An indoor radial permeability test apparatus for dredged mud and its calculation method

Abstract

This invention relates to an indoor radial permeability test device for dredged sludge and its calculation method, belonging to the field of dredged sludge treatment technology. It includes: a base plate, a permeation cylinder, a settling cylinder, a top plate, a water-holding cylinder, and a glass capillary tube. A water-holding ring is fixed to the top surface of the base plate; the permeation cylinder is placed on the base plate with multiple permeation holes evenly distributed on its sidewalls; the settling cylinder is stacked on top of the permeation cylinder; the top plate covers the top of the settling cylinder and has a discharge hole in its middle; the water-holding cylinder is located inside the permeation cylinder and the settling cylinder and is placed on the base plate, with multiple outlet holes on its bottom sidewalls and the discharge hole extending from its top; the glass capillary tube is inserted into the water-holding cylinder. This invention utilizes the lower water level pressure difference created by the higher water level in the water-holding cylinder compared to the water level in the water-holding ring. The water in the water-holding cylinder, under water level pressure, flows out from the outlet holes, through the dredged sludge sample and the permeation holes, and into the water-holding ring. The change in water level in the water-holding cylinder is then visually read on the glass capillary tube, allowing for the calculation of the radial permeability coefficient of the dredged sludge sample.

Description

Technical Field

[0001] This invention relates to the field of dredged sludge treatment technology, and in particular to an indoor radial permeability test device for dredged sludge. Background Technology

[0002] To ensure water quality and navigation capacity, ports and waterways undergo dredging and cleanup annually. With the large-scale dredging projects and waterway construction, a significant amount of dredged mud samples are generated. According to incomplete statistics, my country currently produces at least hundreds of millions of cubic meters of dredged mud samples annually. Currently, my country's method for handling dredged mud is large-scale stockpile storage. However, due to the high particle content, natural water content, and poor permeability of dredged mud, the consolidation rate in stockpiles is slow. This results in a large amount of land being occupied by dredged mud accumulation, hindering land turnover and causing serious social problems. Therefore, to address these issues, researchers have proposed a rapid mud-water separation technology. This technology involves setting up vertical and bottom drainage channels in certain areas of the dredging site. Water flows radially through the dredged mud and then through the vertical drainage channels, achieving rapid mud-water separation. However, the rapid mud-water separation system still faces challenges in understanding the radial permeation pattern of water in dredged mud, and currently, no device has been proposed to simulate the radial permeation of dredged mud indoors.

[0003] From the perspective of experimental principles, indoor methods for determining permeability coefficients can be divided into constant head permeability tests and variable head permeability tests. Traditional indoor methods for determining permeability coefficients can only be used for permeability tests on soil samples with a certain degree of rigidity, and are not suitable for dredged mud samples with high water content under flowing conditions. Most indoor permeability coefficient measuring devices are based on vertical permeability testing of soil samples, while devices for radial permeability testing of soil samples are very rare.

[0004] Therefore, how to provide an indoor radial permeability testing device for dredged mud samples that is simple in structure, low in manufacturing cost, easy to operate, and occupies a small area is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides an indoor radial permeability testing device for dredged mud and its calculation method, solving the technical problem that indoor permeability testing devices are not suitable for testing dredged mud samples with high water content under flowing conditions.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: an indoor radial permeability test device for dredged sludge, comprising: a base plate, a permeation cylinder, a settling cylinder, a top plate, a transparent water-holding cylinder, and a glass tube; a water-holding ring is fixed on the top surface of the base plate; the permeation cylinder is coaxially located inside the water-holding ring and placed on the base plate, and a plurality of permeation holes are evenly provided on the side wall of the permeation cylinder; the settling cylinder is coaxially stacked on top of the permeation cylinder; the top plate is parallel to the base plate and located above it, pressing against the top of the settling cylinder, and a portion of the top plate is provided with a connection to the permeation cylinder. A discharge hole communicating with the settling cylinder; the water-holding cylinder is coaxially located inside the permeation cylinder and the settling cylinder and placed on the bottom plate; the side wall of the water-holding cylinder near its bottom end is provided with multiple water outlet holes and its top end protrudes through the discharge hole; the top end of the water-holding cylinder is fastened with a sealing cap and the middle of the sealing cap is provided with a fixing hole; the gap between the water-holding cylinder and the permeation cylinder and the settling cylinder is a test area, and the test area can be filled with dredged mud samples; the glass tube is inserted into the water-holding cylinder along the axial direction and fixed at the fixing hole.

