Compact air flotation device

Abstract

The utility model discloses a compact air flotation device, which relates to the technical field of petroleum and natural gas treatment and comprises an oil-water separation barrel, an oil collection barrel is erected in the middle of an inner cavity of the oil-water separation barrel, a water collection barrel is arranged on the outer surface of the oil collection barrel, and meanwhile, an oil collection barrel is arranged on the outer surface of the water collection barrel. After the liquid level in the oil collecting barrel continuously rises, separated oil in the oil collecting barrel enters the oil discharging cavity through the special-shaped pipe, and the electromagnetic control valve on the oil phase outlet is opened after the liquid level sensor detects the high liquid level and is closed after the liquid level is reduced to the low liquid level, so that the low-frequency switching type operation mode of the electromagnetic control valve on the oil phase outlet is maintained; valve sealing elements are effectively protected, and the service life of the valve is greatly prolonged. Meanwhile, as the oil discharge cavity is large in size and large in liquid storage amount, the oil discharge cavity can adapt to various treatment capacity changes, liquid seal in the oil discharge cavity of the oil-water separation barrel is effectively formed, and gas covered in the oil-water separation barrel is prevented from channeling to downstream waste oil collection equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and natural gas processing, and in particular relates to a compact air flotation device. Background Art

[0002] In the oil and gas processing process, the compact flotation device is a commonly used processing equipment. Through the principles of flotation and cyclone, a small amount of hydrocarbon components in the produced water can be removed to meet the production water discharge requirements.

[0003] At present, the most prominent problem in the operation of this compact flotation device is that, in order to ensure a good treatment effect, the volume of the internal oil collecting chamber is generally small, the liquid level in the oil chamber rises or falls frequently, and the control valve used to control the oil chamber liquid level is frequently switched on and off, which is very prone to internal leakage. After the oil chamber drain valve leaks, the oil chamber liquid level cannot be established for a long time, and the internal covering gas continuously leaks through the oil chamber to the oil discharge process, increasing the system's gas consumption. In severe cases, the system cannot maintain pressure and the produced water treatment cannot meet the emission requirements. Utility Model Content

[0004] The utility model aims to provide a compact flotation device to solve the problem of the compact flotation device with separate collection and discharge arrangements proposed in the background technology, change the frequently changing liquid level processing into a slowly changing liquid level processing, prevent the occurrence of problems such as increased internal leakage of the valve and instability of the oil phase liquid level control, and effectively increase the service life of the device.

[0005] To achieve the above-mentioned purpose, the specific technical scheme of the utility model is as follows: a compact flotation device, including an oil-water separation cylinder for separating oil and water, and an oil collecting cylinder is arranged in the middle of the inner cavity of the oil-water separation cylinder, and a water collecting cylinder is arranged on the outer surface of the oil collecting cylinder. At the same time, an oil collecting cylinder is arranged on the outer surface of the water collecting cylinder, and a special-shaped tube is arranged through the inner cavity of the oil collecting cylinder, and the other end of the special-shaped tube passes through the water collecting cylinder and extends to the outside of the oil collecting cylinder.

[0006] Preferably, the end of the oil-water separation cylinder is connected to a covering air pipe, and the bottom of the right side of the inner cavity of the oil-water separation cylinder is connected to an oil phase outlet. At the same time, the inner cavity of the oil collecting cylinder is connected to a water phase outlet.

[0007] Preferably, a one-way valve is installed on the surface of the special-shaped pipe, a liquid level sensor is installed on the end of one side of the inner cavity of the oil-water separation cylinder, and a control terminal is installed on the outer side of the oil-water separation cylinder.

[0008] Preferably, a circulation pump is provided on one side of the oil-water separation cylinder for circulating, filtering and separating the oil and water, and the input end and the output end of the circulation pump are respectively connected to connecting pipe one and connecting pipe two.

[0009] Preferably, a medium inlet pipe is connected to the bottom of the inner cavity of the oil-water separation cylinder at a tangential position, a nitrogen pipe is provided on one side of the medium inlet pipe, and a venturi is connected to the other end of the nitrogen pipe, and the end of the venturi is connected to a conduit.

