Membrane defoaming and filtering device

Abstract

The utility model relates to the technical field of gas well defoaming, in particular to a membrane defoaming and filtering device which comprises a defoaming tank and a filter element arranged in the defoaming tank, and the outer surface of the filter element is coated with a hydrophilic and oleophobic coating; a water outlet pipe used for discharging filtered water is arranged at the bottom end of the filter element, the end, away from the end connected with the filter element, of the water outlet pipe penetrates through the bottom of the defoaming tank, and a bubble pipe used for leading bubbles in a gas well into the defoaming tank is arranged at the bottom of the defoaming tank. An exhaust pipe used for exhausting gas is arranged at the upper end of the filter element, and the end, away from the end connected with the filter element, of the exhaust pipe penetrates through the top of the defoaming tank. The method has the effect of solving the problem of environmental pollution caused by direct drainage of gas field water.

Description

Technical Field

[0001] This application relates to the technical field of gas well defoaming, and in particular to a membrane defoaming filtration device. Background Technology

[0002] During the development of natural gas, gas wells usually produce a small amount of gas field water. Because the gas field water is present in small quantities, it cannot be directly extracted by pumps.

[0003] In related technologies, a foaming agent is first added to the gas field water, followed by the introduction of high-pressure air to convert the water into foam. The foam is then extracted from the gas well. Subsequent foam treatment involves adding a defoamer to the foam to remove it.

[0004] Regarding the aforementioned technologies, on the one hand, a large amount of defoaming agent needs to be invested, and on the other hand, the gas field water also contains some crude oil, and direct discharge will cause environmental pollution. Utility Model Content

[0005] In order to improve the environmental pollution caused by direct discharge of gas field water, this application provides a membrane defoaming filtration device.

[0006] The membrane defoaming filtration device provided in this application adopts the following technical solution:

[0007] A membrane defoaming filtration device includes a defoaming tank and a filter element disposed inside the defoaming tank, wherein the outer surface of the filter element is coated with a hydrophilic and oleophobic coating.

[0008] The filter element has an outlet pipe at its bottom for discharging filtered water. The end of the outlet pipe away from the filter element passes through the bottom of the defoaming tank. The defoaming tank has an air bubble pipe at its bottom for introducing air bubbles from the air well into the defoaming tank. The filter element has an exhaust pipe at its top for discharging gas. The end of the exhaust pipe away from the filter element passes through the top of the defoaming tank.

[0009] By adopting the above technical solution, the foamy gas field water extracted from the gas well enters the defoaming tank through the bubble tube and gradually overflows. When the bubbles come into contact with the filter element, the water and gas can pass through the filter element wall and enter the filter element due to the hydrophilic and oleophobic coating on the outer surface of the filter element. The gas is discharged from the top exhaust pipe, and the filtered water forms a water flow and is discharged from the bottom drain pipe. Small oil droplets are separated by the coating on the outside of the filter element and gradually aggregate into larger oil droplets, which then fall off the coating surface, merge into the foam below, and are filtered again. This physical filtration method for gas field water not only eliminates the need to add large amounts of defoamer, reducing environmental pollution, but also allows the discharged water, which still contains a large amount of foaming agent, to be reused in the gas well for foaming operations after impurity removal and concentration treatment, thereby reducing resource waste.

[0010] Furthermore, the filter element includes an upper connecting part, a frame, and a lower connecting part that are coaxially and integrally connected. The upper connecting part and the lower connecting part are respectively disposed at the upper and lower ends of the frame. The outer wall of the frame is circumferentially provided with a plurality of filter membranes arranged in parallel along the length direction. The hydrophilic and oleophobic coating is applied to the outside of each of the filter membranes.

[0011] By adopting the above technical solution, the circumferentially arranged filter membrane can increase the roughness and surface area of ​​the filter element's outer surface, allowing for more thorough contact between air bubbles and the filter element, thereby improving the efficiency of water and gas penetration through the filter element wall. Simultaneously, the gaps between the filter membranes provide more opportunities for the coalescence of small oil droplets, facilitating their detachment from the coating surface and improving oil-water separation. The filter membrane helps guide air bubbles and water flow along specific paths, making it easier for gas to exit from the top and for filtered water to drain smoothly from the bottom, reducing fluid retention and turbulence inside the filter element and improving filtration efficiency. The filter membrane structure not only enhances the mechanical strength of the filter element but also makes the coating adhere more firmly to the filter element surface, reducing the risk of coating peeling or wear, thus extending the service life of the device.

