Two-chamber bidirectional ultrasonic coalescence oil-water separation method and device

Abstract

The invention discloses a two-chamber bidirectional ultrasonic coalescence oil-water separation method and device, and the device comprises a vertical tank body, an ultrasonic transducer, a directional water inlet pipe, a water outlet pipe, an oil outlet pipe, an ultrasonic generator, a flow direction switching device and the like. Meanwhile, micro-aeration is assisted to increase the floating speed of oil drops, self-cleaning of the coalescence material is promoted, the problems of coalescence material pollution, low treatment efficiency, large maintenance workload and the like caused by single flow direction are solved, oil, water and solid three-phase separation of the treated oil-containing produced water can be effectively realized, the treatment requirement is met, the effective service time of the coalescence material is prolonged, and the production cost is reduced. The maintenance workload is reduced.

Description

Technical Field

[0001] The invention belongs to the field of water treatment, and in particular relates to a two-chamber bidirectional ultrasonic and coalescence oil-water separation method and device. Background Art

[0002] In recent years, with the vigorous development of oil extraction, the situation of environmental protection has become increasingly severe. The produced water from the oil field is injected back into the formation to drive oil after treatment. The water quality treatment is the key to avoid formation blockage and is highly valued. At present, the main technologies for treating produced water from oil fields include sedimentation, biochemical, flotation, filtration and other methods.

[0003] Sedimentation is often used as the first-level process for produced water treatment to initially achieve oil-water separation and suspended solids precipitation, reducing the load of subsequent flotation, biochemical, and filtration processes. The principle of sedimentation oil removal is mainly to use the density difference between oil and water to achieve oil-water separation through static sedimentation or slow flow. The main objects of separation are floating oil and finely dispersed oil in the water. However, for polymer-containing produced water and shale oil produced water, the oil in the water mostly exists in a stable emulsified state of oil-in-water and water-in-oil. The separation efficiency of the sedimentation process is very low, resulting in a heavy load on subsequent processes and failure to meet the standards for reinjection. With the development of oil production technology in recent years, ultrasonic demulsification and coalescence oil removal processes have gradually been widely used due to their good demulsification effect and wide adaptability.

[0004] CN202400923U discloses an ultrasonic coalescence flotation oil removal device, comprising a tank body, a water inlet being arranged at one end of the tank body, a water outlet being arranged at the other end opposite to the water inlet, and an ultrasonic pulse system, a coalescence filler area and a flotation system being arranged in sequence in the tank body along the water flow direction.

[0005] CN112479452A discloses an ultrasonic agglomeration and agglomeration produced water oil-water separation combined device, which comprises a coarse separation chamber and a fine separation chamber. The fine separation chamber is arranged on the upper part of the top partition of the coarse separation chamber, an ultrasonic agglomeration filler area is arranged on the outside of the partition on one side of the coarse separation chamber, an ultrasonic transducer is installed in the axial center of the ultrasonic agglomeration filler area, and the fine separation chamber is divided into a lower water outlet buffer area and an upper dirty oil area.

[0006] The above technologies all use the same fixed flow direction, i.e., downstream or countercurrent. Each of the two flow directions has its own advantages and disadvantages. The downstream water flow direction is the same as the direction of the oil droplets. After ultrasound, the water flows through the entire coalescence layer. The coalescence time is long, which is conducive to the floating of oil droplets. However, suspended matter and impurities are very easy to adhere to the inside of the coalescence layer, resulting in the pollution and failure of the coalescence material after a period of operation. Therefore, it is suitable for water with less oil content; the countercurrent water flow direction is opposite to the direction of the oil droplets. Small oil droplets form large oil droplets in the coalescence process and then float up. The water flow carries the impurities on the surface of the coalescence material to sink during the descent process, which plays a certain cleaning role and is more suitable for water with a higher oil content. However, when the water quality fluctuates greatly, the current fixed flow direction process cannot adjust the ultrasonic coalescence flow direction according to the different oil content in the produced water on site, resulting in the coalescence material being easily polluted and difficult to clean, affecting the performance of ultrasonic and coalescence effects, resulting in the gradual deterioration of the oil-water separation effect after a period of operation. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the problem of agglomeration material pollution caused by a single flow direction in the background technology, and to provide a two-chamber bidirectional ultrasonic and agglomeration oil-water separation method and device. The treated oil-containing produced water can effectively achieve the three-phase separation of oil, water and solid to meet the treatment requirements, and extend the effective use time of the agglomeration material and reduce the maintenance workload.

