Aqueous condensate trap used in sample gas line of breathing- or anesthetic gas supply apparatus employs microporous PTFE filtration membranes ahead of analyzer, with visible, convenient and reliable condensation collection chamber

摘要

An aqueous condensation trap comprises microporous polytetrafluoroethylene (PTFE) filtration membranes. The removable casing (1), attached to a holder (2) carries a tank (3) for liquids and gases. The lower section (12) of a chamber (10) partitioned by a hydrophobic membrane (10), connects to the incoming sample gas line (121). It discharges into the tank gas headspace. The upper section (11) connects to a gas analyzer (4) and downstream suction source. A further chamber partitioned by a hydrophobic membrane (20), has a lower section connected to a depressed point (18) in the tank gas headspace. The upper section (21) connects to a volumetric flow meter (8) and the same suction source. Open area and pore sizes of both membranes are selected such that the ratio of flows through them (10, 20) is 5:1 to 20:1, preferably about 10:1. Preferred features: A casing outlet (13) connects to an internal line (14) reaching down to the base of the tank. Pore sizes of first and second hydrophobic membranes are less than 0.45 micro m. Area available for gas flow through the first membrane is about 95-110 mm<2>; pore size is 0.2 micro m. Through the second it is about 15-30 mm<2>; pore size is 0.1 micro m. A pump (6) provides suction. The line (15) from the analyzer, discharges into the line between analyzer (4) and pump (6).