High-cycle-rate and high-density clarification tank

Abstract

The utility model discloses a high-cycle-rate and high-density clarification tank which comprises a tank body, and the bottom of the tank body shrinks inwards to form a conical structure; a flocculation reaction area extending vertically is arranged in the center of the tank body, a settling area is arranged around the outer side of the flocculation reaction area, and a clear water area is arranged above the settling area; a plurality of inverted-cone-shaped mud buckets are arranged at the bottom of the settling zone, and the bottoms of the mud buckets are connected with mud discharging pipelines; a plurality of water quality monitoring probes are arranged in the clear water area, the probes are electrically connected with an automatic control system outside the tank body, and the automatic control system is connected with the flocculant dosing device and the sludge discharge pump through data lines. According to the scheme, real-time water quality monitoring is achieved through combination of the water quality monitoring probe and the automatic control system, the system can automatically adjust the flocculant adding amount and the sludge discharging frequency according to water quality data, the precision and stability of the treatment process are guaranteed through the closed-loop control mechanism, and the treatment efficiency is improved while thorough sludge discharging is guaranteed. And the cleanliness of upper-layer clear water is remarkably improved through intelligent control.

Description

Technical Field

[0001] This utility model relates to the field of clarification tank construction technology, and in particular to a high circulation rate, high density clarification tank. Background Technology

[0002] A clarifier is a device used for coagulation of water to remove suspended solids and colloids. The medium in the clarifier that traps and separates impurity particles is suspended sludge. The coagulation treatment process for water and wastewater includes three stages: mixing water and reagents, reaction, and separation of flocs from water. The clarifier is a specialized device that integrates these three processes.

[0003] A commonly used clarifier includes a clarifier unit and a sludge return and discharge unit. The clarifier unit includes a tank body, a stirring device, a primary reaction zone, a secondary reaction zone, a clear water zone, a sludge zone, a sampling device, a primary reaction zone plug, a secondary reaction zone extended skirt, and a flow guiding device. The stirring device is located at the center of the tank body. The primary reaction zone is located outside the stirring device. The secondary reaction zone is located outside the primary reaction zone. The clear water zone is located outside the secondary reaction zone. The sludge zone is located below the secondary reaction zone. The sludge return and discharge unit includes an activated sludge collection device, a sludge mechanical quantitative lifting device, a return sludge feeding device, a residual sludge discharge device, and an aged residual sludge collection device.

[0004] Existing clarification tanks can only ensure thorough sludge removal when discharging sludge in a timed and quantitative manner, but they cannot guarantee the cleanliness of the supernatant water, and the discharged sludge cannot be dried immediately.

[0005] The process flow of the high-density clarifier involves mixing and flocculation occurring in two adjacent reaction zones. First, raw water, coagulant, and returned activated sludge enter the mixing zone. In this zone, the rapid mixing action of the impeller completes the mixing of the activated sludge, coagulant, and raw water. The mixed water is then lifted by the impeller to the plug flow reaction zone, where a slow flocculation reaction occurs, allowing the flocs to gradually grow and become dense. Finally, the well-flocculated mixed water flows into the inclined plate / tube sedimentation zone for sludge-water separation. The clarified water flows upwards, is collected in a collection tank, and discharged into subsequent treatment processes. The separated sludge flows downwards into the sludge thickening chamber for concentration. The concentrated sludge generally consists of two layers. The lower layer, due to its lower activity, is periodically discharged through the sludge discharge pipe, while the upper layer, with higher activity, is returned to the mixing reaction zone via an external sludge return system to continue its flocculation effect on the raw water.

[0006] For example, the Chinese patent document "A device for adjusting the concentration of sludge returned to the bottom of a clarifier" (application number CN201220433562.1) discloses a device for adjusting the concentration of sludge returned to the bottom of a clarifier consisting of a lifting shaft, a lifting ring, a cone, and a connecting flange. The lifting shaft and the cone are connected by the flange. The lifting shaft is located in the drive shaft of the high-density tank and passes through a reserved hole in the center of the drive head. The outer diameter of the lifting shaft is smaller than the inner diameter of the drive shaft. The lifting shaft and the drive shaft do not contact each other. A locking device is provided at the upper end of the lifting shaft to restrict the up and down movement of the lifting shaft.

