A negative pressure self-limiting device and method

Abstract

The present application relates to the technical field of medical devices, and discloses a negative pressure self-limiting device and method, which comprises a shell, a cavity and at least one baffle are arranged in the shell, the baffle is connected with the side wall of the cavity, a capture groove is arranged on the bottom surface of the cavity, and a second gap is formed between the lower end of the baffle and the bottom surface of the capture groove; an inlet and an outlet are arranged on the shell and are communicated with the cavity, the inlet penetrates through the side wall of the cavity along the tangent direction of the cavity, and the lower end of the baffle is higher than the inlet. The gas-liquid mixed flow can generate vortex flow in the cavity to realize gas-liquid separation, the separated liquid accumulates to form a liquid layer, the liquid layer forms a liquid seal for the gas to change the flow resistance, thereby realizing the function of negative pressure regulation; the static flow channel provided by the device makes the gas and the liquid generate different behavior paths in the cavity, ensures stable performance in a complex fluid environment, and does not need power supply and manual intervention, thereby improving operation standardization and sample quality.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a negative pressure self-limiting device and method. Background Technology

[0002] In the diagnosis of clinical respiratory diseases, lower respiratory tract pathogen and cytological samples are typically obtained using bronchoscopic lavage. Normal saline is injected through the working channel of the bronchoscope, and then a sputum collection system is used for negative pressure suction to recover the lavage fluid sample containing target cells or pathogens. This sputum collection system mainly consists of a collection bottle with dual tubing and a negative pressure suction device. However, a significant contradiction exists in clinical operation regarding negative pressure adjustment: if the negative pressure is set too low, the lavage fluid is difficult to effectively suction out of the body, affecting sample acquisition efficiency; if a higher negative pressure is used, although the suction effect can be improved, it can also easily cause the lavage fluid to be directly aspirated out of the collection bottle, significantly reducing the actual sample recovery and storage rate.

[0003] To address the aforementioned issues, current clinical practice primarily employs two manual intervention methods: one is adjusting the suction device's negative pressure based on experience, and the other is temporarily reducing the negative pressure by manually partially shutting off the tubing. However, both methods have significant drawbacks: the adjustment response is delayed, the precision relies entirely on the operator's experience, making it difficult to achieve accurate control of the negative pressure. This can easily lead to insufficient sample recovery or damage to target cells due to excessive mechanical force.

[0004] Therefore, the manual adjustment method cannot achieve standardized operation, resulting in large fluctuations in sample quality under different operating scenarios, which restricts the stability and accuracy of bronchoscopic lavage in disease diagnosis. There is an urgent need to propose a negative pressure self-limiting device and method to overcome the aforementioned defects. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a negative pressure self-limiting device and method. The gas-liquid mixture entering the cavity is separated into gas and liquid by vortex flow. The liquid settles into the collection tank to form a liquid layer. The liquid layer can form a liquid seal on the gas to change the flow resistance, thereby realizing the regulation of negative pressure.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention proposes a negative pressure self-limiting device, including a housing, wherein the housing has a cavity and at least one baffle inside, the baffle is connected to the side wall of the cavity, the bottom surface of the cavity has a collection groove, and the upper end of the baffle has a first gap with the top surface of the cavity, and the lower end of the baffle has a second gap with the bottom surface of the collection groove.

[0008] The outer shell is provided with an inlet and an outlet communicating with the cavity. The inlet penetrates the side wall of the cavity along the tangential direction of the cavity, and the outlet is located above the inlet. The lower end of the baffle is higher than the inlet.

[0009] Optionally, the outer shell includes a cylindrical shell with a cover installed at the open end of the shell, the cavity being formed between the shell and the cover, the inlet being disposed on the shell, the outlet being disposed on the cover, and the baffle being installed inside the shell.

[0010] Optionally, the baffle is provided in three pieces, which are distributed in a Y-shape, with the outer ends of the baffles fitting against the inner wall of the housing, and the inner ends of the baffles converging at the axis of the cavity.

