Automatic dosing control device and method for purification station

Abstract

The application belongs to the technical field of purification stations, and specifically discloses an automatic dosing control device for a purification station, which comprises a concentrated medicine tank, a PLC controller, a water tank and a factory area, the concentrated medicine tank is provided with a concentrated medicine pipe, the concentrated medicine pipe is provided with a diluted medicine tank, the diluted medicine tank is provided with a water pipe, the water pipe is communicated with the water tank, the diluted medicine tank is provided with a diluted medicine pipe, the diluted medicine pipe is provided with a reaction tank, the reaction tank is provided with a sewage pipe, the reaction tank is provided with a water outlet pipe, the water outlet pipe is communicated with the factory area, a dosing pump is arranged on the concentrated medicine pipe, a liquid level meter is arranged on the diluted medicine tank, electric valves are arranged on the concentrated medicine pipe, the diluted medicine pipe and the water pipe, four metering pumps and flow meters are arranged on the diluted medicine pipe, and turbidimeters are arranged on the sewage pipe and the water outlet pipe; through cooperation of the PLC controller and the electric valves, the ratio of the concentrated medicine to water and the added amount of medicine during sewage treatment can be flexibly controlled, human errors are reduced, and the stirring rate of the medicine liquid is increased through aeration and stirring by a vacuum pump, so that the problems of human errors and low stirring rate caused by manual dosing of the existing purification station are solved.

Description

Technical Field

[0001] This invention relates to the field of purification station technology, specifically to an automatic chemical dosing control device and method for purification stations. Background Technology

[0002] A wastewater treatment plant is a facility or site that centrally treats and purifies wastewater to remove harmful substances and make it meet discharge or reuse standards. It is widely used for the centralized purification of contaminated media, with its core applications covering the purification of municipal sewage, industrial wastewater, surface water, and circulating water in specific industrial processes. Through physical, chemical, and biological methods, it removes impurities, organic matter, heavy metals, pathogens, and other pollutants, ensuring that the treated water meets national discharge standards, environmental safety requirements, or specific reuse standards. It is a key infrastructure for achieving pollution control, environmental protection, and resource recycling.

[0003] The water purification process in a water treatment plant needs to be tailored to the properties of the raw water and the treatment objectives. Typically, it first undergoes physical pretreatment using screens and grit chambers to intercept large impurities and separate sand particles. Next, coagulants are added to form flocs, which are then settled in a sedimentation tank to remove fine suspended particles. Afterward, filter media such as quartz sand and activated carbon are used to further remove residual impurities. Finally, disinfection is performed to kill pathogens. Currently, chemical dosing in water treatment plants is done manually, which leads to inaccurate dosages, waste of chemicals, and low stirring rates after manual dosing. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic dosing control device and method for a purification station, so as to solve the problems of human error and low stirring rate in existing purification stations that rely on manual dosing.

[0005] To achieve the above objectives, the basic solution provided by this invention is as follows: an automatic dosing control device for a purification station, comprising a concentrated chemical tank, a water tank, a PLC controller, and a plant area. A concentrated chemical pipe is connected to the concentrated chemical tank, a diluted chemical tank is connected to the concentrated chemical pipe, a water pipe is connected to the diluted chemical tank, and the water pipe is connected to the water tank. A diluted chemical pipe is connected to the diluted chemical tank, a reaction tank is connected to the diluted chemical pipe, a sewage pipe is connected to the reaction tank, and an outlet pipe is connected to the reaction tank. The outlet pipe is connected to the plant area. A dosing pump is installed on the concentrated chemical pipe, a level gauge is installed on the diluted chemical tank, electric valves are installed on the concentrated chemical pipe, the diluted chemical pipe, and the water pipe, four metering pumps and a flow meter are installed on the diluted chemical pipe, a turbidity meter is installed on the sewage pipe and the outlet pipe, and a vacuum pump is installed on the diluted chemical tank. The level gauge, electric valves, metering pumps, flow meters, turbidity meter, vacuum pump, and dosing pump are all electrically connected to the PLC controller.

