A device for treating oil-containing emulsified wastewater

Abstract

The application discloses a kind of oil-containing emulsified wastewater treatment device, belong to wastewater treatment technical field, the device of the application includes micro-bubble production module and flotation module, the main body of micro-bubble production module is micro-bubble production tank, cyclone-venturi type micro-bubble generator is fixedly connected outside micro-bubble production tank, cyclone-venturi type micro-bubble generator is connected with net-shaped turbulence structure and placed in the inside of micro-bubble production tank, the opening is arranged on the upper side of flotation tank, and hydrophobic membrane is provided, and oil collection tank is fixedly connected on it.The application can realize the cyclic treatment of emulsified oil-containing wastewater, improve the efficiency of treating emulsified oil-containing wastewater and the effect of oil recovery rate, convenient operation, energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically to a device for treating oily emulsified wastewater. Background Technology

[0002] Oily wastewater is wastewater containing oily substances discharged during industrial production processes. If not recycled and treated, it results in waste; if discharged into rivers, lakes, or bays, it pollutes the water and affects aquatic life; if used for agricultural irrigation, it hinders crop growth. Many researchers have studied the treatment of oily wastewater. Currently, the main methods for removing oil from oily wastewater include: gravity sedimentation, physicochemical methods, chemical coagulation, coarse particle removal, filtration, flotation, activated carbon adsorption, biological methods, and electromagnetic methods. To save on wastewater treatment costs and simplify operation, US Patent No. 3869388A provides a method for water-oil separation: by adding a liquid insoluble in oil or water with a density between oil and water, a separation layer is formed between the oil and water. This method uses simple equipment and can achieve oil-water separation, but its wastewater treatment efficiency is low. Designing a simple-to-operate device that can improve wastewater treatment efficiency is a pressing problem in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a treatment device for oily emulsified wastewater to achieve cyclic treatment of emulsified oily wastewater, reduce energy consumption, and improve the efficiency of treating emulsified oily wastewater.

[0004] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A treatment device for oily emulsified wastewater includes a microbubble production module. The main body of the microbubble production module is a microbubble production tank. One end of the microbubble production tank is connected to a vortex-Venturi type microbubble generator, and the other end is connected to the front end of a flotation cell. The flotation cell has an opening at the top, and an oil collection tank is connected thereto.

[0005] Specifically, the microbubble production tank has a built-in turbulence structure, which is a mesh channel connected to the vortex-Venturi type microbubble generator.

[0006] This invention introduces an emulsion and oily wastewater into a vortex-Venturi microbubble generator, where microbubbles are generated in the microbubble production tank. These microbubbles dissolve in oil droplets and act as carriers, forming a float with a density less than water that rises to the surface. A flotation tank separates the oil, emulsion, and water, and an oil collection tank collects the oil, thus treating the oily wastewater. The turbulence structure employs a multi-layered circular filter screen. The microbubbles are further reduced in size after being sheared by the mesh-like turbulence structure, which increases the contact area between the microbubbles and oil droplets, thereby accelerating the flotation process and improving the efficiency of oily wastewater treatment.

[0007] Specifically, the swirling-Venturi type microbubble generator consists of a swirling cavity and a venturi tube, wherein the swirling cavity is sequentially connected to the inlet section, constriction section, throat and diffusion section of the venturi tube.

[0008] In this invention, the fluid forms a swirling flow after passing through the swirling cavity. The swirling flow increases in speed and swirl after passing through the inlet and constriction sections of the venturi tube. When the fluid enters the constriction section, the flow velocity increases due to the reduced cross-section. According to Bernoulli's principle, the increase in flow velocity leads to a decrease in fluid pressure, creating a negative pressure zone. The negative pressure zone will attract surrounding air or other fluids and mix with the main fluid. Under the synergistic effect of multiple microbubble generation mechanisms such as swirling shear, turbulent pulsation, and vortex breaking, microbubbles are formed. The swirling liquid reaches its maximum swirling intensity in the throat of the venturi tube. Subsequently, it enters the diffusion section, where the flow velocity slows down and the pressure gradually recovers to a higher level, forming a gas-liquid two-phase shock wave. Under the action of the shock wave, the microbubbles can further form smaller bubbles.

