Mechanically stirred clarifier and adjustable weir control method

Abstract

This invention relates to the fields of water treatment and solid-liquid separation technology, specifically to a mechanically stirred clarifier and an adjustable overflow weir control method. The mechanically stirred clarifier of this invention includes: a second reaction chamber; a first reaction chamber disposed inside the second reaction chamber; an adjustable overflow weir, including: a fixed weir cylinder; a movable weir cylinder, coaxially sleeved with the fixed weir cylinder, with its upper end forming an overflow port; a water-stop sealing structure, which is an annular elastic sealing ring; the upper annular part of the water-stop sealing structure is fixed to the lower outer side of the movable weir cylinder by a clamping component, and the lower annular part of the water-stop sealing structure is in close contact with the inner wall of the fixed weir cylinder for sealing; a weir height adjustment mechanism, used to drive the movable weir cylinder to rise and fall vertically to change the height of the overflow port; and a mixer, including: a drive shaft and an impeller installed at the lower end of the drive shaft. This invention can increase or decrease the amount of circulating sludge by individually raising or lowering the overflow weir, maintaining the optimal sludge concentration in the tank.

Description

Technical Field

[0001] This invention relates to the fields of water treatment and solid-liquid separation technology, specifically to a mechanically stirred clarifier and an adjustable overflow weir control method. Background Technology

[0002] Mechanically stirred clarifiers are a common water treatment structure. Their working principle involves using mechanical stirring to thoroughly mix and react raw water, chemicals, and returned sludge in a primary reaction chamber (also known as a mixing chamber), forming flocs (lumps). The mixture then flows through an overflow weir located above the primary reaction chamber into a secondary reaction chamber for further flocculation and sludge-water separation.

[0003] Existing mechanically stirred clarifiers typically employ a fixed-height overflow weir. The technical problems with this approach are:

[0004] (1) Inability to adjust the circulation flow rate: The circulation flow rate of the clarifier (i.e., the amount of sludge returned from the separation zone to the first reaction chamber) is crucial for maintaining a stable sludge concentration and good flocculation effect in the tank. However, the height of the fixed overflow weir determines that the overflow level is fixed, so its flow capacity (i.e., circulation flow rate) is also fixed and cannot be flexibly adjusted according to changes in the raw water quality (such as turbidity, water temperature, flow rate, etc.).

[0005] (2) Coupling of stirring intensity and circulation flow rate: The stirring speed (stirring intensity) of the mixer directly affects the flocculation effect and the degree of sludge particle breakage. In actual operation, operators sometimes need to adjust the mixer speed to adapt to changes in water quality. However, while increasing the speed can enhance the stirring intensity, it will also increase the circulation flow rate due to centrifugal effect, which may lead to floc breakage; while decreasing the speed may result in insufficient circulation flow rate, a decrease in sludge concentration, and affect the flocculation effect. That is, stirring intensity and circulation flow rate affect each other, making it difficult to achieve independent and precise separate control, which limits the optimization of the clarifier's operation under different working conditions. Summary of the Invention

[0006] I. Technical problems to be solved

[0007] The present invention aims to at least partially solve one of the above-mentioned technical problems.

[0008] II. Technical Solution

[0009] A first aspect of the present invention provides a mechanically stirred clarifier. The mechanically stirred clarifier includes:

[0010] The second reaction chamber is located on the periphery of the pool.

[0011] The first reaction chamber is located in the middle of the pool body, inside the second reaction chamber;

[0012] Adjustable overflow weir, including:

[0013] A fixed weir is connected to the upper part of the overflow pipe of the first reaction tank;

[0014] The movable weir is coaxially fitted with the fixed weir, and its upper end forms an overflow outlet.

[0015] The water-stop sealing structure is an annular elastic sealing ring with a cross-sectional shape that is smaller at the top and larger at the bottom. The upper annular part of the water-stop sealing structure is fixed to the outer side of the lower end of the movable weir cylinder by a clamping component, and the lower annular part of the water-stop sealing structure is in close contact with the inner wall of the fixed weir cylinder for sealing.

[0016] The weir height adjustment mechanism is connected to the movable weir cylinder and is used to drive the movable weir cylinder to rise and fall vertically to change the height of the overflow outlet.

[0017] The fixed weir, the water-stop sealing structure, and the inner side of the movable weir together form a fluid containment space. Throughout the entire process of the overflow height adjustment mechanism driving the movable weir to rise and fall, the lower annular part of the water-stop sealing structure remains tightly sealed against the inner wall of the fixed weir.

[0018] The mixer includes a drive shaft and an impeller mounted at the lower end of the drive shaft, the impeller extending into the bottom of the first reaction chamber to provide the stirring intensity required for mixing and flocculation in the clarification tank.

[0019] In some embodiments of the present invention, the inner wall of the fixed weir is a smooth metal surface; the water-stop sealing structure includes: an elastic sealing ring, a clamping ring and connecting bolts; the elastic sealing ring has a cross-section that is smaller at the top and larger at the bottom and is provided with an anti-squeezing buckle; the clamping ring reliably fixes the upper part of the elastic sealing ring to the movable weir through the connecting bolts; the lower part of the elastic sealing ring is tightly sealed to the inner wall of the fixed weir by elastic force.

