Device and method for measuring permeation velocity of macroporous material by adopting total water head

Abstract

The invention belongs to the technical field of macropore material permeation velocity testing, and provides a device and method for measuring the permeation velocity of a macropore material by adopting a total water head, the device comprises a first plastic connecting pipe, a second plastic connecting pipe and a third plastic connecting pipe which are sequentially communicated from top to bottom, and the macropore material is arranged in the second plastic connecting pipe; an upper main water head pressure measuring pipe and an upper static water head pressure measuring pipe are arranged at the bottom of the side wall of the first plastic connecting pipe and are respectively used for measuring a main water head and a static water head at the upper part of the macroporous material; the top of the side wall of the third plastic connecting pipe is provided with a lower main water head pressure measuring pipe and a lower static water head pressure measuring pipe, the lower main water head pressure measuring pipe and the lower static water head pressure measuring pipe are respectively used for measuring a main water head and a static water head at the lower part of the macroporous material, and the bottom of the side wall of the third plastic connecting pipe is communicated with a third water faucet. The permeation velocity of the macroporous material can be measured by adopting two different methods, namely a total head method and a static head method.

Description

Technical Field

[0001] The invention belongs to the technical field of macroporous material penetration rate testing, and in particular relates to a device and a method for measuring the penetration rate of macroporous materials by using total water head. Background Art

[0002] With the continuous development of macroporous materials, the porosity and permeability of porous materials are increasing. Therefore, the classical method of measuring the permeability using the Darcy experimental device (when the permeability is small, only the static head is considered and the dynamic head is ignored) has limitations. Therefore, a device and method that can consider the kinetic energy term, that is, the total head method (considering static head and dynamic head) is needed to measure the permeability of macroporous materials. Summary of the invention

[0003] The purpose of the present invention is to provide a device and method for measuring the permeability of macroporous materials using total water head, so as to solve the above-mentioned problem and achieve the purpose of measuring the permeability of macroporous materials using two different methods, namely the total water head method and the static water head method.

[0004] To achieve the above object, the present invention provides the following solution: a device for measuring the permeability of macroporous materials using total water head, comprising:

[0005] A first plastic pipe, a second plastic pipe and a third plastic pipe are connected in sequence from top to bottom, a macroporous material is arranged in the second plastic pipe, and a first faucet is arranged above the first plastic pipe;

[0006] An upper total water head pressure measuring tube and an upper hydrostatic head pressure measuring tube are provided at the bottom of the side wall of the first plastic connecting pipe, and the upper total water head pressure measuring tube and the upper hydrostatic head pressure measuring tube are used to measure the total water head and the hydrostatic head of the upper part of the macroporous material respectively;

[0007] A lower total water head pressure measuring tube and a lower hydrostatic head pressure measuring tube are arranged on the top of the side wall of the third plastic connecting pipe. The lower total water head pressure measuring tube and the lower hydrostatic head pressure measuring tube are used to measure the total water head and the hydrostatic head of the lower part of the macroporous material respectively. The bottom of the side wall of the third plastic connecting pipe is connected to a third faucet.

[0008] Preferably, the bottom of the first plastic connecting pipe and the top of the second plastic connecting pipe, and the bottom of the second plastic connecting pipe and the top of the third plastic connecting pipe are connected via threads respectively.

[0009] Preferably, the bottom of the third plastic connecting pipe is sealed, and a supporting base is provided at the bottom of the third plastic connecting pipe.

[0010] Preferably, it further comprises a large volume measuring cylinder, wherein the large volume measuring cylinder is used to collect water flowing out of the third faucet.

[0011] Preferably, the connection point between the upper total water head pressure measuring tube and the first plastic connecting tube is also connected with a first elbow, and the first elbow is vertically arranged upward away from the opening at one end of the upper total water head pressure measuring tube.

[0012] Preferably, the connection point between the lower total water head pressure measuring tube and the third plastic connecting tube is also connected with a second elbow, and the second elbow is vertically arranged upward away from the opening at one end of the lower total water head pressure measuring tube.