[0008] The present invention adopts the technical solution to achieve:

[0009] A two-chamber bidirectional ultrasonic and coalescing oil-water separation device, comprising a vertical tank, an ultrasonic transducer, a directional water inlet pipe, an ultrasonic generator and a flow direction switching device;

[0010] The vertical tank is divided into two chambers by a weir plate, namely an ultrasonic coalescence chamber and an oil-water separation chamber. An integrated coalescence filler area is arranged in the middle of the ultrasonic coalescence chamber.

[0011] The upper and lower parts of the ultrasonic coalescence chamber and the oil-water separation chamber are both provided with water distributors / collectors. The ultrasonic transducer is installed outside the vertical tank body at a height level with the upper and lower water distributors / collectors. The ultrasonic transducer is connected to the ultrasonic generator.

[0012] The flow direction switching device is used to split the directional water inlet pipe into two directions, upper and lower, and enter the ultrasonic coalescence chamber of the vertical tank through the water distribution / collection device;

[0013] The middle and upper part of the oil-water separation chamber is connected with a U-shaped pipe, the upper part of the oil-water separation chamber is provided with an oil collecting weir, and the bottom of the oil collecting weir is provided with an oil outlet.

[0014] A further improvement of the present invention is that the ultrasonic coalescence chamber is provided with coalescence material, and the coalescence material is made of hydrophilic polyvinyl chloride or stainless steel.

[0015] A further improvement of the present invention is that the flow direction switching device includes an online oil content monitor, a downstream switching valve, a upstream switching valve and a control cabinet thereof. The online oil content monitor is used to detect the oil content in the water and transmit it to the control cabinet. The control cabinet is interlocked to automatically open or close the downstream switching valve or the upstream switching valve. One path is a downstream flow, entering the ultrasonic agglomeration chamber from the bottom of the vertical tank body, and the other path is a upstream flow, entering the ultrasonic agglomeration chamber from the top of the vertical tank body.

[0016] A further improvement of the present invention is that both the downstream switching valve and the upstream switching valve are electric valves.

[0017] A further improvement of the present invention is that the diverting water inlet pipe can be switched to the ultrasonic coalescing chamber outlet pipe in the countercurrent state through a countercurrent water outlet switching valve.

[0018] A further improvement of the present invention is that a water outlet is arranged at the lower middle part of the vertical tank body.

[0019] A further improvement of the present invention is that a conical mud collecting area is provided at the bottom of the vertical tank body, and a mud discharge port is provided at the bottom.

[0020] A further improvement of the present invention is that the mud discharge port is connected with a sewage discharge pipe.

[0021] A further improvement of the present invention is that a micro-aerator is provided at the bottom of the ultrasonic coalescence chamber and is connected to the micro-aeration pipe.

[0022] A two-chamber bidirectional ultrasonic and coalescence oil-water separation method, based on the two-chamber bidirectional ultrasonic and coalescence oil-water separation device, comprises:

[0023] Determination of oil content and properties of water quality;

[0024] Online monitoring of oil content When the oil content in produced water is high, the flow direction switching device automatically switches to countercurrent mode. Produced water enters the vertical tank from the upper water inlet, and enters the coalescing filler area in countercurrent after ultrasonic demulsification. Since oil is lighter, most of the floating oil is retained in the upper part of the coalescing filler area and will not enter the coalescing material with the water flow, avoiding material pollution. After the emulsified oil and water pass through the coalescing material, they flow into the upper middle part of the oil-water separation chamber through the U-shaped pipe. Due to the difference in oil and water density, according to the U-shaped pipe principle, the floating oil in the coalescing filler area gathers to the set thickness and reaches the upper part of the oil-water separation chamber through the weir plate.

