Rainwater recycling system and rainwater recycling method and cleaning method thereof

Abstract

This invention provides a rainwater harvesting system and its rainwater harvesting and cleaning methods. The system comprises a rainwater collection tank, a water storage and filtration tank, and a clean water storage tank connected in sequence. An automatic buoyancy-controlled valve is installed between the rainwater collection tank and the water storage and filtration tank, and a buoyancy-guided dedicated water outlet device is installed between the water storage and filtration tank and the clean water storage tank to extract and guide clean rainwater from the rainwater collection tank and the water storage and filtration tank, thereby improving the initial filtration effect and the final effluent quality. Furthermore, this invention further improves the precipitation and filtration by installing a sedimentation layer and cleaning components at the bottom of the water storage and filtration tank, further precipitating and separating impurities carried by the rainwater. Simultaneously, the cleaning components can clean the silt and other impurities deposited in the water storage and filtration tank using water introduced through an external pipe. This improves both the quality of the effluent rainwater and the ease of cleaning the water storage and filtration tank, thus enhancing the overall operational reliability of the rainwater harvesting system.

Description

Technical Field

[0001] This invention relates to the field of rainwater harvesting and recycling, and more specifically, to a rainwater recycling system and its rainwater recycling and cleaning methods. Background Technology

[0002] Rainwater harvesting and reuse, as a sustainable water resource management strategy, has significant value in many aspects. Ecologically, by collecting and retaining rainwater, the system effectively mitigates peak surface runoff, helping to alleviate urban flooding and reduce the load on drainage networks. Simultaneously, some rainwater can replenish groundwater through natural infiltration, mitigating water level decline caused by over-exploitation and playing a positive role in maintaining regional water cycle balance. Economically, although initial construction of water storage and purification facilities is required, in the long run, rainwater can replace tap water for purposes such as greening irrigation and road cleaning, directly reducing municipal water consumption, lowering water costs, and indirectly alleviating the operational load on sewage treatment plants. In terms of social benefits, rainwater harvesting and reuse is an important component of sponge city construction, helping to improve the city's adaptability to extreme rainfall, while cultivating public awareness of water conservation and resource recycling habits, and promoting the formation of a sustainable community culture.

[0003] However, currently widely used traditional rainwater harvesting systems still suffer from a series of significant drawbacks in actual operation, severely impacting their efficiency and reliability. Firstly, the rainwater initially collected by the system often contains high concentrations of silt particles, leaves, and other suspended solids, resulting in substantial sedimentation of pollutants. Simultaneously, floating debris on the water surface is easily carried into subsequent processes by the inlet structure, contaminating the storage tank and filtration units, leading to poor rainwater quality. This not only results in excessive filtration load and ineffective purification but also ensures that the final effluent still carries suspended solids, affecting the safety of reclaimed water and limiting its application scope.

[0004] Secondly, poor-quality recycled rainwater is more prone to causing blockages within the system. Fine particles and organic impurities accumulate in pipes, valves, and pumps, forming clogs over time and significantly increasing the risk of system failure. Maintenance personnel need to frequently clean and dredge these blockages, which not only consumes more time and manpower but also increases the long-term maintenance costs of the system.

[0005] The aforementioned problems expose the deficiencies of existing rainwater harvesting ponds in terms of initial filtration accuracy, anti-clogging performance, and dredging and maintenance design. Therefore, it is urgent to comprehensively optimize the dredging and filtration processes of rainwater harvesting systems from a system design perspective to improve the reliability and stability of rainwater harvesting systems and achieve more efficient, low-consumption, and stable rainwater resource utilization. Summary of the Invention

[0006] The purpose of this invention is to overcome at least one defect (deficiency) of the prior art and to provide a rainwater recycling system and its rainwater recycling and cleaning methods.

[0007] The present invention provides a rainwater recycling system, comprising a rainwater collection tank, a water storage and filtration tank and a clean water storage tank connected in sequence;

[0008] The rainwater collection tank has a main rainwater inlet on one side to collect rainwater. The rainwater collection tank and the water storage and filtration tank are connected by an inlet, and the inlet is equipped with an automatic opening and closing valve. The rainwater collection tank is also provided with a drain outlet connected to the municipal overflow pipe, and the drain outlet is located above the inlet. The inlet and the main rainwater inlet are located on different sides, and the main rainwater inlet is located higher than the drain outlet.

[0009] The automatic opening and closing valve includes a valve disc and a buoyancy triggering device. When the water level in the rainwater collection tank does not reach the buoyancy triggering device, the valve disc remains normally closed due to gravity. When the water level in the rainwater collection tank exceeds the inlet but does not reach the outlet height, the buoyancy triggering device floats with the water level, causing the valve disc to gradually open from bottom to top. Rainwater below the water level in the rainwater collection tank enters the water storage and filtration tank through the inlet. When the water level in the rainwater collection tank reaches the outlet height, floating debris on the surface of the rainwater collection tank is discharged through the municipal overflow pipe with the water flow.

[0010] A water outlet is provided between the water storage and filtration tank and the clear water storage tank, and a dedicated water outlet device is provided at the water outlet. One end of the dedicated water outlet device is connected to the water outlet, and the water outlet at the other end is driven by a buoyancy device to keep it below the liquid level in the water storage and filtration tank.

[0011] This technical solution utilizes a sequentially connected rainwater collection tank, water storage and filtration tank, and clear water storage tank. By installing an automatic buoyancy-controlled valve between the rainwater collection tank and the water storage and filtration tank, and a dedicated buoyancy-guided effluent device between the water storage and filtration tank, the system extracts and diverts the water layer with fewer impurities from these tanks. This improves upon traditional rainwater harvesting systems, addressing the issues of floating debris contaminating the water storage and filtration stages and the bottom effluent carrying high concentrations of suspended solids. This enhances the initial filtration effect and final effluent quality, thereby improving the overall operational reliability of the rainwater harvesting system. Specifically, by opening the main rainwater inlet and the inlet of the rainwater collection tank on opposite sides, rainwater is filtered through a filter screen installed at the main rainwater inlet before entering the rainwater collection tank. The main rainwater inlet is positioned higher than the drain outlet, and the drain outlet is positioned higher than the inlet of the water storage and filtration tank. This reduces the direct impact of rainwater flowing from the main rainwater inlet onto the inlet area, resulting in a slower flow of water entering the water storage and filtration tank and reducing the likelihood of carrying floating debris. Simultaneously, by installing an automatic opening and closing valve with a valve disc and buoyancy trigger at the inlet, the principle of gravity diversion based on water level difference is utilized. The automatic opening and closing valve is normally closed due to gravity when the water level does not reach the buoyancy trigger, and gradually opens with buoyancy when the water level exceeds the inlet but does not reach the drain outlet. When the water level reaches the drain outlet, surface floating debris is discharged through the municipal overflow pipe. Rainwater below the surface in the rainwater collection tank can enter the water storage and filtration tank through the already opened portion of the automatic opening and closing valve, further preventing floating debris from entering the water storage and filtration tank or clogging the filter screen, thus achieving effective diversion and filtration. Furthermore, by installing a dedicated water outlet device at the outlet, one end of which is connected to the outlet and the other end of which is connected to the outlet pipe and is kept below the liquid level in the water storage and filtration tank by a buoyancy device, the dedicated water outlet device uses the buoyancy device to keep the pipe opening below the liquid level, ensuring that the outflowing water is upper layer water with fewer suspended solids, thus guaranteeing the quality of the outflowing water.

