Integrated sewage treatment equipment based on multi-stage circulating deslagging

Abstract

The invention discloses integrated sewage treatment equipment based on multi-stage circulating deslagging, and relates to the technical field of sewage treatment.The integrated sewage treatment equipment specifically comprises a crushing frame, a first-stage reaction box, a second-stage reaction cylinder and a third-stage reaction cylinder, the first-stage reaction box is installed in the crushing frame, the second-stage reaction cylinder is fixedly communicated with the side of the first-stage reaction box, and the third-stage reaction cylinder is fixedly communicated with the second-stage reaction cylinder; a third-stage reaction cylinder is mounted at the bottom of the second-stage reaction cylinder; according to the invention, the biochemical reaction efficiency is remarkably improved through the dynamic contact between the interception reaction cylinder and the suspended filler in the secondary reaction cylinder and the combination of bubble driving of the microporous aeration disc, and meanwhile, the sludge reflux ratio is dynamically adjusted through a PID algorithm based on a closed-loop control system of an MLSS online monitor and a flowmeter, so that the sludge treatment efficiency is improved. The motor is used for driving the sealing blanking cap on the rotating shaft to intercept the sludge in the reaction cylinders and rapidly obtain the sludge, and compared with a mode of firstly draining water and then conveying the sludge, the discharging efficiency from the second-stage reaction cylinder to the third-stage reaction cylinder is improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an integrated wastewater treatment device based on multi-stage circulating sludge discharge. Background Technology

[0002] Wastewater treatment refers to the process of removing pollutants from water bodies through physical, chemical, and biological technologies to meet discharge standards or reuse requirements. With the development of industrialization and urbanization, wastewater treatment has become an important part of environmental protection and resource recycling.

[0003] The core objective of wastewater treatment is to remove pollutants, including organic matter (COD / BOD), suspended solids (SS), nitrogen and phosphorus (nitrogen and phosphorus removal), heavy metals and pathogenic microorganisms, etc. Common treatment methods include physical, chemical and biological advanced treatment and reuse.

[0004] When treating wastewater sludge, a pretreatment unit is set up to remove large particulate impurities, and a multi-stage reaction zone is set up. The wastewater is graded and optimized according to its characteristics (such as COD / BOD concentration, suspended solids content, grease / fiber impurities, etc.). The first-stage zone treats high-concentration pollutants, the second-stage zone performs fine degradation, the third-stage zone ensures that the effluent meets the standards, the sludge from the second-stage zone is returned to the first-stage zone to replenish biomass, and the sludge from the third-stage zone is concentrated and then discharged or returned.

[0005] For the sludge thickening and recirculation, the core objective of ensuring efficient and stable system operation is to maintain biomass balance in the reaction zone, optimize pollutant degradation efficiency, and reduce operating costs. However, controlling the recirculation ratio after sludge thickening is quite difficult. A high recirculation flow rate leads to fluctuations in dissolved oxygen in the reaction zone, inhibiting denitrification. A low recirculation flow rate results in insufficient biomass and reduced treatment efficiency. At the same time, it is easy for fiber impurities to clog the recirculation pipes. Therefore, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an integrated wastewater treatment device based on multi-stage circulating sludge discharge, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an integrated sewage treatment equipment based on multi-stage circulating sludge discharge, comprising a crushing frame, a primary reaction tank, a secondary reaction cylinder, and a tertiary reaction cylinder, wherein the primary reaction tank is installed inside the crushing frame, the secondary reaction cylinder is fixedly connected to the side of the primary reaction tank, and the tertiary reaction cylinder is installed at the bottom of the secondary reaction cylinder;

[0008] Interception reaction cylinders are evenly installed and fixed on the inner wall partition of the secondary reaction cylinder. An isolation cover is fixedly connected to the inner wall partition of the secondary reaction cylinder and located between the interception reaction cylinders. The isolation cover penetrates the partition and extends to the bottom inner wall of the secondary reaction cylinder.