[0009] Specifically, one end of the swirling cavity is provided with an air inlet, which is connected to an air guide pipe.

[0010] In this invention, the gas guide tube is located on the central axis of the swirling cavity and the venturi tube. Due to the swirling effect, a negative pressure is formed in the central region of the swirling flow. After the gas enters the venturi tube through the gas guide tube, it mixes with the mainstream to form bubbles.

[0011] Specifically, the main body of the vortex cavity is an annular channel with a uniform cross-sectional area. The side of the vortex cavity is provided with a first water inlet and a second water inlet. The first water inlet is connected to a circulation guide pipe, and the second water inlet is connected to the first guide pipe.

[0012] Specifically, the first and second water inlets are arranged in parallel and opposite directions on both sides of the vortex cavity, the ratio of the cross-sectional diameters of the first and second water inlets is 0.8:1 to 1:1, and the ratio of the cross-sectional diameter of the annular channel of the vortex cavity to that of the second water inlet is 0.8:1 to 1.25:1.

[0013] The first inlet introduces the emulsion, and the second inlet introduces the oily wastewater. Both inlets have circular cross-sections with the same diameter. After entering the vortex chamber through the guide pipes on both sides, the fluid is constrained by the geometry of the vortex chamber, forming a vortex. At this point, the emulsion and oily wastewater mix, and the fluid undergoes circular motion while simultaneously entering the Venturi tube. The cross-sectional diameter of the first inlet is slightly smaller than that of the second inlet. When the flow velocities of the emulsion and oily wastewater are the same, the flow rate of the oily wastewater is greater than that of the emulsion, which can save on the amount of emulsion used. It is worth noting that if the cross-sectional areas of the first and second inlets differ too much, it will be detrimental to the formation of the vortex and the discharge of the emulsion from the flotation cell into the circulating guide pipe. To ensure a stable vortex is formed within the vortex chamber, the cross-sectional diameter of the annular channel of the vortex chamber should be similar to the cross-sectional diameters of the first and second inlets.

[0014] Specifically, the end of the flotation cell is connected to the circulation guide pipe, and a section of the circulation guide pipe extends into the flotation cell.

[0015] In this invention, a circulation guide pipe is placed outside the device, with one end connected to the first inlet of the cyclone chamber and the other end connected to the flotation cell. Since the density of water > emulsion > oil, the flotation cell contains water, emulsion, and oil in that order from bottom to top. The emulsion can flow out from the circulation guide pipe in the middle of the flotation cell and then re-enter the cyclone chamber through the first inlet, achieving recycling. This allows the entire device to achieve cyclic treatment of emulsified oily wastewater, thereby improving the efficiency of treating emulsified oily wastewater and increasing the oil recovery rate.

[0016] Specifically, a hydrophobic membrane is provided at the upper opening of the flotation cell.

[0017] Specifically, a drainage pipe is provided below the flotation cell.

[0018] The floating oil layer enters the oil collection tank through a hydrophobic membrane, wherein the hydrophobic membrane is an MPP hydrophobic membrane, and the hydrophobic membrane and the number of openings can be set according to specific conditions. A drain pipe is located below the end of the flotation cell, and the clear water at the bottom of the flotation cell can be discharged through the drain outlet.

[0019] This invention utilizes a cyclone-Venturi microbubble generator to produce microbubbles for emulsifying oily wastewater. The emulsion and oily wastewater pass through a cyclone chamber, a venturi tube, and a turbulence structure to generate microbubbles. Oil, emulsion, and water are then separated using a flotation cell, thus achieving the treatment of oily wastewater. This invention enables the cyclical treatment of emulsified oily wastewater, improving treatment efficiency and oil recovery rate. It is convenient to operate and energy-saving and environmentally friendly. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the device described in Embodiment 1 of the present invention.

