Mixing device for cement stabilized macadam mixture

Abstract

The invention discloses a mixing device for a cement stabilized macadam mixture, and belongs to the technical field of road engineering equipment. A plurality of arc-shaped blades are evenly distributed on a rotating shaft in a mixing cylinder in the circumferential direction, the rotating shaft is of a hollow structure and used for forming a cellosilk conveying channel in the length direction, each arc-shaped blade is of a double-layer structure, temporary storage cavities used for containing cellosilk are formed between the double-layer structures, and the temporary storage cavities in the arc-shaped blades are all connected with the cellosilk conveying channel. The device further comprises a fiber feeding bin, an opening and closing piece and a convex face located on the arc-shaped blade, a fiber releasing opening is formed in the convex face of the arc-shaped blade and communicated with the temporary storage cavity, and the opening and closing piece is arranged at the fiber releasing opening and used for closing or opening the fiber releasing opening. An air flow output pipeline of the impact air flow supply device is communicated with the fiber conveying channel through a rotary joint. According to the invention, uniform mixing of fibers and a mixture can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering equipment, and in particular to a mixing device for cement-stabilized crushed stone mixture. Background Art

[0002] Cement stabilized crushed stone is made of graded crushed stone as aggregate, with a certain amount of cementitious materials and sufficient mortar volume to fill the gaps between aggregates, and is spread and compacted according to the principle of interlocking. Its compaction is close to density, and its strength mainly depends on the interlocking principle between crushed stones, and there is sufficient mortar volume to fill the gaps between aggregates. It has high initial strength, and its strength increases with age and quickly forms a board, so it has high strength, impermeability and frost resistance.

[0003] Cement stabilized gravel base construction technology is widely used in highway pavement engineering. Studies have shown that adding fiber filaments to cement stabilized gravel mixtures can further enhance the performance of cement stabilized gravel. For example, adding polyvinyl alcohol fiber (PVA fiber) to cement stabilized gravel mixtures can significantly improve the crack resistance and durability of cement stabilized gravel. This is because PVA fiber forms a three-dimensional interlaced network structure inside the material, which bears part of the internal stress, squeezes or even blocks the internal capillaries, inhibits the surface tension formed by water loss, thereby alleviating the cracking of the pavement and improving the resistance to shrinkage cracking; at the same time, adding PVA fiber can effectively inhibit the early cracks of the cement stabilized gravel base, improve its toughness and impact resistance, improve the impermeability, frost resistance, wear resistance and carbonization resistance of the base, thereby improving the durability of the base; therefore, PVA fiber is generally added to the cement stabilized gravel mixture when constructing areas with frequent traffic loads such as roadbeds and pavements.

[0004] At present, the common cement-stabilized gravel mixture mixing equipment generally uses stirring and vibration to mix materials. Stirring can make different materials achieve the purpose of mixing; and the vibration function can well avoid the occurrence of cement agglomeration and segregation. However, since PVA fibers have a certain length and good hydrophilicity, when encountering water, the PVA fibers will gather together due to the action of capillary tension to form PVA fiber bundles, which makes the PVA fibers easier to adsorb and aggregate when stirring, especially in an aqueous environment. Therefore, if the existing cement-stabilized gravel mixture mixing equipment is used, it is difficult for the PVA fibers to be evenly dispersed in the cement-stabilized gravel mixture. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems in the prior art and to provide a mixing device for cement-stabilized crushed stone mixture, which can make PVA fibers evenly dispersed in the cement-stabilized crushed stone mixture.

[0006] The present invention provides a mixing device for cement-stabilized crushed stone mixture, comprising a mixing drum arranged horizontally and a rotating shaft passing through the mixing drum in a horizontal direction, wherein a plurality of arc-shaped blades are evenly arranged on the rotating shaft around the circumference, wherein the rotating shaft is a hollow structure, and is used to form a fiber filament conveying channel along the length direction, wherein the arc-shaped blades are a double-layer structure, and a temporary storage cavity for accommodating the fiber filaments is formed between the double-layer structures, and the temporary storage cavity in each arc-shaped blade is connected to the fiber filament conveying channel, and further comprising:

[0007] A fiber filament feeding bin is located on a rotating shaft extending to the outside of the mixing cylinder and is connected to the fiber filament conveying channel. A sealing cover is provided on the fiber filament feeding bin;

[0008] An opening and closing member is located on the convex surface of each of the arc-shaped blades, a fiber release port is provided on the convex surface of the arc-shaped blade, the fiber release port is communicated with the temporary storage cavity, and the opening and closing member is arranged at the fiber release port to close or open the fiber release port;

[0009] The impact airflow supply device has an airflow output pipeline which is connected to the fiber filament conveying channel through a rotary joint.

