Coal; its history and uses . d by it. Coal-gas is made by heating coal or cannel, which isthe special form of coal most valued for the purpose onaccount of the high quality of the gas it produces, incylindrical fire-clay retorts A (Figs. 45 and 46), rangedhorizontally in a furnace. The gases pass up the verticalpipes H fixed to the front of the retorts and are sent intothe hydraulic main G, G, in which the more readily lique-fiable products condense. The height of the liquid in thehydraulic main is so regulated that the pipe n dips to thedepth of three or four inches below the level; this prev
Coal; its history and uses . d by it. Coal-gas is made by heating coal or cannel, which isthe special form of coal most valued for the purpose onaccount of the high quality of the gas it produces, incylindrical fire-clay retorts A (Figs. 45 and 46), rangedhorizontally in a furnace. The gases pass up the verticalpipes H fixed to the front of the retorts and are sent intothe hydraulic main G, G, in which the more readily lique-fiable products condense. The height of the liquid in thehydraulic main is so regulated that the pipe n dips to thedepth of three or four inches below the level; this preventsa rush of air into the main when the ends of a retort areremoved for recharging. As the liquid accumulates inthe hydraulic main it flows over into the tar-well, and the THE CHEMISTRY OF COAL. 205 gas passes on through a series of vertical iron tubestermed refrigerators or condensers, two of which are seenin Fig. 47, in which it is gradually cooled and where it de-posits the remaining portions of the tar. In order to free. Fig. 45.—Coal-gas Ketorts, Front View. From Eoscoe andSchorlemmers Chemistry. it from the last traces of ammonia and the greater portion of the sulphuretted products derived from the sulphur in the coal, it is sent through scrubbers or wrought iron towers (Fig. 48) filled with coke kept constantly moistened by a fine spray of water; afterwards it passes over layers of slaked lime and oxide of iron, or mixtures of green 206 COAL. vitriol, sawdust and slated lime, to remore the carbonic acidand tlie last traces of sulphuretted hydrogen, and thenceit flows into the gas-holders. Although the process issimple enovgh in principle, it nevertheless involves the use
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherlo, booksubjectcoal
