Gravel soil screening device and method for earth-rockfill dam

Abstract

This invention discloses a gravel washing device and method for earth-rock dams, relating to the technical field of soil separation equipment. It includes a first screening cylinder with multiple first screening holes on its sidewall; a second screening cylinder coaxially sleeved outside the first screening cylinder, with multiple second screening holes on its sidewall, and a cavity between its inner sidewall and the outer sidewall of the first screening cylinder capable of accommodating filled gravel; multiple baffles dividing the cavity between the first and second screening cylinders into multiple transition chambers, each transition chamber having an openable discharge plate at its lower end, and each discharge plate having second screening holes; a washing tank capable of receiving the filled gravel discharged through the discharge plates, and equipped with a stirring paddle; and a conveying mechanism capable of conveying the filled gravel out of the washing tank. The first screening cylinder is inclined, and its rotation allows coarse gravel to be discharged through its lower end, reducing the amount of clean water used and wastewater discharged. The washing method is based on the aforementioned washing device.

Description

Technical Field

[0001] This invention relates to the field of soil separation equipment technology, specifically to a gravel soil screening and washing device and method for earth-rock dams. Background Technology

[0002] Earth-rock dams are water-retaining dams constructed from local soil, stone, or a mixture of materials through methods such as dumping and compaction. Because the dam body is a granular structure of soil and rock, it has excellent adaptability to deformation, low foundation requirements, and can utilize locally sourced materials, saving on important building materials such as steel, cement, and timber, and reducing long-distance transportation of dam construction materials. Therefore, it has been widely used in the vigorous development of hydropower resources in western my country.

[0003] The core wall of an earth-rock dam requires good impermeability and high shear strength, which makes it difficult for natural gravel soil to meet the specifications. Therefore, it is necessary to separate the gravel and soil in the natural gravel soil and then mix the gravel with clay to obtain modified gravel soil, thereby improving its shear strength. In existing technologies, most gravel soil washing devices directly wash the natural gravel soil while vibrating and screening it. Although this can separate the gravel used to construct the core wall of an earth-rock dam, it consumes a large amount of water and generates a lot of wastewater, making it unsuitable for ecologically fragile areas with strict environmental protection requirements. Summary of the Invention

[0004] To address the technical problem that existing gravel and soil screening and washing devices are unsuitable for the construction of ecologically fragile earth-rock dams, this invention provides a gravel and soil screening and washing device and method for earth-rock dams. By rotating the first and second screening cylinders, gravel that does not meet the requirements for the core wall seepage prevention is screened out, and then the gravel that meets the usage requirements is washed. This can reduce the amount of clean water used and the discharge of wastewater, meeting the usage needs of areas with strict environmental protection requirements.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a gravel soil screening and washing device for earth-rock dams, comprising: a first screening cylinder capable of rotating along its own axis, having a plurality of first screening holes on its side wall, the first screening holes allowing the passage of fill gravel and fine gravel; a second screening cylinder coaxially sleeved outside the first screening cylinder, having a plurality of second screening holes on its side wall, the second screening holes allowing the passage of fine gravel, and a cavity between its inner side wall and the outer side wall of the first screening cylinder capable of accommodating fill gravel; and a plurality of baffles, all disposed between the first screening cylinder and the second screening cylinder, for baffles... The cavity between the first screening cylinder and the second screening cylinder is divided into multiple transition chambers, which are evenly distributed around the circumference of the second screening cylinder. Each transition chamber is fitted with an openable and closable discharge plate at its lower end, and each discharge plate is provided with a second screening hole. A washing tank is provided to receive the filled gravel sent out through the discharge plate and is fitted with an agitator. A conveying mechanism is provided to send the filled gravel out of the washing tank. The first screening cylinder is inclined and coarse gravel can be sent out through its lower end by rotating the first screening cylinder.

[0007] The gravel and soil screening and washing device for earth-rock dams provided by the present invention has a second screening cylinder coaxially sleeved outside the first screening cylinder. The first screening hole on the side wall of the first screening cylinder allows the filling gravel and fine gravel to pass through, and the second screening hole on the side wall of the second screening cylinder allows the fine gravel to pass through. The cavity between the first screening cylinder and the second screening cylinder is divided into multiple circumferentially distributed transition cavities by a material blocking part. The lower end of each transition cavity is equipped with an opening and closing discharge plate, and each discharge plate is provided with a second screening hole. The washing tank can receive the filling gravel sent out through the discharge plate and is equipped with a stirring paddle. At the same time, the conveying mechanism can send the filling gravel out of the washing tank. The first screening cylinder is inclined, and the rotation of the first screening cylinder can send coarse gravel out through the lower end of the first screening cylinder.

[0008] In operation, clean water is added to the washing tank, and the agitator inside the tank is activated. This drives the first and second screening cylinders to rotate and closes the discharge plate. The gravel and soil to be screened are then fed into the upper part of the first screening cylinder. The rotation of the first screening cylinder transports the gravel and soil to the lower part of the cylinder. During the rotation of the first screening cylinder, the gravel and soil rotate a certain height along the rotation direction and then fall back to the lower side of the length direction of the first screening cylinder under their own gravity. This causes the gravel to collide with each other and continuously impact the side wall of the first screening cylinder. Through the collision between the gravel, some of the sand and soil attached to the gravel is removed, thereby reducing the amount of soil carried by the gravel filling. When the gravel and sand impact the side wall of the first screening cylinder, the gravel, fine gravel, and sand smaller than the first screening hole fall directly into the corresponding transition cavity.