[0010] As a preferred embodiment, the opening and closing member includes:

[0011] An arc-shaped sealing plate is adapted to the convex curvature of the arc-shaped blade at the position, the arc-shaped sealing plate is hinged at the fiber filament release port, and the opening of the arc-shaped sealing plate is away from the rotating shaft;

[0012] The arc-shaped trigger plate is adapted to the curvature of the convex surface of the arc-shaped blade at the position, the arc-shaped sealing plate and the arc-shaped trigger plate are arranged in sequence along the arc length direction of the convex surface, and the arc-shaped trigger plate is hinged at one end of the arc-shaped blade away from the rotating shaft;

[0013] A hinge is arranged on the convex surface of the arc-shaped blade, the middle part of the hinge is hinged to the convex surface of the arc-shaped blade, one end of the hinge is abutted against the open side of the arc-shaped sealing plate, and the other end of the hinge is abutted against the open side of the arc-shaped trigger plate, and the upper end of the arc-shaped trigger plate is at least located on the arc-shaped blade between the center line of the arc-shaped blade parallel to the rotating shaft and the rotating shaft.

[0014] As a preferred embodiment, the convex surface of the arc-shaped blade is provided with a recessed portion, and the arc-shaped trigger plate can be embedded in the recessed portion after being subjected to external force, and the outer surface of the arc-shaped trigger plate after being embedded in the recessed portion is not higher than the plane where the fiber release port is located.

[0015] As a preferred embodiment, after the arc-shaped sealing plate is propped up by the hinge, the angle between the arc-shaped sealing plate and the plane where the fiber release port is located is less than 30 degrees.

[0016] As a preferred embodiment, the fiber filament release opening is a strip-shaped opening, and the length direction of the strip-shaped opening is arranged along the length of the rotating shaft.

[0017] As a preferred embodiment, the strip-shaped opening is designed to be inclined so that the angle between the release trajectory of the fiber filament and the tangent direction of the convex surface of the arc-shaped blade at the position of the strip-shaped opening is less than 30 degrees.

[0018] As a preferred embodiment, the outer periphery of the arc-shaped trigger plate is connected to the outer surface of the arc-shaped blade via a flexible membrane, so as to prevent the mixed material from entering the bottom of the arc-shaped trigger plate.

[0019] As a preferred embodiment, a pressure plate is provided in the fiber filament feeding bin, and the pressure plate is used to apply pressure to the fiber filaments in the fiber filament feeding bin.

[0020] As a preferred embodiment, the mixing drum is divided into a premixing section and a mixing section in sequence along the length direction; an aggregate feed port is provided at the top of the starting position of the premixing section, and an inlet for adding cementitious material and water is provided on the mixing section; one end of the rotating shaft close to the aggregate feed port is connected to an impact airflow supply device, and the other end of the rotating shaft is connected to a driving part for driving the rotating shaft to rotate; the bottom of the premixing section is a plate body inclined downward from the starting end to the mixing section; the end of the premixing section is connected to the mixing section so that the premixed materials enter the mixing section in sequence; the discharge port of the mixing section is located at the bottom of the end of the mixing section; the rotating shaft corresponding to the premixing section is a hollow structure, and the arc-shaped blade corresponding to the premixing section is a double-layer structure.

[0021] As a preferred embodiment, the barrel diameter of the premixing section is smaller than the barrel diameter of the mixing section.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention utilizes the movement law of aggregate on the arc-shaped blade under the action of centrifugation, and adds PAV fiber into the aggregate through the impact airflow during the process of the aggregate falling from top to bottom, thereby realizing the premixing of aggregate and PAV fiber, and avoiding the problem that the PAV fiber aggregates to form PVA fiber bundles after the subsequent addition of water, which makes it difficult to evenly disperse in the cement-stabilized crushed stone mixed slurry.

