A seabed coarse sand extraction device and extraction method
By using the auxiliary sand-dredging components of the seabed coarse sand extraction device, mechanical vibration and jet water flow are used to destroy the sand skeleton, solving the problem of low efficiency in seabed coarse sand extraction and achieving a highly efficient and stable coarse sand extraction process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- OCEAN UNIV OF CHINA
- Filing Date
- 2023-09-19
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies have low efficiency in extracting coarse sand from the seabed, making it difficult to break the sand skeleton of the coarse sand layer, resulting in difficult extraction, easy equipment damage, and high maintenance costs.
The seabed coarse sand extraction device uses components such as solid hammers and uneven mass disks in the auxiliary sand extraction assembly to break the sand skeleton by mechanical vibration and jet water flow, and loosens the coarse sand layer by rotating paddles to form a liquefied state for easy extraction.
It improves the extraction efficiency of coarse sand from the seabed, has a simple structure, reduces the risk of equipment damage, and lowers maintenance costs.
Smart Images
Figure CN117266859B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seabed sand mining technology, specifically to a seabed coarse sand extraction device and extraction method. Background Technology
[0002] Nearshore waters typically consist of a seawater layer, a silt layer, a fine sand layer, and a coarse sand layer. The coarse sand particles in the coarse sand layer form a compact sand skeleton with large pores. In existing technologies, high-pressure water or high-pressure air is usually used to disturb the gravel to extract the sand. However, due to the presence of the coarse sand skeleton, the released high-pressure water or air can easily pass through the coarse sand skeleton and be released, making it difficult to break the coarse sand skeleton. This leads to the problem of "not being able to extract or not being able to extract". Moreover, frequent idling of the motor can easily damage the equipment, resulting in high maintenance costs. Summary of the Invention
[0003] This invention discloses a seabed coarse sand extraction device and method, which solves the technical problems of low extraction efficiency and difficulty in extraction of seabed coarse sand in existing technologies. It features a reasonable structure, effectively improves extraction efficiency, and facilitates easy extraction. The technical solution adopted is as follows:
[0004] A seabed coarse sand extraction device includes a sand extraction pipe and an auxiliary sand extraction assembly. The sand extraction pipe is equipped with a first sand extraction pump and includes an inlet end and an outlet end. The inlet end can extend into the coarse sand layer, and the outlet end can be connected to a sand storage bin on a sand transport vessel at sea. The auxiliary sand extraction assembly includes a pulling drive unit, a pull cable, and a first cylinder extending along the sand extraction pipe. The pull cable passes through the first cylinder and can reciprocate up and down under the action of the pulling drive unit. The first cylinder is equipped with a filling block that can divide the inner cavity of the first cylinder into a lower cavity and an upper cavity. The body contains a solid hammer, and a piston is slidably connected to the upper cavity. The piston can divide the upper cavity into an independent first chamber and a second chamber. The second chamber is connected to an inlet pipe and an outlet pipe respectively. The inlet pipe is equipped with a first one-way valve and the inlet end of the inlet pipe can be located in the seawater layer. The outlet pipe is equipped with a second one-way valve and the outlet end of the outlet pipe is located close to the outlet end of the sand pumping pipe. Seawater can be discharged after passing through the inlet pipe, the second chamber and the outlet pipe. The pull wire is fixedly connected to the piston, and the end of the pull wire passes through the filling block and is fixedly connected downward to the solid hammer.
[0005] Based on the above technical solution, the outer wall surface of the piston and the inner wall surface of the upper cavity are abutted by a sealing gasket to separate the first chamber and the second chamber.
[0006] Based on the above technical solution, the inner top surface of the lower cavity is provided with a shock-absorbing plate, and the solid hammer is slidably connected to the lower cavity and can abut against the shock-absorbing plate upward under the action of the pull line.
[0007] Based on the above technical solution, the first cylinder includes a bottom plate that seals the lower cavity, and the bottom plate is provided with several ribs.
