pa1778data.pdf

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U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 9 6)
just southwest of the remains of Dorothy Six. Built by John Mohr
and Sons Inc., each stove has a total heating surface of 450,781
sq. ft. A 12 f -ll" diameter waste gas stack serving all of the
stoves is located just southwest of them. Each stove is equipped
with a 42" diameter cold blast connection, a 54" inside diameter
refractory lined hot blast connection, and a 56" inside diameter
refractory lined burner connection. A mixing system running from
the cold blast connection to the hot blast connection at each
stove was designed and installed by John Mohr and Sons Inc.
Located at each stove is a 55,000 scfm burner and motor powered
combustion air fan designed and built by the Zimmermann and
Jansen Company of West Germany.
Installation of Stoves and All Related Equipment: 1962.
HISTORY
Essentially, the production and delivery of combustion air
to the blast furnace at modern plants like the Duquesne Works has
consisted of supplying compressed air to a regenerative heating
stove, using waste gas from the blast furnace as fuel, which pre-
heated it before it was delivered to the blast furnace's tuyeres
where it was introduced into the furnace to combine with the
coke, thus creating the combustion necessary to smelt the
limestone, manganese and/or iron ore. The historical development
of this process at Duquesne, as in other plants, became
progressively more complex. This was due, in part, because of a
need to develop a more efficient and productive system of pig
iron manufacturing. More recent developments, however, were due
to wider societal pressures for improvements in the quality of
the environment.
The facilities provided for the production and delivery of
combustion air at the time of the start-up of the four unit blast
furnace plant at Duquesne in 1896 included ten vertical steam
driven blowing engines, four regenerative hot blast stoves per
furnace, and one dust catcher per furnace. The process began at
one of the two original blowing engine houses. Within each
blowing engine house (numbers one and two) were located five
compound condensing steam driven vertical blowing engines
manufactured by the E. P. Allis Company of Milwaukee, Wisconsin.
Two blowing engines furnished the necessary air to one of the
furnaces by compressing air drawn from the atmosphere to a
pressure of 15 psi and delivering it at a maximum rate of 25,000
cubic feet of air per minute. The other two blowing engines (one
in each blowing engine house) were on standby status. Air
emanating from the blowing engines at a temperature of 100
degrees F. was conveyed to the four regenerative hot blast stoves
assigned to each blast furnace by means of a pipeline called the
cold blast main. Separate branches, off the cold blast main,