[0023] The present invention can achieve that after the arc trigger plate is subjected to the pressure of the aggregate impact, the pressure is transmitted to the hinge part through the cooperation of the arc trigger plate, the hinge part gives the arc sealing plate an upward supporting force by rotating, and then opens the arc sealing plate, so that the PVA fibers are released through the fiber release port and mixed with the aggregate during the process of the aggregate falling from top to bottom. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0025] Figure 2 It is a schematic diagram of the arc-shaped blade aggregate sliding down under the action of centrifugal force in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the curved blades after adding baffles in an embodiment of the present invention.

[0027] Figure 4 Schematic diagram of the connection relationship between the arc-shaped blades and the rotating shaft in an embodiment of the present invention.

[0028] Figure 5 For the embodiment of the present invention Figure 4 A partial enlarged view of point A in the middle.

[0029] Figure 6 Schematic diagram of the structure of the hinge according to an embodiment of the present invention.

[0030] Figure 7 It is a schematic diagram of the structure of a flexible film designed on a hinge according to an embodiment of the present invention.

[0031] Figure 8 It is a schematic structural diagram of the convex surface of the arc-shaped blade according to an embodiment of the present invention.

[0032] Fig. 9 The figure is a schematic structural diagram of a mixing cylinder including a premixing section and a mixing section according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 100. Mixing cylinder, 101. Premixing section, 102. Mixing section, 103. Aggregate feed port, 104. Inlet, 200. Rotating shaft, 300. Curved blades, 301. Baffle, 400. Fiber filament conveying channel, 500. Temporary storage chamber, 600. Fiber filament feeding bin, 700. Opening and closing member, 701. Curved sealing plate, 702. Curved trigger plate, 703. Hinge, 705. Flexible membrane, 800. Airflow output pipeline, 900. Fiber filament release port. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0036] Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with ordinary skills in the field to which the present disclosure belongs. "First", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0037] At present, cement-stabilized crushed stone mixtures with polyvinyl alcohol fiber PVA have been put into practical use in many projects because they have advantages in crack resistance and durability compared to conventional cement-stabilized crushed stone mixtures. However, the mixing equipment currently used is still basically the original conventional mixing equipment. Conventional mixing equipment mainly adopts a combination of stirring and vibration to achieve mixing between materials. Since PVA fibers have good hydrophilicity, they will gather together to form fiber bundles when encountering water, resulting in PVA fibers being easier to adsorb and aggregate when stirring, especially in an aqueous environment. If various raw materials such as crushed stone aggregates, cement, water, etc. are added to the mixing equipment according to the designed ratio, and then mixed by stirring, since batches of PVA fibers are added together with water, the problem of PVA fiber aggregation is more prominent. Once aggregated into bundles or balls, it is difficult to separate them and evenly disperse them in the mixture even if stirring and vibration are used. Therefore, the present invention proposes a new mixing method for cement-stabilized gravel mixture added with PVA fibers, that is, first pre-mixing the aggregate and the PVA fibers so that the PVA fibers are relatively evenly dispersed in the aggregate, and then using the aggregate as an isolation medium for the PVA fibers to avoid the problem of PVA fibers aggregating due to their hydrophilicity during subsequent slurry mixing to form fiber bundles or fiber balls.

