IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON, AND IN THE APPARATUS IN CONNECTION THEREWITH
Year: 1871

page_text: LETTERS PATENT to Pierre Adolphe Dormoy, Metallurgist, of No. 6,
Rue des Filles-du-Calvaire, in the City of Paris, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON, AND IN THE
APPARATUS IN CONNECTION THEREWITH."
Sealed the 19th January 1872, and dated the 27th July 1871.
PROVISIONAL SPECIFICATION left by the said Pierre Adolphe Dormoy
at the Office of the Commissioners of Patents, with his Petition,
on the 27th July 1871.
I, PIERRE ADOLPHE DORMOY, Metallurgist, of No. 6, Rue des Filles-
du-Calvaire, in the City of Paris, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON,
AND IN THE APPARATUS IN CONNECTION THEREWITH," to be as follows:―
The object of this Invention is the economical manufacture of homo-
geneous steel and iron, tempered, pulverized, cast, and forged with coke
or coal by means of apparatus having hearths, the flames of which are
inverted, double grates, a canal generator and regulator of the gases,

page_text: and a fusing basin or smelting pot. The same caloric is employed
in the apparatus whether for the fusion or refining of metal.
The accompanying Drawings will by aid of the following description
more clearly be understood.
Fig. 1 represents an apparatus with hearth having inverted flames
and double grates, one B, oblique, and the other D, horizontal. A, A¹,
are elliptical arches forcing the gas to descend and sweep the canal
generator C, which may be enlarged or reduced by lowering or raising
the grate D by manoeuvring the eccentric supports E, E. F is the
aperture for the supply of coke or coal to the hearth D; G is the
I is a sheet iron conduit pipe
smelting basin; H is the refining basin;
lined with refractory clay, whose object is to lead the melted metal from
the basin G to that H; J is the key or regulating register of the air,
adapted to the escapement S; K is a great fire-bridge sheltering the
metal against the current of air; L is a gallery arranged below the
apparatus, and from which escapes by the conduit M a current of forced
or free air mixed with steam; N is a door placed in front of the furnace;
V is an arch of the furnace with projecting bricks.
0, 0, 0,
Fig. 2 represents an apparatus having a cupola with inverted flames,
with a smelting pot P supplied with a culvert escapement R.
represent the twyers or blast pipes. This system is applicable to the
direct fusion of cast and broken iron. The refining basin is not shewn
in the Drawing, but is similar to that of Fig. 1.
To obtain an homogeneous metal, the following is the process I
employ-Having separated the grain metal in projecting it in a state
of incandescence or white heat in a current of cold water, which purifies
it and renders it easy to crush on account of the great hardness it
acquires, I make an intimate mixture of the metal thus crushed, and I
assure myself of its homogeneousness by taking small quantities of the
metal from different parts of the mass and make a separate analysis of
them which I compare. When there is a too sensible difference, I add
to the mixture a sufficient quantity of carbonizing or decarbonizing
matters till I have obtained the desired quality, and from that time I can
operate on the largest masses with the certitude that the metal manu-
factured will be always identical.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Pierre Adolphe Dormoy in the Great Seal Patent
Office on the 26th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
ADOLPHE DORMOY, Metallurgist, of No. 6, Rue des Filles-du-Calvaire,
in the City of Paris, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of July, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Pierre Adolphe Dormoy, Her special licence
that I, the said Pierre Adolphe Dormoy, my executors, administrators,
and assigns, or such others as I, the said Pierre Adolphe Dormoy, 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 "IMPROVEMENTS IN
THE MANUFACTURE OF STEEL AND IRON, AND IN THE APPARATUS IN CONNEXION
THEREWITH," upon the condition (amongst others) that I, the said Pierre
Adolphe Dormoy, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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 Pierre Adolphe Dormoy, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement and accompanying Drawings, that is to
say :-
The object of this Invention is the economical manufacture of homo-
geneous steel and iron, tempered, pulverized, cast, and forged with coke
or coal by means of apparatus having hearths, the flames from which
are inverted, double grates, canal generator and regulator of the gases,
and fusing basin or smelting pot. The same caloric is employed in the
apparatus whether for the fusion or refining of metal.

