Breathing filter

Abstract

The breathing filter comprises a shell, a cover piece and a filtering assembly, the shell comprises a first connector, a first connecting part and a cavity wall which are sequentially connected, a step is formed at the connecting position of the first connecting part and the cavity wall, and a first protrusion extending towards the axis of the shell is arranged in the cavity wall; the cover piece comprises a second connector and a second connecting part which are connected, the end, deviating from the second connector, of the second connecting part is connected to the end, deviating from the first connecting part, of the cavity wall, so that a containing cavity is formed in the cavity wall and used for filling the adsorption module, and the first connector and the second connector communicate with the containing cavity; the filtering assembly comprises a first filtering piece located on the side, facing the step, of the adsorption module and a first supporting piece with the two sides abutting against the first protrusion and the first filtering piece respectively, the first supporting piece can make the first filtering piece abut against the step, it can be avoided that dust and particles of the adsorption module leak out to affect breathing of a patient, and medical accidents are avoided.

Description

Technical Field

[0001] This utility model relates to the field of medical respiratory equipment technology, and in particular to a respiratory filter. Background Technology

[0002] When performing surgery, patients need to be anesthetized. Using an anesthesia machine for general anesthesia is a commonly used general anesthesia technique that is safe and fast. A respiratory anesthesia machine delivers gaseous anesthetic drugs through respiration to achieve general anesthesia for the patient.

[0003] During the respiratory cycle, the anesthesia machine outputs a mixture of oxygen and anesthetic gas, which is then inhaled by the patient through the inhalation tubing to achieve inhalation anesthesia. The patient then exhales a mixture containing carbon dioxide through the exhaust tubing. At this point, an adsorption device is needed to adsorb the exhaled mixture to remove the carbon dioxide and allow the oxygen and anesthetic gas in the mixture to participate in the next respiratory cycle.

[0004] Existing adsorption devices are typically carbon dioxide absorption canisters installed inside anesthesia machines. These canisters contain carbon dioxide adsorption media, which is filled by the doctor. The media is used continuously by multiple patients on the anesthesia machine until it becomes ineffective. Then, medical staff open the canisters to empty the ineffective media and refill it with new media. This refilling process generates significant dust pollution and is cumbersome and time-consuming. This means that the anesthesia machine cannot be disconnected from the respiratory system during surgery to replace the carbon dioxide media. Doctors must assess the surgery duration beforehand to determine if a media replacement is necessary. If the surgery is long and there is insufficient remaining carbon dioxide adsorption media, a preoperative replacement is required, resulting in wasted media. Similarly, if the surgery is short, multiple patients may share the same carbon dioxide adsorption medium in one canister. Although filtered, small amounts of dust and bacteria may remain in the anesthesia machine's tubing. These harmful substances, shared by multiple patients, could pose a risk of cross-infection.

[0005] Furthermore, the existing adsorption devices have small air inlet channels, which increases airflow resistance and affects the patient's breathing. The filter cotton installed at the air inlet and outlet is at risk of fiber shedding, causing the patient to cough or the airway to be blocked. The adsorption medium will generate a large amount of dust or small particles during product transportation and packaging. During transportation or use, the vibration and airflow pressure can easily cause the filter cotton to deform, creating gaps around the filter cotton. This allows dust and particles in the adsorption medium to leak into the breathing tubing through the gaps, affecting the patient's breathing and causing medical accidents.

[0006] Therefore, how to provide a breathing filter that at least partially solves the above-mentioned drawbacks is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0007] The purpose of this invention is to provide a breathing filter that can prevent dust and particulate matter from leaking from the adsorption module and affecting the patient's breathing, thus avoiding medical accidents.

[0008] To achieve the above objectives, this utility model provides a breathing filter, comprising:

[0009] The housing includes a first connector, a first connecting part and a cavity wall connected in sequence. A step is formed at the connection between the first connecting part and the cavity wall. The cavity wall has a first protrusion extending toward the axis of the housing.

[0010] The cover includes a second connector and a second connecting part connected to each other. One end of the second connecting part away from the second connector is connected to one end of the cavity wall away from the first connecting part, so that a receiving cavity is formed inside the cavity wall. The receiving cavity is used to fill the adsorption module. The first connector and the second connector are connected to the receiving cavity.

