GB1488249A - Apparatus for converting a volatile anaesthetic liquid into a vapour - Google Patents

Abstract

1488249 Liquid vaporizing device R F SALAMONSEN 4 Oct 1974 [30 Oct 1973] 50341/73 Heading AST A device for connection to a respiratory anaesthetic system in which flows a respirable carrier gas stream and for converting a volatile liquid anaesthetic into a vapour comprises a vessel having an inlet and an outlet for connection in series with the system whereby in use the carrier gas stream flows through the vessel, a positive displacement device connected to liquid delivering means passing into the vessel, the liquid delivering means having an outlet in the vessel for introducing a volatile liquid anaesthetic into the carrier gas stream, and gas delivering means within the vessel for directing a high velocity stream of respirable gas at the outlet of the liquid delivering means so as to cause the liquid upon introduction into the vessel interior to become substantially totally dispersed and vaporized by the high velocity gas stream, whereby the mixture of respirable gas and vaporized anaesthetic is carried to the vessel 1 outlet by the carrier gas. The vessel comprises a container with a lower part 21, preferably of a transparent material such as glass, and an upper part 20, preferably of metal such as plated brass or stainless steel, the two parts having a seal 28 and being held together by some means (not shown). A removable plug 23 allows for drainage of any liquid collecting in part 21. Liquid anaesthetic from a positive displacement device such as a syringe pump enters through port 24 and passes to nozzle 25, oxygen enters through port 26 and passes through nozzle 27 producing an aerosol of the anaesthetic liquid. Carrier gas from a closed-circuit respiration system passes in the direction of arrows 13. The mixture of carrier gas and anaesthetic then passes through trunk 19 to the patient. The vaporization of the liquid anaesthetic may be aided by impingement of the liquid on a heated plate located adjacent to nozzle 25. The carriergas stream may be heated by passage through a soda-lime cannister which normally produces heat, or by other ancillary means. Flow of carrier gas may be assisted by an electrically-driven impeller in the circuit.