GB641978A - Improvements in apparatus for determining the constituent proportions of a gaseous mixture - Google Patents

Abstract

<PICT:0641978/III/1> <PICT:0641978/III/2> The proportion of a constituent in a gaseous mixture is determined continuously by absorbing the constituent in an electrolyte and comparing the electrical conductivities of the electrolyte before and after absorption of the constituent. The process is effected in an integral unit (Fig. 1) comprising a reference cell 1 and a measuring cell 2, both of which contain a pair of platinized platinum electrodes 22, 26 and both of which are integrally mounted in a constant temperature jacket 3. The electrodes are connected by wires 21, 25 to a Wheatstone bridge, the spacing between electrodes 22 being constant but that between electrodes 26 being adjustable by means of a rack-and-pinion device 24, 27. Electrolyte is fed to reference cell 1 through coiled pipe 5 and overflows into capillary tube 7 by which it is fed through pipe 12 and coiled tube 6 to measuring cell 2. The gaseous mixture under test enters the coiled tube 6 at 11 and bubbles through the electrolyte in the tube until it reaches cell 2 where the residual gas and used electrolyte are led off by pipes 13, 14 respectively. Flow of electrolyte is regulated by a valve 18 provided with a plurality of ports of different cross-sectional area and is measured by a graduated capillary tube 8. The capillary tube 8 is in communication with the atmosphere at 9. In a modification (Fig. 4) the electrolyte flows in a closed circuit by thermosyphonic effect and is regenerated in pipe 33 by means of a heating jacket 35. An inactive gas may be introduced at 39 to urge the thermosyphonic motion and the expulsion of the desorbed gases from bulb 34. When employed to determine the proportion of SO2 and H2S in gaseous mixtures, the electrolyte may be monoethanolamine and the regenerant in jacket 35 may be steam.