Device for testing clogging mechanism of filter layer of decompression well under bidirectional alternating action of unclogging current and turbidity current

Abstract

The utility model discloses a device for testing the clogging mechanism of a pressure relief well filter layer under the two-way alternating action of unclogging current and turbidity current. Comprising a muddy water system, a test tank base, an organic glass tank fixed on the test tank base, a sample bottom support plate arranged at the bottom of the organic glass tank, a porous well pipe mounted on the sample bottom support plate, an inverted filter layer fixing frame mounted on the outer wall of the porous well pipe, and an inverted filter layer sample fixed in the inverted filter layer fixing frame, an inverted filter sample is divided into at least three parts by partition plate clamping grooves, a sample bottom supporting plate is supported on a test tank base through a bottom supporting plate annular support, a bottom water tank is formed between the sample bottom supporting plate and the test tank base, and clear water is introduced into the bottom water tank through a bottom water inlet pipe; the top of the porous well pipe is covered by a sample cover plate, the top of the organic glass tank is covered by a top fixing cover, a top muddy water tank is formed between the sample cover plate and the top fixing cover, and the top muddy water tank is used for receiving muddy water provided by a muddy water system. According to the utility model, the two-way alternating effect of clear and turbid water flow and the quantitative test of the whole clogging process can be realized.

Description

Technical Field

[0001] The utility model relates to the field of test instruments and test methods, in particular to a device for testing the clogging mechanism of a filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flows. Background Art

[0002] Piping is the most common hazard during flood season in the Yangtze River Basin, accounting for over 50% of incidents during all previous floods and presenting significant risks. Relief wells are one of the most effective measures currently in place to mitigate the potential risk of piping during flood season in levee projects. Compared to other seepage control measures (such as vertical cutoff walls or single-use hydraulic fill and capping), they offer significant advantages such as high effectiveness, low cost, high flexibility, minimal footprint, and minimal environmental impact. Currently, levee relief wells have played a significant role in flood prevention and disaster reduction in key risky sections of levees in my country.

[0003] In existing technologies, dike relief wells provide significant drainage and pressure relief in the early stages of construction. However, as their service life increases, the filter layer of the relief wells gradually becomes clogged, reducing their permeability and causing the flow rate of the relief wells to gradually decrease, or even completely fail, leading to the recurrence of dike piping risks. Despite the recent development of relief wells with removable filter elements, the wellheads are typically located below the ground behind the dike, making them difficult to seal. This makes it easy for muddy water to flow back into the relief wells during both the off-season and flood-season rainfall, causing clogging. Therefore, filter clogging of relief wells is an objective and unavoidable problem.

[0004] During the service life of the embankment pressure relief well, whenever the water level of the outer river is high during the flood season (or flood period), the pressure relief well will automatically overflow with water, which is opposite to the direction of muddy water backflow. The overflowing groundwater is clean water, which has a reverse flushing effect on the filter layer that is blocked by backflow, which is equivalent to flushing with clean water to slow down the development of siltation. Research on this issue is still blank.

[0005] One method in the prior art is to use a test flume to inject muddy water in a siltation test study on a dike pressure relief well, and then test the permeability change of the filter material or filter layer to study the siltation mechanism of muddy water backflow;

[0006] One test in the prior art is a chemical clogging test, which mainly uses glucose water to continuously drip immerse the filter layer of the background water body to test the chemical clogging substances and their evolution process in the filter layer;

[0007] There is also a method of using a water tank to flow turbid water through the filter material or filter material, and then testing the clogging state or permeability of the filter material or material after the water supply is cut off.

[0008] In summary, the main problems with the existing clogging test devices and methods are:

[0009] Conventional permeability test equipment cannot achieve the clean water backwashing effect, and cannot fully test and quantify the impact of clean water flushing on the filter layer on siltation reduction;

[0010] Existing test equipment and methods cannot achieve modular installation of the filter layer, and cannot achieve quantitative analysis of the filter layer clogging status and degree during the test;

[0011] When conventional testing instruments and methods are used, it is impossible to achieve the reverse intermittent alternating effects of muddy water and clear water on the filter layer during the test, and it is impossible to test the degree of clogging evolution of the filter layer under the coupling of the two effects.

