Air Volume Flow Research Articles

Harvesting optimization and Omega-3 recovery improvement from Schizochytrium DT3 using surfactant-aided dispersed air flotation: Response surface methodology

Microalgae's potential to produce high value bioactives is contingent on the cost-effective harvesting of algal biomass. The use of CTAB (cetyl trimethylammonium bromide) assisted dispersed air flotation as a harvesting technique for Schizochytrium biomass, was optimized as a cost-effective means for recovery (R) and concentration factor (CF) using Response Surface Methodology. To the best of our knowledge, this is the first study to employ surfactant assisted dispersed air flotation (SDAF) in the recovery of a heterotrophic thraustochytrid strain. A Box-Behnken design of experiment investigating the operating parameters of CTAB amount, air flow rate and volume on Schizochytrium was employed. Initially, both responses were analyzed individually and then used to simultaneously maximize both variables. The optimized conditions of CTAB (500 mg/L), air flow of 2 L/min and volume of 600 mL resulted in a R of 91 % and CF of 19 times. Although a secondary step is necessary for further concentration, this technique utilizes 70 times less energy as compared to conventional centrifugation techniques which are used to recover Schizochytrium sp. This is significant as this technique can be easily adapted to existing bioreactors, as they are already equipped with gas spargers. In addition, the presence of surfactant carried through demonstrated an improvement in the recovery of long chain poly unsaturated fatty acid (PUFA) by 6 %, particularly in DHA and DPA which was not observed in washed biomass.

Air entrainment by a hydrofoil in a high-speed water flow for design of bubbly drag reduction ships

We have investigated the flow behavior around a hydrofoil bubble generator in a high-speed channel flow up to 10 m/s for the first time to understand the air entrainment characteristics of this hydrofoil device caused purely by the inertia effect of water flow. This study is motivated by our previous success in achieving ship drag reduction for full-scale vessels (Kumagai et al., 2015). Depending on the water flow velocity U and the angle of attack of the hydrofoil α, three different major patterns were identified: continuous generation of dispersed bubbles, intermittent formation of an air cavity, and steady formation of a super air cavity that stretched behind the hydrofoil. The transition from the dispersed bubble state to the air cavity formation regime is explained theoretically using the equation of bubble motion coupled with a potential flow analysis. The air volume flow rate increased linearly with U, and its slope was steeper in the dispersed bubble state than in the air cavity formation regime. The highest air flow rate was realized at U = 9 m/s, which corresponds to the nominal air layer thickness at ta = 4.1 mm, and reaches the feasible range for realization of bubbly drag reduction for a long ship hull.

Development and characterization of a through-air thermobonding process with high heating rate for activating the binder and producing preforms for fibre-reinforced polymers

This study focuses on the development of an advanced high heating rate thermobonding process for the manufacture of preforms and the metrological characterisation of the process. The process involves passing hot air, driven by pressure differential, through a textile stack consisting of several plies of a quadraxial fabric coated with a binder. Heat is transferred into the stack and into the binder by forced convection, melting the binder. The process is used in the same way to cool the stack and binder so that the plies are bonded together. The pressure differential compacts the stack. The comprehensive methodological characterisation of the process includes first determining the air permeability of the stack and thus the volume flow of air as a function of the number of plies stacked. Further characterisation focuses on a comprehensive determination of the heating behaviour in the individual plies as a function of time, using thermocouples and thermal imaging to determine the temperatures of hot air and textiles. These are compared and related using a mathematical approach as different values have been found. The results indicate high heating rates, reducing process time by at least 85% compared to previous binder activation methods. In addition, the cantilever method assesses the flexural stiffness of the processed stacks and shows a twofold improvement in bond strength compared to uncompacted stacks. Results and discussions include orifice based volume flow determination, thermography calibration, mathematical modelling, stiffness of bonded textile plies, process comparison, process control and potential energy savings.

