Small-sized annular water tank for sediment starting flow velocity test and arrangement method of small-sized annular water tank

Abstract

The invention discloses a small annular water tank for a sediment starting flow velocity test and an arrangement method thereof, and belongs to the field of sediment starting flow velocity measurement, the water tank comprises an annular water tank, the annular water tank is provided with a closed flow path, and a water flow pushing paddle plate and a test sand sample are arranged in the flow path; the water flow pushing paddle plate is used for providing power for water in the flowing path, the annular water tank is connected with a pressurizing device, and a laser turbidity meter and a pressure flow velocity sensor are further arranged in the flowing path. The device is convenient to operate, assemble and disassemble, stable and advective hydrodynamic force can be quickly formed, and an efficient, easy-to-operate and easy-to-clean environment is provided for a sediment starting flow velocity test.

Description

Technical Field

[0001] The present invention belongs to Sediment start-up velocity measurement field , specifically relating to a small annular water tank for sediment starting velocity test and its arrangement method. Background Art

[0002] The mechanical mechanism of sediment movement includes the initiation, transport and sedimentation of sediment particles. These processes are crucial to understanding the formation of important geomorphic units such as underwater beaches and troughs. However, it is not easy to truly understand the initiation mechanism of sediment particles. Even the very basic problem of judging sediment initiation has many difficulties: first, the water flow that drives sediment movement is turbulent. Even with the same flow rate, the velocity and direction of the water flow in the area of ​​interest fluctuate randomly, which causes the force acting on the sediment particles to change; second, sediment initiation itself has a strong randomness, that is, under the same water flow conditions, not all sediment particles will start at the same time, which objectively brings considerable challenges to the determination of the critical water flow conditions for sediment initiation; there is currently no unified method to judge whether sediment has started. In most cases, the practice is to judge directly by the naked eye. When sediment is observed to start moving on the bed surface, it is considered that the water flow condition is the critical initiation condition for sediment. However, it is impossible for different people to have exactly the same judgment criteria, which leads to a strong subjectivity in the measurement results. On the other hand, for the same sand sample, when the water depth is shallow, the contact between the water flow and the riverbed is more direct, and the kinetic energy of the water flow is more easily transferred to the sediment particles, so the sediment particles are easier to start, and the required starting flow rate is relatively small. On the contrary, when the water depth is greater, the kinetic energy of the water flow needs to be transferred to the riverbed through a deeper water body, and the energy transfer efficiency is lower, so the sediment particles need a greater flow rate to start. The current water depth condition of the sediment starting flow rate test device is gradually adjusted from zero water depth to the target water depth, which can easily lead to the situation where sediment has already started before reaching the test water depth.

[0003] The US invention patent with publication number US11821885B2 discloses a test method for simulating the release of sediment pollutants under the action of river scouring. The test method starts a variable speed motor to drive the flow-making propeller to make the flow rate reach the required flow rate and keep the flow rate constant. After the water flow is constant, the concentration changes and vertical distribution characteristics of sediment pollutants under different simulated power conditions are measured. In the prior art, it is difficult to maintain a stable water flow in the sediment start-up test, which easily causes the sediment to start prematurely when injected into the water body, resulting in test failure. Summary of the invention

[0004] The object of the present invention is to provide a small annular water tank for sediment starting flow velocity test which is easy to operate, has high test efficiency and accurate results, and an arrangement method thereof.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a small annular water tank for sediment starting flow velocity test, comprising: an annular water tank, the annular water tank has a closed flow path, a water flow-driven paddle plate and a test sand sample are arranged in the flow path, the water flow-driven paddle plate is used to provide power for the water body in the flow path, the annular water tank is connected to a pressurizing device, and a laser turbidity meter and a pressure flow velocity sensor are also arranged in the flow path. The flow path of the annular water tank is filled with water, and the water flow pushes the paddle to provide power for the water in the flow path, so that the water can circulate continuously through the test sand sample in the flow path. During the flow of the water, the water flow velocity is adjusted by changing the movement intensity of the water flow pushing the paddle, and the turbidity of the water in the flow path is dynamically monitored in conjunction with a laser turbidity meter, and the flow velocity and pressure of the water are monitored by a pressure flow velocity sensor, so as to observe the starting state of sediment in the flow path and obtain the flow velocity, pressure and sediment starting flow velocity of the water in this state, so as to realize spontaneous reminder of whether the sediment has started, thereby reducing the operating threshold of the test using the water tank, and also improving the timeliness of the obtained data, which is beneficial for professionals to analyze the characteristics of sediment starting flow velocity.