[0009] Simultaneously, during the rotation of the second screening cylinder, the filled gravel, fine gravel, and sand are driven to rotate a certain height along the rotation direction of the second screening cylinder. Under their own gravity, they fall back to the lower side along the length of the second screening cylinder, causing the gravel to collide with each other and continuously impact the side wall of the second screening cylinder. Through the collision between the gravel, some of the sand attached to the gravel is removed, further reducing the amount of soil carried by the filled gravel. When the gravel and sand impact the side wall of the second screening cylinder, the fine gravel and sand smaller than the second screening hole fall directly from the transition cavity, leaving only the filled gravel trapped in the transition cavity. As the second screening cylinder rotates, the discharge plate moves above the washing tank. At this time, the discharge plate is opened, and the filled gravel in the transition cavity enters the washing tank under gravity, where it is then washed by the stirring paddle. The washed filled gravel is then sent out of the washing tank by the conveying mechanism, while the coarse gravel is sent out through the first screening cylinder.

[0010] Therefore, the gravel and soil washing device for earth-rock dams provided by the present invention only washes gravel that meets the usage requirements. Furthermore, before washing the gravel that meets the usage requirements, most of the sand and soil attached to it is removed through two mechanical screenings and collisions, reducing the amount of washing work, thereby reducing the amount of clean water used and the discharge of sewage, and meeting the usage needs of areas with strict environmental protection requirements.

[0011] In an optional embodiment, an arc-shaped guide rail is further included, with a notch provided on the upper part of one side of the arc-shaped guide rail; the arc-shaped guide rail is coaxially mounted outside the second screening cylinder, and the second screening cylinder is rotatable relative to the arc-shaped guide rail; wherein, the discharge plate can be opened when the discharge plate is facing the notch, and the discharge plate remains closed when the discharge plate is facing the arc-shaped guide rail, so that the discharge plate can periodically open and close during the rotation of the second screening cylinder, so as to timely discharge the filled gravel in the transition cavity.

[0012] In an optional embodiment, along the rotation direction of the second screening cylinder, the front side of the discharge plate is hinged to the second screening cylinder, and the rear side of the discharge plate can abut against the outer wall of the second screening cylinder, so that when rotating at the notch of the arc-shaped guide rail, the discharge plate can open downward under its own weight and the weight of the filled gravel, and close when rotating to the arc-shaped guide rail.

[0013] In an optional embodiment, a support roller is provided on the rear outer side of the discharge plate along the rotation direction of the second screening cylinder. When the support roller abuts against the inner side of the arc-shaped guide rail, it can rotate relative to the arc-shaped guide rail around its own axis. On the one hand, it can convert the friction between the discharge plate and the arc-shaped guide rail into rolling, and on the other hand, it can prevent the side wall of the second screening cylinder from sliding directly with the side wall of the arc-shaped guide rail.

[0014] In an optional embodiment, a guide roller is provided at the rear end of the arc-shaped guide rail along the rotation direction of the second screening cylinder to reduce the resistance when the discharge plate moves back towards the arc-shaped guide rail.

[0015] In an optional embodiment, the conveying mechanism includes: a conveyor belt, inclined and extending at its lower end below the rotation path of the stirring paddle, with multiple baffles evenly spaced along its length on the conveying surface, the protrusion height of each baffle being less than the lower limit size of the filled gravel; a discharge channel located on one side of the middle of the conveyor belt; a baffle cover plate, spaced above the middle of the conveyor belt, one side connected to the side wall of the discharge channel, and the gap between the cover plate and the baffles being less than the lower limit size of the filled gravel; and a discharge ramp, inclined downwards towards the feed end of the discharge channel along the moving direction of the conveyor belt; wherein, when the conveyor belt moves relative to the discharge ramp, the discharge ramp can feed the filled gravel on the conveyor belt into the discharge channel, so that the filled gravel is oriented into the discharge channel for collection under the action of the conveyor belt, baffles, baffle cover plate and discharge ramp, and the filled gravel is separated from the mud and sand attached to the conveyor belt.

[0016] In an optional embodiment, the conveyor belt is a mesh belt, and the conveying surface of the conveyor belt is covered with a filter cloth so that the conveyor belt has a filtering function, preventing the conveyor belt from carrying away the water in the cleaning tank, but carrying away the mud and sand in the cleaning tank, thereby reducing the sand content in the cleaning tank, thereby reducing the frequency of adding or changing water in the cleaning tank, and further reducing the amount of clean water used.

[0017] In an optional embodiment, the conveying mechanism further includes a brush assembly located below the conveyor belt and above the cleaning tank on the outer side; as the conveyor belt moves relative to the brush assembly, the brush assembly can brush away the mud and sand on the conveying surface of the conveyor belt to prevent the mud and sand carried out by the conveyor belt from returning to the cleaning tank.