Evaluation of three suction pretreatment systems for the air compressor

Air compressor, as the power source of pneumatic tools, suffers the problems of low efficiency and high failure rate in summer. In this paper, three suction air pretreatment systems are presented, which are characterized by the cold sources: a vapor compression refrigeration unit, a water chilling unit and a combination of water chilling unit with cooling tower. Models for the thermodynamic and economic performance evaluation of the three systems are established and solved. The moisture diffusion coefficient is applied to consider the influence of the moisture condensation and the Marshall and Swift coefficients is introduced to consider the capital change over time. Formula to calculate the efficiency of refrigeration compressor is adopted. Besides, the system total efficiency, percentage of power saving (PPS) and payback period (PBP) are defined as performance indexes. A comparative study with typical meteorological data of hot-dry regions and hot-humid regions is conducted to analyze the superiority of each system under the operation conditions of varied suction air temperature and volume flow. According to the results, optimal spray water flowrate exists for each operation condition and an air–water ratio of 0.8 is recommended. When the suction air temperature decreases, the PBP of each system increases and a sharp increase occurs when the temperature is lower than the air dew point temperature. A suction air temperature of 26 ℃ is suggested. Direct air cooling with an evaporator is preferred when the suction air volume flowrate is smaller than 60 m3/min for hot-humidity regions. The combined system is significantly superior in hot-dry regions. The PBP of the three systems is all longer than 10 months. How to guarantee the usage rate is the key for enterprises to consider the use of suction air pretreatment systems.

Mitigating Coal Spontaneous Combustion Risk within Goaf of Gob-Side Entry Retaining by Roof Cutting: Investigation of Air Leakage Characteristics and Effective Plugging Techniques

Relative to conventional coal pillar retention mining technology (the 121 mining method), gob-side entry retaining by cutting roof (the 110 mining method), a non-pillar mining technique, efficiently addresses issues like poor coal resource recovery and significant rock burst damage. Nonetheless, the open-type goaf created by 110 mining techniques suffers from complex and significant air leaks, increasing the likelihood of coal spontaneous combustion (CSC) within the gob area. To address the CSC problem caused by complex air leakage within the goaf of gob-side entry retaining by roof cutting, this study takes the 17202 working face of Dongrong Second Coal Mine as the object of study. Field tests and simulation calculations are conducted to research the features of air leakage and the distribution of the oxidation zone within the goaf. Subsequently, plugging technology with varying plugging lengths is proposed and implemented. The tests and simulations reveal that the airflow migration within the goaf follows an L-shaped pattern, while air leakage primarily originates from gaps found in the gob-side entry retaining wall. The amount of air leaking into the gob-side entry retaining section is 171.59 m3/min, which represents 7.3% of the overall airflow. The maximum oxidation zone within the goaf ranges from 58.7 m to 151.8 m. After the air leakage is blocked, the airflow migration route within the goaf is transformed into a U-shaped distribution, and the maximum oxidation zone range changes from 42.8 m to 80.7 m. Engineering practice demonstrates that after air leakage plugging, the total air leakage volume within the gob-side entry retaining section significantly reduces to 20.59 m3/min, representing only 0.78% of the total airflow volume. This research provides reference on how to prevent the occurrence of CSC in similar mine goafs.

Novel method for temperature prediction in rotary kiln process through machine learning and CFD

Blast furnace high-proportion pellet smelting stands as a pivotal pathway towards achieving low-carbon and environmentally friendly ironmaking. However, challenges in pellet ore production, particularly through the rotary kiln method, have surfaced due to the scarcity of iron ore resources, leading to issues like “ringing” that hamper production efficiency and energy conservation. Effectively predicting and optimally controlling the temperature field within rotary kilns emerges as a crucial strategy to address this pressing challenge. In a pioneering effort, this paper introduces a data-driven machine learning methodology designed to expedite the prediction of temperature field distributions within rotary kilns. Through a detailed analysis of field data from the factory and the insights of experts, the paper has discussed on the key factors influencing the temperature field dynamics in rotary kilns. Leveraging Computational Fluid Dynamics (CFD), a numerical simulation model was established to replicate rotary kiln oxy-coal combustion scenarios. A comprehensive dataset was generated using high-throughput computing technology, encompassing a variety of conditions such as coal injection rates, return air temperature, return airflow volume, fixed carbon content of pulverized coal, and volatile fraction of pulverized coal. This dataset included a total of 625 distinct cases. Subsequently, employing machine learning techniques including random forest (RF) and genetic algorithm-optimized Random forest (GA-RF), predictive models were developed for rotary kiln temperature field dynamics. A rigorous comparative analysis was conducted to explore the impact of different machine learning dataset sizes on the predictive accuracy of the models. The results of this analysis demonstrate that, enhanced by the genetic algorithm of RF, it surpasses the performance of the standard RF approach. This enhancement resulted in a significant improvement in prediction accuracy, as evidenced by the reduction of the Root Mean Square Error (RMSE) from 25.0879 to 17.5330 and the Mean Absolute Error (MAE) from an initial value of 6.5600 to 4.7661. Furthermore, the novel soft-measurement method introduced in this paper significantly reduces simulation time by several orders of magnitude. It has diminished the response time from the traditional industrial methods, which took two to three weeks, to approximately 10 s, as compared to conventional CFD approaches. Remarkably, this approach successfully preserves a high level of accuracy. The implications of these research findings are far-reaching,providing novel insights into the acceleration of CFD simulation calculations and the design of soft measurement sensors customized for black-box reactors in industrial processes.

