Box culvert connecting section pollution purification system

Abstract

The invention discloses a box culvert connecting section pollution purification system, and relates to the field of sponge city construction, the box culvert connecting section pollution purification system is arranged between a catch basin and a rainwater pipe gallery, and the box culvert connecting section pollution purification system comprises a first water collecting pool, a second water collecting pool and a third water collecting pool, the second water collecting tank is of a tubular structure, the water inlet end of the second water collecting tank communicates with the first water collecting tank, and the water outlet end of the second water collecting tank communicates with the rainwater pipe gallery; the two air bag bodies are respectively mounted at the water inlet end and the water outlet end of the second water collecting tank; the air bag body is U-shaped, the outer wall of the air bag body is tightly connected with the inner wall of the second water collecting tank in an inflated state, and a water passing channel is formed in the middle of the side wall of a U-shaped notch of the air bag body; the inflation and deflation system is connected with the two air bag bodies through air channels and used for controlling the two air bag bodies to be switched between the inflation state and the contraction state, daily greening water is intercepted and purified, the daily greening water can be used as municipal recycling water, and meanwhile the municipal drainage efficiency is not affected when it rains.

Description

Technical Field

[0001] This invention relates to the field of sponge city construction. More specifically, this invention relates to a pollution purification system for box culvert connecting sections. Background Technology

[0002] Sponge cities, as a new concept in modern urban stormwater management, are centered on constructing an urban hydrological system that is as resilient as a sponge through various ecological technologies such as infiltration, retention, storage, purification, utilization, and drainage. In the current urban drainage system, parks and green spaces play a role in rainwater infiltration and regulation. Water used for irrigation of parks and green spaces, as well as rainwater infiltrating through green spaces, eventually collects in rainwater wells around the green belts through surface runoff or groundwater infiltration. Municipal greening water consumption is relatively large, and a considerable portion of this water is discharged into the main urban stormwater culverts through runoff or infiltration, causing usable water resources to be wasted and exacerbating the urban water load.

[0003] Although the water used for greening irrigation carries a lot of silt and suspended particulate matter, resulting in a high sand content and turbidity, it is not polluted by industrial grease, heavy metals, or toxic organic matter compared to domestic sewage or industrial wastewater. After simple physical sedimentation and appropriate filtration and purification, it can fully meet the standards for municipal miscellaneous water use such as secondary irrigation, road washing, and landscape water replenishment, thus achieving localized water resource reuse.

[0004] However, existing technologies still face significant challenges in achieving the recycling of water used in greening projects. Traditional sedimentation tanks and filtration facilities are often built independently, occupying large areas and making integration with existing underground rainwater drainage systems difficult. Furthermore, the damp and flood-prone working environment of underground drainage systems makes it difficult to install conventional above-ground settling and purification devices. Simultaneously, adding corresponding purification equipment to existing rainwater drainage systems presents challenges in dredging and maintenance. The narrow underground space makes cleaning operations time-consuming and labor-intensive, posing safety hazards, and the system must be shut down during maintenance, affecting drainage safety. More importantly, during heavy rainfall, the limited flow capacity of these fixed facilities can create bottlenecks, significantly increasing the risk of upstream flooding.

[0005] Therefore, in the process of implementing the sponge city concept, there is an urgent need for an innovative and intelligent node processing technology. This technology can be applied to existing underground rainwater drainage systems, intercepting and purifying relatively clean runoff during routine greening or light rainfall, creating conditions for water resource reuse; and when rainfall intensity increases, it can switch states to ensure smooth drainage without generating water flow resistance, completely eliminating the risk of urban flooding. Summary of the Invention

[0006] One objective of this invention is to provide a pollution purification system for a box culvert connection section that can be seamlessly integrated into existing rainwater well-box culvert connection sections. In daily life, it can intercept and purify relatively clean runoff from green areas, etc., while not affecting the efficiency of municipal drainage during rainfall. The system has a reliable structure, is quick to maintain, and is easy to clean.

[0007] To achieve these and other advantages according to the present invention, the present invention provides a pollution purification system for a box culvert connecting section, disposed between a stormwater well and a stormwater pipe gallery, comprising: a first collection tank disposed at the lower part of the stormwater well and connected to the stormwater well; a second collection tank, which is a cylindrical structure, with its inlet end connected to the first collection tank and its outlet end connected to the stormwater pipe gallery; two airbags respectively installed at the inlet and outlet ends of the second collection tank, wherein the airbags, in an inflated state, are upright U-shaped, with their outer walls tightly connected to the inner wall of the second collection tank, and the U-shaped notches of the airbags forming a water passage; and an inflation / deflation system, which is connected to... The two airbags are connected by air passages to control the switching between inflated and deflated states. The two airbags and the inflation / deflation system work together, with two operating modes: Purification and water storage mode: When both airbags are inflated, they separate into a semi-enclosed water storage chamber within the second collection tank. The water flowing into the first or second collection tank must accumulate until the water level exceeds the lowest point of the U-shaped notch in the airbag before overflowing through its water passage. Direct flood discharge mode: When both airbags are deflated, the flow section of the second collection tank is restored, and the water flowing into the first collection tank directly enters the rainwater pipe gallery via the second collection tank.

