CERTAIN IMPROVE- MENTS IN ATTARATUS ON FURNACES FOR DIELTING AND FUDDLING METALS.
Year: 1856

page_text: LETTERS PATENT to Pierre Louis Grosrenaud, Engineer, at St. Etienne,
Town in the French Empire, for the Invention of "CERTAIN IMPROVE-
MENTS IN ATTARATUS ON FURNACES FOR DIELTING AND FUDDLING METALS.
Sealed the 8th August 1856, and dated the 28th February 1856.
1
PROVISIONAL SPECIFICATION left by the said Pierre Louis Grosrenaud
at the Office of, the Commissioners of Patents, with his Petition, on the
28th February 1856.
I, PIERRE LOUIS GROSRENAUD," Engineer, at St. Etienne, Town'in the
French Empire, do hereby declare the nature of the said Invention' for
"CERTAIN IMPROVEMENTS IN APPARATUS OR FURNACES FOR MELTING AND PUDDLING
METALS," to be as follows:-
My Invention consists in an improved arrangement of furnace, whereby
fuel is economized and heat applied more directly to the required parts; and
also in the construction of elongated crucibles or melting pots."
My furnaces are of two descriptions; in one description they are provided
with one or more melting pots, in the other they are reverberatory furnaces
modified in such manner as to allow of a higher temperature than in rever-
beratory furnaces of the ordinary construction. The principal difference is in
the method I adopt for heating, or 'rather for accelerating combustion. Both
classes of furnace may be made moveable.

page_text: Figures 1 to 12 of the annexed Drawings illustrate my improved furnaces.
Figure 1 is a vertical section of a furnace, constructed according to my
Invention. A, fire-place (with fire brick casing) for the reception of the fuel,
which may be carbonized coal or coke of a good quality; B, furnace mouth or
feed plate, which should be kept always filled with fuel, to be there dried and
prepared for consumption. The fuel is pushed into the furnace a little at a
time, and at equal intervals, so that the temperature is regularly kept up.
C, ash-pit; the slag and cinders which accumulate here should be heaped up
thickly to prevent the air from the blowing machine, herein-after referred to,
escaping therefrom; D, D, two nozzles converging towards the furnace, as
shewn in Figure. 2, through which air from a blowing machine is blown into
the furnace at a degree of pressure, regulated according to the density of the
fucl; E is the chamber for the melting pots-I, I, encased in fire brick; H, floor
for the melting pots. Figures 3 and 4, views of furnace adapted for 7 melting
pots.
Figures 5, 6, and 7 are modifications, in which there are no sides to the
melting pot floor. In long furnaces there may be several mouths for the
admission of fuel, and the flame is allowed to escape through several flues, so
as not to concentrate the heat in any one part to the prejudice of the others.
By stopping up any one of these flues, the heat may be brought to bear more
strongly on any desired point of the furnace, if required. This description of
furnace is well adapted for melting easily fusible metals or substances such as
glass. F, flue for collecting the flame and products of combustion after they
have acted on the melting pots, and conducting them into the chimney G,
which may be common to several furnaces. The flames may be carried off
from the flue, and applied to heat the generator, of the steam engine, which
works the blowing machine, as shewn in Figure 3.. If the blowing machine
is actuated by other than steam power, the flames might be employed to heat
the air blown into the furnace. If waste heat should not be sufficient for the
boiler and to heat the air, an extra furnace might be employed. The furnaces
may be placed either in rows one on each side of a horizontal steam generator,
as is the case with furnace Figure 3, or arranged around a vertical generator.
While the furnace is at work the mouth of the chamber E is closed by a cover
consisting of fire bricks in an iron frame, and formed with an aperture near
the middle, closed with a fire clay cover, and through which the progress of
the operation may be inspected, and a poker introduced when needful. Each
nozzle is provided with a valve a to regulate or shut off the supply of air. If
very fine coal is used, a grate b may be employed, (as shewn in Figure 5,) under

