pa1778data.pdf
pa1778data.pdf
pa1778data.pdf
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U.S. STEEL DUQUESNE WORKS<br />
HAER No. PA-115<br />
(Page 98)<br />
on the fine particles of flue dust which remained entrained in<br />
the gas after it left the dust catcher. Much of this dust passed<br />
up through the stoves■ combustion chambers and became lodged in<br />
their checkerwork, thus constricting the openings provided for<br />
the passage of the gas as well as the cold blast air. Over time<br />
the checkerwork openings became completely clogged, rendering the<br />
stoves incapable of absorbing heat or giving it up. As a result,<br />
each stove had to be taken off line for a period of five or six<br />
days every two months for a complete cleaning which meant that<br />
for one-third of its time in operation the blast furnaces were<br />
deprived of one-fourth of their heating surface capacity.<br />
The decision to use four 3600 hp gas fired blowing engines,<br />
manufactured by the Snow Steam Pump Works, for the production of<br />
cold blast air at blast furnaces number five and six increased<br />
the need to provide the appropriate blast furnace plant equipment<br />
with clean gas. Because the engines required fuel gas almost<br />
completely free of entrained particulate, plant officials were<br />
faced with the prospect of furnishing them with very clean gas<br />
from the blast furnaces or buying natural gas from outside<br />
sources.<br />
In view of the difficulties experienced in the original<br />
system of producing and delivering combustion air to the blast<br />
furnaces, plant officials in 1908, led by Ambrose N. Diehl,<br />
superintendent of the blast furnace plant, devised an<br />
experimental gas cleaning plan. An industry wide pioneering<br />
effort, the four year long experiment was set up to compare the<br />
more traditional gas cleaning approach to a newly conceived wet<br />
gas cleaning system in terms of efficiency and cost<br />
effectiveness. In both systems gas flowing from the dustcatcher<br />
at each blast furnace was directed through an additional<br />
dustcatcher per furnace before it was combined into a single 8'-<br />
6" diameter rough gas main. From the rough gas main a portion of<br />
the gas was taken directly to the boilers and hot blast stoves at<br />
blast furnaces numbers one and two while the rest of it was<br />
conducted to the newly constructed wet system.<br />
The wet system, which was laid out linearly, consisted of<br />
nine 12 ! -0" diameter x 76'-0" high scrubbers arranged in<br />
parallel, four electric motor driven Sturtevant fans, each with a<br />
capacity of 84,000 cfm, and four horizontal Theisen gas washers.<br />
The scrubbers were theoretically designed to clean the gas to<br />
within one-fifth grain per cu. ft. while cooling it in order to<br />
remove most of its moisture, thus increasing its B. T. U. value.<br />
Under the experiment's original conception, gas traveling through<br />
the rough gas main leading to the wet washing system was first<br />
introduced into the bottom of one of the scrubbers. As the gas<br />
was rising up through the scrubber at a maximum rate of 30,000