[0008] Based on the above technical solution, the pull wire is coaxial with the piston and the solid hammer, and the pull wire includes a steel wire rope.
[0009] Based on the above technical solution, it also includes a first rack, a gear set and a non-uniform mass disk. The first rack is fixedly connected to the solid hammer, and the non-uniform mass disk is rotatably connected to the first cylinder through a shaft. The non-uniform mass disk is offset close to the lower cavity side. The first rack transmits the rotational motion to the non-uniform mass disk through the gear set to drive the lower end of the first cylinder to shake.
[0010] Based on the above technical solution, it also includes a second rack and several rotating paddles. The second rack is fixedly connected to the solid hammer. The rotating paddles are located outside the first cylinder, and the shaft of the rotating paddles passes through the first cylinder and is rotatably connected to the first cylinder. The end of the rotating paddles that extends into the lower cavity is provided with a gear that can mesh with the second rack to loosen the coarse sand layer on the outer periphery of the first cylinder.
[0011] Based on the above technical solution, there are multiple auxiliary sand-draining components arranged circumferentially along the sand-draining pipe. The extraction device also includes a first rack, a gear set, and a non-uniform mass disk. The first rack is fixedly connected to the solid hammer. The non-uniform mass disk is rotatably connected to the first cylinder through a shaft. The non-uniform mass disk is offset close to the lower cavity. The first rack transmits the rotational motion to the non-uniform mass disk through the gear set to drive the lower end of the first cylinder to shake.
[0012] A method for extracting coarse sand from the seabed, using the extraction device described above, includes the following steps:
[0013] Before the inlet end of the sand dredging pipe contacts the seabed silt layer, start the first sand dredging pump;
[0014] When the inlet end of the water inlet pipe is submerged in the seawater layer, the pull-out drive unit is activated simultaneously.
[0015] After the sand dredging is completed, the first sand dredging pump and the dredging drive unit are shut down in sequence.
[0016] Based on the above technical solution, the extraction device has multiple auxiliary sand-draining components arranged circumferentially along the sand-draining pipe. The extraction device also includes a first rack, a gear set, and a non-uniform mass disk. The first rack is fixedly connected to the solid hammer. The non-uniform mass disk is rotatably connected to the first cylinder through a shaft. The non-uniform mass disk is offset closer to the lower cavity. The first rack transmits rotational motion to the non-uniform mass disk through the gear set to drive the lower end of the first cylinder to shake. The multiple non-uniform mass disks are arranged facing the same direction. When the sand-draining pipe extracts coarse sand, the multiple non-uniform mass disks move synchronously or sequentially at intervals.
[0017] Beneficial effects
[0018] This invention has a reasonable structure. While pumping sand, the pull wire can transmit mechanical vibration through the solid hammer in the lower cavity to destroy the sand skeleton at the inlet end of the sand pumping pipe, providing conditions for the liquefaction of the coarse sand layer. On the other hand, it can intermittently form jet water flow at the inlet end of the sand pumping pipe, which can frequently disturb the water flow in the inlet end area of the sand pumping pipe, and even frequently form turbulence, so as to form coarse sand in a liquefied state. In this way, the problem of "not being able to pump out or not being able to pump out" can be effectively solved. It is not only simple in structure and easy to maintain, but also conducive to smooth sand pumping.
[0019] In this invention, the solid hammer is also equipped with a first gear. As the solid hammer slides up and down, the first gear drives the non-uniform mass body to rotate, thereby causing the lower part of the first cylinder to shake, which in turn squeezes the surrounding coarse sand layer, loosening it and allowing it to flow along the side wall of the first cylinder to the inlet end of the sand extraction pipe, providing a continuous supply of coarse sand. Furthermore, several rotating paddles are provided to loosen the coarse sand skeleton outside the first cylinder, and when the lower part of the first cylinder shakes, the sand skeleton can be loosened over a larger area. In addition, after the lower layer of coarse sand liquefies and is extracted, under the action of gravity, the upper layer of sand skeleton collapses and flows downward. The vibration of the solid hammer and the intermittent jet of water can quickly disperse the coarse sand, causing it to liquefy and enter the sand extraction pipe.
