IMPROVE- MENTS IN PUDDLING FURNACES
Year: 1876

page_text: LETTERS PATENT to James Harris Sanders and Samuel Sanders, both of
No. 25, Abchurch Lane, in the City of London, for the Invention of "IMPROVE-
MENTS IN PUDDLING FURNACES." A. communication from abroad by Richard
Bernau and Gustave Oscar Alexandre Sommer, both of Liège, Belgium.
Sealed the 25th July 1876, and dated the 26th May 1876.
PROVISIONAL SPECIFICATION left by the said James Harris Sanders and
Samuel Sanders at the Office of the Commissioners of Patents on the 26th May
1876.
JAMES HARRIS SANDERS and SAMUEL SANDERS, both of No. 25, Abchurch Lane,
in the City of London. "IMPROVEMENTS IN PUDDLING FURNACES."
The object of this Invention is to so construct the fire-places of puddling furnaces
as to obtain an intense and uniform heat, and to effect a very considerable economy
in fuel, and at the same time to produce a better yield and an improved quality
of iron.
The improved furnace differs from those with horizontal hearths as generally
used for puddling furnaces, in that the fuel may be regularly spread over the entire
surface of the grate or fire-bars, and of the hearth or dead plate, in a thin Inyer, so
that the combustible gases may be evolved therefrom and burned in the fire-place
or chamber, so as to produce an intense heat, which is carried into the puddling
chamber. To this end the hearth or dead plate is so inclined that the fuel in
feeding rests thercon in a layer of only moderate thickness. The coal when resting
on this inclined hearth is therefore completely distilled by the intense heat from
the small grate placed below it, as well as by the heat reflected from the walls when
at a white heat.
The combustible gases after distillation are completely burnt in the fire chamber
by the oxygen passing through the layer of incandescent fuel on the grate.
The residuum of the distillation is composed of slag and of pure coke, this latter
forming the fuel by which the fresh coal thrown on to the hearth in the fire-place is
to be distilled.
This system of burning fuel may be likened to a gas retort heated interiorly,
with this difference, that the combustion of the gases takes place instantaneously
upon the spot, or in the chamber where they are produced.
Dan D31

page_text: As the coke when burning on the grate gives passage to very little more oxygen
than is needed for its own combustion there always remains in the flame an access
of free carbonic oxyde and carburetted hydrogen, the result being that the effect of
the flame upon the metal to be worked or treated in the furnace will be but slightly
oxydizing.
More or less oxygen may be supplied to the fire-place by diminishing or increasing
the number of the fire-bars of the grate, and thus enlarging or lessening the open
spaces in the grate.
As the fire-bricks which form the sides of the fire-place would be rapidly dete-
riorated by the great heat produced therein, there are formed in the walls on each
side two corresponding horizontal conduits, the one placed above the other. Three
vertical conduits or air shafts are in communication with the upper horizontal
conduit. The cold air enters by the lower conduits, spreads within the others, and
leaves the furnace by the top of the vertical conduits. A constant current of cold
air being kept up within these conduits the walls of the furnace are thereby cooled
and will last much longer than would otherwise be the case. The number and
position of these air conduits or flues may of course be varied.
The feeding of the fire-place is very simple. The fire is laid in the ordinary
manner by first placing wood upon the grate-bars and a few lumps of coal upon
the wood. The feed opening, which is funnel-shaped and of restricted size,
being then closed with lumps of coal the wood on the fire-grate is lighted from
beneath. When the whole is alight the coal which has been used to stop the feed
opening is pushed down and large and small coal (as it comes to hand) is fed into
the fire-place until the inclined hearth is covered with a layer of about a hand
thick. In other words, as much coal is placed on the inclined hearth as will be
necessary for naturally closing the feed opening.
The fire is then allowed to make head, and in about two hours the interior of
the fire-place will have come to a red heat; the coal first placed upon the grate will
then have been completely burnt, and that resting on the inclined hearth will have
been partially distilled.
Then by means of a poker or fire-iron of a suitable size (passed through the feed
opening) the coke is stirred about and the calcined fuel on the inclined hearth is
spread equally over the grate, and coal is again fed into the fire-place until the
feed opening is closed.
The use of a good and pure coal in this improved furnace gives a greater saving
than the use of inferior coal, but it is in either case very considerable, and the
application of this Invention to an ordinary furnace is very inexpensive.
The result of this improved construction of fire-place for puddling furnaces is (as
regards quantity) at least equal to, if not greater, and as regards quality, it is
superior to that obtained with the ordinary furnaces, this latter advantage being
due to the elevation of the fire-bridge, which does not permit impurities to reach
the bath with such facility as heretofore.
The economy of fuel is very great, as the gaseous products are burned under the
best possible conditions.