Compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence.

Abstract

This utility model relates to the field of petroleum extraction technology, specifically a compact oil-gas-water separation system based on subsurface flow and alternating fiber coalescence synergy. It includes a gas-liquid separation pipe and an oil-water separation pipe, which are connected and fixed. A slanted guide plate is fixedly installed at the lower end of the middle section of the gas-liquid separation pipe, and a flow guide pipe is fixedly installed on one side of the lower end of the gas-liquid separation pipe. A pre-sedimentation zone is formed between the lower end of the gas-liquid separation pipe, the slanted guide plate, and the flow guide pipe. Oleophilic and hydrophilic fiber woven meshes are fixedly installed above and below the middle section of the pre-sedimentation zone. This utility model, by combining subsurface flow design with alternating fiber coalescence, can achieve multi-stage efficient gas-liquid separation and precise oil-water separation, significantly improving the purity of oil, gas, and water separation. Furthermore, by integrating gas-liquid separation, oil-water separation, and impurity discharge functions within a limited space, it does not require a large additional area, making it particularly suitable for space-constrained scenarios on offshore platforms.

Description

Technical Field

[0001] This utility model relates to the field of petroleum extraction technology, specifically to a compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence. Background Technology

[0002] Oil-gas-water separation is a crucial step in the oil extraction and refining process. The mixture produced by oil and gas wells typically contains three phases: oil, gas, and water. Effective separation technology is needed to separate these phases to ensure production efficiency and product quality. The separated oil can be further refined and processed, the gas can be used as fuel or chemical feedstock, and the water needs to be treated to meet discharge standards or reinjected into the formation.

[0003] Traditional separation technologies have significant limitations. For example, gravity separation relies on density differences, resulting in low separation efficiency and long processing cycles. Centrifugal separation equipment is complex, energy-intensive, and has high maintenance costs. Conventional coalescence technology has a weak ability to capture tiny oil droplets, especially emulsion-like oil droplets, and is easily affected by fluid disturbances. At the same time, due to the limited space on offshore platforms, the large size and footprint of traditional separation equipment are even more pronounced, making them difficult to adapt to different environments. Utility Model Content

[0004] The purpose of this invention is to provide a compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence, in order to solve the problems mentioned in the background art. To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A compact oil-gas-water separation system based on subsurface flow and alternating fiber coalescence synergy includes a gas-liquid separation pipe and an oil-water separation pipe, which are connected and fixed. An inclined guide plate is fixedly installed at the lower end of the middle section of the gas-liquid separation pipe, and a flow guide pipe is fixedly installed on one side of the lower end of the gas-liquid separation pipe. A pre-sedimentation zone is formed between the lower end of the gas-liquid separation pipe, the inclined guide plate, and the flow guide pipe. Oleophilic and hydrophilic fiber woven meshes are fixedly installed above and below the middle section of the pre-sedimentation zone. The oil-water separation pipe is connected and fixedly attached to the upper end of a sewage pipe. A pre-weir plate is fixedly installed at one end of the oil-water separation pipe near the gas-liquid separation pipe, and a post-weir plate is fixedly installed in the middle of the other end of the oil-water separation pipe. A post-separation zone is formed between the pre-weir plate and the post-weir plate, and multiple corrugated baffles are fixedly installed in the middle of the post-separation zone, arranged in a stacked manner on one side.

[0005] In some embodiments, a liquid guide pipe is fixedly connected to one side of the upper middle part of the gas-liquid separation pipe, and an inlet baffle is fixedly installed on one side of the inner wall of the gas-liquid separation pipe. The inlet baffle is located at the connection between the liquid guide pipe and the gas-liquid separation pipe.

[0006] In some embodiments, an upper umbrella plate separator and a lower umbrella plate separator are fixedly installed above and below the middle of the inlet baffle, respectively, and the upper umbrella plate separator and the lower umbrella plate separator are both located in the middle of the gas-liquid separation pipe.

