An automatic controlled breakpoint chlorination system and process

Abstract

The present application discloses an automated breakpoint chlorination system and process. By using pH electrodes to feedback the environment during the reaction in each device and combining with the calculation device in the control device, central control management is carried out to form a closed-loop control system with feedback control. A calculation method for online water quality data collection, analysis and feedback is constructed, and the calculation results are directly applied to real-time control of the dosing equipment. It can avoid the excessive situation of instantaneous overdose of chemical agents, optimize the resource allocation, and also expand the application fields and effects of the breakpoint chlorination technology.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly to a breakpoint chlorination system and process for automatic control. Background Art

[0002] For sewage, such as municipal sewage and industrial sewage, ammonia nitrogen is one of the main pollutants. At present, the methods for treating ammonia nitrogen pollutants in sewage mainly include biological denitrification, alkaline stripping, breakpoint chlorination oxidation, etc. Among them, breakpoint chlorination is considered to be the most common ammonia nitrogen removal process in the advanced sewage treatment process stage, but this process has problems such as difficult precise control, high operating cost, unstable ammonia nitrogen removal effect, and residual chlorine.

[0003] At present, there are two methods applied to the control of the breakpoint chlorination process. One is to obtain the ammonia nitrogen concentration and residual chlorine concentration in the influent and effluent and inside the reactor through analysis, and then adjust the dosing amount through equipment or manually. Due to adverse factors such as poor timeliness of sample analysis, inaccurate dosing amount calculated solely from the ammonia nitrogen concentration, and manual operation errors, the dosing amount cannot be accurately controlled. The other is to use ORP to control the dosing. Because the OPR electrode is not sensitive to the reagent concentration and can only display the reaction end point, the dosing amount cannot be truly controlled; moreover, the ORP electrode is relatively easy to damage and difficult to accurately calibrate on site, which leads to the inability of many actual projects to operate normally in the end. On the other hand, the active chlorine required for breakpoint chlorination is mainly hypochlorite and chlorine gas, both of which are toxic substances harmful to human health. In actual engineering operations, they may have an adverse impact on operating personnel and the surrounding environment, and thus become a safety hazard in the process. Summary of the Invention

[0004] In order to solve the above technical problems, the present application discloses an automatic control breakpoint chlorination system and process, which transforms the traditional breakpoint chlorination equipment, manages the process through a closed-loop control system, accurately manages the dosing and drug delivery control parameters, improves the operation efficiency of the breakpoint chlorination system, and reduces the operating cost.

[0005] To achieve this purpose, the present application provides an automatic control breakpoint chlorination system, including an adjustment device, a rapid mixing device, a breakpoint reaction device, a control device, and a dosing device;

[0006] The adjustment device, the rapid mixing device, and the breakpoint reaction device are connected in sequence; the dosing device is respectively connected to the adjustment device, the rapid mixing device, and the breakpoint reaction device; the adjustment device is provided with a first pH electrode, the rapid mixing device is provided with a second pH electrode, and the breakpoint reaction device is provided with a third pH electrode;

[0007] The control device is used to respectively obtain the pH value measurement data collected by the first pH electrode, the second pH electrode and the third pH electrode, perform dosing control calculation based on the pH value measurement data to obtain dosing control parameters; based on the dosing control parameters, control the dosing of the dosing device so that the pH measurement data of the regulating device, the rapid mixing device and the breakpoint reaction device meet their respective preset conditions;

[0008] The control device performs closed-loop control on the dosing control parameters of the dosing device according to the pH value measurement data of the regulating device, the rapid mixing device and the breakpoint reaction device.

[0009] Preferably, the dosing device includes one or more of an oxidant dosing device, an acidic dosing device, and an alkaline dosing device.

[0010] Preferably, the dosing device includes one or more of a dosing pump, a frequency converter, and a flow controller.

[0011] Preferably, the control device is used to perform PID calculation on the dosage based on the pH value measurement data and the target pH value to obtain the dosing control parameters;

[0012] The electrode sampling time of the first pH electrode, the second pH electrode and the third pH electrode is to sample once every 30 - 120 ms, and the sampling time is determined according to the deviation between the pH electrode measurement value and the corresponding target pH value;

[0013] Preferably, the PID calculation device is provided with a data model module, and the data model module includes a data rolling cumulative module and / or a specific algorithm for continuously correcting the operating parameters of the system;

[0014] The data fed back by the electrode is the measurement value, and the output value of the PID control device is the dosing control parameter of the dosing device: perform calculus calculation on the P, I, and D parts of the output value to obtain the final dosing control parameter and control the dosing of the dosing device.

