A large circulating water station tower under the pool on-line deslagging system

Abstract

The application provides an online deslagging system for a large circulating water station tower pool, belonging to the technical field of industrial circulating water treatment. The system comprises a deslagging grid arranged between a tower pool and a water suction pool, a high-pressure flushing execution unit, a deslagging and water separation unit, an intelligent sensing and monitoring unit, and a PLC intelligent linkage control unit. The high-pressure flushing execution unit implements global flushing of the grid through partition flushing branch pipes and array-arranged multi-angle adjustable high-pressure nozzles. The deslagging and water separation unit integrates three-stage processing structures of gravity sedimentation, fine filtration, and spiral deslagging, to realize clean water reuse and automatic sludge transportation. The intelligent sensing and monitoring unit collects data of accumulated deslag thickness, front and rear liquid level difference, and water flow velocity in real time, and a multi-parameter fusion research and judgment model built in the PLC realizes siltation risk prediction, and two intelligent modes of timing normal flushing and early warning emergency flushing are configured. The application can realize full-process non-stop, unattended preventive intelligent deslagging in a large circulating water station tower pool.

Description

Technical Field

[0001] This application relates to the field of industrial circulating water treatment technology, and more specifically, to an online sludge removal system for the under-tower pool of a large circulating water station. Background Technology

[0002] Large-scale industrial circulating water systems are core public works projects in modern heavy industrial production facilities, undertaking crucial roles in cooling and heat exchange of production equipment, system heat balance, pipeline pressure stabilization, and water quality stability control. The operational stability of the circulating water system directly determines the safe production load and continuous operation capacity of the production line. The sludge-blocking screen installed between the lower water tank and the suction tank is a key structure for impurity interception, water buffering, and equipment protection in the circulating water system. During long-term operation, impurities such as silt, pipeline rust, microbial slime, and equipment corrosion products continuously adhere to and deposit on the screen surface, filter gaps, and corners, easily causing problems such as screen blockage, reduced flow cross-section between tanks, increased water flow resistance, and decreased circulation heat exchange efficiency.

[0003] Currently, the operation and maintenance of industrial circulating water stations in China generally adopts a manual shutdown and sludge removal mode. The overall level of automation and intelligent operation and maintenance in the industry is relatively low. The traditional operation and maintenance mode has many unavoidable technical shortcomings: First, shutdown and sludge removal cause huge production losses. Continuous production lines need to be shut down to cooperate with sludge removal operations. Frequent start-ups and shutdowns of equipment aggravate mechanical wear and tear, directly affecting the company's production capacity and economic benefits. Second, the safety risks of working in confined spaces are extremely high. The water tanks and suction tanks under the towers are closed and humid, which easily accumulate harmful gases. Manual entry into the tanks poses high risks of oxygen deficiency, poisoning, and drowning. Third, the operation and maintenance mode is passive and lagging behind. Manual sludge removal is only a post-event treatment after blockages occur, and it cannot achieve pre-emptive prevention. In addition, manual cleaning has blind spots, which easily lead to repeated sludge accumulation and hardening. Fourth, the operation and maintenance costs are high. Dedicated operation and maintenance teams need to be configured to conduct regular inspections and sludge removal. The comprehensive costs of labor, protection, water and electricity, and downtime losses remain high.

[0004] Meanwhile, existing bar screen cleaning equipment still has significant shortcomings in terms of non-stop online cleaning and closed-loop treatment of sludge and wastewater. For example, Chinese utility model patent CN210385092U discloses a quick-disassembly circulating water bar screen, belonging to the field of wastewater treatment equipment. It includes a rectangular fixed frame, a screen transmission device arranged within the frame, and several screen carriers installed on the screen transmission device, with screens installed in the screen carriers. This device is not only simple in structure and low in cost, but also solves the problem of difficult replacement of circulating water bar screens. When the screen is clogged, there is no need to stop the machine and remove the entire device; only the severely clogged screen needs to be removed from the corresponding screen carrier. At the same time, a new screen can be directly replaced in the screen carrier. The removed screen can be reused after simple processing. This solution achieves online replacement and cleaning of the screen through the screen transmission device in conjunction with high-pressure nozzles and brush assemblies. However, it only addresses the disassembly and replacement of the screen itself and lacks a matching sludge and wastewater separation structure. The sludge-containing wastewater generated during rinsing is directly returned to the water tank, which can easily cause secondary siltation in the system. Chinese invention patent CN106049645A discloses an online sludge cleaning system for cooling tower pools in thermal power plants. The system includes a pool at the bottom of the cooling tower, a sludge filtration pool outside the cooling tower, a sludge suction device with one end extending to the bottom of the pool and the other end extending to the top of the sludge filtration pool, a clear water pool connected to the sludge filtration pool, and a water circulation device connected to the cooling tower and the pool. This solution uses a robotic arm to drive a suction cup to remove sludge from the bottom of the pool and, in conjunction with the sludge filtration pool, achieves mud-water separation. However, it cannot solve the problem of washing away accumulated sludge on the grating surface and in the filter screen gaps.

[0005] In summary, existing technologies cannot meet the actual needs of large industrial circulating water stations for non-stop, unattended, and preventative intelligent sludge removal. The industry urgently needs an integrated operation and maintenance system that combines intelligent monitoring and risk prediction, non-stop full-area sludge removal, online solid-liquid separation, and intelligent linkage throughout the entire process to replace the traditional manual shutdown sludge removal mode. Summary of the Invention

[0006] This application provides an online sludge removal system for the under-tower pool of a large circulating water station, which can achieve uninterrupted, unattended, preventative intelligent sludge removal in the under-tower pool of a large circulating water station.

[0007] In the first aspect, this application provides an online slag removal system for the under-tower pool of a large circulating water station. The system includes: a slag-blocking grid installed between the under-tower pool and the suction pool, a high-pressure flushing execution unit, a slag-water separation unit, an intelligent sensing and monitoring unit, and an intelligent linkage control unit. The slag-blocking grid includes a coarse filter screen and a fine filter screen. The coarse filter screen and the fine filter screen are cleaned independently in staggered zones. When any layer of filter screen is cleaned, the remaining filter screens maintain normal flow state to ensure that the water flow between the pools is continuous and uninterrupted. The high-pressure flushing execution unit includes a high-pressure water supply main pipe, multiple partition flushing branch pipes connected to the high-pressure water supply main pipe, electromagnetic control valve groups respectively installed on each partition flushing branch pipe, and flushing brackets arranged at the slag-blocking grid and high-pressure nozzles installed on the flushing brackets. The slag-water separation unit adopts an integrated online slag-water separation device. The inlet of the online slag-water separation device is connected to the bottom sewage guide channel of the slag-blocking bar screen. The inlet of the online slag-water separation device is lower than the outlet of the sewage guide channel at the bottom of the bar screen. The slag-containing wastewater flows into the slag-water separation device by gravity due to the liquid level difference. The bottom of the sewage guide channel is equipped with an opening and closing baffle at a set distance. The opening and closing baffle is rotatably connected to the two sides of the sewage guide channel through a hinge shaft. In the closed state, the opening and closing baffle is in a horizontal state. In the open state, the opening and closing baffle is in an inclined state, and the inclined side is aligned with the inlet of the online slag-water separation device, so that the slag-containing wastewater generated during the cleaning of the slag bar screen flows into the online slag-water separation device by gravity. The intelligent linkage control unit includes a PLC programmable controller, and the output terminals of the PLC programmable controller are electrically connected to the partitioned electromagnetic control valve group, the sludge-water separation device drive mechanism, and the high-pressure water supply unit, respectively.

[0008] Preferably, the PLC programmable controller has a reserved general industrial communication interface, which can realize bidirectional data communication and linkage control with the plant's circulating water pump, side filter equipment, and DCS production control system; the PLC is connected to an external wireless communication module, which can remotely push system operating parameters, slag accumulation warning signals, and equipment fault information to the central control room and maintenance terminal, and receive remote control commands.

[0009] Preferably, the intelligent sensing and monitoring unit includes a sludge thickness sensor, level gauges before and after the bar screen, and a flow velocity sensor between the pools. The signal output terminals of the sludge thickness sensor, level gauges before and after the bar screen, and flow velocity sensor between the pools are all electrically connected to the intelligent linkage control unit.

[0010] Preferably, the high-pressure nozzle is connected to the flushing bracket via a universal ball joint, and the high-pressure nozzle can freely adjust the spray angle within a predetermined angle range.

[0011] Preferably, the partition flushing branch pipes are configured in a one-to-one correspondence with the slag-blocking grids, and each partition flushing branch pipe is equipped with an independent electromagnetic control valve group. The PLC programmable controller is configured to open each electromagnetic control valve group in turn by region and by time sequence, so as to perform full-area high-pressure flushing on each group of slag-blocking grids in turn.

[0012] Preferably, the sludge-water separation device integrates a three-stage treatment structure from top to bottom: a gravity settling chamber, a fine filtration module, and a spiral automatic sludge discharge mechanism. The filtered clean water is returned to the water tank below the tower for recycling, and the solid sludge is transported out by the spiral automatic sludge discharge mechanism at regular intervals.

