Automatic phosphorus removal agent adding system for sewage treatment plant

Abstract

The utility model discloses an automatic phosphorus removal agent adding system for a sewage treatment plant, which comprises a first concentration meter, a first flow meter, a second concentration meter, a phosphorus removal agent adding device, a dilution tank and a control device, the second concentration meter is installed on a water outlet pipeline of the efficient sedimentation tank, a liquid outlet of the phosphorus removal agent adding device is connected with a first liquid inlet of the dilution tank, a second liquid inlet of the dilution tank is connected to a tap water pipe, and a second flow meter and a first electromagnetic valve are arranged on the tap water pipe. A liquid outlet of the dilution tank is communicated with the efficient sedimentation tank through a first metering pump and a second electromagnetic valve. The control accuracy of the dosage of the phosphorus removal agent is improved, the dosage of the agent is saved, the operation cost of a sewage plant is reduced, and the stability of effluent can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, and specifically designs an automatic dosing system for dephosphorization agent in a sewage treatment plant. Background Art

[0002] As one of the main structures for upgrading sewage treatment plants, high-efficiency sedimentation tanks often add dephosphorization agents at the front end to remove total phosphorus (TP) in sewage to ensure that the effluent meets the standards. Sewage treatment plants often use the addition of liquid dephosphorization agents in high-efficiency sedimentation tanks as the main method of terminal dephosphorization. Among them, polyferric sulfate (PFS) is one of the most widely used liquid dephosphorization agents, and the precise control of its dosage has a direct relationship with the operating cost of the sewage treatment plant.

[0003] However, the existing dosing method usually starts to adjust the dosage when the phosphorus content in the effluent reaches the control value below the standard value. Since there is a certain lag in the dosing reaction, in order to avoid the effluent exceeding the standard due to delayed dosing, excessive dosing is usually required. Although this is a very safe approach from the perspective of process assurance, from the perspective of cost control, this extensive approach will increase operating costs. At the same time, the dosage is basically controlled manually, which is very arbitrary and cannot effectively control the dosage of the agent according to the effluent water quality, resulting in unstable effluent. Utility Model Content

[0004] The utility model provides an automatic dosing system for dephosphorization agent in a sewage treatment plant. By real-time detection of the total phosphorus concentration of effluent, the amount of dephosphorization agent added is dynamically adjusted through feedback. On the premise that the effluent quality of the sewage plant is stable and meets the standards, resource savings can be achieved, and the management of the sewage plant can move towards refinement.

[0005] A dephosphorization agent automatic dosing system for a sewage treatment plant comprises a first concentration meter, a first flow meter, a second concentration meter, a dephosphorization agent dosing device, a dilution tank, and a control device, wherein the first concentration meter and the first flow meter are installed on the water inlet pipe of the high-efficiency sedimentation tank, and the second concentration meter is installed on the water outlet pipe of the high-efficiency sedimentation tank. The liquid outlet of the dephosphorization agent dosing device is connected to the first liquid inlet of the dilution tank, and the second liquid inlet of the dilution tank is connected to a tap water pipe, on which a second flow meter and a first solenoid valve are arranged, and the liquid outlet of the dilution tank is connected to the high-efficiency sedimentation tank through a first metering pump and a second solenoid valve, and the first concentration meter, the first flow meter, the second concentration meter, and the second flow meter are all electrically connected to the input end group of the control device, and the output end group of the control device is electrically connected to the control ends of the dephosphorization agent dosing device, the first metering pump, the first solenoid valve, and the second solenoid valve.

[0006] Furthermore, the dephosphorization agent dosing device includes a first liquid storage tank, a second liquid storage tank and a third liquid storage tank, the liquid outlet of the first liquid storage tank is connected to the first liquid inlet of the dilution tank through a third solenoid valve, a second metering pump, a third flowmeter, the liquid outlet of the second liquid storage tank is connected to the liquid inlet of the third flowmeter through a fourth solenoid valve, a third metering pump, and a fifth solenoid valve, the liquid outlet of the third liquid storage tank is connected to the first liquid inlet of the dilution tank through a sixth solenoid valve, a fourth metering pump, and a fourth flowmeter, the liquid outlet of the third metering pump is also connected to the liquid inlet of the fourth flowmeter through a seventh solenoid valve, the third flowmeter and the fourth flowmeter are both electrically connected to the input end group of the control device, and the third solenoid valve, the second metering pump, the fourth solenoid valve, the third metering pump, the fifth solenoid valve, the sixth solenoid valve, the fourth metering pump, and the seventh solenoid valve are all connected to the output end group of the control device.

