Breather valve with self-cleaning function

Abstract

A breather valve with a self-cleaning function relates to the field of breather valves and comprises a cylindrical shell, a first seal head and a second seal head, the first seal head and the second seal head are arranged at two ends of the shell, the shell is provided with an airflow channel communicated with an inner cavity of the shell and the outside, and the second seal head is provided with an air passing hole used for being connected with an ultrapure water storage tank; multiple layers of filter cartridges are sequentially arranged in the shell from inside to outside in a sleeving manner, the projections of the air passing holes in the axial direction of the shell are located in the innermost layer of filter cartridge, an annular channel is formed between every two adjacent layers of filter cartridges, a water distribution ring is arranged on the outer side face of each layer of filter cartridge, and the water distribution rings are located on the upper portions of the filter cartridges; the first sealing head is provided with a water inlet hole capable of conveying clean water to the water distribution ring, the second sealing head is provided with a water outlet hole for discharging water flow in the shell, the technical problem that a breather valve or a filter element of the breather valve of the ultrapure water storage tank needs to be replaced regularly can be solved, and online self-cleaning can be carried out on the breather valve.

Description

TECHNICAL FIELD

[0001] The utility model relates to a breathing valve field, specifically a breathing valve with self-cleaning function. BACKGROUND

[0002] Ultra-pure water is a kind of high-purity water treated by technology, because of its extremely high purity, plays an indispensable role in many high-tech industries and precision manufacturing industries with strict requirements on water quality. After treatment, the ultra-pure water is generally first introduced into the storage tank for temporary storage, and when needed, the ultra-pure water in the storage tank is output to the target position.

[0003] In order to avoid the secondary pollution of ultra-pure water in the storage tank, when storing ultra-pure water at present, nitrogen inlet valve + nitrogen discharge valve nitrogen sealing technology is generally used: when ultra-pure water is introduced into the storage tank, the nitrogen discharge valve is opened to discharge the nitrogen in the storage tank, and when the ultra-pure water in the storage tank is discharged, the nitrogen inlet valve is opened to introduce nitrogen into the storage tank.

[0004] As is known to all, the cost of storing ultra-pure water with nitrogen is high, and in some processes, the solubility of ultra-pure water to carbon dioxide, nitrogen oxide and other acid radical polar molecules and the solubility of dissolved oxygen have no requirements, and a breathing valve is installed on the storage tank, and clean air after filtration is introduced into the storage tank to protect the ultra-pure water in the tank, without the need for more expensive nitrogen sealing technology.

[0005] In order to ensure the water quality of ultra-pure water in the storage tank, it is necessary to replace the breathing valve as a whole or the filter element of the breathing valve regularly, but during the replacement process, unfiltered air will inevitably enter the storage tank, affecting the water quality of the ultra-pure water in the tank, which requires the ultra-pure water in the tank to be emptied in advance, affecting the normal use of the storage tank, also affecting the normal production process to some extent, and reducing the work efficiency. UTILITY MODEL CONTENTS

[0006] In order to solve the technical problem that the breathing valve or the breathing valve filter element of the storage tank needs to be replaced regularly, the utility model provides a breathing valve with self-cleaning function.

[0007] In order to achieve the above object, the utility model adopts the specific scheme of: a breathing valve with self-cleaning function, including the casing of cylindrical, the first head of setting on the upper end of casing and the second head of lower end, the casing is opened with the airflow channel of communicating the inner chamber of casing and the outside, the second head is opened with the gas hole for connecting the ultrapure water storage tank, the projection of gas hole is located in the innermost layer filter drum along the casing axial direction, the annular channel is formed between the two adjacent layers of filter drums, the outer side of each layer of filter drum is provided with water distribution ring, and water distribution ring is located on the upper part of filter drum, each layer of filter drum includes the filter layer of cylindrical and the second fixed cylinder connected in the lower end of filter layer, the water inlet hole of being able to deliver clean water to water distribution ring is opened in the first head, and the water outlet hole for water flow of casing is opened in the second head.

[0008] As the further optimization of the above technical scheme: the louver is arranged in the airflow channel, and the distance between the upper edge of the second fixed cylinder and the lower edge of the louver is less than 50 mm.