[0006] The principle and beneficial effects of this invention are as follows: When the drug solution in the dilution tank is insufficient, the PLC controller adjusts the ratio of concentrated drug solution and water entering the dilution tank according to the real-time turbidity of the influent. The PLC controller controls the dosing pump to pump the concentrated drug solution into the dilution tank, and then the corresponding amount of water is introduced into the dilution tank. A vacuum pump is then used to aerate the dilution tank so that the concentrated drug solution and water are fully mixed to form a dilution solution. When it is necessary to replenish the dilution solution in the reaction tank, the PLC controller controls the metering pump to flow the dilution solution into the reaction tank. During wastewater treatment, the turbidity meter provides real-time feedback on the turbidity of the influent entering the reaction tank to the PLC controller. The PLC controller then controls the metering pump to draw diluted chemical solution into the reaction tank, where it treats the wastewater. Through the coordinated operation of the PLC controller and electric valves, the ratio of concentrated chemical to water and the amount of chemical added during wastewater treatment can be flexibly controlled. This reduces human error, chemical waste, and costs. Simultaneously, the vacuum pump aeration and stirring of the chemical solution ensures uniform mixing, increases the stirring rate, and reduces the risk of incomplete wastewater treatment due to uneven chemical distribution.

[0007] Option 2, which is the basic solution of this invention: an automatic dosing control method for a purification station, comprising the following steps: S1. Set the upper and lower limits of the liquid level in the PLC controller according to actual needs; the liquid level gauge detects the liquid level of the diluent tank in real time; the threshold of influent turbidity is preset, and the influent turbidity meter detects the turbidity of the influent in real time; the threshold of effluent turbidity is preset, and the effluent turbidity meter detects the turbidity of the effluent in real time; the flow meter detects the flow rate of the diluent solution in real time. S2. Wastewater continuously enters the reaction tank, and the dilute chemical solution is controlled to enter the reaction tank based on the real-time turbidity of the influent. S3. Diluted chemical solution enters the reaction tank. When the liquid level in the dilute chemical tank is ≤ the lower limit of the liquid level, the metering pump is turned off and stops delivering dilute chemical solution to the reaction tank. The dosing pump is started and the proportion of concentrated chemical solution in the dilute chemical tank is adjusted according to the turbidity of the influent to control the entry of concentrated chemical solution into the dilute chemical tank. S4. After the spraying pump stops, the electric valve on the water tank opens, and the amount of water entering the dilution tank is controlled according to the preset concentration ratio until the mixed solution rises to the upper limit of the dilution tank level, at which point the electric valve closes. S5. After the electric valve is closed, the vacuum pump starts and injects compressed air into the dilute drug tank to stir the mixed drug solution; The S6.PLC controller starts the metering pump to continue adding dilute chemical solution to the reaction tank. The dilute chemical solution treats the wastewater in the reaction tank, and the treated wastewater is then recycled back to the plant for reuse.

[0008] Option 3, which is the preferred option of Option 2, has an influent turbidity threshold of 10 NTU and an effluent turbidity threshold of 5.9 NTU in step S1.

[0009] Option 4, which is the preferred option of Option 2, involves adjusting the metering pump frequency in step S2 when the turbidity of the influent changes, and sending the diluted drug solution into the reaction tank; and maintaining the metering pump frequency when the turbidity of the influent remains unchanged.

[0010] Option 5 is a preferred option of Option 2. In step S5, the concentrated chemical is polyferric sulfate. When the turbidity of the influent is between 10 and 300 NTU, the proportion of concentrated chemical in the dilution tank is 20%; when the turbidity of the influent is above 300 NTU, the proportion of concentrated chemical in the dilution tank is 35%.

[0011] Option 6, which is the preferred option of Option 2, involves injecting compressed air at a pressure of 0.3 MPa into the dilute drug pool in step S5, and then turning off the vacuum pump after 5 minutes.