[0012] Furthermore, the water storage and filtration tank includes, from top to bottom, a soil cover layer, a supporting water storage layer, and a sedimentation layer;

[0013] The supporting water storage layer is provided with multiple supporting components. The supporting components are combined and supported to form a water storage space. The water storage space is connected to the water inlet and the water outlet.

[0014] The water inlet is located on one side of the top of the supporting water storage layer, and the water outlet is located at the bottom of the supporting layer, with the water inlet and the water outlet located on different sides.

[0015] The support assembly avoids the dedicated water outlet device at the water outlet.

[0016] In this technical solution, the water storage and filtration pond is configured with a top-to-bottom layer of soil cover, a supporting water storage layer, and a sedimentation layer. The layered structure is used for functional zoning. The soil cover layer can improve the aesthetics and environmental adaptability of the water storage and filtration pond, while also providing protection. The supporting water storage layer is used to stabilize and support the water storage space to ensure rainwater storage capacity. The sedimentation layer is used to deposit and separate the sediments in the water storage space, so that the sediments are not easily disturbed during water inflow and outflow, thereby improving the quality of the rainwater used. Specifically, by setting up multiple supporting components in a multi-layered combination within the supporting water storage layer to form a water storage space, and placing the inlet on one side of the top of the supporting water storage layer and the outlet on the bottom of the supporting water storage layer on the opposite side, the opposite-side vertical arrangement of the inlet and outlet creates a top-to-bottom flow path for rainwater within the supporting water storage layer, providing sufficient time for rainwater to settle in the sedimentation layer. Simultaneously, the supporting components are positioned to avoid obstructing the dedicated water outlet device at the outlet, ensuring the proper operation of the dedicated water outlet device. This improves the structural stability of the water storage and filtration tank, extends the residence time of rainwater in the tank to enhance the sedimentation effect, and minimizes disturbance to the sediment during water discharge. Furthermore, by combining the existing automatic opening and closing valves and dedicated water outlet device design, the entire process of rainwater treatment from entry to exit of the water storage and filtration tank is further optimized, improving the stability of the rainwater recycling system, extending the rainwater residence time and sedimentation filtration degree, and enhancing the overall operational reliability and rainwater purification efficiency of the rainwater recycling system.

[0017] Furthermore, the bottom of the supporting water storage layer is provided with multiple supporting legs that contact the bottom plate of the sedimentation layer, and a sedimentation space is formed between the supporting components at the bottom of the supporting water storage layer and the bottom plate of the sedimentation layer;

[0018] A cleaning assembly is installed within the sedimentation space and is connected to an external pipe to clean the water storage and filtration tank.

[0019] A mud outlet is provided on one side of the bottom of the sediment layer, and the mud outlet is connected to the rainwater collection pool.

[0020] A valve is provided at the sludge outlet, which is opened when the water storage and filtration tank is cleaned.

[0021] In this technical solution, multiple support legs are installed at the bottom of the supporting water storage layer to contact the bottom plate of the sedimentation layer, forming a sedimentation space. Impurities carried by rainwater are provided with a dedicated sedimentation area, preventing impurities from accumulating in the supporting water storage layer. Furthermore, a cleaning component connected to an external pipeline is laid in the sedimentation space, and a sludge outlet connected to a rainwater collection tank is opened on one side of the bottom of the sedimentation layer, with a valve installed at the sludge outlet. The sedimentation space formed by the support legs allows the cleaning component to flush impurities in the sedimentation space through water introduced from the external pipeline. The valve at the sludge outlet is opened during cleaning to discharge the flushed sludge into the rainwater collection tank, thereby facilitating the cleaning of sludge and impurities deposited in the water storage and filtration tank. This improves the water quality of the effluent rainwater while enhancing the convenience of the water storage and filtration tank, thus extending its service life. By improving the purification and subsequent cleaning process of rainwater in the water storage and filtration tank, the long-term cleanliness and maintenance convenience of the water storage and filtration tank are improved, enhancing the continuous purification effect and service life of the rainwater recycling system.

[0022] Furthermore, a clean water pump is also provided at the bottom of the clean water storage tank. The clean water pump is connected to the bottom of the clean water storage tank and the external pipeline, and the clean water storage tank is emptied through the reuse pipeline.

[0023] A sewage pump is also installed at the bottom of the rainwater collection tank. The sewage pump is connected to the bottom of the rainwater collection tank and an external pipe, and is used to empty the rainwater collection tank.

[0024] Furthermore, the mud outlet is tubular, and the bottom of the rainwater collection tank is deeper than the bottom of the mud outlet;

[0025] A basket is also installed between the sludge outlet and the sewage pump, and the top opening of the basket is not higher than the bottom of the sludge outlet.

[0026] This technical solution improves the water drainage and pollutant treatment processes of the rainwater harvesting system, overcoming the problems of low clean water drainage efficiency, inconvenient cleaning of rainwater collection tanks, and easy sludge clogging of pipes by sewage pumps in traditional systems. This enhances the overall operational efficiency and maintenance convenience of the system, improving its practicality and stability. Specifically, by installing a clean water pump at the bottom of the clean water storage tank, connecting it to external pipes, and draining the tank through a reuse pipeline, and by installing a sewage pump at the bottom of the rainwater collection tank, connecting it to external pipes, the clean rainwater in the storage tank can be efficiently drained through the clean water pump and reuse pipeline, achieving recycling. The sewage pump can quickly drain the wastewater in the rainwater collection tank, preventing clean and dirty rainwater from interfering with each other, thus improving the efficiency of rainwater cleaning, separation, and utilization. Simultaneously, the clean water pump and sewage pump can quickly drain all the water stored in the rainwater harvesting system, facilitating cleaning and improving cleaning efficiency. Furthermore, the sludge outlet is designed as a tube, and the bottom of the rainwater collection tank is deeper than the bottom of the sludge outlet. At the same time, a basket with its top opening no higher than the bottom of the sludge outlet is installed between the sludge outlet and the sewage pump. The height difference between the bottom of the rainwater collection tank and the sludge outlet causes the sludge to accumulate to the bottom of the tank under the action of gravity. The basket can intercept the sludge discharged from the sludge outlet so that the sludge can be dumped afterward by lifting the basket. This achieves the beneficial effects of conveniently emptying pollutants from the rainwater collection tank, promoting sludge accumulation, and facilitating sludge collection and treatment, which greatly improves the cleanliness and recycling efficiency of the recycled rainwater.

