GB267990A - Improvements in or relating to detecting, indicating and recording the presence of inflammable vapours or gases - Google Patents

Abstract

267,990. Ringrose, H. T. Sept. 28, 1925. Gas analysis.-Apparatus for detecting, indicating or recording the presence of inflammable gases or vapours, such as marsh gas in mines and oil vapour in ships, comprises a porous vessel which is capable of maintaining a gas pressure for a substantial time and through which the inflammable gases diffuse or into which they are aspirated, a reduced pressure proportional to the amount of inflammable gas present being produced in the porous vessel by combustion of the gas without absorption of carbon dioxide or with vapour &c. and operating an indicator or recorder. An audible or visible signal may be given when the inflammable gas reaches predetermined concentratiuns. The combustion may be produced by platinum wire with or without platinum black or other catalytic material and heated by an electric current. To avoid errors due to the heat of the wire and to atmospheric pressure, temperature and humidity, two porous vessels may be connected to a pressure gauge, combustion in one being prevented by totally enclosing it to prevent its exposure to the gas or by enclosing its heating element in a small bulb plugging into electric terminals or by dimensioning its heating element so that its temperature is below the ignition point of the gases. The water vapour produced in the combustion vessel condenses and may be drawn off by a tap or trap without disturbing the pressure and the space within the other porous vessel or within both vessels may be maintained saturated with water vapour by a wick partly immersed in water. A porous vessel 6 may be held by a clamp 7 with interposed rubber washers 12 against a base 2 and closed by a cap 13 carrying insulated .leads to the heating filament 16, the cap 16 being pressed against a rubber ring 17 by a clamp 19. The vessel 6 is surrounded by a perforated cover 1 and the interior of the vessel 6 is connected by a tube 22 to a monometer connected to a similar vessel which has its filament 16 enclosed in a bulb 23. In modifications, a single porous vessel is employed or two porous vessels separated by a partition are combined into a single unit with the indicator or recorder mounted at one side, the outer ends of the vessels being closed by cover plates carrying the filaments and held together by threaded rods. One of the Provisional Specifications states that the products of combustion may be absorbed.