[0007] While the above solution addresses the limitation of existing high-density clarifiers and their non-adjustable sludge circulation / scraping systems by employing an innovative approach that allows for free adjustment of the cone height and thus the concentration of returned sludge during normal operation, it still fails to guarantee the cleanliness of the supernatant water during sludge discharge. Therefore, further optimization of the solution is needed. Utility Model Content

[0008] To address the shortcomings of existing technologies mentioned in the background section, this invention combines a sedimentation zone and a clear water zone, along with an automatic control system and water quality monitoring probes, to achieve real-time monitoring and regulation of water quality, ensuring the stability of the effluent quality. Furthermore, the design of the sludge return system and sludge dewatering system optimizes the sludge treatment process, reduces environmental burden, and thus achieves efficient and environmentally friendly water treatment results.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A high-circulation-rate, high-density clarifier includes a tank body with a conical structure formed by inward contraction at the bottom. A vertically extending flocculation reaction zone is located at the center of the tank body, surrounded by a sedimentation zone, with a clear water zone above the sedimentation zone. Multiple inverted conical sludge hoppers are located at the bottom of the sedimentation zone, with sludge discharge pipes connected to the bottom of each hopper. Multiple water quality monitoring probes are located within the clear water zone, electrically connected to an external automatic control system. The automatic control system is connected to a flocculant dosing device and a sludge discharge pump via data cables.

[0011] The conical structure at the bottom of the tank facilitates sludge concentration and discharge, reducing dead-angle deposition. The central flocculation reaction zone provides ample reaction space for wastewater flocculation, while the surrounding sedimentation zone separates flocs using gravity settling. Multiple inverted conical sludge hoppers increase the sludge collection area and improve sedimentation efficiency. This solution utilizes a combination of water quality monitoring probes and an automatic control system to achieve real-time water quality monitoring. The system can automatically adjust the flocculant dosage and sludge discharge frequency based on water quality data. This closed-loop control mechanism ensures the accuracy and stability of the treatment process, guaranteeing thorough sludge discharge while significantly improving the cleanliness of the upper rinsing water through intelligent control.

[0012] Furthermore, an inlet device is provided at the top of the flocculation reaction zone, which is connected to a mixing and flocculation system located outside the tank. The mixing and flocculation system includes a tubular static mixer connected to the inlet device, with a flocculant dosing device at the outlet of the static mixer. The inlet device's location at the top of the flocculation reaction zone ensures that wastewater can be evenly distributed using gravitational potential energy. The mixing and flocculation system connected to the inlet device uses a tubular static mixer, enabling efficient mixing within a limited space. The static mixer utilizes the fluid kinetic energy within the pipe, generating shear force and turbulence through its special internal structure, promoting rapid and uniform mixing of wastewater and flocculant. The flocculant dosing device at the outlet of the static mixer allows for precise control of the flocculant dosage and timing, ensuring optimal flocculation results. This not only improves flocculation efficiency but also reduces energy consumption, offering significant advantages over traditional mechanical mixing methods. Furthermore, by optimizing the inlet and flocculation processes, this system lays a solid foundation for subsequent sedimentation and separation, contributing to improved overall treatment efficiency and effluent quality of the clarifier.

[0013] Furthermore, a sludge discharge pump is installed on the sludge discharge pipeline, and the outlet of the sludge discharge pump is connected to a sludge dewatering system. The sludge dewatering system includes a sludge thickening tank connected to the outlet of the sludge discharge pump, and a centrifugal dewatering machine is connected to the bottom of the sludge thickening tank via a pipeline. The sludge discharge pump installed on the sludge discharge pipeline can precisely control the sludge discharge rate and time to achieve quantitative sludge discharge. The connection between the sludge discharge pump and the sludge dewatering system solves the problem of sludge from traditional clarification tanks not being dried in time. The sludge thickening tank and the centrifugal dewatering machine of the sludge dewatering system can achieve rapid sludge thickening and dewatering. The sludge thickening tank utilizes the principle of gravity sedimentation to further increase the sludge solids content and reduce the amount of water required for subsequent treatment. The centrifugal dewatering machine uses centrifugal force generated by high-speed rotation to separate the water from the sludge, significantly increasing the dryness of the sludge. This not only improves sludge treatment efficiency but also reduces subsequent treatment costs. By optimizing the sludge discharge and sludge treatment process, rapid sludge dewatering is achieved, reducing the difficulty of sludge storage and transportation, and also reducing the risk of secondary pollution. This helps to improve overall treatment efficiency and environmental protection effects.

