Domestic sewage treatment system and intelligent backwashing device thereof

Abstract

The present application relates to a kind of domestic sewage treatment system and its intelligent backwashing device.The intelligent backwashing device includes control unit, electrolytic cell, blowdown control valve, seawater inlet control valve and detection unit.Blowdown control valve is arranged at the blowdown pipeline of electrolytic cell, and is electrically connected with control unit.Seawater inlet control valve is arranged at the seawater inlet pipeline of electrolytic cell, and is electrically connected with control unit.Detection unit is used to detect actual working data reflecting the current electrolytic capacity of electrolytic cell, and send it to control unit.Control unit is used to judge whether the electrolytic capacity of electrolytic cell is qualified according to whether actual working data is within preset standard range, if not, then upload the judgment result to central control system to alarm, when backwashing mode starts during non-operation period of domestic sewage treatment system, control seawater inlet control valve to open, to clean electrolytic cell, and control blowdown control valve to open when backwashing is completed, to discharge sewage after cleaning.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a domestic wastewater treatment system and its intelligent backwashing device. Background Technology

[0002] Wastewater treatment systems are among the most critical environmental protection devices in offshore production facilities. They are responsible for ensuring that the COD (Chemical Oxygen Demand) of domestic wastewater meets discharge standards, which is crucial for the safe production and compliant operation of the facility. One offshore facility uses an electrolytic wastewater treatment system. However, in this process, impurities in the wastewater easily adhere to the electrode plates, increasing the resistance between the plates, reducing electrolysis efficiency, increasing current, and in severe cases, causing short circuits and damage to the electrode plates. Since its commissioning, the equipment has experienced a particularly high failure rate, requiring backwashing twice a day during peak periods. Therefore, the electrode plates need to be replaced annually as recommended by the manufacturer, resulting in excessive maintenance costs. Thus, the cleanliness of the electrolytic cell is extremely important, as it directly affects the normal operation of the wastewater treatment system. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a domestic sewage treatment system and its intelligent backwashing device.

[0004] The technical solution adopted by the present invention to solve its technical problem is: an intelligent backwashing device for a domestic sewage treatment system, the intelligent backwashing device including a control unit, an electrolytic cell, a sewage discharge control valve, a seawater inlet control valve and a detection unit;

[0005] The sewage discharge control valve is located at the sewage discharge pipeline of the electrolytic cell and is electrically connected to the control unit; the seawater inlet control valve is located at the seawater inlet pipeline of the electrolytic cell and is electrically connected to the control unit.

[0006] The electrolytic cell is used to electrolyze domestic sewage; the detection unit is communicatively connected to the control unit and is used to detect actual working data reflecting the current electrolysis capacity of the electrolytic cell and send it to the control unit.

[0007] The control unit is used to determine whether the electrolysis capacity of the electrolytic cell is qualified based on whether the actual working data is within the preset standard range. If it is not qualified, the judgment result is uploaded to the central control system for alarm prompt. Moreover, during the non-operation period of the domestic sewage treatment system, when the backwashing mode is started, the control unit controls the opening of the seawater inlet control valve to allow seawater to flow into the electrolytic cell through the seawater inlet pipeline for cleaning. When the backwashing is completed, the control unit controls the opening of the sewage discharge control valve to discharge the cleaned sewage through the sewage discharge pipeline.

[0008] Furthermore, in the intelligent backwashing device of the present invention, the detection unit is used to detect the actual discharge data of the domestic sewage treatment system in real time and send it to the control unit;

[0009] Alternatively, the detection unit is used to detect the actual electrolytic current of the electrolyzer during the operation of the domestic sewage treatment system in real time and send it to the control unit.

[0010] Furthermore, in the intelligent backwashing device of the present invention, the detection unit is also used to detect the degree of dirtiness of the electrolytic cell during the backwashing mode, and send the detected current dirtiness detection data to the control unit.

[0011] The control unit is also used for:

[0012] Determine whether the current dirt detection data meets the preset cleanliness standard;

[0013] If so, the cleaning operation will automatically end, or the cleaning operation will end when the user confirms that the cleaning has stopped, and the sewage control valve will be opened to discharge the wastewater after cleaning.

