Filtration system and method for continuous permeation of multiple liquids

Abstract

The invention discloses a filtration system and method for continuous permeation of multiple liquids, and belongs to the technical field of rock-soil body permeation testing, the filtration system comprises a filtration main body, a percolate supply system, a pressure supply system and a percolate storage system, the filtration main body comprises a rigid shell, and a sample chamber is arranged in the rigid shell; a percolate inlet channel and an air inlet channel are respectively arranged at the top end of the rigid shell, and a percolate outlet channel is arranged at the bottom of the rigid shell; a stainless steel filter screen, a rubber gasket, a permeable stone, percolation paper, a soil sample, percolation paper, a permeable stone and a rubber gasket are arranged in the sample chamber from bottom to top; the leachate supply system is communicated with the leachate inlet channel and is used for providing more than two types of leachate; the pressure supply system is communicated with the air inlet channel and provides percolation pressure for the sample chamber; the percolate storage system is communicated with the percolate drainage channel and provides storage of more than two kinds of percolate. According to the invention, rapid measurement of the permeability coefficient of the soil sample under continuous seepage conditions of different solutions can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of rock and soil permeability testing, and in particular discloses a filtration loss system and method for continuous permeation of multiple liquids, which are used to measure the permeability coefficient of a soil sample under continuous seepage conditions of multiple pollutants. Background Art

[0002] Current soil pollution presents complex characteristics, and the actual seepage process often involves the alternating or continuous action of multiple pollutants (such as heavy metals and organic matter). Risk control is an effective soil pollution prevention and control technology. Low permeability is an important engineering indicator for barrier barriers. Conducting indoor tests on barrier materials that are simultaneously and continuously eroded by multiple pollutants has important guiding significance for understanding the actual service performance of barrier barriers. The filter loss meter has the advantages of short cycle and simple operation, and can quickly obtain the permeability coefficient of bentonite slurry and backfill. Traditional filter loss meters only support single solution penetration tests and cannot simulate continuous multi-solution seepage environments. Although flexible wall permeameters can test multiple solutions, they have long cycles and complex operations. Therefore, there is an urgent need for a rapid testing device that can achieve continuous penetration of multiple solutions. Summary of the Invention

[0003] Technical problems to be solved: In response to the technical problems existing in the background technology, the present invention provides a filtration loss system and method for continuous penetration of multiple liquids, which can realize continuous penetration testing of multiple solutions.

[0004] Technical solution: The filtration system for continuous permeation of multiple liquids described in the present invention comprises: The infiltration body comprises a rigid shell, wherein a sample chamber for accommodating a soil sample is provided within the rigid shell; a leachate inlet channel and an air inlet channel are provided at the top of the rigid shell, and a leachate discharge channel is provided at the bottom of the rigid shell; wherein a stainless steel filter screen, a rubber gasket, a permeable stone, a filtration paper, a soil sample, the filtration paper, the permeable stone, and the rubber gasket are provided in the sample chamber from bottom to top; a leachate supply system, the leachate supply system being in communication with the leachate inlet channel and providing at least two or more leachates; a pressure supply system, the pressure supply system being in communication with the air inlet channel and providing filtration pressure for the sample chamber; The exudate storage system is connected to the exudate drainage channel and provides at least two types of exudate storage.

[0005] Preferably, the leachate supply system includes a first leachate storage chamber and a second leachate storage chamber separated by a corrosion-resistant and impermeable membrane. The first leachate storage chamber and the second leachate storage chamber are connected to the leachate inlet channel through branch inlet pipes, respectively, and the branch inlet pipes are respectively connected to the first leachate inlet regulating valve and the second leachate inlet regulating valve for regulating the flow rate, and the leachate inlet channel is connected to a peristaltic pump for controlling the inlet speed.

[0006] Preferably, the connection between the leachate inlet channel and the rigid shell is sealed by a sealing cap, and a leachate inlet switch valve is provided at the sealing cap.

[0007] Preferably, the first diafiltration solution storage chamber and the second diafiltration solution storage chamber are respectively connected to a first diafiltration solution replenishment valve and a second diafiltration solution replenishment valve for replenishing the solution.

[0008] Preferably, the pressure supply system includes an air source connected to an air inlet channel, and the air inlet channel is connected to a pressure regulating valve; the air inlet channel is sealed with the rigid shell at its connection through a sealing cap, and a gas switching valve is provided at the sealing cap.

