A float valve, humidification tank and method of controlling water level in a humidification tank

Abstract

This invention relates to the technical field of medical devices, providing a float valve, a humidification tank, and a method for controlling the water level in the humidification tank. The float valve includes a float valve body, a waterproof and breathable membrane, and a sealing element. The float valve body has a cavity, with at least one vent at the top for connecting the cavity to the external environment. The waterproof and breathable membrane is located at the vent and covers and seals the vent, allowing gas molecules to pass through while preventing liquid water and water vapor from entering the cavity. The sealing element is placed outside the vent and the waterproof and breathable membrane and nested within the float valve body, forming a gas channel between the sealing element and the float valve body. The sealing element is used to seal the water inlet of the humidification tank when the water level in the humidification tank reaches a preset height. This invention, by setting a waterproof and breathable membrane at the vent of the float valve body, allows the float valve to freely exchange gas in alternating hot and cold environments to balance internal and external air pressure, while effectively preventing liquid water from entering the cavity, thereby ensuring the overall mass of the float valve remains constant.

Description

Technical Field

[0001] This invention relates to the technical field of medical devices, and more specifically, to a float valve, a humidification tank, and a method for controlling the water level in the humidification tank. Background Technology

[0002] The humidifier tank is a key component connecting the ventilator to the gas delivery tubing. It is used to warm and humidify the gas delivered to the patient, improving patient comfort and protecting the respiratory mucosa. The humidifier tank contains a float valve for automatic water level control: when the water level reaches a set height, the silicone seal on top of the float valve blocks the inlet, stopping water intake; when the water level drops due to evaporation, the float valve falls, reopening the inlet for automatic water replenishment.

[0003] However, existing humidifiers suffer from the following technical problems during long-term use: The working environment of the humidifier experiences significant temperature fluctuations; the internal temperature rises during heating and drops sharply when heating stops or cold water is injected. During this process, the air inside the float valve's cavity undergoes a "breathing effect" due to thermal expansion and contraction. When heated, the internal gas expands and is expelled; when cooled, high-humidity external air is drawn into the float valve's internal cavity. The absorbed water vapor condenses into liquid water on the inner wall of the float valve and gradually accumulates at the bottom. This increased water accumulation significantly increases the overall mass of the float valve. According to Archimedes' principle of buoyancy, the float valve rises less at the same water level, causing the silicone seal at the top of the float valve to fail to accurately seal the inlet at the preset water level. This results in continuous water intake, excessively high water levels, and even the risk of overflow. In severe cases, this can lead to problems such as choking, suffocation, and ventilator-associated pneumonia in patients.

[0004] Current solutions employ fully sealed hollow float valves to address this issue. However, fully sealed float valves cannot balance internal and external air pressure during thermal expansion and contraction, which exacerbates the aging and deformation of the seals. Therefore, a new type of float valve structure is urgently needed that can prevent liquid water from entering its interior while ensuring normal ventilation. Summary of the Invention

[0005] The purpose of this invention is to provide a float valve, a humidification tank, and a method for controlling the water level in the humidification tank, so as to solve the technical problem in the prior art that water vapor enters the float valve and condenses due to temperature difference, which increases the mass of the float valve and thus affects the accuracy of water intake control.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a float valve for use in a humidification tank, comprising: The float valve body has a cavity, and the top of the cavity is provided with at least one vent for connecting the cavity to the external environment. A waterproof and breathable membrane is disposed at the vent and covers and seals the vent. The waterproof and breathable membrane allows gas molecules to pass through while preventing liquid water and water vapor from entering the cavity. A sealing element is provided, which covers the outside of the vent and the waterproof and breathable membrane and is nested and connected to the float valve body. A gas channel is formed between the sealing element and the float valve body. The sealing element is used to block the water inlet of the humidification tank when the water level in the humidification tank reaches a preset height.

[0007] According to the above-described float valve, the waterproof and breathable membrane includes a modified surface layer, a microporous filter layer, and a support layer arranged and connected in sequence. After the waterproof and breathable membrane is installed on the float valve body, the support layer is disposed on the side closer to the cavity, and the modified surface layer is disposed on the side closer to the external environment.