page_text: which a draft of air is admitted by a passage; J, door for closing the ash-pit.
If a coarse description of fuel is employed, not easily fusible, prejudicial effects
might arise from the large quantity of cinders produced, which would soon
block up the furnace, and have to be frequently removed, whereby cold air
would be admitted into the furnace, and this (especially in fusing steel) would
of course be detrimental to the operation. To remedy this, I adopt an arrange-
ment for mixing the fuel with a quantity of some substance capable of
facilitating the fusion of the cinders, &c. If the fuel is damp, I divide the
furnace into three parts, a preparatory chamber K, combustion chamber M,
and melting chamber N, (Figures 6). The preparatory chamber K is of a
pyramidal or conical form; the fuel is fed into K from the mouth B, which is
left more or less open for the escape of the steam from the fuel; the height
of this chamber is regulated according to the degree of dryness of the fuel.
The combustion chamber M is the part in which the fuel, deprived of the
greater portion of its humidity, becomes changed into oxide of carbon and
carbonated hydrogen; N, melting chamber; L is a passage for receiving the
gases generated by the distillation of the fuel, and conveying them to a flue o,
which carries them off into another furnace,, before entering which they are
consumed by the aid of a current of hot air admitted through a pipe a. b, b,
tubes for supplying air; in this furnace the coarsest description of fuel may
be employed, even refuse. The length of the flue o, between the mouth of the
tube d to the melting chamber, should be sufficient to effect the mixture
of the hot air and combustible gases which thus retain all their heat.
Figure 3 shews the apparatus contrived for burning dry fuel; the preparatory
chamber is dispensed with; here P is the furnace; Q, mouth for feeding in
fuel; a, tubes for admitting currents of hot air; f, d, flat passages for the
same purpose.
Figures 8, 9, and 10 represent a description of furnace adapted for melting
at one operation considerable quantities. These furnaces are of two descriptions,
one is a fixed furnace with melting pots, having a hole at bottom, through
which the metal may be drawn off when sufficiently fluid, while the other is so
fixed as to allow of its being inclined to discharge the metal from the top of the
melting pot. Figure 8 represents a furnace of the first description; it contains a
single large melting pot A, and may be heated by a number of small furnaces B
(similar to that represented in Figure 1). a, a, nozzles for admitting jets of
air; C, C, mouths for feeding in the fuel; they are to be kept full as before;
D, ash-pit; E, flue; the sides of the melting pot should not be too thick, and
they may be strengthened or supported by bringing the brickwork of the
furnace up to the melting pot (leaving vertical or spiral flues between brick-

page_text: work and melting pot for the circulation of the flame, which is allowed to
communicate with all the flues by a passage provided around the bottom of the
melting pot. For the better distribution of the heat; the melting pot may rest
on horizontal flues. (The melting pot may either be cylindrical; as sliewn, or
a parallelopiped with the angles rounded off):
I manufacture my melting pots of the usual composition, namely, fire clay,
refuse of old melting pots; or quartz but I use it in nearly a dry state, and
form the pots with a powerful hydraulic press; thus the mould of the pot con-
taining a greater quantity of the composition' than is required to form a melting
pot, the cavity will be formed by a plunger driven by the hydraulic press? The
melting pots may be formed with ribs on the outer surface, which come against
the sides of the furnace; and form vertical for spiral's flues. This method.of
manufacture is applicable to melting pots of all shapes and sizes employed in
the metallurgical, arts, and I intend to claim it as of my Invention:
Figure 9 is a view of a furnace which turns" on-bearings or pivots so as to
empty the melting pots from the top, and which-permits of the aperture at the
bottom being dispensed with. The flue and 'chimney may bei perpendicular to
the bearings; the fire-place should be far enough away from the chimney, so
that the bottom may fall clear of it when it is tilted up; or the flue may be
placed in the direction of the bearings and above one or other of them, only
leaving between chimney and fire-place sufficient space for the bearings; or
instead of the flue a funnel-shaped- chimney may be employed, supported in a
frame at a suitable height above the fire-place A (Fig. 10) is the melting
pot, resting on flues and supported by vertical or spiral flues, opening at the
upper part of the furnace; B, B, small fire-places-; C, mouths for the-same;
D,-cover, with an aperture d for the escape of the flame; E, chimney-resting
on the rods e, fixed to uprights f; F, pivots or bearings, supported on standards
G, and connected to the upright f...
Fig. 11 is another modification, in which-a-fixed recess A is employed for
holding the metal to be melted instead of a moveable melting pot. It may be
heated by two furnaces placed one at each end; the flames from which'unité in
a common chimney in the middle of the fire-place, which is an arrangement
very suitable for fusing steel: The orifice through-which the melted metal is
poured out would then be on one of the sides and in the middle of the fire-
place, as in Figure 12. The fire-place-c is charged with fuel through lateral
mouths, or by a mouth D at top, through which an instrument might: be
introduced for pushing down the scoria into the ash-pit.
The furnaces shewn in Figures 8 to 12-may be employed for purifying iron
casting for producing common steel; which I effect! by adding to the metal in