[0010] Preferably, a filter plate is provided at the bottom of the inner cavity of the oil-water separation cylinder, and the filter plates are multiple and evenly distributed in annular shape on the inner surface of the oil-water separation cylinder, wherein the filter plates are made of flexible material.

[0011] Preferably, one end of the filter plate is connected to a connecting rod, and one end of the connecting rod passes through the outside of the oil-water separation cylinder and is connected to a gear plate.

[0012] Preferably, a protective cover is connected to the outer side of the oil-water separation cylinder, and an annular plate is provided in the inner cavity of the protective cover, wherein an annular rack 1 and annular rack 2 are respectively provided at the upper and lower ends of the annular plate.

[0013] Preferably, an annular support plate is sleeved on the outer side of the annular plate, and an annular slip ring is slidably mounted on the bottom of the annular support plate.

[0014] Preferably, a driving member is installed at the end of the shield, and the output end of the driving member is connected to a transmission gear, wherein one end of the transmission gear penetrates into the inner cavity of the shield and meshes with an annular rack.

[0015] The compact air flotation device of the utility model has the following advantages:

[0016] The compact air flotation device has the advantages that after the liquid level in the oil collecting cylinder continues to rise, when the liquid level exceeds the top of the internally connected special-shaped pipe, due to the effect of gravity, the separated oil in the oil collecting cylinder will enter the oil discharge chamber on the side opposite to the oil-water separation cylinder and the oil collecting cylinder through the special-shaped pipe, and when the liquid level in the oil discharge chamber is kept stable below the high point of the liquid level sensor, the waste oil separated and accumulated in the oil collecting cylinder will continue to flow into the oil discharge chamber, stabilizing the oil level in the oil collecting chamber at the top of the special-shaped pipe; when the liquid level in the oil discharge chamber exceeds the top of the special-shaped pipe, due to the principle of the communicating vessel, the liquid level in the oil collecting chamber rises with the rise of the liquid level in the oil discharge chamber on the oil collecting cylinder, and keeps changing synchronously; and the electromagnetic control valve on the oil phase outlet can maintain the switch control mode, set to open after the liquid level sensor detects a high liquid level, and close after the liquid level drops to a low liquid level; while maintaining the low-frequency switch operation mode of the oil phase outlet, the valve sealing element is effectively protected, and the service life of the valve is greatly extended. At the same time, due to the large volume of the oil discharge chamber and the large amount of liquid stored, it can adapt to various changes in processing volume, effectively forming a liquid seal in the oil discharge chamber of the oil-water separation cylinder, and preventing the covering gas inside the oil-water separation cylinder from flowing to the downstream waste oil collection equipment;

[0017] When the oil in the oil collecting cylinder enters the oil discharge cavity outside the inner cavity of the oil-water separation cylinder through the special-shaped pipe, the filter plate can purify the oil again, so that the purified oil is finally discharged through the oil phase outlet, and the filtered water is discharged through the water phase outlet. After the filter plate is cleaned, the driving part is driven to turn the gear plate through the transmission gear, the annular rack 1, and the annular rack 2 to drive the filter plate to flip. After the filter plate is flipped, external pure water can be passed into the filter plate to clean it. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the overall explosion structure of the utility model;

[0021] Figure 3 This is a schematic cross-sectional view of the oil-water separation cylinder structure of the utility model;

[0022] Figure 4 It is a schematic diagram of the overall structure of the utility model;

[0023] Figure 5 It is a schematic diagram of the assembly of the filter plate and the shield structure of the utility model;

[0024] Figure 6 It is a schematic diagram of the structure decomposition of the filter plate, the shield and the driving member of the utility model;

[0025] Figure 7 This is a schematic diagram of the filter plate structure of the utility model;

[0026] Figure 8 It is a schematic diagram of the assembly of the protective cover and the driving member structure of the utility model.

