Volume expansion system for breathing gas in closed-circuit breathing apparatus

摘要

A volume expansion system increases the storage volume for breathing gas in a closed-circuit breathing gas apparatus. A flow controller is coupled to an inhalation side of the closed-circuit breathing gas apparatus and is also coupled to an expandable reservoir. The flow controller defines a first flow path that allows breathing gas in the inhalation side to automatically flow into the expandable reservoir when pressure in the inhalation side exceeds a threshold. The flow controller can also include the means to define a second flow path that allows on-demand return of the breathing gas in the expandable reservoir to the inhalation side of the breathing gas apparatus.