[0038] In order to better achieve the premixing of aggregate and PVA fiber, such as Figure 1As shown, this embodiment provides a mixing device for cement-stabilized crushed stone mixture, which includes a horizontally arranged mixing drum 100 and a rotating shaft 200 that passes through the mixing drum 100 in a horizontal direction, and a plurality of arc-shaped blades 300 are evenly arranged on the rotating shaft 200 around the circumference. In this embodiment, a horizontal mixing method is adopted, and at the same time, the arc-shaped blades 300 are arranged on the rotating shaft 200. It should be noted that the arc-shaped blades 300 of this embodiment are arc-shaped blades 300 with a certain width along the length direction of the rotating shaft 200, so that the arc-shaped blades 300 can receive and flip the mixed materials during the rotation process, as shown in this embodiment. Figure 4-Figure 5 The rotating shaft 200 in this embodiment is designed as a hollow structure, which is used to form a fiber conveying channel 400 along the length direction. The fiber conveying channel 400 in this embodiment is mainly used to convey PVA fibers, but it should be understood that the fiber conveying channel 400 in this embodiment can also be used to convey other fiber filaments with similar properties to PVA fibers. The arc-shaped blades 300 are double-layer structures, and a temporary storage cavity 500 for accommodating fiber filaments is formed between the double-layer structures. The temporary storage cavity 500 in each arc-shaped blade 300 is connected to the fiber conveying channel. Channel 400 is connected. In this embodiment, the connecting point between the temporary storage chamber 500 in each arc-shaped blade 300 and the fiber filament conveying channel 400 can be designed at the middle position of the arc-shaped blade 300 along the length direction of the rotating shaft. This can ensure the connection between the temporary storage chamber 500 in each arc-shaped blade 300 and the fiber filament conveying channel 400, and can also ensure the stability of the connection between each arc-shaped blade 300 and the rotating shaft 200. Of course, as a more preferred method, a reinforcing structure can be designed at the connection between each arc-shaped blade 300 and the rotating shaft 200 to further enhance the connection strength.

[0039] The mixing device of this embodiment also includes a fiber feeding bin 600. Please refer to Figure 1The fiber filament feeding bin 600 of the present embodiment is located on the rotating shaft 200 extending to the outside of the mixing cylinder 100, and is connected to the fiber filament conveying channel 400. A detachable sealing cover is provided on the fiber filament feeding bin 600. The specific connection method can be that the sealing cover and the opening end of the fiber filament feeding bin 600 are connected by threads. In order to ensure the sealing performance, a sealing ring can also be added in the sealing cover. Such a design can not only realize the further supplement of the PVA fiber inside the fiber filament conveying channel 400, but also the fiber filament feeding bin 600 of the present embodiment can rotate with the rotating shaft 200 and will not interfere with the rotation of the rotating shaft 200. The present embodiment also includes an opening and closing piece 700, which is located on the convex surface of the arc-shaped blade 300. A fiber filament release port 900 is provided on the convex surface of the arc-shaped blade 300. The fiber filament release port 900 is connected to the temporary storage chamber 500. The opening and closing piece 700 is arranged at the fiber filament release port 900 to close or open the fiber filament release port 900. The present embodiment also includes an impact airflow supply device, whose airflow output pipeline 800 is connected to the fiber filament delivery channel 400 through a rotary joint.

[0040] In this embodiment, aggregates can be added to the arc blades 300 in the mixing cylinder 100 in advance, or the arc blades 300 can be rotated to the bottom of the aggregate addition port by rotating the rotating shaft 200 and then the aggregates can be directly added to the arc blades 300; the dry PVA fibers can be loaded into the fiber filament conveying channel 400 or the fiber filament feeding bin 600 in advance, and then an impact airflow supply device is used to provide an impact airflow, and the PVA fibers are dispersed by airflow impact. The PVA fibers enter the temporary storage chamber 500 along the fiber filament conveying channel 400. Since the fiber filaments are impacted by the impact airflow in the entire fiber filament conveying channel 400 and the temporary storage chamber 500, the fiber filaments are always in a dispersed state. After the opening and closing member 700 is opened, the fiber filaments are released into the mixing cylinder 100 through the fiber filament release port 900, and after the opening and closing member 700 is closed, they are temporarily stored in the temporary storage chamber 500 to a certain release amount.

[0041] In this embodiment, since the rotating shaft 200 rotates under the action of a driving member such as a motor or other power component, the arc blade 300 will also rotate accordingly. When each arc blade 300 is loaded with material, the arc blade 300 flips the material thereon during the rotation process. When each arc blade 300 moves to the top, the aggregate inside it will slide down to the back side of the arc blade 300 located below the arc blade 300 where it is located, that is, the convex surface of the arc blade 300. It should be noted here that in this embodiment, the side of the arc blade 300 that carries the material is called the concave surface of the arc blade, and the back side of the arc blade 300 is called the convex surface of the arc blade 300. Since the material on the arc blade 300 will generate centrifugal force during the rotation process, when the rotation rate is constant and the amount of material on each arc blade 300 is basically the same, such as Figure 2 As shown, when the material slides down from the top, the range of the landing points on the lower arc-shaped blade 300 is basically the same. At the same time, since the side of the lower arc-shaped blade 300 that meets the falling aggregate is convex and slopes downward toward the inner wall of the mixing cylinder, a downward diversion is formed for the falling aggregate. Therefore, a material-free area B is formed on the cross-section of the mixing cylinder 100 between the falling aggregate and the landing point on the convex surface of the arc-shaped blade 300 below it and the rotating shaft 200. Therefore, the fiber release port of this embodiment is located at the material-free area B. By releasing the PVA fiber at the material-free area B, the released PVA fiber can contact the aggregate material scattered from top to bottom and be mixed in the gap between the falling materials, and then follow the aggregate into the subsequent tumbling and mixing process. After multiple tumbling and mixing and multiple PVA fiber additions, the purpose of pre-mixing the PVA fiber and the aggregate is achieved.

