Demulsification device and demulsification method

Abstract

This invention relates to the field of demulsification technology and discloses a demulsification device and method. The device includes a horizontal shell (1) and multiple threaded structures (2). The horizontal shell (1) includes an upper shell (11) and a lower shell (12). An inlet (111) and a pressure stabilizing port are provided on the horizontal shell (1). Mounting holes are symmetrically arranged on the upper shell (11) and the lower shell (12) of the horizontal shell (1). The threaded structures (2) are spaced apart between the upper shell (11) and the lower shell (12) of the horizontal shell (1) through the mounting holes. The pitch of the threaded structures (2) ensures that the threaded structures (2) do not leak liquid. The threaded structures (2) are tightly fitted with the mounting holes on the lower shell (12), and the liquid flows out from the lower end of the threaded structures (2) along the threads. The demulsification device provided in this invention has a simple structure, high demulsification efficiency, low energy consumption, no secondary pollution, can achieve continuous processing, and is suitable for industrial promotion.

Description

Technical Field

[0001] This invention relates to the field of demulsification technology, specifically to a demulsification device and a demulsification method. Background Technology

[0002] In recent years, marine oil spills have occurred frequently. Besides the hazards posed by the oil slick floating on the sea surface, the pollution caused by the dispersed and emulsified state of dissolved fuel oil is also significant. If left untreated, this will not only cause severe environmental pollution but also waste petroleum resources. Therefore, researching oil-water emulsion separation methods is extremely important for purifying industrial processes and optimizing the ecological environment.

[0003] Currently, the main technologies used for oil-water separation include chemical treatment, microbial treatment, and physical treatment. While chemical treatment is less expensive, it is difficult to recover the chemical reagents and can easily cause secondary environmental pollution. Microbial treatment is more environmentally friendly, but it suffers from difficulties in selecting suitable microorganisms and has a limited treatment range.

[0004] Physical treatments include gravity sedimentation, ultrasound, microwave radiation, electric field treatment, and spiral centrifugation. Among these, gravity sedimentation is currently the most widely used separation method, with the density difference between the oil and water phases being the main driving force. While the equipment structure is simple, its processing efficiency is low and its energy consumption is high. Ultrasonic demulsification has high efficiency but limited processing capacity. Microwave radiation demulsification, as a novel demulsification technology, suffers from unclear mechanisms and is difficult to industrialize. Electric field treatment technology is relatively mature, but it is difficult to demulsify emulsions with high water content.

[0005] Spiral centrifugal separation is generally carried out in a spiral oil-water separator. This separator has a vertically mounted spiral blade inside its casing, primarily utilizing centrifugal force within the spiral channel formed by the blade for demulsification. While this type of separator offers advantages such as high operability, low cost, and low energy consumption, it relies solely on the centrifugal motion of the spiral blade for demulsification. This results in a single driving force, a limited range of emulsions it can handle, and generally poor demulsification performance for low-oil-content emulsions. Furthermore, the system is complex, requiring additional pressurization equipment, leading to high power consumption, difficulty in disassembly and cleaning, and high operating costs. Moreover, different mixed media require different centrifugal forces for separation within the spiral oil-water separator, resulting in poor separation performance for multi-mixed media and a need for further improvement in demulsification rate.

[0006] Therefore, there is an urgent need to develop an efficient, green, and highly effective demulsification device and method. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of low demulsification efficiency, high energy consumption, secondary pollution, limited processing range, and difficulty in industrialization of existing technologies, and to provide a demulsification device and demulsification method.

[0008] To achieve the above objectives, a first aspect of the present invention provides a demulsifying device, the device comprising a horizontal housing 1 and a plurality of threaded structures 2; wherein the horizontal housing 1 comprises an upper housing 11 and a lower housing 12, an inlet 111 and a pressure stabilizing port are provided on the horizontal housing 1, and mounting holes are symmetrically provided on the upper housing 11 and the lower housing 12 of the horizontal housing 1, the threaded structures 2 are provided between the upper housing 11 and the lower housing 12 at intervals through the mounting holes, the thread pitch of the threaded structure 2 is such that the threaded structure 2 does not leak liquid, the threaded structure 2 is tightly fitted with the mounting holes on the lower housing 12, and the liquid flows out of the horizontal housing 1 from the lower end of the threaded structure 2 along the thread.