[0009] Preferably, the exudate storage system includes a first exudate storage chamber and a second exudate storage chamber separated by a corrosion-resistant and impermeable membrane. The first exudate storage chamber and the second exudate storage chamber are connected to the exudate drainage channel through branch drainage pipes, respectively, and the branch drainage pipes are respectively connected to the first exudate regulating valve and the second exudate regulating valve for regulating the flow.

[0010] Preferably, the side walls of the first exudate storage chamber and the second exudate storage chamber are respectively provided with scales for measuring volume.

[0011] Preferably, a first exudate switching valve and a second exudate switching valve are respectively provided on the side walls of the first exudate storage chamber and the second exudate storage chamber.

[0012] The present invention also discloses a filtration method for the above-mentioned fluid loss system, comprising the following steps: Step 1: injecting two leachates into the first leachate storage chamber and the second leachate storage chamber respectively; Step 2: Close the percolation inlet valve, the first percolation valve, and the second percolation valve, open the gas source and the gas valve, adjust the pressure in the sample chamber to a predetermined value through the pressure regulating valve, and test the air tightness; Step 3: Assemble the soil sample in the rigid housing: Place the stainless steel filter, rubber gasket, permeable stone, filter paper, soil sample, filter paper, permeable stone, and rubber gasket in the sample chamber in sequence; Step 4: Start the peristaltic pump, the first diafiltration inlet regulating valve, and the first exudate switch valve, and record the volume change of the first exudate storage chamber at equal time intervals; when the difference in volume change for multiple consecutive times is ≤10%, open the second diafiltration inlet regulating valve, and record the volume change of the second exudate storage chamber at equal time intervals, and terminate the test when the difference in volume change for multiple consecutive times is ≤10%; Step 5: Disassemble the sample chamber, measure the height of the soil sample, and calculate the permeability coefficient according to the formula.

[0013] Preferably, the permeability coefficient calculation formula in step 5 is as follows: ; Where: V is the volume of exudate / m 3 ; K is the intrinsic permeability / m 2 ; P0 is the sum of the air pressure and water pressure on the soil sample / kPa; A is the cross-sectional area of ​​the soil sample / m 2 ;µ is the osmotic viscosity / (kN / m 3 ); L is the average height of the soil sample before and after the test / m; k c is the permeability coefficient of soil sample / (m / s); γ w is the density of water / (kN / m 3 ).

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The assembled infiltration main structure adopted by the present invention can conveniently and efficiently realize the installation or removal of soil samples and has high filtering capacity; 2. The leachate supply system and leachate storage system both adopt an impermeable membrane-separated solution storage structure, thus enabling continuous permeation testing of two leachate solutions without cross-contamination; 3. The filtration body is equipped with a pressure supply system, which provides adjustable filtration gas pressure for the filtration body and accurately adjusts the seepage velocity of the filtration body through air pressure control and peristaltic pump liquid inlet control; 4. During the test, the diafiltration method establishes the stable condition of the diafiltration volume as the switching criterion for multiple diafiltration solutions to ensure the reliability of the test process; 5. The filtration loss system has a wide range of application value in complex pollution scenarios and is not limited to the testing process of two filtration solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the filtration loss system of the present invention; Figure 2 for Figure 1 Main view of the main structure of the middle infiltration; Figure 3 for Figure 2 Top view of the main structure of the infiltration; Figure 4 for Figure 1 Schematic diagram of the structure of the leachate supply system; Figure 5 for Figure 1 Schematic diagram of the medium pressure supply system structure; Figure 6 for Figure 1 Schematic diagram of the exudate storage system.

[0016] Reference numerals: 100, percolation body; 200, percolation liquid supply system; 300, pressure supply system; 400, percolation liquid storage system; 1, rigid shell; 2, sample chamber; 3, permeable stone; 4, stainless steel filter; 5, percolation paper; 6, rubber gasket; 7, air source; 8, pressure regulating valve; 9, gas switch valve; 10, sealing cap; 11, percolation liquid inlet switch valve; 12, peristaltic pump; 13, first percolation liquid inlet regulating valve; 14, first percolation solution storage chamber; 1 5. Second leachate inlet regulating valve; 16. Second leachate storage chamber; 17. First leachate replenishing valve; 18. Second leachate replenishing valve; 19. First leachate regulating valve; 20. Second leachate regulating valve; 21. First leachate storage chamber; 22. Second leachate storage chamber; 23. Corrosion-resistant anti-seepage membrane; 24. First leachate on-off valve; 25. Second leachate on-off valve; 26. Leachate discharge channel; 27. Leachate inlet channel; 28. Air intake channel. DETAILED DESCRIPTION

[0017] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following Figures 1-6 The technical solutions of the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0018] Example 1: Figure 1 As shown, the present invention discloses a filtration system for continuous permeation of multiple liquids, including a percolation body 100 , a percolation liquid supply system 200 , a pressure supply system 300 and a percolation liquid storage system 400 .