[0006] Preferably, the flow path includes no less than two test areas and circulation areas, the test area is a rectangular channel, the circulation area is a cylindrical channel with an axis extending longitudinally, adjacent test areas are connected through the circulation area, a water flow-driven paddle board is rotatably arranged in each circulation area, and the rotation axis of the water flow-driven paddle board is colinear with the axis of the cylindrical channel in which it is located. The cylindrical circulation area provides space for the water flow-driven paddle board to rotate, and the water flow-driven paddle boards in each circulation area rotate at the same speed and direction, so that the water body can achieve stable circulation flow between adjacent test areas. Since the rotation axis of the water flow-driven paddle board coincides with the axis of the cylindrical channel, when the water flow drives the paddle board to rotate to generate the power of water flow, the water body can pass through the test area in a horizontal and stable posture, thereby reducing the error between the actual water body flow velocity that causes sediment to start and the flow velocity detected by the pressure flow velocity sensor, and improving the authenticity and accuracy of the sediment starting flow velocity in the sediment starting test; Since the water flow in the two circulation areas pushes the paddles to maintain the same rotation speed and direction, when the water body produces flow velocity attenuation after passing through the circulation area on one side, the circulation area on the other side and the water flow inside it can push the paddles to compensate for the water flow velocity, thereby reducing the difference in water flow velocity between the two test areas. On the one hand, the distribution balance of sediment in the water body is improved, and the accuracy of the laser turbidity meter's dynamic observation of the turbidity degree of the water body is improved. On the other hand, the possibility of turbulence is reduced, and the pressure difference in the water body caused by the flow velocity difference is reduced, thereby improving the accuracy of the pressure flow sensor in capturing the water pressure data when the sediment starts, and improving the accuracy of the test results of the sediment start-up test under this pressure condition.

[0007] Preferably, the water flow pushes the paddle plate to be arranged in a circle and connected to an axis body, the axis body is connected to a turntable, the turntable is located below the annular water tank, and the turntable is connected to a servo motor for driving its rotation. By adjusting the output power of the servo motor, the speed of the turntable can be adjusted to adjust the speed of the water flow push paddle plate in the circulation area, thereby realizing the adjustment of the water flow velocity in the flow path, which is convenient for obtaining the sediment starting velocity by changing the water flow motion intensity; after obtaining the required sediment starting data in a single test, the servo motor is turned off, and the water flow carried by the turntable pushes the paddle plate to stop rotating. The water body continues to carry the sediment due to its initial kinetic energy. At this time, the water flow pushes the paddle plate to form a barrier to the water body and sediment passing through the circulation area, thereby quickly weakening the water flow velocity and accelerating the flowing water body in the annular water tank to return to a static state. On the one hand, it can shorten the interval time between multiple tests and improve the test efficiency of multiple tests. On the other hand, the water flow pushes the paddle plate to reduce the speed of the water flow, which can accelerate the suspended sediment to sink to the bottom in the flow path, which is convenient for collecting the sample sediment that has left the original sample and reduces the difficulty of cleaning the water tank; The water flow pushes the paddle plate through a servo motor arranged at the bottom of the annular water tank. Compared with the prior art of installing a pump body in the water flow path, it avoids damage to the driving device by the test sand sample and reduces maintenance costs.

