A pipe network water purification pipeline and a method for treating pipe water

Abstract

The present invention provides a pipe network water purification pipeline and a method for treating pipe water. The pipe network water purification pipeline comprises a pipe network water purification pipeline body, the outer periphery of the pipe body is provided with a shell with an air cavity formed inside; the air cavity is connected with the inner cavity of the pipe, and the pressure of the air cavity is greater than that of the inner cavity of the pipe; a film is provided at the connection between the air cavity and the inner cavity of the pipe for gas to enter the inner cavity of the pipe from the air cavity; in the inner cavity of the pipe, a gas-liquid mixing zone with micro-nano bubbles is formed in the area below the film; an ultrasonic defoamer is installed downstream of the gas-liquid mixing zone. The device has a simple structure. Compared with traditional chlorine disinfection, it solves the dependence of traditional disinfection technology on drugs, avoids the input of harmful substances in water, and eliminates the influence of disinfection by-products through source control.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe network water quality safety assurance, and in particular to a pipe network water quality purification pipe and a method for treating pipe water. Background Art

[0002] Micro-nano bubbles are a type of tiny bubbles with diameters in the micrometer and nanometer levels. Different scholars define their diameter ranges slightly differently, and most are less than 100μm. Compared with traditional bubbles, micro-nano bubbles have the characteristics of small volume, large specific surface area, long existence time, good mass transfer efficiency, high surface potential, strong biological activity, and the ability to generate free radicals. Among them, the hydroxyl radicals generated in situ in micro-nano bubble water have strong oxidizing properties and are not selective in the removal of pollutants. They can effectively remove various organic pollutants, difficult-to-degrade pollutants and pathogenic microorganisms in water bodies; for example, the invention patent with patent number CN103723803A discloses a method for disinfecting, detoxifying and purifying water using hydroxyl radicals, and uses hydroxyl radicals to solve the technical problems of existing water treatment methods and devices that cannot remove residual carcinogens in water and cannot remove excessive heavy metals and organic compounds; the invention patent with patent number CN108585285A discloses a treatment system for mineralizing antibiotics in drinking water with hydroxyl radicals, and uses hydroxyl radicals to mineralize antibiotics in drinking water. However, there are no reports on the use of hydroxyl radicals to maintain water quality stability in water supply networks.

[0003] Based on the above, it is necessary to propose a device with strong operability to treat abnormal water quality of secondary water supply. Summary of the invention

[0004] The present invention provides a pipe network water purification pipeline and a method for treating pipe water. The incoming water is treated with OH formed by breaking micro-nano bubbles formed in the pipe, so that the incoming water quality meets the standard. The device has a simple structure. Compared with the traditional chlorine disinfection treatment, it solves the dependence of the traditional disinfection technology on the agent, avoids the input of harmful substances in the water, and eliminates the influence of disinfection by-products through source control.

[0005] The specific technical solutions are as follows:

[0006] A pipe network water purification pipe comprises a pipe body, wherein a shell with an air cavity formed inside is provided on the outer periphery of the pipe body; the air cavity is connected with an inner cavity of the pipe, and the pressure of the air cavity is greater than that of the inner cavity of the pipe; a film is provided at the connection between the air cavity and the inner cavity of the pipe for allowing gas to enter the inner cavity of the pipe from the air cavity; in the inner cavity of the pipe, a gas-liquid mixing zone with micro-nano bubbles is formed in the area below the film; an ultrasonic defoamer is installed downstream of the gas-liquid mixing zone.

[0007] Furthermore, the shell is annular and is sleeved on the outer wall of the pipeline body; an air inlet and an exhaust port are opened on the shell, an air pump and a barometer are arranged inside the shell, the inlet of the air pump is connected to the air inlet, and the outlet is arranged inside the shell.

[0008] The annular shell can wrap the pipe to the greatest extent, create an air cavity, and is easier to seal than other shapes.

[0009] Furthermore, the film is a SPG film.

[0010] The full name of SPG membrane is Shirasu Porous Glass, which is a porous glass membrane. The SPG membrane has uniform micropores. In the present invention, the air in the air cavity will pass through the SPG membrane into the inner cavity of the pipeline under the action of pressure difference to form bubbles.

[0011] Furthermore, a negative pressure valve plate with a plate surface perpendicular to the water flow is provided in the inner cavity of the pipeline, and a channel for water flow is formed between the negative pressure valve plate and the inner wall of the pipeline; the ratio of the diameter of the negative pressure valve plate to the diameter of the pipeline is 1:2 to 1:3; along the direction of water flow, the negative pressure valve plate is arranged upstream of the film and adjacent to the film.