[0027] Description of the markings in the figure:

[0028] 100, oil-water separation cylinder; 101, covering air pipe; 102, oil phase outlet; 103, water phase outlet;

[0029] 200, oil collecting cylinder; 210, water collecting cylinder; 220, oil collecting cylinder;

[0030] 300, special-shaped pipe; 301, one-way valve; 302, liquid level sensor;

[0031] 400, circulation pump; 401, connecting pipe 1; 402, connecting pipe 2;

[0032] 500, medium inlet pipe; 510, nitrogen pipe; 520, venturi tube; 530, catheter;

[0033] 600, filter plate; 601, connecting rod; 602, gear plate;

[0034] 700, shield; 710, annular plate; 720, annular rack 1; 730, annular rack 2; 740, annular support plate; 741, annular slip ring;

[0035] 800, driving member; 810, transmission gear;

[0036] 900. Control terminal. DETAILED DESCRIPTION

[0037] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0038] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0040] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0041] The disclosure below provides many different embodiments or examples for realizing different structures of the embodiments of the present utility model. In order to simplify the disclosure of the embodiments of the present utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present utility model. In addition, the embodiments of the present utility model can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0042] In order to better understand the purpose, structure and function of the utility model, the following is a further detailed description of a compact air flotation device of the utility model in conjunction with the accompanying drawings.

[0043] like Figure 1-Figure 8 As shown, a compact air flotation device of the utility model comprises an oil-water separation cylinder 100 for separating oil and water, and the oil-water separation cylinder 100 is conical; the end of the oil-water separation cylinder 100 is connected with a covering air pipe 101, and the bottom of the right side of the inner cavity of the oil-water separation cylinder 100 is connected with an oil phase outlet 102, and at the same time, the inner cavity of the oil collecting cylinder 220 is connected with a water phase outlet 103, and the surfaces of the covering air pipe 101, the oil phase outlet 102, the water phase outlet 103, the connecting pipe 1 401, the connecting pipe 2 402 and the nitrogen pipe 510 are all installed with electromagnetic valves for controlling the opening and closing of the inner cavity;

[0044] Specifically, an oil collecting cylinder 200 is arranged in the middle of the inner cavity of the oil-water separation cylinder 100, and a water collecting cylinder 210 is arranged on the outer surface of the oil collecting cylinder 200. At the same time, an oil collecting cylinder 220 is arranged on the outer surface of the water collecting cylinder 210, wherein the bottoms of the water collecting cylinder 210 and the oil collecting cylinder 220 are both connected to the bottom of the inner cavity of the oil-water separation cylinder 100;

[0045] Specifically, through the cooperation of the oil collecting cylinder 200, the water collecting cylinder 210 and the oil collecting cylinder 220, the oil-water separation cylinder 100 can be divided into several chambers. The inner cavity of the oil collecting cylinder 200 is an oil collecting chamber for storing separated oil, wherein the side opposite to the oil collecting cylinder 200 and the water collecting cylinder 210 is an oil-water separation chamber for sending the oil and water to be separated for separation, and the side opposite to the water collecting cylinder 210 and the oil collecting cylinder 220 is a water chamber for storing the separated water liquid. The oil collecting chamber and the water chamber cooperate to separately collect the separated oil liquid, and the inner cavity of the oil-water separation cylinder 100 and the side opposite to the oil collecting cylinder 220 are an oil drain chamber, which is larger than the oil collecting chamber, and is used to send the oil collected by the oil collecting cylinder 200 into the oil drain chamber for storage;

[0046] Specifically, the inner cavity of the oil collecting cylinder 200 is penetrated by a special-shaped pipe 300, and the other end of the special-shaped pipe 300 penetrates the water collecting cylinder 210 and extends to the outside of the oil collecting cylinder 220. The special-shaped pipe 300 is an inverted U-shape, and when the oil in the oil collecting cylinder 200 reaches a certain liquid level, it can flow into the special-shaped pipe 300 and be sent to the oil discharge cavity on the opposite side of the oil collecting cylinder 220 and the oil-water separation cylinder 100;

[0047] Among them, a one-way valve 301 is installed on the surface of the special-shaped pipe 300, so as to prevent the oil from flowing back through the special-shaped pipe 300 when the oil in the oil collecting cylinder 200 is discharged into the oil discharge chamber through the special-shaped pipe 300. A liquid level sensor 302 is installed at the end of one side of the inner cavity of the oil-water separation cylinder 100, and the liquid level sensor 302 is used to control the oil collected in the oil discharge chamber. When the internal oil reaches a certain liquid level and is detected by the liquid level sensor 302, the control terminal 900 controls the valve on the oil phase outlet 102 to open and discharge the separated oil, so as to avoid the frequent opening of the valve on the oil phase outlet 102.