[0018] In an optional embodiment, the brush assembly is adapted to a sand collection hopper for collecting the mud and sand brushed off by the brush assembly. The lower end of the sand collection hopper is provided with a sand outlet that extends to the outside of the washing tank to facilitate the collection of mud and sand brushed off from the conveyor belt.

[0019] Secondly, the present invention provides a method for screening and washing gravel soil for earth-rock dams, based on the above-mentioned gravel soil screening and washing device for earth-rock dams, comprising the following steps:

[0020] Drive the first and second screening cylinders to rotate and close the discharge plate to feed the gravel and soil material to be screened into the upper end of the first screening cylinder.

[0021] By rotating the first screening cylinder and the second screening cylinder, coarse gravel is trapped in the first screening cylinder, filling gravel is trapped in the transition cavity, and gravel is transported to the coarse gravel stockpile. Fine gravel and silt that have passed through the second screening hole are transported to the fine gravel stockpile.

[0022] The discharge plate is opened by rotating the second screening cylinder, and the gravel trapped in the transition cavity is sent into the washing tank.

[0023] Add clean water to the cleaning tank and start the agitator inside the cleaning tank;

[0024] Start the conveyor mechanism to send the cleaned gravel to the gravel stockpile.

[0025] The mud and sand conveyed by the conveyor belt are removed by brushing with a brush assembly.

[0026] The gravel washing method for earth-rock dams provided by this invention uses the rotation of a first screening cylinder and a second screening cylinder to retain coarse gravel in the first screening cylinder and fill gravel in the transition cavity. The fill gravel retained in the transition cavity is then sent into a washing tank, thereby washing only the gravel that meets the usage requirements. Furthermore, before washing the fill gravel, most of the sand and soil attached to it is removed through two mechanical screenings and collisions, reducing the amount of washing work, thereby reducing the amount of clean water used and the discharge of wastewater, meeting the usage requirements of areas with strict environmental protection requirements.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. The gravel and soil screening and washing device for earth-rock dams provided by the present invention comprises a second screening cylinder coaxially sleeved outside the first screening cylinder. The first screening hole on the side wall of the first screening cylinder allows the passage of both filled gravel and fine gravel, while the second screening hole on the side wall of the second screening cylinder allows the passage of fine gravel. The cavity between the first and second screening cylinders is divided into multiple circumferentially distributed transition cavities by a baffle portion. Each transition cavity has an opening and closing discharge plate at its lower end, and each discharge plate has a second screening hole. The washing tank receives the filled gravel discharged through the discharge plate and is equipped with a stirring paddle. Simultaneously, a conveying mechanism transports the filled gravel out of the washing tank. The first screening... The screening cylinders are tilted, and the rotation of the first screening cylinder allows coarse gravel to be sent out through the lower end of the first screening cylinder. During the rotation of the first screening cylinder, some of the sand and soil attached to the gravel can be removed and coarse gravel can be retained. During the rotation of the second screening cylinder, some of the sand and soil attached to the gravel can be removed and the filled gravel can be retained in the transition cavity. Thus, only gravel that meets the usage requirements is cleaned. Moreover, before cleaning, most of the sand and soil attached to it is removed through two mechanical screenings and collisions, reducing the amount of cleaning work, thereby reducing the amount of clean water used and the discharge of wastewater, meeting the usage requirements of areas with strict environmental protection requirements.

[0029] 2. The gravel washing method for earth-rock dams provided by the present invention uses the rotation of the first screening cylinder and the second screening cylinder to retain coarse gravel in the first screening cylinder and retain the filling gravel in the transition cavity. The filling gravel retained in the transition cavity is then sent into the washing tank, thereby washing only the gravel that meets the usage requirements. Furthermore, before washing the filling gravel, most of the sand and soil attached to it is removed through two mechanical screenings and collisions, reducing the amount of washing work, thereby reducing the amount of clean water used and the discharge of wastewater, and meeting the usage requirements of areas with strict environmental protection requirements. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] In the attached diagram:

[0032] Figure 1 This is a schematic cross-sectional view of the gravel soil screening and washing device for earth-rock dams according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram showing the connection relationship between the first screening cylinder and the second screening cylinder in an embodiment of the present invention;

[0034] Figure 3 for Figure 1 Enlarged schematic diagram of part A;

[0035] Figure 4 for Figure 1 A schematic diagram of the structure of part B.

[0036] The attached diagram shows the markings and corresponding component names:

[0037] 10 - First screening cylinder; 11 - First screening hole;

[0038] 20-Second screening cylinder, 21-Second screening hole, 22-Baffle part, 23-Transition cavity, 24-Discharge plate, 25-Support roller;

[0039] 30 - Cleaning tank; 31 - Agitator;

[0040] 40-Conveying mechanism, 41-Conveyor belt, 41a-Blocking protrusion, 42-Discharge channel, 43-Blocking cover plate, 44-Discharge inclined bar, 45-Brush assembly, 46-Sand collection hopper, 46a-Sand outlet;

[0041] 50 - Arc-shaped guide rail; 51 - Guide roller;

[0042] 60 - Feed chute.

