A multi-stage surface aerated wastewater treatment tank

Abstract

The application belongs to the technical field of water treatment, and specifically discloses a multi-stage surface aeration sewage treatment tank. The support of the sewage treatment tank is stacked with multiple layers of sewage treatment tanks from top to bottom; the tank body of the sewage treatment tank is arranged on the support, the surface aeration disc is in an umbrella-shaped structure and is arranged in the tank body, the upper surface of the surface aeration disc is provided with a flow guide strip, the flow guide pipe is fixed in the tank body and has an inlet extending to below the surface aeration disc, the lower part of the flow guide pipe penetrates through the tank body and extends to above the center of the surface aeration disc of the next layer, the outlet of the water inlet pipe extends to above the center of the surface aeration disc of the top layer of the sewage treatment tank, and the water outlet pipe is communicated with the outlet of the flow guide pipe of the bottom layer of the sewage treatment tank. The application utilizes the surface aeration disc for reoxygenation, biochemical reaction in the sewage treatment tank for degradation of pollutants and consumption of dissolved oxygen, and multiple reoxygenation and oxygen consumption for degradation of pollutants, and has the characteristics of simple structure, strong aeration effect, energy saving and consumption reduction, convenient maintenance, and small land occupation.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a multi-stage surface aeration wastewater treatment tank that is simple in structure, has a strong aeration effect, saves energy and reduces consumption, is easy to maintain, and occupies a small area. Background Technology

[0002] Aeration is a core process in wastewater treatment, aiming to efficiently oxygenate the wastewater and achieve sludge-water mixing, providing the necessary conditions for aerobic microorganisms to degrade organic pollutants. The aeration system is the most energy-intensive unit in a wastewater treatment plant, typically accounting for over 50% of the total energy consumption of the entire process. Therefore, energy conservation and consumption reduction in the aeration stage are key technological directions for improving the economic efficiency of wastewater treatment and reducing operating costs.

[0003] Currently, the mainstream aeration methods in the wastewater treatment industry are mainly divided into two categories: blower aeration and surface aeration. Blower aeration uses a blower to pressurize air and deliver it to underwater aerators, oxygenating the water in the form of bubbles. Surface aeration, on the other hand, uses impellers, inverted umbrellas, and other mechanical components to agitate the water surface, scattering water into the air to achieve gas-liquid contact oxygenation. Because both of these aeration methods require the simultaneous movement of both gaseous and liquid media, they share the common problems of high energy consumption and high power costs, making it difficult to meet the industry's development needs for low-carbon and energy-saving practices.

[0004] Based on the distribution patterns of dissolved oxygen in water bodies, surface water in natural water bodies has a higher dissolved oxygen content due to direct contact with the atmosphere; while deep water, due to its higher density and isolation from the atmosphere, experiences continuous consumption of dissolved oxygen with little replenishment, easily forming an anaerobic layer, leading to blackening and foul odors in the water and low pollutant degradation efficiency. Based on this pattern, surface water-deep water exchange and reoxygenation technology has emerged. This technology achieves dissolved oxygen redistribution solely through water exchange within the liquid phase, theoretically consuming extremely low energy, making it an ideal alternative to traditional aeration. However, existing surface water-deep water exchange and reoxygenation technologies still have many significant drawbacks: 1. The single-stage reoxygenation efficiency of non-powered drop and ditch-type reoxygenation devices is low, so a long process and a large drop are required, resulting in a large footprint and making them unsuitable for narrow spaces.

[0005] 2. Multi-stage water tanks and siphon-type potential energy oxygenation devices have complex structures, and the internal packing is prone to clogging, making cleaning and maintenance difficult. In addition, the water flow path is singular, and uneven water distribution leads to insufficient gas-liquid contact.

[0006] 3. Traditional multi-stage biological filters and aeration devices have low integration and poor alternation between aerobic and anoxic environments, resulting in insufficient efficiency in nitrogen removal and organic matter degradation, making it difficult to meet the needs of large-scale industrial treatment.

[0007] 4. Most of the equipment has poor modularity and disassembly, which means that the whole machine must be shut down during maintenance. Moreover, the replacement of packing and the cleaning of the pool are complicated, resulting in high operation and maintenance costs.

[0008] 5. The surface aeration components lack flow guidance optimization, resulting in high water flow velocity and short residence time on the aeration surface. This leads to insufficient contact area and time between the water and air, thus limiting the reoxygenation effect.