[0013] Preferably, the top of the side wall of the first plastic connecting pipe is connected to a second faucet.

[0014] Preferably, a sealing material is provided between the side wall of the macroporous material and the inner wall of the second plastic connecting pipe.

[0015] A method for measuring the permeability of macroporous materials using total water head, the operating steps comprising:

[0016] Put the macroporous material into the second plastic pipe, and connect the first plastic pipe, the second plastic pipe and the third plastic pipe from top to bottom;

[0017] After the water level in the first plastic pipe reaches a predetermined height, the third faucet is turned on to conduct a permeability test of the macroporous material;

[0018] When the permeability test is stable, record the head heights of the upper total head piezometer, upper hydrostatic head piezometer, lower total head piezometer and lower hydrostatic head piezometer, and record them as H, H2, H3, and H4 respectively. Calculate the permeability rate of the macroporous material according to the calculation formula of the total head method or the hydrostatic head method.

[0019] Preferably, the volume flow rate Q of water passing through the cross section of the macroporous material is proportional to the cross-sectional area A and the total head difference H1-H3, and inversely proportional to the length L of the macroporous material, that is,

[0020]

[0021] Where K' is the hydraulic conductivity, which has the dimension of velocity, is the hydraulic gradient;

[0022] According to the principles of hydraulics, the energy e of a unit mass of fluid on a unit cross section consists of three parts: pressure potential energy, position potential energy, and kinetic energy, namely:

[0023]

[0024] Where z is the height from the reference surface, p is the pressure (intensity) at the corresponding height, and equation (2) is expressed in terms of total water head as

[0025]

[0026] The total head difference H1-H3 between the upper and lower ends of the macroporous material has the following relationship

[0027] H1-H3=ΔH2 (4)

[0028] Substituting equation (4) into equation (1), we can get the penetration rate:

[0029]

[0030] From K′=Kρg / μ, where K is the permeability of the macroporous material, the permeability rate of the macroporous material is:

[0031]

[0032] If the hydrostatic head method is used, the kinetic energy term is not considered, and the hydrostatic head difference H2-H4 is the penetration rate of the macroporous material:

[0033]

[0034] Compared with the prior art, the present invention has the following advantages and technical effects: the present invention can be applied to the determination of the permeation rate of various macroporous materials, and can realize the measurement of the permeation rate of macroporous materials by using two different methods, namely, the total hydraulic head method, i.e., considering the static hydraulic head and the dynamic hydraulic head, and the static hydraulic head method, thereby realizing the accurate measurement of the permeation rate of macroporous materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 is a schematic diagram of a testing device of the present invention;

[0037] Among them, 1. the second faucet; 2. the upper total water head pressure measuring tube; 3. the lower total water head pressure measuring tube; 4. the sealing material; 5. the large-pore material; 6. the third faucet; 7. the large-volume measuring cylinder; 8. the first faucet; 9. the first plastic connecting pipe; 10. the upper hydrostatic head pressure measuring tube; 11. the lower hydrostatic head pressure measuring tube; 12. the second plastic connecting pipe; 13. the third plastic connecting pipe; 14. the supporting base; 15. the first bend pipe; 16. the second bend pipe. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figure 1 The present invention provides a device for measuring the permeability of macroporous materials using total water head, comprising:

[0041] A first plastic pipe 9, a second plastic pipe 12 and a third plastic pipe 13 are connected in sequence from top to bottom, a macroporous material 5 is arranged in the second plastic pipe 12, and a first faucet 8 is arranged above the first plastic pipe 9;

[0042] The bottom of the side wall of the first plastic connecting pipe 9 is provided with an upper total water head pressure measuring tube 2 and an upper hydrostatic head pressure measuring tube 10, which are used to measure the total water head and the hydrostatic head of the upper part of the macroporous material 5 respectively;

[0043] A lower total water head pressure measuring tube 3 and a lower hydrostatic head pressure measuring tube 11 are provided at the top of the side wall of the third plastic connecting pipe 13. The lower total water head pressure measuring tube 3 and the lower hydrostatic head pressure measuring tube 11 are respectively used to measure the total water head and the hydrostatic head at the lower part of the macroporous material 5. The bottom of the side wall of the third plastic connecting pipe 13 is connected to a third faucet 6.