[0012] Therefore, in the prior art, there is no equipment that can test and quantify the development and change process of filter layer clogging under the conditions of alternating reverse action of clear water and muddy water. Summary of the Invention

[0013] In view of the above-mentioned defects or deficiencies in the prior art, the utility model provides a test device for the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid water flows, which solves the shortcomings of the current common clogging test devices that cannot achieve the bidirectional alternating action of clear and turbid water flows and cannot quantitatively test the entire clogging process. It has a small size and is easy to install.

[0014] A device for testing the clogging mechanism of a pressure relief well filter layer under the bidirectional alternating action of clear and turbid flow comprises: a turbid water system, a test tank base, an organic glass tank fixed to the test tank base, a sample bottom support plate arranged at the bottom of the organic glass tank, a porous well pipe installed on the sample bottom support plate, a filter layer fixing frame installed on the outer wall of the porous well pipe, and a filter layer sample fixed in the filter layer fixing frame. The filter layer sample is divided into at least three parts by a partition slot. The sample bottom support plate is supported on the test tank base by a bottom support plate annular bracket. A bottom water tank is formed between the sample bottom support plate and the test tank base. The bottom water tank is connected to clean water through a bottom water inlet pipe. The top of the porous well pipe is covered by a sample cover plate, and the top of the organic glass tank is covered by a top fixed cover. A top turbid water tank is formed between the sample cover plate and the top fixed cover. The top turbid water tank is used to connect to turbid water provided by the turbid water system. The turbid water system is connected to the top fixed cover.

[0015] Furthermore, it also includes a water outlet pipe connected to the bottom of the bottom water tank, the water outlet pipe is connected through the test tank base and is controlled by the water outlet pipe control valve.

[0016] Furthermore, the bottom water inlet pipe is connected to the side wall of the bottom water tank and is controlled by a bottom water inlet valve.

[0017] Furthermore, the side wall of the bottom water tank is connected to the bottom overflow pipe, and the bottom overflow pipe is provided with a bottom overflow valve.

[0018] Furthermore, the turbid water system is controlled by a turbid water regulating valve to control water inlet. The turbid water enters the organic glass tank through the turbid water system, the top fixed cover, and the top turbid water tank, and then enters the porous well pipe through the hole in the middle of the sample cover. The amount of turbid water inflow is adjusted by the turbid water regulating valve.

[0019] Furthermore, the side wall of the top turbid water tank is connected to the top overflow pipe.

[0020] Furthermore, the filter layer sample is divided into 6 parts by partition slots.

[0021] The utility model can test and quantitatively analyze the clogging evolution process of the filter layer of the embankment pressure relief well under the action of muddy water backflow and clear water self-overflow flushing in the flood season. It has important value and significance for analyzing and predicting the effect and life of the embankment pressure relief well, has good application prospects, and fills the gaps at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the test device for the filter layer clogging mechanism of a pressure relief well under the bidirectional alternating action of clear and turbid flow;

[0023] Figure 2 yes Figure 1 Sectional diagram of part A in the middle;

[0024] Figure 3 yes Figure 1 Schematic diagram of the cross section of part B;

[0025] Figure 4 yes Figure 1 Schematic diagram of the structure of the middle sample cover;

[0026] Figure 5 yes Figure 1 Schematic diagram of the structure of the bottom support plate of the medium specimen.

[0027] Figure 6 It is a curve showing the relationship between the water permeability attenuation, muddy water clogging amount and clean water flushing frequency and time of the filter layer sample of the embodiment of the present utility model.