[0012] Furthermore, the defoaming tank is provided with an oil drain pipe at the bottom for discharging crude oil.

[0013] By adopting the above technical solution, the addition of an oil drain pipe can effectively separate and discharge crude oil from gas field water. In traditional treatment processes, after adding large amounts of foaming and defoaming agents, crude oil will be converted into sludge through chemical reactions, which will then be discharged along with wastewater, resulting in resource waste and environmental pollution. The oil drain pipe allows for separate collection of crude oil, and since this treatment method does not involve the addition of large amounts of defoaming agents, the crude oil retains its original properties, facilitating recycling and improving the crude oil recovery rate while reducing resource waste.

[0014] Furthermore, the defoaming tank includes a tank body and an upper blind plate and a lower blind plate connected to both ends of the tank body by flanges. An upper pipe seat for installing the exhaust pipe is inserted and fixedly connected to the upper blind plate at the middle position, and a lower pipe seat for installing the water outlet pipe is inserted and fixedly connected to the lower blind plate at the middle position.

[0015] By adopting the above technical solution, flange connections are used to securely connect the upper and lower blind plates to the tank body, improving the overall structural strength of the defoaming tank, ensuring the sealing between components, preventing gas or liquid leakage, and providing a robust structure that can withstand greater working pressure and fluid impact, ensuring long-term stable operation of the device. The flange connections and pipe seats simplify and expedite the installation of the exhaust pipe and outlet pipe. Furthermore, it facilitates the disassembly and assembly of components when cleaning, replacing filter elements, or performing other maintenance, reducing maintenance difficulty and costs. The upper and lower pipe seats allow gas and liquid to flow smoothly along predetermined paths. Gas enters the exhaust pipe through the upper pipe seat and exits, while filtered water enters the outlet pipe through the lower pipe seat and exits, optimizing the fluid flow path, reducing fluid retention and turbulence within the device, and improving filtration efficiency.

[0016] Furthermore, one end of the water outlet pipe is fixedly connected to the lower connecting part, and the end of the water outlet pipe away from the lower connecting part is fixedly connected to the lower pipe seat;

[0017] One end of the exhaust pipe is fixedly connected to the upper connecting part, and the end of the exhaust pipe away from the upper connecting part is fixedly connected to the upper pipe seat.

[0018] By adopting the above technical solution, the water outlet pipe and the vent pipe are directly fixedly connected to the upper and lower connecting parts of the filter element, and then passed through the lower and upper pipe seats respectively to be fixed to the lower and upper blind plates. This multi-layer connection method enhances the stability of the connection, ensures the stability of the fluid during transmission, and reduces the risk of leakage due to loose connections. Since the water outlet pipe and the vent pipe are fixedly connected to the lower and upper pipe seats when passing through them, it helps to optimize the sealing performance, ensure the sealing of the connection, prevent gas or liquid leakage during transmission, and thus ensure the filtration effect.

[0019] Furthermore, the upper side of the lower blind plate is provided with a liquid distribution pipe inside the tank that is connected to the bubble tube and used to guide the bubbles.

[0020] By adopting the above technical solution, the liquid distribution pipe allows the foam entering from the bubble tube to flow smoothly along a predetermined path to the area around the filter element. This prevents foam from flowing directly out of the drain pipe or defoaming, which would affect the filtration effect. It also prevents bubbles from spreading and accumulating disorderly within the tank, reducing their interference with the filtration process and improving filtration efficiency. Guided by the liquid distribution pipe, the bubbles are more evenly distributed around the filter element, increasing the contact area and contact time between the bubbles and the outer surface of the filter element. This helps water and gas in the bubbles penetrate the filter element wall, improving both defoaming and filtration effects.

[0021] Furthermore, the drain pipe is installed on the lower blind plate, and a drain valve for controlling its opening and closing is provided at the position where the drain pipe extends out of the lower blind plate.