[0043] It should be noted that, for Figure 1 To visually demonstrate the relative positions and corresponding structures of the first screening cylinder 10, the second screening cylinder 20, the transition cavity 23, and the arc-shaped guide rail 50, the first screening cylinder 10 and the second screening cylinder 20 are placed horizontally for structural illustration. This avoids having too many curves on the side walls of the first screening cylinder 10 and the second screening cylinder 20, which would prevent them from being clearly displayed. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] In the description of the embodiments of this application, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in when in use, or the orientation or positional relationship that is commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0046] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set up," "have," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Example 1

[0048] Combination Figure 1 and Figure 2This embodiment provides a gravel and soil screening and washing device for earth-rock dams, comprising: a first screening cylinder 10, rotatable along its own axis, with multiple first screening holes 11 on its side wall, the first screening holes 11 allowing the passage of fill gravel and fine gravel; a second screening cylinder 20, coaxially sleeved outside the first screening cylinder 10, with multiple second screening holes 21 on its side wall, the second screening holes 21 allowing the passage of fine gravel, and a cavity between its inner side wall and the outer side wall of the first screening cylinder 10 capable of accommodating fill gravel; and multiple baffles 22, all disposed between the first screening cylinder 10 and the second screening cylinder 20, and baffles the first screening cylinder 10... The cavity between the first screening cylinder 10 and the second screening cylinder 20 is divided into multiple transition cavities 23. The multiple transition cavities 23 are evenly distributed around the second screening cylinder 20. The lower end of each transition cavity 23 is adapted to be equipped with an opening and closing discharge plate 24, and each discharge plate 24 is provided with a second screening hole 21. A washing tank 30 is capable of receiving the filled gravel sent out through the discharge plate 24, and is adapted to be equipped with a stirring paddle 31. A conveying mechanism 40 is capable of sending the filled gravel out of the washing tank 30. The first screening cylinder 10 is inclined, and the rotation of the first screening cylinder 10 can send coarse gravel out through the lower end of the first screening cylinder 10.

[0049] It should be noted that fill gravel refers to gravel whose size meets the requirements for the construction of the core wall seepage barrier. The size of fill gravel is a range value. Fine gravel refers to gravel whose size is smaller than the lower limit of fill gravel size, and coarse gravel refers to gravel whose size is larger than the upper limit of fill gravel size.

[0050] The first screening cylinder 10 and the second screening cylinder 20 can rotate synchronously or in stages; that is, the first screening cylinder 10 and the second screening cylinder 20 can be fixedly connected, rotatably connected, or have a clearance fit. The rotation of the first screening cylinder 10 and the second screening cylinder 20 can be achieved through the engagement of a drive gear and a gear ring driven by a motor, the engagement of a sprocket and a chain driven by a motor, or friction drive by a rotating friction wheel driven by a motor. The first screening cylinder 10 and the second screening cylinder 20 can be a cage structure or a mesh plate structure for ease of processing. Material baffles are provided at corresponding ends of the first screening cylinder 10 and the second screening cylinder 20. When the first screening cylinder 10 and the second screening cylinder 20 rotate synchronously, a corresponding transition cavity 23 is formed by the outer wall of the first screening cylinder 10, the inner wall of the second screening cylinder 20, the material baffles, and the material baffle part 22.

[0051] Combined again Figure 2In this embodiment, an arc-shaped guide rail 50 is also included, with a notch provided on the upper part of one side of the arc-shaped guide rail 50. The arc-shaped guide rail 50 is coaxially mounted outside the second screening cylinder 20, and the second screening cylinder 20 can rotate relative to the arc-shaped guide rail 50. The discharge plate 24 can be opened when it is facing the notch, and it remains closed when it is facing the arc-shaped guide rail 50, so that the discharge plate 24 can periodically open and close during the rotation of the second screening cylinder 20 to discharge the filled gravel in the transition cavity 23 in a timely manner.

[0052] Specifically, along the rotation direction of the second screening cylinder 20, the front side of the discharge plate 24 is hinged to the second screening cylinder 20, and the rear side of the discharge plate 24 can abut against the outer wall of the second screening cylinder 20, so that when rotating at the notch of the arc guide rail 50, the discharge plate 24 can open downward under its own weight and the weight of the filled gravel, and when rotating to the arc guide rail 50, it gradually closes under the abutment of the arc guide rail 50.

[0053] Based on this, combined Figure 3 Along the rotation direction of the second screening cylinder 20, a support roller 25 is provided on the outer rear side of the discharge plate 24. When the support roller 25 abuts against the inner side of the arc-shaped guide rail 50, it can rotate relative to the arc-shaped guide rail 50 around its own axis. On the one hand, this can convert the friction between the discharge plate 24 and the arc-shaped guide rail 50 into rolling, and on the other hand, it can prevent the side wall of the second screening cylinder 20 from sliding directly against the side wall of the arc-shaped guide rail 50. Optionally, the support roller 25 is made of a flexible material to absorb the impact when the discharge plate 24 collides with other structural components (frame or guide trough 60) when the discharge plate 24 is opened.