[0025] When the oil content in produced water is relatively low and the emulsification degree is high, the flow direction switching device automatically switches to the downstream mode. Produced water enters the vertical tank from the lower water inlet, enters the coalescing packing area downstream after ultrasonic treatment, and the outlet water enters the upper part of the oil-water separation chamber through the weir plate; the split-way water inlet pipe controls the dual flow direction through the switching valve, and the split-way water inlet pipe is the outlet pipe of the ultrasonic coalescing chamber when it is in the downstream state at the same time;

[0026] The water after ultrasound and coalescence is separated by sedimentation in the oil-water separation chamber, and the oil, water and solid are separated into three phases to achieve the treatment effect.

[0027] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0028] The present invention provides a two-chamber bidirectional ultrasonic and coalescence oil-water separation device, which is divided into an ultrasonic coalescence chamber and an oil-water separation chamber. The ultrasonic coalescence chamber is provided with an upper ultrasonic zone, a lower ultrasonic zone and a middle coalescence zone. The mechanical vibration and thermal action of unidirectional ultrasound cause oil droplets and water droplets to collide and coalesce under the action of the sound field, and then the coalescence material is used to form large oil droplets that float up to achieve oil-water separation. The oil content of produced water containing oil varies greatly depending on the water quality. When the oil content is high, the proportion of floating oil and dispersed oil is large. The upper water inlet countercurrent flow direction is adopted. The oil layer formed after ultrasound floats up directly, and the produced water containing only a small amount of emulsified oil passes through the coalescence layer and coalesces and floats up again, avoiding the pollution of the coalescence layer by floating oil and dispersed oil. When the oil content is low, the proportion of dispersed oil and emulsified oil is large. The lower water inlet downstream flow direction is adopted. The oil-containing produced water is ultrasonically demulsified and then flows downstream through the entire coalescence layer, giving the oil droplets enough time to form, grow and aggregate, thereby achieving oil-water separation. Compared with single-direction ultrasonic coalescence, it is more adaptable to different water qualities, and can protect the coalescence layer to reduce pollution and extend the service life when the oil content is high. Micro-aeration is set at the bottom of the device to increase turbulence in the coalescence zone, reduce the attachment of debris to the coalescence material through micro-vibration, keep the coalescence channel smooth, extend the coalescence service life, and reduce maintenance workload.

[0029] The present invention provides a two-chamber bidirectional ultrasonic and coalescence oil-water separation method, which separates oil and water through the synergistic effect of ultrasound and coalescence. Ultrasound has mechanical vibration and thermal effect, which promotes the collision and aggregation of oil droplets and water droplets under the action of the sound field. The coalescence material has the function of aggregating small oil droplets and growing them into large oil droplets, and the oil droplets float up to achieve oil-water separation. The technical characteristics of the present invention are that the ultrasonic coalescence chamber is equipped with upper and lower ultrasound and middle coalescence, and the inlet water automatically switches to select the downstream and countercurrent ultrasonic coalescence flow directions according to the water quality of the oil-containing produced water. When the oil content is large, the upper water inlet countercurrent process is adopted, and the oil layer formed after ultrasound floats directly, and the produced water containing only a small amount of emulsified oil passes through the coalescence layer and coalesces again to float, avoiding the pollution of the coalescence layer by floating oil and dispersed oil; when the oil content is small, the lower water inlet downstream flow direction is adopted, and the oil-containing produced water is demulsified by ultrasound, and then flows downstream through the coalescence layer throughout the process, giving the oil droplets enough time to form, grow and aggregate, thereby improving the oil-water separation effect. The technical solution of the present invention is more adaptable to different water quality conditions in different development stages through a two-chamber, dual-flow design. The flow direction is easy to switch and has an auxiliary micro-aeration self-cleaning function, which is more conducive to oil-water separation. At the same time, it reduces the pollution of agglomeration materials, extends the service life, and reduces maintenance workload.