[0007] Furthermore, liquid level sensors are provided in the first liquid storage tank, the second liquid storage tank and the third liquid storage tank.

[0008] Furthermore, the control device includes a PLC controller, a first frequency converter, a second frequency converter, a third frequency converter, and a fourth frequency converter. The first concentration meter, the first flow meter, the second concentration meter, the second flow meter, the third flow meter, and the fourth flow meter are all electrically connected to the signal input terminal group of the PLC controller. The control signal output terminal group of the PLC controller is respectively connected one-to-one with the control signal input terminals of the first metering pump, the second metering pump, the third metering pump, and the fourth metering pump through the first frequency converter, the second frequency converter, the third frequency converter, and the fourth frequency converter. The control signal output terminal group of the PLC controller is also electrically connected to the control signal input terminals of the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, and the seventh solenoid valve.

[0009] Furthermore, a display module is connected to the PLC controller.

[0010] Furthermore, the PLC controller is also connected to a communication module for communicating with a background control terminal.

[0011] Furthermore, a medicine mixing mechanism is provided at the bottom of the dilution tank, and a liquid inlet of the medicine mixing mechanism is connected to the water outlet end of the tap water pipe.

[0012] Furthermore, the medicine mixing mechanism comprises a liquid mixing disk, a liquid inlet hole provided at the center of the liquid mixing disk is detachably connected to the water outlet end of the tap water pipe, and a plurality of liquid outlet holes are evenly provided around the liquid inlet hole.

[0013] Beneficial effects:

[0014] 1. First, send the dephosphorus agent of known concentration in the storage tank into the dilution tank and add tap water for dilution. Then, collect the sewage inlet flow rate and phosphorus content in the inlet water, and then input the control device to control the work of the metering pump to send the dephosphorus agent in the dilution tank to the high-efficiency sedimentation tank for phosphorus removal treatment. At the same time, collect the phosphorus content in the sewage effluent, and feedback and adjust the dosage of the dephosphorus agent, thereby improving the accuracy of the dephosphorus agent dosage control, effectively saving the amount of agent added, reducing the operating cost of the sewage treatment plant, and increasing the stability of the effluent, which solves the problem of lag between the addition of drugs and the effluent water quality reaching the standard to the greatest extent, and makes the sewage treatment plant management move towards refinement.

[0015] 2. The mixing mechanism can mix the phosphorus removal agent and tap water simply, efficiently and evenly.

[0016] 3. The PLC controller communicates with the background control terminal through the communication module, and can upload and store the operating data of the entire system in a timely manner, which helps to remind the staff to conduct remote monitoring and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the pipeline structure of the utility model;

[0018] Figure 2 It is a schematic diagram of the piping structure of the dephosphorization agent dosing device;

[0019] Figure 3 It is the control principle block diagram of the utility model;

[0020] Figure 4 It is a schematic diagram of the installation position of the drug mixing mechanism;

[0021] Figure 5 It is a structural diagram of a drug mixing mechanism. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with embodiments and drawings.

[0023] like Figure 1-Figure 2As shown, a dephosphorization agent automatic dosing system for a sewage treatment plant comprises a first concentration meter 9, a first flow meter 10, a second concentration meter 12, a dephosphorization agent dosing device 1, a dilution tank 5, and a control device 6. The first concentration meter 9 and the first flow meter 10 are installed on the water inlet pipe of the high-efficiency sedimentation tank 11, and the second concentration meter 12 is installed on the water outlet pipe of the high-efficiency sedimentation tank 11. The liquid outlet of the dephosphorization agent dosing device 1 is connected to the first liquid inlet of the dilution tank 5, and the second liquid inlet of the dilution tank 5 is connected to the tap water pipe 4. The second flow meter 3 and the first solenoid valve 2 are arranged on the tap water pipe 4. The liquid outlet of the dilution tank 5 is connected to the high-efficiency sedimentation tank 11 through the first metering pump 7 and the second solenoid valve 8. The first concentration meter 9, the first flow meter 10, the second concentration meter 12, and the second flow meter 3 are all electrically connected to the input end group of the control device 6, and the output end group of the control device 6 is electrically connected to the control ends of the dephosphorization agent dosing device 1, the first metering pump 7, the first solenoid valve 2, and the second solenoid valve 8.

