IMPROVEMENTS IN PUDDLING FURNACES
Year: 1872

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "IMPROVEMENTS IN PUDDLING FURNACES."-A com-
munication from abroad by George Edward Harding, of the City
and State of New York, United States of America.
Sealed the 10th October 1872, and dated the 15th August 1872..
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his - Petition,
on the 15th August 1872.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN PUDDLING FURNACES,"
a communication, to be as follows:-
This Invention relates to that class of furnaces used for reducing the
metals directly from their ores. I utilize the waste heat and gases
of a puddling or reverberatory furnace-by-passing these gases. through
a double series of roasting .hearths or ovens placed intermediately
between the stack and the puddling hearth, and into which the ore is fed.
I also utilize the waste heat of a furnace by passing all the air from the
blast under the entire length of the puddling hearth through a hollow
or false bottom, and thence through a bridge wall to the ash-pit.

page_text: I assist the reduction of the ore by introducing a jet of superheated
steam combined with heated air forced through concentric tubes whoso
nozzles project into the furnace immediately over or near the bridge wall
thereof. In the case of iron ore reduction I transform the metal into
steel, thereby producing steel from the ore at one operation by causing a
jet of steam to impinge in combination with suitable chemical gases
upon the fluid metal at or about its "boiling point." And in connection
therewith a small portion of the chemicals are introduced into the cinder
bath at or about the same time. This part of my Invention is applicable
to the ordinary puddling furnace for reducing "pig" iron.
I provide a puddling or reverberatory furnace with a hinged or pivotted
damper at the ash-pit end of the air blast passage whose arbor connecting
with the points of a quadrant on the outside of the furnace shall indicate
with exactness the amount of damper opening.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 15th February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of August, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Robert Lake, Her special
licence that I, the said William Robert Lake, my executors, administra-
tors, and assigns, or such others as I, the said William Robert Lake, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for “IMPROVEMENTS
IN PUDDLING FURNACES," a communication to me from abroad by George
Edward Harding, of the City and State of New York, United States of
America, upon the condition (amongst others) that I, the said William

page_text: Robert Lake, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing, forming a part of this Specification:-
This Invention relates to that class of furnaces used for reducing the
metals directly from their ores. I utilize the waste heat and gases of a
puddling or reverberatory furnace by passing these gases through a
double series of roasting hearths or ovens placed intermediately between
the stack and the puddling hearth, and into which the ore is fed. I
utilize the waste heat of a furnace by forcing all the air from the blast
under the entire length of the puddling hearth through a hollow or false
bottom, and thence through a bridge wall to the ash-pit.
I assist the reduction of the ore by introducing a jet of superheated steam
combined with heated air forced through concentric tubes whose nozzles
project into the furnace immediately over or near the bridge wall thereof..
In the case of iron ore reduction I transform the metal into steel,
thereby producing steel from the ore at one operation by causing a jet of
steam to impinge in combination with suitable chemical gases upon the
fluid metal at or about its "boiling point.". And in connection ..there-.
with a small portion of the chemicals are introduced into the cinder
bath at or about the same time. This part of my Invention is applicable
to the ordinary puddling furnace for reducing pig iron.
I provide a puddling or reverberatory furnace with a hinged or pivotted'
damper at the ash-pit end of the air blast passage whose arbor connecting
with the points of a quadrant on the outside of the furnace shall indicate
with exactness the amount of damper opening.