[0054] Furthermore, along the rotation direction of the second screening cylinder 20, a guide roller 51 is provided at the rear end (lower end) of the arc-shaped guide rail 50. When the rear end of the arc-shaped guide rail 50 of the discharge plate 24 moves, it can drive the guide roller 51 to rotate, thereby making the discharge plate 24 and the end of the arc-shaped guide rail static friction, so as to reduce the resistance when the discharge plate 24 moves towards the arc-shaped guide rail 50.

[0055] In detail, the arc-shaped guide rail 50 has a C-shaped structure, and the size of the notch portion should be larger than the width of the discharge plate 24, thereby ensuring that the discharge plate 24 can open when the notch is open, while the discharge plate 24 remains closed under the support of the arc-shaped guide rail 50. To ensure that the transition cavity 23 located on the lower side of the first screening cylinder 10 can properly hold the filled gravel, based on the bottom of the first screening cylinder 10 along its length, the lower end of the arc-shaped guide rail 50 should be higher than half the radius of the first screening cylinder 10, and the upper end of the arc should be higher than three-quarters of the radius of the first screening cylinder 10, and the two ends of the arc-shaped guide rail 50 are respectively located on both sides of the axial direction of the first screening cylinder 10.

[0056] Typically, there are two transition chambers 23. Since the first screening cylinder 10 is inclined, and the second screening cylinder 20 is coaxially positioned outside the first screening cylinder 10 and also inclined, the gravel entering the transition chamber 23 is moved towards the lower end of the transition chamber 23 and accumulates there under the rotation of the second screening cylinder 20. Therefore, only a discharge plate 24 needs to be installed at the lower end of the transition chamber 23. Simultaneously, this allows the washing tank 30 to effectively collect the gravel that slides off the discharge plate 24.

[0057] Combination Figure 4 The conveying mechanism 40 includes: a conveyor belt 41, inclined and extending at its lower end below the rotation path of the stirring paddle 31, with a plurality of baffle ridges 41a evenly spaced along its length on the conveying surface, the protrusion height of each baffle ridge 41a being less than the lower limit size of the filled gravel; a discharge channel 42 located on one side of the middle of the conveyor belt 41; baffle covers 43, spaced above the middle of the conveyor belt 41, one side connected to the side wall of the discharge channel 42, and the gap between the cover and the baffle ridges 41a being less than the lower limit size of the filled gravel; and a discharge slant bar 44, inclined downwards along the moving direction of the conveyor belt 41, directly opposite the feed end of the discharge channel 42; wherein, when the conveyor belt 41 moves relative to the discharge slant bar 44, the discharge slant bar can feed the filled gravel on the conveyor belt 41 into the discharge channel 42.

[0058] Because the conveyor belt 41 is inclined, and the protrusion height of the retaining ridge 41a is less than the lower limit dimension of the gravel, when the conveyor belt 41 is working, the cooperation between the conveyor belt 41 and the retaining ridge 41a allows the gravel to be arranged in a single layer on the conveyor belt 41. As the conveyor belt 41 moves, the gravel is transported to the retaining cover plate 43 and the discharge ramp 44. As the conveyor belt 41 moves the gravel relative to the discharge ramp 44, the pushing action of the discharge ramp 44 causes the gravel to enter the discharge channel 42. Through the action of the conveyor belt 41, the retaining ridge 41a, the retaining cover plate 43, and the discharge ramp 44, the gravel is directionally input into the discharge channel 42 for collection, and the gravel is separated from the mud and sand adhering to the conveyor belt 41.

[0059] In this embodiment, the conveyor belt 41 is a mesh belt, and the conveying surface of the conveyor belt 41 is covered with a filter cloth so that the conveyor belt 41 has a filtering function, preventing the conveyor belt 41 from carrying away the water in the cleaning tank 30, but carrying away the mud and sand in the cleaning tank 30, thereby reducing the sand content in the cleaning tank 30, thereby reducing the frequency of adding or changing water in the cleaning tank 30, and further reducing the amount of clean water used.

[0060] Continue to combine Figure 4 Furthermore, the conveying mechanism 40 also includes a brush assembly 45, which is located on the lower side of the conveyor belt 41 and on the upper outer side of the cleaning tank 30. When the conveyor belt 41 moves relative to the brush assembly 45, the brush assembly 45 can brush away the mud and sand on the conveying surface of the conveyor belt 41. That is, the brush head of the brush assembly 45 can abut against the lower surface of the conveyor belt 41 and brush away the mud and sand attached to the conveying surface of the conveyor belt 41 on the outer side of the cleaning tank 30, so as to prevent the mud and sand carried out by the conveyor belt 41 from returning to the cleaning tank 30.

[0061] Generally, the brush assembly 45 is equipped with a sand collection hopper 46, which is used to collect the mud and sand brushed off by the brush assembly 45. The lower end of the sand collection hopper 46 is provided with a sand outlet 46a, which extends to the outside of the washing tank 30 to facilitate the collection of mud and sand brushed off from the conveyor belt 41.