[0008] According to the float valve described above, the waterproof and breathable membrane is applied to the float valve body via a secondary injection molding process involving overmolding.

[0009] According to the aforementioned float valve, the waterproof and breathable membrane is circular.

[0010] According to the above-described float valve, the top of the float valve body is provided with a insertion groove, and the sealing element is provided with an insertion part, wherein the insertion part and the insertion groove are nested and inserted.

[0011] According to the float valve described above, the groove wall of the insertion slot is provided with at least one air passage groove, and the air passage groove extends to form the air inlet. After the sealing member is nested and fitted with the float valve body, the inner wall of the sealing member and the air passage groove form the gas channel.

[0012] According to the float valve described above, the edge of the upper surface of the seal is provided with a circumferential baffle, and the water inlet of the humidification tank is closed within the area enclosed by the baffle when the float valve rises.

[0013] Secondly, the present invention also provides a humidification tank, including the float valve described above, wherein the humidification tank further includes: The tank body has a water inlet, an air inlet, and an air outlet at the top, and the float valve is located inside the tank body and directly below the water inlet; A heating plate is located at the bottom of the tank.

[0014] According to the humidification tank described above, the float valve body includes: First float valve section; The second float valve part is located above the first float valve part and connected to the first float valve part. The first float valve part and the second float valve part communicate to form the cavity. The outer diameter of the second float valve part is smaller than the outer diameter of the first float valve part. The second float valve part and the first float valve part form a convex shape. The top of the tank is provided with a guide limiting cylinder, which is sleeved outside the second float valve part and located above the first float valve part. The bottom end of the guide limiting cylinder is used to limit the radial floating of the float valve body within a preset range. The inner wall of the guide limiting cylinder is provided with at least two serrated limiting protrusions. The multiple limiting protrusions are in clearance fit with the second float valve part to limit the circumferential floating of the float valve body within a preset range.

[0015] Thirdly, the present invention also provides a method for controlling the water level in a humidification tank, applied to the humidification tank described above, wherein the water level control method includes: A cavity is provided inside the float valve, and a waterproof and breathable membrane is provided between the cavity and the external environment; When the temperature inside the tank rises, the excess gas that expands due to heat in the cavity is discharged through the waterproof and breathable membrane to balance the internal and external air pressure. When the temperature inside the tank decreases, the waterproof and breathable membrane draws external gas into the cavity, while the hydrophobic properties of the waterproof and breathable membrane prevent liquid water from entering the cavity in the high-humidity environment. Maintaining the mass of the float valve constant during operation ensures that the seal accurately blocks or opens the inlet of the humidification tank at the preset water level.

[0016] The beneficial effects of the float valve, humidification tank, and water level control method of the humidification tank provided by the present invention are at least as follows: The float valve, humidification tank, and water level control method provided by this invention, by setting a waterproof and breathable membrane at the vent of the float valve body and utilizing the gas channel formed by the nested connection between the seal and the float valve body, allows the float valve to freely exchange gas in alternating hot and cold environments to balance the internal and external air pressures, while effectively preventing liquid water from entering the cavity. This ensures a constant overall mass of the float valve and avoids the buoyancy inaccuracy and water level control drift caused by internal water accumulation in traditional float valves. Based on the constant mass of the float valve body, the float valve can accurately drive the seal to close or open the inlet according to water level changes, achieving high-precision automatic water level control, eliminating water overflow caused by excessively high water levels, and reducing the medical safety risks of patient choking, suffocation, and ventilator-associated pneumonia. In addition, the float valve provided in this embodiment has a compact structure, with each component working collaboratively without interference, and a mature manufacturing process with low cost, significantly improving the reliability and service life of the humidification tank under long-term hot and cold cycles. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A three-dimensional structural diagram of the humidification tank provided by the present invention; Figure 2 This is a schematic diagram of the exploded structure of the humidification tank provided by the present invention; Figure 3 This is a cross-sectional structural diagram of the humidification tank provided by the present invention; Figure 4 This is an exploded structural diagram of the float valve provided by the present invention; Figure 5 A schematic diagram of the layered structure of the waterproof and breathable membrane provided by the present invention; Figure 6 The flowchart shows the humidification tank water level control method provided by the present invention.