[0028] In the figure: 1 - organic glass tank; 2 - sample cover; 3 - filter layer fixing frame; 4 - porous well pipe; 5 - filter layer sample; 6 - partition slot; 7 - sample bottom support plate; 8 - bottom support plate ring bracket; 9 - bottom water tank; 10 - test tank base; 11 - outlet pipe; 12 - outlet pipe control valve; 13 - bottom water inlet pipe; 14 - bottom water inlet valve; 15 - bottom overflow pipe; 16 - bottom overflow valve; 17 - top fixing cover; 18 - top overflow pipe; 19 - turbid water regulating valve; 20 - turbid water system. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below with reference to the accompanying drawings of the present invention.

[0030] Please refer to Figure 1-5The embodiment of the utility model provides a test device for the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flow, including a porous well pipe 4, a filter layer sample 5, a sample bottom support plate 7, a bottom support plate annular bracket 8, a bottom water tank 9, a test tank base 10, a water outlet pipe 11, a water outlet pipe control valve 12, a bottom water inlet pipe 13, a bottom water inlet valve 14, a bottom overflow pipe 15, a bottom overflow valve 16, a top fixed cover 17, a top overflow pipe 18, and a turbid water regulating valve 19.

[0031] Please also refer to Figure 3 The filter layer sample 5 is fixed within the filter layer fixing frame 3 and adhered to the outer wall of the porous well pipe 4. The filter layer sample 5 is divided into at least three sections by a partition slot 6. The porous well pipe 4 is connected to the sample bottom support plate 7, which is in turn supported by the bottom support plate annular bracket 8 on the test tank base 10. The top of the porous well pipe 4 is covered by the sample cover plate 2 and then placed as a whole within the organic glass tank 1. The organic glass tank 1 is installed on the test tank base 10, and a bottom water tank 9 is formed between the sample bottom support plate 7 and the test tank base 10. The outlet pipe 11 connected to the bottom of the bottom water tank 9 is connected through the test tank base 10 and controlled by the outlet pipe control valve 12. The bottom water inlet pipe 13 is connected to the side wall of the bottom water tank 9 and is controlled by the bottom water inlet valve 14. The bottom overflow pipe 15 is connected to the other side wall of the bottom water tank 9 and is controlled by the bottom overflow valve 16; the top of the organic glass tank 1 is covered by the top fixed cover 17, and a top turbid water tank is formed between the sample cover plate 2 and the top fixed cover 17. The side wall of the top turbid water tank is connected to the top overflow pipe 18, and the turbid water system 20 is connected to the top fixed cover 17 and is controlled by the turbid water regulating valve 19.

[0032] When using the utility model to conduct a test on the clogging mechanism of a pressure relief well under the condition of alternating clear and turbid flow in both directions, the method includes the following steps:

[0033] Step 1: The turbid water in the turbid water system 20 is mixed with mud and flows through the turbid water regulating valve 19 and the holes of the sample cover plate 2 into the porous well pipe 4, and then flows into the filter layer sample 5. Part of the turbid water is filtered by the filter layer, and the mud is deposited in the filter layer sample 5. During the test, the filter layer sample 5 will experience water permeability reduction due to clogging. In order to quantitatively analyze the amount of turbid water clogging in the filter layer sample and the degree of water permeability reduction of the filter layer test, the turbid water regulating valve 19 can be closed, the sample cover plate 2 can be opened, and one of the filter layer samples 5 in the partition card slot 6 can be taken out for quantitative analysis to obtain the amount of turbid water clogging and water permeability reduction of the filter layer sample 5 at this time;

[0034] Step 2: To analyze the flushing effect of the overflow relief well on siltation during floods or high-water-level relief wells during the flood season, the turbid water regulating valve 19, the outlet pipe control valve 12, and the bottom overflow valve 16 are closed during the test. The clean water bottom inlet pipe 13 is regulated by the bottom inlet valve 14 and enters the filter layer sample 5 to form a backwashing effect. The water overflows from the top of the porous well pipe 4 and enters the top overflow pipe 18 to overflow the test system. To quantitatively analyze the impact of the clean water flushing time and number on the siltation amount and water permeability of the filter layer sample 5, the bottom inlet valve 14 can be closed, the sample cover 2 can be opened, and another filter layer sample 5 in the partition slot 6 can be taken out for quantitative analysis to obtain the turbid water siltation amount and water permeability attenuation of the filter layer sample 5 at this time;

