Backwashing device for filter tank of underground water purification plant

Abstract

The invention relates to an underground water purification plant filter backwashing device which comprises a cylindrical filter, wherein a tap water inlet pipe and a sewage drain pipe with a valve are arranged at the top of the cylindrical filter; a backwashing water inlet pipe is arranged in the middle of the side surface; and a tap water outlet pipe with a valve is arranged at the bottom. An elastic placing net is arranged in the middle, gaps are formed in the elastic placing net, and a filter material is placed on the gaps. And a rotating opening is formed in the middle of the elastic placing net. And the upper part of the rotating column is provided with a shifting rod, and the lower part of the rotating column is provided with an inclined arc-shaped fin. The filter material stirring device has the advantages that the filter material is stirred in the backwashing operation, the filtering efficiency is improved, the intervention of an external active driving mechanism is reduced, and the service life of the filter material and the filter material stirring device is prolonged.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a backwashing device for a filter bed in an underground water purification plant. Background Technology

[0002] Underground water purification plants have been widely used in municipal water purification projects due to their advantages such as saving surface space, low noise pollution, and suitability for construction in densely populated urban areas. As the core treatment unit of an underground water purification plant, the filter bed's filtration efficiency directly determines the quality of the effluent. However, after long-term operation, the filter media layer adsorbs a large amount of suspended impurities and pollutants, leading to increased filtration resistance and decreased filtration efficiency. Therefore, it is necessary to periodically clean the filter media layer using a backwashing device to restore the filter bed's filtration performance. Existing backwashing filter beds have weak filter media agitation capabilities, failing to effectively lift the purified water particles. Impurities trapped in the filter layer are difficult to remove, the filter media easily caking, filtration efficiency drops sharply, and the filter media's lifespan is shortened, affecting the effluent quality and the stability of the water plant's operation.

[0003] Existing technologies address these issues by automatically adjusting the backwashing time. This ensures the backwashing effect while reducing rinsing costs and resolving problems such as increased energy consumption, increased water consumption, and deterioration of effluent quality caused by fixed backwashing times. However, the filter media in existing backwashing structures has weak agitation capabilities, making it difficult to effectively lift the purified water particles. Impurities trapped in the filter layer are difficult to remove, the filter media is prone to caking, filtration efficiency drops sharply, and the service life of the filter media is shortened, affecting the effluent quality and the stability of water plant operation.

[0004] Existing technologies also include a solution that uses an active drive device to agitate the filter media. However, such solutions require the active drive device to be installed in the filter tank. As a workpiece in a water treatment environment, it is at great risk of corrosion and damage during long-term operation. Furthermore, for large-scale wastewater treatment, the energy consumption of the active drive is also extremely high, increasing the cost of water treatment and reducing energy utilization.

[0005] Therefore, how to design a backwashing device that can fully agitate the filter media during backwashing, reduce structural complexity, minimize the intervention of active driving force, and form a stable backwashing device in water treatment filter tanks is an urgent problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a backwashing device for filter beds in underground water purification plants, which can realize the stirring of filter media during backwashing operations, improve filtration efficiency, reduce the intervention of external active drive mechanisms, and extend the service life of filter media and filter media stirring device.

[0007] To achieve the above objectives, a backwashing device for an underground water purification plant filter is designed, comprising: a cylindrical filter body, with a tap water inlet pipe and a sewage outlet pipe at the top, a backwashing inlet pipe at the middle of the side, and a tap water outlet pipe at the bottom; a first valve on the sewage outlet pipe and a second valve on the tap water outlet pipe; an elastic placement net, horizontally positioned in the middle of the inner cavity of the cylindrical filter body, the elastic placement net having several gap channels, and several filter media stacked on the elastic placement net, with an outer dimension larger than the size of the gap channels; a support frame, horizontally positioned in the middle of the inner cavity of the cylindrical filter body and located below the elastic placement net, the support frame having a vertically penetrating rotating opening in the middle; a rotating column inserted into the vertical through hole for rotational engagement; several actuating rods arranged radially around the upper part of the rotating column and located in the gap between the elastic placement net and the support frame; and several arc-shaped fins arranged radially around the lower part of the rotating column and located below the support frame, all of the arc-shaped fins being inclined.