[0009] A transmission assembly is fixedly connected to the top of the secondary reaction cylinder. The motor output end of the transmission assembly passes through the top of the secondary reaction cylinder and is fixedly connected to a rotating shaft. One end of the rotating shaft passes through the isolation cover and a sealing plug is fixed to the bottom of the partition plate of the secondary reaction cylinder. The rotating shaft is located inside the isolation cover and has evenly spaced connecting grooves. A reflux box is fixedly connected to the side of the isolation cover through a connecting pipe. A sludge return detection box is installed inside the reflux box. The sludge return detection box is used for sludge concentration monitoring.

[0010] Furthermore, a receiving hopper is bolted to the top of the crushing frame, and a material winding blade is installed inside the receiving hopper. A crushing roller is installed at the bottom of the receiving hopper and inside the crushing frame. A feeding drum is fixedly connected to the bottom of the crushing roller and the top of the primary reaction tank. A waste filter box is fixedly connected to the end of the feeding drum and the top of the primary reaction tank. An MLSS online monitoring instrument and a DO sensor are installed on the primary reaction tank.

[0011] Furthermore, the bottom of the feeding drum wall is connected to the primary reaction chamber, and a low-speed propeller with a rotation speed ≤60rpm is installed inside the primary reaction chamber.

[0012] Furthermore, a throttling valve is installed at the connection between the secondary and tertiary reaction cylinders. A filter assembly is installed inside the tertiary reaction cylinder. The filter assembly includes an ultrafiltration membrane layer and a sand filter membrane layer from the outside to the inside. The pore size of the sand filter membrane layer is 0.5-1.2 mm, and the pore size of the ultrafiltration membrane layer is 0.1 μm. A slag outlet is provided at the bottom of the tertiary reaction cylinder.

[0013] Furthermore, a liquid collection tank is provided inside the reflux box, and a filter cartridge is installed and fixed inside the liquid collection tank. The bottom of the filter cartridge is connected to a sludge return detection box, which includes a flow meter and a sludge concentration meter for detecting the flow rate of the sludge mixture entering the sludge return detection box.

[0014] Furthermore, a circulation pump is installed on the side of the sludge return detection box, and the circulation pump side is connected to the primary reaction box via a connecting pipe. The reflux box side is connected to the bottom of the secondary reaction cylinder partition via a pipe.

[0015] The integrated wastewater treatment method with multi-stage circulating sludge discharge is as follows:

[0016] Multi-stage slag discharge utilizes the crushing roller at the bottom of the receiving hopper on the crushing frame to crush fibrous materials in wastewater, and discharges them into the waste filter box for dewatering through the feeding drum;

[0017] The remaining wastewater enters the primary reaction tank, where a low-speed flow promoter rotates and promotes hydrolysis and acidification through composite packing. The wastewater retention time is controlled at 2-4 hours.

[0018] The wastewater is then discharged into the secondary reaction chamber. Under the operation of the microporous aeration disc, the suspended packing generates bubbles, driving the suspended packing to react with the wastewater in the interception reaction chamber. During the reaction, the installed MLSS online monitoring instrument monitors the sludge concentration in the primary reaction chamber. At the same time, the transmission component controls the rotating shaft to rotate, and its bottom sealing plug begins to connect with the single set of interception reaction chambers, causing the wastewater mixed with sludge in the interception reaction chamber to flow back to the isolation hood. Then, it enters the reverse flow box through the isolation hood. After being dewatered by the filter cartridge, the sludge enters the sludge return box for concentration detection. Then, it is pumped back into the primary reaction chamber by the circulation pump. The sludge return ratio is automatically adjusted according to the sludge concentration monitoring in the primary reaction chamber.

[0019] After the wastewater in the secondary reaction tank has completed nitrogen and phosphorus removal (6-8 hours), the throttle valve is opened according to the load to send the wastewater into the tertiary reaction tank. The filtration time is 1-2 hours, and the wastewater is filtered using the filter components. Sludge and other impurities are discharged through the sludge discharge port.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. In this invention, efficient pollutant degradation and stable equipment operation are achieved through dynamic contact between the interception reaction cylinder and the suspended packing in the secondary reaction cylinder, combined with the bubble drive of the microporous aeration disc, which significantly improves the efficiency of the biochemical reaction. At the same time, based on the closed-loop control system of the MLSS online monitoring instrument and flow meter, the sludge return ratio is dynamically adjusted through the PID algorithm. The sludge in the interception reaction cylinder is quickly obtained by using the sealing plug on the motor-driven rotating shaft. Compared with the method of first draining water and then transporting sludge, the discharge efficiency from the secondary reaction cylinder to the tertiary reaction cylinder is improved, while ensuring the stability of the sludge concentration in the primary reaction tank and avoiding the decrease in treatment efficiency caused by insufficient or excessive biomass.