[0008] Preferably, the airbag is fixed to a mounting sleeve, which is coaxial with the second water collection tank. The mounting sleeve includes a fixing ring, a first pressure plate, and a second pressure plate. The fixing ring is annular with an I-shaped radial cross-section. The fixing ring consists of an outer ring, an inner ring, and an annular web connecting the two. The outer ring and inner ring are coaxial. The U-shaped notch sidewall of the airbag fits against the outer wall of the outer ring, and the airbag is attached to the outer ring. A flange extends from each of the two sides, and the flange is rolled up between the outer ring and the inner ring and fits against the inner wall of the outer ring. The first pressure plate and the second pressure plate are both annular and match the inner walls of the outer ring located on both sides of the annular web. The first pressure plate and the second pressure plate are provided with flanges that mate with the annular web. The first pressure plate and the second pressure plate are fixed to the annular web to press the flange against the inner wall of the outer ring. The mounting sleeve is fixed in the second water collection tank by a bracket.

[0009] Preferably, the support body includes a support column and a fixed shaft. One end of the support column is fixed to the inner wall of the second water collection tank, and the other end of the support column is equipped with the fixed shaft. The fixed shaft is fitted into the inner ring sleeve. The end of the fixed shaft extends out of the inner ring sleeve and is provided with a threaded section. A threaded sleeve is screwed onto the threaded section and axially presses the inner ring sleeve onto the fixed shaft.

[0010] Preferably, the inner wall of the second water collection pool is provided with an annular rubber sealing ring at a position opposite to the outer wall of the airbag in the inflated state.

[0011] Preferably, the outer wall of the airbag is provided with multiple watertight skirts along its circumference. The watertight skirts extend along the circumference of the airbag, and the height of both ends of the skirts exceeds the lowest point of the U-shaped notch. When the airbag is in an inflated state, the watertight skirts are deformed by pressure and tightly abut against the inner wall of the second water collection pool.

[0012] Preferably, the top of the second water collection tank is provided with an opening, and the second water collection tank is connected to the ground air through an exhaust pipe connected to the opening.

[0013] Preferably, the second water collection tank is positioned with its axial direction as a reference, and the outlet end is at a low position, with a slope of 0.1% to 3%.

[0014] Preferably, the inflation / deflation system includes an air pump, an inlet three-way valve, an exhaust three-way valve, and air valves that correspond one-to-one with each airbag and are connected to an independent air path. The air pump's inlet is connected to the first port of the inlet three-way valve, and the air pump's outlet is connected to the first port of the exhaust three-way valve. The second port of the inlet three-way valve is connected to the atmosphere, and its third port is connected to each of the air valves through a pipeline. The second port of the exhaust three-way valve is connected to the atmosphere, and its third port is connected to each of the air valves through a pipeline.

[0015] Preferably, it also includes a flocculant dosing module, which includes a storage tank and a dosing pump. The inlet of the dosing pump is connected to the storage tank, and the outlet extends through a dosing pipeline to the inlet of the rainwater well or the inlet of the first collection tank.

[0016] Preferably, it also includes a first water level sensor installed in the first water collection tank for monitoring its water level and the rate of water level change, and a second water level sensor installed in the water storage chamber of the second water collection tank for monitoring its water level and the rate of water level change.

[0017] The present invention has at least the following beneficial effects: First, the present invention adopts a modular design, which can be used to transform the existing rainwater pipe gallery-rainwater well system. It is well compatible with the existing rainwater drainage system's well and culvert system, has a short construction period, has little impact on the surrounding environment, does not require excessive occupation of ground space for civil construction, and does not change the surface landscape and function, which meets the sponge city transformation needs of developed parks and green spaces. Secondly, this invention switches between the inflation states of two airbags, allowing for two operating modes to adapt to different hydrological conditions. During routine landscaping or light rainfall, the system operates in purification and water storage mode, where the landscaping water and sand-laden water from seepage undergo two-stage sedimentation in the first and second collection tanks, effectively removing suspended particulate matter. The clean supernatant after sedimentation can be pumped to a water storage facility and directly reused for municipal purposes such as garden irrigation and road sweeping, achieving in-situ collection and recycling of water resources. When increased rainfall intensity is detected, the inflation and deflation system controls the airbags to contract, switching to a direct flood discharge mode to ensure unobstructed flood discharge, thus completely solving the core problem of traditional fixed treatment facilities hindering flood discharge and causing urban flooding during the flood season. Third, this invention simplifies maintenance and cleaning. When it is necessary to clean up the sediment accumulated over a long period of operation, the airbag is fully contracted. Maintenance personnel can extend the suction hose of the municipal vacuum truck into the bottom of the first and second collection tanks from the ground through the opening of the exhaust pipe or from the opening of the rainwater well. The sludge at the bottom of the tanks can be directly sucked up and transported to the designated sludge treatment site, realizing a closed-loop and harmless sludge removal operation. For areas with severe compaction, high-pressure water guns can be used to stir the area. This process does not require personnel to go down into the well, making it safe and efficient, and avoiding secondary accumulation of pollutants in the downstream pipe network. Fourth, the airbag in this invention only relies on inflation and deflation for its operation, and there are no common faults such as short circuits in electronic components, burnout of motors or mechanical jamming. Compared with rainwater pretreatment systems that use electric valves, its maintenance and replacement are extremely simple. Maintenance personnel can enter from the rainwater well after the water is shut off to replace the old airbag as a whole.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall system in one technical solution of the present invention; Figure 2 This is a schematic diagram of system installation in one technical solution of the present invention; Figure 3 This is a schematic side cross-sectional view of the system in one technical solution of the present invention; Figure 4 This is a schematic diagram of the second water collection tank in one technical solution of the present invention; Figure 5 This is a schematic diagram of the cross-section of the second water collection tank in one technical solution of the present invention, wherein (a) is a schematic diagram of cross-section A and (b) is a schematic diagram of cross-section B; Figure 6 This is a schematic diagram of an airbag in one technical solution of the present invention, wherein (a) the airbag is in a contracted state and (b) the airbag is in an inflated state; Figure 7 This is a schematic diagram of the cross-section of the airbag in one technical solution of the present invention, wherein (a) is a schematic diagram of cross-section C and (b) is a schematic diagram of cross-section D; Figure 8 This is a schematic diagram of the airbag installation in one technical solution of the present invention; Figure 9 This is a schematic diagram of the installation kit in one technical solution of the present invention; Figure 10 This is a schematic diagram of the disassembly of the mounting sleeve in one technical solution of the present invention; Figure 11 This is a schematic diagram of the inflation / deflation system in one technical solution of the present invention.

