Acoustic field-based respiratory smoke particle separation device and control method thereof

Abstract

The application relates to the technical field of respiratory particle separation devices, in particular to a respiratory smoke particle separation device based on a sound field and a control method thereof. The device is arranged on a mask body and comprises a sound wave separation chamber, a sound field generating device and an adjusting control module. The air inlet of the device is provided with a filter layer. The sound wave separation chamber is a hollow cavity. A first one-way valve is arranged on one side of the hollow cavity, and a second one-way valve is arranged on the other side. The hollow cavity is communicated with the air inlet of the mask body through the second one-way valve. The adjusting control module controls the sound field generating device to generate sound waves with a dynamically adjustable frequency, so that the fine particles in the smoke collide and agglomerate rapidly, form particles with a larger particle size, and part of the smoke particles are naturally settled at the bottom of the sound wave separation chamber or are more easily filtered under the action of gravity. The separation device can be self-adaptively adjusted according to the environment, has a higher filtering efficiency, effectively reduces the breathing resistance of the wearer, and improves the escape and survival ability of the wearer in a fire environment.

Description

Technical Field

[0001] This application relates to the field of respiratory particle separation device technology, and in particular to a respiratory smoke particle separation device and its control method based on sound field. Background Technology

[0002] Fire smoke contains a large number of fine-sized solid particles and droplets. The particle size and distribution vary depending on the type of combustible material and the fire environment. PM2.5 and smaller particles can enter the lungs with the breathing air, causing serious harm to the human respiratory system. Conventional fire masks or smoke masks mainly rely on the physical interception of particles by the filter layer to achieve separation. However, their filtration efficiency for submicron particles is limited, especially at high smoke concentrations where they are prone to clogging, leading to increased breathing resistance and reduced escape ability.

[0003] Acoustic agglomeration technology is a highly efficient aerosol pretreatment technique. Its principle involves using a suitable intensity sound field to induce relative motion and collisions in fine particles, causing them to agglomerate and form larger particles, thus significantly reducing the number of particles. This technology has been applied in industrial dust removal and environmental defogging, but there is currently no technology that combines acoustic agglomeration technology with fire masks. How to combine acoustic agglomeration technology with fire masks and, through appropriate control methods, match it to the escape environment of a fire to ensure personnel's escape and survival capabilities is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this application is to provide a sound field-based breathing smoke particle separation device and its control method, which aims to combine the sound field with the fire mask so that it can adapt to the fire environment and ensure the escape and survival capabilities of personnel.

[0005] On one hand, this application provides a sound field-based respiratory smoke particle separation device, which is disposed on a mask body. The mask body has a connected air inlet, a sealed chamber, and an air outlet. The air inlet is provided with a filter layer. The separation device includes a sound wave separation chamber, a sound field generating device connected to the sound wave separation chamber, and an adjustment control module for controlling the sound field generating device. The sound wave separation chamber is connected to the mask body. The sound wave separation chamber has a hollow cavity. A first one-way valve for allowing external gas to enter is provided on one side of the hollow cavity, and a second one-way valve is provided on the other side of the hollow cavity. The hollow cavity is connected to the air inlet of the mask body through the second one-way valve.

[0006] Furthermore, the acoustic separation chamber is equipped with a horizontal hollow circular tube and a vertical hollow circular tube, which are connected to each other; the axis of the horizontal hollow circular tube is perpendicular to the axis of the vertical hollow circular tube; the horizontal hollow circular tube is connected to the first one-way valve and the second one-way valve; the vertical hollow circular tube is connected to the sound field generating device.

[0007] Furthermore, a horn is provided between the sound field generating device and the vertical hollow tube; the horn has a small port and a large port, the small port of the horn is connected to the vibrating end of the sound field generating device, and the large port of the horn is connected to the port of the vertical hollow tube.

[0008] Furthermore, it also includes sound-absorbing sponge, which is disposed on one side of the sound wave separation chamber; the sound-absorbing sponge is laid and covered on the end of the vertical hollow circular tube away from the sound field generating device.

[0009] Furthermore, it also includes a laser emitter and a laser power receiving module; the laser emitter is located at one end of the acoustic separation chamber near the second one-way valve, and the laser emitter faces the hollow cavity; the laser power receiving module is located in the acoustic separation chamber and faces the laser emitter.

[0010] Furthermore, the laser emitter faces the interior of the horizontal hollow tube, and the laser emitter and the laser power receiving module are directly opposite each other along the diameter of the horizontal hollow tube.

[0011] Furthermore, the adjustment control module is disposed on the mask body, and the adjustment control module is electrically connected to the sound field generating device and the laser emitter; the adjustment control module includes a circuit board, an MCU main control chip electrically connected to the circuit board, and a power supply.

[0012] Furthermore, it also includes noise-canceling earplugs, which are disposed on the outer side wall of the mask body.