[0027] Furthermore, the cleaning assembly includes a sludge removal assembly disposed at the bottom of the sediment layer and a flushing assembly disposed at the bottom of the supporting water storage layer;

[0028] The dredging assembly includes at least a dredging ditch disposed on the bottom plate of the sediment layer, the dredging ditch being connected to the sludge outlet; the backwash dredging pipe includes a backwash head and a pressure-resistant hose, one end of the pressure-resistant hose being connected to the backwash head, and the other end passing through the sludge outlet and being connected to an external pipe, the backwash head including at least a plurality of spray nozzles with the water flow direction inclined toward the pressure-resistant hose.

[0029] The flushing assembly includes a flushing pipe that is laid along the side wall of the bottom of the supporting water storage layer and is fixed by multiple points of support by a bracket. The flushing pipe has multiple water spray holes spaced apart on its inner side for flushing the surface of the supporting assembly, the inner wall of the supporting water storage layer, and the floor or side wall of the sedimentation layer. The flushing pipe is connected to the outlet pipe of the clean water pump in the clean water storage tank, and a control valve is provided between the flushing pipe and the reuse pipe.

[0030] In this technical solution, by setting the cleaning components as sludge removal components at the bottom of the sedimentation layer and flushing components supporting the bottom of the water storage layer, targeted cleaning of each area of ​​the water storage and filtration tank is achieved, sludge discharge efficiency is improved, impurity residue is reduced, and the problems of incomplete cleaning and difficult sludge discharge in traditional systems are improved. This enhances the cleaning effect and maintenance convenience of the system and improves the long-term operating performance of the rainwater recycling system. Specifically, the dredging assembly includes a dredging ditch connected to the sludge outlet and a backwashing dredging pipe with a spray nozzle angled towards the pressure-resistant hose. The dredging ditch guides and collects sludge, while the backwash head thoroughly flushes the sediment, guiding the sludge through the dredging ditch to the sludge outlet and then flushing it out with the water flow from the backwash head, improving dredging efficiency and convenience. Simultaneously, the flushing assembly includes a flushing pipe laid along the bottom sidewall of the supporting water storage layer and fixed by a bracket, forming a spray column of water at a certain height. Multiple spray holes are located inside the pipe; by setting different orientations for these spray holes, the walls and bottom of the supporting assembly, supporting water storage layer, and sediment layer can be cleaned, flushing the attached sludge and impurities into the dredging ditch, improving the overall cleaning effect of the water storage and filtration tank. Furthermore, the pipe connects to the outlet pipe of the clean water pump and is equipped with a control valve. By utilizing external water channels or reusing clean rainwater from the clean water tank, the surface of the supporting assembly, the walls and bottom of the supporting water storage layer and sediment layer are thoroughly flushed, improving the performance of the rainwater harvesting system.

[0031] Furthermore, the dredging assembly also includes a movable backwashing guide rail and a track trolley; the movable backwashing guide rail is laid along the dredging ditch, and the backwashing dredging pipe is suspended on the track trolley and moves along the backwashing track;

[0032] The flushing assembly also includes flushing nozzles spaced apart on the flushing pipe, the flushing nozzles facing the floor or sidewall of the deposit layer.

[0033] In this technical solution, by adding a movable backwashing guide rail laid along the dredging ditch and a track trolley suspending the backwashing dredging pipe to the dredging component, the backwashing dredging pipe can move along the guide rail to achieve efficient flushing of the entire dredging ditch. In the flushing component, flushing nozzles are set at intervals on the flushing pipes facing the floor or sidewalls of the sediment layer. The flushing nozzles can specifically clean the floor and sidewalls of the sediment layer, expanding the coverage of the cleaning component in the water storage filter tank, further enhancing the flushing targeting, improving the overall cleaning effect, improving the thoroughness of cleaning and the convenience of maintenance of the water storage filter tank, and improving the long-term operational stability of the rainwater recycling system.

[0034] Furthermore, the dredging ditch includes a main channel and multiple branch channels connected to the main channel. The main channel is connected to the mud outlet. The dredging ditch is arranged in a tree-like or fishbone-like shape.

[0035] The mobile backwashing guide rail is laid along the main channel, and the transverse feet of the mobile backwashing guide rail are placed on the edge of the silt cleaning ditch. The mobile backwashing guide rail is in an overall shape of "king" character;

[0036] The backwashing and silt cleaning pipe is placed in the main channel.

[0037] In this technical solution, by setting the silt cleaning ditch as a tree-shaped or fishbone-shaped structure including a main channel and multiple branch channels, using the tree-shaped / fishbone-shaped structure for diversion and convergence, the aggregation degree of the flushed silt is improved. At the same time, the main channel is connected to the mud outlet, which is convenient for discharging all the converged silt in the silt cleaning ditch to the mud outlet through the main channel during cleaning; preferably, the set width and depth of the main channel are both greater than those of the branch channels, which is convenient for the silt in the silt cleaning ditch to be discharged along the main channel. Further, the mobile backwashing guide rail is laid along the main channel and is in the shape of "king" character, its transverse feet are placed on the edge of the silt cleaning ditch, and the backwashing and silt cleaning pipe is placed in the main channel, which not only enables the guide rail to stably support and guide, but also allows the backwashing and silt cleaning pipe to centrally scour the converged silt along the main channel under the guidance of the guide rail, improving the silt convergence efficiency, enhancing the movement stability of the silt cleaning pipe, improving the silt cleaning effect in the main channel, improving the pertinence and efficiency of the silt cleaning of the rainwater recycling pool, and improving the cleaning and maintenance performance of the system.

[0038] Preferably, the main channel and the branch channels are straight channels; and the included angle between the main channel and the branch channels is 30° to 90°; correspondingly, the backwashing and silt cleaning pipe is provided with a water spraying port with an inclination angle matching the angle of the branch channels. Specifically, the branch channels are arranged on both sides of the main channel and the main channel is located in the middle. The straight arrangement of the branch channels enables the sewage on both sides of the main channel to be quickly drained to the main channel, avoiding the accumulation of sewage and dirt at the corners and the influence on the sewage flow rate when it is bent; at the same time, by making the included angle between the branch channels and the main channel larger, the speed of the sewage in the branch channels entering the main channel is further ensured, thereby improving the sewage discharge speed. Correspondingly, the backwashing and silt cleaning pipe body is arranged in the main channel, and the backwashing and silt cleaning pipe is provided with a water spraying port with an inclination angle matching the angle of the branch channels, ensuring that the water spraying port can directionally wash the branch channels during flushing and silt discharging, improving the efficiency and effect of silt discharging and sewage discharging.