[0009] To overcome the shortcomings of existing technologies in terms of energy consumption, land occupation, reoxygenation efficiency, ease of operation and maintenance, and biochemical treatment effect, and to meet the treatment needs of large-scale industrial wastewater, it is urgent to develop a high-efficiency integrated wastewater treatment device that can achieve efficient reoxygenation without power and modular and convenient operation and maintenance. Summary of the Invention

[0010] To address the problems mentioned in the background section, this invention provides a multi-stage surface aeration wastewater treatment tank that is simple in structure, has a strong aeration effect, saves energy and reduces consumption, is easy to maintain, and occupies a small area.

[0011] The multi-stage surface aeration wastewater treatment tank of the present invention is implemented as follows: it includes a support frame, an inlet pipe, and an outlet pipe, wherein the support frame is stacked and fixedly arranged with multiple layers of wastewater treatment tanks from top to bottom; The wastewater treatment tank includes a tank body, surface aeration discs, and guide pipes. The tank body is mounted on a support frame. The surface aeration discs are umbrella-shaped structures with a high center and low perimeter, and are enclosed inside the tank body. The top of the surface aeration discs extends to below the bottom surface of the tank body above. A raised guide strip is fixedly installed on the upper surface of the surface aeration discs. The guide pipes are vertically fixed inside the tank body, with the top inlet extending to the upper part of the tank body and located below the surface aeration discs. The lower part of the guide pipes is sealed and penetrates the bottom wall of the tank body and extends to above the center of the next layer of surface aeration discs. One end of the inlet pipe is connected to the sewage supply port and the other end extends to the center above the surface aeration disc of the top sewage treatment tank. The outlet pipe is connected to the outlet of the guide pipe of the bottom sewage treatment tank.

[0012] Furthermore, the guide strips on the surface aeration disc are flow guide strips, and the extension direction of the flow guide strips intersects the radial direction of the water flow on the upper surface of the surface aeration disc. At least two water passage openings are spaced apart on the flow guide strips, and the water passage openings of adjacent flow guide strips on the surface aeration disc are staggered.

[0013] Furthermore, the guide strips on the surface aeration disc are spiral guide strips, which extend spirally from the center of the surface aeration disc to the surrounding area.

[0014] Furthermore, the tank is filled with biological packing material whose top is lower than the inlet of the guide pipe. The biological packing material includes at least one of ceramsite, activated carbon, volcanic rock, elastic packing material, flexible packing material, and combined packing material. The surface aeration disc is placed on the biological packing material filled in the tank, and a gap is left between the bottom outer wall of the surface aeration disc and the inner wall of the tank.

[0015] Furthermore, the surface aeration disc is detachably and horizontally fixed inside the tank body, and a gap is left between the bottom surface and the bottom outer wall of the surface aeration disc and the corresponding inner bottom and inner wall of the tank body.

[0016] Furthermore, a drain outlet and a drain valve are provided on the lower part of the side wall or bottom of the pool body, and the drain valve outlets of each layer of sewage treatment pools on the support are all connected to the drain pipe.

[0017] Furthermore, the support is composed of multiple stackable support units. Each support unit includes vertical members and support members. The vertical members are cylindrical structural members and adjacent vertical members are detachably stacked and fixedly connected. At least two support members are fixedly arranged circumferentially inside the vertical members. The sewage treatment tank is detachably fixedly arranged on the support members inside the vertical members.

[0018] Furthermore, the vertical member is a plate-shaped cylindrical body or a polygonal prism body with multiple vent holes spaced apart circumferentially, and the vertical member has multiple suspended horizontal support members spaced apart circumferentially or at least two horizontal support members arranged crosswise.

[0019] Furthermore, the vertical member is a cylindrical structure formed by multiple vertical rods, and the vertical rods are fixedly connected to each other by connecting rods. The cylindrical structure is provided with multiple suspended horizontal support members at intervals along its inner circumference or with at least two horizontal support members arranged at intersections.

[0020] The present invention has the following beneficial effects: 1. Addressing the shortcomings of existing surface aeration technologies that rely on motor-driven rotating impellers / inverted umbrellas, such as high energy consumption, easy wear, and high noise, as well as the chaotic water distribution, short contact time, and limited reoxygenation of cascading reoxygenation devices, this invention replaces all rotating aeration components with a static umbrella-shaped surface aeration disc and guide strips. The entire wastewater surface aeration process only requires a certain height difference, resulting in lower energy consumption, no moving parts, no noise, and no maintenance. Furthermore, the guide strips (flow-prone / spiral structure) force water flow to form a uniform thin layer along the disc surface, prolonging the water-air contact time and increasing the contact area, thereby significantly improving reoxygenation efficiency and overcoming the aforementioned shortcomings of existing surface aeration technologies and cascading reoxygenation devices.