[0013] On the other hand, this application also provides a control method applicable to the above-mentioned sound field-based respiratory smoke particle separation device, comprising the following steps: S1: The mask body (1) is tightly worn on the wearer's face, the sealed chamber fits seamlessly with the wearer's face, and noise-canceling earplugs are inserted into both ears at the same time; S2: The adjustment and control module is started, the laser emitter and laser power receiving module are started synchronously to detect the transmittance in real time, and the sound field generating device is started with the preset frequency and initial power. S3: Airflow is introduced into the acoustic separation chamber in a one-way manner. The acoustic separation chamber constrains the airflow to stay for the duration of the breathing interval of the personnel. The laser power receiving module transmits the transmittance to the adjustment and control module at a preset cycle. S4: The adjustment and control module calculates and matches the sound field frequency based on the light transmittance, and then controls the sound field generator to adjust the parameters of the sound field generator to the corresponding values ​​to match the characteristics of the smoke particles in the current fire scene. S5: A uniform sound field is generated in the acoustic separation chamber and acts on the airflow, causing fine particles with a diameter ≤10μm in the airflow to collide and aggregate rapidly, forming large particles. The large particles naturally settle to the bottom of the acoustic separation chamber by gravity. S6: The remaining airflow is filtered, and the filtered airflow enters the sealed chamber of the mask body in a one-way manner. S7: Expels the airflow inhaled by the wearer in a one-way manner.

[0014] Furthermore, the specific steps of S4 are as follows: obtaining transmittance measured at time The adjustment and control module adjusts according to the light transmittance. Calculated Volume fraction of fire smoke in the acoustic separation chamber at any given time The calculation formula is: ; in, This represents the initial volume fraction of the fire smoke. The initial transmittance of the fire smoke; according to Obtain the corresponding sound field frequency and adjust the sound field generating device according to the sound field frequency.

[0015] Furthermore, the aforementioned according to The steps to obtain the corresponding sound field frequency are as follows: according to Obtain the median particle size in the hollow cavity. ; Based on the median particle size Obtain the initial operating frequency f0; according to The frequency F1Hz that maximizes the light transmittance is obtained by traversing the range f0-1000≤f≤f0+1000 with a step size of 10Hz. F1 is used as the sound field aggregation efficiency to adjust the sound field generating device (3).

[0016] Furthermore, the "according to" Obtain the median particle size in the hollow cavity. The specific steps are as follows: For volume fraction of Log-normal distribution of smoke particles Satisfy the following formula: ; in as well as for The corresponding particle size range [ , ], The average particle size is The mean of the logarithmic particle size is... The standard deviation of the logarithmic particle size, and the mean of the logarithmic particle size. and logarithmic particle size standard deviation Satisfy the following formula: , ; Based on the normal distribution parameters of combustible material index in typical fires, the median particle size and standard deviation can be obtained, and its volume fraction can be calculated. This makes the median particle size, standard deviation, and volume fraction... There is a corresponding relationship, thus based on the volume fraction The median particle size can be obtained. .

[0017] Furthermore, the phrase "based on the median particle size" Get the starting operating frequency The specific steps are as follows: For a particle with a median particle size d 50 Isolated spherical smoke particles at sound wave frequencies of When moving within the sound field, the movement of particles in the fire smoke is determined by the entrainment rate. To describe its involvement rate Described as: ; in: The dynamic viscosity of air in the fire environment; This is the slip correction factor; Calculate the frequency range or frequency value of the sound wave. , making This causes the particles to be almost completely engulfed by the sound field; this range of values ​​or sound wave frequency values That is, as , This refers to the high-efficiency frequency range for particle aggregation.

[0018] Furthermore, it also includes S8: when the transmittance measured by the laser power receiving module is ≥80%, the adjustment and control module shuts down the sound field generating device; when the transmittance measured by the laser power receiving module is <80%, the adjustment and control module starts the sound field generating device.

[0019] The beneficial effects of this application are: 1. This application discloses a sound field-based respiratory smoke particle separation device, installed on the mask body, comprising a sound wave separation chamber and a sound field generating device. Utilizing a first one-way valve and a second one-way valve, the separation device forms a one-way gas path consisting of the first one-way valve, a hollow cavity, the second one-way valve, an air inlet, a sealed chamber, and an air outlet. When the wearer inhales, the airflow enters the hollow cavity of the sound wave separation chamber through the first one-way valve. Under the action of the adjustment and control module, the sound field generating device generates sound waves of corresponding frequency and power, forming a uniform and stable sound field within the sound wave separation chamber. Under the action of this sound field, fine particles in the smoke collide rapidly and agglomerate, forming larger particles. These particles naturally settle to the bottom of the sound wave separation chamber under gravity. The filtered gas continues to enter the mask body, is filtered by the filter layer, and then inhaled by the wearer, thus ensuring that the wearer can inhale safe and clean gas for an extended period. The separation device possesses the ability to eliminate toxic gases and has higher filtration efficiency, while also being able to adaptively adjust according to the fire environment to ensure the wearer's escape and survival capabilities in a fire situation.

[0020] 2. The breathing smoke particle separation device based on sound field of this application can effectively absorb reflected sound waves by setting sound-absorbing sponge, improve the structure of the sound field in the closed sound field agglomeration chamber, optimize the form of sound wave action, reduce the sound wave cancellation phenomenon caused by sound wave reflection, thereby ensuring the stability of the maximum sound pressure level in the cavity, further improving the uniformity and stability of sound field agglomeration, and improving the utilization rate of sound wave energy.

[0021] 3. The breathing smoke particle separation device based on sound field of this application can effectively reduce the potential harm to the hearing of the user by adding noise-canceling earplugs while wearing the mask. Moreover, the present invention can realize the opening and closing of the device with only one control switch, which is simple to operate and can be adapted to various groups of people without professional operation. It is suitable for both professional rescue by firefighters and emergency escape of people trapped in ordinary fires.

[0022] 4. The present application discloses a sound field-based breathing smoke particle separation device, which, through a control method, confines the gas in the sound wave separation chamber after the gas is inhaled, with the interval between two inhalations as the residence time. During this time window, the sound field generated by the agglomeration chamber is used to agglomerate the smoke particles to be burned, thereby purifying the gas by utilizing the regularity of the human breathing rhythm, which is effectively adapted to fire scene scenarios.

