| 摘要 |
1439469 Pyrolytic analysis BAYER AG 13 Dec 1973 [15 Dec 1972] 57744/73 Heading G1B A process for the pyrolytic analysis of liquids, for example sewage, comprises injecting a sample of the liquid together with a carrier gas comprising air into a combustion furnace and passing it repeatedly through the hottest zone of the furnace where the sample is burnt in the absence of a catalyst at temperatures of from 1000‹ to 1200‹C, and delivering the combustion gases to an analyzer. In the furnace 3 of Fig. 2, the carrier gas is preheated by passing it through line 8, and the preheated carrier gas entering at 7 together with injected sample passes through concentric tubes 6, 5 in the hottest part of the furnace for the combustion step. The process may be carried out to determine organic carbon using the apparatus of Fig. 1 (not shown) in which air as carrier gas passes through zeolite adsorbers and through precombustion line 8, and the combustion gases pass through a CaCl 2 bottle and a dust filter to a CO 2 analyzer. In the apparatus of Fig. 3 (not shown), total oxygen demand may be determined using a high temperature zirconium oxide measuring cell. In the apparatus of Fig. 4, used for the determination of total mercury in sewage, the carrier gas passes through dust filter 20 and mercury filter 21 of silver wool to pump 22 and the combustion system. Combustion gases flow through shortest possible tube 24, which may be capillary tubing and is heated, to heated measuring cell 25 of a mercury absorption photometer. The windows 30 of the cell may be kept clear of deposit by streams of heated air injected through annular nozzles (31), Fig. 5 (not shown). In another embodiment a windowless cell may be used and tube 24 has i.d. 1 to 4 mm. and length 200 to 400mm. |