[0019] The following are the labeling elements in the figure: 1000, Humidification tank; 100, Float valve; 10, Float valve body; 11, Cavity; 12, Vent; 13, Insert groove; 14, Air passage groove; 15, First float valve section; 16, Second float valve section; 17, Recess; 20, Waterproof and breathable membrane; 21, Modified surface layer; 22, Microporous filter layer; 23, Support layer; 30, Seal; 31, Insert section; 32, Stop section; 200, Tank body; 210, Guide limiting cylinder; 220, Limiting protrusion; 230, First inclined plate; 240, Second inclined plate; 250, Water inlet; 260, Air inlet; 270, Air outlet. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0022] Please see Figure 1 and Figure 2 This embodiment provides a float valve 100, which is applied to a humidification tank 1000 and includes a float valve body 10, a waterproof and breathable membrane 20, and a sealing element 30.

[0023] Please see Figure 3 and Figure 4 The float valve body 10 has a cavity 11, and the top of the cavity 11 is provided with at least one vent 12 for connecting the cavity 11 and the external environment. The waterproof and breathable membrane 20 is provided at the vent 12 and covers and seals the vent 12. The waterproof and breathable membrane 20 allows gas molecules to pass through while preventing liquid water and water vapor from entering the cavity 11. The sealing member 30 is covered outside the vent 12 and the waterproof and breathable membrane 20 and is nested and connected to the float valve body 10. A gas channel is formed between the sealing member 30 and the float valve body 10. The sealing member 30 is used to block the water inlet 250 of the humidification tank 1000 when the water level in the humidification tank 1000 reaches a preset height.

[0024] The working principle of the float valve 100 provided in this embodiment is as follows: The float valve 100 provided in this embodiment has a cavity 11 inside the float valve body 10. The vent 12 at the top of the cavity 11 is covered and sealed by a waterproof and breathable membrane 20. The sealing element 30, which is covered on the outside, is nested and connected to the float valve body 10 to form a gas channel. This allows gas molecules to enter and exit the cavity 11 through the gas channel and the waterproof and breathable membrane 20, so as to achieve the balance of internal and external air pressure during the alternation of hot and cold, while preventing liquid water from entering the cavity 11, so that the overall mass of the float valve 100 remains constant. As the water level in the humidification tank 1000 rises, the buoyancy of the float valve 100 increases. When the water level reaches a preset height, the float valve 100 drives the sealing element 30 to move upward and seal the water inlet 250, stopping the water intake. When the water level drops due to evaporation, the float valve 100 falls, the sealing element 30 disengages from the water inlet 250, the water inlet 250 opens, and water intake is automatically restored. This cycle achieves precise and stable water level control.

[0025] The beneficial effects of the float valve 100 provided in this embodiment are as follows: The float valve 100 provided in this embodiment, by setting a waterproof and breathable membrane 20 at the vent 12 of the float valve body 10, and utilizing the gas channel formed by the nested connection between the sealing element 30 and the float valve body 10, allows the float valve 100 to freely exchange gas in alternating hot and cold environments to balance the internal and external air pressures. Simultaneously, it effectively prevents liquid water from entering the cavity 11, thereby ensuring a constant overall mass of the float valve 100 and avoiding buoyancy inaccuracies and water level control drift caused by internal water accumulation in traditional float valves 100. Based on the constant mass of the float valve body 10, the float valve 100 can accurately drive the sealing element 30 to seal or open the inlet 250 according to water level changes, achieving high-precision automatic water level control. This eliminates water overflow caused by excessively high water levels, reducing the medical safety risks of patient choking, suffocation, and ventilator-associated pneumonia. Furthermore, the float valve 100 provided in this embodiment has a compact structure, with each component working together without interfering with the others. It also has a mature manufacturing process and low cost, which significantly improves the reliability and service life of the humidification tank 1000 under long-term hot and cold cycles.