[0039] Preferably, the backwashing head of the backwashing and silt cleaning pipe can be a rotary nozzle, a fan-shaped nozzle or other structures that are convenient for increasing the scouring area or flushing efficiency of the backwashing head, so as to further improve the efficiency and effect of silt discharging and sewage discharging of the rainwater recycling system.

[0040] Another object of the present invention is to provide a rainwater recycling method for the rainwater recycling system as shown in this technical solution, including the following steps:

[0041] S1. Rainwater collection and preliminary filtration: Rainwater flows into the rainwater collection tank after being filtered through the filter screen at the main rainwater inlet. When the water level in the rainwater collection tank is lower than the inlet, the automatic opening and closing valve remains closed under the action of gravity.

[0042] When the water level in the rainwater collection tank exceeds the inlet but does not reach the outlet, the buoyancy trigger device causes the valve to gradually open as the liquid level rises, allowing rainwater at a certain depth below the liquid level to flow into the water storage and filtration tank through the inlet, while floating debris remains at the upper liquid level in the rainwater collection tank; the outlet is normally open, and when the water level in the rainwater collection tank reaches the outlet, the floating debris on the upper layer of the liquid surface is discharged through the outlet along the municipal overflow pipe;

[0043] S2. Sedimentation and secondary filtration: After the rainwater is initially filtered in step S1, it enters the water storage and filtration tank through the inlet. In the supporting water storage layer, the flow rate is slowed down by collision and filtration, and the water is stored and settled. The outlet pipe of the special water outlet device is a flexible hose. The pipe opening is held above the outlet and below the liquid surface in the water storage and filtration tank by the buoyancy device. It always draws water with fewer suspended solids below the liquid surface, and after secondary filtration, it is discharged into the clear water storage tank for recycling through the outlet.

[0044] In this technical solution, the rainwater harvesting method is set up in two steps: rainwater collection and preliminary filtration, sedimentation, and secondary filtration. The preliminary filtration is achieved by an automatic opening and closing valve between the rainwater collection tank and the water storage and filtration tank. At the same time, the secondary filtration is achieved by a dedicated water outlet device between the water storage and filtration tank and the clear water storage tank. This achieves graded filtration of rainwater, reduces the amount of floating matter and impurities in the rainwater entering subsequent stages, and ensures that the recovered water is clean rainwater with less suspended solids and sediment. This improves the problems of insufficient filtration and easy contamination of the recovered water by floating matter in traditional rainwater harvesting methods, improves the filtration effect and water quality of rainwater harvesting, and improves the efficiency and reliability of rainwater harvesting and utilization. Specifically, in step S1, during rainwater collection and preliminary filtration, suspended solids typically concentrate above the liquid surface in the tank. An automatic valve is used to close due to gravity when the water level is below the inlet, and when the water level exceeds the inlet but does not reach the outlet, a buoyancy-triggered device gradually opens the valve, allowing rainwater with fewer suspended solids below the valve opening to enter the storage and filtration tank. Simultaneously, when the water level reaches the outlet, floating solids are discharged through the municipal overflow pipe, discarding the upper layer of rainwater rich in floating solids. This achieves preliminary filtration and waste disposal of the collected rainwater. In step S2, during the sedimentation and secondary filtration process, the buoyancy device of the special water outlet is used to keep the pipe opening below the liquid surface of the water storage filter tank and at a distance from the sediment layer. This avoids the upper layer of liquid that has just entered the water storage filter tank, which has not been effectively settled and is rich in fine floating matter, as well as the lower layer of liquid that is close to the sediment layer at the bottom of the water storage filter tank and is rich in suspended matter. This allows for the continuous extraction of the settled upper layer of clean rainwater with less fine floating matter, greatly improving the cleanliness and recycling efficiency of the rainwater.

[0045] Another object of the present invention is to provide a cleaning method for a rainwater harvesting and utilization system as shown in this technical solution, comprising the following steps:

[0046] A1. Flushing and maintenance: Periodically open the control valve of the flushing pipe and spray high-pressure water through the nozzle of the flushing pipe onto the surface of the support component, the inner wall of the support water storage layer, and the floor or side wall of the sediment layer to flush away the residual silt into the dredging ditch.

[0047] A2. Dredging Operation: When dredging is required, drain the water stored in the water storage and filtration tank, open the valve of the sludge outlet, and extend the backwash dredging pipe into the dredging ditch through the sludge outlet. Use municipal tap water as the backwash water source. After turning on the backwash water source, use the backwash force of the water flow to extend the backwash dredging pipe into the innermost part of the dredging ditch. While using high-pressure water flow to flush the sludge from the inside out, manually pull the backwash dredging pipe to flush the sludge to the sludge outlet, collect it through the basket, and transport it away. At the same time, turn on the sewage pump to discharge the sewage in the rainwater collection tank.

[0048] In this technical solution, the cleaning method is divided into two steps: flushing maintenance and dredging. In step A1, during the flushing maintenance, the control valve of the flushing pipe is periodically opened, and high-pressure water is sprayed onto the surface of the support components, the pool walls, and the sediment layer using nozzles to flush the sludge into the dredging ditch. This maintains the cleanliness of the water storage and filtration pool and the surface of the support components, improving the cleanliness and service life of the rainwater harvesting system. In step A2, during the dredging operation, the water storage and filtration pool is emptied, the sludge outlet valve is opened, and the backwash dredging pipe is extended into the dredging ditch, utilizing the flow of municipal tap water. The force of the flushing pipe pushes it deep into the sludge-removing pipe and washes it from the inside out. With manual pulling, the sludge is flushed to the outlet and collected in a basket. At the same time, the sewage pump is turned on to discharge the sewage from the rainwater collection tank. The backflow of the water propels the sludge deeper into the sludge-removing ditch. Combined with the multi-directional flushing of the high-pressure water flow and the gravity drainage caused by the height difference at the outlet, the sludge is completely collected. This achieves regular cleaning and centralized discharge of residual sludge from all parts of the system, improving the problems of incomplete sludge removal and cumbersome operation in traditional cleaning methods. It improves the comprehensiveness and convenience of the system cleaning, and enhances the long-term operating efficiency and service life of the rainwater harvesting system.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] 1. A rainwater harvesting system is provided, which improves the traditional rainwater harvesting system by using an integrated structure design of a rainwater collection tank, a water storage and filtration tank and a clean water storage tank connected in sequence. The system improves the problem of floating matter easily contaminating the water storage and filtration stage and the problem of suspended solids easily carrying in the effluent in the traditional rainwater harvesting system. The system improves the preliminary filtration effect of rainwater and the quality of the final effluent, and improves the overall operational reliability of the rainwater harvesting system.