[0020] In this invention, the auxiliary sand-dredging component has multiple non-uniform mass bodies that can move synchronously or sequentially at intervals. When multiple non-uniform mass bodies move synchronously, the swing amplitude of the lower part of the first cylinder can be increased, thereby enhancing the destructive effect on the coarse sand layer skeleton. When multiple non-uniform mass bodies move sequentially at intervals, the lower part of the first cylinder will shake frequently, which is beneficial to improving the uniformity of vibration, thereby making the sand-dredging process more stable and continuous. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.
[0022] Figure 1 Schematic diagram of the invention Figure 1 ;
[0023] Figure 2 : Figure 1 A magnified schematic diagram of the extraction device;
[0024] Figure 3 : A schematic diagram of the structure when the solid hammer in the auxiliary sand-dredging assembly contacts the bottom plate downwards;
[0025] Figure 4 : A schematic diagram of the structure when the solid hammer in the auxiliary sand-dredging assembly comes into contact with the damping plate upwards;
[0026] Figure 5 : A schematic diagram of the structure after the first rack, the non-uniform mass disk, the second rack, and the rotating propeller are assembled; Detailed Implementation
[0027] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.
[0028] The terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this document to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are used solely for the convenience of describing the document and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description herein, unless otherwise specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two elements; they can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0029] In this document, unless otherwise stated, the term "multiple" means two or more.
[0030] In this article, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.
[0031] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.
[0032] like Figures 1-5 The device shown is a seabed coarse sand extraction device, which includes a sand extraction pipe 1 and an auxiliary sand extraction assembly. The sand extraction pipe 1 is equipped with a first sand extraction pump and includes an inlet end and an outlet end. The inlet end can extend into the coarse sand layer, and the outlet end can be connected to the sand storage bin on a sand transport vessel on the sea surface.
[0033] like Figures 2-4 As shown, the auxiliary sand dredging assembly includes a pull-drive unit 2, a pull wire 3, and a first cylinder 4 extending along the sand dredging pipe 1. The pull wire 3 passes through the first cylinder 4 and can move up and down reciprocally under the action of the pull-drive unit 2. In this embodiment, the pull-drive unit 2 includes a winch fixed on the sand transport vessel, the pull wire 3 is a steel wire rope, and the first cylinder 4 is cylindrical and connected to the outer wall of the sand dredging pipe 1 through an elastic element. In this embodiment, the outer wall of the first cylinder 4 is connected to the outer wall of the sand dredging pipe 1 through several springs. In other embodiments of the present invention, the first cylinder 4 can also be bonded to the outer wall of the sand dredging pipe 1 through a rubber pad.
[0034] like Figure 3 and 4As shown, the first cylinder 4 is provided with a filling block 5, which can divide the inner cavity of the first cylinder 4 into a lower cavity and an upper cavity. Specifically, the filling block 5 is made of foam or lightweight plastic and occupies most of the cavity of the first cylinder 4. On the one hand, it can give the first cylinder 4 sufficient structural strength and good resistance to deformation even in deep sea. On the other hand, the presence of the filling block 5 can easily form independent upper and lower cavities in the first cylinder 4. At the same time, the volume of the upper and lower cavities can be controlled by adjusting the filling block 5, which is flexible. In addition, the filling block 5 is also provided with a wire hole for the pull wire 3 to pass through, and the axis of the wire hole is parallel to the axis of the first cylinder 4.