[0012] Preferably, the ratio of the diameter of the negative pressure valve plate to the diameter of the pipeline is 1:2.

[0013] The setting of the negative pressure valve plate will cause turbulence when the water flows through, thereby accelerating the water flow speed in this area, generating negative pressure and forming a gas-liquid mixing area.

[0014] Furthermore, a first bubble concentration detection component and a second bubble concentration detection component are also provided in the inner cavity of the pipeline; the first bubble concentration detection component is provided between the gas-liquid mixing zone and the ultrasonic defoamer; and the second bubble concentration detection component is provided downstream of the ultrasonic defoamer.

[0015] The present invention also provides a combined pipe network pipeline, comprising a first pipe and a second pipe connected in parallel, the second pipe being such as the pipe network water purification pipe described above; the water inlet ends of the first pipe and the second pipe are both provided with control valves, and a water quality detection device is provided upstream of the control valves.

[0016] The present invention also provides a method for treating pipe water using the combined pipe network pipe described above, comprising:

[0017] (1) The water quality of the incoming water is determined by a water quality detection device, and the incoming water quality is divided into abnormal water quality and normal water quality;

[0018] (2) When the incoming water quality is abnormal, the incoming water enters the second pipe, and the air pump controls the pressure in the air cavity, so that the air in the air cavity passes through the SPG membrane and enters the inner cavity of the pipe to generate bubbles, forming a gas-liquid mixing zone. The bubbles generate micro-nano bubbles under the action of the shear force of the water flow;

[0019] (3) starting an ultrasonic defoamer to break up the micro-nano bubbles in step (2) and using the generated ·OH to improve the quality of the incoming water;

[0020] (4) The water quality of the upstream water is determined by a water quality detection device, and steps (1) to (4) are repeated.

[0021] In the present invention, the water from the pipeline first passes through the water quality detector arranged in front of the device, and the water quality is detected by the water quality detector. When the water quality is normal, the valve in front of the first pipeline is opened, the valve in front of the second pipeline is closed, and the incoming water passes through the first pipeline for subsequent water supply. When the water quality is abnormal, the valve in front of the first pipeline is closed, the valve in front of the second pipeline is opened, and the incoming water passes through the second pipeline. At the same time, the air pump located in the air cavity on the second pipeline and the ultrasonic defoamer located in the inner cavity of the second pipeline are started, and a gas supply is provided at the connection between the air cavity and the inner cavity of the pipeline to enter the inner cavity of the pipeline from the air cavity When the incoming water passes through the negative pressure valve plate in the second pipe, the flow rate is accelerated to form negative pressure. At this time, a pressure difference is formed with the air in the air cavity. The air in the air cavity enters the inner cavity of the second pipe through the membrane to form bubbles. Under the action of the shear force of the incoming water, the bubbles are sheared into smaller micro-nano bubbles. The micro-nano bubbles enter the started sonic defoamer with the water flow and are broken under the action of ultrasonic waves to produce a large amount of ·OH, which improves the incoming water. When the water quality detector located in front of the device detects that the water quality is normal, the normal water quality treatment step is immediately performed.

[0022] Furthermore, in step (1), when the water quality is normal, the incoming water is supplied through the first pipe; when the water quality is abnormal, the control valve at the water inlet end of the first pipe is closed, and the control valve at the water inlet end of the second pipe is opened. At the same time, the air pump in the air cavity of the second pipe and the ultrasonic defoamer in the inner cavity of the pipe are both turned on; the incoming water enters the second pipe.

[0023] Furthermore, in step (2), the relationship between the average membrane pore size D1 of the SPG membrane and the average diameter r of the micro-nano bubbles is:

[0024] r=8.6D1 (1)

[0025] In formula (1), r is the average diameter of micro-nano bubbles, D1 is the average membrane pore size of SPG membrane;

[0026] The relationship between the area S of the SPG membrane and the diameter D of the second pipe is:

[0027] S=πDL (2)

[0028] In formula (2), S is the area of ​​the SPG membrane; D is the diameter of the second pipe; L is the width of the SPG membrane; and π is the circumference of a circle.

[0029] Furthermore, in step (2), the conditions for generating stable micro-nano bubbles are: 1≤n≤2; n=P0 / P2; P0 is the pressure in the air cavity, and P2 is the pressure in the gas-liquid mixing zone; the calculation formula of n is:

[0030]

[0031] In formula (3), P0 is the pressure in the air cavity; P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; ρ L is the density of water; the calculation formula of P2 is:

[0032]

[0033] In formula (4), P1 is the pipeline pressure when the incoming water enters the second pipeline; V1 is the water velocity when the incoming water enters the second pipeline; V2 is the water velocity after the incoming water passes through the gas-liquid mixing zone in the second pipeline cavity; ρ L is the density of water;

[0034] The calculation formula of V2 is:

[0035] V2=V1 / {1-(d / D) 2} (5)

[0036] In formula (5), d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; and V1 is the water velocity when the incoming water enters the second pipe.