[0023] 5. The present application discloses a sound field-based respiratory smoke particle separation device, which automatically shuts down the sound field generator when the transmittance detected by the laser power receiving module is ≥80%; and automatically starts the sound field generator when the detected transmittance is <80%, thereby restoring sound wave aggregation and purification, thereby extending the service life of the separation device and further adapting to the needs of subdivided scenarios in the fire scene. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a respiratory smoke particle separation device based on a sound field provided in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the steps of the control method provided in Embodiment 2 of this application.

[0025] Explanation of reference numerals in the attached figures: 1. Mask body; 2. Sound wave separation chamber; 3. Sound field generating device; 4. Adjustment and control module; 5. First one-way valve; 6. Second one-way valve; 7. Sound-absorbing sponge; 8. Laser emitter; 9. Laser power receiving module; 10. Noise-canceling earplugs. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0029] Example 1 Reference Figure 1 On one hand, this application provides a sound field-based respiratory smoke particle separation device. The separation device is installed on the mask body 1 and includes a sound wave separation chamber 2, a sound field generating device 3 connected to the sound wave separation chamber 2, and an adjustment and control module 4 for controlling the sound field generating device 3. The sound wave separation chamber 2 is connected to the mask body 1. After the separation device is worn, it operates. External gas enters the sound wave separation chamber 2 under the wearer's breathing. The adjustment and control module 4 drives the sound field generating device 3 to operate. The sound field generating device 3 generates a sound field in the sound wave separation chamber 2, causing the fine particles in the smoke to collide and agglomerate rapidly, forming larger particles. The particles naturally settle to the bottom of the sound wave separation chamber 2 under the action of gravity. The filtered gas continues to enter the mask body 1, is filtered by the filter layer, and is then inhaled by the wearer, thereby ensuring the wearer's survival and escape capabilities.

[0030] Specifically, the mask body 1 has a connected air inlet, a sealed chamber, and an air outlet. The air inlet is equipped with a filter layer. The filter layer can be a KP95-grade self-priming filter escape respirator filter element. The filter layer is fitted to the side of the air inlet away from the sealed chamber. The air entering from the outside is filtered by the filter layer before entering the sealed chamber. A silicone pad is provided at the part of the mask body 1 that fits against the face to increase the wearer's comfort. The air outlet of the mask body 1 is equipped with a one-way exhaust valve, which allows the exhaled air to be discharged in one direction without backflow, ensuring the protective airtightness and the cohesion effect.

[0031] In this embodiment, the mask body 1 is made of thickened food-grade silicone to form a mask structure with a sealed chamber. The edges are integrally molded with double-layer sealing strips, which ensures a seamless fit with the wearer's face and meets the airtightness standard when worn. The air inlet is an integrally molded 30mm diameter circular air inlet at the front end of the mask body 1, and the air outlet is an arc-shaped air inlet set in the mask body 1 to fit the mouth and nose. The KP95 grade self-priming filter escape respirator filter element is fixed to the air inlet by a ring buckle. The silicone pad is a 3mm thick silicone pad in the area where the mask body 1 fits with the face, which takes into account both airtightness and wearing comfort, so that there is no pressure on the face when worn for a long time.

[0032] The acoustic separation chamber 2 has a hollow cavity. A first one-way valve 5 is provided on one side of the hollow cavity to allow outside gas to enter, and a second one-way valve 6 is provided on the other side of the hollow cavity. The hollow cavity is connected to the air inlet of the mask body 1 through the second one-way valve 6. The second one-way valve 6 abuts against the front end face of the filter layer, so that gas passes through the filter layer after passing through the second one-way valve 6 and enters the air inlet.

[0033] In addition, the sound wave separation chamber 2 is equipped with a horizontal hollow circular tube and a vertical hollow circular tube. The horizontal and vertical hollow circular tubes are located in the hollow cavity and intersect perpendicularly. The horizontal hollow circular tube and the vertical central circular tube are connected. The axis of the horizontal hollow circular tube is perpendicular to the axis of the vertical hollow circular tube. The horizontal hollow circular tube is connected to the first one-way valve 5 and the second one-way valve 6. The vertical hollow circular tube is connected to the sound field generating device 3. It should be noted that the descriptions of "horizontal" and "vertical" for the horizontal hollow circular tube and the vertical central circular tube are used to indicate that their axial direction is approximately horizontal or approximately vertical within the hollow cavity, and are not used to restrict their direction to only be horizontal or vertical.

[0034] In this embodiment, the horizontal hollow circular tube has a diameter of 30mm. One end is the air inlet, which is sealed to the first one-way valve 5; the other end is the air outlet, which is sealed to the second one-way valve 6. Furthermore, an arc-shaped guide surface is integrally formed inside the horizontal hollow circular tube, thereby improving the uniformity of the smoke airflow velocity. The vertical hollow circular tube also has a diameter of 30mm. The middle part of the vertical hollow circular tube connects to the horizontal hollow circular tube. The upper end of the vertical hollow circular tube is the covering end, and the lower end is the connecting end, which is connected to the sound field generating device 3. This allows the sound field generating device 3 to form a sound field within both the horizontal and vertical hollow circular tubes.

