Gravity water supply filtration device and filtration control method

Abstract

This invention discloses a gravity-fed water filtration device and filtration control method, relating to the field of water purifiers. It includes a tank, a partition plate separating upper and lower chambers, a filter, a water collection tank, an exhaust return channel, a liquid level sensor, a miniature air pump, and a controller. The air inlet of the miniature air pump is connected to the top of the lower chamber, and the air outlet is connected to the outer wall of the filter via the exhaust return channel. The controller is configured to execute a corresponding control mode based on the liquid level. This invention has the following advantages: at high water levels, it actively extracts compressed air from the lower chamber to eliminate air lock and maintain continuous filtration; at low water levels, it converts the extracted air into pulse bubbles to perform in-situ physical flushing of the filter's outer wall, effectively alleviating filter clogging and ensuring long-term stable water output.

Description

Technical Field

[0001] This invention relates to the field of water purifiers, and in particular to a gravity-fed water filtration device and filtration control method. Background Technology

[0002] In the field of drinking water purification, gravity-fed water filtration devices are widely used due to their compact structure and lack of external power supply. These devices typically consist of a raw water chamber and a purified water chamber stacked vertically. Raw water permeates through the filter element into the purified water chamber under its own gravity for static storage. However, within the closed purified water chamber, as the water level rises, the air at the top is continuously compressed. Since the hydrostatic pressure generated by gravity is relatively limited, the reverse air pressure created by the compressed air quickly balances the hydrostatic pressure above, causing the filtration process to completely stop, leaving users without water when they turn on the tap. Summary of the Invention

[0003] The purpose of this invention is to provide a gravity-fed water filtration device, which has the advantages of automatically depressurizing to break air resistance, ensuring continuous filtration of raw water, and performing physical flushing with air bubbles to extend the life of the filter element.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A gravity-fed water filtration device, comprising: Barrel body; A filter canister is installed inside the canister. The bottom wall of the filter canister is a partition plate that divides the internal space of the canister into an upper cavity and a lower cavity. The partition plate has a downward-extending inverted conical bottom wall in the center. The filter is fixedly connected to the center of the inverted conical bottom wall, and the internal space of the filter is in communication with the lower cavity; A water collection tank is installed in the lower cavity; A water outlet pipe connects the water collection tank to the outside of the barrel; and, An exhaust return channel is provided, the lower port of which is connected to the lower cavity, and the upper port of which passes upward through the partition plate and opens at the inverted conical bottom wall between the outer wall of the filter and the inner wall of the filter barrel; a one-way water-blocking and air-permeable valve is provided on the exhaust return channel. A liquid level sensor is suitable for detecting the liquid level of purified water in the water collection tank; and has a first position at a high point and a second position at a low point. A miniature air pump and controller, wherein the air inlet of the miniature air pump is connected to the top space of the lower cavity, and the air outlet is sealed and connected to the lower port of the exhaust return channel; The controller is electrically connected to the micro air pump and the liquid level sensor, and the controller is configured to have a pressure relief working mode in response to a first position and a self-cleaning working mode in response to a second position.

[0005] As a further feature, an annular air distribution groove is provided at the junction of the inverted conical bottom wall and the outer wall of the filter; The annular air distribution groove surrounds the filter circumferentially, with the groove opening facing obliquely upwards towards the outer wall of the filter, and the upper port of the exhaust return channel connecting to the bottom side of the annular air distribution groove.

[0006] Further, a buoyancy ring is included; the density of the buoyancy ring is less than that of water, and the buoyancy ring can be slidably fitted around the filter in the vertical direction. The inner wall of the buoyancy ring has a conical structure that is wider at the top and narrower at the bottom. An annular flow section is formed between the inner wall of the buoyancy ring and the outer wall of the filter, so that the buoyancy ring moves down synchronously as the water level in the upper cavity drops.

[0007] Furthermore, the vertical projection of the inner wall of the buoyancy ring at least partially covers the upper port of the exhaust return channel.

[0008] Furthermore, the buoyancy ring is injection molded from food-grade PP or PE material with a material density of 0.89-0.96 g / cm³.

[0009] Further, the buoyancy ring includes a first half-ring and a second half-ring; the first half-ring and the second half-ring are connected by a tenon and mortise joint.

