Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Development of a device for analyzing the functionality of N95 respirators regarding the efficiency of the filtering fiber
Submission Author:
Claysson Vimieiro , MG
Co-Authors:
João Victor Felisberto, João Grego, Mateus Giori, Saulo Gonçalves, Guilherme de Paula Rúbio, Rudolf Huebner, Viviane Vimieiro, Claysson Vimieiro
Presenter: Claysson Vimieiro
doi://10.26678/ABCM.COBEM2023.COB2023-1229
Abstract
N95 respirators intended to prevent the airborne transmission of diseases such as tuberculosis, and are also recommended for use in aerosol-generating procedures during the new coronavirus pandemic. In this case, health agencies recommend protocols for reusing the respirators due to the shortage of the product on the world market in order to conserve the limited supply. However, there is no scientific evidence on the implications of the duration of use ensuring its capability to retain particles up to 0.3 microns (μm), with a minimum filter efficiency of 95%. In this sense, the objective of this work will be to construct an equipment in accordance with the standards of the National Institute for Occupational Safety and Health, United States (Certified Under 42 CFR 84) to analyze the functionality of the filtering material of the N95 respirators in terms of the minimum filtration capacity of 95% of airbone particles and quantify their breathability in reuse protocols (seven and 15 days). Therefore, the N95 respirators will be cut into a circular shape with an approximate diameter of 5.0 centimeters where it will be fixed in a cylindrical tube with an inner diameter of the same size. NaCl particles with an average size of 0.3μm will be aerosolized using an aerosol generator at one end of the equipment and a vacuum generator at the other end to create suction and consequently an airflow in the indicated direction, with a variation between 35 and 90 liters/minute (intending to replicate human breathing). Using a particle counter, the concentration of particles before and after the N95 respirator sample will be evaluated, thus obtaining the Particle Filtration Efficiency (PFE). In addition, breathability will be determined by measuring the pressure difference in the material (ΔP). Thus, it will be possible to measure the efficiency of each filtering element, where high PFE and low (ΔP) should be obtained. In that manner, it will be possible to evaluate after how long the respiratory device still maintains its minimum filtration efficiency (95%) after the reuse, ensuring the safety of health professionals.
Keywords
N95 Respirators, Personal protective equipment, occupational health
