Modular rain flood resource deep purification and underground storage integrated device

Abstract

The application relates to the technical field of ecological environment engineering, and discloses a modular rain flood resource deep purification and underground storage integrated device, which comprises a radial shear purification module, a hydraulic closed locking assembly and a spiral push flow storage module which are coaxially and communicatively arranged from top to bottom; the radial shear purification module comprises a first shell, a composite filter material layer filled in the first shell, an inverted funnel-shaped flow guide cover arranged above the composite filter material layer and a central siphon assembly, a horizontal annular flow channel is formed between the lower edge of the inverted funnel-shaped flow guide cover and the upper surface of the composite filter material layer; the spiral push flow storage module comprises a second shell and a spiral flow guide plate arranged in the second shell. Through cooperation of the inverted funnel-shaped flow guide cover and the central siphon assembly, vertical gravity flow during cleaning is converted into horizontal radial converging flow along the filter material surface, the integrity of a biofilm structure is maintained, and long-term stable operation of the filter layer can be realized without external power.

Description

Technical Field

[0001] This invention relates to the field of ecological and environmental engineering technology, specifically to a modular integrated device for deep purification and underground storage of rainwater resources. Background Technology

[0002] With the deepening of the sponge city construction concept and the increasing demand for decentralized water supply in rural areas, on-site collection and utilization of rainwater resources has become an important way to solve regional water shortages and ecological water replenishment. In remote mountainous areas, islands, or scattered farmhouses far from municipal pipe networks, the construction of low-maintenance, non-powered, and long-term stable rainwater harvesting and storage systems is particularly crucial. Traditional rainwater treatment systems typically consist of independent primary filtration units, slow sand filters, and underground storage tanks connected in series. While these systems have solved the problem of "having water available" to some extent, they still face irreconcilable technical contradictions in terms of long-term operational stability, water quality maintenance sustainability, and system maintenance convenience.

[0003] In the purification process, while traditional slow sand filters or gravity-fed valveless filters offer high filtration accuracy, their core drawback lies in the fact that the regeneration mechanism of the filter media surface is heavily reliant on external power or complex hydraulic structures. As the filtration cycle lengthens, the filter media surface inevitably traps a large amount of suspended solids, forming a dense biofilm, leading to a sharp decline in permeability. Existing backwashing technologies often employ high-speed, vertically upward water flow to expand and fluidize the filter layer. This method not only requires energy-intensive backwashing pumps or tall water towers to provide sufficient head, but the frequent vertical disturbances easily damage the precious biofilm structure in the slow-filtration layer, resulting in slow recovery of filtration efficiency. Furthermore, in remote areas lacking power supply, automatic backwashing systems relying on electric valves and sensors are not only costly to build but also highly susceptible to system failure due to electrical malfunctions.

[0004] In the storage stage, existing underground water storage facilities are mostly simple static containers made of concrete or plastic. While this large tank-like design meets capacity requirements, it neglects the impact of fluid dynamics on water quality. In actual operation, newly injected rainwater tends to form a short flow between the inlet and outlet, directly passing through the storage area, while most of the water stored in the early stages remains stagnant in the dead zones of the container, unable to participate in circulation and replacement. The existence of these hydraulic dead zones leads to the rapid depletion of dissolved oxygen, resulting in secondary pollution problems such as the proliferation of anaerobic bacteria, blackening and foul odor of the water, and accumulation of nitrites. This renders the painstakingly collected rainwater unusable after a period of storage.

[0005] More critically, existing rainwater harvesting systems often lack logical coordination between their functional modules. Purification and storage units are typically physically isolated, lacking information feedback mechanisms. When the reservoir is full, the upstream purification unit often continues operating, causing clean rainwater to be directly discharged through overflow pipes, resulting in water waste. Alternatively, during heavy rainstorms, the system lacks self-protection mechanisms, leading to excessive rainwater not only impacting the filter layer but also potentially causing overload damage to the underground water storage structure. Currently, the market lacks an integrated system capable of intelligently coordinating the three states of "filtration," "cleaning," and "full reservoir protection" solely based on the fluid's own gravity and pressure changes, without the aid of any electronic components. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a modular integrated device for deep purification and underground storage of rainwater resources. It solves the technical problems in existing decentralized rainwater utilization systems, such as the reliance on external power backwashing for traditional filtration technology, which easily damages the biofilm structure of the filter layer; the formation of hydraulic dead zones in underground water storage containers due to fluid short circuits, leading to anaerobic deterioration of water quality; and the lack of automatic feedback and overload protection mechanisms based on physical state between the purification unit and the storage unit.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a modular rainwater resource deep purification and underground storage integrated device, comprising a radial shear purification module, a hydraulic interlocking connection component, and a spiral flow storage module arranged coaxially from top to bottom;

[0008] The radial shear purification module includes a first housing, a composite filter layer filled in the first housing, an inverted funnel-shaped flow guide hood disposed above the composite filter layer, and a central siphon assembly. A horizontal annular flow channel is formed between the lower edge of the inverted funnel-shaped flow guide hood and the upper surface of the composite filter layer.

[0009] The spiral flow storage module includes a second housing and a spiral guide plate disposed inside the second housing. The spiral guide plate divides the internal storage space of the second housing into continuous spiral flow channels.