[0015] Preferably, the dosing control parameters include the dosing amount of acidic substances, the dosing amount of alkaline substances or the dosing amount of oxidant substances;

[0016] The control device is used to control the dosing amount of the acidic dosing device and / or the dosing amount of the alkaline dosing device based on the dosing control parameter corresponding to the regulating device so that the pH measurement value in the regulating device meets the target pH value of the regulating device;

[0017] The control device is used to control the chemical dosing amount of the oxidant dosing device based on the chemical dosing control parameters corresponding to the adjustment device, so that the pH measurement value in the rapid mixing device meets the target pH value of the rapid mixing device;

[0018] The control device is used to control the chemical dosing amount of the acidic dosing device and / or the alkaline dosing device based on the chemical dosing control parameters corresponding to the breakpoint reaction device, so that the pH measurement value in the breakpoint reaction device meets the target pH value of the breakpoint reaction device.

[0019] Preferably, the dosing device includes a reducing agent dosing device, the system further includes a reduction device, the reduction device is communicated with the breakpoint reaction device, and the control device and the reducing agent dosing device are respectively connected to the reduction device.

[0020] Preferably, the reduction device further includes a first ORP electrode, which is used to measure the ORP measurement value of the reduction device and send it to the control device, and the ORP measurement value reflects the residual chlorine content in the reduction device.

[0021] The control device is used to perform chemical dosing control calculation based on the ORP measurement value of the reduction device to obtain the chemical dosing control parameters corresponding to the reduction device; and based on the chemical dosing control parameters corresponding to the reduction device, control the addition of the reducing agent to the reduction device by the reducing agent dosing device, so that the ORP measurement value of the reduction device meets the preset conditions corresponding to the reduction device.

[0022] On the other hand, the present application also provides an automated control breakpoint chlorination process, which is applied to an automated control breakpoint chlorination system as described above. The process includes the following steps:

[0023] The collected sewage is introduced into the adjustment device, and after sewage treatment in the adjustment device, it is sequentially introduced into the rapid mixing device and the breakpoint reaction device for sewage treatment;

[0024] During the sewage treatment process, the pH value measurement data of the adjustment device, the rapid mixing device, and the breakpoint reaction device are respectively collected through the first pH electrode, the second pH electrode, and the third pH electrode;

[0025] The control device performs chemical dosing control calculation based on the pH value measurement data to obtain chemical dosing control parameters; and based on the chemical dosing control parameters, controls the chemical dosing of the dosing device, so that the pH measurement data of the adjustment device, the rapid mixing device, and the breakpoint reaction device meet the respective preset conditions.

[0026] Preferably, the sewage treatment process is:

[0027] S1: Feed the collected sewage into the adjustment device, and monitor the pH value of the adjustment device in real time through the first pH electrode. The control device performs dosing control calculations based on the measured value fed back by the first pH electrode, generates control parameters for the dosing device connected to the adjustment device. After the sewage is treated by the adjustment device, the first pretreated sewage is obtained;

[0028] S2: Feed the first pretreated sewage into the rapid mixing device, and monitor the pH value of the rapid mixing device in real time through the second pH electrode. The control device performs dosing control calculations based on the measured value fed back by the second pH electrode, generates control parameters for the dosing device connected to the rapid mixing device. After the sewage is treated by the rapid mixing device, the second pretreated sewage is obtained;

[0029] S3: Feed the second pretreated sewage into the breakpoint reaction device. The control device generates control parameters for the dosing device connected to the breakpoint reaction device based on the data monitored in real time by the third pH electrode in the breakpoint reaction device. After the second pretreated sewage is treated by the breakpoint reaction device, the pre-discharge sewage is obtained.

[0030] Preferably, the process further includes:

[0031] Feed the sewage discharged from the breakpoint reaction device into the reduction device, and collect the ORP measured value of the reduction device in real time according to the first ORP electrode in the reduction device;

[0032] The control device performs dosing control calculations based on the ORP measured value of the reduction device, obtains the dosing control parameters corresponding to the reduction device; and based on the dosing control parameters corresponding to the reduction device, controls the addition of the reducing agent to the reduction device by the reducing agent dosing device, so that the ORP measured value of the reduction device meets the preset conditions corresponding to the reduction device;

[0033] If the sewage after reduction treatment in the reduction device meets the discharge standard, it is discharged from the breakpoint chlorination system;

[0034] If it does not meet the discharge standard, the sewage after reduction treatment in the reduction device is returned to the adjustment device for cyclic treatment.

