Hot blast

Further information: Cowper stove
Blast furnace (left), and three Cowper stoves (right) used to preheat the air blown into the furnace.
Hot blast furnace: note the flow of air from the stove in the background to the two blast furnaces, and hot air from the foreground furnace being drawn off to heat the stove.

Hot blast refers to the preheating of air blown into a blast furnace or other metallurgical process. As this considerably reduced the fuel consumed, hot blast was one of the most important technologies developed during the Industrial Revolution.[1] Hot blast also allowed higher furnace temperatures, which increased the capacity of furnaces.[2][3]

As first developed, it worked by alternately storing heat from the furnace flue gas in a firebrick-lined vessel with multiple chambers, then blowing combustion air through the hot chamber. This is known as regenerative heating. Hot blast was invented and patented for iron furnaces by James Beaumont Neilson in 1828 at Wilsontown Ironworks[citation needed] in Scotland, but was later applied in other contexts, including late bloomeries. Later the carbon monoxide in the flue gas was burned to provide additional heat.

  1. ^ Belford, Paul (2012). "Hot blast iron smelting in the early 19th century" (PDF). Historical Metallurgy. 46 (1). Historical Metallurgy Society: 32–44.
  2. ^ Landes, David S. (1969). The Unbound Prometheus: Technological Change and Industrial Development in Western Europe from 1750 to the Present. Cambridge, New York: Press Syndicate of the University of Cambridge. p. 92. ISBN 0-521-09418-6.
  3. ^ Ayres, Robert (1989). "Technological Transformations and Long Waves" (PDF): 21<Fig. 7 shows C/Fe ratio time series> {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: postscript (link)