Research On The Gap Sealing Structure Of Positive Pressure Respiratory Protection Masks

The novel coronavirus(COVID-19)has a fast transmission rate and a high fatality rate,so individual protection has received extensive attention.The medical staff has the risk of infection with the virus during the treatment of novel coronavirus patients,so the design and research of respiratory protective masks have become a top priority.In this thesis,the positive pressure respiratory protective mask is the main research object,and the gap-sealing structure of the positive pressure respiratory protective mask was studied.Simplified modeling of breathing chamber and sealing apron based on structure principle of positive pressure gap seal and flow field parameters in the mask.Combined with the gas leakage model of the respiratory chamber,the related factors affecting the pressure change in the respiratory chamber and the size of the sealing apron are analyzed,which provides the basis for subsequent numerical simulation.The finite element analysis software ANSYS was used to explore the variation law of pressure in the coupling area of the mask.The effects of different parameters of sealing apron material,width,thickness,sealing clearance and inlet flow on the pressure change in the coupling area of the mask were analyzed.Find out the optimal structural parameter range,and compare the two working conditions with or without respiratory interference to verify the safety of the mask under actual working conditions.Simplified modeling according to sealed apron structure.The fluid-solid coupling module in ANSYS is used to simulate the self-adaptability of the sealing apron.That is the influence of the above parameter changes on the shape variable of the sealing apron is analyzed,and the optimal structural parameters suitable for the sealing apron are obtained.Combined with the presence or absence of respiratory interference two conditions for simulation verification.Based on the optimal structural parameters in the numerical simulation results,the experimental prototype of the sealed apron and the positive pressure respiratory protective mask was fabricated,and a data acquisition platform was built.The pressure of the breathing chamber,the pressure of the coupling area of the mask and the deformation of the sealing apron were measured.The experimental results are compared with the numerical simulation results to verify the feasibility,safety,and comfort of the flexible sealing apron in the positive pressure respiratory protective mask.