page_text: Figure 3 is a transverse section on the lines, z, Figure 2.
Figure 4 is an clevation of the fire end of the said furnace, shewing
the ash-pit open.
Figure 5 is a front elevation of the said furnace.
Figure 6 is a transverse section of the stack.
Figure 7 is a section drawn to an enlarged scale of the aforesaid con-
centric tubes with branches.
As shown by the Drawing this furnace differs from the ordinary
puddling furnaces by having its hearth or puddling chamber extended:
to form the space for these hearths in a line a, a¹, a¹¹, while at the
extreme end the flame traverses a double set of roasting hearths or
ovens b, b, cach three tiers in height, and communicating with its
separate stack. Into the top of these ovens the ore is fed by the
hoppers o.
Between these sets of ovens there is provided a central flue or passago
communicating with its own stack d.
The hearths b, b, are used to roast the ore previous to its entering the
puddling furnace. The ore is introduced through the hopper o upon
the first or upper hearth, and after a suitable time it is drawn to
openings in the flue when it falls to the next hearth where the heat is
greater; from there it is afterward drawn in similar manner to the third
or lower hearth, whenco it is moved upon the puddling hearth as wanted.
From a it is gradually worked to a¹ and thence to a" by means of the
various doors provided, where it comes to "nature" and is removed to
the hammer. The two sets of hearths with their independent stacks
allow alternate "charging" and delivery, and consequently more
continuous puddling. The independent central flues give greater control
of the heat in the puddling hearth and in the ovens.
The bottom of the puddling hearth is formed as usual by the cast-iron
plates f, but with a second similar plate 9 placed in the masonry
below to form a chamber ŉ between these plates, throughout the entire
length of which the blast is driven.
The bridge wall is peculiarly formed with the slanting plate k in order
to afford more space for the air to circulate and present more heating

page_text: surface to the flame. The blast after passing through the air chamber h
passes up into the bridge wall space and down through the passago k¹ to
the ash-pit. The entire air passage from the entrance i to its exit at the
dampers is made gradually contracting in section to retain the air in
contact with the heated plates as long as possible.
:
At m over the bridge wall I introduce several pipës, each composed of
two concentric tubes, shewn somewhat enlarged, and which may vary in
number. These tubes connect with their main pipes which pass trans
versely over the furnace arch and contain respectively superheated steam
and heated air. The supply of the latter is not dependent upon the
suction of the steam to carry it into the furnace, but is forced into tho,
furnace in such quantities as may be desired.
. The object of so introducing these gases is to supply oxygen to the
carbonic acid gas of the flame to convert it into useful effect, and also to
act upon
the free carbon from the fuel which is momentarily arrested
and deflected upon the iron, producing a most intense heat. The steam
is decomposed and acts upon the impurities of the iron, as for instance
sulphur and phosphorus, converting them into compounds of hydrogen.
The proportions of steam and air are varied as the iron "comes to
nature," but the introduction of these gases by means of this arrange-
ment of concentric tubes gives the most useful effect as it most effectually
intermingles their particles at the moment of contact with the flame of
the furnace.
At the point n, Figure 2, I introduce similar concentric tubes trans-
versely through the bridge wall, as shewn also at n; Figure 1; which has
its concentric branch tubes projecting, into the furnace at the interior
portion of the bridge wall, these pipes or tubes are supplied with
steam and nitrogenous or ammoniacal gases.
. I
The object of these last pipes is to introduce a combined jet of steam
and suitable chemical gases upon the metal at or about the period of its
boiling point to transform the iron into steel, by which process if ore is
used steel can be produced at one operation direct from the ore, or pig
iron may be transformed into steel in an ordinary puddling or reverbera-
tory furnace. In practice more uniform steel is produced by introducing
into the cinder bath a very small quantity of the chemical substances
from which the gases are produced, at the same time the impinging gases
i

page_text: act upon the metal. Instead of the ordinary sliding damper to regulato
the admission of the blast the hinged dampers provided with an arbor
extending outside the furnace is used.. The outer end of the arbor has
an arm arranged in connection with a quadrant so that the exact arca of
the air passage can be observed and regulated with exactness.
Having thus fully described the said Invention, as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim,―
5
First. The peculiar puddling or reverberatory furnace herein described,
provided with a double set of roasting hearths and an independent 1
central flue for the production of metal direct from the ores.
Second. The bottom of a reverberatory furnace formed of double iron
plates connecting with a hollow bridge wall, so that all the blast is
passed through the same to the ash-pit.
Third. Introducing superheated steam and heated air into a rover- 1
beratory furnace through concentric tubes and branches directly over
the bridge wall, for the purpose described.
Fourth. Introducing steam and chemical gases through concentrio
tubes into a reverberatory furnace at or near the bridge wall to convert
iron into steel in combination with a small quantity of chemical com- 2
pounds introduced directly into.the furnace at the same time.
Fifth. The hinged dampers provided with an arm and quadrant on
the outside of the furnace for the purpose specified.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Fifteenth day of February, in 2
the year of our Lord One thousand eight hundred and seventy-
three.
Witness,
W. J. LowE.
W. ROBT. LAKE. (L.S.)