Liquid-liquid multistage separation system

Abstract

The utility model discloses a liquid liquid multistage separation system, including the air floatation tank of vertical structure, the air floatation tank side is provided with pressure dissolved gas tank, the inside air floatation tank is provided with a plurality of air floatation cavities along the longitudinal direction, is equipped with the partition plate between adjacent air floatation cavities, the partition plate bottom is installed with the communicating pipe, and the liquid solenoid valve is installed on the communicating pipe, the bottom of air floatation cavity all is installed with the dissolved gas release ware, and the dissolved gas release ware is installed in the export end of dissolved gas branch pipe, and the top of dissolved gas release ware all is installed with the air distribution plate of circular structure, and the air distribution plate all has evenly distributed a plurality of openings. The liquid liquid multistage separation system provided by the utility model can realize the cascade fine treatment of sewage through multistage series connection, improve the treatment effect of small and emulsified oil drops, and can improve the air floatation utilization rate and separation efficiency.

Description

Technical Field

[0001] This utility model relates to a liquid-liquid multi-stage separation system, belonging to the field of oily wastewater treatment technology. Background Technology

[0002] In oilfield development, especially in the middle and later stages, large amounts of water are injected into the oil-bearing reservoir to maintain formation pressure and improve crude oil recovery. This water is extracted along with the crude oil, forming a large amount of oil-bearing produced water. The produced water contains a large amount of dispersed oil, emulsified oil, and dissolved oil, requiring strict treatment. Oil removal is a key step in the treatment process.

[0003] Traditional air flotation separation and oil removal devices generally suffer from the following technical problems during use: 1. The short contact time and limited opportunities between oil droplets and bubbles result in incomplete removal of emulsified and dispersed oils with small particle sizes that are difficult to separate; 2. Bubbles tend to concentrate and rise, forming air columns and creating dead zones in the air flotation process. This reduces the collision efficiency between bubbles and oil droplets, resulting in low air flotation utilization.

[0004] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0005] This invention addresses the shortcomings of the prior art by providing a multi-stage liquid-liquid separation system that can achieve tiered fine treatment of wastewater through multi-stage series connection, improve the treatment effect on fine and emulsified oil droplets, and increase the utilization rate and separation efficiency of air flotation.

[0006] To solve the above technical problems, the present invention adopts the following technical solution: The liquid-liquid multi-stage separation system includes a vertically structured flotation tank with a pressure dissolved gas tank on the side. Multiple flotation chambers are longitudinally arranged inside the flotation tank, with partition plates between adjacent chambers. A connecting pipe is installed at the bottom of the partition plate, and a liquid solenoid valve is installed on the connecting pipe. A dissolved gas release device is installed at the bottom of each flotation chamber, located at the outlet end of a dissolved gas branch pipe. A circular gas distribution plate with several openings is installed above each dissolved gas release device.

[0007] Furthermore, the partition plate has a circular structure and is fixed to the inner wall of the flotation tank.

[0008] Furthermore, the dissolved gas branch pipes are installed horizontally and fixed inside the tank wall of the flotation tank, and each dissolved gas branch pipe is equipped with a liquid solenoid valve.

[0009] Furthermore, the inlet end of the dissolved gas branch pipe is connected to the dissolved gas main pipe, and the inlet end of the dissolved gas main pipe is connected to the bottom of the pressure dissolved gas tank.

[0010] Furthermore, a liquid solenoid valve and a booster pump are installed on the dissolved gas main pipe.

[0011] Furthermore, the air distribution plate is fixed to the inner wall of the flotation tank.

[0012] Furthermore, an inlet is provided on one side of the top of the uppermost air flotation chamber.

[0013] Furthermore, a drain pipe is connected to the bottom of the lowest air flotation chamber.

[0014] Furthermore, the top side of the air flotation chamber is connected to the inlet end of the oil drain branch pipe, and a liquid solenoid valve is installed on the oil drain branch pipe.

[0015] Furthermore, the outlet end of the drain branch pipe is connected to the drain main pipe.

[0016] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages: This invention achieves high integration by constructing multiple air flotation chambers within a vertical tank using partition plates. These multiple air flotation chambers are connected in series longitudinally, enabling tiered fine treatment of wastewater and progressively removing oil droplets of different sizes, significantly improving the removal rate of difficult-to-treat fine and emulsified oil droplets.

[0017] By installing an air distribution plate in each flotation chamber, the concentrated release of microbubbles can be redistributed, ensuring that the bubbles rise evenly and steadily across the entire cross-section. This greatly increases the contact area and probability between the bubbles and oil droplets, thereby improving the utilization efficiency of dissolved air water and the separation efficiency of oil and water.

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0020] In the diagram, 1-flotation tank, 2-pressure dissolved air tank, 3-flotation cavity, 4-partition plate, 5-connecting pipe, 6-dissolved air release device, 7-air distribution plate, 8-dissolved air branch pipe, 9-dissolved air main pipe, 10-lift pump, 11-oil drain branch pipe, 12-oil drain main pipe, 13-liquid inlet, 14-drain pipe. Detailed Implementation

[0021] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0022] like Figure 1 and Figure 2 As shown in the diagram, this utility model provides a multi-stage liquid-liquid separation system, including a vertically structured flotation tank 1, a pressure dissolved air tank 2 located on the side of the flotation tank 1, and multiple flotation chambers 3 arranged longitudinally inside the flotation tank 1. A partition plate 4 is provided between adjacent flotation chambers 3, and a connecting pipe 5 is installed at the bottom of the partition plate 4. A liquid solenoid valve is installed on the connecting pipe 5. The oily wastewater to be treated achieves multi-stage separation during its longitudinal flow through each flotation chamber 3.

