IMPROVEMENTS IN FURNACES
Year: 1860

page_text: LETTERS PATENT to Frederick Collier Bakewell, of No. 6, Haverstock
Terrace, Hampstead, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN FURNACES."-A communication from abroad by Jacob'
PROVISIONAL SPECIFICATION left by the said Frederick Collier Bake-
well at the Office of the Commissioners of Patents, with his Petition,
on the 11th October 1860.
I, FREDERICK COLLIER BAKEWELL, of No. 6, Haverstock Terrace, Hampstead,
in the County of Middlesex, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN FURNACES," being a communication to me from
abroad by Jacob Reese, of Pittsburgh, U.S., North America, to be as
follows:-
This Invention consists in the construction of the fire chambers of furnaces
in such manner as to prevent the entrance of air beneath the fire bottom
which is closed, and to introduce the blast at a point or points in the fire cham-
ber sufliciently above the level of the furnace bottom to leave a receptacle below
for the collection of the cinder in a fused state, and yet not so high as the
top of the burning coal. To facilitate the melting of the cinder, oxide of iron
or other suitable flux is thrown upon the coal, and the melted cinder is allowed

page_text: to flow off as it forms. By this means the formation and accumulation of
"clinker" in the furnace is avoided. The under surface of the cinder forms,
with the addition of a layer of sand, a good protection to the bottom of the
fire chamber. The coal is lighter than the fused cinder and therefore floats on
the top, and the air being heated as it passes over the melted surface, and thence
through the hottest part of the fire to the top of the burning coal, it becomes
sufficiently heated to consume the smoke. By the admission of the air in the
manner described especial advantage is gained in puddling furnaces, for the
oxygen of the heated air being united with the carbon does not combine with
the iron, and thus the waste usually caused in such furnaces by the formation
of oxide of iron is prevented.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Collier Bakewell in the Great Seal Patent Ollice
on the 10th April 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, FREDERICK
COLLIER BAKEWELL, of No. 6, Haverstock Terrace, Hampstead, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of October, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Frederick Collier Bakewell, Her special licence that I, the said Frederick
Collier Bakewell, my executors, administrators, and assigns, or such others
as I, the said Frederick Collier Bakewell, 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 Inven-
tion for "IMPROVEMENTS IN FURNACES," a communication to him from abroad
by Jacob Reece, of Pittsburgh, United States, North America, upon the
condition (amongst others) that I, the said Frederick Collier Bakewell, 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 per-
formed, 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.

page_text: NOW KNOW YE, that I, the said Frederick Collier Bakewell, 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:-
This Invention consists in the construction of the fire chambers of furnaces
in such manner as to prevent the accumulation within them of the molten
incombustible portions of the coal called "clinkers," and to facilitate the
combustion of the fuel. It is well known that the coal commonly used for
fuel contains, in addition to its combustible constituents, other matters, such as
silica, alumina, and sulphate of iron. These usually form the hard masses
called clinkers during the process of combustion of the coal, which settle about
the grate bars, choke up the air passages, and cause a great loss of heat.
The accumulation of hard clinker in the furnace is owing to the melting of
the incombustible matters contained in the coal in the hottest part of the fire,
and as the melted slag runs down towards the fire bars, it is cooled by the
entrance of cold air, and becomes solidified before it can escape.
This Invention prevents the formation and accumulation of clinker in this
manner by causing the superfluous melted slag to run out of the fire chamber,
and the combustion is further facilitated by heating the blast of air within the
furnace before it reaches the coal on the top of the fire, so as to consume the
smoke. To effect these objects the fire chamber is constructed in such a
manner as to prevent the entrance of air from beneath the furnace bottom,
either by having a close bottom, or, if grate bars be used, by closing up the space
underneath. In either case the blast or current of air is introduced. only at a
point or points in the fire chamber above the furnace bottom, and a. contracted
receptacle below the entrance of the blast collects the cinder in a fused state,.
which may be allowed to run off as it is formed through an aperture made for
that purpose. A quantity of the cinder or slag is collected in a vitreous
melted mass in the bottom of the fire chamber, and forms a good protection to.
it, for the lower part of the mass is comparatively cool. The coal is lighter
than the fused cinder, and therefore floats upon it, and the air being heated as
it passes over the molten surface of the cinder, and thence through. the hottest.
part of the fire to the top of the burning coal, it becomes. sufficiently hot to
consume the smoke.
To enable those who are skilled in the art to apply this improvement in the
construction of furnaces, I will proceed to describe it, more fully in its practical
application to a puddling furnace, referring to the accompanying Drawing, in
which like letters and marks denote the same parts.
Figure 1 is a perspective representation of a puddling furnace with these