[0008] Preferably, the test sand sample, laser turbidity meter and pressure flow rate sensor are all arranged in the test area. Since the test area is a rectangular channel, the flow of water is relatively balanced and stable when passing through the test area, which helps to reduce the representativeness of the data obtained by the laser turbidity meter and the pressure flow rate sensor for capturing water body related data.

[0009] Preferably, a detachable placement container is provided at the bottom of the test area, the upper end of the placement container has an opening and the interior is filled with sand samples.

[0010] Preferably, the test area has a screw hole at the bottom, and the upper part of the placement container has a thread adapted to the screw hole. The placement container is installed in the screw hole through the thread, which facilitates the removal and installation of the test sand sample on the annular water tank, and optimizes the preparation work before the test and the recovery work after the test; After a test is completed, the placement container and the remaining test sand sample therein are taken out by rotation, so as to facilitate the discharge of the test water in the annular water tank and the sediment settled in the flow path, thereby further improving the efficiency of the cleaning work of the annular water tank after the test.

[0011] Preferably, the pressurizing device includes a compression device and a compression air pipe, the compression device is connected to the inside of the annular water tank through the compression air pipe, and the compression device can adjust the internal pressure of the flow path through the compression air pipe. The pressure value of the internal space of the annular water tank is changed by the compression device, so as to achieve different pressure values ​​of a fixed water depth in the annular water tank, that is, the water pressure value can be changed without gradually adjusting the water depth in the annular water tank, thereby reducing the possibility of premature start of sediment due to water disturbance caused by water injection before reaching the test water depth.

[0012] Preferably, a flow stabilizer is provided at the junction of the test area and the circulation area. The flow stabilizer is arranged horizontally, and there are multiple flow stabilizers arranged at intervals in the longitudinal direction. The flow stabilizer forms a rectification for the water body flowing through, so that the water flow entering the test area has good horizontal flow characteristics, and reduces the possibility of turbulence in the height direction of the water body affecting the starting flow rate of sediment.

[0013] Preferably, the servo motor is connected to a bracket at the bottom, and a control terminal is provided on the bracket and connected to the servo motor. The control terminal is used to receive electrical signals and control the output power of the servo motor, thereby controlling the rotation speed of the water flow to drive the paddle, and providing adjustable power for the flow of water in the annular water tank; the above scheme has a simple overall structure, which is convenient for quickly adjusting the experimental power conditions, and can quickly make the water and sediment still after a single experiment, greatly improving the ease of operation and efficiency of the sediment starting flow velocity experiment.

[0014] Since the present invention is provided with a water flow-propelled paddle plate as a water flow power source, it has the following beneficial effects: the water flow-propelled paddle plate realizes water flow circulation, cooperates with the laser turbidity meter and the pressure flow rate sensor to realize the spontaneous reminder of sediment start, reduces the test operation threshold, and improves the timeliness of the acquired data; the two circulation areas compensate for the water flow velocity passing through the test area, reduces the flow rate difference, and improves the accuracy of the laser turbidity meter in dynamic observation of the turbidity degree of the water body; the two water flow-propelled paddle plates maintain a consistent rotation state, ensure the stability of the circulating water body, reduce the pressure difference, and enable the pressure flow rate sensor to capture the test data when the sediment starts in time and accurately; the rotation speed of the water flow-propelled paddle plate is adjusted by the servo motor, so as to realize the rapid and wide-range adjustment of the water flow power in the test; the stopped water flow-propelled paddle plate blocks the water flow and slows down, accelerates the sediment to sink to the bottom, facilitates the collection of sample sediment, and reduces the cleaning difficulty; the pressurizing device can change the water pressure value under the premise of unchanged water depth, and reduce the possibility of water body disturbance caused by water injection leading to early start of sediment; the placement container and the annular water tank are assembled by thread to realize the convenient loading of the test sand sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the overall layout of the annular water tank according to the first embodiment of the present invention; Figure 2 It is a top view schematic diagram of the annular water tank; Figure 3 A schematic diagram of the position of the paddle board pushed by water flow in the annular water tank from a bird's-eye view; Figure 4 The schematic diagram of the turntable is shown in FIG. Figure 5 It is a schematic diagram of the connection relationship between the placement container and the annular water tank; Figure 6 This is a schematic diagram of the location of the laser receiving device; Figure 7 This is a schematic diagram of the position of the flow stabilizer plate according to the second embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a paddle driven by a steady water flow according to the second embodiment of the present invention.