[0009] As the further optimization of the above technical scheme: the upper end of the filter layer of each layer of filter drum is fixed on the first fixed cylinder, the first fixed cylinder is installed on the inner wall of the first head, and the second fixed cylinder is installed on the inner wall of the second head; the water distribution ring is fixed on the outer side of the filter layer and / or the outer side of the first fixed cylinder.

[0010] As the further optimization of the above technical scheme: the material of the filter layer is non-woven fabric.

[0011] As the further optimization of the above technical scheme: the distance between the water distribution ring of the multi-layer filter drum and the first head gradually increases from the inner layer to the outer layer.

[0012] As the further optimization of the above technical scheme: a gap is left between the outer circle of the water distribution ring of each layer of filter drum and the filter layer of the adjacent layer of filter drum.

[0013] As the further optimization of the above technical scheme: the material of the water distribution ring is sponge.

[0014] As the further optimization of the above technical scheme: a plurality of water inlet holes are opened in the first head, and each water distribution ring corresponds to at least one water inlet hole.

[0015] As the further optimization of the above technical scheme: the filter drum is n layers, the outermost filter drum is the first layer, the innermost filter drum is the n layer, the second fixed cylinder of the first to the n-1 layer of filter drum is opened with a water hole close to one end of the second head, and the water outlet hole is opened between the n-1 layer and the n layer of filter drum.

[0016] As the further optimization of the above technical scheme: the water outlet hole is a plurality of, and the adjacent two sides of filter drum directly correspond to at least one water outlet hole.

[0017] As a further optimization of the above technical solution, louvers are installed in the airflow channel.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention features a multi-layered filter cartridge within the housing, each comprising a cylindrical filter layer to filter air entering the ultrapure water storage tank. A water inlet is located on the first end cap to allow clean water to flow into the breather valve. The clean water passes through a water distribution ring and flows down the filter layer, flushing away dust particles trapped on the filter layer. This achieves online self-cleaning of the breather valve, eliminating the need for periodic replacement of the breather valve filter element. Attached Figure Description

[0020] Figure 1 This is a side view of the structure of this utility model;

[0021] Figure 2 for Figure 1 Cross-sectional view along the AA direction;

[0022] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0024] Figure 5 for Figure 1 Cross-sectional view along the middle BB direction;

[0025] Figure 6 This is a three-dimensional structural diagram of the present invention (along the direction of the first end cap);

[0026] Figure 7 This is a three-dimensional structural diagram of the present invention (along the direction of the second end cap);

[0027] Figure 8 This is an enlarged cross-sectional view of the nonwoven fabric.

[0028] Figure 9 This is a schematic diagram of the water guide ring structure;

[0029] Figure 10 This is a schematic diagram showing the connection relationship between the breather valve and the ultrapure water storage tank described in this utility model;

[0030] Figure 11 A schematic diagram showing the smaller aperture through which the water film is opened when the pressure is low;

[0031] Figure 12 This is a schematic diagram showing the larger aperture of the water film that is broken open under high pressure.

[0032] Reference numerals: 1. First end cap; 2. Shell; 3. Airflow channel; 4. Louver; 5. Second end cap; 6. Water outlet; 7. Air pipe; 8. Water inlet; 9. Filter cylinder; 901. First fixed cylinder; 902. Filter layer; 903. Second fixed cylinder; 10. Air outlet; 11. Water distribution ring; 12. Water outlet; 13. Ultrapure water storage tank; 14. Drain pipe; 15. Water inlet pipe; 16. Non-woven fabric; 17. Fiber filament; 18. Water guide ring. Detailed Implementation

[0033] The technical solution of this utility model will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of this utility model should be understood as prior art known or should be known by those skilled in the art, such as the preparation process of ultrapure water and the structure of ultrapure water storage tank.

[0034] This utility model discloses a breather valve with a self-cleaning function, such as Figure 10 As shown, the breather valve is installed on the ultrapure water storage tank 13. When the ultrapure water storage tank 13 discharges water to the outside through the drain pipe 14, the negative pressure environment inside the ultrapure water storage tank 13 draws in air through the breather valve and filters the air. The filtered clean air enters the ultrapure water storage tank 13. When water is sent into the ultrapure water storage tank 13 through the water inlet pipe 15, the air in the storage tank is discharged through the breather valve. The breather valve can also use clean water to flush away impurities in the air such as dust and particles filtered out, thus achieving self-cleaning.