[0007] In some embodiments, a natural gas pipe is fixedly connected to the upper end of the gas-liquid separation pipe, and a defoaming screen is fixedly installed in the middle of the upper end of the gas-liquid separation pipe, with the defoaming screen located at the upper end of the upper umbrella plate separator.

[0008] In some embodiments, a base plate is fixedly installed on one side of the lower end of the gas-liquid separation pipe, a side support is fixedly installed on one side of the base plate, and the oil-water separation pipe is fixedly installed on the upper end of the side support.

[0009] In some embodiments, a drain pipe is fixedly connected to one side of the lower end of the gas-liquid separation pipe, and the drain pipe is connected to the pre-sedimentation zone of the gas-liquid separation pipe.

[0010] In some embodiments, the inner diameter of the guide tube is approximately one-third that of the gas-liquid separation tube, a flow space is provided between the lower end of the guide tube and the bottom of the gas-liquid separation tube, and the guide tube is connected to the pre-sedimentation zone.

[0011] In some embodiments, an oil storage area is formed between the post-weir plate and the other end of the oil-water separation pipe, and an oil drain pipe is fixedly connected to the other end of the oil-water separation pipe. A drain pipe is fixedly connected to one side of the middle part of the oil-water separation pipe, and the oil drain pipe and the drain pipe are respectively connected to the oil storage area and the post-separation area.

[0012] This utility model has at least the following beneficial effects: 1. In use, this utility model has high separation efficiency and a compact structure. The system combines subsurface flow design, such as inclined guide plates and corrugated baffles, to optimize the flow field and extend the separation time. The alternating coalescence of fibers, such as the coalescence of tiny oil droplets by oleophilic and hydrophilic fiber woven mesh, can achieve multi-stage efficient separation of gas and liquid, and can also accurately complete fine separation of oil and water, which can significantly improve the separation purity of oil, gas and water and meet the requirements of subsequent processing and discharge. Furthermore, through the integrated connection design of gas-liquid separation pipe and oil-water separation pipe, it integrates gas-liquid separation, oil-water separation and impurity discharge functions in a limited space without occupying a large area of ​​space, which is especially suitable for the space-constrained scenario of offshore platforms.

[0013] 2. This utility model has low operation and maintenance costs and strong stability when in use: On the one hand, the sewage pipe is directly connected to the pre-sedimentation area, which can discharge solid impurities in a timely manner, avoid clogging of the oleophilic and hydrophilic fiber woven mesh, and reduce the frequency of manual cleaning; on the other hand, the combination of the base plate and the side support frame can stably support the equipment, reduce the impact of vibration or fluid impact on the component connection, reduce the probability of failure, extend the service life of the equipment, and reduce long-term operation and maintenance costs from multiple aspects such as cleaning, maintenance, and replacement. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the first appearance structure of the present utility model; Figure 2 This is a schematic diagram of the second appearance structure of the present utility model; Figure 3 This is a schematic diagram of the first cross-sectional structure of the gas-liquid separation tube of this utility model; Figure 4 This is a schematic diagram of the second cross-sectional structure of the gas-liquid separation tube of this utility model; Figure 5 This is a cross-sectional disassembly diagram of the oil-water separator pipe of this utility model. Figure 6 This utility model Figure 5 A magnified structural diagram of region A in the middle.