[0042] In order to better form a material-free zone, such as Figure 3 As shown, the arc-shaped blade 300 of the present embodiment can also be designed with an end baffle 301 extending in the arc length direction on the side close to the rotating shaft 200. The baffle 301 will not only not affect the load-bearing capacity of the arc-shaped blade 300, but also will block the falling of the aggregate at that location during the falling process of the aggregate, so that the aggregate at that location will not fall directly above the fiber release port 900 as the rotating shaft 200 rotates and the guide plate is guided.

[0043] As a preferred embodiment, Figure 5 and Figure 8As shown, the opening and closing member 700 of this embodiment includes: an arc-shaped sealing plate 701 and an arc-shaped triggering plate 702, which are adapted to the convex curvature of the arc-shaped blade 300 at the position, and the arc-shaped sealing plate 701 is hinged at the fiber release port 900, and the opening of the arc-shaped sealing plate 701 is away from the rotating shaft 200; the opened arc-shaped sealing plate 701 forms a certain angle with the convex surface of the arc-shaped blade 300 and guides the ejected airflow carrying the fiber filaments, so that the PVA fiber can enter the angle formed by the falling aggregate and the landing point on the back of the arc-shaped blade 300, and be mixed in the aggregate that falls in sequence. The arc-shaped trigger plate 702 is adapted to the curvature of the convex surface of the arc-shaped blade 300 at its position, and the arc-shaped closing plate 701 and the arc-shaped trigger plate 702 are arranged in sequence along the arc length direction of the convex surface, and the arc-shaped trigger plate 702 is hinged at one end of the arc-shaped blade 300 away from the rotating shaft 200; the arc-shaped trigger plate 702 of this embodiment is mainly used to receive the impact of falling aggregates, and after being impacted by the aggregates, drive the hinge to open the arc-shaped closing plate 701 to release the PVA fibers; therefore, the hinge of this embodiment is a component that can convert the impact force received by the arc-shaped trigger plate 702 into power to drive the arc-shaped closing plate 701 to open.

[0044] As an example, the attached Figure 6 and Figure 7 The hinge 703 of this embodiment is illustrated. The hinge 703 is arranged on the convex surface of the arc blade 300. The middle part of the hinge 703 is hinged to the convex surface of the arc blade 300. One end of the hinge 703 abuts against the open side of the arc sealing plate 701. The other end of the hinge 703 abuts against the open side of the arc trigger plate 702. The upper end of the arc trigger plate 702 is at least located on the arc blade 300 between the center line of the arc blade 300 parallel to the rotating shaft 200 and the rotating shaft 200. The purpose is to make the arc trigger plate 702 located within the falling point range of the falling aggregate so that it can better withstand the impact force. Of course, based on the design principle of the hinge 703 of this embodiment, there can be a variety of structural designs that can realize the opening of the arc sealing plate 701 after the arc trigger plate 702 is compressed. It should be understood that the above-mentioned equivalent replacement hinge design is also within the protection scope of this embodiment. It should be noted that the hinge 703 of this embodiment has a built-in torsion spring to achieve rotation after receiving pressure from the arc-shaped trigger plate 702 and reset after the pressure disappears.

[0045] In this embodiment, the arc trigger plate 702, the arc sealing plate 701 and the hinge 703 cooperate to realize that after the arc trigger plate 702 is subjected to the pressure of the aggregate impact, the pressure will be transmitted to the hinge 703, and the hinge 703 will provide an upward supporting force to the arc sealing plate 701 by rotating, thereby realizing the opening of the arc sealing plate 701, and realizing that the PVA fibers are released through the fiber release port 900 and mixed with the aggregate.