[0022] Figure 2 This is a cross-sectional view of the device described in Embodiment 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of a vortex-Venturi type microbubble generator.

[0024] Figure 4 This is a schematic diagram of swirling flow formation.

[0025] Figure 5 This is a schematic diagram of the assembly of the oil collection tank and the flotation tank.

[0026] Figure 6 This is a schematic diagram of the turbulence structure in Example 2.

[0027] Explanation of reference numerals in the attached drawings: 1-Swirl-Venturi type microbubble generator; 2-Air guide pipe; 3-First guide pipe; 4-Circulation guide pipe; 5-Turbulence structure; 501-Filter screen; 502-Blade; 6-Microbubble production tank; 7-Flotation tank; 8-Hydrophobic membrane; 9-Drainage pipe; 10-Oil collection tank; 101-Swirl chamber; 102-Inlet section; 103-Contraction section; 104-Throat; 105-Diffuser section; 106-Air inlet; 107-First water inlet; 108-Second water inlet. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] Example 1 like Figures 1-5 As shown, the present invention provides a treatment device for oily emulsified wastewater, including a microbubble production module. The main body of the microbubble production module is a microbubble production tank 6. One end of the microbubble production tank 6 is connected to a vortex-Venturi type microbubble generator 1, and the other end is connected to the front end of a flotation cell 7. The flotation cell 7 has an opening at the top, and an oil collection tank 10 is connected to it.

[0031] Specifically, the microbubble production tank 6 has a built-in turbulence structure 5, which is a mesh channel and is connected to the vortex-Venturi type microbubble generator 1.

[0032] Specifically, the swirling-Venturi type microbubble generator 1 consists of a swirling cavity 101 and a venturi tube, wherein the swirling cavity 101 is sequentially connected to the inlet section 102, the contraction section 103, the throat 104, and the diffusion section 105 of the venturi tube.

[0033] This invention introduces an emulsion and oily wastewater into a vortex-Venturi microbubble generator 1, where microbubbles are generated in a microbubble production tank 6. These microbubbles dissolve in oil droplets and act as carriers, forming a float with an overall density less than water that rises to the surface. A flotation tank 7 separates the oil, emulsion, and water, and an oil collection tank 10 collects the oil, thus treating the oily wastewater. The turbulence structure 5 employs a multi-layered circular filter screen. The microbubbles are further reduced in size after being sheared by the mesh-like turbulence structure 5, which increases the contact area between the microbubbles and oil droplets, thereby accelerating the flotation process and improving the efficiency of oily wastewater treatment.

[0034] Specifically, one end of the swirling cavity 101 is provided with an air inlet 106, which is connected to the air guide pipe 2. In this invention, the air guide pipe is located on the central axis of the swirling cavity 101 and the venturi tube. Due to the swirling effect, a negative pressure is formed in the central region of the swirling flow. After the gas enters the venturi tube through the air guide pipe 2, it mixes with the mainstream to form bubbles.

[0035] Specifically, the main body of the vortex cavity 101 is an annular channel with equal cross-sectional area. The side of the vortex cavity 101 is provided with a first water inlet 107 and a second water inlet 108. The first water inlet 107 is connected to the circulation guide pipe 4, and the second water inlet 108 is connected to the first guide pipe 3.

[0036] Specifically, the first inlet 107 and the second inlet 108 are arranged in parallel and opposite directions on both sides of the vortex cavity 101. The ratio of the cross-sectional diameters of the first inlet 107 and the second inlet 108 is 0.8:1 to 1:1, and the ratio of the cross-sectional diameter of the annular channel of the vortex cavity 101 to the cross-sectional diameter of the second inlet 108 is 0.8:1 to 1.25:1.