[0022] 2. In this invention, for high-concentration wastewater or high-fiber wastewater, the crushing roller at the bottom of the receiving hopper on the crushing frame is used to crush the material. At the same time, the feeding drum transports some impurities to the waste filter cylinder for storage. The combination of the crushing roller and the waste filter box completely solves the problem of fiber impurities clogging the transport pipeline. At the same time, the filter components in the three-stage reaction cylinder are cleaned, and the backwash water is returned to the first-stage reaction tank to realize the recycling of water resources. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to the present invention;

[0024] Figure 2 This is a schematic diagram of the integrated sewage treatment equipment based on multi-stage circulating sludge discharge of the present invention with the top cover removed;

[0025] Figure 3 This is a front view schematic diagram of the integrated sewage treatment equipment based on multi-stage circulating sludge discharge according to the present invention;

[0026] Figure 4 This is a rear view schematic diagram of the integrated sewage treatment equipment based on multi-stage circulating sludge discharge according to the present invention;

[0027] Figure 5 This is a schematic cross-sectional view of the secondary and tertiary reaction chambers of the present invention;

[0028] Figure 6 This is a schematic cross-sectional view of the reflux box structure of the present invention.

[0029] In the diagram: 1. Crusher; 2. Primary reaction chamber; 3. Secondary reaction cylinder; 4. Tertiary reaction cylinder; 5. Receiving hopper; 6. Material winding blade; 7. Crushing roller; 8. Feeding drum; 9. Waste filter box; 10. Transmission assembly; 11. Interception reaction cylinder; 12. Isolation cover; 13. Rotating shaft; 14. Connecting groove; 15. Sealing plug; 16. Microporous aeration disc; 17. Throttling valve; 18. Filter assembly; 19. Slag outlet; 20. Backflow box; 21. Liquid collection tank; 22. Filter cartridge; 23. Sludge return detection box; 24. Circulation pump. Detailed Implementation

[0030] 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.