[0020] Reference numerals: 1-First water collection tank, 10-Settling chamber, 2-Second water collection tank, 20-Water storage chamber, 21-Rubber sealing ring, 3-Rainwater pipe gallery, 4-Rainwater well, 5-Exhaust pipe, 6-Airbag body, 61-Flanged body, 62-Watertight skirt, 7-Support body, 70-Threaded sleeve, 71-Fixed shaft, 711-First straight section, 712-First conical section, 713-Threaded section, 72-Support column, 73-Fixed plate, 8-Inflation and deflation system, 9-Installation sleeve, 91-Fixed ring body, 911-Outer ring sleeve, 912-Annular web, 913-Inner ring sleeve, 9131-Second conical section, 9132-Second straight section, 92-First pressure plate, 93-Second pressure plate. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can implement it based on the description.

[0022] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0023] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the structures and components described are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] like Figures 1-11 As shown, this invention provides a pollution purification system for a box culvert connecting section, located between a rainwater well 4 and a rainwater pipe gallery 3, comprising: a first collection tank 1, located at the lower part of the rainwater well 4 and connected to the rainwater well 4; a second collection tank 2, which is a cylindrical structure, with its inlet end connected to the first collection tank 1 and its outlet end connected to the rainwater pipe gallery 3; two airbags 6, respectively installed at the inlet and outlet ends of the second collection tank 2, wherein in the inflated state, the airbags 6 are upright U-shaped, with their outer walls tightly connected to the inner walls of the second collection tank 2, and the U-shaped notches of the airbags 6 forming water passages; and an inflation / deflation system 8, connected to the air passages of the two airbags 6. This system controls the switching between inflated and deflated states of the two airbags 6. The two airbags 6 and the inflation / deflation system 8 work together and have two operating modes: Purification and water storage mode: When both airbags 6 are inflated, they separate a semi-enclosed water storage chamber 20 within the second water collection tank 2. The water flowing into the first water collection tank 1 or the second water collection tank 2 must accumulate until the water level exceeds the lowest point of the U-shaped notch of the airbag 6 before it can overflow through the water passage of the airbag 6. Direct flood discharge mode: When both airbags 6 are deflated, the flow section of the second water collection tank 2 is restored, and the water flowing into the first water collection tank 1 directly enters the rainwater pipe gallery 3 via the second water collection tank 2.

[0025] In this technical solution, surface runoff flows into the rainwater well 4 via rainwater pipes, underground drainage ditches, or open channels, and then into the first collection tank 1. The first collection tank 1 is a concrete or fiberglass box with a cross-section larger than that of the rainwater well 4. The first collection tank 1 serves as the primary sedimentation chamber of the entire system and is installed below the rainwater well 4. The first collection tank 1, together with the airbag 6 located at the inlet end of the second collection tank 2, forms a settling chamber 10. To prevent large, sharp debris such as branches, plastic blocks, and stones from entering the system and to ensure the long-term reliable operation of the airbag 6, a fixed grating can be installed at the inlet of the rainwater pipe, underground drainage ditch, or open channel connecting to the rainwater well 4, or a basket-type grating can be installed at the junction of the rainwater well 4 and the first collection tank 1. The heavier sand particles and suspended solids in the water entering the first collection tank 1 are initially separated by gravity and settle to the bottom of the first collection tank 1. After this primary sedimentation, the surface water with fewer suspended solids overflows into the second collection tank 2 through the air bladder 6 located at the inlet end of the second collection tank 2.

[0026] The second collection tank 2 can be made of precast concrete pipes. Its inlet and outlet ends are respectively connected to the reserved openings of the first collection tank 1 and the rainwater pipe gallery 3 by cast-in-place concrete. During construction, firstly, align the end of the second collection tank 2 with the reserved opening on the corresponding side, set up a formwork on the outside of the interface, and then pour micro-expansion concrete at the interface to form an integral joint. The waterproofing measures for the joint refer to the existing joint waterproofing practices. The inner wall of the second collection tank 2 can be specially waterproofed before installation, such as by applying a cement-based penetrating crystalline waterproof coating or spraying a polymer cement mortar waterproof layer to form a rigid waterproof barrier.

[0027] As a modular consumable in the system, the material selection for the airbag body 6 needs to strike a balance between cost, performance, and replacement cycle. The main body of the airbag body 6 can be made of synthetic rubber combined with high-strength polyester fiber or aramid fabric. The material should have good hydrolysis resistance, resistance to corrosion from common chemicals in municipal sewage, and antimicrobial properties. The airbag body 6 can be manufactured using a mature compression molding process. A dedicated metal mold is made according to the designed U-shaped three-dimensional shape. Uncured rubber sheets and pre-cut reinforcing fabric are laid in layers in the mold cavity, and air nozzles made of metal or high-strength plastic are pre-embedded and fixed in designated positions. Then, the mold is closed and heated and pressurized, causing the rubber to undergo a vulcanization and cross-linking reaction at high temperature, thus firmly bonding it with the reinforcing fabric and air nozzles into a whole elastic airbag with a predetermined shape. After molding, the airbag body 6 needs to undergo rigorous airtightness testing and pressure testing to ensure that it does not leak under maximum working pressure and can stably form the expected outer contour and water passage shape after inflation.