[0044] The main function of the first plastic pipe 9 is to store water for testing, and it acts as a water tank; the main function of the second plastic pipe 12 is to place the macroporous material 5, and the main function of the third faucet 6 is to control the start and stop of the test; the upper total water head pressure measuring tube 2 is provided with a scale, and its main function is to measure the total water head of the upper part of the macroporous material 5; the upper hydrostatic head pressure measuring tube 10 is provided with a scale, and its main function is to measure the hydrostatic head of the upper part of the macroporous material 5; the lower total water head pressure measuring tube 3 is provided with a scale, and its main function is to measure the total water head of the lower part of the macroporous material 5; the lower hydrostatic head pressure measuring tube 11 is provided with a scale, and its main function is to measure the hydrostatic head of the lower part of the macroporous material 5. On the whole, the present invention can be applied to the determination of the penetration rate of various macroporous materials (asphalt concrete, foamed concrete), and can realize the measurement of the penetration rate of macroporous materials by two different methods, the total water head method (considering the hydrostatic head and the dynamic head) and the hydrostatic head method, and can realize the accurate measurement of the penetration rate of macroporous materials.

[0045] According to a further optimized solution, the bottom of the first plastic connecting pipe 9 and the top of the second plastic connecting pipe 12 , and the bottom of the second plastic connecting pipe 12 and the top of the third plastic connecting pipe 13 are connected respectively by threads.

[0046] The lower end of the first plastic pipe 9, the upper and lower ends of the second plastic pipe 12 and the top of the third plastic pipe 13 are respectively provided with threads, and the first plastic pipe 9, the second plastic pipe 12 and the third plastic pipe 13 can be connected to each other through the threads.

[0047] According to a further optimized solution, the bottom of the third plastic connecting pipe 13 is sealed, and a supporting base 14 is provided at the bottom of the third plastic connecting pipe 13 .

[0048] A further optimized solution further includes a large-volume measuring cylinder 7 , which is used to collect water flowing out of the third faucet 6 .

[0049] like Figure 1 As shown, the main function of the support base 14 is to support the plastic pipe on the upper part. At the same time, the water discharged by the third faucet 6 can be collected by the large volume measuring cylinder 7.

[0050] According to a further optimization scheme, the connection point between the upper total water head pressure measuring tube 2 and the first plastic connecting tube 9 is also connected with a first elbow 15 , and the first elbow 15 is vertically arranged upward away from the opening at one end of the upper total water head pressure measuring tube 2 .

[0051] According to a further optimization scheme, the connection point between the lower total water head pressure measuring tube 3 and the third plastic connecting tube 13 is also connected with a second elbow 16 , and the second elbow 16 is vertically arranged away from the opening at one end of the lower total water head pressure measuring tube 3 .

[0052] like Figure 1 As shown, the open end of the first elbow 15 is arranged opposite to the direction of the water flow. When the water in the first plastic connecting pipe 9 flows downward into the macroporous material 5, the water flow can directly enter the upper total water head pressure measuring tube 2 through the first elbow 15, and the static water head and the dynamic water head are considered at the same time, so that the upper total water head pressure measuring tube 2 can measure the total water head of the upper part of the macroporous material 5. Similarly, after the water flows through the macroporous material 5, the water flow can directly enter the lower total water head pressure measuring tube 3 through the second elbow 16, so that the lower total water head pressure measuring tube 3 can measure the total water head of the lower part of the macroporous material 5.

[0053] According to a further optimization scheme, the top of the side wall of the first plastic connecting pipe 9 is connected to a second faucet 1 , and a first faucet 8 is arranged above the first plastic connecting pipe 9 . The first faucet 8 is used to provide water to the first plastic connecting pipe 9 .