[0031] Please see Figure 1-6 The present invention provides a technical solution: Integrated wastewater treatment equipment based on multi-stage circulating sludge discharge, such as Figure 1 As shown, it is divided into a crushing frame 1, a primary reaction tank 2, a secondary reaction cylinder 3, and a tertiary reaction cylinder 4, which are connected in series. It is mainly used to maintain the biomass balance in the reaction zone, optimize the pollutant degradation efficiency, and reduce operating costs during the sewage treatment process. Microorganisms in activated sludge are the core carriers for degrading organic matter and removing nitrogen and phosphorus. By circulating sludge, active microorganisms in the sedimentation tank can be reintroduced into the reaction zone to replenish the biomass lost due to sludge discharge or natural decay. If all sludge is directly discharged during the wastewater treatment sludge discharge process, the concentration of microorganisms in the reaction zone will drop sharply, and the treatment capacity will decrease. Therefore, sludge return is guided in the process from the secondary reaction tank 3 to the primary reaction tank 2, and the sludge return ratio is dynamically adjusted according to the load of the primary reaction tank 2. Generally, the return ratio is 20%-30% in the anaerobic zone and 50%-70% in the aerobic zone. like Figure 2As shown, wastewater first enters the receiving hopper 5. Guided by the upper winding blades 6 and crushed by the crushing rollers 7, large particles and fibrous materials in the wastewater are broken down into smaller particles, such as... Figure 3 As shown, the bottom of the box where the crushing roller 7 is located is connected to the feeding drum 8, and the end of the feeding drum 8 and the top of the primary reaction box 2 are connected to and fixed to the waste filter box 9. The crushing roller 7 crushes the fiber material in the sewage to prevent the subsequent pipeline from being blocked. The crushed sewage impurities are transported to the waste filter box 9 through the feeding drum 8 for storage and dehydration, which is convenient for subsequent recycling and centralized treatment. The wastewater that has undergone preliminary screening flows into the primary reaction tank 2 through a pipeline. The primary reaction tank 2 is equipped with a low-speed flow promoter and composite packing material. Under anaerobic conditions, the large organic molecules such as proteins and fats in the wastewater are decomposed into small acid molecules. The wastewater retention time is controlled at 2-4 hours. At the same time, an MLSS online monitoring instrument and a DO sensor are installed on the top of the tank to monitor the sludge concentration and dissolved oxygen in real time. The relevant collected data are fed back to the external control system. Wastewater treated in the primary reaction tank 2 is piped into the secondary reaction cylinder 3, where multiple interception reaction cylinders 11 are evenly installed. Figure 2 As shown, an isolation cover 12 is installed between the interception reaction cylinders 11, and wastewater from the primary reaction tank 2 enters as a result. Figure 5 As shown, the water level gradually rises, and the sewage begins to pass through the interception reaction cylinder 11 to the top of the baffle. Most of the suspended packing material in the sewage is intercepted inside the interception reaction cylinder 11. During the actual reaction, the microporous aeration disc 16 installed at the bottom of the secondary reaction cylinder 3 generates bubbles to drive the suspended packing material and sewage to fully contact and react at the top of the baffle of the interception reaction cylinder 11, completing the COD / BOD degradation and nitrification reaction, with a residence time of 6-8 hours. In order to reintroduce the active microorganisms in the secondary reaction chamber 3 into the primary reaction chamber 2, a transmission assembly 10 is installed on the top of the entire secondary reaction chamber 3. The motor end of the transmission assembly 10 is connected to a rotating shaft 13. One end of the rotating shaft 13 passes through the interception reaction chamber 11 and is fitted with a connecting upper sealing plug 15 at the partition position. After the wastewater finishes reacting in the secondary reaction tank 3, the transmission component 10 controls the rotating shaft 13 to rotate, and the motor drives the rotating shaft 13 to rotate the bottom sealing plug 15, so that the sealing plug 15 is connected to the single interception reaction tank 11, and the sludge mixture in the interception reaction tank 11 flows into the isolation cover 12 through the connecting groove 14 on the rotating shaft 13. At this time, the wastewater has a high sludge content. like Figure 2 and Figure 4As shown, the isolation cover 12 is connected to the outside of the reflux box 20 of the secondary reaction cylinder 3. The mixed liquid enters the liquid collection tank 21 of the reflux box 20 through the connecting pipe. After being dewatered by the filter cartridge 22, the sludge enters the sludge return detection box 23. The detection box integrates a flow meter and a sludge concentration meter to monitor the flow rate and concentration of the returned sludge in real time. The MLSS online monitoring instrument installed in the primary reaction tank 2 collects the sludge concentration in real time at a sampling frequency of 1 time / minute. The data is filtered and then transmitted to the external PLC system. The electromagnetic flow meter in the sludge return detection tank 23 monitors the return sludge flow rate in real time and transmits it to the PLC system synchronously. According to the characteristics of the influent water quality, the preset MLSS target range of the primary reaction tank 2 is 2000-4000 mg / L. The frequency of the circulation pump 24 or the valve opening is dynamically adjusted by the PID control algorithm. If the MLSS is lower than the lower limit and the MLSS < 2000 mg / L for 10 minutes, the frequency of the circulation pump 24 is increased to increase the sludge return flow rate. The return ratio is gradually increased from 20% to 50%. If the MLSS still does not meet the standard, the backup sludge dosing system at the top of the primary reaction tank 2 is started. If the MLSS is within the target range of 2000-4000 mg / L, the PLC system fine-tunes the pump frequency based on the real-time deviation to maintain the reflux ratio at 30%-40%. If the MLSS is higher than the upper limit, and the MLSS is >4000 mg / L for 10 minutes, the frequency of the circulation pump 24 is reduced, the return flow is reduced, and the return ratio is reduced from 50% to 20%. Compared with the sludge discharge procedure, this application disconnects the sealing plug 15 on the rotating shaft 13 from the bottom of the interception reaction cylinder 11, cuts off the continuous sludge return, and at the same time starts to discharge the sewage into the tertiary reaction cylinder 4. The throttle valve 17 between the tertiary reaction cylinder 4 and the secondary reaction cylinder 3 is opened. As the sewage enters the tertiary reaction cylinder 4, it begins to undergo solid-liquid separation through the installed filter assembly 18. Excess sludge is discharged through the sludge discharge port. Using a three-stage reaction chamber 4 for filtration and sludge discharge, the sludge discharge volume is 5%-10% of the total sludge volume. Through a three-stage control strategy of real-time monitoring, algorithm regulation, and abnormal redundancy, this invention achieves precise dynamic adjustment of the sludge return ratio, ensuring that the biomass in the first-stage reaction chamber 2 is always within the optimal range. This design significantly improves the system's resistance to shock loads, while reducing the need for manual intervention and operating energy consumption. Water enters the third-stage reaction chamber 4 through the throttling valve 17. The filter assembly 18 consists of a sand filter layer and an ultrafiltration membrane from the outside to the inside, which further intercepts suspended solids and colloids. The retention time is 1-2 hours. The concentrated sludge is discharged through the bottom sludge outlet 19 and processed by the screw press dewatering machine. The dried sludge is transported off-site for disposal. Similarly, water can be passed through the sludge outlet to perform backwashing operation on the filter assembly 18. The backwash wastewater is returned to the first-stage reaction tank 2 through the pipeline to realize the recycling of water resources.