[0035] Specifically, such as Figure 1 As shown, the breather valve includes a cylindrical housing 2, a first end cap 1 and a second end cap 5 disposed at both ends of the housing 2. In use, the housing 2 is vertically positioned, with the first end cap 1 located at the upper end of the housing 2 and the second end cap 5 located at the lower end of the housing 2. The housing 2 can be a cylindrical, square, or polygonal cylinder. In this embodiment, the housing 2 is cylindrical, and the cross-sections of the first end cap 1 and the second end cap 5 are both circular. The housing 2, the first end cap 1, and the second end cap 5 together enclose the inner cavity of the breather valve.

[0036] The side wall of the housing 2 has an airflow channel 3 that connects the inner cavity of the breathing valve to the outside. The airflow channel 3 is equipped with a louver 4, which is a horizontal annular louver that has the function of breathability and waterproofing. Outside air enters the inner cavity of the breathing valve through the gap between adjacent blades of the louver 4, and can also send the air in the breathing valve to the outside.

[0037] like Figure 2 , 5As shown, the housing 2 is provided with a plurality of layers of filter cartridges 9, the filter cartridges 9 are cylindrical, the housing 2 and the plurality of layers of filter cartridges 9 are coaxially distributed, and the spacing between adjacent two layers of filter cartridges 9 is the same. Each layer of filter cartridges 9 comprises a filter layer 902, a first fixed cylinder 901 connected to one end of the filter layer 902, and a second fixed cylinder 903 connected to the other end of the filter layer 902. Similarly, the filter layer 902, the first fixed cylinder 901, and the second fixed cylinder 903 are also cylindrical, the first fixed cylinder 901 is fixedly installed on the inner wall of the first end cover 1 away from the filter layer 902, and the second fixed cylinder 903 is fixedly installed on the inner wall of the second end cover 5 away from the filter layer 902. The first fixed cylinder 901 and the second fixed cylinder 903 are fixedly installed between the inner wall of the corresponding end cover in the prior art, such as welding and bonding.

[0038] The material of the filter layer 902 is non-woven fabric, and the non-woven fabric is also called non-woven fabric, such as Figure 8 As shown, the non-woven fabric 16 is a new generation of environmentally friendly material formed by oriented or random fibers 17, and has a biomimetic lung structure formed by the fibers 17 similar to mammals. The filter layer 902 can filter the air entering the breathing valve, so that clean air flows into the ultrapure water storage tank 13. The first fixed cylinder 901 and the second fixed cylinder 903 are made of rigid materials such as hard plastic and stainless steel, and the first fixed cylinder 901 and the second fixed cylinder 903 are convenient for fixing the flexible filter layer 902 in the housing 2.

[0039] As shown in Figure 1 , 2 The second end cover 5 is provided with a gas passing hole 10 for connecting the ultrapure water storage tank 13, and the projection of the gas passing hole 10 along the axis of the housing 2 is located in the innermost layer of filter cartridges 9. The gas passing hole 10 in the embodiment is circular, and the diameter of the gas passing hole 10 is smaller than the inner diameter of the innermost layer of filter cartridges 9. The second end cover 5 is fixedly provided with a gas passing pipe 7 in communication with the gas passing hole 10, and the gas passing pipe 7 is used for communicating with the gas inlet and outlet of the ultrapure water storage tank 13.

[0040] After the external air enters the breathing valve through the air flow channel 3, it is filtered layer by layer through a plurality of filter layers 902 to remove impurities in the air, and the filtered clean air enters the ultrapure water storage tank 13 through the gas hole 10 and the gas passing pipe 7.

[0041] As shown in Figure 2 , 6As shown in Figure 7, the first end cap 1 has an inlet hole 8 for supplying clean water to the inner cavity of the breather valve, and the second end cap 5 has an outlet hole 6 for discharging clean water from the breather valve. An annular channel is formed between adjacent filter cartridges 9 and between the outermost filter cartridge 9 and the shell 4. The inlet hole 8 and outlet hole 6 are connected one-to-one with the annular channel. Specifically, the filter cartridges 9 inside the shell 2 are arranged in n layers, and there are n channels. The inlet holes 8 on the first end cap 1 are arranged in n rings, with at least one inlet hole 8 per ring. In this embodiment, there are four inlet holes 8 per ring, and the four inlet holes 8 in the same ring are evenly spaced along the circumference of the first end cap 1. The outlet holes 6 on the second end cap 5 are arranged in n rings, with at least one outlet hole 6 per ring. In this embodiment, there are four outlet holes 6 per ring, and the four outlet holes 6 in the same ring are evenly spaced along the circumference of the second end cap 5.

