IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND PURIFIED IRON, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1865

page_text: ETTERS PATENT to Henri Adrien Bonneville, of the British and
Foreign Patent Offices, 24, Rue du Mont Thabor, Paris, in the Empire
of France, and 38, Porchester Terrace, Bayswater, in the County of
Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF STEEL AND PURIFIED IRON, AND IN THE APPARATUS EMPLOYED
THEREIN." -A communication from Antoine Galy-Cazalat, residing at
Belleville, in the Departement of the Seine, and Empire of France.
ealed the 6th February 1866, and dated the 21st December 1865.
COMPLETE SPECIFICATION filed by the said Henri Adrien Bonneville
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 21st December 1865, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRI
ADRIEN BONNEVILLE, of the British and Foreign Patent Offices, 24, Rue
du Mont Thabor, Paris, in the Empire of France, and 38, Porchester
Terrace, Bayswater, in the County of Middlesex, Patent Agent. send
greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF STEEL AND PURIFIED IRON, AND IN THE APPARATUS EMPLOYED
THEREIN." communicated to me by Antoine Galy-Cazalat, a person residing
at Belleville, in the Departement of the Seine, and Empire of France, afore-
said, and have petitioned Her Majesty to grant unto me, my executors

page_text: administrators, and assigns, Her Royal Letters Patent for the same, and have
made solemn Declaration that it is a communication.
NOW KNOW YE, that I, the said Henri Adrien Bonneville, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the Invention, and the
manner in which the same is to be performed, reference being had to the
accompanying Drawing, in which Fig. 1 is a section by the line 1-2 of
Fig. 2; Fig. 2 a section by the line 3-4 of Fig. 1; Fig. 3 a section by the
line 5-6 of Fig. 2; and Fig. 4 a section by the line 7-8 of same Figure,
and to the letters marked thereon, that is to say:-
This Invention consists in an improved mode of and apparatus for decar-
bonising progressively masses of liquid iron in order to convert the same
into purified iron or common steel, and principally into homogenous cast
steel free from bubbles.
DESCRIPTION OF THE IMPROVED APPARATUS OR FURNACE.
Figs. 1, 2, 3, and 4, of the accompanying Drawings (made to the scale
of one-twentieth) represent sections of a reverbating furnace provided
with a vertical tubular boiler or boiler with a double jacket, the interior
B, A, of which serves as a chimney. L is a stair by which access is obtained
to the ash-box placed under the grate G. This latter is charged with coal
by the opening P, provided with a door lined with bricks and closed after
charging the furnace. The doors Q, Q', serve for introducing
between the fire-bridge and the transversal bank p, p, a suitable
quantity of iron sows H, whose opposite ends are held in an inclined position
above the sole of the furnace, as shown in Figures 2 and 3. A second and
more considerable charge of common cast iron is introduced by the doors
Q", Q", near the centre of the sole, where the SOWS are held
and placed like those of Fig. 3. When the coal placed on the
grate G is lit, the flame thrown off by the refractary arch X, Y,
passes through the two charges of cast iron, which it heats before
escaping by the chimney B, A, surrounded by water C, D, which it
vaporises. As the impure cast iron melts it accumulates in the upper reservoir
between the fire-bridge c, and the transversa! bank inclined towards
the sand heap p¹ which retains it. Shortly after the entire mass
of sows forming the second charge is transformed into a second metallic
bath on the sole of the furnace, and held back by the refractary bank F,
This metal must then be suitably purified and decarbonised. For this
purpose a plate of the clay used for making crucibles, about four inches

page_text: in thickness, is cemented on each lateral surface or side of the reverbrating
furnace. Each of these plates, M, M, N, N, is provided with a row of
vertical tubes H, formed in its thickness, and conducting into a chamber
common to all, shown by the letters M, M, in Fig. 2. The vapour engen-
dered in B, A, is led into M, M, by the tube 0, 0. This latter is
provided with a tap R, preceded by a tap R', which serves for evacuating
the condensed steam. When the tap R is opened the dry steam enters M,
from whence it descends by the tube I, I, in which it enters transversally
by their orifices x, y, . formed at the lower part of the opposite surfaces
of the two plates M, N. In passing through the liquid or molten metal, the
steam greatly superheated becomes decomposed. Its oxygen oxidises the iron
and burns the carbon of the cast-iron, while the corresponding or co-existing
hydrogen purifies the steel, removing the sulphur and other metallic com-
pounds which would render it brittle. After allowing the steam to leave
alternately twice by M, M. and twice by N, N, during 6 or 8 minutes each
time, the decarbonised metal should be tried. To do this. the two entrance
taps are closed in order to dip a ladle-ful, from which a trial ingot is formed.
If this ingot when placed on an anvil splits under the blows of the hammer
the metal is still too much carburetted for steel.
Liquid Oxide of Iron-If it is wished to convert the bath of iron too much
carburetted into purified molten iron the tap R is opened in order to allow
the steam to act until the metal is completely decarbonised, which is easily
ascertained before running it into the moulds.
Common Steel. To obtain common steel it is necessary to return to the
metallic bath the carbon which is wanting for its conversion into steel. For
this purpose the sand bank p' is removed froin the upper reservoir c, c, p', p¹,
in which is held in a liquid state cast iron containing the quantity of carbon
to be distributed to the mass of oxide of iron. During the running of the
impure cast iron the two currents of steam are allowed to act on each side of
the sole for a few seconds, so as to pass through the alloy. Then this metal,
known as "Bessemer steel" or homogenous steel, employed for making rails
and similar purposes, may be run into suitable moulds.
Continuous Manufacture of Steel.-After the running off, while the refractary
walls are still in a state of incandescence, the two charges of cast iron may
be renewed by opening the doors q, q, q, q", of the furnace which doors
are suitably disposed or arranged for the purpose, and by reforming the bank F¹
and the plug K. Thus the large quantity of coal necessary for heating the
vault X, Y, the two sides, and the sole of the furnace before the iron can be
melted may be economised,