[0028] To ensure long-term reliable operation of the system in a humid underground environment, the inflation / deflation system 8 and its controller can be integrated and installed in a ground protection box or a waterproof electrical compartment on the side wall of a rainwater well 4. The system can be powered by the municipal power grid combined with an uninterruptible power supply, or by an off-grid solution using solar panels and battery packs, to ensure normal operation even in extreme weather conditions.

[0029] The purification and water storage mode is the main working state of the system under daily greening irrigation or light rain conditions. At this time, the two air bladders 6 are kept inflated under the control of the inflation and deflation system, and their expanded elastic outer walls are tightly fitted with the inner wall of the second water collection tank 2, creating a semi-closed water storage chamber 20 in the middle of the second water collection tank 2. The water flowing from the ground first undergoes primary sedimentation in the first collection tank 1, removing most of the sand and heavy suspended solids. Once the water volume in the first collection tank 1 reaches a certain height, it overflows into the storage chamber 20 through the water passage of the airbag 6 located at the inlet end of the second collection tank 2, forming secondary sedimentation. When both the first and second collection tanks are at high water levels, newly flowing water into the first collection tank 1 participates in the primary sedimentation process, simultaneously pushing the existing water sequence within the system to overflow sequentially. Ultimately, an equal amount of relatively clean water, located in the upper layer of the storage chamber 20 and having undergone sufficient secondary sedimentation, overflows into the rainwater pipe gallery 3 through the water passage of the airbag 6 located at the outlet end of the second collection tank 2. This process ensures that the system maintains an effective two-stage sedimentation purification effect even under continuous water inflow conditions, and slowly releases the treated water. The purification and storage mode utilizes the existing pipeline network node space to achieve efficient in-situ purification and interception of decentralized greening water or initial rainwater, creating conditions for water resource recycling. The overflow weir-type water flow mode is calm and stable, with high sedimentation efficiency.

[0030] The direct-flow flood discharge mode is the system's mechanism for responding to moderate to heavy rainfall and ensuring urban flood control safety. When the rainfall intensity exceeds the set threshold or a flood discharge command is received, the inflation / deflation system 8 completely discharges the gas from the two airbags 6, forcing them to contract and form folds. After the airbags 6 contract and fold, the flow cross-section they occupy in the second collection tank 2 is fully released, forming a continuous, smooth, and unobstructed drainage channel between the first collection tank 1, the second collection tank 2, and the stormwater pipe gallery 3. At this time, the flow does not need to overflow and can pass directly along the second collection tank 2. The system's drainage capacity depends on the size and slope of the pipe itself, resulting in excellent flood discharge efficiency. This completely solves the contradiction that traditional fixed purification facilities hinder flood discharge and easily cause urban flooding during the flood season.

[0031] For routine maintenance and cleaning, when it is necessary to clean the silt deposited at the bottom of the first collection tank 1 and the second collection tank 2, the system can be switched to direct-flow drainage mode to retract the airbag 6. Maintenance personnel do not need to go down into the well; they can directly insert the suction hose of the municipal vacuum truck into the ground rainwater well opening or the dedicated exhaust pipe opening for remote suction cleaning. For the hardened silt attached to the tank walls, it can be flushed with water using a pre-installed high-pressure water gun. As an essential consumable, the airbag 6 needs to be replaced promptly if it leaks or reaches the end of its service life. After the system is shut off, maintenance personnel can enter through the rainwater well 4, loosen the mechanical mounting kit of the airbag 6, and then disassemble and replace it completely. The operation process is standardized, the working window is short, and the maintenance difficulty, risk, and cost are greatly reduced.

[0032] This technical solution differs from traditional solutions such as "rigid sedimentation tank + overflow weir" or "mechanical movable weir gate," which are complex, prone to jamming, difficult to maintain, and may create bottlenecks during flood discharge. By using the flexible medium of the airbag body 6, it achieves a convenient transition between two drastically different operating conditions—"highly efficient sedimentation and purification" and "unimpeded flood discharge and drainage"—within the same underground space. This technical solution is not only highly modular, seamlessly integrating into existing drainage nodes and saving land space, but more importantly, it offers rapid and reliable operation mode switching and simple maintenance, fundamentally and collaboratively resolving the contradiction between the two major needs of green space water recycling and urban flood control.

[0033] In another technical solution, the airbag body 6 is fixed to a mounting sleeve 9, which is coaxial with the second water collection tank 2. The mounting sleeve 9 includes a fixing ring 91, a first pressure plate 92, and a second pressure plate 93. The fixing ring 91 is annular with an I-shaped radial cross-section. The fixing ring 91 is composed of an outer ring sleeve 911, an inner ring sleeve 913, and an annular web plate 912 connecting the two. The outer ring sleeve 911 and the inner ring sleeve 913 are coaxial. The U-shaped concave sidewall of the airbag body 6 fits against the outer wall of the outer ring sleeve 911, and the airbag body 6 extends a flange 61 from each side of the outer ring sleeve 911. The flange 61 is rolled up between the outer ring sleeve 911 and the inner ring sleeve 913 and fits against the inner wall of the outer ring sleeve 911. Both the first pressure plate 92 and the second pressure plate 93 are annular, respectively matching the inner walls of the outer ring sleeves 911 located on both sides of the annular web 912. Both the first pressure plate 92 and the second pressure plate 93 are provided with flanges that mate with the annular web 912. The first pressure plate 92 and the second pressure plate 93 are fixed to the annular web 912, thereby pressing the flanged body 61 against the inner wall of the outer ring sleeve 911. The mounting sleeve 9 is fixed in the second water collection pool 2 by a bracket body 7. The airbag body 6 is mechanically pressed onto the fixed ring body 91 by the flanged body 61. When the airbag body 6 needs to be replaced, only a set of bolts needs to be loosened to unfasten the flanges connected to the annular web 912, and the first pressure plate 92 and the second pressure plate 93 can be removed, thereby taking out the old airbag body 6 and replacing it, which greatly simplifies the downhole replacement operation.