[0023] The partition plate 4 is a circular structure and is fixed to the inner wall of the flotation tank 1.

[0024] Each air flotation chamber 3 is equipped with a dissolved gas release device 6 at the bottom. The dissolved gas release device 6 is installed at the outlet end of the dissolved gas branch pipe 8. The dissolved gas branch pipe 8 is installed horizontally and fixed inside the tank wall of the air flotation tank 1. Each dissolved gas branch pipe 8 is equipped with a liquid solenoid valve. The inlet end of the dissolved gas branch pipe 8 is connected to the dissolved gas main pipe 9.

[0025] The inlet end of the dissolved gas pipe 9 is connected to the bottom of the pressure dissolved gas tank 2. A liquid solenoid valve and a booster pump 10 are installed on the dissolved gas pipe 9.

[0026] The dissolved air release device 6 can introduce a large number of microbubbles released from pressurized dissolved air water into the oily wastewater to be treated, and use the buoyancy of the bubbles to bring the oil droplets to the water surface for separation.

[0027] Each dissolved gas releaser 6 is equipped with a circular air distribution plate 7, which is fixed to the inner wall of the flotation tank 1. The air distribution plate 7 has several openings evenly distributed on it. The air distribution plate 7 is used to disperse the bubbles released by the dissolved gas releaser 6, ensuring that the bubbles are evenly distributed and preventing the bubbles released by the dissolved gas releaser 6 from rising in a concentrated manner like a jet or plume, which would cause some areas of the flotation chamber 3 to be densely populated with bubbles while other areas have almost no bubbles.

[0028] An inlet 13 is provided on one side of the top of the uppermost air flotation chamber 3, through which the oily wastewater to be separated and treated enters.

[0029] The bottom of the lowest air flotation chamber 3 is connected to a drain pipe 14, which is used to output the water after multi-stage oil removal.

[0030] The top side of the air flotation chamber 3 is connected to the inlet end of the oil drain branch pipe 11. A liquid solenoid valve is installed on the oil drain branch pipe 11, and the outlet end of the oil drain branch pipe 11 is connected to the main oil drain pipe 12.

[0031] The specific working principle of this utility model is as follows: The oily wastewater to be treated first enters the uppermost air flotation chamber 3. At the same time, the dissolved air release device 6 at the bottom of the chamber releases a large number of micro bubbles. The bubbles rise evenly under the action of the air distribution plate 7. The bubbles collide and adsorb with the oil droplets in the liquid to form a bubble-oil droplet composite. The composite quickly floats to the liquid surface due to buoyancy, forming a floating oil layer. After initial separation, the wastewater with reduced oil content enters the second-stage flotation chamber 3 through the bottom connecting pipe 5 under the control of the solenoid valve; the liquid enters the second-stage flotation chamber 3 and repeats the above process; since the first stage has removed most of the oil droplets, the second stage mainly deals with the finer and more difficult-to-separate oil droplets. Wastewater flows through all stages of flotation chamber 3 in sequence, and oil droplets are removed step by step; after deep treatment in the last stage of flotation chamber 3, the clean water is discharged from the drain pipe 14. The floating oil that accumulates on the surface of each flotation chamber 3 is collected through the oil drain branch pipe 11 at the top of each chamber, flows into the main oil drain pipe 12, and is then discharged from the system for further treatment or recycling.

[0032] The above description provides examples of the preferred embodiments of this utility model. Any aspects not detailed herein are common knowledge to those skilled in the art. The scope of protection of this utility model is determined by the claims. Any equivalent modifications based on the technical teachings of this utility model are also within the scope of protection of this utility model.

Claims

1. A liquid-liquid multi-stage separation system, characterized in that: The system includes a vertically oriented air flotation tank (1), a pressure dissolved air tank (2) on the side of the air flotation tank (1), multiple air flotation chambers (3) arranged longitudinally inside the air flotation tank (1), a partition plate (4) between adjacent air flotation chambers (3), a connecting pipe (5) installed at the bottom of the partition plate (4), and a liquid solenoid valve installed on the connecting pipe (5); a dissolved air release device (6) is installed at the bottom of each air flotation chamber (3), the dissolved air release device (6) is installed at the outlet end of the dissolved air branch pipe (8), and a circular air distribution plate (7) is installed above each dissolved air release device (6), with several openings evenly distributed on the air distribution plate (7).

2. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The partition plate (4) is a circular structure and is fixed to the inner wall of the flotation tank (1).

3. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The dissolved gas branch pipe (8) is installed horizontally and fixed inside the tank wall of the flotation tank (1). Liquid solenoid valves are installed on the dissolved gas branch pipe (8).

4. The liquid-liquid multi-stage separation system as described in claim 3, characterized in that: The inlet end of the dissolved gas branch pipe (8) is connected to the dissolved gas main pipe (9), and the inlet end of the dissolved gas main pipe (9) is connected to the bottom of the pressure dissolved gas tank (2).

5. The liquid-liquid multi-stage separation system as described in claim 4, characterized in that: A liquid solenoid valve and a booster pump (10) are installed on the dissolved gas main pipe (9).

6. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The air distribution plate (7) is fixed to the inner wall of the air flotation tank (1).

7. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The top side of the uppermost air flotation chamber (3) is provided with a liquid inlet (13).

8. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The bottom of the lowest air flotation chamber (3) is connected to a drain pipe (14).

9. The liquid-liquid multi-stage separation system as described in claim 1, characterized in that: The top side of the air flotation chamber (3) is connected to the inlet end of the oil drain branch pipe (11), and a liquid solenoid valve is installed on the oil drain branch pipe (11).

10. The liquid-liquid multi-stage separation system as described in claim 9, characterized in that: The outlet end of the drain branch pipe (11) is connected to the drain main pipe (12).

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