[0015] In the diagram: 1. Gas-liquid separation pipe; 11. Liquid guide pipe; 12. Sewage discharge pipe; 13. Inlet baffle; 14. Upper umbrella plate separator; 15. Lower umbrella plate separator; 16. Defoaming screen; 17. Natural gas pipe; 18. Inclined guide plate; 19. Flow guide pipe; 20. Pre-sedimentation zone; 21. Oleophilic and hydrophilic fiber woven mesh; 22. Bottom plate; 23. Side support frame; 24. Oil-water separation pipe; 25. Oil discharge pipe; 26. Pre-weir plate; 27. Corrugated folding plate; 28. Post-weir plate; 29. ​​Oil storage area; 30. Post-separation zone; 31. Drainage pipe. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Example 1: Please refer to Figure 1 - Figure 6This utility model provides a technical solution: a compact oil-gas-water separation system based on subsurface flow and alternating fiber coalescence synergy, including a gas-liquid separation pipe 1 and an oil-water separation pipe 24, which are connected and fixed. An inclined guide plate 18 is fixedly installed at the lower end of the middle section of the gas-liquid separation pipe 1, and a guide pipe 19 is fixedly installed on one side of the lower end of the gas-liquid separation pipe 1. A pre-sedimentation zone 20 is formed between the lower end of the gas-liquid separation pipe 1, the inclined guide plate 18, and the guide pipe 19. Oil- and hydrophilic fiber woven meshes 21 are fixedly installed above and below the middle section of the pre-sedimentation zone 20. The oil-water separation pipe 24 is connected and fixedly installed at the upper end of a drain pipe 12. A pre-weir plate 26 is fixedly installed at one end of the oil-water separation pipe 24 near the gas-liquid separation pipe 1, and the other end of the oil-water separation pipe 24... A rear weir plate 28 is fixedly installed in the middle. A rear separation zone 30 is formed between the front weir plate 26 and the rear weir plate 28. Multiple corrugated baffles 27 are fixedly installed in the middle of the rear separation zone 30. The multiple corrugated baffles 27 are stacked and arranged on one side. The inner diameter of the guide pipe 19 is about one-third of that of the gas-liquid separation pipe 1. A flow space is provided between the lower end of the guide pipe 19 and the bottom of the gas-liquid separation pipe 1. The guide pipe 19 is connected to the front sedimentation zone 20. An oil storage zone 29 is formed between the rear weir plate 28 and the other end of the oil-water separation pipe 24. An oil drain pipe 25 is fixedly connected to the other end of the oil-water separation pipe 24. A drain pipe 31 is fixedly connected to one side of the middle of the oil-water separation pipe 24. The oil drain pipe 25 and the drain pipe 31 are respectively connected to the oil storage zone 29 and the rear separation zone 30.

[0018] In this embodiment, the gas-liquid separation pipe 1 can separate the three liquids through its internal structure. The separated oil-water mixture will fall and enter the guide pipe 19 along the inclined guide plate 18. Since there is still a flow space between the bottom of the guide pipe 19 and the bottom of the gas-liquid separation pipe 1, the oil-water mixture will enter the pre-sedimentation zone 20 through this space. During the process, the inclined guide plate 18 can play a guiding and buffering role, guiding the falling oil-water mixture to enter the guide pipe 19 smoothly along a fixed path, avoiding the mixture directly impacting the bottom of the equipment and generating violent turbulence, and preventing the oil and water that have been initially separated from mixing again. The flow space between the bottom of the guide pipe 19 and the gas-liquid separation pipe 1 further provides a transition buffer area for the fluid, allowing the oil-water mixture to enter the pre-sedimentation zone 20 at a more uniform flow rate, creating a stable flow field environment for subsequent impurity sedimentation and oil droplet coalescence. As the oil-water mixture continues to enter the pre-sedimentation zone 20, the liquid level of the oil-water mixture will continue to rise. The oil-water mixture will pass through two layers of oleophilic and hydrophilic fiber weaving. The mesh 21, made of oleophilic and hydrophilic fiber woven mesh, can coalesce oil droplets in the liquid, causing tiny oil droplets to agglomerate into larger droplets, facilitating subsequent oil-water separation and improving the efficiency and effectiveness of oil-water separation. Simultaneously, the pre-sedimentation zone 20 allows larger particulate impurities in the liquid to settle. At this point, the oil-water mixture will be separated into layers, with water containing large particulate impurities located below the pre-sedimentation zone 20, while water containing the oil phase will overflow through the pre-weir plate 26 into the post-sedimentation zone formed between the pre-weir plate 26 and the post-weir plate 28. In the separation zone 30, the mixture then passes through multiple corrugated baffles 27. These baffles effectively increase the flow path and residence time of the oil-water mixture within the separation zone, allowing for thorough separation of the oil and water phases. Due to its lower density, the oil phase passes through the post-weir plate 28 into the oil storage zone 29 and is discharged from the oil drain pipe 25. The water phase remains in the post-separation zone 30 and is discharged from the drain pipe 31, achieving complete separation of oil and water. The device has a compact overall structure and a small footprint, making it particularly suitable for use on offshore platforms with limited space.

