A three-layer filter sleeve type sewage filter assembly

Abstract

The present application relates to sewage treatment technical field, disclose a kind of three-layer filter material sleeve type sewage filter material assembly, including shell, center water inlet pipe, annular filter core and flow guide assembly, center water inlet pipe is fixed on the shell, one end is communicated with external sewer pipe, for introducing sewage;The shell is equipped with annular water inlet cavity with the bottom end of center water inlet pipe communication;Annular filter core is set in shell around the center water inlet pipe, so that sewage can be radially passed through annular filter core and outwardly discharged;Flow guide assembly is set in water inlet cavity, it includes flow guide piece that can be lifted along vertical direction and the elastic reset piece for providing vertical direction elastic reset force for flow guide piece.The present application can avoid lower filter material long-term sustained high load ahead of consolidation blockage, solve the problem that upper filter material is long-term idle, can balance filter material layer load, prolong the service life of overall filter material assembly.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a three-layer filter media sleeve-type wastewater filter media assembly. Background Technology

[0002] The treatment of decentralized domestic sewage and excrement in rural areas is a core challenge in the improvement of rural living environments. Traditional septic tank effluent generally suffers from high suspended solids content, high organic load, and drastic fluctuations in effluent flow rate, and direct discharge can easily cause pollution to surrounding water bodies and soil.

[0003] Currently, the mainstream technologies for terminal purification of septic tank effluent fall into two categories. One is bulk filter media, which is filled on-site with a single filter media. This has problems such as limited purification capabilities, easy clogging, difficulty in replacement, and inability to adapt to standardized renovations. The other is modular sleeve-type filter media components, which encapsulate multiple layers of filter media into a coaxial sleeve structure. This can be directly sleeved onto the outside of the effluent pipe, integrating multi-stage purification functions. It is easy to install and replace and is the mainstream development direction for terminal purification in rural toilet renovation projects.

[0004] Current three-layer sleeve-type filter media components are mostly static structures with fixed cavities and gravity-fed water intake. Wastewater flows upwards from the bottom due to gravity, and the filter layers filter sequentially from bottom to top. The inlet height and effective flow area are naturally determined by the inlet flow rate. However, this static inlet mode has two drawbacks, particularly considering the strong pulse, large fluctuations, and high intermittency characteristics of rural septic tank effluent: First, the filtration rate fluctuates greatly, resulting in poor stability of the effluent water quality. The filtration rate passively changes with the influent flow rate. When the flow rate is high instantaneously, the filtration rate exceeds the standard, which can easily lead to problems such as suspended solids penetrating the filter layer and the biofilm being washed away. When the flow rate is low, only a small amount of filter media in the lower layer participates in filtration, resulting in a significant reduction in purification efficiency.

[0005] Secondly, the filter media layer has an uneven load distribution, resulting in premature clogging of the lower layer and prolonged idleness of the upper layer. Wastewater consistently enters the filtration process from the lower layer, which bears the entire filtration load for extended periods, making it prone to caking and compaction. The middle and upper layers only participate in filtration briefly during peak flow rates, remaining idle most of the time. Clogging of the lower layer reduces the effective flow area, further increasing the filtration rate, creating a vicious cycle that causes the actual lifespan of the equipment to fall far short of design expectations. Summary of the Invention

[0006] The purpose of this invention is to provide a three-layer filter media sleeve-type sewage filter media assembly to solve the above-mentioned technical problems.

[0007] The present invention solves the above-mentioned technical problems through the following technical solutions: This invention provides a three-layer filter media sleeve-type wastewater filter media assembly, comprising: The outer casing has a water outlet at its bottom; A central water inlet pipe is fixed to the outer casing, with one end connected to an external sewage pipe for introducing sewage; the outer casing is provided with an annular water inlet cavity that is connected to the bottom end of the central water inlet pipe. An annular filter element is disposed inside the housing, surrounding the central inlet pipe, so that sewage can pass radially through the annular filter element to the outlet. A flow guiding assembly is disposed in the water inlet chamber. It includes a flow guiding component that can be raised and lowered in the vertical direction and an elastic reset component for providing a vertical elastic reset force to the flow guiding component. The outer periphery of the flow guiding component is slidably sealed with the inner wall of the annular filter element to divide the water inlet chamber into an upper water passage area and a lower isolation area. When the inlet flow rate increases, the water pressure in the water passage zone drives the guide to overcome the elastic restoring force and decrease, thereby increasing the effective inlet height of the annular filter element; when the inlet flow rate decreases, the guide rises under the action of the elastic restoring force, thereby decreasing the effective inlet height.

