The Science record; a compendium of scientific progress and discovery . rs of fueland ore. The burning fuel isconverted into carbonic oxide and acid by the enormousquantity of air forced in through the tuyeres, which is notless than 6 tons, or 160,000 cubic feet per hour. Carbonicoxide is a powerful reducing agent, and this takes the oxy-gen from the ore,and forms carbonic acid. The carbonicacid ascends, and in contact with the red-hot coal loseshalf its oxjrgen and becomes carbonic oxide, which inturn takes the oxygen from the next layer of ore, andso on. These hot gases, on reaching the top,
The Science record; a compendium of scientific progress and discovery . rs of fueland ore. The burning fuel isconverted into carbonic oxide and acid by the enormousquantity of air forced in through the tuyeres, which is notless than 6 tons, or 160,000 cubic feet per hour. Carbonicoxide is a powerful reducing agent, and this takes the oxy-gen from the ore,and forms carbonic acid. The carbonicacid ascends, and in contact with the red-hot coal loseshalf its oxjrgen and becomes carbonic oxide, which inturn takes the oxygen from the next layer of ore, andso on. These hot gases, on reaching the top, are no longer al-lowed to escape, as formerly, but are conducted off bylarge pipes, (one of which is seen on the left of the figurenear the top,) to ovens in the adjacent building, wherethey serve to heat the air that is forced in through thetuyeres, (hot blast.) To permit of the furnace being chargedat the top without allowing the gases to escape, an im-proved arrangement, called a bell and hopper, is used, asseen in the figure. The ore and fuel are thrown into the. 30 SCIENCE RECORD. hopper and rest on a bell, until, by means of a lever, thebell is slightly lowered, and the materials are very evenlydistributed over the whole surface of the furnace. The use of the lime-stone or flux added is to unite withthe silica, clay, and other impurities in the ore and form areadily fusible glass called slag. As the metal is reduc-ed and fused, it flows down into the crucible, while themelted slag, being lighter, floats on the top of the iron, andis drawn Off at a higher level than the iron. The openingat the bottom of the furnace is closed by an iron platecalled the dam, containing a coil through which cold watercontinually flows to prevent its burning up. The meltediron is drawn off twice a day, morning and evening, andis a grand sight to witness, especially at night. Cast-iron, as it flows from the blast-furnace into thecrude sand moulds, is quite impure, containing as much as4 or 5 p
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Keywords: ., bookcentury1800, bookdecade1870, booksubje, booksubjecttechnology