[0014] Furthermore, an annular overflow weir is provided at the top of the clear water zone along the circumference of the pool, and an annular clear water collection trough connected to the overflow weir is provided outside the weir. The annular structure ensures uniform water flow distribution and avoids floc-carrying problems caused by excessively fast local water flow. When water flows through the overflow weir, kinetic energy is converted into potential energy, and the speed is slowed down, which is conducive to floc settling. The height of the overflow weir can precisely control the water level, maintaining a head difference of about 0.5-1m, which ensures sufficient flow while avoiding turbulence caused by excessive head difference. The annular clear water collection trough increases the collection area, reaching more than 95% of the pool circumference, which greatly improves the collection efficiency. Compared with point or local collection methods, this scheme can improve the collection uniformity by about 30% and significantly improve the stability of the effluent water quality.

[0015] Furthermore, an inclined annular guide plate is provided between the flocculation reaction zone and the sedimentation zone. The bottom of the guide plate is connected to the outer wall of the flocculation reaction zone, and the top extends outward into the sedimentation zone. The inclination angle of the guide plate is typically set between 30° and 45°, a range that achieves a balance between gravity and hydrodynamic forces. According to Stokes' law, the settling velocity of flocs is proportional to the square of their diameter.

[0016] v=92μ(ρp-ρf)gr2

[0017] Where v is the settling velocity, ρp is the floc density, ρf is the liquid density, g is the acceleration due to gravity, r is the floc radius, and μ is the liquid viscosity. The inclined guide plate can prolong the residence time of flocs in the sedimentation zone, increasing sedimentation efficiency by 20%-30% and effectively reducing short-circuit flow and dead zones, thereby significantly improving the treatment efficiency of the clarifier and the quality of the effluent. In summary, the bottom of the guide plate is connected to the outer wall of the flocculation reaction zone, and the stable structure ensures the stability of the flow field.

[0018] Furthermore, a sludge return system is installed at the bottom of the sedimentation zone, including a return pump and a return pipe. One end of the return pipe connects to the bottom of the sedimentation zone, and the other end extends into the flocculation reaction zone, ensuring that the returned sludge can be fully mixed with the new influent. The return ratio is typically controlled between 10% and 30%, and can be adjusted according to the influent water quality and treatment requirements. This return design not only improves flocculation efficiency but also maintains an appropriate microbial concentration within the system, which is beneficial to the biodegradation process. In addition, the return system can effectively regulate the hydraulic load within the system, improve the system's resistance to shocks, and enable the clarifier to maintain a stable treatment effect even when faced with fluctuations in influent water quality.

[0019] Furthermore, the flocculation reaction zone is equipped with multiple layers of radial stirring blades, which are connected to a motor at the top of the tank via a central shaft. The motor is electrically connected to the automatic control system via a frequency converter. By adjusting the motor speed, the fluid velocity gradient can be precisely controlled to adapt to different water quality conditions and flocculation stages. The multi-layer design ensures uniform mixing within the reaction zone, avoiding the dead zone problem easily caused by traditional single-layer stirrers. The radial stirring blades help generate moderate turbulence, promoting floc formation. The combination of the frequency converter and the automatic control system enables real-time adjustment of the stirring intensity, automatically optimizing the stirring strategy based on parameters such as influent water quality and flocculant dosage.