[0007] The beneficial effects of this invention are: by utilizing the lower water level difference created by the higher water level in the water-holding cylinder compared to the water level in the water-holding ring, the water in the water-holding cylinder, under the pressure of the water level, flows out from the outlet hole, passes through the dredged mud sample and the seepage hole, and flows into the water-holding ring. At this time, the change value of the water level in the water-holding cylinder on the glass tube can be directly read, and the radial permeability coefficient of the dredged mud sample can be calculated. The above-mentioned testing device has a simple structure, is easy to operate, has low manufacturing cost, and can directly obtain test data.

[0008] Instructions for the Radial Permeability Test Method of Indoor Dredged Sludge:

[0009] S1. Fill the test area with dredged mud through the discharge box;

[0010] S2. Fill the water ring and water cylinder with water to ensure that the water ring is full and the water level in the water cylinder is higher than the water level in the water ring.

[0011] S3. By utilizing the water level in the water-holding cylinder to create a water pressure difference that is higher than the water level in the water-holding ring, the water in the water-holding cylinder flows out from the outlet hole, passes through the dredged mud sample and the seepage hole, and flows into the water-holding ring.

[0012] S4. By visually reading the water level change in the water-filled cylinder on the glass capillary tube, the radial permeability coefficient of the dredged mud sample can be calculated.

[0013] Based on the above technical solution, the present invention can be further improved as follows.

[0014] Furthermore, there are multiple settling cylinders, which are stacked coaxially from top to bottom, with the bottommost settling cylinder placed coaxially on top of the permeation cylinder; the top plate covers the top of the highest settling cylinder.

[0015] The further beneficial effect of adopting the above is that the design of multiple settling cylinders from top to bottom can hold more dredged mud samples, which is convenient for testing.

[0016] Furthermore, it also includes an annular cover, which is fitted around the outer periphery of the water-holding cylinder and covers the discharge hole.

[0017] The further beneficial effect of adopting the above is that the design of the ring cover at the discharge hole can prevent water seeping from the dredged mud sample from flowing out through the discharge hole.

[0018] Furthermore, it also includes a consolidation stress application component, which includes: an annular pressure plate, multiple connecting columns, and an annular weight. The annular pressure plate is sleeved on the outer periphery of the water-holding cylinder and has multiple drainage holes evenly distributed on it. The annular pressure plate movably passes through the discharge hole and is slidably connected to the test area along the axial direction of the permeation cylinder and the settling cylinder, and can press on the dredged mud sample. The multiple connecting columns are fixed vertically at intervals on the top surface of the annular pressure plate, and their top ends all extend out of the discharge hole. The annular weight is placed on the top of the multiple connecting columns.

[0019] The further beneficial effect of the above is that the annular pressure plate is slidably connected inside the infiltration cylinder and the settling cylinder and presses against the dredged mud sample. Since multiple connecting columns are fixed on the annular pressure plate and annular weights are placed on it, different consolidation stresses can be applied to the dredged mud sample by using annular weights of different weights, thereby testing the radial permeability of the dredged mud sample under different consolidation stresses.

[0020] Furthermore, it also includes multiple locking bolts, and the bottom plate has multiple first threaded holes on its surface near its edge; the top plate has multiple second threaded holes on its surface near its edge, and the multiple second threaded holes are respectively arranged vertically opposite to the multiple first threaded holes; the multiple locking bolts are respectively screwed into the opposite first threaded holes and second threaded holes.

[0021] The further beneficial effect of adopting the above is that by using multiple locking bolts to fix the top plate and the bottom plate, the permeation cylinder and the settling cylinder can be fixed, thereby improving the stability and reliability of the device test.

[0022] Furthermore, it also includes a vent valve, wherein the sealing cover is provided with a vent hole, and the vent valve is fixed at the vent hole.

[0023] The further beneficial effect of adopting the above is that by fixing the vent valve at the vent hole of the sealing cover, the water container can be connected to the atmosphere.

[0024] Furthermore, it also includes multiple sealing rings, which are respectively fixed at the joint between the permeation cylinder and the bottom plate, the joint between the permeation cylinder and the settling cylinder, and the joint between the settling cylinder and the top plate.

[0025] In addition, a method for calculating the radial permeability of indoor dredged sludge samples is provided, including the aforementioned indoor dredged sludge sample radial permeability testing device.

[0026] The radial permeability coefficient of dredged mud samples is calculated using the following formula: K =

[0027] q is the seepage flow rate of the water-holding cylinder (5) per unit time, r1 is the radius of the water-holding cylinder (5), r2 is the radius of the settling cylinder (3), h1 is the distance from the bottom plate (1) to the bottom of the glass tube (6) inside the water-holding cylinder (5), and h2 is the distance from the bottom plate (1) to the top surface of the bottom plate (1) where the water-holding ring (7) is fixed.