[0046] As a preferred embodiment, the convex surface of the arc-shaped blade 300 is provided with a recessed portion, and the arc-shaped trigger plate 702 can be embedded in the recessed portion after being subjected to an external force, and the outer surface of the arc-shaped trigger plate 702 after being embedded in the recessed portion is not higher than the plane where the fiber filament release port 900 is located, so as to avoid the arc-shaped trigger plate 702 from blocking the PVA fibers released from the fiber filament release port 900, and ensure that the PVA fibers enter the falling area of ​​the falling aggregate.

[0047] As a preferred embodiment, after the arc-shaped sealing plate 701 is propped up by the hinge 703, the angle between it and the plane where the fiber release port 900 is located is less than 30 degrees, in order to confine the released PVA fibers to a certain area so that they can enter the falling area of ​​the falling aggregate.

[0048] As another preferred embodiment, the outer periphery of the arc-shaped trigger plate 702 is connected to the outer surface of the arc-shaped blade 300 through a flexible membrane 705, which is used to prevent aggregate from entering the bottom of the arc-shaped trigger plate 702. The aggregate here refers to aggregates of different particle sizes. As an example, the flexible membrane 705 can cover the entire arc-shaped trigger plate 702 to prevent the mixture from entering the area between the arc-shaped trigger plate 702 and the arc-shaped blade 300, so as to avoid affecting the normal movement of the arc-shaped trigger plate 702. As another example, Figure 7 As shown, the flexible membrane 705 at least covers the outside of the hinge 703 to ensure the normal rotation of the hinge 703. The flexible membrane 705 can serve as a barrier to block aggregates and will not affect the closing and opening of the arc trigger plate 702, the arc sealing plate 701 and the hinge 703.

[0049] As another preferred embodiment, the connection between the fiber filament conveying channel 400 and the temporary storage chamber 500 is a smooth transition structure, which is used to reduce the dead corner of PVA fiber accumulation and ensure the smooth release of PVA fibers.

[0050] As another preferred embodiment, the fiber release port 900 is a strip-shaped port, and the length direction of the strip-shaped port is arranged along the length of the rotating shaft 200 on the arc-shaped blade 300, which can ensure the rapid release of the PVA fiber. At the same time, the long strip outlet allows the PVA fiber to be released along the length direction of the rotating shaft 200, which can improve the incorporation range and effect with the aggregate.

[0051] As another preferred embodiment, the fiber filament release port 900 is designed to be an inclined strip-shaped port, so that the angle between the release trajectory of the fiber filament and the tangent direction of the convex surface of the arc-shaped blade 300 at the position of the strip-shaped port is less than 30 degrees. On the one hand, it is to give the PVA fiber enough airflow impact force so that it can enter the gap of the falling aggregate, and at the same time, it also limits the PVA fiber to the angle range formed by the falling aggregate and the convex surface of the arc-shaped blade 300, so that the PVA fiber is wrapped therein after the aggregate contacts the convex surface of the arc-shaped blade 300, and further uniformity is achieved with subsequent flipping.

[0052] As another preferred embodiment, a pressing plate is provided in the fiber filament feeding bin 600, and the pressing plate is used to apply pressure to the fiber filaments in the fiber filament feeding bin 600. The shape of the pressing plate matches the shape of the inner wall of the fiber filament feeding bin 600. Since the fiber filaments are lightweight materials, the weight of the pressing plate only needs to be sufficient to form downward pressure on the fiber filaments, so that the fiber filaments enter the fiber filament conveying channel 400. Therefore, the design of the pressing plate will still not affect the rotation of the rotating shaft 200. As the rotating shaft 200 rotates, the pressing plate can move downward under the action of gravity when the fiber filament feeding bin 600 rotates to the upper position of the rotating shaft 200, so that the fiber filaments are squeezed into the fiber filament conveying channel 400 and move along the fiber filament conveying channel 400 under the action of the impact airflow.

