Large roof opening
Large, white smoke cloud spewing from the roof openings.
Figure 2-64. Bessemer Converter.
(3) Open-hearth furnaces are 'the most common method of steel production
throughout the world because large amounts of high quality steel are produced
(a) The open-hearth is a large, enclosed shallow basin, containing from 60
to 300 tons of molten metal at one time. This charge of molten iron is composed of
50 percent pig iron and 50 percent scrap steel. Measured amounts of limestone flux
and certain alloy metal are added to this batch.
(b) On each side of the basin is a set of two heating chambers filled with
layers of open brickwork. Each set of heating chambers includes one to preheat air
and one to preheat gas.
These chambers operate on the same principle as the hot
stoves. Gas and air are piped through one set of heating chambers where they pick
up heat from the hot brickwork.
The preheated gas and air are directed into the
open-hearth chambers where they mix and ignite with a high temperature.
exhaust gases are then piped out of the open-hearth chamber and passed through
alternate chambers to heat them.