[0020] Furthermore, the sedimentation zone is equipped with multiple vertically installed inclined plate assemblies arranged in a ring. Each inclined plate assembly consists of multiple parallel inclined plates with gaps between them. The inclined plate structure has a self-cleaning effect; flocs deposited on the plate surface will slide down into the sludge hopper under gravity, reducing the frequency of cleaning and maintenance. Moreover, the inclined plate assembly structure can process a larger volume of water within the same floor space, improving the space utilization efficiency of the clarifier.

[0021] Therefore, this utility model has the following beneficial effects.

[0022] The intelligent control system enables automatic adjustment of flocculant dosage and sludge discharge frequency, improving the accuracy and stability of the treatment process and thus enhancing the cleanliness of the upper layer of water.

[0023] By employing a multi-layer radial stirring impeller and a variable frequency control system, the stirring intensity within the flocculation reaction zone can be precisely adjusted, improving flocculation efficiency by 20%-30% while reducing energy consumption by 15%-25%.

[0024] A sludge return system is installed to utilize the existing flocs as flocculation nuclei for new influent, thereby accelerating the flocculation process, improving treatment efficiency, and reducing the amount of chemical reagents used.

[0025] Setting up inclined plate groups in the sedimentation zone increases the effective settling area and significantly improves the stability of the effluent quality. Attached Figure Description

[0026] Figure 1 This is a top view of the present invention.

[0027] Figure 2 This is a side sectional view of the present invention.

[0028] In the diagram: 1. Tank body; 2. Flocculation reaction zone; 3. Sedimentation zone; 4. Clear water zone; 5. Inverted conical sludge hopper; 6. Sludge discharge pipe; 7. Water quality monitoring probe; 8. Flocculant dosing device; 9. Sludge discharge pump; 10. Water inlet device; 11. Mixing flocculation system; 12. Tubular static mixer; 13. Sludge dewatering system; 14. Centrifugal dewatering machine; 15. Annular overflow weir; 16. Annular clear water collection tank; 17. Annular guide plate; 18. Return pipe; 19. Multi-layer radial agitator; 20. Inclined plate assembly. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figure 1 , 2As shown, the high-circulation-rate, high-density clarifier design proposed in this embodiment optimizes the structure and parameters of each treatment unit, significantly improving wastewater treatment efficiency and effluent quality. The tank body is constructed of reinforced concrete with a wall thickness of 250-300mm and a compressive strength of not less than C30. The bottom tapers inward to form a 45°-60° conical structure, which facilitates sludge collection and discharge. The inner wall of the tank is coated with an epoxy resin anti-corrosion coating, 2-3mm thick, exhibiting excellent acid and alkali resistance and a pH tolerance range of 2-13.

[0032] The flocculation reaction zone is located at the center of the tank, in a vertical cylindrical shape with a diameter of 40%-45% of the tank's diameter. The inner wall is lined with 316L stainless steel, 3-5mm thick, offering excellent corrosion resistance. The top water inlet device employs a multi-pore structure with pore sizes ranging from 10-30mm, ensuring uniform water distribution. The mixing and flocculation system uses a tubular static mixer, 15 times the pipe diameter in length, internally containing 8-12 layers of V-shaped or spiral mixing units made of PP or PVDF, offering strong corrosion resistance. The shear force generated by the mixer can reach 500-1000 s^-1, ensuring rapid and uniform mixing of the flocculant and wastewater.

[0033] The flocculant dosing device uses a dual-plunger metering pump with a flow rate range of 0.1-100 L / h, an accuracy of ±0.5%, and a maximum working pressure of 1.0 MPa. The pump body is made of 316L stainless steel, offering strong corrosion resistance. The bottom of the sedimentation zone is equipped with 4-6 inverted conical sludge hoppers, each with a 55° cone angle, made of fiberglass with a wall thickness of 8-10 mm. The bottom of each hopper connects to a DN100-DN150 sludge discharge pipe made of HDPE material with a pressure resistance ≥1.0 MPa. The inclined plate assembly is made of PP material, 2 mm thick, spaced 60 mm apart, and inclined at a 57° angle. Each inclined plate assembly measures 1000 mm × 1000 mm × 1000 mm, providing an effective settling area up to four times that of traditional sedimentation tanks. The surface roughness Ra of the inclined plates is ≤3.2 μm, facilitating floc slippage. The sludge return system uses a screw pump with a flow rate of 0-30 m³ / h. 3 The pump head is adjustable ( / h), with a head of 20-30m and a motor power of 3-5kW. The return pipe uses DN80 UPVC pipe with a pressure resistance of ≥1.6MPa, extending to the bottom 1 / 3 of the flocculation reaction zone.

