IMPROVEMENTS IN FURNACES INTENDED TO WORK IRON ORE
Year: 1860

page_text: LETTERS PATENT to Joseph Bonne, Merchant, of Cluis (Indre), Empire
of France, for the Invention of "IMPROVEMENTS IN FURNACES INTENDED TO
WORK IRON ORE."
Sealed the 7th February 1861, and dated the 7th August 1860.
PROVISIONAL SPECIFICATION left by the said Joseph Bonne at the
Office of the Commissioners of Patents, with his Petition, on the
7th August 1860.
I, JOSEPH BONNE, Merchant, of Cluis (Indre), Empire of France, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
FURNACES INTENDED TO WORK IRON ORE," to be as follows :-
I purpose giving but little elevation to my improved furnace, and shall
consequently be enabled to place the furnace mouth level with the ground,
thus obviating the necessity of hoisting the material when charging the furnace.
The melting pot or crucible formed of four strong iron plates tied together
will be lined interiorly with refractory bricks and clay. The front will be
entirely closed by a cast-iron dam, in which will be made one opening at tho
bottom for the flow of metal, and one at the top for the overflow of the dross,
which will fall into a chariot on wheels, which, when filled, may be withdrawn
by a single workman. A balance shovel will arrest the dross until the chariot
be brought back. The arch roof will also be of refractory brickwork, and
above the arch will be a cast-iron furnace mouth, in which will be established
a gas apparatus destined to heat steam boilers, and at the same time burn (if
desired) large quantities of lime for agricultural and building purposes. The
furnace.mouth will be completely closed for the compression of the gasses by
four cast-iron plates with cap above. A door closing hermetically will admit

page_text: the load or charge. There will be upon the load a counterweight with move-
able cover to drive back the gasses into the pipes, and concentrate the caloric
within the furnace; this counterpoise will be graduated to indicate the move-
ment of the charge or load. The charging will be effected by means of a
chariot running on a railway permitting it to be done, and the door closed very
quickly, preventing escape of gas. I also utilise the waste coal produced by
making it into balls, with the addition of an alloy of fusible mineral.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Bonne in the Great Seal Patent Office on the
7th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
'BONNE, Merchant, of Cluis (Indre), Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of August, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Iler heirs and successors, give and grant unto me, the
said Joseph Bonne, Iler special licence that I, the said Joseph Bonne,
my executors, administrators, and assigns, or such others as I, the said
Joseph Bonne, 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 "IMPROVE-
MENTS IN FURNACES INTENDED TO WORK IRON ORE," upon the condition (amongst
others) that I, the said Joseph Bonne, 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 Joseph Bonne, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheets of Drawings hereunto annexed
and to the figures and letters of reference marked thereon:-

page_text: In existing high furnaces extraordinary variations take place in the move-
ment of the charges, occasioning frequent failures, followed by cessations for
cleansing several times repeated in the year, and always very costly, and under
the present system it cannot be otherwise, as I will explain. In a furnace of
large size, when you have supplied it with more or less ore than the property
of the fuel requires, at least twenty-four hours must pass before you can
discover the changes you have made and remedy them. During this time you
are burning fuel uselessly if the charge has been too small, or you fail or
produce white pig iron if the charge is too great. By my process, on the contrary,
you ascertain the change four hours after it has taken place, and you preserve
a regular and continuous process in your furnace. Further, the workmen
employed on the present furnaces work by routine without reflection, and with
extraordinary indifference. The guards, who are nearly everywhere instructed
to watch the progress of the furnace, do not know the quality or the property
of the ore they use. The chargers or feeders of the furnace are not always
exact in their work, and the result of all this is, that there is no precision in
an operation of the greatest importance. My low-furnace system will compel
the guards as soon as they are shewn their work to learn their business and
work with care, intelligence, and economy. They will themselves feed the
furnace, which will contain, say, eight charges of one cubic yard each; thus in
running or casting at sixteen charges, one may judge by the passage of the
first cight whether the quantity of ore should be increased or diminished, and
even if necessary, change the medley or mixture in the last eight charges. By
this means I obtain a regular process, bringing the metal at.each running off to
the desired state without hurtful variation. To stimulate the zeal of my two
guards, I would put each upon a certain quantity of fuel, and pay them
separately by the ton of smelted ore, and I should see thereby which worked
the best, and they also employing the same materials, would see their work at
each running off, and judge their respective merits, and I would upon a
different calculation pay all the other workmen by the quantity of ore smelted.
My furnace from its slight elevation will permit me to place the month level
with the ground, so that all the materials are easily introduced and no hoisting
apparatus is required. The basin of reception or crucible formed of four strong
cast-iron plates tied together from the bottom to the cornets, is lined with
refractory bricks and earth. The front is entirely closed by a cast-iron dam,
in which is left one opening at the bottom for running off the metal, and oue
at the top for the dross to run off and fall into a small chariot or waggon ou
wheels. When this chariot is full a single workman can withdraw it. During
this operation, that is to say, awaiting the return of the waggon, a balance

