Sewage treatment plant sodium hypochlorite dosing device

Abstract

This invention discloses a sodium hypochlorite dosing device for a wastewater treatment plant, belonging to the technical field of wastewater treatment equipment. It includes an operating room with a base connected to its lower end. A dosing component is connected to the upper end of the base. Storage components are connected to both sides of one end of the dosing component, and a data cable is connected to the end of the dosing component furthest from the storage components. A PLC controller is connected to the end of the data cable furthest from the storage components. The PLC-controlled system is linked with a flow meter in real time. A data acquisition module collects the instantaneous flow rate of the effluent in seconds. An algorithm model automatically calculates and adjusts the appropriate dosing amount. An instruction execution module dynamically adjusts the speed of the peristaltic pump, achieving precise matching of more dosing for large volumes and less for small volumes, eliminating errors from manual adjustment. This avoids incomplete disinfection and excessive fecal coliform levels due to insufficient dosing, while also preventing excessive dosing from causing excessive residual chlorine, waste of reagents, and secondary pollution of the water body, ensuring that the disinfection effect of the effluent consistently meets standards.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment equipment technology, and more specifically, to a sodium hypochlorite dosing device for a wastewater treatment plant. Background Technology

[0002] In the advanced treatment process of urban wastewater treatment plants, effluent disinfection is a key step in ensuring that the effluent meets the discharge standards. Sodium hypochlorite has become the most widely used disinfectant in the field of wastewater treatment due to its advantages of high bactericidal efficiency, convenient operation, and controllable cost. The operational stability and dosing accuracy of its dosing device directly determine the effect of killing pathogenic microorganisms, which is related to the ecological safety of water bodies and the effluent compliance rate.

[0003] Most existing dosing devices rely on manual adjustment of pump speed and valve opening based on experience, which cannot dynamically match the dosage of chemicals according to the instantaneous flow rate of the effluent from the wastewater treatment plant. This easily leads to dosing imbalance. If the dosage is insufficient, the residual chlorine in the effluent will be low, and pathogenic microorganisms such as bacteria and viruses will not be completely killed, resulting in excessive levels of indicators such as fecal coliforms. On the other hand, if the dosage is excessive, the residual chlorine in the effluent will exceed the standard, which not only wastes chemicals and increases operating costs, but also causes secondary pollution to the receiving water body and damages the aquatic ecological environment. Summary of the Invention

[0004] The purpose of this invention is to provide a sodium hypochlorite dosing device for a wastewater treatment plant to solve the problems mentioned in the background art.

[0005] A sodium hypochlorite dosing device for a wastewater treatment plant includes an operating room. The lower end of the operating room is connected to a base, and the upper end of the base is connected to a dosing component. One end of the dosing component is connected to two storage components on both sides, and the end of the dosing component away from the storage components is connected to a data cable. The end of the data cable away from the storage components is connected to a PLC controller. The dosing assembly includes a dosing peristaltic pump, the output end of which is connected to a first delivery pipe. The end of the first delivery pipe facing the storage assembly is connected to a delivery pipeline assembly, and the end of the first delivery pipe away from the delivery pipeline assembly is connected to the inlet of the disinfection tank. A flow meter is installed in the inlet of the disinfection tank. The dosing peristaltic pump adopts a hose extrusion delivery structure, and the sodium hypochlorite stock solution only flows within the pump body hose, realizing direct dosing of the stock solution without contact. The storage assembly includes a rectangular frame, the inner cavity of which is connected to a storage tank. The end of the storage tank facing the dosing assembly is connected to a second valve, and the top of the storage tank is connected to a feed inlet. The inner cavity of the storage tank is connected to a liquid level detection assembly. The second valve is a wastewater backflow check valve, and the storage tank is a corrosion-resistant and light-proof sodium hypochlorite stock solution storage tank. The PLC controller internally builds a PLC linkage control system, which includes a data acquisition module, an algorithm model construction module, and an automatic execution module.

[0006] Preferably, the lower end of the operating room is connected to a disinfection pool, one side of the front end of the disinfection pool is connected to a staircase, and the front end of the operating room is connected to a sliding door.

