An efficient oily water separation facility

Abstract

This invention relates to a high-efficiency oil-water separation facility, comprising a closed-loop cyclone flotation separation system. The closed-loop cyclone flotation separation system includes a first shell; the first shell is a horizontal, closed cylindrical structure with a first inlet connected to an inlet pipe at its front end and a first outlet at its rear end. Inside, it houses a first cyclone generating component and at least one first dissolved air release device, and at least one first oil collecting device at its top. The cyclone generating component is located at the front of the shell and is connected to the inlet. The oil collecting devices are interconnected via combined pipes and then connected to an oil discharge pipe. The dissolved air release device is located in the middle to rear of the first shell and is connected to an external dissolved air generating device to form a dissolved air zone around it. Thus, the oil separation and flotation processes in oil-water treatment can be effectively integrated, significantly reducing the footprint, lowering construction and operating costs, and simplifying installation and construction processes.

Description

Technical Field

[0001] This invention relates to an environmental protection facility, particularly a facility for treating oily wastewater, specifically a high-efficiency oil-wastewater separation facility. Background Technology

[0002] Waste oil in oily wastewater mainly exists in three forms: floating oil, emulsified oil, and dissolved oil. These are classified according to the distribution diameter of oil droplets in the water. Floating oil: oil droplets have a relatively large size, generally greater than 100 μm, are easy to separate and float, and account for 80% to 90% of the total oil content. Emulsified oil: the droplets have a small size, generally less than 10 μm, are suspended, are not easy to separate, and account for about 10% to 15%. Dissolved oil: it is in a near-molecular dissolved state and accounts for about 0.2% to 0.5%. Oily wastewater treatment is generally divided into primary treatment and secondary treatment. Primary treatment separates free oil, dispersed oil, and oil sludge from water and emulsions. Secondary treatment breaks down the oil-water emulsion and separates the remaining oil.

[0003] Traditional oil-water separation methods often employ a combination of oil-water separation and air flotation. Oil-water separation removes initially dispersed flotation particles, while air flotation removes emulsified oil and finely dispersed oil. Depending on process requirements, at least two oil-water separation tanks and air flotation tanks are typically required, each independently designed to ensure separate operation and maintenance. Furthermore, traditional oil-water separation tanks and air flotation facilities are mostly water-based structures, resulting in a large footprint, increasing the difficulty of centralized and remote control, and leading to a significant workload for manual maintenance, wasting human and material resources. In addition, these oil-water separation tanks and air flotation tanks cannot switch between different processes and cannot automatically adjust water volume, making them unsuitable for adapting to changing operating conditions and failing to meet production demands.

[0004] Therefore, improvements are urgently needed to fully meet production demands. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a highly efficient oil-water separation facility that effectively integrates oil separation and flotation treatment, thereby greatly reducing the footprint, increasing the degree of intensification, lowering investment and operating costs, and fully meeting production needs.

[0006] The technical solution of this invention is: A high-efficiency oil-water separation facility includes a closed-loop cyclone flotation separation system. The closed-loop cyclone flotation separation system includes a first shell. The first shell is a horizontal, closed cylindrical shell with a first inlet connected to an inlet pipe at its front end and a first outlet at its rear end. Inside the shell are a first cyclone generating component and at least one first dissolved gas release device. At least one first oil collecting device is located at the top of the shell. The cyclone generating component is located at the front of the first shell and is connected to the first inlet. The first oil collecting devices are interconnected through combined pipes and are connected to an oil discharge pipe. The first dissolved gas release device is located in the middle and rear of the first shell and is connected to an external dissolved gas generating device to form a dissolved gas zone around it.

[0007] Furthermore, it also includes at least one oil droplet trapping device; the oil droplet trapping device includes a cylindrical shell; the shell wall of the shell is provided with a plurality of through-hole-shaped filter holes, and a filter element is provided inside; the oil droplet trapping device is disposed inside the first shell and is connected to the side wall of the first shell.

[0008] Furthermore, it also includes a mesh-like agglomerating filler, disposed inside the first housing and located below the oil droplet trapping device.

[0009] Furthermore, there are two first dissolved gas release devices, which are arranged at intervals and are located in the middle and rear part of the first housing, and can form different dissolved gas zones around them respectively.

[0010] Furthermore, it also includes a closed-loop micro-nano air flotation system; the closed-loop micro-nano air flotation system includes a second shell; the second shell is a horizontal closed cylinder with a second water inlet at its front end and a second water outlet at its rear end, and a second dissolved air release device and at least one baffle plate inside, and a second oil collection device at its top; the second water inlet is connected to the first water outlet through a pipe; the second water outlet is connected to a drain pipe; the second dissolved air release device is located at the front of the second shell; the baffle plate is a straight plate, perpendicular to the central axis of the second shell, and has multiple through-hole-shaped guide holes; the second oil collection device is connected to the oil discharge pipe.