[0020] In some embodiments of the present invention, N lead screws are provided on the outer side of the fixed weir cylinder, where N≥2; the weir height adjustment mechanism includes: M guide rods, uniformly fixed to the periphery of the fixed weir cylinder and extending vertically upward, each guide rod being provided with a guide rod slider that can slide up and down, the guide rod slider being connected inward to the movable weir cylinder, where M≥2; a drive mounting platform, horizontally positioned above the M guide rods; a drive mechanism, fixed on the drive mounting platform; and N drive screws, corresponding to the N lead screws, each drive screw including: a fixing part, uniformly fixed on the drive mounting platform; and a rotating part, the upper end of which drives a sprocket driven by the drive mechanism, and the lower end extending downward and screwed into the corresponding lead screw bolt.

[0021] In some embodiments of the present invention, the driving mechanism is a drive motor; the weir height adjustment mechanism further includes: a transmission mechanism, which is a drive chain that passes around the upper end of the rotating part of N drive screws and is driven by the drive shaft of the drive motor.

[0022] In some embodiments of the present invention, the weir height adjustment mechanism further includes: a stroke limiting device, comprising: an upper limit block and a lower limit block, respectively disposed at the upper limit threshold and the lower limit threshold of the overflow port height corresponding to the guide rod.

[0023] In some embodiments of the present invention, the fixed weir and the movable weir are made of stainless steel or fiberglass composite material, and the outer surface has a corrosion-resistant coating.

[0024] In some embodiments of the present invention, the effective lifting stroke of the movable weir is 5mm to 300mm, and the weir height setting resolution is no greater than 1mm.

[0025] In some embodiments of the present invention, the outer wall of the fixed weir is provided with an installation flange assembly for detachable connection with the existing clarifier wall to adapt to the installation interface of new construction or renovation projects.

[0026] In some embodiments of the present invention, the weir height adjustment mechanism is provided with a dual anti-fall protection structure, including a combination of a reverse self-locking screw and a mechanical locking device, to prevent the movable weir from accidentally sliding down in abnormal conditions.

[0027] In some embodiments of the present invention, the weir height adjustment mechanism further includes: a manual emergency drive component, which, in the event of a power outage or malfunction, replaces the drive motor and drives the drive screw by handwheel or hand crank; and / or a mechanical locking device, which locks the height position of the movable weir cylinder in the event of maintenance or shutdown; and / or a position detection component, which monitors the real-time height of the overflow port, wherein the position detection component is at least one of a limit switch, an encoder, or a displacement sensor.

[0028] In some embodiments of the present invention, the device further includes: a sensor group comprising: a flow sensor for sensing the influent flow rate of the clarifier; a turbidity sensor for sensing the turbidity of the raw water in the clarifier; a water temperature sensor for sensing the water temperature of the raw water in the clarifier; and an intelligent control module having a built-in expert system for closed-loop control of the weir height adjustment mechanism and the mixer based on internally stored raw water turbidity thresholds and water temperature thresholds, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the water temperature sensor.

[0029] In some embodiments of the present invention, the speed of the mixer is adjustable from 10 to 120 revolutions per minute.

[0030] In some embodiments of the present invention, the control logic of the intelligent control module prioritizes increasing the stirring speed and moderately reducing the circulation flow rate by reducing the height of the movable weir for low temperature and low turbidity conditions; for high turbidity and high load conditions, prioritizes increasing the circulation flow rate by increasing the height of the movable weir and limiting the stirring speed to within a preset upper limit.

[0031] In some embodiments of the present invention, the intelligent control module is configured with input parameter limiting and anomaly judgment logic, which is used to trigger weir height retraction and speed limit protection and issue an alarm when sensor failure, arrival signal timeout or drive current abnormality occurs.

[0032] A second aspect of the present invention provides an adjustable overflow weir control method. This adjustable overflow weir control method, used in the aforementioned mechanically stirred clarifier, is executed by an intelligent control module and includes:

[0033] Step A: Monitor the inlet water flow rate, turbidity, and water temperature in real time;

[0034] Step B: Accept the user's selection of the control mode. If the user selects the automatic mode, proceed to step C.

[0035] Step C: Using the expert system, based on the internally stored raw water turbidity threshold and water temperature threshold, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the water temperature sensor, set the mixer speed and weir height, and then execute step D.

[0036] Step D: Drive the mixer motor with a frequency converter to reach the set speed; control the weir height adjustment mechanism to raise and lower synchronously to the target weir height, and then execute step E;

[0037] Step E: Determine compliance based on online effluent turbidity detection results. If compliance is not met, return to step C; if compliance is met, maintain stable operation of current parameters.

[0038] In some embodiments of the present invention, step B further includes: if the user selects manual mode, step F is executed; in step F, after receiving the mixer speed and overflow weir height manually set by the operator, step E is executed.

[0039] III. Beneficial Effects

[0040] As can be seen from the above technical solution, the present invention has at least one of the following beneficial effects compared to the prior art:

[0041] (1) The adaptability and stability are enhanced by the height-adjustable overflow weir.

[0042] In the face of fluctuations in water quality and quantity, this invention can increase or decrease the amount of circulating sludge by adjusting the overflow weir individually, maintaining the optimal sludge concentration in the pool without changing the pre-set stirring intensity that is most favorable for floc formation, thereby ensuring the stability of the effluent water quality.

