GB219236A - Apparatus for detecting or estimating and recording combustible constituents in gaseous mixtures - Google Patents

Abstract

219,236. Uehling, F. F. Dec. 12, 1923. Testing heating, illuminating, and motivepower gases.-In an apparatus for estimating and recording the combustible constituents of a gaseous mixture, the gas is passed through a chamber having an inlet and an outlet, which are both heated, and the variation in the pressure of the gas in the chamber due to the prior combustible constituents is indicated on a suitable gauge. The inlet and the outlet are :constructed so as to offer resistance to the flow of gas, and means are provided for regulating the flow so that in the absence of a combustible constituent there is always a constant pressure-difference between the inlet and the outlet. The chamber 1 has a restricted inlet A and a restricted' outlet B, these parts consisting, in the apparatus shown, of platinum capillary tubes protected from atmospheric influences bv insulated casings 31, 32. The tubes A, B are electrically heated from a battery 4, the current passing by way of pipe 3, tube B, chamber 1, tube A, and rheostat 8; the pipes 3, 2 are electrically insulated as at 6. The temperature to which the tubes are heated is above that required for the complete combustion of combustible constituents, and' the length of the tubes is such that combustion is completed during passage of the gas through the inlet A. Gas is drawn through the apparatus by an aspirator 21, and to ensure a normally constant pressure-difference between the tubes A, B a regulating device is provided comprising tubes 24 - - 26 immersed in water to different depths as shown in the Figure. The tube 26 is open to the atmosphere and serves to compensate for any fluctuations in the capacity of the aspirator, which is arranged to draw gas through all three tubes so that the normal pressure difference between the pipes 2, 3 is represented by the head b, c. Gas, previously filtered and dried, enters the apparatus through an orifice 20, the combustible constituents are ignited in the tube A, and the corresponding change in pressure in the chamber 1 is duly recorded by the manometer 10 and the gauge 11.