[0010] Further, a support base is also included, wherein the top surface of the support base and the bottom surface of the barrel are rotatably locked by a locking protrusion and a guide groove.

[0011] Furthermore, conductive contacts are provided on the protrusion and the guide groove, so that the protrusion is energized when it enters the guide groove and de-energized when it exits the guide groove.

[0012] Furthermore, the bucket is equipped with a faucet, and the water outlet pipe has a downward-bending water storage section.

[0013] Another object of the present invention is to provide a control method for a gravity-fed water filtration device, comprising the following steps: S1. Real-time acquisition of the water level height signal in the water collection tank detected by the liquid level sensor; S2. Determine the water level status based on the liquid level height signal and execute the corresponding control mode, wherein, When the liquid level is detected to be at the highest point, the pressure relief mode is executed: the micro air pump is started to extract the compressed air generated in the lower cavity due to the rise of the purified water level, and actively exhausts and relieves pressure in the upper cavity through the exhaust return channel to eliminate air resistance in the lower cavity and maintain continuous filtration of the filter. When the liquid level is detected to be at the second position where it is at its lowest point, the self-cleaning working mode is executed: the micro air pump is controlled to work in a pulse form, and the extracted air is forced into the exhaust return channel, so that the air is intermittently squeezed out at the upper port and forms pulse bubbles. The buoyancy of the pulse bubbles is used to rise against the current along the outer wall of the filter to perform flushing.

[0014] In summary, the present invention has the following beneficial effects: First, during gravity filtration, as the water level in the collection tank rises, the air at the top of the lower chamber is continuously compressed, creating an air pressure opposite to the filtration direction. This air pressure hinders water flow from passing through the filter. When the level sensor detects that the water level has reached its highest point, the controller activates the micro-pump to enter pressure relief mode. The micro-pump extracts compressed air from the top space of the lower chamber and discharges it through the exhaust return channel, thereby reducing the air pressure inside the lower chamber. This transforms the passive pressure-bearing state of the lower chamber into an active air extraction and pressure relief state, overcoming the filtration stagnation caused by the pressure balance between the upper and lower chambers in traditional gravity filtration devices, allowing the gravity permeation process to proceed stably and continuously.

[0015] Furthermore, when the level sensor detects that the water level is at the second low position, the controller instructs the micro air pump to enter self-cleaning mode. The micro air pump delivers air from the lower chamber to the top of the partition plate via the exhaust return channel. Because the upper port of the exhaust return channel opens at the inverted conical bottom wall between the outer wall of the filter and the inner wall of the filter barrel, the discharged gas rises against the flow of water along the outer surface of the filter. The rising airflow generates fluid friction and dynamic scouring on the outer wall of the filter, causing impurities attached to the filter surface to fall off, alleviating physical clogging of the filter, and helping to maintain the filter's flow rate. At the same time, the structural feature of the inverted conical bottom wall helps guide the rising airflow to fit more closely to the outer wall of the filter, improving scouring efficiency. The one-way water-blocking and venting valve installed on the exhaust return channel, while ensuring smooth gas discharge, blocks the path of unfiltered raw water in the upper chamber flowing back down through the exhaust channel, maintaining the independence and safety of the purified water environment in the lower chamber.

[0016] Secondly, this invention further optimizes the self-cleaning hydrodynamic structure of the device by adding an annular air distribution groove at the junction of the inverted conical bottom wall and the outer wall of the filter. In conventional single-point exhaust structures, bubbles can usually only rise vertically along a single path, resulting in only a local area of ​​the outer wall of the filter being washed by gas-liquid mixing. The remaining circumferential areas not covered by bubbles still face the risk of impurity adhesion and micropore blockage, thus limiting the overall self-cleaning efficiency.

[0017] The upper end of the exhaust return channel connects to the bottom of the annular air distribution groove, allowing the extracted air to be buffered and reorganized within the annular channel before formally entering the upper chamber water. The groove structure surrounding the filter forces the incoming air to physically diffuse in a circumferential direction, transforming the originally single-point incoming airflow into a uniformly distributed annular air source. Simultaneously, the opening of the annular air distribution groove opens obliquely upwards towards the outer wall of the filter, a specific orientation that spatially guides the gas about to overflow. Under this upward physical constraint, the gas detaches from the opening, and the resulting bubble clusters follow the opening direction, concentrating and tightly adhering to the perimeter of the filter's outer wall as they slide upwards. This structural guidance constrains the disorderly dispersion of bubbles towards the surrounding water, allowing the bubbles to be released uniformly along the filter's circumference, forming a rising bubble curtain that surrounds the filter's outer wall. It eliminates the cleaning blind spots caused by single-point flushing, ensuring that all parts of the filter's circumferential surface are subjected to continuous and uniform fluid friction and physical flushing, improving the comprehensiveness of deposit removal, and thus more stably maintaining the overall water flow rate of the filter.