[0008] Furthermore, the flow guide includes a conical flow guide block and two guide rods. The two guide rods are vertically fixed to the bottom wall of the water inlet chamber. The bottom of the flow guide block is provided with two movable grooves, and the tops of the two guide rods are respectively slidably engaged with the two movable grooves.

[0009] Furthermore, each of the movable grooves is provided with a sealing ring at its lower end, and the inner ring surface of the sealing ring is in contact with the outer side of the corresponding guide rod.

[0010] Furthermore, each guide rod has a ball bearing evenly distributed around its circumference at its upper end, and the inner wall of the movable groove has a guide groove arranged along its height direction and corresponding to the ball bearing, and the ball bearing rolls in cooperation with the corresponding guide groove.

[0011] Furthermore, the elastic reset element is a spring respectively disposed in two movable slots, and the two ends of each spring abut against the top end of the corresponding guide rod and the inner top wall of the movable slot respectively.

[0012] Furthermore, the outer periphery of the flow guide block is detachably fitted with an elastic scraping lip, which fits tightly against the inner wall of the annular filter element to achieve a sliding seal.

[0013] Furthermore, the generatrix of the conical surface of the guide block is a curve, exhibiting a variable curvature shape with a steep upper section and a gentler lower section.

[0014] Furthermore, a base plate is detachably installed at the bottom of the outer shell, the top surface of the base plate forms the inner bottom wall of the water inlet cavity, the bottom ends of the two guide rods are fixed to the top surface of the base plate, and the top surface of the base plate is provided with an annular sediment groove.

[0015] Furthermore, the annular filter element includes a first filter element, a second filter element, and a third filter element arranged coaxially from the inside out. The first filter element, the second filter element, and the third filter element are all divided into multiple independent fan-shaped filter element units along the circumference. The upper and lower end faces and the inner and outer walls of each fan-shaped filter element unit are permeable grid structures.

[0016] Furthermore, the first filter element is composed of volcanic rock filter media, the second filter element is composed of columnar biochar filter media, and the third filter element is composed of iron-carbon composite filter media and modified zeolite particles.

[0017] The beneficial effects of this invention are as follows: This invention employs a liftable flow guide that automatically adjusts the effective inlet height of the annular filter element according to the inlet water flow rate. At high flow rates, the effective filtration area is increased, and the filtration rate is reduced to prevent suspended solids from penetrating the filter layer and the biofilm from being washed away due to excessive filtration rate, thus ensuring stable effluent quality. At low flow rates, the effective inlet height is reduced, allowing wastewater to be concentrated in a smaller area of ​​the filter media layer for filtration, preventing the filtration rate from being too low and reducing filtration efficiency. At the same time, different height areas of the entire annular filter element can take turns bearing the filtration load, preventing the lower filter media from being subjected to high loads for a long time and prematurely caking and blocking. This solves the problem of the upper filter media being idle for a long time, balances the load on the filter media layer, and extends the service life of the overall filter media assembly. Attached Figure Description

[0018] Figure 1 This is a first-view structural schematic diagram of the three-layer filter media sleeve-type sewage filter media assembly of the present invention; Figure 2 This is a second-view structural schematic diagram of the three-layer filter media sleeve-type sewage filter media assembly of the present invention; Figure 3 This is a schematic diagram of the internal structure of the three-layer filter media sleeve-type sewage filter media assembly of the present invention; Figure 4 This is the present invention. Figure 3 A magnified view of a portion of point A in the middle; Figure 5 This is a schematic diagram of the structure between the flow guiding component and the bottom plate in the three-layer filter media sleeve-type sewage filter media assembly of the present invention; Figure 6 This is a schematic diagram of the internal structure of the outer shell of the three-layer filter media sleeve-type sewage filter media assembly of the present invention; Figure 7 This is a schematic diagram of the installation and use of the three-layer filter media sleeve-type sewage filter media assembly of the present invention.