[0007] Preferably, the delivery pipeline assembly includes a second delivery pipe, a first valve connected to the end of the second delivery pipe away from the first delivery pipe, a third delivery pipe connected to the end of the first valve away from the second delivery pipe, a tee connector connected to the end of the third delivery pipe away from the first valve, and a fourth delivery pipe connected to the end of the tee connector facing the storage assembly. The first delivery pipe is a flexible hose made of fluororubber corrosion-resistant material, and the first valve is a backflow prevention check valve.

[0008] Preferably, the end of the three-way connector away from the third drug delivery tube is connected to a fifth drug delivery tube, the end of the fifth drug delivery tube away from the three-way connector is connected to a two-way connector, and the end of the two-way connector facing the storage assembly is connected to a sixth drug delivery tube.

[0009] Preferably, the fourth and sixth drug delivery pipes are respectively connected to the second valve in the storage assembly connected to both sides of one end of the dosing component.

[0010] Preferably, the liquid level detection component includes a circular frame, with grooves at both ends of the circular frame, and a circular guide rod connected to the inner cavity of the circular frame. A circular float is slidably connected to the inner cavity of the groove, and a circular hole is formed at the center of the circular float, with the circular hole fitting into the circular guide rod.

[0011] Preferably, the data acquisition module is communicatively connected to the flow meter to collect instantaneous flow data in real time, the algorithm calculation module has a built-in sodium hypochlorite dosage calculation formula, and the instruction execution module is electrically connected to the dosing peristaltic pump.

[0012] Preferably, the PLC linkage control system is electrically connected to the dosing component and the flow meter, forming a closed-loop linkage control system.

[0013] Compared with the prior art, the advantages of this invention are: 1. In this invention, the PLC linkage control system is linked with the flow meter in real time. The data acquisition module collects the instantaneous flow rate of the tailwater in seconds. The algorithm model automatically calculates and adapts the dosage. The instruction execution module dynamically adjusts the speed of the peristaltic pump to achieve precise matching of more dosage for large water volumes and less dosage for small water volumes, eliminating the error of manual adjustment. This avoids incomplete disinfection and excessive fecal coliform index caused by insufficient dosage, and also prevents excessive dosage from causing excessive residual chlorine, waste of chemicals and secondary pollution of water bodies, ensuring that the disinfection effect of the tailwater continuously meets the standards.

[0014] 2. In this invention, by adopting a peristaltic pump hose compression delivery structure, the sodium hypochlorite stock solution flows only within the pump hose, achieving no contact between the agent and pump components, avoiding pump corrosion and sludge buildup, and simultaneously preventing the formation of calcium and magnesium ion crystals during dilution. Combined with a short-distance pipeline layout, it eliminates the problem of scaling and clogging on the inner wall of the pipeline, eliminating the need for frequent shutdowns for cleaning, significantly reducing manual labor intensity and maintenance costs, and ensuring the continuous and stable operation of the dosing system.

[0015] 3. In this invention, the dosing component and the storage component are integrated in the operating room and arranged adjacent to the disinfection tank 1, which shortens the agent delivery distance, reduces delivery pressure fluctuations, ensures uniform agent delivery flow rate, and achieves rapid mixing at the inlet of the disinfection tank, eliminating disinfection blind spots. At the same time, the storage tank is equipped with a special liquid level detection component, which achieves accurate liquid level monitoring through the cooperation of a circular float and a guide rod, provides automatic low liquid level warning, and prompts the operator to add sodium hypochlorite stock solution through the inlet to ensure sufficient agent reserves in the storage tank. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a partial structural schematic diagram of the present invention; Figure 4 This is a schematic diagram of the system flow structure of the present invention; Figure 5 This is a schematic diagram of the dosing component structure of the present invention; Figure 6 This is a schematic diagram of the delivery pipeline assembly structure of the present invention; Figure 7 This is a schematic diagram of the material storage assembly structure of the present invention; Figure 8 This is a schematic diagram of the liquid level detection component of the present invention.

