Water inflow and outflow control device for sewage treatment system

Abstract

The application relates to the water treatment technical field and provides a sewage treatment system water inflow and outflow flow control device, which comprises a coarse grid, a lifting pump, a fine grid, a biochemical pool, an electromagnetic flowmeter, an opening and closing machine, a secondary sedimentation tank and a water distribution well, the lifting pump is used for conveying sewage into the biochemical pool, the coarse grid is arranged at an input port of the lifting pump and is used for coarsely filtering the sewage, the fine grid is arranged at an output port of the lifting pump and is used for finely filtering the coarsely filtered sewage, the biochemical pool is provided with an ultrahigh size, the biochemical pool is arranged in communication with the water distribution well, the electromagnetic flowmeter is arranged between the biochemical pool and the water distribution well and is used for detecting the sewage amount going to the water distribution well, the opening and closing machine is arranged at a water outlet output end of the biochemical pool and is used for controlling the water outlet amount of the biochemical pool, and the water distribution well is arranged in communication with the secondary sedimentation tank. The application has the effect of improving the uniformity of the biochemical pool water inflow and reflux mud water.

Description

Technical Field

[0001] This application relates to the field of water treatment technology, and in particular to a wastewater treatment system influent and effluent flow control device, which is applicable to different water quality types such as domestic sewage and industrial wastewater, as well as wastewater treatment plants of different sizes such as small, medium and large. It can achieve stable influent and effluent flow and balanced water distribution among multiple sets of biological treatment tanks through the volume buffer of the biological treatment tank and intelligent feedback control. Background Technology

[0002] A biological treatment tank, also known as a biochemical reaction tank, is a key structure in a wastewater treatment system. It utilizes the metabolic processes of microorganisms to convert organic pollutants in wastewater into harmless carbon dioxide, water, and the cellular material of the microorganisms themselves, thus purifying the wastewater. The optimal operating condition for a wastewater treatment plant is a stable influent and effluent flow, which facilitates process control and chemical dosing, and helps ensure stable effluent compliance with standards at low cost.

[0003] However, many wastewater treatment plants experience periodic fluctuations in their influent and effluent, such as daily peak influent times in the morning, noon, and evening, and seasonal variations in wastewater volume. If the pumping stations along the pipeline network are not coordinated to ensure stable influent flow, it becomes difficult to control the booster pumps at their highest efficiency, resulting in low efficiency. Furthermore, fluctuating effluent makes it difficult to control phosphorus removal agents, leading to waste and potentially causing sludge to float in the secondary sedimentation tank. In addition, large and medium-sized wastewater treatment plants require several sets of reaction tanks. If the influent and return sludge distribution in each set of biological treatment tanks are uneven, it is very detrimental to the biological reaction. Therefore, measures should be taken to ensure that the influent and return sludge-water distribution in each set of biological treatment tanks are uniform and consistent, and that the influent to the secondary sedimentation tank is stable.

[0004] Current solutions used by wastewater treatment plants to address the above problems have significant shortcomings: The variable frequency speed control solution for booster pumps can only cope with small flow fluctuations within ±10%. When the influent fluctuations are too large, in order to ensure stable influent to the biological treatment tank, the water level in the collection well where the pump is located will change significantly, forcing the booster pump to deviate from the optimal operating range. This not only accelerates the mechanical wear of the pump body but also increases energy consumption. The manual valve adjustment scheme for the water distribution well relies on manual adjustment based on experience, resulting in a delayed response (it takes 30-60 minutes from the detection of flow fluctuations to the completion of adjustment). It cannot match flow changes in real time, which can easily cause the secondary sedimentation tank to be overloaded with water in a short period of time, leading to an increase in the frequency of sludge floating. Therefore, it needs to be improved. Utility Model Content

[0005] In order to improve the uniformity of influent and return sludge in the biological treatment tank, as well as the stability of influent in the secondary sedimentation tank, this application provides a wastewater treatment system influent and effluent flow control device.