[0011] Optionally, the housing, the cover, and the baffle are integrally formed and connected, the axis of the outlet is perpendicular to the cover, and the outlet is coaxially distributed with the cavity.

[0012] Optionally, multiple baffles are provided, and a guide plate is provided on the side of the baffles near the inlet. The guide plate and the multiple baffles are distributed in parallel along the radial direction of the cavity, and adjacent two baffles are staggered vertically. The lower end of the guide plate is lower than the inlet.

[0013] Secondly, the present invention also proposes a negative pressure self-limiting method, employing the negative pressure self-limiting device described in the first aspect, comprising the following steps:

[0014] S1. The gas-liquid mixture flows tangentially into the cavity through the inlet to obtain a tangential velocity along the side wall of the cavity;

[0015] S2. The gas-liquid mixture with tangential velocity forms a centrifugal vortex in the cavity, and gas-liquid separation is achieved under the action of the centrifugal vortex.

[0016] S3. The separated gas bypasses the baffle and is discharged through the outlet, while the separated liquid settles down along the side wall of the cavity into the collection tank to form a liquid layer.

[0017] S4. The liquid layer forms a liquid seal that generates local fluid resistance to the separated gas, and this resistance increases synchronously with the rise of the liquid layer, so as to achieve adaptive adjustment of negative pressure.

[0018] Optionally, in step S4:

[0019] When the height of the liquid layer is lower than the lower end of the baffle, the separated gas can pass through the first gap and the second gap and be discharged through the outlet;

[0020] When the liquid layer overflows the lower end of the baffle, the separated gas penetrates the liquid layer to form a bubbling path, and the negative pressure is reduced by the local fluid resistance generated during the bubbling process.

[0021] Optionally, the height of the centerline of the inlet from the bottom surface of the cavity and the height of the second gap satisfy the following relationship:

[0022] H < G2;

[0023] Wherein, H is the height of the center line of the inlet from the bottom surface of the cavity, and G2 is the height of the second gap.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) In this invention, the gas-liquid mixture can generate eddies in the cavity to achieve gas-liquid separation. The separated liquid accumulates to form a liquid layer, and the liquid layer then forms a liquid seal on the gas to change the flow resistance, thereby achieving the function of negative pressure regulation. The static flow channel provided by this device allows the gas and liquid to generate different behavioral paths in the cavity, ensuring stable performance in complex fluid environments. Furthermore, it does not require power supply or manual intervention, thus improving the standardization of operation and sample quality.

[0026] (2) In this invention, the liquid level trigger can accurately respond to the state of continuous liquid flow. When the liquid accumulates to a preset height, the resistance to gas will increase as the height of the liquid layer in the cavity increases, but it will not completely block the negative pressure, thereby achieving smooth automatic flow restriction without blocking the negative pressure system, so as to adapt to clinical applications.

[0027] (3) The present invention achieves negative pressure regulation through liquid seal. Based on the operating logic of limiting when there is liquid and allowing flow when there is no liquid, it maintains low resistance and does not affect normal suction when there is little gas or secretions. When a large amount of irrigation fluid is drawn out, it automatically intervenes for protection. This eliminates the need for the operator to manually adjust the negative pressure, reducing the complexity of operation.

[0028] (4) The present invention does not require the assembly of precision moving parts, electronic sensors or circuits. Its material cost and manufacturing complexity are significantly lower than existing products containing metal springs, silicone diaphragms or electronic control components, thus enabling it to be widely used as a low-cost disposable consumable, avoiding the cost of disinfection and reuse and the risk of cross-infection. Attached Figure Description

[0029] Figure 1 This is an exploded structural diagram of the negative pressure self-limiting device in an embodiment of the present invention;

[0030] Figure 2 This is a perspective structural diagram of the negative pressure self-limiting device in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the internal structure of the negative pressure self-limiting device in an embodiment of the present invention;

[0032] Figure 4 yes Figure 3 Schematic sectional view of section AA;

[0033] Figure 5 This is a schematic diagram of the structure in which the baffles are distributed in a maze-like manner in an embodiment of the present invention;

[0034] The components are: 1. Shell; 2. Shell cover; 3. Baffle; 4. Inlet; 5. Outlet; 6. Collection tank; 7. Guide plate. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention and therefore only show the components relevant to the present invention.

