving device is connected to the material transfer screw.

8. A pulping and mixing apparatus according to any one of claims 1 to 7, characterized in that, A second driving device is provided on the side of the mixing tank near the feed end. The second driving device includes a gearbox and a drive motor. The drive motor is connected to the gearbox, and the gearbox is connected to the first mixing shaft and the second mixing shaft through a coupling.

Images