[0006] The wastewater treatment system inlet and outlet flow control device provided in this application adopts the following technical solution: A wastewater treatment system influent and effluent flow control device includes a coarse screen, a lift pump, a fine screen, a biological treatment tank, an electromagnetic flow meter, a gate hoist, a secondary sedimentation tank, and a distribution well. The lift pump is used to transport wastewater into the biological treatment tank. The coarse screen is located at the inlet of the lift pump and is used for coarse filtration of the wastewater. The fine screen is located at the outlet of the lift pump and is used for fine filtration of the coarsely filtered wastewater. The biological treatment tank is connected to the water distribution well. The electromagnetic flow meter is located between the biological treatment tank and the water distribution well to detect the amount of sewage going to the water distribution well. The gate hoist is located at the outlet of the biological treatment tank to control the outflow of the biological treatment tank. The water distribution well is connected to the secondary sedimentation tank.

[0007] By adopting the above technical solution, by adding an electromagnetic flow meter to the outlet pipe of the biological treatment tank, the opening degree of the electric gate of the water inlet of the distribution well at the end of the outlet pipe of the biological treatment tank is controlled by the flow value feedback, thereby controlling the water output of the biological treatment tank. By using the huge volume of the biological treatment tank as a water buffer, the water output flow of the biological treatment tank can be stabilized.

[0008] Compared to existing wastewater treatment processes, the core improvements in this application lie in the design of the electromagnetic flowmeter, its placement, and the extra-high design of the biological treatment tank (extra-high refers to the height of the tank wall above the designed water surface). The electromagnetic flowmeter collects the effluent flow rate from the biological treatment tank in real time and uses this data to adjust the opening of the electric gate of the distribution well, forcing a stable output of effluent based on the "daily average flow rate." For example, in a scenario with an influent flow rate of 80,000 m³ / d, the gate opening precisely controls the effluent flow rate to remain at a constant value of 55.6 m³ / min. When the influent is at its peak in the morning, noon and evening (such as when the instantaneous flow rate exceeds 55.6 m³ / min), the excess sewage will be intercepted in the biological treatment tank (using the "ultra-high volume" of the biological treatment tank as a buffer) to prevent the outflow rate from rising sharply with the peak. When the influent decreases or even stops intermittently (such as the intermittent influent problem during the winter off-season at the Qinhuangdao plant), the wastewater with extremely high water levels accumulated in the biochemical tank will continue to flow out at an average flow rate of 55.6 m³ / min, without any interruption of the outflow or a sudden drop in flow.

[0009] Ultimately, the system ensures that the outflow rate remains constant at the "daily average flow rate" even when the inflow fluctuates, thus resolving the issues of flow interruption or overflow caused by intermittent / peak inflow and providing a stable water volume basis for subsequent processes.

[0010] Secondly, the improved process also solved the problem of "sludge overturning" in the secondary sedimentation tank, ensuring that the suspended solids (SS) in the effluent consistently meet the standards. The core function of the secondary sedimentation tank is sludge settling and separation, and its designed retention time is 3.3 hours (data from the Qinhuangdao plant). It has extremely high requirements for the stability of the influent flow rate. If the influent flow rate fluctuates too much, when the water volume suddenly increases, it will cause the water flow velocity in the secondary sedimentation tank to increase and the hydraulic load to exceed the limit, which will damage the stability of the sludge layer and cause sludge to be lost with the effluent (i.e., "sludge overturning"), resulting in the SS in the effluent exceeding the standard. After the process improvement, the inflow rate from the distribution well to the secondary sedimentation tank is precisely controlled by the gate hoist, always matching the design load of the secondary sedimentation tank (4 secondary sedimentation tanks with D=40m can stably receive constant effluent). The water flow velocity and sludge settling environment in the tank remain stable, and the phenomenon of "impact sludge overturning" no longer occurs. The effluent SS and other indicators are stably controlled.

[0011] Thirdly, the improved process also achieves a balance between the influent and return sludge in the biological treatment tank, ensuring stable biological treatment effects and reducing fluctuations in effluent quality from the source. The biological treatment tank is the core of wastewater purification (using microorganisms to degrade organic pollutants). If too much water enters a certain group of biological treatment tanks, it will lead to an overload of microorganisms (excessive organic pollutants that the microorganisms cannot consume), resulting in incomplete degradation. If too little water enters, the activity of microorganisms will decrease due to insufficient food, which will also affect the treatment effect, ultimately leading to inconsistent effluent quality from different groups of biological treatment tanks.