[0035] like Figure 3 and 4 As shown, the upper cavity forms a relatively sealed structure, and a piston 6 is slidably connected inside it. The piston 6 can divide the upper cavity into an independent first chamber and a second chamber. Specifically, the outer wall surface of the piston 6 and the inner wall surface of the upper cavity abut against each other through a sealing gasket to separate the first chamber and the second chamber. The second chamber is connected to an inlet pipe 8 and an outlet pipe 9. The inlet pipe 8 is equipped with a first one-way valve and its inlet end can be located in the seawater layer. The outlet pipe 9 is equipped with a second one-way valve and its outlet end is located near the outlet end of the sand dredging pipe 1. The outlet end of the outlet pipe 9 is connected to a jet nozzle (not shown). The outlet of the jet nozzle is downward and inward. Seawater can be discharged after passing through the inlet pipe 8, the second chamber, and the outlet pipe 9. In addition, the pull line 3 is fixedly connected to the piston 6. Thus, when the winch pulls the pull line 3 up and down, the piston 6 does work, continuously sucking in and discharging seawater, which in turn continuously impacts the coarse sand at the inlet end of the sand dredging pipe 1. This helps to form turbulence at this point, destroy the sand skeleton, and liquefy the coarse sand for easy extraction.
[0036] A solid hammer 7 is provided in the lower cavity. In this embodiment, the solid hammer 7 includes a solid metal body, and the solid metal body is covered with a plastic layer, which helps to reduce deformation and prevent rusting. In other embodiments of the present invention, a slider is provided on the outer wall surface of the solid hammer 7, and a groove is provided at the corresponding position of the inner wall surface of the lower cavity to accommodate the slider, so as to guide the solid hammer. The end of the pull wire 3 passes through the wire hole on the filling block 5 and is fixed downward to the solid hammer 7. When the pull wire 3 is pulled up and down, it can drive the piston block 6 to move up and down and impact the inner top surface and inner bottom surface of the lower cavity, generating mechanical vibration and transmitting the mechanical vibration to the surrounding coarse sand layer to destroy the sand skeleton of the coarse sand layer. In this embodiment, a shock-absorbing plate 10 is provided on the inner top surface of the lower cavity. The solid hammer 7 can impact and contact the shock-absorbing plate 10 upward under the action of the pull wire to avoid direct contact with the filling block 5 and damage to the filling block 5. The shock-absorbing plate 10 can be made of plastic material and fixed to the inner wall surface of the first cylinder 4. In addition, the first cylinder 4 includes a bottom plate 11 that seals the lower cavity. The bottom plate 11 is provided with several ribs. The bottom plate 11 can be made of steel plate with a certain thickness, which is beneficial for better transmitting mechanical vibration to the surrounding area. In this embodiment, the pull wire 3 is coaxial with the piston 6 and the solid hammer 7, which is beneficial for improving the stability during pulling.
[0037] like Figure 5 As shown, it also includes a first rack 12, a gear set, a non-uniform mass disk 13, a second rack 14, and three rotating paddles 15. The first rack 12 is located in the lower cavity and is fixedly connected to the solid hammer 7. The non-uniform mass disk 13 is rotatably connected to the first cylinder 4 via a shaft, and a bearing is sleeved at its rotatable connection. In this embodiment, the gear set includes a large gear and a small gear located in the lower cavity. The shaft of the large gear is rotatably connected to the side wall of the first cylinder 4, and the large gear can mesh with the first rack and the small gear, and can transmit rotational motion to the small gear. The small gear is coaxially sleeved on the shaft of the non-uniform mass disk 13. Furthermore, the non-uniform mass disk 13 is offset close to the lower cavity. The first rack 12 transmits rotational motion to the non-uniform mass disk 13 through a gear set to drive the lower end of the first cylinder 4 to shake, thereby squeezing and destroying the coarse sand layer skeleton on the outer periphery of the first cylinder 4. At the same time, the coarse sand particles after the sand skeleton is crushed can flow downward along the outer periphery of the first cylinder 4 to the inlet end of the sand suction pipe 1 under the action of gravity, and can also slide quickly to the inlet end of the sand suction pipe 1 under the action of the first sand suction pump. Meanwhile, the water outlet pipe 9 can continuously spray water, forming a coarse sand liquefaction zone at the inlet end of the sand suction pipe 1. Figure 2 As shown, this allows for easy extraction of coarse sand onto the sand transport vessel.