[0018] Third, this invention further enhances the self-cleaning kinetic energy and cleaning coverage of the filter by adding a buoyancy ring fitted around the filter. In conventional bubble flushing processes, freely rising bubbles tend to lose velocity as the distance increases in a wide body of water, making it difficult to effectively remove some stubborn impurities.

[0019] The density of the buoyancy ring is limited to less than that of water, allowing the component to float on the water surface due to buoyancy. The buoyancy ring can move vertically and synchronously downwards as the water level in the upper chamber drops, without relying on any external power components, solely through the physical balance of its own weight and the buoyancy of the water. Further cleaning of the outer ring of the filter at higher elevations is then performed.

[0020] Meanwhile, the inner wall of the buoyancy ring has a conical structure that is wider at the top and narrower at the bottom. This specific shape forms an annular flow cross-section that gradually narrows from bottom to top between the inner wall of the buoyancy ring and the outer wall of the filter. When the bubbles discharged from below float upward and pass through the flow cross-section, the contracting physical space will compress the gas-liquid mixture, causing a local surge in the flow velocity of the fluid as it passes through the slit, and generating a more intense mixing turbulence within the confined space.

[0021] During operation, as the water level in the upper chamber gradually decreases, the buoyancy ring moves downwards synchronously. The aforementioned localized high-intensity turbulent scouring area formed by the annular flow cross-section is located in the lower accumulation zone, significantly enhancing the fluid friction and peeling force on the outer wall of the filter's lower accumulation zone. This effectively improves the filter's overall self-cleaning efficiency and long-term flux stability.

[0022] Fourth, during routine maintenance and cleaning or in the event of an accidental collision or tipping, the barrel body is subjected to external force, causing the locking tab to disengage from the guide groove. The moment the mechanical connection loses its restraint, the conductive contacts simultaneously separate and the underlying low-voltage power supply circuit is cut off. This allows the device to forcibly disconnect power in abnormal assembly positions or under drop conditions, improving electrical safety.

[0023] Fifth, this invention incorporates a downward-bending water storage section along the outlet pipe path. When the device uses pneumatic components to adjust the air pressure in the lower chamber to assist filtration, it is necessary to prevent external air pressure from interfering with the internal fluid state. When the faucet is closed and water flow stops, due to the downward-bending pipe structure, a small amount of purified water will remain in the low-lying area of ​​the storage section by gravity. This remaining liquid fills the cross-section inside the pipe, forming a natural physical liquid seal barrier, blocking the path of external air flowing back into the lower chamber through the faucet. Without adding moving parts such as one-way valves, this effectively prevents reverse airflow leakage from damaging the air resistance regulation environment, and also isolates the potential for suspended dust or impurities in the external environment to contaminate the internal water quality through the drain pipe. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the gravity-fed water filtration device of the present invention.

[0025] Figure 2 This is a top view schematic diagram of the gravity-fed water filtration device of the present invention.

[0026] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along line AA in the middle.

[0027] Figure 4 for Figure 3 A magnified schematic diagram of the structure at point A in the middle.