[0008] Preferably, the present invention further includes: the elastic placement net is made of a deformable elastic material, which deforms downward under the gravity of the filter material stacked above.

[0009] Preferably, the present invention further includes: the backwash inlet pipe is located on the same horizontal plane as the arc-shaped fins.

[0010] Preferably, the present invention further includes: a downwardly recessed disc-shaped space in the middle of the support frame, the disc-shaped space being located below the actuating rod and conforming to the circumferential trajectory of the actuating rod's rotation, and the limiting plate having several through holes for water flow.

[0011] Preferably, the present invention further includes: a radial groove is provided on the rotating column at the location where it cooperates with the support frame, and a radially protruding limiting disk is provided above the radial groove; the radial groove cooperates with the rotating opening, and the limiting disk forms a limiting block on the rotating opening, thereby forming a vertical limiting between the rotating column and the support frame.

[0012] Preferably, the present invention further includes: a spray pipe is provided at the backwash inlet pipe, the spray pipe is a conical structure with a hollow inner cavity, the small end face of the conical structure is connected and conductive with the backwash inlet pipe, the large end face of the conical structure is arranged facing the arc-shaped fins, and a number of rectifiers are also provided at the large end face of the conical structure.

[0013] Preferably, the present invention further includes: a rotating disk is provided at the lower part of the rotating column, and the arc-shaped fins are disposed on the radial circumference of the rotating disk.

[0014] Preferably, the present invention further includes: a sealing door is provided on the end face of the cylindrical filter body near the backwash inlet pipe, the sealing door is provided with a connecting port, the connecting port is connected to the backwash inlet pipe, and the sealing door is used to prevent liquid from overflowing.

[0015] Preferably, the present invention further includes: a ladder at the top of the cylindrical filter body for easy use by operators, and a base at the bottom of the cylindrical filter body to provide a supporting foundation.

[0016] Preferably, the present invention further includes: the elastic placement net making slight contact with the actuating rod, and the curvature and tilt angle of the arc-shaped fin being set to rotate at low speed when subjected to vertical impact and rotate at high speed when subjected to lateral impact.

[0017] Compared with the prior art, the advantages of this invention are: The backwashing device for the filter tank in this underground water purification plant, thanks to the structure of the actuating rods, allows the backwash liquid to enter the backwash inlet pipe through the inlet and be precisely sprayed onto the arc-shaped fins through the spray pipe. The arc-shaped fins are tilted, which greatly improves the rotation efficiency, causing the rotating disk and rotating column to rotate rapidly within the rotation port of the support frame. The limiting disk at the top of the rotating column rotates at high speed synchronously, and the multiple actuating rods evenly arranged on its outer periphery collide with the elastic placement net at high frequency and violently. The elastic placement net shakes up and down with the collision, violently turning over the water purification particles on the elastic placement net, which can effectively lift the filter media, thoroughly remove the impurities trapped in the filter layer, and prevent the filter media from caking due to the accumulation of impurities. This not only prevents a sudden drop in filtration efficiency but also reduces filter media wear, extends the service life of the filter media, ensures that the effluent water quality meets the standards, and guarantees the stability of the underground water purification plant's operation.

[0018] This underground water purification plant's filter backwashing device, thanks to its dual protective structure of a cylindrical filter body and a sealed door, effectively prevents liquid spillage from the underground water purification plant, avoiding environmental pollution and equipment damage. The reverse control of the first and second valves during the purification and backwashing processes completely isolates wastewater and purified water, preventing cross-contamination and further ensuring the quality of the effluent. Meanwhile, the steps at the top of the cylindrical filter body facilitate daily inspection, maintenance, and filter media replenishment by operators. The rotating column is prevented from falling off via a limit plate, and the coordination between the arc-shaped fins and the spray pipe requires no additional power, simplifying the device structure, reducing energy consumption and maintenance costs, and improving the stability and practicality of the device's operation. Attached Figure Description

[0019] Figure 1 This is a partial cross-sectional schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle; Figure 4 For the present invention Figure 1 Enlarged view of point B in the middle.

