Sodium hypochlorite dosing system

Abstract

The utility model provides a sodium hypochlorite dosing system which comprises a medicine tank used for storing a sodium hypochlorite solution, an outlet of the medicine tank is connected to an inlet of a bypass exhaust valve, an outlet of the bypass exhaust valve is connected to a disinfection tank through a dosing pipeline, and an electromagnetic valve, a dosing pump, a pressure gauge and the like are sequentially arranged in the dosing pipeline. One end of the flushing pipeline is connected to the section, located between the electromagnetic valve and the dosing pump, of the dosing pipe through a tee joint, and the other end of the flushing pipeline is connected to the water storage tank, so that flushing water in the water storage tank is introduced into the dosing pipeline, and flushing of the dosing pipeline is achieved. By additionally arranging the flushing pipeline, corrosion of the solution to the pipeline is reduced, the maintenance cost is reduced, stable operation is guaranteed, equipment does not need to be frequently replaced and maintained, normal use of the disinfection tank is guaranteed, and the water quality is improved. Meanwhile, the whole system adopts an automatic flushing mode, a large amount of manpower can be saved, and the use working efficiency of the dosing system of the disinfection tank is also obviously improved as the cleaning times of pipeline disassembly are reduced.

Description

Technical Field

[0001] This utility model relates to the field of wastewater purification, and in particular to a sodium hypochlorite dosing system. Background Technology

[0002] Sodium hypochlorite, an inorganic compound with the chemical formula NaClO, is a hypochlorite salt. It appears as a white crystalline powder, dissolving in water to form a yellowish-green solution. It is the most common household chlorine bleach. In wastewater treatment, it is primarily used in the dosing system of the ultraviolet (UV) disinfection tank in wastewater treatment plants to perform final disinfection of the treated water, ensuring it meets national discharge standards. The disinfection tank dosing system is a structure located at the inlet of the wastewater treatment plant's outlet pumping station. Before being discharged into the Yangtze River, domestic and industrial wastewater undergoes the final disinfection step in the UV disinfection tank. The main chemical in the dosing system is sodium hypochlorite, which works in conjunction with the UV lamps in the disinfection tank to further enhance the disinfection effect.

[0003] Due to the chemical properties of sodium hypochlorite, its decomposed crystals gradually adsorb into the PVC pipes of the dosing system, easily causing blockages. Cleaning is generally required every two weeks, as the internal crystals are quite hard, and the cleaning effect diminishes over time. Furthermore, excessive pipe vibration combined with the corrosive properties of sodium hypochlorite severely damages the dosing pumps. The diaphragm inside the pump typically ruptures or fails within a month, and the pump body corrodes and perforates every quarter. Pump maintenance costs are substantial: a single cleaning requires 1000 yuan in labor, replacing a damaged pump costs 30,000 yuan, and a diaphragm costs 8000 yuan. The equipment is subject to high wear and tear, resulting in extremely high maintenance costs. Moreover, as a crucial component of the disinfection tank, the shutdown of the sodium hypochlorite dosing system significantly impacts the wastewater treatment plant's effluent quality standards.

[0004] Therefore, it is necessary to improve the existing dosing system piping to reduce sodium hypochlorite corrosion, reduce pipeline vibration, and lower maintenance costs. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a dosing system to solve the problem of easy clogging of pipelines in the prior art.

[0006] To achieve the above and other related objectives, this utility model provides a sodium hypochlorite dosing system, which includes a tank for storing sodium hypochlorite solution. The outlet of the tank is connected to the inlet of a bypass vent valve, and the outlet of the bypass vent valve is connected to a disinfection tank through a dosing pipeline. From the bypass vent valve to the disinfection tank, a solenoid valve, a dosing pump, and a pressure gauge are sequentially installed in the dosing pipeline.

[0007] One end of the flushing pipeline is connected to the section of the dosing pipeline located between the solenoid valve and the dosing pump via a tee, and the other end of the flushing pipeline is connected to the water storage tank, so that the flushing water in the water storage tank is introduced into the dosing pipeline to achieve flushing of the dosing pipeline.

[0008] Optionally, the length of the dosing pipeline is 20-40m and the inner diameter is greater than 40mm.

[0009] Optionally, the dosing pipeline is further equipped with a pulsation damper, which is installed in the section of the dosing pipeline between the pressure gauge and the disinfection tank.