[0051] 2. By setting multiple support legs at the bottom of the supporting water storage layer to contact the bottom plate of the sedimentation layer to form a sedimentation space, impurities carried by rainwater are provided with a dedicated sedimentation area, preventing impurities from accumulating in the supporting water storage layer. Furthermore, a cleaning component connected to an external pipeline is laid in the sedimentation space, and a sludge outlet connected to the rainwater collection tank is opened on one side of the bottom of the sedimentation layer, with a valve installed at the sludge outlet. The sedimentation space formed by the support legs allows the cleaning component to flush the impurities in the sedimentation space through water introduced from the external pipeline. The valve at the sludge outlet is opened during cleaning to discharge the flushed sludge into the rainwater collection tank, thereby facilitating the cleaning of sludge and impurities deposited in the water storage and filtration tank. This improves the water quality of the effluent rainwater and enhances the convenience of the water storage and filtration tank, thus extending its service life. By improving the purification and post-cleaning process of rainwater in the water storage and filtration tank, the long-term cleanliness and maintenance convenience of the water storage and filtration tank are improved, enhancing the continuous purification effect and service life of the rainwater recycling system.

[0052] 3. A rainwater harvesting and utilization method for a rainwater harvesting and utilization system is provided. The method consists of two steps: rainwater collection and preliminary filtration, and sedimentation and secondary filtration. The preliminary filtration is achieved by an automatic opening and closing valve between the rainwater collection tank and the water storage and filtration tank. At the same time, the secondary filtration is achieved by a dedicated water outlet device between the water storage and filtration tank and the clear water storage tank. This achieves graded filtration of rainwater, reduces the amount of floating matter and impurities in the rainwater entering subsequent stages, and ensures that the recovered water is clean rainwater with less suspended solids and sediment. This method improves the problems of insufficient filtration and easy contamination of the recovered water by floating matter in traditional rainwater harvesting methods, improves the filtration effect and water quality of rainwater harvesting, and improves the efficiency and reliability of rainwater harvesting and utilization.

[0053] 4. A cleaning method for a rainwater harvesting system is provided, which consists of two steps: flushing maintenance and dredging. In step A1, during the flushing maintenance, the control valve of the flushing pipe is periodically opened, and high-pressure water is sprayed onto the surface of the support components, the pool walls, and the sediment layer using nozzles to flush the sludge into the dredging ditch, thereby maintaining the cleanliness of the water storage and filtration pool and the surface of the support components, improving the cleanliness and service life of the rainwater harvesting system. In step A2, during the dredging operation, the water storage and filtration pool is emptied, the sludge outlet valve is opened, and the backwash dredging pipe is extended into the dredging ditch, utilizing municipal [resources / facilities]. The backflow of tap water forces the sludge pipe deeper and flushes it from the inside out. With manual pulling, the sludge is flushed to the outlet and collected in a basket. At the same time, the sewage pump is turned on to discharge the wastewater from the rainwater collection tank. The backflow of water propels the sludge deeper into the sludge ditch. Combined with the multi-directional flushing of high-pressure water and the gravity drainage caused by the elevation difference at the outlet, the sludge is completely collected. This achieves regular cleaning and centralized discharge of residual sludge from all parts of the system, improving the problems of incomplete sludge removal and cumbersome operation in traditional cleaning methods. It improves the comprehensiveness and convenience of system cleaning, and enhances the long-term operating efficiency and service life of the rainwater harvesting system. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a rainwater recycling system according to the present invention.

[0055] Figure 2 This is a schematic diagram of the structure of a water storage and filtration tank in a rainwater recycling system according to the present invention.

[0056] Figure 3 This is a schematic diagram of the structure of an automatic opening and closing valve in a rainwater recycling system according to the present invention.

[0057] Figure 4 This is a schematic diagram of the structure of a dedicated water outlet device in a rainwater recycling system according to the present invention.

[0058] Figure 5 This is a schematic diagram of the dredging component in a rainwater recycling system according to the present invention.

[0059] Figure 6 This is a schematic flowchart of a rainwater recycling method for a rainwater recycling system according to the present invention.

[0060] Figure 7 This is a schematic flowchart of a cleaning method for a rainwater recycling system according to the present invention.

[0061] Figure Descriptions: Rainwater collection tank 100, rainwater main outlet 101, drain outlet 102, sewage pump 110, water storage and filtration tank 200, water inlet 201, water outlet 202, sludge outlet 203, soil cover layer 210, supporting water storage layer 220, supporting component 2200, automatic opening and closing valve 221, valve disc 2211, buoyancy triggering device 2212, special water outlet device 222, buoyancy device 223, sedimentation layer 230, clear water storage tank 300, clear water pump 310, flushing component 400, flushing pipe 410, sludge removal component 500, sludge removal ditch 510, backflushing sludge removal pipe 520, backflushing head 521, pressure-resistant hose 522, basket 530. Detailed Implementation

[0062] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below. Obviously, what is described is only a part of the embodiments of the present invention, and not all of the embodiments.

[0063] Example 1

[0064] like Figures 1-5 As shown, a rainwater recycling system is provided, including a rainwater collection tank 100, a water storage and filtration tank 200 and a clean water storage tank 300 connected in sequence.

[0065] The rainwater collection tank 100 has a main rainwater inlet 101 on one side to collect rainwater, and a water inlet 201 connecting the rainwater collection tank 100 and the water storage and filtration tank 200. An automatic opening and closing valve 221 is provided at the water inlet 201. The rainwater collection tank 100 also has a drain outlet 102 connected to the municipal overflow pipe. The drain outlet 102 is located above the water inlet 201. The water inlet 201 and the main rainwater inlet 101 are opened on different sides, and the opening position of the main rainwater inlet 101 is higher than that of the drain outlet 102.

[0066] The automatic opening and closing valve 221 includes a valve disc 2211 and a buoyancy triggering device 2212. When the water level in the rainwater collection tank 100 does not reach the buoyancy triggering device 2212, the valve disc 2211 remains closed due to gravity. When the water level in the rainwater collection tank 100 exceeds the inlet 201 but does not reach the outlet 102, the buoyancy triggering device 2212 floats with the water level, causing the valve disc 2211 to gradually open from bottom to top. Rainwater below the water level in the rainwater collection tank 100 enters the water storage and filtration tank 200 through the inlet 201. When the water level in the rainwater collection tank 100 reaches the outlet 102, the floating matter on the surface of the rainwater collection tank 100 is discharged through the municipal overflow pipe with the water flow.

