| 摘要 |
<p>1497894 Mixing apparatus DRAGERWERK AG 26 Nov 1975 [26 Nov 1974] 48689/75 Heading BIC In a method of and apparatus for mixing first and second gases in a predetermined ratio the first gas A is supplied to a mixing container 5 through a first valve 3 which is arranged to open when the pressure in the container has fallen below a first value and to close when it exceeds a second higher value, the second gas B then being supplied through a second valve 4 until a third, still higher value is exceeded, whereupon valve 4 is closed and a third valve 7 is opened permitting discharge of the gas mixture until the pressure again falls below the first value. The cycle is then repeated. Control means 15 are provided in conjunction with a pressure-measuring device 6 to control the opening and closing of the valves, the value of the intermediate or second pressure being adjustable in order to adjust the proportions of the gases. The apparatus may be applied to providing mixtures of gases for respiration and in this case control means may be provided e.g. to provide an alarm and/or ensure continuity of supply of a breathable gas in the event of failure of one of the valves. In a second embodiment of the apparatus (Fig. 2 not shown) two-way valves are used i.e. for supply of gas A or B and for filling or discharging the mixing vessel.</p> |