[0053] The mixing device for the cement-stabilized gravel mixture of the present embodiment can be used for premixing aggregates and PVA fibers and then remixing them with other raw materials and water; of course, it can also be used for direct mixing of mixed slurry and PVA fibers. When used for direct mixing of mixed slurry and PVA fibers, since the mixed slurry is also scattered from top to bottom in sequence, and the PVA fibers can be dispersed and contacted with the scattered mixed slurry, the contact area between the mixed slurry and the PVA fibers is increased, and the subsequent multiple flipping, multiple scattering and multiple release of PVA fibers can further promote the uniform dispersion of PVA fibers in the mixed slurry. Compared with the conventional method of simply mixing the PVA fibers with the mixed slurry, the dispersion uniformity of the PVA fibers in the mixture can be significantly improved, while the mixing efficiency can be improved.

[0054] After the aggregate and PVA fibers are premixed, the aggregate can serve as an isolation medium for the PVA fibers to effectively avoid the aggregation of the PVA fibers after the subsequent addition of other materials and water, thereby achieving the purpose of uniformly dispersing the PVA fibers in the mixed slurry. Therefore, as a more preferred embodiment, Fig. 9As shown, the mixing drum 100 of this embodiment is composed of a premixing section 101 and a mixing section 102 in sequence along the length direction. An aggregate feed port 103 is provided at the top of the starting position of the premixing section 101, and an inlet 104 for adding cementitious materials such as cement and water is provided on the mixing section 102. One end of the rotating shaft 200 close to the aggregate feed port 103 is connected to an impact airflow supply device, and the other end of the rotating shaft 200 is connected to a driving part for driving the rotating shaft 200 to rotate. The bottom of the premixing section 101 is a plate body inclined downward from the starting end to the mixing section 102. The end of the premixing section 101 is connected to the mixing section 102 so that the materials in the premixing port enter the mixing section 102 in sequence. The discharge port of the mixing section 102 is located at the bottom of the end of the mixing section 102. The rotating shaft 200 corresponding to the premixing section 101 is a hollow structure, and the arc blade 300 corresponding to the premixing section 101 is a double-layer structure. It should be noted that the inclination of the front half of the bottom of the premixing section 101 is less than 5 degrees to prevent the material from falling into the mixing section 102 too quickly. At the same time, such a design can gradually increase the gap between the outer end of the arc blade 300 and the bottom of the premixing section 101. For example, in the initial stage, the gap between the arc blade 300 and the bottom is very small, and the material can be shoveled into the arc blade 300 again for flipping during the rotation process. However, as the inclination of the bottom increases, the gap between the outer end of the arc blade 300 and the bottom of the premixing section 101 increases. Therefore, the basically mixed material is no longer shoveled into the arc blade 300 for flipping, but enters the mixing section 102 along the inclined surface.

[0055] The cylinder diameter of the premixing section 101 is smaller than the cylinder diameter of the mixing section 102, so that the mixed aggregate and PVA fiber can enter the mixing section 102 from the premixing section 101 through the inclined bottom.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A mixing device for cement-stabilized crushed stone mixture, comprising a mixing drum (100) arranged horizontally and a rotating shaft (200) extending horizontally through the mixing drum (100), wherein a plurality of arc-shaped blades (300) are evenly arranged around the circumference of the rotating shaft (200), characterized in that: The rotating shaft (200) is a hollow structure, and is used to form a fiber filament conveying channel (400) along the length direction; the arc-shaped blades (300) are double-layer structures, and a temporary storage cavity (500) for accommodating fiber filaments is formed between the double-layer structures; the temporary storage cavity (500) in each arc-shaped blade (300) is connected to the fiber filament conveying channel (400), and further comprises: A fiber filament feeding bin (600) is located on a rotating shaft (200) extending to the outside of the mixing cylinder (100) and is connected to the fiber filament conveying channel (400). A sealing cover is provided on the fiber filament feeding bin (600); An opening and closing member (700) is located on the convex surface of each of the arc-shaped blades (300); a fiber release port (900) is provided on the convex surface of the arc-shaped blade (300); the fiber release port (900) is communicated with the temporary storage chamber (500); the opening and closing member (700) is arranged at the fiber release port (900) and is used to close or open the fiber release port (900); An impingement airflow supply device, wherein the airflow output pipeline (800) is connected to the fiber filament conveying channel (400) via a rotary joint.