[0012] Option 7, a preferred option of Option 2, involves the following steps in step S6: When the effluent turbidity is ≥5.9 NTU and when 10 NTU ≤ effluent turbidity < 30 NTU, the frequency of metering pump 1 is set to 30%; when 30 NTU ≤ effluent turbidity < 100 NTU, the frequency of metering pump 1 is set to 30%, and the frequency of metering pump 3 is set to 20%; when 100 NTU ≤ effluent turbidity < 300 NTU, all four metering pumps are set to 30% and an alarm is triggered; when 300 NTU ≤ effluent turbidity, PLC automatic control is disabled, and the actual frequency of the metering pumps is manually set in the PLC based on the actual effluent and effluent turbidity until the effluent turbidity returns to below 300 NTU, at which point the frequency of the metering pumps is controlled by the PLC controller again; when the effluent turbidity is <5.9 NTU, the current frequency of the metering pumps is maintained. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an automatic dosing control method for a purification station according to the present invention. Detailed Implementation

[0014] The present invention will be further described in detail below through specific embodiments: The reference numerals in the accompanying drawings of the instruction manual include: 1. Concentrated chemical tank, 101 concentrated chemical pipe, 2. Level gauge, 3. Electric valve, 5. Diluted chemical tank, 501 dilute chemical pipe, 6. Metering pump, 7. Flow meter, 8. Water tank, 801 water pipe, 9. Reaction tank, 901 effluent pipe, 10. Turbidity meter, 11. Plant area, 12. Vacuum pump, 14. Sewage pipe, 15. Spraying pump.

[0015] Example 1 like Figure 1The diagram shows an automatic chemical dosing control device for a purification station, comprising a concentrated chemical tank 1, a water tank 8, a PLC controller, and a plant area 11. A concentrated chemical pipe 101 is connected to the concentrated chemical tank 1, which in turn connects to a diluted chemical tank 5. A water pipe 801 is connected to the diluted chemical tank 5 and is connected to the water tank 8. A diluted chemical pipe 501 is connected to the diluted chemical tank 5, which in turn connects to a reaction tank 9. A sewage pipe 14 is connected to the reaction tank 9, and an outlet pipe 901 is connected to the reaction tank 9 and is connected to the plant area 11. The length, width, and height of the diluted chemical tank 5 and the concentrated chemical tank 1 are 3.5m, 2.5m, and 1.9m, respectively. A dosing pump 15 is installed on the concentrated chemical pipe 101, and a level gauge 2 (model SYLW-31PFGAXMN500) is installed on the diluted chemical tank 5. Electric valves 3 (model BY-08) are installed on the concentrated chemical pipe 101, diluted chemical pipe 501, and water pipe 801. Four metering pumps 6 and flow meters 7 are installed on the diluted chemical pipe 501. The rated flow rates of the four metering pumps 6 are 946 L / h, 1500 L / h, 656 L / h, and 656 L / h, respectively. The flow meters 7 are electromagnetic flow meters. Turbidity meters 10 (model XG-ZD100+XG-ZD0011) are installed on the sewage pipe 14 and the effluent pipe 901. Vacuum pumps 12 (model SLOW150-570) are installed on the diluted chemical tank 5. The level gauge 2, electric valves 3, metering pumps 6, flow meters 7, turbidity meters 10, vacuum pumps 12, and spraying pumps 15 are all electrically connected to the PLC controller.

[0016] The implementation method of this embodiment is as follows: When the drug solution in the dilution tank 5 is insufficient, the PLC controller adjusts the ratio of concentrated drug solution and water entering the dilution tank 5 according to the real-time influent turbidity. The PLC controller controls the dosing pump 15 to pump the concentrated drug solution into the dilution tank 5, and then the corresponding amount of water is introduced into the dilution tank 5. Then, the vacuum pump 12 is used to aerate the dilution tank 5 so that the concentrated drug solution and water are fully mixed to form a dilution solution. When it is necessary to replenish the dilution solution into the reaction tank 9, the PLC controller controls the metering pump 6 to flow the dilution solution into the reaction tank 9. When treating wastewater, the turbidity meter 10 feeds back the turbidity of the influent entering the reaction tank 9 to the PLC controller in real time. The PLC controller controls the metering pump 6 to draw dilute chemical solution into the reaction tank 9, where the dilute chemical solution treats the wastewater.

