Closed-loop conveying system for sludge discharge from machining tanks and method for resource utilization of wastewater and sludge

Abstract

This invention discloses a closed-loop conveying system for sludge discharge from a machining tank and a method for the resource-based treatment of wastewater and sludge. The system includes a sludge tank, a variable frequency positive displacement pump set, and a pretreatment device connected in sequence. It also includes a source collection module, an intelligent conveying module, a graded treatment module, a resource recycling module, and an intelligent control module. The source collection module includes sludge discharge pipelines connecting the sludge tank and the machining tank. One end of the sludge discharge pipeline is connected to the machining tank, and the other end is connected to the inlet of the sludge tank. The sludge tank is equipped with adjustable partition baffles and a bottom cleaning scraper. This invention, through the reuse and renovation of the sludge tank, forms a complete chain of sludge storage, intelligent conveying, and a closed-loop resource system. It avoids resource waste caused by the abandonment of the sludge tank and ensures conveying efficiency through precise adaptation of the positive displacement pump. Ultimately, it achieves coordinated discharge and recycling of machining sludge, highlighting the dual benefits of circular economy and environmental protection from multiple dimensions, including facility reuse, conveying optimization, and resource recycling.

Description

Technical Field

[0001] This invention relates to the field of mechanical processing wastewater treatment technology, specifically to a closed-loop conveying system for sludge discharge from machining tanks and a method for the resource-based treatment of wastewater and sludge. Background Technology

[0002] In the machining industry, sludge from machining tanks is a complex type of industrial wastewater containing large amounts of metal scrap, mineral oil, emulsions, and high concentrations of silt. Direct discharge not only causes severe water pollution but also leads to a significant waste of metal and water resources. Furthermore, long-term accumulation of this sludge in machining workshops can corrode equipment and negatively impact the workshop environment. Therefore, efficient collection, transportation, treatment, and resource recovery are crucial for ensuring environmental compliance, reducing operating costs, and implementing a circular economy for machining companies. However, the industry currently faces numerous unresolved issues regarding the treatment of machining sludge. Firstly, there is insufficient reuse of existing facilities and inadequate adaptability to transportation: Although most machining companies have built mud pits, they are often left idle for a long time due to their simple design and low compatibility with subsequent transportation equipment. Building new mud storage facilities would increase costs significantly. The concentration of sludge discharged from machining facilities fluctuates greatly. Conventional centrifugal pumps are prone to wear and tear and have low efficiency when transporting high-concentration sludge. Existing positive displacement pumps mostly operate with fixed parameters and cannot adaptively adjust according to the sludge concentration, resulting in frequent pipe blockages at high concentrations and energy waste at low concentrations. The final treatment stage mostly only achieves mud-water separation. Metal scraps are not specially recycled and are directly discarded with the mud cake. The mud cake is mostly disposed of in landfills, and the clear liquid is discharged directly after simple treatment. Resources have not formed a collaborative recycling loop, which not only causes serious waste of metal, mud, and water resources, but also exacerbates the pressure of environmental discharge. Secondly, there is a lack of energy consumption and intelligent linkage: the energy consumption of conveying and pretreatment of sludge from mechanical processing is high. Traditional treatment systems rely entirely on grid power, and energy costs account for a significant proportion of operating costs. Although some companies have tried to introduce photovoltaic energy, it is mostly limited to the overall power supply of the plant area and has not penetrated into the equipment-level linkage control of the wastewater treatment unit. The power generation of photovoltaic modules and the energy consumption demand of conveying pumps and pretreatment devices lack intelligent matching, resulting in energy waste when there is excess photovoltaic power and a surge in grid load when there is insufficient power generation. The system has poor operational stability and has failed to fully realize the green economic value of photovoltaic energy. Third, there are obvious shortcomings in resource recovery and wastewater reuse: the dewatered mud cake is mostly disposed of by landfill, which not only occupies a lot of land resources, but may also cause soil pollution due to the leaching of heavy metals and other harmful substances from the mud cake; industrial solid waste such as metal cutting slag and waste grinding wheel powder generated in machining workshops also lack efficient resource utilization pathways, and long-term accumulation not only occupies space, but also increases the cost of solid waste treatment; the reuse pipelines for treated wastewater have a very short reuse cycle due to the scaling of calcium and magnesium ions and the growth of microorganisms in the water, and enterprises have to frequently replace the clean water, which increases water consumption and the overall cost of wastewater treatment, making it difficult to guarantee the economic efficiency and sustainability of wastewater reuse; Therefore, it is essential to design a closed-loop conveying system for sludge discharge from the machining tank and a method for the resource-based treatment of wastewater and sludge. Summary of the Invention

[0003] The purpose of this invention is to provide a closed-loop conveying system for sludge discharge from machining tanks and a method for the resource utilization of wastewater and sludge, in order to solve the problems mentioned in the background art, such as idle and wasteful sludge tanks, inability of conveying pump sets to adapt to sludge concentration fluctuations, lack of closed-loop resource recovery, high energy consumption in the conveying and pretreatment stages and lack of intelligent linkage between photovoltaic energy and equipment, insufficient resource utilization of sludge cake and industrial solid waste, and easy scaling and short reuse cycle of clear liquid reuse pipelines.