[0019] In the diagram: 100, outer casing; 101, water outlet; 102, water inlet chamber; 103, bottom plate; 104, sediment groove; 105, cover plate; 200, central water inlet pipe; 300, annular filter element; 301, first filter element; 302, second filter element; 303, third filter element; 400, flow guiding assembly; 401, flow guiding block; 402, guide rod; 403, movable groove; 404, sealing ring; 405, ball bearing; 406, guide groove; 407, spring; 408, scraper lip; 500, septic tank; 501, drain pipe. Detailed Implementation

[0020] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0021] Please refer to the following: Figures 1 to 4 A three-layer filter media sleeve-type sewage filter media assembly mainly includes a shell 100, a central water inlet pipe 200, an annular filter element 300, and a flow guiding component 400.

[0022] The outer casing 100 is a vertical cylindrical structure with multiple circumferentially distributed water outlets 101 near its outer edge at the bottom. A central water inlet pipe 200 is fixed to the top center of the outer casing 100, and its upper end is used to connect to an external drain pipe 501 (e.g., Figure 7 As shown, wastewater is introduced. A removable cover plate 105 is installed on the top of the housing 100. When replacing the filter element 300, the cover plate 105 can be removed for replacement. Inside the housing 100 and directly below the central inlet pipe 200, an annular inlet chamber 102 is formed, communicating with the bottom end of the central inlet pipe 200. The annular filter element 300 is arranged around the central inlet pipe 200 inside the housing 100, so that the wastewater flowing into the inlet chamber 102 can pass through the annular filter element 300 radially from the inside to the outside, complete the filtration and purification, and finally be discharged from the outlet 101 at the bottom.

[0023] The flow guiding assembly 400 is mainly used to adjust the effective filtration height of the annular filter element 300 participating in filtration within the inlet chamber 102. Specifically, the flow guiding assembly 400 includes a conical flow guiding block 401 that can be raised and lowered vertically, and an elastic reset member that provides an upward elastic reset force for it. The outer periphery of the flow guiding block 401 slides and seals with the innermost inner wall of the annular filter element 300, thereby dividing the entire inlet chamber 102 into an upper water passage area (the area where sewage can contact the filter element) and a lower isolation area (the area where sewage is blocked).

[0024] In addition, for the guide block 401, in this embodiment, its conical generatrix is ​​designed as a variable curvature curve with a steep upper part and a gentle lower part. This shape is beneficial to guide the water flow more evenly to the surrounding filter surface under different flow rates and submersion depths, avoiding local scouring.

[0025] A flexible scraping lip 408, such as a rubber lip, is detachably installed around the outer periphery of the guide block 401 using snap-fit ​​or other means. This scraping lip 408 fits tightly against the inner wall of the annular filter element 300, achieving both a sliding seal and, during each raising and lowering of the guide block 401, automatically scraping away sticky fecal matter and dirt adhering to the inner wall like a scraper. The scraped-off dirt settles to the bottom of the inlet chamber 102 under gravity, achieving continuous self-cleaning and preventing scale buildup on the inner wall that could lead to seal failure or poor water flow.

[0026] When flushing toilets generates a large instantaneous flow rate, the water pressure in the central inlet pipe 200 increases, increasing the pressure acting on the conical surface of the guide block 401. This drives the guide block 401 to move downwards against the elastic restoring force. At this time, the upper water passage area expands, meaning that the effective inlet height of the annular filter element 300 for sewage to pass through increases, thereby increasing the effective filtration area. Conversely, in the low-flow stage of minimal seepage, the water pressure decreases, and the guide block 401 rises upwards under the action of the elastic restoring force, shrinking the upper water passage area and consequently reducing the effective inlet height and filtration area. Through this dynamic matching, the flow area can be adjusted accordingly regardless of changes in the inlet flow rate, thereby stabilizing the filtration rate (the ratio of flow rate to area) within the designed optimal range and ensuring uniform and stable effluent quality.