[0017] The diagram labels are as follows: 1. Disinfection pool; 2. Staircase; 3. Operating room; 4. Sliding door; 5. Base; 6. Dosing assembly; 601. Peristaltic pump for drug dosing; 602. First drug delivery pipe; 603. Second drug delivery pipe; 604. First valve; 605. Third drug delivery pipe; 606. T-connector; 607. Fourth drug delivery pipe; 608. Fifth drug delivery pipe; 609. Two-way connector; 610. Sixth drug delivery pipe; 611. Delivery pipeline assembly; 7. Storage assembly; 701. Rectangular frame; 702. Storage tank; 703. Inlet; 704. Second valve; 705. Liquid level detection assembly; 706. Circular frame; 707. Slide chute; 708. Circular guide rod; 709. Circular float; 710. Circular hole; 8. Data cable; 9. PLC controller. Detailed Implementation

[0018] Example: Please refer to Figure 1 , Figure 2 and Figure 3 A sodium hypochlorite dosing device for a wastewater treatment plant includes an operating room 3, a base 5 connected to the lower end of the operating room 3, a dosing component 6 connected to the upper end of the base 5, storage components 7 connected to both sides of one end of the dosing component 6, and a data cable 8 connected to the end of the dosing component 6 away from the storage components 7, and a PLC controller 9 connected to the end of the data cable 8 away from the storage components 7, wherein the PLC controller 9 is a controller model: S7-200Smart. Please see Figure 5 The dosing component 6 includes a dosing peristaltic pump 601. The output end of the dosing peristaltic pump 601 is connected to a first delivery pipe 602. The end of the first delivery pipe 602 facing the storage component 7 is connected to a delivery pipeline component 611. The end of the first delivery pipe 602 away from the delivery pipeline component 611 is connected to the inlet of the disinfection tank. A flow meter is installed in the inlet of the disinfection tank. The dosing peristaltic pump 601 adopts a hose extrusion delivery structure. The sodium hypochlorite stock solution only flows in the pump body hose, realizing direct dosing of the stock solution without contact, avoiding the formation of calcium and magnesium ion crystals from the source, and preventing pipeline blockage. Please see Figure 7 The storage component 7 includes a rectangular frame 701, and a storage tank 702 is connected to the inner cavity of the rectangular frame 701. A second valve 704 is connected to the end of the storage tank 702 facing the dosing component 6, and a feed inlet 703 is connected to the top of the storage tank 702. A liquid level detection component 705 is connected to the inner cavity of the storage tank 702. The second valve 704 is a check valve to prevent sewage backflow. The storage tank 702 is a corrosion-resistant and light-proof sodium hypochlorite stock solution storage tank. The two storage components 7 can supply materials individually or simultaneously to ensure a continuous supply of reagents. Please see Figure 4The PLC controller 9 internally builds a PLC linkage control system, which includes a data acquisition module, an algorithm model construction module, and an automatic execution module.

[0019] Specifically, the PLC linkage control system is linked with the flow meter in real time. The data acquisition module collects the instantaneous flow rate of the tailwater in seconds, the algorithm model automatically calculates and adapts the dosage, and the instruction execution module dynamically adjusts the speed of the peristaltic pump to achieve precise matching of more dosage for large water volumes and less dosage for small water volumes, eliminating the error of manual adjustment. This avoids incomplete disinfection and excessive fecal coliform index caused by insufficient dosage, and also prevents excessive dosage from causing excessive residual chlorine, waste of chemicals and secondary pollution of water bodies, ensuring that the disinfection effect of tailwater continues to meet the standards.

[0020] Please see Figure 1 The lower end of the operating room 3 is connected to a disinfection pool 1, the front end of the disinfection pool 1 is connected to a staircase 2, and the front end of the operating room 3 is connected to a sliding door 4.

