IMPROVE MENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1856

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, for the Invention of "IMPROVE
MENTS IN THE MANUFACTURE OF IRON AND STEEL."
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the
15th March 1856.
I HENRY BESSEMER of Queen Street Place New Cannon Street in the
City of London, do hereby declare the nature of the Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL" to be as follows:-
These improvements relate firstly to the peculiar modes by which the
decarbonization or partial decarbonization and refinement of iron is effected
by means of currents or jets of atmospheric air or steam (alone or mixed)
and which is made to impinge upon the surface or pass through or in contact
with the metal while in a fluid state.
Secondly in assisting the decarbonization and refinement of iron by the
use of oxides of iron and in the use of carbonaceous matters during such
process.
And thirdly in the manner in which the metal so treated is formed into
ingots or masses suitable for being afterwards made into bars plates or rods
by the process of hammering or rolling.
19080.

page_text: In carrying the first part of my said Invention into operation in some cases
I force atmospheric air or steam or a mixture of air and steam below the
surface of the melted metal which collects in the hearths of blast and cupola
furnaces used for smelting and founding iron and, to allow the air or steam to
bubble up through the metal and then mingle with the blast used for keeping
up the combustion of the fuel above. So also in like manner I force air
or steam below the fluid metal in the finery or running out furnace used for
the refinement of crude iron such air or steam being conveyed into the iron
by means of fire clay pipes or perforated bricks or by means of iron pipes
protected from fusion by the passage of water air or other cooling fluid
through them or the chamber containing the metal may be partially covered
and the air or steam made to pass beneath such cover in contact with the fluid
metal. When air or steam is thus applied to molten iron in blast or cupola
furnaces I prefer to carry on the process only so far as to refine the iron to
such a degree as will render it suitable for the process of puddling although
the process of refining may be carried on if desired until steel or malleable
iron is produced.
For the process of decarbonization and refinement of the iron without the
use of additional fuel for that purpose I construct a box or chamber of brick
fire stone or iron lined with loam or other slow conductor of heat. The
chamber should be closed except at one end where there is a raised outlet for
the escape of the air steam and aeriform matters produced. At the opposite
end the cover rises so as to form a space for the admission of the air or steam
above the surface of the metal. The metal in a fluid state is run into the
box or chamber (which may be previously heated) so as to fill it up to the
cover and at least a few inches up the raised parts the air or steam is then
forced into the space above the surface of the metal which will be displaced
therefrom and allow the air or steam to find its way along the cover of the
chamber and pass up through the metal in the raised outlet where it will
escape and where the slag formed in the process will also be carried. The
cover may be flat or corrugated or it may have projecting ribs with or without
perforations to obstruct the too easy passage of the air.
•
Another mode by which I decarbonize or partially decarbonize iron in its
fluid state without additional fuel is to run the crude metal into a chamber
constructed of or lined with fire-bricks or other slow conductor of heat and
then direct jets of air or steam on to its surface so as to act on the metal
and its impurities. I prefer to use numerous jets with such force as to
remove the slag from the surface and cause a rapid circulation of the fluid
metal.

page_text: Secondly when the decarbonization and refining of iron is effected by
either of the modes herein mentioned or by any other method in which jets
of steam or air are applied to fluid iron for that purpose and in which the
metal is kept in a fluid state until the completion of the process I force on to
or into such fluid metal carburetted gases or introduce therein fluid or solid
carbonaceous substances in sufficient quantity to combine with any oxide of
iron that may exist in or interfere with the malleability of the metal.
I
Towards the completion of the process of decarbonization and refinement of
the metal it will be found that a portion of the iron is converted into an oxide
I therefore put into the crucible or chamber any suitable carbonaceous matter
such as charcoal anthracite coal or a carbonate of iron that is rich in carbon
such as hematite iron ore in order to reduce the oxides existing in the crucibles
or chambers and thus add to the weight of the charge of metal obtained or in
lieu of putting charcoal into the crucible or vessel with the metal I put charcoal
into a cylinder or other shaped vessel and when it is in a state of combustion
pass air or steam or a mixture of both through the ignited fuel and from
thence into the fluid metal under operation the gaseous products having:
become highly heated before coming into contact with the metal and here I
would observe that the vapours thus forced into the metal may be made to have
a carbonising or decarbonising effect according to the properties in which the
constituents of the different gaseous vapours predominate and whereby I am
enabled to produce malleable iron or steel as may be desired. In the refine-
ment of iron by means of jets of air or steam in crucibles or vessels I some-
times assist the process of decarbonization by putting into such vessels or
crucibles some scales of iron or other iron oxides or iron ore part of which
becomes produced to the metallic state and thus adds to the quantity of metal
while it assists the decarbonising process.
The third part of my said Invention consists in forming masses of refined
iron or steel of a suitable form or configuration for hammering or rolling or
for other purposes by forming the vessel or chamber in which the iron is
refined or partially refined by air or steam of such form and dimensions as
will admit of the metal being retained therein after the process of refinement
until it is sufficiently solidified to be removed therefrom the decarbonising
vessel serving as the mould for giving the desired form to the mass and thus
saving the labour of pouring the refined metal into a separate mould and at
the same time avoiding the unsoundness sometimes caused by pouring the
metal into a separate mould. When however I refine the metal in vessels
unsuited by their form for the formation of ingot or article desired I construct
an ingot mould having a runner or gate communicating with the bottom of