[0017] Example 2 An automatic chemical dosing control method for a purification station includes the following steps: S1. Set the upper and lower limits of the liquid level in the PLC controller according to actual needs, with an upper limit of 1.7m and a lower limit of 0.5m; the level gauge 2 monitors the liquid level of the diluent tank 5 in real time; the threshold value of the influent turbidity is preset to 10 NTU, and the influent turbidity meter 10 monitors the turbidity of the influent in real time; the threshold value of the effluent turbidity is preset to 5.9 NTU, and the effluent turbidity meter 10 monitors the turbidity of the effluent in real time; the flow meter 7 monitors the flow rate of the diluent solution in real time. S2. Wastewater continuously enters the reaction tank 9. The dilute chemical solution is controlled to enter the reaction tank 9 according to the real-time influent turbidity. When the influent turbidity changes, the frequency of the metering pump 6 is adjusted to send the dilute chemical solution into the reaction tank 9. When the influent turbidity remains unchanged, the frequency of the metering pump 6 is maintained. S3. The diluted chemical solution enters the reaction tank 9. When the liquid level in the diluted chemical tank 5 is ≤ the lower limit, the metering pump 6 is turned off, stopping the delivery of diluted chemical solution to the reaction tank 9. The dosing pump 15 is started, and the proportion of concentrated chemical in the diluted chemical tank 5 is adjusted according to the turbidity of the influent, controlling the amount of concentrated chemical entering the diluted chemical tank 5. The concentrated chemical is polyferric sulfate. When the turbidity of the influent is in the range of 10-300 NTU, the proportion of concentrated chemical in the diluted chemical tank 5 is 20%; when the turbidity of the influent is above 300 NTU, the proportion of concentrated chemical in the diluted chemical tank 5 is 35%. S4. After the spraying pump 15 stops, the electric valve 3 on the water tank 8 opens, and the amount of water entering the dilute tank 5 is controlled according to the preset concentration ratio until the mixed solution rises to the upper limit of the liquid level in the dilute tank 5, and then the electric valve 3 closes. S5. After the electric valve 3 is closed, the vacuum pump 12 is started, and compressed air is injected into the dilute drug tank 5 to stir the mixed drug solution. The pressure of the compressed air is 0.3MPa. The vacuum pump 12 is turned off after 5 minutes. The S6 PLC controller controls metering pump 6 to continue running. Metering pump 6 starts when the effluent turbidity is >5.9 NTU and the influent turbidity is >10 NTU. When 10 NTU ≤ influent turbidity <30 NTU, metering pump 6 starts at a frequency of 30%. When 30 NTU ≤ influent turbidity <100 NTU, metering pump 6 starts at a frequency of 30%, and metering pump 6 starts at a frequency of 20%. When 100 NTU ≤ influent turbidity <300 NTU, all four metering pumps 6 start at a frequency of 30%, and metering pump 6 issues a report. Warning: When the influent turbidity is 300 NTU or less, the PLC automatic control is deactivated. The actual frequency of metering pump 6 is manually set in the PLC according to the actual influent and effluent turbidity until the influent turbidity returns to below 300 NTU. Then, the frequency of metering pump 6 is controlled by the PLC controller to continue delivering diluted chemical solution to reaction tank 9. When the effluent turbidity is < 5.9 NTU, the current frequency of metering pump 6 is maintained. After metering pump 6 delivers diluted chemical solution to reaction tank 9, the diluted chemical solution treats the wastewater in reaction tank 9. The treated wastewater is then recycled back to the plant for reuse.