[0010] The hydraulic interlocking connection assembly includes a connecting guide pipe that connects the outlet of the radial shear purification module and the inlet of the spiral propulsion storage module, and a coaxial breathing pipe for adjusting the air pressure inside the spiral propulsion storage module.

[0011] Preferably, the inverted funnel-shaped guide shroud is coaxially suspended inside the first housing. A ring-shaped gap is maintained between the large-diameter edge at the bottom of the inverted funnel-shaped guide shroud and the inner wall of the first housing for water flow. The inverted funnel-shaped guide shroud divides the water space inside the first housing into a free water surface area outside the inverted funnel-shaped guide shroud and a negative pressure convergence area inside the inverted funnel-shaped guide shroud. The two are connected only through a horizontal annular flow channel.

[0012] Preferably, the central siphon assembly includes an inverted U-shaped siphon tube, the inlet of which is located at the geometric center apex of the inverted funnel-shaped guide shroud and is directly connected to the negative pressure convergence area. The bend of the inverted U-shaped siphon tube is higher than the upper surface of the composite filter layer and lower than the top overflow port of the first housing.

[0013] Preferably, the connecting guide pipe is constructed as a unidirectional fluid channel. The upper end of the connecting guide pipe is connected to the water collection funnel at the bottom of the radial shear purification module, and its lower end extends vertically into the interior of the spiral flow storage module. The position of its lower end pipe opening is lower than the full reservoir warning water level line of the spiral flow storage module, forming a water seal structure.

[0014] Preferably, the coaxial breathing tube is the only airflow channel connecting the spiral propulsion storage module with the outside atmosphere. The lower end of the coaxial breathing tube is fixed at the full reservoir warning water level inside the spiral propulsion storage module, and the upper end extends upward through the hydraulic interlocking connection component and connects to the outside atmosphere or the bend of the central siphon component.

[0015] When the water level in the spiral flow storage module rises and submerges the lower port of the coaxial breathing tube, a closed air chamber is formed at the top of the spiral flow storage module. The air pressure generated by the closed air chamber hinders the downward flow of water in the connecting guide tube, forcing the water level in the radial shear purification module to rise and triggering the central siphon component to start.

[0016] Preferably, the spiral guide plate is a fully continuous Archimedean spiral structure. The outer edge of the spiral guide plate is sealed to the inner wall of the second shell, and its inner edge is sealed to the central axis of the second shell, forcing the water flow to rotate and move downwards only along the spiral channel.

[0017] Preferably, the spiral flow storage module further includes a water intake sleeve, which vertically penetrates the spiral guide plate, and the water intake port of the water intake sleeve is located at the bottom end of the spiral flow channel.

[0018] Preferably, the composite filter layer comprises, from top to bottom, a quartz sand fine filter layer, an activated carbon layer, and a gravel support layer, and the bottom of the first housing is provided with a porous support plate for supporting the composite filter layer.

[0019] Preferably, both the first shell and the second shell are prefabricated cylindrical structural components, and are connected by flanges to form a vertically integrated tower structure.

[0020] This invention provides a modular integrated device for deep purification and underground storage of rainwater resources. It offers the following advantages:

[0021] 1. This invention utilizes an inverted funnel-shaped flow guide hood in conjunction with a central siphon assembly to transform the vertical gravity flow during cleaning into a horizontal radial converging flow along the filter media surface. According to fluid mechanics principles, as the water flows from the periphery towards the central suction port, the flow velocity increases sharply as the radius decreases, thus creating high-intensity horizontal shear stress on the filter media surface. This shearing flow precisely peels away the dense sludge trapped on the surface and draws it into the siphon for discharge. Meanwhile, the deep filter media, compacted by gravity and undisturbed by vertical forces, maintains the integrity of the biofilm structure, enabling long-term stable operation of the filter layer without external power.

[0022] 2. This invention constructs a purely mechanical gas-liquid linkage mechanism through the cooperation of a coaxial breathing tube and a water seal connecting the guide tube. When the water level in the spiral flow storage module rises and submerges the lower port of the coaxial breathing tube, a closed air chamber is formed at the top of the module. As water continues to flow in, the pressure in the air chamber increases, creating back pressure, which reaches mechanical equilibrium with the downward water flow above, forming an airlock and physically cutting off the downward water path. This state forces the water level in the radial shear purification module to rise rapidly and trigger a siphon, using the excess rainwater that should have overflowed to perform an additional forced deep cleaning of the filter layer, preventing overload overflow of the underground storage module and maximizing the utilization of water resources.

[0023] 3. This invention, by incorporating a fully continuous Archimedes spiral guide plate within the storage module and placing the water intake sleeve at the end of the flow channel, forces the incoming clean water to rotate downwards along the spiral path, adhering to the "first-in, first-out" replacement principle. This structure utilizes weak hydraulic flow and thermal convection generated by the geothermal gradient to eliminate hydraulic dead zones found in traditional water tanks. Without the need for aeration equipment, it effectively inhibits the growth of anaerobic bacteria, maintaining the freshness of the stored water. Attached Figure Description

[0024] Figure 1 This is a perspective view of the present invention;

[0025] Figure 2 This is a cross-sectional schematic diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the internal structure of the first housing in this invention;

[0027] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0028] Figure 5 This is a schematic diagram of the internal structure of the second housing in this invention.