[0026] In one embodiment, see Figure 5 The waterproof and breathable membrane 20 includes a modified surface layer 21, a microporous filter layer 22, and a support layer 23 arranged and connected in sequence. After the waterproof and breathable membrane 20 is installed on the float valve body 10, the support layer 23 is arranged on the side closer to the cavity 11, and the modified surface layer 21 is arranged on the side closer to the external environment.

[0027] The waterproof and breathable membrane 20 employs a three-layer composite structure consisting of a modified surface layer 21, a microporous filter layer 22, and a support layer 23, installed with the support layer 23 facing the internal cavity 11 of the float valve 100 and the modified surface layer 21 facing the external environment. During operation, gas from the external environment first contacts the modified surface layer 21, which effectively repels liquid water. Gas molecules (including air and water vapor) then enter the microporous filter layer 22, which has a microporous structure with a specific pore size, allowing gas molecules to pass freely while blocking liquid water. Finally, the gas smoothly enters the cavity 11 via the support layer 23, achieving internal and external pressure balance. Conversely, gas also flows smoothly out of the cavity 11.

[0028] As can be seen, the modified surface layer 21 serves as the first line of defense to prevent liquid water from wetting the membrane surface, the microporous filter layer 22 serves as the core functional layer to achieve precise gas-liquid separation, and the support layer 23 provides mechanical strength to ensure that the waterproof and breathable membrane 20 does not crack during injection molding and long-term use. Furthermore, the synergistic effect of the modified surface layer 21, the microporous filter layer 22, and the support layer 23, along with the defined layer orientation, ensures that the waterproof and breathable membrane 20 maintains its excellent performance of being breathable but impermeable to water under long-term alternating hot and cold environments, thereby maintaining the constant mass of the float valve 100 and the accuracy of water level control.

[0029] In one embodiment, see Figure 3 and Figure 4 The waterproof and breathable membrane 20 is bonded to the float valve body 10 via a secondary injection molding process involving overmolding. The specific injection molding process is as follows: First, the float valve body 10 is injection molded, with a pre-reserved overmolding recess 17. Then, the waterproof and breathable membrane 20 is precisely placed within the recess 17, followed by a secondary injection molding process. This allows the molten plastic material to directly wrap around and fuse with the edge of the waterproof and breathable membrane 20. After cooling, an integrated overmolding structure is formed, thus completely sealing and anchoring the edge of the waterproof and breathable membrane 20 to the float valve body 10. This secondary injection molding process achieves a seamless and permanent bond between the waterproof and breathable membrane 20 and the float valve body 10, eliminating the need for any adhesives and avoiding problems such as adhesive aging and volatile contamination. It provides extremely high sealing reliability and bonding strength, capable of withstanding long-term temperature fluctuations and water pressure impacts in the humidification tank 1000. Furthermore, the two-stage injection molding process ensures high positioning accuracy, suitability for mass automated production, and good consistency, effectively reducing manufacturing costs. The encapsulation structure also protects the membrane edges, further extending the service life of the float valve 100.

[0030] In one embodiment, the waterproof and breathable membrane 20 is circular. Compared to square or other polygonal shapes, the circular shape of the waterproof and breathable membrane 20 results in a more uniform stress distribution when subjected to the impact of molten plastic during secondary injection molding and water pressure fluctuations within the humidification tank 1000. It eliminates stress concentration points that are prone to occur at sharp corners or right angles, thus significantly reducing the risk of membrane edge tearing or cracking at the overlay joint. Furthermore, the circular waterproof and breathable membrane 20 perfectly matches the circular vent 12 and the overlay recess 17, ensuring the concentricity and consistency of the membrane covering the vent 12.