[0022] By adopting the above technical solution, the drain valve enables more precise control of the draining process, allowing it to be opened or closed at appropriate times as needed. When closed, the drain valve prevents crude oil leakage from the drain pipe and also prevents foam loss, thus improving filtration efficiency.

[0023] Furthermore, a drain adapter is connected to the outlet pipe at the position where it extends out of the lower blind plate, and the diameter of the drain adapter is smaller than the diameter of the outlet pipe.

[0024] By adopting the above technical solution, the diameter of the drain adapter is smaller than that of the outlet pipe. According to the principles of fluid mechanics, the fluid velocity increases when passing through a pipe with a smaller diameter. Increasing the fluid velocity at the outlet without increasing the pump pressure helps to discharge the filtered liquid more efficiently. By adjusting the diameter of the drain adapter, the effluent flow rate can be controlled to some extent to adapt to different treatment needs or process requirements. In some cases, if the pressure in the outlet pipe suddenly drops (such as when the pump stops working), backflow may occur. The drain adapter can reduce the possibility of backflow to some extent, and the smaller diameter makes the fluid flow in the pipe more stable. The drain adapter can also act as a barrier, reducing the possibility of external impurities or contaminants entering the outlet pipe, thereby protecting downstream equipment and treatment processes from contamination.

[0025] Furthermore, the drain pipe is detachably connected to a backwashing mechanism at the end away from the outlet pipe.

[0026] By adopting the above technical solution, the backwashing mechanism effectively removes dirt and blockages from the filter element surface by injecting cleaning fluid or water into the drain pipe and directing it through the filter element in the opposite direction to the normal filtration direction. This is more thorough and efficient than traditional forward cleaning. The detachable connection between the backwashing mechanism and the drain pipe makes the cleaning process more flexible and convenient. When cleaning is required, the backwashing mechanism can be quickly connected to the drain pipe, and then disassembled after cleaning, without interfering with the normal operation of the device.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. By coating the outer surface of the filter element with a hydrophilic and oleophobic coating, water and gas in the foam can be effectively penetrated, while small oil droplets are blocked, causing them to coalesce into larger oil droplets and then fall off, thus improving the efficiency of oil-water separation. The circumferentially arranged filter membrane increases the roughness and surface area of ​​the outer surface of the filter element, improves the contact efficiency between the bubbles and the filter element, promotes the coalescence and fall off of small oil droplets, and further enhances the oil-water separation effect.

[0029] 2. The filtered water contains foaming agent, and after impurity removal and concentration treatment, it can be reused in the gas well, reducing resource waste and environmental pollution. The added oil drain pipe effectively separates and collects crude oil in the gas field water, avoiding resource waste and environmental pollution caused by crude oil being discharged with wastewater, and improving the crude oil recovery rate.

[0030] 3. The detachable connection between the backwashing mechanism and the drain pipe makes the cleaning operation more flexible, does not interfere with the normal operation of the device, and improves the maintenance efficiency and service life of the equipment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of a membrane defoaming filtration device according to Embodiment 1 of this application.

[0032] Figure 2 This is a schematic diagram of the overall structure of the membrane defoaming filtration device in Embodiment 1 of this application.

[0033] Figure 3 This is a cross-sectional structural diagram of the membrane defoaming filtration device in Embodiment 1 of this application.

[0034] Figure 4 This is a schematic diagram of the overall structure of the filter element in Embodiment 1 of this application.

[0035] Figure 5 This is a schematic diagram of the overall structure of a membrane defoaming filtration device according to Embodiment 2 of this application.

[0036] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Defoamer tank; 21. Tank body; 22. Upper blind flange; 23. Lower blind flange; 24. Upper pipe seat; 25. Lower pipe seat; 3. Filter element; 31. Hydrophilic and oleophobic coating; 32. Upper connecting part; 33. Skeleton; 331. Filter membrane; 34. Lower connecting part; 4. Bubble tube; 41. Liquid distribution tube; 5. Water outlet tube; 51. Drainage adapter tube; 52. Quick connector; 6. Exhaust pipe; 61. Exhaust adapter tube; 62. Pressure relief pipe; 7. Oil drain pipe; 71. Oil drain valve; 8. Backwashing mechanism; 81. Flushing pipe; 82. Pump body. Detailed Implementation

[0037] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with Embodiment 1, Embodiment 2, and the appendix. Figure 1-5This application will be described in further detail below.