[0020] In the diagram: 1. Columnar filter body; 101. Base; 102. Steps; 103. Water inlet pipe; 104. Sewage outlet pipe; 105. First valve; 106. Water outlet pipe; 107. Second valve; 2. Sealing door; 201. Connecting port; 3. Support frame; 301. Rotating port; 302. Rotating column; 303. Limiting plate; 304. Actuating rod; 305. Rotating disc; 306. Arc-shaped fins; 4. Backwash inlet pipe; 401. Spray pipe; 402. Flexible placement net. Detailed Implementation

[0021] To make the purpose, principle and structure of the present invention clearer, the following description is provided in conjunction with the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 4 As shown, this invention provides a backwashing device for an underground water purification plant filter, comprising: a cylindrical filter body 1 for preventing liquid overflow from the underground water purification plant. The cylindrical filter body 1 is a horizontally arranged columnar structure. A base 101 is installed at the bottom of the cylindrical filter body 1, and a tap water outlet pipe 106 is connected to the bottom of the cylindrical filter body 1. A second valve 107 for controlling liquid flow is installed on the tap water outlet pipe 106. A ladder 102 for easy operation is installed at the top of the cylindrical filter body 1, and a tap water inlet pipe 103 is connected to the top of the cylindrical filter body 1. The tap water to be treated enters the cylindrical filter body 1 through the tap water inlet pipe 103, is filtered, and then discharged through the tap water outlet pipe 106. A sewage drain pipe 104 is connected to the top of the cylindrical filter body 1, and a first valve 105 is installed on the sewage drain pipe 104. Under water purification conditions, a backwashing inlet pipe 4 is also provided on the side of the cylindrical filter body 1. The device purifies raw water according to a preset process, with the first valve 105 closed and the second valve 107 open, effectively preventing pollution caused by the mixing of wastewater and purified water during the purification process. Tap water enters the cylindrical filter body 1 through the tap water inlet pipe 103. The cylindrical filter body 1 serves to contain liquid and prevent liquid overflow from the underground water purification plant. The base 101 provides stable support for the cylindrical filter body 1, and operators can inspect and maintain the top components of the device via the ladder 102. The raw water entering the cylindrical filter body 1 permeates downwards, flows through the filtration device to complete preliminary purification, and the purified tap water is finally discharged through the tap water outlet pipe 106. The second valve 107 can flexibly control the flow and closure of the liquid in the tap water outlet pipe 106.

[0023] A support frame 3 is provided inside the internal cavity of the cylindrical filter body 1. The support frame 3 is a plate-like structure, horizontally positioned in the middle of the internal cavity of the cylindrical filter body 1, and its periphery is fixedly connected to the inner sidewall of the cylindrical filter body 1. A rotation port 301 is provided in the middle of the support frame 3 to provide stable rotation space. The rotation port 301 is vertically positioned, has a circular cross-section, and is located at the connection center of the support frame 3, maximizing the rotation radius of the rotating component with the rotation port 301 as the rotation center.

[0024] A rotating column 302 is fitted into a rotating opening 301. The outer diameter of the rotating column 302 matches the inner diameter of the rotating opening 301, forming a rotatable fit with a slight clearance. A limiting disk 303 is located at the upper part of the rotating column 302, and a rotating disk 305 is located at the lower part. Both the limiting disk 303 and the rotating disk 305 are coaxially arranged with the rotating column 302, or radially arranged around the rotating column 302. The radii of both the limiting disk 303 and the rotating disk 305 are larger than the inner diameter of the rotating opening 301, forming a limiting barrier between them and the rotating opening 301, preventing the rotating column 302 from dislodging from the rotating opening 301 in the vertical direction. Furthermore, the design of the upper and lower positions of the limiting disk 303 and the rotating disk 305, as well as the radius difference design between them and the rotating column 302, results in a groove structure being formed between the limiting disk 303 and the rotating disk 305 in the radial direction of the rotating column 302. The groove width of the groove structure matches the thickness of the support frame 3, allowing the rotating column 302 to rotate laterally, but it is strictly limited in the vertical direction.