page_text: The characteristic features of novelty constituting my economical
principle of manufacture embrace an ensemble of elements comprising
the peculiar combinations of apparatus as well as the modus operandi,
points which I shall describe by aid of the accompanying Drawings,
which represent apparatus destined to serve in the manufacture of
coarse metal, and in reheating for forging, combining the requisite
conditions for attaining a very high temperature, whilst at the same
time effecting a notable economy in fuel with the advantage of burning
all kinds of combustibles, coarse or otherwise, coke, coal, turf, peat, and
other substances, simultaneously utilizing the caloric for fusing the cast
iron and heating the furnace of the refining laboratory. These systems
are arranged to work at will with free or forced air, hot or cold, simple
or mixed, with steam or vapour of water doubly employed, for cooling
the body as well as the basin of the puddling furnace and serving to
quicken the furnace.
Fig. 1 is a section of an apparatus with hearth having inverted flames
and double grates, one oblique, the other horizontal; Fig. 2 is an end
view, the door being removed; Fig. 3 is the fusing basin; Fig. 4 is a
middle section of the regulating register.
This system is distinguished from those actually employed, first, by a
the elliptic arch A, which follows an inclination almost parallel with
the oblique grate B for forcing the gases to descend and sweep the canal
generator X, and are forced to traverse the incandescent coal (being
confined by the elliptic arch A¹) before reaching the laboratory of the
refining basin H; secondly, by the canal generator X, which consists of 2
an horizontal grate regulator D movable in any position, connected to
the oblique grate B, having the elliptic arch A', which is united with
the arch A of the grate B in such wise that the air, free or forced, or
the fluid of combustion which simultaneously traverses the two grates B
and D, actively induce the combustion of the gases as they traverse the a
incandescent coal on the horizontal grate D and the confined canal X.
The oblique grate B is formed of wrought or cast iron bars on which
refracting bricks are placed, the object being to heighten the drawing of
the fire. The horizontal grate D is rendered movable by means of two
turning and eccentric supports E, E, which raise or lower it at will, a
moving it backwards or forwards, thus forming a regulator of the grate
for combustion by increasing or decreasing the canal X.

page_text: I should here mention that this canal regulator effects the combustion
of the gases as completely as possible, its dimensions being variable
and subordinate to the nature of fuel employed and the quantity of the
gases to burn; if the latter should be very abundant and difficult to
burn the canal should be lengthened more than six feet, so as the better
to prepare them for complete combustion, that is to say, so that no
smoke is seen at the top of the chimney. In this case I place the
horizontal grate D at the end of the generator X, which should always
be inclined, as shown in Fig. 5, so as to facilitate the descent of the
incandescent fuel with which it should be well furnished. In all
cases the plan of the arch of the puddling furnace, Fig. 5, should be
followed, which is very elliptic and completes combustion, and obviates
lengthening the canal X.
When small spare fuel is burnt which can only produce gas and
cinders, without producing incandescent coal capable of furnishing the
canal X and the horizontal grate D, for instance, turf, tan, sawdust, or
too fine wood, I add a portion of coke or coal with which to garnish the
grate D as far as the arch A' as desired, so that the gas produced is
forced to traverse this bed of incandescent coal to reach the refining
laboratory. In this case the coke or coal is introduced by the doors F, F,
made in one side of the apparatus in such a manner that it spreads itself
naturally on the grate D, where it rapidly ignites.
When only wood or charcoal is used, iron and steel of an excellent
quality is produced, which advantageously replaces the charcoal iron
obtained by the ordinary refining furnaces.
The apparatus, Figs. 1 and 2, differs again from those usually
employed by the fusing basin G (which is also used for reheating)
being placed in front of and above the level of the refining basin H, so
as to cause the melted metal to fall directly into the latter by aid of the
sheet iron conduit I, lined with refracting brick and communicating
with the orifice R of the basin G. Between the refining laboratory H
and the escapement or flue S is the key or regulating register (J, Fig. 4)
with air currents drawn by the draught of the chimney; it is formed of
two rows of bricks supported by a piece of iron, between which the
drawn air passes, and the whole may be raised or lowered in a cast-iron
guide placed finely on the arch of the furnace. The arch V is arranged
above the refining basin H with projecting inside, so as to retard the
escape of gas or flame. These gases lighter than the air rise naturally