[0067] A water outlet 202 is provided between the water storage and filtration tank 200 and the clear water storage tank 300, and a special water outlet device 222 is provided at the water outlet 202; one end of the special water outlet device 222 is connected to the water outlet 202, and the water outlet at the other end is kept below the liquid level in the water storage and filtration tank 200 by a buoyancy device 223.

[0068] Specifically, by opening the rainwater main inlet 101 and the inlet 201 on opposite sides of the rainwater collection tank 100, with the rainwater main inlet 101 positioned higher than the drain outlet 102, and the drain outlet 102 positioned higher than the inlet 201 of the water storage and filtration tank 200, the direct impact of rainwater on the inlet 201 area when it flows in is reduced, making the water flow into the water storage and filtration tank 200 through the inlet 201 slower and less likely to carry floating objects; at the same time, by installing an automatic opening and closing valve 2211 containing a valve disc 2211 and a buoyancy triggering device 2212 at the inlet 201, 21. Utilizing the gravity guiding principle of water level difference, and in conjunction with the design of the automatic opening and closing valve 221, the valve is normally closed due to gravity when the water level does not reach the buoyancy trigger device 2212, and gradually opens with buoyancy when the water level exceeds the inlet 201 but does not reach the outlet 102. When the water level reaches the outlet 102, the surface floating matter is discharged through the municipal overflow pipe. The clean rainwater below the liquid surface in the rainwater collection tank 100 can enter the water storage and filtration tank 200 through the already opened part of the automatic opening and closing valve 221, further preventing floating matter from entering the water storage and filtration tank 200, and achieving effective diversion and filtration. Furthermore, by setting up a dedicated water outlet device 222 at the outlet 202, one end of which is connected to the outlet 202 and the other end of which is driven by the buoyancy device 223 to be kept below the liquid level in the water storage and filtration tank 200, the dedicated water outlet device 222 is kept below the liquid level by the buoyancy device 223, ensuring that the water flowing out is upper water with less suspended solids, which has undergone collision and sedimentation and is far away from the lower sediment layer 230, thus ensuring the quality of the water.

[0069] Furthermore, the water storage and filtration tank 200 includes a soil cover layer 210, a supporting water storage layer 220, and a sedimentation layer 230 arranged sequentially from top to bottom;

[0070] The water storage layer 220 is provided with multiple support components 2200. The support components 2200 are combined and supported to form a water storage space. The water storage space is connected to the inlet 201 and the outlet 202.

[0071] The inlet 201 is located on one side of the top of the supporting water storage layer 220, and the outlet 202 is located at the bottom of the supporting layer, with the inlet 201 and the outlet 202 located on different sides.

[0072] The support component 2200 avoids the dedicated water outlet device 222 at the water outlet 202.

[0073] Specifically, by setting up multiple support components 2200 in a multi-layer combination within the supporting water storage layer 220 to form a water storage space, and setting the inlet 201 on one side of the top of the supporting water storage layer 220 and the outlet 202 on the bottom of the supporting water storage layer 220 on a different side from the inlet 201, the opposite vertical arrangement of the inlet 201 and the outlet 202 allows rainwater to form a top-to-bottom flow path within the supporting water storage layer 220, providing sufficient time for rainwater to settle in the sedimentation layer 230. At the same time, the support components 2200 are positioned at the outlet 202 to avoid the dedicated water outlet device 222, ensuring the normal operation of the dedicated water outlet device 222. This achieves the beneficial effects of improving the structural stability of the water storage and filtration tank 200, extending the residence time of rainwater in the tank to enhance the sedimentation effect, and ensuring that the function of the dedicated water outlet device 222 is not disturbed. Furthermore, by combining the existing automatic opening and closing valve 221 and the dedicated water outlet device 222 design, the entire process of rainwater treatment from entering to exiting the water storage and filtration tank 200 has been further optimized, which has improved the stability of the rainwater recycling system, extended the rainwater retention time and the degree of sedimentation and filtration, and improved the overall operational reliability and rainwater purification efficiency of the rainwater recycling system.

[0074] Furthermore, multiple support legs are provided at the bottom of the supporting water storage layer 220 to contact the bottom plate of the sedimentation layer 230, and a sedimentation space is formed between the support component 2200 at the bottom of the supporting water storage layer 220 and the bottom plate of the sedimentation layer 230.

[0075] A cleaning assembly is installed within the sedimentation space and connected to external pipes to clean the water storage and filtration tank 200.

[0076] A mud outlet 203 is provided on one side of the bottom of the sediment layer 230, and the mud outlet 203 is connected to the rainwater collection tank 100.

[0077] A valve is installed at the mud outlet 203, which is opened when cleaning the water storage and filtration tank 200.

[0078] Specifically, by setting multiple support legs at the bottom of the supporting water storage layer 220 to contact the bottom plate of the sedimentation layer 230 to form a sedimentation space, impurities carried by rainwater are provided with a dedicated sedimentation area, preventing impurities from accumulating in the supporting water storage layer 220. Furthermore, a cleaning component connected to an external pipe is laid in the sedimentation space, and a sludge outlet 203 connected to the rainwater collection tank 100 is opened on one side of the bottom of the sedimentation layer 230, with a valve installed at the sludge outlet 203. The sedimentation space formed by the support legs allows the cleaning component to flush the impurities in the sedimentation space through water introduced from the external pipe. When the valve at the sludge outlet 203 is opened during cleaning, the flushed sludge can be discharged into the rainwater collection tank 100, thereby facilitating the cleaning of sludge and impurities deposited in the water storage and filtration tank 200. This improves the water quality of the effluent rainwater, enhances the convenience of the water storage and filtration tank 200, and thus extends the service life of the water storage and filtration tank 200.

[0079] Furthermore, a clean water pump 310 is also provided at the bottom of the clean water storage tank 300. The clean water pump 310 is connected to the bottom of the clean water storage tank 300 and the external pipe, and the clean water storage tank 300 is emptied through the reuse pipe.

[0080] A sewage pump 110 is also provided at the bottom of the rainwater collection tank 100. The sewage pump 110 is connected to the bottom of the rainwater collection tank 100 and the external pipe, and is used to empty the rainwater collection tank 100.

[0081] Furthermore, the mud outlet 203 is tubular, and the bottom of the rainwater collection pool 100 is deeper than the bottom of the mud outlet 203.

[0082] A basket 530 is also installed between the mud outlet 203 and the sewage pump 110. The top opening of the basket 530 is not higher than the bottom of the mud outlet 203.