[0037] When n<1, no bubbles will be generated in the pipeline because the bubbles cannot enter the gas-liquid mixing zone; when 1≤n≤2, monodisperse nanobubbles can be stably generated in the gas-liquid mixing zone; when n>2, due to the large transmembrane pressure, the particle size dispersion coefficient increases, the bubble particle size distribution range increases, and stable monodisperse nanobubbles cannot be generated in the water.

[0038] The shear force of water in the gas-liquid mixing zone is related to the difference between P0 and P2. The larger the difference between the two, the greater the shear force and the better the effect of cutting bubbles entering the pipeline.

[0039] The performance of the micro-nano bubble generator in the device is affected by the ratio of the diameter d of the negative pressure valve plate in the tube to the diameter D of the tube.

[0040] When the incoming water quality is abnormal, the bubble concentrations detected by the first bubble concentration detection component and the second bubble concentration detection component reflect the operation status of the micro-nano bubble generating component and the ultrasonic defoamer.

[0041] T 1前 is the bubble concentration 1, obtained by the first bubble concentration detection component; T 1后 is the bubble concentration 2, obtained by the second bubble concentration detection component;

[0042] When T 1前 >10 6 / ml, it means that the micro-nano bubble generating components are operating normally; when T 1后 <10 2 / ml, it indicates that the ultrasonic defoamer is operating normally;

[0043] When T 1前 <<80%·10 6 , indicating that the micro-nano bubble generating component fails; when T 1后 >>10 2 pcs / ml, indicating that the ultrasonic defoamer is malfunctioning.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) The present invention provides a pipe network water purification pipeline and a method for treating pipe water, wherein the incoming water is treated with OH formed by breaking the micro-nano bubbles formed in the pipe, so that the incoming water quality meets the standard; the device has a simple structure, and compared with the traditional chlorine disinfection treatment, it solves the dependence of the traditional disinfection technology on the agent, avoids the input of harmful substances in the water, and eliminates the influence of disinfection by-products through source control.

[0046] (2) Compared with the traditional chlorine disinfection treatment, the present invention uses natural air to continuously generate micro-nano bubbles in the water through physical shearing, and uses the hydroxyl free radicals generated in situ by the collapse of the micro-nano bubbles to degrade the pollutants in the water.

[0047] (3) The present invention utilizes the pressure difference between the gas cavity and the gas-liquid mixture to make the gas pass through the SPG membrane to generate micro-nano bubbles, which then burst under the action of the ultrasonic defoamer to produce a large amount of ·OH. This constructs a method for efficiently generating hydroxyl radicals based on micro-nano bubbles with controllable particle size, solving the bottleneck problem that micro-nano bubble technology cannot continuously treat pollutants in water in situ.

[0048] (4) The present invention utilizes the pressure difference between the gas cavity and the gas-liquid mixture to perform secondary mechanical shearing on the gas passing through the SPG membrane to generate micro-nano bubbles. The entire process is carried out spontaneously through the negative pressure effect formed by the reduction of the flow cross-section, which greatly reduces the energy consumption of the generation of micro-nano bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of the main structure of the pipe network water purification pipeline described in Example 1.

[0050] Figure 2 for Figure 1 An enlarged view of point A is shown.

[0051] Figure 3 for Figure 1 An enlarged front view of point B is shown.

[0052] Figure 4 for Figure 1 An enlarged top view of point B is shown.

[0053] Figure 5 for Figure 1 This is an enlarged front view of point B after the SPG film is removed.

[0054] Figure 6 This is a schematic diagram of the main structure of the combined pipe network described in Example 2.

[0055] Figure 7 for Figure 6 The cross-sectional view at CC of the combined pipe network pipeline is shown when the first control valve is open and the second control valve is closed.

[0056] Figure 8 for Figure 6 The cross-sectional view at CC of the combined pipe network pipeline is shown when the first control valve is closed and the second control valve is opened.

[0057] Fig. 9 for Figure 7 The schematic diagram of the structure is shown in D where the outer peripheral shell of the second pipeline is opened.

[0058] Fig.10 for Fig. 9 An enlarged view of point F is shown.

[0059] Fig.11 It is a linear relationship diagram between the pore size D1 of the SPG membrane and the average bubble diameter r in the application example.