page_text: shovel will arrest the escape of the dross. The dross will run off naturally,
and never require any working, which in the first place will prevent any
coolings and loss of time, and in the second, economise all the fuel and ore,
which is constantly withdrawn when working with the usual tool, and which
constitutes a somewhat considerable loss of material. The arch roof is also
constructed of refractory earth and bricks, and above it is a cast-iron throat or
mouth containing exactly the measure of a charge, say, about one cubic yard.
In this throat is a gas receiver intended to heat the steam boilers, and at the
same time to burn an abundance of lime for agricultural and building pur-
poses. The throat is completely closed for the compression of the gases by
four cast-iron plates, with a cap above and a door closing hermetically, serves
to introduce the charge. There will be upon the charge a counterbalance
with moveable cover to force the gases into the pipes and concentrate the
caloric within the furnace, and this counterbalance will have a graduated scale
to shew the movement of the charges. The feeding or charging will be
effected by means of a chariot or waggon running on a small railway, which
will permit the feeding to be done, and the door shut quickly to prevent
escape of gas, and this mode of feeding will give little trouble and require but
few workmen.
My furnace, from its construction and arrangements, will be fired at a small
cost, the reheating will be easily and cheaply effected, and the fire may be
stopped and rekindled when desired without experiencing the enormous losses
which must occur in a large furnace.
In the economical and easily worked system above described 1 turn to
account all the waste fuel or cinder by forming it into lumps with an
admixture of fusible ore in powder; this waste fuel constitutes in all works a
considerable loss in the consumption of fuel, and from which I draw beyond
the saving first set forth an equal advantage. My system presents the
following advantages:-a saving of about fifty per cent. in fuel, of thirty per
cent. in labour, of sixty per cent. in construction of furnace and reheating
(there being no more enormous blocks of stone nor great expense in fitting
and demolishing them and reheating the furnace), better product from the ore,
and with it a more regular system of working, no loss of time, positive and
foreseen products, no fuel burnt uselessly, failure impossible, work with pure
charcoal and cold air or blast, and production of very superior metal.
The construction of my furnace will be more readily understood by reference
to the annexed Drawings, Figure 1 (Sheet 1) shewing elevation of furnace;
Figure 2, section taken at A, B, C, D, Figure 3.
A, bottom of the basin of reception or crucible formed of refractory bricks