[0035] The sound field generating device 3 can specifically use a loudspeaker with a rated operating frequency of 0.8kHz~10.8kHz, an operating voltage of 12V, and a rated power of 20W. The sound field generating device 3 is embedded in the sound wave separation chamber 2 and connected to the lower end of the vertical hollow circular tube. To ensure the sound field formation effect, the sound field generating device 3 also includes a horn, which is positioned between the sound field generating device 3 and the vertical hollow circular tube. The horn has a small port and a large port. The small port of the horn is connected to the vibrating end of the sound field generating device 3, and the large port of the horn is connected to the port of the vertical hollow circular tube, that is, the large port of the horn is connected to the connecting end of the vertical hollow circular tube. In this embodiment, the horn is a miniature conical horn made of acrylic material. The small end of the horn has a diameter of 15mm, which seamlessly connects to the vibrating end of the sound field generating device 3. The large end has a diameter of 30mm, which matches the lower end of the vertical hollow circular tube of the sound wave separation chamber 2. The overall length of the horn is 30mm, the taper is 15°, and the inner wall of the horn is polished to a smooth structure, reducing the energy loss of sound wave transmission (loss rate ≤5%) and enhancing the directivity of the sound field. By setting the horn in this way, the horn can directionally transmit the sound waves generated by the sound field generating device 3 to the agglomeration chamber cavity, and convert the point sound source into a uniform surface sound field, covering the entire hollow cavity of the sound wave separation chamber 2.

[0036] In addition, the separation device also includes a sound-absorbing sponge 7, which is disposed on one side of the sound wave separation chamber 2. The sound-absorbing sponge 7 is laid and covers the end of the vertical hollow circular tube away from the sound field generating device 3. The sound-absorbing sponge 7 can be made of polyurethane sponge with a thickness of 3-21mm. The lower side of the sound-absorbing sponge 7 is connected to the sound field generating device 3. In this embodiment, the sound-absorbing sponge 7 is laid on the covering end, thereby effectively sealing and improving the structure of the sound field in the sound wave separation chamber 2, optimizing the action mode of sound waves, reducing the sound wave cancellation phenomenon caused by sound wave reflection, thereby ensuring the stability of the maximum sound pressure level in the cavity, further improving the uniformity and stability of the sound field aggregation, and improving the sound wave energy utilization rate. The sound-absorbing sponge 7 can be further connected to the vertical hollow circular tube through a horn, that is, the horn is connected to the covering end, and the sound-absorbing sponge 7 covers the side of the horn away from the covering end, so as to better form a sound field.

[0037] It is worth mentioning that, in this embodiment, the first one-way valve 5 is a silicone one-way air inlet valve with a diameter of 30mm and an opening pressure of -50Pa to -100Pa. It is sealed at the air inlet end of the horizontal hollow circular tube of the acoustic separation chamber 2, allowing the smoke airflow to enter the agglomeration chamber only in the direction of airflow, completely preventing airflow backflow. The first one-way valve 5 and the second one-way valve 6 are silicone one-way air inlet valves of the same specification, sealed at the connection between the air outlet end of the horizontal hollow circular tube and the mask body 1. The two air inlet valves cooperate to form an airflow constraint channel. By setting the opening pressure of the first one-way valve 5 and the second one-way valve 6, or by using solenoid valves as the first one-way valve 5 and the second one-way valve 6, the residence time of the smoke airflow in the acoustic separation chamber 2 can be controlled to 3 to 5 seconds, thereby providing sufficient time for particle agglomeration.

[0038] With this setup, fine particles with a diameter of ≤10μm in the fire smoke entering through the air inlet will collide and agglomerate under the action of the sound field, forming large particles with a diameter of >10μm. About 53.8% of the large particles will naturally settle to the bottom of the hollow cavity by gravity, while the remaining 46.2% will be physically intercepted by the filter layer, achieving dual purification and improving the overall removal efficiency of ultrafine particles.

[0039] To collect large particles that settle to the bottom of the hollow cavity, the acoustic separation chamber 2 is also equipped with a dust collection trough, located between the acoustic separation chamber 2 and the sound field generating device 3. Specifically, the dust collection trough can be positioned between the large port and the connecting end of the vertical hollow circular tube. In this embodiment, the dust collection trough is a tubular structure with a diameter of 30mm. One end of the dust collection trough has an opening, and the other end has a filter screen; that is, the dust collection trough is a section of tubular material with a filter screen. The dust collection trough is detachably connected to the acoustic separation chamber 2 via a sliding connection. After the dust collection trough is installed, the open end of the dust collection trough connects to the connecting end, and the filter screen end of the dust collection trough connects to the large port. When a sound field is formed, the settled large particles will fall from the connecting end onto the filter screen, preventing the large particles from entering the large port. When cleaning is required, the dust collection trough can be removed to clean the large particles. It is important to understand that the dust collection trough is designed for the recycling and sustainable use of protective masks. For scenarios requiring disposable use and low-cost production, the dust collection trough can be omitted, and the connection can be directly connected to the large port of the horn.

[0040] To monitor the gas conditions inside the acoustic separation chamber 2 in real time, the separation device also includes a laser emitter 8 and a laser power receiving module 9. The laser emitter 8 is located at the end of the acoustic separation chamber 2 near the second one-way valve 6, facing the hollow cavity. The laser power receiving module 9 is located in the acoustic separation chamber 2 and faces the laser emitter 8. To improve detection accuracy, the laser emitter 8 faces the inside of the horizontal hollow tube, and the laser emitter 8 and the laser power receiving module 9 are directly opposite each other along the diameter of the horizontal hollow tube.