[0036] In existing clinical applications, the working channel of a bronchoscope is connected to a negative pressure system (such as a negative pressure suction device) via a flexible tube. A sputum collector is also connected to the flexible tube to collect lavage fluid samples obtained from negative pressure suction; typically, a collection bottle is used. The negative pressure self-limiting device proposed in this invention is installed between the bronchoscope's working channel and the sputum collector. During use, it requires no power supply or manual intervention, operating automatically based entirely on fluid dynamics principles to attenuate and limit the effective negative pressure upstream of the sputum collector within a preset safe range.

[0037] Example 1, as Figures 1-4 As shown, a negative pressure self-limiting device includes a housing with a cylindrical cavity inside. An inlet 4 and an outlet 5 communicating with the cavity are fixedly installed on the housing. The inlet 4 penetrates the side wall of the cavity along the tangential direction. The outlet 5 is located above the inlet 4. A baffle 3 is also provided inside the cavity and is connected to the side wall of the cavity. A collection groove 6 is provided on the bottom surface of the cavity. There is a first gap between the upper end of the baffle 3 and the top surface of the cavity, and a second gap between the lower end of the baffle 3 and the bottom surface of the collection groove 6. The lower end of the baffle 3 is higher than the inlet 4.

[0038] As described above, the interior of the cavity, from inlet 4 to outlet 5, can be divided into a tangential vortex generation zone, an inertial settling and liquid collection zone, and a liquid level-triggered flow restriction zone. The gas-liquid mixture drawn out from the working channel of the bronchoscope by negative pressure first enters the tangential vortex generation zone inside the cavity through inlet 4. After gas-liquid separation is achieved through vortex, the liquid slides down the side wall of the cavity in the inertial settling zone to the liquid collection zone, while the gas passes through the liquid level-triggered flow restriction zone to achieve negative pressure regulation and is discharged into the sputum collector through outlet 5.

[0039] Tangential vortex generation zone: The end of the flow channel of inlet 4 is connected to the side wall of the cavity in a tangential direction, so that all the medium entering the cavity obtains a tangential velocity along the side wall of the cavity, thereby forming a stable rotating vortex in the cavity, providing initial power for gas-liquid inertial separation.

[0040] Inertial settling and liquid collection zone: A liquid collection tank 6 is provided at the bottom of the cavity. In the eddy current field, dense liquid particles are thrown towards the side wall of the cavity by centrifugal force. After the collision, the kinetic energy is lost, and the particles slide down the wall and are collected and stored in the collection tank 6.

[0041] Liquid level triggered flow restriction zone: This zone is provided with at least one vertically fixed baffle 3. The side of the baffle 3 is sealed to the side wall of the cavity. A first gap is reserved between the upper end of the baffle 3 and the top surface of the cavity. The lower end of the baffle 3 is suspended and a second gap is reserved between it and the bottom surface of the collection tank 6. The height of the second gap is less than the height of the triggered liquid level pressure limit, that is, the lower end of the baffle 3 is higher than the inlet 4.

[0042] Specifically, under normal conditions, only gas or a small amount of liquid flows into the cavity. The separated liquid is stored in the collection tank 6 to form a liquid layer, the liquid level of which is lower than the lower end of the baffle 3. The separated gas mainly passes through the path of least resistance, that is, the gas passes smoothly through the first gap and the second gap of the baffle 3. At this time, the fluid resistance of the device is extremely small. In the triggered state, liquid flows in continuously. When the liquid continues to flow in and the liquid level of the liquid layer rises to the trigger height, that is, when the lower end of the baffle 3 is submerged, the original second gap passage of the gas is blocked by the liquid. The airflow here is forced to penetrate the liquid layer to form a bubbling path, and then enters the outlet 5 from the first gap. During the bubbling process, the airflow generates huge local flow resistance, thereby significantly limiting the effective negative pressure upstream of the sputum collector to a preset safe range.