page_text: the mould and extending upwards to the top of it so that the mould is filled
from its lower end the metal rising upwards until it is filled. When the
mould is of iron the runner should be lined with loam to prevent the metal
from becoming solidified therein before the ingot is completed but I some-
times form such ingot mould of porous fire clay fire stone or other slow
conductor of heat so that the metal will retain its fluidity sufficiently long to
allow much of the gaseous matters to escape which would otherwise render
the casting cellular the tendency to this defect in cast ingots may be also
lessened or removed by forming the mould as nearly air-tight as possible it
should be placed so that an opening in the lower part of the mould will dip
into the fluid metal a partial vacuum is then to be formed in the mould by
opening a cock which communicates with the previously exhausted vessel and
by means of which the air occupying the mould will be removed and the fluid
metal caused by atmospheric pressure to fill the mould the metal rising
upwards into the vacuous space without producing that admixture of air which
results from pouring in the metal from above while the lessened pressure of
the air above the surface of the metal will assist in the disengagement of any
gaseous matters contained therein.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed.
by the said Henry Bessemer in the Great Seal Patent Office on the
15th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME I HENRY
BESSEMER of Queen Street Place New Cannon Street in the City of
London send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Fifteenth day of March 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 Henry Bessemer Her special licence that I the said Henry
Bessemer my executors administrators and assigns or such others as I
the said Henry Bessemer 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 THE MANUFACTURE OF IRON AND STEEL," upon the condition (amongst

page_text: others) that I the said Henry Bessemer 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 Henry Bessemer do hereby declare
the nature of the 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, that is to say
In the Specification of a Patent granted to me for "Improvements in the
Manufacture of Iron and Steel" bearing date the Twelfth day of February
One thousand eight hundred and fifty-six I have shewn how by means of jets
or currents of air or steam the process of decarbonization of crude or pig iron
is made to produce a pure or nearly pure steel or malleable iron and how
I retain by such means the malleable metal in a fluid state so as to allow of
its being poured or run into ingots or masses capable of being afterwards
hammered or rolled. It may be desirable that furnaces now used in smelting
remelting and refining iron should be made use of in their present state for
or be altered and adapted to the carrying out of my new mode of working
with jets of air or steam and thus by a single process produce iron more or
less decarbonized according to the object to which it is to be applied and
my present Invention relates firstly to the peculiar modes by. which the
decarbonization or partial decarbonization and refinement of iron is effected
by means of currents or jets of atmospheric air or steam (alone or mixed) and
which is made to impinge upon the surface or pass through or in contact with
the metal while in a fluid state secondly in assisting the decarbonization and
refinement of iron by the use of oxides of iron and in the use of carbonaceous
matters during such process and thirdly in the manner in which the metal
so treated is formed into ingots or masses suitable for being afterwards mado
into bars plates or rods by the process of hammering or rolling.
In carrying the first part of my said Invention into operation in some cases I
force atmospheric air or steam or a mixture of air and steam below the surface
of the melted metal which collects in the hearths of blast and cupola furnaces
used for smelting and founding iron and to allow the air or steam to bubble
up through the metal and then mingle with the blast used for keeping up the
combustion of the fuel above.
The mode by which this part of my Invention may be carried into practical
operation is represented on the Sheet of Drawings hereunto annexed where