[0013] Preferably, the coarse filter and the fine filter are lifted to the rinsing station by a crane for cleaning.

[0014] Preferably, the intelligent sensing and monitoring unit collects multi-dimensional operating data such as the thickness of the sludge accumulation in the bar screen, the difference in liquid level before and after the bar screen, and the flow rate of water between the pools in real time and uploads them to the PLC programmable controller. The PLC has a built-in multi-parameter fusion intelligent judgment model, which automatically identifies the bar screen's slight sludge accumulation and severe blockage conditions based on multi-level thresholds, and executes early warning prompts and emergency flushing actions respectively.

[0015] Secondly, this application provides an online slag removal method for the under-tower pool of a large-scale circulating water station based on the above-mentioned system. The system is configured with two collaborative operation modes: a time-sequential normal flushing mode and a multi-parameter early warning emergency flushing mode. The time-sequential normal flushing mode is as follows: the PLC programmable controller sequentially opens the electromagnetic control valve groups of each zone according to a preset cycle and preset duration, and performs full-area high-pressure flushing on each group of slag-blocking grids in turn. After flushing, the valve groups are shut off after a delay to achieve normalized preventive slag removal. The multi-parameter early warning emergency flushing mode is as follows: when the monitoring data of the slag accumulation thickness of the grid or the difference in liquid level before and after the grid exceeds a preset safety threshold, the PLC programmable controller prioritizes pushing an early warning signal, and then automatically starts the high-pressure flushing operation of the corresponding area and synchronously links the slag-water separation device to operate until the monitoring parameters fall back to the normal safety range, after which the system automatically resets and stops.

[0016] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: This application achieves preventative intelligent slag removal and maintenance by systematically integrating a high-pressure flushing execution unit, a slag-water separation unit, an intelligent sensing and monitoring unit, and an intelligent linkage control unit. This enables the slag-blocking screen between the lower pool and the suction pool of the circulating water tower to operate continuously without machine interruption or manual operation. It effectively innovates the traditional manual shutdown slag removal mode, eliminating safety hazards in confined space operations and production line downtime losses. First, either a fan-shaped wide-angle nozzle or a rotary impact nozzle is used. The fan-shaped wide-angle nozzle has a large coverage area and high flushing efficiency, suitable for the rapid removal of loose deposits on the screen surface. The rotary impact nozzle has strong impact force and good penetration, reaching deep into the gaps and corners of the filter screen to remove stubborn, hardened deposits. The two nozzles work together to achieve thorough cleaning without dead angles, with a cleaning efficiency far exceeding that of traditional single-nozzle flushing methods, and a significant effect on restoring the pressure difference before and after the screen.

[0017] Secondly, the slag-blocking screen adopts a series arrangement of coarse and fine filter screens. The two layers of filter screens are cleaned independently in staggered zones. While cleaning one layer of filter screen, the other layers maintain normal flow, ensuring continuous and uninterrupted water flow between the tanks. This design effectively solves the technical problem of traditional single-layer screens requiring shutdown or reduced load operation for cleaning, truly achieving continuous operation of the circulating water system without shutdown, ensuring uninterrupted flow between tanks, and eliminating production losses and safety risks caused by shutdown for slag removal.

[0018] Furthermore, the inlet of the slag-water separation device is lower than the outlet of the sewage guide channel at the bottom of the screen. An opening and closing baffle is installed at a set bottom distance of the sewage guide channel. The opening and closing baffle is rotatably connected to the two sides of the sewage guide channel through a hinge shaft. In the closed state, the opening and closing baffle is horizontal, and in the open state, the opening and closing baffle is inclined, with the inclined side facing the inlet of the online slag-water separation device. This allows the slag-containing wastewater generated during the cleaning of the slag screen to flow into the online slag-water separation device by gravity, eliminating the need for secondary lifting. This effectively avoids splashing of slag-containing wastewater, greatly simplifies the system pipeline structure and equipment configuration, reduces operating energy consumption and equipment maintenance costs, and eliminates the risk of system downtime caused by lift pump failure.

[0019] Then, the intelligent linkage control unit sets two levels of thresholds to achieve hierarchical control. The first-level threshold triggers an early warning, reminding maintenance personnel to pay attention and arrange planned cleaning; the second-level threshold triggers automatic emergency flushing and activates the slag-water separation device. This hierarchical control strategy realizes the transformation from passive slag removal to proactive preventive treatment, avoiding water waste and equipment wear caused by excessive flushing, while ensuring that the bar screen always operates within a safe range, achieving a unity of intelligence and energy saving.

[0020] Finally, the integrated online sludge-water separation device performs three-stage treatment on the sludge cleaning wastewater. The clean water is returned to the water tank below the tower for recycling, and the solid sludge is automatically transported off-site at regular intervals, eliminating secondary pollution and system siltation problems caused by direct discharge of sludge-containing wastewater. High-pressure flushing water is supplied by bypassing the high-pressure side of the plant's existing circulating water pump outlet, eliminating the need for an additional high-pressure water supply pump station and significantly reducing system investment and operating costs. The PLC has reserved a general industrial communication interface and wireless communication module, enabling bidirectional data communication and remote control with the DCS system and maintenance terminals, achieving unattended operation and remote intelligent management of sludge cleaning. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view of the structure of the online sludge removal system for the large-scale circulating water station's lower pool in this application; Figure 2 This is an isometric schematic diagram of the overall installation of the high-pressure flushing execution unit of this application, with the slag-collecting grid located between the water tank and the suction tank below the tower. Figure 3This is a structural diagram of the adjustable high-pressure nozzle with universal ball joint in this application; Figure 4 This is a flowchart illustrating the intelligent control logic of the three-mode online sludge removal system for the large-scale circulating water station's lower pool in this application.

[0022] In the diagram: 1. Flushing water pipe; 2. Solenoid valve; 3. High-pressure nozzle; 4. Grille guide rail; 5. Flushing bracket; 6. Crane; 7. Fine grille; 8. Sewage discharge guide channel; 9. Online sludge-water separation device; 10. Coarse grille; 11. Opening and closing baffle; 12. Inlet of online sludge-water separation device; 13. Threaded interface; 14. Universal ball joint; 15. Fan-shaped wide-angle nozzle. Detailed Implementation

[0023] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] In some embodiments of this application, an online sludge removal system for a large circulating water station's under-tower pool includes: a sludge-blocking grid installed between the under-tower pool and the suction pool, a high-pressure flushing execution unit, a sludge-water separation unit, an intelligent sensing and monitoring unit, and an intelligent linkage control unit. The slag-blocking screen includes a coarse filter and a fine filter. The coarse and fine filters are cleaned independently in staggered zones. When any layer of filter is being cleaned, the remaining filters maintain normal flow to ensure continuous and uninterrupted water flow between the tanks. The high-pressure flushing unit includes a high-pressure water supply main, multiple zone flushing branch pipes connected to the high-pressure water supply main, electromagnetic control valve assemblies respectively installed on each zone flushing branch pipe, a flushing bracket arranged at the slag-blocking screen, and high-pressure nozzles installed on the flushing bracket. The slag-water separation unit adopts an integrated online slag-water separation device. The inlet of the online slag-water separation device is connected to the bottom sewage guide channel of the slag-blocking screen, and the inlet of the online slag-water separation device is lower than the bottom discharge channel of the screen. At the outlet of the wastewater diversion channel, wastewater containing slag flows into the slag-water separation device by gravity due to the difference in liquid level. A baffle is installed at a predetermined distance at the bottom of the wastewater diversion channel. The baffle is rotatably connected to both sides of the channel via a hinge shaft. In the closed state, the baffle is horizontal; in the open state, it is inclined, with the inclined side aligned with the inlet of the online slag-water separation device. This allows wastewater containing slag generated during the cleaning of the slag screen to flow downstream into the online slag-water separation device by gravity. The intelligent linkage control unit includes a PLC programmable controller. The output of the PLC is electrically connected to the zoned electromagnetic control valve group, the slag-water separation device drive mechanism, and the high-pressure water supply unit.

[0025] refer to Figure 1This figure is a schematic cross-sectional view of the structure of the online sludge removal system for the large-scale circulating water station tower pool of this application. In the figure, the flushing support 5 is fixedly installed on the pool wall, and the frame of the crane 6 is fixedly connected to the middle of the top crossbeam of the two side flushing supports 5. Flushing water pipes 1 are fixedly installed on the two side flushing supports 5 respectively. Multiple sets of high-pressure nozzles 3 are fixedly installed on the bottom surface of the flushing water pipes 1 by threaded connection. The spraying end of the high-pressure nozzles 3 faces downward and is directly facing the lower grid plate surface. The grid guide rails 4 are vertically fixedly installed on the pool wall respectively, and the grid guide rails 4 are arranged from top to bottom. The two sides of the fine grid 7 are slidably engaged with the upper section of the two side grid guide rails 4 respectively, and can move up and down along the grid guide rails 4. The sewage diversion channel 8 is fixedly installed below the flushing support 5. An opening and closing baffle 11 is set at a set distance at the bottom of the sewage diversion channel 8. The set distance is higher than the bottom surface of the sewage diversion channel and lower than the outer edge of the sewage diversion channel. The maximum flipping angle of the opening and closing baffle 11 is set at... Preferred This allows the wastewater containing slag to be effectively diverted to the online slag-water separation device. The opening and closing baffle 11 is rotatably connected to both sides of the sewage diversion channel 8 via a hinge shaft, which can control the opening and closing of the sewage diversion channel. The bottom of the sewage diversion channel 8 is in an open state, and the flow is diverted by the inclination of the opening and closing baffle 11. The two sides of the coarse screen 10 are slidably engaged with the lower section of the two side screen guide rails 4, located below the opening and closing baffle 11, and can move up and down along the screen guide rails 4. The inlet 12 of the online slag-water separation device is connected to the outlet on the inclined side of the opening and closing baffle 11 in the sewage diversion channel 8 through a pipe. The online slag-water separation device 9 is fixedly installed on the outer side of the side wall of the suction pool. The solenoid valve 2 is fixedly installed on the side wall of the water tank below the tower through a flange connection. The outlet of the solenoid valve 2 is connected to the inlet of the flushing water pipe 1, which is used to control the water supply of the flushing water pipe 1.