page_text: to the arch V, where they come in contact with the projections instead
of an even surface, as is ordinarily the case, and strike against the
projections or steps and reflow whirling; the result being a more
perfect assimilation of the gases still carbureted and unburned with the
oxygen, which instantaneously effects combustion. The great fire-
bridge K, the height of which is great, and is necessitated by the level
of the fusing basin G, presents the important advantage of protecting
the metal against the current of air which is established here.
Below the apparatus a gallery L is arranged, which runs its whole
length, and acts as conduit and generator of hot air; small jets of water
are introduced into this gallery sufficient to be absorbed and converted
into steam. At the end of the side of the flue S a current of free or
forced air is introduced by the conduit M, which debouches in the
gallery, and there overruns all its parts, in mixing with the steam cools
the plates of the body, and the fusing basin acquires heat and passes out
in front of and below the hearth, into which it penetrates by the grates B
and D, and by the tuyeres, forming a very active fluid of combustion.
This air current can therefor serve to cool the basin of the puddling
furnace H in causing it to pass right round the exterior mantle, as
shown by the arrows Fig. 5, by an entry made below the bottom, and
in causing its exit by the opposite opening, from whence it is directed
below the grate, which it traverses by the natural aspiration of the
hearth, in front of which is a door N for attending to the grates, and
for closing the air gallery; it is opened and closed by an up-and-down
movement with counterbalances, in the same manner as the ordinary
furnace doors. The fusing basin G is placed between the hearth and
the refining furnace H, because the temperature for melting the metal
is higher there than at the escapement, where the small furnace is
usually placed, and also because the carbon which disengages itself
from the cast iron during fusion increases the caloric, the result
of which is that by the several arrangements above mentioned an
extreme temperature is produced in the refining furnace H, where
the cast iron is refined in the best manner with a consumption of fuel
relatively small.
The apparatus shown in longitudinal section, Fig. 5, consists of a
cupola furnace with inverted flames with tuyeres t, t, t, and fusing
basin P, canal generator X, elliptical arch A', horizontal grate D. The
refining basin H separated from the fire-bridge K receives the cast iron

page_text: of the basin P. The regulator J is the same as in Fig. 1 between the
basin H and the flue S, only there is a space Q forming a small furnace
wherein to place the bars for melting, and thus profiting by the heat lost
in heating them before they are thrown into the cupola. By the
conduit M air is admitted as before described for cooling the mantles
of the basin H and its body, and at the same time to encourage com-
bustion by a forced drawing.
The circular form of the refining basin H, Figs. 1, 5, 6, and 7,
constructed of sheet or cast iron contributes greatly to the encourage-
ment of decarbonization by reason of its very inclined form offering a
greater surface of metal to the action of the air, where the metal is
refined progressively, lodging itself all over the circumference of the
interior mantle of the basin, whose great inclination avoids reparation
whilst working. In order to gain all the advantages consequent on the
configuration of the basin, 1 employ my system of rotative tools and
compressed air, for which I obtained Letters Patent on the 5 November
1866.
The cupola furnace is generally employed when cast iron and broken
iron are to be melted. The metal is melted in the basin P, and is
thence directed by a gutter or by means of ladles to the refining
basin H. When a gutter is used the level of the reservoir P is raised
above the basin H. The charges are supplied as in the ordinary cupolas
with ascending flames by layers of coal and metal. If the second fusing
basin H is dispensed with, the plan Fig. 5 is adopted, and advantage is
again taken of the lost flame to heat the cast iron placed in the small
furnace Q. Finally, in case it should not be desired to melt the metal
in the cupola, the canal generator X is used without a fusing reservoir,
and with a regulating grate similar to Fig. 1, with turning and eccentric
supports.
Old burnt castings and scrap or broken iron soiled with impurities,
which could not be used in an ordinary puddling furnace, may be recast
in my cupola with an excellent result, without necessitating for the
operation an increase of fuel, since the combustible gases serving to
melt the metal are employed for refining purposes.
When a superior quality of metal is desired, the cupola is used in the
following manner :-Good cast iron and the best broken iron only is
employed, which is melted with charcoal and torrefied wood, and steel
and iron is produced superior to that refined with wood.