[0011] Furthermore, the water baffle is composed of multiple pieces, evenly distributed along the axial direction of the second shell; the diameter of the guide holes on each water baffle gradually decreases along the water flow direction.

[0012] Furthermore, the guide holes on the water baffle are distributed in an equilateral triangle pattern.

[0013] Furthermore, the dissolved gas generating device is a high-efficiency dissolved gas system; the high-efficiency dissolved gas system includes a pressure dissolved gas tank; the top and bottom of the pressure dissolved gas tank are respectively provided with an air inlet valve and an air outlet valve; the air inlet valve is connected to an external compressed air source; the air outlet valve is connected to the first dissolved gas release device, the second dissolved gas release device and the water inlet pipe respectively.

[0014] Furthermore, the pressure dissolved gas tank is also provided with a return water port; the rear end of the first shell is provided with a first drain port; the rear end of the second shell is provided with a second drain port; the return water port is connected to the first drain port or the second drain port through a return pipe; and a booster pump is provided on the return water pipe.

[0015] Furthermore, it also includes a skid-mounted frame; the skid-mounted frame is a standardized three-dimensional skid body with a steel structure; the closed-loop cyclone air flotation separation system, the closed-loop micro-nano air flotation system and the ultra-efficient dissolved air system are respectively installed on the skid-mounted frame for easy installation.

[0016] The beneficial effects of this invention are: This invention is reasonably designed, has a simple structure, and is easy to use. It can effectively integrate the oil separation and flotation processes in the oily wastewater treatment process, thereby greatly reducing the footprint, lowering construction and operating costs, simplifying the installation and construction process, and creating favorable conditions for remote control. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the closed-loop cyclone flotation separation system of the present invention.

[0019] Figure 3 This is a schematic diagram of the closed-loop micro / nano air flotation system of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the high-efficiency dissolved gas system of the present invention.

[0021] Among them, 1-Closed-loop cyclone flotation separation system; 101-Oil droplet trapping device; 102-First oil collection device; 103-First water inlet; 104-Cyclone generating component; 105-First shell; 106-First drain outlet; 107-Mesh coalescing packing; 108-First dissolved gas release device; 109-First drain outlet; 110-First water outlet; 111-Buffer structure; 2-Closed-loop micro-nano air flotation system; 201-Second water inlet; 202-Second shell; 203-Second dissolved gas release device; 204-Second drain outlet; 205-Water baffle; 206-Second oil collection device; 207-Second water outlet; 208-Second drain outlet; 3-High-efficiency dissolved gas system; 301-Pressure dissolved gas tank; 302-Inlet valve; 303-Return water inlet; 304-Packing; 305-Exhaust valve; 4-Booster pump; 5-Combined pipeline. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figure 1-4 As shown.

[0024] A high-efficiency oil-water separation facility includes a closed-loop cyclone flotation separation system 1, a closed-loop micro-nano flotation system 2, and a high-efficiency dissolved air system 3.

[0025] The closed-loop cyclone flotation separation system 1 includes a first housing 105. The first housing 105 is a horizontal, closed cylindrical shape, with a first water inlet 103 connected to a water inlet pipe at its front end, a first water outlet 110 and a first water outlet 109 at its rear end, and a cyclone generating component 104, three oil droplet trapping devices 101, a mesh agglomerating packing 107 and two first dissolved gas release devices 108 inside. At least one first oil collecting device 102 is provided at its top.

[0026] The cyclone generator 104 is located at the front of the first housing 105 and is connected to the first inlet 103. It can generate centrifugal force through high-speed cyclone to fully mix the introduced sewage with dissolved air. Preferably, the cyclone generator 104 can be a commercially available hydrocyclone, such as Weihai Haiwang, etc. Its processing capacity and flow ratio can be selected according to specific working conditions. Its inlet and outlet are connected to the first housing 105 through flanges for easy installation.

[0027] The oil droplet trapping device 101 is cylindrical, with multiple through-hole-shaped filter holes on its outer shell wall. An internal filter element is installed, one end of which is horizontally mounted to the side wall of the first housing 105 via an external connecting flange, facilitating installation and disassembly. Preferably, the filter element is made of common oleophilic and hydrophobic materials such as modified polypropylene fibers wound together to "capture" oil droplets through its oleophilic properties. The oil droplet trapping device is evenly distributed at the front of the first housing to effectively intercept, adsorb, and coalesce oil droplets.