[0054] like Figure 1As shown, an opening is provided at the top of the first plastic pipe 9. The main function of the first faucet 8 is to connect tap water to the first plastic pipe 9 through the opening at the top of the first plastic pipe 9 to provide a water source for the test. After the second faucet 1 is turned on, when the water level in the first plastic pipe 9 is higher than the second faucet 1, the water will automatically flow out, thereby ensuring that the water level in the first plastic pipe 9 is maintained at a constant value.

[0055] According to a further optimized solution, a sealing material 4 is provided between the side wall of the macroporous material 5 and the inner wall of the second plastic connecting pipe 12 .

[0056] like Figure 1 As shown, the sealing material can be a rubber sleeve or a plastic wrap. The sealing material 4 is used to seal the gap between the macroporous material 5 and the inner wall of the second plastic connecting pipe 12 to ensure that all water in the second plastic connecting pipe 12 can flow down through the macroporous material 5.

[0057] A method for measuring the permeability of macroporous materials using total water head, the operating steps comprising:

[0058] Put the macroporous material 5 into the second plastic pipe 12, and connect the first plastic pipe 9, the second plastic pipe 12 and the third plastic pipe 13 from top to bottom;

[0059] The axial side wall of the macroporous material 5 is wrapped with the sealing material 4, and the macroporous material 5 is fixed to the second plastic pipe 12. The three groups of plastic pipes are connected in sequence and a sealing test is performed.

[0060] After the water level in the first plastic pipe 9 reaches a predetermined height, the third faucet 6 is turned on to perform a permeability test on the macroporous material 5;

[0061] Open the first faucet 8 to fill the first plastic pipe 9 with water, and at the same time open the second faucet 1. When the water in the first plastic pipe 9 reaches the height of the second faucet 1, open the third faucet 6 to start the test.

[0062] When the permeability test is stable, record the head heights of the upper total head pressure gauge 2, the upper hydrostatic head pressure gauge 10, the lower total head pressure gauge 3 and the lower hydrostatic head pressure gauge 11, and record them as H1, H2, H3, and H4 respectively. The permeability rate of the macroporous material 5 can be obtained according to the calculation formula of the total head method or the hydrostatic head method.

[0063] Further optimizing the scheme, the volume flow rate Q of water passing through the cross section of the macroporous material 5 is proportional to the cross-sectional area A and the total head difference H1-H3, and inversely proportional to the length L of the macroporous material 5, that is,

[0064]

[0065] Where K' is the hydraulic conductivity, which has the dimension of velocity, is the hydraulic gradient;

[0066] According to the principles of hydraulics, the energy e of a unit mass of fluid on a unit cross section consists of three parts: pressure potential energy, position potential energy, and kinetic energy, namely:

[0067]

[0068] Where z is the height from the reference surface, p is the pressure (intensity) at the corresponding height, and equation (2) is expressed in terms of total water head as

[0069]

[0070] The total head difference H1-H3 between the upper and lower ends of the macroporous material has the following relationship

[0071] H1-H3=ΔH2 (4)

[0072] Substituting equation (4) into equation (1), we can get the penetration rate:

[0073]

[0074] From K′=Kρg / μ, where K is the permeability of the macroporous material, the permeability rate of the macroporous material is:

[0075]

[0076] If the hydrostatic head method is used, the kinetic energy term is not considered, and the hydrostatic head difference H2-H4 is the penetration rate of the macroporous material:

[0077]

[0078] When the permeability test is stable, the recorded values ​​of H1, H2, H3, and H4 can be used to obtain the permeability rate of the macroporous material 5 by the total water head method by substituting the relevant values ​​into formula (6); the permeability rate of the macroporous material can be obtained by the static water head method by substituting the relevant values ​​into formula (7).