[0004] To achieve the above objectives, the present invention provides the following technical solution: Firstly, a closed-loop conveying system for sludge discharge from the machined tank is provided, including a sludge tank, a variable frequency volumetric pump set and a pretreatment device connected in sequence, as well as a source collection module, an intelligent conveying module, a graded treatment module, a resource recycling module and an intelligent control module. The source collection module includes a mud tank and a sludge discharge pipeline for the machining tank. One end of the sludge discharge pipeline for the machining tank is connected to the machining tank, and the other end is connected to the inlet of the mud tank. The mud tank is equipped with adjustable partition baffles and a bottom cleaning scraper. The mud tank is a renovation of existing facilities and can be adapted to the existing layout of the machining workshop. The partition baffles enable preliminary sedimentation and stratification of mud and water through partitioned temporary storage. The bottom cleaning scraper operates periodically to prevent mud from accumulating and hardening at the bottom of the tank, ensuring long-term effective temporary storage capacity. The intelligent conveying module includes a variable frequency positive displacement pump set and an anti-clogging conveying pipeline. The inlet of the variable frequency positive displacement pump set is connected to the outlet of the mud tank. One end of the anti-clogging conveying pipeline is connected to the outlet of the variable frequency positive displacement pump set, and the other end is connected to the grading and processing module. Electric backwash valves are installed at intervals on the anti-clogging conveying pipeline. The variable frequency positive displacement pump set can flexibly adjust its output power according to the mud-water concentration. With the help of the electric backwash valves, it can effectively cope with the fluctuation of the machined mud-water concentration, avoid pipe blockage and machine shutdown, and ensure the continuity of conveying. The graded treatment module includes a pretreatment device and a deep dewatering device. The feed end of the pretreatment device is connected to the end of the anti-clogging conveying pipeline away from the variable frequency positive displacement pump group. The pretreatment device includes a screen, a biofilm reactor, and a demulsification component. The feed end of the deep dewatering device is connected to the discharge end of the pretreatment device. The deep dewatering device includes a plate and frame filter press and a hot air dryer. In the pretreatment device, the screen removes large-particle impurities, the biofilm reactor degrades organic pollutants, and the demulsification component achieves oil-water separation. The three work together to make the mud and water meet the feeding requirements for deep dewatering. The deep dewatering device dewaters the mud and water to a mud cake state suitable for resource recovery through plate and frame filter press and hot air drying. The resource recycling module includes a metal scrap recycling device, a sludge cake treatment device, and a clear liquid reuse device. The feed end of the metal scrap recycling device is connected to the grid impurity outlet of the pretreatment device, the feed end of the sludge cake treatment device is connected to the sludge cake outlet of the deep dewatering device, and the feed end of the clear liquid reuse device is connected to the clear liquid outlet of the deep dewatering device. The discharge end of the clear liquid reuse device is connected to the machining tank. The metal scrap recycling device separates metal and non-metal impurities through electromagnetic separation, and the metal scrap is reused for smelting. The sludge cake treatment device mixes the sludge cake with industrial solid waste and cementing materials to make non-fired bricks. The clear liquid reuse device filters, sterilizes, and inhibits scale formation in the clear liquid before returning it to the machining tank, realizing a closed-loop system for all resources of mud, water, and slag. The intelligent control module includes a PLC control cabinet and sensing components. The sensing components include a mud-water concentration sensor and a pipeline pressure sensor. The mud-water concentration sensor is installed at the discharge port of the mud tank, and the pipeline pressure sensor is installed at the discharge end pipeline of the variable frequency positive displacement pump unit. The PLC control cabinet is electrically connected to the bottom cleaning scraper, the variable frequency positive displacement pump unit, the electric backwash valve, the pretreatment device, the deep dewatering device, and the sensing components. The PLC control cabinet receives signals from each sensing component, centrally controls the operating parameters of the entire process, realizes automated control, reduces manual intervention, and improves system stability.

[0005] As a further technical solution of the present invention, the adjustable partition baffles are arranged at intervals along the length of the mud pool, and the height of the adjustable partition baffles can be adjusted in the vertical direction; the bottom cleaning scraper is arranged along the length of the mud pool and fits against the bottom of the mud pool.

[0006] As a further technical solution of the present invention, it also includes an energy auxiliary module, which includes photovoltaic modules, energy storage battery packs, and a photovoltaic-storage grid switching cabinet; the photovoltaic modules are laid on the top of the mud pit, and the power output end of the photovoltaic modules is electrically connected to the power input end of the energy storage battery pack; the photovoltaic modules are adapted to different mud pit top space layouts during installation; the energy storage battery pack stores photovoltaic power to provide green energy support for the system; The power input terminal of the photovoltaic-storage-grid switching cabinet is electrically connected to the energy storage battery pack and the power grid, respectively. The power output terminal of the photovoltaic-storage-grid switching cabinet is electrically connected to the variable frequency positive displacement pump group and the pretreatment device, respectively. The photovoltaic-storage-grid switching cabinet is electrically connected to the PLC control cabinet. The photovoltaic-storage-grid switching cabinet is used to switch the power source, giving priority to the use of photovoltaic energy storage power, and switching to the grid when it is insufficient, thereby reducing the system operating cost while ensuring energy supply.

[0007] As a further technical solution of the present invention, the variable frequency positive displacement pump group includes at least two variable frequency positive displacement pumps connected in parallel; the electric backflushing valve is an electromagnetically controlled valve and is connected to the anti-blockage delivery pipeline.