[0028] In the diagram: 10. Support base; 11. Guide groove; 12. Power supply; 20. Barrel body; 21. Divider plate; 22. Upper cavity; 23. Lower cavity; 24. Protrusion; 30. Filter barrel; 31. Inverted conical bottom wall; 40. Filter; 50. Water outlet pipe; 51. Faucet; 52. Water storage section; 60. Exhaust return channel; 61. One-way water-blocking and venting valve; 70. Annular air distribution groove; 80. Buoyancy ring; 90. Water collection tank; 100. Liquid level sensor; 110. Miniature air pump; 111. Air inlet pipe; 112. Air outlet pipe; 120. Controller. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] This invention provides a gravity-fed water filtration device and its control method. (Combined with...) Figures 1-4 In practical applications, gravity-fed water filtration devices can be exemplified as desktop household water purifiers that primarily rely on gravitational potential energy to drive water flow through the filter cartridge. The core of the device lies in an integrated intelligent active adjustment system comprised of a micro air pump 110 and a controller 120. As the device's operational hub, the system can execute differentiated adjustment actions based on real-time feedback from the internal fluid state. Specifically, the device actively extracts compressed air from the lower space via the micro air pump 110, thereby breaking airlock and maintaining the continuous water production capacity of the filter 40. Under low water level conditions, the system can utilize the extracted air at variable frequency, converting it into kinetic pulse bubbles, and, in conjunction with a specific fluid guiding structure, perform in-situ physical flushing of the filter 40. This effectively solves the problems of water production stagnation caused by air pressure imbalance and clogging caused by impurities accumulating on the filter cartridge surface in traditional gravity water purifiers.

[0032] To facilitate understanding, this invention establishes a specific application scenario throughout. Assume a user pours 3 liters of raw water to be filtered into the raw water tank at the top of the device. After receiving this raw water, the system needs to convert it into purified drinking water and store it in the lower chamber 23. Simultaneously, it automatically performs air pressure regulation or filter self-cleaning actions when the filtration efficiency decreases or when the user takes water. The specific structure and control steps of the device are described in detail below.

[0033] refer to Figure 4 The gravity-fed water filtration device comprises a tank 20, a filter barrel 30, a filter 40, a water collection tank 90, a water outlet pipe 50, an exhaust return channel 60, a liquid level sensor 100, a miniature air pump 110, and a controller 120. The filter barrel 30 is nested inside the tank 20, and its bottom wall is a partition plate 21. The partition plate 21 strictly divides the internal space of the tank 20 into an upper cavity 22 and a lower cavity 23. The partition plate 21 has a downward-extending inverted conical bottom wall 31 at its center. The filter 40 is fixedly connected to the center of the inverted conical bottom wall 31. The filter 40 can be a composite filter element made of ceramic core, nanofiltration membrane, or PP cotton. The internal flow space of the filter 40 is directly connected to the lower cavity 23, thus forming a single filtration path from top to bottom.

[0034] During gravity filtration, the raw water generates hydrostatic pressure due to its own weight. When the depth h of the raw water in the upper chamber 22 is 15 cm, the initial hydrostatic pressure P on the surface of the filter 40 can be calculated using the following formula: P = ρ·g·h; Regarding the units of measurement used in the formula, P is the hydrostatic pressure in Pascals; ρ is the density of water in kilograms per cubic meter; g is the acceleration due to gravity in meters per second squared; and h is the depth of water in meters.

[0035] As filtration proceeds, for example, when 500 ml of purified water enters the lower chamber 23, the rising water level in the relatively sealed lower chamber 23 drastically compresses the air volume at the top of the chamber. According to the ideal gas law, the reverse air pressure within the lower chamber 23 will rapidly increase. Since the driving force for gravity filtration comes only from the limited hydrostatic pressure, when the reverse air pressure below and the hydrostatic pressure above reach physical equilibrium, the water flow can no longer infiltrate, resulting in airlock.

[0036] To break this deadlock, the present invention includes a water collection tank 90 and an exhaust return channel 60 within the lower cavity 23. The lower end of the exhaust return channel 60 connects to the lower cavity 23, and the upper end extends upward through the partition plate 21, opening at the inverted conical bottom wall 31 between the outer wall of the filter 40 and the inner wall of the filter tank 30. A one-way water-blocking and ventilating valve 61 is provided on the exhaust return channel 60, allowing only unidirectional gas flow from bottom to top and absolutely preventing the upper raw water from flowing back downwards. A miniature air pump 110 is located within the lower cavity 23, preferably in the waterproof space isolated at the bottom of the water collection tank 90. ​​(Reference) Figure 3The miniature air pump 110 has an air inlet pipe 111 and an air outlet pipe 112. Both the air inlet pipe 111 and the air outlet pipe 112 are located inside the lower cavity 23. The miniature air pump 110 is connected to the lower part of the water collection tank 90 and extends through the side wall of the water collection tank 90 to the upper part of the water collection tank 90. ​​The air inlet end of the air inlet pipe 111 extends to the upper part of the water collection tank 90 and connects to the top space of the lower cavity 23. The air outlet end of the air outlet pipe 112 extends to the upper part of the water collection tank 90 and is sealed to the lower port of the exhaust return channel 60.