[0021] Please see Figure 6 The delivery pipeline assembly 611 includes a second delivery pipe 603. The end of the second delivery pipe 603 away from the first delivery pipe 602 is connected to a first valve 604. The end of the first valve 604 away from the second delivery pipe 603 is connected to a third delivery pipe 605. The end of the third delivery pipe 605 away from the first valve 604 is connected to a tee connector 606. The end of the tee connector 606 facing the storage assembly 7 is connected to a fourth delivery pipe 607. The first delivery pipe 602 is a flexible hose made of fluororubber corrosion-resistant material. The first valve 604 is a sewage backflow check valve.

[0022] Please see Figure 6 The end of the three-way connector 606 away from the third drug delivery pipe 605 is connected to the fifth drug delivery pipe 608. The end of the fifth drug delivery pipe 608 away from the three-way connector 606 is connected to the two-way connector 609. The end of the two-way connector 609 facing the storage component 7 is connected to the sixth drug delivery pipe 610.

[0023] Please see Figure 3 The fourth drug delivery pipe 607 and the sixth drug delivery pipe 610 are respectively connected to the second valve 704 in the storage component 7 connected to both sides of one end of the dosing component 6.

[0024] Specifically, by adopting the 601 peristaltic pump with a hose compression delivery structure, the sodium hypochlorite stock solution flows only within the pump hose, achieving no contact between the agent and pump components, avoiding pump corrosion and sludge buildup, and preventing the formation of calcium and magnesium ion crystals during dilution. Combined with a short-distance pipeline layout, it eliminates the problem of scaling and clogging on the inner wall of the pipeline, eliminating the need for frequent shutdowns for cleaning, significantly reducing manual labor intensity and maintenance costs, and ensuring the continuous and stable operation of the dosing system.

[0025] Please see Figure 8The liquid level detection component 705 includes a circular frame 706, with grooves 707 at both ends of the circular frame 706. A circular guide rod 708 is connected to the inner cavity of the circular frame 706. A circular float 709 is slidably connected to the inner cavity of the groove 707. A circular hole 710 is formed at the center of the circular float 709, and the circular hole 710 fits with the circular guide rod 708. The liquid level detection component 705 inside the storage tank 702 monitors the liquid level of the raw liquid in real time, while the circular float 709 rises and falls with the liquid level of the sodium hypochlorite raw liquid, sliding smoothly along the circular guide rod 708 within the groove 707. The liquid level signal is transmitted to the PLC controller 9 in real time. If the circular guide rod 708 separates from the circular float 709, it indicates that the current liquid level is lower than the preset threshold. At this time, the PLC controller 9 will issue a material shortage warning, prompting the operator to replenish sodium hypochlorite stock solution through the feed inlet 703 to ensure that the storage tank 702 has sufficient reagent reserves. When the PLC controller 9 issues a material shortage warning, if no operator performs a feeding operation within half an hour, the PLC controller 9 will automatically reduce the peristaltic pump speed or suspend the feeding to prevent the pump from running dry and being damaged. The device will automatically restart the feeding process after the liquid level is restored.

[0026] Please see Figure 4 The data acquisition module is connected to the flow meter to collect instantaneous flow data in real time. The algorithm calculation module has a built-in formula for calculating the dosage of sodium hypochlorite. The instruction execution module is electrically connected to the dosing peristaltic pump 601. PLC System Debugging and Algorithm Model Construction The PLC controller and flow meter are connected via a 0-10V voltage signal to control the speed of the peristaltic pump 601, thereby precisely controlling the sodium hypochlorite dosage. Simultaneously, a preset effluent disinfection formula is imported. Step 1: Determine the available chlorine dosage (C) Small-scale test results: After adding 2-10 mg of available chlorine, the laboratory determined that when the available chlorine content was 2-7 mg / L, the residual chlorine in the effluent met the standard. Therefore, 5 mg / L was determined as the available chlorine content, that is, the mass of available chlorine to be added per liter of water is 5 mg. Step 2: Set the sodium hypochlorite solution dosage (Q) disinfection formula Q = C × 3600F × 10⁻⁶ × α - 1 × 1000 In the formula: Q is the sodium hypochlorite solution dosage (L / h), C is the available chlorine dosage (mg / L), F is the instantaneous effluent flow rate of the wastewater treatment plant (m³ / s), 3600 converts the effluent flow rate from m³ / s to m³ / h, α is the available chlorine mass fraction of the commercial sodium hypochlorite solution (currently taken as 10%), 106 is the unit conversion factor (1m³ water = 106g), and 1000 converts the calculation result from m³ / h to L / h (1m³ = 1000L). After simplification: Q = C × F × 36.