[0008] As a further technical solution of the present invention, the metal scrap recycling device is an electromagnetic separator, and the metal discharge end of the electromagnetic separator is connected to the metal smelting equipment. The mud cake processing device includes a material mixer and a non-fired brick forming machine. The discharge end of the material mixer is connected to the feed end of the non-fired brick forming machine. The material mixer fully mixes the mud cake with industrial solid waste and cementitious materials, giving the materials good molding properties. The non-fired brick forming machine presses the mixed materials into molds to form building materials that can be used directly. The clarified liquid reuse device includes a multi-media filter, an ultraviolet sterilizer, and an electromagnetic scale inhibitor, which are connected in series. The feed end of the multi-media filter is connected to the clarified liquid outlet of the deep dewatering device, and the discharge end of the electromagnetic scale inhibitor is connected to the machining tank. The multi-media filter removes suspended impurities, the ultraviolet sterilizer kills microorganisms, and the electromagnetic scale inhibitor inhibits scale formation in the pipeline. The three work together to ensure that the quality of the returned water meets the reuse standards of the machining tank.

[0009] Secondly, a wastewater and sludge resource utilization method is provided for a closed-loop conveying system for sludge discharge from machining tanks, including the following steps: S1: Source collection. High-concentration sludge from the machining tank enters the sludge tank through the sludge discharge pipeline. Adjustable partition baffles temporarily store the sludge in separate zones. A bottom cleaning scraper runs along the bottom of the tank. A sludge concentration sensor detects the sludge concentration and transmits the signal to the PLC control cabinet. The partitioned storage allows the sludge to initially settle in the sludge tank, reducing load fluctuations in subsequent transportation processes. The bottom cleaning scraper ensures long-term effective storage of sludge in the sludge tank, preventing sludge accumulation from affecting system operation. S2: Intelligent conveying. The PLC control cabinet receives signals from the mud-water concentration sensor and the pipeline pressure sensor, and adjusts the operating frequency of the variable frequency positive displacement pump set. The mud-water is conveyed to the pretreatment device through the anti-clogging conveying pipeline. When the pipeline pressure exceeds the preset range, the PLC control cabinet controls the electric backwash valve to open and flush the anti-clogging conveying pipeline. Through the dual signal adjustment of concentration and pressure, the variable frequency positive displacement pump set adapts to the conveying needs of mud-water with different concentrations. The electric backwash valve effectively avoids pipeline blockage and ensures continuous and stable conveying. S3: Graded treatment. The mud and water enter the pretreatment unit, where large-particle impurities are removed by a screen, organic pollutants are degraded by a biofilm reactor, and oil and water are separated by a demulsification component. The treated mud and water then enter the deep dewatering unit, where solid-liquid separation is performed by a plate and frame filter press. The separated mud cake is then dried by a hot air dryer. The synergistic effect of each stage of graded treatment ensures that the mud and water are fully purified and dewatered, providing high-quality mud cake and clear liquid raw materials for subsequent resource recovery. S4: Resource recycling. Large-diameter impurities separated by the pretreatment unit enter the metal scrap recycling unit. The sorted metal scraps are then transported to the metal smelting equipment. The dried mud cake enters the material mixer, where it is mixed with industrial solid waste and cementitious materials, and then transported to the non-fired brick forming machine. The clear liquid separated by the deep dewatering unit is processed sequentially through a multi-media filter, an ultraviolet sterilizer, and an electromagnetic scale inhibitor before being returned to the machining tank. The resource recycling process converts mud, water, and metal impurities into usable resources, realizing the closed-loop utilization of all resources in machining mud and water, which meets the requirements of circular economy and environmental protection.

[0010] As a further technical solution of the present invention, in S2, the photovoltaic module converts solar energy into electrical energy and stores it in the energy storage battery pack; the photovoltaic-storage grid switching cabinet prioritizes the transmission of electrical energy from the energy storage battery pack to the variable frequency positive displacement pump and the pretreatment device; when the photovoltaic module's power generation is insufficient, the photovoltaic-storage grid switching cabinet switches to grid power supply, and the PLC control cabinet synchronously adjusts the operating frequency of the variable frequency positive displacement pump and the operating parameters of the pretreatment device; the energy auxiliary module effectively utilizes green energy, reduces grid dependence, and at the same time ensures the stability of system operation through adjustment.

[0011] As a further technical solution of the present invention, in S2, when the PLC control cabinet adjusts the variable frequency positive displacement pump set, it synchronously adjusts the output power of the pump set according to the concentration value detected by the mud-water concentration sensor and the pressure value detected by the pipeline pressure sensor; the synchronous adjustment of dual parameters ensures that the pump set always operates efficiently, taking into account both delivery efficiency and energy consumption control.

[0012] As a further technical solution of the present invention, in S4, the industrial solid waste is metal cutting slag or waste grinding wheel powder generated in the machining workshop, and the cementing material is cement; after the mud cake, industrial solid waste and cementing material are mixed in the material mixer, they are conveyed to the non-fired brick forming machine for pressing and molding.

[0013] As a further technical solution of the present invention, in S4, when the electromagnetic scale inhibitor is running, the matching slow-release scale inhibitor component adds scale inhibitor to the clear liquid; the clear liquid after being treated by the clear liquid recycling device is returned to the machining tank through the pipeline; the addition of scale inhibitor prolongs the unobstructed cycle of the return pipeline, improving the overall economy and environmental protection of the system.