[0019] like Figure 2-Figure 3As shown, the infiltration body 100 includes a rigid shell 1, in which a sample chamber 2 for accommodating a soil sample is provided; a leachate inlet channel 27 and an air inlet channel 28 are provided at the top of the rigid shell 1, and a leachate discharge channel 26 is provided at the bottom of the rigid shell 1; wherein, a stainless steel filter screen 4, a rubber gasket 6, a permeable stone 3, a filter paper 5, a soil sample, a filter paper 5, a permeable stone 3 and a rubber gasket 6 are provided in the sample chamber 2 from bottom to top; the infiltration body adopts an assembled structure, which can conveniently and efficiently realize the installation or disassembly of the soil sample, and has a high filtering capacity.

[0020] like Figure 4 As shown, the leachate supply system 200 is connected to the leachate inlet channel 27 and provides at least two or more leachates. Specifically, the leachate supply system 200 includes a first leachate solution storage chamber 14 and a second leachate storage chamber 16 separated by a corrosion-resistant and impermeable membrane 23. The first leachate solution storage chamber 14 and the second leachate storage chamber 16 are respectively connected to the leachate inlet channel 27 via branch inlet pipes, and the branch inlet pipes are respectively connected to the first leachate inlet regulating valve 13 and the second leachate inlet regulating valve 15 for regulating the flow rate. The leachate inlet channel 27 is connected to the peristaltic pump 12 for controlling the inlet speed. The leachate inlet channel 27 is sealed with a sealing cap 10 at the connection with the rigid shell 1, and the sealing cap 10 is provided with a leachate inlet switch valve 11. The first leachate solution storage chamber 14 and the second leachate storage chamber 16 are respectively connected to the first leachate replenishment valve 17 and the second leachate replenishment valve 18 for replenishing the solution. It should be noted that the leachate supply system 200 can also be provided with more leachate solution storage chambers and branch liquid inlet pipes as required to meet the requirements of more types of leachate tests.

[0021] like Figure 5 As shown, a pressure supply system 300 communicates with the air inlet channel 28 to provide filtration pressure for the sample chamber 2. Specifically, the pressure supply system includes a gas source 7 connected to the air inlet channel 28, which is connected to a pressure regulating valve 8. The air inlet channel 28 is sealed to the rigid housing 1 via a sealing cap 10, which is also equipped with a gas switching valve 9. This pressure supply system provides adjustable filtration gas pressure to the filtration body, precisely regulating the filtration flow rate through air pressure control and peristaltic pump liquid inlet control.

[0022] like Figure 6As shown, the exudate storage system 400 is connected to the exudate drainage channel 26 and provides at least two types of exudate storage. Specifically, the exudate storage system 400 includes a first exudate storage chamber 21 and a second exudate storage chamber 22 separated by a corrosion-resistant and impermeable membrane 23. The first exudate storage chamber 21 and the second exudate storage chamber 22 are respectively connected to the exudate drainage channel 26 via branch drainage pipes, and the branch drainage pipes are respectively connected to the first exudate regulating valve 19 and the second exudate regulating valve 20 for regulating flow. The side walls of the first exudate storage chamber 21 and the second exudate storage chamber 22 are respectively provided with a scale for measuring volume. The side walls of the first exudate storage chamber 21 and the second exudate storage chamber 22 are respectively provided with a first exudate on-off valve 24 and a second exudate on-off valve 25. The leachate supply system and the exudate storage system both adopt an impermeable membrane-separated solution storage structure, which can realize cross-free continuous penetration testing of the two leachate solutions; it should be noted that the number of liquid storage chambers used in the leachate supply system and the exudate storage system is the same to meet the corresponding storage requirements of the leachate and exudate.

