Foam removing device at the inlet of a secondary sedimentation tank

Abstract

The utility model relates to a kind of foam removing device at the import of two sedimentation tanks of week in and week out, including the soft rubber scraper in the water inlet channel of two sedimentation tanks, the rubber scraper is connected with driving mechanism, to facilitate the movement of rubber scraper along the circumferential direction of water inlet channel, the water inlet channel is provided with residue overflow, and the upper portion of the water inlet channel is also circumferentially distributed with several sprinklers, to facilitate the water surface foam in water inlet channel to be sprayed and defoamed.The foam removing device at the import of two sedimentation tanks of week in and week out is provided with rubber scraper in the water inlet channel of two sedimentation tanks, and the rubber scraper moves in the circumferential direction of water inlet channel, and the foam scum on the water surface in water inlet channel can be scraped to residue overflow and discharged;Still provided with several sprinklers to spray and defoam the water surface foam in water inlet channel, avoid that foam is not easy to scrape due to " size " too big.

Description

Technical Field

[0001] This utility model relates to a foam removal device at the inlet of a secondary sedimentation tank with cyclic inflow and outflow, and relates to the field of wastewater treatment. Background Technology

[0002] The secondary sedimentation tank is one of the core structures in the activated sludge wastewater treatment process. Its main function is to achieve sludge-water separation: the activated sludge flocs in the effluent from the aeration tank are separated by sedimentation. The supernatant is discharged as treated water or enters the advanced treatment unit, while the settled sludge is partially returned to the aeration tank to maintain the sludge concentration required for biological reactions, and partially discharged as excess sludge. As a key upstream structure of the secondary sedimentation tank, the inlet channel plays a crucial role in uniformly and stably introducing wastewater containing mixed sludge (usually the mixed liquor from the aeration tank) into the sedimentation tank. Its hydraulic conditions and operating status directly affect the separation efficiency, effluent quality, and long-term operational stability of the secondary sedimentation tank.

[0003] In actual operation, the wastewater in the secondary sedimentation tank inlet channel typically contains a large amount of activated sludge flocs, microbial metabolites, and a small amount of undegraded organic matter. Foam and scum easily form on the surface of the inlet channel for the following reasons: 1. Role of surfactants: Detergents in sewage, surfactants in industrial wastewater, or extracellular polymers produced by microbial metabolism can reduce the surface tension of water and promote foam formation. 2. Gas entrainment and release: Dissolved gases such as oxygen and nitrogen in the sludge returned to the aeration tank are released due to pressure changes when flowing through the inlet channel, or tiny bubbles wrapped inside the sludge flocs escape, forming a bubble-sludge floc composite scum. 3. Local anaerobic environment: If the water flow rate in the inlet channel is too slow or there are dead corners, the sludge will stay for too long and local anaerobic reactions will easily occur, producing biogas (such as methane and hydrogen sulfide), which will further aggravate the accumulation of foam and scum.

[0004] Currently, existing technologies do not include a dedicated removal device for the aforementioned foam and scum problem in the design of the secondary sedimentation tank inlet channel, resulting in the following prominent issues during long-term operation: 1. Affects mud-water separation efficiency When foam and scum accumulate in large quantities on the water surface, they can alter the flow pattern within the inlet channel. On the one hand, the scum layer hinders heat exchange between the water and the air, leading to a localized increase in water temperature and affecting sludge settling performance. On the other hand, the accumulation of scum may create a "dam effect," causing uneven distribution of water flow within the channel (such as excessively fast or slow flow velocities in certain areas). This, in turn, results in uneven water distribution in the subsequent sedimentation tank, disrupting the sludge settling trajectory within the tank and reducing the efficiency of sludge-water separation.

[0005] 2. Leads to secondary pollution and water quality deterioration The scum is rich in undegraded organic matter, activated sludge and microorganisms. If it remains in the inlet channel for a long time, it is prone to putrefaction and release malodorous gases (such as hydrogen sulfide and ammonia), causing air pollution in the surrounding environment. At the same time, the small molecule organic acids, ammonia nitrogen and other substances produced in the putrefaction process will be re-dissolved into the water, causing the wastewater quality in the inlet channel to deteriorate and increasing the load on subsequent treatment units.