[0037] In this configuration, the miniature air pump 110 acts as a pressure bridge connecting the lower high-pressure zone and the upper low-pressure zone. The controller 120 is electrically connected to the miniature air pump 110 and the level sensor 100, and is configured to execute two response logics. When the level sensor 100 detects that the water level in the collection tank 90 has reached the first high position, the system enters a depressurization mode, actively evacuating air to break the balance. When the water level drops to the second low position, the system uses the extracted air to perform a self-cleaning mode.

[0038] Furthermore, an annular air distribution groove 70 is provided at the junction of the inverted conical bottom wall 31 and the outer wall of the filter 40. In a conventional single-point exhaust structure, bubbles tend to rise vertically along the shortest path after leaving the pipe opening. This unconstrained single-point rising trajectory causes bubbles to only rub against a local strip-shaped area on the outer wall of the filter 40, leaving a large area of ​​scouring blind zone in the circumferential direction of the filter 40, where impurities can still easily deposit.

[0039] To overcome this limitation, the annular air distribution groove 70 in this embodiment is designed as a connected cavity that surrounds the circumference of the filter 40, and the upper port of the exhaust return channel 60 is not directly open to the water body, but is concealed and connected to the bottom side of the annular air distribution groove 70. When the micro air pump 110 pressurizes gas into the exhaust return channel 60, the squeezed gas first enters the annular air distribution groove 70. Due to the physical constraint of the side wall of the groove, the gas is forced to diffuse and flow evenly in the circumferential direction, thereby transforming the original single-point concentrated gas source into a 360-degree annular gas source. In addition, the groove opening of the annular air distribution groove 70 opens obliquely upward toward the outer wall of the filter 40. When the gas accumulates and overflows from the groove opening, the obliquely upward opening provides an initial inward guiding force for the bubbles, allowing the generated bubble group to gather inward with the help of buoyancy, closely adhering to the outer wall surface of the filter 40 and floating upward, effectively preventing the bubbles from dispersing disorderly into the water body.

[0040] In some embodiments, the single air inlet and multiple air outlets of the annular air distribution channel 70 can be achieved through diversion and overflow. Specifically, the upper port of the exhaust return channel 60 is connected to a single air inlet at the bottom of the annular air distribution channel 70. The top of the annular air distribution channel 70 has multiple air outlets. When gas enters through the single air inlet, it is diverted and escapes simultaneously from the multiple air outlets.

[0041] In some embodiments, the gravity-fed water filtration device further includes a buoyancy ring 80. Even with circumferential uniform airflow, the kinetic energy of freely rising bubbles in the wide upper cavity 22 gradually decreases with increasing upward stroke, potentially limiting the peeling force for firmly attached biofilms or colloids. Therefore, this embodiment introduces a buoyancy ring 80 with a density less than water, i.e., less than 1.0 kg / m³, which can be slidably fitted around the filter 40 in the vertical direction.

[0042] Leveraging the low-density properties of its material, the buoyancy ring 80 can remain afloat at the water-air interface of the upper chamber 22 without the need for any motor or transmission components, relying solely on natural buoyancy. Continuing with the scenario of adding 3 liters of raw water, as filtration continues, the water level in the upper chamber 22 may gradually decrease from 12 cm to 3 cm. During this process, under the self-balancing force of gravity and buoyancy, the buoyancy ring 80 smoothly and synchronously moves down along the outer wall of the filter 40, adapting to the drop in water level, achieving passive adaptive tracking of the dynamic water level.

[0043] More importantly, the inner wall of the buoyancy ring 80 has a conical structure that is wider at the top and narrower at the bottom. Between the conical surface and the outer wall of the cylindrical filter 40, an annular flow section with a sudden change in cross-sectional area is artificially constructed. When the bubbles released below rise and enter this area, the sudden contraction of the flow channel space forces the gas-liquid mixture to accelerate through the slit, generating a fluid acceleration effect similar to the Venturi effect. This acceleration effect locally generates relatively strong mixing turbulence. As the buoyancy ring 80 moves downward synchronously, this high-intensity turbulence zone located at the bottom slit dynamically applies high-pressure water to the accumulation area at the bottom of the filter, significantly improving the self-cleaning efficiency.