[0035] Adopting the above technical solution, an automated control breakpoint chlorination system and its process provided by the present application have the following beneficial effects:

[0036] The present application discloses an automated controlled breakpoint chlorination system and process. In order to precisely manage the chemical dosing and dosing control parameters and improve the operation efficiency of the breakpoint chlorination system, the present application proposes to feedback the environment during the reaction in each device through a pH electrode, and combine with the calculation device in the control device to perform central control management, forming a closed-loop control system with feedback type PID control. This system can control the dosing control parameters such as dosing frequency and dosing flow rate according to real-time data, achieve precise control of chemical dosing and the amount of chemical added in the system of the present application, and further achieve automatic adaptation to the water quality changes in the regulating device, rapid mixing device, and breakpoint reaction device.

[0037] A data model module is newly added in the control device to collect and analyze the past data of the system and automatically correct the operation parameters of the control system, construct a calculation method for online water quality data collection, analysis and feedback, and directly apply the calculation results to the real-time control of the chemical dosing equipment. The real-time feedback of data and the combined control of the calculation device can promptly return the reaction in each device to the equilibrium state, making the reaction in each device in a stable state.

[0038] The present application also monitors the online data of the discharged water quality in real time, sets a reduction device, and uses the control device to control the dosing dose of the reducing agent dosing device to remove the excess residual chlorine in the pre-discharged sewage and ensure that the drained water quality meets the standards. If the situation of unqualified water quality is monitored, the sewage will be refluxed back into the system for repeated treatment.

[0039] Since the system process of the present application combines the contact oxidation technology and the stripping technology, inside the system, it can achieve automatic adaptation of water quality changes and chemical dosing, achieve precise control, avoid the excessive situation of instantaneous overdose of chemical dosing, optimize the resource allocation; the result of automatic adaptation also enables the entire process to achieve unmanned management, avoids the adverse effects of harmful chemicals on the operating personnel and the surrounding environment, and eliminates the potential safety hazards in the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific implementation and effects of the automated controlled breakpoint chlorination system and process of the present application, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 It is a schematic diagram of an automated controlled breakpoint chlorination system of the present application.

[0042] Figure 2 It is a schematic diagram of the process flow of an automated controlled breakpoint chlorination of the present application

[0043] Among them, the reference numerals in the drawings correspond to:

[0044] 1 - First pH electrode, 3 - Second pH electrode, 5 - Third pH electrode; 2 - Acidic and alkaline chemical dosing device; 4 - Oxidant chemical dosing device; 7 - First ORP electrode; 8 - Reductant chemical dosing device. Detailed implementation manners

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts belong to the scope of protection of the present application.

[0046] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present application. The content of the present invention can be more easily understood by referring to the following detailed description of the preferred implementation methods of the present invention and the included embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. In case of conflict, the definitions in this specification shall prevail.

[0047] For the purposes of the following detailed description, it should be understood that the present invention may employ various alternative variations and step sequences, unless explicitly specified to the contrary. In addition, except in any operating examples, or otherwise indicated, all numbers representing the amounts of ingredients used in the specification and claims should be understood to be modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0048] Although the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0049] When a numerical range is disclosed in this document, the above range is considered continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed in this document should be understood to include any and all sub-ranges subsumed therein. For example, a specified range from "1 to 10" should be considered to include any and all sub-ranges between the minimum value 1 and the maximum value 10. Exemplary sub-ranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0050] In the prior art, ORP control is mostly used for dosing, but because the OPR electrode is not sensitive to the reagent concentration and can only display the reaction end point. The time for the ammonia nitrogen monitor to obtain the monitoring result is very slow, and the monitoring result of the water quality in the system lags seriously; in the actual reaction, in addition to the ammonia nitrogen in the water body participating in the reaction, other substances will also participate in the breakpoint chlorination reaction, and the concentration of ammonia nitrogen cannot truly reflect the water quality. Therefore, using the above detection means, the dosing amount cannot be truly controlled in the breakpoint chlorination reaction.

[0051] For this reason, the present application provides an automated control breakpoint chlorination system and its process.

[0052] Refer to Figure 1 , Figure 1 is a schematic diagram of an automated control breakpoint chlorination system. The system includes an adjustment device, a rapid mixing device, a breakpoint reaction device, a control device, and a dosing device.

