IMPROVEMENTS IN AND CONNECTED WITH FURNACES, ESPECIALLY THOSE USED for Melting, ROASTING, AND ANNEALING METALS AND MINERALS
Year: 1877

page_text: {
LETTERS PATENT to Joseph Toussaint, formerly of Saint Jean d'Angely,
France, but now of Icknield Port Road, Birmingham, in the County of
Warwick, Scientific Chemist, for the Invention of IMPROVEMENTS IN AND
CONNECTED WITH FURNACES, ESPECIALLY THOSE USED for Melting, ROASTING,
AND ANNEALING METALS AND MINERALS."
Sealed the 14th August 1877, and dated the 15th February 1877.
PROVISIONAL SPECIFICATION left by the said Joseph Toussaint at the
Office of the Commissioners of Patents on the 15th February 1877.
JOSEPH TOUSSAINT, formerly of Saint Jean d'Angely, France, but now of Icknield
Port Road, Birmingham, in the County of Warwick, Scientific Chemist. "IMPROVE-
MENTS IN AND CONNECTED WITH FURNACES, ESPECIALLY THOSE USED FOR MELTING,
ROASTING, AND ANNEALING METALS AND MINERALS."
The object of this Invention is to construct furnaces with a chamber or chambers
formed below the fire-grate to a depth of 30 feet, more or less, to serve as an air
shaft by which the fire is fed with air and the supply of air and the heat regulated
and maintained, especially with furnaces employed for treating metals and other
mineral bodies, also for annealing purposes.
The fire and heat may be caused to act direct upon or against crucibles or other
containers arranged above, or in flues or passages leading to the outlet, as desired,
but it is particularly applicable when crucibles such as I have referred to in my
Provisional Specification, dated 12 February 1877, No. 584, and described as sus-
pended or supported by oblique or angled projections below, and at the side, said
crucible being formed with a rounded bottom and with a spout or nozzle from its
lower part to the outside of the brickwork or structure to facilitate the molten
metal being drawn off.
One method of forming the upper part of the furnace structure above the fire-
grate, and which I claim as part of my Invention, the part below the grate being
in all cases by my Invention of great depth, whether the structure bo vertical or
oblique, is as follows:-This furnace may be square, round, or of six or eight sides,
or oval; under the fire-grate bars it has a perfectly straight construction, and is
closed in the form of a chimney of a depth from three to thirty feet or more. At
the bottom of this construction there is a "door" of the same diameter. This door is

page_text: double so as to introduce between the two, sand or dust, in order to interrupt the
current of air to keep the fire alight night and day. This construction is made so
as to give a current of air very rapid and very strong, according to its depth beneath
the fire-grate; the greater the depth the stronger and more rapid will be the coluinn
of air.
The construction above the fire is preferably of the same form and same diameter
as the construction beneath, and at the level of the grate with the ground there is
a door which serves to clean the furnace grate, and two feet above this door there
is another door which serves to make the fire and heat to smelt the metallic matters.
or metals contained in the crucible. Above this door which serves to introduce
the coal and coke around the top edge of the crucible and between it there is a
screen with an opening or passage of half an inch in width, more or less, all round
between it and the edge of the crucible if a crucible is fitted in, to allow the smoke
and gases from the fire to pass up into a chamber above. This chamber has a cover
with an opening in the centre for the passage of the smoke and gases from it. The
area of this aperture is about one-half the area of the opening between the pot and
the screen,
to prevent the rapid escape of the top heat and thereby retain the heat
on the top of the crucible.
The top of the furnace brickwork is provided with a cap to compel the escaping
gases from the cover to pass through an opening in the side wall leading to the
chimney. This chimney is placed above the furnace, and is also to direct the smoke
and gas from out the foundry.
This furnace constructed as above described is available for ordinary crucibles,
and four or six of such crucibles may be placed in, as found convenient, in order to
economise fuel. The heat in this furnace is strongly induced through the length
or height of the furnace structure below the fire-grate, and without having recourse
to a steam engine, by the great force of the column of air which comes from the
bottom of the furnace, which is as before stated, very deep in the form of a chimney,
the fire thereby drawing in the air with avidity.
The gases from the fuel in this furnace are very much lighter than the outer air,
and exert great heating power around and against the crucible.
By this Invention the heat from the fire when cone-shaped crucibles are used
always finds itself contracted against the sides when ascending to the top of the
crucible and gives to it greater heat. The space above the top of the crucible
enables the heat to be kept on the top as well as all around..
The heat at the top of the crucible is however slightly greater than that of the
sides because it is lighter and concentrated by the opposition of the narrow passage
in the cover.
By this Invention the usual outside high stack or chimney is dispensed with,
and also the steam engine and the blowing and suction apparatus which now
induces draught and regulates heat in such furnaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Toussaint in the Great Seal Patent Office on the 15th
August 1877.
JOSEPH TOUSSAINT, formerly of St. Jean d'Angely, but now of Icknield Port 4
Road, Birmingham, in the County of Warwick, Scientific Chemist. " IMPROVE-
MENTS IN AND CONNECTED WITH FURNACES, ESPECIALLY THOSE USED FOR MELTING,
ROASTING, AND ANNEALING METALS AND MINERALS."
The object of this Invention is to construct furnaces with a chamber or chambers
formed below the fire-grate to a depth of 30 feet, more or less, below the level of 5
the ground to serve as an air shaft by which the fire is fed with air and the supply
of air and the heat regulated and maintained, especially with furnaces employed