[0034] In this technical solution, the airbag body 6 is reliably fixed within the second water collection tank 2 by a matching mounting sleeve 9. The fixing ring body 91 achieves reliable fixing and sealing of the airbag body 6 through an I-shaped cross-section design. The cross-section of the fixing ring body 91 is formed by welding an outer ring sleeve 911 (as the "upper flange"), an inner ring sleeve 913 (as the "lower flange"), and an annular web plate 912 vertically connecting the two. During processing, the cylindrical blanks of the outer ring sleeve 911 and the inner ring sleeve 913, as well as the annular web plate, are first prepared separately. After the mating surfaces are precision machined on a lathe, they are positioned by a fixture and continuously welded around the perimeter to form a rigid whole.

[0035] The first pressure plate 92 and the second pressure plate 93 are annular metal parts. After being laser-cut or stamped into their basic shape, their inner diameter is machined by a lathe to ensure the fitting accuracy with the outer ring 911. The flanges on the first pressure plate 92 and the second pressure plate 93 can be obtained by laser cutting the steel plate first, and then connected to the first pressure plate 92 or the second pressure plate 93 by continuous welding.

[0036] The flange 61 is integrally molded with the airbag body 6 during manufacturing, and the molding die is specially optimized according to the size of the outer ring 911. The connection between the flange 61 and the airbag body 6 can be thickened to allow for smooth folding during installation. When assembling the airbag body 6 and the mounting sleeve 9, the airbag body 6 is first attached to the outer wall of the outer ring sleeve 911. Then, the two flanges 61 on it are folded over and flattened to the inner wall of the outer ring sleeve 911. Finally, the first pressure plate 92 and the second pressure plate 93 are pushed in from both sides of the fixed ring body 91 and press down on the flanges 61. A set of bolts are used to pass through the corresponding through holes on the first pressure plate 92, the annular web plate 912 and the second pressure plate 93 in sequence, and nuts are set at the ends. The tension generated by tightening the bolts causes the two pressure plates to press the flanges 61 onto the inner wall of the outer ring sleeve 911. The first pressure plate 92 and the second pressure plate 93 generate uniform radial pressure, which firmly presses the flanges 61 of the airbag body 6 into the inner wall of the outer ring sleeve 911, forming a mechanical lock and static seal to resist the inflation force. The U-shaped notch of the airbag body 6 is supported and positioned by the outer ring sleeve 911 and the first pressure plate 92 and the second pressure plate 93. When the flange 61 is pressed against the inner wall of the outer ring sleeve 911 by the first pressure plate 92 and the second pressure plate 93 and the airbag 6 is in an inflated state, the actual overflow water level is higher than the lowest point of the U-shaped notch because the mounting sleeve 9 and the airbag 6 are kept watertight.

[0037] The annular web 912 divides the space between the outer ring 911 and the inner ring 913 into two annular chambers, allowing the two flanges 61 of the airbag body 6 to be inserted separately and fixed by the first pressure plate 92 or the second pressure plate 93 located on the corresponding side. A uniform and firm mechanical clamping mechanism is formed between the fixed ring 91 and the flange 61, which achieves a lightweight node installation method while ensuring high bending stiffness and shape stability. This is beneficial to the reliability of the seal between the airbag body 6 and the fixed ring 91, and also facilitates the maintenance and replacement of the airbag body 6.

[0038] The support body 7 can be welded from steel profiles. One end of it is fixed to the inner wall of the pipe in the second water collection tank 2 by chemical anchors or other mechanical connections. Since the airbag 6 is an upright U-shape when inflated, the fixing point between the support body 7 and the second water collection tank 2 can be set at the top of the inner wall of the second water collection tank. The support body 7 is located between the water passages to avoid affecting the inflation and deflation process of the airbag 6 and to prevent the main body of the support body 7 from being immersed in water for a long time. The other end of the support body 7 is connected to the fixing ring 91 by a flange or clamp, thereby positioning the entire airbag 6 in the second water collection tank 2.

[0039] In another technical solution, the support body 7 includes a support column 72 and a fixed shaft 71. One end of the support column 72 is fixed to the inner wall of the second water collection tank 2, and the other end of the support column 72 is fitted with the fixed shaft 71. The fixed shaft 71 is fitted into the inner ring sleeve 913, and the end of the fixed shaft 71 extends out of the inner ring sleeve 913 and is provided with a threaded section 713. A threaded sleeve 70 is screwed onto the threaded section 713, and the inner ring sleeve 913 is axially pressed against the fixed shaft 71. The main body of the support body 7 includes a support column 72 and a fixed shaft 71. The support column 72 can be made of square steel or round steel pipe, and a fixed plate 73 is provided at one end, which is connected to a steel plate pre-embedded in the inner wall of the second water collection tank 2. The fixed shaft 71 is a shaft that matches the inner surface of the inner ring sleeve 913. One end of the fixed shaft 71 is fixed to the support column 72 by a flange or welding, and the other end of the fixed shaft 71 is machined with a threaded section 713.

