Patent ID: 8657938

Claim:
A system for supplying breathing air to a workspace, comprising: a main air-supply unit for compressing, drying and filtering air supplied from atmosphere so that breathing air is supplied to the work space; a plant air-supply unit for supplying industrial air used in a process plant to the work space; and an emergency air-supply unit for supplying breathing air to the work space in an emergency, wherein the main air-supply unit comprises: a compressor for compressing air from the atmosphere so that compressed air is supplied; a receiver tank which provides a space for receiving the compressed air and includes a pressure gauge for measuring air pressure therein; an air dryer for removing moisture of the compressed air discharged from the receiver tank; and a filtering part for removing impurities of the compressed air passed through the air dryer, wherein the plant air-supply unit is operated when the measured pressure of the receiver tank is less than 6 kgf/cm 2 , and the emergency air-supply unit is operated when the pressure of an air transferred to the work space by the main air-supply unit and the plant air-supply unit is less than 4.5 kgf/cm 2 or when an oxygen content of the industrial air transferred from the plant air-supply unit is less than 21% of oxygen concentration.