[0044] Furthermore, to ensure the energy conversion rate of the aforementioned high-intensity scouring zone, the vertical projection of the inner wall of the buoyancy ring 80 at least partially covers the upper port of the exhaust return channel 60. If the gas release point is located outside the working radius of the buoyancy ring 80, a large number of bubbles will directly bypass the buoyancy ring 80 during their ascent and dissipate into the wide open source water, resulting in a waste of the kinetic energy output by the micro air pump 110. By limiting the coverage relationship of the vertical projection of the inner wall to the upper port, a physical interception surface is effectively set up on the inevitable path of the bubbles. When the intermittently extruded bubbles leave the annular air distribution groove 70 and move upward, their upward trajectory is exactly within the shielding range of the inner wall of the buoyancy ring 80. The bubble group inevitably collides with the conical inner wall of the buoyancy ring 80 and is forcibly guided and converged into the aforementioned annular flow section.

[0045] In some embodiments, considering that the buoyancy ring 80 needs to be immersed in clean water for a long time and maintain stable physical buoyancy, the buoyancy ring 80 is preferably molded from food-grade polypropylene (PP) or food-grade polyethylene (PE) through integral injection molding. The intrinsic material density of these polymer materials is 0.89-0.96 g / cm³. Since the density of water is approximately 1.0 g / cm³, this density range is chosen so that the overall density of the buoyancy ring 80 is slightly less than that of water. In actual immersion, approximately 90% of the volume of the buoyancy ring 80 is submerged in water, with only about 10% of the top volume exposed above the water surface. This slight density difference ensures that the buoyancy ring 80 can float stably without sinking, and also gives it a sufficiently large draft to allow for sufficient physical collision and interception with rising air bubbles below.

[0046] The above describes one embodiment where the buoyancy ring 80 is molded from a solid, lightweight plastic. In other embodiments, the buoyancy ring 80 can also be made of a rigid material with a density greater than water. For example, the buoyancy ring 80 can be molded from food-grade ABS, PC, or stainless steel, but its interior is hollowed out and sealed to form a hollow air cavity. This hollow structure also allows the overall equivalent average density of the buoyancy ring 80 to be less than the density of water, thereby achieving the aforementioned passive buoyancy follow-up effect.

[0047] In some embodiments, considering that the surface of the filter 40 or the interior of the buoyancy ring 80 may require deep manual cleaning after long-term operation, or that the filter 40 may need to be replaced as a whole when it reaches the end of its service life, the traditional closed-loop structure is often difficult to disassemble without damage after being fitted around the filter 40. Therefore, the buoyancy ring 80 is designed as a detachable, modular assembly structure, specifically comprising a symmetrical first half-ring and a second half-ring. The mating end faces of the first half-ring and the second half-ring are respectively provided with matching tenons and mortises, forming a tenon-and-mortise connection. In actual disassembly and assembly scenarios, users do not need to use screwdrivers or other hardware tools; they only need to align the tenons and mortises of the two half-rings horizontally and push them in to assemble the complete buoyancy ring 80. Pulling it back allows it to be removed from the outside of the filter 40, effectively improving the convenience of daily maintenance.

[0048] In some embodiments, the bottom of the gravity water supply filtration device is also equipped with a support base 10. The controller 120 is disposed within the support base 10.

[0049] The top surface of the support base 10 and the bottom surface of the barrel 20 are locked together by a locking protrusion 24 and a guide groove 11. Specifically, during installation, the user first slides the locking protrusion 24 on the bottom of the barrel 20 vertically into the inlet of the guide groove 11 on the top of the support base 10, and then rotates the barrel 20 by a small angle, such as 15 to 30 degrees. With this rotation, the locking protrusion 24 slides into the end position of the guide groove 11 and forms a mechanical interference lock, so that the barrel 20 and the support base 10 are tightly connected into a single force-bearing unit.