[0040] To ensure the positioning of the mounting sleeve 9 and prevent it from rotating around the fixed shaft 71 during use, the fixed shaft 71 can be divided into a threaded section 713, a first tapered section 712, and a first straight section 711. The inner wall of the inner ring sleeve 913 is configured with a second tapered section 9131 and a second straight section 9132 that match the shape of the fixed shaft 71. When the fixed ring body 91 is fitted onto the fixed shaft 71, the second tapered section 9131 fits against the first tapered section 712. The threaded sleeve 70 screwed onto the threaded section 713 presses the fixed ring body 91 onto the fixed shaft 71. A rubber friction layer can be provided on the first tapered section 712 to generate friction between the first tapered section 712 and the second tapered section 9131, thus restricting the rotation of the fixed ring body 91.

[0041] In this technical solution, the mounting sleeve 9 and the airbag body 6 are installed as a whole, which can be quickly installed with the fixed shaft 71, making it convenient for maintenance personnel to quickly install and remove the airbag body 6 during downhole operations.

[0042] In another technical solution, an annular rubber sealing ring 21 is provided on the inner wall of the second water collection tank 2, opposite to the outer wall of the inflated airbag 6. To form a reliable seal between the outer wall of the inflated airbag 6 and the inner wall of the second water collection tank 2, preventing water leakage from microscopic unevenness at the contact surface, an annular rubber sealing ring 21 is pre-installed on the inner wall of the second water collection tank 2. The rubber sealing ring 21 can be made of water-resistant and aging-resistant EPDM rubber or neoprene rubber. During the prefabrication or installation of the second water collection tank 2, an annular mounting groove is machined at a specific circumferential position on its inner wall. Then, the rubber sealing ring 21 is pressed into and fixed in this groove, making its working surface slightly higher than or flush with the inner wall of the pipe. When the airbag 6 inflates and its outer wall presses against this position, the rubber sealing ring 21 is compressed and undergoes elastic deformation, filling all possible gaps between the airbag 6 and the second water collection tank 2, ensuring the effective formation of the water storage chamber 20.

[0043] In another technical solution, the outer wall of the airbag 6 is provided with multiple watertight skirts 62 along its circumference. The watertight skirts 62 extend circumferentially along the airbag 6, with their ends exceeding the lowest point of the U-shaped notch. When the airbag 6 is inflated, the watertight skirts 62 deform under pressure, tightly abutting against the inner wall of the second water collection pool 2. The watertight skirts 62 and the main body of the airbag 6 are made of the same material and manufactured in one piece through a molding process. The cross-sectional shape of the watertight skirts 62 is designed as a wave or wedge shape facing the inner wall of the second water collection pool 2. When the airbag 6 is inflated, its expansion pushes each watertight skirt 62 outward, causing its lip or bevel to tightly press against the inner wall of the second water collection pool 2. Even if there are local unevenness in the inner wall of the second water collection pool 2 or slight fluctuations in the inflation pressure of the airbag 6, the flexible watertight skirts 62 can deform accordingly and always maintain contact, forming multiple layers of follow-through sealing defense. This design not only enhances the redundancy of the seal, but also reduces wear on the airbag body 6 through flexible contact. When the airbag body 6 deflates and contracts, the watertight skirt 62 also relaxes and retracts, fitting snugly against the outer wall of the airbag without obstructing the contraction.

[0044] In another technical solution, the top of the second water collection tank 2 is provided with an opening, and the second water collection tank 2 is connected to the ground air through an exhaust pipe 5 connected to the opening. The top of the second water collection tank 2 is provided with an opening for ventilation and water intake, and this opening is connected to the ground through a vertically arranged exhaust pipe 5. The exhaust pipe 5 can be a UPVC pipe or a galvanized steel pipe with a diameter of 100mm~200mm. The top end of the exhaust pipe 5 extends into the ground equipment box and is equipped with a removable flange cover or dust cover.

[0045] The exhaust pipe 5 has two functions in practical applications. First, during normal system operation, when it is necessary to reuse the purified water after sedimentation treatment, the operator can open the flange cover or dust cover at the top of the exhaust pipe 5 and place a flexible hose with an outer diameter smaller than that of the exhaust pipe 5 downwards into the inner cavity until its lower end is below the water surface of the second collection tank 2. Water samples can then be extracted or reused using a connected small water pump or vacuum device. Second, during maintenance and repair of the second collection tank 2, to ensure operational safety, maintenance personnel can connect the air outlet of the blower to the ground port of the exhaust pipe 5 through a quick connector, and start the blower to continuously blow fresh air into the second collection tank 2.

[0046] In another technical solution, the second water collection tank 2 is based on its axial direction and has a slope of 0.1% to 3% with the water outlet end as the lowest position, so that the airbag 6 does not accumulate water when it is in the contracted state. When installing the second water collection tank 2, its water inlet end can be raised by hoisting equipment to make the cylindrical second water collection tank 2 form a slope, or the second water collection tank 2 can be laid flat and then the slope is created by plastering inside the pipe.

[0047] In another technical solution, the inflation / deflation system 8 includes an air pump, an inlet three-way valve, an exhaust three-way valve, and air valves that correspond one-to-one with each airbag body 6 and are connected to an independent air path. The air inlet of the air pump is connected to the first port of the inlet three-way valve, and the air outlet of the air pump is connected to the first port of the exhaust three-way valve. The second port of the inlet three-way valve is connected to the atmosphere, and the third port is connected to each of the air valves through a pipeline. The second port of the exhaust three-way valve is connected to the atmosphere, and its third port is connected to each of the air valves through a pipeline.