[0014] Furthermore, in the intelligent backwashing device of the present invention, the intelligent backwashing device also includes a button unit, which includes a cleaning start button, a cleaning stop button, and a cleaning completion confirmation button.

[0015] The control unit is used for:

[0016] Receives a cleaning start command triggered by the user through the cleaning start button, and starts the backwash mode according to the cleaning start command;

[0017] Receive a stop cleaning command triggered by the user through the stop cleaning button, and end the cleaning operation according to the stop cleaning command;

[0018] The system receives a confirmation command triggered by the user through the "cleaning complete confirmation" button, and controls the sewage discharge control valve to open according to the confirmation command so that the sewage after cleaning can be discharged.

[0019] Furthermore, in the intelligent backwashing device of the present invention, the backwashing mode includes cleaning frequency, cleaning duration and / or backwashing mode operation time.

[0020] Furthermore, in the intelligent backwashing device described in this invention, the control unit is also used to adjust the cleaning frequency, cleaning duration, and / or running time according to the actual operating conditions of the domestic sewage treatment system.

[0021] Furthermore, in the intelligent backwashing device of the present invention, the control unit adjusts the cleaning time according to the service life information of the electrolytic cell and the sewage discharge situation; or, the control unit adjusts the cleaning time according to the actual cleaning degree received.

[0022] Furthermore, in the intelligent backwashing device of the present invention, the electrolytic cell includes a first electrolytic cell and a second electrolytic cell, each electrolytic cell being provided with a sewage discharge control valve and a seawater inlet control valve at corresponding positions; or,

[0023] The intelligent backwashing device also includes a visualization unit connected to the control unit, which is used to display the cleaning status of the electrolytic cell transmitted from the control unit in real time.

[0024] In addition, the present invention also provides a domestic sewage treatment system, including the intelligent backwashing device as described above.

[0025] Furthermore, the domestic sewage treatment system of the present invention also includes a regulating treatment unit, a mixing tank, a primary clear water tank on a main skid, and a digestion and filtration skid tank group. The regulating treatment unit includes a pulverizing unit, a buffer tank, and a liquid level detection unit disposed in the buffer tank.

[0026] The liquid level detection unit is connected to the control unit and is used to detect the actual liquid level of domestic sewage in the buffer tank;

[0027] The control unit is also used for:

[0028] Determine whether the preset sewage discharge level has been reached based on the actual liquid level.

[0029] If so, the domestic sewage shall be treated as follows:

[0030] The crushing unit is activated to crush impurities in the domestic sewage, and the crushed domestic sewage enters the mixing tank to mix with a preset amount of seawater.

[0031] The electrolytic cell is controlled to electrolyze the mixed domestic sewage. After the domestic sewage undergoes electrolysis treatment, it enters the primary clear water tank of the main skid for degassing. The discharge pump is then controlled to allow the degassed sewage to enter the digestion and filtration skid tank group for final treatment, including sterilization, homogenization, filtration, and sedimentation.

[0032] Obtain the current COD value of the domestic sewage after final treatment;

[0033] When the current COD value reaches the preset qualified standard, the sewage outlet is opened to discharge sewage.

[0034] The domestic sewage treatment system and its intelligent backwashing device of this invention have the following beneficial effects: This invention can fundamentally solve the problem of electrolytic cells easily becoming dirty and sticky, leading to tripping or excessive current damage to the equipment. It can reduce the maintenance workload and cost of electrolytic cells and effectively extend their service life. It ensures the normal operation of domestic sewage treatment equipment, guaranteeing the safe production and compliant operation of the facility. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0036] Figure 1 This is a schematic diagram of the intelligent backwashing device provided in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the intelligent backwashing device provided in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the intelligent backwashing device provided in an embodiment of the present invention. Detailed Implementation

[0039] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0040] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0041] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0042] Because the wastewater treatment system lacked a filtration device in the electrolyzer design phase, wastewater, after passing through the pulverizing pump, entered the electrolyzer directly without filtration. Impurities in the wastewater easily adhered to the electrode plates. Current techniques require stopping the electrolyzer and manually opening the backwash valves during backwashing. After cleaning, the valves are closed, and the system is restarted. However, this approach creates maintenance blind spots. If personnel fail to detect a tripped electrolyzer shutdown, wastewater discharge may fail to meet standards. Furthermore, frequent operation leads to severe valve wear and aging, increasing maintenance difficulty and costs.