[0034] The mixing system employs a three-layer radial mixing impeller, with blades made of fiberglass and a diameter 60% of the reaction zone diameter. The central shaft is made of 304 stainless steel and has a diameter of 80-100mm. The top motor has a power of 15kW and is equipped with a frequency converter to achieve speed adjustment from 10-60rpm, corresponding to a speed gradient G value range of 20-100s^-1. The clear water collection system includes an annular overflow weir and a clear water collection tank. The overflow weir adopts a V-shaped structure, with the weir plate made of 304 stainless steel, 4mm thick, and a weir opening width of 25mm, controlling the head difference at 0.8m. The clear water collection tank is 250mm wide and 200mm deep, made of fiberglass, with a wall thickness of 6mm.

[0035] The automatic control system includes water quality monitoring probes and a PLC controller. The water quality monitoring probes include turbidity sensors, pH sensors, and conductivity sensors, each featuring high accuracy and a wide measurement range. The control system uses a Siemens S7-1200 PLC, which has multiple analog inputs and digital outputs, offering fast response time and high control precision.

[0036] This embodiment optimizes each treatment unit to form a highly efficient sludge collection system and solid-liquid separation mechanism. The multi-layer stirring system in the flocculation reaction zone, combined with a static mixer and precise dosing device, achieves fine control of the flocculation process. The sludge return system utilizes the seed effect of already formed flocs to further improve flocculation efficiency. The annular clear water collection system ensures uniform collection and reduces floc-carrying problems caused by excessively rapid local water flow. The automatic control system monitors water quality parameters in real time, precisely controlling the flocculant dosage and sludge discharge frequency, effectively solving the problem of upper clear water cleanliness. Simultaneously, through integration with the sludge dewatering system, it achieves rapid sludge-water separation, solving the problem of timely sludge drying. Compared to traditional clarifiers, this solution significantly improves treatment capacity, reagent usage, and energy consumption. Furthermore, the application of the automatic control system enhances operational accuracy and stability, ensuring the stability of the effluent quality.

[0037] In summary, the clarification tank comprises a tank body with a conical bottom that tapers inwards, facilitating sludge collection and discharge. A vertically extending flocculation reaction zone is located at the center of the tank, surrounded by a sedimentation zone, with a clear water zone at the top, achieving a three-stage wastewater treatment process. An inlet device is located at the top of the flocculation reaction zone, connected to an external mixing and flocculation system. The mixing and flocculation system employs a tubular static mixer, utilizing fluid kinetic energy to generate shear force and turbulence, achieving rapid and uniform mixing of wastewater and flocculant. A flocculant dosing device at the static mixer outlet allows for precise control of dosage and timing. Multiple inverted conical sludge hoppers are located at the bottom of the sedimentation zone, connected to sludge discharge pipes for quantitative sludge discharge. Water quality monitoring probes in the clear water zone are electrically connected to an external automatic control system, controlling the flocculant dosing device and sludge discharge pump via data lines, forming a closed-loop control mechanism. A ring-shaped overflow weir and clear water collection trough are installed around the circumference of the clear water zone, ensuring 360-degree uniform collection of clear water. An inclined annular baffle between the flocculation reaction zone and the sedimentation zone optimizes the transition process of flocs, prolongs floc residence time, and improves sedimentation efficiency. The sludge return system at the bottom of the sedimentation zone utilizes existing flocs as new influent flocculation nuclei to promote the flocculation process. Multi-layer radial agitators in the flocculation reaction zone achieve precise control of agitation intensity via a frequency converter, generating moderate turbulence to promote floc formation. Vertically installed inclined plate groups in the sedimentation zone significantly increase the effective settling area, improving solid-liquid separation efficiency. This not only improves treatment efficiency and effluent quality but also enables intelligent control and optimized energy utilization. This system can increase treatment efficiency by 15%-30%, reduce chemical reagent usage by 20%-30%, and reduce energy consumption by 15%-25%.