[0053] The adjustment device, the rapid mixing device, and the breakpoint reaction device are connected in sequence; the dosing device is respectively connected to the adjustment device, the rapid mixing device, and the breakpoint reaction device; the adjustment device is provided with a first pH electrode, the rapid mixing device is provided with a second pH electrode, the breakpoint reaction device is provided with a third pH electrode, and the control device is used to respectively obtain the pH value measurement data collected by the first pH electrode, the second pH electrode, and the third pH electrode, perform dosing control calculations based on the pH value measurement data, and obtain dosing control parameters; based on the dosing control parameters, control the dosing of the dosing device to make the pH measurement data of the adjustment device, the rapid mixing device, and the breakpoint reaction device meet their respective preset conditions. The electrode sampling time is once every 30 - 120 ms.

[0054] The pH value measurement data collected by the pH electrode represents the sufficiency of the dosing amount and can be used as a control index for the breakpoint chlorination reaction. In some embodiments, the electrode sampling time varies according to the deviation value between the pH value measurement data and the preset adjustment, and the variation range is once every 40 - 100 ms.

[0055] The chemical dosing device includes one or more of an oxidant dosing device, an acidic dosing device, and an alkaline dosing device.

[0056] In some embodiments, the control device is used to perform PID calculation for the chemical dosage based on the pH measurement data and the target pH value, and obtain the chemical dosing control parameters. The chemical dosing control parameters include the dosage of acidic substances, the dosage of alkaline substances, or the dosage of oxidant substances.

[0057] In some embodiments, the chemical dosing control parameters include one or more of the dosing frequency and the dosing flow rate, and are used to control the chemical dosage of the chemical dosing device.

[0058] The acidic dosing device contains one or more of hydrochloric acid, sulfuric acid, and carbonic acid;

[0059] The alkaline dosing device contains one or more of sodium hydroxide and potassium hydroxide;

[0060] The oxidant dosing device contains one or more of hypochlorous acid and hypochlorite;

[0061] In some embodiments, the chemical dosing device includes one or more of a chemical dosing pump, a frequency converter, and a flow controller. Among them, the chemical dosing pump is a variable-frequency pump and is controlled by the variable-frequency data in the control signal.

[0062] Thus, according to the actual working conditions of the sewage, the target pH value of the regulating device is set in the control device. According to the pH measurement data collected in real time by the first pH electrode, based on each measurement data, chemical dosing control calculation is performed to obtain the chemical dosing control parameters of the acidic and alkaline dosing devices connected to the regulating device; based on the chemical dosing control parameters, control the chemical dosing control parameters such as the dosing frequency, dosing flow rate, and dosing duration of the chemical dosing device, so that the pH measurement data of the regulating device meets the corresponding preset conditions.

[0063] In some embodiments, the pH preset condition range of the regulating device is 10 to 6; specifically, the preset conditions of the regulating device are 9.25, 8.8, 8.3, and 7.2.

[0064] In the rapid mixing tank, the pH measurement data collected in real time by the second pH electrode is converted into a digital signal and transmitted to the control device to generate water quality data. The target pH value of the rapid mixing device is set in the control device. The control device calculates the breakpoint chlorination dosing dose based on the water quality data fed back in real time by the rapid mixing tank, and generates a control signal for the chemical dosing control parameters, which is transmitted to the oxidant dosing device. The oxidant dosing device adjusts the dosing pump frequency, dosing flow rate, and dosing time according to the control signal.

[0065] In some embodiments, the pH preset condition range of the rapid mixing device is 7 to 10; specifically, the preset conditions of the rapid mixing device are 7.25, 7.6, 8.4, 8.8, 9.2, 9.5, 9.8.

[0066] The third pH electrode collects the pH value of the breakpoint oxidation device in real time to monitor the progress of the oxidation reaction in the breakpoint oxidation device. Set the target pH value of the breakpoint oxidation device in the control device. Based on the pH value measurement data each time, the control device performs dosing control calculations for acidic and alkaline substances to obtain the dosing control parameters of the acidic and alkaline dosing devices connected to the breakpoint oxidation device; based on the dosing control parameters, control dosing control parameters such as the dosing frequency, dosing flow rate, and dosing duration of the dosing device, so that the pH measurement data of the breakpoint oxidation device meets the corresponding preset conditions.

[0067] In some embodiments, the pH preset condition range of the breakpoint oxidation device is 6 to 9; specifically, the preset conditions of the breakpoint oxidation device are 6.8, 7.0, 7.2, 7.8, 8.2, 8.8.

[0068] In some embodiments, the PID method is adopted in the control device to operate the parameters of the closed-loop control system. The data fed back by the electrode is used as the measured value, and the output value of the PID control device is the dosing control parameter of the dosing device: perform calculus calculations on the P, I, and D parts of the output value to obtain the final control parameter of the dosing device and control the dosing of the dosing device.

[0069] In some embodiments, the system further includes a reduction device, and the reduction device is connected to the breakpoint reaction device. The reduction device includes one or more of a reduction tank, a control device, and a reducing agent dosing device.