[0014] Compared with existing technologies, the beneficial effects of this closed-loop conveying system for sludge discharge from the machine-made tank and the wastewater sludge resource utilization method are: By renovating and upgrading existing mud pits, the system utilizes adjustable partition baffles and bottom cleaning scrapers to achieve efficient temporary storage and self-cleaning of mud and water. Combined with variable frequency positive displacement pumps, it precisely delivers mud and water of different concentrations. Then, it connects to a terminal resource recycling module. A metal scrap recycling device recovers metal for reuse in smelting, a mud cake treatment device uses mud cake and industrial solid waste to make non-fired bricks, and a clear liquid recycling device returns the clear liquid to the machining tank, forming a complete chain of mud and water storage, intelligent transportation, and a closed-loop system for all resources. This not only avoids the resource waste caused by the abandonment of mud pits, but also ensures transportation efficiency through the precise adaptation of positive displacement pumps. Ultimately, it achieves the coordinated discharge and recycling of machining mud and water, highlighting the dual benefits of circular economy and environmental protection from multiple dimensions, including facility reuse, transportation optimization, and resource recycling. The photovoltaic modules of the energy auxiliary module are laid on the top of the mud tank, converting solar energy into electrical energy and storing it in the energy storage battery pack. The photovoltaic-storage-grid switching cabinet intelligently switches the power source, giving priority to powering the variable frequency positive displacement pump and the pretreatment device. This linkage design not only provides green energy support for the positive displacement pump transportation and pretreatment process, reducing the dependence on grid energy consumption, but also enables the system to operate stably when photovoltaic power generation fluctuates through the synchronous adjustment of the pump operating frequency and pretreatment parameters by the PLC control cabinet. This achieves integrated coordination of low-energy transportation and pretreatment, significantly improving the system's energy economy and operational stability. The material mixer of the sludge cake treatment unit mixes the sludge cake from the deep dewatering unit with industrial solid waste and cement from the machining workshop. The mixture is then pressed into non-fired bricks by a non-fired brick forming machine, realizing the synergistic resource utilization of sludge cake and industrial solid waste. The clear liquid reuse unit uses a multi-media filter, an ultraviolet sterilizer, and an electromagnetic scale inhibitor to sequentially treat the deep dewatered clear liquid. A slow-release scale inhibitor component is used to add scale inhibitors to ensure that the pipeline for returning the clear liquid to the machining tank remains unobstructed for a long time. This design transforms sludge cake and industrial solid waste into high-value building materials on the one hand, and extends the clear liquid reuse cycle through scale inhibition treatment on the other hand. This significantly reduces the environmental protection costs of the machining workshop while improving resource utilization. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the method flow of the present invention; In the diagram: 101, mud tank; 1011, adjustable partition baffle; 1012, bottom cleaning scraper; 102, sludge discharge pipeline for machined tank; 200, energy auxiliary module; 2011, photovoltaic module; 2012, energy storage battery pack; 2013, photovoltaic-storage-grid switching cabinet; 301, variable frequency positive displacement pump set; 302, anti-clogging conveying pipeline; 3021, electric backflushing valve; 401, pretreatment device; 4011, bar screen; 4012, biofilm reactor; 4013, demulsification component; 4 02. Deep dewatering device; 4021. Plate and frame filter press; 4022. Hot air dryer; 501. Metal scrap recovery device; 502. Mud cake treatment device; 5021. Material mixer; 5022. Non-fired brick forming machine; 503. Clear liquid reuse device; 5031. Multi-media filter; 5032. Ultraviolet sterilizer; 5033. Electromagnetic scale inhibitor; 601. PLC control cabinet; 602. Sensing components; 6021. Mud-water concentration sensor; 6022. Pipeline pressure sensor. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see the appendix Figure 1 The present invention provides an embodiment 1: a closed-loop conveying system for sludge discharge from a mechanical processing tank, comprising a sludge tank 101, a variable frequency volumetric pump set 301 and a pretreatment device 401 connected in sequence, and further comprising a source collection module, an intelligent conveying module, a graded treatment module, a resource recycling module and an intelligent control module. The source collection module includes a mud tank 101 and a sludge discharge pipe 102 for the machining tank. One end of the sludge discharge pipe 102 is connected to the machining tank, and the other end is connected to the inlet of the mud tank 101. The mud tank 101 is equipped with adjustable partition baffles 1011 and bottom cleaning scrapers 1012. The adjustable partition baffles 1011 are spaced along the length of the mud tank 101, and their height can be adjusted vertically. The bottom cleaning scrapers 1012 are set along the length of the mud tank 101 and fit against the bottom of the mud tank 101. The mud tank 101 is an existing facility that has been renovated and can be adapted to the existing layout of the machining workshop. The partition storage function of the adjustable partition baffles 1011 achieves preliminary sedimentation and stratification of mud and water. The periodic operation of the bottom cleaning scrapers 1012 prevents the accumulation and hardening of mud at the bottom of the tank, ensuring long-term effective storage capacity. The intelligent conveying module includes a variable frequency positive displacement pump set 301 and an anti-clogging conveying pipeline 302. The variable frequency positive displacement pump set 301 includes at least two variable frequency positive displacement pumps connected in parallel. The electric backwash valve 3021 is an electromagnetically controlled valve and is connected to the anti-clogging conveying pipeline 302. The feed end of the variable frequency positive displacement pump set 301 is connected to the discharge port of the mud tank 101. One end of the anti-clogging conveying pipeline 302 is connected to the discharge end of the variable frequency positive displacement pump set 301, and the other end is connected to the grading module. The electric backwash valve 3021 is installed at intervals on the anti-clogging conveying pipeline 302. The variable frequency positive displacement pump set 301 can flexibly adjust its output power according to the mud-water concentration. In conjunction with the electric backwash valve 3021, it can effectively cope with the fluctuation of the machined mud-water concentration, avoid pipe blockage and shutdown, and ensure the continuity of conveying. The graded treatment module includes a pretreatment device 401 and a deep dewatering device 402. The feed end of the pretreatment device 401 is connected to the end of the anti-clogging conveying pipeline 302 away from the variable frequency positive displacement pump group 301. The pretreatment device 401 includes a screen 4011, a biofilm reactor 4012, and a demulsification component 4013. The feed end of the deep dewatering device 402 is connected to the discharge end of the pretreatment device 401. The deep dewatering device 402 includes a plate and frame filter press 4021 and a hot air dryer 4022. In the pretreatment device 401, the screen 4011 removes large-particle impurities, the biofilm reactor 4012 degrades organic pollutants, and the demulsification component 4013 achieves oil-water separation. The three work together to make the mud and water meet the requirements for deep dewatering. The deep dewatering device 402 dewaters the mud and water to a mud cake state suitable for resource recovery through plate and frame filter press and hot air drying. The resource recycling module includes a metal scrap recycling device 501, a sludge cake treatment device 502, and a clear liquid reuse device 503. The feed end of the metal scrap recycling device 501 is connected to the impurity outlet of the grid 4011 of the pretreatment device 401. The feed end of the sludge cake treatment device 502 is connected to the sludge cake outlet of the deep dewatering device 402. The feed end of the clear liquid reuse device 503 is connected to the clear liquid outlet of the deep dewatering device 402. The discharge end of the clear liquid reuse device 503 is connected to the machining tank. The metal scrap recycling device 501 separates metal and non-metal impurities through electromagnetic separation, and the metal scrap is reused for smelting. The sludge cake treatment device 502 mixes the sludge cake with industrial solid waste and cementing materials to make non-fired bricks. The clear liquid reuse device 503 filters, sterilizes, and inhibits scale formation in the clear liquid before returning it to the machining tank, realizing a closed-loop system for all resources of mud, water, and slag. The metal scrap recycling device 501 is an electromagnetic separator, and the metal discharge end of the electromagnetic separator is connected to the metal smelting equipment. The mud cake processing device 502 includes a material mixer 5021 and a non-fired brick forming machine 5022. The discharge end of the material mixer 5021 is connected to the feed end of the non-fired brick forming machine 5022. The material mixer 5021 fully mixes the mud cake with industrial solid waste and cementitious materials, giving the materials good forming properties. The non-fired brick forming machine 5022 presses the mixed materials into shape to form building materials that can be used directly. The clear liquid reuse device 503 includes a multi-media filter 5031, an ultraviolet sterilizer 5032, and an electromagnetic scale inhibitor 5033. The multi-media filter 5031, the ultraviolet sterilizer 5032, and the electromagnetic scale inhibitor 5033 are connected in series. The feed end of the multi-media filter 5031 is connected to the clear liquid outlet of the deep dewatering device 402, and the discharge end of the electromagnetic scale inhibitor 5033 is connected to the machining tank. The multi-media filter 5031 removes suspended impurities, the ultraviolet sterilizer 5032 kills microorganisms, and the electromagnetic scale inhibitor 5033 inhibits scaling in the pipeline. The three work together to ensure that the quality of the returned water meets the reuse standards of the machining tank. The intelligent control module includes a PLC control cabinet 601 and a sensing component 602. The sensing component 602 includes a mud-water concentration sensor 6021 and a pipeline pressure sensor 6022. The mud-water concentration sensor 6021 is installed at the discharge port of the mud tank 101, and the pipeline pressure sensor 6022 is installed at the discharge end pipeline of the variable frequency positive displacement pump unit 301. The PLC control cabinet 601 is electrically connected to the bottom cleaning scraper 1012, the variable frequency positive displacement pump unit 301, the electric backwash valve 3021, the pretreatment device 401, the deep dewatering device 402, and the sensing component 602. The PLC control cabinet 601 receives signals from each sensing component 602, centrally controls the operating parameters of the entire process, realizes automated control, reduces manual intervention, and improves system stability. It also includes an energy auxiliary module 200, which includes photovoltaic modules 2011, energy storage battery packs 2012, and a photovoltaic-storage grid switching cabinet 2013. The photovoltaic modules 2011 are laid on the top of the mud tank 101, and the power output terminal of the photovoltaic modules 2011 is electrically connected to the power input terminal of the energy storage battery pack 2012. The photovoltaic modules 2011 are adapted to different top space layouts of the mud tank 101 during installation. The energy storage battery pack 2012 stores photovoltaic power to provide green energy support for the system. The power input terminal of the photovoltaic-storage grid switching cabinet 2013 is electrically connected to the energy storage battery pack 2012 and the power grid, respectively. The power output terminal of the photovoltaic-storage grid switching cabinet 2013 is electrically connected to the variable frequency positive displacement pump group 301 and the pretreatment device 401, respectively. The photovoltaic-storage grid switching cabinet 2013 is electrically connected to the PLC control cabinet 601. The photovoltaic-storage grid switching cabinet 2013 is used to switch the power source, giving priority to the use of photovoltaic energy storage power, and switching to the grid when it is insufficient, thereby reducing the system operating cost while ensuring energy supply.