page_text: (of the usual size) placed on end and in double rows; B, stones serving to
support the bottom of the cast-iron plates forming the crucible; C, lining of
refractory earth and bricks forming the sides; D, D', cast-iron plates rising
from the bottom of the crucible up to the cornets (see section E, F, G,
Figure 3) keyed or bolted to the back side and the tymp; E, cornets of cast
iron, supporting the refractory brickwork F at an angle of seventy degrees to
the horizontal plane; G, brick arch serving to concentrate the heat; H, throat
or space by which each charge is introduced; I, plates forming the top of the
throat to prevent escape of the gasses, and force them beneath the steam
boiler and into the lime kiln; J, flues to allow the vapour or steam to escape
from the masonry; K, tuyère or conical pipe introducing the air or blast into
the crucible; L, leather piece or boot permitting the direction of the tue iron
to be changed; M, cock for escape of air or blast; N, glasses by which the
fusion at the tuyères may be seen; 0, wind or blast pipe; P, gas receptacle
(see section K, L, Figure 4); Q, balustrade; R, cast-iron tuyère.
Figure 8, section taken at E, F, G, Figure 2. A, bottom of crucible or
basin of reception; B, right-hand tuyère plate; C, left tuyère plate; D, back
plate; E, conical dam, having at its lower part a rectangular opening for the
exit of the cast metal, and at its upper part an opening for the escape of the
dross or scoria. This dam will be keyed or bolted to the two tuyère plates;
F, pillars supporting the cast-iron cornets; G, right-hand pipe of cast iron;
H, left pipe; I,,wind or blast pipe.
Figure 4, section taken at K, L, Figure 2. A, masonry; B, counter-
funnel forming the key of the arch; C, gas receiver; D, funnel carrying a
collar to be bolted to the counter funnel and the four plates closing the throat;
E, opening for charging the furnace, formed by means of throat door
(Figure 5); F, cap of the throat; G, pressure plate forcing the gas; H,
cylinder for raising the pressure plate; I, counterpoise moving in front of a
graduated scale, shewing the progress of the charge.
Figure 5, door of throat. A, cast-iron plate strengthened with bars;
B, balanco furnished with two press screws; D, axle of the balance.
Figure 6, section at M, N, Figure 5; Figure 7, section at H, I, Figure 2.
A, square part, carried from the ground up to the cornets (cut stone);
B, round part rising from the cornets to the interior mass or lining of
refractory brickwork; the exterior is of ordinary brickwork circled with iron;
C, stones forming entablement, and and giving increased size to the mass
(space surrounding the throat); D, counterflue; E, circular gallery of the gas
receptacle; F, hopper or flue; G; pipe conducting the gas into a purifier.
Figure 8, front of the basin of reception or crucible. A, cast-iron dam;

page_text: B, opening for exit of metal; C, opening for exit of dross or scoria; D, balance
shovel, serving to stop the escape of scoria; E, tymp; F, slides of the shovel;
G, handle for lifting and lowering the shovel.
Figure 9, section at O, P, Figure 8; and Figure 10, section at Q, R,
Figure 8.
Figure 1 (Sheet 2), elevation of furnace, having the double advantage of
heating the steam boiler and burning lime.
Figure 2, section of lime kiln (to be heated by gas) taken at A, B, C, D,
Figure 3. a, throat (opening by which the lime stones are introduced;
a, b, space in which the lime is baked or burnt; b, c, space in which the lime
cools; d, rectangular opening by which the lime is withdrawn; e, grating by
which the gasses are admitted; f, chamber in which the gas burns; g, door by
which air is introduced into the gas chamber to make it burn; h, rack for
giving more or less air to the gas; i, butterfly valve to give an equal quantity
of gas to the four burners; ;, gas pipes.
Figure 8, section at E, F, Figure 2. The interior of the lime kiln, by
horizontal section, gives a rectangle, the angles of which are rounded, the
exterior an oval, and the base a rectangle of cut stone up to a certain height,
say, of about two yards. All the oval part will be constructed of brickwork
circled with iron. To use my system of low furnace where pure coke or a
mixture is used, it will suffice to give greater dimension to the basin of
reception and its lining, and greater thickness to the masonry.
The plan herein described and shewn in the Drawing is based upon
proportions intended only for treating iron ores with pure charcoal and
cold blast.
In witness whereof, I, the said Joseph Bonne, have hereunto set my
hand and seal, this Second day of February, in the year of our Lord One
thousand eight hundred and sixty.
Witness,
CYR COUSIN,
Instituteur Public,
à Cluis (Indre).
JOSEPH BONNE. (L.S.)