Revitalization of air using a potassium superoxide plate in hypoxic space: Performance and kinetic model under natural convection conditions

Abstract

Potassium superoxide-based oxygen supply systems demonstrate a tremendous potential for applications associated with mine emergency rescue. In this study, the air revitalization performance of a potassium superoxide plate operating under natural convection conditions was investigated by a series of passive tests in a sealed chamber. Reaction resistance analysis based on experimental data revealed that increasing air temperature and humidity accelerates oxygen generation but reduces the system respiratory quotient as a result of the increased resistance of internal diffusion. Increasing the amount of plates or using them in combination with a carbon dioxide absorption curtain is a practical, effective method for meeting requirements of both oxygen generation rate and system respiratory quotient in underground refuge. Kinetics model that predicted the mean oxygen generation rate, carbon dioxide absorption rate, system respiratory quotient and total thermal output (Q) was also derived from experimental data in this study. Predicted results were found to be in good agreement with experimental data. The proposed model can aid in the design of air revitalization systems used in refuge stations for underground mines.