[0038] In practical applications, the operation procedures and usage schemes for high-circulation-rate, high-density clarifiers include: First, the installation process of the clarifier should ensure the levelness and sealing of the tank body, especially the connection between the bottom conical structure and the sludge hopper, which should be treated to prevent leakage. When coating the inner wall of the tank with an epoxy resin anti-corrosion layer, the coating thickness should be ensured to be uniform, and multiple quality inspections should be conducted to guarantee its acid and alkali resistance. When installing the 316L stainless steel lining in the flocculation reaction zone, care should be taken to ensure a tight fit with the tank body to avoid air bubbles or detachment.

[0039] In the initial stage of operation, the system should be debugged and optimized. First, adjust the multi-pore distribution of the inlet device to ensure that the water flow is evenly distributed within the flocculation reaction zone. The installation angle and position of the static mixer should be fine-tuned according to the actual water quality to achieve the best mixing effect. The initial settings of the flocculant dosing device should be based on laboratory test results, and the dosage and timing of dosing should be continuously optimized during actual operation. Adjusting the speed of the stirring system is a critical step, usually starting from a low speed and gradually increasing to the optimal speed while observing floc formation. During the initial operation, water samples should be collected every 2-4 hours to analyze parameters such as floc size and settling velocity, and the stirring intensity and flocculant dosage should be adjusted accordingly.

[0040] During the commissioning phase of the sludge return system, the return ratio needs to be controlled. Initially, it can be set to 10% of the treated water volume, and then gradually adjusted to the optimal value based on the flocculation effect, typically between 15% and 25%. The start-up and shutdown frequency of the return pump should be optimized based on actual operating conditions to avoid excessive damage to the formed flocs. During the installation of the inclined plate assembly, ensure that the spacing and inclination angle of each inclined plate are strictly consistent, as this directly affects the settling efficiency. In the initial stage of operation, the inclined plates should be cleaned weekly to remove attached flocs and algae. As operation stabilizes, the cleaning frequency can be gradually reduced to once a month.

[0041] Regarding the parameter settings of the automatic control system, such as the calibration of water quality monitoring probes, regular adjustments should be made, at least once a week. The PLC controller program should be continuously optimized based on actual operating data, especially during seasonal changes or when there are significant fluctuations in influent water quality; control parameters should be adjusted promptly in these situations. For example, in summer when water temperatures are higher, the flocculation reaction rate accelerates, so the stirring intensity and reaction time can be appropriately reduced; while in winter, these parameters should be increased accordingly.

[0042] In practical applications, when treating high-turbidity raw water, a pre-sedimentation tank or equalization tank should be added to alleviate the load on the main clarification tank. For oily wastewater, an air flotation device can be added before the inlet to improve the removal efficiency of oily substances. When treating wastewater containing heavy metals, specific chelating agents or precipitants should be added to the flocculant to improve the removal rate of heavy metals.

[0043] In addition, several optimization schemes can be considered to further improve treatment efficiency. For example, installing a microbubble generator at the top of the flocculation reaction zone can assist flocs in floating using the principle of air flotation, which is particularly effective for some lightweight flocs that are difficult to settle. Another optimization scheme is to add an activated carbon filter unit to the clear water zone, which can further remove residual organic matter and color from the water, improving the quality of the effluent.

[0044] With proper operation and maintenance, this high-circulation-rate, high-density clarifier can significantly improve wastewater treatment efficiency, reduce the amount of chemical reagents used, and lower energy consumption. Furthermore, with the continuous advancement of automation control technology, it is foreseeable that this system will become even more intelligent in the future, capable of autonomously adapting to changes in water quality and achieving true "one-click" operation, bringing greater economic and environmental benefits to the water treatment industry.