[0018] Please see the appendix Figure 2 The present invention provides an embodiment 2: a wastewater and sludge resource utilization treatment method for a closed-loop conveying system for sludge discharge from a machining tank, comprising the following steps: S1: Source collection. High-concentration sludge discharged from the machining tank enters the sludge tank 101 through the machining tank sludge discharge pipe 102. Adjustable partition baffles 1011 temporarily store the sludge in separate partitions. The bottom cleaning scraper 1012 runs along the bottom of the tank. The sludge concentration sensor 6021 detects the sludge concentration and transmits the signal to the PLC control cabinet 601. The partitioned temporary storage allows the sludge to initially settle in the sludge tank 101, reducing load fluctuations in subsequent transportation links. The bottom cleaning scraper 1012 ensures that the sludge tank 101 can effectively store sludge for a long time, avoiding sludge accumulation that could affect system operation. S2: Intelligent conveying. The PLC control cabinet 601 receives signals from the mud-water concentration sensor 6021 and the pipeline pressure sensor 6022, and adjusts the operating frequency of the variable frequency positive displacement pump set 301. The mud-water is conveyed to the pretreatment device 401 through the anti-clogging conveying pipeline 302. When the pipeline pressure exceeds the preset range, the PLC control cabinet 601 controls the electric backwash valve 3021 to open and flush the anti-clogging conveying pipeline 302. Through the dual signal adjustment of concentration and pressure, the variable frequency positive displacement pump set 301 adapts to the conveying needs of mud-water of different concentrations. The electric backwash valve 3021 effectively avoids pipeline blockage and ensures continuous and stable conveying. The photovoltaic module 2011 converts solar energy into electrical energy and stores it in the energy storage battery pack 2012. The photovoltaic-storage grid switching cabinet 2013 prioritizes the storage of solar energy. The energy from the battery pack 2012 is delivered to the variable frequency positive displacement pump 301 and the pretreatment device 401. When the photovoltaic module 2011 generates insufficient power, the photovoltaic-storage grid switching cabinet 2013 switches to grid power supply, and the PLC control cabinet 601 synchronously adjusts the operating frequency of the variable frequency positive displacement pump 301 and the operating parameters of the pretreatment device 401. The energy auxiliary module 200 effectively utilizes green energy, reduces grid dependence, and ensures system stability through adjustment. When the PLC control cabinet 601 adjusts the variable frequency positive displacement pump 301, it synchronously adjusts the pump output power based on the concentration value detected by the mud-water concentration sensor 6021 and the pressure value detected by the pipeline pressure sensor 6022. The synchronous adjustment of dual parameters ensures that the pump always operates efficiently, balancing delivery efficiency and energy consumption control. S3: Graded treatment. The muddy water enters the pretreatment unit 401, where large-particle impurities are removed by the screen 4011, organic pollutants are degraded by the biofilm reactor 4012, and oil-water separation is performed by the demulsification component 4013. The treated muddy water enters the deep dewatering unit 402, where solid-liquid separation is performed by the plate and frame filter press 4021, and the separated mud cake is dried by the hot air dryer 4022. The synergistic effect of each stage of graded treatment ensures that the muddy water is fully purified and dewatered, providing high-quality mud cake and clear liquid raw materials for subsequent resource recovery. S4: Resource recovery. Large-diameter impurities separated by pretreatment device 401 enter metal scrap recovery device 501. The sorted metal scraps are then transported to metal smelting equipment. The dried mud cake enters material mixer 5021, where it is mixed with industrial solid waste and cementitious materials, and then transported to non-fired brick forming machine 5022. The clear liquid separated by deep dewatering device 402 is sequentially treated by multi-media filter 5031, ultraviolet sterilizer 5032, and electromagnetic scale inhibitor 5033 before being returned to the machining tank. The resource recovery process converts mud, water, and metal impurities into usable resources, realizing machining. The closed-loop utilization of mud and water resources aligns with the requirements of circular economy and environmental protection. The industrial solid waste consists of metal cutting slag or waste grinding wheel powder generated in the machining workshop, and the cementing material is cement. After the mud cake, industrial solid waste, and cementing material are mixed in the material mixer 5021, they are transported to the non-fired brick forming machine 5022 for pressing and molding. When the electromagnetic scale inhibitor 5033 is running, the matching slow-release scale inhibitor component adds scale inhibitor to the clear liquid. The clear liquid, after being treated by the clear liquid recycling device 503, is returned to the machining tank through pipelines. The addition of scale inhibitor extends the unobstructed cycle of the return liquid pipeline, improving the overall economy and environmental protection of the system.