Investigating Olfactory Sensory Neurons Facilitation For Aerobic Exercise-induced Spatial Memory Improvement.

The positive effects of exercise on spatial memory and learning have been demonstrated in research. The olfactory sensory neurons (OSNs) respond to mechanical stimulation induced by nasal airflow which is associated with airflow intensity. Accordingly, nasal breathing can modulate brain oscillations in nonolfactory areas, and respiration-entrained oscillations aid the improvement of cognitive abilities. Given that aerobic exercise increases the rate of respiration and intensity of nasal airflow, this study evaluates the role of OSNs in mediating the effects of aerobic exercise on memory. We examined spatial memory following exercise in animal models of olfactory sensory neuron impairment (methimazole injection 300 mg/kg/week). Destroying OSNs significantly reduces olfactory bulb (OB) activity at delta and theta frequency bands as well as its coupling to respiration. More importantly, it abolished the positive effect of exercise on spatial memory (P<0.05). The OB activity is one of the probable mechanisms for improving spatial memory following exercise.

Research and practice of high-speed spiral composite drilling technology in complex and weak coal seams

In response to the difficult slag discharge and low hole formation rate encountered in the Wangpo Coal Mine, a study was conducted on high-speed spiral composite drilling technology. This study was integrated with the performance characteristics of the ZDY6000LR-type high-speed pit rig, resulting in the design of drill bits in three different specifications: Φ110/63.5 mm, Φ95/60.3 mm, and Φ88/50 mm. Additionally, the study optimized the three-wing drill pipe's feed speed, rotation speed, and airflow volume. The industrial field test, conducted on the 3206 working face of the Wangpo Coal Mine, resulted in the design of three drill bit combinations that exhibited high strength and stiffness. This design improvement led to enhanced hole integrity, elevated slag removal efficiency, and extended service life for both the drill pipe and bit. The high-speed spiral composite drilling technology, alongside the supporting equipment, effectively addresses the challenges of slag discharge and nozzle top drilling encountered during operations. It significantly improves the deep hole drilling rate, achieving a drilling depth of over 100 m with a success rate exceeding 70%. This technology provides vital support for the extraction of gas from coal seams within the mine. Notably, the Φ95/60.3 mm screw pipe and its corresponding drill bit demonstrated the optimal holeforming effect, with an average hole depth of 111.2 m and a hole formation rate of 90.9%. These findings offer valuable insights for drilling operations under similar conditions of complex and weak coal seams.

Horizontal laminar flow cabinet with a low background and clean air

The publication presents the design, construction of a prototype, and the course of verification tests of a special horizontal laminar flow cabinet made entirely of plastics. In the cabinet design process, numerical simulations and airflow analyses were used to achieve a laminar, uniform flow in the device's workspace. A prototype was built and subjected to verification tests regarding the intensity and nature of airflow as well as air cleanliness. The cabinet is equipped with its own filtration-ventilation module providing clean air to the workspace and removing used air to the external ventilation system. It ensures an increased level of protection for workers dealing with microorganisms and hazardous airborne chemicals, as well as complete corrosion resistance inside the workspace. A particular area of application for the cabinet is research involving radionuclides, volatile, toxic chemical compounds for which air-recirculating devices cannot be used in the room where they are placed. The developed solution has been protected by industrial property rights and used to implement a contract for the supply of a set of equipment to the laboratory of the Institute of Nuclear Physics of the Polish Academy of Sciences.