[0043] The gas-liquid mixture can generate eddies within the cavity to achieve gas-liquid separation. The separated liquid accumulates to form a liquid layer, which then forms a liquid seal on the gas to change the flow resistance, thereby achieving the function of negative pressure regulation. The static flow channel provided by this device allows the gas and liquid to generate different behavioral paths within the cavity, ensuring stable performance in complex fluid environments. Furthermore, it requires no power supply or manual intervention, improving operational standardization and sample quality.

[0044] Furthermore, the outer shell includes a shell 1 and a cover 2. The shell 1 has a cylindrical structure with one end open and the other end closed. The cover 2 is installed at the open end of the shell 1. The collection groove 6 is opened on the inside of the closed end of the shell 1. The inlet 4 is provided on the shell 1, the outlet 5 is provided on the cover 2, the baffle 3 is installed inside the shell 1, and the cavity is formed between the shell 1 and the cover 2.

[0045] The shell 1, shell cover 2 and baffle 3 are integrally molded and connected, which can significantly reduce the manufacturing cost of the device and ensure high production efficiency and good quality consistency.

[0046] The negative pressure self-limiting device can be injection molded as a whole, with a transparent shell made of medical-grade polypropylene or polycarbonate. It does not require the assembly of precision moving parts, electronic sensors or circuits. Its material cost and manufacturing complexity are comparable to ordinary medical plastic three-way valves, far lower than existing products containing metal springs, silicone diaphragms or electronic control components. This allows it to be widely used as a low-cost disposable consumable, avoiding the cost of disinfection and reuse and the risk of cross-infection. Moreover, its simple structure is suitable for large-scale injection molding production with high-precision molds, resulting in high part consistency, no need for complex adjustments, high production line qualification rate, and ensuring product quality stability and supply reliability.

[0047] Furthermore, by consistently limiting the negative pressure during lavage to an optimal range, this device ensures a more sufficient and stable sample volume for each lavage operation, reducing repetitive operations due to insufficient sample volume. It also standardizes the lavage fluid recovery process, helping to reduce technical differences between operators and making the technology easier to master and promote, thus possessing significant value in medical quality control. Moreover, the device's automatic pressure limiting prevents excessive negative pressure suction due to negligence, reducing the potential risk of damage to the patient's respiratory mucosa and improving operational safety.

[0048] Example 2, as Figures 1-4 As shown, based on Embodiment 1, three baffles 3 are provided. The three baffles 3 are distributed in a Y-shaped structure. The outer end of the baffle 3 is attached to the inner wall of the shell 1, and the inner end of the baffle 3 converges at the axis of the cavity. In the top view projection, it is radial. At the same time, the axis of the outlet 5 is perpendicular to the shell cover 2, and the outlet 5 is coaxially distributed with the cavity.

[0049] Preventing liquid spillage and suction: When the amount of liquid in the cavity increases or the airflow speed changes drastically, the liquid (especially when it contains foam or viscous substances) is prone to splashing or being directly sucked up by the vortex. The baffle 3 located in the airflow path can form a physical barrier, so that the splashed droplets directly hit the baffle 3 and flow back to the bottom, and cannot enter the top outlet 5 in a straight line, thus preventing a large amount of liquid from flowing out and avoiding damage or contamination to the equipment behind.

[0050] Disrupting the bottom vortex and promoting liquid sedimentation: The high-speed tangential airflow will form a strong rotating vortex in the cavity. At the bottom of the cavity, the rotational force of the rotating vortex will prevent the liquid that has reached the wall from gathering and settling into the collection tank 6, and may even stir the liquid up again. The baffle 3 here can interfere with and break the bottom vortex structure, reduce the rotational energy, and ensure that the liquid can fall steadily into the collection tank 6 under the action of gravity, thereby improving the collection efficiency.