[0010] Optionally, the dosing pipeline is also equipped with a flow meter, which is installed in the section of the dosing pipeline between the pulsation damper and the disinfection tank.

[0011] Optionally, the flow meter is a digital electronic flow meter.

[0012] Optionally, the number of dosing lines is at least two, and multiple dosing lines are connected in parallel to the outlet of the bypass exhaust valve.

[0013] Optionally, the flushing pipeline includes a main flushing pipeline and multiple branch flushing pipelines, with one end of each branch flushing pipeline connected to the main flushing pipeline and the other end connected to the chemical dosing pipeline.

[0014] Optionally, the flushing branch line is equipped with a control valve.

[0015] Optionally, the dosing system may also include a control unit.

[0016] Optionally, the control unit is a PLC.

[0017] As described above, the sodium hypochlorite dosing system of this invention has the following beneficial effects:

[0018] (1) Save labor costs and improve work efficiency.

[0019] Thanks to the adoption of an automatic reclaimed water flushing device, manual cleaning of the pipelines is no longer required, saving a significant amount of manpower. At the same time, the efficiency of the disinfection tank dosing system is also significantly improved because the number of times the pipelines need to be disassembled for cleaning is reduced.

[0020] (2) Reduce maintenance costs and ensure stable operation.

[0021] The equipment does not need to be replaced or repaired frequently, ensuring the normal use of the disinfection pool and improving water quality.

[0022] (3) Reduce safety risks, increase safety factor and protect the environment.

[0023] Sodium hypochlorite is a volatile, toxic, and hazardous chemical. It is not only highly corrosive to equipment but also harmful to human health. High concentrations of sodium hypochlorite can cause serious and irreversible damage if the fumes enter the lungs or the liquid splashes onto the skin. Furthermore, as mentioned earlier, if the pump body leaks due to cavitation or pipeline rupture, spraying the chemicals into the eyes can cause blindness. Therefore, increasing equipment stability and safety plays a crucial role in ensuring safe production. Attached Figure Description

[0024] Figure 1 The diagram shows the connection of each component of the dosing system in Embodiment 1 of this utility model.

[0025] Component designation explanation

[0026] 11 Control Unit

[0027] 12 medicine jars

[0028] 13 Bypass exhaust valve

[0029] 14 Solenoid valve

[0030] 15. Dosing pump

[0031] 16 Pressure gauges

[0032] 17. Pulsation damper

[0033] 18 Digital Electronic Flow Meter

[0034] 19 Disinfection Pool

[0035] 20 water storage tanks Detailed Implementation

[0036] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0037] In the detailed description of the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0038] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for the device in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0039] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0040] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment provides a sodium hypochlorite dosing system, including:

[0043] The medicine tank 12 is used to store sodium hypochlorite solution; the outlet of the medicine tank 12 is connected to the inlet of the bypass vent valve 13, and the outlet of the bypass vent valve 13 is connected to the disinfection tank 19 through the dosing pipeline. From the bypass vent valve 13 to the disinfection tank 19, the dosing pipeline is sequentially equipped with a solenoid valve 14, a dosing pump 15, and a pressure gauge 16; the length of the dosing pipeline is 20-40m, and the inner diameter is greater than 40mm.

[0044] The flushing pipeline has one end connected to the section of the dosing pipeline located between the solenoid valve 14 and the dosing pump 15 via a tee, and the other end connected to the water storage tank 20, so that the flushing water in the water storage tank 20 is introduced into the dosing pipeline to flush the dosing pipeline.

[0045] Specifically, for sodium hypochlorite solutions (5%-15%), due to their easy vaporization, insufficient NPSH in the pump can easily lead to cavitation, affecting the accuracy of dosing and, in severe cases, causing interruption of the dosing process. Therefore, a bypass vent valve is installed to discharge sodium hypochlorite gas, effectively improving the vaporization process of the sodium hypochlorite solution and ensuring the normal operation of the dosing pump.

[0046] Meanwhile, the solubility of sodium hypochlorite solution changes significantly with increasing temperature. Saturated solutions crystallize upon cooling, and as temperature rises, a large amount of water is lost, leading to the formation of hard sodium hypochlorite pentahydrate crystals. The chemical formula is 2NaClO ==== 2NaCl + O2↑. Therefore, this technical solution adds a flushing pipeline to the existing dosing pipeline. The opening and closing of the flushing pipeline can be controlled by a PLC. After each dosing cycle, the pipeline is immediately flushed with clean water through the flushing pipeline, effectively mitigating crystallization and vaporization. The flushing water uses reclaimed water from the plant for recycling. The flushing wastewater is discharged into a dedicated sodium hypochlorite storage tank, neutralized with sodium hydroxide, and then centrally treated. The flushing water and sodium hypochlorite solution share the same dosing pump, eliminating the need for additional pump units. Furthermore, the flushing water is connected to the dosing pipeline before the dosing pump, cleaning both the pipeline and the pump unit simultaneously.

