Accurate dosing system of coagulant for preparing water by using whole membrane method
By combining variable frequency dosing pipelines and control systems, precise dosing of coagulants is achieved using raw water detection modules and PID calculation modules, solving the problems of insufficient or excessive dosing in existing technologies and improving the reliability and treatment efficiency of filtration equipment.
Patent Information
- Application Number
- CN202520336115.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-02-28
AI Technical Summary
Existing dosing control systems are difficult to achieve precise dosing, resulting in insufficient or excessive coagulant dosage, which affects filter efficiency and treatment capacity, and also suffers from lag and unreliability.
The system employs a variable frequency dosing pipeline and control system, combined with a raw water detection module, an effluent turbidity meter, a flow meter, and a PID calculation module. It controls the variable frequency dosing pump in real time, achieving precise dosing based on changes in influent water quality and flow rate. The dosing amount is optimized through a dosing calculation model and feedback correction signals.
It achieves precise control of coagulant dosing, improves the reliability and processing capacity of downstream filtration equipment, avoids problems of excessive or insufficient dosage, and ensures stable effluent quality.
Smart Images
Figure CN223866438U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water treatment equipment technology, and in particular to a precision dosing system for coagulants in a full-membrane water treatment process. Background Technology
[0002] Raw water pretreatment is a core step in water production processes, directly impacting effluent quality. Coagulant dosing is a common pretreatment method in water treatment. It utilizes the charge neutralization and adsorption bridging effects of colloidal particles to coagulate suspended solids and colloids in the water into larger particles, facilitating filtration and removal in subsequent systems. The dosage of coagulant plays a crucial role in the filtration efficiency and treatment capacity of reverse osmosis security filters. Insufficient dosage results in poor impurity coagulation, making it difficult to form large flocs, significantly reducing the filter's efficiency and treatment capacity. Excessive dosage, while causing impurities to coagulate into large flocs, generates a large number of flocs in the water, increasing the burden on the ultrafiltration system and raising the reverse osmosis security filtration resistance. This leads to inaccurate pretreatment dosage control, directly affecting the reliability of downstream equipment. However, due to the presence of multiple variables such as influent water quality and flow rate, existing dosing control systems suffer from significant lag and unreliability, making precise dosing control difficult. Summary of the Invention
[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a precision dosing system for coagulants in a full-membrane water treatment process, which can achieve precise dosing control of coagulants according to changes in influent water quality and flow rate, thereby improving the reliability of downstream equipment.
[0004] Technical Solution: To achieve the above objectives, this utility model provides a precision dosing system for coagulants in a membrane-based water treatment process, comprising a variable frequency dosing pipeline. The variable frequency dosing pipeline connects a dosing tank and a mixer in the raw water pipeline. The outlet end of the raw water pipeline is connected to a sedimentation tank. A raw water detection module is installed at the inlet end of the raw water pipeline. The signal output terminal of the raw water detection module is electrically connected to a control system. The control signal output terminal of the control system is electrically connected to the variable frequency dosing pump of the variable frequency dosing pipeline.
[0005] The raw water detection module includes a raw water turbidity meter, and an effluent turbidity meter is installed at the outlet of the sedimentation tank. The effluent turbidity meter is electrically connected to the control system.
[0006] Furthermore, the raw water detection module includes a raw water flow meter, and a dosing flow meter is installed at the outlet end of the variable frequency dosing pipeline. The raw water flow meter and the dosing flow meter are electrically connected to the dosing concentration calculation module of the control system. The raw water flow meter and the dosing flow meter are both located relatively close to the mixer.
[0007] Furthermore, the control system includes a PID calculation module, the effluent turbidity meter is electrically connected to the PID calculation module through a feedback correction signal interface, the output terminal of the dosing concentration calculation module is electrically connected to the input terminal of the PID calculation module, and the control signal output terminal of the PID calculation module is electrically connected to the variable frequency dosing pump.
[0008] Furthermore, the raw water detection module also includes a thermometer and a pH meter. The thermometer, the pH meter, the raw water turbidity meter, and the raw water flow meter are all electrically connected to the dosing calculation module of the control system. The signal output terminal of the dosing calculation module is electrically connected to the PID calculation module.
[0009] Furthermore, two variable frequency dosing pumps are provided. The inlet pipes of the two variable frequency dosing pumps are connected to the dosing tank, and the outlet pipes of the two variable frequency dosing pumps converge to form a dosing header. Each variable frequency dosing pump is equipped with a switch valve at its inlet and outlet. The control signal output terminal of the PID calculation module is electrically connected to both variable frequency dosing pumps.
[0010] Furthermore, the main dosing pipe is equipped with a master control valve, and the dosing tank is equipped with a level gauge, which is electrically connected to the master control valve via a controller.