[0028] Furthermore, by decomposing the void ratio e of the dredged mud samples in the infiltration tube and the settling tube during different test time periods, the eK curve can be obtained. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a type 1 indoor dredged mud radial permeability test device according to the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of a type 2 indoor dredged mud radial permeability test device according to the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the water-filled cylinder, glass tube, sealing cap, and ventilation valve in an indoor radial permeability test device for dredged mud according to the present invention.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. Base plate, 2. Permeation cylinder, 21. Permeation cylinder, 3. Settling cylinder, 4. Top plate, 41. Discharge hole, 5. Water tank, 51. Water outlet, 6. Glass tube, 7. Water ring, 8. Sealing cap, 9. Annular cap, 10. Consolidation stress application component, 101. Annular pressure plate, 102. Connecting column, 11. Locking bolt, 12. Vent valve, 13. Sealing ring. Detailed Implementation

[0034] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0035] like Figure 1As shown, an indoor radial permeation test device for dredged sludge includes: a base plate 1, a permeation cylinder 2, a settling cylinder 3, a top plate 4, a transparent water-holding cylinder 5, and a glass capillary tube 6. A water-holding ring 7 is fixed to the top surface of the base plate 1; the permeation cylinder 2 is coaxially located inside the water-holding ring 7 and placed on the base plate 1, and multiple permeation holes 21 are evenly provided on the side wall of the permeation cylinder 2; the settling cylinder 3 is coaxially stacked on top of the permeation cylinder 2; the top plate 4 is parallel to the base plate 1 and is located above and covers the top of the settling cylinder 3, and the middle of the top plate 4 is provided with a permeation cylinder... 2. A discharge hole 41 is connected to the settling cylinder 3; a water-holding cylinder 5 is coaxially located inside the permeation cylinder 2 and the settling cylinder 3 and is placed on the bottom plate 1. The side wall of the water-holding cylinder 5 near its bottom end is provided with multiple water outlet holes 51 and its top end protrudes through the discharge hole 41. The top end of the water-holding cylinder 5 is fastened with a sealing cap 8 and the middle of the sealing cap 8 is provided with a fixing hole. The gap between the water-holding cylinder 5 and the permeation cylinder 2 and the settling cylinder 3 is the test area, which can be filled with dredged mud samples; a glass tube 6 is inserted into the water-holding cylinder 5 along the axial direction of the water-holding cylinder 5.

[0036] In some specific embodiments, there can be multiple settling cylinders 3, which are stacked coaxially from top to bottom, with the bottom settling cylinder 3 placed coaxially on top of the permeation cylinder 2; the top plate 4 is pressed over the top of the highest settling cylinder 3.

[0037] In some specific embodiments, an annular cover 9 may also be included, which is sleeved on the outer periphery of the water-holding cylinder 5 and covers the discharge hole 41.

[0038] In some specific embodiments, a consolidation stress application component 10 is also included. The consolidation stress application component 10 includes: an annular pressure plate 101, multiple connecting columns 102, and an annular weight. The annular pressure plate 101 is sleeved on the outer periphery of the water-holding cylinder 5 and has multiple drainage holes evenly provided thereon. The annular pressure plate 101 moves through the discharge hole 41 and slides along the axial direction of the permeation cylinder 2 and the settling cylinder 3 in the test area and can press on the dredged mud sample. The multiple connecting columns 102 are fixed vertically at intervals on the top surface of the annular pressure plate 101 and their top ends all extend out of the discharge hole 41. The annular weight is placed on the top of the multiple connecting columns 102.

[0039] In some specific embodiments, multiple locking bolts 11 may also be included. The bottom plate 1 has multiple first threaded holes on its plate surface near its edge. The top plate 4 has multiple second threaded holes on its plate surface near its edge. The multiple second threaded holes are arranged vertically opposite to the multiple first threaded holes. The multiple locking bolts 11 are screwed into the opposite first threaded holes and second threaded holes respectively.

[0040] In some specific embodiments, a vent valve 12 may also be included, and a vent hole is provided on the sealing cover 8, with the vent valve 12 fixed at the vent hole.

[0041] In some specific embodiments, a plurality of sealing rings 13 may also be included, which are respectively fixed at the joint between the permeation cylinder 2 and the bottom plate 1, the joint between the permeation cylinder 2 and the settling cylinder 3, and the joint between the settling cylinder 3 and the top plate 4.

[0042] In addition, a method for calculating the radial permeability of indoor dredged sludge samples is provided, including an indoor dredged sludge sample radial permeability testing device.

[0043] The radial permeability coefficient of dredged mud samples is calculated using the following formula: K = ,

[0044] q is the seepage flow rate of the water-holding cylinder (5) per unit time, r1 is the radius of the water-holding cylinder (5), r2 is the radius of the settling cylinder (3), h1 is the distance from the bottom plate (1) to the bottom of the glass tube (6) inside the water-holding cylinder (5), and h2 is the distance from the bottom plate (1) to the top surface of the bottom plate (1) where the water-holding ring (7) is fixed.