[0006] 3. Affects effluent quality and operational stability If foam and scum enter the main body of the secondary sedimentation tank with the water flow, some of the scum will adhere to the surface of the sedimentation tank to form a "floating mud layer", or stick to the tank wall and the effluent weir plate, resulting in an increase in suspended solids in the effluent. In addition, the light sludge flocs in the scum may overflow with the supernatant, causing the COD, BOD and other indicators of the effluent to exceed the standards, making it difficult to meet the strict discharge standards.

[0007] 4. Increased operation and maintenance costs and security risks Manual cleaning of foam scum requires interrupting the operation of the inlet channel or working in narrow channels, which is inefficient, labor-intensive, and poses safety risks such as slipping and contact with toxic and harmful substances. If cleaning is not done in time, the scum may clog the inlet grille, guide holes and other structures, resulting in a decrease in the channel's water flow capacity, requiring shutdown for maintenance and further increasing operation and maintenance costs. Utility Model Content

[0008] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a foam removal device at the inlet of a cyclically inlet and cyclically outlet secondary sedimentation tank.

[0009] To solve the above-mentioned technical problems, the technical solution of this utility model is: a foam removal device at the inlet of a secondary sedimentation tank with circumferential inflow and outflow, comprising a flexible rubber scraper installed in the inlet channel of the secondary sedimentation tank, the rubber scraper being connected to a driving mechanism to facilitate driving the rubber scraper to move along the circumference of the inlet channel, the inlet channel being provided with a slag overflow outlet, and several sprayers being circumferentially distributed above the inlet channel to facilitate spraying and defoaming the foam on the water surface in the inlet channel.

[0010] Preferably, the driving mechanism is the same as the driving mechanism of the sludge scraper in the sedimentation zone of the secondary sedimentation tank.

[0011] Preferably, a horizontal straight rod located above the secondary sedimentation tank is fixedly connected to the top of the rubber scraper. Several mounting sleeves are fixedly connected to the horizontal straight rod along its length. Each mounting sleeve is fitted onto a mounting straight rod parallel to the horizontal straight rod below it, and each mounting sleeve is screwed with a set screw.

[0012] Preferably, a vertical rod is fixedly connected to the mounting rod, and the bottom end of the vertical rod is fixedly connected to the horizontal connecting rod of the skimming device of the secondary sedimentation tank.

[0013] Preferably, the slag discharge overflow outlet is located on the bottom of the inner channel of the inlet channel and includes a slag discharge channel. The top of the slag discharge channel is provided with a slag discharge inlet that is higher than the water level in the inlet channel. The slag discharge inlet is connected to the bottom of the inlet channel via guide slopes on two opposite sides in the circumferential direction of the inlet channel.

[0014] Preferably, the lengths of the slag discharge inlet and the guide ramp in the radial direction of the secondary sedimentation tank are both equal to the width of the inlet channel.

[0015] Preferably, the bottom end of the rubber scraper is located below the water surface in the inlet channel.

[0016] Preferably, the sprayer is a spray head, and its spraying direction is directly downward and diagonally downward around the circumference.

[0017] Preferably, all the sprayers are connected to the annular main water inlet pipe via branch water inlet pipes.

[0018] Preferably, the water source for the main inlet pipe comes from the sedimentation zone of the secondary sedimentation tank.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The foam removal device at the inlet of the circumferential sedimentation tank is equipped with a rubber scraper in the inlet channel of the secondary sedimentation tank. The rubber scraper moves circumferentially in the inlet channel and can scrape the foam and scum on the water surface in the inlet channel to the scum discharge overflow port and discharge it away; it is also equipped with several sprayers to spray and defoam the foam on the water surface in the inlet channel, so as to avoid the foam being too large to be easily scraped off.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0021] Figure 1 This is a simplified top view of an embodiment of the present utility model.