[0009] A second aspect of the present invention provides a demulsification method, the method comprising passing oily wastewater into the demulsification apparatus described in the first aspect of the present invention for treatment.

[0010] The technical effects achieved by the present invention through the above technical solution are as follows:

[0011] 1) The demulsification device provided in this invention uses a physical method to demulsify, and no new pollution is generated during the demulsification process;

[0012] 2) The demulsification device provided in this invention can achieve continuous operation and improve processing efficiency;

[0013] 3) The demulsification device provided in this invention also has a better treatment effect on oil-in-water emulsions with low oil content;

[0014] 4) The demulsification method provided in this invention has high demulsification efficiency, low energy consumption, no secondary pollution, can achieve continuous processing, and is suitable for industrial promotion. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the demulsifying device in one embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the demulsifying device in one embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures

[0018] 1. Horizontal shell 11, upper shell 111, water inlet

[0019] 12. Lower housing; 13. Adjusting buckle; 14. Support rod

[0020] 2. Threaded structure; 3. Liquid collection tank; 31. Discharge port.

[0021] 4. Support column Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] A first aspect of the present invention provides a demulsifying device, the device comprising a horizontal housing 1 and a plurality of threaded structures 2; wherein the horizontal housing 1 comprises an upper housing 11 and a lower housing 12, an inlet 111 and a pressure stabilizing port are provided on the horizontal housing 1, and mounting holes are symmetrically provided on the upper housing 11 and the lower housing 12 of the horizontal housing 1, the threaded structures 2 being spaced apart between the upper housing 11 and the lower housing 12 through the mounting holes, the thread pitch of the threaded structures 2 being such that the threaded structures 2 are leak-proof, the threaded structures 2 being tightly fitted with the mounting holes on the lower housing 12, and the liquid flowing out of the horizontal housing 1 from the lower end of the threaded structures 2 along the threads, such as... Figure 1 As shown.

[0024] The demulsification device provided by this invention can be used to treat oily wastewater formed by various organic phases in water, especially oil-in-water emulsions. When treating oily wastewater, the pressure stabilizing port is opened, and the oily wastewater is pumped in from the inlet, allowing the oily wastewater to gradually fill the horizontal shell. During the process of the oily wastewater filling the horizontal shell, the flow velocity at the outlet is lower than that at the inlet, or even almost no liquid flows out.

[0025] Furthermore, because the thread pitch on the threaded structure is relatively small, oily wastewater will form liquid bridges on the threaded structure, hindering its penetration into the center of the threaded structure. Therefore, the space enclosed by the threaded structure is a liquid-free space where no oil or water can penetrate. The threaded structure submerged in the oily wastewater can provide adsorption sites for small oil droplets in the wastewater, while the threaded structure located in the mounting hole of the lower shell can provide an outflow channel for the oily wastewater to leave the horizontal shell.

[0026] Once the horizontal shell is filled with oily wastewater, water continues to flow in through the inlet, and water begins to flow steadily out from the lower end of the threaded structure. At this point, the oily wastewater entering through the inlet generates a horizontal driving force, causing it to flow around the threaded structure. Furthermore, due to the unique shape of the threaded structure, the oily wastewater spirals downwards along its surface. This coupling effect of flow around and downward flow effectively reduces the repulsive force between oil droplets and promotes their rapid migration. This increases the collision probability of small oil droplets within the wastewater, promoting their accumulation on the threaded structure and converging them into larger droplets. This process washes the oil droplets adsorbed on the threaded structure off, allowing them to drain from the lower end and complete the demulsification process, resulting in the separation of the oil and water phases.

[0027] In a preferred embodiment, the present invention does not impose special limitations on the manner in which the threaded structure is connected to the horizontal housing via the mounting hole. For example, the dimensions of the threaded structure and the mounting hole can be controlled to achieve a tight fit. A tight fit in this invention refers to a diameter difference of 0.1-1 mm between the diameter of the threaded structure and the diameter of the mounting hole. Conventional methods can also be used to seal the connection to prevent liquid from leaking out from the gap between the mounting hole and the threaded structure.

[0028] In a preferred embodiment, the thread structure 2 is an adjustable-pitch thread structure; wherein, in this invention, the demulsification rate of the demulsification device can be adjusted by adjusting the pitch of the thread structure to adapt to different treatment requirements of oily wastewater. For example, the pitch of the thread structure can be 0.2-0.5 mm, preferably 0.29-0.45 mm. In this invention, the pitch of the thread structure should not be too large to prevent water seepage and disruption of flow.

