GB1034983A - Oxygen therapy system - Google Patents

Abstract

1,034,983. Liquid oxygen vaporizers. UNION CARBIDE CORPORATION. April 20, 1964 [May 9, 1963], No. 16378/64. Heading F4P. [Also in Division A5R] A portable liquid oxygen converter B and a larger liquid oxygen converter A either of which may be used independently, each comprise a liquid storage container with a liquid transfer conduit and a vaporizing conduit, complementary valve assemblies being secured to each container so that the portable converter may be inverted over the larger converter with the valve assemblies mating with each other to interconnect the transfer conduits of each container and vapour venting passages of each container and permit the portable converter to be filled from the larger converter. The converters each comprise a double-walled liquid oxygen container 10, 90 the space between the walls being evacuated and containing insulation material and a gas adsorbent 24, 108. Bursting discs 28, 112 are provided in the outer wall of each container. A liquid transfer tube 34, 118 extends from near the base of each container to a spud 30, 114 which gas-tightly closes a passage 20, 114 at the top of each container. The transfer tube 34 of the larger converter communicates through the spud 30 with a normally closed valve 140 comprising a fixed stem 154 and a movable seat 156 and with a passage leading to a vaporizer 70. The vaporizer comprises helical grooves formed outside an electric heater 72 enclosed in a tube, or heat-exchange coils (Fig. 2, not shown), arranged outside the container and warmed by the ambient atmosphere. Oxygen vapour passes from the vaporizer to the user through a manually controlled valve 44. A working pressure is built up in the container by a heating resistance 56 controlled by a pressure switch which is connected to the spud 30 and is responsive to the pressure in the container. A thermal switch 66 prevents overheating of the container, e.g. when the vessel requires refilling. The fluid transfer tube 118 of the portable converter communicates through a cap 116 with a vaporizer coil 120 which is connected to a breathing mask through a valve 130, and with a normally closed valve 166 through which the converters are interconnected for filling the portable converter. A double-walled tube 100 forming a space around the transfer tube 118 communicates at one end with a vent tube 124 within the container and at the other end with a normally closed valve 168. The valves 166, 168 comprise movable stems 176 and fixed seats 178, so that when the portable converter is inverted over the larger converter, the valves 166, 168 engage with the connecting valve 140 and a similar vent valve 142 to open the four valves. Air is vented from the portable converter through the vent valves as liquid oxygen flows into the container 90. A shielded thermistor 134 in the container 90 causes closure of a valve 122 to prevent exhaust of vapour when liquid oxygen has reached a predetermined level so that as filling continues a working pressure is built up. The portable converter may be used during filling.