[0029] The components include: 1. First shell; 2. Composite filter media layer; 201. Quartz sand fine filter layer; 202. Activated carbon layer; 203. Gravel support layer; 3. Inverted funnel-shaped guide hood; 4. Inverted U-shaped siphon; 5. Horizontal annular flow channel; 6. Second shell; 7. Spiral guide plate; 8. Connecting guide pipe; 9. Coaxial breathing pipe; 10. Annular gap; 11. Water collection funnel; 12. Water intake sleeve; 13. Porous support plate. 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 the appendix Figure 1 - Appendix Figure 5 This invention provides a modular rainwater resource deep purification and underground storage integrated device, which is a vertically integrated water treatment device that utilizes gravity drive and gas-liquid linkage control. The main structure is an upright cylindrical tower shape, including a radial shear purification module, a hydraulic interlocking connection component and a spiral flow storage module that are coaxially connected from top to bottom.

[0032] The radial shear purification module includes a first housing 1, a composite filter layer 2 filled in the first housing 1, an inverted funnel-shaped flow guide hood 3 disposed above the composite filter layer 2, and a central siphon assembly. A horizontal annular flow channel 5 is formed between the lower edge of the inverted funnel-shaped flow guide hood 3 and the upper surface of the composite filter layer 2.

[0033] The spiral flow storage module includes a second housing 6 and a spiral guide plate 7 disposed inside the second housing 6. The spiral guide plate 7 divides the internal storage space of the second housing 6 into continuous spiral flow channels.

[0034] The hydraulic interlock connection assembly includes a connecting guide pipe 8 that connects the outlet of the radial shear purification module and the inlet of the spiral flow storage module, and a coaxial breathing pipe 9 for adjusting the air pressure inside the spiral flow storage module.

[0035] The inverted funnel-shaped guide shroud 3 is coaxially suspended inside the first housing 1. A ring gap 10 for water flow is maintained between the large-diameter edge at the bottom of the inverted funnel-shaped guide shroud 3 and the inner wall of the first housing 1. The inverted funnel-shaped guide shroud 3 divides the water space inside the first housing 1 into a free water surface area outside the inverted funnel-shaped guide shroud 3 and a negative pressure convergence area inside the inverted funnel-shaped guide shroud 3. The two are connected only through a horizontal annular flow channel 5.

[0036] The central siphon assembly includes an inverted U-shaped siphon tube 4. The inlet of the inverted U-shaped siphon tube 4 is located at the geometric center apex of the inverted funnel-shaped guide hood 3 and is directly connected to the negative pressure convergence area. The bend of the inverted U-shaped siphon tube 4 is higher than the upper surface of the composite filter layer 2 and lower than the top overflow port of the first housing 1.

[0037] The composite filter layer 2 consists of a quartz sand fine filter layer 201, an activated carbon layer 202, and a gravel support layer 203 from top to bottom. The bottom of the first housing 1 is provided with a porous support plate 13 for supporting the composite filter layer 2.

[0038] Both the first shell 1 and the second shell 6 are prefabricated cylindrical structural components, connected by flanges to form a vertically integrated tower structure.

[0039] In terms of overall spatial layout, the device physically comprises three coaxially arranged and interconnected functional modules from top to bottom: a radial shear purification module, a hydraulically interlocked connection assembly, and a spiral flow storage module. These three modules are sealed together via flanges or socket joints, forming a unified whole with internal fluid connectivity and external isolation from the soil. The radial shear purification module is located above ground or in a shallow buried layer for rainwater reception and filtration; the spiral flow storage module is buried deep underground below the permafrost layer for constant-temperature storage of purified water; and the hydraulically interlocked connection assembly serves as an intermediate transition section, connecting the upper and lower modules and handling gas-liquid signal transmission.

[0040] The radial shear purification module mainly consists of a first housing 1, a composite filter media layer 2, an inverted funnel-shaped flow guide hood 3, and a central siphon assembly. The first housing 1 is a cylindrical body made of corrosion-resistant material, with a rainwater inlet at the center of its top cover. Below the inlet, a disc-type or perforated water distributor is installed to dissipate the kinetic energy of the incoming water and prevent the vertical water flow from directly scouring and damaging the filter media layer structure below.

[0041] The composite filter media layer 2 is filled in the lower middle part of the first housing 1. To ensure a balance between filtration efficiency and permeability, the filter media layer is laid out in a multi-stage gradation. The bottom layer is a porous support plate 13 located at the bottom of the first housing 1, on which anti-clogging filter heads are evenly distributed. Above the porous support plate 13, a supporting gravel layer 203, an activated carbon adsorption layer 202, and the topmost quartz sand fine filter layer 201 are laid in sequence. The upper surface of the quartz sand fine filter layer 201 is trimmed to a horizontal plane, serving as the main area for biofilm adhesion and the target interface for subsequent radial shear cleaning.

[0042] The inverted funnel-shaped flow guide shroud 3 is the core component for achieving radial shear cleaning in this invention. This inverted funnel-shaped flow guide shroud 3 is shaped like a frustum of a cone or a trumpet, with a smaller top and a larger bottom, and is coaxially suspended and fixed inside the first housing 1 by support rods. The lower edge diameter of the inverted funnel-shaped flow guide shroud 3 is smaller than the inner diameter of the first housing 1, thus maintaining a continuous annular gap 10 for water inlet between the larger edge of the inverted funnel-shaped flow guide shroud 3 and the inner wall of the first housing 1.