[0029] In a preferred embodiment, the threaded structure 2 passes through the horizontal housing 1, and an adjusting buckle 13 is provided on the portion of the threaded structure 2 extending out of the horizontal housing 1, and the adjusting buckle 13 contacts the surface of the upper housing 11. The adjusting buckle 13 is used to adjust the thread pitch.

[0030] In this invention, when adjusting the pitch, the threaded structure is first stretched by an external force, and then the adjusting buckle is inserted into the threaded structure against the upper surface of the horizontal housing (i.e., the surface of the upper housing). The threaded structure is stretched under the action of the adjusting buckle and the upper surface of the horizontal housing, thereby achieving the adjustment of the pitch.

[0031] In a preferred embodiment, when adjusting the pitch, in order to increase the connection strength between the threaded structure 2 and the rotating hole of the lower housing 12, a hook is provided at the lower end of the threaded structure 2, and a support rod 14 is fixedly provided below the lower housing 12, wherein the threaded structure 2 is connected to the support rod 14 by the hook.

[0032] In this invention, there is no particular limitation on the way the support rod is fixedly installed below the lower shell. Any method in which the support rod can be fixedly installed below the lower shell can be used in this invention. For example, the support rod can be welded in an inverted "Π" shape or integrally formed on the lower shell.

[0033] In a preferred embodiment, the threaded structure 2 is perpendicular to the central axis of the horizontal housing 1 and is evenly distributed along the central axis of the horizontal housing 1.

[0034] In a preferred embodiment, the spacing between adjacent threaded structures 2 is 5-15 mm, preferably 6-12 mm. In this invention, the spacing between adjacent threaded structures refers to the distance between the outermost edges of adjacent threaded structures.

[0035] In a preferred embodiment, the threaded structure is a spring.

[0036] In a preferred embodiment, the surface of the threaded structure 2 is provided with an oleophilic-hydrophobic layer. The method for preparing the oleophilic-hydrophobic layer includes: first immersing the chemically etched threaded structure in an organic solvent containing stearic acid (octadecanoic acid), and then drying it.

[0037] In this invention, the use of stearic acid to modify the thread structure can form an oleophilic and hydrophobic layer on the surface of the thread structure, making it easier for oil droplets in oily wastewater to be adsorbed onto the modified thread structure, further increasing the probability of collision and aggregation between oil droplets, and improving the demulsification effect of the demulsification device.

[0038] In a preferred embodiment, to improve the effect of chemical etching, the thread structure is cleaned before chemical etching. The present invention does not specifically limit the cleaning method; it can be first soaked in a mixture of petroleum ether, ethanol, and deionized water for 10-20 minutes, then ultrasonically cleaned for 10-20 minutes, followed by soaking in a 0.5-1.5 mol / L hydrochloric acid solution for 10-30 minutes to remove the surface oxide film, and finally rinsed with deionized water and dried.

[0039] In a preferred embodiment, the chemical etching operation includes: first immersing the threaded structure in a FeCl3 solution with a concentration of 0.5-1.5 mol / L for 120-200 seconds, and then rinsing with deionized water and drying.

[0040] In a preferred embodiment, the organic solvent containing stearic acid has a stearic acid mass concentration of 0.5-2%, and the organic solvent is an alcohol solvent, preferably ethanol.

[0041] In a preferred embodiment, the chemically etched thread structure is immersed in an organic solvent containing stearic acid (octadecanoic acid) for 40-800 minutes.

[0042] In a preferred embodiment, the drying temperature is 100-150°C and the drying time is 10-30 minutes.

[0043] In a preferred embodiment, the horizontal housing 1 is a cuboid, comprising an upper housing, a lower housing, a left housing, a right housing, a front housing, and a rear housing. The distance h from the outermost edge of the threaded structure 2 to the front housing of the horizontal housing 1 is 25-45% of the width H of the horizontal housing (the distance between the front and rear housings), preferably 33-42%. Figure 2 As shown.

[0044] In this invention, the larger the thread structure, the more space it can provide for accumulating small oil droplets in oily wastewater. However, an excessively large surface area of ​​the thread structure increases the difficulty of the surface renewal process. The inventors of this invention have discovered that the demulsification effect is better when the distance h from the outermost edge of the thread structure 2 to the front shell of the horizontal shell 1 is 33-42% of the width H of the horizontal shell.