[0027] Please combine Figures 3 to 5 To achieve the aforementioned smooth and reliable lifting action, the present invention provides the following specific structural solution: The flow guiding assembly 400 includes two vertically fixed guide rods 402. The bottom of the flow guiding block 401 has two corresponding movable slots 403. The tops of the two guide rods 402 are inserted into the two movable slots 403 respectively and slide in cooperation with them. This double-guide-rod 402 design, compared to a single-rod solution, provides strong anti-tilting torque, effectively preventing the flow guiding block 401 from tilting or jamming under the impact of eccentric water flow, and ensuring the long-term effectiveness of the outer peripheral sliding seal.

[0028] Preferably, in this embodiment, the elastic reset component consists of two springs 407, which are respectively installed inside the two movable slots 403. The two ends of each spring 407 abut against the top of the guide rod 402 and the inner top wall of the movable slot 403, respectively. When the guide block 401 descends, the movable slot 403 compresses the springs 407; when the water pressure decreases, the elastic force of the springs 407 pushes the guide block 401 back to its original position.

[0029] To further protect the spring 407 and ensure smooth sliding, a sealing ring 404 is provided at the opening at the lower end of each movable groove 403. The inner ring surface of the sealing ring 404 fits tightly against the outer wall of the guide rod 402, forming a tight barrier that effectively prevents sewage containing mud, sand, and fibers from entering the movable groove 403. This avoids dirt from clogging the spring 407 or wearing down the sliding surface, ensuring the long-term reliability of the mechanism.

[0030] To prevent the sealing effect of the sealing ring 404 from creating a closed space in the movable tank 403 during lifting and lowering, thus causing air cushion damping and hindering the smooth sliding of the guide block 401, an exhaust channel running through both ends of the guide rod 402 can be opened inside the guide rod 402. The upper end of this exhaust channel communicates with the inner cavity of the movable tank 403, while the lower end communicates with the isolation area at the bottom of the water inlet chamber 102. Thus, when the movable tank 403 moves up and down relative to the guide rod 402, air or trace amounts of moisture inside the tank can be freely discharged or drawn in through the exhaust channel, maintaining a dynamic balance of air pressure inside and outside the movable tank 403, eliminating the air cushion effect, and ensuring that the lifting and lowering of the guide block 401 is driven sensitively by water pressure and spring force with zero hysteresis. Simultaneously, the winding path of the exhaust channel effectively utilizes the principle of gravity settling, preventing impurities in external sewage from easily entering the interior of the movable tank 403 through this channel.

[0031] To further optimize the smoothness of the lifting process and prevent the guide block 401 from rotating circumferentially, several balls 405 are evenly embedded in the upper end of each guide rod 402 along its circumference. Simultaneously, a guide groove 406 extending along the height direction is formed on the inner wall of the movable groove 403, allowing the balls 405 to roll within the corresponding guide groove 406. This structure transforms the sliding friction between the guide rod 402 and the movable groove 403 into rolling friction, significantly reducing motion resistance and making the lifting action more sensitive and smooth.

[0032] To facilitate the collection and discharge of sediment generated during self-cleaning and heavy particles carried by the sewage, this embodiment further optimizes the above-mentioned aspects. Specifically, a base plate 103 is detachably installed at the bottom of the outer casing 100. In this embodiment, a threaded detachable method is preferred. The top surface of the base plate 103 forms the inner bottom wall of the water inlet chamber 102. The bottom ends of the two guide rods 402 are firmly fixed to this base plate 103. A ring-shaped sediment groove 104 is also formed on the top surface of the base plate 103 to receive and collect all fallen dirt. When thorough cleaning is required, the base plate 103 can be easily removed for rinsing. When the guide block 401 descends to its lowest position, it can also squeeze the water at the bottom to form a pulse water flow, which serves to flush the groove and assist in the discharge of sediment.

[0033] Please see Figure 3 and Figure 6 The annular filter element 300 is a three-layer composite structure consisting of a first filter element 301, a second filter element 302, and a third filter element 303 arranged coaxially from the inside out. The first filter element 301 is a physical filtration layer, preferably filled with high-pollution-holding capacity filter media such as volcanic rock, used to intercept large suspended solids; the second filter element 302 is a biofilm layer, preferably filled with high specific surface area filter media such as columnar biochar, used to enrich organic matter and ammonia nitrogen degraded by microorganisms; the third filter element 303 is a deep efficiency enhancement layer, preferably using a mixture of iron-carbon composite filter media and modified zeolite particles, used for micro-electrolytic degradation of difficult-to-treat pollutants and flocculation removal of phosphorus.