[0041] In this embodiment, the laser emitter 8 is a 630nm red laser diode with a rated power of 5mW. It is fixed to the upper part of the horizontal hollow cylindrical tube of the acoustic separation chamber 2, with the emitting end horizontally facing the inside of the cavity and precisely aligned with the laser power receiving module 9. The laser detection distance is 60mm, and the emitted stable laser beam provides a precise light source for transmittance detection. The laser power receiving module 9 is a high-sensitivity photodiode with a detection accuracy of ±1%. It is fixed to the lower part of the horizontal hollow cylindrical tube of the acoustic separation chamber 2. The laser power receiving module 9 fits seamlessly with the inner wall of the hollow cavity, with no airflow leakage points. It can accurately receive the laser signal and convert it into a transmittance analog signal, with a detection data error of ≤1%.

[0042] The adjustment control module 4 is disposed on the mask body 1 and electrically connected to the sound field generating device 3 and the laser emitter 8. The adjustment control module 4 includes a circuit board, an MCU main control chip electrically connected to the circuit board, and a power supply. In this embodiment, the adjustment control module 4 is an integrated circuit board assembly, embedded in the outer wall of the mask body 1. The MCU main control chip is an STM32 series chip. The power supply module is a rechargeable lithium-ion battery equipped with a USB fast charging interface, which can provide continuous power supply for ≥10 hours after a single full charge, meeting the requirements for long-term wear. The adjustment control module 4 is electrically connected to the sound field generating device 3, the laser emitter 8, and the laser power receiving module 9 through high-temperature resistant wires to realize power supply and signal transmission, complete the rapid conversion between analog and digital signals of transmittance, the transmittance detection cycle is 0.1s / time, and the sound field parameter adjustment response time is ≤1s. The adjustment and control module 4 has a control switch. The control switch is embedded in the outer wall of the body 1 and close to the adjustment and control module 4. It is waterproof and fogproof, has a short pressing stroke, and is suitable for emergency operation in fire situations. The control switch is electrically connected to the adjustment and control module 4 to realize the overall opening and closing of all electrical components.

[0043] Since the formation of the sound field may damage the wearer's hearing, the separation device also includes a noise-canceling earplug 10, which is installed on the outer wall of the mask body 1. The noise-canceling earplug 10 is a professional sound-insulating slow-rebound foam structure with a noise reduction of 25dB, which can effectively isolate the sound field noise of the gathering room and prevent the wearer's hearing from being damaged. The earplug is fixedly connected to the outer wall of the mask body 1 by a 20cm long flexible nylon connecting cable. The end of the connecting cable is equipped with a stainless steel anti-loss metal buckle, which can be detachably connected to the mask hanging point to prevent the earplug from being lost during wear.

[0044] The working principle of the sound field-based respiratory smoke particle separation device disclosed in this application is as follows: When the separation device is needed, the mask body 1 is tightly worn on the face, ensuring a seamless fit between the sealed chamber and the face. Simultaneously, noise-canceling earplugs 10 are inserted into both ears to ensure a noise-canceling and sealing effect, preventing sound field noise from damaging hearing. Then, the control switch is pressed, activating the adjustment control module 4. The sound field generator 3 starts at the initial frequency and initial power, and the laser emitter 8 and laser power receiving module 9 start synchronously, beginning real-time detection of light transmittance. Under the negative pressure of the wearer's breathing, the airflow enters the horizontal hollow tube of the sound wave separation chamber 2 through the first one-way valve 5. Through the combined constraint of the first one-way valve 5 and the second one-way valve 6, the airflow remains within the sound wave separation chamber 2 for several seconds, ensuring sufficient time for particle aggregation.

[0045] The laser power receiving module 9 transmits the detected transmittance analog signal to the adjustment and control module 4 at a fixed period. The adjustment and control module 4 dynamically and adaptively adjusts the sound field frequency and power of the sound field generator 3 according to the transmittance and the corresponding sound field frequency, ensuring the sound field continuously matches the characteristics of the smoke particles in the current fire scene. The uniform sound field within the acoustic separation chamber 2 acts on the smoke airflow, causing smaller fine particles to collide and aggregate rapidly, forming larger particles. Some of these larger particles settle naturally to the bottom of the acoustic separation chamber 2 due to gravity and are collected. The remaining larger particles move with the airflow through the second one-way valve 6 towards the filter layer, where they are completely physically intercepted by the filter element of the KP95-grade self-priming escape respirator. Combined with the settling effect, this achieves an overall high efficiency in removing ultrafine particles from the fire smoke. Clean air, purified by both gravity settling and physical interception, is inhaled by the wearer through the air inlet of the mask body 1. The wearer's exhaled air is discharged unidirectionally through the exhaust valve of the mask body 1, preventing the exhaled air from flowing back into the acoustic separation chamber 2 and affecting the purification effect. This ensures the smoothness of the breathing process and the effectiveness of protection, thereby guaranteeing the wearer's escape and survival capabilities.

[0046] It should be noted that the sound field-based breathing smoke particle separation device proposed in this application can be used not only in fire environments, but also in smoke and dust environments or other scenarios that require filtering and separating breathing particles, adapting to different usage needs.

[0047] Example 2 Reference Figure 2 On the other hand, embodiments of this application provide a control method applicable to the above-mentioned sound field-based respiratory smoke particle separation device, comprising the following steps: S1: The mask body 1 is tightly worn on the wearer's face, and the sealed chamber fits seamlessly with the wearer's face. At the same time, the noise-canceling earplugs 10 are inserted into both ears. Specifically, the separation device is worn on the user's face through the mask body 1, that is, the mask body 1 is tightly worn on the wearer's face, so that the double-layer sealing strip fits seamlessly with the face, ensuring protective airtightness, while the noise-canceling earplugs 10 are tightly inserted into both ears to achieve a 35dB noise reduction effect and avoid sound field noise from damaging hearing.