[0026] In the specific implementation process, the procedure for the crane to lift the slag-collecting screen for cleaning is as follows: The multi-parameter fusion intelligent judgment model built into the PLC programmable controller continuously receives real-time operating data from the ultrasonic slag thickness sensor, the remote level gauges before and after the slag-collecting screen, and the flow velocity sensor between the pools. When the monitored parameters reach the preset flushing threshold, the crane is powered on and lifts the slag-collecting screen (fine or coarse) to be cleaned upwards along the screen guide rail. When it contacts the opening and closing baffle inside the sewage diversion channel, the opening and closing baffle is subjected to upward pressure and flips, allowing the slag-collecting screen to pass through the sewage diversion channel. Upon reaching the flushing station directly below the high-pressure nozzle, the system locks in position. At this point, the opening and closing baffle returns to its original horizontal state after being relieved of pressure. Once the slag-blocking screen is in place, the PLC issues a command to open the solenoid valve of the corresponding zone. High-pressure water from the existing circulating water pumps in the plant is then transported to the high-pressure nozzles via the flushing water pipes. When a wide-angle fan-shaped nozzle is used, it forms a wide-width high-pressure water jet to peel and flush away large areas of loose sludge and floating scum on the screen surface. When a rotary impact nozzle is used, it utilizes high impact force to specifically remove stubborn slag buildup in the filter screen gaps and corners. The nozzles are connected via a universal ball joint. The spray angle of the head can be adjusted within ±30° to cover the entire slag accumulation area, achieving full-area flushing. During the flushing process, the slag-containing wastewater flows downwards into the sewage diversion channel. When the opening and closing baffles in the sewage diversion channel are subjected to the downward pressure of the slag-containing wastewater, the baffles tilt, allowing the slag-containing wastewater to flow into the inlet of the online slag-water separation device along the tilted side. The slag-containing wastewater generated during the cleaning of the slag screen is discharged into the online slag-water separation device by gravity. The opening and closing baffles have a maximum threshold for their flipping angle; when the maximum threshold is reached, they no longer flip or tilt. During this process, the coarse and fine... The two layers of filters are cleaned independently in staggered zones. When one layer of the screen is being cleaned, the other layer remains in its normal filtration position and continues to flow. The water flow between the tanks is continuous and uninterrupted, ensuring that the circulating water system operates without stopping. The sludge-containing wastewater that is washed off falls into the sewage discharge channel at the bottom of the screen and flows by gravity along the inclination of the opening and closing baffles. It then flows into the sludge-water separation device by gravity due to the difference in liquid level. Inside the sludge-water separation device, it passes through the gravity settling chamber to settle large particles of silt, the fine filtration module to intercept fine flocculent sludge, and the spiral automatic sludge discharge mechanism to transport solid sludge out at regular intervals. The clean water after separation returns to the water tank below the tower through the return pipe for recycling.After the bar screen has been flushed for the preset time, the PLC closes the corresponding zone solenoid valve to stop the water supply. The crane lowers the bar screen back to its original position along the guide rail. Then, the opening and closing baffle is flipped back under downward pressure, causing the bar screen to fall. This coordinated action ensures that the flushing wastewater is discharged in an orderly manner throughout the process, without overflowing into the pool area. This achieves continuous online cleaning without shutting down the machine. The entire cleaning operation is intelligently controlled by the PLC and completed automatically without human intervention. If the PLC determines that the current mode is a multi-parameter early warning emergency mode, it will automatically start the above process after sending a remote early warning signal and automatically reset and stop the machine after the monitored parameters return to a safe range.

[0027] In practical implementation, the high-pressure flushing execution unit relies on the existing circulating water pump in the plant area to provide high-pressure water, eliminating the need for a separate high-pressure water pump set. This results in low equipment investment and strong operational stability. The system's flushing pipeline network adopts a main pipe plus zoned branch pipe layout. The main water supply pipe uses carbon steel anti-corrosion pipe, and each grid zone branch pipe is independently equipped with an electromagnetic control valve group, enabling precise flushing by area and time period, avoiding the problems of water pressure attenuation and insufficient flushing force caused by synchronous flushing of the entire area. High-pressure nozzles are arrayed on both sides of the grid flushing support. All nozzles are oriented towards the surface, gaps, and bottom sewage guide channel of the slag-blocking grid filter plate, ensuring that the flushing water flow can fully cover all slag accumulation areas of the grid. The slag thickness sensor in the intelligent sensing monitoring unit collects the thickness data of the deposits on the grid surface in real time. The level gauges before and after the grid measure the water level height upstream and downstream of the grid to calculate the level difference, and the inter-pool flow velocity sensor monitors the real-time flow velocity of the water flow channel between the pools. The three types of sensors mentioned above upload data to the PLC programmable controller in real time via 4mA-20mA analog signals. The PLC programmable controller, as the control center of the entire system, receives all sensor signals in a coordinated manner and sends control commands to the electromagnetic control valve group and the drive mechanism of the slag-water separation unit, so as to realize the intelligent linkage control of the entire system.

[0028] By adopting the above technical solution, the systematic integration of four core units—high-pressure flushing execution unit, slag-water separation unit, intelligent sensing and monitoring unit, and intelligent linkage control unit—has enabled continuous online slag removal of the circulating water slag screen, effectively replacing the traditional manual shutdown slag removal mode and eliminating safety hazards and production stoppage losses in confined spaces.

[0029] refer to Figure 2This figure is an isometric view of the overall installation of the high-pressure flushing execution unit of the present invention in the slag-trapping grid between the tower water tank and the suction tank. The high-pressure flushing execution unit is installed in the tank wall area between the tower water tank and the suction tank. The tower water tank and the suction tank are separated by a middle tank wall with a channel for circulating water flow. A slag-trapping grid is installed at this channel. The slag-trapping grid consists of a coarse grid 10 and a fine grid 7. The coarse grid 10 is used to intercept larger particles of silt, filler debris, and suspended impurities, while the fine grid 7 is used to further intercept fine impurities in the water after passing through the coarse grid 10. Together, they achieve graded interception of various impurities in the circulating water. A flushing support is installed at the top of the tank wall. The flushing support is a steel frame spanning both sides of the tank wall, with its cantilevered ends extending into the tower water tank and the suction tank, respectively. A flushing water pipe 1 is installed at each cantilevered end of the flushing support. The flushing water pipe 1 is a vertically arranged water supply pipe, with its lower end extending to the area below the slag. Each flushing water pipe 1 is longitudinally spaced with multiple high-pressure nozzles 3, the spray direction of which is directed towards the grid plate surface, filter screen gaps, and bottom area on its respective side. In this embodiment, each flushing water pipe 1 is equipped with two layers of high-pressure nozzles 3: the upper layer of high-pressure nozzles 3 is used for large-area flushing of the grid plate surface, and the lower layer of high-pressure nozzles 3 is used for flushing the bottom of the grid and the sewage diversion channel area, thereby achieving full coverage of the grid. Cranes 6 are installed at both ends of the top of the flushing support 5. The cranes 6 are electric winches or hydraulic lifting devices, connected to the coarse grid 10 and fine grid 7 by steel wire ropes or chains, and are used to lift the grid filter screen to the flushing position during the flushing operation and to reset it after flushing. The cranes are arranged on the top of the flushing support 5, using the pool wall structure as the support foundation, without the need for an additional independent lifting frame. Sewage drainage channels 8 are respectively installed on both sides of the bottom of the flushing support 5, that is, below the coarse screen 10 and the fine screen 7. The sewage drainage channels 8 are used to collect the sludge-containing wastewater peeled off from the surface of the filter screen during the screen flushing process and the impurities deposited at the bottom of the screen. The opening and closing baffle 11 at the bottom of the sewage drainage channel 8 is used to control the opening and closing of the sewage drainage channel 8, so that the sludge-containing wastewater and the impurities deposited at the bottom of the screen are diverted and discharged through the opening and closing baffle 11 to avoid splashing. The solenoid valve is connected to the flushing main pipe, which is a horizontally arranged manifold pipe laid under the suction tank cover plate. It collects the sludge-containing wastewater collected by the sewage drainage channels 8 on both sides and transports it to the sludge-water separation unit. A suction tank cover plate is installed above the suction tank. The suction tank cover plate is a reinforced concrete or steel structure cover plate, which is used to close the top of the suction tank to prevent debris from falling in and to ensure operational safety. The flushing main pipe is laid in the space under the suction tank cover plate, which does not occupy ground space and has a compact overall layout. In terms of structural connection, the upper end of flushing water pipe 1 is connected to the high-pressure water outlet pipe of the plant's circulating water pump via a bypass branch pipe, utilizing the outlet water pressure of the circulating water pump as the flushing power source, eliminating the need for a separate high-pressure water pump. A control valve is installed on the pipeline between flushing water pipe 1 and the bypass branch pipe to start and stop the flushing water supply.The solenoid valves are controlled by a PLC programmable controller. The PLC automatically controls the opening and closing of the solenoid valves in each zone based on a preset flushing sequence or sludge accumulation signals from sensors, enabling zoned and time-sequential flushing. Spatially, the water tank below the tower and the suction tank are arranged along the tank wall, with multiple sets of sludge-blocking grilles evenly spaced along the length of the tank wall. Each set of grilles corresponds to an independent flushing support 5, flushing water pipe 1, high-pressure nozzle 3, sewage discharge guide channel 8, and solenoid valve, forming an independent flushing zone. The main flushing pipes of each zone converge into the same main manifold, ultimately transporting the sludge-containing wastewater to an integrated sludge-water separation device for three-stage treatment: gravity sedimentation, fine filtration, and spiral sludge discharge. The clean water is then returned to the water tank below the tower for recycling.