[0045] In a preferred embodiment, the device further includes a liquid collection tank 3, which is used to collect the liquid flowing out of the horizontal shell 1 and allow the liquid flowing out of the horizontal shell 1 to stand, thereby further realizing the stratification of the oil phase and the water phase and reducing the oil content in the lower water phase.

[0046] In a preferred embodiment, a support column 4 is provided on the lower shell 11, and the horizontal shell 1 is placed in the liquid collection tank 3 by the support column 4.

[0047] In a preferred embodiment, a fixed beam is provided on the horizontal shell 1, and the horizontal shell 1 is supported above the liquid collection tank 3 by the fixed beam.

[0048] In a preferred embodiment, a discharge port 31 is provided below the liquid collection tank for discharging the liquid in the liquid collection tank 3.

[0049] In a preferred embodiment, the present invention does not impose any special limitation on the material of the device. Preferably, the material of the threaded structure 2 is 304 stainless steel, and the material of the remaining parts, such as the horizontal housing 1, the adjusting buckle and the liquid collection tank 3, is acrylic, preferably transparent acrylic.

[0050] In this invention, the thread structure is made of 304 stainless steel to prevent oxidation and avoid affecting its use. The horizontal shell and liquid collection tank are made of acrylic to facilitate observation of experimental phenomena during the processing.

[0051] A second aspect of the present invention provides a demulsification method, the method comprising passing an oil-in-water emulsion into the demulsification apparatus described in the first aspect of the present invention for processing, preferably by pumping the oil-in-water emulsion into the demulsification apparatus described in the first aspect of the present invention for processing.

[0052] In this invention, when using the demulsification device to treat oil-in-water emulsions, the inlet flow rate can be adjusted according to the size of the device. In one embodiment, the inlet flow rate of the oil-in-water emulsion can be increased first, allowing the emulsion to quickly fill the horizontal shell, and then the inlet flow rate can be adjusted again to achieve a basic balance between the inlet and outlet flow rates. In another embodiment, the inlet flow rate can be fixed, allowing the oil-in-water emulsion to first fill the horizontal shell and then flow out steadily from the outlet of the horizontal shell.

[0053] Liquid flowing out of the horizontal shell is preferably collected in a collection tank. The collection tank collects the flowing liquid while allowing it to stand. After a period of standing, the oil phase and the aqueous phase separate into layers in the collection tank. The demulsified liquid can then be discharged from the drain outlet at the bottom of the collection tank. The invention will be described in detail below through embodiments. Among them, the method for preparing the spring oleophilic-hydrophobic layer is as follows:

[0054] 1) First, soak the spring in 50 mL of petroleum ether, ethanol and deionized water for 10 min respectively, then ultrasonically clean it for 10 min, wash and dry it, then soak it in 1 mol / L hydrochloric acid solution for 15 min, wash it again with deionized water and dry it.

[0055] 2) After cleaning, immerse the spring in a 1 mol / L FeCl3 solution for chemical etching for 150 seconds. After removal, rinse with deionized water and dry.

[0056] 3) After chemical etching, the spring is immersed in a 1% stearic acid / ethanol solution for 1 hour and then removed and dried at 120°C for 15 minutes to obtain a spring with an oleophilic and hydrophobic layer.

[0057] The formula for calculating the demulsification rate η is as follows:

[0058] Wherein, ψ is the concentration of oil in the oil-water mixture before demulsification, in mg / L; The concentration of oil in the lower aqueous phase after demulsification is expressed in mg / L.

[0059] Example 1

[0060] The demulsifying device includes a rectangular horizontal housing, 177.5 mm long, 9 mm wide, and 17 mm high. The upper housing has a 0.8 mm diameter pressure stabilizing port, and the lower housing has an inverted "Π" shaped support rod. Fifteen pairs of mounting holes are evenly arranged along the central axis on both the upper and lower housings. Each mounting hole houses a spring with an oleophilic-hydrophobic layer on its surface. The spring has a diameter of 0.3 mm and a height of 20 mm. The spacing between adjacent springs is 7.7 mm, and the distance h from the outermost edge of the spring to the front housing of the horizontal housing is 33% of the width H of the horizontal housing. Hooks are located at the upper and lower ends of the spring, with the lower hook connected to the support rod. An adjusting latch is located between the spring and the upper housing, allowing the pitch to be adjusted to 0.29 mm.