[0062] In addition, to facilitate the feeding of the filled gravel that rolls off the discharge plate 24 into the washing tank 30, a guide trough 60 is provided between the washing tank 30 and the second screening cylinder 20. The guide trough 60 is inclined, with the lower outlet extending above one side of the washing tank 30 and the upper inlet located on the moving path of the discharge plate 24, so that when the discharge plate 24 is open, the support roller 25 abuts against the bottom of the guide trough 60.

[0063] The gravel soil washing device for earth-rock dams provided in this embodiment is used by adding clean water to the washing tank 30, starting the stirring paddle 31 in the washing tank 30, driving the first screening cylinder 10 and the second screening cylinder 20 to rotate and closing the discharge plate 24. Then, the gravel soil to be washed is sent to the upper end of the first screening cylinder 10, thereby the gravel soil can be conveyed to the lower end of the first screening cylinder 10 by the rotation of the first screening cylinder 10. During the rotation of the first screening cylinder 10, the gravel soil can be driven to rotate a certain height along the rotation direction of the first screening cylinder 10, and then fall back to the lower side of the length direction of the first screening cylinder 10 under its own gravity. This causes the gravel to collide with each other and continuously impact the side wall of the first screening cylinder 10. Through the collision between the gravel, some of the sand attached to the gravel is removed, thereby reducing the amount of soil carried by the gravel filling. When the gravel and sand impact the side wall of the first screening cylinder 10, the filling gravel, fine gravel and sand with a size smaller than the first screening hole 11 fall directly into the corresponding transition cavity 23.

[0064] Meanwhile, during the rotation of the second screening cylinder 20, the gravel, fine gravel, and sand can be rotated a certain height along the rotation direction of the second screening cylinder 20, and then fall back to the lower side of the length direction of the second screening cylinder 20 under their own gravity. This causes the gravel to collide with each other and continuously impact the side wall of the second screening cylinder 20. Through the collision between the gravel, some of the sand attached to the gravel will be removed, further reducing the amount of soil carried by the gravel. When the gravel and sand impact the side wall of the second screening cylinder 20, the fine gravel and sand smaller than the second screening hole 21 will fall directly from the transition cavity 23 (they can be directly piled under the second screening cylinder 20, or sent to the fine gravel stockpile via the fine gravel conveying mechanism 40), leaving only the gravel trapped in the transition cavity 23. As the second screening cylinder 20 rotates, the discharge plate 24 moves above the washing tank 30. At this time, the discharge plate 24 is opened, and the gravel in the transition cavity 23 enters the washing tank 30 under gravity. Then, the agitator 31 drives the gravel to be washed. The washed gravel is then sent out of the washing tank 30 by the conveyor belt 41 of the conveying mechanism 40, while the coarse gravel is sent out by the first screening cylinder 10 (usually sent to the coarse gravel stockpile by the coarse gravel conveying mechanism 40).

[0065] During the operation of the conveyor belt 41, the gravel is first collected by the conveyor belt 41, the baffle 41a, the baffle cover plate 43, and the discharge inclined bar 44, and the gravel is directionally fed into the discharge channel 42 for collection, separating the gravel from the mud and sand attached to the conveyor belt 41. Simultaneously, the conveyor belt 41 carries away the mud and sand in the washing tank 30, reducing the sand content and thus reducing the frequency of water addition or replacement. Furthermore, as the conveyor belt 41 moves relative to the brush assembly 45, the brush assembly 45 brushes away the mud and sand attached to the conveyor surface of the conveyor belt 41 on the outside of the washing tank 30, preventing the mud and sand carried out by the conveyor belt 41 from returning to the washing tank 30, thereby effectively cleaning the washing tank 30.

[0066] Therefore, the gravel and soil washing device for earth-rock dams provided in this embodiment only washes gravel that meets the usage requirements. Furthermore, before washing the fill gravel that meets the usage requirements, it removes most of the sand and soil attached to it through two mechanical screenings and collisions, reducing the amount of washing work, thereby reducing the amount of clean water used and the discharge of sewage, and meeting the usage needs of areas with strict environmental protection requirements.

[0067] Example 2

[0068] This embodiment provides a method for screening and washing gravel soil for earth-rock dams, based on the gravel soil screening and washing device for earth-rock dams provided in Embodiment 1, including the following steps:

[0069] S10: Drive the first screening cylinder 10 and the second screening cylinder 20 to rotate and close the discharge plate 24, feeding the gravel and soil to be screened into the upper end of the first screening cylinder 10. That is, before screening, drive the first screening cylinder 10 and the second screening cylinder 20 to rotate coaxially, and the discharge plate 24 gradually closes through the action of the arc-shaped guide rail 50 during the rotation of the second screening cylinder 20. The gravel and soil can be fed into the feed hopper at the upper end of the first screening cylinder 10 by a loader or soil conveying mechanism 40, so that the gravel and soil can be conveyed downward along the length of the first screening cylinder 10 under the weight of the soil itself or under the action of the force transmitted by the first screening cylinder 10 and the weight of the soil itself.

[0070] S20. Through the rotation of the first screening cylinder 10 and the second screening cylinder 20, coarse gravel is trapped in the first screening cylinder 10, the filling gravel is trapped in the transition cavity 23, and the gravel is transported to the coarse gravel stockpile. The fine gravel and silt that have passed through the second screening hole 21 are transported to the fine gravel stockpile.