[0030] The above structure enables in-situ online high-pressure flushing of the slag-blocking bar without shutting down, automatic collection and closed-loop treatment of slag-containing wastewater, and intelligent flushing control by region and time sequence, effectively replacing the traditional manual shutdown and slag removal mode.

[0031] In some preferred embodiments of this application, the slag-blocking grid includes a coarse filter screen and a fine filter screen. The coarse filter screen and the fine filter screen are cleaned independently in staggered zones. When any layer of filter screen is cleaned, the remaining filter screens maintain normal flow conditions to ensure continuous and uninterrupted water flow between the pools.

[0032] In the specific implementation process, the coarse filter screen is arranged on one side of the water tank below the tower to intercept larger particles of silt, packing debris, and suspended impurities. The mesh size can be selected according to the actual working conditions; for example, a stainless steel wire mesh with a mesh size of 2cm × 2cm can be used. The fine filter screen is arranged on one side of the water intake tank to intercept fine impurities in the water after passing through the coarse filter screen. The mesh size is smaller than that of the coarse filter screen; for example, a stainless steel wire mesh with a mesh size of 0.5cm × 0.5cm can be used. Both layers of filter screens adopt a structure design that can be lifted independently. During the cleaning operation, the coarse filter screen can be lifted separately for high-pressure washing first, while the fine filter screen remains in place and continues to perform the flow filtration function. After the coarse filter screen is washed and reset, the fine filter screen is lifted again for washing, at which point the coarse filter screen has been reset and is performing the flow function. This staggered and alternating cleaning ensures that at least one layer of filter screen is in a normal flow state during any cleaning period, and the flow capacity between the tanks of the circulating water system is not interrupted.

[0033] Specifically, regarding the structure of coarse and fine filter screens arranged in series in the partition wall channel between the water tank and the suction tank, unlike the traditional technology of simultaneous shutdown cleaning or alternating manual cleaning of dual-screen screens, this solution achieves continuous operation of the circulating water system without interruption during the cleaning process by staggered and independent cleaning in different zones. Specifically, through independent timing control of the zoned electromagnetic control valve groups by a PLC programmable controller, the coarse and fine screens are assigned to their respective independent cleaning zones, with strict staggered and layer-by-layer rotation in the cleaning sequence. The PLC first controls the opening and closing of the baffle and starts the crane, lifting the fine screen along the screen guide rail to the flushing position below the high-pressure nozzle. The corresponding zone's electromagnetic control valve group then opens to supply water for high-pressure flushing. At this time, the coarse screen remains in its normal filtration position, continuously intercepting large particles and maintaining uninterrupted flow between the tanks. After the fine screen is flushed and reset, the PLC switches back to the coarse screen zone and controls the opening and closing of the valve groups. The baffle is opened, and the crane lifts the coarse screen to the rinsing station. Another set of electromagnetic control valves opens to supply water for rinsing, while the fine screen is reset to continue filtering and intercepting small particles of impurities, ensuring continuous water flow. Throughout the entire process, at least one of the two filter layers is always in a flow-through state, and the water flow channel between the tanks is uninterrupted and unloaded at any cleaning stage. This allows the entire sludge removal operation to be completed online without shutting down the system under normal operating conditions. The technical advantages of this design are that, on the one hand, it avoids the production capacity loss and safety risks of confined space operations caused by traditional shutdown sludge removal; on the other hand, it avoids the risk of instantaneous flow interruption and water shortage in downstream equipment caused by simultaneous cleaning of both filter screens; and on the other hand, by staggering the cleaning time, it ensures that while one filter layer is being cleaned, the other layer is still in a filtering and intercepting state, preventing the chain reaction problem of the uncleaned layer being aggravated by the sudden increase in instantaneous load, effectively ensuring the long-term continuous and stable operation of the circulating water system.

[0034] It should be noted that during the coarse filter's lifting and flushing process, because the coarse filter is temporarily detached from the flow channel, large particles that were originally intercepted by the coarse filter will briefly reach the surface of the fine filter. Considering the short flushing cycle of a single-layer coarse filter (approximately 480 seconds) and the fine filter's inherent ability to trap large particles, this temporary overload will not cause clogging or damage to the fine filter. To further reduce the risk of temporary overload, the water flow rate corresponding to this channel is automatically reduced during the coarse filter flushing process, decreasing the inlet flow rate to 50%-70% of the rated flow rate. This reduces the instantaneous load on the fine filter by decreasing the incoming water volume. After the coarse filter is flushed and reset, full flow operation is immediately resumed.

[0035] It should be noted that stainless steel water-retaining guide covers are installed above and around the filter screen lifting and rinsing station, and the bottom outlet of the water-retaining guide covers is connected to the sewage discharge channel. When the filter screen is lifted to the rinsing station for high-pressure rinsing, the wastewater containing slag generated during rinsing is collected by the water-retaining guide covers, guided into the sewage discharge channel through the bottom outlet, and then flows by gravity to the slag-water separation unit for treatment based on the height difference between the tanks, thus avoiding the rinsing wastewater from splashing directly into the tank body and causing secondary pollution.

[0036] By adopting the above technical solution, the coarse and fine double-layer filter screens are arranged in series and combined with the staggered and zoned independent cleaning strategy. While ensuring the interception effect, the circulating water system can be operated continuously without stopping during the cleaning process, effectively eliminating the risk of production line downtime caused by screen cleaning.

[0037] In some preferred embodiments of this application, the high-pressure nozzle is a fan-shaped wide-angle nozzle. Alternatively, a rotary impact nozzle can be used. The fan-shaped wide-angle nozzle forms a wide high-pressure water jet for peeling off loose mud and scum from a large area of ​​the grating plate surface, while the rotary impact nozzle is used to remove stubborn scum from the gaps and corners of the filter screen.

[0038] refer to Figure 3 This figure shows the structure of the adjustable high-pressure nozzle with a universal ball joint according to this application. The figure includes three parts connected coaxially in series: a threaded interface 13, a universal ball joint 14, and a fan-shaped wide-angle nozzle 15. The threaded interface is located at the water inlet end, with an external thread section at one end, which is fixedly connected to the water outlet end of the flushing branch pipe by threaded engagement, achieving a sealed connection of the high-pressure water circuit. The universal ball joint is located between the threaded interface and the fan-shaped wide-angle nozzle. The ball head end of the universal ball joint is hinged to the spherical surface of the water outlet end of the threaded interface, and the ball socket end is... The inlet end of the fan-shaped wide-angle nozzle is spherically fitted, allowing the universal ball joint to rotate freely at multiple angles in both horizontal and vertical directions. The fan-shaped nozzle is located at the outlet end, with its inlet end fixedly connected to the ball joint's socket end via an internal thread. The outlet end spreads out in a fan shape to spray high-pressure water into a wide fan-shaped water jet. High-pressure water flows in from the flushing branch pipe through the threaded interface, passes through the internal flow channel of the universal ball joint, and is then ejected from the fan-shaped outlet of the fan-shaped nozzle. The universal ball joint allows the fan-shaped nozzle to rotate freely at multiple angles in both horizontal and vertical directions. The spray angle and direction can be adjusted within the range to adapt to the directional flushing needs of different positions of the grid plate surface, gaps and sewage guide channel area. The fan-shaped wide-angle nozzle can also be replaced with a rotating impact nozzle for removing stubborn deposits that have hardened on the filter screen gaps and corners.