[0083] Specifically, by installing a clean water pump 310 at the bottom of the clean water storage tank 300, connecting the tank bottom to an external pipe, and emptying the clean water storage tank 300 through a reuse pipeline, and installing a sewage pump 110 at the bottom of the rainwater collection tank 100, connecting the tank bottom to an external pipe, the clean rainwater in the clean water storage tank 300 can be efficiently emptied through the clean water pump 310 and the reuse pipeline, thus achieving recycling. The sewage pump 110 can quickly empty the sewage in the rainwater collection tank 100, preventing clean and dirty rainwater from interfering with each other and improving the efficiency of rainwater cleaning, separation, and utilization. At the same time, by installing the clean water pump 310 and the sewage pump 110, all the water stored in the rainwater recycling system can be quickly drained, facilitating cleaning and improving cleaning efficiency. Furthermore, the sludge outlet 203 is designed as a tube, and the bottom of the rainwater collection tank 100 is deeper than the bottom of the sludge outlet 203. At the same time, a basket 530 with its top opening not higher than the bottom of the sludge outlet 203 is installed between the sludge outlet 203 and the sewage pump 110. The height difference between the bottom of the rainwater collection tank 100 and the sludge outlet 203 causes the sludge to accumulate to the bottom of the tank under the action of gravity. The basket 530 can intercept the sludge discharged from the sludge outlet 203 so that the sludge can be dumped afterward by lifting the basket 530. This achieves the beneficial effects of conveniently emptying pollutants in the rainwater collection tank 100, promoting sludge accumulation, and facilitating sludge collection and treatment, greatly improving the cleanliness and recycling efficiency of rainwater.

[0084] Furthermore, the cleaning components include a sludge removal component 500 disposed at the bottom of the sedimentation layer 230 and a flushing component 400 disposed at the bottom of the supporting water storage layer 220;

[0085] The dredging assembly 500 includes at least a dredging ditch 510 and a backwash dredging pipe 520 disposed on the bottom plate of the sediment layer 230. The dredging ditch 510 is connected to the mud outlet 203. The backwash dredging pipe 520 includes a backwash head 521 and a pressure-resistant hose 522. One end of the pressure-resistant hose 522 is connected to the backwash head 521, and the other end passes through the mud outlet 203 and is connected to an external pipe. The backwash head 521 includes at least a plurality of spray nozzles that are inclined toward the pressure-resistant hose 522 in the direction of water flow.

[0086] The flushing assembly 400 includes a flushing pipe 410, which is laid along the side wall of the bottom of the supporting water storage layer 220 and fixed by multiple points of support by a bracket. Multiple water spray holes are spaced apart on the inner side of the flushing pipe 410 for flushing the surface of the supporting assembly 2200, the inner wall of the supporting water storage layer 220, and the floor or side wall of the sedimentation layer 230. The flushing pipe 410 is connected to the outlet pipe of the clean water pump 310 in the clean water storage tank 300, and a control valve is provided between the flushing pipe 410 and the reuse pipe.

[0087] Specifically, the dredging assembly 500 includes a dredging ditch 510 connected to the mud outlet 203 and a backwash dredging pipe 520 with a water spray nozzle inclined towards the pressure-resistant hose 522. Utilizing the guiding and silt-gathering characteristics of the dredging ditch 510 and the comprehensive flushing characteristics of the backwash head 521, the silt from the sediment layer 230 is guided through the dredging ditch 510 to the mud outlet 203 and flushed out by the water flow of the backwash head 521, improving dredging efficiency and convenience. Simultaneously, the flushing assembly 400 includes a flushing pipe 410 laid along the bottom sidewall of the supporting water storage layer 220 and fixed by a bracket, forming a spray water column of a certain height. Multiple water spray holes are provided on the side. By setting the different directions of the multiple water spray holes, the pool walls and bottom of the support component 2200, the support water storage layer 220, and the sediment layer 230 can be cleaned, and the attached silt and impurities are flushed into the sludge ditch 510, which improves the overall cleaning effect of the water storage and filtration pool 200. At the same time, the pipeline is connected to the outlet pipeline of the clean water pump 310 and equipped with a control valve. By using the external water channel or reusing clean rainwater from the clean water pool, the surface of the support component 2200, the support water storage layer 220, and the pool walls and bottom of the sediment layer 230 can be thoroughly rinsed, which improves the performance of the rainwater recycling system.

[0088] Furthermore, the dredging assembly 500 also includes a movable backwashing guide rail and a track trolley; the movable backwashing guide rail is laid along the dredging ditch 510, and the backwashing dredging pipe 520 is suspended on the track trolley and moves along the backwashing track.

[0089] The flushing assembly 400 also includes flushing nozzles spaced apart on the flushing conduit 410, the flushing nozzles facing the floor or sidewall of the deposit layer 230.

[0090] Specifically, by adding a movable backwashing guide rail laid along the dredging ditch 510 and a track trolley suspending the backwashing dredging pipe 520 to the dredging assembly 500, the backwashing dredging pipe 520 can move along the guide rail to achieve efficient flushing of the entire dredging ditch 510. In the flushing assembly 400, flushing nozzles are spaced on the flushing pipe 410 and directed toward the floor or sidewall of the sediment layer 230. The flushing nozzles can specifically clean the floor and sidewall of the sediment layer 230, expanding the coverage of the cleaning assembly in the water storage filter tank 200, further enhancing the flushing targeting, improving the overall cleaning effect, improving the thoroughness of cleaning and ease of maintenance of the water storage filter tank 200, and improving the long-term operational stability of the rainwater recycling system.

[0091] Furthermore, the dredging ditch 510 includes a main channel and a plurality of branch channels connected to the main channel. The main channel is connected to the mud outlet 203, and the dredging ditch 510 is integrally arranged in a tree shape or a fishbone shape. By using the tree-shaped / fishbone-shaped structure for diversion and convergence, the aggregation degree of the flushed silt is improved. At the same time, the main channel is connected to the mud outlet 203, which is convenient for discharging all the converged silt in the dredging ditch 510 to the mud outlet 203 through the main channel during cleaning. Preferably, the set width and depth of the main channel are both greater than those of the branch channels, so as to more conveniently discharge the silt in the dredging ditch 510 along the main channel.

[0092] Furthermore, by laying the mobile backwashing guide rail along the main channel and the cross feet of the mobile backwashing guide rail are placed on the edge of the dredging ditch 510, the mobile backwashing guide rail is integrally in a "king" shape.

[0093] The backwashing and dredging pipe 520 is placed in the main channel, which not only enables the guide rail to stably support and guide, but also allows the backwashing and dredging pipe 520 to centrally scour the converged silt along the main channel under the guidance of the guide rail, improving the silt convergence efficiency, enhancing the movement stability of the dredging pipe, improving the silt cleaning effect in the main channel, increasing the pertinence and efficiency of the dredging of the water storage and filtration pool 200, and improving the cleaning and maintenance performance of the system.