[0025] The elastic placement net 402 is disposed on the upper side of the support frame 3 and is also horizontally disposed within the cavity of the cylindrical filter body 1. The periphery of the elastic placement net 402 is also fixedly connected to the inner wall of the cylindrical filter body 1. Multiple actuating rods 304 are connected to the outer periphery of the limiting disk 303 to contact the bottom of the elastic placement net 402 to increase the agitation of the purified water particles. The actuating rods 304 are radially arranged around the outer periphery of the limiting disk 303 (i.e., radially surrounding the coaxial rotating column 302), and the actuating rods 304 and the elastic placement net 402 are in slight contact. A number of clean water granular materials are placed on the elastic placement net 402. The clean water granular materials (i.e. filter media) are several dispersed monomers with the same structure. The elastic placement net 402 is provided with several flow gaps. The outer dimensions of the clean water granular materials are all larger than the dimensions of the flow gaps of the elastic placement net 402, so that the clean water granular materials and the flow gaps of the elastic placement net 402 form a limiting barrier. The clean water granular materials carried on the elastic placement net 402 will not flow into the lower part through the flow gaps. However, the liquid in the columnar filter body 1 can flow into the flow gaps of the elastic placement net 402 through the gaps between the clean water granular materials, and finally flow into the lower cavity of the columnar filter body 1.

[0026] Multiple arc-shaped fins 306 are mounted on the outer periphery of the rotating disk 305 to contact the liquid and drive the rotating column 302 to rotate. These arc-shaped fins 306 are inclined to improve rotational efficiency. Each arc-shaped fin 306 is an arc-shaped blade with varying curvature; its projected area in the vertical direction is smaller, while its projected area in the horizontal direction is larger. This means that when fluid of the same impact force impacts the arc-shaped fins 306 from above and the side, the contact area between the lateral fluid and the arc-shaped fins 306 is larger than that between the upper fluid and the lower fluid, resulting in a more significant force effect. When a vertical water flow is generated, the arc-shaped fins 306 drive the rotating column 302 to rotate slowly; when a horizontal lateral water flow is generated, the arc-shaped fins 306 drive the rotating column 302 to rotate faster. This provides superior backwashing conditions for the backwash water flow of the subsequently side-mounted backwash inlet pipe 4. Specifically, in the normal water purification process, the water flows vertically from above to the arc-shaped fins 306. This water is the tap water that needs to be purified. It only needs to be properly "stirred" to prevent the filter media from becoming clogged. Excessive "stirring" will cause impurities on the surface of the filter media to fall off and be discharged with the treated tap water, affecting the quality of the filtered tap water. When backwashing is required, the columnar filter body 1 is a fully enclosed internal circulation system, and no tap water will be discharged at this time. Therefore, it is necessary to maximize the effect of the backwash water discharged from the backwash inlet pipe 4. The special design of the arc-shaped fins 306 makes them rotate at high speed during backwashing, driving the agitator 304 to make high-frequency collision impact vibration on the elastic placement net 402. The filter media can be maximally and intensely agitated, so that impurities on the surface of the filter media can be removed as much as possible. After being washed, the backwash wastewater full of impurities will be discharged from the separate wastewater drain pipe 104. The backwash water not only provides a flushing water flow to carry away impurities, but also converts its water flow impact force into agitation force on the filter media, thus enhancing the effect of the backwash water.