[0048] The electrical and pneumatic components of the inflation / deflation system 8 are all housed in a waterproof compartment on the side wall of a ground equipment box or rainwater well to ensure that it operates in a dry environment. The air pump can be a small, oil-free, silent air compressor, and the intake three-way valve and exhaust three-way valve can be two-position, three-way normally closed solenoid valves. The air valves connected to each airbag body 6 can be two-position, two-way normally closed solenoid valves.

[0049] Each airbag body 6 has an integrally molded air inlet, which is fitted with a threaded nozzle. A metric thread to quick-connect adapter can be screwed onto this nozzle. The end of the air tube leading from the air valve is equipped with a corresponding quick-connect male connector. When the male connector is inserted into the female connector, the internal stainless steel retaining sleeve and O-ring seal automatically lock and achieve an airtight connection, forming a waterproof seal.

[0050] When air needs to be inflated into the airbag 6, the controller issues a command: the second port of the inlet three-way valve opens and the third port closes; the second port of the exhaust three-way valve closes and the third port opens; simultaneously, the air valve corresponding to the target airbag 6 opens. After the air pump starts, it draws in outside air through the second port of the inlet three-way valve, and through the third port of the exhaust three-way valve and the opened air valve into the target airbag 6. When air needs to be deflated, the second port of the inlet three-way valve closes and the third port opens; the second port of the exhaust three-way valve opens and the third port closes; the target air valve remains open. At this time, the air pump starts and extracts the air from the airbag 6 and directly discharges it into the atmosphere. This technical solution avoids the problem of frequent failures of traditional underwater electric valves and actuators due to long-term immersion and corrosion. The inflation and deflation of the airbag 6 is achieved solely through the opening and closing of air, resulting in very few system failure points. Furthermore, the clear and independent inflation and deflation paths and quick-connect coupling design make air circuit diagnosis and component replacement simple and quick, greatly reducing the difficulty and cost of long-term system maintenance.

[0051] In another technical solution, a flocculant dosing module is also included. The flocculant dosing module includes a storage tank and a dosing pump. The inlet of the dosing pump is connected to the storage tank, and the outlet extends through a dosing pipeline to the inlet of the rainwater well 4 or the inlet of the first collection tank 1. If the flocculant is added at the inlet of the rainwater well 4, it can start to mix with the water flow in the initial stage of entering the first collection tank 1. The natural turbulence of the falling water flow is used to achieve initial dispersion, leaving a longer hydraulic residence time for the subsequent full reaction in the first collection tank 1. After the flocculant is fully mixed with the water flow, it can quickly flocculate the fine suspended particles and colloidal substances in the water into larger flocs, thereby accelerating the sedimentation process in the first collection tank 1. This maximizes the use of the entire volume of the first collection tank 1 to complete the flocculation reaction and particle sedimentation, improves the primary sedimentation effect, reduces the purification load of the subsequent water storage chamber 20, and ensures the stability of the final effluent water quality.

[0052] In another technical solution, a first water level sensor is installed in the first water collection tank 1 to monitor its water level and the rate of water level change, and a second water level sensor is installed in the water storage chamber 20 of the second water collection tank 2 to monitor its water level and the rate of water level change. The first and second water level sensors can be commercially available ultrasonic sensors, float sensors, or water pressure sensors. The first water level sensor is installed on the inner wall of the first water collection tank 1 to accurately monitor the real-time water level of the first water collection tank 1. The second water level sensor is installed on the inner wall of the water storage chamber 20 of the second water collection tank 2 to monitor water level changes within the water storage chamber 20. The water level sensors can be submersible hydrostatic level sensors or ultrasonic level sensors, and should have an IP68 or higher protection rating to adapt to harsh underground environments with high humidity and sediment content.

[0053] By integrating the monitoring data from the first and second water level sensors and combining them with the system's preset control logic, the purification system can achieve more intelligent and efficient operation and management. Exemplary control logic includes, but is not limited to, the following states.

[0054] (a) Water Aging Determination and Automatic Drainage: A flow meter can also be installed at the outlet of the second collection tank 2. When the system is in purification and storage mode, if the flow rate detected by the flow meter is continuously lower than a minimum threshold (e.g., close to zero), and the water levels fed back by the first and second water level sensors are continuously maintained at a level that can form an overflow exceeding a preset time threshold (e.g., 24-48 hours), the system determines that the water in the storage chamber 20 has been retained for too long and may pose a risk of eutrophication or microbial growth, making it unsuitable for recycling. At this time, the control system can automatically start the drainage program, controlling the inflation and deflation system 8 to vent the two air bladders 6, emptying the water stored in the first collection tank 1 and the second collection tank 2, in preparation for receiving subsequent new, purifiable water.

[0055] (b) Rainfall Intensity Sensing and Mode Pre-Switching: The control system receives data from the first water level sensor in real time and calculates the rate of water level rise. When the rate of water level rise is detected to continuously exceed the set high threshold within a short period of time, it is determined that moderate to heavy rainfall is approaching. The control system can immediately send a command to the inflation / deflation system 8 to switch the two airbags 6 to the contracted state, so that the system enters the direct flood discharge mode in advance, thereby fully opening the drainage channel before the flood peak arrives, maximizing the smooth drainage and proactively preventing urban flooding.

[0056] It should be noted that although the steps are described in a specific order above, this does not mean that they must be performed in that order. In fact, some of these steps can be executed concurrently, or even in a different order, as long as the required functionality is achieved. The number of devices and processing scale described herein are for simplification of the invention; applications, modifications, and variations of this invention will be readily apparent to those skilled in the art.