[0048] S2: The adjustment and control module 4 is started, the laser emitter 8 and the laser power receiving module 9 are started synchronously to detect the transmittance in real time, and the sound field generating device 3 is started with a preset frequency and initial power. Specifically, when the control switch is pressed, the laser emitter 8 and the laser power receiving module 9 start synchronously, start the adjustment control module 4, and the sound field generating device 3 starts with an initial frequency of 4kHz and an initial power of 20W, and begins to detect the transmittance in real time at a cycle of 0.1s / time, with a detection accuracy of ±1%.

[0049] S3: Airflow is introduced into acoustic separation chamber 2 in a one-way manner. Acoustic separation chamber 2 constrains the airflow to stay for the duration of the breathing interval of the personnel. Laser power receiving module 9 transmits the transmittance to adjustment and control module 4 at a preset cycle. Specifically, under the negative pressure of breathing, the fire smoke airflow enters the horizontal hollow tube of the acoustic separation chamber 2 in a one-way manner through the first one-way valve 5. Under the combined constraint of the first one-way valve 5 and the second one-way valve 6, the airflow stays in the acoustic separation chamber 2 for 3 to 5 seconds, which is the breathing interval of a human body, ensuring that the particles have sufficient time to aggregate. The laser power receiving module 9 continuously transmits the real-time detected transmittance analog signal to the adjustment and control module 4.

[0050] S4: The adjustment control module 4 calculates and matches the sound field frequency based on the light transmittance, and then controls the sound field generating device 3 to adjust the parameters of the sound field generating device 3 to the corresponding values ​​to match the characteristics of the smoke particles in the current fire scene. Specifically, the main control chip of the adjustment and control module 4 quickly converts the light transmittance analog signal into a digital signal and traverses the best sound field frequency. With a response time of ≤1s, it adaptively adjusts the sound field frequency of the sound field generator 3 to 0.8kHz~10.8kHz and the power to 8W~20W, so that the sound field accurately matches the characteristics of the smoke particles in the current fire scene and achieves an aggregation efficiency of more than 60%.

[0051] More specifically, the specific steps of S4 are: obtain transmittance measured at time The adjustment and control module 4 adjusts according to the light transmittance. Calculated Volume fraction of fire smoke in the acoustic separation chamber at any given time The calculation formula is: ; in, This represents the initial volume fraction of the fire smoke. This represents the initial transmittance of the fire smoke. Numerous studies have shown that the particle size of smoke particles in a fire follows a log-normal distribution. The distribution parameters can be inferred from the volume fraction, thus yielding particle size information. The volume fraction is calculated. Then, based on the particle size distribution model, it can be determined according to the volume fraction. Estimate the median particle size d in the hollow cavity at this time. 50 (Unit: μm), i.e., based on volume fraction Obtain the median particle size d 50 The process is as follows: The particle size of smoke particles in a fire usually follows a log-normal distribution: for a volume fraction of... Log-normal distribution of smoke particles ,in as well as for The corresponding particle size range [ , ], The average particle size is The mean of the logarithmic particle size is... The standard deviation of the logarithmic particle size, at the same time, , , This represents the median particle size (50% of particles are smaller than this size). For a typical fire smoke particle scenario, the distribution statistics of particle size measurements are shown in Table 1: Table 1. Normal Distribution Parameters of Combustible Material Index in Typical Fires combustibles Median particle size (nm) Standard deviation cotton core 123.0 1.74 fir 177.3 1.65 bamboo 104.0 1.84 cotton fabrics 173.0 1.69 cardboard 229.9 1.67 Polyester 128.8 2.08 paper 272.2 1.69 wool yarn 80.6 1.52 nylon 96.3 1.55 PVC (Polyvinyl Chloride) 263.2 1.77 Insulating rubber 137.6 1.99 polystyrene 80.2 1.93 Mosquito plate 165.1 1.85 polyethylene 180.3 1.54 kerosene 300.8 1.70 PPR 278.3 1.55 N-heptadecane 308.5 1.45 NBR / PVC (Nitrile Butadiene Rubber / Polyvinyl Chloride) 176.8 1.53 That is, for different combustible materials, their volume fraction can be calculated based on the median particle size and standard deviation. Therefore, correspondingly, based on this correspondence, according to the volume fraction This allows for a quick estimation of the median particle size. .

[0052] For a particle with a median particle size d 50 Isolated spherical smoke particles (unit: μm) at sound wave frequencies of When moving within a sound field (unit: kHz), the movement of particles in fire smoke is determined by the entrainment rate. To describe its involvement rate Described as: ; in: The dynamic viscosity of air in the fire environment; This is the slip correction factor; and The change is very small and can be considered a constant; the particle entrainment rate With sound wave frequency The decrease in concentration leads to an increase in concentration; in the case of a certain condition, most particles are in a stationary state; while in the case of a certain condition, only a portion of the smoke particles are entrained. In the case of (unit: kHz*), the particles are almost completely engulfed by the sound field; this range is the efficient frequency range for particle aggregation. As can be seen from this formula: lower frequencies result in larger acoustic amplitudes, but excessively large amplitudes cannot enhance the relative motion of the particles, reducing the aggregation effect; while higher frequencies produce smaller acoustic amplitudes, keeping the particles almost stationary, similarly hindering relative motion and limiting aggregation.