Toxic dye removal by thermally modified lignocellulosic waste in a threephase air-lift reactor: Kinetic insights

This paper investigates the influence of the air flow rate in a three-phase air-lift reactor on the sorption of toxic dye, Brilliant green, onto a promising and efficient sorbent, sour cherry stone biochar. In order to gain a comprehensive insight into the sorbent/sorption behaviour, sour cherry stone biochar was characterized by Fourier transform infrared spectroscopy with attenuated total reflection, pH of the suspension, point of zero charge, scanning electron microscopy with energy-dispersive X-ray spectroscopy and X-ray diffraction. The experiments were performed in an air-lift reactor using airflows of 2.50 and 5.55 dm3 h-1. The experimental data of sorption kinetics experiments were fitted by non-linear form of pseudo-first and, pseudo-second models as well as the Weber-Morris model based on intraparticle diffusion. The overall sorption rate was found to be limited by the Brilliant Green mass transport rate to the sorbent at a lower airflow and thus mixing intensity, while it was kinetically controlled at a higher rate following the pseudo-second order kinetic model. Furthermore, sorption at lower air flow was delayed by mass transfer resistance through the liquid boundary layer surrounding sorbent particles. Presented results clearly indicate that airflow intensity plays a significant role in the overall sorption kinetics and support possible application of the applied biochar for efficient Brilliant Green sorption.

Shotcrete 3D Printing ‐ Effect of material‐process interaction on the global and local material density

AbstractShotcrete 3D Printing is a 3D printing process in which the concrete is applied layer by layer using a wet mix process. In the print process, a large number of different process as well as material parameters can be varied, which also influence the hardened concrete properties. A systematic understanding of the interaction between material and process is required to define limits for material and process control variables with respect to the resulting component quality. Therefore, in this paper we present results on the effect of concrete volume flow (0.4; 0.8 m3/h), air volume flow (30; 40; 50 m3/h) and accelerator dosage (0; 3; 6 % by weight of cement) on global density, local density distribution as well as flexural strength. The results show that the combination of an increasing concrete volume flow, a decreasing air volume flow and an increasing accelerator dosage lead to a decrease in global density and flexural strength. A high correlation between the global density and flexural strength can be demonstrated despite the layer‐by‐layer fabrication. In addition, an inhomogeneous density distribution over the cross section is shown. Finally, the underlying mechanisms are discussed regarding the influence of the material and process parameters.

A pilot study on the antimicrobial efficacy of a novel UV-LED system against drainage stack bioaerosol emissions during flushing episodes

Inactivation of airborne microorganisms by ultraviolet (UV) light has been considered one of the most effective procedures among disinfection methods. Ultraviolet light-emitting diodes (UV-LEDs) have a unique place as an emerging technology in air disinfection processes because of their rapid effectiveness and lack of material deterioration. In this study, the efficacy of high-power 285 nm UV-LEDs was explored for Escherichia coli (E. coli) (ATCC15597) inactivation in drainage stack airflow under continuous- and pulsed-UV irradiation conditions. Most relevant photoelectric properties influencing the device operation and performance, including duty cycles and input voltage, were thoroughly investigated. Antimicrobial efficiency varied from 29.0% to 88.0%. The antimicrobial efficiency of pulsed UV irradiation at different duty cycles but the same UV dose was similar. Antimicrobial efficiency was positively correlated with input voltage but negatively correlated with airflow velocity. Moreover, antimicrobial efficiency increased almost linearly with input power per airflow volume (P/Qa). The estimated Z-values of E. coli ranged from 0.0027 to 0.0341 cm2/µJ, and about 29–370 μJ/cm2 of UV dose can be used to obtain one-log inactivation of E. coli, depending on the experimental conditions. The results of this investigation indicate that UVB units can inactivate gastrointestinal drainage stack bioaerosols effectively. This study provides critical information and guidelines for disinfecting drainage stacks with UV, which may aid pathogen infection control in public environments during outbreaks.

Prediction of airflow temperature in underground long-distance excavation roadway and ventilation duct: Numerical simulation and field test validation