[0039] In practical implementation, the fan-shaped wide-angle nozzle forms a wide-area high-pressure water jet with a large spray angle and wide coverage, used for the efficient removal of large areas of loose sludge and scum on the surface of the grating and frame. The rotary impact nozzle rotates automatically under the drive of high-pressure water flow, generating pulsed impact force with strong impact and good penetration, specifically used for deep removal of hardened and stubborn scum in filter gaps and corners. The choice of two nozzles allows the system to select the optimal flushing strategy according to different types of scum conditions. For fresh and loose scum, the fan-shaped wide-angle nozzle is used for large-area rapid removal, while for long-term hardened and stubborn scum, the rotary impact nozzle is switched to deep impact removal, achieving a highly efficient and comprehensive scum removal effect.

[0040] By adopting the above technical solution, the selection of fan-shaped wide-angle nozzles and rotating impact nozzles can be adapted to two different working conditions: loose sludge removal and stubborn sludge removal. This achieves efficient cleaning of the entire bar screen without dead angles and effectively eliminates cleaning blind spots.

[0041] In some preferred embodiments of this application, the high-pressure nozzle is connected to the flushing bracket via a universal ball joint, and the high-pressure nozzle can freely adjust the spray angle within a predetermined angle range.

[0042] In practical implementation, the universal ball joint adopts a metal ball joint structure. The high-pressure nozzle achieves multi-degree-of-freedom angle adjustment through the cooperation between the ball joint core and the ball joint seat. The predetermined angle range is preferably... During actual installation and commissioning, maintenance personnel can adjust the spray angle of each nozzle according to the specific installation angle of the bar screen, the characteristics of the accumulated sludge distribution, and the situation of blind spots in flushing. This ensures that the high-pressure water flow can accurately target all areas with high sludge accumulation, such as the bar screen surface, filter screen gaps, and bottom sewage drainage channel. The adjustment process of the universal ball joint does not require disassembling the nozzle; it can be locked simply by manually adjusting the ball joint angle. After adjustment, the nozzle will not shift its angle under the impact of high-pressure water flow, ensuring long-term operational stability.

[0043] By adopting the above technical solution, the universal ball joint allows each nozzle to independently adjust the spray angle, adapting to different bar screen installation conditions and slag distribution characteristics, ensuring that the high-pressure water flow accurately covers all slag areas of the bar screen, further improving the flushing effect and eliminating flushing dead corners.

[0044] In some preferred embodiments of this application, the partition flushing branch pipes are configured one-to-one with the slag-blocking grids, and each partition flushing branch pipe is equipped with an independent electromagnetic control valve group. The PLC programmable controller opens each electromagnetic control valve group in turn according to the region and time sequence, so as to perform full-area high-pressure flushing on each group of slag-blocking grids in turn.

[0045] In practical implementation, when the circulating water station is equipped with multiple sets of screens, each set of screens corresponds to an independent flushing branch pipe and electromagnetic control valve group. The PLC programmable controller, according to the preset flushing sequence, first opens the electromagnetic control valve group corresponding to the first set of screens. High-pressure water flows through the flushing branch pipe of this group into the flushing support, performing full-area high-pressure flushing of this set of screens. After the preset flushing time is completed, the electromagnetic control valve group of this group is closed, and after a set delay, the electromagnetic control valve group corresponding to the second set of screens is opened, and so on, completing the flushing operation of all screens one by one. This zoned, rotating flushing design avoids the problems of sudden drop in system water pressure and insufficient flushing force caused by simultaneous flushing of multiple sets of screens, ensuring that each set of screens receives sufficient high-pressure flushing water pressure and guarantees the flushing effect.

[0046] Using the above technical solution, the zoned flushing branch pipes, together with independent electromagnetic control valve groups, realize zoned and timed sequential flushing, avoid water pressure attenuation caused by simultaneous flushing of multiple sets of screens, ensure that each set of screens receives sufficient flushing force, and at the same time reduce the instantaneous water load of the system.

[0047] In some preferred embodiments of this application, the sludge-water separation unit is an integrated online sludge-water separation device. The inlet of the sludge-water separation device is connected to the sewage discharge guide channel at the bottom of the sludge-blocking grid. The sludge-water separation device integrates a three-stage treatment structure from top to bottom: a gravity settling chamber, a fine filtration module, and a spiral automatic sludge discharge mechanism. The filtered clean water is returned to the water pool below the tower for recycling, and the solid sludge is transported out by the spiral automatic sludge discharge mechanism at regular intervals.

[0048] In practical implementation, the sludge-water separation device is located on the upper platform or ground of the suction pool, with its inlet connected to the sewage discharge channel at the bottom of the sludge-blocking grid via a pipe. Sludge-containing wastewater generated during grid flushing flows into the sludge-water separation device by gravity due to the height difference between the pools, eliminating the need for a secondary booster pump. The first-stage gravity settling chamber has a large volume, causing a sharp drop in flow velocity after wastewater enters. Large particles of silt and lumpy impurities settle to the bottom of the chamber under gravity and are periodically discharged through the bottom sludge discharge port. The second-stage fine filtration module uses stainless steel filter screens or filter cartridges to trap fine flocculent sludge and suspended colloidal impurities remaining in the water after gravity settling. The filtration precision can be selected according to actual water quality requirements. The third-stage spiral automatic sludge discharge mechanism uses a spiral conveyor structure to periodically push the trapped solid sludge along the spiral blades to the sludge discharge port for transport to the plant's sludge disposal system. The clean water after three stages of treatment flows directly back to the water tank below the tower through a return pipe, achieving recycling.

[0049] In the specific design, the effective volume of the gravity settling chamber is designed with a residence time of not less than 30 seconds to ensure that particulate impurities with a diameter greater than 0.5 mm complete effective settling within the chamber; the filtration area of ​​the fine filtration module is designed with a surface load of not more than The design ensures a balance between filtration accuracy and throughput; the diameter of the spiral blades of the automatic spiral slag discharge mechanism matches the slag discharge port at the bottom of the settling chamber, and the spiral conveying angle is [value missing]. The conveying capacity meets the slag discharge requirements under maximum siltation conditions. The coordination of the above design parameters ensures that the three-stage slag-water separation unit can operate stably under various operating conditions, and the effluent quality meets the requirements of the circulating water makeup standard.

[0050] Using the above technical solution, the integrated three-stage slag-water separation structure realizes closed-loop treatment of slag and wastewater, with automatic external transportation of solid slag and recycling of clean water, effectively preventing secondary siltation caused by direct return of flushing wastewater to the water tank, while achieving the environmental protection goal of zero discharge.

[0051] In some preferred embodiments of this application, the sludge thickness sensor is an ultrasonic sludge thickness sensor, which is arranged at the high sludge accumulation position of the sludge-blocking grid; the level gauges before and after the grid are remote level gauges, which are respectively arranged in the water bodies upstream and downstream of the grid; and the inter-pool flow velocity sensor is arranged in the inter-pool water flow channel.

[0052] In the specific implementation process, two ultrasonic sludge thickness sensors are arranged upstream and downstream of each set of sludge-collecting screens. The sensors are mounted on fixed brackets above the screens, with the probes pointing downwards towards the screen surface. By emitting ultrasonic waves and receiving echo signals, the thickness of the sludge on the screen surface is calculated in real time, with a measurement accuracy of millimeters. A remote level gauge, preferably an ultrasonic level gauge or a radar level gauge, is installed in the water body upstream and downstream of the screens to measure the water level height in real time. The PLC programmable controller calculates the difference between the two levels to obtain the water level difference in front of and behind the screens, which directly reflects the flow resistance of the screens. A flow velocity sensor, preferably a Doppler ultrasonic flow velocity sensor, is installed in the inter-pool flow channel to monitor the flow velocity in real time. When the screen is blocked, causing the flow area to shrink, the flow velocity in the inter-pool will show an abnormal decrease. The above three types of sensors are connected to the analog input module in the PLC control cabinet via 4mA-20mA analog signal cables to achieve synchronous acquisition of multiple parameters.

[0053] Using the above technical solution, the three types of sensors can perceive the working condition of the grid in real time from three different dimensions: sludge thickness, flow resistance (liquid level difference) and water flow state (flow velocity), providing a comprehensive and reliable data foundation for multi-parameter fusion analysis and effectively avoiding misjudgment and malfunction caused by single data deviation.

[0054] Furthermore, the inter-pool flow velocity sensor data also serves as an independent clogging criterion in the fusion analysis: the system has a preset lower flow velocity threshold. (For example =0.3m / s, this value is the reference flow velocity in the clean state of the grille. (60%), when the inter-pool flow velocity V is lower than When the flow area of ​​the grid has been significantly reduced, even if the thickness of the sludge and the liquid level difference have not yet reached their respective thresholds, the system will still trigger a first-level warning to prevent the local sensors from failing to capture the true blockage state due to uneven distribution of sludge.

[0055] In some preferred embodiments of this application, the PLC programmable controller has a built-in multi-parameter fusion siltation judgment model. Based on the multi-dimensional operating data collected by the sludge thickness sensor, the liquid level gauges before and after the bar and the flow velocity sensor between the pools, it automatically identifies the slight siltation and severe blockage conditions of the bar through multi-level thresholds, and performs early warning prompts and emergency flushing actions respectively.