[0043] In the vertical direction, the lower edge of the inverted funnel-shaped guide hood 3 is not in close contact with the filter media, but rather has a horizontal annular channel 5 with a height of 20 mm to 50 mm reserved between it and the upper surface of the quartz sand fine filter layer 201. This horizontal annular channel 5 physically divides the water space within the first housing 1 into two parts: a free water surface area located outside and above the inverted funnel-shaped guide hood 3, and a negative pressure convergence area located in the conical space inside the inverted funnel-shaped guide hood 3. Fluid exchange between the two can only occur through this narrow horizontal annular channel 5. Under normal filtration conditions, rainwater enters through the inlet annular gap 10, slowly passes through the horizontal annular channel 5, and then permeates vertically downwards.

[0044] The central siphon assembly is responsible for generating the negative pressure required for cleaning. This assembly includes an inverted U-shaped siphon tube 4. The suction inlet of the inverted U-shaped siphon tube 4 is located at the geometric center apex of the inverted funnel-shaped guide shroud 3, and this suction inlet directly connects to the cone-shaped apex space inside the inverted funnel-shaped guide shroud 3. The main pipeline of the inverted U-shaped siphon tube 4 extends upward, forming a siphon bend after reaching a preset height, and then extends downward through the side wall of the first housing 1 to the drain ditch outside the device.

[0045] The inner bottom elevation of the siphon elbow is set as the cleaning trigger water level of the device. This height is higher than the upper surface of the quartz sand fine filter layer 201 and lower than the overflow port at the top of the first housing 1. To ensure timely destruction at the end of the siphon, a small-diameter siphon destruction pipe is also connected to the siphon elbow. The opening of the destruction pipe extends to a preset low water level inside the inverted funnel-shaped guide shroud 3.

[0046] Based on the above structure, when the device enters the cleaning state, the inverted funnel-shaped guide hood 3 forces the externally accumulated water to flow downwards instead of vertically. The water must first flow downwards through the inlet annular gap 10, then turn 90 degrees into the horizontal annular flow channel 5, and finally converge from all sides towards the central suction inlet. Because the perimeter of the flow cross-section decreases with decreasing radius, the water velocity increases sharply during centripetal movement, thus forming a high-velocity horizontal shear flow on the surface of the quartz sand fine filter layer 201. This shears off the trapped sludge and draws it into the inverted U-shaped siphon pipe 4 for discharge.

[0047] The connecting guide pipe 8 is constructed as a unidirectional fluid channel. The upper end of the connecting guide pipe 8 is connected to the water collection funnel 11 at the bottom of the radial shear purification module. Its lower end extends vertically into the interior of the spiral flow storage module, and the position of its lower end pipe opening is lower than the full reservoir warning water level line of the spiral flow storage module, forming a water seal structure.

[0048] The coaxial breathing tube 9 is the only airflow channel connecting the spiral flow storage module to the outside atmosphere. The lower end of the coaxial breathing tube 9 is fixed at the full reservoir warning water level inside the spiral flow storage module, and the upper end extends upward through the hydraulic interlocking connection component and connects to the outside atmosphere or the bend of the central siphon component.

[0049] When the water level in the spiral flow storage module rises and submerges the lower port of the coaxial breathing tube 9, a closed air chamber is formed at the top of the spiral flow storage module. The air pressure generated by the closed air chamber hinders the downward flow of water in the connecting guide tube 8, forcing the water level in the radial shear purification module to rise and triggering the central siphon assembly to start.

[0050] The radial shear purification module is directly connected to the hydraulic interlocking connection assembly below it via the porous support plate 13 at its bottom, forming a physical interface for fluid transmission. The hydraulic interlocking connection assembly mainly consists of a water collecting funnel 11, a connecting guide pipe 8, and a coaxial breathing pipe 9. The water collecting funnel 11 is located directly below the porous support plate 13 and has an inverted conical structure. Its upper diameter is adapted to the inner diameter of the first housing 1, and it is used to collect all the effluent purified by the permeation of the composite filter layer 2.

[0051] The connecting guide pipe 8 is vertically connected to the bottom outlet of the water collection funnel 11, passes downward through the intermediate partition separating the purification zone and the storage zone, and extends into the internal space of the spiral flow storage module. The end port of the connecting guide pipe 8 is designed to be below the normal water level of the spiral flow storage module, or it has a U-shaped water trap structure at the end. This structure ensures that the connecting guide pipe 8 is blocked by water under any operating condition, thereby blocking the path of gas in the lower storage space back to the upper purification space through this pipe, making the connecting guide pipe 8 a channel that only allows liquid to flow downward in one direction.

[0052] The coaxial breathing tube 9 is a key component for realizing the gas-liquid linkage logic control of this invention. This tube is independently set up from the connecting guide tube 8, and its lower end is fixed at a preset full-tank warning water level line inside the spiral flow storage module. This full-tank warning water level line is lower than the height of the top plate of the spiral flow storage module, thus reserving a certain volume of gas compression chamber between the top plate and the water surface. The upper end of the coaxial breathing tube 9 extends upwards, passing through the middle partition and the interior or exterior of the radial shear purification module, ultimately connecting to the external atmosphere or to the back of the elbow of the central siphon assembly. In the non-full-tank state, the coaxial breathing tube 9 serves as the only exhaust channel from the spiral flow storage module to the outside, ensuring pressure balance during the water intake process.