[0016] Figure numbers: annular water tank 1; water tank top cover 10; flow stabilizer 11; test area 101; circulation area 102; placement container 13; thread 130; screw hole 131; water flow pushes paddle 2; turntable 20; servo motor 21; control terminal 22; groove 200; bracket 3; pressurizing device 6; compression equipment 60; compressed air pipe 61; laser turbidity meter 7; laser emitting device 70; laser receiving device 71; pressure flow sensor 8. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below in conjunction with specific implementations and drawings: Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1: See attached Figure 1 -Attached Figure 6 A small annular water tank 1 for a sediment starting flow velocity test comprises: an annular water tank 1 having a closed flow path, a water flow-driven paddle board 2 and a test sand sample being arranged in the flow path, the water flow-driven paddle board 2 being used to provide power for the water body in the flow path, the annular water tank 1 being connected to a pressurizing device 6, and a laser turbidity meter 7 and a pressure flow velocity sensor 8 being also arranged in the flow path.

[0019] It should be noted that a detachable water tank top cover plate 10 is installed on the top of the annular water tank 1, and the annular water tank 1 and the water tank top cover plate 10 are sealed to form a seal of the flow path.

[0020] It should be noted that a sealing ring is provided at the position where the top cover plate 10 of the water tank is installed and in contact with the annular water tank 1 , and the top cover plate 10 of the water tank and the annular water tank 1 are sealed and connected by extrusion.

[0021] The flow path of the annular water tank 1 is filled with water, and the water flow pushes the paddle 2 to provide power for the water in the flow path, so that the water can circulate continuously through the test sand sample in the flow path. During the flow of the water, the water flow speed is adjusted by changing the movement intensity of the water flow pushing the paddle 2, and the laser turbidity meter 7 is used to dynamically monitor the turbidity of the water in the flow path, and the pressure flow sensor 8 monitors the flow rate and pressure of the water, so as to observe the starting state of the sediment in the flow path and obtain the flow rate, pressure and sediment starting flow rate of the water in this state, so as to realize spontaneous reminder of whether the sediment has started, reduce the operation threshold of the test using the water tank, and also improve the timeliness of the obtained data, which is beneficial for professionals to analyze the characteristics of the sediment starting flow rate.

[0022] The flow path includes no less than two test areas 101 and a circulation area 102. The test area 101 is a rectangular channel, and the circulation area 102 is a cylindrical channel with an axis extending longitudinally. Adjacent test areas 101 are connected through the circulation area 102. A water-driven paddle board 2 is rotatably arranged in each circulation area 102, and the rotation axis of the water-driven paddle board 2 is colinear with the axis of the cylindrical channel in which it is located.

[0023] The cylindrical circulation area 102 provides a space for the water flow to drive the paddle board 2 to rotate. The water flow in each circulation area 102 drives the paddle board 2 to rotate at the same speed and direction, so that the water body can achieve stable circulation between adjacent test areas 101. Since the rotation axis of the water flow driving the paddle board 2 coincides with the axis of the cylindrical channel, when the water flow drives the paddle board 2 to rotate to generate the power of water flow, the water body can pass through the test area 101 in a horizontal and stable posture, thereby reducing the error between the actual water body flow velocity that causes the sediment to start and the flow velocity detected by the pressure flow velocity sensor 8, and improving the authenticity and accuracy of the sediment starting flow velocity in the sediment starting test. Since the water flow in the two circulation areas 102 pushes the paddle 2 to maintain the same rotation speed and rotation direction, when the water body produces flow velocity attenuation after passing through the circulation area 102 on one side, the circulation area 102 on the other side and the water flow inside it can push the paddle 2 to compensate for the water flow velocity, thereby reducing the difference in water flow velocity between the two test areas 101. On the one hand, the distribution balance of sediment in the water body is improved, and the accuracy of dynamic observation of water turbidity by the laser turbidity meter 7 is improved. On the other hand, the possibility of turbulence is reduced, and the pressure difference in the water body caused by the flow velocity difference is reduced, thereby improving the accuracy of the pressure flow sensor 8 in capturing water pressure data when sediment starts, and improving the accuracy of the test results of the sediment starting test under this pressure condition.