[0043] (2) Adjustable overflow structure

[0044] The adjustable overflow structure of this invention realizes the basic function of a liftable overflow weir, allowing continuous adjustment of the overflow port height and liquid level, breaking the limitation of the fixed weir structure where the circulation flow rate cannot be changed. The weir body rises and falls smoothly and is reliably sealed, enabling dynamic adjustment of the clarifier without shutting down the system, significantly improving the system's operational flexibility and adaptability.

[0045] (3) Adjustable overflow structure achieved by drive screw, etc.

[0046] This invention features an adjustable overflow mechanism with a simple structure and uniform force distribution. Multi-point screw support ensures smooth raising and lowering of the weir. Compared to single-point raising and lowering, four-point linkage avoids uneven liquid level caused by weir tilting, ensuring precise and reliable weir height adjustment.

[0047] Furthermore, the multi-layered precision and safety design enables the adjustable overflow structure to operate with high precision even in complex environments. Dual mechanical and electrical protection ensures equipment safety; position detection enables closed-loop automatic control; and a variety of material options enhances aging resistance and corrosion resistance, extending service life.

[0048] (4) It achieves precise independent control, improving processing efficiency and energy-saving potential.

[0049] This invention successfully decouples the two key operating parameters, circulation flow rate and agitation intensity. Operators can independently optimize the agitator speed and overflow weir height based on the influent water quality and desired flocculation effect, achieving more precise process control.

[0050] When operating at low loads or with good water quality, the overflow weir height can be appropriately reduced to decrease the circulation flow rate and minimize unnecessary energy consumption (sludge circulation itself requires energy). Simultaneously, maintaining the optimal stirring intensity ensures reaction efficiency.

[0051] (5) Simple structure, easy to modify, and highly practical for engineering applications:

[0052] The scheme has a clear principle and a relatively simple structure. It can be applied to the design and construction of new pools, and it is also convenient for technical transformation of existing fixed overflow weir clarification pools. The implementation cost is low and the benefits are significant. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structure of a mechanically stirred clarifier with an adjustable overflow weir according to an embodiment of the present invention.

[0054] Figure 2A and Figure 2B They are respectively Figure 1 The front and top views of the adjustable overflow weir and weir height adjustment mechanism in the mechanically stirred clarifier are shown.

[0055] Figure 3 for Figure 1 The flowchart shown is a control logic flowchart of the intelligent control module in the mechanical stirring clarification tank. Detailed Implementation

[0056] This invention aims to overcome the shortcomings of the prior art and provide a mechanically stirred clarifier with an adjustable overflow weir and its control method. The primary objective of this invention is to achieve flexible and continuous adjustment of the flow capacity of the reaction chamber in the clarifier by providing an adjustable overflow weir. A further objective is to achieve decoupling and separate control of the flow capacity (circulation flow rate) and the agitator speed (stirring intensity) by independently adjusting the flow capacity (circulation flow rate) and the agitator speed (stirring intensity), thereby broadening the adaptability of the clarifier, optimizing operating conditions, and improving the stability of effluent quality and treatment efficiency.

[0057] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0058] The first aspect of the present invention provides a mechanically stirred clarifier with an adjustable overflow weir. Figure 1 This is a schematic diagram of the structure of a mechanically stirred clarifier with an adjustable overflow weir according to an embodiment of the present invention. Figure 2A and Figure 2B They are respectively Figure 1 The figure shows a front view and a top view of the adjustable overflow weir and weir height adjustment mechanism in the mechanically stirred clarifier. As shown in the figure, the mechanically stirred clarifier with an adjustable overflow weir in this embodiment includes: a tank body, a first reaction chamber (mixing chamber) disposed at the center of the tank body, a second reaction chamber, a separation zone, a stirrer, and an overflow device for introducing the mixed liquid in the first reaction chamber into the second reaction chamber.

[0059] The core improvement of this invention lies in the fact that the overflow device is an adjustable overflow weir arranged around the upper part of a reaction chamber. The height of this adjustable overflow weir can be adjusted vertically relative to the wall of the first reaction chamber.

[0060] Those skilled in the art should understand that the adjustable overflow weir structure in this embodiment can also be applied to other fields and is not limited to mechanically stirred clarifiers. Regarding the adjustable overflow structure, no separate embodiment will be given; those skilled in the art should be able to derive its relevant content from this embodiment.

[0061] Please refer to Figure 1 , Figure 2A , Figure 2B In this embodiment, the adjustable overflow weir includes:

[0062] Fix the vertical pipe, i.e. fix the weir cylinder 7;

[0063] The movable vertical pipe, namely the movable weir 10, is coaxially sleeved with the fixed weir 7, and its upper end forms an annular overflow outlet.

[0064] The water-stop sealing structure is an annular elastic sealing ring with a cross-sectional shape that is smaller at the top and larger at the bottom. The upper part of the annular water-stop sealing structure is fixed to the outer side of the lower end of the movable vertical pipe by a clamping component, and the lower part of the annular water-stop sealing structure is in close contact with the inner wall of the fixed vertical pipe for sealing.