[0051] Guiding the airflow path and optimizing separation: Baffle 3 can force the airflow to change direction and speed when passing through, which helps to cause smaller droplets to impact the surface of baffle 3 through inertia and be intercepted, thus playing a role in secondary separation and filtration.

[0052] Defoaming: For liquids that are prone to foaming (such as body fluids containing protein), the foam can be directly inhaled. Baffle 3 can mechanically break up the foam, causing it to liquefy and fall back.

[0053] Example 3, as Figure 5 As shown, based on Embodiment 1, the number of baffles 3 can be set to multiple (e.g., 2-5) depending on the required flow resistance and cavity size. The shape of the baffles 3 can be non-strictly radial, and can also have a flow guiding surface or a slight inclination angle, in order to form a labyrinth structure with alternating high and low baffles. At this time, multiple baffles 3 are distributed in parallel along the radial direction of the cavity, and adjacent baffles 3 are staggered vertically.

[0054] In the above structure, the baffle 3 divides the cavity into a meandering labyrinth flow channel. When the liquid level triggers the pressure limiting function of the device, the airflow repeatedly folds back and forth in the labyrinth to penetrate the liquid layer, thereby providing a more stable pressure drop gradient and enhancing the ability to resist flow field disturbances.

[0055] In addition, a guide plate 7 is provided on one side of the first baffle 3 near the inlet 4. The guide plate 7 and the multiple baffles 3 are distributed radially parallel to each other in the cavity. The lower end of the guide plate 7 is lower than the inlet 4, and there is a gap between the upper end of the guide plate 7 and the top surface of the cavity. This ensures that after the liquid submerges the lower end of the guide plate 7, the gas can rise along the guide plate 7 and then enter the labyrinth structure formed by the baffles 3.

[0056] Example 4: Based on the above examples, the present invention also proposes a negative pressure self-limiting method. This method can accurately respond to the state of continuous liquid flow through liquid level triggering. When the liquid volume reaches a preset height, the resistance to gas will increase as the height of the liquid layer in the cavity increases, but it will not completely block the negative pressure, thereby achieving smooth automatic flow limitation without blocking the negative pressure system, so as to adapt to actual clinical applications.

[0057] A negative pressure self-limiting method includes the following steps:

[0058] S1. The gas-liquid mixture flows tangentially into the cavity through inlet 4 to obtain a tangential velocity along the side wall of the cavity. The gas-liquid mixture drawn out from the working channel of the bronchoscope by negative pressure enters the cavity through inlet 4. Since inlet 4 penetrates the side wall of the cavity tangentially, and the cavity is cylindrical, the gas-liquid mixture entering the cavity obtains a tangential velocity.

[0059] S2. The gas-liquid mixture with tangential velocity forms a centrifugal vortex within the cavity, and gas-liquid separation is achieved under the action of the centrifugal vortex. After the gas-liquid mixture forms a stable rotating vortex within the cavity, it can provide initial power for gas-liquid inertial separation. In the vortex field, denser liquid particles are thrown towards the sidewall of the cavity by centrifugal force, thereby achieving gas-liquid separation.

[0060] S3. The separated gas bypasses the baffle 3 and is discharged through the outlet 5. The separated liquid settles along the side wall of the cavity into the collection tank 6 to form a liquid layer. The liquid particles thrown against the side wall of the cavity lose kinetic energy after collision and slide down the wall under the action of gravity and are collected and stored in the collection tank 6. The separated gas bypasses the baffle 3 after interacting with it and is discharged through the outlet 5 into the subsequent sputum collector.

[0061] S4. The liquid layer forms a liquid seal, which generates local fluid resistance to the separated gas. This resistance increases synchronously with the rise of the liquid layer, thereby achieving adaptive adjustment of the negative pressure. The side of the baffle 3 is sealed to the side wall of the cavity. A first gap is reserved between the upper end of the baffle 3 and the top surface of the cavity. The lower end of the baffle 3 is suspended and a second gap is reserved between it and the bottom surface of the collection tank 6. The height of the second gap is less than the height of the trigger liquid level pressure limit.