page_text: improvements; Figure 2 is a longitudinal sectional perspective representation
of the puddling furnace shown in Figure 1; Figure 3 is a longitudinal vertical
section of the fire chamber of the puddling furnace, showing the relative position
of the sand, cinder, and fuel when the furnace is in operation.
The puddling furnace represented in, the Drawing is the ordinary construc-
tion of such furnaces as used in Western Pennsylvania,. in North America, as
far as relates to the hearth in which the iron is puddled, and the stack or
chimney. The fire chamber also above the line X-
-X (see Figs. 2
and 3) is constructed in the usual manner, but below that line the fire chamber
is continued downwards of fire brick, and is gradually contracted by sloping its
sides, as seen in Figs. 2 and 3, to a convenient depth (say about 15 inches)
below the line X-
-X. Just below the level of that line there is a
small opening a through the side or front wall of the fire chamber to allow the
melted cinder to flow out when it rises above that level. Just above the
opening a is the aperture b, for the blast pipe on either or on both sides.
for the admission of air to the fire. In arranging the position of the blast
it is better to incline the opening downwards, and insert a tuyere, to direct
the current of air against the surface of the hot cinder, and to prevent the
choking up of the blast hole by the influx of the melted cinder. The fire
chamber may be built upon an iron plate d, to which is attached a hinged
iron door that shuts up against the opening in the bottom of the fire chamber.
(which opening may be about 24 inches square), and is of the full size of the
bottom of the fire chamber. That door may be kept closed in
any convenient
way, as by a bar shown in Figs. 2 and 3. A few inches above the bottom
plate or hinged door d, is another small opening similar to a, designed for
running out the melted cinder when it is desired to clean out the fire chamber.
The hinged door affords an opportunity for emptying the entire contents of the
fire chamber, and the door g in the side is for the purpose of obtaining admis-
sion when repairs are required. The square opening is the "stock hole,"
through which the fuel. is supplied to the furnace, it is kept closed by the coal.
Below the line X
X is the receptacle for the melted cinder, the use
of which and the mode of working the furnace I will now describe. When
the furnace is to be put in operation the hinged door d is closed and fastened;
a layer of sand i (about 4 inches deep) is laid upon it as high as the bottom of
the opening to protect the door plate from the action of heat. The opening f
is kept closed while the furnace is at work, but the upper opening a is left open.
On the layer of sand the fire is built, and the blast is turned on through the
tuyere or opening b. When the fire is well lighted some oxide of iron or
other suitable flux is thrown on the coals from time to time. This melts and

page_text: runs down into the bosh or receptacle below the line X-
-x. The
flux serves to assist in melting the substances in the coal that form the cinder,
and they run down into the bosh. As the melted cinder thus forms, the fuel
which floats upon it rises until the bosh is full of melted cinder to the opening a,
the fuel and cinder then occupying their proper relative positions. The melted
cinder as it accumulates above the level of the opening a runs out and the
portion below that level serves to keep the lower part of the fuel fully ignited.
The blast of air as it enters through the tuyere at strikes against the surface
of the melted cinder and is heated, and rising through the hottest part of the
fire unites with the smoke at the top of the fuel, and causes its combustion,
and effects a saving of fuel and increase of heat. Another advantage arising
from the admission of air in the manner described is, that the oxygen combines
with the carbon during combustion to form carbonic acid gas, and when in
that state it passes over into the puddling furnace chamber, it does not combine
with the iron ore and with the scrap iron used for "fixing," as the oxygen
usually does in puddling furnaces of the ordinary construction. By thus avoiding
the formation of oxide of iron there is a great saving of cost in the "fixing" in
a puddling furnace..
These improvements in furnaces are applicable not only to puddling and
boiling furnaces, as described, but also to furnaces for reheating iron. The use
of oxide of iron or of any other flux is not essential in the use of these furnaces,
for the cinder will melt and run down in the furnace without it, though not so
readily. Neither is it necessary to retain the melted cinder in any large
quantity in the bottom or bosh of the fire chamber, but it may if preferred be
allowed to run off as rapidly as it accumulates. This may be done either by
filling up the bosh with sand, or by building the fire chamber with a very
shallow bosh, so as to diminish the depth between the bottom of the fire
chamber and the point of exit.
Having now described the nature of these improvements in the construction
of furnaces for puddling, boiling, and reheating iron, the parts claimed by the
Inventor as new, and what I desire to secure by Letters Patent, are,-
First, the construction of the fire chambers of reverbatory furnaces for
puddling, boiling, or re-heating iron, in which coal is used as fuel, so as to
form at the bottom a contracted receptacle for collecting the melted cinder
below the point at which the blast of air is admitted, in combination with a
close air-tight fire chamber bottom for the purpose of retaining the cinder in a
melted state so long as it remains in the fire chamber, and thus preventing the
formation of clinker as described.
Second, the application in the fire chamber of a puddling, boiling, or

page_text: re-heating furnace constructed as above described of a suitable flux for the
purpose of keeping the cinder in a state of fusion so long as it remains in
the fire chamber bottom, so as to enable it to run off as it accumulates
in the manner herein-before set forth.
Third, the introduction of the blast into the fire chamber of a puddling,
boiling, or re-heating furnace, constructed as before described, near the surface
of the melted cinder, so as to heat the air before it ascends through the
mass of fuel in the fire chamber, and thus increase the intensity of the
combustion.
In witness whereof, I, the said Frederick Collier Bakewell, have
hereunto set my hand and seal, this Tenth day of April, in the year of
our Lord 1861.