[0018] The implementation method of this embodiment is as follows: When it is necessary to prepare a diluted drug solution in the diluted drug tank 5, when the depth of the diluted drug solution in the diluted drug tank 5 is ≤0.5m and the turbidity range of the influent is 10-300 NTU, the proportion of concentrated drug in the diluted drug tank 5 is 20%; when the turbidity range of the influent is above 300 NTU, the proportion of concentrated drug in the diluted drug tank 5 is 35%. The PLC controller controls the dosing pump 15 to pump the concentrated drug solution into the diluted drug tank 5. After the concentrated drug reaches a depth of 0.34m in the diluted drug tank, water is then introduced into the diluted drug tank 5 until the depth of the mixed liquid in the diluted drug tank 5 is 1.7m. Then, the vacuum pump 12 introduces compressed air with a pressure of 0.3MPa into the diluted drug tank 5 for 5 minutes. By aerating and stirring the mixed liquid, the concentrated drug solution and water are fully mixed to form a diluted drug solution. During wastewater treatment, the turbidity meter 10 provides real-time feedback of the influent turbidity entering the reaction tank 9 to the PLC controller. The PLC controller then controls the metering pump 6 to draw dilute chemical solution into the reaction tank 9. When the effluent turbidity is ≥5.9 NTU and 10 NTU ≤ influent turbidity < 30 NTU, metering pump 6 is activated at a frequency of 30%. When the effluent turbidity is ≥5.9 NTU and 30 NTU ≤ influent turbidity < 100 NTU, metering pump 6 is activated at a frequency of 30%, and metering pump 6 is activated at a frequency of 20%. When the effluent turbidity is ≥5.9 NTU and 100 NTU ≤ influent turbidity < 300 NTU, all four metering pumps 6 are activated at a frequency of 30%, and metering pump 6 issues an alarm. When the effluent turbidity is ≥5.9 NTU and 300 NTU ≤ influent turbidity, the PLC automatic control is deactivated. The operator sets the actual frequency of metering pump 6 based on the actual influent and effluent turbidity. The wastewater is treated with diluted chemicals in reaction tank 9. When influent turbidity is between 300 NTU and 1000 NTU, and effluent turbidity is ≥ 5.9 NTU, the four metering pumps 6 are started at 60% frequency until the influent turbidity returns to below 300 NTU. Then, the frequency of metering pump 6 is controlled by the PLC controller. When effluent turbidity is ≥ 5.9 NTU, and 1000 NTU is less than influent turbidity, and effluent turbidity is ≥ 5.9 NTU, the influent valve on wastewater pipe 14 is closed, and the four metering pumps 6 are started at 90% frequency until the influent turbidity returns to below 300 NTU. Then, the frequency of metering pump 6 is controlled by the PLC controller. When effluent turbidity is < 5.9 NTU, the current frequency of metering pump 6 is maintained.