[0053] The spiral guide plate 7 is a fully continuous Archimedes spiral structure. The outer edge of the spiral guide plate 7 is sealed to the inner wall of the second shell 6, and its inner edge is sealed to the central axis of the second shell 6, forcing the water flow to rotate and move downward along the spiral channel.

[0054] The spiral flow storage module also includes a water intake sleeve 12, which vertically penetrates the spiral guide plate 7, and the water intake port of the water intake sleeve 12 is located at the bottom end of the spiral flow channel.

[0055] The spiral flow storage module includes a second housing 6 buried underground, which is a fully enclosed cylindrical container except for the inlet, snorkel, and outlet. A central column is located at the axis inside the second housing 6, and a fully continuous spiral guide plate 7 is welded or fixed between this central column and the inner wall of the second housing 6. The spiral guide plate 7 has a continuous Archimedean spiral shape, extending from the top to the bottom of the second housing 6.

[0056] The outer spiral edge of the spiral guide plate 7 is sealed to the inner wall of the second shell 6, and its inner spiral edge is also sealed to the outer surface of the central column. This bidirectional sealing structure physically divides the originally monolithic cylindrical storage space into a long, narrow, continuous, and closed spiral flow channel. This channel has no bypass, forcing the incoming water to follow a spiral trajectory, rotating downwards layer by layer from the top to the bottom. This forced flow path eliminates the stagnant water zones and short-circuiting phenomena common in traditional water tanks, utilizing the kinetic energy and gravitational potential energy of the water flow to maintain the micro-circulation activity of the water body.

[0057] In this embodiment, to facilitate the first-in-first-out (FIFO) water intake logic of the spiral flow channel, the device is also equipped with a water intake sleeve 12. This water intake sleeve 12 vertically passes through each layer of spiral guide plates 7 (with a sealing sleeve at the point of penetration), and its bottom intake port is located at the very end of the spiral flow channel, i.e., at the inner bottom surface of the second housing 6. Using an external water pump or other water lifting equipment, the water intake sleeve 12 preferentially extracts the bottom water that has remained in the flow channel for the longest time and has undergone sufficient sedimentation and geothermal heat exchange. Newly entering purified water then replenishes the beginning of the flow channel, thereby establishing an orderly push-flow displacement mechanism within the storage module.

[0058] When the water level in the spiral flow storage module rises and completely submerges the lower port of the coaxial breathing tube 9, the reserved gas compression chamber above the full reservoir warning water level line immediately forms a closed air chamber. At this time, due to the water seal in the connecting guide pipe 8 and the liquid level blocking the coaxial breathing tube 9, the air in the closed air chamber cannot be discharged. As the upper purified water continues to be injected, the air pressure in the closed air chamber rises rapidly, forming a back pressure that resists the gravity of the incoming water. When this back pressure reaches a critical value, it will physically cut off the downward water flow in the connecting guide pipe 8, causing the water level in the upper water collection funnel 11 and the radial shear purification module to rise abnormally, thereby triggering the aforementioned siphon cleaning process, thus achieving automatic coupling between full reservoir protection and forced regeneration of the filter layer.

[0059] The device achieves full-process linkage of rainwater purification, automatic cleaning, and closed storage through the geometrical positional association between various functional modules and the spontaneous switching of fluid dynamic states. Under normal filtration conditions, the collected rainwater enters the radial shear purification module through the inlet and establishes an initial water level within the first housing 1. Driven by gravity, the water flows through the edge gap of the inverted funnel-shaped guide hood 3 and then vertically through the composite filter layer 2. During this process, suspended solids, colloids, and some organic pollutants in the water are trapped on the surface of the quartz sand fine filter layer 201. The purified water is collected by the porous support plate 13 into the water collection funnel 11 and flows into the spiral propulsion storage module along the connecting guide pipe 8.

[0060] In this embodiment, when the surface pores of the composite filter layer 2 become clogged with impurities due to long-term operation, its permeability coefficient decreases, causing the water level in the first housing 1 to gradually exceed the top of the inverted funnel-shaped guide hood 3. When the water level reaches the trigger elevation of the siphon bend, the inverted U-shaped siphon pipe 4 fills with fluid and discharges air, thereby inducing a strong siphon effect. Since there is only a tiny gap between the lower edge of the inverted funnel-shaped guide hood 3 and the surface of the filter media, and the suction inlet is located at the apex of the cone, the external water is forced to be converted into a radial flow that converges towards the center along the surface of the quartz sand fine filter layer 201.

[0061] According to the continuity equation in fluid mechanics, as the radial flow approaches the center point, its cross-sectional area gradually contracts, causing the flow velocity to increase exponentially as it approaches the inlet. This high-speed radial shear flow adheres tightly to the filter media surface, generating a powerful horizontal scouring effect that strips off particles attached to the filter media and discharges them to the external drainage ditch with the siphon flow. As the water level drops to the height of the siphon breaking pipe inside the inverted funnel-shaped guide hood 3, air enters the pipeline, the siphon terminates instantly, and the system automatically returns to the low-water-level filtration state, achieving online in-situ regeneration of the filter media particles.