page_text: a state of fusion, a certain quantity of pure iron. The cast iron may be
decarburetted by adding very pure oxide of iron.
.
The furnaces 1 to 10 are well adapted for puddling and soldering metals.
The bars of metal are heated suddenly in the melting pots which keep them
from contact with the air, and 'so prevent oxidation and decarbonization,
whereby the metal would sustain very trifling waste. To assist the removal of
the layer of oxide on the bars, they should be immersed in clayey water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Pierre Louis Grosrenaud in the Great Seal Patent Office
on the 27th August 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,. PIERRE
LOUIS GROSRENAUD, Engineer, at St. Etienne, Town in the French Empire,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, .by Her Letters.
Patent, bearing date the Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and fifty-six; in the nineteenth year of Her.
reign, did, for Herself, Her heirs and-successors, give and grant unto me, the
said Pierre Louis Grosrenaud, Her special licence that I, the said Pierre
Louis Grosrenaud, my executors, administrators, and assigns, or such others
as I, the said Pierre Louis Grosrenaud, 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 In-
vention for "CERTAIN IMPROVEMENTS IN APPARATUS OR FURNACES FOR MELTING AND
PUDDLING METALS," upon the condition (amongst others) that I, the said Pierre
Louis Grosrenaud, 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 Scal 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 Louis Grosrenaud, 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 thereof, reference being had to the Drawings hereunto
annexed (that is to say):-

page_text: The present Invention is intended to meet the defects of furnaces for melting
and puddling metals as hitherto constructed, in which the highest temperature
is expended in parts where it is liable to exercise a detrimental effect on
the material of which the furnace is constructed, and wliere it is compara-
tively of no service for beating purposes, thereby. occasioning costs of repair,
delaying the operations, and expending fuel disadvantageously. Now;
my Invention consists in an improved construction and arrangement of
furnace in which fuel is economized, and the beat applied more directly to
the required parts, and also in the construction of elongated crucibles or
melting pots.
จ
My improved furnaces are of two descriptions; in one description they are
provided with one or more melting pots; in the other they are reverberatory
furnaces, but modified in such manner as to allow of a higher temperature
being attained than in reverberatory furnaces of ordinary construction, tho
principal difference being in the method I adopt for heating, or rather for.
accelerating combustion. Both classes of furnaces may be made moveable..
The Drawings annexed explain the nature of my Invention, and the manner
in which the same is carried into effect.
Figure 1 is a sectional elevation of a furnace constructed according to my:
Invention; Fig. 2, a horizontal section of the same, on the line a, b, of
Figure 1; Fig. 3 is an clevation (partly in section) of a similar furnace;
Fig. 4, horizontal section through the line g, h, of Figure 3; Figure 5, front
view; Fig. 6, top view.
A is the fire-place with fire-brick casing for the reception of the fuel, which,
may be carbonized coal or coke of good quality; B is the furnace mouth or
feed plate, which should always be kept filled with fuel, to be there dried aud
prepared for consumption; instead of being supplied into the fire-place with
its watery particles, the volatilization of which therein would absorb a portion
of the caloric, the fuel is pushed into the furnace a little at a time, and at
equal intervals, so that the temperature is regularly kept up, which is very.
important when the furnace is employed to melt metals of a not easily fusible
character, such as steel. D, D, are two nozzles converging towards the furnace,
as shewn in Figure 2, through which air from a blowing machine is blown into
the furnace at a degree of pressure regulated according to the density of the
fuel; E, chamber for the melting pots I, I, encased in fire-brick; H, floor for
the melting pots.
Figure 7 is a vertical, and Figure 8 a horizontal section of a furnace.
adapted for seven melting pots. C is the ash-pit. The slag, cinders, &c.,
which accumulate in the front of the ash-pit should be heaped up in thick