[0070] Specifically, the control device further includes a first ORP electrode. The first ORP electrode is arranged in the reduction device to measure the ORP measured value of the reduction device. The electrical signal of the first ORP electrode is converted into a digital signal and transmitted to the control device to generate the water quality data in the reduction device. The control device automatically generates a control signal according to the water quality data and conducts it to the reducing agent dosing device. The dosing device injects a corresponding dose of reducing agent into the reduction tank according to the control signal to react the reducing agent with the excess residual chlorine in the sewage, ensuring that the drained water quality meets the standard. If the water quality does not meet the standard, the water in the drainage tank will flow back to the regulating device or the collection device before the regulating device for cyclic treatment. After the sewage in the reduction device is treated by reduction and meets the discharge standard, it is discharged from the breakpoint chlorination system.

[0071] In some embodiments, the preset condition range of the oxidation-reduction potential of the reduction device is 160 to 250 mV; specifically, the preset conditions of the reduction device are 180 mV and 200 mV.

[0072] In some embodiments, an on-line ammonia nitrogen electrode and a residual chlorine electrode are respectively added at the inlet and outlet of the system. The data monitored by the electrodes is summarized in real time into the control device to assist in guiding the operation of the system.

[0073] An automated breakpoint chlorination process provided by the present application is applied to an automated breakpoint chlorination system as described above. As shown in the appendix Figure 2 It includes the following steps:

[0074] S1: The collected sewage is introduced into the adjustment device, and sewage treatment is carried out in the adjustment device. The pH value in the pre-adjustment device is monitored in real time by the first pH electrode. The pH electrode feeds back the data to the control device, and the control device generates control parameters for the dosing device, thereby controlling the dosing control parameters of the acidic dosing pump and the alkaline dosing pump. After the sewage is treated by the adjustment device, the first pretreated sewage is obtained.

[0075] Specifically, the dosing control parameters can be dosing frequency, dosing flow rate, dosing time, etc.

[0076] S2: The first pretreated sewage is introduced into the rapid mixing device. The pH value of the rapid mixing device is monitored in real time by the second pH electrode. The control device performs dosing control calculation according to the measured value fed back by the second pH electrode and generates control parameters for the oxidant dosing device. After the sewage is treated by the rapid mixing device, the second pretreated sewage is obtained;

[0077] Specifically, the dosing control parameters can be dosing frequency, dosing flow rate, dosing time, etc.

[0078] S3: The second pretreated sewage is introduced into the breakpoint reaction device, and this device will provide sufficient reaction time for the breakpoint reaction. In the breakpoint reaction device, the pH of the sewage water body continuously decreases. The control device generates control parameters for the dosing device connected to the breakpoint reaction device according to the data monitored in real time by the third pH electrode in the breakpoint reaction device. After the second pretreated sewage is treated by the breakpoint reaction device, the pre-discharge sewage is obtained. Specifically, the dosing devices connected to the breakpoint reaction device are acidic and alkaline dosing devices.

[0079] In some embodiments, the residual chlorine content of the pre-discharge sewage is relatively high and does not meet the discharge standard. The pre-discharge sewage is introduced into the reduction device. The control device generates control parameters for the reduction dosing device connected to the reduction device according to the data monitored in real time by the first ORP electrode in the reduction device, thereby controlling the dosing frequency and dosing flow rate of the reduction dosing device. If the pre-discharge sewage does not meet the discharge standard after reduction treatment, it will be returned to S1 for cyclic treatment.

[0080] In some embodiments, an on-line ammonia nitrogen electrode and a residual chlorine electrode are respectively added at the system inlet and outlet, that is, before step S1 and after step S3. The data monitored by the electrodes is summarized in real time into the computing device to assist in guiding the process operation.

[0081] To better illustrate the beneficial effects of the present application, specific embodiments will be described below.

[0082] Embodiment 1:

[0083] After collecting domestic sewage, it is introduced into the regulating device. The set value of pH in the regulating tank, that is, the target pH value, is set to 8.8. When the deviation between the measured value of pH electrode 1 and the set value > 5, it is set to test once every 100 ms; when the deviation between the measured value of the pH electrode and the set value < 5, it is set to test once every 40 ms. The test signal is transmitted to the PLC control device, and the PID computing device respectively generates the frequencies and dosages of acid, alkali, and oxidant addition, and transmits them to the corresponding frequency converters to control the variable-frequency acid and alkali dosing devices and the oxidant dosing device. When the pH in the tank exceeds the set value of 8.8, the flow rate of the acid pump will increase, and the increased amount is the difference between the measured value and the set value. When the pH in the tank is less than 8.8, the flow rate of the acid pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the pH in the tank is equal to 8.8, the flow rate of the acid pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the pH sampling test frequency.