page_text: for treating metals and other minerals, also for annealing purposes and for burning,
heating, and drying plastic bodies and for operating upon materials generally by.
heat.
The fire and heat may be caused to act direct upon or against crucibles and other
containers arranged above, or in flues or passages leading to the outlet, as desired,
but it is particularly applicable when crucibles such as I have referred to in my
Specification, dated 12th February 1877, No. 584, and described as suspended or
supported by oblique or angled projections below and at the side, or by a foot at
the bottom, said crucible being formed with a rounded bottom and with a spout or
nozzle from its lower part to the outside of the brickwork or structure to facilitate
the molten metal being drawn off.
One method of forming the upper part of the furnace structure above the fire-
grate (and which is important as part of my Invention,) the part below the grate
being in all cases by my Invention of great depth whether the structure be vertical
or oblique, is as follows:-This furnace may be square, round, or of six or eight
sides, or oval; under the fire-grate bars it is in the form of a chimney of a depth
from three to thirty feet or more. It may have parallel sides from the bottom to
the grate bars, or it may be tapered with its smaller diameter at the upper part,
the air door or opening being somewhat larger than the grate bar part to furnish
a full supply of air. At the bottom of this construction there is a "door" of about·
same diameter or rather more than the top of the chimney directly below the fire-
grate. This door is double so as to introduce between the two, sand or dust, in
order to interrupt the current of air to keep the fire alight night and day. This
construction is made so as to give a current of air very rapid and very strong
according to its depth beneath the fire-grate; the greater the depth the stronger
and more rapid will be the column of air.
At the level of the grate, which is about level with the ground, there is a door
which serves to clean the furnace grate, and about two feet above this door there
is another door which serves to make the fire from which the heat is derived.
The top of the furnace brickwork is provided with a cap to compel the escaping
gases from the cover to pass through an opening in the side wall leading to the
chimney. This chimney is placed above the furnace and is available, if desired, to
direct the smoke and gas from out the foundry.
The outlet from the furnace may be directed by a flue or flues in a downward
direction to about three feet above the air supply door to check the outflow of the
escaping gases. By this means the gases, which become developed at the top of
the furnace, may be utilized by their expansion and consequent pressure on the
top of the metals under operation, or upon other bodies which may be in the furnace,
say for bricks, which have to be dried or burnt.
This furnace constructed as above described is available for ordinary crucibles.
and four or six of such crucibles may be placed in, as found convenient, in order to
economise fuel. The heat in this furnace is strongly induced through the length or
height of the furnace structure below the fire-grate, and without having recourse
to a steam engine by the great force of the column of air which comes from the
bottom of the furnace which is, as before stated, very deep in the form of a chimney,
the fire thereby drawing in the air with avidity.
The gases from the fuel in this furnace are very much lighter than the outer air
and exert great heating power around and against the crucible or material under
operation.
By this Invention the heat from the fire when cone-shaped crucibles are used
always finds itself contracted against the sides when ascending to the top of the
crucible and gives to it greater heat. The space above the top of the crucible
enables the heat to be kept on the top as well as all around.
The heat at the top of the crucible is however slightly greater than that of the
sides because it is lighter and concentrated by the opposition of the narrow passage
in the cover.
By this Invention the usual outside high stack or chimney is dispensed with, and

page_text: also the steam engine and the blowing and suction apparatus which now induces
draught and regulates heat in such furnaces.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim; the construction and employ-
ment of a pit structure below the level of the ground, to which structure air is free
to enter at its lower part to supply the fire or furnace which is at the upper part
with said air for supporting combustion and for burning, melting, drying, or heating
articles or material placed in said furnace above the fire; or in the fire, or in the
flues leading therefrom, as described.
In witness whereof, I, the said Joseph Toussaint, have hereunto set my
hand and seal, this Fifth day of July, One thousand eight hundred and
seventy-seven.
JOSEPH TOUSSAINT. (L.S.)