[0019] After improving the control method of the dosing system according to the above method, the failure probability of the dosing device, the amount of concentrated chemical used, the cost, and the effluent turbidity were compared before and after the improvement. The comparison results are shown in Table 1 below: Table 1. Comparison of data before and after improvement Before improvement 2-3 times / month 129t 172,596 yuan 40-60min 3.5-5.9 NTU Improved 0.3 times / month 35t 46,655 yuan 5min 1.2-2.5 NTU The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An automatic dosing control device for a purification station, characterized in that, The system includes a concentrated chemical tank (1), a water tank (8), a PLC controller, and a plant area (11). A concentrated chemical pipe (101) is connected to the concentrated chemical tank (1), and a diluted chemical tank (5) is connected to the concentrated chemical pipe (101). A water pipe (801) is connected to the diluted chemical tank (5), and the water pipe (801) is connected to the water tank (8). A diluted chemical pipe (501) is connected to the diluted chemical tank (5), and a reaction tank (9) is connected to the diluted chemical pipe (501). A sewage pipe (14) is connected to the reaction tank (9), and an outlet pipe (901) is connected to the reaction tank (9). The outlet pipe (901) is connected to the plant area (11). A spraying pump (15) is installed on the pipe (101), a level gauge (2) is installed on the dilution tank (5), an electric valve (3) is installed on the concentrated drug pipe (101), the dilution drug pipe (501) and the water pipe (801), four metering pumps (6) and a flow meter (7) are installed on the dilution drug pipe (501), a turbidity meter (10) is installed on the sewage pipe (14) and the effluent pipe (901), and a vacuum pump (12) is installed on the dilution tank (5). The level gauge (2), electric valve (3), metering pump (6), flow meter (7), turbidity meter (10), vacuum pump (12) and spraying pump (15) are all electrically connected to the PLC controller. The control method of the control device includes the following steps: S1. Set the upper and lower limits of the liquid level in the PLC controller according to actual needs; the liquid level gauge detects the liquid level of the diluent tank in real time; the threshold of influent turbidity is preset, and the influent turbidity meter detects the turbidity of the influent in real time; the threshold of effluent turbidity is preset, and the effluent turbidity meter detects the turbidity of the effluent in real time; the flow meter detects the flow rate of the diluent solution in real time. S2. Wastewater continuously enters the reaction tank, and the dilute chemical solution is controlled to enter the reaction tank based on the real-time turbidity of the influent. S3. Diluted chemical solution enters the reaction tank. When the liquid level in the dilute chemical tank is ≤ the lower limit of the liquid level, the metering pump is turned off and stops delivering dilute chemical solution to the reaction tank. The dosing pump is started and the proportion of concentrated chemical solution in the dilute chemical tank is adjusted according to the turbidity of the influent to control the entry of concentrated chemical solution into the dilute chemical tank. S4. After the spraying pump stops, the electric valve on the water tank opens, and the amount of water entering the dilution tank is controlled according to the preset concentration ratio until the mixed solution rises to the upper limit of the dilution tank level, at which point the electric valve closes. S5. After the electric valve is closed, the vacuum pump starts and injects compressed air into the dilute drug tank to stir the mixed drug solution; The S6.PLC controller starts the metering pumps to continue adding dilute chemical solution to the reaction tank. The dilute chemical solution treats the wastewater in the reaction tank, and the treated wastewater is then recycled back to the plant for reuse. The specific control method for the metering pumps is as follows: when the effluent turbidity is ≥5.9 NTU, and when 10 NTU ≤ influent turbidity < 30 NTU, the frequency of starting metering pump 1 is 30%; when the effluent turbidity is ≥5.9 NTU, and when 30 NTU ≤ influent turbidity < 100 NTU, the frequency of starting metering pump 1 is 30%, and the frequency of starting metering pump 3 is 2 ...%. When the turbidity of the influent is ≥5.9 NTU and 100 NTU ≤ influent turbidity < 300 NTU, the frequency of the four metering pumps is started at 30%, and the metering pumps issue an alarm. When the turbidity of the effluent is ≥5.9 NTU and 300 NTU ≤ influent turbidity, the PLC automatic control is exited. The actual frequency of the metering pumps is set manually in the PLC according to the actual influent and effluent turbidity until the influent turbidity recovers to below 300 NTU. Then, the frequency of the metering pumps is controlled by the PLC controller again. When the turbidity of the effluent is <5.9 NTU, the current frequency of the metering pumps is maintained.

2. The automatic dosing control device for a purification station according to claim 1, characterized in that, In step S1, the influent turbidity threshold is 10 NTU and the effluent turbidity threshold is 5.9 NTU.

3. The automatic dosing control device for a purification station according to claim 1, characterized in that, In step S2, when the turbidity of the influent changes, the frequency of the metering pump is adjusted to send the diluted drug solution into the reaction tank; when the turbidity of the influent remains unchanged, the frequency of the metering pump is maintained.

4. The automatic dosing control device for a purification station according to claim 1, characterized in that, In step S3, the concentrated chemical is polyferric sulfate. When the influent turbidity range is 10-300 NTU, the proportion of concentrated chemical in the dilution tank is 20%; when the influent turbidity range is above 300 NTU, the proportion of concentrated chemical in the dilution tank is 35%.

5. The automatic dosing control device for a purification station according to claim 1, characterized in that, In step S5, compressed air at a pressure of 0.3 MPa is injected into the dilute drug pool, and the vacuum pump is turned off after 5 minutes.

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