[0050] Furthermore, conductive contacts are embedded in the locking protrusion 24 and the guide groove 11, respectively. These two conductive contacts are connected in series in the bottom power supply circuit of the micro air pump 110, the liquid level sensor 100, and the controller 120. In the normal assembly state, when the locking protrusion 24 is screwed into the locking end of the guide groove 11, the conductive contacts on both sides fit tightly together, thereby conducting the power supply circuit of the whole machine. Once an abnormal working condition occurs, such as when the user forcibly lifts the barrel 20 during equipment operation, or when the device is violently impacted and overturns, the conductive contacts immediately separate the moment the locking protrusion 24 comes out of the guide groove 11. This safety mechanism, which forcibly binds physical displacement with electrical connection and disconnection, can automatically cut off the power supply 12 of the controller 120 and the air pump in the early stage of an abnormality, completely eliminating the safety hazard of short circuit and fire of internal electronic components when the equipment is tilted and leaking water. In this embodiment, the power supply 12 is arranged in the support base 10 and connected to an external power source through the base. Alternatively, the power supply can be a portable power source.

[0051] In some embodiments, a faucet 51 for users to draw water is provided at the lower outer end of the tank 20, and a downward-bending water storage section 52 is specially provided in the path of the water outlet pipe 50. Since this device relies on a micro air pump 110 to actively draw air from the lower cavity 23 to maintain the pressure difference required for filtration, the entire lower system must maintain a relatively strict airtight state outside the air path. When the user closes the faucet 51 and stops discharging water, due to the influence of gravity, a small amount of clean water will always remain in the low-lying part of the downward bend in the water outlet pipe 50, that is, in the water storage section 52. This remaining liquid will naturally fill the pipe diameter section at that point, forming a physical liquid seal. The liquid seal structure can effectively block the path of external air flowing back into the lower cavity 23 through the gap of the faucet 51 without adding any one-way valves or other moving parts, preventing the internal air pressure regulation environment from being disrupted, and also isolating suspended impurities in the external environment.

[0052] The control method of the gravity water supply filtration device is jointly completed by the controller 120, the sensor and the actuator, and the method includes sub-steps S1-S2.

[0053] S1. Real-time acquisition of the water level height signal in the water collection tank 90 detected by the liquid level sensor 100.

[0054] S2. Determine the water level status based on the liquid level height signal and execute the corresponding control mode.

[0055] Specifically, the maximum designed water depth of the water collection tank 90 is, for example, 20cm. The liquid level sensor 100 is preset to a first position at the highest point, for example, 18cm, and a second position at the lowest point, for example, 5cm. When the liquid level is detected at the first position at the highest point, i.e., the purified water level reaches 18cm, the controller 120 determines that the air resistance in the lower layer is high and then executes the pressure relief mode. At this time, the controller 120 outputs a stable drive voltage to the micro air pump 110, controlling the micro air pump 110 to start and extract the compressed air accumulated in the lower chamber 23 due to the rise in the purified water level. The extracted compressed air actively exhausts and relieves pressure in the upper chamber 22 through the exhaust return channel 60, thereby eliminating the air resistance in the lower chamber 23 and maintaining the continuous filtration state of the filter 40.

[0056] When the user turns on the tap 51 to draw a large amount of water, and the water level drops to the second lowest position (5cm), the controller 120 activates the self-cleaning mode. At this time, the controller 120 changes its output strategy, controlling the micro air pump 110 to operate in a pulsed manner, for example, alternating between on for 1 second and off for 0.5 seconds. The micro air pump 110 intermittently pumps air into the exhaust return channel 60, causing the air to be squeezed out at the upper port and forming highly explosive pulse bubbles. Under low water level conditions, the static water resistance outside the filter 40 is small. The system utilizes the buoyancy of the pulse bubbles to rise counter-currently along the outer wall of the filter 40, performing a high-intensity physical flush. This not only accelerates the infiltration of residual raw water but also fundamentally removes the adhering dirt from the filter element surface.