[0045] Example 2

[0046] This embodiment provides a high-circulation-rate, high-density clarifier, the core of which lies in optimizing the wastewater treatment process and improving the cleanliness of the treated water and the efficiency of sludge treatment. The clarifier consists of a tank body, a flocculation reaction zone, a sedimentation zone, and a clear water zone, forming a highly efficient three-stage treatment system. The bottom of the tank body adopts an inwardly tapering conical structure, with the diameter gradually decreasing from 10-15 meters at the top to 3-5 meters at the bottom, and an inclination angle of 30°-45°. This design facilitates sludge concentration and discharge. The flocculation reaction zone, located at the center of the tank body, is a vertical cylinder with a diameter approximately 1 / 3 to 1 / 2 of the tank body diameter and a height of 2 / 3 of the total tank height. An inlet device is installed at the top of the flocculation reaction zone, connecting to an external mixing and flocculation system. The mixing and flocculation system uses a tubular static mixer, with a length 10-20 times the pipe diameter, and internally equipped with special spiral blades or baffles, enabling thorough mixing of wastewater and flocculant within 0.5-1 seconds, achieving a mixing uniformity of over 95%. The flocculant dosing device at the outlet of the static mixer uses a precision metering pump with a dosing accuracy of ±1%, ensuring precise control of the flocculant dosage.

[0047] An inclined annular guide plate, with an inclination angle of 30°-45°, is installed between the flocculation reaction zone and the sedimentation zone. It is made of 316L stainless steel or engineering plastic and is 5-10mm thick. The bottom of the guide plate connects to the outer wall of the flocculation reaction zone, and the top extends outward into the sedimentation zone, forming a smooth transition surface. This effectively reduces floc breakage during the transition process and extends the residence time of flocs in the sedimentation zone, theoretically increasing sedimentation efficiency by 20%-30%. Multiple inverted conical sludge hoppers, with a cone angle of 50°-60°, are installed at the bottom of the sedimentation zone to ensure smooth sludge flow. The sludge discharge pipes connected to the bottom of the sludge hoppers have a diameter of 100-200mm and are made of corrosion-resistant materials. Multiple sets of inclined plates, made of high-molecular polymer with a thickness of 1-2mm, are installed within the sedimentation zone, spaced 50-80mm apart, and inclined at an angle of 55°-60°. The inclined plate sets are arranged in a ring, with each set consisting of 20-30 parallel plates, effectively increasing the settling area and theoretically increasing treatment capacity by 50%-100%.

[0048] To further improve treatment efficiency, this embodiment also employs a sludge recirculation system, including a recirculation pump and recirculation piping. The recirculation pump is a wear-resistant screw pump, and its flow rate can be adjusted within the range of 10%-30% of the designed treatment capacity. The recirculation piping is made of corrosion-resistant material, with a diameter of 50-100 mm, extending from the bottom of the sedimentation zone to the bottom third of the flocculation reaction zone, ensuring thorough mixing with the new influent. Utilizing the already formed flocs as flocculation nuclei for the new influent significantly accelerates the flocculation process, theoretically increasing flocculation efficiency by 15%-25% while reducing chemical reagent usage by 20%-30%.

[0049] The flocculation reaction zone is equipped with multiple layers of radial agitators, typically 3-4 layers. The agitators are made of stainless steel or fiberglass, and their diameter is approximately 1 / 2 to 2 / 3 of the reaction zone diameter. The agitators are connected to a motor at the top of the tank via a central shaft. The motor power is determined based on the tank volume, generally between 10-30 kW. The motor is electrically connected to the automatic control system via a frequency converter, enabling speed adjustment from 10-60 rpm, corresponding to a speed gradient G value range of 20-100 s^-1. The agitation intensity can be adjusted in real time according to the influent water quality and treatment requirements, generating moderate turbulence to promote floc formation. Theoretically, this can increase flocculation efficiency by 20%-30% while reducing energy consumption by 15%-25%.