[0024] like Figure 2 As shown, the dephosphorization agent dosing device 1 includes a first liquid storage tank 101, a second liquid storage tank 102 and a third liquid storage tank 103. The liquid outlet of the first liquid storage tank 101 is connected to the first liquid inlet of the dilution tank 5 through a third solenoid valve 104, a second metering pump 105, and a third flowmeter 107. The liquid outlet of the second liquid storage tank 102 is connected to the liquid inlet of the third flowmeter 107 through a fourth solenoid valve 108, a third metering pump 109, and a fifth solenoid valve 1010. The liquid outlet of the third liquid storage tank 103 is connected to the first liquid inlet of the dilution tank 5 through a sixth solenoid valve 1011, a fourth metering pump 1012, and a fourth flowmeter 1013. The liquid outlet of the third metering pump 109 is also connected to the liquid inlet of the fourth flow meter 1013 through the seventh solenoid valve 1014, the third flow meter 107 and the fourth flow meter 1013 are both electrically connected to the input end group of the control device 6, the third solenoid valve 104, the second metering pump 105, the fourth solenoid valve 108, the third metering pump 109, the fifth solenoid valve 1010, the sixth solenoid valve 1011, the fourth metering pump 1012, and the seventh solenoid valve 1014 are all connected to the output end group of the control device 6, and liquid level sensors 106 are provided in the first liquid storage tank 101, the second liquid storage tank 102 and the third liquid storage tank 103.

[0025] The dephosphorization agent dosing device 1 adopting the above-mentioned structure can not only form two main and standby modes for adding dephosphorization agent, but also can adjust the dephosphorization agent supply source in real time according to the content of liquid dephosphorization agent in the first liquid storage tank 101, the second liquid storage tank 102 and the third liquid storage tank 103, avoiding shutdown for replenishment, thereby helping to achieve all-weather continuous sewage treatment.

[0026] Preferably, the second metering pump 105, the third metering pump 109, and the fourth metering pump 1012 all use mechanical diaphragm metering pumps, and the model is Milton Roy GM0330PP4MNN. The mechanical diaphragm metering pump consists of two major parts: the drive end and the hydraulic end. The output flow depends on the stroke speed of the drive end, the size of the hydraulic end parts, and the stroke length. Whether the pump is in operation or stopped, the stroke length can be changed by adjusting the stroke adjustment handle, and the drive end works according to the principle of a variable eccentric mechanism. The diaphragm assembly and the connecting rod are mechanically connected and perform linear reciprocating motion simultaneously with the connecting rod. During the suction stroke, the diaphragm begins to move backward, and the pressure in the pump head decreases. When the pressure in the pump head is lower than the pressure in the suction line, the suction port one-way valve ball is "pushed open" upward, and the medium in the inlet line enters the pump head chamber. When the suction stroke ends, the diaphragm movement stops instantly, the pressure in the pump head is the same as the pressure in the inlet line, and the suction port one-way valve ball is reset.

[0027] See attached Figure 3 The control device 6 includes a PLC controller, a first frequency converter, a second frequency converter, a third frequency converter, and a fourth frequency converter. The first concentration meter 9, the first flowmeter 10, the second concentration meter 12, the second flowmeter 3, the third flowmeter 107 and the fourth flowmeter 1013 are all electrically connected to the signal input terminal group of the PLC controller. The control signal output terminal group of the PLC controller is respectively connected to the control signal input terminals of the first metering pump 7, the second metering pump 105, the third metering pump 109 and the fourth metering pump 1012 through the first frequency converter, the second frequency converter, the third frequency converter, the fourth frequency converter, and one-to-one correspondence. The control signal output terminal group of the PLC controller is also electrically connected to the control signal input terminals of the first solenoid valve 2, the second solenoid valve 8, the third solenoid valve 104, the fourth solenoid valve 108, the fifth solenoid valve 1010, the sixth solenoid valve 1011 and the seventh solenoid valve 1014.