[0079] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0080] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for measuring the permeability of macroporous materials using total water head, characterized in that: include: A first plastic pipe (9), a second plastic pipe (12) and a third plastic pipe (13) are connected in sequence from top to bottom, the second plastic pipe (12) is provided with a macroporous material (5), and a first faucet (8) is provided above the first plastic pipe (9); An upper total water head pressure measuring tube (2) and an upper hydrostatic head pressure measuring tube (10) are provided at the bottom of the side wall of the first plastic connecting pipe (9), and the upper total water head pressure measuring tube (2) and the upper hydrostatic head pressure measuring tube (10) are used to measure the total water head and the hydrostatic head of the upper part of the macroporous material (5), respectively; A lower total water head pressure measuring tube (3) and a lower hydrostatic head pressure measuring tube (11) are arranged at the top of the side wall of the third plastic connecting pipe (13); the lower total water head pressure measuring tube (3) and the lower hydrostatic head pressure measuring tube (11) are used to measure the total water head and the hydrostatic head at the lower part of the macroporous material (5), respectively; and a third faucet (6) is connected to the bottom of the side wall of the third plastic connecting pipe (13).

2. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: The bottom of the first plastic connecting pipe (9) and the top of the second plastic connecting pipe (12), and the bottom of the second plastic connecting pipe (12) and the top of the third plastic connecting pipe (13) are connected respectively by threads.

3. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: The bottom of the third plastic connecting pipe (13) is sealed, and a supporting base (14) is provided at the bottom of the third plastic connecting pipe (13).

4. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: It also comprises a large volume measuring cylinder (7), and the large volume measuring cylinder (7) is used to collect water flowing out of the third faucet (6).

5. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: The connection point between the upper total water head pressure measuring tube (2) and the first plastic connecting tube (9) is also connected with a first curved tube (15), and the first curved tube (15) is vertically arranged upward away from the opening at one end of the upper total water head pressure measuring tube (2).

6. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: The connection point between the lower total water head pressure measuring tube (3) and the third plastic connecting tube (13) is also connected with a second curved tube (16), and the second curved tube (16) is vertically arranged upward away from the opening at one end of the lower total water head pressure measuring tube (3).

7. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: The top of the side wall of the first plastic connecting pipe (9) is connected to a second faucet (1).

8. The device for measuring the permeability of macroporous materials using total water head according to claim 1, characterized in that: A sealing material (4) is arranged between the side wall of the macroporous material (5) and the inner wall of the second plastic connecting pipe (12).

9. A method for measuring the permeability of macroporous materials using total water head, based on the device for measuring the permeability of macroporous materials using total water head as claimed in claim 1, characterized in that: The steps include: Put the macroporous material (5) into the second plastic pipe (12), and connect the first plastic pipe (9), the second plastic pipe (12) and the third plastic pipe (13) from top to bottom; After the water level in the first plastic pipe (9) reaches a predetermined height, the third faucet (6) is turned on to conduct a permeability test of the macroporous material (5); When the permeability test is stable, the water head heights of the upper total water head pressure gauge (2), the upper hydrostatic head pressure gauge (10), the lower total water head pressure gauge (3) and the lower hydrostatic head pressure gauge (11) are recorded as H1, H2, H3 and H4 respectively, and the permeability rate of the macroporous material (5) is obtained according to the calculation formula of the total water head method or the hydrostatic head method.

10. The method for measuring the permeability of macroporous materials using total water head according to claim 9, characterized in that: The volume flow rate Q of water passing through the cross section of the macroporous material (5) is proportional to the cross-sectional area A and the total head difference H1-H3, and inversely proportional to the length L of the macroporous material (5), that is, Where K' is the hydraulic conductivity, which has the dimension of velocity, is the hydraulic gradient; According to the principles of hydraulics, the energy e of a unit mass of fluid on a unit cross section consists of three parts: pressure potential energy, position potential energy, and kinetic energy, namely: Where z is the height from the reference surface, p is the pressure at the corresponding height, and equation (2) is expressed in terms of total water head as The total head difference H1-H3 between the upper and lower ends of the macroporous material has the following relationship H1-H3=ΔH2 (4) Substituting equation (4) into equation (1), we can get the penetration rate: From K′=Kρg / v, where K is the permeability of the macroporous material, the permeability rate of the macroporous material is: If the hydrostatic head method is used, the kinetic energy term is not considered, and the hydrostatic head difference H2-H4 is the penetration rate of the macroporous material:

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