GB1116504A - Improvements in or relating to underwater breathing equipment - Google Patents

Abstract

Exhaled air from a diver, or in a submarine, or from other under-water enclosure, is enriched with oxygen from the surrounding sea water either by bubbling the air through sea water or by bringing the air into contact with means for extracting oxygen from the sea water, the enriched air then being conducted back to the diver &c., for breathing. Breathing apparatus for a diver (see Figs. 1-5, not shown) comprises a device (34) which allows carbon dioxide to pass from the exhaled air into the water, oxygen to pass from the water into the air, and which prevents water from entering the breathing system, and consists of a number of parallel units (20) through which the air passes, the walls of the units comprising a thin membrane (23) of silicone rubber or microporous polyethylene which allows the permeation of the oxygen and carbon dioxide and resists water. Each unit (20) also includes frame members (25), an inner core (21) of perforated corrugated sheet material, and reinforcing elements (22). The atmosphere in a submarine may be enriched with oxygen obtained by pumping the surrounding sea water through a similar gas exchange device. In an underwater construction (Figure 9, not shown) having living space maintained with an atmosphere at a pressure equal to that of the outside water, the air brought into contact with the gas exchange device 65 is first reduced in pressure at a valve (69) so that the partial pressures of the nitrogen in the air and that dissolved in the water are about the same to ensure that nitrogen is not lost from the breathing circuit.