[0062] When the height of the liquid layer is lower than the lower end of the baffle 3, the separated gas can pass through the first gap and the second gap and be discharged through the outlet 5; when the liquid layer overflows the lower end of the baffle 3, the separated gas penetrates the liquid layer to form a bubbling path, and the local fluid resistance generated by the bubbling process is used to attenuate the negative pressure and limit it within a preset safe range.

[0063] The device is in normal operation when only gas or trace amounts of liquid flow into the cavity. The separated liquid is stored in the collection tank 6 to form a liquid layer with its liquid level below the lower end of the baffle 3. The separated gas mainly passes through the path of least resistance, that is, the gas passes smoothly through the first gap and the second gap of the baffle 3. At this time, the fluid resistance of the device is small.

[0064] When continuous liquid flows into the cavity, the device is in the triggered state. The continuous flow of liquid causes the liquid level to rise to the trigger height, that is, when it overflows the lower end of the baffle 3, the original second gap passage of the gas is blocked by the liquid. The airflow here is forced to penetrate the liquid layer to form a bubbling path, and then enters the outlet 5 from the first gap. During the bubbling process, the airflow generates a large local flow resistance, thereby significantly limiting the effective negative pressure upstream of the sputum collector to a preset safe range.

[0065] This method regulates negative pressure through a liquid seal. Based on the operating logic of limiting when there is liquid and allowing flow when there is no liquid, it maintains low resistance and does not affect normal suction when there is little gas or secretions. When a large amount of irrigation fluid is aspirated, it automatically intervenes for protection. This eliminates the need for operators to manually adjust the negative pressure, reducing the complexity of operation.

[0066] In Example 5, based on Example 4, the tangential direction of inlet 4 can be left-handed or right-handed, and the height of its centerline from the bottom surface of the cavity satisfies the requirement that the guided gas-liquid flow can achieve effective separation and facilitate liquid storage. Furthermore, the height of the centerline of inlet 4 from the bottom surface of the cavity and the height of the second gap satisfy the following relationship:

[0067] H < G2;

[0068] Where H is the height of the centerline of inlet 4 from the bottom surface of the cavity, and G2 is the height of the second gap. This design ensures that the initial trajectory of the separated liquid is located in the area below the baffle 3, which is conducive to its flow into the collection tank 6 and guiding the main gas flow through the first gap.

[0069] The pressure reduction capacity of this device is related to the properties of the irrigation fluid (such as viscosity) and the size of the device. Taking the baffle 3 distribution structure in Example 2 as an example, the specific parameters are as follows:

[0070] The cavity has an inner diameter of 30mm and a height of 40mm;

[0071] The height of the collection tank 6 is 10mm, and the bottom diameter of the collection tank 6 is 25mm.

[0072] The height of the Y-shaped baffle 3 is 20mm. The distance G1 between the upper end of the Y-shaped baffle 3 and the top surface of the cavity is 5mm. The distance between the lower end of the Y-shaped baffle 3 and the bottom surface of the collection groove 6 of the cavity is 15mm. The distance between the bottom surface of the non-collection groove 6 part and the bottom surface of the cavity is 5mm.

[0073] The pipe wall thickness at inlet 4 is 1mm, the inner diameter is 3.67mm, and the height from the bottom surface of the non-collection tank 6 is 2mm.

[0074] The pipe wall thickness at outlet 5 is 1 mm, and the inner diameter is 3.67 mm.

[0075] At this time, the volume of the pressure limiting trigger of the device is 7ml, the trigger height is 15mm, when the liquid surface just submerges the lower end of the baffle 3, the pressure (vacuum value) of the negative pressure suction device decreases by 5-10kPa, and when the liquid fills the cavity, the pressure (vacuum value) decreases by 10-20kPa.