[0043] like Figure 1As shown, in one embodiment of the present invention, the intelligent backwashing device for a domestic sewage treatment system is mainly applied to a domestic sewage treatment system. The domestic sewage treatment system includes a regulating treatment unit, a mixing tank, a primary clear water tank on a main skid, and a digestion and filtration skid tank group. The regulating treatment unit includes a pulverizing unit, a buffer tank, and a liquid level detection unit 50 located in the buffer tank. The pulverizing unit includes a blower and a pulverizing pump. Under normal operation, sewage from the residential area enters the buffer tank of the regulating treatment unit. When the sewage level reaches the electrolysis operation height level, the PLC control unit 10 automatically starts the blower and the pulverizing pump to pulverize impurities and dirt in the sewage. The filtered sewage enters the mixing tank, where a certain amount of seawater is added in proportion. The mixture is then pumped to the electrolysis tank 20 for electrolysis treatment, and then degassed in the primary clear water tank on the main skid. The degassed clear water is pumped to each tank of the digestion and filtration skid unit by the outlet pump for further sterilization, homogenization, and filtration and sedimentation. After the COD value of the sewage is tested and found to be qualified, it is discharged.

[0044] The intelligent backwashing device in this embodiment includes a control unit 10, an electrolytic cell 20, a sewage discharge control valve 30, a seawater inlet control valve 40, and a detection unit 50. Alternatively, the control unit 10 can be a PLC control unit.

[0045] A sewage discharge control valve 30 is located at the sewage discharge pipeline of the electrolytic cell 20 and is electrically connected to the control unit 10. A seawater inlet control valve 40 is located at the seawater inlet pipeline of the electrolytic cell 20 and is electrically connected to the control unit 10. The electrolytic cell 20 is used to electrolyze domestic sewage. Alternatively, the electrolytic cell 20 may include a first electrolytic cell and a second electrolytic cell, each of which has a sewage discharge control valve 30 and a seawater inlet control valve 40 at corresponding positions.

[0046] The detection unit 50 is communicatively connected to the control unit 10 and is used to detect actual working data reflecting the current electrolytic capacity of the electrolytic cell, and send it to the control unit 10. The control unit 10 determines whether the electrolytic capacity of the electrolytic cell is qualified based on whether the actual working data is within a preset standard range. If it is unqualified, the determination result is uploaded to the central control system for alarm notification. Furthermore, during non-operational periods of the domestic sewage treatment system, when the backwashing mode is activated, the control unit 10 controls the opening of the seawater inlet control valve 40 to allow seawater to flow into the electrolytic cell 20 through the seawater inlet pipeline for cleaning. Upon completion of backwashing, the control unit 10 controls the opening of the sewage discharge control valve 30 to discharge the cleaned sewage through the sewage discharge pipeline. The control unit 10 can upload the determination result of whether the electrolytic capacity is qualified to the central control system in real time for notification. Moreover, when the determination result of unqualified electrolytic capacity is uploaded, an alarm notification can also be issued through a preset alarm method, such as by popping up an alarm sign. Alternatively, the backwashing device can also be equipped with an alarm unit (not shown) to issue an alarm notification when the electrolytic capacity determination result is unqualified, so that the user can confirm whether to activate the backwashing mode based on the alarm notification. The detection unit in this embodiment helps determine the conditions for starting the backwash mode.

[0047] Optionally, the detection unit 50 can detect the actual discharge data of the domestic sewage treatment system in real time and send it to the control unit. For example, it can monitor the actual discharge concentration or actual discharge flow rate of the domestic sewage treatment system in real time. The control unit 10 can determine whether the current electrolysis capacity of the electrolyzer is qualified based on whether the actual discharge concentration or actual discharge flow rate is within the corresponding preset standard range. If it is within the preset standard range, it means that the current electrolysis capacity of the electrolyzer is qualified and backwashing is not required. If it is not within the preset standard range, it means that the current electrolysis capacity of the electrolyzer is unqualified and backwashing is required.