[0027] Specifically, the elastic placement net 402 is made of an elastic deformable material. Its design ensures that after production and assembly, the lower surface of the elastic placement net 402 will make slight contact with the upper surface of the actuating rod 304. Furthermore, when clean water particles are piled onto the elastic placement net 402, due to its elastic deformable characteristics, the elastic placement net 402 will also bend downwards under the gravity of the piled filter material, deepening the contact between the actuating rod 304 and the lower surface of the elastic placement net 402. Thus, when the actuating rod 304 rotates with the rotating column 302, the radially arranged actuating rods 304... It will continuously collide with the lower side of the elastic placement net 402. Each time it collides, the elastic placement net 402 will deform upward once, and the impact force generated by the collision will be transmitted to the water purification granular material piled above through the elastic placement net 402. This causes the water purification granular material to jump due to the continuous periodic deformation of the elastic placement net 402 and the transmission of impact force. This allows the originally statically stacked water purification granular material to continuously generate a loose "jumping" movement relationship, preventing the flow gap of the water purification granular material from being blocked due to long-term static work and reducing filtration efficiency. Furthermore, after prolonged water purification operations, a large amount of impurities are adsorbed on the surface of the water purification granules. At this time, the upper part of the elastic placement net 402 not only needs to bear the weight of the water purification granules but also the weight of the adsorbed impurities. The increased weight causes the elastic placement net 402 to deform downward under gravity, which means that the contact between the elastic placement net 402 and the agitator 304 is also deepened. The area of ​​force of the collision between the agitator 304 and the elastic placement net 402 with each rotation is also increased, and the collision effect is also strengthened. The "stirring" action of the elastic placement net 402 on the water purification granules is also increased, forming a self-cleaning system that does not require human monitoring and automatically adjusts the "stirring" force. Under this system design, the longer the working time, the more impurities adsorbed by the water purification granules, and the smaller the filtration gap between the water purification granules, the greater the "tumbling" stroke of the elastic placement net 402. After being "tumbled," some impurities fall off the water purification granules, reducing their weight. The degree of deformation of the elastic placement net 402 downward under gravity decreases, and the "tumbling" stroke of the elastic placement net 402 becomes smaller, forming an adaptive dynamic adjustment. This avoids stress damage to components caused by long-term large-area contact and impact between the elastic placement net 402 and the actuating rod 304.

[0028] A sealing door 2 is installed on the side of the cylindrical filter body 1 to prevent liquid overflow. This sealing door 2 is an openable structure, and its placement on the side of the cylindrical filter body 1 is a deliberate design. By simply opening the sealing surface 2, one can simultaneously access the inner cavity of the cylindrical filter body 1, which is divided into upper and lower chambers by the support frame 3 and the elastic placement net 402. This allows for cleaning of the upper and lower inner cavities of the cylindrical filter body 1 and convenient replacement of the filter media. The side of the sealing door 2 is also provided with a connecting port 201 for backwash liquid to enter. One end of the connecting port 201, closer to the inside of the cylindrical filter body 1, is connected to a backwash water inlet pipe 4. The end of the backwash water inlet pipe 4, away from the connecting port 201, is equipped with a spray pipe 401 for driving the rotation of the arc-shaped fins 306. Preferably, the spray pipe 401 is a conical structure with a through cavity in the middle. The small end face of the conical structure is connected to the backwash inlet pipe 4, and the large end face of the conical structure faces the arc-shaped fins 306. Several guide plates are also provided at the large end face. The conical structure further increases the flow velocity of the high-pressure water. When the backwash liquid enters the backwash inlet pipe 4 from the inlet 201, it flows through the conical structure of the spray pipe 401. Due to the rapid expansion of the flow cross-sectional area, according to Bernoulli's principle, the fluid can obtain higher static pressure and lower momentum when entering a wide flow channel from a narrow channel. This makes it easier for the fluid to adhere to the curved surface structure of the arc-shaped fins 306, and the rotation of the arc-shaped fins 306 is more stable. Furthermore, the impact reaction force between the actuating rod 304 and the elastic placement net 402 generated by the backwash water can absorb part of the high static pressure of the fluid, preventing the rotation of the rotating column 302 from having uneven movement under the action of positive and negative impact forces. Meanwhile, several guide vanes at the large end face of the conical structure rectify and guide the high-speed water flow, causing the water to be sprayed onto the surface of the arc-shaped fins 306 at a specific angle and direction. The conical structure design of the spray pipe 401 also causes the water flow to form a fan-shaped diffusion surface after being sprayed out, expanding the impact coverage of the backwash water and increasing the interaction area between the backwash water and the arc-shaped fins 306.