[0011] The filter assembly includes a first filter element located on the side of the adsorption module facing the step, and a first support element on both sides abutting against the first protrusion and the first filter element respectively, wherein the first support element enables the first filter element to abut against the step.

[0012] Preferably, the second connecting portion includes:

[0013] The second connecting part body is connected to the second connector;

[0014] The first extension is connected to the body of the second connector and extends in a direction away from the second connector.

[0015] The second extension is connected to the body of the second connecting part and is spaced out and sleeved on the outer periphery of the first extension. The outer circumferential surface of the second extension can fit against the inner side of the cavity wall.

[0016] Preferably, the second extension is provided with a second protrusion extending toward the axis of the cover;

[0017] The filtering components also include:

[0018] The second filter element is disposed on the side of the adsorption module facing the first extension.

[0019] The second support member is engaged with the second protrusion, and the side of the second support member facing the first extension abuts against the second filter member, so that the second filter member abuts against the first extension.

[0020] Preferably, a first guide plate is provided on the side of the first connecting part near the first connector, and the first guide plate is evenly arranged along the circumference of the first connecting part;

[0021] A second guide plate is provided on the side of the second connector body near the second joint, and the second guide plate is evenly arranged along the circumference of the second connector body.

[0022] Preferably, the first guide plate and the first filter element have a gap in the axial direction of the housing to form a first gas buffer zone;

[0023] The second guide plate and the second filter have a gap in the axial direction of the housing to form a second gas buffer zone.

[0024] Preferably, both the first support member and the second support member include a support member body with a larger cross-sectional diameter and an abutting portion with a smaller cross-sectional diameter. The abutting portion is located on the opposite side of the two support member bodies to abut against the first filter member or the second filter member.

[0025] Preferably, both the first filter element and the second filter element include electrostatic cotton and non-woven fabric disposed on both sides of the electrostatic cotton.

[0026] Preferably, both abutting parts are welded to the nonwoven fabric that is in contact with them.

[0027] Preferably, the first guide plate and the second guide plate are in one-to-one correspondence and both are plate structures.

[0028] Preferably, the first protrusion is uniformly distributed circumferentially along the interior of the cavity wall, or the first protrusion is an annular protrusion; and,

[0029] The second protrusion is evenly distributed along the circumference of the second extension, or the second protrusion is an annular protrusion.

[0030] Compared to the aforementioned background technology, the breathing filter provided by this utility model includes a housing, a cover, and a filter assembly. The housing includes a first connector, a first connecting portion, and a cavity wall connected in sequence. A step is formed at the connection between the first connecting portion and the cavity wall. A first protrusion extending toward the axis of the housing is provided inside the cavity wall. The cover includes a second connector and a second connecting portion connected together. One end of the second connecting portion away from the second connector is connected to one end of the cavity wall away from the first connecting portion, so that a receiving cavity is formed inside the cavity wall. The receiving cavity is used to fill the adsorption module. The first connector and the second connector communicate with the receiving cavity. The filter assembly includes a first filter element located on the side of the adsorption module facing the step, and first support members on both sides abutting against the first protrusion and the first filter element respectively. The first support members enable the first filter element to abut against the step.

[0031] Specifically, by forming a step at the connection between the first joint and the cavity wall, and providing a first protrusion extending toward the axis of the housing inside the cavity wall, the first support member abutting against the first protrusion can press the first filter element to the step. With the fixation of the first support member, when the airflow pressure impacts the first filter element, gaps cannot be formed around the first filter element, thereby preventing dust and particles from the adsorption module filled in the cavity from leaking out along the first filter element and affecting the patient's breathing, thus avoiding medical accidents. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 An exploded view of the breathing filter provided in an embodiment of this utility model;

[0034] Figure 2 This is a cross-sectional view of the structure of the breathing filter provided in an embodiment of the present invention;

[0035] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0036] Figure 4 This is a schematic diagram of the structure of the cover provided in an embodiment of the present utility model;

[0037] Figure 5 This is a schematic diagram of the structure of the shell provided in an embodiment of the present utility model;

[0038] Figure 6 This is a schematic diagram of the structure of the cover provided in another embodiment of the present utility model;

[0039] Figure 7 This is a schematic diagram of the structure of the housing provided in another embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of the first support member and the second support member provided in the embodiment of this utility model;

[0041] Figure 9 This is a schematic diagram of the structure of the first filter element and the second filter element provided in the embodiment of this utility model.