[0094] Preferably, the main channel and the branch channels are straight channels; and the included angle between the main channel and the branch channels is 30° to 90°; correspondingly, the backwashing and dredging pipe 520 is provided with a water spray nozzle with an inclination angle matching the angle of the branch channels. Specifically, the branch channels are arranged on both sides of the main channel and the main channel is located in the middle. The straight arrangement of the branch channels enables the sewage on both sides of the main channel to be quickly drained to the main channel, avoiding the accumulation of sewage and dirt at the corners and the influence on the sewage flow rate when it is bent. At the same time, by making the included angle between the branch channels and the main channel larger, the speed of the sewage in the branch channels entering the main channel is further ensured, thereby increasing the sewage discharge speed. Correspondingly, the main body of the backwashing and dredging pipe 520 is arranged in the main channel, and the backwashing and dredging pipe 520 is provided with a water spray nozzle with an inclination angle matching the angle of the branch channels, ensuring that the water spray nozzle can directionally wash the branch channels during flushing and silt discharging, improving the efficiency and effect of silt discharging and sewage discharging.

[0095] Preferably, the backwashing head 521 of the backwashing and dredging pipe 520 can be a rotary nozzle, a fan-shaped nozzle or other structures that are convenient for increasing the scouring area or flushing efficiency of the backwashing head 521, so as to further improve the efficiency and effect of silt discharging and sewage discharging of the rainwater recycling system.

[0096] Embodiment 2

[0097] As Figure 6As shown, a rainwater harvesting and utilization method for the rainwater harvesting and utilization system provided in Embodiment 1 is provided, comprising the following steps:

[0098] S1. Rainwater collection and preliminary filtration: Rainwater flows into the rainwater collection tank 100 after being filtered by the filter screen of the rainwater main outlet 101. When the water level in the rainwater collection tank 100 is lower than the inlet 201, the automatic opening and closing valve 221 remains closed under the action of gravity.

[0099] When the water level in the rainwater collection tank 100 exceeds the inlet 201 but does not reach the outlet 102, the buoyancy trigger device 2212 drives the valve 2211 to gradually open as the liquid level rises, so that rainwater at a certain depth below the liquid level flows into the water storage and filtration tank 200 through the inlet 201, while floating objects remain at the upper part of the rainwater collection tank 100; the outlet 102 is normally open, and when the water level in the rainwater collection tank 100 reaches the outlet 102, the floating objects on the upper part of the liquid level are discharged through the outlet 102 along the municipal overflow pipe.

[0100] After rainwater enters the rainwater collection tank 100, suspended solids usually concentrate above the liquid surface. In step S1, the automatic opening and closing valve 221 closes due to gravity when the water level is below the inlet 201. When the water level is above the inlet 201 but below the outlet 102, the buoyancy trigger device 2212 drives the valve disc 2211 to gradually open, allowing rainwater with fewer suspended solids at the valve opening below the liquid surface to enter the water storage and filtration tank 200 through the valve opening. At the same time, when the water level reaches the outlet 102, the floating solids are discharged through the municipal overflow pipe, discarding the upper rainwater rich in floating solids. This achieves the initial filtration and discarding of the collected rainwater.

[0101] S2. Sedimentation and Secondary Filtration: After preliminary filtration in step S1, the rainwater enters the water storage and filtration tank 200 through inlet 201. In the supporting water storage layer 220, it undergoes collision-guided flow and sedimentation. The outlet of the dedicated outlet device 222 is held above outlet 202 and below the liquid surface in the water storage and filtration tank 200 by buoyancy device 223. This ensures that water with less suspended solids and sedimentation below the surface is consistently drawn, achieving secondary filtration. The water is then discharged through outlet 202 into the clear water storage tank 300 for recycling.

[0102] In step S2, by using the buoyancy device 223 of the dedicated water outlet device 222 to keep the pipe opening below the liquid surface of the water storage and filtration tank 200 and at a distance from the sedimentation layer 230, the upper layer of liquid that has just entered the water storage and filtration tank 200 and is rich in fine floating matter without effective sedimentation is avoided, as well as the lower layer of liquid that is close to the sedimentation layer 230 at the bottom of the water storage and filtration tank 200 and is rich in sediment. This allows for the continuous extraction of clean upper layer rainwater that has been settled and contains less fine floating matter, greatly improving the cleanliness and recycling efficiency of the rainwater.

[0103] Specifically, the rainwater harvesting method is set up in two steps: rainwater collection and preliminary filtration, and sedimentation and secondary filtration. The preliminary filtration is achieved by an automatic opening and closing valve 221 between the rainwater collection tank 100 and the water storage and filtration tank 200. At the same time, the secondary filtration is achieved by a dedicated water outlet device 222 between the water storage and filtration tank 200 and the clear water storage tank. This achieves graded filtration of rainwater, reduces the amount of floating matter and impurities in the rainwater entering subsequent stages, and ensures that the recovered water is clean rainwater with less suspended solids and sediment. This improves the problems of insufficient filtration and easy contamination of the recovered water by floating matter in traditional rainwater harvesting methods, improves the filtration effect and water quality of rainwater harvesting, and improves the efficiency and reliability of rainwater harvesting.

[0104] Example 3

[0105] like Figure 7 As shown, a cleaning method for a rainwater harvesting system as provided in Example 1 is provided, comprising the following steps:

[0106] A1. Flushing and maintenance: Regularly open the control valve of the flushing pipe 410 to spray high-pressure water onto the surface of the flushing support component 2200, the inner wall of the supporting water storage layer 220, and the floor or side wall of the sediment layer 230 through the nozzles of the flushing pipe 410, flushing residual sludge into the dredging ditch 510; By regularly opening the control valve of the flushing pipe 410, high-pressure water is sprayed onto the surface of the support component 2200, the pool wall, and the sediment layer 230 through the nozzles to flush sludge into the dredging ditch 510, thereby keeping the water storage filter pool 200 and the surface of the support component 2200 clean, improving the cleanliness of the rainwater harvesting system and its service life.

[0107] A2. Dredging Operation: When dredging is required, drain the water stored in the water storage and filtration tank 200, open the valve of the mud outlet 203, and extend the backwash dredging pipe 520 into the dredging ditch 510 through the mud outlet 203. Use municipal tap water as the backwash water source. After turning on the backwash water source, use the backwash force of the water flow to extend the backwash dredging pipe 520 into the innermost part of the dredging ditch 510. While using high-pressure water flow to flush the sludge from the inside out, manually pull the backwash dredging pipe to flush the sludge to the mud outlet 203, collect it through the basket 530, and transport it away. At the same time, turn on the sewage pump 110 to discharge the sewage in the rainwater collection tank 100. The backwash force of the water flow propels the sludge into the depth of the dredging ditch 510. At the same time, the multi-directional flushing of the high-pressure water flow and the gravity diversion generated by the height difference at the mud outlet 203 achieve complete collection of sludge, realizing the regular cleaning and centralized discharge of residual sludge in various parts of the system.

[0108] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

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