[0021] 2. Addressing the practical problems of existing cascading / siphon devices, such as short effluent paths, insufficient retention time, and inadequate pollutant degradation, as well as the clogging and difficult cleaning of traditional filters, this invention adopts a structure with the inlet of the guide pipe at the top and the outlet at the bottom. This significantly extends the biochemical retention time of wastewater within the tank, forming both anaerobic and aerobic layers. This ensures effective contact between the microorganisms on the biological packing material and the wastewater, significantly improving the BOD removal rate. Furthermore, the straight-through guide pipe, without bends or dead angles, is less prone to sludge accumulation and clogging. The tank can also be independently emptied, inspected, and cleaned, making maintenance convenient and overcoming the aforementioned problems of existing cascading / siphon devices.

[0022] 3. To address the shortcomings of existing multi-stage cascading / tank devices, such as severe water flow deviation, splashing, unstable reoxygenation, and large efficiency fluctuations, this invention employs precise center-to-center docking between stages. This ensures that the upper effluent falls precisely into the center of the lower surface aeration disc, resulting in a vertically falling, non-deviationing, splash-free, and stable water flow. Furthermore, the water flow evenly diffuses and reoxygenates along the umbrella discs of the surface aeration discs, ensuring stable and controllable reoxygenation effects at each stage. This significantly improves the overall reoxygenation efficiency and solves the aforementioned shortcomings of existing multi-stage cascading / tank devices.

[0023] 4. Addressing the problem of low nitrogen removal efficiency caused by the inability of existing single aeration / filters to create a stable alternating aerobic-anoxic environment, this invention employs a multi-stage series connection and a progressive reoxygenation-in-tank oxygen consumption cycle. This allows each tank to form an aerobic zone (nitrification, BOD degradation) in the upper reoxygenation stage and an anoxic zone (denitrification) in the lower anoxic stage, creating a natural multi-stage A / O process. This eliminates the need for additional anaerobic / anoxic tanks, efficiently enhancing nitrogen removal while progressively degrading BOD and ensuring stable effluent quality. This solves the aforementioned technical challenges of existing single aeration / filters.

[0024] 5. The present invention adopts a modular design of stacked support frame + independent tank, which can flexibly increase or decrease the number of stages as needed, so as to adapt to the treatment needs of different water quality and water volume; moreover, the vertical stacking arrangement occupies a very small area, which is particularly suitable for sewage treatment in small spaces; and the tanks at each level have the same structure, are detachable and can be inspected and maintained independently, which makes daily maintenance simple and application costs low, significantly better than traditional large aeration tanks and filters.

[0025] In summary, this invention addresses the long-standing shortcomings of existing technologies, such as high energy consumption, poor reoxygenation, easy clogging, weak denitrification, poor flexibility, large footprint, and difficult operation and maintenance, through the combination of four core innovative technologies: static umbrella-shaped surface aeration discs + guide strips, top-inlet and bottom-outlet operation of surface aeration discs with guide pipes, center-to-center operation between stages, and multi-stage reoxygenation-alternating oxygen consumption. It provides a feasible solution for surface aeration technology in the wastewater treatment industry. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is an enlarged view of the support unit and the sewage treatment tank structure on it according to the present invention; Figure 3 for Figure 2 Top view; Figure 4 This is one of the top views of the surface aeration disc of the present invention; Figure 5 This is a second top view of the surface aeration disc of the present invention; In the diagram: 1-bracket, 11-vertical component, 12-support component, 2-inlet pipe, 3-outlet pipe, 4-tank body, 5-surface aeration disc, 6-guide pipe, 7-flow guide strip, 8-spiral guide strip. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this does not limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0028] like Figures 1 to 5 As shown, the multi-stage surface aeration wastewater treatment tank of the present invention includes a support 1, an inlet pipe 2, and an outlet pipe 3. The support 1 is stacked and fixedly arranged with multiple layers of wastewater treatment tanks from top to bottom. The wastewater treatment tank includes a tank body 4, surface aeration discs 5, and guide pipes 6. The tank body 4 is mounted on a support 1. The surface aeration discs 5 are umbrella-shaped structures with a high center and low periphery, and are housed inside the tank body 4. The top of the surface aeration discs 5 extends to below the bottom surface of the upper tank body 4. A raised guide strip is fixedly installed on the upper surface of the surface aeration discs 5. The guide pipes 6 are vertically fixed inside the tank body 4, with the inlet at the top extending to the upper part of the tank body 4 and located below the surface aeration discs 5. The lower part of the guide pipes 6 is sealed and penetrates the bottom wall of the tank body 4 and extends to above the center of the next layer of surface aeration discs 5. One end of the inlet pipe 2 is connected to the sewage supply port and the other end extends to the center of the surface aeration disc 5 of the top sewage treatment tank. The outlet pipe 3 is connected to the outlet of the guide pipe 6 of the bottom sewage treatment tank.