[0065] The weir height adjustment mechanism is connected to the movable vertical pipe and is used to drive the movable vertical pipe to rise and fall in the vertical direction to change the height of the annular overflow outlet.

[0066] The fixed vertical pipe, the water-stop sealing structure, and the inner side of the movable vertical pipe together form a fluid containment space. Throughout the entire process of the weir height adjustment mechanism driving the movable vertical pipe to rise and fall, the lower annular part of the water-stop sealing structure is always tightly sealed against the inner wall of the fixed vertical pipe.

[0067] This embodiment of the adjustable overflow weir realizes the basic functions of a liftable overflow weir, allowing continuous adjustment of the overflow port height and liquid level, breaking the limitation of the fixed weir structure where the circulation flow rate cannot be changed. The weir body rises and falls smoothly and is reliably sealed, enabling dynamic adjustment of the clarifier without shutting down the system, significantly improving the system's operational flexibility and adaptability.

[0068] The following sections will provide a detailed description of each component of the adjustable overflow weir in this embodiment.

[0069] In this embodiment, the fixed vertical pipe and the movable vertical pipe are respectively the fixed weir 7 and the movable weir 10 of the first reaction chamber. The fixed weir 7 and the movable weir 10 are made of stainless steel or fiberglass composite material, and the outer surface has a corrosion-resistant coating. The outer wall of the fixed weir 7 is provided with a mounting flange assembly for detachable connection with the existing clarifier wall to adapt to the installation interface of new construction or renovation projects.

[0070] Those skilled in the art should understand that, in addition to stainless steel or fiberglass composite materials, fixed and movable vertical pipes can also be made of other materials, as long as the inner wall of the fixed vertical pipe is a smooth metal surface, which facilitates the water-stopping sealing mechanism to achieve water stop.

[0071] The water-stop sealing structure includes: an elastic sealing ring 12, a clamping ring, and connecting bolts 11; the elastic sealing ring 12 has a cross-section that is smaller at the top and larger at the bottom and is equipped with an anti-extrusion buckle; the clamping ring reliably fixes the upper part of the elastic sealing ring 12 to the movable vertical pipe via the connecting bolts 11; the lower part of the elastic sealing ring 12 is tightly sealed to the inner wall of the fixed vertical pipe by elastic force. The elastic sealing ring 12 is made of at least one of nitrile rubber, fluororubber, or polyurethane material.

[0072] As shown in the figure, four lead screws 4 are installed on the outer side of the fixed vertical pipe. The weir height adjustment mechanism includes: four guide rods 6, which are evenly fixed to the outer periphery of the fixed vertical pipe and extend vertically upward. Each guide rod 6 is provided with a guide rod slider 5 that can slide up and down. The guide rod slider 5 is connected inward to the movable vertical pipe; a drive mounting platform 3, which is horizontally set above the four guide rods 6; a drive mechanism, which is fixed on the drive mounting platform 3; and four drive screws 4, which are corresponding to N lead screws. For each drive screw 4, it includes: a fixing part, which is evenly fixed on the drive mounting platform 3; and a rotating part, the upper end of which drives the sprocket 2 driven by the drive mechanism, and the lower end of which extends downward and is screwed into the corresponding lead screw.

[0073] As described above, the adjustable overflow mechanism in this embodiment has a simple structure and uniform force distribution. Multi-point screw support ensures smooth raising and lowering of the weir. Compared to single-point raising and lowering, four-point linkage avoids uneven liquid level caused by weir tilting, ensuring precise and reliable weir height adjustment.

[0074] In this embodiment, the effective lifting stroke of the movable weir cylinder 10 is 5mm to 300mm, and the weir height setting resolution is no greater than 1mm. Based on this, to ensure control accuracy, the synchronization error of the four drive screws of the weir height adjustment mechanism is no greater than 1mm; the clearance between the guide rod 6 and the guide rod slider 5 is no greater than 0.5mm; and the coaxiality of the movable vertical pipe and the fixed vertical pipe is no greater than 0.5mm.

[0075] Specifically, in this embodiment, the driving mechanism is a drive motor 1; the weir height adjustment mechanism also includes a transmission mechanism, which is a drive chain 8. The drive chain 8 passes around the upper end of the rotating part of the four drive screws and is driven by the drive shaft of the drive motor.

[0076] Preferably, the weir height adjustment mechanism further includes a stroke limiting device, comprising an upper limit block and a lower limit block, respectively set at the upper and lower threshold values ​​of the overflow weir height corresponding to the guide rod 6.

[0077] Preferably, the weir height adjustment mechanism further includes: a manual emergency drive component, used to drive the drive screw by handwheel or hand crank in the event of power failure or malfunction.

[0078] Preferably, the weir height adjustment mechanism further includes a mechanical locking device for locking the height position of the movable riser during maintenance or shutdown. Furthermore, the weir height adjustment mechanism is equipped with a dual anti-fall protection structure, including a combination of a reverse self-locking screw and a mechanical locking device, to prevent the movable riser from accidentally sliding down in abnormal conditions.

[0079] In this embodiment, the aforementioned multi-layered precision and safety design enables the adjustable overflow structure to operate with high precision even in complex environments. Dual mechanical and electrical protection ensures equipment safety; position detection enables closed-loop automatic control; and multiple material selections enhance aging resistance and corrosion resistance, extending service life.