[0034] Each of the aforementioned annular filter elements is divided circumferentially into multiple independent sector-shaped filter element units. Each sector-shaped filter element unit is an independent, closed filter media chamber, with its upper and lower end faces and inner and outer walls being permeable grid structures, and containing corresponding filter media. Each unit is equipped with a lifting handle at the top. When the filter media in a certain area becomes clogged or fails, the operator does not need to disassemble the entire device from the pipeline; they only need to open the top cover 105 to individually pull out any sector-shaped filter element unit from the top vertically for cleaning or replacement. This makes maintenance more convenient and reduces the difficulty and cost of operation and maintenance.

[0035] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A three-layer filter media sleeve-type sewage filter media assembly, characterized in that, include: The outer casing has a water outlet at its bottom; A central water inlet pipe is fixed to the outer casing, with one end connected to an external sewage pipe for introducing sewage. The outer casing is provided with an annular water inlet cavity that communicates with the bottom end of the central water inlet pipe; An annular filter element is disposed inside the housing, surrounding the central inlet pipe, so that sewage can pass radially through the annular filter element to the outlet. A flow guiding assembly is disposed in the water inlet chamber. It includes a flow guiding component that can be raised and lowered in the vertical direction and an elastic reset component for providing a vertical elastic reset force to the flow guiding component. The outer periphery of the flow guiding component is slidably sealed with the inner wall of the annular filter element to divide the water inlet chamber into an upper water passage area and a lower isolation area. When the inlet flow rate increases, the water pressure in the water passage zone drives the guide to overcome the elastic restoring force and decrease, thereby increasing the effective inlet height of the annular filter element; when the inlet flow rate decreases, the guide rises under the action of the elastic restoring force, thereby decreasing the effective inlet height.

2. The three-layer filter media sleeve-type sewage filter media assembly according to claim 1, characterized in that, The flow guide includes a conical flow guide block and two guide rods. The two guide rods are vertically fixed to the bottom wall of the water inlet chamber. The bottom of the flow guide block is provided with two movable grooves, and the tops of the two guide rods are respectively slidably engaged with the two movable grooves.

3. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, Each of the movable grooves is provided with a sealing ring at its lower end, and the inner ring surface of the sealing ring is in contact with the outer side of the corresponding guide rod.

4. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, Each guide rod has balls evenly distributed around its upper end, and the inner wall of the movable groove has guide grooves arranged along its height direction and corresponding to the balls. The balls roll into the corresponding guide grooves.

5. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, The elastic reset component is a spring respectively disposed in two movable slots, with the two ends of each spring abutting against the top of the corresponding guide rod and the inner top wall of the movable slot respectively.

6. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, The outer periphery of the flow guide block is detachably fitted with an elastic scraping lip, which fits tightly against the inner wall of the annular filter element to achieve a sliding seal.

7. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, The generatrix of the conical surface of the guide block is a curve, with a variable curvature shape that is steep at the top and gentle at the bottom.

8. The three-layer filter media sleeve-type sewage filter media assembly according to claim 2, characterized in that, The bottom of the outer shell is detachably mounted with a base plate, the top surface of which forms the inner bottom wall of the water inlet cavity. The bottom ends of the two guide rods are fixed to the top surface of the base plate, and the top surface of the base plate is provided with an annular sediment groove.

9. The three-layer filter media sleeve-type sewage filter media assembly according to claim 1, characterized in that, The annular filter element includes a first filter element, a second filter element, and a third filter element arranged coaxially from the inside out. The first filter element, the second filter element, and the third filter element are all divided into multiple independent fan-shaped filter element units along the circumference. The upper and lower end faces and the inner and outer walls of each fan-shaped filter element unit are permeable grid structures.

10. The three-layer filter media sleeve-type sewage filter media assembly according to claim 9, characterized in that, The first filter element is made of volcanic rock filter media, the second filter element is made of columnar biochar filter media, and the third filter element is made of iron-carbon composite filter media and modified zeolite particles.

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