page_text: It will be observed that by the very elliptical form of the arch A¹ of
the canal X and of its inclined position, it is extremely easy to regulate
the fire by agglomerating the coal at the end of the grate D, where it
naturally tends to bear, and narrows the canal and slackens the escape
of the gases by forcing them to traverse this bed of incandescent com-
bustible; but the most remarkable feature of economy in this system is
the utilizing of the same caloric of the cupola for refining the metal.
Nevertheless, if the combustible should be of a nature to give insufficient
flame for heating the fusing basin at the same time as puddling the
cupola Fig. 6 should be employed, which consists in utilizing the lost
heat of the puddling furnace H mixed with that which escapes from the
cupola C for preparing the metal placed on the upper part of it before
throwing it into it. The melted metal runs from the gutter R into the
basin H. The blocks of metal placed round or in proximity to the
mouth of the cupola, heated by the heat from the chimney o of:
the puddling furnace, are ready for melting when they are tumbled into
the cupola. Besides this economy in fuel, by this arrangement there is
always sufficient melted metal to supply several puddling furnaces;
there are always 5 or 6 charges heating and melting simultaneously.
U is the canal of the cupola communicating with the chimney O; N is
the door for attending to and cleaning the crucible of the cupola; T is
the tuyere, and J, the register.
Fig. 7 is a section of a cupola adapted for returning the flame for
heating steam generators, which necessitates inverting the flame after
it has heated the blocks of the small furnace arranged at the head of
the cupula C, and force the flame to redescend, otherwise there is no
difference from that of Fig. 6, where the lost flame rises instead of
descending after having been employed on the bars for melting.
A greater homogeneousness of the products is effected, 1st, by a
superficial purification of the metal to free it from sand and other
foreign substances, by submitting it to a preliminary fusion in a basin
separate from where it is refined, where it should be worked whilst
mixing, to which the greatest energy of action is applied by aid of my
system of rotating tools before mentioned. 2ndly, in throwing the
incandescent metal in a current of cold water as soon as it has attained
the degree of decarbonization which converts it into steel, that is to say,
as soon as the metal is ready to form the loop, whilst spungy and
in disseminated particles; it acquires by this means great hardness,

page_text: rendering it very brittle, at the same time it purifies itself by casting
off the scoriæ surrounding it, and the sulphureted hydrogen which
disengages itself; this latter may be collected and used as combustible
gas, or for lighting or any other purpose. 3rdly, by breaking up these
picces of rough tempered steel so as to effect a great separation by
reducing them to small grain under stampers, where a current of water
reaches them, so as to separate the scoriæ from the particles of metal,
which when in a pulverized state is dried by being submitted to strong
ventilation. 4thly, by making a most intimate mixture, either by hand
or mechanically, of all the broken metal, which is worked together in
such a manner that the products of all the charges are equally spread
throughout the whole mass, so as to form a homogeneous composition
weighing several hundred tons. Its homogeneousness is tested by taking
small quantities of the metal from various parts of the mass, and making
a separate analysis of them; when too sensible a difference exists, they
are remixed until a uniform composition is obtained. A preliminary
trial of the crushed metal is then made for producing either cast steel,
refined steel, or iron, and should the result of the trial not conform to
the nature of metal desired, a proportionate quantity of carbonizing or
decarbonizing matters are added until the quality required is attained;
a fresh and intimate mixture of the whole is then made, after which the
melting or refining takes place with the certitude that the metal thus
manufactured will be identical with the specimens. By this it will be
observed that all difficulties encountered in the usual methods employed
for effecting homogeneousness of the mass, and where it is necessary to
operate on the metal in a state of fusion, or remove by hand too great a
quantity is avoided. The rough metal being thus prepared its compo-
sition and homogeneousness being insured by the analysis for producing
cast steel the fusion is effected in crucibles, or by other means ordinarily
employed.
For obtaining refined steel, a charge of steel ingrain is introduced into
the refining basin and made almost level; this is covered with a layer
of powdered charcoal about three-quarters of an inch thick, on which is
spread another layer of wood ashes, mixed with clay and silicious sand
or powdered glass to protect the metal against the decarbonizing action
of the air. The metal is then heated till it has attained a sufficient
temperature to weld it; the whole is then heaped together by aid of
a rotary tool round at the end and very heavy, which is moved about for
some time all over it; a compact mass is thus formed, which is quickly