[0080] The weir height adjustment mechanism is equipped with a position detection component, which is at least one of a limit switch, an encoder, or a displacement sensor.

[0081] It should be noted that in this embodiment, four drive screws 4 and four guide rods 6 are provided. The four guide rods 6 are evenly arranged around the periphery of the fixed vertical tube; the lower ends of the rotating parts of the four drive screws 4 are evenly arranged around the periphery of the movable vertical tube. However, the present invention is not limited thereto. In other embodiments of the present invention, there may be three, five, six or more drive screws and guide rods, depending on the diameter of the fixed vertical tube. Furthermore, the number of drive screws and guide rods may also be different.

[0082] Please continue to refer to Figure 1 This embodiment of the mechanically stirred clarification tank includes: a second reaction chamber located on the periphery of the tank body; a first reaction chamber located in the middle of the tank body; an adjustable overflow weir located on the upper part of the second reaction chamber; and a stirrer including a drive shaft and an impeller mounted on the lower end of the drive shaft, the impeller extending into the bottom of the first reaction chamber to provide the stirring intensity required for mixing and flocculation within the clarification tank. The adjustable overflow weir is the aforementioned adjustable overflow structure. The fixed vertical pipe and the movable vertical pipe are coaxially arranged on the upper part of the first reaction chamber, and are respectively a fixed weir cylinder and a movable weir cylinder.

[0083] In this embodiment, the adjustable overflow weir is connected to the fixed wall of the first reaction chamber via a screw lifting mechanism. The entire annular overflow weir can be vertically raised or lowered by manually or by a motor-driven adjustment mechanism.

[0084] In this embodiment, the speed adjustment range of the mixer is 10 to 120 revolutions per minute. The mixer includes a drive shaft and an impeller mounted on the drive shaft. The impeller is located inside a reaction chamber, and its speed is controlled by a variable frequency motor, enabling stepless speed regulation.

[0085] As shown in the figure, the mechanical stirring clarifier in this embodiment also includes a sensor group, including: a flow sensor for sensing the influent flow rate of the clarifier; a turbidity sensor for sensing the turbidity of the raw water in the clarifier; and a water temperature sensor for sensing the water temperature of the raw water in the clarifier.

[0086] Based on this, the mechanical stirring clarification tank in this embodiment also includes 13: an intelligent control module, which has a built-in expert system for closed-loop control of the weir height adjustment mechanism and the mixer based on the internally stored raw water turbidity threshold and water temperature threshold, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the water temperature sensor.

[0087] Based on the above-described apparatus, a second aspect of the present invention provides an adjustable overflow weir control method for the mechanically stirred clarifier, used to achieve water flow control. The core of this adjustable overflow weir control method lies in: changing the overflow level by raising or lowering the adjustable overflow weir, thereby independently adjusting the circulation flow rate of the clarifier; and independently adjusting the stirring intensity within a reaction chamber by adjusting the rotational speed of the agitator motor. These two control variables (weir height and rotational speed) can be operated independently without interference.

[0088] Figure 3 for Figure 1 The flowchart shown is the control logic of the intelligent control module in the mechanically stirred clarifier. Figure 3 As shown, the adjustable overflow weir control method in this embodiment includes:

[0089] Step 0, Start: System initialization, setting initial parameters;

[0090] Step A: Monitor the inlet water flow rate, turbidity, and water temperature in real time;

[0091] Step B: Accept the user's selection of control mode. If the user selects automatic mode, proceed to step C; if the user selects manual mode, proceed to step F.

[0092] Step C: Using the expert system, based on the internally stored raw water turbidity threshold and water temperature threshold, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the water temperature sensor, set the mixer speed and weir height, and then execute step D.

[0093] Step D: Drive the mixer motor with a frequency converter to reach the set speed; control the weir height adjustment mechanism to raise and lower synchronously to the target weir height, and then execute step E;

[0094] Optionally, after the inverter-driven motor reaches the target speed, the actual speed and flocculation effect are monitored in real time. Optionally, after the synchronous lifting mechanism reaches the target weir height, the actual weir height and circulation flow rate are monitored in real time.

[0095] Step E: Determine compliance based on online effluent turbidity detection results. If compliance is not met, return to step C; if compliance is met, maintain stable operation of current parameters.

[0096] Step F: After receiving the mixer speed and overflow weir height manually set by the operator, proceed to step E.

[0097] It is important to note that in the control logic of the intelligent control module, for low-temperature and low-turbidity operating conditions, the stirring speed is prioritized to be increased and the circulation flow rate is appropriately reduced by lowering the height of the movable weir; for high-turbidity and high-load operating conditions, the circulation flow rate is prioritized to be increased by increasing the height of the movable weir and the stirring speed is limited to within the preset upper limit. Furthermore, the intelligent control module is configured with input parameter limiting and anomaly detection logic, which triggers weir height retraction and speed limit protection, and issues an alarm, in the event of sensor failure, arrival signal timeout, or abnormal drive current.

[0098] In this embodiment, two independent control inputs (speed setting and weir height setting) are shown to act on two independent actuators (frequency converter and weir adjustment mechanism), which ultimately affect two independent outputs (stirring intensity and circulation flow rate).