page_text: masses, to prevent the air injected by the blowing machine from escaping
through the ash-pit. The cinders may be removed therefrom from time
to time.
Figure 9, vertical section, and Figure 10, horizontal section through the line.
x, y, of Figure 9, represent a furnace of the same description, constructed
to receive eight melting pots, four on each side.
Figures 11 and 12 are modifications, in which there are no sides. to the
melting pot floor. In long furnaces there may be several mouths for the
admission of fuel, and the flame is allowed to escape through several flues, so'
as not to concentrate the heat in any one part to the prejudice of the others.
By stopping up any one of these flues, the heat may be brought to bear more
strongly on any desired point of the furnace, if required. This description of
furnace is well adapted for melting easily fusible metals, or substances such as
glass. F is à flue, shewn also in Figs. 1 'and 3, for collecting the flame and
products of combustion after they have acted on the melting pots, and for con-
ducting them into the chimney G, Fig. 1, 4, and 6, 11, and 12, &c., which may
be common to several furnaces. The flames may be carried off from the flue,
and applied to heat the generator of the steam engine, which works the blowing'
machine, as shewn in Figures 7 and 8. If the blowing machine is actuated'
by other than steam power, the flames might be employed to heat the air
blown into the furnace. If waste heat should not be sufficient for the boiler`
and to heat the air, an extra furnace might be employed. The furnaces may
be placed either in rows, one on each side of a horizontal steam generator, as
is the case with the furnace shewn in Figure 7, or arranged round a vertical
generator, and in that case the waste products of combustion from each might
be carried off into a spiral or other flue, embracing the generator up to the
water level. While the furnace is at work the mouth of the chamber E is
closed by a cover consisting of fire-bricks mounted in an iron frame, and
formed with an aperture near the middle, also closed with a fire-clay
cover, and through which the progress of the operation may be inspected,"
and a poker introduced to stir the fuel, or when otherwise needful. The.
melting pots are placed in my improved furnaces as in a furnace of ordinary
construction, and may be removed by opening the moveable cover gradually,
in case the heat should inconvenience the workman when the cover is
entirely raised or opened. Each air nozzle D, D, is provided with a valve*
or tap, for regulating or shutting off the supply of air to the furnace."
When the operation is commenced the flue may be left quite free or open,
so that the heating of all parts of the furnace may be accelerated, but when
the furnace is in full work, and the temperature very intense, the heat may be:

page_text: concentrated round about the melting pots, by partially stopping up, the
passage through, the flues by means of a piece of fire-brick (which may be
easily put in and taken out) or otherwise. If very fine coal is used, or coal
yielding very little, cinder, the form of the furnace may be modified, as, for
example, a grate of the description shewn in Figs. 11 and 12 may be,
employed for burning fine coal. This, grate, may be adapted to any of the
furnaces shewn in Figures 1 to 10; the height to which the fuel reaches will
be, nearly always the same as when it rests on the cinders or scorice produced.
during the operation. To support combustion a current of air may be admitted
under the grate through a pipe opening beneath it, the ash-pit being, closed by
a register J (Figs. 11 and 12). If a coarse, description of fuel is employed,
or, cinders not easily fusible, prejudicial effects might result from the large
quantity of cinders so produced, which would soon, block up, the furnace
and, have to be frequently removed, whereby cold air, would be, admitted
into the furnace,, and, this. (especially in fusing steel,, and other metals, of
a refractory nature) would prevent the metal acquiring a proper degree of
liquidity, and would be of course detrimental. To remedy this, I adopt
an arrangement for mixing the fuel, with a quantity of some substance.
capable of facilitating the fusion of the cinders, as foundry scoria, for example..
If the fuel is damp, I divide the furnace into three parts,, a preparatory
chamber K,,combustion chamber M, and melting chamber.N (Figs. 9 and 10).
The dimensions and forms of these parts may be, varied according to the nature
of the fuel. The preparatory chamber K may be of a pyramidal or conical
form, as shewn in Figures 9 and 10. The fuel is fed into the chamber from
the mouth B, which is left more or less, open for the escape of steam and gas
from, the, fuel. The height of this chamber is regulated according to the
degree of dryness of the fuel. The combustion chamber M is the part in
which the fuel, having been deprived of the greater portion of its, humidity,
becomes changed into oxide of carbon and, carbonated hydrogen. The melting
chamber N is the part in which the melted substances are collected. The
object of the preparatory chamber is to dry the fuel, and prepare it for the
distillation it afterward undergoes in the combustion chamber; the furnace
mouth being open to allow of the escape of the steam and gas. The fuel
in the chamber, offers, so strong a resistance to the gases formed beneath it;
as to force these gases to collect in a flue or passage L,.which passes round
the furnace, at the part where the chambers M and K meet.. From this
passage. L the gases are carried off through a flue o into another furnace,
before entering which they are burnt or consumed by the aid of a current, of
hot air admitted through a pipe d, through, two flattened horizontal pipes
.
***