[0037] The first inlet 107 introduces the emulsion, and the second inlet 108 introduces the oily wastewater. Both the first inlet 107 and the second inlet 108 have circular cross-sections with the same diameter. After the fluid enters the vortex chamber 101 from the guide pipes on both sides, it is constrained by the geometry of the vortex chamber 101, forming a vortex. At this time, the emulsion and the oily wastewater mix, and the fluid undergoes circular motion while simultaneously entering the Venturi tube. The cross-sectional diameter of the first inlet 107 is slightly smaller than that of the second inlet 108. When the flow rates of the emulsion and the oily wastewater are the same, the flow rate of the oily wastewater is greater than that of the emulsion, which can save on the amount of emulsion used. It is worth noting that if the cross-sectional areas of the first inlet 107 and the second inlet 108 differ too much, it will be detrimental to the formation of the vortex and the discharge of the emulsion from the flotation tank 7 into the circulation guide pipe 4. In order to form a stable swirling flow in the swirling cavity 101, the cross-sectional diameter of the annular channel of the swirling cavity 101 should be similar to the cross-sectional diameter of the first inlet 107 and the second inlet 108.

[0038] Specifically, the end of the flotation cell 7 is connected to the circulation guide pipe 4, and a section of the circulation guide pipe 4 extends into the flotation cell 7.

[0039] In this invention, the circulation guide pipe 4 is placed outside the device, with one end connected to the first inlet 107 of the vortex chamber 101 and the other end connected to the flotation cell 7. Since the density of water > emulsion > oil, the flotation cell 7 contains water, emulsion, and oil from bottom to top. The emulsion can flow out from the circulation guide pipe 4 in the middle of the flotation cell 7 and then enter the vortex chamber 101 from the first inlet 107, achieving recycling. This allows the entire device to achieve the effect of recycling emulsified oily wastewater, thereby improving the efficiency of emulsified oily wastewater treatment and the oil recovery rate.

[0040] Specifically, a hydrophobic membrane 8 is provided at the upper opening of the flotation cell 7, and a drain pipe 9 is provided at the lower part of the flotation cell 7. The floating oil layer enters the oil collection tank 10 through the hydrophobic membrane 8, wherein the hydrophobic membrane 8 is an MPP hydrophobic membrane, and the hydrophobic membrane and the number of openings can be set according to specific conditions. The drain pipe 9 is located below the end of the flotation cell 7, and the clear water at the bottom of the flotation cell 7 can be discharged through the drain port.

[0041] This invention enables the recycling of emulsified oily wastewater, thereby improving the efficiency of treating emulsified oily wastewater and increasing oil recovery rate. It is convenient to operate and energy-saving and environmentally friendly.

[0042] Example 2 Further optimization of the turbulence structure in Example 1: like Figure 6As shown, the turbulence structure 5 consists of interlaced semi-circular filter screens 501, with at least two screens. A cylinder surrounds each filter screen, and blades 502 are attached to the inner wall of the cylinder. The blades 502 rotate under the influence of the swirling flow, which in turn drives the cylinder and filter screens 501 to rotate. The kinetic energy of the water flow is converted into the kinetic energy of the rotating blades 502 and cylinder, slowing down the water flow and allowing the oily wastewater and emulsion to react fully. Simultaneously, the fluid flowing through the turbulence structure 5 experiences collisions, friction, and cavitation due to the rotation of the cylinder and filter screens 501. Through the mesh shearing of the semi-circular filter screens 501, smaller microbubbles are generated in the microbubble production tank 6. Furthermore, the rotation reduces the adhesion of impurities to the filter screen. Impurity particles move towards the periphery of the filter screen due to centrifugal force, thus preventing impurities from accumulating in the central area of ​​the filter screen and affecting the passage of microbubbles.

[0043] In this embodiment, the interlayer transition angle of the semi-circular filter screen 501 is 90°~180°, and the interlayer gap is one-half to one filter screen 501 thickness. The filter screens 501 are arranged in this staggered manner to prevent the problem of mesh clogging when filtering impurities. At the same time, it can make microbubbles and mesh shear to generate more and finer microbubbles, thereby improving the treatment efficiency of emulsified oily wastewater.