[0019] In summary, this invention utilizes the existing mud tank 101 for efficient storage and self-cleaning by incorporating adjustable partition baffles 1011 and bottom cleaning scrapers 1012. Combined with a variable frequency positive displacement pump 301 for precise delivery of mud and water of varying concentrations, and further connected to a terminal resource recycling module, a metal scrap recycling device 501 recovers metal for reuse in smelting, a mud cake treatment device 502 processes mud cake and industrial solid waste into non-fired bricks, and a clear liquid reuse device 503 returns the clear liquid to the machining tank. This forms a complete chain of mud and water storage, intelligent transportation, and a closed-loop resource system. It avoids resource waste caused by abandoning the mud tank 101 and ensures efficient transportation through precise adaptation of the positive displacement pump. Ultimately, it achieves coordinated discharge and recycling of machining mud and water, highlighting the dual benefits of circular economy and environmental protection from multiple dimensions, including facility reuse, transportation optimization, and resource recycling. The photovoltaic modules 2011 of the energy auxiliary module 200 are laid on the top of the mud tank 101, converting solar energy into electrical energy and storing it in the energy storage battery pack 2012. The photovoltaic-storage-grid switching cabinet 2013 intelligently switches the power source, giving priority to powering the variable frequency positive displacement pump 301 and the pretreatment device 401. This linkage design not only provides green energy support for the positive displacement pump transportation and pretreatment process, reducing the dependence on grid energy consumption, but also enables the system to operate stably when the photovoltaic power generation fluctuates by synchronously adjusting the pump operating frequency and pretreatment parameters through the PLC control cabinet 601. This achieves integrated coordination of low-energy transportation and pretreatment, significantly improving the energy economy and operational stability of the system. The material mixer 5021 of the mud cake treatment device 502 mixes the mud cake from the deep dewatering device 402 with industrial solid waste and cement from the machining workshop, and then presses it into non-fired bricks through the non-fired brick forming machine 5022, realizing the synergistic resource utilization of mud cake and industrial solid waste. The multi-media filter 5031, ultraviolet sterilizer 5032, and electromagnetic scale inhibitor 5033 of the clear liquid recycling device 503 sequentially treat the deep dewatered clear liquid, and the scale inhibitor component adds scale inhibitor to ensure that the pipeline for returning clear liquid to the machining tank is unobstructed for a long time. This design transforms mud cake and industrial solid waste into high-value building materials on the one hand, and extends the clear liquid recycling cycle through scale inhibition treatment on the other hand, thereby improving resource utilization and significantly reducing the environmental protection treatment cost of the machining workshop.