[0029] During the water purification process, the natural flow of water causes multiple arc-shaped fins 306 on the outer periphery of the rotating disc 305 to rotate slightly. This rotation intensity is carefully controlled to effectively prevent excessive disturbance to the water purification filter media on the elastic placement net 402, thus avoiding negative filtration effects. Although the arc-shaped fins 306 are angled to improve rotation efficiency during backwashing, under water purification conditions, the slight rotation only causes the rotating column 302 to rotate slowly within the rotation port 301 of the support frame 3. The limiting disc 303, installed on top of the rotating column 302, prevents the rotating column 302 from detaching from the rotation port 301 and rotates slowly synchronously with the rotating column 302. Multiple actuating rods 304, evenly arranged circumferentially around the limiting disc 303, only cause slight disturbance, which neither affects the filtration effect of the water purification filter media nor causes slight clumping of the water purification particles, ensuring that the water purification particles maintain good filtration and adsorption effects, thus guaranteeing water purification efficiency and quality.

[0030] When the device needs to perform backwashing to remove impurities adsorbed on the surface of the purified water particles, the valve status is reversed compared to the water purification operation, i.e., the first valve 105 is open and the second valve 107 is closed, to prevent wastewater generated during backwashing from entering the tap water outlet pipe 106 and causing secondary pollution. The backwash liquid enters through the inlet 201 on the side of the sealing door 2. The sealing door 2 can prevent liquid from overflowing from the column filter body 1 and facilitates later inspection and maintenance. The backwash liquid flows into the backwash inlet pipe 4 through the inlet 201 and is then sprayed out through the spray pipe 401 at the end of the backwash inlet pipe 4. The backwash liquid sprayed from the spray pipe 401 acts directly on the arc-shaped fins 306, further pushing the rotating column 302 to rotate faster, causing the agitator 304 to more violently agitate the water purification particles on the elastic placement net 402, so that the impurities on the surface of the water purification particles are thoroughly washed away and removed. The wastewater generated by backwashing is discharged through the wastewater drain pipe 104 at the top of the column filter body 1. The first valve 105 can control the flow rate and opening / closing of the wastewater discharge. After the backwashing is completed, the device switches back to the water purification mode and resumes normal water purification operation.

[0031] To ensure the long-term stable operation of the backwashing device in the underground water purification plant and mitigate the impact of environmental factors, maintenance, sealing, materials, component compatibility, and personnel operation on its normal operation, targeted prevention and control measures must be implemented based on the structural characteristics of the device. This will comprehensively guarantee the filtration and backwashing effects of the device and extend its service life. Regarding the environment, underground water purification plants experience high humidity and are prone to accumulating corrosive gases and impurities. Regular ventilation and dehumidification of the surrounding environment are necessary to control the humidity within a reasonable range and prevent humid gases from corroding the column filter body 1, base 101, and all metal components. Simultaneously, regular cleaning of debris around the device is required to prevent blockage of the tap water inlet pipe 103, sewage drain pipe 104, and backwash inlet pipe 4, thus avoiding impacts on device operation due to poor water intake and drainage. Furthermore, effective pollution prevention measures must be implemented to prevent external pollutants from entering the column filter body 1 and contaminating the water purification media and effluent quality.

[0032] In terms of maintenance, a regular inspection and maintenance mechanism should be established to avoid operational failures caused by component aging and dirt accumulation. Regularly check the water purification granular material on the flexible placement net 402, replenish worn filter media in a timely manner, and replace clumped or ineffective filter media to prevent insufficient or ineffective filter media from affecting filtration efficiency. Regularly clean the impurities accumulated on the surfaces of the agitator 304 and arc-shaped fins 306 to prevent impurities from adhering and reducing the agitation effect and rotation efficiency. At the same time, check the rotation flexibility of the rotating column 302 within the rotating port 301, and add lubricating oil regularly to reduce rotational friction. Regularly check the opening and closing flexibility of the first valve 105 and the second valve 107, and promptly repair or replace valves that are not sealing properly or are malfunctioning, ensuring accurate valve switching between water purification and backwashing operations to prevent leakage and cross-contamination. In addition, regularly check the sturdiness of the ladder 102, and promptly reinforce loose parts to ensure the safety of operators.