[0019] Example 2: Figure 1 - Figure 4 As shown, a liquid guide pipe 11 is fixedly connected to one side of the upper part of the gas-liquid separation pipe 1. An inlet baffle 13 is fixedly installed on one side of the inner wall of the gas-liquid separation pipe 1. The inlet baffle 13 is located at the connection between the liquid guide pipe 11 and the gas-liquid separation pipe 1. An upper umbrella plate separator 14 and a lower umbrella plate separator 15 are fixedly installed above and below the middle part of the inlet baffle 13, respectively. Both the upper umbrella plate separator 14 and the lower umbrella plate separator 15 are located in the middle of the gas-liquid separation pipe 1. A natural gas pipe 17 is fixedly connected to the upper end of the gas-liquid separation pipe 1. A defoaming screen 16 is fixedly installed in the middle of the upper end of the gas-liquid separation pipe 1. The defoaming screen 16 is located above the upper umbrella plate separator 14.

[0020] In this embodiment, the three-phase liquid enters the gas-liquid separation pipe 1 through the liquid guide pipe 11; the inlet baffle 13 is located at the connection point, which can directly block and redirect the high-speed flowing mixture. During the process, collisions will occur, resulting in preliminary separation of gas and liquid. Some gas will float due to its lower density, while the oil-water mixture, with its higher density, will fall to the lower umbrella plate separator 15. When the gas-liquid mixture flows through the lower umbrella plate separator 15, the liquid will flow down the inclined surface of the umbrella plate due to gravity and the adsorption effect of the umbrella plate surface, while the gas will flow upward through the gaps between the umbrella plates, achieving further stratification of gas and liquid. The upper umbrella plate separator 14 can intercept tiny droplets entrained in the floating gas. The air bubbles carried in the liquid will further escape at the lower umbrella plate. The defoaming net 16 is located at the upper end of the upper umbrella plate separator 14, which can perform final fine filtration on the upward flowing gas. The tiny droplets remaining in the gas, such as oil mist and water mist, will be intercepted and aggregated by the fine mesh of the defoaming net 16, forming larger droplets that fall back under gravity. This ultimately makes the gas entering the natural gas pipe more pure, avoiding the waste of resources or pipeline corrosion caused by liquid being discharged with natural gas, and ensuring the safety of subsequent natural gas transportation and utilization. The natural gas after multi-stage separation is directly discharged through the natural gas pipe at the upper end of the gas-liquid separation pipe 1. The path is short and independent, avoiding the gas from being retained in the separation pipe or mixing with the liquid again.

[0021] Example 3: As Figure 1 - Figure 4 As shown, a base plate 22 is fixedly installed on one side of the lower end of the gas-liquid separation pipe 1, and a side support 23 is fixedly installed on one side of the base plate 22. The oil-water separation pipe 24 is fixedly installed on the upper end of the side support 23. A drain pipe 12 is fixedly connected to one side of the lower end of the gas-liquid separation pipe 1. The drain pipe 12 is connected to the pre-sedimentation zone 20 of the gas-liquid separation pipe 1.

[0022] In this embodiment, the combination of the base plate 22 and the side support frame 23 provides a stable support structure for the system. This ensures the stability of the gas-liquid separation pipe 1 during upright operation and allows the side support frame 23 to precisely fix the position of the oil-water separation pipe 24, ensuring that the connection between the two is subjected to balanced forces. This prevents the connection from becoming loose due to equipment vibration or fluid impact, thus improving operational safety. It is especially suitable for working conditions such as offshore platforms where there is turbulence. The drain pipe 12 is directly connected to the pre-sedimentation zone 20, which can promptly discharge the solid impurities or aged sludge that have settled in the pre-sedimentation zone 20. This prevents the accumulation of impurities from clogging the oleophilic and hydrophilic fiber woven mesh, avoids obstruction of the flow channel and affecting the flow efficiency of the oil-water mixture, and reduces the frequency of manual cleaning, thereby reducing maintenance costs and ensuring the continuous and efficient separation function of the pre-sedimentation zone 20.