[0038] Example 1

[0039] Reference Figure 1 and Figure 2 This application provides a membrane defoaming filtration device, including a frame 1, a defoaming tank 2, a filter element 3, a bubble tube 4 disposed in the defoaming tank 2, a water outlet pipe 5, an exhaust pipe 6, and an oil outlet pipe 7. The defoaming tank 2 is vertically mounted on the frame 1, combined with... Figure 3 The filter element 3 is located inside the defoaming tank 2, and its outer surface is coated with a hydrophilic and oleophobic coating 31. The bubble tube 4 is connected to the gas well to introduce gas field water foam from the gas well into the defoaming tank 2. The filtered water is discharged from the water outlet pipe 5, the filtered crude oil is discharged from the oil outlet pipe 7, and the gas is discharged from the exhaust pipe 6.

[0040] Reference Figure 3 and Figure 4 The filter element 3 includes an upper connecting part 32, a frame 33 and a lower connecting part 34 arranged coaxially. The upper connecting part 32 and the lower connecting part 34 are integrally connected to the upper and lower ends of the frame 33, respectively. The frame 33 is used to defoam and filter the foamy gas field water. The upper connecting part 32 and the lower connecting part 34 are used to connect to the upper and lower ends of the defoaming tank 2, respectively.

[0041] The outer wall of the skeleton 33 is circumferentially circumferentially provided with several parallel filter membranes 331, and a hydrophilic and oleophobic coating 31 is applied to the exterior of each filter membrane 331. The arrangement of multiple filter membranes 331 increases the friction and contact area between the foam and the coating, increasing the probability of foam adhering to the outer wall of the coating, thereby improving the defoaming, filtration, and separation effect on gas field water foam. In this embodiment, each filter membrane 331 can optimize the flow path of foam on the surface of the skeleton 33, improving the defoaming effect. The filter membranes 331 can also improve the hydrodynamic performance by increasing the sharpness of their edges, which helps bubble breakage and improves separation efficiency.

[0042] The defoaming tank 2 includes a tank body 21 and an upper blind plate 22 and a lower blind plate 23 connected to the upper and lower ends of the tank body 21 by flanges. The upper blind plate 22 is provided with an upper pipe seat 24 for installing the air supply and exhaust pipe 6 at the middle position, and the lower blind plate 23 is provided with a lower pipe seat 25 for installing the water supply pipe 5 at the middle position.

[0043] The lower end of the exhaust pipe 6 is fixedly connected to the upper connecting part 32 of the filter element 3, and the upper end of the exhaust pipe 6 is fixedly connected to the upper pipe seat 24. The upper end of the upper pipe seat 24 passes through the upper blind plate 22 so that the exhaust pipe 6 communicates with the outside of the defoaming tank 2.

[0044] An exhaust adapter 61, which communicates with the exhaust pipe 6, is fixedly connected at the center of the upper pipe seat 24. The diameter of the exhaust adapter 61 is smaller than that of the exhaust pipe 6. The exhaust adapter 61 can be used to connect to a gas collection device for convenient subsequent treatment and discharge. A pressure relief pipe 62 for balancing the gas pressure in the defoaming tank 2 is provided at the adjacent position where the upper blind plate 22 passes through the upper pipe seat 24.

[0045] The upper end of the water outlet pipe 5 is fixedly connected to the lower connecting part 34 of the filter element 3, and the lower end of the water outlet pipe 5 is fixedly connected to the lower pipe seat 25. The lower end of the lower pipe seat 25 passes through the lower blind plate 23 so that the water outlet pipe 5 is connected to the outside of the defoaming tank 2.

[0046] The lower pipe seat 25 is fixedly connected at the center to a drain adapter 51 that communicates with the outlet pipe 5. The diameter of the drain adapter 51 is smaller than the diameter of the outlet pipe 5. The drain adapter 51 can be used to connect to a liquid collection device for easy subsequent treatment and discharge.