page_text: Figure 1 is a vertical section of so much of a blast furnace as is necessary to
render my Invention understood and Figure 2 is a sectional plan of the same.
a a are the massive walls of the furnace having arched recesses at
opposite sides. a strong wall of masonry c serves to retain the molten metal in
the hearth d-of the furnace. At e there are openings made in the walls c c
into which the tuyere pipes ff are inserted these tuyeres I prefer to make
of fire clay or other suitable refractory substance they may be inserted as
.shewn in openings ee and secured there by ramming around them some
loam or fire clay. 99. are pipes for the conveyance of a blast of air or of
steam or of steam or of air and steam mixed which may be used at their
ordinary temperatures or they may be highly heated in any suitable manner
previous to being forced into the fluid metal which occupies the hearth of
the furnace I however prefer to use atmospheric air at its ordinary tem-
perature because air is better capable of generating a very high temperature
but I use steam in lieu thereof or mixed with it when treating iron containing
a large quantity of sulphur or other impurities having an affinity for the
hydrogen evolved from steam. The small branch pipes / are jointed to the
pipe so as to admit of their being moved on one side when a new tuyere is
to be fixed and which is to be done immediately after tapping the furnace and
when there is no metal above the level of the openings e e in all cases the
pressure of the air or steam must exceed the pressure of the fluid metal over
the area of each orifice of the tuyeres in order to prevent the fluid metal from
entering into them. The general arrangements of the blast furnace may be
similar to those in general use being also provided with tuyere pipes i i
through which the ordinary supply of blast is conveyed for the combustion of
the fuel I however prefer to place the tuyere pipes i higher than usual above
the level of the fluid metal in the hearth in order to prevent them being acted
upon by the splashes and boiling up of the metal and slags the latter being
allowed to flow from the furnace as usual. The blast furnace having thus
been furnished with tuyeres situated below the surface of the fluid metal and
having been charged with iron ore fuel and lime or other flux may be
blown into and the ore smelted therein in the usual manner a powerful blast
of air or steam is then admitted through the tuyeres ff into the fluid mass
of metal as it accumulates in the hearth and which will become violently
agitated by the passing upwards of the currents of air or air and steam which
will in part combine with the carbon contained in the fluid metal and produce
combustion, and thus add to the temperature of the molten mass a part of
the heat so generated will ascend among the materials occupying those parts of
the furnace that are situated above the fluid metal and assist in the smelting

page_text: of the ores at the same time the action of the air or steam passing upwards
through and among the particles of fluid metal will refine and purify it to an
extent dependant chiefly on the quantity of air or steam admitted as compared
with the mass of fluid metal so treated. The metal may be drawn off from
the furnace of a quality or in a state of decarbonization suitable to the peculiar
purposes for which such metal is required and according to the extent that
the decarbonization and refinement of the metal may have been carried on.
I however prefer when thus making steel and malleable iron to cause the
metal while in the blast furnace to be brought into the state of highly refined
plate metal and then to run the metal into an apparatus not containing fuel
and in which air or other gaseous matters may be forced into the fluid iron
until it is thereby refined purified, and converted into steel or into malleable
iron while still retaining the fluid state as was described in my said former
Specification or the refined plate metal produced in a blast furnace as afore-
said may if desired be puddled or treated by any known process capable of
converting it into steel or malleable iron.
Cupola furnaces used for the remelting of crude or pig iron for foundry or
other purposes may also be used to refine and convert crude iron by forcing
air or steam or a mixture of air and steam into and below the surface of the
molten mass which collects in the lower part of such cupola furnaces. The
mode by which this part of my Invention is carried into effect is shown at
Figure 3 which is a vertical section thereof and at Figure 4 which is a hori-
zontal cross section of the same. m represents the outer iron case or shell of
the furnace lined with fire bricks p near to the bottom of the furnace I insert
several small perforated bricks or tuyeres n which are connected externally
with the vertical branch pipes r and main supply pipes by means of which
air or steam may be conducted into the tuyeres and pass from thence upward.
through and among the particles of molten metal which will thus be purified
and acted upon in the manner herein-before described in reference to the blast-
furnace. The refined metal may also in like manner be tapped therefrom and
be afterwards applied or used as desired. In this way the quality of foundry'
iron may be improved and modified so as to render it more suitable to par-
ticular uses and when desired the iron may be converted into steel or into
malleable iron by continuing the blast of air or of air and steam through the
melted metal after the fuel employed for melting the iron has been consumed
and thus in the same furnace remelt and convert the iron. So also in like-
manner I force air or steam below the fluid metal in the finery or running-out-
furnace used for the refinement of crude iron such air or steam being conveyed-
into the iron by means of fire clay pipes or perforated .bricks or by means of