[0057] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A pollution purification system for the connecting section of a box culvert, located between a rainwater well (4) and a rainwater pipe gallery (3), characterized in that, include: The first water collection tank (1) is located at the lower part of the rainwater well (4) and is connected to the rainwater well (4); The second water collection tank (2) is a cylindrical structure. The inlet of the second water collection tank (2) is connected to the first water collection tank (1), and the outlet of the second water collection tank (2) is connected to the rainwater pipe gallery (3). Two airbags (6) are installed at the inlet and outlet of the second water collection tank (2) respectively. When inflated, the airbag (6) is an upright U-shape. The outer wall of the airbag (6) is in close contact with the inner wall of the second water collection tank (2). The U-shaped notch of the airbag (6) forms a water passage. An inflation / deflation system (8) is connected to the air passages of two airbags (6) and is used to control the switching between the inflation and deflation states of the two airbags (6); The two airbags (6) and the inflation / deflation system (8) work together, and have two operating modes: Purification and water storage mode: When both airbags (6) are in an inflated state, they are separated into a semi-closed water storage chamber (20) in the second water collection pool (2). The water flowing into the first water collection pool (1) or the second water collection pool (2) must be accumulated until the water level exceeds the lowest point of the U-shaped notch of the airbag (6) before it can overflow through the water passage of the airbag (6). Direct flood discharge mode: When the two airbags (6) are in a contracted state, the flow section of the second water collection pool (2) is restored, and the flow entering the first water collection pool (1) directly enters the rainwater pipe gallery (3) through the second water collection pool (2).

2. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The airbag body (6) is fixed on a mounting sleeve (9), which is coaxial with the second water collection tank (2). The mounting sleeve (9) includes a fixing ring (91), a first pressure plate (92) and a second pressure plate (93). The fixing ring (91) is ring-shaped with an I-shaped radial cross section. The fixing ring (91) is composed of an outer ring sleeve (911), an inner ring sleeve (913) and an annular web plate (912) connecting the two. The outer ring sleeve (911) and the inner ring sleeve (913) are coaxial. The U-shaped notch sidewall of the airbag body (6) is attached to the outer wall of the outer ring sleeve (911), and the airbag body (6) extends a flange (61) on each side of the outer ring sleeve (911). The flange (61) is rolled up between the outer ring sleeve (911) and the inner ring sleeve (913) and is attached to the inner wall of the outer ring sleeve (911). Both the first pressure plate (92) and the second pressure plate (93) are annular and match the inner walls of the outer ring sleeves (911) located on both sides of the annular web (912). Both the first pressure plate (92) and the second pressure plate (93) are provided with flanges that mate with the annular web (912). The first pressure plate (92) and the second pressure plate (93) press the flanged body (61) against the inner wall of the outer ring sleeve (911) by fixing it to the annular web (912). The mounting sleeve (9) is fixed inside the second water collection tank (2) by a bracket (7).

3. The pollution purification system for the box culvert connecting section as described in claim 2, characterized in that, The support body (7) includes a support column (72) and a fixed shaft (71). One end of the support column (72) is fixed to the inner wall of the second water collection tank (2), and the other end of the support column (72) is equipped with the fixed shaft (71). The fixed shaft (71) is fitted into the inner ring sleeve (913). The end of the fixed shaft (71) extends out of the inner ring sleeve (913) and is provided with a threaded section (713). A threaded sleeve (70) is screwed onto the threaded section (713) and axially presses the inner ring sleeve (913) onto the fixed shaft (71).

4. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The inner wall of the second water collection pool (2) is provided with an annular rubber sealing ring (21) at a position opposite to the outer wall of the airbag (6) in the inflated state.

5. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The outer wall of the airbag (6) is provided with multiple watertight skirts (62) along its circumference. The watertight skirts (62) extend along the circumference of the airbag (6), and the height of both ends exceeds the lowest point of the U-shaped notch. When the airbag (6) is in an inflated state, the watertight skirts (62) are deformed by pressure and closely abut against the inner wall of the second water collection pool (2).

6. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The top of the second water collection tank (2) is provided with an opening, and the second water collection tank (2) is connected to the ground air through an exhaust pipe (5) connected to the opening.

7. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The second water collection pool (2) is based on its axial direction and has a slope of 0.1% to 3% with the water outlet end as the lowest position.

8. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, The inflation / deflation system (8) includes an air pump, an inlet three-way valve, an exhaust three-way valve, and air valves that correspond one-to-one with each airbag body (6) and are connected to an independent air path. The air inlet of the air pump is connected to the first port of the inlet three-way valve, the air outlet of the air pump is connected to the first port of the exhaust three-way valve, the second port of the inlet three-way valve is connected to the atmosphere, and the third port is connected to each of the air valves through a pipeline. The second port of the exhaust three-way valve is connected to the atmosphere, and its third port is connected to each of the air valves through a pipeline.

9. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, It also includes a flocculant dosing module, which includes a storage tank and a dosing pump. The inlet of the dosing pump is connected to the storage tank, and the outlet extends through a dosing pipeline to the inlet of the rainwater well (4) or the inlet of the first collection tank (1).

10. The pollution purification system for the box culvert connecting section as described in claim 1, characterized in that, It also includes a first water level sensor installed in the first water collection tank (1) for monitoring its water level and the rate of water level change, and a second water level sensor installed in the water storage chamber (20) of the second water collection tank (2) for monitoring its water level and the rate of water level change.

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