[0047] A bubble tube 4 is located adjacent to the lower pipe seat 25 on the lower blind plate 23. The lower end of the bubble tube 4 is used to connect to the gas well, and the upper end of the bubble tube 4 protrudes above the lower blind plate 23. A liquid distribution tube 41 is detachably connected to the upper end of the bubble tube 4. In this embodiment, the liquid distribution tube 41 is preferably a flexible hose with deformability. The liquid distribution tube 41 extends upward in a spiral shape, and the upper end of the liquid distribution tube 41 is located at the frame 33 of the filter element 3. The liquid distribution tube 41 is connected to the bubble tube 4 to guide the foam to the frame 33 of the filter element 3.

[0048] The oil drain pipe 7 is located adjacent to the lower pipe seat 25 that passes through the lower blind plate 23. The positions of the oil drain pipe 7 and the bubble pipe 4 are centrally symmetrical about the central axis of the drain pipe. The upper end of the oil drain pipe 7 is fixedly connected to the lower blind plate 23, and the upper end of the oil drain pipe 7 is flush with the lower blind plate 23. An oil drain valve 71 for controlling the opening and closing is provided at the position where the oil drain pipe 7 extends out of the lower blind plate 23.

[0049] The implementation principle of this embodiment is as follows: Foamy gas field water in the gas well enters the defoaming tank 2 through the bubble pipe 4, and the liquid distribution pipe 41 guides the foam to the skeleton 33 of the filter element 3. When the foam passes through the skeleton 33 of the filter element 3, it breaks due to the action of the filter membrane 331 and the hydrophilic and oleophobic coating 31. Water molecules pass through the coating and flow down along the filter element 3, while crude oil is separated to the outside of the filter element 3 due to its oleophobicity. After being filtered by the filter element 3, the water is discharged from the outlet pipe 5. At this time, the filtered water still contains a large amount of defoamer. The drain pipe 51 is connected to the liquid collection device to realize the subsequent treatment of the liquid and facilitate the recycling of the defoamer. Gas is discharged through the filter element 3 and the exhaust pipe 6. The exhaust pipe 61 is convenient to connect to the gas collection device for subsequent treatment or discharge. The separated crude oil accumulates on the outside of the filter element 3 and can be discharged through the oil drain pipe 7. The oil drain valve 71 controls the oil draining process to ensure precise control of the discharge.

[0050] Example 2

[0051] Reference Figure 5 The difference between this embodiment and embodiment 1 is that the drain pipe 51 is provided with a quick connector 52 at the end away from the outlet pipe 5, and the drain pipe 51 can be quickly connected to the liquid collection and treatment device through the quick connector 52.

[0052] A backwashing mechanism 8 is provided on one side of the frame 1. The backwashing mechanism 8 includes a flushing pipe 81 and a pump body 82 mounted on the flushing pipe 81. One end of the flushing pipe 81 is detachably connected to the outlet pipe 5 via a quick connector 52. The other end of the flushing pipe 81 is used to supply cleaning fluid. The backwashing mechanism 8 enables the filter to perform periodic self-cleaning, effectively removing impurities from the filter element, thereby preventing clogging, improving its filtration efficiency, and ensuring the stable operation of the device.

[0053] This embodiment further optimizes the hydrophilic and oleophobic coating 31 in filter element 3. The hydrophilic and oleophobic coating 31 can be achieved not only through materials such as polyurethane and polytetrafluoroethylene, but also through nano-coating technology, using materials with high hydrophilicity and low surface energy, such as nano-coatings made of silica and polytetrafluoroethylene composites. This coating can provide better hydrophilic and oleophobic properties without increasing the thickness excessively, thereby further improving foam bursting efficiency and the overall performance of the device.

