The pit at the back of the open-hearth furnace
is perhaps eight feet deep and ten feet in diameter.
Basic Oxygen Furnace (BOF) The updated replacement of the traditional open-hearth furnace
, the BOF refines molten iron mixed with steel scrap in a process that can take place in less than one hour.
Big steel came out of World War II with 40 million tons of open-hearth furnace
worked with open-hearth furnaces
that turned out "semi-killed" steel, which has higher concentrations of phosphorus, oxygen and sulfur in the metal.
The steel plate was made using acid-lined open-hearth furnaces
Ashinsky closed down its open-hearth furnaces
in 2010 and launched a single electric-arc furnace, boosting crude steel capacity to 1m tonnes.
The men who ran the steel companies never liked to close a plant; they always wanted to keep a margin of extra capacity to take care of their best customers at the top of the economic cycle--even if that meant keeping open ancient open-hearth furnaces
that should have been banked twenty years before.