[0060] In the figure, 1-water quality detector, 2-first control valve, 3-barometer, 4-air pump, 5-housing, 6-air cavity, 7-air cavity exhaust port, 8-SPG membrane, 9-negative pressure valve plate, 10-gas-liquid mixing area, 11-first bubble concentration detection component, 12-ultrasonic defoamer, 13-second bubble concentration detection component, 14-second pipeline, 15-first pipeline, 16-second control valve, 17-air cavity air inlet, 18-pipeline body, 19-pipeline inner cavity (or second pipeline inner cavity), 20-first pipeline inner cavity, 401-air pump air inlet, 402-air pump switch, 403-air pump air outlet, 404-air pump cover, 405-inlet pipeline, 406-inlet interface, 501-hinge, 502-sealing gasket, 801-bolt, 802-first movable splint, 803 second fixed splint. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with specific embodiments. The following are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto.

[0062] Example 1

[0063] This embodiment provides a water purification pipeline for a pipe network, Figure 1 It is a schematic diagram of the main structure of the water purification pipeline in the pipeline network, which is mainly composed of a pipeline body 18 and a shell 5 surrounding the outer circumference of the pipeline body 18. The shell wall of the shell 5 and the outer wall of the pipeline body 18 are fixed by welding to form an air cavity 6 between the two; there is a pipeline inner cavity 19 in the pipeline body 18; an air cavity air inlet 17 is opened on the top wall of the shell 5 away from the pipeline body 18, and an air cavity exhaust port 7 is provided on the side wall close to the pipeline body 18; a barometer 3 is installed on the inner wall of the shell 5, and an air pump 4 is provided in the air cavity 6 formed between the shell 5 and the pipeline body 18. An opening is provided on the pipe wall where the pipe body 18 is connected to the air cavity 6, and an SPG membrane 8 is fixed at the opening. The air cavity 6 is connected to the pipe inner cavity 19 of the pipe body 18 through the SPG membrane 8 at the opening; after the air in the air cavity 6 enters the pipe inner cavity 19 through the SPG membrane 8, a gas-liquid mixing area 10 is formed below the SPG membrane 8; an ultrasonic defoamer 12 is also provided downstream of the gas-liquid mixing area 10; a first bubble concentration detection component 11 is also provided between the gas-liquid mixing area 10 and the ultrasonic defoamer 12; a second bubble concentration detection component 13 is also provided downstream of the ultrasonic defoamer 12, and a negative pressure valve plate 9 with a plate surface perpendicular to the water flow is provided in the pipe inner cavity 19 of the pipe body 18, and the negative pressure valve plate 9 is fixed in the pipe inner cavity 19 by a bracket, and a channel for water flow to pass through is formed between the negative pressure valve plate 9 and the inner wall of the pipe. Along the water flow direction, the negative pressure valve plate 9 is provided upstream of the SPG membrane 8 and adjacent to the SPG membrane 8.

[0064] like Figure 2As shown, the air pump 4 is fixed to the outer wall of the pipeline body 18 by bolts and is close to the SPG membrane 8. The air pump 4 is composed of an air pump air inlet 401, an air pump switch 402, an air pump air outlet 403 and an air pump cover 404. An air inlet pipeline 405 is provided at the air pump air inlet 401, and the air inlet pipeline 405 is connected to the air cavity air inlet 17 through an air inlet interface 406, so that the air pump 4 is connected to the outside air. The gas pumped in by the air pump 4 is pumped out through the air pump outlet 403.

[0065] like Figure 3 , 4 As shown, the SPG membrane 8 disposed on the pipe wall at the opening of the pipe body 18 is fixed by bolts 801; Figure 5 As shown, two sets of first movable clamps 802 and second fixed clamps 803 are installed on the pipe wall at the opening of the pipe body 18, the second fixed clamp 803 is fixedly connected to the pipe wall, and the first movable clamp 802 is movably connected to the pipe wall, and the SPG membrane 8 is inserted between the first movable clamp 802 and the second fixed clamp 803 and fixed by bolts 801.