[0030] In summary, the present invention adopts bidirectional ultrasound and coalescence methods, automatically switches the ultrasonic coalescence flow direction according to the water quality, and is more adaptable to the fluctuation of upstream water quality; the double-chamber design makes the arrangement of ultrasound, coalescence and oil-water separation more compact; the coalescence filler area is provided with micro-aeration with self-cleaning function, which prolongs the effective use time of the coalescence material and reduces the maintenance workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a two-chamber bidirectional ultrasonic and coalescence oil-water separation device of the present invention.

[0032] Description of reference numerals:

[0033] 1. Vertical tank, 2. Ultrasonic coalescence chamber, 3. Oil-water separation chamber, 4. Ultrasonic transducer, 5. Coalescence filler area, 6. Directional water inlet pipe, 7. Micro-aeration pipe, 8. Water outlet pipe, 9. Oil outlet pipe, 10. Overflow pipe, 11. Drain pipe, 12. Distribution / collection device, 13. Ultrasonic generator, 14. U-shaped pipe, 15. Weir plate, 16. Oil collecting weir, 17. Oil outlet, 18. Water outlet, 19. Downstream switching valve, 20. Countercurrent switching valve, 21. Conical mud collecting area, 22. Mud outlet, 23. Micro-aerator, 24. Countercurrent water outlet switching valve, 25. Oil content online monitor, 26. Control cabinet, 27. Flow direction switching device. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0036] For the convenience of description, if the words "up", "down", "left" and "right" appear in this application, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0037] Terminology explanation section: The terms "install", "connected", "connect", "fixed" and the like in this application should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral whole; it can be a direct connection, or an indirect connection through an intermediate medium, it can be an internal connection between two elements, or an interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0038] like Figure 1 As shown, the present invention provides a two-chamber bidirectional ultrasonic and coalescence oil-water separation device, which includes a vertical tank body 1, an ultrasonic coalescence chamber 2, an oil-water separation chamber 3, an ultrasonic transducer 4, a coalescence filler area 5, a directional water inlet pipe 6, a micro-aeration pipe 7, a water outlet pipe 8, an oil outlet pipe 9, an overflow pipe 10 and a sewage pipe 11, and also includes a flow direction switching device 27 and its control cabinet 26.

[0039] The tank body is provided with an overflow port connected to an overflow pipe 10. The overflow pipe is 100 to 200 mm higher than the normal operating liquid level in the tank. When the water outlet and oil outlet pipes of the treatment device are blocked due to abnormal conditions, the liquid level rises and flows out from the overflow port to avoid overflowing the tank.

[0040] The vertical tank body 1 of the two-chamber bidirectional ultrasonic and coalescing oil-water separation device is divided into two chambers by a weir plate 15, namely an ultrasonic coalescing chamber 2 and an oil-water separation chamber 3. In the ultrasonic coalescing chamber 2, the mechanical vibration and thermal action of ultrasound and the coarsening effect of coalescing materials on oil droplets are utilized to increase the kinetic energy and thermal motion of dispersed oil and emulsified oil in oil-containing produced water, promote the collision opportunities between particles, thereby utilizing the affinity between the same particles to accelerate the completion of the ultrasonic demulsification and coalescing process of the oil-containing produced water, and improve the oil-water separation effect.

[0041] The ultrasonic coalescence chamber 2 is provided with an integrated coalescence filler area 5 in the middle to facilitate the filling and replacement of coalescence materials. The coalescence materials are made of regular hydrophilic polyvinyl chloride and stainless steel. The ultrasonic transducer 4 is installed outside the vertical tank body 1, and its height is level with the upper and lower water inlet / collector 12. The ultrasonic transducer 4 is connected to the ultrasonic generator 13.

[0042] The flow direction switching device 27 divides the directional water inlet pipe 6 into two directions, upper and lower, to enter the ultrasonic coalescing chamber 2 of the vertical tank body 1. The flow direction switching device 27 includes an online oil content monitor 25, a downstream switching valve 19, a reverse flow switching valve 20 and a control cabinet 26. The control cabinet 26 automatically opens or closes the downstream switching valve 19 or the reverse flow switching valve 20 according to the online monitoring data of the oil content of the inlet water. One way is the downstream flow, entering from the bottom of the vertical tank body 1, and the other way is the reverse flow, entering from the top of the vertical tank body 1. A water distributor / collector 12 is provided at the water inlet.