[0011] Beneficial effects: This utility model provides a precision dosing system for coagulants in a full-membrane water treatment process. It calculates the basic dosage of coagulant based on collected influent water quality parameters using a pre-set dosing calculation model. Then, it combines the correction amount calculated from effluent water quality feedback with the detected dosing concentration to calculate the real-time control amount for the variable frequency dosing pump 11. This maintains good effluent water quality while avoiding excessive dosing concentration, achieving the optimal dosing mode for pretreatment. It avoids significantly reducing the efficiency and treatment capacity of subsequent filters, and also avoids placing a heavy burden on them, thus comprehensively improving the reliability of downstream filtration equipment. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of a precision dosing system for coagulants in water treatment using a full-membrane method according to this utility model. Detailed Implementation
[0013] The present invention will be further described below with reference to the accompanying drawings.
[0014] As attached Figure 1The aforementioned all-membrane water treatment coagulant precision dosing system includes a variable frequency dosing pipeline 1, which connects a dosing tank 2 and a mixer 31 of a raw water pipeline 3. The outlet end of the raw water pipeline 3 is connected to a sedimentation tank 4, and the inlet end of the raw water pipeline 3 is equipped with a raw water detection module 5. The signal output end of the raw water detection module 5 is electrically connected to a control system 6, and the control signal output end of the control system 6 is electrically connected to a variable frequency dosing pump 11 of the variable frequency dosing pipeline 1. The raw water detection module 5 includes a raw water turbidity meter 51, and the outlet end of the sedimentation tank 4 is equipped with an effluent turbidity meter 7, which is electrically connected to the control system 6. The effluent pipeline of the sedimentation tank is connected to a microfiltration system, such as a V-type filter, to separate suspended particles in the effluent.
[0015] The raw water detection module 5 is used to detect the influent water quality of the raw water pipeline. The control system 6 adopts a PLC / DCS control system, which calculates the amount of coagulant to be added based on the collected influent water quality parameters through a preset dosing calculation model. The calculation is mainly based on the monitoring value of the raw water turbidity meter 51. On this basis, the effluent water quality is detected by the effluent turbidity meter 7, and the corrected dosing amount is calculated. Thus, the dosing amount is adjusted accordingly by increasing or decreasing the amount based on the original calculated dosing amount, thereby controlling the working frequency of the variable frequency dosing pump 11, realizing dynamic dosing control based on changes in influent water quality, and ensuring the accuracy and reliability of the dosing amount.
[0016] In addition to fluctuations in water quality, the influent flow rate also fluctuates. Therefore, the raw water detection module 5 includes a raw water flow meter 52, and a dosing flow meter 12 is installed at the outlet of the variable frequency dosing pipeline 1. The raw water flow meter 52 and the dosing flow meter 12 are electrically connected to the dosing concentration calculation module 61 of the control system 6. By simultaneously monitoring the influent flow rate of the raw water and the outlet flow rate of the dosing, with both the raw water flow meter and the dosing flow meter positioned relatively close to the mixer 31, the dosing concentration calculated based on the feedback data from both meters reflects the concentration of coagulant in the pretreated water output from the mixer in real time, avoiding misalignment and lag, and improving measurement accuracy.
[0017] The control system 6 includes a PID calculation module 62. The effluent turbidity meter 7 is electrically connected to the PID calculation module 62 via a feedback correction signal interface 63. The output terminal of the dosing concentration calculation module 61 is electrically connected to the input terminal of the PID calculation module 62. The control signal output terminal of the PID calculation module 62 is electrically connected to the variable frequency dosing pump 11. By combining the dosing amount calculated based on the raw water quality, the correction amount calculated based on the effluent water quality feedback, and the detected dosing concentration, the control amount for the variable frequency dosing pump 11 is calculated. This maintains good effluent water quality while avoiding excessive dosing concentration, achieving the optimal dosing mode for pretreatment. This avoids significantly reducing the efficiency and treatment capacity of subsequent filters, while also avoiding placing a heavy burden on them, thereby comprehensively improving the reliability of the downstream filtration equipment.
[0018] Preferably, the raw water detection module 5 further includes a thermometer and a pH meter. The thermometer, pH meter, raw water turbidity meter 51, and raw water flow meter 52 are all electrically connected to the dosing calculation module 64 of the control system 6. The signal output terminal of the dosing calculation module 64 is electrically connected to the PID calculation module 62. To further ensure the accuracy of the dosing, the temperature, pH value, and flow rate of the raw water are used as the calculation parameters for the baseline dosing, reflecting a more comprehensive picture of the influent water quality and thus obtaining a more accurate baseline dosing value. Based on this, the control quantity obtained by combining feedback correction from the effluent water quality and the detection of the dosing concentration is more accurate and reliable. Both the dosing concentration calculation module 61 and the dosing calculation module 64 can use existing arithmetic modules. They calculate the corresponding values using preset mathematical functions based on the input detection parameters. The calculated values, along with the correction values from the effluent water quality feedback, are then input into the PID calculation module. After integrated calculation, the final control signal is output.