[0053] Based on the above theoretical calculations, the initial operating frequency of the device can be preliminarily estimated. The specific process is as follows: based on volume fraction Estimated median particle size Then, based on this median particle size The corresponding starting sound field frequency can then be obtained. That is, there exists a range of sound wave frequencies or a range of sound wave frequency values. , making This causes the particles to be almost completely engulfed by the sound field; this range of values ​​or sound wave frequency values That is, as The sound field generating device 3 is initially configured based on the sound field frequency. This provides theoretical support for setting the initial parameters and clarifies the initial range. Considering the errors in theoretical calculations and the dynamic changes of smoke particles in the fire field, in this embodiment, based on... The steps to obtain the corresponding sound field frequency are as follows: fix the sound field power as a preset value, and then... exist -1000≤ ≤ The frequency F1Hz, which maximizes light transmittance, is obtained by iterating through the range of +1000 with a step size of 10Hz. F1 is then used as the sound field cohesion efficiency to adjust the sound field generator 3. By setting it in this way, F1 can be quickly determined as the optimal sound field cohesion efficiency at that time, allowing for fine-tuned control of the sound field generator 3 and achieving rapid response.

[0054] At a given frequency, as the acoustic power increases, the agglomeration efficiency of smoke particles increases, but the degree of increase decreases and energy consumption increases. Therefore, there exists an energy-saving and efficient optimal acoustic power, which varies depending on the structural characteristics of the agglomeration chamber.

[0055] S5: A uniform sound field is generated in the acoustic separation chamber 2 and acts on the airflow, causing the fine particles with a particle size ≤10μm in the airflow to collide and agglomerate rapidly, forming large particles. The large particles naturally sink to the bottom of the acoustic separation chamber 2 due to gravity. Specifically, the uniform and stable sound field in the acoustic separation chamber 2 acts on the smoke airflow, causing ultrafine particles with a particle size ≤10μm to collide and agglomerate rapidly and fully, forming large particles with a particle size >10μm. In this embodiment, about 53.8% of the large particles naturally settle to the detachable dust collection trough at the bottom of the acoustic separation chamber 2 by gravity, effectively reducing the particle interception load of the filter layer and reducing the breathing resistance of the filter layer by at least 60%.

[0056] S6: The remaining airflow is filtered, and the filtered airflow enters the sealed chamber of the mask body 1 in a one-way manner. Specifically, the remaining 46.2% of large particles move with the airflow through the second one-way valve 6 to the filter layer, and are completely physically intercepted when passing through the filter element of the KP95 grade self-priming filter escape respirator. Combined with the settling effect, this achieves an overall removal efficiency of more than 95% for ultrafine particles in fire smoke.

[0057] S7: Expels the airflow inhaled by the wearer in a one-way manner.

[0058] Specifically, the clean air, purified by both gravity settling and physical interception, is inhaled by the wearer through the air inlet of the mask body 1. The wearer's exhaled air is discharged unidirectionally through the exhaust valve at the air outlet of the mask body 1, preventing the exhaled air from flowing back into the acoustic separation chamber 2 and affecting the purification effect, thus ensuring the smoothness of the breathing process and the effectiveness of the protection.

[0059] In addition, step S8 may be included: when the transmittance measured by the laser power receiving module 9 is ≥80%, the adjustment control module 4 shuts down the sound field generating device 3; when the transmittance measured by the laser power receiving module 9 is <80%, the adjustment control module 4 starts the sound field generating device 3, thereby extending the service life of the separation device and further adapting to the needs of subdivided scenarios in the fire scene. It is understood that step S8 is optional and can be set or omitted according to actual needs.

[0060] Exemplary embodiments of this disclosure have been specifically shown and described above. It should be understood that this disclosure is not limited to the detailed structures, arrangements, or implementations described herein; rather, this disclosure is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims.

Claims

1. A sound field-based respiratory smoke particle separation device, disposed on a mask body (1), the mask body (1) having a communicating air inlet, a sealed chamber, and an air outlet, the air inlet being provided with a filter layer, characterized in that, The mask includes a sound wave separation chamber (2), a sound field generating device (3) connected to the sound wave separation chamber (2), and an adjustment control module (4) for controlling the sound field generating device (3). The sound wave separation chamber (2) is connected to the mask body (1). The sound wave separation chamber (2) has a hollow cavity. A first one-way valve (5) for allowing external gas to enter is provided on one side of the hollow cavity, and a second one-way valve (6) is provided on the other side of the hollow cavity. The hollow cavity is connected to the air inlet of the mask body (1) through the second one-way valve (6).

2. The sound field-based respiratory smoke particle separation device according to claim 1, characterized in that, The sound wave separation chamber (2) is equipped with a horizontal hollow tube and a vertical hollow tube, which are connected to each other; the axis of the horizontal hollow tube is perpendicular to the axis of the vertical hollow tube; the horizontal hollow tube is connected to the first one-way valve (5) and the second one-way valve (6); the vertical hollow tube is connected to the sound field generating device (3).

3. The sound field-based respiratory smoke particle separation device according to claim 2, characterized in that, A horn is provided between the sound field generating device (3) and the vertical hollow tube; the horn has a small port and a large port, the small port of the horn is connected to the vibrating end of the sound field generating device (3), and the large port of the horn is connected to the port of the vertical hollow tube.