[0071] Specifically, during the rotation of the first screening cylinder 10, the gravel soil is driven to rotate a certain height along the rotation direction of the first screening cylinder 10, and then falls back to the lower side of the length direction of the first screening cylinder 10 under its own gravity. This causes the gravel to collide with each other and continuously impact the side wall of the first screening cylinder 10. Through the collision between the gravel, some of the sand attached to the gravel is removed, thereby reducing the amount of soil carried by the gravel filling. When the gravel and sand impact the side wall of the first screening cylinder 10, the filling gravel, fine gravel and sand smaller than the first screening hole 11 fall directly into the corresponding transition cavity 23. The coarse gravel trapped in the first screening cylinder 10 is sent out through the first screening cylinder 10 to the gravel conveying mechanism 40, and then sent to the coarse gravel stockpile through the coarse gravel conveying mechanism 40.

[0072] During the rotation of the second screening cylinder 20, the gravel, fine gravel, and sand are rotated a certain height along the rotation direction of the second screening cylinder 20. Under their own gravity, they fall back to the lower side of the length direction of the second screening cylinder 20, causing the gravel to collide with each other and continuously impact the side wall of the second screening cylinder 20. Through the collision between the gravel, some of the sand attached to the gravel will be removed, further reducing the amount of soil carried by the gravel. When the gravel and sand impact the side wall of the second screening cylinder 20, the fine gravel and sand smaller than the second screening hole 21 fall directly from the transition cavity 23 and pile up below the second screening cylinder 20, while the gravel is trapped in the transition cavity 23.

[0073] S30. The discharge plate 24 is opened by rotating the second screening cylinder 20, and the gravel trapped in the transition cavity 23 is sent into the washing tank 30.

[0074] Understandably, the gravel trapped in the transition cavity 23 is transported downwards along the length of the second screening cylinder 20 under its own weight or the combined force of the transmission force from the second screening cylinder 20 and the gravel's own weight, accumulating at the lower part of the transition cavity 23. As the second screening cylinder 20 rotates, the discharge plate 24 moves to the notch section of the arc-shaped guide rail 50. Under its own weight and the lateral pressure of the gravel trapped in the transition cavity 23, the discharge plate 24 rotates outwards and opens, allowing the gravel trapped in the transition cavity 23 to enter the washing tank 30.

[0075] S40. Add clean water to the cleaning tank 30 and start the agitator 31 in the cleaning tank 30.

[0076] Specifically, the washing tank 30 contains clean water and a stirring paddle 31 that rotates along its own axis under the drive of a motor. The stirring paddle 31 agitates the gravel, washing away most of the mud and sand remaining on the gravel, so that the cleanliness of the gravel reaches the standard for mixing with clay. Most of the washed-off mud and sand settles at the bottom of the washing tank 30.

[0077] S50, start the conveyor mechanism 40 to send the cleaned gravel to the gravel stockpile.

[0078] Specifically, as the conveyor belt 41 moves, the gravel is conveyed to the baffle plate 43 and the discharge ramp 44. As the conveyor belt 41 moves the gravel relative to the discharge ramp 44, the gravel is pushed into the discharge channel 42 by the ramp 44. Under its own weight, the gravel is then transported to the gravel stockpile or collection container, separating it from the silt and sand adhering to the conveyor belt 41. The conveyor belt 41 also has a filtering function, carrying away silt and sand from the washing tank 30 while preventing water from being carried away, thus reducing the sand content in the washing tank 30 and reducing the frequency of water addition or replacement.

[0079] S60, The mud and sand conveyed by the conveyor belt 41 are brushed away by the brush assembly 45.

[0080] Specifically, when the conveyor belt 41 moves relative to the brush assembly 45, the brush assembly 45 brushes away the mud and sand adhering to the conveyor surface of the conveyor belt 41 on the outside of the cleaning tank 30 and collects it by the sand collection bucket 46, so as to prevent the mud and sand carried out by the conveyor belt 41 from returning to the cleaning tank 30, thereby playing the role of cleaning the cleaning tank 30.

[0081] In summary, the gravel washing method for earth-rock dams provided in this embodiment retains coarse gravel in the first screening cylinder 10 and fill gravel in the transition chamber 23. The fill gravel retained in the transition chamber 23 is then sent into the washing tank 30, thereby washing only the gravel that meets the usage requirements. Furthermore, before washing the fill gravel, most of the sand and soil attached to it is removed through two mechanical screenings and collisions, reducing the amount of washing work, thereby reducing the amount of clean water used and the discharge of wastewater, meeting the usage requirements of areas with stringent environmental protection requirements.