[0057] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A gravity-fed water filtration device, characterized in that, include: Barrel body (20); A filter barrel (30) is installed inside the barrel body (20). The bottom wall of the filter barrel (30) is a partition plate (21). The partition plate (21) divides the internal space of the barrel body (20) into an upper cavity (22) and a lower cavity (23). The partition plate (21) has a downwardly extending inverted conical bottom wall (31) in the center. The filter (40) is fixedly connected to the center of the inverted conical bottom wall (31), and the internal space of the filter (40) is in communication with the lower cavity (23); A water collection tank (90) is installed in the lower cavity (23); A water outlet pipe (50) connects the water collection tank (90) to the outside of the barrel body (20); and, An exhaust return channel (60) is provided, the lower port of which is connected to the lower cavity (23), and the upper port of which passes upward through the partition plate (21) and opens at the inverted conical bottom wall (31) between the outer wall of the filter (40) and the inner wall of the filter barrel (30); a one-way water-blocking and breathable valve (61) is provided on the exhaust return channel (60); A level sensor (100) is adapted to detect the level of purified water in the collection tank (90); and has a first position at a high point and a second position at a low point; A miniature air pump (110) and a controller (120) are provided. The air inlet of the miniature air pump (110) is connected to the top space of the lower cavity (23), and the air outlet is sealed to the lower port of the exhaust return channel (60). The controller (120) is electrically connected to the micro air pump (110) and the liquid level sensor (100), and the controller (120) is configured to have a pressure relief working mode in response to a first position and a self-cleaning working mode in response to a second position.

2. The gravity-fed water filtration device according to claim 1, characterized in that, An annular air distribution groove (70) is provided at the junction of the inverted conical bottom wall (31) and the outer wall of the filter (40); The annular air distribution groove (70) surrounds the filter (40) circumferentially, and the groove opening of the annular air distribution groove (70) is open to the upper side of the outer wall of the filter (40), and the upper port of the exhaust return channel (60) is connected to the bottom side of the annular air distribution groove (70).

3. The gravity-fed water filtration device according to claim 2, characterized in that, It also includes a buoyancy ring (80); the density of the buoyancy ring (80) is less than that of water, and the buoyancy ring (80) can be slidably fitted around the filter (40) in the vertical direction; The inner wall of the buoyancy ring (80) has a conical structure that is wider at the top and narrower at the bottom. The inner wall of the buoyancy ring (80) and the outer wall of the filter (40) form an annular flow section, so that the buoyancy ring (80) moves down synchronously as the water level in the upper cavity (22) drops.

4. The gravity-fed water filtration device according to claim 3, characterized in that, The vertical projection of the inner wall of the buoyancy ring (80) at least partially covers the upper port of the exhaust return channel (60).

5. The gravity-fed water filtration device according to claim 3, characterized in that, The buoyancy ring (80) is injection molded from food-grade PP or PE material with a material density of 0.89-0.96 g / cm³.

6. The gravity-fed water filtration device according to claim 3, characterized in that, The buoyancy ring (80) includes a first half-ring and a second half-ring; the first half-ring and the second half-ring are connected by mortise and tenon joints.

7. The gravity-fed water filtration device according to claim 1, characterized in that, It also includes a support base (10), the top surface of which is rotatably locked to the bottom surface of the barrel body (20) by means of a locking protrusion (24) and a guide groove (11).

8. The gravity-fed water filtration device according to claim 7, characterized in that, The protrusion (24) and the guide groove (11) are respectively provided with conductive contacts so that the protrusion (24) is energized when entering the guide groove (11) and de-energized when exiting the guide groove (11).

9. The gravity-fed water filtration device according to claim 1, characterized in that, The barrel (20) is equipped with a faucet (51), and the water outlet pipe (50) has a downward-bending water storage section (52).

10. A control method for a gravity-fed water filtration device as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Real-time acquisition of the water level height signal in the water collection tank (90) detected by the liquid level sensor (100); S2. Determine the water level status based on the liquid level height signal and execute the corresponding control mode, wherein, When the liquid level is detected to be at the first position of the highest point, the pressure relief working mode is executed: the micro air pump (110) is started to extract the compressed air generated in the lower cavity (23) due to the rise of the clean water level, and actively exhausts and relieves pressure in the upper cavity (22) through the exhaust return channel (60) to eliminate the air resistance in the lower cavity (23) and maintain the continuous filtration of the filter (40); When the liquid level is detected to be at the second position where it is at the lowest point, the self-cleaning working mode is executed: the micro air pump (110) is controlled to work in a pulse form, and the extracted air is pressed into the exhaust return channel (60), so that the air is intermittently squeezed out at the upper port and forms pulse bubbles. The buoyancy of the pulse bubbles is used to flush the filter (40) by flowing back up along the outer wall of the filter.

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