[0047] Furthermore, due to the inherent crystallization properties of 10% sodium hypochlorite solution, thinner pipelines are highly susceptible to narrowing or even blockage caused by crystallization, which can also lead to high-pressure damage to the diaphragm. Since dosing pipelines can reach 20-40 meters in length, excessively long pipelines necessitate increasing the inner diameter of the dosing pipeline to over 40 mm. This effectively slows down the crystallization rate, reduces pipeline pressure, and minimizes the frequency of pipeline cracking.

[0048] Furthermore, the dosing pipeline is also equipped with a pulsation damper 17, which is installed in the section of the dosing pipeline between the pressure gauge 16 and the disinfection tank 19.

[0049] Pumps, operating at full load, endure excessive pressure, leading to cumulative vibrations that cause significant damage to the pump body and pipelines. For pipelines, this can cause loosening of connections, resulting in cracking under pressure and subsequent pesticide spraying. For dosing pumps, loose seals can lead to gradual pesticide leakage. Furthermore, due to the highly corrosive nature of sodium hypochlorite, the pump body can easily be permeated or even rotted through. By installing a pulsation damper and setting a reasonable opening threshold—for example, when the pump body withstands pressure exceeding 3 kg, the pulsation damper activates, releasing excess pressure and stabilizing the internal pressure within a normal operating range. Simultaneously, accurately adjusting the inflation pressure can effectively reduce pipeline vibration and ensure the normal operation of the dosing pump.

[0050] Furthermore, the dosing pipeline is also equipped with a digital electronic flow meter 18, which is installed in the section between the pulsation damper 17 and the disinfection tank 19 in the dosing pipeline.

[0051] Specifically, digital electronic flow meters are more accurate than traditional manually adjustable floating flow switches and scale flow meters. They can also determine the thickness of sodium hypochlorite solution crystals on the inner wall of the dosing pipeline based on the daily values ​​of the electronic flow meter over a period of time, thus eliminating the need for manual cleaning or replacement, and are more effective and targeted.

[0052] Furthermore, the number of dosing lines is at least two, and multiple dosing lines are connected in parallel to the outlet of the bypass exhaust valve 13.

[0053] Furthermore, the flushing pipeline includes a main flushing pipeline and multiple branch flushing pipelines. One end of each branch flushing pipeline is connected to the main flushing pipeline, and the other end is connected to the chemical dosing pipeline. Control valves can be added to each branch flushing pipeline to control the opening degree of each pipeline.

[0054] Furthermore, the dosing system also includes a control unit 11, which can be a PLC. The control unit is electrically connected to various components such as solenoid valves, dosing pumps, pressure gauges, pulsation dampers, and digital electronic flow meters to achieve automatic control. For example, the opening and closing of the flushing pipeline can be controlled by the control unit. After each dosing operation, the solenoid valve is closed to stop the supply of sodium hypochlorite, and then the control valve of the flushing pipeline is opened to flush the pipeline with clean water, which can effectively reduce crystallization and vaporization in the pipeline.

[0055] Before the upgrade and installation of the flushing pipeline, blockages in the pipeline required cleaning approximately every two weeks. Furthermore, excessive vibration and the corrosive effects of sodium hypochlorite severely damaged the metering pump, causing the diaphragm inside the pump to rupture and fail within a month or so, and the pump body to corrode and perforate every quarter. After the upgrade, only quarterly cleaning of the tank and the entire pipeline is needed, and the pump only requires quarterly maintenance. Based on a cleaning cost of 1000 yuan per cleaning, this saves 50,000 yuan in additional labor costs annually. The pump, costing 30,000 yuan, previously required replacement quarterly; now it only needs replacement annually, saving approximately 360,000 yuan in additional maintenance costs. The diaphragm, previously requiring monthly replacement, is now replaced quarterly, saving an additional 64,000 yuan. In total, annual savings reach approximately 474,000 yuan (excluding losses due to disinfection pool shutdowns), demonstrating significant effectiveness.