[0061] Four support columns are also provided below the horizontal shell, and the horizontal shell is placed in the liquid collection tank through the support columns; a discharge port is provided below the liquid collection tank; the spring is made of 304 stainless steel, and the rest of the material is acrylic.

[0062] An oil-in-water emulsion (a mixture of diesel and water, with diesel at a volume fraction of 5%) was introduced into the demulsifier through a metering pump at a flow rate of 12 mL / min. After 10 minutes, the liquid in the lower aqueous phase of the collection tank was taken for testing, and the demulsification rate was found to be 52.94%.

[0063] Example 2

[0064] Similar to Example 1, except that the feed flow rate of the oil-in-water emulsion was adjusted to 4 mL / min, 8 mL / min, 16 mL / min and 20 mL / min respectively, and the demulsification rates were measured to be 21.85%, 36.80%, 42.51% and 33.65% respectively.

[0065] Example 3

[0066] Similar to Example 1, except that the spring pitch was adjusted to 0.33mm, 0.37mm, 0.41mm and 0.45mm respectively, and the demulsification rates were measured to be 43.14%, 36.58%, 30.09% and 20.98% respectively.

[0067] Example 4

[0068] Similar to Example 1, except that the spring was not modified, that is, no oleophilic and hydrophobic layer was provided on the spring, and the demulsification rate was measured to be 31.56%.

[0069] Comparative Example 1

[0070] Similar to Example 1, except that the spring pitch is 0.8 mm and the measured demulsification rate is 12.71%.

[0071] By comparing Example 1 and Comparative Example 1, it can be seen that the pitch in Comparative Example 1 is large, the spring is not protective, and oily wastewater can enter the spring through the gaps on the spring, the lateral flow is weakened or even disappears, and thus the demulsification effect is reduced.

[0072] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An emulsion breaking device, characterized in that, The device includes a horizontal housing (1) and multiple threaded structures (2); wherein, the horizontal housing (1) includes an upper housing (11) and a lower housing (12), and an inlet (111) and a pressure stabilizing port are provided on the horizontal housing (1). Mounting holes are symmetrically provided on the upper housing (11) and the lower housing (12) of the horizontal housing (1). The threaded structures (2) are provided between the upper housing (11) and the lower housing (12) of the horizontal housing (1) through the mounting holes. The pitch of the threaded structure (2) makes the threaded structure (2) impermeable to liquid. The threaded structure (2) fits tightly with the mounting holes on the lower housing (12). Liquid flows out of the horizontal housing (1) from the lower end of the threaded structure (2) along the thread.

2. The demulsifying device of claim 1, wherein, The thread structure (2) is a thread structure with adjustable pitch.

3. The demulsifying device of claim 1 or 2, wherein, The threaded structure (2) passes through the horizontal housing (1). An adjusting buckle (13) is provided on the part of the threaded structure (2) that extends out of the horizontal housing (1), and the adjusting buckle (13) contacts the surface of the upper housing (11); wherein the adjusting buckle (13) is used to adjust the pitch.

4. The demulsifying device of claim 3, wherein, A hook is provided at the lower end of the threaded structure (2), and a support rod (14) is fixedly provided below the lower housing (12). The threaded structure (2) is connected to the support rod (14) by the hook.

5. The demulsifying device of claim 1 or 2, wherein, The threaded structure (2) is perpendicular to the central axis of the horizontal housing (1) and is evenly distributed along the central axis of the horizontal housing (1).

6. The demulsifying device of claim 1 or 2, wherein, The spacing between adjacent threaded structures (2) is 5-15 mm.

7. The demulsifying device of claim 6, wherein, The spacing between adjacent threaded structures (2) is 6-12 mm.

8. The demulsifying device of claim 1 or 2, wherein, The threaded structure (2) is a spring.

9. The demulsifying device according to claim 1 or 2, wherein, An oleophilic and hydrophobic layer is provided on the surface of the threaded structure (2).

10. The demulsifying device according to claim 1 or 2, wherein, The device also includes a liquid collection tank (3) for collecting liquid flowing out of the horizontal housing (1) and allowing the collected liquid to stand.

11. A method for demulsifying, characterized in that, The method includes treating oily wastewater by passing it through the demulsifying apparatus according to any one of claims 1-10.

Images