[0038] The second rack 14 is located in the lower cavity and fixedly connected to the solid hammer 7, and can slide down and up synchronously with the solid hammer 7. The rotating paddle 15 is located outside the first cylinder 4, and the shaft of the rotating paddle 15 passes through the first cylinder 4 and is rotatably connected to the first cylinder 4. The end of the rotating paddle 15 extending into the lower cavity is provided with a gear that can mesh with the second rack 14 to loosen the coarse sand layer on the outer periphery of the first cylinder 4. In this embodiment, the three rotating paddles 15 are close to the uneven mass disk 13 to enhance the swaying amplitude of the first cylinder 4 under inertia, and at the same time, can further improve the formation efficiency of the coarse sand liquefaction zone. Figure 2 As shown.
[0039] Multiple auxiliary sand-dredging components are arranged circumferentially along the sand-dredging pipe 1, and the multiple non-uniform mass disks 13 are arranged facing the same direction. The multiple non-uniform mass disks 13 can operate synchronously or sequentially at intervals. For example, when the sand-dredging pipe 1 has a large diving depth and the first cylinder 4 has a large swaying resistance, the multiple non-uniform mass disks 13 can be controlled to operate synchronously to quickly and efficiently form a coarse sand liquefaction zone when the sand-dredging pipe 1 has a large diving depth. When the sand-dredging pipe 1 has a small diving depth and the first cylinder 4 has a small swaying resistance, the multiple non-uniform mass disks 13 can be controlled to operate sequentially at intervals to make the first cylinder 4 sway frequently and improve the efficiency of destroying the sand skeleton.
[0040] A method for extracting coarse sand from the seabed, using the extraction device described above, includes the following steps:
[0041] Before the inlet end of the sand dredging pipe 1 contacts the seabed silt layer, the first sand dredging pump is turned on. At this time, the silt layer and fine sand layer are relatively loose, and the dredging process can be successfully carried out.
[0042] When the inlet end of the water inlet pipe 8 is submerged in the seawater layer, the pulling drive unit 2 is activated at the same time. At this time, the winch reciprocates, causing the pull line 3 to be pulled up and down, which in turn drives the solid hammer 7 to move up and down and generate mechanical vibration, drives the water inlet pipe 8 to intermittently spray water through the jet nozzle, and drives the uneven mass disk 13 and the rotating paddle 15 to rotate. This ensures that the coarse sand layer skeleton on the outer periphery of the sand pumping pipe 1 is effectively destroyed, and at the same time, a coarse sand liquefaction zone is formed at the inlet end of the sand pumping pipe 1, which facilitates the extraction of coarse sand.
[0043] After the sand pumping is completed, the first sand pumping pump and the traction drive unit 2 are shut down in sequence.
[0044] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A device for extracting coarse sand from the seabed, characterized in that, The system includes a sand dredging pipe (1) and an auxiliary sand dredging assembly. The sand dredging pipe (1) is equipped with a first sand dredging pump and includes an inlet end and an outlet end. The inlet end can extend into the coarse sand layer, and the outlet end can be connected to the sand storage bin on a sand transport vessel. The auxiliary sand dredging assembly includes a pull-drive unit (2), a pull line (3), and a first cylinder (4) extending along the sand dredging pipe (1). The pull line (3) passes through the first cylinder (4) and can move up and down reciprocally under the action of the pull-drive unit (2). The first cylinder (4) is equipped with a filling block (5) and can divide the inner cavity of the first cylinder (4) into a lower cavity and an upper cavity. The lower cavity is equipped with a solid hammer (7). A piston (6) is slidably connected in the upper cavity. The piston (6) can divide the upper cavity into an independent first chamber and a second chamber. The second chamber is connected to an inlet pipe (8) and an outlet pipe (9). The inlet pipe (8) is equipped with a first one-way valve and the inlet end of the inlet pipe (8) can be located in the seawater layer. The outlet pipe (9) is equipped with a second one-way valve and the outlet end of the outlet pipe (9) is located close to the outlet end of the sand pumping pipe (1). Seawater can be discharged after passing through the inlet pipe (8), the second chamber and the outlet pipe (9). The pull wire (3) is fixedly connected to the piston (6), and the end of the pull wire (3) passes through the filling block (5) and is fixedly connected downward to the solid hammer (7).