[0042] in:

[0043] 100-Shell, 110-First connector, 120-First connecting part, 121-First guide plate, 130-Cavity wall, 131-First protrusion, 140-Step, 150-First gas buffer zone;

[0044] 200-Cover, 210-Second connector, 221-Second connecting body, 222-First extension, 223-Second extension, 224-Second protrusion, 225-Second guide plate, 230-Second gas buffer zone;

[0045] 300 - Adsorption module;

[0046] 400-Filter assembly, 410-First filter element, 411-Electrostatic cotton, 412-Non-woven fabric, 420-First support element, 421-Support element body, 422-Abutting part, 430-Second filter element, 440-Second support element. Detailed Implementation

[0047] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0048] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left" and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the indicated position or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations of this utility model.

[0050] The purpose of this invention is to provide a breathing filter that prevents dust and particles from leaking from the adsorption module 300 and affecting the patient's breathing, thus avoiding medical accidents. The breathing filter is installed between the end of the exhalation tube at the patient's end and the air inlet of the anesthesia machine. It can be quickly replaced by inserting the second connector 210 and the first connector 110 of the breathing filter into the end of the exhalation tube at the patient's end and the connector of the air inlet of the ventilator, respectively, without stopping the operation of the anesthesia machine. Since the carbon dioxide absorbent in the breathing filter is pre-filled, there are different product specifications with different filling amounts. Doctors can also select the appropriate product specification before surgery according to the patient's condition, ensuring that a single product is used by a single patient, avoiding the risk of cross-infection caused by multiple patients sharing the same product.

[0051] Please see Figures 1 to 9 To achieve the above objectives, this utility model provides a breathing filter, including a housing 100, a cover 200, and a filter assembly 400.

[0052] The housing 100 includes a first connector 110, a first connecting portion 120, and a cavity wall 130 connected in sequence. A step 140 is formed at the connection between the first connecting portion 120 and the cavity wall 130. The cavity wall 130 has a first protrusion 131 extending toward the axis of the housing 100. The first connector 110 is a hollow structure with a first flow channel inside. The first connecting portion 120 is connected to one side of the first connector 110 and extends outward to form a flared structure to expand the space connected to the first flow channel. The cover 200 includes a second connector 210 and a second connecting portion connected together. One end of the second connecting portion opposite to the second connector 210 is connected to one end of the cavity wall 130 opposite to the first connecting portion 120, so that a receiving cavity is formed inside the cavity wall 130. The receiving cavity is used to fill the adsorption module 300. The first connector 110 and the second connector 210 communicate with the receiving cavity. The filter assembly 400 includes a first filter element 410 located on the side of the adsorption module 300 facing the step 140, and a first support member 420 on both sides abutting against the first protrusion 131 and the first filter element 410 respectively. The first support member 420 enables the first filter element 410 to abut against the step 140.

[0053] The second connector 210 is a hollow structure with a second flow channel inside. The second connecting part extends outward from one side of the second connector 210 to form a flared structure, which is used to expand the space connected to the second flow channel. One of the first connector 110 and the second connector 210 is used to connect with the air outlet of the patient end, and the other is used to connect with the air inlet of the anesthesia machine, so that the gas exhaled by the patient can be adsorbed with carbon dioxide for use in the subsequent gas circulation during the anesthesia process. In this embodiment, the first filter 410 is pressed to the step 140 by the first support member 420. The first connector 110 can be used to connect with the air inlet of the anesthesia machine to prevent exhaled bacteria and dust and particles from the adsorption module 300 from entering the subsequent gas circulation through the first connector 110.