[0032] Integrated wastewater treatment equipment based on multi-stage circulating sludge discharge, such as Figure 1 As shown, it is divided into a crushing frame 1, a primary reaction tank 2, a secondary reaction cylinder 3, and a tertiary reaction cylinder 4, which are connected in series. It is mainly used to maintain the biomass balance in the reaction zone, optimize the pollutant degradation efficiency, and reduce operating costs during the sewage treatment process.

[0033] Microorganisms in activated sludge are the core carriers for degrading organic matter and removing nitrogen and phosphorus. By circulating sludge, active microorganisms in the sedimentation tank can be reintroduced into the reaction zone to replenish the biomass lost due to sludge discharge or natural decay. If all sludge is directly discharged during the wastewater treatment sludge discharge process, the concentration of microorganisms in the reaction zone will drop sharply, and the treatment capacity will decrease. Therefore, sludge return is guided in the process from the secondary reaction tank 3 to the primary reaction tank 2, and the sludge return ratio is dynamically adjusted according to the load of the primary reaction tank 2. Generally, the return ratio is 20%-30% in the anaerobic zone and 50%-70% in the aerobic zone.

[0034] like Figure 2 As shown, wastewater first enters the receiving hopper 5. Guided by the upper winding blades 6 and crushed by the crushing rollers 7, large particles and fibrous materials in the wastewater are broken down into smaller particles, such as... Figure 3 As shown, the bottom of the box where the crushing roller 7 is located is connected to the feeding drum 8, and the end of the feeding drum 8 and the top of the primary reaction box 2 are connected to and fixed to the waste filter box 9. The crushing roller 7 crushes the fiber material in the sewage to prevent the subsequent pipeline from being blocked. The crushed sewage impurities are transported to the waste filter box 9 through the feeding drum 8 for storage and dehydration, which is convenient for subsequent recycling and centralized treatment.

[0035] The wastewater that has undergone preliminary screening flows into the primary reaction tank 2 through a pipeline. The primary reaction tank 2 is equipped with a low-speed flow promoter and composite packing material. Under anaerobic conditions, the large organic molecules such as proteins and fats in the wastewater are decomposed into small acid molecules. The wastewater retention time is controlled at 2-4 hours. At the same time, an MLSS online monitoring instrument and a DO sensor are installed on the top of the tank to monitor the sludge concentration and dissolved oxygen in real time. The relevant collected data are fed back to the external control system.