[0012] After the improvement, the effluent flow rate of each group of biological treatment tanks is controlled constant by the gate opener: if a group receives too much water, the excess water will raise the water level of that tank, increasing the resistance to water intake, and the water intake will be automatically reduced; if the water intake is insufficient, the water level of that tank will be low and the resistance will be low, and the water intake will be automatically increased. Without manual adjustment, "uniform water intake and consistent sludge-water ratio in each group of biological treatment tanks" can be achieved, and the microorganisms in each group of tanks will be in an optimal state of activity, with stable degradation efficiency, thus avoiding fluctuations in effluent water quality caused by uneven biological treatment from the source.

[0013] Fourthly, and most importantly, the improved process ensures "constant and precise" dosing of phosphorus removal agents and other chemicals, avoiding waste and fluctuations in effluent parameters (such as total phosphorus). Conventional processes struggle to control phosphorus removal agent dosing due to effluent fluctuations—if the effluent flow rate suddenly increases, adding the original dosage will result in insufficient agent concentration, incomplete phosphorus (TP) removal, and excessive TP in the effluent; conversely, if the flow rate suddenly decreases, the agent concentration will be too high, leading not only to waste but also potential agent residue that could affect subsequent processes.

[0014] After the improvement, the effluent flow rate is constant, and the phosphorus removal agent can be added according to a "constant dosage + matched flow rate" (e.g., accurately calculate the required phosphorus removal agent concentration per liter of wastewater based on a flow rate of 55.6 m³ / min), eliminating the need for frequent dosage adjustments. The agent can fully react with phosphorus in the wastewater, avoiding waste and ensuring stable TP removal performance, with the effluent TP index always meeting the standards.

[0015] Preferably, the coarse grid includes a U-shaped frame, a connecting plate, horizontal plates, and vertical plates. The connecting plate is disposed at the U-shaped opening of the U-shaped frame. The horizontal plates are spaced apart along the width direction of the U-shaped frame. The vertical plates are detachably connected to each of the horizontal plates and are provided in a plurality of such plates. The vertical plates are spaced apart along the length direction of the horizontal plates.

[0016] After prolonged use, the coarse grating requires surface cleaning. By detachably connecting the longitudinal plates to the transverse plates, it facilitates the removal of accumulated impurities from both the longitudinal and transverse plates.

[0017] Preferably, the U-shaped frame has a plurality of first slots, each of the first slots being distributed along the width direction of the U-shaped frame, and both ends of the horizontal plate being engaged in the first slots and locked with bolts.

[0018] By adopting the above technical solution, during installation, the two ends of the horizontal plate are engaged in the first slot, relying on friction to achieve pre-positioning. Then, bolts are used to lock the horizontal plate, achieving a detachable connection between the horizontal plate and the U-shaped frame. Of course, in some application scenarios, it is also possible to weld the horizontal plate to the U-shaped frame, leaving only the vertical plate detachably connected to the horizontal plate.

[0019] Preferably, the horizontal plate is provided with a plurality of second slots, and each second slot is distributed at intervals along the length direction of the horizontal plate, and the vertical plate is engaged in each second slot; Both the U-shaped frame and the connecting plate have limiting grooves, and the two ends of the longitudinal plate are respectively locked in the limiting grooves; the connecting plate is movably connected to the U-shaped frame and moves along the length direction of the longitudinal plate.

[0020] By adopting the above technical solution, after the horizontal plates are installed, the vertical plates are respectively snapped into the second slots to achieve initial positioning. Then, one end of the vertical plate is abutted into the limiting groove on the U-shaped frame. Next, the connecting plate is controlled to move and approach each vertical plate, so that the other end of the vertical plate abuts into the limiting groove of the connecting plate. This completes the fixation of the end of the vertical plate and prevents the separation of the vertical plate and the horizontal plate.

[0021] Preferably, it also includes a screw, the U-shaped frame has a groove, the connecting plate is connected to a slider, the slider is slidably connected to the groove; the screw is rotatably connected to the groove, and the slider is slidably connected to the screw.

[0022] By adopting the above technical solution, the operator can control the screw to rotate, and the rotation of the screw can be converted into the linear motion of the slider, so that the slider can move along the groove and the connecting plate can move closer to or away from the longitudinal plate.

[0023] Preferably, the outer surface of the coarse grid is coated with an epoxy resin layer.