[0031] In other embodiments, the waterproof and breathable membrane 20 can also be elliptical, suitable for float valve bodies 10 with elliptical vents 12, and also has the characteristics of no sharp corners and uniform stress.

[0032] In other embodiments, the waterproof and breathable membrane 20 may be racetrack shaped, i.e., semicircular at both ends and rectangular in the middle, increasing the breathable area while maintaining the absence of sharp corners at the edges.

[0033] In other embodiments, the waterproof and breathable membrane 20 may be a regular polygon with all corners rounded, which eliminates stress concentration while taking into account the convenience of mold processing.

[0034] In one embodiment, the top of the cavity 11 is provided with a single vent 12. Providing a single vent 12 simplifies mold design and facilitates injection molding, eliminating the need to consider the positional accuracy and consistency between multiple holes, thus reducing manufacturing difficulty and cost. Furthermore, a single vent 12 can achieve rapid pressure balancing.

[0035] In one embodiment, the top of the cavity 11 is provided with multiple vents 12, which are arranged in an array. When the temperature inside the tank 200 changes, gas can simultaneously enter and exit the cavity 11 through multiple vents 12, and the gas flow is more uniform, greatly improving the efficiency of gas exchange and enabling the internal and external air pressures to reach equilibrium more quickly. This is particularly suitable for scenarios with rapid temperature changes. Furthermore, the multiple vents not only ensure air permeability but also provide support for the waterproof and breathable membrane 20, making the waterproof and breathable membrane 20 durable.

[0036] In other embodiments, the multiple vents 12 can also be configured as a combination of different apertures, wherein the central vent 12 has a larger aperture and is used for the main airflow exchange, while the surrounding annularly distributed small aperture vents 12 serve as auxiliary and redundant channels to achieve graded airflow management.

[0037] In other embodiments, the plurality of vents 12 may also be arranged in a concentric circle, a grid, or a spiral pattern, and different distribution patterns can be adapted to different flow rate requirements of the humidification tank 1000 model.

[0038] In one embodiment, see Figure 3 and Figure 4 The top of the float valve body 10 is provided with a plug groove 13, and the sealing member 30 is provided with a plug part 31. The plug part 31 and the plug groove 13 are nested and plugged together.

[0039] During assembly, the insertion part 31 on the seal 30 is inserted into the insertion groove 13 on the top of the float valve body 10. The geometric fit between the two achieves rapid positioning and connection, ensuring that the seal 30 will not fall off during operation while allowing for slight relative movement or gas passage between them. The non-completely sealed gap formed by the insertion fit can also serve as part of the gas passage, working in conjunction with the waterproof and breathable membrane 20 to achieve air pressure balance. Furthermore, the nested insertion method results in a simple structure, convenient assembly, and eliminates the need for glue or complex tooling, making disassembly and replacement easy.

[0040] In one embodiment, see Figure 4 The insertion groove 13 has at least one air passage groove 14 on its wall, and the air passage groove 14 extends to form the air vent 12. After the sealing member 30 is nested with the float valve body 10, the inner wall of the sealing member 30 and the air passage groove 14 form the gas passage. By setting the air passage groove 14, the efficiency of gas exchange is greatly improved, allowing the internal and external air pressures to reach equilibrium more quickly.

[0041] In one embodiment, see Figure 4 The edge of the upper surface of the sealing element 30 is provided with a circumferential baffle 32, and the water inlet 250 of the humidification tank 1000 is closed within the area enclosed by the baffle 32 when the float valve 100 rises.

[0042] When the water level rises and pushes the float valve 100 upward, the lower end of the inlet 250 extends into the area enclosed by the baffle 32. The baffle 32 acts as a limit, enclosing the inlet 250 inside the baffle 32 to prevent sealing failure caused by lateral displacement. Even when there is water flow impact or slight shaking of the float valve 100, an effective seal can be maintained, thereby further improving the reliability of water level control in the humidification tank 1000.