page_text: opening at opposite sides of the space A, which serves as a furnace or com-
bustion chamber when fine coal is used. This arrangement is shewn in Figure 9.
1; 1, are pipes for supplying hot air to the furnace; these pipes are on opposite
sides, of the chamber N; but their axial lines are not precisely. opposite cach
other. In. this furnace the coarsest. description of fuel may be employeil,
even refuse, in which case, however, pieces of coal should be mixed with.it.
The length of the flue O between the mouth of the tube.d to the melting
pots should be such as to allow of the mixing of hot air and combustible gases,
which thus retain all their heat, and afford the highest temperature they are
capable of. If, however, dry fuel is used, I then simplify the construction of
the furnaces, and fulfil satisfactorily the important condition of burning the
gases at the point where they are formed, but dispense with the preparatory
chamber. '
Figures 7 and 8 shew apparatus in which dry fuel is to be employed. Pis
the furnace; Q, mouth; képt filled with fuel, which is here gradually, heated
before falling in the furnace, and liberates itself from the trifling amount. of
humidity which it may yet contain. The driest possible fuel should be
employed, and it should be frequently fed in 'and in small pieces. Combustion
is supported by streams of air admitted through tubes a', a', under pressure,
in proportion to the degree of density of the fuel, and to the size of the pieces.
On account of the height of the mass of fuel above the tubes, the carbonic
acid which is first formed becomes: changed into oxide of carbon. When .it
comes to the upper part of the furnace currents of air are thrown in through
the flattened tubes opening on the two opposite sides of the furnace, and serve
to re-transform the oxide of carbon into carbonic acid gas, which..undergoes
combustion near the bottom of the melting pots, resting on the floor H of the
chamber E; the floor H is formed on three out of the four sides of the upper
part of the furnace P. F is.. a flue, through which..the flames and certain
products of combustion escape after having passed round and heated the melting
pots, while the heat still. retained in the. flame may be applied to the heating
of the steam generator which actuates the blowing machine.
My furnaces, which I have: previously described, are chiefly intended: for
comparatively small melting pots, containing, say,..from 50 to 60 lb. metal;
and which have to be taken from the fire to run the metal into bars or moulds,
and are, therefore, not so well adapted for important operations: To adapt
these furnaces for larger quantities of metal, I construct them so that they.
may receive one or more melting pots of large capacity. The dimensions and
capacity of the furnace should be regulated according to the character of the
metal under treatment; thus, for example, steel requires a very high tempera-