[0020] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A closed-loop conveying system for sludge discharge from a machining tank, comprising a sludge tank (101), a variable frequency positive displacement pump set (301), and a pretreatment device (401) connected in sequence, characterized in that: It also includes a source collection module, an intelligent conveying module, a graded processing module, a resource recycling module, and an intelligent control module; The source collection module includes a mud tank (101) and a sludge discharge pipe (102) for the machining tank. One end of the sludge discharge pipe (102) is connected to the machining tank, and the other end is connected to the inlet of the mud tank (101). The mud tank (101) is equipped with an adjustable partition baffle (1011) and a bottom cleaning scraper (1012). The intelligent conveying module includes a variable frequency positive displacement pump set (301) and an anti-clogging conveying pipeline (302). The feed end of the variable frequency positive displacement pump set (301) is connected to the discharge port of the mud tank (101). One end of the anti-clogging conveying pipeline (302) is connected to the discharge end of the variable frequency positive displacement pump set (301), and the other end is connected to the grading processing module. An electric backwash valve (3021) is provided at intervals on the anti-clogging conveying pipeline (302). The graded processing module includes a pretreatment device (401) and a deep dewatering device (402). The feed end of the pretreatment device (401) is connected to the end of the anti-clogging conveying pipeline (302) away from the variable frequency positive displacement pump group (301). The pretreatment device (401) includes a grid (4011), a biofilm reactor (4012), and a demulsification component (4013). The feed end of the deep dewatering device (402) is connected to the discharge end of the pretreatment device (401). The deep dewatering device (402) includes a plate and frame filter press (4021) and a hot air dryer (4022). The resource recycling module includes a metal scrap recycling device (501), a sludge cake treatment device (502), and a clear liquid reuse device (503). The feed end of the metal scrap recycling device (501) is connected to the impurity outlet of the grid (4011) of the pretreatment device (401). The feed end of the sludge cake treatment device (502) is connected to the sludge cake outlet of the deep dewatering device (402). The feed end of the clear liquid reuse device (503) is connected to the clear liquid outlet of the deep dewatering device (402). The discharge end of the clear liquid reuse device (503) is connected to the machining tank. The intelligent control module includes a PLC control cabinet (601) and a sensing component (602). The sensing component (602) includes a mud-water concentration sensor (6021) and a pipeline pressure sensor (6022). The mud-water concentration sensor (6021) is installed at the outlet of the mud tank (101), and the pipeline pressure sensor (6022) is installed on the outlet pipeline of the variable frequency positive displacement pump set (301). The PLC control cabinet (601) is electrically connected to the bottom cleaning scraper (1012), the variable frequency positive displacement pump set (301), the electric backwash valve (3021), the pretreatment device (401), the deep dewatering device (402), and the sensing component (602).

2. The closed-loop conveying system for sludge discharge from the machining tank according to claim 1, characterized in that: The adjustable partition baffles (1011) are arranged at intervals along the length of the mud tank (101), and the height of the adjustable partition baffles (1011) can be adjusted in the vertical direction; the bottom cleaning scraper (1012) is arranged along the length of the mud tank (101) and is in contact with the bottom of the mud tank (101).

3. The closed-loop conveying system for sludge discharge from the machining tank according to claim 1, characterized in that: It also includes an energy auxiliary module (200), which includes a photovoltaic module (2011), an energy storage battery pack (2012), and a photovoltaic-storage grid switching cabinet (2013); the photovoltaic module (2011) is laid on the top of the mud tank (101), and the power output terminal of the photovoltaic module (2011) is electrically connected to the power input terminal of the energy storage battery pack (2012); The power input terminal of the photovoltaic-storage-grid switching cabinet (2013) is electrically connected to the energy storage battery pack (2012) and the power grid, respectively. The power output terminal of the photovoltaic-storage-grid switching cabinet (2013) is electrically connected to the variable frequency positive displacement pump group (301) and the pretreatment device (401), respectively. The photovoltaic-storage-grid switching cabinet (2013) is electrically connected to the PLC control cabinet (601).

