Enhanced PM filtration and self-adaptive oxygen supply by intelligent powered respirators under extreme conditions with high dust and low oxygen.

Mine workers in high-altitude regions confront the combined physiological threats of severe respirable dust and reduced oxygen partial pressure. Conventional powered air-purifying respirators (PAPRs) are often plagued by premature filter clogging, excessive airflow resistance, compromised facial sealing, and insufficient oxygen delivery. An intelligent PAPR system was disclosed in this work, which synergistically integrates prolonged dust filtration with adaptive oxygen enrichment. The key technical route involved in-situ metal-organic framework (MOF) functionalization of high-efficiency particulate air (HEPA) media, geometric optimization of pleated configurations, intelligent self-adaptive oxygen regulation, and systematic performance validation. Quantitative evaluations reveal that the HEPA membrane subjected to a 6 h MOF treatment demonstrates optimal integrated filtration properties, attaining a total particulate filtration efficiency of 83.9∼87.0% against PM particles-a 2.4% enhancement relative to the unmodified counterpart. Under average respiratory flow rates of 30, 60, and 85 L·min-1, the mean oxygen volume fractions within the facepiece reached 23.36%, 24.83%, and 26.67%, respectively, consistently exceeding the ambient atmospheric oxygen concentration of approximately 21%, while the intra-mask relative pressure followed a sinusoidal variation. The proposed PAPR system substantially elevates comprehensive respiratory safety in harsh, hypoxic, and highly dust-laden environments, thereby offering a safer and more comfortable protective solution for high-altitude mining personnel.