[0048] Optionally, the detection unit 50 can detect the actual electrolytic current of the electrolyzer during the operation of the domestic sewage treatment system in real time and send it to the control unit. The control unit 10 can determine whether the current electrolytic capacity of the electrolyzer is qualified based on whether the actual electrolytic current is within the corresponding preset standard range. If it is within the preset standard range, it means that the current electrolytic capacity of the electrolyzer is qualified and backwashing is not required. If it is not within the preset standard range, it means that the current electrolytic capacity of the electrolyzer is unqualified and backwashing is required. For example, in this embodiment, the preset standard range can be set based on the rated electrolytic current of 10A. Outside this range, it means that the actual electrolytic current is too small or too large, which is abnormal, thus indicating that the current electrolytic capacity of the electrolyzer is unqualified.

[0049] Alternatively, the backwashing mode may include, but is not limited to, cleaning frequency, cleaning duration, and backwashing mode operation time. The control unit 10 can adjust the cleaning frequency, cleaning duration, and / or operation time according to the actual operating conditions of the domestic sewage treatment system. Specifically, the control unit 10 can adjust the cleaning duration based on the service life information of the electrolytic cell 20 and the sewage discharge situation.

[0050] This embodiment fundamentally solves the problem of electrolytic cells 20 easily becoming dirty and sticky, leading to tripping or excessive current damage. It reduces the maintenance workload and cost of electrolytic cells 20, effectively extending their service life. It ensures the normal operation of the domestic sewage treatment equipment, guaranteeing the safe production and compliant operation of the facility.

[0051] Alternatively, the intelligent backwashing device in this embodiment may include a manual mode and an automatic mode. In automatic mode, parameters such as cleaning frequency, cleaning time, and cleaning duration can be set according to actual operating conditions to automatically perform backwashing. In manual mode, personnel can perform maintenance, testing, and manual cleaning according to actual working conditions. Actual working conditions include, for example, quarterly chemical cleaning, replacement and debugging, maintenance and testing, and major overhauls. For example, the frequency can be adjusted; if there are few people in the living area, cleaning can be done once a week, while if there are many people, cleaning can be done every two days. For example, the operating time can be adjusted according to the personnel's work and rest schedule, such as choosing to clean between 0:00 and 2:00 AM when people are sleeping, thus maximizing the operation of the domestic sewage treatment device. For example, the cleaning duration can be appropriately adjusted according to the service life of the electrolytic cell 20 and the sewage discharge situation, or it can be adjusted according to the detected cleaning degree.

[0052] This embodiment allows for flexible setting of the cleaning frequency and duration based on the degree of clogging in the electrolytic cell 20, reducing the duration of clogging and maintaining cleanliness over a longer period, thus reducing the failure rate. This intelligent backflushing device also features a manual cleaning function, allowing for separate cleaning and testing in case of malfunction or maintenance. It solves the problem of debris easily adhering to the electrolytic cell 20 in domestic sewage treatment devices and can be widely applied in the construction of intelligent oilfields by CNOOC.

[0053] In some embodiments, the detection unit 50 of the intelligent backwashing device of this embodiment can also be used to detect the degree of dirt on the electrolytic cell 20 during non-operation periods of the domestic sewage treatment system, and send the detected current dirt detection data to the control unit 10. The control unit 10 determines whether the current dirt detection data meets the preset cleanliness standard. If the preset cleanliness standard is met, the cleaning operation is automatically ended, or the cleaning operation is ended upon receiving a confirmation instruction from the user to stop the cleaning, and the drain control valve 30 is opened to discharge the cleaned sewage. Optionally, the detection unit 50 can perform real-time detection of the degree of dirt on the electrolytic cell 20 during non-operation periods of the domestic sewage treatment system.