[0054] One of the first connector 110 and the second connector 210 is used to connect to the patient's air outlet, and the other is used to connect to the anesthesia machine's air inlet. This allows for rapid replacement of the breathing filter without stopping the anesthesia machine. The carbon dioxide absorbent is pre-filled, and different dosages can be set according to actual needs. Doctors can select the appropriate dosage before surgery based on each patient's actual situation, ensuring that a single breathing filter is used by a single patient and avoiding the risk of cross-infection from multiple patients sharing the same breathing filter.

[0055] By forming a step 140 at the connection between the first connecting part 120 and the cavity wall 130, and providing a first protrusion 131 extending toward the axis of the housing 100 inside the cavity wall 130, the first support member 420 abutting against the first protrusion 131 can press the first filter 410 to the step 140. With the fixation of the first support member 420, when the airflow pressure impacts the first filter 410, gaps cannot be formed around the first filter 410, thereby preventing dust and particles from the adsorption module 300 filled in the receiving cavity from leaking out along the first filter 410 and affecting the patient's breathing, thus avoiding medical accidents.

[0056] In some embodiments, the second connecting portion includes a second connecting portion body 221, a first extension 222, and a second extension 223. The second connecting portion body 221 is connected to the second connector 210. The first extension 222 is connected to the second connecting portion body 221 and extends in a direction away from the second connector 210. The second extension 223 is connected to the second connecting portion body 221 and is spaced around the outer periphery of the first extension 222. The outer circumferential surface of the second extension 223 can fit against the inner side of the cavity wall 130. The second extension 223 is provided with a second protrusion 224 extending toward the axis of the cover 200. The filter assembly 400 also includes a second filter element 430 and a second support element 440. The second filter element 430 is disposed on the side of the adsorption module 300 facing the first extension 222. The second support element 440 is engaged with the second protrusion 224, and the side of the second support element 440 facing the first extension 222 abuts against the second filter element 430, so that the second filter element 430 abuts against the first extension 222.

[0057] Understandably, the second support member 440 engages with the second protrusion 224, causing the second support member 440 to press the second filter element 430 against the first extension 222. A gap exists between the second extension 222 and the first extension 222, providing a certain deformation space for the first extension 222 and a certain buffering effect for the airflow passing through the second filter element 430. For example, when the pressure on the first extension 222 is too great, the first extension 222 can be partially bent to form an elastic element in a compressed state, while clamping the second filter element 430. Meanwhile, to avoid problems such as the second filter element 430 being too tight and breaking, the first support element 420 and the first filter element 410 can achieve gas filtration at the first flow channel and prevent dust and particles from flowing out of the receiving cavity. The second support element 440 and the second filter element 430 can achieve gas filtration at the second flow channel and prevent dust and particles from flowing out of the receiving cavity. In this way, either the first connector 110 and the second connector 210 can be connected to the air inlet of the anesthesia machine, which can prevent dust and particles from the adsorption module 300 from entering the subsequent gas circulation.

[0058] In this embodiment, a first guide plate 121 is provided on the side of the first connecting part 120 near the first connector 110, and the first guide plate 121 is evenly arranged along the circumference of the first connecting part 120; a second guide plate 225 is provided on the side of the second connecting part body 221 near the second connector 210, and the second guide plate 225 is evenly arranged along the circumference of the second connecting part body 221. The first guide plate 121 and the second guide plate 225 correspond one-to-one and are both plate structures.

[0059] Taking the example of gas entering along the first flow channel and exiting along the second flow channel, the arrangement of the first guide plate 121 disperses the gas entering the first connecting part 120 along the first flow channel among the first guide plates 121, making the airflow more evenly distributed at all angles within the first connecting part 120. This ensures sufficient contact with the adsorbent in the adsorption zone, resulting in uniform and thorough adsorption. The gas, after evenly entering the adsorption module 300, is evenly discharged between the second guide plates 225 on the second connecting part body 221, and then exits along the second flow channel. When the gas enters along the second flow channel and exits along the first flow channel, the effect is similar to the above, and will not be elaborated here.