page_text: and successively removed in loops without troubling about their form,
and are immediately conveyed to the steam hammer, where they are
converted into lumps or blooms. These pieces whilst still hot are placed
in the fusing basin, where they are reheated. To avoid superficial
decarbonization they are sprinkled over with silicious sand mixed with
from five to ten per cent. of prussiate of potash, and when they reach
a red welding heat they are rolled into bars if they are to be forged;
otherwise they are again made into lumps; if steel is to be made unforged,
and whilst the reheating takes place, a fresh charge of grain metal is
introduced in the refining basin.
In manufacturing fine grain iron, the charge is similarly made, with
the exception that instead of covering it with carbonizing matters, the
metal is garnished with a layer of rich oxyd of iron or fine burnt scrap
iron. These oxyds in fusing traverse the metal and effect its decar-
bonization. All the lumps, loops, or blooms are made before removing
the first, and they are thoroughly heated, rolling them in the scoria
or dross in fusion before shingling.
To obtain sinewy iron the grain metal is constantly turned by means
of a rotary cutting tool, which progressively separates and unites it
whilst heating before forming the loops or blooms.
The advantageous results characterizing the special novelty of this
Invention are the following
First. Obtaining from coarse metal different kinds of iron and steel, as
pure as possible and very homogeneous, with the remarkable difference
that the refining process does not terminate in the middle of the scoria
arising from the impurities of the iron, as is the case in the ordinary
puddling process.
Secondly. Readily producing in large quantities metal whose homo-
geneousness and character can be previously insured with certainty by
analysis compared and modified at will, by adding either carbonizing or
decarbonizing matters, which are spread throughout the mass of coarse
metal and very regularly on account of the great separation of the
pulverized metal.
Thirdly. Increasing the production by quickening the charges with
.cast iron always in a state of fusion, and emptying it directly into
the puddling furnace with an augmentation of fuel.

page_text: Burnt Castings.
Fifthly. Obtaining products advantageously, replacing much more
costly iron and steel produced by wood fire refineries.
Sixthly. The capability of burning all kinds of fuel, large or small,
wood, coal, anthracite or stone coal, turf, lignite, tan, sawdust, very
fine slender wood.
Seventhly. Producing a more perfect combustion of the gases emitted
from the fuel, and at the same time employing the caloric for the
fusion, forging, refining, and heating of the steam generators.
.
Finally. Readily producing several thousand tons of iron or steel of
a most homogeneous nature, and obtaining with low priced matters in
the first instance products of good quality.
What I claim therefor as my exclusive privilege is, the herein-before
recited economical method of manufacturing homogeneous iron and steel
in large and unlimited quantities by means of the principles already
stated and illustrated by the accompanying Drawings, especially,-
Firstly. The method employed for effecting a great separation of the
metal by protecting it while in an incandescent state in a current of
cold water, rendering the metal thereby extremely pure and easy to
crush, by which means the homogeneousness of a great mass of metal
is easily secured, the nature of which may be modified by cold in a
decided manner, so that any desired metal can be produced.
Secondly. The principle of the grate with inverted flames, the canal
generator and regulatar, with movable and regulating grate; the
fusing and reheating basin placed in front of the refining furnace, as
well as the system of cupola combined with the puddling furnaces, for
economically producing hot cast iron.
In witness whereof, I, the said Pierre Adolphe Dormoy, have
hereunto set my hand and seal, this Twenty-second day of
January, in the year of our Lord One thousand eight hundred
and seventy-two.