[0054] It should be noted that the detection unit of this invention is only a general term. Different detection units can be used to check different data, and the corresponding detection modules, such as sensors, are installed in the corresponding positions to obtain the actual data of the object. The detection unit used in this embodiment to determine the detection data of the backwashing mode stop condition may be different from the detection unit in the previous embodiment, and is located inside the electrolytic cell 20. The detection unit in the previous embodiment, which is used to monitor the actual working data reflecting the current electrolysis capacity of the electrolytic cell, can be located at the sewage outlet of the domestic sewage treatment system to obtain the actual discharge data, or it can be located on the electrolytic cell plate and connected to the electrolytic cell plate to obtain the actual electrolysis current.

[0055] In other words, optionally, during the non-operational period of the domestic sewage treatment system, the detection unit 50 detects the degree of dirtiness in the electrolytic cell 20 and sends the current dirtiness detection data to the control unit 10. The control unit 10 determines whether the current dirtiness detection data meets the preset cleaning standard. If the preset cleaning standard is met, the backwashing mode is automatically started to clean the electrolytic cell 20. When the current dirtiness detection data reaches the preset cleanliness standard, the cleaning operation is automatically ended, and the sewage discharge control valve 30 is opened to discharge the cleaned sewage.

[0056] Optionally, during non-operational periods of the domestic sewage treatment system, the detection unit 50 detects the degree of dirtiness in the electrolytic cell 20 and sends the current dirtiness detection data to the control unit 10. The control unit 10 determines whether the current dirtiness detection data meets the preset cleaning standard. If it does, it automatically starts the backwashing mode to clean the electrolytic cell 20. When the current dirtiness detection data reaches the preset cleanliness standard and the control unit receives a confirmation instruction from the user to stop the cleaning, it ends the cleaning operation and controls the drain control valve 30 to open so that the cleaned sewage can be discharged. It can be understood that when the control unit 10 determines that the current dirtiness detection data has reached the preset cleanliness standard, it can issue a prompt message asking whether to confirm the cleaning has stopped and display it visually to remind the user to provide confirmation.

[0057] Optionally, the control unit 10 can also activate the backwash mode to clean the electrolytic cell 20 when it determines that the current dirt detection data has reached the preset cleaning standard and receives a confirmation instruction from the user. When the current dirt detection data reaches the preset cleanliness standard, the cleaning operation is automatically ended and the drain control valve 30 is opened to discharge the wastewater after cleaning.

[0058] Optionally, the control unit 10 can also activate the backwash mode to clean the electrolytic cell 20 when it determines that the current dirt detection data has reached the preset cleaning standard and receives a confirmation instruction from the user to clean. The cleaning operation ends when the current dirt detection data reaches the preset cleanliness standard and receives a confirmation instruction from the user to stop cleaning, and the drain control valve 30 is opened to discharge the wastewater after cleaning.

[0059] It is understandable that when the control unit 10 determines that the current dirt detection data has reached the preset cleaning standard, it can issue a prompt message asking whether to clean and display it visually to remind the user to provide feedback and confirmation.

[0060] This embodiment allows for flexible setting of the cleaning frequency and duration based on the degree of fouling in the electrolytic cell 20, enabling intelligent automatic backwashing control. This reduces the duration of fouling in the electrolytic cell 20, maintaining cleanliness over a longer period and reducing the failure rate. It solves the problem of the electrolytic cell 20 easily becoming dirty and sticky, leading to tripping or excessive current damage. It reduces the maintenance workload and cost of the electrolytic cell 20, effectively extending its service life. It ensures the normal operation of the domestic sewage treatment equipment, guaranteeing the safe production and compliant operation of the facility. This can be promoted and applied in the construction of intelligent oilfields by CNOOC.

[0061] In some embodiments, reference Figure 2 The intelligent backwashing device in this embodiment also includes a button unit 60, which includes a cleaning start button, a cleaning stop button, and a cleaning completion confirmation button. The control unit 10 receives a cleaning start command triggered by the user via the cleaning start button and starts the backwashing mode according to the cleaning start command. It receives a cleaning stop command triggered by the user via the cleaning stop button and ends the cleaning operation according to the cleaning stop command. It receives a cleaning completion confirmation command triggered by the user via the cleaning completion confirmation button and controls the drain control valve 30 to open so that the wastewater after cleaning can be discharged.