[0029] The guide strip on the surface aeration disc 5 is a flow guide strip 7. The extension direction of the flow guide strip 7 intersects the radial direction of the water flow on the upper surface of the surface aeration disc 5. At least two water passage openings are spaced apart on the flow guide strip 7. The water passage openings of adjacent flow guide strips 7 on the surface aeration disc 5 are staggered.

[0030] The guide strip on the surface aeration disc 5 is a spiral guide strip 8, which extends spirally from the center of the surface aeration disc 5 to the surrounding area.

[0031] The pool body 4 is filled with biological packing material whose top is lower than the inlet of the guide pipe 6. The biological packing material includes at least one of ceramsite, activated carbon, volcanic rock, elastic packing material, flexible packing material, and combined packing material. The surface aeration disc 5 is placed on the biological packing material filled in the pool body 4, and a gap is left between the bottom outer wall of the surface aeration disc 5 and the inner wall of the pool body 4.

[0032] The elastic packing includes YDT type elastic three-dimensional packing and TA type elastic wave packing; the flexible packing includes soft fiber packing and vinylon filament packing; and the combined packing includes combined double ring packing and combined porous ring packing.

[0033] The surface aeration disc 5 is detachably and horizontally fixed inside the tank body 4, with gaps between the bottom surface and the outer bottom wall of the surface aeration disc 5 and the corresponding inner bottom and inner wall of the tank body 4. These gaps allow air to enter the upper surface of the surface aeration disc 5, thereby enabling reoxygenation of wastewater on the upper surface of the surface aeration disc 5.

[0034] The lower part or bottom of the side wall of the pool body 4 is provided with a sewage outlet and a sewage valve. The sewage valve outlet of each layer of sewage treatment pool on the support 1 is connected to the sewage pipe.

[0035] The support frame 1 is composed of multiple stackable support units. Each support unit includes vertical members 11 and supporting members 12. The vertical members 11 are cylindrical structures, and adjacent vertical members 11 are detachably stacked and fixedly connected. At least two supporting members 12 are fixedly arranged circumferentially inside each vertical member 11. The sewage treatment tank is detachably fixedly mounted on the supporting members 12 inside the vertical members 11. The support frame 1 is composed of multiple stackable support units, which allows for flexible adjustment of the number of layers in the sewage treatment tank to adapt to different sewage treatment requirements. It also facilitates the separation of each layer of support units by disassembling the interconnections between them, thereby facilitating the replacement of biological packing material in the sewage treatment tank, sludge removal inside the tank 4, and maintenance of various components.

[0036] The vertical member 11 is a plate-shaped cylindrical body or a polygonal prism body with multiple vent holes spaced apart around the circumference. The vertical member 11 has multiple suspended horizontal support members 12 spaced apart around the circumference or at least two horizontal support members 12 arranged in a cross pattern.

[0037] The vertical member 11 is a cylindrical structure formed by multiple vertical rods. The vertical rods are fixedly connected to each other by connecting rods. The cylindrical structure is provided with multiple suspended horizontal support members 12 at intervals along its inner circumference or with at least two horizontal support members 12 arranged in a cross pattern.

[0038] The working principle and process of this invention: like Figures 1 to 5As shown, during operation, wastewater flows from the inlet pipe 2 to the top of the surface aeration disc 5 in the top layer of the wastewater treatment tank. It then flows naturally down the upper surface of the surface aeration disc 5. During this downward flow, the guide strips (such as the flow guide strips 7 and spiral guide strips 8) of the surface aeration disc 5 ensure uniform water distribution on the upper surface of the surface aeration disc 5, increasing the contact area and extending the contact time between the water and air, thus improving the surface aeration effect. Then, the wastewater flows from the surface aeration disc 5 into the tank body 4. Due to the flow of wastewater within the tank body 4 (especially when the lower end of the surface aeration disc 5 extends below the water surface in the tank body 4), the difference in dissolved oxygen distribution creates stratified aerobic and anoxic zones, thus achieving... The alternating operation of anaerobic and aerobic biochemical reactions (especially the biological packing material in tank 4 provides sufficient attachment carriers for microorganisms, thereby forming a dense biofilm, effectively improving the efficiency of biochemical reactions, and the biological packing material also filters particulate matter in the wastewater) effectively removes pollutants such as BOD from the wastewater and consumes dissolved oxygen. The wastewater after the dissolved oxygen is consumed flows by gravity through the guide pipe 6 into the top of the surface aeration disc 5 of the next stage wastewater treatment tank. The wastewater undergoes multiple reoxygenation and oxygen-consuming degradation through the multi-level wastewater treatment tanks on the support 1, thereby effectively degrading the pollutants in the wastewater, and finally flows out through the guide pipe 6 of the bottom wastewater treatment tank and the effluent pipe 3.