[0076] In summary, this invention proposes a negative pressure self-limiting device and method, which realizes negative pressure regulation based on the principles of eddy current settling and liquid resistance. It adopts a static structure and automatically distinguishes between gas and continuous liquid flow through the dynamic behavior of the fluid itself. When the liquid reaches a predetermined accumulation amount, the pressure limiting function is passively triggered, which greatly increases the flow channel resistance, thereby limiting the effective negative pressure upstream of the sputum collector to a safe range.

[0077] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many improvements and modifications under the guidance of the present invention without departing from the spirit and scope of the claims. These improvements and modifications should also be considered within the scope of protection of the present invention.

[0078] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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 invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0080] Furthermore, the terms "first," "second," etc., 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 indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

Claims

1. A negative pressure self-limiting device, characterized in that, The device includes an outer shell, the interior of which is provided with a cavity and at least one baffle. The baffle is connected to the side wall of the cavity. A collection groove is formed on the bottom surface of the cavity. A first gap is formed between the upper end of the baffle and the top surface of the cavity, and a second gap is formed between the lower end of the baffle and the bottom surface of the collection groove. The outer shell is provided with an inlet and an outlet communicating with the cavity. The inlet penetrates the side wall of the cavity along the tangential direction of the cavity, and the outlet is located above the inlet. The lower end of the baffle is higher than the inlet.

2. The negative pressure self-limiting device according to claim 1, characterized in that, The outer shell includes a cylindrical shell with a cover installed at the open end of the shell. The cavity is formed between the shell and the cover. The inlet is located on the shell, the outlet is located on the cover, and the baffle is installed inside the shell.

3. The negative pressure self-limiting device according to claim 2, characterized in that, The baffle is provided in three pieces, which are distributed in a Y-shape. The outer ends of the baffles are attached to the inner wall of the shell, and the inner ends of the baffles converge at the axis of the cavity.

4. The negative pressure self-limiting device according to claim 3, characterized in that, The housing, the cover, and the baffle are integrally formed and connected. The axis of the outlet is perpendicular to the cover, and the outlet is coaxially distributed with the cavity.

5. The negative pressure self-limiting device according to claim 1, characterized in that, The baffle is provided in multiple pieces, and a guide plate is provided on the side of the baffle near the inlet. The guide plate and the multiple baffles are distributed in parallel along the radial direction of the cavity. Adjacent baffles are staggered vertically, and the lower end of the guide plate is lower than the inlet.

6. A negative pressure self-limiting method, employing the negative pressure self-limiting device according to any one of claims 1-5, characterized in that, Includes the following steps: S1. The gas-liquid mixture flows tangentially into the cavity through the inlet to obtain a tangential velocity along the side wall of the cavity; S2. The gas-liquid mixture with tangential velocity forms a centrifugal vortex in the cavity, and gas-liquid separation is achieved under the action of the centrifugal vortex. S3. The separated gas bypasses the baffle and is discharged through the outlet, while the separated liquid settles down along the side wall of the cavity into the collection tank to form a liquid layer. S4. The liquid layer forms a liquid seal that generates local fluid resistance to the separated gas, and this resistance increases synchronously with the rise of the liquid layer, so as to achieve adaptive adjustment of negative pressure.

7. The negative pressure self-limiting method according to claim 6, characterized in that, In step S4: When the height of the liquid layer is lower than the lower end of the baffle, the separated gas can pass through the first gap and the second gap and be discharged through the outlet; When the liquid layer overflows the lower end of the baffle, the separated gas penetrates the liquid layer to form a bubbling path, and the negative pressure is reduced by the local fluid resistance generated during the bubbling process.

8. The negative pressure self-limiting method according to claim 7, characterized in that, The height of the centerline of the inlet from the bottom surface of the cavity and the height of the second gap satisfy the following relationship: H < G2; Wherein, H is the height of the center line of the inlet from the bottom surface of the cavity, and G2 is the height of the second gap.

Images