[0048] Among them, a control terminal 900 is installed on the outer side of the oil-water separation cylinder 100, and the control terminal 900 is bidirectionally electrically connected to the liquid level sensor 302, and the output end of the control terminal 900 is electrically connected to the circulation pump 400 and the input end of the solenoid valve respectively;

[0049] Specifically, a circulation pump 400 is provided on one side of the oil-water separation cylinder 100 for circulating, filtering and separating the oil and water. The input end and the output end of the circulation pump 400 are respectively connected to the connecting pipe 1 401 and the connecting pipe 2 402, wherein the other end of the connecting pipe 1 401 is connected to the surface of the water phase outlet 103, and the other end of the connecting pipe 2 402 is connected to one end of the venturi 520, so that the separation liquid in the water cavity can be pumped into the venturi 520 through the connecting pipe 1 401 and the connecting pipe 2 402 by the circulation pump 400, and finally sent back into the oil-water separation cylinder 100 through the conduit 530 and the medium inlet pipe 500;

[0050] Specifically, a medium inlet pipe 500 is connected to the tangential position of the bottom of the inner cavity of the oil-water separation cylinder 100, and the medium inlet pipe 500 is used to transport oil-containing produced water. In order to feed nitrogen, a nitrogen pipe 510 is arranged on one side of the medium inlet pipe 500, and the other end of the nitrogen pipe 510 is connected to a venturi 520, and the end of the venturi 520 is connected to a conduit 530, and the other end of the conduit 530 is connected to the surface of the medium inlet pipe 500, wherein the end of the nitrogen pipe 510 connected to the venturi 520 is connected through a flange, thereby connecting the pipe 2 402, the venturi 520 and the nitrogen pipe 510, so that the circulating water can enter the venturi 520. 0, it is fused with nitrogen and fully mixed to form a large number of extremely small bubble particles. When the feed produced water spirals upward in the oil-water separation cylinder 100, the bubble particles absorb organic hydrocarbons and accelerate their ascent and gather toward the center due to the density difference with water, while the hydrocarbon components in the outer circle of the produced water are continuously adsorbed, and the density becomes larger and larger. Finally, after being transported to the upper part of the inner cavity of the oil-water separation cylinder 100, a funnel-shaped liquid surface is formed, which gradually decreases from the outside to the inside. The inside of the liquid surface is oil, and the outside of the liquid surface is water. In this way, the oil-liquid separation is performed on the oil-containing produced water, and the oil-liquid separation is sent to the oil collecting cylinder 200, while the produced water enters the water cavity on the opposite side of the oil collecting cylinder 220 and the water collecting cylinder 210;

[0051] Specifically, a filter plate 600 is provided at the bottom of the inner cavity of the oil-water separation cylinder 100, wherein the filter plate 600 is located on the side opposite to the oil-water separation cylinder 100 and the oil collecting cylinder 220, and the filter plates 600 are multiple and evenly distributed in annular shape on the inner surface of the oil-water separation cylinder 100, wherein the filter plates 600 are made of flexible material, and two adjacent filter plates 600 are rounded, so that the separated oil can be purified under the action of the multiple filter plates 600; one end of the filter plate 600 is connected to a connecting rod 601, and one end of the connecting rod 601 penetrates the outside of the oil-water separation cylinder 100 and is connected to a gear plate 602, and the connection between the connecting rod 601 and the oil-water separation cylinder 100 is movably connected through a sealed bearing;

[0052] Specifically, the outer side of the oil-water separation cylinder 100 is connected to the shield 700, and the inner cavity of the shield 700 is provided with an annular plate 710, wherein the upper and lower ends of the annular plate 710 are respectively provided with an annular rack 1 720 and an annular rack 2 730; the outer side of the annular plate 710 is sleeved with an annular support plate 740, and the bottom of the annular support plate 740 is slidably equipped with an annular slip ring 741, wherein the outer surface of the annular slip ring 741 is connected to the inner surface of the shield 700, therefore, under the action of the annular support plate 740 and the annular slip ring 741, the annular plate 710 is slidably supported, thereby increasing the stability of the annular plate 710 during subsequent movement;