[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-stage surface aeration wastewater treatment tank, characterized in that: Includes a support (1), an inlet pipe (2), and an outlet pipe (3). The support (1) is stacked and fixed with multiple layers of sewage treatment tanks from top to bottom. The wastewater treatment tank includes a tank body (4), a surface aeration disc (5), and a guide pipe (6). The tank body (4) is mounted on a support (1). The surface aeration disc (5) is an umbrella-shaped structure with a high center and low periphery and is covered inside the tank body (4). The top of the surface aeration disc (5) extends to the bottom surface of the upper tank body (4). A raised guide strip is fixedly installed on the upper surface of the surface aeration disc (5). The guide pipe (6) is vertically fixed inside the tank body (4) and the inlet at the top extends to the upper part of the tank body (4) and is located below the surface aeration disc (5). The lower part of the guide pipe (6) is sealed through the bottom wall of the tank body (4) and extends to the center above the next layer of surface aeration disc (5). One end of the inlet pipe (2) is connected to the sewage supply port and the other end extends to the center above the surface aeration disc (5) of the top sewage treatment tank. The outlet pipe (3) is connected to the outlet of the guide pipe (6) of the bottom sewage treatment tank.

2. The multi-stage surface aeration wastewater treatment tank according to claim 1, characterized in that: The guide strip on the surface aeration disc (5) is a flow guide strip (7). The extension direction of the flow guide strip (7) intersects the radial direction of the water flow on the surface aeration disc (5). At least two water passage openings are spaced apart on the flow guide strip (7). The water passage openings of adjacent flow guide strips (7) on the surface aeration disc (5) are staggered.

3. The multi-stage surface aeration wastewater treatment tank according to claim 1, characterized in that: The guide strip on the surface aeration disc (5) is a spiral guide strip (8), which extends spirally from the center of the surface aeration disc (5) to the surrounding area.

4. The multi-stage surface aeration wastewater treatment tank according to claim 1, characterized in that: The pool (4) is filled with biological filler material whose top is lower than the inlet of the guide pipe (6). The biological filler material includes at least one of ceramsite, activated carbon, volcanic rock, elastic filler, flexible filler, and combined filler. The surface aeration disc (5) is placed on the biological filler material filled in the pool (4). A gap is left between the bottom outer wall of the surface aeration disc (5) and the inner wall of the pool (4).

5. The multi-stage surface aeration wastewater treatment tank according to claim 1, characterized in that: The surface aeration disc (5) is detachably and horizontally fixed inside the tank body (4), and there is a gap between the bottom surface and the bottom outer wall of the surface aeration disc (5) and the corresponding inner bottom and inner wall of the tank body (4).

6. The multi-stage surface aeration wastewater treatment tank according to claim 1, characterized in that: The lower part or bottom of the side wall of the pool (4) is provided with a sewage outlet and a sewage valve. The sewage valve outlets of each layer of sewage treatment pool on the support (1) are all connected to the sewage pipe.

7. The multi-stage surface aeration wastewater treatment tank according to any one of claims 1 to 6, characterized in that: The support (1) is composed of multiple stackable support units. The support unit includes a vertical member (11) and a support member (12). The vertical member (11) is a cylindrical structure and adjacent vertical members (11) are detachably stacked and fixedly connected. At least two support members (12) are fixedly arranged circumferentially inside the vertical member (11). The sewage treatment tank is detachably fixedly arranged on the support member (12) inside the vertical member (11).

8. The multi-stage surface aeration wastewater treatment tank according to claim 7, characterized in that: The vertical member (11) is a plate-shaped cylindrical body or a multi-faceted prism body with multiple vent holes spaced apart in the circumference. The vertical member (11) has multiple suspended horizontal support members (12) spaced apart in the circumference or at least two horizontal support members (12) arranged in a cross pattern.

9. The multi-stage surface aeration wastewater treatment tank according to claim 7, characterized in that: The vertical member (11) is a cylindrical structure formed by multiple vertical rods. Each vertical rod is fixedly connected by a connecting rod. The cylindrical structure is provided with multiple suspended horizontal support members (12) at intervals along its inner circumference or with at least two horizontal support members (12) arranged in a cross pattern.

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