High geothermal conditions in deep mineral excavation pose significant heat hazards, limiting safe and efficient resource extraction. In this work, we numerically established a comprehensive mathematical model to predict the airflow temperature in underground long-distance excavation roadway and ventilation duct. Our model was then solved using a self-developed numerical simulator based on the finite volume method (FVM) and finite difference method (FDM). Finally, the simulation results were validated by field measured data and the effect of key parameters on airflow temperature was discussed. The results show that (i) The simulation results are consistent with the measured data within a maximum error rate of 2 %, indicating that the developed model and simulator can accurately predict the thermal environment of long-distance excavation roadway. (ii)The heat release from electromechanical equipment and surrounding rock accounts for more than 90 % of the total heat load, which is the decisive factor leading to high-temperature heat hazards. (iii) The airflow temperature in the roadway is proportional to the original rock temperature, and the thermal environment will deteriorate rapidly with the increase of mining depth. (iv) For every 1000 m increase in roadway excavation length, the airflow temperature at the heading face will rise by 0.88℃. (v) As the average excavation speed increases, the airflow temperature in the roadway increases in a parabolic trend. (vi) Increasing the inlet airflow volume and cooling the inlet airflow can effectively improve the overall thermal environment in the roadway. This research provides theoretical support for controlling the high-temperature heat hazard in roadway excavation.

Numerical and experimental analysis of pollen inhalation exposure in nasal airways following various middle turbinectomy

BackgroundMiddle turbinectomy (MT) has always been controversial. MT significantly alters the anatomy and redistributes the inhaled air. The current study is designed to quantify the effect of MT with varying resection volumes on airflow and associated pollen inhalation exposure characteristics in the nasal airways. MethodsSix realistic models following bilateral comprehensive Functional Endoscopic Sinus Surgery (FESS) deriving from CT images were constructed and their corresponding post-MT models with four types of MT procedures were virtually conducted. Inhalation exposure to pollen particles was simulated by the Computational Fluid-Particle Dynamics (CFPD) approach and validated through in vitro experiments. ResultsFollowing the excision of the middle turbinate, a significant escalation in airflow was observed within the upper-middle region of the nasal cavities. Pollen deposition was observed to be more prominent in the nasal septum, laryngopharynx, and maxillary sinus, varying with the types of MT procedures. Notably, particles with diameters smaller than 50 μm exhibited two distinct “high peaks” and three “small peaks” within the nasal airways. ConclusionMT resulted in increased airflow volume within the upper-middle region of the nasal cavities. Following MT, notable shifts in pollen particle deposition hot spots were observed, transitioning from the nasal vestibule, nasal septum, and middle meatus to the nasal septum and laryngopharynx. These findings are anticipated to contribute valuable perspectives on pollen inhalation exposure risk assessments following diverse MT surgical interventions.

A hydrodynamic interaction between bubbles and gas supply system during gas bubble departures in liquids: an experimental study

In the present paper, the hydrodynamic interactions between bubbles and the gas supply system to a needle were experimentally investigated. In experimental investigations in one of the needles, the air volume flow rate was constant, and in the neighbouring needle, it was changed. In the paper, the methods of data analysis: wavelet decomposition, and FFT were used. It was shown that the hydrodynamic interaction becomes stronger with the increase in air volume flow rate supply to the needle. The occurrence of hydrodynamic interaction modifies bubble growth time slightly, but it significantly modifies the bubble waiting time. In the case when the liquid penetration into the needle is repeatable, then the percentage disturbances in bubble growth time and bubble waiting time are close to each other. Moreover, it can be concluded that synchronized or alternative bubble departures from twin neighbouring needles (occurring due to hydrodynamic interaction) are possible by modifying the bubble waiting time. The modification of hydrodynamic interaction between bubbles, the bubbles themselves, and gas supply systems can be used to control the bubble departure process.

Analysis of indoor air parameters in the occupied zone

Since the COVID-19 pandemic, the number of occupants in many office buildings has decreased around the world, but the comfort parameters in the buildings had to be maintained. Various measures have been taken by the facilities to ensure that the people in the buildings are as protected and safe as possible. Put plexiglass sheets on the desks between the people as a physical barrier and arranged the desks to manage to keep a distance from each other. As a result of these measures, the existing air ventilation system may not be able to provide the designed condition. Analysis of the fresh air ratio was carried out with two different desk arrangements and examined the effect of barriers. As the HVAC systems contribute significantly towards the final energy consumption by buildings it is important to minimalize the level of ventilation. This study focused on the air volume flow, and the mean air velocity. Furthermore investigated the turbulence intensity in percentage as well as the drought rate and comfort levels according to standards. After analyzing the measurement results, various proposals for action have been established.

