pa1778data.pdf
pa1778data.pdf
pa1778data.pdf
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U.S. STEEL DUQUESNE WORKS<br />
HAER No. PA-115<br />
(Page 104)<br />
providing a return on the company's investment. Yet, even though<br />
the briquettes contained approximately 21 percent manganese, the<br />
inability of company metallurgists to discover a method by which<br />
to separate the manganese from the 12 percent alkali contained<br />
within them prohibited the productive reuse of the briguettes.<br />
As a result, then, of the negative cost-benefit character of the<br />
gas cleaning plant, ferromanganese operations at the Isabella<br />
Furnaces and Clairton Works were shut down while the Duquesne<br />
Works became the company*s principal producer of ferromanganese<br />
within Allegheny County. Consequently, the expansion of<br />
ferromanganese production at Duquesne must be seen as an effort<br />
by the corporation to cut its losses. 4<br />
Beginning with the start-up of rebuilt blast furnace number<br />
three in 1953, plant officials embarked on a program designed to<br />
upgrade the facilities related to the production of cold blast<br />
air by installing a turbo-blower designed and manufactured by the<br />
Ingersoll-Rand Corporation. Adhering to the more traditional<br />
positive cost-benefit rationale for changes to the system, the<br />
turbo-blower replaced three of the old steam engines and was<br />
capable of delivering 90,000 cfra of air at 30 psi to the hot<br />
blast stoves associated with blast furnace number three while<br />
using 50 percent less steam. Moreover, the turbo-blower's<br />
accompanying surface condenser allowed it to recycle the<br />
condensate of the spent steam to the boiler feed water system<br />
without pre-treatment. The production and delivery of cold blast<br />
air to blast furnaces number one, two and four were modernized<br />
with the addition of another 90,000 cfm Ingersoll-Rand turbo-<br />
blower in 1954 and a 125,000 cfm Ingersoll-Rand turbo-blower,<br />
with spilt wind capabilities in 1955. 5<br />
County wide governmental measures to improve the quality of<br />
river water combined with improved technology for reclaiming<br />
suspended particulate in the waste water from the gas scrubbers<br />
and Theisen gas washers to provide plant managers with the<br />
incentive to add a clarifier/thickener to the gas cleaning system<br />
in 1957. Slurry from the gas scrubbers and Theisen washers were<br />
taken by pipeline to the bottom of a 90'-0" diameter x 12'-0"<br />
high clarifier manufactured by the Dorr-Oliver Company. The<br />
waste water was admitted to the top of the clarifier through its<br />
centerwell where a dosage of anionic polymers was fed into it for<br />
the purpose of aiding the flocculation of fine entrained<br />
particles. Slurry water spilled over the centerwell to the<br />
bottom of the clarifier and rose, at a rate of 2900 gpm, upwards<br />
while the suspended solids within the slurry dropped to its<br />
bottom. The treated water overflowed the side of the clarifier<br />
at a constant rate into a launderer, which was an approximately<br />
2'-0" wide x 3'-0" deep ring encircling its outside diameter. A<br />
connecting sewer line, located at the bottom of the launderer.