[0035] Step 3: According to the needs of quantitative analysis, different turbid water flow time, turbidity; clean water flow time, frequency, etc. can be used to repeat step 1 and step 2 until all 6 filter layer samples 5 in the partition card slot 6 are taken out for analysis, and the relationship curve between a certain turbid water flow time, clean water flushing frequency or time and the permeability attenuation and clogging amount of the filter layer sample 5 can be obtained, see Figure 6 .

[0036] The utility model can finally obtain a curve diagram of the relationship between the permeability attenuation, muddy water clogging amount and clean water flushing frequency and time of the filter layer sample 5, as shown in FIG. Figure 6 shown.

[0037] The utility model is mainly used to study the clogging of embankment pressure relief wells caused by muddy water backflow and the self-overflow flushing of clear water during flood season, and to reveal the clogging evolution mechanism of the filter layer of the pressure relief wells. It has important value and significance for quantitative test analysis and prediction of the effect and life of the pressure relief wells, and also provides theoretical and support for flood control and disaster reduction of embankments, and has good application prospects.

[0038] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention are intended to be covered by the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A test device for the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flow, characterized in that: include: A turbid water system (20), a test tank base (10), an organic glass tank (1) fixed to the test tank base (10), a sample bottom support plate (7) provided at the bottom of the organic glass tank (1), a porous well pipe (4) installed on the sample bottom support plate (7), a filter layer fixing frame (3) installed on the outer wall of the porous well pipe (4), and a filter layer sample (5) fixed in the filter layer fixing frame (3), wherein the filter layer sample (5) is divided into at least three parts by a partition slot (6), and the sample bottom support plate (7) is supported by a bottom support plate annular bracket (8). A bottom water tank (9) is formed between the test tank base (10), the sample bottom support plate (7) and the test tank base (10), and the bottom water tank (9) is connected to clean water through the bottom water inlet pipe (13); the top of the porous well pipe (4) is covered by the sample cover plate (2), and the top of the organic glass tank (1) is covered by the top fixed cover (17). A top turbid water tank is formed between the sample cover plate (2) and the top fixed cover (17), and the top turbid water tank is used to connect turbid water provided by the turbid water system (20), and the turbid water system (20) is connected to the top fixed cover (17).

2. The test device for the filter layer clogging mechanism of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: It also includes a water outlet pipe (11) connected to the bottom of the bottom water tank (9), the water outlet pipe (11) is connected through the test tank base (10) and is controlled by the water outlet pipe control valve (12).

3. The test device for the filter layer clogging mechanism of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: The bottom water inlet pipe (13) is connected to the side wall of the bottom water tank (9) and is controlled by a bottom water inlet valve (14).

4. The device for testing the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: The side wall of the bottom water tank (9) is connected to a bottom overflow pipe (15), and a bottom overflow valve (16) is provided on the bottom overflow pipe (15).

5. The test device for the filter layer clogging mechanism of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: The turbid water system (20) is controlled by a turbid water regulating valve (19) to control water inlet. The turbid water passes through the turbid water system (20), the top fixed cover (17), and the top turbid water tank into the organic glass tank (1), and then enters the porous well pipe (4) through the hole in the middle of the sample cover plate (2). The amount of turbid water inflow is regulated by the turbid water regulating valve (19).

6. The device for testing the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: The side wall of the top turbid water tank is connected to the top overflow pipe (18).

7. The device for testing the clogging mechanism of the filter layer of a pressure relief well under the bidirectional alternating action of clear and turbid flow as claimed in claim 1, characterized in that: The filter layer sample (5) is divided into six parts by the partition plate slot (6).

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