[0024] The water flow pushes the paddle board 2 to be arranged around and connected to a shaft body, the shaft body is connected to a turntable 20, the turntable 20 is located below the annular water tank 1, and the turntable 20 is connected to a servo motor 21 for driving its rotation. By adjusting the output power of the servo motor 21, the speed of the turntable 20 can be adjusted, thereby adjusting the speed of the water flow push paddle board 2 in the circulation area 102, thereby achieving the adjustment of the water flow velocity in the flow path, and facilitating the acquisition of the sediment starting velocity by changing the water flow motion intensity; After obtaining the required sediment starting data in a single test, the servo motor 21 is turned off. At this time, the water flow carried by the turntable 20 pushes the paddle plate 2 to stop rotating. The water body continues to carry the sediment due to its initial kinetic energy. At this time, the water flow pushes the paddle plate 2 to form a barrier to the water body and sediment passing through the circulation area 102, thereby quickly weakening the water flow velocity and accelerating the flowing water body in the annular water tank 1 to return to a static state. On the one hand, it can shorten the interval time between multiple tests and improve the test efficiency of multiple tests. On the other hand, the water flow pushes the paddle plate to slow down the water flow, which can accelerate the suspended sediment to sink to the bottom in the flow path, making it easier to collect the sample sediment that has left the original sample and reducing the difficulty of cleaning the water tank. The water flow pushes the paddle 2 to be driven by a servo motor 21 arranged at the bottom of the annular water tank 1. Compared with the prior art of installing a pump body in the water flow path, it avoids damage to the driving device by the test sand sample and reduces maintenance costs.

[0025] The test sand sample, the laser turbidity meter 7 and the pressure and flow rate sensor 8 are all arranged in the test area 101 .

[0026] It should be noted that the laser turbidity meter 7 includes a laser emitting device 70 and a laser receiving device 71 which are arranged opposite to each other and electrically connected. The laser emitting device 70 and the laser receiving device 71 are respectively arranged on two relatively vertical walls of the test area 101. The laser emitting device 70 emits a detection laser that passes through the water body and the sediment. The laser receiving device 71 receives the emitted laser and records the characteristic data of the current laser, thereby assisting in analyzing the turbidity of the current water body to determine whether the sediment is effectively started.

[0027] Since the test area 101 is a rectangular channel, the flow of water is relatively balanced and stable when passing through the test area 101, which helps to reduce the representativeness of the data obtained by the laser turbidity meter 7 and the pressure flow rate sensor 8 for capturing water body related data.

[0028] A detachable placement container 13 is provided at the bottom of the test area 101. The placement container 13 has an opening at the upper end and is filled with sand samples.

[0029] The test area 101 has a screw hole 131 at the bottom, and the upper part of the placement container 13 has a thread 130 adapted to the screw hole 131. The placement container 13 is installed in the screw hole 131 through the thread 130, which facilitates the removal and installation of the test sand sample on the annular water tank 1, and optimizes the preparation work before the test and the recovery work after the test; After a test is completed, the placement container 13 and the remaining test sand sample therein are taken out by rotation, so as to facilitate the discharge of the test water in the annular water tank 1 and the sediment settled in the flow path, thereby further improving the efficiency of the cleaning work of the annular water tank 1 after the test.