page_text: Continuous Manufacture of Pure and Homogenous Cast Steel.-To
convert the common steel into homogenous cast steel, it is necessary to keep
it in a state of tranquil fusion at a very high temperature. For this purpose
it suffices to close the taps R and to open the tap r which leads the steam
into the chimney z, whose draft it increases as well as the combustion;
then the chemical reactions take place in such a way as to cause the oxygen
to abandon the iron in order to burn the free carbon which renders the cast
steel made in large masses as good as that recast in small crucibles. As the
metallic bath is not deteriorated by even a long tranquil fusion in the rever-
brating superheated furnace, several samples may be tried successively until
the metal is found to forge and temper like the best of steel, then only the
running off is performed by opening the sand bank F¹, and the heap or pad K,
which may be built up again at pleasure.
Running off the Steel under High Pressure.--It is known that articles
of steel run into moulds are full of blisters, which considerably weaken
its tenacity. To give the metal suitable strength it is necessary after suitably
heating it to submit it to the pressure of a rolling mill, or to the shock of a
steam hammer, which brings the particles in more intimate contact,
and causes the blisters to disappear. The handles, pivots, and form
of cannon not admitting the use of the steam hammer or rolls, I
propose to submit these and similar articles to a high pressure during the
casting in sand moulds strengthened by iron frames. Immediately after
casting the cannon, its runner is covered hermetically by a metal cap fixed
by vertical bolts with linch pins, forming part of the frame of suit-
able strength which surrounds the mould. The metal cap is also provided at
its centre with a vertical tube having a tap at its base; its upper end is
closed by a collar of less resistance, pressed by a screw plug bored in the
direction of its axis, which serves as a safety valve. In supposing that
before placing the cap at about two centimeters (two-fifths of an inch)
above the surface of the liquid steel ten grammes (one-third of an ounce of
a powder composed of eighty parts of saltpetre and 20 parts of carbon,
without sulphur, are introduced between the tap and safety collar, when
the tap is opened this powder falls on the metal, which inflames it and
developes instantaneously ten litres (about six quarts & a half pint) of
gas at fourteen hundred degrees. This gas produces on the liquid mass a
pressure which is transmitted to the whole surface of the mass,
whose particles are pressed together while effacing the blisters. The effect
produced is equal to the pressure due to the weight of a runner of liquid
steel composed of a column whose height is twenty-eight metres (about

page_text: thirty-two yards), in supposing the space comprised between the cap and the
surface of the metal in the mould is of the capacity of half a litre (say about
five-eighths of a pint). By giving suitable strength to the frame which surrounds
the mould, the charge of powder may be varied so as to produce by its
explosion an uniform and general pressure superior to the partial, irregular,
and momentaneous pressure of a steam hammer.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, I claim the use of the improved reverbrating
furnace constructed in the manner substantially as above described and repre-
sented in the accompanying Drawing, and specially,-
Firstly, the plates of crucible clay or fire-clay fixed to the sides of the
furnace. These plates are provided in their thickness with a chamber above
and parallel to the surface of the molten bath, in which the ends of tubes
entering the molten metal are led. The liquid metal remains fluid on entering
them by the orifices by which the steam passes when the entrance tap of the
upper chamber is closed.
Secondly, the upper reservoir of melted metal, intended for returning
to the purified iron the carbon required for its conversion into common
steel.
Thirdly, the conversion of the common steel into homogenous steel
by fulfilling the two conditions united in recasting crucibles, which are,
keeping the steel in a state of tranquil fusion, and at a very high tempe-
rature in the reverbrating furnace whose combustion is actuated by the
steam injected into the chimney.
Fourthly, the means above indicated for submitting steel when run into
moulds to the pressure of gases which drive its particles into close contact
and efface the blisters, in connection with the above-described improve-
ments.
In witness whereof, I, the said Henri Adrien Bonneville, have hereunto
set my hand and seal, this Thirtieth day of November, in the year of
our Lord One thousand eight hundred and sixty-five.