[0044] Example 3 The principle of the vortex-Venturi microbubble generator: The swirling-Venturi type microbubble generator 1 consists of a swirling cavity 101 and a venturi tube, wherein the swirling cavity 101 is sequentially connected to the inlet section 102, the contraction section 103, the throat 104 and the diffusion section 105 of the venturi tube.

[0045] In this invention, the fluid forms a swirling flow after passing through the swirling cavity 101. The swirling flow increases in speed and swirl after passing through the inlet section 102 and the contraction section 103 of the venturi tube. When the fluid enters the contraction section 103, the fluid velocity increases due to the reduced cross-section. According to Bernoulli's principle, the increase in velocity leads to a decrease in fluid pressure, creating a negative pressure zone. The negative pressure zone will attract surrounding air or other fluids and mix with the main fluid. Under the synergistic effect of multiple microbubble generation mechanisms such as swirling shear, turbulent pulsation, and vortex breaking, microbubbles are formed. The swirling liquid reaches its maximum swirling intensity at the throat 104 of the venturi tube. Subsequently, it enters the diffusion section 105, where the flow velocity slows down and the pressure gradually recovers to a higher level, forming a gas-liquid two-phase shock wave. Under the action of the shock wave, the microbubbles can further form smaller bubbles.

[0046] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in this specification, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0047] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0048] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention. This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A treatment device for oily emulsified wastewater, comprising a microbubble production module, characterized in that: The main body of the microbubble production module is a microbubble production tank (6). One end of the microbubble production tank (6) is connected to a vortex-Venturi type microbubble generator (1), and the other end is connected to the front end of a flotation tank (7). The flotation tank (7) has an opening at the top, and an oil collection tank (10) is connected to it. The microbubble production tank (6) has a built-in turbulence structure (5). The turbulence structure (5) is a mesh channel and is connected to the vortex-Venturi type microbubble generator (1). The turbulence structure (5) includes at least two semi-circular filter screens (501) arranged in an interlayer staggered manner. A cylinder is provided around the filter screen (501). The inner wall of the cylinder is connected to blades (502). The blades (502) drive the cylinder and the filter screen (501) to rotate under the action of vortex.

2. The treatment device for oily emulsified wastewater according to claim 1, characterized in that: The swirling-Venturi type microbubble generator (1) consists of a swirling cavity (101) and a venturi tube, wherein the swirling cavity (101) is connected in sequence to the inlet section (102), the contraction section (103), the throat (104) and the diffusion section (105) of the venturi tube.

3. The device for treating oily emulsified wastewater according to claim 2, characterized in that: One end of the swirling chamber (101) is provided with an air inlet (106), and the air inlet (106) is connected to the air guide pipe (2).

4. The treatment device for oily emulsified wastewater according to claim 2, characterized in that: The main body of the vortex cavity (101) is an annular channel with equal cross-sectional area. The side of the vortex cavity (101) is provided with a first inlet (107) and a second inlet (108). The first inlet (107) is connected to the circulation guide pipe (4), and the second inlet (108) is connected to the first guide pipe (3).

5. The treatment device for oily emulsified wastewater according to claim 4, characterized in that: The first water inlet (107) and the second water inlet (108) are arranged in parallel and opposite directions on both sides of the vortex cavity (101). The ratio of the cross-sectional diameters of the first water inlet (107) and the second water inlet (108) is 0.8:1 to 1:

1. The ratio of the cross-sectional diameter of the annular channel of the vortex cavity (101) to that of the second water inlet (108) is 0.8:1 to 1.25:

1.

6. The treatment device for oily emulsified wastewater according to claim 1, characterized in that: The end of the flotation cell (7) is connected to the circulation guide pipe (4), and a section of the circulation guide pipe (4) extends into the flotation cell (7).

7. The treatment device for oily emulsified wastewater according to claim 1, characterized in that: A hydrophobic membrane (8) is provided at the upper opening of the flotation cell (7).

8. The device for treating oily emulsified wastewater according to claim 1, characterized in that: A drainage pipe (9) is provided below the flotation cell (7).

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