[0023] Working principle: like Figure 1 - Figure 6As shown, during use, the three-phase liquid enters the gas-liquid separation pipe 1 through the liquid guide pipe 11. The inlet baffle 13 can directly block the high-speed inflow of the mixture and change its flow direction. When the mixture collides with the baffle, the gas-liquid density difference can achieve preliminary gas-liquid separation. The principle is that the less dense gas rises upward, while the denser oil-water mixture flows downward. The downward-flowing oil-water mixture will first contact the lower umbrella plate separator 15. The liquid is affected by gravity and the adsorption force on the umbrella plate surface, and slowly flows down the inclined surface of the umbrella plate; the gas continues to flow upward through the gap between the umbrella plates, completing the secondary gas-liquid stratification. When the upward-floating gas then passes through the upper umbrella plate separator 14, the tiny liquid droplets entrained in the gas are intercepted by the umbrella plate and flow down the umbrella plate back into the liquid. At the same time, a small number of bubbles carried in the liquid will further escape in the lower umbrella plate area and flow upward. Next, the gas passes through the defoaming net 16 located at the upper end of the upper umbrella plate separator 14. The fine mesh of the defoaming net 16 intercepts and agglomerates the tiny droplets such as residual oil mist and water mist in the gas, forming larger droplets that fall back under gravity. Finally, the natural gas that meets the purity standard is directly discharged through the natural gas pipe at the upper end of the gas-liquid separation pipe 1, avoiding stagnation in the pipe or re-mixing with the liquid.

[0024] After gas-liquid separation, the oil-water mixture falls under gravity and smoothly enters the guide pipe 19 along the inclined guide plate 18. The inclined guide plate 18 reduces the flow velocity of the oil-water mixture, preventing it from directly impacting the bottom of the equipment and generating turbulence, and avoiding the remixing of the oil and water that have already partially separated in the initial oil-water mixture. At the same time, the flow space at the bottom of the guide pipe 19 and the gas-liquid separation pipe 1 provides a transition buffer for the fluid, allowing the oil-water mixture to enter the pre-sedimentation zone 20 at a uniform flow rate. As the mixture continues to enter, the liquid level in the pre-sedimentation zone 20 gradually rises, and it passes through two layers of oleophilic and hydrophilic fiber woven mesh 21. The fiber mesh adsorbs tiny oil droplets through its surface oleophilic properties, causing them to coalesce into larger oil droplets, facilitating subsequent separation. Meanwhile, larger particulate impurities in the liquid settle at the bottom of the pre-sedimentation zone 20. The oil-water mixture that has completed the initial treatment gradually overflows through the pre-weir plate 26 into the post-separation zone 30 as the liquid level rises, and then passes through multiple stacked corrugated baffles 27. Multiple corrugated baffles 27 can effectively extend the flow path of the oil-water mixture and increase its residence time in the separation zone, allowing the less dense oil phase and the more dense water phase to fully separate. After separation, the oil phase overflows through the post-weir plate 28 into the oil storage zone 29 and is finally discharged from the oil drain pipe 25; the water phase remains in the post-separation zone 30 and is discharged through the drain pipe 31, achieving complete oil-water separation.