[0066] In this embodiment, after the incoming water enters the pipe cavity 19 of the pipe body 18, the air pump 4 located inside the shell 5 and the ultrasonic defoamer 12 in the pipe cavity 19 are started. Under the suction action of the air pump 4, the pressure in the air cavity 6 increases, and air pressure is formed inside the air cavity 6. At the same time, the flow rate of the incoming water accelerates after passing through the negative pressure valve plate 9, and negative pressure will be formed in the area behind the negative pressure valve plate 9 and below the SPG membrane 8, further causing the pressure in the air cavity 6 to be greater than the pipe cavity 19. Under the action of pressure difference, the air in the air cavity 6 enters into the inner cavity 19 of the pipe through the SPG membrane 8 to form bubbles. In the inner cavity 19 of the pipe, in the area below the SPG membrane 8, the bubbles are sheared into micro-nano bubbles under the action of the shear force of the incoming water, forming a gas-liquid mixing zone 10 with micro-nano bubbles; the micro-nano bubbles flow into the ultrasonic defoamer 12 arranged downstream of the gas-liquid mixing zone 10 with the water flow, and under the action of the ultrasonic wave of the ultrasonic defoamer 12, the generated micro-nano bubbles are broken, and a large amount of ·OH is generated, thereby improving the water quality of the incoming water; wherein the first bubble concentration detection component 11 is used to detect the generation of micro-nano bubbles; the second bubble concentration detection component 13 is used to detect the breaking process of the ultrasonic defoamer 12; the air cavity exhaust port 7 is used to open and release the pressure when the pressure inside the air cavity 6 is too high.

[0067] Example 2

[0068] As attached Figure 6As shown, this embodiment provides a combined pipe network pipeline, which includes a first pipe 15 and a second pipe 14 connected in parallel; the water inlet ends of the first pipe 15 and the second pipe 14 are both provided with control valves, the first pipe 15 is provided with a first control valve 16, the second pipe 14 is provided with a second control valve 2, and a water quality detection device 1 is provided upstream of the first control valve 16 and the second control valve 2. The first pipe 15 adopts the pipe network water quality purification pipe described in Example 1; the second pipe 14 is a conventional pipe network pipe.

[0069] The operation mode of the combined pipe network pipeline is as follows: the water in the pipeline first passes through the water quality detector 1, and the water quality is detected by the water quality detector. When the water quality detector 1 detects that the water quality of the incoming water is normal, the first control valve 16 is opened, the second control valve 2 is closed, and the incoming water enters the first pipe 15; through the first pipe cavity 20, subsequent water supply is carried out. When the water quality detection device 1 detects that the water quality of the incoming water is abnormal, the first control valve 16 is closed, the second control valve 2 is opened, and the incoming water enters the second pipe 14 and passes through the second pipe cavity 19.

[0070] After the incoming water enters the second pipe cavity 19 of the second pipe 14, the air pump 4 located inside the shell 5 and the ultrasonic defoamer 12 in the second pipe cavity 19 are started. Under the suction action of the air pump 4, the pressure in the air cavity 6 increases, and air pressure is formed inside the air cavity 6. At the same time, the flow rate of the incoming water accelerates after passing through the negative pressure valve plate 9, and negative pressure will be formed in the area behind the negative pressure valve plate 9 and below the SPG membrane 8, further causing the pressure in the air cavity 6 to be greater than the pipe cavity 19. Under the action of the pressure difference, the air in the air cavity 6 enters the second pipe cavity 19 through the SPG membrane 8 to form bubbles. In the second pipe cavity 19, in the area below the SPG membrane 8, the bubbles are sheared into micro-nano bubbles under the action of the shear force of the incoming water, forming a gas-liquid mixing area 10 with micro-nano bubbles; the micro-nano bubbles flow into the ultrasonic defoamer 12 arranged downstream of the gas-liquid mixing area 10 with the water flow, and under the action of the ultrasonic wave of the ultrasonic defoamer 12, the generated micro-nano bubbles are broken, and a large amount of ·OH is generated, thereby improving the water quality of the incoming water; wherein the first bubble concentration detection component 11 is used to detect the generation of micro-nano bubbles; the second bubble concentration detection component 13 is used to detect the breaking process of the ultrasonic defoamer 12; the air cavity exhaust port 7 is used to open and release the pressure when the pressure inside the air cavity 6 is too high.

[0071] When the water quality detector 1 detects that the water quality is normal, the first control valve 16 opens, the second control valve 2 closes, and the incoming water re-enters the first pipe 15; at the same time, the air pump 4 inside the shell 5 and the ultrasonic defoamer 12 in the second pipe cavity 19 are closed.

[0072] like Figure 7As shown, when the water quality detector 1 detects that the incoming water quality is abnormal, the first control valve 16 is closed, the second control valve 2 is opened, and the incoming water enters the second pipe 14 and passes through the second pipe inner cavity 19.

[0073] like Figure 8 As shown, when the water quality detector 1 detects that the incoming water quality is normal, the first control valve 16 is opened, the second control valve 2 is closed, and the incoming water enters the first pipe 15; and passes through the first pipe cavity 20 for subsequent water supply.

[0074] like Fig. 9 As shown, in order to solve the problem that when the internal device of the shell 5 fails and needs to be repaired or the SPG membrane 8 is replaced, the shell wall around the second pipeline is set to an openable and closable structure.