[0030] The pressurizing device 6 includes a compression device 60 and a compression air pipe 61. The compression device 60 is connected to the inside of the annular water tank 1 through the compression air pipe 61. The compression device 60 can adjust the internal pressure of the flow path through the compression air pipe 61. The pressure value of the internal space of the annular water tank 1 is changed by the compression device 60, so as to achieve different pressure values ​​of a fixed water depth in the annular water tank 1, that is, the water pressure value can be changed without gradually adjusting the water depth in the annular water tank 1, thereby reducing the possibility of premature start of sediment due to water disturbance caused by water injection before reaching the test water depth.

[0031] A flow stabilizer 11 is provided at the connection between the test area 101 and the circulation area 102. The flow stabilizer 11 is arranged horizontally, and there are multiple flow stabilizers 11 arranged at intervals in the longitudinal direction. The flow stabilizer 11 forms a rectification for the water body flowing through, so that the water flow entering the test area 101 has good horizontal flow characteristics, and reduces the possibility of turbulence in the height direction of the water body affecting the starting flow rate of sediment.

[0032] It should be noted that the flow stabilizer 11 is located in the test area of ​​the rectangular channel.

[0033] The servo motor 21 is connected to a bracket 3 at the bottom, and a control terminal 22 is provided on the bracket 3 and connected to the servo motor 21. The control terminal 22 is used to receive electrical signals and control the output power of the servo motor 21, thereby controlling the rotation speed of the water flow to push the paddle 2, and providing adjustable power for the flow of water in the annular water tank 1; the above scheme has a simple overall structure, is convenient for quickly adjusting the experimental power conditions, and can quickly let the water and sediment stand still after a single experiment, greatly improving the ease of operation and efficiency of the sediment starting flow velocity experiment.

[0034] Embodiment 2: See attached Figure 7 -Attached Figure 8On the basis of the first embodiment of the present invention, the annular water tank 1 includes an arc-shaped wall and a vertical wall that can contact the water body. The arc-shaped wall and the vertical wall are arranged tangently on the side contacting the water body. The water flow pushes the paddle plate 2 to cooperate with the arc-shaped wall. The outer edge of the water flow pushes the paddle plate 2 to be longitudinally spaced with grooves 200. The flow stabilizer 11 is also longitudinally spaced on the arc-shaped wall. Each flow stabilizer 11 is arranged corresponding to each groove 200 in height. The lower end surface of the groove 200 can contact the upper end surface of the flow stabilizer 11 at the same horizontal height. When the water flow pushes the paddle plate 2 to rotate, the flow stabilizer 11 can relatively pass through the groove 200 at the same horizontal height.

[0035] The water flow pushes the paddle board 2 to rotate and generates water flow power. The water flow can be rectified by the flow stabilizer 11 in the circulation area 102 to form a stable water flow at different depths below the water surface, which is conducive to reducing the possibility of the water flow pushing the paddle board 2 due to turbulence, thereby reducing the water flow pushing the paddle board 2 to receive interference from the lateral water body and transmitting it to the servo motor 21 through the turntable 20, which is conducive to reducing the interference received by the driving end of the servo motor 21, reducing maintenance costs, and increasing the service life of the motor; When the groove 200 rotates and sweeps through the flow stabilizing plate 11, the upper end of the flow stabilizing plate 11 can form a contact support with the lower end surface of the groove 200, thereby improving the coaxiality of the water flow driving the paddle plate 2 to rotate, thereby improving the stability of the water flow dynamics, making the circulating water flow velocity more gentle and stable, which is conducive to making the actual value of the sediment starting velocity close to the measured value, and improving the test accuracy; When the groove 200 leaves the flow stabilizer 11, the water flow pushes the portion of the paddle plate 2 between adjacent grooves 200 to form agitation at various depths of the water body, which is beneficial to improving the balance of the longitudinal distribution of sediment in the water body, thereby homogenizing the mixed fluid of sediment and water, keeping the turbidity of the water body stable at various positions, improving the accuracy of the laser turbidity meter 7 in measuring the turbidity of sediment, and ensuring that the data records are true and valid.