[0062] In this invention, the device's response to a full storage state embodies the logical coordination of gas-liquid coupling. When the water level in the spiral flow storage module continues to rise until it submerges the lower port of the coaxial breathing tube 9, the gas storage space at the top of the second housing 6 loses its connection to the atmosphere. Since the end of the connecting guide pipe 8 is always in a water-sealed state, the originally atmospheric pressure storage environment transforms into a sealed air chamber. At this time, as the purified water continues to flow in from the top, the air in the air chamber is compressed, generating back pressure. When this back pressure is balanced with the hydraulic head height in the first housing 1, the fluid in the connecting guide pipe 8 stops flowing downwards, forming an airlock interception phenomenon.

[0063] This airlock effect creates a reverse feedback mechanism in the system. Because the purified water cannot drain into the bottom storage channel, the water level in the radial shear purification module rises rapidly at a rate much faster than under normal filtration conditions. This surge in water level triggers the siphon assembly to activate again, thereby using the rainwater that would otherwise overflow to perform an additional forced flushing of the filter media. This process not only automatically limits the overflow of the storage module, preventing flooding in underground structures, but also cleverly utilizes the overflow water to achieve deep cleaning of the filter layer, ensuring that the device's permeability efficiency is at its optimal level when the rainy season arrives.

[0064] In the storage phase of this embodiment, the purified water entering the spiral flow channel, driven by the subsequent flow rate, forms an orderly flow of fresh water within the second housing 6. The spiral guide plate 7 not only eliminates the fluid dead zone in the center of a traditional vertical water storage tank, but also increases the heat exchange time between the water and the ground by extending the flow path, thus maintaining the stored water temperature at a low level year-round. When the user pumps water through the water intake sleeve 12, the clean water that enters first at the bottom is pumped out preferentially, while the newly purified water flow replenishes the top of the spiral flow channel. This logic ensures the freshness and consistency of the water quality throughout the storage period, completing a closed loop from rainwater collection to high-quality storage.

[0065] To ensure the structural stability and sealing reliability of the device during long-term underground operation, both the first housing 1 of the radial shear purification module and the second housing 6 of the spiral flow storage module are assembled using modular prefabricated components. A reinforced flange is provided at the connection between the first housing 1 and the second housing 6, and the two are fixed together with corrosion-resistant high-strength bolts. O-rings made of EPDM rubber or nitrile rubber are embedded between the contact surfaces of the flanges. This sealing structure can not only withstand the lateral pressure of the external soil but also ensure that the gas-liquid linkage logic inside the device is not disturbed by groundwater infiltration or internal gas leakage, guaranteeing the accurate triggering of the gas-lock interlocking mechanism.

[0066] In this embodiment, to further enhance the underground compressive strength of the spiral flow storage module, the outer wall of the second shell 6 is designed with circumferential reinforcing ribs or a corrugated structure. It is worth noting that the internally installed spiral guide plate 7, in addition to its hydraulic function of forced flow, also acts as a structural support rib within the second shell 6. The continuous welding of the outer edge of the spiral guide plate 7 to the inner wall of the second shell 6, and the rigid connection of its inner edge to the central column, together construct a honeycomb-like overall load-bearing framework. This structural design significantly improves the storage module's resistance to radial compression deformation, allowing the device to be buried deeper below the permafrost layer, utilizing the constant temperature characteristics of the deep soil to prevent water freezing or overheating.

[0067] In terms of maintenance design in this embodiment, the top of the radial shear purification module is equipped with a removable sealing cover. This cover is connected to the first housing via a quick-opening clamp or hinge, allowing maintenance personnel to periodically open it to check the siphon pipeline's patency or replenish consumed filter media. Simultaneously, the interface of the initial diversion diverter is located on the upper side of the first housing, connected to the external diversion well pipeline. To prevent external insects or small animals from entering the device and contaminating the water quality, all openings to the atmosphere, including the upper port of the coaxial breathing pipe 9 and the drain outlet of the inverted U-shaped siphon pipe 4, are equipped with insect-proof mesh covers or one-way flap gate structures.

[0068] In actual operation, the device relies entirely on the principles of fluid mechanics and the dynamic balance of gas and liquid states for automated control, requiring no electrical drive or manual intervention. During the initial rainfall phase or when the filter layer is clean, the device operates under normal filtration conditions. At this time, rainwater collected externally enters the radial shear purification module through the inlet and forms a stable working water level within the first housing 1. Under the influence of gravity, the water flows through the annular gap 10 at the edge of the inverted funnel-shaped guide hood 3, and then penetrates vertically downwards through the composite filter media 2. The purified water, after physical interception and biodegradation, flows through the porous support plate 13 into the water collection funnel 11, and is smoothly injected into the spiral propulsion storage module along the connecting guide 8. During this process, the air displaced within the spiral propulsion storage module is freely discharged to the atmosphere through the coaxial breathing tube 9, ensuring an atmospheric pressure environment within the second housing 6, so that the filtration process is not hindered by back pressure.

[0069] In this embodiment, as the operating time increases, suspended particles and organic impurities carried in the rainwater gradually accumulate on the surface of the quartz sand fine filter layer 201, forming a dense filter cake layer, which leads to a significant decrease in the permeability coefficient of the filter media. With the influent flow rate remaining constant while the permeation flow rate decreases, the water level inside the first housing 1 begins to rise continuously. When the water level rises to submerge the siphon bend of the central siphon assembly, the air inside the pipe is quickly carried away, and the system instantly switches to automatic cleaning mode. At this time, the inverted U-shaped siphon pipe 4 generates a strong negative pressure suction force, causing the pressure inside the inverted funnel-shaped guide hood 3 to drop sharply.

