At a recent meeting of the Industrial Society of Amiens, Mr. Schmidt,
engineer of the Steam Users' Association, read a paper in which he
described the process employed in the construction of a large chimney
of peculiar character for the Rocourt distillery, at St. Quentin.
[Illustration: FIG. 1--ELEVATION.]
This chimney, which is cylindrical in form, is 140 feet in height, and
has an internal diameter of 8½ feet from base to summit. The coal
consumed for the nine generators varies between 860 and 1,200 pounds
per hour and per 10 square feet of section.
The ground that was to support this chimney consisted of very
aquiferous, cracked beds of marl, disintegrated by infiltrations of
water from the distillery, and alternating with strata of clay. It
became necessary, therefore, to build as light a chimney as possible.
The problem was solved as follows, by Mr. Guendt, who was then
superintendent of the Rocourt establishment.
Upon a wide concrete foundation a pedestal was built, in which were
united the various smoke conduits, and upon this pedestal were erected
four lattice girders, C, connected with each other by St. Andrew's
crosses. The internal surface of these girders is vertical and the
external is inclined. Within the framework there was built a five-inch
thick masonry wall of bricks, made especially for the purpose. The
masonry was then strengthened and its contact with the girders assured
by numerous hoops, especially at the lower part; some of them
internal, others external, to the surface of the girders, and others
of angle irons, all in four parts.
[Illustration: FIG. 2--HORIZONTAL SECTION.]
The anchors rest upon a cast iron foundation plate connected, through
strong bolts embedded in the pedestal, with a second plate resting
upon the concrete.
As the metallic framework was calculated for resisting the wind, the
brick lining does not rest against it permanently above. The weight of
the chimney is 1,112,200 pounds, and the foundation is about 515
square feet in area; and, consequently, the pressure upon the ground
is about 900 pounds to the square inch. The cost was $3,840.
[Illustration: FIG. 3--VERTICAL SECTION OF THE CHIMNEY.]
The chimney was built six years ago, and has withstood the most
violent hurricanes.
The mounting of the iron framework was effected by means of a motor
and two men, and took a month. The brick lining was built up in eight
days by a mason and his assistant.
A chimney of the same size, all of brick, erected on the same
foundation, would have weighed 2,459,600 pounds (say a load of 3,070
pounds to the square inch), and would have cost about $2,860.
The chimney of the Rocourt distillery is, therefore, lighter by half,
and cost about a third more, than one of brick; but, at the present
price of metal, the difference would be slight.--_Annales
Industrielles._
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