[0099] The following describes a specific application scenario of this embodiment: a water plant's mechanically stirred clarifier originally used a fixed overflow weir. The system was technically upgraded by installing the adjustable overflow weir described in this invention.

[0100] (1) Installation

[0101] A ring-shaped weir is installed at the original overflow outlet at the top of a reaction chamber. The weir is connected to the tank body through four evenly distributed screw lifting mechanisms. The screws are synchronously driven by a motor through a chain, which can be remotely controlled from the central control room.

[0102] (2) Run

[0103] 1) When the raw water is cold and turbid in spring, the overflow weir height is lowered to a higher position. This reduces the circulation flow rate appropriately, avoids excessive dilution of low-concentration influent, and at the same time increases the mixer speed to enhance the mixing intensity to compensate for the adverse effects of low temperature on the reaction rate. This overcomes the contradiction that increasing the speed under fixed weir conditions would lead to excessive circulation flow rate.

[0104] 2) When the raw water has high turbidity after heavy summer rains, the overflow weir height is adjusted to a lower position. This increases the circulation flow rate, raises the sludge concentration in the tank, and enhances the flocculation and adsorption capacity. At the same time, the mixer speed is adjusted to medium intensity to ensure thorough mixing while preventing the already formed flocs from being broken. Through the above independent adjustments, the turbidity stability of the clarifier effluent has improved by more than 30%, and the chemical consumption has been reduced.

[0105] Compared with the prior art, the present invention has the following significant advantages:

[0106] (1) Precise independent control was achieved: the two key operating parameters of circulation flow rate and stirring intensity were successfully decoupled. Operators can optimize the stirring speed and overflow weir height separately and independently according to the influent water quality and the desired flocculation effect, thus achieving more refined process control.

[0107] (2) Enhanced adaptability and stability: In the face of fluctuations in water quality and quantity, the amount of circulating sludge can be increased or decreased by adjusting the overflow weir separately to maintain the optimal sludge concentration in the pool without changing the already set stirring intensity that is most favorable for floc formation, thereby ensuring the stability of the effluent water quality.

[0108] (3) Improved treatment efficiency and energy-saving potential: Under low load or good water quality, the overflow weir height can be appropriately reduced to reduce the circulation flow and reduce unnecessary energy loss (sludge circulation itself requires energy consumption). At the same time, the most suitable stirring intensity is always maintained to ensure reaction efficiency.

[0109] (4) Simple structure and easy to modify: The principle of this scheme is clear and the structure is relatively simple. It can be applied to the design and construction of new pools, and it is also convenient to carry out technical transformation of existing fixed overflow weir clarification pools. The implementation cost is low and the benefits are significant.

[0110] A third aspect of the present invention provides an adjustable overflow structure. This adjustable overflow structure is an application of the adjustable overflow weir in the previous embodiment to other fields. In the following embodiments, the fixed vertical pipe, the movable vertical pipe, and the overflow port height adjustment structure correspond to the fixed weir cylinder, the movable weir cylinder, and the weir height adjustment mechanism in the previous embodiment, respectively. However, since this is not applied to an overflow weir, a more similar description is used.

[0111] Please refer to Figure 1 , Figure 2A , Figure 2B The adjustable overflow structure in this embodiment includes:

[0112] Fix the vertical pipe;

[0113] A movable vertical pipe is coaxially sleeved with the fixed vertical pipe, and an overflow port is formed at its upper end.

[0114] The water-stop sealing structure is an annular elastic sealing ring with a cross-sectional shape that is smaller at the top and larger at the bottom; the upper annular part of the water-stop sealing structure is fixed to the outer side of the lower end of the movable vertical pipe by a clamping member, and the lower annular part of the water-stop sealing structure is in close contact with the inner wall of the fixed vertical pipe for sealing.

[0115] An overflow outlet height adjustment mechanism is connected to the movable vertical pipe and is used to drive the movable vertical pipe to rise and fall in the vertical direction to change the height of the overflow outlet;

[0116] The fixed vertical pipe, the water-stop sealing structure, and the inner side of the movable vertical pipe together form a fluid containment space; throughout the entire process of the overflow port height adjustment mechanism driving the movable vertical pipe to rise and fall, the lower annular part of the water-stop sealing structure is always tightly sealed against the inner wall of the fixed vertical pipe.

[0117] In this embodiment, the inner wall of the fixed vertical pipe is a smooth metal surface; the water-stop sealing structure includes: an elastic sealing ring, a clamping ring, and a connecting bolt; the elastic sealing ring has a cross-section that is smaller at the top and larger at the bottom and is provided with an anti-squeezing buckle; the clamping ring reliably fixes the upper part of the elastic sealing ring to the movable vertical pipe via the connecting bolt; the lower part of the elastic sealing ring is tightly sealed to the inner wall of the fixed vertical pipe by elastic force.

[0118] In this embodiment, N lead screws are provided on the outer side of the fixed vertical pipe, where N ≥ 2; the overflow port height adjustment mechanism includes:

[0119] M guide rods are evenly fixed to the periphery of the fixed vertical tube and extend vertically upward. Each guide rod is equipped with a guide rod slider that can slide up and down. The guide rod slider is connected inward to the movable vertical tube. M≥2.