[0019] Two variable frequency dosing pumps 11 are provided. The inlet pipes of the two variable frequency dosing pumps 11 are connected to the dosing tank 2, and the outlet pipes of the two variable frequency dosing pumps 11 converge to form a dosing header. Each variable frequency dosing pump 11 is equipped with a switch valve at its inlet and outlet. The control signal output terminal of the PID calculation module 62 is electrically connected to both variable frequency dosing pumps 11. The two variable frequency dosing pumps are used in pairs, with one in operation and the other on standby. During dosing, only one pump is turned on. The coagulant is selectively passed to a particular pump by opening and closing the switch valves at both ends of each pump. However, both pumps simultaneously receive control signals from the control system 6. That is, when both pumps are working, their control values are synchronized, which ensures that there is no lag in control during switching.
[0020] The main dosing pipe is equipped with a master control valve 8, and the dosing tank 2 is equipped with a level gauge 9. The level gauge 9 is electrically connected to the master control valve 8 via a controller. By detecting the level in the dosing tank, the system reminds users to replenish the reagent in a timely manner. When the reagent dosage is insufficient, the system automatically closes the outlet of the main dosing pipe to prevent raw water backflow from contaminating the reagent pipeline. This also avoids affecting the reading of the dosing flow meter 12, preventing errors in the calculation of the control volume, and ensuring the stability of the system.
[0021] The above are merely preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.
Claims
1. A precision dosing system for coagulants in a membrane-based water treatment process, characterized in that: Includes a variable frequency dosing pipeline (1), which connects the dosing tank (2) and the mixer (31) of the raw water pipeline (3). The outlet end of the raw water pipeline (3) is connected to the sedimentation tank (4). The inlet end of the raw water pipeline (3) is equipped with a raw water detection module (5). The signal output end of the raw water detection module (5) is electrically connected to the control system (6). The control signal output end of the control system (6) is electrically connected to the variable frequency dosing pump (11) of the variable frequency dosing pipeline (1). The raw water detection module (5) includes a raw water turbidity meter (51), and an effluent turbidity meter (7) is provided at the outlet end of the sedimentation tank (4). The effluent turbidity meter (7) is electrically connected to the control system (6).
2. The all-membrane water coagulant precision dosing system according to claim 1, characterized in that: The raw water detection module (5) includes a raw water flow meter (52), and a dosing flow meter (12) is provided at the outlet end of the variable frequency dosing pipeline (1). The raw water flow meter (52) and the dosing flow meter (12) are electrically connected to the dosing concentration calculation module (61) of the control system (6). The raw water flow meter (52) and the dosing flow meter (12) are both located relatively close to the mixer (31).
3. The precision dosing system for coagulants in a membrane-based water treatment process according to claim 2, characterized in that: The control system (6) includes a PID calculation module (62). The effluent turbidity meter (7) is electrically connected to the PID calculation module (62) through a feedback correction signal interface (63). The output terminal of the dosing concentration calculation module (61) is electrically connected to the input terminal of the PID calculation module (62). The control signal output terminal of the PID calculation module (62) is electrically connected to the variable frequency dosing pump (11).
4. The all-membrane water treatment coagulant precision dosing system according to claim 3, characterized in that: The raw water detection module (5) also includes a thermometer and a pH meter. The thermometer, the pH meter, the raw water turbidity meter (51) and the raw water flow meter (52) are all electrically connected to the dosing calculation module (64) of the control system (6). The signal output terminal of the dosing calculation module (64) is electrically connected to the PID calculation module (62).
5. The all-membrane water coagulant precision dosing system according to claim 4, characterized in that: Two variable frequency dosing pumps (11) are provided. The inlet pipes of the two variable frequency dosing pumps (11) are connected to the dosing tank (2). The outlet pipes of the two variable frequency dosing pumps (11) converge to form a dosing header. Each variable frequency dosing pump (11) is provided with a switch valve at its inlet and outlet. The control signal output terminal of the PID calculation module (62) is electrically connected to both variable frequency dosing pumps (11).
6. The all-membrane water coagulant precision dosing system according to claim 5, characterized in that: The main dosing pipe is equipped with a master control switch valve (8), and the dosing tank (2) is equipped with a level gauge (9). The level gauge (9) is electrically connected to the master control switch valve (8) through a controller.