4. The closed-loop conveying system for sludge discharge from the machining tank according to claim 1, characterized in that: The variable frequency positive displacement pump set (301) includes at least two variable frequency positive displacement pumps connected in parallel; the electric backwash valve (3021) is an electromagnetically controlled valve and is connected to the anti-blockage delivery pipeline (302).

5. The closed-loop conveying system for sludge discharge from the machining tank according to claim 1, characterized in that: The metal scrap recycling device (501) is an electromagnetic separator, and the metal discharge end of the electromagnetic separator is connected to the metal smelting equipment. The mud cake processing device (502) includes a material mixer (5021) and a non-fired brick forming machine (5022), wherein the discharge end of the material mixer (5021) is connected to the feed end of the non-fired brick forming machine (5022); The clear liquid recycling device (503) includes a multi-media filter (5031), an ultraviolet sterilizer (5032), and an electromagnetic scale inhibitor (5033). The multi-media filter (5031), the ultraviolet sterilizer (5032), and the electromagnetic scale inhibitor (5033) are connected in series. The feed end of the multi-media filter (5031) is connected to the clear liquid outlet of the deep dewatering device (402), and the discharge end of the electromagnetic scale inhibitor (5033) is connected to the machining tank.

6. A method for the resource-based treatment of wastewater and sludge from a closed-loop conveying system for sludge discharge from a machining tank, characterized in that: Includes the following steps: S1: Source collection. High-concentration mud and water discharged from the machining tank enter the mud tank (101) through the sludge discharge pipe (102). Adjustable partition baffles (1011) temporarily store the mud and water in partitions. The bottom cleaning scraper (1012) runs along the bottom of the tank. The mud and water concentration sensor (6021) detects the mud and water concentration and transmits the signal to the PLC control cabinet (601). S2: Intelligent conveying. The PLC control cabinet (601) receives signals from the mud and water concentration sensor (6021) and the pipeline pressure sensor (6022), and adjusts the operating frequency of the variable frequency positive displacement pump set (301). The mud and water are conveyed to the pretreatment device (401) through the anti-clogging conveying pipeline (302). When the pipeline pressure exceeds the preset range, the PLC control cabinet (601) controls the electric backwash valve (3021) to open and flush the anti-clogging conveying pipeline (302). S3: Graded treatment, the mud and water enter the pretreatment device (401), and large-particle impurities are removed by the screen (4011). The biofilm reactor (4012) degrades organic pollutants, and the demulsification component (4013) performs oil-water separation. The treated mud and water enter the deep dewatering device (402), and solid-liquid separation is performed by the plate and frame filter press (4021). The separated mud cake is dried by the hot air dryer (4022). S4: Resource recovery, large-particle impurities separated by the pretreatment device (401) enter the metal scrap recycling device (501), and the sorted metal scraps are transported to the metal smelting equipment; the dried mud cake enters the material mixer (5021), and after being mixed with industrial solid waste and cementitious materials, it is transported to the non-fired brick forming machine (5022); the clear liquid separated by the deep dewatering device (402) is processed by the multi-media filter (5031), the ultraviolet sterilizer (5032) and the electromagnetic scale inhibitor (5033) in sequence, and then returned to the machining tank.

7. The wastewater and sludge resource utilization treatment method of the closed-loop conveying system for sludge discharge from the machining tank according to claim 6, characterized in that: In S2, the photovoltaic module (2011) converts solar energy into electrical energy and stores it in the energy storage battery pack (2012); the photovoltaic-storage grid switching cabinet (2013) prioritizes the transmission of electrical energy from the energy storage battery pack (2012) to the variable frequency positive displacement pump (301) and the pretreatment device (401); when the photovoltaic module (2011) generates insufficient power, the photovoltaic-storage grid switching cabinet (2013) switches to grid power supply, and the PLC control cabinet (601) synchronously adjusts the operating frequency of the variable frequency positive displacement pump (301) and the operating parameters of the pretreatment device (401).

8. The wastewater and sludge resource utilization treatment method of the closed-loop conveying system for sludge discharge from the machining tank according to claim 6, characterized in that: In S2, when the PLC control cabinet (601) adjusts the variable frequency positive displacement pump group (301), it synchronously adjusts the output power of the pump group according to the concentration value detected by the mud and water concentration sensor (6021) and the pressure value detected by the pipeline pressure sensor (6022).

9. The wastewater and sludge resource utilization treatment method of the closed-loop conveying system for sludge discharge from the machining tank according to claim 6, characterized in that: In S4, the industrial solid waste is metal cutting slag or waste grinding wheel powder generated in the machining workshop, and the cementing material is cement. After the mud cake, industrial solid waste and cementing material are mixed in the material mixer (5021), they are transported to the non-fired brick forming machine (5022) for pressing and molding.

10. The wastewater and sludge resource utilization treatment method of the closed-loop conveying system for sludge discharge from the machining tank according to claim 6, characterized in that: In S4, when the electromagnetic scale inhibitor (5033) is running, the matching slow-release scale inhibitor component adds scale inhibitor to the clear liquid; the clear liquid after being treated by the clear liquid recycling device (503) is returned to the machining tank through the pipeline.

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