[0024] By adopting the above technical solution, the epoxy resin layer has good anti-corrosion performance and can extend the service life of the coarse bar.

[0025] In summary, this application includes at least one of the following beneficial technical effects: (1) By setting up an electromagnetic flow meter, the electromagnetic flow meter can monitor the flow rate of the biological tank outlet pipe. The flow rate feedback can control the opening degree of the end of the biological tank outlet pipe, that is, the electric gate of the water distribution well, and control the outflow of the biological tank. The huge volume of the biological tank can be used as a water buffer tank to achieve the stability of the outflow of the biological tank.

[0026] (2) By setting the longitudinal plates to be detachable, it is convenient for workers to disassemble the longitudinal plates and clean the coarse screen. At the same time, when a longitudinal plate is damaged, it can be replaced individually, reducing maintenance costs.

[0027] (3) By setting an epoxy resin layer on the coarse screen, the epoxy resin layer has good anti-corrosion properties, which can resist the corrosion of sewage and extend the service life of the coarse screen. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the process framework of the water flow control device in the embodiments of this application; Figure 2 This is a schematic diagram of the coarse grille structure in an embodiment of this application; Figure 3 This is a partial structural schematic diagram of the coarse grille in an embodiment of this application.

[0029] Reference numerals in the attached drawings: 1. U-shaped frame; 2. Connecting plate; 3. Horizontal plate; 4. Vertical plate; 5. First slot; 6. Second slot; 7. Limiting slot; 8. Slide groove; 9. Screw; 10. Slider. Detailed Implementation

[0030] The technical solutions of this application will now be described with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can be embodied in many different forms and is not limited to the embodiments described herein.

[0031] In the representation of this application, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic represented in connection with that embodiment or example is included in at least one embodiment or example of this application. Moreover, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples.

[0032] Unless otherwise defined, 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; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection; a detachable connection; an integral part; or a mechanical connection. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0034] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, those skilled in the art can combine and integrate the different embodiments or examples shown in this application, as well as the features of those embodiments or examples.

[0035] This application discloses an influent and effluent flow control device for a wastewater treatment system. (Refer to...) Figure 1 The water flow control device includes a coarse screen, a booster pump, a fine screen, a biological treatment tank, an electromagnetic flow meter, a gate hoist, a secondary sedimentation tank, and a distribution well. The booster pump generates pressure by driving an impeller with a motor, using mechanical power to pressurize and lift the sewage from a lower position, forcibly propelling it into the biological treatment tank. The coarse screen is installed at the booster pump's inlet, used for coarse filtration of the incoming sewage. The coarse screen intercepts large-particle impurities, preventing them from entering subsequent units such as the fine screen and biological treatment tank, thus protecting critical downstream equipment. The fine screen is located between the booster pump's outlet and the biological treatment tank, used for fine filtration of the coarsely filtered sewage. Installed after the coarse screen, the fine screen provides "secondary fine filtration," focusing on intercepting small impurities that the coarse screen cannot remove, ensuring smooth sewage transport and the stability of subsequent fine treatment, and preventing "chronic sludge buildup."

[0036] The biological treatment tank is connected to the distribution well, and an electromagnetic flowmeter is installed between the biological treatment tank and the distribution well. The biological treatment tank (full name "biochemical reaction tank") is the core unit of the biological treatment process in the wastewater treatment system. It includes anaerobic, anoxic, and aerobic tanks, and is very large. Its core function is to utilize the metabolic activities of microorganisms (bacteria, fungi, protozoa, etc.) to decompose or convert organic pollutants (such as COD, BOD), nitrogen, phosphorus, and other nutrients in the wastewater into harmless substances (such as CO2, H2O, N2). It is a key step in achieving "harmless and compliant" wastewater treatment. The electromagnetic flowmeter sensor is made of stainless steel. An electromagnetic flowmeter is a flow measurement device based on the principle of electromagnetic induction. Its core function is to accurately measure the volumetric flow rate of conductive fluids. In this embodiment, the electromagnetic flowmeter is used to detect the amount of wastewater heading to the distribution well, providing crucial data support for the "flow monitoring, metering, and process control" of the water flow control device.