[0056] In practical implementation, the multi-parameter fusion sedimentation judgment model runs as a logic operation program within the PLC programmable controller. The PLC receives three types of data in real time: sediment thickness D, liquid level difference ΔH before and after the screen, and inter-pool flow velocity V, and compares them with preset safety thresholds. The multi-level thresholds include a first-level warning threshold and a second-level emergency threshold. The first-level warning threshold is: sediment thickness D ≥ 10mm or liquid level difference ΔH before and after the screen ≥ 200mm. At this time, the PLC triggers a first-level warning and pushes warning information to the central control room and maintenance terminal via the wireless communication module, reminding maintenance personnel to pay attention to the operating status of the screen. The second-level emergency threshold is: sediment thickness D ≥ 20mm or liquid level difference ΔH before and after the screen ≥ 300mm. At this time, the PLC determines that the screen has entered a state of severe blockage, automatically starts high-pressure flushing operation in the corresponding area, and simultaneously links the sludge-water separation device to operate. The advantage of multi-parameter fusion judgment is that even if a certain sensor deviates due to environmental interference, the cross-validation of other parameters can still ensure the accuracy of the judgment conclusion, greatly reducing the misjudgment rate. For example, if the sludge thickness sensor shows an abnormal reading due to water surface fluctuations, the system will not trigger emergency flushing if the liquid level difference and flow rate data do not exceed the threshold.

[0057] Specifically, the multi-parameter fusion sedimentation assessment model uses a weighted comprehensive scoring method for fusion calculation. After normalizing the data from the three types of sensors, the PLC programmable controller calculates the comprehensive sedimentation index S according to the following formula: Where D is the current slag thickness, This represents the full-scale value of the slag thickness. The difference in liquid level before and after the grating V is the full-scale value of the liquid level difference; V is the flow velocity of the water between the tanks. The reference flow rate is defined as the flow rate under clean conditions. This reference flow rate is automatically calibrated and stored by the system during initial commissioning, and will not be elaborated further here. α, β, and γ are the weighting coefficients for sludge thickness, liquid level difference, and flow rate, respectively, and α + β + γ = 1, preferably α = 0.4, β = 0.4, and γ = 0.2. When the comprehensive siltation index S reaches the first warning threshold... (For example When the comprehensive siltation index S reaches 0.4, a Level 1 warning is triggered; when the comprehensive siltation index S reaches the second emergency threshold... (For example When the value is 0.7, an emergency flushing operation is automatically initiated. The advantage of this weighted fusion algorithm is that even if a sensor experiences a brief data anomaly due to environmental interference, the normal readings of the other two parameters can still keep the comprehensive index below the threshold, thus effectively avoiding false triggering caused by a single parameter anomaly. At the same time, the flow velocity V, as a reverse correlation parameter (a decrease in flow velocity indicates increased blockage), forms a positive feedback cross-validation with the sludge thickness and liquid level difference, significantly improving the robustness of the judgment conclusion.

[0058] By adopting the above technical solution, the multi-parameter fusion siltation judgment model upgrades the traditional passive response based on a single parameter to an active preventive treatment based on multi-dimensional data. It can identify the risk of siltation in the grid in advance and start the flushing operation in time before the impurities harden and block it, which greatly reduces the frequency of high-intensity emergency flushing and saves water and electricity consumption.

[0059] In some preferred embodiments of this application, the system is configured with two collaborative operation modes: a time-sequential normal flushing mode and a multi-parameter early warning emergency flushing mode. In the time-sequential normal flushing mode, the PLC programmable controller sequentially opens the electromagnetic control valve groups of each zone according to a preset cycle and preset duration to perform full-area high-pressure flushing of each group of slag-blocking grids. After flushing, the valve groups are shut off after a delay. In the multi-parameter early warning emergency flushing mode, when the monitoring data of the slag accumulation thickness on the grid or the difference in liquid level before and after the grid exceeds a preset safety threshold, the PLC programmable controller automatically pushes an early warning signal and initiates high-pressure flushing operation in the corresponding area, simultaneously coordinating with the slag-water separation unit until the monitored parameters return to the normal safe range, at which point the system automatically resets and shuts down.

[0060] In practical implementation, the scheduled normal flushing mode is the system's default operating mode. The PLC programmable controller has a time-series control program that automatically starts full-area rotational flushing according to a preset cycle (e.g., every 48 hours). The flushing process for each set of screens is as follows: The PLC first sends a lifting command to lift the filter screen of the screen to be flushed to the flushing station, with a lifting time of approximately 180 seconds; then, the electromagnetic control valve group corresponding to the screen is opened, and the high-pressure nozzles perform full-area high-pressure flushing on the screen surface, filter screen gaps, and bottom guide channel, with a flushing time of approximately 120 seconds; after flushing, the valve group is shut off after a set delay, and the screen is reset, with a reset time of approximately 180 seconds. Subsequently, the PLC automatically switches to the next set of screens, and so on, until all screens are flushed. The multi-parameter early warning emergency flushing mode is the system's active protection mode. When the multi-parameter fusion judgment model detects that the slag thickness or the difference in liquid level before and after a certain set of screens exceeds the safety threshold, the PLC prioritizes pushing an early warning signal to the central control room, and then automatically starts the high-pressure flushing operation in that area, while simultaneously coordinating the operation of the slag-water separation device. During the rinsing process, the PLC continuously monitors the operating parameters of the bar screen. When the slag thickness and liquid level difference both fall back to the safe range, the system automatically resets and stops, returning to the normalized sequential rinsing mode.

[0061] In the multi-parameter early warning emergency flushing mode, the PLC programmable controller simultaneously monitors the changing trend of the inter-pool flow velocity V as an auxiliary criterion for terminating the flushing: if the inter-pool flow velocity V continues to rise during the flushing process and returns to the reference flow velocity... If the flow rate reaches 85% or more, it indicates that the flow capacity of the screen has been effectively restored, and the PLC can terminate the flushing operation in advance to reduce water consumption; if the flow velocity V between the pools has not recovered to the reference flow velocity after the set flushing time, the flow rate V is considered to be below the reference flow rate. If 70% of the material is obstructed, the system determines that the grille may have serious blockage, automatically extends the flushing time, and sends a high-level alarm signal to the central control room to prompt maintenance personnel to come to the site for inspection.

[0062] By adopting the above technical solution, two modes, namely regular flushing and multi-parameter early warning emergency flushing, work together to prevent the accumulation of impurities through regular preventive flushing, and to deal with sudden high-load conditions through real-time monitoring and emergency flushing, thereby realizing intelligent closed-loop management of the entire life cycle of the bar screen.

[0063] In some preferred embodiments of this application, the PLC programmable controller has a reserved general industrial communication interface, which can realize bidirectional data communication and linkage control with the plant's circulating water pump, side-stream filtration equipment, and DCS production control system; the PLC is connected to an external wireless communication module, which can remotely push system operating parameters, slag accumulation warning signals, and equipment fault information to the central control room and maintenance terminal, and can also receive remote control commands.

[0064] In practical implementation, the PLC programmable controller reserves general industrial communication interfaces such as RS485 and Modbus TCP, enabling bidirectional data communication with the plant's circulating water pump control system and DCS production management system via wired communication cables. The PLC can receive production scheduling instructions from the DCS system, such as appropriately increasing the flushing frequency during high-load production periods. It can also upload system operating status data to the DCS system for unified plant-wide management. The PLC's external wireless communication module supports 4G / 5G / Wi-Fi and other wireless communication methods, allowing real-time system operating parameters (including sensor monitoring data, solenoid valve on / off status, slag-water separation device operating status, etc.), slag accumulation warning signals, and equipment fault information to be remotely pushed to the central control room's large screen and maintenance personnel's mobile terminals. Maintenance personnel can remotely control the system, such as modifying parameters, manually starting / stopping, and switching modes, via a mobile APP or the central control room's remote operation interface.

[0065] By adopting the above technical solution, the configuration of the industrial communication interface and wireless communication module enables seamless integration between the system and the factory production control system, supports remote monitoring, parameter modification, fault alarm and data upload, achieves unmanned closed-loop control of the entire process, and greatly improves the level of intelligent operation and maintenance.

[0066] In some preferred embodiments of this application, a non-stop intelligent slag removal control method based on the above-mentioned system is provided. The system is configured with two collaborative operation modes: a time-sequential normalized flushing mode and a multi-parameter early warning emergency flushing mode. The time-sequential normalized flushing mode involves the PLC programmable controller sequentially opening the electromagnetic control valve groups of each zone according to a preset cycle and preset duration, performing full-area high-pressure flushing on each group of slag-blocking grids in turn. After flushing, the valve groups are shut off after a delay, achieving normalized preventative slag removal. The multi-parameter early warning emergency flushing mode involves the PLC programmable controller prioritizing the push of an early warning signal when the monitored data of the slag accumulation thickness on the grid or the difference in liquid level before and after the grid exceeds a preset safety threshold. It then automatically starts the high-pressure flushing operation in the corresponding area and simultaneously links the slag-water separation device until the monitored parameters return to the normal safe range, at which point the system automatically resets and shuts down.