4. The sound field-based respiratory smoke particle separation device according to claim 2, characterized in that, It also includes a sound-absorbing sponge (7), which is disposed on one side of the sound wave separation chamber (2); the sound-absorbing sponge (7) is laid and covered on the end of the vertical hollow tube away from the sound field generating device (3).

5. The sound field-based respiratory smoke particle separation device according to any one of claims 2-4, characterized in that, It also includes a laser emitter (8) and a laser power receiving module (9); the laser emitter (8) is located at one end of the acoustic separation chamber (2) near the second one-way valve (6), and the laser emitter (8) faces the hollow cavity; the laser power receiving module (9) is located in the acoustic separation chamber (2) and faces the laser emitter (8).

6. The sound field-based respiratory smoke particle separation device according to claim 5, characterized in that, The laser emitter (8) faces the interior of the horizontal hollow tube, and the laser emitter (8) and the laser power receiving module (9) are directly opposite each other along the diameter of the horizontal hollow tube.

7. The sound field-based respiratory smoke particle separation device according to claim 6, characterized in that, The adjustment control module (4) is disposed on the mask body (1), and the adjustment control module (4) is electrically connected to the sound field generating device (3) and the laser emitter (8); the adjustment control module (4) includes a circuit board, an MCU main control chip electrically connected to the circuit board, and a power supply.

8. The sound field-based respiratory smoke particle separation device according to claim 1, characterized in that, It also includes noise-canceling earplugs (10), which are disposed on the outer side wall of the mask body (1).

9. A control method applicable to the sound field-based respiratory smoke particle separation device according to any one of claims 1-8, characterized in that, Includes the following steps: S1: The mask body (1) is tightly worn on the wearer's face, the sealed chamber fits seamlessly with the wearer's face, and the noise-canceling earplugs (10) are inserted into both ears at the same time. S2: The adjustment control module (4) is started, the laser emitter (8) and the laser power receiving module (9) are started synchronously to detect the transmittance in real time, and the sound field generating device (3) is started with a preset frequency and initial power; S3: The airflow is introduced into the acoustic separation chamber (2) in a one-way manner. The acoustic separation chamber (2) constrains the airflow to stay for the duration of the breathing interval of the personnel. The laser power receiving module (9) transmits the transmittance to the adjustment and control module (4) at a preset cycle. S4: The adjustment control module (4) calculates and matches the sound field frequency based on the light transmittance, and then controls the sound field generating device (3) to adjust the parameters of the sound field generating device (3) to the corresponding values ​​to match the characteristics of the smoke particles in the current fire scene. S5: A uniform sound field is generated in the acoustic separation chamber (2) and acts on the airflow, causing fine particles with a diameter ≤10μm in the airflow to collide and agglomerate rapidly, forming large particles. The large particles naturally sink to the bottom of the acoustic separation chamber (2) by gravity. S6: The remaining airflow is filtered, and the filtered airflow enters the sealed chamber of the mask body (1) in a one-way manner. S7: Expels the airflow inhaled by the wearer in a one-way manner.

10. The control method according to claim 9, characterized in that, The specific steps of S4 are as follows: obtaining transmittance measured at time The adjustment and control module adjusts according to the light transmittance. Calculated Volume fraction of fire smoke in the acoustic separation chamber at any given time The calculation formula is: ； in, This represents the initial volume fraction of the fire smoke. The initial transmittance of the fire smoke; according to Obtain the corresponding sound field frequency and adjust the sound field generating device (3) according to the sound field frequency.

11. The control method according to claim 10, characterized in that, According to The steps to obtain the corresponding sound field frequency are as follows: according to Obtain the median particle size in the hollow cavity. ; Based on the median particle size Get the starting operating frequency ; according to exist -1000≤f≤ The frequency F1Hz, which maximizes the light transmittance, is obtained by traversing the range of +1000 with a step size of 10Hz. F1 is then used as the sound field aggregation efficiency to adjust the sound field generating device (3).

12. The control method according to claim 11, characterized in that, The "according to" Obtain the median particle size in the hollow cavity. The specific steps are as follows: For volume fraction of Log-normal distribution of smoke particles Satisfy the following formula: ； in as well as for The corresponding particle size range [ , ], The average particle size is The mean of the logarithmic particle size is... The standard deviation of the logarithmic particle size, and the mean of the logarithmic particle size. and logarithmic particle size standard deviation Satisfy the following formula: ， ； Based on the normal distribution parameters of combustible material index in typical fires, the median particle size and standard deviation can be obtained, and its volume fraction can be calculated. This makes the median particle size, standard deviation, and volume fraction... There is a corresponding relationship, thus based on the volume fraction The median particle size can be obtained. .

13. The control method according to claim 11, characterized in that, The phrase "based on the median particle size" is used to describe the situation. Get the starting operating frequency The specific steps are as follows: For a particle with a median particle size d 50 Isolated spherical smoke particles at sound wave frequencies of When moving within the sound field, the movement of particles in the fire smoke is determined by the entrainment rate. To describe its involvement rate Described as: ； in: The dynamic viscosity of air in the fire environment; This is the slip correction factor; Calculate the frequency range or frequency value of the sound wave. , making This causes the particles to be almost completely engulfed by the sound field; this range of values ​​or sound wave frequency values That is, as , This refers to the high-efficiency frequency range for particle aggregation.

14. The control method according to claim 9, characterized in that, It also includes S8: when the transmittance measured by the laser power receiving module is ≥80%, the adjustment control module shuts down the sound field generating device (3); when the transmittance measured by the laser power receiving module is <80%, the adjustment control module starts the sound field generating device (3).

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