[0075] like Fig.10 As shown, the shell 5 is composed of arcs of the same curvature, each arc can be disassembled, and the arcs are connected by hinges 501. The connection between the hinges 501 is sealed by a sealing gasket 502 to make the air cavity 6 in a closed state.

[0076] Example 3

[0077] The combined pipe network pipeline of Example 2 is used to process the secondary water supply in a city water supply network;

[0078] (1) The water quality of the incoming water is determined by a water quality detection device, and the incoming water quality is divided into abnormal water quality and normal water quality;

[0079] When the water quality is normal, the incoming water is supplied through the first pipeline. When the water quality is abnormal, the control valve at the water inlet end of the first pipeline is closed, the control valve at the water inlet end of the second pipeline is opened, the air pump in the air cavity of the second pipeline and the ultrasonic defoamer in the inner cavity of the pipeline are turned on; the incoming water enters the second pipeline.

[0080] (2) When the incoming water quality is abnormal, the incoming water enters the second pipe, and the air pump controls the pressure in the air cavity, so that the air in the air cavity passes through the SPG membrane and enters the inner cavity of the pipe to generate bubbles, forming a gas-liquid mixing zone. The bubbles generate micro-nano bubbles under the action of the shear force of the water flow;

[0081] The relationship between the average membrane pore size D1 of the SPG membrane and the average diameter r of the micro-nano bubbles is:

[0082] r=8.6D1 (1)

[0083] In formula (1), r is the average diameter of micro-nano bubbles, D1 is the average membrane pore size of SPG membrane;

[0084] The relationship between the area S of the SPG membrane and the diameter D of the second pipe is:

[0085] S=πDL (2)

[0086] In formula (2), S is the area of ​​the SPG membrane; D is the diameter of the second pipe; L is the width of the SPG membrane; π is the circumference of a circle;

[0087] The conditions for generating stable micro-nano bubbles are: 1≤n≤2; n=P0 / P2; P0 is the pressure in the air cavity, P2 is the pressure in the gas-liquid mixing zone; the calculation formula of n is:

[0088]

[0089] In formula (3), P0 is the pressure in the air cavity; P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; ρ L is the density of water; the calculation formula of P2 is:

[0090]

[0091] In formula (4), P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; V2 is the water velocity after the incoming water passes through the gas-liquid mixing zone in the inner cavity of the second pipe; ρL is the density of water;

[0092] The calculation formula for V2 is:

[0093] V2=V1 / {1-(d / D) 2} (5)

[0094] In formula (5), d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; V1 is the water velocity when the incoming water enters the second pipe;

[0095] When n<1, no bubbles will be generated in the pipeline because bubbles cannot enter the gas-liquid mixing zone; when 1≤n≤2, monodisperse nanobubbles can be stably generated in the gas-liquid mixing zone; when n>2, due to the large transmembrane pressure, the particle size dispersion coefficient increases, the bubble particle size distribution range increases, and stable monodisperse nanobubbles cannot be generated in the water;

[0096] The shear force of water in the gas-liquid mixing zone is related to the difference between P0 and P2. The greater the difference between the two, the greater the shear force, and the better the effect of cutting the bubbles entering the pipeline.

[0097] When the incoming water quality is abnormal, the bubble concentration detected by the first bubble concentration detection component and the second bubble concentration detection component reflects the operation status of the micro-nano bubble generating component and the ultrasonic defoamer;

[0098] T 1前is the bubble concentration 1, obtained by the first bubble concentration detection component; T 1后 is the bubble concentration 2, obtained by the second bubble concentration detection component;

[0099] When T 1前 >10 6 / ml, it means that the micro-nano bubble generating components are operating normally; when T 1后 <10 2 / ml, indicating that the ultrasonic defoamer is operating normally

[0100] When T 1前 <<80%·10 6 , indicating that the micro-nano bubble generating component fails; when T 1后 >>10 2 pcs / ml, indicating that the ultrasonic defoamer is malfunctioning;

[0101] (3) starting an ultrasonic defoamer to break up the micro-nano bubbles in step (2) and using the generated ·OH to improve the quality of the incoming water;

[0102] (4) The water quality of the upstream water is determined by a water quality detection device, and steps (1) to (4) are repeated.

[0103] Application Examples

[0104] The combined pipe network of Example 2 is adopted, taking the steel pipe network with a diameter of DN110mm as an example, to process the secondary water supply, assuming that the water velocity when the water flows into the second pipe is 2.0m / s and the pressure is 0.28Mpa.