page_text: ture, wherefore furnaces intended for steel should be so constructed as to
allow of the heat being well concentrated.
My furnaces intended for melting large quantities of metal at one operation
are of two descriptions; one description, stationary, having melting pots with an
orifice at bottom, through which the metal may be drawn off or run into bars
and moulds when sufficiently fluid; the other is so arranged as to allow of
its being inclined to discharge the metal from the top of the melting pot.
These furnaces are represented in Figures 13, 14, 15, and 16 of the annexed
Drawings; Figures 13 and 15, (vertical sections); Figures 14 and 16, (hori-
zontal sections).
.
In Figure 13, A is a single melting pot of large dimensions, which may be
heated by gas or by a number of small furnaces B, similar to those repre-
sented in Figures 1 to 6. a², a², are nozzles for admitting jets of air to support
combustion; C, C, mouths for feeding in the fuel; they are to be kept full
as before. The opening of the furnaces is closed by a fire-clay diaphragm,
which forces the flame to pass through a flue E¹, leading into a chimney, which
may be common to several furnaces. D¹ is the ash-pit. The sides of the
melting pot should not be too thick, in order better to conduct the heat, but
they may be strengthened or supported by bringing the brickwork of the
furnace up to the melting pot, to prevent its breaking under the pressure of
the metal, but vertical or spiral flues should be left between the brickwork and
melting pot for the circulation of the flame which is allowed to communicate
with all the flues by passing into a passage formed round the bottom of the
melting pot; for the better distribution of the heat the melting pot may rest
on horizontal flues. The melting pot may either be cylindrical, as shewn, or
of parallelopipedal form, with the angles rounded. off.
I now proceed to describe the manner in which I manufacture my improved
inelting pots. I manufacture my melting pots of the composition hitherto
employed for that purpose, namely, fire-clay, refuse of old melting pots, or quartz,
but I use it in nearly a dry state, and form the pots with a powerful hydraulic
press. Thus, the mould of the melting pot containing a greater quantity of
the composition than is required to form the pot, the cavity will be formed by
a plunger driven in by the hydraulic press. The clay, which forms a compact
mass at the bottom of the mould, will fill up the space between the sides of
the mould and those of the plunger, and the excess comes out through
openings left near the edges of the mould, the diameter of which is calculated
by the pressure to which the melting pot is to be subjected. Melting
pots of any reasonable capacity may be thus manufactured, and they will
bé found capable of resisting the high degree of heat to which they are

page_text: subjected, and the pressure of the metal. The melting pots may be formed
with ribs on the outer surface, which come against the sides of the furnace,
and form vertical or spiral flues. This method of manufacture is applica-
ble to melting pots of all shapes and sizes employed in the metallurgical
arts. In using these furnaces, care must be taken to prevent the steel
from making a passage for itself between the sides of the discharge hole and.
the fire-clay stopper by which it is closed. The layer of metal or scorice which
may remain after the metal has run out, must be carefully removed to prevent
leakage. I also employ moveable furnaces, suspended about the height of
their centre of gravity on two pivots or bearings, so that by tilting the furnace,
the melting pots may be emptied or discharged from the top, whereby the orifice
at bottom may be dispensed with, as also the chamber beneath into which the
melted metal is run out, and which may in these furnaces be employed for the
reception of a fire-place; three or more fire-places may be used. If a square
melting pot is employed, there should be a fire-place at each of the four sides..
The flue and chimney should be placed in a perpendicular position to the line
of the bearings (Fig. 20); and the furnace should be at a sufficient distance
from the chimney, so that the bottom may come clear of the chimney when.
the furnace is tilted up to run out the contents; or the flue may be placed in
the same direction as the bearings, and above them; there would then be only
just sufficient space between the chimney and furnace to place the bearing,
and the flue would not be so long. The furnace is connected to the flue
which leads into the chimney by a branch g (Figure 20), which after every
running off of metal is stopped up by a fire-clay stopper; or instead of the flue
a funnel-shaped chimney may be employed, supported on a frame or standards
at a suitable height over the fire-place.
A, Figures 14, 17, is a melting pot resting on flues, and supported by
vertical or spiral flues opening at the upper part of the furnace; B, B, small
fire-places; C, mouths for the same; D³, cover or plate, with an aperture d³
for the escape of the flame; E, chimney resting on rods e³, e, fixed to uprights
ff, embedded in the earth; F, pivots or bearings supporting the furnace ;.
these bearings are mounted in standards G, and connected to the uprights f;
II, sheet-iron platform, on which the workmen can get at the door h through
which the melting pot is charged.
Figures 18, 19, and 20 represent a furnace, in which a stationary recess or
chamber A is employed for holding the metal instead of a moveable melting
pot; the chamber may be oblong, square, or circular, or of other suitable
shape, and may be heated by one or two or more furnaces, or by two furnaces
at each end, the flame from which unite in a common chimney in the middle