[0028] The mesh-like coalescing packing 107 is formed by alternating folds of multiple layers of stainless steel corrugated mesh and is fixed to a support inside the first housing via slots on its outer frame. This forms a tortuous flow channel, acting as a coarse-grained bed. Utilizing shallow layer theory, wastewater is intercepted through processes such as coarse-grain capture and folding collisions, then adsorbed and coalesced by the packing, and floats during the coalescence process, enhancing the adsorption effect on oil droplets. Preferably, the mesh-like coalescing packing 107 is located below the oil droplet trapping device 101 to improve the interception and adsorption effect of oil droplets through the synergistic effect of both.

[0029] The first oil collecting device 102 can be a commercially available cylindrical oil collector, and is welded to the first housing via a vertical steel plate. Multiple first oil collecting devices 102 are arranged at intervals and interconnected via a combined pipe 5, and then connected to an oil discharge pipe to fully collect floating oil from the wastewater, which is then discharged into the collecting device via the oil discharge pipe.

[0030] The first dissolved gas release device 108 is located in the middle and rear part of the first housing 105 and is connected to the high-efficiency dissolved gas system 3 to form a dissolved gas zone around it, promoting the separation of oil droplets and water. Preferably, the first dissolved gas release device 108 can be a commercially available disc-type microporous aerator head, such as the TS or TJ type. It can generate micro-nano bubbles through its internal micron-level pores, forming a bubble enrichment area around it, promoting the floating of oil droplets and thus separating oil droplets from water. Furthermore, there are two first dissolved gas release devices 108, spaced apart, to further improve the separation effect.

[0031] A buffer structure 111 is also provided at the rear of the first housing 105. This buffer structure 111 is located behind the dissolved gas release device and is a conventional structure in the art. Its shape is a cuboid module embedded inside the tank body, with a set of closely arranged parallel inclined plates inside. These inclined plates divide the interior into multiple small spaces, thereby increasing the separation area and improving the oil-water separation effect. Preferably, a first oil collecting device is provided above the buffer structure 111 to collect the floating oil that ultimately separates and rises to the surface in this area.

[0032] The closed-loop micro-nano air flotation system 2 includes a second housing 202. The second housing 202 is a horizontal closed cylindrical shape, with a second water inlet 201 at its front end, a second water outlet 207 and a second water outlet 208 at its rear end, multiple baffles 205 and a second dissolved air release device 203 inside, and a second oil collection device 206 at its top.

[0033] The second inlet 201 is connected to the first outlet 110 via a pipe. The second outlet 207 is connected to a drain pipe. Thus, water treated by the closed-loop cyclone flotation separation system 1 can flow into the second housing 201 for further oil-water separation. Then, it is discharged from the drain pipe, completing the oil-water separation process.

[0034] The water baffle 205 is a thin plate, the shape of which is adapted to the cross-sectional shape of the inner cavity of the second housing 202, and is perpendicular to the axis of the second housing 202, and the spacing between each water baffle is the same.

[0035] The baffle plate 205 is provided with multiple through-hole-shaped guide holes. The diameter and number of these guide holes can be calculated and determined according to specific working conditions and set flow rates. The opening ratio of each baffle plate is approximately 20%. Furthermore, the guide holes on each baffle plate are distributed in an equilateral triangle pattern, achieving a "dense at the bottom and sparse at the top" layout. The diameter of the guide holes on each baffle plate gradually decreases along the water flow direction, which can dissipate the kinetic energy of the high-speed water flow at the bottom, prevent the high-speed flow at the bottom from dispersing oil droplets, and ensure smooth and uniform water flow within the shell, achieving stable upward separation of oil droplets. Preferably, the baffle plate is connected to the inner wall of the second shell via a flange for easy disassembly and cleaning.

[0036] The second dissolved gas release device 203 is located at the front of the second housing 202. Meanwhile, the second oil collection device 206 is located at the rear of the second housing 202. This improves the efficiency of oil-water separation and oil droplet collection.

[0037] Multiple closed-loop micro-nano air flotation systems 2 can be connected in series to meet the treatment needs of oily wastewater with different concentrations.