[0042] In other embodiments of this utility model, such as Figure 4 As shown, the water outlet 6 can also be set as a ring: the filter cylinder 9 has n layers, the outermost filter cylinder 9 is the 1st layer, the innermost filter cylinder 9 is the nth layer, and the second fixed cylinder 903 of the filter cylinders 1 to n-1 layers has a water passage hole 12 at one end near the second end cap 5. The water outlet 6 is located between the n-1th layer and the nth layer filter cylinder 9. The position of the second end cap 5 between the n-1th layer and the nth layer filter cylinder 9 is relatively low, so the water between the other filter cylinders 9 can flow into the n-1th layer and the nth layer filter cylinder 9 through the water passage hole 12, and then be discharged through the water outlet 6.

[0043] In this embodiment, the filter cylinder 9 has 10 layers, which are layer 1, layer 2... layer 10 from the outside to the inside, forming 10 channels. The corresponding water inlet hole 8 is set to 10 rings, which are layer 1, layer 2... layer 10 from the outside to the inside.

[0044] like Figure 2 , 3 As shown, each filter layer 902 of each filter cylinder 9 is connected to a water distribution ring 11 at one end facing the first fixed cylinder 901. The water distribution ring 11 is fixed to the outside of the filter layer 902 and / or the outside of the first fixed cylinder 901.

[0045] In this embodiment, a water distribution ring 11 is provided on the first fixed cylinder 901 of each filter cylinder 9. The inner circular surface of the water distribution ring 11 is fixed to the outer wall of the first fixed cylinder 901 by adhesive bonding. The lower end face of the water distribution ring 11 abuts against the upper end of the filter layer 902 on the filter cylinder 9.

[0046] The material of the water distribution ring 11 is sponge. The cleaning water is sent into the inner cavity of the breathing valve through the water inlet hole 8, and directly falls on the water distribution ring 11. Part of the water flow flows downward along the outer wall of the first fixed cylinder 901 to the water distribution ring 11. Since the water inlet hole 8 of the cleaning water is limited, the water distribution ring 11 corresponding to the water inlet hole 8 below is first wetted. Due to the surface tension and gravity of water molecules, part of the cleaning water flows downward along the filter layer 902, and the other part first moves circumferentially along the water distribution ring 11 and then flows downward. With the progress of the water inlet process, the entire water distribution ring 11 can be wetted. The cleaning water flows to the filter layer 902 after passing through the water distribution ring 11, and the distribution of the cleaning water by the water distribution ring 11 increases the coverage area of the water flow on the surface of the filter layer 902.

[0047] The cleaning water for cleaning is introduced through the water inlet hole 8, and flows downward along the surface of the filter layer 902 after being distributed by the water distribution ring 11. On the one hand, the filter layer 902 is washed by the impact of the water flow. The washed water flows out of the breathing valve through the water outlet hole 6. On the other hand, when the airflow enters the inner cavity of the breathing valve from the outside, the non-woven fabric surface is pre-formed with a water film by the water flow. The water film is formed by the water flow hanging on the pore diameter of the non-woven fabric. When the pressure (negative pressure formed when the ultrapure water storage tank is drained) is different, the pore diameter of the non-woven fabric surface washed by water is large or small due to the action of surface tension. When the pressure is large, the pore diameter is large (as shown in Figure 11 ), and the thickness of the water film formed on the surface of the non-woven fabric is thin (surface tension effect). When the pressure is small, the pore diameter is small (as shown in Figure 12 ).

[0048] The spatial structure of the non-woven fabric determines that the pores and the channels between the pores are curved (as shown in Figure 8 ). Therefore, under different pressures, the pore diameter of the same non-woven fabric will form different channels. This curved trajectory motion makes solid particles easily collide with the water film on the non-woven fabric due to the conservation of angular momentum and the law of inertia, so that the particles are captured. The captured particles will flow out of the breathing valve through the water outlet hole 6 due to the surface adhesion effect.