[0053] Specifically, a driving member 800 is installed at the end of the shield 700, and the output end of the driving member 800 is connected to a transmission gear 810, wherein one end of the transmission gear 810 penetrates into the inner cavity of the shield 700 and meshes with the annular rack 720, wherein a through cavity cooperating with the transmission gear 810 is opened on the surface of the shield 700, so that when the driving member 800 is working, the transmission gears 810 and 830 are driven to rotate through the transmission gear 810 and the annular rack 720, and the rotation of 830 drives the gear plate 602 to rotate, which can then drive the filter plate 600 to flip, thereby facilitating the subsequent cleaning of impurities collected on the filter plate 600.

[0054] A compact flotation device has a working principle: the medium inlet pipe 500 can send the produced water into the oil-water separation cylinder 100 for oil-water separation, the circulating pump 400 can work on the filtered water to make it flow back to the venturi 520, merge with nitrogen, and fully mix to form a large number of extremely small bubble particles. When the feed produced water spirals upward in the oil-water separation cylinder 100, the bubble particles absorb organic hydrocarbons to accelerate the rise and gather toward the center due to the density difference with water, while the hydrocarbon components in the outer circle of the produced water are continuously absorbed, and the density is getting larger and larger. Finally, after moving to the upper part of the inner cavity of the oil-water separation cylinder 100, a funnel-shaped liquid surface is formed with the liquid level gradually decreasing from the outside to the inside. The inside of the liquid surface is oil, and the outside of the liquid surface is water. In this way, the oil-liquid separation of the oil-containing produced water is carried out, and the oil-liquid separation is sent to the oil collecting cylinder 200, while the produced water enters the water cavity on the opposite side of the oil collecting cylinder 220 and the water collecting cylinder 210;

[0055] The oil overflows upwards to the oil collecting cylinder 200 and accumulates, while the water overflows to the water chamber on the opposite side of the oil collecting cylinder 220 and the water collecting cylinder 210 and accumulates. The electromagnetic control valves on the oil phase outlet 102 and the water phase outlet 103 in the two chambers realize liquid level stability and continuous processing.

[0056] In order to ensure that the treatment quality meets the standards, the circulation pump 400 pressurizes and aerates the treated production water again and then enters the oil-water separation cylinder 100 for further treatment. The production water that has been treated multiple times meets the oil content requirements and meets the discharge standards.

[0057] After the liquid level in the oil collecting barrel 200 continues to rise, when the liquid level exceeds the top of the internally connected special-shaped pipe 300, due to the effect of gravity, the separated oil in the oil collecting barrel 200 will enter the oil discharge chamber on the side opposite to the oil-water separation cylinder 100 and the oil collecting barrel 220 through the special-shaped pipe 300. While the liquid level in the oil discharge chamber is kept stable below the high point of the liquid level sensor 302, the waste oil separated and accumulated in the oil collecting barrel 200 will continue to flow into the oil discharge chamber, stabilizing the oil level in the oil collecting chamber at the top of the special-shaped pipe 300. When the liquid level in the oil discharge chamber exceeds the top of the special-shaped pipe 300, due to the principle of communicating vessels, the liquid level in the oil collecting chamber rises with the liquid level in the oil discharge chamber on the oil collecting barrel 200, and keeps changing synchronously.

[0058] Due to the design of the small volume of the oil collecting chamber and the large volume of the oil drain chamber on the oil collecting cylinder 200, after the waste oil separated by the oil-water separation cylinder 100 is transported to the outer oil drain chamber, it will take a long time to cause a significant change in the liquid level. The electromagnetic control valve on the oil phase outlet 102 can maintain the switch control mode, and is set to open after the liquid level sensor 302 detects a high liquid level, and close after the liquid level drops to a low liquid level. While maintaining the low-frequency switch operation mode of the oil phase outlet 102, the valve sealing components are effectively protected and the service life of the valve is greatly extended. At the same time, due to the large volume of the oil drain chamber and the large amount of liquid stored, it can adapt to various changes in processing volume, effectively forming a liquid seal in the oil drain chamber of the oil-water separation cylinder 100, and preventing the internal covering gas of the oil-water separation cylinder 100 from flowing to the downstream waste oil collection equipment;