[0120] The drive mounting platform is horizontally positioned above the M guide rods;

[0121] The drive mechanism is fixed on the drive mounting platform;

[0122] N drive screws are provided, corresponding to N screw bolts. Each drive screw includes: a fixed part, which is uniformly fixed on the drive mounting platform; and a rotating part, the upper end of which drives the sprocket driven by the drive mechanism, and the lower end of which extends downward and is screwed into the corresponding screw bolt.

[0123] In this embodiment, the driving mechanism is a drive motor; the overflow port height adjustment mechanism further includes: a transmission mechanism, which is a drive chain that passes over the upper ends of the rotating parts of N drive screws and is driven by the drive shaft of the drive motor; and / or,

[0124] In a preferred embodiment of the present invention, the overflow port height adjustment mechanism further includes a travel limiting device, comprising an upper limit block and a lower limit block, respectively disposed at the upper limit threshold and lower limit threshold of the overflow port height corresponding to the guide rod.

[0125] In a preferred embodiment of the present invention, the overflow port height adjustment mechanism further includes: a manual emergency drive component, which, in the event of a power outage or malfunction, replaces the drive motor and drives the drive screw by handwheel or hand crank; and / or a mechanical locking device, which locks the height position of the movable vertical pipe in the event of maintenance or shutdown; and / or a position detection component, which monitors the real-time height of the overflow port, wherein the position detection component is at least one of a limit switch, an encoder, or a displacement sensor.

[0126] In this embodiment, the materials of the fixed vertical pipe and the movable vertical pipe are: stainless steel or fiberglass composite material; M=N=4; wherein, 4 guide rods are evenly arranged around the periphery of the fixed vertical pipe; the lower ends of the rotating parts of 4 drive screws are evenly arranged around the periphery of the movable vertical pipe; the synchronization error of the N drive screws of the overflow port height adjustment mechanism is not greater than 1mm; the fit clearance between the guide rod and the guide rod slider is not greater than 0.5mm; the elastic sealing ring is made of at least one of nitrile rubber, fluororubber, or polyurethane material.

[0127] For more detailed information regarding this embodiment, please refer to the relevant content on the adjustable overflow weir in the previous embodiment of the mechanically stirred clarifier. All of this relevant content is incorporated herein by reference.

[0128] This concludes the description of the various embodiments of the present invention. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0129] It should be noted that for certain implementation methods, if they are not the key content of this invention and are well known to those skilled in the art, they are not described in detail in the accompanying drawings or text due to space limitations. In such cases, they can be understood by referring to the relevant prior art.

[0130] Unless explicitly stated otherwise, the numerical values ​​and ranges mentioned in this invention are approximate and can be changed according to the content of this invention. Specifically, all figures in the specification and claims indicating the content of composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases, meaning that they include variations of ±10% in certain embodiments.

[0131] The directional terms used in this invention, such as "center," "lateral," "longitudinal," "top," "bottom," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," indicate only the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the purpose of facilitating and simplifying the description of this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. Also, the shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but are only illustrative of embodiments of this invention.

[0132] The terms "connected" and "linked" used in this invention should be interpreted broadly unless otherwise explicitly specified and limited. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the connection of a portion of two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0133] Those skilled in the art will understand that in the claims and specification of this invention, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "a" or "an" preceding an element (or step) does not exclude the presence of a plurality of such elements (or steps).

[0134] Furthermore, the above embodiments are provided only to enable the invention to meet legal requirements, and the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0135] Similarly, it should be understood that, for the sake of brevity, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of invention should not be construed as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, the various inventive aspects consist of fewer than all the features of the preceding single embodiment. Furthermore, embodiments may be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0136] The above specific embodiments have provided a detailed description of the purpose, technical means, and beneficial effects of the present invention. It should be understood that the purpose of the detailed description is to enable those skilled in the art to better understand the present invention, and it is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mechanically stirred clarifier, characterized in that, include: The second reaction chamber is located on the periphery of the pool. The first reaction chamber is located in the middle of the pool body, inside the second reaction chamber; Adjustable overflow weir, including: A fixed weir is connected to the upper part of the overflow pipe of the first reaction tank; A movable weir cylinder, which is coaxially sleeved with the fixed weir cylinder, and an overflow outlet is formed at its upper end; The water-stop sealing structure is an annular elastic sealing ring with a cross-sectional shape that is smaller at the top and larger at the bottom; the upper annular part of the water-stop sealing structure is fixed to the outer side of the lower end of the movable weir cylinder by a clamping member, and the lower annular part of the water-stop sealing structure is in close contact with the inner wall of the fixed weir cylinder for sealing. A weir height adjustment mechanism, connected to the movable weir cylinder, is used to drive the movable weir cylinder to rise and fall vertically to change the height of the overflow outlet; The fixed weir, the water-stop sealing structure, and the inner side of the movable weir together form a fluid containment space; throughout the entire process of the overflow port height adjustment mechanism driving the movable weir to rise and fall, the lower annular part of the water-stop sealing structure is always tightly sealed against the inner wall of the fixed weir. A mixer includes: a drive shaft and an impeller mounted at the lower end of the drive shaft, the impeller extending into the bottom of a first reaction chamber to provide the stirring intensity required for mixing and flocculation in a clarification tank; The sensor group includes: a flow sensor for sensing the influent flow rate of the clarifier; a turbidity sensor for sensing the turbidity of the raw water in the clarifier; and a water temperature sensor for sensing the water temperature of the raw water in the clarifier. The intelligent control module, with its built-in expert system, is used to perform closed-loop control of the weir height adjustment mechanism and the mixer based on internally stored raw water turbidity and temperature thresholds, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the temperature sensor. Specifically, in the control logic of the intelligent control module, for low-temperature and low-turbidity conditions, it prioritizes increasing the mixing speed and moderately reducing the circulation flow rate by lowering the height of the movable weir; for high-turbidity and high-load conditions, it prioritizes increasing the circulation flow rate by increasing the height of the movable weir and limiting the mixing speed to within a preset upper limit.