page_text: of the fire-place, which is an arrangement very suitable for fusing steel, as
it allows of a very high and regular temperature being obtained; the orifice B
through which the melted metal is poured out, will then be on one of the sides
and in the middle of the fire-place C². The fire-place C is charged with fuel
through lateral mouths, or by a mouth D. at top, through which an
instrument might be introduced for pushing down the scoria into the ash-pit
E; the cinders therein should be massed up towards the front to prevent the
escape of the air introduced through the nozzles F'.
Figure 20 shews the position of the flue and chimney when the furnace is
constructed.to. oscillate on bearings F, and the metal is intended to be run out
by the passage C³.
The furnaces shewn in Figures 1 to 6 and 13 to 20, constructed without
fire-bars, and in which. combustion is assisted: by two streams of air
which cross cach other at a more or less obtuse angle, are suited for the
production of very high temperatures, and applicable for fusing and puddling
metals, also for reheating thick bars of steel, for welding bundles of iron. and
steel, which are fed in and removed through the door G in the oblong furnace,
shewn in Figure 18; in these instances the diaphragm H might be dispensed
with. There are. doors with registers or feed plates (not shewn in the
Drawings) in one of the sides of the furnace for the admission of the pieces of
metal to be melted, and also (when the furnace is. used. for. welding. metals)
for the introduction of silex for eliminating the scoria and oxides. interspersed
between the bars of metal. The two furnaces last described (Figures 13 to 20)
may be. applied for purifying or refining iron castings of good quality, and
obtaining therefrom common steel, which I. effect. by adding to the metal in a
state of fusion a certain quantity of pure iron. The cast-iron may be
decarburetted by adding very pure oxide of iron. The high temperature which
may be obtained in these furnaces. would render them applicable for refining
ordinary castings by adding suitable re-agents. To melt. large pieces of steel
or other.metal.by means of my furnaces, by employing the oscillating furnaces
shewn in Figures 13 to 17, and 18, 19, and 20, I arrange a number of these
furnaces in a circle, and place the ingot mould or iron mould. in the centre;
I tilt or incliné all the furnaces at the same time, and pour or run the metal
from them into the ingot or iron mould; or I.melt the metal in small melting
pots in furnaces of the description shewn in Figures 1 to 12, withdraw them
one after another from the furnaces, and pour. their contents into a large
melting pot. of the description. used, with; furnaces shewn in Figures 13, 17, 18,
20; but before receiving the metal the melting pot should have acquired such
a temperature as to prevent the cooling of the steel when poured therein;
.

page_text: when sufficient metal has been poured in, it is run off, either through a holo
at bottom or by pouring it off from the top if a tilting furnace be used.
The furnaces, Figs. 1 to 17, may be used for. welding and puddling metals
when not required for melting metals. The bars or bundles, being composed
of a number of pieces, are heated within the melting pots, which keep them
from contact with the air, and prevent their being decarburetted or oxidized,
whereby but little loss of metal will be sustained on account of the elimination
of clayey matters contained in the iron; to facilitate the separation of the
oxide which covers the pieces of iron, they should be immersed in clayey water.
By this method of puddling steel, free from contact with the outer air, the
steel is not exposed to become decarburetted. The fuel used in my furnaces
for puddling steel should be of a nature to give off but little vapour, as it is
desirable to remove the scorice from time to time so as not to impede the
process. I prefer to use furnaces heated by gas, of the description shewn in
Figures 13, 14, 15, and 16, having an exit for the removal of the scoria as
they are formed.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the improved furnaces herein-before described, and represented in the
Drawings annexed.
And, second, the improved melting pots herein-before described.
In witness whereof, I, the said Pierre Louis Grosrenaud, have hereunto
set my hand and seal, this Sixteenth day of August, in the year of our
Lord One thousand eight hundred and fifty-six.
Witness,
CH. ARMENGAUD, Ing* Civil,
23, Boulev de Strasbourg,
à Paris.
P. L. GROSRENAUD. (L.S.)