[0050] A ring-shaped overflow weir and a clear water collection trough are installed around the top of the clear water zone, circumferentially around the pool. The overflow weir has a V-shaped structure, with the weir plate made of 304 stainless steel, 3-5mm thick, and a weir opening width of 25mm, with a head difference controlled at 0.7-0.9m. The ring-shaped clear water collection trough is 250mm wide and 200mm deep, made of fiberglass, ensuring 360-degree uniform collection of clear water and effectively solving the problem of floc carryover caused by excessively fast local water flow. Multiple water quality monitoring probes are also installed in the clear water zone, including sensors for turbidity, pH, and conductivity, with accuracies of ±1NTU, ±0.1pH, and ±1%FS, respectively. These probes are electrically connected to an external automatic control system, controlling the flocculant dosing device and sludge pump via data cables, forming a closed-loop control mechanism.

[0051] The automatic control system employs advanced PLC or DCS, possessing data acquisition, analysis, and control functions, with a response time of <1 second and a control accuracy of ±2%. Based on real-time monitoring data, the system automatically adjusts the flocculant dosage, stirring intensity, and sludge discharge frequency, ensuring the precision and stability of the treatment process. This intelligent design not only improves the quality of the effluent but also optimizes the utilization of energy and chemicals.

[0052] This embodiment can be further considered by adding a membrane separation unit or advanced oxidation device at the top of the clear water zone to improve the effluent quality. The membrane separation technology can employ ultrafiltration or nanofiltration membranes with a pore size range of 0.01-0.1 μm, effectively removing suspended solids and some dissolved pollutants. The advanced oxidation device can be an ozone or UV-H2O2 system with an oxidation-reduction potential >2.8V, which can further degrade recalcitrant organic matter.

Claims

1. A high-circulation-rate, high-density clarifier, characterized in that, The system includes a tank body with a tapered bottom that tapers inward to form a cone shape. A vertically extending flocculation reaction zone is located at the center of the tank body, surrounded by a sedimentation zone. Above the sedimentation zone is a clear water zone. Multiple inverted conical sludge hoppers are located at the bottom of the sedimentation zone, with sludge discharge pipes connected to the bottom of each hopper. Multiple water quality monitoring probes are located within the clear water zone. These probes are electrically connected to an external automatic control system, which is connected to a flocculant dosing device and a sludge discharge pump via data cables.

2. The high-circulation-rate, high-density clarifier according to claim 1, characterized in that, The top of the flocculation reaction zone is equipped with a water inlet device, which is connected to a mixing and flocculation system located outside the tank. The mixing and flocculation system includes a tubular static mixer connected to the water inlet device, and a flocculant dosing device is provided at the outlet of the static mixer.

3. The high-circulation-rate, high-density clarifier according to claim 1, characterized in that, The sludge discharge pipeline is equipped with a sludge discharge pump, and the outlet of the sludge discharge pump is connected to a sludge dewatering system; the sludge dewatering system includes a sludge thickening tank connected to the outlet of the sludge discharge pump, and a centrifugal dewatering machine is connected to the bottom of the sludge thickening tank through a pipeline.

4. The high-circulation-rate, high-density clarifier according to any one of claims 1-3, characterized in that, The top of the clear water zone is provided with an annular overflow weir along the circumference of the pool, and an annular clear water collection trough connected to the overflow weir is provided on the outside of the overflow weir.

5. The high-circulation-rate, high-density clarifier according to any one of claims 1-3, characterized in that, An inclined annular guide plate is provided between the flocculation reaction zone and the sedimentation zone. The bottom of the guide plate is connected to the outer wall of the flocculation reaction zone, and the top extends outward to the sedimentation zone.

6. The high-circulation-rate, high-density clarifier according to any one of claims 1-3, characterized in that, The bottom of the sedimentation zone is equipped with a sludge return system, including a return pump and a return pipe; one end of the return pipe is connected to the bottom of the sedimentation zone, and the other end extends into the flocculation reaction zone.

7. The high-circulation-rate, high-density clarifier according to any one of claims 1-3, characterized in that, The flocculation reaction zone is equipped with multiple layers of radial stirring blades, which are connected to a motor at the top of the tank via a central shaft; the motor is electrically connected to the automatic control system via a frequency converter.

8. The high circulation rate, high density clarifier according to claim 1, characterized in that, The sedimentation zone is equipped with multiple vertically installed inclined plate groups, which are arranged in a ring. Each inclined plate group consists of multiple parallel inclined plates with gaps between them.

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