[0084] The treated sewage enters the rapid mixing tank. The set value of PID in the rapid mixing tank, that is, the target pH value, is set to 7.0. The signal of pH electrode 3 is transmitted to the PLC, and the oxidant addition PID calculation unit generates oxidant addition parameters and transmits them to the corresponding frequency converter to control the variable-frequency oxidant dosing pump 4. When the measured pH value in the rapid mixing tank is greater than the set value of 7.0, the flow rate of the oxidant dosing device will increase, and the increased amount is the difference between the measured value and the set value; as the dosage of the oxidant increases, the pH in the rapid mixing tank will decrease. When the measured pH value in the rapid mixing tank is less than the set value, the flow rate of the oxidant dosing device will decrease, and the decreased amount is the difference between the measured value and the set value; when the measured pH value in the rapid mixing tank is equal to the set value, the flow rate of the oxidant dosing device remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the pH sampling test frequency.

[0085] In the breakpoint reaction device, a PID calculation device is used to control the acid and alkali dosing devices. The set value of the PID in the breakpoint reaction device is set to 7.8. When the signal of the pH electrode 5 in the tank is less than the set value of 7.8, the flow rate of the alkali dosing device 6 increases, and the increased amount is the difference between the measured value and the set value; when the signal of the pH electrode 5 in the tank is greater than the set value, the flow rate of the alkali dosing device 6 decreases, and the decreased amount is the difference between the measured value and the set value; when the signal of the pH electrode 5 in the tank is equal to the set value, the flow rate of the alkali dosing device 6 remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the pH sampling test frequency. The final effluent ammonia nitrogen is lower than 2 mg / L, and the pre-discharged sewage is obtained.

[0086] Example 2:

[0087] After collecting domestic sewage, it is introduced into the regulation tank. The set value of the pH in the regulation tank is set to 9.25. When the deviation between the measured value of the pH electrode 1 and the set value is >5, it is set to be tested once every 100 ms; when the deviation between the measured value of the pH electrode 1 and the set value is <5, it is set to be tested once every 40 ms. The test signal is transmitted to the PLC, and the PID calculation device generates the acid and alkali dosing frequencies and dosing amounts, which are transmitted to the corresponding frequency converters to control the variable-frequency acid and alkali dosing pumps 2. When the pH in the tank exceeds 9.25, the flow rate of the acid pump will increase, and the increased amount is the difference between the measured value and the set value; when the pH in the tank is less than 9.25, the flow rate of the acid pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the pH in the tank is equal to 9.25, the flow rate of the acid pump remains unchanged; (the above adjustment process is carried out continuously during the operation of the equipment, and the adjustment frequency is the same as the PH sampling frequency)

[0088] The treated sewage enters the rapid mixing tank. The set value of the PH in the rapid mixing tank is set to 7.25. The signal of the pH electrode 3 is transmitted to the PLC, and the oxidant dosing PID calculation unit generates the oxidant dosing parameters, which are transmitted to the corresponding frequency converters to control the variable-frequency oxidant dosing pumps 4. When the pH in the tank exceeds 7.25, the flow rate of the oxidant dosing pump will increase, and the increased amount is the difference between the measured value and the set value; when the pH in the tank is less than 7.25, the flow rate of the oxidant dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the pH in the tank is equal to 7.25, the flow rate of the oxidant dosing pump remains unchanged. (the above adjustment process is carried out continuously during the operation of the equipment, and the adjustment frequency is the same as the PH sampling frequency)

[0089] In the breakpoint reaction device, a PID calculation device is used to control the acid and alkali dosing devices. The set value of pH in the breakpoint reaction device is set to 8.3. When the pH in the pool is less than 8.3, the flow rate of the alkali dosing pump will increase, and the increased amount is the difference between the measured value and the set value; when the pH in the pool is greater than 8.3, the flow rate of the alkali dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the pH in the pool is equal to 8.3, the flow rate of the alkali dosing pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the pH sampling test frequency.

[0090] The pre-discharged sewage is introduced into the reduction device. The set value of PID in the reduction device is set to 200 mV. The signal of the ORP electrode 7 is transmitted to the PLC, and the PID calculation device generates the dosing frequency of the reducing agent and transmits it to the corresponding frequency converter to control the variable-frequency reducing agent dosing device 8. When the ORP in the pool is greater than 200 mV, the flow rate of the reducing agent dosing pump will increase, and the increased amount is the difference between the measured value and the set value; when the ORP in the pool is less than 200 mV, the flow rate of the reducing agent dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the ORP in the pool is equal to 200 mV, the flow rate of the reducing agent dosing pump remains unchanged.. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the sampling test frequency. At this time, the residual chlorine in the effluent can meet the effluent requirement of less than 0.5 mg / L and can be discharged.