[0054] The implementation principle of this embodiment is as follows: A quick connector 52 is added to the end of the drain pipe 51 furthest from the outlet pipe 5, allowing the drain pipe 51 to be easily connected and disconnected from the liquid collection and treatment device, improving operational efficiency and facilitating equipment maintenance and replacement. A backwashing mechanism 8 is added to one side of the frame 1. The flushing pipe 81 is connected to the outlet pipe 5 via the quick connector 52, and the other end is used to introduce cleaning fluid. The pump body 82 drives the cleaning fluid to flow backward through the filter element 3, performing periodic self-cleaning of the filter element. The backwashing mechanism can effectively remove impurities from the filter element, prevent filter element blockage, thereby ensuring the continuous and efficient filtration capacity of the filter element, extending the service life of the equipment, and improving the overall stability and operating efficiency of the device.

[0055] This embodiment upgrades the hydrophilic and oleophobic coating 31 on the filter element 3 by employing nano-coating technology. The nano-coating is made using materials with high hydrophilicity and low surface energy (such as silica and polytetrafluoroethylene composite materials), which significantly improves the hydrophilic and oleophobic properties of the coating without increasing its thickness.

[0056] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A membrane defoaming filtration device, characterized in that: It includes a defoaming tank (2) and a filter element (3) disposed inside the defoaming tank (2), the outer surface of the filter element (3) being coated with a hydrophilic and oleophobic coating (31); The filter element (3) has an outlet pipe (5) at its bottom for discharging filtered water. The end of the outlet pipe (5) away from the filter element (3) passes through the bottom of the defoaming tank (2). The defoaming tank (2) has an air bubble pipe (4) at its bottom for introducing air bubbles from the gas well into the defoaming tank (2). The filter element (3) has an exhaust pipe (6) at its top for discharging gas. The end of the exhaust pipe (6) away from the filter element (3) passes through the top of the defoaming tank (2).

2. The membrane defoaming filtration device according to claim 1, characterized in that: The filter element (3) includes an upper connecting part (32), a frame (33) and a lower connecting part (34) that are coaxially and integrally connected. The upper connecting part (32) and the lower connecting part (34) are respectively located at the upper and lower ends of the frame (33). The outer wall of the frame (33) is circumferentially provided with a plurality of filter membranes (331) arranged in parallel along the length direction. The hydrophilic and oleophobic coating (31) is coated on the outside of each filter membrane (331).

3. The membrane defoaming filtration device according to claim 2, characterized in that: The defoaming tank (2) is provided with an oil drain pipe (7) at the bottom for discharging crude oil.

4. The membrane defoaming filtration device according to claim 3, characterized in that: The defoaming tank (2) includes a tank body (21) and an upper blind plate (22) and a lower blind plate (23) connected to both ends of the tank body (21) by flanges. The upper blind plate (22) has an upper pipe seat (24) for installing the exhaust pipe (6) through and fixedly connected at the middle position. The lower blind plate (23) has a lower pipe seat (25) for installing the water outlet pipe (5) through and fixedly connected at the middle position.

5. The membrane defoaming filtration device according to claim 4, characterized in that: One end of the water outlet pipe (5) is fixedly connected to the lower connecting part (34), and the end of the water outlet pipe (5) away from the lower connecting part (34) is fixedly connected to the lower pipe seat (25). One end of the exhaust pipe (6) is fixedly connected to the upper connecting part (32), and the end of the exhaust pipe (6) away from the upper connecting part (32) is fixedly connected to the upper pipe seat (24).

6. The membrane defoaming filtration device according to claim 4, characterized in that: The upper side of the lower blind plate (23) is provided with a liquid distribution pipe (41) inside the tank body (21) that is connected to the bubble tube (4) and used to guide the bubbles.

7. The membrane defoaming filtration device according to claim 4, characterized in that: The drain pipe (7) is installed on the lower blind plate (23), and a drain valve (71) for controlling the opening and closing is provided at the position where the drain pipe (7) extends out of the lower blind plate (23).

8. The membrane defoaming filtration device according to claim 5, characterized in that: The outlet pipe (5) is connected to a drain adapter pipe (51) at the position where it extends out of the lower blind plate (23), and the diameter of the drain adapter pipe (51) is smaller than the diameter of the outlet pipe (5).

9. A membrane defoaming filtration device according to claim 8, characterized in that: The drain pipe (51) is detachably connected to a reverse flushing mechanism (8) for flushing the frame (33) at the end away from the outlet pipe (5).

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