[0038] The highly efficient dissolved air system 3 includes a horizontal pressure dissolved air tank 301. This pressure dissolved air tank 301 is cylindrical, with an inlet valve 302 at its top and an outlet valve 305 at its bottom, and packing material 304 inside. The inlet valve 302 is connected to an external compressed air source. The outlet valve 305 is connected to the first dissolved air release device 108, the second dissolved air device 203, and the water inlet pipe. The packing material 304 is a common type used in air flotation processes, such as stepped rings or Pall rings, to increase the contact area between the gas and water. In use, external compressed air enters the pressure dissolved air tank, and after sufficient contact with the packing material, saturated dissolved air water is formed. It then flows out through the outlet valve and enters the first dissolved air release device, the second dissolved air device, and the water inlet pipe for release.

[0039] The pressure dissolved air tank 301 is also equipped with a return water inlet 303. This return water inlet 303 is connected to the second drain outlet 208 via a return pipe. Alternatively, when the closed-loop micro-nano air flotation system is not used, the return water inlet 303 is connected to the first drain outlet 109 via a return pipe. Simultaneously, a booster pump 4 is installed on the return water pipe, allowing a portion of the water in the second shell 202 or the first shell 105 to flow back into the pressure dissolved air tank 301, recovering and reusing the dissolved air trapped in the water, thus avoiding gas waste.

[0040] The bottom of the first housing 105 and the bottom of the second housing 202 are respectively provided with a plurality of first drain ports 106 and a plurality of second drain ports 204, so as to drain the water completely in the first housing and / or the second housing during maintenance.

[0041] The closed-loop cyclone air flotation separation system, the high-efficiency dissolved air system, and the closed-loop micro-nano air flotation system are all mounted on a skid-mounted frame. This skid-mounted frame is a standard three-dimensional skid with a conventional steel structure, which facilitates overall hoisting and connection of external pipes and cables, improves installation efficiency, reduces footprint, and allows for flexible combination.

[0042] The working process of this invention is as follows: First, the invention is moved to the designated work area, and the closed cyclone air flotation separation system, the closed micro-nano air flotation system, and the ultra-efficient dissolved air system are assembled in sequence.

[0043] Before separating the oil and wastewater, the air inlet valve of the high-efficiency dissolved air system is opened to continuously introduce compressed air into the system. The high-efficiency dissolved air conversion device then processes the compressed gas into the required dissolved gas. As the dissolved gas volume within the high-efficiency dissolved air system gradually increases, a portion of the dissolved gas is continuously compressed into the distribution pipe. From there, the dissolved gas is sequentially transported to the water inlet pipe, the first dissolved gas release device, and the second dissolved gas release device, forming a dissolved gas zone around these devices.

[0044] Pretreated oily wastewater is introduced into the closed-loop cyclone flotation separation system 1 through the inlet pipe 1. Within the cyclone generating component, a self-generating cyclone forms and merges with dissolved air injected from the inlet pipe 1. Under the centrifugal force generated by the high-speed cyclone, the interaction between bubbles and oil droplets is facilitated, accelerating their aggregation towards the central region of the cyclone. Subsequently, the initially coagulated oily wastewater enters the oil collection device 1, and is then transported and collected into the oily wastewater tank via the combined pipe 1 and the oil discharge pipe.

[0045] The treated wastewater continues to flow towards the tail end of the closed-loop cyclone flotation separation system 1, and when it enters the oil droplet trapping device, it can be quickly intercepted, adsorbed, and aggregated into oil droplets. Then, it enters the interior of the mesh agglomeration packing, where the oil droplets float during the adsorption and agglomeration process by the packing. This allows smaller oil droplets to accumulate into liquid floating oil in a short time, and then be discharged from the oil discharge pipe after passing through the oil collection device.

[0046] The treated wastewater continues to flow towards the tail end of the closed-loop cyclone flotation separation system 1, and sequentially passes through the dissolved gas zone surrounding the first dissolved gas release device. At this point, the wastewater combines with the air bubbles, accelerating the rise of oil droplets, and causing the floating oil to be discharged through the oil collection device and the oil discharge pipe.

[0047] Next, the wastewater undergoes static gravity separation in a buffer zone, allowing fine oil droplets to be collected by an oil collection device and discharged from the oil drain pipe. Then, the wastewater continuously enters the closed-loop micro-nano air flotation system.

[0048] The wastewater first passes through the dissolved gas zone surrounding the second dissolved gas release device, separating any remaining oil droplets. Then, after passing through multiple baffles, it flows smoothly to the rear of the second casing. Finally, the oil droplets in the wastewater are collected by the second oil collection device and discharged through the oil drain pipe. Simultaneously, the clean water after oil-water separation is discharged through the drainage pipe.