[0033] Regarding sealing, it is crucial to ensure the sealing performance of all connections and protective components to prevent liquid spillage and impurity infiltration. Regularly check the sealing performance of the sealing door 2, promptly replace aged or damaged seals, and ensure that the sealing door 2 fits tightly against the column filter body 1 when closed to prevent liquid spillage from the column filter body 1. Inspect the connections between the inlet pipe 201 and the backwash inlet pipe 4, tap water inlet pipe 103, sewage drain pipe 104, and the column filter body 1, reinforce the connections, and replace damaged gaskets to prevent leakage of backwash liquid, clean water, or sewage. This prevents water waste, avoids leakage that could corrode surrounding components, and prevents external impurities from seeping into the device through the connections, affecting component fit.

[0034] Regarding the materials and component matching, the materials of each component of the device must be suitable for the working environment of the underground water purification plant. Corrosion-resistant, high-strength, and wear-resistant materials should be given priority in the production of core components such as the column filter body 1, rotating column 302, actuating rod 304, and arc-shaped fins 306 to avoid damage to components due to rapid material corrosion and wear. During installation, ensure that each component is precisely matched, the support frame 3 is firmly fixed, the rotating port 301 and the rotating column 302 are sized to match, the limit plate 303 is installed in place to prevent the rotating column 302 from detaching from the rotating port 301, the actuating rods 304 are evenly distributed and make precise contact with the bottom of the elastic placement net 402, and the water spray pipe 401 is aligned with the arc-shaped fins 306 to ensure that the arc-shaped fins 306 can be effectively driven to rotate during backwashing, ensuring the agitation effect of the filter media. Regularly check the connection between the rotating plate 305 and the rotating column 302 and the arc-shaped fins 306, and promptly reinforce any loose components to prevent them from falling off and affecting the operation of the device.

[0035] Regarding personnel operation, standardized operating procedures must be implemented to prevent equipment malfunctions caused by human error. Operators must undergo professional training, be proficient in the working principles of the equipment, the functions of each component, and operating procedures, and clearly understand the valve operation requirements under both purified water and backwashing conditions. Incorrect switching between the first valve 105 and the second valve 107 must be avoided to prevent cross-contamination between wastewater and purified water. During operation, avoid forcefully opening or closing sealing doors 2, valves, and other components to prevent damage. When performing filter media replacement or component maintenance, relevant valves must be closed first to cut off the inlet water and backwash liquid sources. Safety precautions must be taken to prevent liquid spillage, personnel injury, or component damage due to improper operation. Furthermore, operators must maintain accurate operation records, promptly identify and report any abnormalities during equipment operation, and prevent minor malfunctions from escalating and affecting normal equipment operation, thus ensuring the stable and efficient operation of the equipment.