[0070] Under this cleaning condition, due to the physical shielding effect of the inverted funnel-shaped guide hood 3 on the vertical water flow, the high-level water to be filtered cannot directly and vertically flush the filter layer. Instead, it is forced to flow horizontally from the inlet annular gap 10 and enter the horizontal annular flow 5 below the inverted funnel-shaped guide hood 3. According to the principle of fluid continuity, when the water flow converges from the periphery to the central inlet, the cross-sectional area of ​​the flow path shrinks sharply as the radius decreases, resulting in an exponential increase in radial velocity. This high-speed radial water flow passes closely along the surface of the quartz sand fine filter layer 201, generating high-intensity horizontal shear stress, which forcefully peels off the sludge and impurities attached to the surface and converges with the water flow to the inlet, and is finally discharged to the outside of the device through the inverted U-shaped siphon pipe 4. When the water level drops to the position of the siphon destruction pipe opening, air enters to destroy the siphon, the cleaning ends, and the device automatically returns to normal filtration conditions.

[0071] Furthermore, the device in this embodiment achieves coordinated protection of full-capacity self-locking and forced cleaning through a gas-liquid coupling mechanism. When the water level in the spiral flow storage module reaches its upper limit, i.e., when the water level rises and submerges the lower port of the coaxial breathing tube 9, the remaining space at the top of the second housing 6 forms a closed air chamber. Since the coaxial breathing tube 9 is blocked by water, and the end of the connecting guide tube 8 is also deeply buried underwater or equipped with a water trap, the air in the closed air chamber cannot escape.

[0072] In this critical airlock state, as the upper radial shear purification module continues to inject water, the gas volume within the sealed chamber is compressed, and the air pressure rapidly increases, creating back pressure to counteract the downward water flow. When this back pressure in the chamber reaches equilibrium with the hydrostatic pressure within the connecting guide pipe 8, airlock occurs, physically cutting off the downward flow path of the connecting guide pipe 8 and forcing purified water to stop entering the spiral flow storage module. This mechanism effectively prevents the underground storage container from experiencing excessive hydrostatic pressure due to excessive water inflow, avoiding structural damage or groundwater cross-contamination.

[0073] With the downstream pathway blocked, the water entering the radial shear purification module has nowhere to drain, causing its internal water level to surge much faster than when the filter layer is normally clogged. This dramatic fluctuation in water level quickly triggers the activation of the central siphon component. The resulting siphon effect utilizes the excess rainwater that would otherwise be wasted to perform an additional forced deep cleaning of the composite filter layer 2. This process not only converts excess water into cleaning power, avoiding water waste, but also ensures that the filter layer maintains optimal permeability under continuous heavy rainfall conditions, hydraulically preparing it for subsequent rainwater reception.

[0074] Furthermore, during the extraction of stored water resources, an external water pump draws water from the bottom of the spiral flow storage module through the water intake sleeve 12. Because the spiral guide plate 7 restricts the water flow, ensuring it moves downwards along the spiral path, the water extracted from the bottom is necessarily the highest quality water that has been stored for the longest time and has undergone sufficient heat exchange and sedimentation. As the old water at the bottom is extracted, new purified water replenishes from the top and propels along the spiral flow channel. This strict flow displacement mode completely eliminates storage dead zones and disrupts the stagnant environment conducive to anaerobic bacteria growth, thus achieving long-term water preservation without power.

[0075] In a typical engineering application embodiment of the present invention, the installation location of the device is vertically arranged according to the local meteorological and geological conditions. To fully utilize geothermal energy and prevent water freezing, the spiral propulsion storage module is entirely buried below the local frost line. During construction, a vertical foundation pit is first excavated at the predetermined site, and a reinforced concrete load-bearing platform is poured at the bottom of the pit. The base of the second housing 6 is anchored to this load-bearing platform with anchor bolts to prevent the device from tilting or the pipeline from breaking due to uneven settlement of the foundation.

[0076] The installation height of the hydraulic interlocking connection assembly is set as the "horizontal dividing point" of the device. The first housing 1 and its internal radial shear purification module are located above ground level, or shallowly buried in the surface layer by constructing inspection wells. Crucially, the discharge outlet of the radial shear purification module (i.e., the outlet of the siphon pipe) must be higher than the highest flood level of the external drainage ditch or municipal stormwater network to ensure that the siphon discharge process proceeds smoothly by gravity and to prevent backflow of external sewage into the system.

[0077] Regarding pipeline connections, the inlet at the top of the device is connected to the roof rainwater downpipe of the building via PVC or PE pipes. It is recommended to install a first-flush diversion well or a screen sedimentation tank upstream of the inlet to intercept leaves, large particles of silt, and other debris, reducing the load on the composite filter layer 2. The upper end of the coaxial breathing pipe 9 extends at least 50 cm above the ground and is shaped like an inverted U or fitted with a rainproof and breathable cap to prevent ground runoff or dust from directly falling into the storage chamber. In cold regions, the inlet pipe, siphon pipe, and breathing pipe exposed above the ground must be wrapped with insulation cotton or heating tape to prevent freezing in winter, which could cause the gas-liquid linkage logic to malfunction.