[0049] During the separation process, PAC dosing stations are located at the rear end of the mesh-like aggregate packing material in the closed-loop cyclone flotation separation system and at the inlet of the closed-loop micro-nano flotation system. PAM dosing stations are located at the front end of the dissolved air release device 1 and at the end effluent zone of the closed-loop cyclone flotation separation system. The dosing sequence is the same as in the standard flotation process: PAC is added first, followed by PAM, to achieve optimal solid-liquid separation. The dosage of PAC and PAM can be calculated and confirmed according to the operating conditions and water quality, following conventional pretreatment processes. When the volume of water to be treated increases, this device can be directly connected in parallel to increase the treatment capacity.

[0050] In summary, this invention can effectively integrate the oil separation and flotation processes in the oily wastewater treatment process, thereby not only greatly reducing the footprint and lowering construction and operating costs, but also simplifying the installation and construction process and creating favorable conditions for remote control.

[0051] All parts not covered in this invention are the same as or can be implemented using existing technologies.

Claims

1. A high-efficiency oil-water separation facility, comprising a closed-loop cyclone flotation separation system, characterized in that, The closed-loop cyclone flotation separation system includes a first shell; the first shell is a horizontal, closed cylindrical shell with a first inlet connected to an inlet pipe at its front end and a first outlet at its rear end. Inside the shell are a first cyclone generating component and at least one first dissolved gas release device, and at least one first oil collecting device at its top. The cyclone generating component is located at the front of the first shell and is connected to the first inlet. The first oil collecting devices are interconnected through combined pipes and are connected to an oil discharge pipe. The first dissolved gas release device is located in the middle and rear of the first shell and is connected to an external dissolved gas generating device to form a dissolved gas zone around it.

2. The high-efficiency oil-water separation facility according to claim 1, characterized in that, It also includes at least one oil droplet trapping device; the oil droplet trapping device includes a cylindrical shell; the shell wall of the shell is provided with a plurality of through-hole-shaped filter holes, and a filter element is provided inside; the oil droplet trapping device is disposed inside the first shell and is connected to the side wall of the first shell.

3. The high-efficiency oil-water separation facility according to claim 2, characterized in that, It also includes a mesh-like agglomerating filler, disposed inside the first housing and located below the oil droplet trapping device.

4. The high-efficiency oil-water separation facility according to claim 1, characterized in that, There are two first dissolved gas release devices, which are arranged at intervals and are located in the middle and rear part of the first housing, and can form different dissolved gas zones around them respectively.

5. The high-efficiency oil-water separation facility according to claim 1, characterized in that, It also includes a closed-loop micro-nano air flotation system; the closed-loop micro-nano air flotation system includes a second shell; the second shell is a horizontal closed cylindrical shell with a second water inlet at the front end and a second water outlet at the rear end, and a second dissolved air release device and at least one baffle plate inside, and a second oil collection device at the top; the second water inlet is connected to the first water outlet through a pipe; the second water outlet is connected to a drain pipe; the second vortex generating component is located at the front of the second shell; the baffle plate is a straight plate, perpendicular to the central axis of the second shell, and has multiple through-hole-shaped guide holes; the second oil collection device is connected to the oil discharge pipe.

6. The high-efficiency oil-water separation facility according to claim 5, characterized in that, The water baffle consists of multiple pieces, evenly distributed along the axial direction of the second shell; the diameter of the guide holes on each water baffle gradually decreases along the water flow direction.

7. The high-efficiency oil-water separation facility according to claim 5, characterized in that, The guide holes on the water baffle are arranged in an equilateral triangle.

8. The high-efficiency oil-water separation facility according to claim 5, characterized in that, The dissolved gas generating device is a high-efficiency dissolved gas system; the high-efficiency dissolved gas system includes a pressure dissolved gas tank; the top and bottom of the pressure dissolved gas tank are respectively provided with an air inlet valve and an air outlet valve; the air inlet valve is connected to an external compressed air source; the air outlet valve is connected to the first dissolved gas release device, the second dissolved gas release device and the water inlet pipe respectively.

9. The high-efficiency oil-water separation facility according to claim 8, characterized in that, The pressure dissolved gas tank is also provided with a return water port; the rear end of the first shell is provided with a first drain port; the rear end of the second shell is provided with a second drain port; the return water port is connected to the first drain port or the second drain port through a return pipe; a booster pump is provided on the return water pipe.

10. The high-efficiency oil-water separation facility according to claim 8, characterized in that, It also includes a skid-mounted frame; the skid-mounted frame is a standardized three-dimensional skid body with steel structure; the closed cyclone air flotation separation system, the closed micro-nano air flotation system and the ultra-efficient dissolved air system are respectively installed on the skid-mounted frame for easy installation.

Images