[0062] In some embodiments, reference Figure 3 The intelligent backwashing device in this embodiment also includes a visualization unit 70 connected to the control unit 10. The visualization unit 70 is used to display the cleaning status of the electrolytic cell 20 transmitted from the control unit 10 in real time. For example, the visualization unit 70 may be a touch screen or the like.

[0063] In one specific embodiment, the intelligent backwashing device of this embodiment includes an electrical control box, an S7-200 PLC (PLC control unit 10), a 24V power supply, five buttons, a selector switch, eight indicator lights, and four 24V electric valves. The electrical control system (including the S7-200 PLC and several other electrical components) is installed in the electrical control box. The S7-200 PLC is mainly used for the intelligent control of the device. An electric valve is added to both the drain line and the seawater inlet line of the electrolytic cell 20. The electric valves have valve position indicators, and the corresponding contacts actuate when the valves are opened and closed. For example: drain electric valve A1 and seawater inlet solenoid valve A2 for electrolytic cell A 20 (first electrolytic cell 20); drain electric valve B1 and seawater inlet solenoid valve B2 for electrolytic cell B 20 (second electrolytic cell 20). The five buttons function as follows: cleaning start button for electrolytic cell A, cleaning start button for electrolytic cell B, cleaning completion confirmation button, cleaning stop button, and fault reset button, etc. The eight indicator lights function as follows: power indicator, fault indicator, B-wash indicator, A-wash indicator, A1 valve open, A2 valve open, B1 valve open, and B2 valve open. The selector switch is used to select between automatic and manual modes.

[0064] Regarding the automatic function, when the selector switch is turned on, the system will automatically perform cleaning. The cleaning frequency, cleaning time, and cleaning duration can be set according to actual working conditions. The automatic cleaning function steps are as follows:

[0065] (1) SA1 is set to automatic. (2) The intelligent backwashing device sends a cleaning command to the domestic sewage treatment system. The domestic sewage treatment system automatically shuts down, waiting for the system to stop operating. (3) The intelligent device starts cleaning electrolytic cell A, and the cleaning indicator light for A illuminates. (4) The intelligent device sends an opening command to valves A1 and A2 of electrolytic cell A. (5) After receiving the feedback command to open valves A1 and A2, the opening indicator light for valves A1 and A2 illuminates. The cleaning timer starts, which can be adjusted according to the actual situation. (6) After cleaning electrolytic cell A 20, valves A1 and A2 of electrolytic cell A are closed, and the opening indicator light for valves A1 and A2 goes out. (7) After receiving the feedback command to open valves A1 and A2, the intelligent device starts cleaning electrolytic cell B 20. (8) The intelligent device sends an opening command to valves B1 and B2 of electrolytic cell B. The opening indicator light for valves B1 and B2 illuminates. The cleaning timer starts, which can be adjusted according to the actual situation. (9) After cleaning electrolytic cell 20, close valves B1 and B2 of electrolytic cell B. The indicator lights of valves B1 and B2 will turn off when they are open. After receiving the valve closing command, the intelligent backwashing device sends a signal to the PLC control unit 10 indicating that the cleaning is complete, so that the domestic sewage treatment system can start running again. (10) The intelligent cleaning device waits for the next cleaning time. (11) If the valve cannot be opened or closed properly during the automatic cleaning process, a fault alarm will be issued and the abnormal signal will be transmitted to the central control system for timely dispatch and handling. (12) After the process is completed, press the reset button again, and the device will be put into normal use again.

[0066] Regarding the manual function, when the selector switch is set to manual, the system can manually control the opening and closing of each valve, and can individually control the cleaning of each electrolytic cell 20. (1) The personnel manually stop the domestic sewage treatment system. (2) Set the selector switch SA1 to manual. (3) Press the button "A Wash", and the "A Wash" indicator light will illuminate. (4) The electric valves A1 / A2 will open. (5) After a period of time, the indicator light of the fully opened A1 / A2 valves will illuminate. (6) Press the "Stop Wash" button, and the A1 / A2 valves will close, and the indicator light will turn off. (7) The A Wash indicator light will turn off. (8) Then press the "Wash Complete" button, and the domestic sewage treatment system can be flushed and started. (9) Press the button "B Wash", and the "B Wash" indicator light will illuminate. (10) The electric valves B1 / B2 will open. (11) After a period of time, the indicator light of the fully opened B1 / B2 valves will illuminate. (12) Press the "Stop Wash" button, and the B1 / B2 valves will close, and the indicator light will turn off. (13) The B Wash indicator light will turn off. (14) Then press the “wash complete” button to start the domestic sewage treatment system.