[0067] In practical implementation, the core of the control method lies in the intelligent coordinated switching between the two modes. During normal system operation, the PLC primarily operates in the time-series normal flushing mode, automatically rinsing each group of screens according to a preset cycle to keep the screens clean. When the multi-parameter fusion analysis model detects an abnormal siltation trend in a certain group of screens, the system automatically switches to the multi-parameter early warning emergency flushing mode to immediately flush that group of screens and remove abnormal sludge. After flushing, the system automatically switches back to the time-series normal flushing mode. The switching between the two modes is entirely executed automatically by the PLC based on real-time monitoring data, without manual intervention. In addition, the PLC can also adaptively adjust based on historical operating data, such as appropriately shortening the normal flushing cycle in summer when water temperatures are high and microbial slime reproduction is vigorous, and appropriately extending the flushing cycle in winter when water temperatures are low, to achieve dynamic optimization of the flushing strategy.

[0068] By adopting the above technical solution, the dual-mode collaborative control method has realized a fundamental transformation of bar screen cleaning from passive response to active prevention. The time-sequential routine flushing maintains the bar screen in a basically clean state, while the early warning emergency flushing responds to sudden high-load conditions. The two complement each other to ensure that the bar screen is always in the optimal flow state.

[0069] In some preferred embodiments of this application, the slag-blocking grid includes a coarse filter and a fine filter arranged in series. In the time-series normalized flushing mode, the coarse filter and the fine filter adopt a staggered and zoned independent cleaning strategy. When one layer of filter is being flushed, the other layer of filter remains in a flow state, so as to maintain the flow capacity of the circulating water system without interruption during the cleaning operation.

[0070] In practical implementation, taking a large circulating water station containing 12 sets of double-layer coarse and fine series sludge-collecting screens as an example, each set of sludge-collecting screens includes a coarse filter and a fine filter. In the time-sequential normal flushing mode, the PLC flushes only one layer of filter screen from one set of screens at a time according to the preset sequence. For example, firstly, the coarse filter screen of the first set of screens is lifted for high-pressure flushing, while the fine filter screen of this set of screens remains in place for flow, and the coarse and fine filters of the remaining 11 sets of screens operate normally; after the coarse filter screen of the first set of screens is flushed and reset, the fine filter screen of this set of screens is lifted for flushing, at which point the coarse filter screen has reset and assumes the flow function. This process is carried out alternately set by set and layer by layer to ensure that the inter-pool flow capacity of the circulating water system is uninterrupted at any time.

[0071] By adopting the above technical solution, the staggered and zoned independent cleaning strategy of coarse and fine double-layer filter screens ensures that each group of screens can be effectively cleaned while ensuring that the circulating water system can operate continuously without stopping, thereby eliminating the impact of screen cleaning on the production line.

[0072] In some preferred embodiments of this application, the multi-parameter fusion sedimentation judgment model comprehensively evaluates three types of parameters: sediment thickness, liquid level difference before and after the screen, and water flow velocity between pools, and sets two threshold levels: when the sediment thickness reaches the first thickness threshold or the liquid level difference before and after the screen reaches the first liquid level difference threshold, a first-level early warning is triggered; when the sediment thickness reaches the second thickness threshold or the liquid level difference before and after the screen reaches the second liquid level difference threshold, an emergency flushing operation is automatically started, wherein the second thickness threshold is greater than the first thickness threshold, and the second liquid level difference threshold is greater than the first liquid level difference threshold.

[0073] In practical implementation, taking a large chemical enterprise's circulating water station as an example, the first thickness threshold is set to 10mm, and the second thickness threshold is set to 20mm; the first liquid level difference threshold is set to 200mm, and the second liquid level difference threshold is set to 300mm. When the slag thickness of a certain set of screens reaches 10mm or the liquid level difference before and after reaches 200mm, the PLC triggers a first-level warning, pushing warning information to the central control room and maintenance personnel's mobile phones via wireless communication module, reminding them to pay attention to the status of the screen. When the slag thickness continues to increase to 20mm or the liquid level difference before and after reaches 300mm, the PLC automatically starts emergency flushing. In addition, the inter-pool flow velocity sensor data serves as an auxiliary verification parameter. When both slag thickness and liquid level difference alarm simultaneously and the inter-pool flow velocity shows a significant decrease, the system increases the alarm priority and accelerates the emergency response. The cross-validation of the three levels of parameters effectively reduces the false alarm rate caused by a single sensor failure or environmental interference.

[0074] By adopting the above technical solution, the two-level threshold hierarchical control strategy realizes the hierarchical response of early warning prediction and emergency flushing. This not only avoids the waste of resources caused by excessively frequent emergency flushing, but also ensures timely response when the bar screen is truly at risk of blockage, thus achieving precise and efficient intelligent operation and maintenance.

[0075] In some preferred embodiments of this application, the sludge-containing wastewater from the bar screen washing and stripping flows by gravity into the sludge-water separation unit via the bottom sewage diversion channel. It then undergoes gravity settling to remove large particles of impurities, fine filtration to remove fine sludge and suspended solids, and a spiral automatic sludge discharge mechanism to periodically remove solid sludge. The separated clean water is returned to the water tank below the tower for recycling, forming a closed-loop treatment of the sludge-washing wastewater.

[0076] In the specific implementation process, the sludge-containing wastewater generated from the bar screen washing is first collected through the sewage guide channel at the bottom of the bar screen and flows into the sludge-water separation device by gravity due to the height difference between the tanks. In the gravity settling chamber, the wastewater flow velocity is reduced to below 0.1m / s, and large particles of silt and lumpy impurities with a particle size greater than 0.5mm settle to the bottom of the chamber under gravity, with a settling efficiency of over 80%. The wastewater after gravity settling enters the fine filtration module, which uses a stainless steel wedge wire filter screen with a filtration accuracy of 0.1mm-0.3mm, intercepting residual fine flocculent sludge and suspended colloidal impurities in the water. The filtered clean water flows directly back to the water tank below the tower through the return pipe, and the water quality meets the circulating water replenishment standard, realizing the recycling and reuse of water resources. The spiral automatic sludge discharge mechanism pushes the solid sludge intercepted by the settling chamber and the filtration module to the sludge discharge port according to a set sequence (e.g., running once every 4 hours, each run lasting 10 minutes), and transports it to the plant's sludge disposal system for unified treatment.

[0077] refer to Figure 4This diagram is a flowchart of the intelligent control logic of the three-mode system in this application. It illustrates the complete control logic chain from data acquisition, multi-parameter fusion analysis, threshold judgment, to execution output. As shown, the control logic diagram is divided into three main functional areas: the left-side data acquisition layer, the central PLC controller processing layer, and the right-side execution output layer. In the left-side data acquisition layer, sludge thickness sensors, liquid level difference sensors, and flow velocity sensors collect real-time data on sludge thickness at the sludge-blocking grid, liquid level difference before and after the grid, and water flow velocity between the pools, respectively. The signals from these three types of sensors are uploaded to the data acquisition layer via 4-20mA analog cables. The data acquisition layer performs A / D conversion and standardization on the multiple analog signals before transmitting the digitized sensor data to the central PLC controller. The PLC controller has a built-in multi-parameter fusion analysis model. After receiving the data from the three types of sensors, it calculates the comprehensive siltation index S based on the normalized sludge thickness, liquid level difference, and flow velocity using a weighted comprehensive scoring method with preset weighting coefficients. The comprehensive siltation index S is then compared and judged against the first-level early warning threshold and the second-level emergency threshold. When the comprehensive siltation index S reaches the first-level warning threshold, the PLC controller triggers the first-level warning logic, pushing the warning information to the DCS wired connection system and wireless operation and maintenance terminal through the remote communication output module. At the same time, a local audible and visual alarm is activated to remind on-site operation and maintenance personnel to pay attention to the operation status of the screen. At this time, the system does not start the flushing operation, but only issues a warning. When the comprehensive siltation index S further rises to the second-level emergency threshold, the PLC controller automatically activates the emergency flushing logic, sending control commands sequentially or synchronously to the four execution modules: the screen lifting mechanism, the zone flushing solenoid valve, the slag-water separation and spiral slag discharge mechanism, and the local audible and visual alarm. The PLC first controls the screen lifting mechanism to lift the filter screen of the screen to be flushed to the flushing station, then opens the flushing solenoid valve of the corresponding zone. The high-pressure flushing execution unit performs full-area high-pressure flushing of the screen, while simultaneously coordinating the operation of the slag-water separation unit and the spiral slag discharge mechanism to perform three-level closed-loop treatment on the slag-containing wastewater generated during flushing. The local audible and visual alarm is activated simultaneously to remind on-site personnel that the system is performing an emergency flushing operation. In addition, the PLC controller has a built-in timed periodic flushing logic, which automatically performs timed and sequential flushing of each group of slag-blocking grids according to a preset flushing cycle (e.g., every 48 hours). The output signal of the timed periodic flushing and the output signal of the secondary emergency threshold are combined through a logic OR gate (⊕ symbol in the figure) to jointly drive the above four execution modules, realizing seamless coordination and switching between normal preventive flushing and early warning emergency flushing modes. This ensures that the slag-blocking grid is always in the optimal flow state throughout its entire life cycle, effectively eliminating the safety hazards and production losses caused by manual shutdown for slag removal.