[0028] The frequency converter is used to control the frequency of each metering pump, so that the dosage of the dephosphorization agent can be controlled more accurately.

[0029] In this example, a display module is also connected to the PLC controller to display the phosphorus content in the sewage collected by the concentration meter, the sewage and dephosphorization agent flow rates used by the flow meter, the working parameters of each metering pump and the opening and closing status of each solenoid valve.

[0030] In this example, the PLC controller is also connected to a communication module for communicating with the background control terminal, so that the operating data of the entire system can be uploaded and stored in time, which helps to remind the staff to conduct remote monitoring and control, which can not only ensure the security of the operating data, but also improve the convenience of system control.

[0031] like Figure 4 and Figure 5As shown, a medicine mixing mechanism 13 is provided at the bottom of the dilution tank 5, and the liquid inlet of the medicine mixing mechanism 13 is connected to the water outlet of the tap water pipe 4. Specifically, the medicine mixing mechanism 13 includes a mixing plate 131, a liquid inlet hole 132 provided at the center of the mixing plate 131, and liquid outlet holes 133 uniformly provided on the mixing plate around the liquid inlet hole 132. The liquid inlet hole 132 is detachably connected to the water outlet of the tap water pipe 4, and the liquid inlet hole 132 is connected to the liquid outlet hole 133 through a liquid infusion channel. The tap water is dispersed through the multiple liquid outlet holes 133 and mixed with the dephosphorizing agent, so that the dephosphorizing agent and the tap water are efficiently and uniformly mixed.

[0032] Working principle:

[0033] First, the high-concentration dephosphorus agent with a known concentration in the dephosphorus agent dosing device 1 is mixed with tap water in a dilution tank to obtain a dephosphorus agent with a desired concentration;

[0034] Then, the phosphorus content in the sewage and the flow rate of the sewage in the water inlet pipe of the high-efficiency sedimentation tank 11 are respectively collected in real time by the first concentration meter 9 and the first flow meter 10, so as to determine the dosage of the dephosphorization agent, and control the first metering pump 7 and the second solenoid valve 8 to send the required dosage of the dephosphorization agent into the high-efficiency sedimentation tank 11 to perform dephosphorization treatment on the sewage;

[0035] Afterwards, the phosphorus content in the sewage in the outlet pipe of the high-efficiency sedimentation tank 11 is collected by the second concentration meter 12, and fed back to the control device 6, which automatically performs feedback control on the dosage of the dephosphorization agent, thereby improving the accuracy of the dephosphorization agent dosage control, effectively saving the amount of agent added, reducing the operating cost of the sewage treatment plant, and increasing the stability of the effluent, solving the problem of the lag between the addition of drugs and the compliance of the effluent water quality to the greatest extent, and making the sewage treatment plant management move towards refinement.

[0036] In the above process, the PLC controller controls the frequency of each metering pump through the frequency converter, so that the dosage control of the dephosphorization agent is more accurate.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make a variety of similar expressions without violating the purpose and claims of the present invention, and such changes fall within the scope of protection of the present invention.

Claims

1. An automatic dosing system for phosphorus removal in a sewage treatment plant, characterized in that: The invention comprises a first concentration meter (9), a first flow meter (10), a second concentration meter (12), a dephosphorization agent dosing device (1), a dilution tank (5), and a control device (6), wherein the first concentration meter (9) and the first flow meter (10) are installed on the water inlet pipeline of the high-efficiency sedimentation tank (11), the second concentration meter (12) is installed on the water outlet pipeline of the high-efficiency sedimentation tank (11), the liquid outlet of the dephosphorization agent dosing device (1) is connected to the first liquid inlet of the dilution tank (5), the second liquid inlet of the dilution tank (5) is connected to the tap water pipe (4), and the tap water pipe (4) is connected to the second liquid inlet of the dilution tank (5). ) is provided with a second flow meter (3) and a first electromagnetic valve (2); the liquid outlet of the dilution tank (5) is connected to the high-efficiency sedimentation tank (11) via the first metering pump (7), the second electromagnetic valve (8); the first concentration meter (9), the first flow meter (10), the second concentration meter (12), and the second flow meter (3) are all electrically connected to the input end group of the control device (6); the output end group of the control device (6) is electrically connected to the control ends of the dephosphorization agent dosing device (1), the first metering pump (7), the first electromagnetic valve (2), and the second electromagnetic valve (8); A medicine mixing mechanism (13) is provided at the bottom of the dilution tank (5), and a liquid inlet of the medicine mixing mechanism (13) is connected to a water outlet of the tap water pipe (4); The medicine mixing mechanism (13) comprises a liquid mixing disk (131), a liquid inlet hole (132) arranged at the center of the liquid mixing disk (131), and liquid outlet holes (133) evenly arranged on the liquid mixing disk around the liquid inlet hole (132); the liquid inlet hole (132) is detachably connected to the water outlet end of the tap water pipe (4); and the liquid inlet hole (132) and the liquid outlet hole (133) are connected via a liquid infusion channel.