[0105] Calculate V2 according to the formula, where V2 is the water velocity after the incoming water passes through the gap of the negative pressure valve plate:

[0106] V2=V1 / {1-(d / D) 2}(I)

[0107] In formula (I), d is the diameter of the negative pressure valve plate; D is the pipe diameter; v1 is the water velocity when the water flows into the second pipe.

[0108] The value of V2 is 2.67m / s;

[0109] Then calculate P2 according to the formula, where P2 is the pipeline pressure at the gap of the negative pressure valve plate:

[0110]

[0111] In formula (2), P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; V2 is the water velocity after the incoming water passes through the gap of the negative pressure valve plate;

[0112] Substituting (I) into (II), we get the combined formula:

[0113]

[0114] In formula (III), P0 is the pressure in the air cavity; P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; d is the diameter of the negative pressure valve plate; and D is the pipe diameter.

[0115] It can be seen from formula (III) that the performance of the micro-nano bubble generator in the device is affected by the ratio of the diameter d of the negative pressure valve plate in the tube to the diameter D of the tube. When d / D=0.5, the length of the negative pressure valve plate is 55 mm.

[0116] It turns out that P2 is -0.39Mpa;

[0117] When n<1, bubbles cannot enter the gas-liquid mixing zone (6), so no bubbles are generated in the pipeline; when 1≤n≤2, monodisperse nanobubbles can be stably generated in the gas-liquid mixing zone (6); when n>2, due to the large transmembrane pressure, the particle size dispersion coefficient increases, the bubble particle size distribution range increases, and stable monodisperse nanobubbles cannot be generated in water.

[0118] When the ratio n is between 1 and 2, the relationship between the SPG membrane pore size D1 and the average bubble diameter r is as shown in the attached figure. Fig.11 As shown:

[0119] It can be seen that the average diameter r of micro-nano bubbles increases linearly with the increase of the average pore diameter D1 of the membrane, and the proportional coefficient is 8.6, r = 8.6D1;

[0120] If n=2, the pressure P0 in the air cavity must reach -0.195Mpa.

[0121] By using an SPG membrane with an average pore size of 43 to 85 nm, the average particle size of the generated micro-nano bubbles can be 360 ​​to 720 nm according to the proportional relationship.

[0122] Assuming that the turbidity ratio (bubble turbidity T1 / water turbidity T2) of pipeline water when the water quality is abnormal is X1, then:

[0123]

[0124] The pipeline turbidity ratio is 0. When the micro-nano bubble device is started, a large number of micro-nano bubbles begin to be generated, and the turbidity ratio 1 value increases to 1000. Then the micro-nano bubbles are broken by the action of ultrasound, and the turbidity ratio 2 value decreases to the normal level of 0. The micro-nano bubble generator and ultrasonic defoamer are working normally.

[0125] The number of oscillators a required for different water quality conditions and water speeds is also different. For example, nW of power is required to process 1L of water. Assuming that the amount of water processed by the oscillators in the pipe network is Q and the power of a single oscillator is b, the following relationship can be obtained:

[0126] In step (3), the power of the ultrasonic defoamer is determined by the number of vibrators on the ultrasonic defoamer and the power of a single vibrator; the relationship between the number of vibrators and the amount of water treated is:

[0127] a=Q·W1 / b(V)

[0128] In formula (V), a is the number of oscillators; Q is the amount of water treated; b is the power of a single oscillator, and W1 is the power required to treat 1L of water;

[0129] If 15W of power is required to process 1L of water, the amount of water processed per second is:

[0130]

[0131] The power required to process water per second is: W = Q·W1 = 19×15 = 285W;

[0132] Therefore, the number of oscillators required is: a = Q·W1 / b = 285 / 50≈6;

[0133] Under the conditions of 285W and 28KHz, the ·OH content generated in the pipeline was measured to be 4.4×10 -2 μmol / L, turbidity and COD of water after treatment by the device Mn The total colony count was significantly reduced to undetectable level, the degradation rate of phenol was 52.8%, and no disinfection by-products such as nitrite, chlorate, bromate, formaldehyde and trihalomethane were generated during the disinfection process. All indicators met the standards of "Specifications for Urban Water Supply Engineering Projects" (GB 55026-2022).

[0134] During the operation of the device, when the turbidity ratio 1 value does not increase to V, it indicates that the micro-nano bubble generating component fails. The shell can be opened for maintenance, and the pump or SPG membrane can be removed for testing, and the maintenance or replacement plan can be determined based on its test performance; when the ratio of the value θ2 of the first bubble turbidity meter 1 to the value θ1 of the first bubble turbidity meter 1 at the original normal level is 80%, that is, θ2 / θ1=0.8, the shell can be opened to replace the SPG membrane; when the pressure in the air cavity cannot reach the predetermined pressure, the shell can be opened to repair or replace the air pump.