[0067] This embodiment allows for flexible setting of the cleaning frequency and duration based on the degree of clogging in the electrolytic cell 20, reducing the duration of clogging and maintaining cleanliness over a longer period, thus reducing the failure rate. This intelligent backflushing device also features a manual cleaning function, allowing for separate cleaning and testing in case of malfunction or maintenance. It solves the problem of debris easily adhering to the electrolytic cell 20 in domestic sewage treatment devices and can be widely applied in the construction of intelligent oilfields by CNOOC.

[0068] In another embodiment of the present invention, the domestic sewage treatment system of this embodiment includes the intelligent backwashing device of the above embodiment. The domestic sewage treatment system also includes a regulating treatment unit, a mixing tank, a primary clear water tank on the main skid, and a digestion and filtration skid tank group. The regulating treatment unit includes a pulverizing unit, a buffer tank, and a liquid level detection unit 50 disposed in the buffer tank. The liquid level detection unit 50 is connected to the control unit 10 and is used to detect the actual liquid level of domestic sewage in the buffer tank. The control unit 10 is also used to: determine whether the preset sewage discharge level has been reached based on the actual liquid level. If so, the domestic sewage is treated as follows: the pulverizing unit is started to pulverize the impurities in the domestic sewage, and the pulverized domestic sewage enters the mixing tank to be mixed with a preset quantitative amount of seawater. The electrolytic cell 20 is controlled to electrolyze the mixed domestic sewage, and after the electrolyzed domestic sewage enters the primary clear water tank on the main skid for degassing, the outlet pump is controlled to make the degassed sewage enter the digestion and filtration skid tank group for final treatment of sterilization, homogenization, filtration and sedimentation. The current COD value of the domestic sewage after final treatment is obtained. When the current COD value reaches the preset acceptable standard, the sewage outlet is opened to discharge sewage. In other words, under normal operating conditions, sewage from the residential area enters the buffer tank of the regulating treatment unit. When the sewage level reaches the electrolysis operation height level (preset discharge level), the PLC control unit 10 automatically starts the blower and pulverizing pump to pulverize impurities in the sewage. The filtered sewage enters the mixing tank, where a certain amount of seawater is added in proportion. The mixture is then pumped to the electrolysis tank 20 for electrolysis treatment, followed by degassing in the primary clear water tank of the main skid. The degassed clear water is pumped to the tanks of the digestion and filtration skid unit for further sterilization, homogenization, and filtration and sedimentation. After the COD value of the sewage is tested and found to be acceptable, it is discharged.

[0069] This embodiment fundamentally solves the problem of electrolytic cells easily becoming dirty and sticky, leading to tripping or excessive current damage to the equipment. It reduces the maintenance workload and cost of electrolytic cells, effectively extending their service life. It ensures the normal operation of domestic sewage treatment equipment, guaranteeing the safe production and compliant operation of the facility.