[0078] By adopting the above technical solution, the three-stage sludge-water separation closed-loop treatment achieves zero discharge and zero secondary sludge accumulation of wastewater, clean water recycling saves system water replenishment, and solid sludge is automatically transported off-site at regular intervals to avoid sludge accumulation, thus achieving the dual goals of environmental protection and energy conservation.

[0079] The invention will be further illustrated below with reference to a specific engineering embodiment.

[0080] This embodiment is applied to the circulating water station of a large chemical enterprise. The total length of the water tank below the tower is 160m, and the total length of the suction tank is 75m. Twelve sets of double-layer coarse and fine series slag-blocking screens are installed between the tanks. The original operation and maintenance mode was to manually clean the slag during an 8-hour shutdown per month, which had problems such as large production losses, high safety risks, and incomplete slag cleaning. The intelligent technical transformation was completed using the system of this application. The specific configuration and operating parameters are as follows: High-pressure flushing execution unit configuration: relying on the high-pressure water source of the plant's circulating water pump, the water supply pressure is 0.6MPa; the main pipeline adopts DN100 carbon steel anti-corrosion pipe, and the branch pipes of the zones adopt DN50 carbon steel anti-corrosion pipe; each of the 12 sets of bar screens is independently equipped with a DN50 electromagnetic ball valve to achieve independent and controllable flushing of each zone; each set of bar screens is equipped with a combination of wide-angle fan-shaped nozzles and rotating impact nozzles, and the angle is adjusted by a universal ball joint to fully cover the bar screen surface and the gap of the filter screen.

[0081] Sludge-water separation unit configuration: The integrated sludge-water separation device is arranged on the upper platform of the suction tank. The water inlet is connected to the sewage discharge guide channel at the bottom of the bar screen. It integrates a gravity settling chamber, a fine filter module and a spiral automatic sludge discharge mechanism. The clear water return pipe is connected to the water tank below the tower. The separated sludge is automatically transported to the plant sludge treatment system through the spiral mechanism.

[0082] Intelligent sensing and monitoring unit configuration: Two ultrasonic sludge thickness sensors and two remote level gauges are arranged before and after each set of grids. Two flow velocity sensors are arranged in the water flow channel between the pools. All measurement point signals are connected to the PLC control cabinet through 4-20mA analog signals.

[0083] Intelligent control parameter configuration: Automatic rotation flushing every 48 hours, with each set of screens requiring 180 seconds to lift, 120 seconds for high-pressure flushing, and 180 seconds for screen reset, completing full-area cleaning one set at a time. Emergency flushing thresholds: A level 1 warning is triggered when the sludge thickness is ≥10mm or the liquid level difference before and after the screen is ≥200mm; an emergency flushing is automatically initiated when the sludge thickness is ≥20mm or the liquid level difference is ≥300mm, continuing until parameters return to a safe range.

[0084] On-site operation results: The system operates 24 hours a day without human intervention and is fully automatic, with the circulating water system running continuously without interruption; screen blockage faults are eliminated, completely replacing manual shutdown and slag removal operations, effectively eliminating the risks of working in confined spaces; it effectively saves downtime losses, labor costs, water and electricity consumption and maintenance costs, and significantly improves the stability and intelligence level of the circulating water system.

[0085] This application achieves continuous, unattended, and preventative intelligent cleaning and maintenance of the circulating water slag-blocking screen through the systematic integration of four core units: a high-pressure flushing execution unit, a slag-water separation unit, an intelligent sensing and monitoring unit, and an intelligent linkage control unit. It is combined with staggered independent cleaning of coarse and fine double-layer filters and dual-mode collaborative control based on multi-parameter fusion intelligent analysis. This effectively revolutionizes the traditional manual shutdown slag cleaning mode, effectively eliminates safety hazards in confined spaces and production line downtime losses, reduces system water consumption, energy consumption, and overall operation and maintenance costs, and improves the long-term stable operation capability and intelligence level of the circulating water system.

[0086] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An online sludge removal system for the under-tower pool of a large-scale circulating water station, characterized in that, The system includes: a slag-blocking grid located between the water tank and the suction tank, a high-pressure flushing execution unit, a slag-water separation unit, an intelligent sensing and monitoring unit, and an intelligent linkage control unit; The slag-blocking grid includes a coarse filter screen and a fine filter screen. The coarse filter screen and the fine filter screen are cleaned independently in staggered zones. When any layer of filter screen is cleaned, the remaining filter screens maintain normal flow state to ensure that the water flow between the pools is continuous and uninterrupted. The high-pressure flushing execution unit includes a high-pressure water supply main pipe, multiple partition flushing branch pipes connected to the high-pressure water supply main pipe, electromagnetic control valve groups respectively installed on each partition flushing branch pipe, and flushing brackets arranged at the slag-blocking grid and high-pressure nozzles installed on the flushing brackets. The slag-water separation unit adopts an integrated online slag-water separation device. The inlet of the online slag-water separation device is connected to the bottom sewage guide channel of the slag-blocking bar screen. The inlet of the online slag-water separation device is lower than the outlet of the sewage guide channel at the bottom of the bar screen. The slag-containing wastewater flows into the slag-water separation device by gravity due to the liquid level difference. The bottom of the sewage guide channel is equipped with an opening and closing baffle at a set distance. The opening and closing baffle is rotatably connected to the two sides of the sewage guide channel through a hinge shaft. In the closed state, the opening and closing baffle is in a horizontal state. In the open state, the opening and closing baffle is in an inclined state, and the inclined side is aligned with the inlet of the online slag-water separation device, so that the slag-containing wastewater generated during the cleaning of the slag bar screen flows into the online slag-water separation device by gravity. The intelligent linkage control unit includes a PLC programmable controller, and the output terminals of the PLC programmable controller are electrically connected to the partitioned electromagnetic control valve group, the sludge-water separation device drive mechanism, and the high-pressure water supply unit, respectively.

2. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The PLC programmable controller has a reserved general industrial communication interface, which can realize two-way data communication and linkage control with the plant's circulating water pumps, side-filter equipment, and DCS production control system; the PLC is connected to an external wireless communication module, which can remotely push system operating parameters, slag accumulation warning signals, and equipment fault information to the central control room and operation and maintenance terminal, and receive remote control commands.

3. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The intelligent sensing and monitoring unit includes a sludge thickness sensor, level gauges before and after the bar screen, and a flow velocity sensor between the pools. The signal output terminals of the sludge thickness sensor, level gauges before and after the bar screen, and flow velocity sensor between the pools are all electrically connected to the intelligent linkage control unit.

4. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The high-pressure nozzle is connected to the flushing bracket via a universal ball joint, and the high-pressure nozzle can freely adjust the spray angle within a predetermined angle range.

5. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The partition flushing branch pipes are configured one-to-one with the slag-blocking grids. Each partition flushing branch pipe is equipped with an independent electromagnetic control valve group. The PLC programmable controller is configured to open each electromagnetic control valve group in turn by region and time sequence, so as to perform full-area high-pressure flushing on each group of slag-blocking grids in turn.

6. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The sludge-water separation device integrates a three-stage treatment structure from top to bottom: a gravity settling chamber, a fine filtration module, and a spiral automatic sludge discharge mechanism. The filtered clean water is returned to the water tank below the tower for recycling, and the solid sludge is transported out by the spiral automatic sludge discharge mechanism at regular intervals.

7. The large-scale circulating water station tower bottom pool online sludge removal system as described in claim 1, characterized in that, The coarse filter and the fine filter are lifted by a crane to the rinsing station for cleaning.

8. The online sludge removal system for the under-tower pool of a large-scale circulating water station as described in claim 1, characterized in that, The intelligent sensing and monitoring unit collects multi-dimensional operating data such as the thickness of the sludge accumulation on the screen, the difference in liquid level before and after the screen, and the flow velocity of water between the pools in real time and uploads them to the PLC programmable controller. The PLC has a built-in multi-parameter fusion intelligent judgment model, which automatically identifies the screen's slight sludge accumulation and severe blockage conditions based on multi-level thresholds, and executes early warning prompts and emergency flushing actions respectively.

9. A method for online sludge removal from the underside pool of a large-scale circulating water station based on the system described in any one of claims 1 to 8, characterized in that, The system is configured with two collaborative operation modes: a time-sequential normal flushing mode and a multi-parameter early warning emergency flushing mode. In the time-sequential normal flushing mode, the PLC programmable controller sequentially opens the electromagnetic control valve groups of each zone according to a preset cycle and preset duration, performing full-area high-pressure flushing on each group of slag-blocking grids in turn. After flushing, the valve groups are shut off after a delay, achieving normalized preventative slag removal. In the multi-parameter early warning emergency flushing mode, when the monitored data of the slag accumulation thickness or the liquid level difference before and after the grid exceeds a preset safety threshold, the PLC programmable controller prioritizes pushing an early warning signal, then automatically starts the high-pressure flushing operation in the corresponding area and simultaneously links the slag-water separation device to operate, until the monitored parameters fall back to the normal safe range, at which point the system automatically resets and stops.

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