Claims

1. A method for treating pipe water in a combined pipe network, characterized in that: including a first pipeline and a second pipeline connected in parallel; The second pipeline comprises a pipeline body, the outer periphery of which is provided with a shell with an air cavity formed inside; the air cavity is connected with the inner cavity of the pipeline, and the pressure of the air cavity is greater than that of the inner cavity of the pipeline; a film is provided at the connection between the air cavity and the inner cavity of the pipeline for gas to enter the inner cavity of the pipeline from the air cavity; in the inner cavity of the pipeline, a gas-liquid mixing zone with micro-nano bubbles is formed in the area below the film; an ultrasonic defoamer is provided downstream of the gas-liquid mixing zone; The shell is annular and sleeved on the outer wall of the pipeline body; A negative pressure valve plate whose plate surface is perpendicular to the water flow is provided in the inner cavity of the pipeline, and a channel for the water flow to pass through is formed between the negative pressure valve plate and the inner wall of the pipeline; A first bubble concentration detection component and a second bubble concentration detection component are also provided in the inner cavity of the pipeline; the first bubble concentration detection component is provided between the gas-liquid mixing zone and the ultrasonic defoamer; the second bubble concentration detection component is provided downstream of the ultrasonic defoamer; Two sets of first movable clamps and second fixed clamps are installed on the pipe wall at the opening of the pipe body, the second fixed clamp is fixedly connected to the pipe wall, the first movable clamp is movably connected to the pipe wall, and the film is inserted between the first movable clamp and the second fixed clamp; The film is an SPG film; The processing method comprises: (1) The water quality of the incoming water is determined by a water quality detection device, and the incoming water quality is divided into abnormal water quality and normal water quality; (2) When the incoming water quality is abnormal, the incoming water enters the second pipe, and the pressure in the air cavity is controlled by the air pump, so that the air in the air cavity passes through the SPG membrane and enters the inner cavity of the pipe to generate bubbles, forming a gas-liquid mixing area. The bubbles generate micro-nano bubbles under the action of the shear force of the water flow; (3) starting the ultrasonic defoamer to break the micro-nano bubbles in step (2) and using the generated ·OH to improve the quality of the incoming water; (4) Using a water quality detection device to determine the water quality of the upstream water, and then repeating steps (1) to (4); In step (2), the conditions for generating stable micro-nano bubbles are: 1≤n≤2; n= P0 / P2; P0 is the pressure in the air cavity, and P2 is the pressure in the gas-liquid mixing zone; the calculation formula of n is: n （3） In formula (3), P0 is the pressure in the air cavity; P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; ρ L is the density of water; The calculation formula of P2 is: （4） In formula (4), P1 is the pipe pressure when the incoming water enters the second pipe; V1 is the water velocity when the incoming water enters the second pipe; V2 is the water velocity after the incoming water passes through the gas-liquid mixing zone in the second pipe cavity; ρ L is the density of water; The calculation formula of V2 is: （5） In formula (5), d is the diameter of the negative pressure valve plate; D is the diameter of the second pipe; V1 is the water velocity when the incoming water enters the second pipe.

2. The processing method according to claim 1, characterized in that An air inlet and an air outlet are provided on the shell, an air pump and a barometer are arranged inside the shell, the inlet of the air pump is communicated with the air inlet, and the outlet is arranged inside the shell.

3. The processing method according to claim 1, characterized in that: The ratio of the diameter of the negative pressure valve plate to the diameter of the pipeline is 1:2-1:3; along the water flow direction, the negative pressure valve plate is arranged upstream of the film and adjacent to the film.

4. The processing method according to claim 1, characterized in that: In step (1), when the water quality is normal, the incoming water is supplied through the first pipe; when the water quality is abnormal, the control valve at the water inlet end of the first pipe is closed, the control valve at the water inlet end of the second pipe is opened, and the air pump in the air cavity of the second pipe and the ultrasonic defoamer in the inner cavity of the pipe are turned on at the same time; the incoming water enters the second pipe.

5. The processing method according to claim 1, characterized in that In step (2), the relationship between the average membrane pore size D1 of the SPG membrane and the average diameter r of the micro-nano bubbles is: r＝8.6D1（1） In formula (1), r is the average diameter of micro-nano bubbles, D1 is the average membrane pore size of SPG membrane; The relationship between the area S of the SPG membrane and the diameter D of the second pipe is: S = πDL (2) In formula (2), S is the area of ​​the SPG membrane; D is the diameter of the second pipe; L is the width of the SPG membrane; and π is the circumference of a circle.

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