[0027] Please see Figure 3 The PLC linkage control system is electrically connected to the dosing component 6 and the flow meter, forming a closed-loop linkage control system.

[0028] Specifically, the dosing component 6 and the storage component 7 are integrated into the operating room 3 and arranged adjacent to the disinfection tank 1, which shortens the agent delivery distance, reduces delivery pressure fluctuations, ensures uniform agent delivery flow rate, and achieves rapid mixing at the inlet of the disinfection tank, eliminating disinfection blind spots. At the same time, the storage tank 702 is equipped with a dedicated liquid level detection component 705, which uses a circular float 709 in conjunction with a guide rod to achieve accurate liquid level monitoring, automatic low liquid level warning, and prompts the operator to add sodium hypochlorite stock solution through the feed inlet 703 to ensure that the agent reserve in the storage tank 702 is sufficient.

[0029] Working principle: First, the effluent from the wastewater treatment plant continuously flows into the inlet of the contact disinfection tank. The flow meter installed inside the inlet of the contact disinfection tank collects the instantaneous flow data of the effluent in real time. The flow analog signal or digital signal is synchronously transmitted to the data acquisition module built into the PLC controller 9 through data line 8. Then, the data acquisition module filters and calibrates the flow signal, removes interference data, and transmits the accurate instantaneous flow value to the algorithm model construction module. At this time, after receiving the real-time flow data, the algorithm model construction module calls the built-in sodium hypochlorite dosage calculation formula, combines the preset effective chlorine dosage concentration and the effective chlorine content of the raw solution in the storage tank 702, automatically calculates the required sodium hypochlorite raw solution dosage under the current working conditions, and converts it into the target speed of the dosing peristaltic pump 601. Then, the automatic execution module converts the speed control command into an electrical signal and sends it to the dosing peristaltic pump 601 through data line 8. After receiving the speed command from the PLC controller 9, the peristaltic pump 601 starts the hose squeezing delivery action. At this time, the peristaltic pump 601 generates negative pressure, which sequentially draws out the sodium hypochlorite stock solution from the two storage tanks 702. The stock solution flows through the second valve 704, the fourth delivery pipe 607 and the sixth delivery pipe 610, and then through the three-way connector 606 and the two-way connector 609 to the third delivery pipe 605. It then enters the peristaltic pump 601 through the first valve 604 and the second delivery pipe 603. At this time, the sodium hypochlorite stock solution only flows in the first delivery pipe 602 of the peristaltic pump 601. Then, the stock solution, which is accurately metered by the peristaltic pump, is directly delivered to the inlet of the contact disinfection tank through the first delivery pipe 602 and enters the disinfection tank 1 at the same time as the tailwater, so as to realize the instant mixing of the agent and the sewage, ensure the uniformity of disinfection, and make the sewage meet the discharge standards. Once the device enters a stable operating state, if the effluent flow rate of the wastewater treatment plant fluctuates, the flow meter immediately collects the updated instantaneous flow data and transmits it to the PLC controller 9. Then, the algorithm module quickly recalculates the dosage, and finally, the automatic execution module adjusts the speed of the dosing peristaltic pump 601 in real time to achieve higher dosage for large volumes and lower dosage for small volumes, ensuring that the residual chlorine in the effluent remains stable and meets the standards. This avoids insufficient dosage leading to disinfection failure and excessive dosage leading to excessive residual chlorine. During the operation of the device, the liquid level detection component 705 monitors the liquid level inside the storage tank 702 in real time. If the circular guide rod 708 separates from the circular float 709, it indicates that the current liquid level has reached the preset threshold. At this time, the PLC controller 9 will issue a low-material warning and send the warning to the user's mobile phone, prompting the operator to replenish sodium hypochlorite stock solution through the inlet 703 to ensure that the reagent reserve in the storage tank 702 is sufficient. When the wastewater treatment plant is shut down for maintenance or when disinfection is not required, the PLC controller 9 issues a shutdown command, and the peristaltic pump 601 gradually decelerates until it stops running, thus ending all operations.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sodium hypochlorite dosing device for a wastewater treatment plant, comprising an operating room (3), characterized in that: The lower end of the operating room (3) is connected to a base (5), the upper end of the base (5) is connected to a feeding component (6), one end of the feeding component (6) is connected to two sides of a storage component (7), and the end of the feeding component (6) away from the storage component (7) is connected to a data line (8), and the end of the data line (8) away from the storage component (7) is connected to a PLC controller (9). The dosing component (6) includes a dosing peristaltic pump (601), the output end of which is connected to a first delivery pipe (602). The end of the first delivery pipe (602) facing the storage component (7) is connected to a conveying pipeline component (611), and the end of the first delivery pipe (602) away from the conveying pipeline component (611) is connected to the inlet of the disinfection tank. A flow meter is installed in the inlet of the disinfection tank. The storage assembly (7) includes a rectangular frame (701), the inner cavity of the rectangular frame (701) is connected to a storage tank (702), the end of the storage tank (702) facing the feeding assembly (6) is connected to a second valve (704), and the top of the storage tank (702) is connected to a feed inlet (703). The inner cavity of the storage tank (702) is connected to a liquid level detection assembly (705). The PLC controller (9) has a built-in PLC linkage control system, which includes a data acquisition module, an algorithm model construction module, and an automatic execution module.