[0043] This embodiment also provides a humidification tank 1000, including the float valve 100 described above. The humidification tank 1000 further includes a tank body 200 and a heating plate. The top of the tank body 200 is provided with a water inlet 250, an air inlet 260, and an air outlet 270. The float valve 100 is located inside the tank body 200 and directly below the water inlet 250. The heating plate is located at the bottom of the tank body 200.

[0044] The heating plate heats the liquid water in the tank 200. The dry gas output by the ventilator enters the tank 200 through the air inlet 260, flows over the heated water surface, is heated and humidified, and is output to the patient through the air outlet 270. The float valve 100 is located directly below the water inlet 250. When the water level drops, the float valve 100 falls, causing the water inlet 250 to open and automatically replenish water. When the water level rises to the preset height, the float valve 100 drives the sealing element 30 to block the water inlet 250 and stop replenishing water. The waterproof and breathable membrane 20 and gas channel on the float valve 100 ensure that the float valve 100 has a constant quality and precise opening and closing.

[0045] In one embodiment, see Figure 3 and Figure 4 The float valve body 10 includes a first float valve portion 15 and a second float valve portion 16. The second float valve portion 16 is disposed above the first float valve portion 15 and connected to the first float valve portion 15. The first float valve portion 15 and the second float valve portion 16 communicate to form the cavity 11. The outer diameter of the second float valve portion 16 is smaller than the outer diameter of the first float valve portion 15. The second float valve portion 16 and the first float valve portion 15 form a convex shape.

[0046] The top of the tank body 200 is provided with a guide limiting cylinder 210. The guide limiting cylinder 210 is sleeved on the outside of the second float valve part 16 and located above the first float valve part 15. The bottom end of the guide limiting cylinder 210 is used to limit the radial floating of the float valve body 10 within a preset range. The inner wall of the guide limiting cylinder 210 is provided with at least two serrated limiting protrusions 220. The plurality of limiting protrusions 220 are clearance-fitted with the second float valve part 16 to limit the circumferential floating of the float valve body 10 within a preset range.

[0047] The serrated limiting protrusion 220 is provided, which ensures that water can pass through. The limiting protrusion 220 realizes circumferential limiting of the float valve 100, and the bottom end of the guide limiting cylinder 210 realizes radial limiting of the float valve 100, thereby realizing all-round limiting of the float valve 100.

[0048] Optionally, the guide limiting cylinder 210 has three equally spaced limiting protrusions 220 inside, making the circumferential limiting of the float valve 100 more stable and reliable. It should be understood that the number and arrangement of the limiting protrusions 220 are not limited to the above situation, and other situations are also possible, which are not limited here.

[0049] Optionally, the tank body 200 is provided with a first inclined plate 230, which is located below the air inlet 260; the tank body 200 is provided with a second inclined plate 240, which is located below the air outlet 270. The arrangement of the first inclined plate 230 and the second inclined plate 240 can prevent liquid backflow.

[0050] Please see Figure 6 This embodiment also provides a humidification tank water level control method, applied to the humidification tank 1000 described above, the water level control method comprising: A cavity 11 is provided inside the float valve 100, and a waterproof and breathable membrane 20 is provided between the cavity 11 and the external environment.

[0051] When the temperature inside the tank 200 rises, the excess gas that has expanded due to heat in the cavity 11 is discharged through the waterproof and breathable membrane 20 to balance the internal and external air pressure and prevent pressure buildup inside the cavity 11.

[0052] When the temperature inside the tank 200 decreases, the waterproof and breathable membrane 20 draws external gas into the cavity 11, while the hydrophobic properties of the waterproof and breathable membrane 20 prevent liquid water from entering the cavity 11 in the high humidity environment, thereby ensuring that the float valve 100 maintains a constant mass during operation.

[0053] Maintaining the mass of the float valve 100 constant during operation ensures that the seal 30 accurately seals or opens the inlet 250 of the humidification tank at the preset water level.