[0078] After completing the pipeline connection and sealing tests, the foundation pit was backfilled in layers. Plain soil or medium-coarse sand was preferred as the backfill material, and compaction was carried out every 30 centimeters. The tightly compacted backfill layer provides uniform lateral support for the second shell 6 of the spiral flow storage module, working in conjunction with the internal spiral guide plate 7 to resist the lateral pressure from the deeper soil. Furthermore, the backfill layer, acting as a large thermal inert body, effectively isolates the water from drastic fluctuations in surface air temperature, maintaining the water temperature within the spiral flow channel within a constant underground temperature range (typically 10℃-15℃) year-round, thereby physically inhibiting algal photosynthesis and microbial metabolic activity.

[0079] In the maintenance scenario of this embodiment, since the radial shear purification module is located on the ground or in a shallow layer, maintenance personnel can access the internal components through the top cover without digging. When it is necessary to replace the activated carbon adsorption layer or replenish the depleted quartz sand, it is only necessary to open the top cover and remove the suspension of the inverted funnel-shaped guide hood 3 to carry out open-type operations. This layered design of "easy maintenance at the top and maintenance-free at the bottom" perfectly matches the current situation of rural areas and remote mountainous areas where there is a lack of professional operation and maintenance equipment, ensuring low-cost operation of the device throughout its entire life cycle.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular integrated device for deep purification and underground storage of rainwater resources, characterized in that, It includes a radial shear purification module, a hydraulic interlocking connection component, and a spiral flow storage module, all coaxially connected from top to bottom; The radial shear purification module includes a first housing (1), a composite filter layer (2) filled in the first housing (1), an inverted funnel-shaped flow guide (3) disposed above the composite filter layer (2), and a central siphon assembly. A horizontal annular flow channel (5) is formed between the lower edge of the inverted funnel-shaped flow guide (3) and the upper surface of the composite filter layer (2). The spiral flow storage module includes a second housing (6) and a spiral guide plate (7) disposed inside the second housing (6). The spiral guide plate (7) divides the internal storage space of the second housing (6) into continuous spiral flow channels. The hydraulic interlocking connection assembly includes a connecting guide pipe (8) that connects the outlet of the radial shear purification module and the inlet of the spiral flow storage module, and a coaxial breathing pipe (9) for adjusting the air pressure inside the spiral flow storage module.

2. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 1, characterized in that, The inverted funnel-shaped guide hood (3) is coaxially suspended inside the first shell (1). The large-diameter edge at the bottom of the inverted funnel-shaped guide hood (3) and the inner wall of the first shell (1) are separated by an annular gap (10) for water flow. The inverted funnel-shaped guide hood (3) divides the water space inside the first shell (1) into a free water surface area outside the inverted funnel-shaped guide hood (3) and a negative pressure convergence area inside the inverted funnel-shaped guide hood (3). The two are connected only through a horizontal annular flow channel (5).

3. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 2, characterized in that, The central siphon assembly includes an inverted U-shaped siphon tube (4). The inlet of the inverted U-shaped siphon tube (4) is located at the geometric center apex of the inverted funnel-shaped guide hood (3) and is directly connected to the negative pressure convergence area. The bend of the inverted U-shaped siphon tube (4) is higher than the upper surface of the composite filter layer (2) and lower than the top overflow port of the first shell (1).

4. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 1, characterized in that, The connecting guide pipe (8) is constructed as a unidirectional fluid channel. The upper end of the connecting guide pipe (8) is connected to the water collection funnel (11) at the bottom of the radial shear purification module, and its lower end extends vertically into the interior of the spiral flow storage module. The position of its lower end pipe opening is lower than the full reservoir warning water level line of the spiral flow storage module, forming a water seal structure.

5. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 4, characterized in that, The coaxial breathing tube (9) is the only airflow channel connecting the spiral propulsion storage module with the outside atmosphere. The lower port of the coaxial breathing tube (9) is fixed at the full reservoir warning water level inside the spiral propulsion storage module, and the upper port extends upward through the hydraulic interlocking connection component and connects to the outside atmosphere or the bend of the central siphon component. When the water level in the spiral flow storage module rises and submerges the lower port of the coaxial breathing tube (9), a closed air chamber is formed at the top of the spiral flow storage module. The air pressure generated by the closed air chamber blocks the water flow in the connecting guide tube (8) from flowing downward, forcing the water level in the radial shear purification module to rise and triggering the central siphon assembly to start.

6. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 1, characterized in that, The spiral guide plate (7) is a fully continuous Archimedes spiral structure. The outer edge of the spiral guide plate (7) is sealed to the inner wall of the second shell (6), and its inner edge is sealed to the central axis of the second shell (6), forcing the water flow to rotate and move downward along the spiral channel.

7. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 6, characterized in that, The spiral flow storage module also includes a water intake sleeve (12), which vertically penetrates the spiral guide plate (7), and the water intake port of the water intake sleeve (12) is located at the bottom end of the spiral flow channel.

8. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 1, characterized in that, The composite filter layer (2) includes, from top to bottom, a quartz sand fine filter layer (201), an activated carbon layer (202), and a gravel support layer (203). The bottom of the first housing (1) is provided with a porous support plate (13) for supporting the composite filter layer (2).

9. The modular integrated device for deep purification and underground storage of rainwater resources according to claim 1, characterized in that, The first shell (1) and the second shell (6) are both prefabricated cylindrical structural components, and are connected by flanges to form a vertically integrated tower structure.

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