[0060] The first guide plate 121 and the first filter element 410 have a gap in the axial direction of the housing 100 to form a first gas buffer 150; the second guide plate 225 and the second filter element 430 have a gap in the axial direction of the housing 100 to form a second gas buffer 230. By setting the first gas buffer 150 and the second gas buffer 230, the airflow disperses after entering the first gas buffer 150 and the second gas buffer 230. Since the dispersion area of ​​the gas buffer is large, the airflow entering the adsorption module 300 through the gas inlet end of the gas buffer, and then flowing through the adsorption module 300 and the gas outlet end of the gas buffer, will significantly reduce the airflow resistance, making the patient's breathing smooth.

[0061] The adsorption module 300 is a carbon dioxide absorbent, usually calcium lime or soda lime granules. The outer shell of the breathing filter is transparent, allowing full observation of the color change of the carbon dioxide absorbent. When the carbon dioxide is saturated, the color may turn red, at which point a new breathing filter can be replaced. Replacement is simple: just disconnect the first connector 110 and the second connector 210 and install the new breathing filter. Replacement is convenient and quick. Generally, one breathing filter is sufficient for one patient at a time. For patients with long surgery times, two breathing filters can fully meet their needs, avoiding the risk of infection between surgical patients.

[0062] It is understood that both the first support member 420 and the second support member 440 include a support member body 421 with a larger cross-sectional diameter and an abutting portion 422 with a smaller cross-sectional diameter. The abutting portion 422 is located on the opposite side of the two support member bodies 421 to abut against the first filter member 410 or the second filter member 430.

[0063] Specifically, the support body 421 has a ring-shaped structure, including a first ring on the inner side and a second ring on the outer side. A radially extending reinforcing rib connects the first ring and the second ring, and all the reinforcing ribs converge at the center to form a disk. A hollow structure is formed between the reinforcing ribs, the first ring, and the second ring, which reduces the weight of the support body 421 and facilitates the flow of gas along the hollow structure. The abutting part 422 has a ring-shaped structure with a cross-sectional dimension smaller than that of the second ring. The abutting part 422 has a certain thickness in the axial direction of the support body 421, so that there is a certain gap between the support body 421 of the first support 420 and the first filter 410, and between the support body 421 of the second support 440 and the second filter 430. This avoids direct contact between the support body 421 and the first filter 410 or the second filter 430, thereby increasing the effective contact area between the gas and the first filter 410 or the second filter 430.

[0064] The abutment portion 422 of the annular structure has a cross-sectional dimension smaller than that of the first filter element 410 and the second filter element 430, so as to avoid the abutment portion 422 pressing against the edge of the first filter element 410 or the second filter element 430, which could lead to easy detachment. The abutment portion 422 of the second support member 440 should be provided corresponding to the first extension portion 222 to facilitate clamping the second filter element 430. The diameter of the abutment portion 422 of the first support member 420 should be larger than the inner diameter of the annular first step, so that the abutment portion 422 of the first support member 420 can correspond to the end face of the first step to press the first filter element 410.

[0065] In some embodiments, both the first filter element 410 and the second filter element 430 include electrostatic cotton 411 and non-woven fabric 412 disposed on both sides of the electrostatic cotton 411. The breathable non-woven fabric 412, located on both sides of the electrostatic cotton 411 and wrapping it, prevents the fibers of the electrostatic cotton 411 from falling out, ensuring patient breathing safety. Both abutment portions 422 are welded integrally with the non-woven fabric 412 using ultrasonic welding technology, ensuring that the electrostatic cotton 411 wrapped in the non-woven fabric 412 remains flat, solving the problem of edge gaps after wrinkles in the electrostatic cotton 411. The support frame body and the shell 100 or cover 200 are connected by mechanical assembly or ultrasonic welding, firmly fixing the electrostatic cotton 411 wrapped in the non-woven fabric 412 and preventing the adsorbent dust from leaking out. This protects patient safety, while the first filter element 410 and the second filter element 430 can block the flow of bacteria, preventing harmful substances such as bacteria from accompanying the respiratory cycle.