[0023] Example 2: The present invention also discloses a filtration method for a fluid loss system, comprising the following steps: (1) The two leachates are injected into the first leachate storage chamber 14 and the second leachate storage chamber 16 respectively.

[0024] (2) Close the percolation liquid on-off valve 11, the first percolation liquid on-off valve 24, and the second percolation liquid on-off valve 25, open the gas source 7 and the gas on-off valve 9, adjust the air pressure in the sample chamber 2 to a predetermined value through the pressure regulating valve 8, and check whether the air tightness is good; after checking that the air tightness of the percolation body 100 is good, close the gas on-off valve 9.

[0025] (3) Assemble the soil sample within the rigid housing 1: Place the stainless steel filter 4, rubber gasket 6, permeable stone 3, filter paper 5, soil sample, filter paper 5, permeable stone 3, and rubber gasket 6 in the sample chamber 2 in this order. Pre-wet the permeable stone 3 and filter paper 5, and apply petroleum jelly to the rubber gasket to ensure airtightness within the sample chamber 2. After the rigid housing 1 is assembled, open the gas on / off valve 9 to adjust the air pressure within the sample chamber 2 to the predetermined value.

[0026] (4) Open the peristaltic pump 12, the first diafiltration liquid inlet regulating valve 13 and the first exudate switch valve 24, and record the volume change of the first exudate storage chamber 21 at equal time intervals; when the difference in volume change for multiple consecutive times is ≤10%, open the second diafiltration liquid inlet regulating valve 15; record the volume change of the second exudate storage chamber 22 at equal time intervals, and terminate the test when the difference in volume change for multiple consecutive times is ≤10%.

[0027] (5) Disassemble the sample chamber 2, measure the height of the soil sample, and calculate the permeability coefficient according to the formula.

[0028] The calculation formula for the infiltration system of soil samples measured by filtration loss test is as follows: ; Where: V is the volume of exudate / m 3 ; K is the intrinsic permeability / m 2 ; P0 is the sum of the air pressure and water pressure on the soil sample / kPa; A is the cross-sectional area of ​​the soil sample / m 2 ;µ is the osmotic viscosity / (kN / m 3 ); L is the average height of the soil sample before and after the test / m; k c is the permeability coefficient of soil sample / (m / s); γ w is the density of water / (kN / m 3 ).

[0029] During the test, the water pressure of the seepage solution is much lower than the infiltration air pressure provided by the pressure supply system. Therefore, the water pressure during the infiltration process can be ignored. The simplified permeability coefficient calculation formula is as follows: ; Where: k FL is the permeability coefficient of the soil sample measured by the filtration test; V is the volume of seepage liquid corresponding to time t / m 3 ; A is the cross-sectional area of ​​the sample / m 2 ; i is the hydraulic gradient, and its calculation formula is It should be noted that the exudate volume V is roughly linearly related to the time t, and the permeability coefficient k measured at four adjacent time intervals differs by no more than ±25%, and the permeability coefficient is less than 1×10 -10 The test can be terminated when the soil sample pressure difference of m / s is no more than ±50% and there is no trend of increase or decrease.

[0030] During the test process, the filtration method adopted by the present invention establishes the stable condition of the seepage volume as the switching criterion for multiple filtration solutions, thereby ensuring the reliability of the test process. The filtration system and filtration method have wide application value in complex pollution scenarios and are not limited to the test process of two filtration solutions.

[0031] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A filtration system for continuous permeation of multiple liquids, characterized in that: include: A percolation body (100), the percolation body (100) comprising a rigid shell (1), a sample chamber (2) for accommodating a soil sample being provided in the rigid shell (1); a percolation liquid inlet channel (27) and an air inlet channel (28) being provided at the top of the rigid shell (1), and a percolation liquid discharge channel (26) being provided at the bottom of the rigid shell (1); wherein a stainless steel filter screen (4), a rubber gasket (6), a permeable stone (3), a percolation paper (5), a soil sample, the percolation paper (5), the permeable stone (3) and the rubber gasket (6) are provided in the sample chamber (2) from bottom to top; a leachate supply system (200), the leachate supply system (200) being in communication with the leachate inlet channel (27) and providing at least two or more leachates; A pressure supply system (300), the pressure supply system (300) being in communication with the air inlet channel (28) and providing filtration pressure for the sample chamber (2); An exudate storage system (400) is connected to the exudate drainage channel (26) and provides at least two or more types of exudate storage.