[0036] Wastewater treated in the primary reaction tank 2 is piped into the secondary reaction cylinder 3, where multiple interception reaction cylinders 11 are evenly installed. Figure 2 As shown, an isolation cover 12 is installed between the interception reaction cylinders 11, and wastewater from the primary reaction tank 2 enters as a result. Figure 5As shown, the water level gradually rises, and the sewage begins to pass through the interception reaction cylinder 11 to the top of the baffle. Most of the suspended packing material in the sewage is intercepted inside the interception reaction cylinder 11. During the actual reaction, the microporous aeration disc 16 installed at the bottom of the secondary reaction cylinder 3 generates bubbles to drive the suspended packing material and sewage to fully contact and react at the top of the baffle of the interception reaction cylinder 11, completing the COD / BOD degradation and nitrification reaction, with a residence time of 6-8 hours.

[0037] In order to reintroduce the active microorganisms in the secondary reaction chamber 3 into the primary reaction chamber 2, a transmission assembly 10 is installed on the top of the entire secondary reaction chamber 3. The motor end of the transmission assembly 10 is connected to a rotating shaft 13. One end of the rotating shaft 13 passes through the interception reaction chamber 11 and is fitted with a connecting upper sealing plug 15 at the partition position.

[0038] After the wastewater finishes reacting in the secondary reaction tank 3, the transmission component 10 controls the rotating shaft 13 to rotate, and the motor drives the rotating shaft 13 to rotate the bottom sealing plug 15, so that the sealing plug 15 is connected to the single interception reaction tank 11, and the sludge mixture in the interception reaction tank 11 flows into the isolation cover 12 through the connecting groove 14 on the rotating shaft 13. At this time, the wastewater has a high sludge content.

[0039] like Figure 2 and Figure 4 As shown, the isolation cover 12 is connected to the outside of the reflux box 20 of the secondary reaction cylinder 3. The mixed liquid enters the liquid collection tank 21 of the reflux box 20 through the connecting pipe. After being dewatered by the filter cartridge 22, the sludge enters the sludge return detection box 23. The detection box integrates a flow meter and a sludge concentration meter to monitor the flow rate and concentration of the returned sludge in real time.

[0040] The MLSS online monitoring instrument installed in the primary reaction tank 2 collects the sludge concentration in real time at a sampling frequency of 1 time / minute. The data is filtered and then transmitted to the external PLC system. The electromagnetic flow meter in the sludge return detection tank 23 monitors the return sludge flow rate in real time and transmits it to the PLC system synchronously. According to the characteristics of the influent water quality, the preset MLSS target range of the primary reaction tank 2 is 2000-4000 mg / L. The frequency of the circulation pump 24 or the valve opening is dynamically adjusted by the PID control algorithm. If the MLSS is lower than the lower limit and the MLSS < 2000 mg / L for 10 minutes, the frequency of the circulation pump 24 is increased to increase the sludge return flow rate. The return ratio is gradually increased from 20% to 50%. If the MLSS still does not meet the standard, the backup sludge dosing system at the top of the primary reaction tank 2 is started.

[0041] If the MLSS is within the target range of 2000-4000 mg / L, the PLC system fine-tunes the pump frequency based on the real-time deviation to maintain the reflux ratio at 30%-40%.

[0042] If the MLSS is higher than the upper limit, and the MLSS is >4000 mg / L for 10 minutes, the frequency of the circulation pump 24 is reduced, the return flow is reduced, and the return ratio is reduced from 50% to 20%. Compared with the sludge discharge procedure, this application disconnects the sealing plug 15 on the rotating shaft 13 from the bottom of the interception reaction cylinder 11, cuts off the continuous sludge return, and at the same time starts to discharge the sewage into the tertiary reaction cylinder 4. The throttle valve 17 between the tertiary reaction cylinder 4 and the secondary reaction cylinder 3 is opened. As the sewage enters the tertiary reaction cylinder 4, it begins to undergo solid-liquid separation through the installed filter assembly 18. Excess sludge is discharged through the sludge discharge port.

[0043] Using a three-stage reaction chamber 4 for filtration and sludge discharge, the sludge discharge volume is 5%-10% of the total sludge volume. Through a three-stage control strategy of real-time monitoring, algorithm regulation, and abnormal redundancy, this invention achieves precise dynamic adjustment of the sludge return ratio, ensuring that the biomass in the first-stage reaction chamber 2 is always within the optimal range. This design significantly improves the system's resistance to shock loads, while reducing the need for manual intervention and operating energy consumption.