[0036] A small annular water tank for sediment starting flow velocity test, the arrangement method of which specifically comprises the following steps: Step 1: Place the test sand tank in the annular water tank 1; Step 2: Fill the annular water tank 1 with water to a specified depth; Step 3: Connect the pressurizing device 6 to the annular water tank 1, and create an equivalent water depth effect required for the test by pressurizing the inside of the annular water tank 1.

[0037] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A small annular water tank for sediment starting flow velocity test, comprising: An annular water tank (1) having a closed flow path, wherein a water flow-driven paddle plate (2) and a test sand sample are arranged in the flow path, wherein the water flow-driven paddle plate (2) is used to provide power for the water body in the flow path, the annular water tank (1) is connected to a pressurizing device (6), and a laser turbidity meter (7) and a pressure flow rate sensor (8) are also arranged in the flow path.

2. A small annular water tank for sediment starting flow velocity test according to claim 1, characterized in that: The flow path comprises at least two test areas (101) and a circulation area (102); the test area (101) is a rectangular channel; the circulation area (102) is a cylindrical channel with an axis extending longitudinally; adjacent test areas (101) are connected via the circulation area (102); a water flow driven paddle plate (2) is rotatably arranged in each circulation area (102); the rotation axis of the water flow driven paddle plate (2) is colinear with the axis of the cylindrical channel in which it is located.

3. A small annular water tank for sediment starting flow velocity test according to claim 1, characterized in that: The water flow pushes the paddle plate (2) to be arranged around and connected to a shaft body, the shaft body is connected to a rotating disk (20), the rotating disk (20) is located below the annular water tank (1), and the rotating disk (20) is connected to a servo motor (21) for driving the rotating disk (20) to rotate.

4. A small annular water tank for sediment starting flow velocity test according to claim 2, characterized in that: The test sand sample, the laser turbidity meter (7) and the pressure flow rate sensor (8) are all arranged in the test area (101).

5. A small annular water tank for sediment starting flow velocity test according to claim 2, characterized in that: A detachable placement container (13) is provided at the bottom of the test area (101); the placement container (13) has an opening at the upper end and is filled with the sand sample.

6. A small annular water tank for sediment starting flow velocity test according to claim 5, characterized in that: The test area (101) has a screw hole (130) at the bottom, and the upper part of the placement container (13) has a thread (131) adapted to the screw hole (130).

7. A small annular water tank for sediment starting flow velocity test according to claim 1, characterized in that: The pressurizing device (6) comprises a compression device (60) and a compression air pipe (61); the compression device (60) is connected to the interior of the annular water tank (1) via the compression air pipe (61); and the compression device (60) can adjust the internal pressure of the flow path via the compression air pipe (61).

8. A small annular water tank for sediment starting flow velocity test according to claim 2, characterized in that: A flow stabilizing plate (11) is provided at the connection between the test area (101) and the circulation area (102); the flow stabilizing plate (11) is arranged horizontally; there are a plurality of flow stabilizing plates (11) which are arranged at intervals in the longitudinal direction.

9. A small annular water tank for sediment starting flow velocity test according to claim 2, characterized in that: The servo motor (21) is connected to a bracket (3) at the bottom, and a control terminal (22) is provided on the bracket (3) and is connected to the servo motor (21).

10. A method for arranging a small annular water tank for a sediment starting flow velocity test, using the small annular water tank for a sediment starting flow velocity test according to claim 1, wherein the method for arranging the small annular water tank comprises the following steps: Step 1: placing the test sandy beach in the annular water tank (1); Step 2: Filling the annular water tank (1) with water to a specified depth; Step three: Connect the pressurizing device (6) to the annular water tank (1), and create an equivalent water depth effect required for the test by pressurizing the inside of the annular water tank (1).

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