2. The mixing device for cement-stabilized crushed stone mixture according to claim 1, characterized in that: The opening and closing member (700) comprises: An arc-shaped sealing plate (701) is adapted to the convex curvature of the arc-shaped blade (300) at the position, the arc-shaped sealing plate (701) is hinged at the fiber release port (900), and the opening of the arc-shaped sealing plate (701) is away from the rotating shaft (200); The arc-shaped trigger plate (702) is adapted to the curvature of the convex surface of the arc-shaped blade (300) at the position, the arc-shaped closing plate (701) and the arc-shaped trigger plate (702) are arranged in sequence along the arc length direction of the convex surface, and the arc-shaped trigger plate (702) is hinged to one end of the arc-shaped blade (300) away from the rotating shaft (200); The hinge (703) is arranged on the convex surface of the arc-shaped blade (300), the middle part of the hinge (703) is hinged to the convex surface of the arc-shaped blade (300), one end of the hinge (703) is in contact with the open side of the arc-shaped sealing plate (701), and the other end of the hinge (703) is in contact with the open side of the arc-shaped trigger plate (702), and the upper end of the arc-shaped trigger plate (702) is at least located on the arc-shaped blade (300) between the center line of the arc-shaped blade (300) parallel to the rotating shaft (200) and the rotating shaft (200).

3. The mixing device for cement-stabilized crushed stone mixture according to claim 2, characterized in that: The convex surface of the arc-shaped blade (300) is provided with a recessed portion, and the arc-shaped trigger plate (702) can be embedded in the recessed portion after being subjected to an external force, and the outer surface of the arc-shaped trigger plate (702) after being embedded in the recessed portion is not higher than the plane where the fiber release port (900) is located.

4. The mixing device for cement-stabilized crushed stone mixture according to claim 2, characterized in that: After the arc-shaped sealing plate (701) is propped up by the hinge (703), the angle between the arc-shaped sealing plate (701) and the plane where the fiber release port (900) is located is less than 30 degrees.

5. The mixing device for cement-stabilized crushed stone mixture according to claim 1, characterized in that: The fiber release opening (900) is a strip-shaped opening, and the length direction of the strip-shaped opening is arranged along the length of the rotating shaft (200).

6. The mixing device for cement-stabilized crushed stone mixture according to claim 5, characterized in that: The strip-shaped opening is designed to be inclined so that the angle between the release trajectory of the fiber filament and the tangent direction of the convex surface of the arc-shaped blade (300) at the position of the strip-shaped opening is less than 30 degrees.

7. The mixing device for cement-stabilized crushed stone mixture according to claim 2, characterized in that: The outer periphery of the arc-shaped trigger plate (702) is connected to the outer surface of the arc-shaped blade (300) via a flexible membrane (705) to prevent the mixed material from entering the bottom of the arc-shaped trigger plate (702).

8. The mixing device for cement-stabilized crushed stone mixture according to claim 1, characterized in that: A pressing plate is arranged in the fiber filament feeding bin (600), and the pressing plate is used to apply pressure to the fiber filaments in the fiber filament feeding bin (600).

9. The mixing device for cement-stabilized crushed stone mixture according to claim 1, characterized in that: The mixing drum (100) is composed of a premixing section (101) and a mixing section (102) in sequence along the length direction; an aggregate feed port (103) is provided at the top of the starting position of the premixing section (101); an inlet (104) for adding cementitious materials and water is provided on the mixing section (102); one end of the rotating shaft (200) close to the aggregate feed port (103) is connected to an impact airflow supply device; the other end of the rotating shaft (200) is connected to a driving unit for driving the rotating shaft (200) to rotate; The bottom of the premixing section (101) is a plate body that slopes downward from the starting end toward the mixing section (102); the end of the premixing section (101) is connected to the mixing section (102) so that the premixed materials enter the mixing section (102) in sequence; the discharge port of the mixing section (102) is located at the bottom of the end of the mixing section (102); the rotating shaft (200) corresponding to the premixing section (101) is a hollow structure; and the arc-shaped blade (300) corresponding to the premixing section (101) is a double-layer structure.

10. The mixing device for cement-stabilized crushed stone mixture according to claim 9, characterized in that: The cylinder diameter of the premixing section (101) is smaller than the cylinder diameter of the mixing section (102).

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