[0037] The gate hoist is installed at the effluent outlet of the biological treatment tank and is also electrically connected to an electromagnetic flowmeter. The hoist controls the effluent flow from the biological treatment tank based on feedback from the electromagnetic flowmeter. The seals of the hoist are made of fluororubber. A distribution well is connected to the secondary sedimentation tank. The distribution well's function is to evenly and stably distribute the treated water into the secondary sedimentation tank, preventing overload and idleness in some units due to uneven flow distribution. Through precise flow control, the sludge-water separation efficiency of the secondary sedimentation tank is maximized, ensuring that the system's effluent meets standards. The secondary sedimentation tank is the core unit for sludge-water separation in the wastewater treatment process. It mainly receives the effluent from the biological reactor, separating activated sludge from the purified water. The purified water meets standards for discharge or enters further treatment, while the sludge is returned to the biological reactor or discharged for further treatment.

[0038] Specifically, in this embodiment, two biological treatment tanks are provided, and the booster pump is connected to both tanks simultaneously. Both tanks are connected to the distribution well. The number of biological treatment tanks is not limited to the above-mentioned number and can be reasonably set according to actual needs in practice. In this embodiment, the secondary sedimentation tank adopts a circular inlet and outlet structure. The surface area / perimeter ratio of the circular tank is higher than that of the rectangular tank, and the water flow evenly covers the entire tank surface, with no areas of excessive local load. The effective sedimentation area of ​​the tank is almost equal to the actual footprint (the effective area of ​​the rectangular tank is usually lower than the actual area due to stagnant water flow at the corners), resulting in a stronger treatment capacity per unit area.

[0039] Conventional wastewater treatment plant flow control is mostly "passive response"—after the influent flow exceeds the design value, the speed of the booster pump or the opening of the valve is manually adjusted, which has a lag and can easily lead to shocks to subsequent processes. This device improves the wastewater treatment process by adopting a closed-loop control of "active prediction + real-time feedback": the effluent flow of the biological treatment tank is collected in real time by an electromagnetic flowmeter, and the opening of the electric gate of the water distribution well is adjusted accordingly to force the effluent to be output at a constant "daily average flow" (e.g., when the influent is 80,000 m³ / d, the effluent is controlled to be constant at 55.6 m³ / min). This logic transforms "responding to flow fluctuations" into "preemptive interception and buffering," eliminating the impact of sudden flow changes on subsequent processes at the source, and achieving "influent fluctuations do not affect effluent stability."

[0040] Meanwhile, this device also utilizes an automatic "flow-water level" feedback mechanism: if an excessive amount of water enters a certain group of biological treatment tanks, its outflow rate remains constant due to the control of the gate valve, and the excess water will accumulate in the tank, causing the water level to rise; the increased water level increases the inflow resistance, automatically reducing the inflow rate of that group; conversely, if the inflow to a biological treatment tank is insufficient, the water level is low and the resistance is small, so the inflow will be automatically increased. The entire process requires no manual intervention, achieving "balance between the inflow and return sludge water of each group of biological treatment tanks," providing a stable reaction environment for subsequent processes (such as chemical dosing, nitrogen and phosphorus removal).

[0041] In addition, it is worth noting that this device represents a significant improvement over existing conventional wastewater treatment processes in its chemical dosing system. In conventional processes, fluctuations in influent flow rate can lead to drastic changes in pollutant loads (such as TP, TN, and COD) (e.g., a 50% increase in flow rate will result in a 50% increase in load even if the pollutant concentration remains constant). Due to rapid flow fluctuations and the lag in manual adjustments, conventional chemical dosing often employs a "conservative overdosing" approach (to avoid insufficient chemicals leading to substandard effluent during sudden flow increases), which results in chemical waste. Conversely, if adjustments are not made in time, "underdosing" can lead to substandard effluent.

[0042] After the improvement, because the effluent flow rate is constant, the retention time (HRT) of wastewater in the biological treatment tank is stable after the influent passes through the buffer tank. The fluctuation range of the product of pollutant concentration and flow rate (i.e., load) is significantly reduced (only the single variable of "pollutant concentration fluctuation" needs to be addressed, rather than the dual variables of "flow rate + concentration"). At this time, the dosing system can combine the "stable flow rate data of the electromagnetic flowmeter + pollutant concentration data of the online monitoring instrument" to accurately calculate the dosage using the formula (dosage = flow rate × target removal concentration × reagent effectiveness coefficient), completely eliminating the dilemma of "over-conservative dosing" and improving the accuracy of reagent dosing.