[0043] When the oil content in produced water is high, countercurrent is used. The downstream switching valve 19 is closed and the countercurrent switching valve 20 is opened. The produced water enters the vertical tank 1 from the upper water inlet, and enters the coalescing filler area 5 in the countercurrent after ultrasonic demulsification. Since the oil is lighter, most of the floating oil will be retained in the upper part of the coalescing filler area 5 and will not enter the coalescing material with the water flow to avoid material pollution. After the emulsified oil and water pass through the coalescing material, they flow into the upper middle part of the oil-water separation chamber 3 through the U-shaped tube 14. Due to the difference in density between oil and water, according to the principle of the U-shaped tube 14, When the floating oil in the coalescing filler area 5 gathers to a certain thickness, it will pass through the weir plate 15 to reach the upper part of the oil-water separation chamber 3; when the oil content is relatively low and the emulsification degree is high, the downstream type is adopted, the downstream switching valve 19 is opened, and the reverse current switching valve 20 is closed, and the produced water enters the vertical tank body 1 from the lower water inlet, and then enters the coalescing filler area 5 downstream after ultrasonic treatment. The outlet water turns over the triangular weir plate 15 and enters the upper part of the oil-water separation chamber 3, and an oil collecting weir 16 is provided on the upper part, and an oil outlet 17 is provided at the bottom of the oil collecting weir 16, which is connected to the oil outlet pipe 9.

[0044] A water outlet 18 is provided in the middle and lower part of the vertical tank body 1, and a water outlet pipe 8 is connected to the water outlet 18 and is located in the clarifying area in the middle and lower part of the oil-water separation chamber.

[0045] The diverter water inlet pipe 6 controls the dual flow directions through a downstream switching valve 19 or a reverse switching valve 20. The valve is an electric valve and is started in conjunction with an online oil content monitor.

[0046] The diverting water inlet pipe 6 can be switched to the water outlet pipe of the ultrasonic coalescing chamber 2 in the countercurrent state through the countercurrent water outlet switching valve 24 .

[0047] The bottom of the vertical tank body 1 is provided with a conical mud collecting area 21 , and the bottom is provided with a mud discharge port 22 , which is connected to a sewage pipe 11 .

[0048] A micro-aerator 23 is provided at the bottom of the ultrasonic coalescence chamber 2 and is connected to the micro-aeration pipe 7. It is opened regularly or always opened according to the water quality. On the one hand, it accelerates the floating speed of oil droplets, and on the other hand, it promotes the self-cleaning of the coalescence material and reduces the pollution and blockage of the coalescence filler area 5.

[0049] The present invention provides a two-chamber bidirectional ultrasonic and coalescence oil-water separation method, comprising the following steps:

[0050] (1) Determination of oil content and properties of water;

[0051] (2) Online monitoring of oil content When the oil content in produced water is high, the flow direction switching device 27 automatically switches to countercurrent mode. Produced water enters the vertical tank 1 from the upper water inlet, and enters the coalescing filler area 5 in a countercurrent manner after ultrasonic demulsification. Since oil is lighter, most of the floating oil will remain in the upper part of the coalescing filler area 5 and will not enter the coalescing material with the water flow, thereby avoiding material pollution. After the emulsified oil and water pass through the coalescing material, they flow into the upper middle part of the oil-water separation chamber 3 through the U-shaped tube 14. Due to the difference in density between oil and water, according to the principle of the U-shaped tube 14, the floating oil in the coalescing filler area 5 gathers to a certain thickness and reaches the upper part of the oil-water separation chamber 3 through the weir plate 15.