[0022] Figure 2 for Figure 1 A schematic diagram of a local structure.

[0023] Figure 3 for Figure 2 The main view.

[0024] Figure 4 This is a simplified diagram illustrating the scraping and removal action of foam scum in an embodiment of this utility model.

[0025] In the diagram: 1. Secondary sedimentation tank; 2. Inlet channel; 3. Rubber scraper; 4. Sprayer; 5. Drive mechanism; 6. Horizontal straight rod; 7. Mounting sleeve; 8. Mounting straight rod; 9. Set screw; 10. Vertical straight rod; 11. Skimming device; 12. Connecting rod; 13. Slag discharge channel; 14. Slag discharge inlet; 15. Guide slope; 16. Inlet branch pipe; 17. Inlet main pipe; 18. Sedimentation zone; 19. Foam and scum; 20. Outlet zone; 21. Water surface. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] like Figures 1-4 As shown, this embodiment provides a foam removal device at the inlet of a secondary sedimentation tank with circumferential inflow and outflow, including a flexible rubber scraper 3 installed in the inlet channel 2 of the secondary sedimentation tank 1. The rubber scraper is connected to a driving mechanism to facilitate the movement of the rubber scraper along the circumferential direction of the inlet channel for scraping foam and scum on the water surface in the inlet channel. The inlet channel is provided with a scum overflow outlet, and several sprayers 4 are circumferentially distributed above the inlet channel to facilitate spraying and defoaming the foam on the water surface in the inlet channel.

[0030] In this embodiment of the present invention, the driving mechanism is the drive mechanism 5 of the sludge scraper in the sedimentation zone 20 of the secondary sedimentation tank, which is an existing mechanism in the prior art secondary sedimentation tank.

[0031] In this embodiment of the utility model, a horizontal straight rod 6 located above the secondary sedimentation tank is fixedly connected to the top of the rubber scraper. Several mounting sleeves 7 are fixedly connected along the length of the horizontal straight rod. Each mounting sleeve is fitted onto a mounting straight rod 8 located parallel to the horizontal straight rod below it, and each mounting sleeve is screwed with a set screw 9. By tightening or loosening the set screws, the position of the rubber scraper can be finely adjusted within a certain size range.

[0032] In this embodiment of the utility model, a vertical rod 10 is fixedly connected to the mounting rod, and the bottom end of the vertical rod is fixedly connected to the horizontal connecting rod 12 of the skimming device 11 in the sedimentation zone of the secondary sedimentation tank. The skimming device is also an existing device in the secondary sedimentation tank of the prior art.

[0033] Adding a foam removal device to the skimming device in the existing secondary sedimentation tank and then adding a foam removal device to the inlet channel does not require any modification to the original drive mechanism or skimming device of the secondary sedimentation tank, and does not affect the normal operation of the original drive mechanism or skimming device.

[0034] In this embodiment of the utility model, the slag discharge overflow port is set on the bottom of the inner channel of the water inlet channel and includes a slag discharge channel 13. The top of the slag discharge channel is provided with a slag discharge inlet 14 that is higher than the water surface 21 in the water inlet channel. The slag discharge inlet is connected to the bottom of the water inlet channel via guide ramps 15 on both opposite sides in the circumferential direction of the water inlet channel.

[0035] In this embodiment of the invention, the lengths of the slag discharge inlet and the guide slope in the radial direction of the secondary sedimentation tank are both equal to the width of the inlet channel.

[0036] In this embodiment of the invention, the bottom end of the rubber scraper is located below the water surface in the inlet channel.

[0037] In this embodiment of the utility model, the sprayer is a spray head, and its spraying direction is to spray directly downwards and diagonally downwards around the circumference.

[0038] In this embodiment of the utility model, the sprayers are all connected to the annular main water inlet pipe 17 via water inlet branch pipes 16.

[0039] In this embodiment of the present invention, the water source of the main inlet pipe comes from the water in the sedimentation zone 18 of the secondary sedimentation tank.