2. The sodium hypochlorite dosing device for a wastewater treatment plant according to claim 1, characterized in that: The lower end of the operating room (3) is connected to a disinfection pool (1), the front end of the disinfection pool (1) is connected to a staircase (2), and the front end of the operating room (3) is connected to a sliding door (4).

3. The sodium hypochlorite dosing device for a wastewater treatment plant according to claim 2, characterized in that: The delivery pipeline assembly (611) includes a second delivery pipe (603), the end of the second delivery pipe (603) away from the first delivery pipe (602) is connected to a first valve (604), the end of the first valve (604) away from the second delivery pipe (603) is connected to a third delivery pipe (605), the end of the third delivery pipe (605) away from the first valve (604) is connected to a tee connector (606), and the end of the tee connector (606) facing the storage assembly (7) is connected to a fourth delivery pipe (607).

4. A sodium hypochlorite dosing device for a wastewater treatment plant according to claim 3, characterized in that: The end of the three-way connector (606) away from the third drug delivery tube (605) is connected to the fifth drug delivery tube (608), the end of the fifth drug delivery tube (608) away from the three-way connector (606) is connected to the two-way connector (609), and the end of the two-way connector (609) facing the storage assembly (7) is connected to the sixth drug delivery tube (610).

5. A sodium hypochlorite dosing device for a wastewater treatment plant according to claim 4, characterized in that: The fourth drug delivery pipe (607) and the sixth drug delivery pipe (610) are respectively connected to the second valve (704) in the storage component (7) connected to both sides of one end of the dosing component (6).

6. A sodium hypochlorite dosing device for a wastewater treatment plant according to claim 5, characterized in that: The liquid level detection component (705) includes a circular frame (706), both ends of which are provided with sliding grooves (707), and a circular guide rod (708) is connected in the inner cavity of the circular frame (706). A circular float (709) is slidably connected in the inner cavity of the sliding groove (707), and a circular hole (710) is provided at the center of the circular float (709).

7. A sodium hypochlorite dosing device for a wastewater treatment plant according to claim 6, characterized in that: The data acquisition module is connected to the flow meter to collect instantaneous flow data in real time. The algorithm calculation module has a built-in sodium hypochlorite dosage calculation formula. The instruction execution module is electrically connected to the dosing peristaltic pump (601).

8. A sodium hypochlorite dosing device for a wastewater treatment plant according to claim 7, characterized in that: The PLC linkage control system is electrically connected to the dosing component (6) and the flow meter, and forms a closed-loop linkage control system.

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