[0044] Water enters the third-stage reaction chamber 4 through the throttling valve 17. The filter assembly 18 consists of a sand filter layer and an ultrafiltration membrane from the outside to the inside, which further intercepts suspended solids and colloids. The retention time is 1-2 hours. The concentrated sludge is discharged through the bottom sludge outlet 19 and processed by the screw press dewatering machine. The dried sludge is transported off-site for disposal. Similarly, water can be passed through the sludge outlet to perform backwashing operation on the filter assembly 18. The backwash wastewater is returned to the first-stage reaction tank 2 through the pipeline to realize the recycling of water resources.

[0045] Working principle of this invention:

[0046] Assemble the crushing frame 1, the primary reaction box 2, the secondary reaction cylinder 3 and the tertiary reaction cylinder 4, ensuring that all components are tightly connected and there is no leakage. The sewage first enters the receiving hopper 5, and after being crushed by the crushing roller 7, the large particles and fibrous materials in the sewage are crushed into smaller particles. The crushed sewage is discharged into the waste filter box 9 through the feeding drum 8.

[0047] After pretreatment, the wastewater enters the primary reaction tank 2. The internal low-speed flow promoter starts working, driving the wastewater to circulate within the tank. The composite packing material promotes the hydrolysis and acidification process in the primary reaction tank 2, decomposing the organic matter in the wastewater into small molecules. The sludge return system starts working, automatically adjusting the sludge return ratio based on the sludge concentration monitoring results in the primary reaction tank 2 to ensure the balance of biomass within the primary reaction tank 2.

[0048] Wastewater is discharged from the primary reaction tank 2 into the secondary reaction cylinder 3. The suspended packing generates bubbles under the operation of the microporous aeration disc 16, which drives the suspended packing to fully react with the wastewater in the interception reaction cylinder 11. After the reaction is completed, the transmission component 10 controls the rotating shaft 13 to rotate, so that the bottom sealing plug 15 starts to connect with the single interception reaction cylinder 11, causing the wastewater mixed with sludge in the interception reaction cylinder 11 to flow back to the isolation cover 12. The returned sludge mixture enters the backflow tank 20 through the pipeline. After being dewatered by the filter cylinder 22, it enters the sludge return detection tank 23 for concentration detection. The detected sludge is used to activate the circulation pump 24 according to the return ratio, and the quantitative sludge is pumped back into the primary reaction tank 2.

[0049] After the denitrification and phosphorus removal of the wastewater in the secondary reaction tank 3 is completed, the throttle valve 17 is opened according to the load adjustment to send the wastewater into the tertiary reaction tank 4. The filter assembly 18 is installed in the tertiary reaction tank 4 to perform final filtration treatment on the wastewater. After filtration, sludge and other impurities are discharged from the equipment through the sludge discharge port, completing the entire wastewater treatment process.

[0050] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An integrated wastewater treatment device based on multi-stage circulating slag discharge, comprising a crushing frame (1), a primary reaction tank (2), a secondary reaction cylinder (3), and a tertiary reaction cylinder (4), characterized in that, The crushing frame (1) is equipped with a primary reaction chamber (2), and a secondary reaction cylinder (3) is fixedly connected to the side of the primary reaction chamber (2). A tertiary reaction cylinder (4) is installed at the bottom of the secondary reaction cylinder (3). Interception reaction cylinders (11) are uniformly installed and fixed on the inner wall partition of the secondary reaction cylinder (3). An isolation cover (12) is fixedly connected on the inner wall partition of the secondary reaction cylinder (3) and between the interception reaction cylinders (11). The isolation cover (12) penetrates the partition and extends to the bottom inner wall of the secondary reaction cylinder (3). A transmission assembly (10) is fixedly connected to the top of the secondary reaction cylinder (3). The motor output end of the transmission assembly (10) passes through the top of the secondary reaction cylinder (3) and is fixedly connected to a rotating shaft (13). One end of the rotating shaft (13) passes through the isolation cover (12) and a sealing plug (15) is fixed at the bottom of the partition of the secondary reaction cylinder (3). The rotating shaft (13) is located inside the isolation cover (12) and a connecting groove (14) is evenly opened. A reflux box (20) is fixedly connected to the side of the isolation cover (12) through a connecting pipe. A sludge return detection box (23) is installed inside the reflux box (20). The sludge return detection box (23) is used for sludge concentration monitoring.

2. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 1, characterized in that, The top of the crushing frame (1) is fixed with a receiving hopper (5) by bolts, and a material winding blade (6) is installed inside the receiving hopper (5). A crushing roller (7) is installed at the bottom of the receiving hopper (5) and inside the box of the crushing frame (1). A feeding drum (8) is fixedly connected to the bottom box of the crushing roller (7). A waste filter box (9) is fixedly connected to the end of the feeding drum (8) and at the top of the primary reaction box (2). An MLSS online monitoring instrument and a DO sensor are installed on the primary reaction box (2).

3. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 2, characterized in that, The bottom of the feed drum (8) is connected to the primary reaction chamber (2), and a low-speed propeller with a rotation speed ≤60rpm is installed inside the primary reaction chamber (2).

4. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 3, characterized in that, A throttling valve (17) is installed at the connection between the secondary reaction cylinder (3) and the tertiary reaction cylinder (4). A filter assembly (18) is installed inside the tertiary reaction cylinder (4). The filter assembly (18) includes an ultrafiltration membrane layer and a sand filter membrane layer from the outside to the inside. The pore size of the sand filter membrane layer is 0.5-1.2 mm, and the pore size of the ultrafiltration membrane layer is 0.1 μm. A slag outlet (19) is opened at the bottom of the tertiary reaction cylinder (4).

5. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 4, characterized in that, The reflux box (20) is provided with a liquid collection tank (21), and a filter cartridge (22) is installed and fixed in the liquid collection tank (21). The bottom of the filter cartridge (22) is connected to a sludge return detection box (23). The sludge return detection box (23) includes a flow meter and a sludge concentration meter, which are used to detect the flow rate of the sludge mixture entering the sludge return detection box (23).

6. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 5, characterized in that, The sludge return detection box (23) is equipped with a circulation pump (24), and the circulation pump (24) is connected to the primary reaction box (2) via a connecting pipe. The reflux box (20) is connected to the bottom of the partition of the secondary reaction cylinder (3) via a pipe.

7. The integrated wastewater treatment equipment based on multi-stage circulating sludge discharge according to claim 6, characterized in that, The integrated wastewater treatment method with multi-stage circulating sludge discharge is as follows: Multi-stage slag discharge: the fibrous materials in the sewage are crushed by the upper receiving hopper (5) and the bottom crushing roller (7) of the crushing frame (1), and discharged into the waste filter box (9) for dewatering through the feeding drum (8); The remaining wastewater enters the primary reaction tank (2). The low-speed flow promoter inside the primary reaction tank (2) rotates and promotes hydrolysis and acidification through the composite packing. The wastewater retention time is controlled at 2-4 hours. Then it is discharged into the secondary reaction tank (3). Under the operation of the microporous aeration disc (16), the suspended packing generates bubbles to drive the suspended packing to react with the sewage in the interception reaction tank (11). During the reaction, the MLSS online monitoring instrument installed monitors the sludge concentration in the primary reaction tank (2). At the same time, the transmission component (10) controls the rotating shaft (13) to rotate. Its bottom sealing plug (15) begins to connect with the single interception reaction tank (11), causing the sewage mixed with sludge in the interception reaction tank (11) to flow back to the isolation cover (12). Then it enters the backflow box (20) through the isolation cover (12). After being dewatered by the filter cartridge (22), the sludge enters the sludge return box for concentration detection. Then it is pumped back into the primary reaction tank (2) by the circulation pump (24). The sludge return ratio is automatically adjusted according to the sludge concentration monitoring in the primary reaction tank (2). After the wastewater in the secondary reaction tank (3) has completed nitrogen and phosphorus removal, the time is 6-8 hours. According to the load adjustment, the throttle valve (17) is opened to send the wastewater into the tertiary reaction tank (4). The filtration time is 1-2 hours. The wastewater is filtered using the filter assembly (18), and sludge and other impurities are discharged through the sludge discharge port.

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