2. The automatic dosing system for dephosphorization agent in sewage treatment plant according to claim 1 is characterized in that: The dephosphorization agent dosing device (1) comprises a first liquid storage tank (101), a second liquid storage tank (102) and a third liquid storage tank (103); the liquid outlet of the first liquid storage tank (101) is connected to the first liquid inlet of the dilution tank (5) via a third solenoid valve (104), a second metering pump (105) and a third flow meter (107); the liquid outlet of the second liquid storage tank (102) is connected to the liquid inlet of the third flow meter (107) via a fourth solenoid valve (108), a third metering pump (109) and a fifth solenoid valve (1010); the liquid outlet of the third liquid storage tank (103) is connected to the liquid inlet of the third flow meter (107) via a sixth solenoid valve (1011), a fourth metering pump (1012) and a fourth flow meter (107). The meter (1013) is connected to the first liquid inlet of the dilution tank (5); the liquid outlet of the third metering pump (109) is also connected to the liquid inlet of the fourth flow meter (1013) via the seventh solenoid valve (1014); the third flow meter (107) and the fourth flow meter (1013) are both electrically connected to the input end group of the control device (6); the third solenoid valve (104), the second metering pump (105), the fourth solenoid valve (108), the third metering pump (109), the fifth solenoid valve (1010), the sixth solenoid valve (1011), the fourth metering pump (1012), and the seventh solenoid valve (1014) are all connected to the output end group of the control device (6).

3. The automatic dosing system for dephosphorization agent in sewage treatment plant according to claim 2 is characterized in that: Liquid level sensors (106) are provided in the first liquid storage tank (101), the second liquid storage tank (102) and the third liquid storage tank (103).

4. The automatic dosing system for dephosphorization agent in sewage treatment plant according to claim 2 is characterized in that: The second metering pump (105), the third metering pump (109), and the fourth metering pump (1012) are all mechanical diaphragm metering pumps.

5. The automatic dosing system for dephosphorization agent in a sewage treatment plant according to claim 2, 3 or 4, characterized in that: The control device (6) comprises a PLC controller, a first frequency converter, a second frequency converter, a third frequency converter and a fourth frequency converter; the first concentration meter (9), the first flow meter (10), the second concentration meter (12), the second flow meter (3), the third flow meter (107) and the fourth flow meter (1013) are all electrically connected to a signal input terminal group of the PLC controller; the control signal output terminal group of the PLC controller is respectively connected to the control signal input terminals of the first metering pump (7), the second metering pump (105), the third metering pump (109) and the fourth metering pump (1012) through the first frequency converter, the second frequency converter, the third frequency converter and the fourth frequency converter in a one-to-one correspondence; the control signal output terminal group of the PLC controller is also electrically connected to the control signal input terminals of the first solenoid valve (2), the second solenoid valve (8), the third solenoid valve (104), the fourth solenoid valve (108), the fifth solenoid valve (1010), the sixth solenoid valve (1011) and the seventh solenoid valve (1014).

6. The automatic dosing system for dephosphorization agent in a sewage treatment plant according to claim 5, characterized in that: The PLC controller is also connected with a display module.

7. The automatic dosing system for dephosphorization agent in a sewage treatment plant according to claim 5, characterized in that: The PLC controller is also connected to a communication module for communicating with a background control terminal.

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