[0082] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gravel soil screening and washing device for earth-rock dams, characterized in that, include: The first screening cylinder (10) can rotate along its own axis, and multiple first screening holes (11) are provided on the side wall. The first screening holes (11) can allow the filling gravel and fine gravel to pass through. The second screening cylinder (20) is coaxially sleeved outside the first screening cylinder (10) and can rotate along its own axis. The side wall is provided with a plurality of second screening holes (21). The second screening holes (21) can allow fine gravel to pass through. The cavity between the inner side wall and the outer side wall of the first screening cylinder (10) can accommodate the filled gravel. Multiple baffles (22) are disposed between the first screening cylinder (10) and the second screening cylinder (20), and divide the cavity between the first screening cylinder (10) and the second screening cylinder (20) into multiple transition cavities (23). The multiple transition cavities (23) are evenly distributed around the second screening cylinder (20). The lower end of each transition cavity (23) is adapted to be equipped with an opening and closing discharge plate (24), and each discharge plate (24) is provided with a second screening hole (21). The washing tank (30) is capable of receiving the fill gravel delivered by the discharge plate (24) and is equipped with an agitator (31). The conveying mechanism (40) is capable of conveying the filled gravel out of the washing tank (30). The first screening cylinder (10) is inclined, and the coarse gravel can be sent out through the lower end of the first screening cylinder (10) by the rotation of the first screening cylinder (10). The conveying mechanism (40) includes: The conveyor belt (41) is inclined and extends to the bottom of the rotation path of the stirring paddle (31). Multiple material-blocking protrusions (41a) are evenly spaced along its own length on the conveyor surface. The protrusion height of each material-blocking protrusion (41a) is less than the lower limit size of the filling gravel. The discharge channel (42) is located on one side of the middle of the conveyor belt (41); The baffle plate (43) is spaced above the middle of the conveyor belt (41), one side of which is connected to the side wall of the discharge channel (42), and the gap between it and the baffle protrusion (41a) is smaller than the lower limit size of the filling gravel; The discharge slant bar (44) is inclined downwards along the moving direction of the conveyor belt (41) and directly opposite the feed end of the discharge channel (42); The conveyor belt (41) is a mesh belt, and the conveying surface of the conveyor belt (41) is covered with a filter cloth. When the conveyor belt (41) moves relative to the discharge inclined bar (44), the discharge inclined bar (44) can send the filled gravel on the conveyor belt (41) into the discharge channel (42).

2. The gravel soil screening and washing device for earth-rock dams according to claim 1, characterized in that, It also includes an arc-shaped guide rail (50), which has a notch on the upper part of one side; The arc-shaped guide rail (50) is coaxially mounted outside the second screening cylinder (20), and the second screening cylinder (20) can rotate relative to the arc-shaped guide rail (50); The discharge plate (24) can be opened when it is facing the notch, and it remains closed when it is facing the arc-shaped guide rail (50).

3. The gravel soil screening and washing device for earth-rock dams according to claim 2, characterized in that, Along the rotation direction of the second screening cylinder (20), the front side of the discharge plate (24) is hinged to the second screening cylinder (20), and the rear side of the discharge plate (24) can abut against the outer wall of the second screening cylinder (20).

4. The gravel and soil screening and washing device for earth-rock dams according to claim 3, characterized in that, Along the rotation direction of the second screening cylinder (20), a support roller (25) is provided on the rear outer side of the discharge plate (24). When the support roller (25) abuts against the inner side of the arc-shaped guide rail (50), it can rotate relative to the arc-shaped guide rail (50) around its own axis.

5. The gravel soil screening and washing device for earth-rock dams according to claim 2, characterized in that, Along the rotation direction of the second screening cylinder (20), a guide roller (51) is provided at the rear end of the arc-shaped guide rail (50).

6. The gravel soil screening and washing device for earth-rock dams according to claim 1, characterized in that, The conveying mechanism (40) also includes a brush assembly (45) located on the underside of the conveyor belt (41) and on the outer side above the cleaning tank (30). As the conveyor belt (41) moves relative to the brush assembly (45), the brush assembly (45) is able to brush away mud and sand from the conveyor surface of the conveyor belt (41).

7. The gravel soil screening and washing device for earth-rock dams according to claim 6, characterized in that, The brush assembly (45) is adapted to a sand collection hopper (46), which is used to collect the mud and sand brushed off by the brush assembly (45). The lower end of the sand collection hopper (46) is provided with a sand outlet (46a), which extends to the outside of the cleaning tank (30).

8. A method for screening and washing gravel soil for earth-rock dams, characterized in that, The gravel soil screening and washing device for earth-rock dams according to claim 6 includes the following steps: Drive the first screening cylinder (10) and the second screening cylinder (20) to rotate and close the discharge plate (24) to send the gravel and soil material to be screened into the upper end of the first screening cylinder (10); By rotating the first screening cylinder (10) and the second screening cylinder (20), coarse gravel is trapped in the first screening cylinder (10), filling gravel is trapped in the transition cavity (23), coarse gravel is transported to the coarse gravel stockpile, and fine gravel and silt passing through the second screening hole (21) are transported to the fine gravel stockpile. The discharge plate (24) is opened by the rotation of the second screening cylinder (20), and the gravel trapped in the transition cavity (23) is sent into the washing tank (30); Add clean water to the cleaning tank (30) and start the agitator (31) in the cleaning tank (30); Start the conveyor (40) to send the cleaned gravel to the gravel stockpile. The mud and sand conveyed by the conveyor belt (41) are brushed away by the brush assembly (45).

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