[0045] In some specific embodiments, the porosity e of the dredged mud samples in the infiltration tube 2 and the settling tube 3 during different test time periods can be used to obtain the eK curve.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An indoor radial permeability test device for dredged sludge, characterized in that, include: A base plate (1) has a water-holding ring (7) fixed on its top surface. The permeation cylinder (2) is coaxially located inside the water-holding ring (7) and placed on the bottom plate (1). The side wall of the permeation cylinder (2) is uniformly provided with a plurality of permeation holes (21). A settling cylinder (3) is coaxially stacked on top of the permeation cylinder (2); Top plate (4), which is located parallel to the bottom plate (1) above and covers the top of the settling cylinder (3). The top plate (4) has a discharge hole (41) in the middle that communicates with the permeation cylinder (2) and the settling cylinder (3). A transparent water-holding cylinder (5) is coaxially located inside the infiltration cylinder (2) and the settling cylinder (3) and placed on the bottom plate (1). The side wall of the water-holding cylinder (5) near its bottom end is provided with multiple water outlet holes (51) and its top end protrudes through the discharge hole (41). The top end of the water-holding cylinder (5) is fastened with a sealing cap (8) and the middle part of the sealing cap (8) is provided with a fixing hole. The gap between the water-holding cylinder (5) and the infiltration cylinder (2) and the settling cylinder (3) is the test area, and the test area is filled with dredged mud samples. A glass tube (6) is inserted into the water container (5) along the axial direction and fixed at the fixing hole.

2. The indoor dredged sludge radial permeability test device according to claim 1, characterized in that, There are multiple settling cylinders (3), which are stacked coaxially from top to bottom, with the bottom settling cylinder (3) placed coaxially on top of the permeation cylinder (2); the top plate (4) is pressed on the top of the highest settling cylinder (3).

3. The indoor dredged sludge radial permeability test device according to claim 1, characterized in that, It also includes an annular cover (9), which is fitted around the outer periphery of the water container (5) and covers the discharge hole (41).

4. The indoor dredged sludge radial permeability test device according to claim 1, characterized in that, It also includes a consolidation stress application assembly (10), which includes: An annular pressure plate (101) is sleeved on the outer periphery of the water-holding cylinder (5) and has a plurality of drainage holes evenly provided thereon. The annular pressure plate (101) moves through the discharge hole (41) and slides along the axial direction of the permeation cylinder (2) and the settling cylinder (3) in the test area and can press on the dredged mud sample. Multiple connecting columns (102) are vertically fixed at intervals on the top surface of the annular pressure plate (101), and their top ends all extend out of the discharge hole (41). A ring-shaped weight is placed at the top of the plurality of connecting posts (102).

5. The indoor dredged sludge radial permeability test device according to claim 1, characterized in that, It also includes multiple locking bolts (11), and the bottom plate (1) has multiple first threaded holes on its plate surface near its edge; the top plate (4) has multiple second threaded holes on its plate surface near its edge, and the multiple second threaded holes are respectively arranged vertically opposite to the multiple first threaded holes; the multiple locking bolts (11) are respectively screwed into the opposite first threaded holes and second threaded holes.

6. The indoor radial permeability test device for dredged sludge according to claim 1, characterized in that, It also includes a vent valve (12), and the sealing cover (8) is provided with a vent hole, and the vent valve (12) is fixed at the vent hole.

7. The indoor dredged sludge radial permeability test device according to claim 1, characterized in that, It also includes multiple sealing rings (13), which are respectively fixed at the joint between the permeation cylinder (2) and the bottom plate (1), the joint between the permeation cylinder (2) and the settling cylinder (3), and the joint between the settling cylinder (3) and the top plate (4).

8. A method for calculating radial permeability of indoor dredged mud samples, characterized in that, Includes the indoor dredged mud sample radial permeability testing device as described in any one of claims 1-7. The radial permeability coefficient of dredged mud samples is calculated using the following formula: K = , q is the seepage flow rate of the water-holding cylinder (5) per unit time, r1 is the radius of the water-holding cylinder (5), r2 is the radius of the settling cylinder (3), h1 is the distance from the bottom plate (1) to the bottom of the glass tube (6) inside the water-holding cylinder (5), and h2 is the distance from the bottom plate (1) to the top surface of the bottom plate (1) where the water-holding ring (7) is fixed.

9. The method for calculating radial permeability of indoor dredged mud samples according to claim 8, characterized in that, By decomposing the void ratio e of the dredged mud samples in the infiltration tube (2) and the settling tube (3) during different test periods, the eK curve can be obtained.

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