[0025] The device has a compact overall structure and a small footprint, making it particularly suitable for use on offshore platforms with limited space. In the entire system, the bottom plate 22 and the side support frame 23 work together to provide stable support: the bottom plate 22 ensures that the gas-liquid separation pipe 1 operates vertically and stably, and the side support frame 23 precisely fixes the position of the oil-water separation pipe 24, so that the force at the connection point of the two is balanced, avoiding loosening of the connection due to vibration or fluid impact; at the same time, the drain pipe 12 is connected to the pre-sedimentation zone 20, which can discharge the settled solid impurities or aged sludge in a timely manner, preventing blockage of the fiber mesh or obstruction of the flow channel, and ensuring the continuous and efficient operation of the system.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A compact oil-gas-water separation system based on subsurface flow and fiber alternating coalescence synergy, comprising a gas-liquid separation pipe (1) and an oil-water separation pipe (24), wherein the gas-liquid separation pipe (1) and the oil-water separation pipe (24) are connected and fixed, characterized in that: An inclined guide plate (18) is fixedly installed at the lower end of the middle section of the gas-liquid separation pipe (1), and a guide pipe (19) is fixedly installed on one side of the lower end of the gas-liquid separation pipe (1). A pre-sedimentation zone (20) is formed between the lower end of the gas-liquid separation pipe (1), the inclined guide plate (18), and the guide pipe (19). Oil- and hydrophilic fiber woven meshes (21) are fixedly installed above and below the middle section of the pre-sedimentation zone (20). The oil-water separation pipe (24) is connected to and fixedly connected to the sewage pipe (1). At the upper end of 2), a pre-weir plate (26) is fixedly installed at one end of the oil-water separation pipe (24) close to the gas-liquid separation pipe (1), and a post-weir plate (28) is fixedly installed at the middle of the other end of the oil-water separation pipe (24). A post-separation zone (30) is formed between the pre-weir plate (26) and the post-weir plate (28). Multiple corrugated baffles (27) are fixedly installed in the middle of the post-separation zone (30), and the multiple corrugated baffles (27) are stacked and arranged on one side.

2. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 1, characterized in that: A liquid guide pipe (11) is fixedly connected to one side of the upper middle part of the gas-liquid separation pipe (1), and an inlet baffle (13) is fixedly installed on one side of the inner wall of the gas-liquid separation pipe (1). The inlet baffle (13) is located at the connection between the liquid guide pipe (11) and the gas-liquid separation pipe (1).

3. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 2, characterized in that: The upper umbrella plate separator (14) and the lower umbrella plate separator (15) are fixedly installed on the upper and lower sides of the middle part of the inlet baffle (13), respectively. The upper umbrella plate separator (14) and the lower umbrella plate separator (15) are both located in the middle of the gas-liquid separation pipe (1).

4. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 2, characterized in that: The upper end of the gas-liquid separation pipe (1) is connected to a natural gas pipe (17), and a defoaming net (16) is fixedly installed in the middle of the upper end of the gas-liquid separation pipe (1). The defoaming net (16) is located at the upper end of the upper umbrella plate separator (14).

5. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 1, characterized in that: A base plate (22) is fixedly installed on one side of the lower end of the gas-liquid separation pipe (1), and a side support (23) is fixedly installed on one side of the base plate (22). The oil-water separation pipe (24) is fixedly installed on the upper end of the side support (23).

6. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 1, characterized in that: A drain pipe (12) is fixedly connected to one side of the lower end of the gas-liquid separation pipe (1), and the drain pipe (12) is connected to the pre-sedimentation zone (20) of the gas-liquid separation pipe (1).

7. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 1, characterized in that: The inner diameter of the guide tube (19) is about one-third of that of the gas-liquid separation tube (1). A flow space is provided between the lower end of the guide tube (19) and the bottom of the gas-liquid separation tube (1). The guide tube (19) is connected to the pre-sedimentation zone (20).

8. The compact oil-gas-water separation system based on the synergistic effect of subsurface flow and fiber alternating coalescence as described in claim 1, characterized in that: An oil storage area (29) is formed between the other end of the post-weir plate (28) and the oil-water separation pipe (24). The other end of the oil-water separation pipe (24) is connected to and fixed with an oil drain pipe (25). One side of the middle part of the oil-water separation pipe (24) is connected to and fixed with a drain pipe (31). The oil drain pipe (25) and the drain pipe (31) are respectively connected to the oil storage area (29) and the post-separation area (30).

Images