Analysis or other processing of gaseous fluids

摘要

Gases are analysed in respect of a particular ingredient by conducting a fluid containing said gas or a derivative thereof through one side of a dialyser, conducting a liquid through the other side of the dialyser (whereby a portion of said ingredient or a reaction product thereof passes into said liquid) and thereafter through a colorimeter for analysis, a colour indicator being added to or present in said liquid prior to entry into the colorimeter. The actual result of the analysis, which may not be made available, may be employed in a control operation. As described, the invention is applied to gases containing HCN or HCl. In a first embodiment (see Fig. 1) a gas containing HCN is passed into line 24 of a tube pump 10 of known construction and sodium hydroxide is passed through tube 26. The streams meet in 25 and form a segmented fluid stream which is passed through a mixing coil 12 and then through one side of a dialyser 14. A similarly produced segmented stream of air and sodium hydroxide is passed to the other side of the dialyser and taken off through line 22. An alkaline picrate indicator solution is added to this stream and the mixture passed to a mixing coil 16 and heating coil 18. Thereafter the fluid stream is passed to a blending vessel 39 to remove the air before analysis in colorimeter 20 having a recorder 22. In an alternative flow system (Fig. 3, not shown), the gas is contacted with sodium hydroxide outside the apparatus and the NaCN-containing stream segmented with air and mixed with distilled water before being conducted through the dialyser; an alkaline picrate indicator segmented with air is passed to the other side of the dialyser and the stream analysed as before. In a second alternative (Fig. 4, not shown) for analysis of gases containing HCl, water is employed in the place of the sodium hydroxide used as the second liquid in connection with Fig. 1, a saturated mercuric thiocyanate solution takes the place of the alkaline picrate solution, a ferric ammonium sulphate solution is added after the segmented liquid passes from coil 16, and heating coil 18 is replaced by a second mixing coil. Specifications 774,711, 827,924 and 827,925 are referred to.