[0040] In this embodiment of the invention, the working principle of the foam removal device at the inlet of the secondary sedimentation tank with circumferential inflow and outflow is as follows: several sprayers spray and defoam the foam on the water surface in the inlet channel to prevent the foam from being too large to be easily scraped off. A rubber scraper is installed in the inlet channel of the secondary sedimentation tank. The rubber scraper moves circumferentially in the inlet channel and can scrape the foam scum 19 on the water surface in the inlet channel toward the scum discharge overflow port. When the bottom of the rubber scraper touches one of the guide slopes, the bottom of the rubber scraper will gradually deform and scrape the defoamed foam scum along the guide slope into the scum discharge channel and discharge it downwards. When the rubber scraper continues to move and passes the scum discharge overflow port, the bottom shape of the rubber scraper returns to its original shape and moves again to carry out a new round of foam scum removal operation.

[0041] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from its technical solution shall still fall within the protection scope of this utility model.

Claims

1. A foam removal device at the inlet of a secondary sedimentation tank with cyclic inflow and outflow, characterized in that: It includes a flexible rubber scraper installed in the inlet channel of the secondary sedimentation tank. The rubber scraper is connected to a driving mechanism to facilitate the movement of the rubber scraper along the circumference of the inlet channel. The inlet channel is provided with a slag discharge overflow port, and several sprayers are also distributed circumferentially above the inlet channel to facilitate spraying and defoaming of the water surface foam in the inlet channel.

2. The foam removal device at the inlet of the secondary sedimentation tank with cyclic inflow and cyclic outflow as described in claim 1, characterized in that: The driving mechanism is the same as the sludge scraper driving mechanism used in the sedimentation zone of the secondary sedimentation tank.

3. The foam removal device at the inlet of the secondary sedimentation tank with cyclic inflow and cyclic outflow as described in claim 2, characterized in that: The top of the rubber scraper is fixedly connected to a horizontal straight rod located above the secondary sedimentation tank. Several mounting sleeves are fixedly connected to the horizontal straight rod along its length. Each mounting sleeve is fitted onto a mounting straight rod parallel to the horizontal straight rod below it, and each mounting sleeve is screwed with a set screw.

4. The foam removal device at the inlet of the secondary sedimentation tank with circumferential inlet and outlet as described in claim 3, characterized in that: A vertical rod is fixedly connected to the mounting rod, and the bottom end of the vertical rod is fixedly connected to the horizontal connecting rod of the skimming device of the secondary sedimentation tank.

5. The foam removal device at the inlet of the secondary sedimentation tank with cyclic inflow and cyclic outflow as described in claim 1, characterized in that: The slag discharge outlet is located on the bottom of the inner channel of the inlet channel and includes a slag discharge channel. The top of the slag discharge channel is provided with a slag discharge inlet that is higher than the water level in the inlet channel. The slag discharge inlet is connected to the bottom of the inlet channel via guide slopes on two opposite sides in the circumferential direction of the inlet channel.

6. The foam removal device at the inlet of the secondary sedimentation tank with circumferential inlet and outlet as described in claim 5, characterized in that: The lengths of the slag discharge inlet and the guide ramp in the radial direction of the secondary sedimentation tank are both equal to the width of the inlet channel.

7. The foam removal device at the inlet of the secondary sedimentation tank with circumferential inlet and outlet as described in claim 1, characterized in that: The bottom end of the rubber scraper is located below the water surface in the inlet channel.

8. The foam removal device at the inlet of the secondary sedimentation tank with cyclic inflow and cyclic outflow as described in claim 1, characterized in that: The sprayer is a spray head, and its spraying direction is directly downward and diagonally downward around the circumference.

9. The foam removal device at the inlet of the secondary sedimentation tank with circumferential inlet and outlet as described in claim 1, characterized in that: All the sprayers are connected to the circular main water inlet pipe via branch water inlet pipes.

10. The foam removal device at the inlet of the secondary sedimentation tank with circumferential inlet and outlet as described in claim 9, characterized in that: The water source for the main inlet pipe comes from the sedimentation zone of the secondary sedimentation tank.

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