[0054] The water level control method for the humidifier 1000 provided in this embodiment fundamentally solves the technical problems of internal water accumulation, increased mass, and buoyancy inaccuracy caused by alternating hot and cold temperatures in the traditional float valve 100 through the adaptive air pressure balance and water blocking function of the waterproof and breathable membrane 20. This ensures that the float valve 100 always maintains its designed buoyancy characteristics, and that the sealing element 30 accurately and reliably seals or opens the inlet 250 at the preset water level, thereby significantly improving the accuracy, long-term stability, and clinical safety of the water level control of the humidifier 1000.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A float valve, applied to a humidification tank, characterized in that, include: The float valve body has a cavity, and the top of the cavity is provided with at least one vent for connecting the cavity to the external environment. A waterproof and breathable membrane is disposed at the vent and covers and seals the vent. The waterproof and breathable membrane allows gas molecules to pass through while preventing liquid water and water vapor from entering the cavity. A sealing element is provided, which covers the outside of the vent and the waterproof and breathable membrane and is nested and connected to the float valve body. A gas channel is formed between the sealing element and the float valve body. The sealing element is used to block the water inlet of the humidification tank when the water level in the humidification tank reaches a preset height.

2. The float valve according to claim 1, characterized in that, The waterproof and breathable membrane includes a modified surface layer, a microporous filter layer, and a support layer arranged and connected in sequence. After the waterproof and breathable membrane is installed on the float valve body, the support layer is arranged on the side closer to the cavity, and the modified surface layer is arranged on the side closer to the external environment.

3. The float valve according to claim 1, characterized in that, The waterproof and breathable membrane is applied to the float valve body via a secondary injection molding process involving overmolding.

4. The float valve according to claim 1, characterized in that, The waterproof and breathable membrane is circular.

5. The float valve according to claim 1, characterized in that, The top of the float valve body is provided with a insertion groove, and the sealing element is provided with an insertion part, the insertion part and the insertion groove are nested and inserted.

6. The float valve according to claim 5, characterized in that, The groove wall of the insertion slot is provided with at least one air passage groove, and the air passage groove extends to form the air inlet. After the sealing member is nested and fitted with the float valve body, the inner wall of the sealing member and the air passage groove form the gas channel.

7. The float valve according to claim 1, characterized in that, The edge of the upper surface of the seal is provided with a circumferential baffle, and the water inlet of the humidification tank is closed within the area enclosed by the baffle when the float valve rises.

8. A humidification tank, characterized in that, The humidification tank further includes the float valve according to any one of claims 1 to 7, and further includes: The tank body has a water inlet, an air inlet, and an air outlet at its top, and the float valve is located inside the tank body and directly below the water inlet; A heating plate is located at the bottom of the tank.

9. The humidification tank according to claim 8, characterized in that, The float valve body includes: First float valve section; The second float valve part is located above the first float valve part and connected to the first float valve part. The first float valve part and the second float valve part communicate to form the cavity. The outer diameter of the second float valve part is smaller than the outer diameter of the first float valve part. The second float valve part and the first float valve part form a convex shape. The top of the tank is provided with a guide limiting cylinder, which is sleeved outside the second float valve part and located above the first float valve part. The bottom end of the guide limiting cylinder is used to limit the radial floating of the float valve body within a preset range. The inner wall of the guide limiting cylinder is provided with at least two serrated limiting protrusions. The multiple limiting protrusions are in clearance fit with the second float valve part to limit the circumferential floating of the float valve body within a preset range.

10. A method for controlling the water level in a humidification tank, applied to the humidification tank according to any one of claims 8 to 9, characterized in that, The water level control method includes: A cavity is provided inside the float valve, and a waterproof and breathable membrane is provided between the cavity and the external environment; When the temperature inside the tank rises, the excess gas that expands due to heat in the cavity is discharged through the waterproof and breathable membrane to balance the internal and external air pressure. When the temperature inside the tank decreases, the waterproof and breathable membrane draws external gas into the cavity, while the hydrophobic properties of the waterproof and breathable membrane prevent liquid water from entering the cavity in the high-humidity environment. Maintaining the mass of the float valve constant during operation ensures that the seal accurately blocks or opens the inlet of the humidification tank at the preset water level.

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