[0052] (3) Online monitoring of oil content When the oil content in the produced water is relatively low and the emulsification degree is high, the flow direction switching device 27 automatically switches to the downstream mode. The produced water enters the vertical tank 1 from the lower water inlet, enters the coalescing packing area 5 downstream after ultrasonic treatment, and the effluent enters the upper part of the oil-water separation chamber 3 through the weir plate 15; the upper part of the oil-water separation chamber 3 is provided with an oil collecting weir 16, the bottom is provided with a sewage outlet 17, and the middle and lower part is provided with a water outlet 18. The bidirectional water inlet pipe 6 controls the dual flow direction through the switching valve. The bidirectional water inlet pipe 6 is the outlet pipe of the ultrasonic coalescing chamber 2 when it is in the downstream state at the same time.

[0053] (4) Micro-aeration can be turned on regularly according to water quality conditions to speed up the floating speed of oil droplets and promote the self-cleaning of the agglomeration material;

[0054] (5) The water after ultrasonic and coalescence is separated by sedimentation in the oil-water separation chamber 3, and the oil, water and solid are separated to achieve the treatment effect.

[0055] Embodiment 1:

[0056] When the oil content is high (e.g. >100 mg / L) when online monitoring, the produced water automatically switches to countercurrent ultrasonic coalescence oil-water separation through the flow switching device, closes the downstream switching valve 19, opens the countercurrent switching valve 20, and the produced water enters the vertical tank 1 from the upper water inlet, and enters the coalescence packing area 5 in reverse flow after ultrasonic demulsification. Since the oil is light, most of the floating oil will be retained in the upper part of the coalescence packing area 5, and will not enter the coalescence material with the water flow to avoid material pollution. After the emulsified oil and water pass through the coalescence material, they flow into the upper middle part of the oil-water separation chamber 3 through the U-shaped pipe 14. Due to the difference in density between oil and water, according to the U-shaped pipe principle, the floating oil in the coalescence packing area 5 gathers to a certain thickness and reaches the upper part of the oil-water separation chamber 3 through the weir plate 15. The upper part is provided with an oil collecting weir 16, and the bottom of the oil collecting weir 16 is provided with an oil outlet 17 connected to the oil outlet pipe 9. The clarified produced water is discharged through the distribution / collection device 12 to the downstream deep treatment. A micro-aerator 23 is provided at the bottom of the ultrasonic coalescence chamber 2 , which is opened regularly or always opened according to the water quality. On the one hand, it accelerates the floating speed of oil droplets, and on the other hand, it promotes the self-cleaning of the coalescence material and reduces the pollution and blockage of the coalescence filler area 5 .

[0057] Embodiment 2:

[0058] When the oil content is slightly lower (such as ≤100mg / L) when online monitoring, the produced water automatically switches to the downstream ultrasonic coalescence oil-water separation through the flow switching device 27, opens the downstream switching valve 19, closes the reverse flow switching valve 20, and the produced water enters the vertical tank 1 from the lower water inlet, enters the coalescence packing area 55 downstream after ultrasonic treatment, and the effluent water goes over the weir plate 15 and enters the upper part of the oil-water separation chamber 3. After sedimentation, the oil floats to the surface. The upper part is provided with an oil collecting weir 16, and the bottom of the oil collecting weir 16 is provided with an oil outlet 17, which is connected to the oil outlet pipe 9. The clarified produced water is discharged through the distribution / collection device 12 to the downstream deep treatment. A micro aerator 23 is provided at the bottom of the ultrasonic coalescence chamber 2, which is opened regularly or always opened according to the water quality. On the one hand, it accelerates the floating speed of oil droplets, and on the other hand, it promotes the self-cleaning of the coalescence material and reduces the pollution and blockage of the coalescence packing area 5.

[0059] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device, characterized in that: It comprises a vertical tank body (1), an ultrasonic transducer (4), a directional water inlet pipe (6), an ultrasonic generator (13) and a flow direction switching device (27); The vertical tank body (1) is divided into two chambers by a weir plate (15), namely an ultrasonic coalescence chamber (2) and an oil-water separation chamber (3). An integrated coalescence filler area (5) is arranged in the middle of the ultrasonic coalescence chamber (2); The upper and lower parts of the ultrasonic coalescence chamber (2) and the oil-water separation chamber (3) are both provided with water distributors / collectors (12); the ultrasonic transducer (4) is installed outside the vertical tank body (1) at a height level with the upper and lower water distributors / collectors (12); the ultrasonic transducer (4) is connected to an ultrasonic generator (13); The flow direction switching device (27) is used to split the directional water inlet pipe (6) into two directions, upper and lower, and enter the ultrasonic coalescing chamber (2) of the vertical tank body (1) through the water distribution / collection device (12); The middle upper part of the oil-water separation chamber (3) is connected to a U-shaped pipe (14), the upper part of the oil-water separation chamber (3) is provided with an oil collecting weir (16), and the bottom of the oil collecting weir (16) is provided with an oil outlet (17).

2. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 1, characterized in that: The ultrasonic agglomeration chamber (2) is provided with agglomeration material, and the agglomeration material is made of hydrophilic polyvinyl chloride or stainless steel.

3. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 1, characterized in that: The flow direction switching device (27) comprises an online oil content monitor (25), a downstream switching valve (19), a reverse flow switching valve (20) and a control cabinet (26). The online oil content monitor (25) is used to detect the oil content in the water and transmit it to the control cabinet (26). The control cabinet (26) automatically opens or closes the downstream switching valve (19) or the reverse flow switching valve (20) in a chain. One path is a downstream flow, which enters the ultrasonic coalescence chamber (2) from the bottom of the vertical tank body (1). The other path is a reverse flow, which enters the ultrasonic coalescence chamber (2) from the top of the vertical tank body (1).

4. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 3, characterized in that: The downstream switching valve (19) and the upstream switching valve (20) are both electric valves.

5. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 3, characterized in that: The diversion water inlet pipe (6) can be switched to the ultrasonic coalescence chamber water outlet pipe in the countercurrent state through the countercurrent water outlet switching valve (24).

6. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 1, characterized in that: A water outlet (18) is arranged at the middle and lower part of the vertical tank body (1).

7. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 1, characterized in that: A conical mud collecting area (21) is arranged at the bottom of the vertical tank body (1), and a mud discharge port (22) is arranged at the bottom.

8. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 7, characterized in that: The mud discharge port (22) is connected to a sewage discharge pipe (11).

9. A two-chamber bidirectional ultrasonic and coalescing oil-water separation device according to claim 1, characterized in that: A micro-aerator (23) is provided at the bottom of the ultrasonic agglomeration chamber (2) and is connected to the micro-aeration pipe (7).

10. A two-chamber bidirectional ultrasonic and coalescence oil-water separation method, the method is based on a two-chamber bidirectional ultrasonic and coalescence oil-water separation device according to any one of claims 1 to 9, comprising: Determination of oil content and properties of water quality; When the oil content in the produced water is high during online monitoring, the flow direction switching device (27) automatically switches to a countercurrent flow mode. The produced water enters the vertical tank (1) from the upper water inlet, and enters the coalescing filler area (5) in a countercurrent flow after ultrasonic demulsification. Since the oil is relatively light, most of the floating oil is retained in the upper part of the coalescing filler area (5) and will not flow into the coalescing material with the water flow, thereby avoiding material pollution. After the emulsified oil and water pass through the coalescing material, they flow into the upper middle part of the oil-water separation chamber (3) through the U-shaped tube (14). Due to the difference in density between oil and water, according to the principle of the U-shaped tube (14), the floating oil in the coalescing filler area (5) gathers to a set thickness and reaches the upper part of the oil-water separation chamber (3) through the weir plate (15); When the oil content in the produced water is relatively low and the emulsification degree is high during online monitoring of the oil content, the flow direction switching device (27) automatically switches to the downstream mode, and the produced water enters the vertical tank body (1) from the lower water inlet, enters the coalescing packing area (5) downstream after ultrasonic treatment, and the outlet water enters the upper part of the oil-water separation chamber (3) through the weir plate (15); the bidirectional water inlet pipe (6) controls the dual flow direction through the switching valve, and the bidirectional water inlet pipe (6) is the outlet pipe of the ultrasonic coalescing chamber (2) when it is in the downstream state at the same time; The water after ultrasonic and coalescence is separated by sedimentation in the oil-water separation chamber (3), and the three phases of oil, water and solid are separated to achieve the treatment effect.

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