Theoretical design and drainage characteristic of a C-type heat exchanger in duct air conditioner

The conventional duct air conditioner typically uses an A-type heat exchanger for indoor units, which has poor drainage behavior under wet conditions. In this research, a C-type heat exchanger is developed for drainage improvement. The innovative design employs a unitary fin and a curved profile instead of the sectional fin and linear profile. Theoretical calculations are conducted, determining that the droplet sliding time on the cycloid is the shortest among the curves. The C-type is then produced and subjected to dynamic dip testing to assess its drainage performance. Results reveal that it achieves steady drainage within 3 s and reduces residual water by 10.9% compared to the A-type. A CFD model is generated to simulate the drainage process, with a calculated deviation of less than 10% for residual water. Finally, the C-type prototype is installed in the duct unit for performance measurement under wet conditions. It exhibits a 7.12% increase in heat transfer capacity and a 12.74% increase in drainage rate under the basic condition. The lower evaporating temperature, higher inlet air temperature, higher relative humidity, and larger air volume flow rate contribute to the more apparent drainage enhancement of the C-type.

Quality and mass transport properties of sugar beet roots under short duration, high airflow post-harvest storage

Active ventilation of stored sugar beet roots is used to control system temperature and slow the loss of quality that occurs with plant respiration and the growth of pathogens. Ventilation can at the same time increase rates of dehydration and dehydration related stresses of the stored sugar beet roots. Recent research into the use of forced ventilation to modify temperature in in-field sugar beet root stores has suggested that a controlled dehydration of roots could lead to improvements in quality. This work aimed to investigate the impacts to sugar beet root quality from short-term, high volume airflow during post-harvest storage. A modified environment experimental setup was developed. The experiment tested four airflow rates over three levels of ventilation duration, with the longest duration being seven days. Air temperature and relative humidity was constant within each seven day run, but varied between runs. Results showed that a mean weight loss of 11.7% with a corresponding increase in sucrose content of 13.2% was achieved at the highest airflow rate and ventilation duration. These changes in quality were a result of the transfer of water from the sugar beet roots. No reduction in total sucrose or other quality parameters was observed. The dependence of the rate of water transfer from the roots on airflow rate was quantified as the convective mass transfer coefficient. Estimates are given and cross-validated using dimensional analysis.

Distribution and evolution of particles in flash converting furnace under different operational conditions

A series of industrial experiments were conducted, not only to reveal the distribution and evolution of particle mass and size inside the flash converting furnace, but also to investigate the influence of airflows on the particle distribution. The results showed that the average size of particles grows 2–3 times when falling through the reaction shaft, and large aggregated particles were mainly distributed in the center and outer part of the material cone. This phenomenon was attributed to the collision and aggregation of molten particles caused by the high turbulent intensity of airflow, high particle mass concentration, and positions of natural gas combusting. Moreover, increasing the momentum ratio of the distribution air to the process air helped the particles to be distributed more uniformly, which could be beneficial to matte oxidation. Compared with changing process air, adjusting the distribution air could improve the particle spatial distribution more efficiently.

Study on the transport and deposition of micron-sized particles with different densities in the coal mine environment in miners

To address the health problems caused by the long-term intrusion of high-concentration dust generated in coal mining operations into the human respiratory tract, this study reconstructed a 3D digital model of the upper airway based on fine industrial CT scanning images, and established the micron particle migration calculation model by Euler-Lagrange method. The transport and deposition mechanisms of dust with different densities under different inspiratory intensities were simulated and analyzed. The simulated results were compared with the results of dust exposure experiments in the upper airway combined with 3D printing technology, and the relative errors obtained were in the range of 2.9% to 6.3%. The results showed that the airflow volume peaked in the nasopharynx, oropharynx, epiglottis, and larynx, leading to the airflow separation and formation of circulation that tend to cause dust deposition in these regions. As the dust density and inspiratory airflow volume increased, the deposition fraction of small dust particles (<1μm) in the upper airway slightly changed, and most of them escaped to the lung. For 7.07 μm dust particles, as the dust density increased from 1210 kg/m3 to 2750 kg/m3, the escape rate decreased from 31.43% to 0.48%, and this trend can be seen in the fitting function of escape rate and inspiratory airflow volume Y7.07μm=(80–1.37ν + 0.0064ν2) × 100%. When the dust particle diameter exceeded 20 μm, the impact of dust density was weakened by the large size of the dust, and the escape rate was close to 0% when the inspiratory airflow volume was 50–110 L/min. This study can provide theoretical support for the research and development of respiratory dust sensors and targeted dust prevention technologies.