[0056] According to actual statistics, before upgrading and installing the flushing pipeline, the annual operating cost of the entire dosing system was: labor cost of 62,000 yuan + maintenance cost of 574,000 yuan + equipment downtime loss due to disinfection tank equipment of 1,220,000 yuan = 1,856,000 yuan. After upgrading and installing the flushing pipeline, the annual operating cost of the entire dosing system was: labor cost of 12,000 yuan + equipment maintenance cost of 150,000 yuan + equipment downtime loss due to disinfection tank equipment of 120,000 yuan = 282,000 yuan. This shows that the application of the flushing pipeline greatly reduced operating costs.

[0057] In summary, this utility model provides a sodium hypochlorite dosing system, including a tank for storing sodium hypochlorite solution. The outlet of the tank is connected to the inlet of a bypass vent valve, and the outlet of the bypass vent valve is connected to a disinfection tank via a dosing pipeline. The dosing pipeline includes a solenoid valve, a dosing pump, and a pressure gauge, arranged sequentially. One end of a flushing pipeline is connected via a tee to the section of the dosing pipeline located between the solenoid valve and the dosing pump, and the other end is connected to a water storage tank, thereby allowing flushing water from the water storage tank to be introduced into the dosing pipeline for flushing. The flushing water and the sodium hypochlorite solution share the same dosing pump, eliminating the need for an additional pump set.

[0058] This invention relates to a sodium hypochlorite dosing system. By adding a flushing pipeline, it reduces the corrosion of the pipeline by the solution, lowers maintenance costs, ensures stable operation, and eliminates the need for frequent equipment replacement and maintenance, thus guaranteeing the normal use of the disinfection tank and improving water quality. Simultaneously, the entire system employs an automatic flushing mode, eliminating the need for repeated manual pipeline cleaning and saving significant manpower. Due to the reduced number of times the pipeline needs to be disassembled for cleaning, the efficiency of the disinfection tank dosing system is also significantly improved. Furthermore, the added pulsation damper relieves excess pressure in the pipeline, effectively reducing pipeline vibration and ensuring the normal operation of the dosing pump.

[0059] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A sodium hypochlorite dosing system, characterized in that, The sodium hypochlorite dosing system includes a tank for storing sodium hypochlorite solution. The outlet of the tank is connected to the inlet of a bypass vent valve. The outlet of the bypass vent valve is connected to a disinfection tank via a dosing pipeline. From the bypass vent valve to the disinfection tank, a solenoid valve, a dosing pump, and a pressure gauge are sequentially installed in the dosing pipeline. One end of the flushing pipeline is connected to the section of the dosing pipeline located between the solenoid valve and the dosing pump via a tee, and the other end of the flushing pipeline is connected to the water storage tank, so that the flushing water in the water storage tank is introduced into the dosing pipeline to achieve flushing of the dosing pipeline.

2. The sodium hypochlorite dosing system according to claim 1, characterized in that: The length of the dosing pipeline is 20-40m, and the inner diameter is greater than 40mm.

3. The sodium hypochlorite dosing system according to claim 1, characterized in that: The dosing pipeline is also equipped with a pulsation damper, which is installed in the section between the pressure gauge and the disinfection tank in the dosing pipeline.

4. The sodium hypochlorite dosing system according to claim 3, characterized in that: The dosing pipeline is also equipped with a flow meter, which is installed in the section between the pulsation damper and the disinfection tank in the dosing pipeline.

5. The sodium hypochlorite dosing system according to claim 4, characterized in that: The flow meter is a digital electronic flow meter.

6. The sodium hypochlorite dosing system according to claim 1, characterized in that: The number of dosing lines is at least two, and multiple dosing lines are connected in parallel to the outlet of the bypass exhaust valve.

7. The sodium hypochlorite dosing system according to claim 1, characterized in that: The flushing pipeline includes a main flushing pipeline and multiple flushing branch pipelines. One end of each flushing branch pipeline is connected to the main flushing pipeline, and the other end is connected to the chemical dosing pipeline.

8. The sodium hypochlorite dosing system according to claim 7, characterized in that: The flushing branch line is equipped with a control valve.

9. The sodium hypochlorite dosing system according to claim 1, characterized in that: The dosing system also includes a control unit.

10. The sodium hypochlorite dosing system according to claim 9, characterized in that: The control unit is a PLC.

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