[0043] The reaction between chemicals and pollutants relies on a stable hydraulic retention time (HRT) and uniform mixing intensity. In conventional processes, flow fluctuations can cause sudden increases or decreases in the flow velocity within the biological treatment tank: when the flow velocity is too high, the contact time between the chemicals and pollutants is insufficient (e.g., phosphorus removal agents do not fully react with phosphates before entering the secondary sedimentation tank), easily leading to "chemicals being lost with the effluent before they take effect"; when the flow velocity is too low, although the retention time is sufficient, the stagnation of water flow may cause local accumulation and waste of chemicals.

[0044] After the improvement, due to the constant flow rate, the water flow velocity and HRT in the biological treatment tank are completely stable (e.g., the HRT of the Qinhuangdao No. 3 Wastewater Treatment Plant is stable at 19.5h). The reagents can fully mix and react with pollutants within the "optimal retention time" (e.g., the reaction time of phosphorus removal agent with phosphate to generate iron phosphate / aluminum precipitate is stable), avoiding reagent waste caused by fluctuations in hydraulic conditions and improving the actual utilization rate of reagents.

[0045] This embodiment takes the Qinhuangdao Third Wastewater Treatment Plant as an example, applying the water flow control device to this site. Specific parameters are as follows: Design capacity is 120,000 m³ / d, total design flow rate Q = 5750 m³ / h. The biological treatment tank dimensions are 155.4m × 84.8m × 9.6m (freeboard 1.1m). Total effective tank volume V = 110670 m³, effective water depth H = 8.5m, and retention time T = 19.5h at the design flow rate. A 0.1m increase in water level allows for the storage of (155.4 * 84.88 * 0.1) = 1318 m³ of water. The number of circular inlet and outlet secondary sedimentation tanks is set to 4, with a size D = 40m, a water depth at the tank edge of 4.5m, and a design retention time of 3.3h.

[0046] Located in a coastal tourist city, the wastewater treatment plant experiences intermittent inflows during the winter off-season due to insufficient water supply. This hinders process control and significantly impacts the sedimentation tanks, frequently causing sludge buildup. The principle behind this system for controlling the stable influent and effluent flow of the wastewater treatment plant is as follows: 1. The elevated section of the biological treatment tank can store a large amount of wastewater. For example, in the above case, raising the water level by 0.1 meters can store 1318 m³ of wastewater. 3 sewage; 2. The opening of the electric gate valve at the end of the biological treatment tank's effluent pipe, i.e., the water distribution well's inlet, must be controlled by feedback to ensure the passage of the average daily water volume. For example, if the inflow is 80,000 m³ / d, the valve opening must ensure the passage of the average water volume per unit time (set as needed), i.e., 80,000 / 24 / 60 = 55.6 m³ / min. This way, only wastewater exceeding 55.6 m³ / min will be intercepted in the biological treatment tank, causing the water level to rise. When the wastewater treatment plant stops receiving water, the high water level in the biological treatment tank will allow the wastewater to continue flowing out at the average flow rate, maximizing the stability of the effluent. 3. In cases where the influent and return flow rates of different groups of biological treatment tanks in a large wastewater treatment plant are inconsistent, the water level of the group of biological treatment tanks with a larger influent flow will rise relatively due to the consistent effluent flow rate, thereby increasing the influent resistance. Automatic feedback adjustment of the influent flow rate ensures that the influent to each group of biological treatment tanks is balanced, which facilitates process adjustment.

[0047] Applying the water flow control device of this application to a wastewater treatment plant can generate numerous benefits: 1. Pumping stations along the pipeline network and wastewater treatment plant booster pumping stations can be controlled to operate in the high-efficiency zone, eliminating the need to consider the instantaneous acceptance capacity of the wastewater treatment plant, thus achieving cost reduction and efficiency improvement; 2. Each group of biological treatment tanks can be automatically adjusted through water level feedback to balance the influent, which is conducive to precise control of the microbial environment in the tank and improves the COD removal rate; 3. The effluent is stable, the secondary sedimentation tank no longer experiences sludge impact and floating, the sludge floating frequency is reduced by more than 90%, and the workload of manual sludge cleaning is reduced; 4. The effluent is stable, and constant dosing of chemicals (phosphorus removal agent) can be achieved, reducing workload, improving chemical efficiency and reducing chemical costs; 5. When the water volume is large, the retention time of the incoming wastewater is extended, stabilizing the treatment effect and ensuring that the effluent meets the standards.