[0049] In other embodiments of the utility model, the water distribution ring 11 is arranged as two layers of upper and lower layers which are arranged axially and spaced apart along the filter cylinder 9, one layer (i.e. the upper water distribution ring 11) close to the first head 1 is fixed to the outside of the first fixed cylinder 901, and the other layer (i.e. the lower water distribution ring 11) away from the first head 1 is fixed to the upper end of the filter layer 902 and located outside the filter layer 902, the inner side of the upper end of the filter layer 902 is bonded to the first fixed cylinder 901, and the outer side is bonded and fixed to the inner circular surface of the lower water distribution ring 11. The outer circular surface of the water distribution ring 11 of each layer of filter cylinders 9 and the filter layer 902 of the adjacent layer of filter cylinders 9 are left with a gap, when the clean water flow from the shell 2 is large, the upper water distribution ring 11 can form a buffer for the water flow, reduce the water flow speed, and the water flow slowly falls into the lower water distribution ring 11, avoiding the water flow from rapidly passing through the water distribution ring 11 and directly flowing downward due to the large water flow, facilitating the effective distribution of the water flow by the water distribution ring 11.

[0050] The distance between the water distribution ring 11 of the multi-layer filter cylinder 9 and the first head 1 gradually increases from the inner layer to the outer layer, the multi-layer water distribution ring 11 forms a tapered opening which gradually increases from bottom to top, and the axial length of the filter layer 902 gradually increases from the inside to the outside, facilitating the installation and replacement of the filter layer 902.

[0051] The second fixed cylinder 903 provided by the utility model can be used for fixing the filter layer 902, and on the other hand, the second fixed cylinder 903 can prevent the sewage after cleaning the filter layer 902 from flowing into the ultrapure water storage tank 13. The distance between the upper edge of the second fixed cylinder 903 and the lower edge of the louver 4 is less than 50mm.

[0052] Further, in other embodiments of the utility model, as shown in Figure 9 As shown in the drawings, the lower end of each filter cylinder 9 is provided with a water guide ring 18, and the water guide ring 18 is fixed to the outer side of the filter layer 902, which can make the sewage after cleaning flow in a specific direction.

[0053] In use, first, install the breather valve on the ultrapure water storage tank 13, and keep the breather valve vertically arranged, the first head 1 of the breather valve faces upward, and the second head 5 faces downward; then connect each of the 10 water inlet holes 8 corresponding to the 10 layers of filter cylinders 9 to a clean water source, the clean water source is ultrapure water, and the water inlet amount of each water inlet hole 8 is controlled separately.

[0054] When the ultrapure water tank 13 discharges ultrapure water outward, a negative pressure is formed in the tank body of the ultrapure water tank 13, and the breather valve sucks in air. When the air speed is below 0.2 m / s, the probability of dust escaping the non-woven fabric bonding is smaller. During use, the air speed entering the breather valve is controlled to be below 0.2 m / s. The gas entering the inner cavity of the shell 2 from the airflow channel 3 passes through the 10 layers of filter layers 902 for layer-by-layer filtration, and then enters the inner cavity of the innermost filter cylinder 9. In this process, ultrapure water is supplied to the first to fifth circle of water inlet holes 8 as cleaning water, and the cleaning water falls into the water distribution ring 11. The cleaning water is distributed by the water distribution ring 11, so that the water flows downward along the filter layers 902 after passing through the water distribution ring 11. At the same time, the sixth to tenth circle of water inlet holes 8 are not supplied with water. This is because when the air flows, the air flow moves from the first filter layer to the tenth filter layer. Since the air flow has an entraining effect, it is easy to entrain air inclusions in the form of mist droplets (water-solid). The sixth to tenth circle of water inlet holes 8 are not supplied with water, and the sixth to tenth layers of filter layers are non-woven fabrics without water. The non-woven fabric without water is easy to hang the mist droplets entraining air inclusions on its surface, forming a filter, and preventing such inclusions from entering the ultrapure water tank. Five or more layers of non-woven fabrics can achieve this effect.