2. The mechanically stirred clarifier according to claim 1, characterized in that, The inner wall of the fixed weir cylinder is a smooth metal surface; The water-stop sealing structure includes: an elastic sealing ring, a clamping ring, and connecting bolts; The elastic sealing ring has a small upper and large lower cross section and is equipped with an anti-extrusion buckle. The clamping ring secures the upper part of the elastic sealing ring to the movable weir cylinder via the connecting bolts; the lower part of the elastic sealing ring is tightly sealed to the inner wall of the fixed weir cylinder by elastic force.

3. The mechanically stirred clarifier according to claim 2, characterized in that, The outer side of the fixed weir cylinder is provided with N threaded bolts, where N≥2; The weir height adjustment mechanism includes: M guide rods are evenly fixed around the periphery of the fixed weir cylinder and extend vertically upward. Each guide rod is equipped with a guide rod slider that can slide up and down. The guide rod slider is connected inward to the movable weir cylinder. M≥2. The drive mounting platform is horizontally positioned above the M guide rods; The drive mechanism is fixed on the drive mounting platform; N drive screws are provided, corresponding to N screw bolts. Each drive screw includes: a fixed part, which is uniformly fixed on the drive mounting platform; and a rotating part, the upper end of which drives the sprocket driven by the drive mechanism, and the lower end of which extends downward and is screwed into the corresponding screw bolt.

4. The mechanically stirred clarifier according to claim 3, characterized in that, The driving mechanism is a drive motor; the weir height adjustment mechanism further includes: a transmission mechanism, which is a drive chain that passes over the upper end of the rotating parts of N drive screws and is driven by the drive shaft of the drive motor; and / or, The weir height adjustment mechanism further includes a travel limit device, comprising an upper limit block and a lower limit block, respectively set at the upper and lower threshold values ​​of the overflow port height corresponding to the guide rod.

5. The mechanically stirred clarifier according to claim 4, characterized in that, The fixed and movable weir cylinders are made of stainless steel or fiberglass composite materials, and their outer surfaces have a corrosion-resistant coating; and / or, The effective lifting stroke of the movable weir is 5mm to 300mm, and the weir height setting resolution is no greater than 1mm; and / or, The fixed weir cylinder is equipped with a mounting flange assembly on its outer wall for detachable connection to the existing clarifier wall, adapting to the installation interface of new or renovated projects; and / or, The weir height adjustment mechanism is equipped with a dual anti-fall protection structure, including a combination of a reverse self-locking screw and a mechanical locking device, to prevent the movable weir from sliding down unexpectedly in abnormal conditions.

6. The mechanically stirred clarifier according to claim 5, characterized in that, The weir height adjustment mechanism also includes: A manual emergency drive component, which, in the event of a power outage or malfunction, replaces the drive motor and drives the drive screw by handwheel or hand crank; and / or, A mechanical locking device that locks the height position of the movable weir cylinder during maintenance or shutdown; and / or, A position detection component that monitors the real-time height of the overflow port, the position detection component being at least one of a limit switch, an encoder, or a displacement sensor.

7. The mechanically stirred clarifier according to claim 6, characterized in that, The speed adjustment range of the mixer is 10 to 120 revolutions per minute; and / or, The intelligent control module is configured with input parameter limiting and anomaly judgment logic, which is used to trigger weir height retraction and speed limit protection and issue an alarm when sensor failure, arrival signal timeout or abnormal drive current occurs.

8. An adjustable overflow weir control method, characterized in that, The mechanical stirring clarifier as described in claim 1, executed by an intelligent control module, includes: Step A: Monitor the inlet water flow rate, turbidity, and water temperature in real time; Step B: Accept the user's selection of the control mode. If the user selects the automatic mode, proceed to step C. Step C: Using the expert system, based on the internally stored turbidity threshold and water temperature threshold of the raw water, the influent flow rate measured by the flow sensor, the raw water turbidity measured by the turbidity sensor, and the raw water temperature measured by the water temperature sensor, the mixer speed and weir height are set, and step D is executed. Step D: Drive the mixer motor with a frequency converter to reach the set speed; control the weir height adjustment mechanism to synchronously raise and lower to the target weir height, and then execute step E; Step E: Determine compliance based on online effluent turbidity detection results. If compliance is not met, return to step C; if compliance is met, maintain stable operation of current parameters.

9. The adjustable overflow weir control method according to claim 8, characterized in that, Step B further includes: if the user selects manual mode, proceed to step F; Step F: After receiving the mixer speed and overflow weir height manually set by the operator, proceed to step E.

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