[0048] This device has outstanding economic benefits throughout its entire life cycle and is suitable for wastewater treatment scenarios of different scales and water qualities. For large-scale domestic wastewater treatment plants (such as the Qinhuangdao Third Wastewater Treatment Plant with a treatment capacity of 120,000 m³ / d), the impact of wastewater volume on the pumping stations along the route and the external network pumping stations of the sludge plant is no longer a concern. The water pump can operate within a high-efficiency range, resulting in lower energy consumption and improved operating efficiency. This increases the efficiency of the booster pump from 55%-60% to 65%-70%, saving 48,000 yuan in electricity costs annually. Phosphorus removal agent usage is reduced by 10% with fluctuations narrowed to ±3%, saving 29,000 yuan in reagent costs annually. The frequency of sludge removal in the secondary sedimentation tank is reduced by over 90%, minimizing the impact on subsequent operating units and reducing sludge cleaning costs by 90,000 yuan annually, resulting in comprehensive annual cost savings exceeding 170,000 yuan. For small township sewage treatment plants (treatment capacity of 10,000 m³ / d), the overall renovation cost is only 45,000 yuan, saving a total of 17,900 yuan annually in electricity, reagent, and sludge cleaning costs, recovering the entire investment in 2.8 years. For industrial wastewater treatment plants (such as dyeing and printing wastewater plants), the selection of corrosion-resistant materials extends equipment life to 8-10 years, reducing equipment replacement costs by 30,000-40,000 yuan per replacement, while saving over 45,000 yuan annually in reagent and maintenance costs. Wastewater treatment equipment requires no additional new structures. By optimizing energy consumption, reducing chemical waste, lowering operation and maintenance costs, and extending equipment life, it achieves low-cost and high-efficiency operation, resulting in significant economic benefits and strong practicality.

[0049] In addition, refer to Figure 2 and Figure 3The outer surface of the coarse grating is coated with an epoxy resin layer (not shown in the figure). The coarse grating includes a U-shaped frame 1, connecting plates 2, horizontal plates 3, and vertical plates 4. The connecting plates 2 are installed at the U-shaped opening of the U-shaped frame 1. Several horizontal plates 3 are provided, spaced apart along the width direction of the U-shaped frame 1. Vertical plates 4 are detachably connected to each horizontal plate 3, perpendicular to the horizontal plates 3, and are provided in several units, spaced apart along the length direction of the horizontal plates 3. After long-term use, the coarse grating requires surface cleaning. By detachably connecting the vertical plates 4 to the horizontal plates 3, the vertical plates 4 can be removed first during cleaning, allowing workers to remove accumulated impurities from both the horizontal plates 3 and the vertical plates 4.

[0050] The U-shaped frame has several first slots 5, which are distributed along the width of the U-shaped frame 1. Both ends of the horizontal plate 3 are engaged in the first slots 5 and locked with bolts, thereby achieving a detachable connection of the horizontal plate 3. In some embodiments, the horizontal plate 3 can also be directly welded to the U-shaped frame 1.

[0051] The horizontal plate 3 has several second slots 6, which are spaced apart along the length of the horizontal plate 3. The vertical plate 4 is engaged in each of the second slots 6. Both the U-shaped frame 1 and the connecting plate 2 have limiting grooves 7, and both ends of the vertical plate 4 are engaged in the limiting grooves 7. The connecting plate 2 is movably connected to the U-shaped frame 1 and moves along the length of the vertical plate 4. The U-shaped frame 1 has a sliding groove 8, in which a screw 9 is rotatably connected. The length of the screw 9 is parallel to the length of the vertical plate 4. A slider 10 is slidably connected to the screw 9 and moves linearly along the length of the screw 9. The slider 10 is connected to the connecting plate 2, and the movement of the slider 10 drives the connecting plate 2 to move linearly.