[0055] When ultrapure water is supplied to the ultrapure water tank 13, the newly supplied ultrapure water presses the air in the tank, and the air is discharged outward and sequentially passes through the 10 layers of filter layers 902 and is discharged to the outside of the breather valve. In this process, ultrapure water is supplied to the sixth to tenth circle of water inlet holes 8 as cleaning water, which washes down the impurities attached to the sixth to tenth layers of filter layers 902 during the previous air intake. During the water intake and air discharge stage of the ultrapure water tank, a part of the inclusions hanging on the tenth to sixth filter layers is washed down by water, and another part of the inclusions is separated from the current filter layer 902 with the air flow and floats towards the first to fifth layers of filter layers 902. Solid particles can be carried away by the water flow or continue to float outward until they are washed away by the water flow (note: they can be washed away at the fourth layer, or they can be washed away at the third layer or the second layer, or the first layer).

[0056] With the water intake and discharge reaction operation of the ultrapure water tank 13, effective online self-cleaning of the breather valve is realized, and there is no need to stop production for replacement of the breather valve filter element, which ensures the continuous production and improves the production efficiency.

[0057] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A breathing valve with self-cleaning function, comprising a cylindrical housing (2), a first head (1) arranged at the upper end of the housing (2) and a second head (5) arranged at the lower end of the housing (2), characterized in that: The shell (2) is provided with an air flow channel (3) for connecting the inner cavity of the shell (2) with the outside, and the second end cover (5) is provided with a gas passing hole (10) for connecting an ultrapure water storage tank (13); The shell (2) is provided with a plurality of filter cartridges (9) from inside to outside, and the projection of the gas passing hole (10) along the axial direction of the shell (2) is located in the innermost filter cartridge (9); an annular channel is formed between adjacent two layers of filter cartridges (9), and each filter cartridge (9) is provided with a water distribution ring (11) on the outer side thereof, and the water distribution ring (11) is located at the upper portion of the filter cartridge (9); each filter cartridge (9) comprises a cylindrical filter layer (902) and a second fixing cylinder (903) connected to the lower end of the filter layer (902). The first end cover (1) is provided with a water inlet hole (8) for conveying clean water to the water distribution ring (11), and the second end cover (5) is provided with a water outlet hole (6) for discharging water flow in the shell (2).

2. The breather valve with self-cleaning function according to claim 1, characterized in that: The air flow channel (3) is provided with a louver (4), and the distance between the upper edge of the second fixing cylinder (903) and the lower edge of the louver (4) is less than 50 mm.

3. The breather valve with self-cleaning function according to claim 1, characterized in that: The upper end of the filter layer (902) of each filter cartridge (9) is fixed to the first fixing cylinder (901), the first fixing cylinder (901) is installed on the inner wall of the first end cover (1), and the second fixing cylinder (903) is installed on the inner wall of the second end cover (5); the water distribution ring (11) is fixed to the outer side of the filter layer (902) and / or the outer side of the first fixing cylinder (901).

4. The breather valve with self-cleaning function according to claim 1, characterized in that: The material of the filter layer (902) is non-woven fabric.

5. The breather valve with self-cleaning function according to claim 1, characterized in that: The distance between the water distribution ring (11) of the plurality of filter cartridges (9) and the first end cover (1) gradually increases from the inner layer to the outer layer.

6. The breather valve with self-cleaning function according to claim 1, characterized in that: A gap is left between the outer ring of the water distribution ring (11) of each filter cartridge (9) and the filter layer (902) of the adjacent filter cartridge (9).

7. The breather valve with self-cleaning function according to claim 1, characterized in that: The material of the water distribution ring (11) is sponge.

8. The breather valve with self-cleaning function according to claim 1, characterized in that: The first end cover (1) is provided with a plurality of water inlet holes (8), and each water distribution ring (11) corresponds to at least one water inlet hole (8).

9. The breather valve with self-cleaning function according to claim 1, characterized in that: The filter cartridge (9) is n layers, the outermost filter cartridge (9) is the first layer, the innermost filter cartridge (9) is the nth layer, the second fixing cylinder (903) of the first to (n-1)th layer filter cartridges (9) is provided with a water passing hole (12) at one end close to the second end cover (5), and the water outlet hole (6) is arranged between the (n-1)th and nth layer filter cartridges (9).

10. The breather valve with self-cleaning function according to claim 1, characterized in that: The water outlet hole (6) is a plurality of, and adjacent two filter cartridges (9) directly correspond to at least one water outlet hole (6).

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