[0091] Example 3:

[0092] After collecting the industrial sewage, it is introduced into the adjustment pool. The set value of pH in the adjustment pool is set to 8.3. When the deviation between the measured value of the pH electrode 1 and the set value > 5, it is set to test once every 100 ms; when the deviation between the measured value of the pH electrode 1 and the set value < 5, it is set to test once every 40 ms. The test signal is transmitted to the PLC, and the PID calculation device generates the dosing frequency and dosing amount of the acid and alkali and transmits them to the corresponding frequency converter to control the variable-frequency acid and alkali dosing pump 2. When the pH in the pool exceeds 8.3, the flow rate of the acid pump will increase, and the increased amount is the difference between the measured value and the set value; when the pH in the pool is less than 8.3, the flow rate of the acid pump will decrease, and the decreased amount is the difference between the measured value and the set value; when the pH in the pool is equal to 8.3, the flow rate of the acid pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the sampling test frequency.;

[0093] The treated sewage enters the rapid mixing tank. The set value of pH in the rapid mixing tank is set to 7.5. The signal of the pH electrode 3 is transmitted to the PLC. The oxidant dosing PID calculation unit generates the oxidant dosing parameters and transmits them to the corresponding frequency converter to control the variable-frequency oxidant dosing pump 4. When the pH in the tank exceeds 7.5, the flow rate of the oxidant dosing pump will increase, and the increased amount is the difference between the measured value and the set value. When the pH in the tank is less than 7.5, the flow rate of the oxidant dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value. When the pH in the tank is equal to 7.5, the flow rate of the oxidant dosing pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the sampling test frequency.

[0094] In the breakpoint reaction device, a PID calculation device is used to control the acid and alkali dosing devices. The set value of pH of the PID in the breakpoint reaction device is set to 7.2. When the signal of the pH electrode 5 in the tank is less than 7.2, the flow rate of the alkali dosing pump will increase, and the increased amount is the difference between the measured value and the set value. When the pH in the tank is greater than 7.2, the flow rate of the alkali dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value. When the pH in the tank is equal to 7.2, the flow rate of the alkali dosing pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the sampling test frequency.

[0095] The pre-discharged sewage is introduced into the reduction device. The set value of the PID in the reduction device is set to 180 mV. The signal of the ORP electrode 7 is transmitted to the PLC. The PID calculation device generates the reduction agent dosing frequency and transmits it to the corresponding frequency converter to control the variable-frequency reduction agent dosing device 8. When the ORP in the tank is greater than 180 mV, the flow rate of the reduction agent dosing pump will increase, and the increased amount is the difference between the measured value and the set value. When the ORP in the tank is less than 180 mV, the flow rate of the reduction agent dosing pump will decrease, and the decreased amount is the difference between the measured value and the set value. When the ORP in the tank is equal to 180 mV, the flow rate of the reduction agent dosing pump remains unchanged. During the operation of the equipment, the above adjustment process is carried out continuously, and the adjustment frequency is the same as the ORP sampling frequency. At this time, the residual chlorine in the effluent can meet the effluent requirement of less than 5 mg / L, and then it can be discharged.

[0096] It should be noted that the selection of materials and experimental parameters involved in the above embodiments is only for better obtaining the control experiment results to better reflect the beneficial effects of the ozone treatment system and process provided by this application. It is only a specific and feasible embodiment, and the actually implementable materials and parameters of this application are not limited to those in the embodiments, and the specific range in the implementation manner can be referred to.