2. The filtration system for continuous permeation of multiple liquids according to claim 1, characterized in that: The leachate supply system (200) comprises a first leachate storage chamber (14) and a second leachate storage chamber (16) separated by a corrosion-resistant and impermeable membrane (23); the first leachate storage chamber (14) and the second leachate storage chamber (16) are connected to a leachate inlet channel (27) via branch inlet pipes, respectively; the branch inlet pipes are connected to a first leachate inlet regulating valve (13) and a second leachate inlet regulating valve (15) for regulating flow, respectively; and the leachate inlet channel (27) is connected to a peristaltic pump (12) for controlling the inlet speed.

3. The multi-liquid continuous permeation filtration system according to claim 2, characterized in that: The connection between the leachate inlet channel (27) and the rigid shell (1) is sealed via a sealing cap (10), and a leachate inlet switch valve (11) is provided at the sealing cap (10).

4. The multi-liquid continuous permeation filtration system according to claim 2, characterized in that: The first diafiltration solution storage chamber (14) and the second diafiltration solution storage chamber (16) are respectively connected to a first diafiltration solution replenishment valve (17) and a second diafiltration solution replenishment valve (18) for replenishing the solution.

5. The multi-liquid continuous permeation filtration system according to claim 1, characterized in that: The pressure supply system (300) includes an air source (7) in communication with an air inlet channel (28), and the air inlet channel (28) is connected to a pressure regulating valve (8); the air inlet channel (28) is sealed at a connection with the rigid housing (1) via a sealing cap (10), and a gas switch valve (9) is provided at the sealing cap (10).

6. The multi-liquid continuous permeation filtration system according to claim 1, characterized in that: The exudate storage system (400) comprises a first exudate storage chamber (21) and a second exudate storage chamber (22) separated by a corrosion-resistant anti-seepage membrane (23); the first exudate storage chamber (21) and the second exudate storage chamber (22) are respectively connected to an exudate drainage channel (26) via branch drainage pipes, and the branch drainage pipes are respectively connected to a first exudate regulating valve (19) and a second exudate regulating valve (20) for regulating flow.

7. The multi-liquid continuous permeation filtration system according to claim 6, characterized in that: The side walls of the first exudate storage chamber (21) and the second exudate storage chamber (22) are respectively provided with scales for measuring volume.

8. The multi-liquid continuous permeation filtration system according to claim 6, characterized in that: A first exudate switching valve (24) and a second exudate switching valve (25) are respectively provided on the side walls of the first exudate storage chamber (21) and the second exudate storage chamber (22).

9. A filtration method for a fluid loss system according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: injecting two leachates into the first leachate storage chamber (14) and the second leachate storage chamber (16) respectively; Step 2: Close the percolation inlet switch valve (11), the first percolation switch valve (24), and the second percolation switch valve (25), open the gas source (7) and the gas switch valve (9), adjust the gas pressure in the sample chamber (2) to a predetermined value through the pressure regulating valve (8), and test the air tightness; Step 3, assembling the soil sample in the rigid housing (1): placing the stainless steel filter (4), rubber gasket (6), permeable stone (3), filter paper (5), soil sample, filter paper (5), permeable stone (3) and rubber gasket (6) in the sample chamber (2) in sequence; Step 4: Open the peristaltic pump (12), the first diafiltration inlet regulating valve (13) and the first exudate switch valve (24), and record the volume change of the first exudate storage chamber (21) at equal time intervals; when the difference in volume change for multiple consecutive times is ≤10%, open the second diafiltration inlet regulating valve (15), and record the volume change of the second exudate storage chamber (22) at equal time intervals, and terminate the test when the difference in volume change for multiple consecutive times is ≤10%; Step 5: Disassemble the sample chamber (2), measure the height of the soil sample, and calculate the permeability coefficient according to the formula.

10. The filtration method for a fluid loss system according to claim 9, wherein: The formula for calculating the permeability coefficient in step 6 is as follows: ； Where: V is the volume of exudate / m 3 ; K is the intrinsic permeability / m 2 ; P0 is the sum of the air pressure and water pressure on the soil sample / kPa; A is the cross-sectional area of ​​the soil sample / m 2 ;µ is the osmotic viscosity / (kN / m 3 ); L is the average height of the soil sample before and after the test / m; k c is the permeability coefficient of soil sample / (m / s); γ w is the density of water / (kN / m 3 ).

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