2. The seabed coarse sand extraction device according to claim 1, characterized in that, The outer wall of the piston (6) and the inner wall of the upper cavity are abutted by a sealing gasket to separate the first chamber and the second chamber.
3. The seabed coarse sand extraction device according to claim 1, characterized in that, The inner top surface of the lower cavity is provided with a shock-absorbing plate (10), and the solid hammer (7) is slidably connected to the lower cavity and can abut against the shock-absorbing plate (10) upward under the action of the pull line (3).
4. The seabed coarse sand extraction device according to claim 3, characterized in that, The first cylinder (4) includes a bottom plate (11) that seals the lower cavity, and the bottom plate (11) is provided with several ribs.
5. The seabed coarse sand extraction device according to claim 3, characterized in that, The pull wire (3) is coaxial with the piston (6) and the solid hammer (7), and the pull wire (3) includes a steel wire rope.
6. The seabed coarse sand extraction device according to any one of claims 1 to 5, characterized in that, It also includes a first rack (12), a gear set and a non-uniform mass disk (13). The first rack (12) is fixedly connected to the solid hammer (7). The non-uniform mass disk (13) is rotatably connected to the first cylinder (4) through a shaft. The non-uniform mass disk (13) is biased and close to the lower cavity. The first rack (12) transmits the rotational motion to the non-uniform mass disk (13) through the gear set to drive the lower end of the first cylinder (4) to shake.
7. The seabed coarse sand extraction device according to claim 6, characterized in that, It also includes a second rack (14) and several rotating paddles (15). The second rack (14) is fixedly connected to the solid hammer (7). The rotating paddles (15) are located outside the first cylinder (4), and the shaft of the rotating paddles (15) passes through the first cylinder (4) and is rotatably connected to the first cylinder (4). The end of the rotating paddles (15) extending into the lower cavity is provided with a gear that can mesh with the second rack (14) to loosen the coarse sand layer on the outer periphery of the first cylinder (4).
8. The seabed coarse sand extraction device according to claim 7, characterized in that, The first cylinder (4) has multiple parts arranged around the sand extraction pipe (1), and the multiple non-uniform mass disks (13) are arranged in the same direction.
9. A method for extracting coarse seabed sand, employing the extraction device as described in any one of claims 1 to 5, 7, and 8, characterized in that, Includes the following steps: Before the inlet end of the sand dredging pipe (1) contacts the seabed silt layer, start the first sand dredging pump; When the inlet end of the water inlet pipe (8) is submerged in the seawater layer, the pull-out drive unit (2) is activated at the same time. After the sand pumping is completed, the first sand pumping pump and the pumping drive unit (2) are shut down in sequence.
10. The method for extracting coarse seabed sand according to claim 9, characterized in that, The extraction device has multiple auxiliary sand extraction components arranged circumferentially along the sand extraction pipe (1). The extraction device also includes a first rack (12), a gear set and a non-uniform mass disk (13). The first rack (12) is fixedly connected to the solid hammer (7). The non-uniform mass disk (13) is rotatably connected to the first cylinder (4) through a shaft. The non-uniform mass disk (13) is offset close to the lower cavity. The first rack (12) transmits the rotational motion to the non-uniform mass disk (13) through the gear set to drive the lower end of the first cylinder (4) to shake. The multiple non-uniform mass disks (13) are arranged facing the same direction. When the sand extraction pipe (1) extracts coarse sand, the multiple non-uniform mass disks (13) move synchronously or sequentially at intervals.