[0070] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0071] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0072] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An intelligent backwashing device for a domestic sewage treatment system, characterized in that, The intelligent backwashing device includes a control unit, an electrolytic cell, a sewage discharge control valve, a seawater inlet control valve, and a detection unit; The sewage discharge control valve is located at the sewage discharge pipeline of the electrolytic cell and is electrically connected to the control unit; the seawater inlet control valve is located at the seawater inlet pipeline of the electrolytic cell and is electrically connected to the control unit. The electrolytic cell is used to electrolyze domestic sewage; the detection unit is communicatively connected to the control unit and is used to detect actual working data reflecting the current electrolysis capacity of the electrolytic cell and send it to the control unit; the electrolytic cell includes a first electrolytic cell and a second electrolytic cell, and each electrolytic cell is respectively provided with a sewage discharge control valve and a seawater inlet control valve at corresponding positions; The control unit is used to determine whether the electrolysis capacity of the electrolytic cell is qualified based on whether the actual working data is within the preset standard range. If it is not qualified, the judgment result is uploaded to the central control system for alarm prompt. Moreover, during the non-operation period of the domestic sewage treatment system, when the backwashing mode is started, the control unit controls the opening of the seawater inlet control valve to allow seawater to flow into the electrolytic cell through the seawater inlet pipeline for cleaning. When the backwashing is completed, the control unit controls the opening of the sewage discharge control valve to discharge the cleaned sewage through the sewage discharge pipeline. The detection unit is used to detect the actual discharge data of the domestic sewage treatment system in real time and send it to the control unit. Alternatively, the detection unit is used to detect the actual electrolysis current of the electrolyzer during the operation of the domestic sewage treatment system in real time and send it to the control unit; The backwashing mode includes the cleaning frequency, cleaning duration, and / or the backwashing mode's operating time.

2. The intelligent backwashing device according to claim 1, characterized in that, The detection unit is also used to detect the degree of dirtiness of the electrolytic cell during backwashing mode, and send the current dirtiness detection data obtained to the control unit; The control unit is also used for: Determine whether the current dirt detection data meets the preset cleanliness standard; If so, the cleaning operation will automatically end, or the cleaning operation will end when the user confirms that the cleaning has stopped, and the sewage control valve will be opened to discharge the wastewater after cleaning.

3. The intelligent backwashing device according to claim 1, characterized in that, The intelligent backwashing device also includes a button unit, which includes a cleaning start button, a cleaning stop button, and a cleaning completion confirmation button. The control unit is used for: Receives a cleaning start command triggered by the user through the cleaning start button, and starts the backwash mode according to the cleaning start command; Receive a stop cleaning command triggered by the user through the stop cleaning button, and end the cleaning operation according to the stop cleaning command; The system receives a confirmation command triggered by the user through the "cleaning complete confirmation" button, and controls the sewage discharge control valve to open according to the confirmation command so that the sewage after cleaning can be discharged.

4. The intelligent backwashing device according to claim 1, characterized in that, The control unit is also used to adjust the cleaning frequency, cleaning duration and / or running time according to the actual operating conditions of the domestic sewage treatment system.

5. The intelligent backwashing device according to claim 4, characterized in that, The control unit adjusts the cleaning time based on the service life of the electrolytic cell and the sewage discharge situation; or, the control unit adjusts the cleaning time based on the actual cleaning level received.

6. The intelligent backwashing device according to claim 1, characterized in that, The intelligent backwashing device also includes a visualization unit connected to the control unit, which is used to display the cleaning status of the electrolytic cell transmitted from the control unit in real time.

7. A domestic sewage treatment system, characterized in that, Includes the intelligent backwashing device as described in any one of claims 1 to 6.

8. The domestic sewage treatment system according to claim 7, characterized in that, It also includes a regulating and processing unit, a mixing tank, a primary clear water tank on a main skid, and a digestion and filtration skid tank assembly. The regulating and processing unit includes a pulverizing unit, a buffer tank, and a liquid level detection unit located in the buffer tank. The liquid level detection unit is connected to the control unit and is used to detect the actual liquid level of domestic sewage in the buffer tank; The control unit is also used for: Determine whether the preset sewage discharge level has been reached based on the actual liquid level. If so, the domestic sewage shall be treated as follows: The crushing unit is activated to crush impurities in the domestic sewage, and the crushed domestic sewage enters the mixing tank to mix with a preset amount of seawater. The electrolytic cell is controlled to electrolyze the mixed domestic sewage. After the domestic sewage undergoes electrolysis treatment, it enters the primary clear water tank of the main skid for degassing. The discharge pump is then controlled to allow the degassed sewage to enter the digestion and filtration skid tank group for final treatment, including sterilization, homogenization, filtration, and sedimentation. Obtain the current COD value of the domestic sewage after final treatment; When the current COD value reaches the preset qualified standard, the sewage outlet is opened to discharge sewage.

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