[0097] The above are only optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. An automated controlled breakpoint chlorination system, characterized in that: It includes a regulating device, a quick mixing device, a breaking point reaction device, a control device and a dosing device; The regulating device, the quick mixing device, and the inflection point reaction device are connected in sequence; the dosing device is connected to the regulating device, the quick mixing device, and the inflection point reaction device respectively; the regulating device is provided with a first pH electrode, the quick mixing device is provided with a second pH electrode, and the inflection point reaction device is provided with a third pH electrode; The control device is used to respectively obtain pH value measurement data collected by the first pH electrode, the second pH electrode and the third pH electrode, and perform dosing control calculation based on the pH value measurement data to obtain dosing control parameters; Based on the dosing control parameter, controlling the dosing of the dosing device so that the pH measurement data of the regulating device, the fast mixing device and the inflection point reaction device meet the corresponding preset conditions; The control device is used to perform PID calculation for the dosage based on the pH value measurement data and the target pH value to obtain the dosing control parameter. The PID calculation device is provided with a data model module, and the data model module includes a data rolling accumulation module and / or a specific algorithm continuous correction module for the operation parameters of the system; The pH electrode sampling time varies according to the pH value measurement data and the preset adjustment deviation value, and the electrode sampling time of the first pH electrode, the second pH electrode and the third pH electrode is once every 30 to 120 ms; The dosing control parameters include the dosing amount of the acidic substance, the dosing amount of the alkaline substance or the dosing amount of the oxidant substance; The control device is used to control the dosage of the acidic dosing device and / or the dosage of the alkaline dosing device based on the dosing control parameters corresponding to the regulating device, so that the pH measurement value in the regulating device meets the target pH value of the regulating device; The control device is used to control the dosage of the oxidant dosing device based on the dosing control parameters corresponding to the fast mixing device, so that the pH measurement value in the fast mixing device meets the target pH value of the fast mixing device; The control device is used to control the dosage of the acidic dosing device and / or the alkaline dosing device based on the dosing control parameters corresponding to the breakpoint reaction device, so that the pH measurement value in the breakpoint reaction device meets the target pH value of the breakpoint reaction device.

2. A kind of automatic controlled breakpoint chlorination system according to claim 1, characterized in that, The dosing device includes one or more of an oxidant dosing device, an acid dosing device, and an alkaline dosing device.

3. A kind of automatic controlled breakpoint chlorination system according to claim 1, characterized in that, The dosing device includes one or more of a dosing pump, a frequency converter, and a flow controller.

4. A kind of automatic controlled breakpoint chlorination system according to claim 1, characterized in that, The dosing device includes a reducing agent dosing device, and the system also includes a reducing device, the reducing device is connected to the inflection point reaction device, and the control device and the reducing agent dosing device are respectively connected to the reducing device.

5. A kind of breakpoint chlorination system of automatic control according to claim 4, characterized in that The reduction device further comprises a first ORP electrode, the first ORP electrode is used to measure the ORP measurement value of the reduction device and send it to the control device, the ORP measurement value is fed back to the residual chlorine content in the reduction device; The control device is used to perform dosing control calculation based on the ORP measurement value of the reduction device to obtain the dosing control parameters corresponding to the reduction device; and based on the dosing control parameters corresponding to the reduction device, control the reducing agent dosing device to add reducing agent to the reduction device so that the ORP measurement value of the reduction device meets the preset conditions corresponding to the reduction device.

6. An automated controlled breakpoint chlorination process, which is treated with an automated controlled breakpoint chlorination system as claimed in any one of claims 1 to 5, the process comprising the following steps: The collected sewage is passed into a regulating device, and after being treated in the regulating device, it is passed into a quick mixing device and a breakpoint reaction device in sequence for sewage treatment; During the sewage treatment process, pH value measurement data of the regulating device, the fast mixing device and the inflection point reaction device are collected respectively by the first pH electrode, the second pH electrode and the third pH electrode; The control device performs dosing control calculation based on the pH value measurement data to obtain dosing control parameters; and based on the dosing control parameters, controls the dosing of the dosing device so that the pH measurement data of the regulating device, the fast mixing device and the inflection point reaction device meet their respective corresponding preset conditions.

7. A breakpoint chlorination process with automated control according to claim 6, characterized in that: Also includes: The sewage discharged from the inflection point reaction device is passed into a reduction device, and the ORP measurement value of the reduction device is collected in real time according to the first ORP electrode in the reduction device; The control device performs dosing control calculation based on the ORP measurement value to obtain dosing control parameters corresponding to the reduction device; and based on the dosing control parameters corresponding to the reduction device, controls the reducing agent dosing device to add reducing agent to the reduction device so that the ORP measurement value of the reduction device meets the preset conditions corresponding to the reduction device; If the wastewater treated by reduction in the reduction device meets the discharge standard, it is discharged from the breakpoint chlorination system; If the discharge standard is not reached, the wastewater after reduction treatment in the reduction device is returned to the regulating device for circulation treatment.

8. A breakpoint chlorination process with automatic control according to claim 7, characterized in that, The preset conditions are set according to the properties of the sewage to be treated. The preset conditions of the regulating device are pH equal to 6-10, the preset conditions of the fast mixing device are pH equal to 7-10, and the preset conditions of the breakpoint oxidation device are pH equal to 6-9.

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