[0066] To ensure that the first filter element 410 and the second filter element 430 are of the same size for easy processing and installation, and that the first support element 420 and the second support element 440 are of the same size for easy processing and installation, the cavity wall 130 of the housing 100 adopts a barrel-shaped structure with a certain angle between its extension direction and the axis of the housing 100. Specifically, the cross-sectional diameter of the end of the cavity wall 130 away from the first connector 110 is slightly larger than the cross-sectional diameter of the end of the cavity wall 130 near the first connector 110, so that the cross-sectional diameter of the second extension 223 extending into the end of the cavity wall 130 away from the first connector 110 is consistent with the cross-sectional diameter of the end of the cavity wall 130 near the first connector 110. This makes the dimensions of the first filter element 410 and the second filter element 430 consistent, and the dimensions of the first support element 420 and the second support element 440 consistent. Each component has a simple structure, can be produced individually, and is easy to assemble into a product.

[0067] The outer side of the second extension 223 is provided with a radially extending annular structure, which abuts against the end face of the cavity wall 130. Then, the annular structure is fixedly connected to the end face of the cavity wall 130 by bonding or ultrasonic welding, thereby stabilizing the entire breathing filter structure. In addition, the first protrusion 131 is uniformly arranged circumferentially inside the cavity wall 130, or the first protrusion 131 is an annular protrusion; and the second protrusion 224 is uniformly arranged circumferentially inside the second extension 223, or the second protrusion 224 is an annular protrusion, which can achieve the fixation of the first support member 420 and the second support member 440.

[0068] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0070] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A respiratory filter, characterized in that, The filter comprises: a housing comprising a first joint, a first connecting part and a cavity wall connected in sequence, a step being formed at the connecting part of the cavity wall and the first connecting part, and a first protrusion being arranged inside the cavity wall and extending towards the axis of the housing; a cover comprising a second joint and a second connecting part connected in sequence, the second connecting part being connected to one end of the cavity wall away from the first connecting part to form an accommodating cavity inside the cavity wall for loading an adsorption module, and the first joint and the second joint being communicated with the accommodating cavity; a filter assembly comprising a first filter arranged on one side of the adsorption module away from the step, and a first support abutting against the first protrusion and the first filter on two sides respectively, the first support being capable of abutting the first filter against the step.

2. The filter according to claim 1, wherein the second connecting part comprises: a second connecting part body connected to the second joint; a first extension part connected to the second connecting part body and extending away from the second joint; and a second extension part connected to the second connecting part body and spacedly sleeved on the outer periphery of the first extension part, the outer circumferential surface of the second extension part being capable of abutting against the inner surface of the cavity wall.

3. The filter according to claim 2, wherein the second extension part is provided with a second protrusion extending towards the axis of the cover; the filter assembly further comprises: a second filter arranged on one side of the adsorption module away from the first extension part; and a second support clamped on the second protrusion, and one side of the second support away from the first extension part abutting against the second filter so as to abut the second filter against the first extension part.

4. The filter according to claim 3, wherein the first connecting part is provided with a first flow guide plate on one side close to the first joint, and the first flow guide plate is uniformly arranged along the circumference of the first connecting part; the second connecting part body is provided with a second flow guide plate on one side close to the second joint, and the second flow guide plate is uniformly arranged along the circumference of the second connecting part body.

5. The filter according to claim 4, wherein the first flow guide plate and the first filter have a gap in the axial direction of the housing to form a first gas buffer zone; the second flow guide plate and the second filter have a gap in the axial direction of the housing to form a second gas buffer zone.

6. The filter according to claim 5, wherein the first support and the second support each comprise a support body with a larger cross-sectional diameter and an abutting part with a smaller cross-sectional diameter, the abutting part being arranged on one side away from the support body to abut against the first filter or the second filter.

7. The filter according to claim 6, wherein the first filter and the second filter each comprise electrostatic cotton and non-woven fabric arranged on two sides of the electrostatic cotton.

8. The filter according to claim 7, wherein Both of the abutting portions are welded with the corresponding non-woven fabric.

9. The respiratory filter of claim 7, wherein, The first guide vane and the second guide vane are one-to-one corresponding and are both plate structures.

10. The respiratory filter of any one of claims 3-9, wherein, The first protrusions are uniformly arranged along the circumference inside the cavity wall, or the first protrusions are annular protrusions; and The second protrusions are uniformly arranged along the circumference of the second extension, or the second protrusions are annular protrusions.

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