[0052] During installation, the two ends of the horizontal plate 3 are engaged in the first slot 5, relying on friction to achieve pre-positioning. Then, bolts are used to lock the horizontal plate 3, achieving a detachable connection between the horizontal plate 3 and the U-shaped frame 1. After the horizontal plate 3 is installed, the vertical plates 4 are engaged in the second slot 6 respectively, achieving initial positioning. Then, one end of the vertical plate 4 is abutted in the limiting groove 7 on the U-shaped frame 1. Next, the screw 9 is rotated, causing the connecting plate 2 to move and approach each vertical plate 4, so that the other end of the vertical plate 4 abuts in the limiting groove 7 of the connecting plate 2. This completes the fixation of the end of the vertical plate 4, preventing the separation of the vertical plate 4 and the horizontal plate 3.

[0053] The implementation principle of the wastewater treatment system inlet and outlet flow control device in this application embodiment is as follows: Wastewater filtered by a coarse screen is sent to the biological treatment tank by a booster pump, and the wastewater entering the biological treatment tank through a fine screen is further filtered. By adding an electromagnetic flow meter to the outlet pipe of the biological treatment tank, the opening degree of the electric gate of the outlet pipe of the biological treatment tank, i.e., the water distribution well, is controlled through flow value feedback, thereby controlling the outflow of the biological treatment tank. By utilizing the huge volume of the biological treatment tank as a water volume buffer, the outflow of the biological treatment tank can be stabilized.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wastewater treatment system influent and effluent flow control device, characterized in that, The system includes a coarse screen, a lift pump, a fine screen, a biological treatment tank, an electromagnetic flow meter, a gate hoist, a secondary sedimentation tank, and a distribution well. The lift pump is used to transport sewage into the biological treatment tank. The coarse screen is located at the inlet of the lift pump and is used for coarse filtration of the sewage. The fine screen is located at the outlet of the lift pump and is used for fine filtration of the coarsely filtered sewage. The biological treatment tank has an extra-high dimension and is connected to the water distribution well. The electromagnetic flow meter is installed between the biological treatment tank and the water distribution well to detect the amount of sewage going to the water distribution well. The gate hoist is installed at the outlet of the biological treatment tank to control the outflow of the biological treatment tank. The water distribution well is connected to the secondary sedimentation tank.

2. The wastewater treatment system influent and effluent flow control device according to claim 1, characterized in that, The coarse grid includes a U-shaped frame (1), a connecting plate (2), a horizontal plate (3) and a vertical plate (4). The connecting plate (2) is located at the U-shaped opening of the U-shaped frame (1). The horizontal plates (3) are distributed at intervals along the width direction of the U-shaped frame (1). The vertical plates (4) are detachably connected to each of the horizontal plates (3) and are provided in several quantities. Each of the vertical plates (4) is distributed at intervals along the length direction of the horizontal plate (3).

3. The wastewater treatment system influent and effluent flow control device according to claim 2, characterized in that, The U-shaped frame (1) has several first slots (5), each of which is distributed along the width direction of the U-shaped frame (1). Both ends of the horizontal plate (3) are engaged in the first slots (5) and locked with bolts.

4. The wastewater treatment system influent and effluent flow control device according to claim 3, characterized in that, The horizontal plate (3) is provided with a plurality of second slots (6), each second slot (6) is distributed at intervals along the length direction of the horizontal plate (3), and the vertical plate (4) is engaged in each second slot (6); Both the U-shaped frame (1) and the connecting plate (2) have limiting grooves (7), and the two ends of the longitudinal plate (4) are respectively clamped in the limiting grooves (7); the connecting plate (2) is movably connected to the U-shaped frame (1), and the connecting plate (2) moves along the length direction of the longitudinal plate (4).

5. The wastewater treatment system influent and effluent flow control device according to claim 4, characterized in that, It also includes a screw (9), a groove (8) is provided on the U-shaped frame (1), a slider (10) is connected on the connecting plate (2), and the slider (10) is slidably connected in the groove (8); the screw (9) is rotatably connected in the groove (8), and the slider (10) is slidably connected on the screw (9).

6. The wastewater treatment system influent and effluent flow control device according to claim 1, characterized in that, The outer surface of the coarse grid is coated with an epoxy resin layer.

Images