IMPROVEMENTS IN CUPOLA PROVISIONAL SPECIFIC
Year: 1881

page_text: LETTERS PATENT to Hector Auguste Dufrené, of No. 10, Rue de la Fidélité,
Paris, in the Republic of France, aud 4, South Street, Finsbury, London, Civil
Engineer and Patent Agent, for an Invention of "IMPROVEMENTS IN CUPOLA
PROVISIONAL SPECIFICATION left by the said Hector Auguste Dufrené at
the Office of the Commissioners of Patents on the 6th April 1881.
HECTOR AUGUSTE DUFRENÉ, of No. 10, Rue de la Fidélité, Paris, in the
Republic of France, and 4, South Street, Finsbury, London, Civil Engineer and
Patent Agent.
"IMPROVEMENTS IN CUPOLA FURNACES."
This Invention relates to improvements in cupola furnaces, the object of the
improvements being to separate the iron from contact with the fuel. For this
purpose I heat the cupola by gas, and I produce this gas in a separate gas generator
(for solid fuel) formed of three moveable parts. The blast arriving under the grate
is divided into two parts; the one part serves for burning the fuel, the other
part passes around the generator, becomes heated, and passes above to assist in the
combustion of the gases. If in place of solid fuel liquid fuel be employed, I
arrange a gas generator which will convert these products into gases. I can also
place an ordinary grate near the cupola on which solid fuel can be burned, the
gases from the combustion afterwards entering the cupola.
To prevent the solid iron from mixing with the liquid iron in the cupola I
arrange a vault or arch which retains the solid iron whilst the liquid iron collects
at the bottom. I may also employ an exterior crucible for collecting the liquid
iron.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hector Auguste Dufrené in the Great Seal Patent Office on the
6th October 1881.
HECTOR AUGUSTE DUFRENÉ, of 10, Rue de la Fidélité, Paris, in the Republic of
France, and 4, South Street, Finsbury, London, Civil Engineer and Patent Agent.
IMPROVEMENTS IN CUPOLA FURNACES."
This Invention relates to improvements in cupola furnaces, the object of the
improvements being to separate the iron from contact with the fuel. For this
purpose I heat the cupola by gas, and I produce this gas in a separate gas generator
(for solid fuel) formed of three moveable parts. The blast arriving under the grate
is divided into two parts; the one part serves for burning the fuel, the other part
passes around the generator, becomes heated, and passes above to assist in the
combustion of the gases. If in place of solid fuel liquid fuel be employed, I
arrange a gas generator which will convert these products into gases. I can also
place an ordinary grate near the cupola on which solid fuel can be burned, the
gases from the combustion afterwards entering the cupola.
The solid iron in descending is traversed in an opposite direction by the products
of combustion.
To prevent the solid iron from mixing with the liquid iron in the cupola I
arrange a vault or arch which retains the solid iron whilst the liquid iron collects
at the bottom. I may also employ an exterior crucible for collecting the liquid
iron, but this arrangement although requiring less attention occupies more
space.
Air is supplied to the grate by means of a ventilator. A register or clack valve
is placed over the opening.
But to make my Invention better understood I will proceed to describe the same
by reference to the accompanying Drawings.
Figures 1, 2, 3, 4, 5, 6, 7, and 8, Sheet 1, represent the cupola furnace with a
vault or arch. The flame enters at the upper portion of the crucible, passes across
the arch, and rises through the column of solid iron and heats it.
The vault or arch is supported by a vertical wall which is connected to the
brickwork in such a manner as to prevent it being raised by the liquid iron.
This wall is provided with openings in its lower part for the mixture of the
liquid iron, and in the upper part for the proper distribution of the pressure of the
gases.
Openings a allow the level of the liquid iron to be seen when the crucible
becomes full; moveable bricks b allow of examining the condition of the arch or
vault; angle irons c support the refractory lining of the cupola.
At the mouth of the furnace there is an ordinary opening for charging the iron
whilst working. For the first charges, in order that the arch or vault shall not be
damaged by too violent shocks, the iron is lowered onto the arch by means of an
arrangement shewn in Figures 7 and 8, Sheet 1. At the mouth of the furnace the
upper door is opened; the pigs of iron are placed in a suitable receptacle which is
lowered onto the arch or vault by means of two chains. The back of the receptacle
is then raised and the pigs of iron slide out and are deposited with scarcely any
shock.
In the cupola with exterior crucible, represented in Figures 18 and 19, Sheet 1,
the flame, as herein before described, enters into the upper part of the crucible and
passes through the pile of iron.
Openings d allow the filling of the crucible with liquid iron to be seen. Angle
irons e support the refractory lining of the cupola.
The hearth not being so liable to breakage, the precautions to be taken, as
hereinbefore described in referring to Figures 1 to 8, Sheet 1, for the first charges

page_text: of iron, are not necessary; the charges may be introduced through the door made
in the lower part of the cupola. This door may also be employed for facilitating
repairs.
When working either of the hereinbefore described cupolas the tap hole is
opened until the crucible is highly heated by the circulation of the flame. The
interior lining of these cupolas should be refractory and durable. Outside these
requirements this lining will be found to be economical, and further, will comply
with the nature of the chemical reactions which it is required that the lining shall
exercise on the iron.
Figures 11, 12, 13, 14, and 15, Sheet 2, shew the method of heating by means of
gaseous fuel. The gas generator shewn is applicable to obtaining gas from coal.
By modifying its dimensions it may be made applicable to other combustibles.
The combustible becomes dry whilst in the charging hopper. Its descent onto
the grate is regulated by means of openings a.
The gas generator of sheet iron is formed in three parts; these parts not being
subjected to the same degree of heat the middle part will be worn out less quickly
than the top and bottom parts, and will therefore require to be renewed less
frequently.
The whole of the air required passes under the grate through the pipe C; a
portion passes through the grate for gasifying the combustible; the other portion,
the supply of which is regulated by means of the clack valve c, circulates around
the generator and becomes heated whilst cooling successively the three parts of the
generator. It enters through the passage d at a high temperature, that is to say,
in good condition for combining with the gases which it meets. The combustion
continues in the upper part of the crucible.
When working, to facilitate the combustion, a brick is raised for placing a
lighted combustible in the passage d.
Figures 9, 10, and (9, 10,) Sheet 1, shew the method of heating by means of
liquid fuel. In view of the present cost of mineral oils, and even of heavy oils,
this mode of heating would only be employed with the object of obtaining a very
high temperature or a rapid production, or to avoid altering in any respect the
quality of the iron to be treated.
The air passes through the channel f in front of the oil, which it projects onto
the plate i, so as to increase its division. This oil has its delivery regulated by a
cock placed in front of the pipe g. Between this pipe and the distributor h there
are two small cocks for the proper distribution of the oil.
The chamber is sufficiently large to allow the combustion to be nearly complete
when the flame comes in contact with the solid iron.
For igniting it a lighted combustible should be placed in the passage j.
Figures 16 and 17, Sheet 2, shew the method of heating by means of solid fuel.
The thickness of the fuel on the grate should be sufficient to prevent the passage of
cold air, this thickness however should not be such as to cause a great production
of oxyde of carbon.
The grate shewn is applicable for the combustion of a slightly bituminous
coal.
The air passes under the grate by the passage b. The flame passes through the
passage d into the upper part of the crucible, and finally into the pile of solid
iron.
In witness whereof, I, the said Hector Auguste Dufrené, have hereto set
my hand and seal, the Fourth day of October, in the year of our Lord
One thousand eight hundred and eighty one.