[0059] When the oil in the oil collecting cylinder 200 enters the oil discharge cavity outside the inner cavity of the oil-water separation cylinder 100 through the special-shaped pipe 300, the filter plate 600 can purify the oil again, so that the purified oil is finally discharged through the oil phase outlet 102, and the filtered water is discharged through the water phase outlet 103. After cleaning the filter plate 600, the driving member 800 is driven to move the gear plate 602 through the transmission gear 810, the annular rack 1 720, and the annular rack 2 730, so as to drive the filter plate 600 to flip over. After the filter plate 600 is flipped, external pure water can be passed into the filter plate 600 to clean it.

[0060] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A compact air flotation device, characterized in that: The invention comprises an oil-water separation cylinder (100) for separating oil and water, an oil collecting cylinder (200) is arranged in the middle of the inner cavity of the oil-water separation cylinder (100), and a water collecting cylinder (210) is arranged on the outer surface of the oil collecting cylinder (200). At the same time, an oil collecting cylinder (220) is arranged on the outer surface of the water collecting cylinder (210), and a special-shaped pipe (300) is arranged through the inner cavity of the oil collecting cylinder (200), and the other end of the special-shaped pipe (300) passes through the water collecting cylinder (210) and extends to the outside of the oil collecting cylinder (220).

2. The compact air flotation device according to claim 1, characterized in that: The end of the oil-water separation cylinder (100) is connected to a covering air pipe (101), and the bottom of the right side of the inner cavity of the oil-water separation cylinder (100) is connected to an oil phase outlet (102). At the same time, the inner cavity of the oil collecting cylinder (220) is connected to a water phase outlet (103).

3. The compact air flotation device according to claim 2, characterized in that: A one-way valve (301) is installed on the surface of the special-shaped pipe (300), a liquid level sensor (302) is installed at the end of one side of the inner cavity of the oil-water separation cylinder (100), and a control terminal (900) is installed on the outside of the oil-water separation cylinder (100).

4. The compact air flotation device according to claim 1, characterized in that: A circulation pump (400) is provided on one side of the oil-water separation cylinder (100) for circulating, filtering and separating oil and water. The input end and the output end of the circulation pump (400) are respectively connected to a connecting pipe 1 (401) and a connecting pipe 2 (402).

5. The compact air flotation device according to claim 1, characterized in that: A medium inlet pipe (500) is connected to a tangential position of the bottom of the inner cavity of the oil-water separation cylinder (100), a nitrogen pipe (510) is arranged on one side of the medium inlet pipe (500), and the other end of the nitrogen pipe (510) is connected to a venturi (520), and the end of the venturi (520) is connected to a conduit (530).

6. The compact air flotation device according to claim 1, characterized in that: A filter plate (600) is arranged at the bottom of the inner cavity of the oil-water separation cylinder (100), and the filter plates (600) are multiple and evenly distributed in an annular shape on the inner surface of the oil-water separation cylinder (100), wherein the filter plates (600) are made of a flexible material.

7. The compact air flotation device according to claim 6, characterized in that: One end of the filter plate (600) is connected to a connecting rod (601), and one end of the connecting rod (601) penetrates to the outside of the oil-water separation cylinder (100) and is connected to a gear plate (602).

8. The compact air flotation device according to claim 1, characterized in that: The outer side of the oil-water separation cylinder (100) is connected to a protective cover (700), and the inner cavity of the protective cover (700) is provided with an annular plate (710), wherein an annular rack 1 (720) and an annular rack 2 (730) are respectively provided at the upper and lower ends of the annular plate (710).

9. The compact air flotation device according to claim 8, characterized in that: An annular support plate (740) is sleeved on the outer side of the annular plate (710), and an annular sliding ring (741) is slidably mounted on the bottom of the annular support plate (740).

10. The compact air flotation device according to claim 8, characterized in that: A driving member (800) is installed at the end of the shield (700), and the output end of the driving member (800) is connected to a transmission gear (810), wherein one end of the transmission gear (810) penetrates into the inner cavity of the shield (700) and meshes with an annular rack (720).

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