[0036] Working Principle: In use, the backwashing device for the filter tank of this underground water purification plant, with the base 101 providing stable support, allows operators to maintain it via the ladder 102. During water purification, the first valve 105 is closed and the second valve 107 is open to prevent contamination. Tap water enters the cylindrical filter body 1 through the tap water inlet pipe 103, permeating the purified water particles on the elastically placed mesh 402 at the top of the limiting disc 303, completing the filtration and adsorption of impurities. At this time, the natural water flow only slightly rotates the arc-shaped fins 306 on the outer periphery of the rotating disc 305 (the inclined arc-shaped fins 306 do not play a high-efficiency rotational role at this time). The rotating column 302 rotates slowly within the rotating port 301 of the support frame 3. The limiting disc 303 prevents the rotating column 302 from falling off, and the outer peripheral agitator 304 slightly agitates the filter media, preventing slight clumping without affecting filtration. After purification, the tap water is discharged through the tap water outlet pipe 106. During backwashing, the first valve 105 is opened and the second valve 107 is closed. The backwash liquid enters the backwash inlet pipe 4 through the inlet 201 of the sealing door 2 and is sprayed out by the spray pipe 401, which pushes the arc-shaped fins 306 to rotate rapidly, causing the rotating column 302 to rotate faster. The agitator 304 violently agitates the filter media, peeling off surface impurities. Wastewater accumulates in the column filter body 1, forming repeated rinsing. Finally, when the total amount of backwash water is greater than the volume of the column filter body 1, the wastewater will overflow upwards and be discharged through the wastewater drain pipe 104. Since the spray pipe 401 is located in the middle of the side of the column filter body 1 (flush with the arc-shaped fins 306), the impurities peeled off from the purified water particles will not settle downwards but will be continuously impacted upwards by the backwash water and finally discharged through the wastewater drain pipe 104 at the top by overflowing upwards. After the backwashing is completed, the device switches back to the purified water mode.

[0037] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the invention, based on the technical solution and concept of the invention, should be covered within the scope of protection of the invention.

Claims

1. A backwashing device for a filter tank in an underground water purification plant, characterized in that, include: The cylindrical filter body is provided with a tap water inlet pipe and a sewage outlet pipe at the top, a backwash inlet pipe in the middle of the side, and a tap water outlet pipe at the bottom. The sewage outlet pipe is provided with a first valve, and the tap water outlet pipe is provided with a second valve. An elastic placement net is horizontally positioned in the middle of the inner cavity of the cylindrical filter body. The elastic placement net has several gap channels, and several filter media are stacked on the elastic placement net, with the outer dimensions being larger than the size of the gap channels. The support frame is horizontally arranged in the middle of the inner cavity of the cylindrical filter body and located below the elastic placement net. The support frame has a vertically penetrating rotating opening in the middle. A rotating column is inserted into a vertical through hole for rotational engagement; Several actuating rods are arranged radially around the upper part of the rotating column and are located within the gap between the elastic placement net and the support frame. Several arc-shaped fins are arranged around the radial periphery of the lower part of the rotating column and located below the support frame, and all the arc-shaped fins are arranged at an angle.

2. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The elastic placement net is made of a deformable elastic material and deforms downward under the gravity of the filter media stacked above.

3. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The backwash inlet pipe is located on the same horizontal plane as the arc-shaped fins.

4. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The support frame has a downward-recessed disc-shaped space in the middle, which is located below the actuating rod and is similar in shape to the circumferential trajectory of the actuating rod. The limiting plate has several through holes for water to flow through.

5. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The rotating column has a radial groove at the point where it mates with the support frame, and a radially protruding limiting disc is provided above the radial groove; The radial groove engages with the rotating opening, and the limiting disc forms a limiting block on the rotating opening, thus creating a vertical limit between the rotating column and the support frame.

6. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, A spray pipe is provided at the backwash inlet pipe. The spray pipe is a conical structure with a hollow inner cavity. The small end face of the conical structure is connected to the backwash inlet pipe. The large end face of the conical structure is set towards the arc-shaped fins. Several rectifiers are also provided at the large end face of the conical structure.

7. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The lower part of the rotating column is also provided with a rotating disk, and the arc-shaped fins are arranged on the radial circumference of the rotating disk.

8. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The cylindrical filter body has a sealing door on the end face near the backwash inlet pipe. The sealing door has a connecting port, which is connected to the backwash inlet pipe for conduction. The sealing door is used to prevent liquid from overflowing.

9. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The top of the cylindrical filter body is provided with a ladder for easy access by operators, and the bottom of the cylindrical filter body is provided with a base to provide a supporting foundation.

10. The backwashing device for a filter tank in an underground water purification plant as described in claim 1, characterized in that, The elastic placement net makes slight contact with the actuating rod, and the curvature and tilt angle of the arc-shaped fin are set to rotate at low speed when subjected to vertical impact and rotate at high speed when subjected to lateral impact.

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