page_text: iron pipes protected from fusion by the passage of water air or other cooling
fluid through them or the chamber containing the metal may be partially
covered and the air or steam made to pass beneath such cover in contact with
the fluid metal. The finery or running-out furnace may be used advantageously
for these purposes especially as the crude metal to be treated therein may
when the furnaces are conveniently situated be run direct from the smelting
furnace into the refinery furnace and be retained therein until it is converted
into steel or malleable iron and may then be run or poured into suitable moulds
while in a fluid state. Before however going more fully into the details of
this portion of my said Invention I desire it to be understood that I am
aware that the finery or running-out furnace has been much used in the iron
works in Great Britain for the purpose of separating the grosser impurities
from the crude metal which is generally melted therein with coke fuel. This
description of finery furnace is however sometimes used to refine charges of
fluid iron run direct from the blast furnace in which case the finery furnace is
sometimes distinguished by the name of running-in furnace coke or other
fuel being used in both cases in order to keep up the temperature of the
furnace and of the metal therein. And I would here observe that in both
cases whether the pig metal be melted therein or the crude iron be run therein
direct from the blast furnace that the process of refinement in such furnaces
has been only as a preparatory step to its more complete refinement and con-
version by puddling in a puddling furnace. The finery or plate metal after
leaving the refinery furnace has heretofore been extremely hard and brittle
and it has possessed less malleability and softness than iron presents in almost
any other known condition the requisite properties of softness and malleability
having been obtained by severe and continual manipulation of the iron in
puddling so far removed from the malleable condition is iron after it leaves
the finery furnace that of late years in many instances iron manufacturers have
in some cases abandoned the use of their finery furnaces preferring to perform
the entire process of refinement and the conversion in the reverberatory
or puddling furnace. And it may also be stated that heretofore wherever
the finery or the running-out furnace or the running-in furnace has been used
that fuel has been employed to keep up the temperature of the furnace and of
the metal therein manufacturers having been ignorant of the fact discovered
by me that by a judicious application of a powerful blast of air so high a
temperature can be produced in the metal without the employment of fuel,
that the crude iron may be completely refined and converted into steel or into
malleable iron and this part of my Invention consists in carrying out, my
Invention in a refinery furnace. such as has heretofore been used simply to

page_text: refine iron preparatory to puddling and I thus obtain in such furnace steel or
malleable iron in a fluid state which may be run or cast into ingots or masses
capable of being afterwards hammered or rolled into bars plates or rods or
of being founded or cast into other articles of malleable metal without under-
going the process of puddling in a reverberating furnace.
And in order that this part of my said Invention may be fully understood I
have shewn two different modifications though other modifications may be used
of the finery furnace on the Sheet of Drawings hereunto annexed. The first
modification is shewn at Figures 5 and 6 which are vertical sections taken at
right angles to each other and Figure 7 is a plan of the same. tt represent a
portion of the sides of a finery furnace of the kind usually employed and to which
I have adapted tuyere pipes made of fire clay for the purpose of conveying into
the fluid metal contained in the hearth jets or currents of air or of steam or
of a mixture of air and steam either heated or at its natural temperature
these tuyeres are shewn at 2 z and are so put into the sides of the furnace as
to be easily removed and replaced by others when worn out they are held in
place by ramming in loam around them and are connected at their outer ends
to the blast pipes v. The ordinary tuyeres are shewn at w and are used when
fuel is employed for. melting pig metal or otherwise. When working in a
refinery furnace and when running in melted metal from the blast furnace I
leave in the hearth of the furnace after each charge has been drawn off a con-
siderable quantity of the rich oxide produced in the previous process so that
when a fresh charge of fluid iron is run into the finery furnace from the blast
furnace this fluid oxide will float upon it and prevent much less of heat from
the upper surface of the metal the metallic oxide will also assist in the decar-
bonization of the crude metal. With this covering to the fluid metal I prefer
to dispense with the use of any fuel as a covering to the metal, because the
combustion thereof is not necessary or beneficial in the process.
It may be observed, that in this and in all other modifications of apparatus
used to carry out my Invention by conducting jets or currents of air or of
steam by means of tuyeres situated below the surface of fluid iron that the
pressure of the air or steam so used must exceed the pressure of the fluid metal
over the area of the orifice of such tuyeres and thus effectually prevent the
fluid metal from entering them. It is also necessary to turn on the blast to the
lower tuyeres before running in the fluid metal and to continue doing so until
the crude iron has been converted into steel of a malleable quality or into pure
or nearly pure malleable iron as may be desired. As soon as the metal has
acquired the necessary malleable condition it may be run out by the tap hole
into suitable moulds and the ingots or masses so produced may be taken to the

page_text: forge hammer or to the rolls and be there extended and worked into bars
plates or rods of malleable iron and steel. In order that the metal in the
finery furnace may present a less radiating surface in some cases I cover over
a portion of the hearth on one or more sides thereof preferring the two opposite
sides as shewn in the second modification thercof at Figure 8 of the annexed
Sheet of Drawings, which represents so much of the lower part of a finery or
running-out furnace as is necessary to render this modification of my Invention
understood.
A A are the side walls and hearth of the furnace which I prefer to make
of fire-brick or fire-stone and not to be cooled by water, blocks in order to
prevent an unnecessary loss of heat. It will be seen that at A* there are
projections running along each side of the furnace having a hollow groove or
space B into which the blast pipe C enters. At the back of the furnace there
are tuyeres D situated above the surface of the fluid metal and at an angle to
its surface as generally employed and which may be used to keep up the com-
bustion of charcoal or other fuel should it be thought desirable to use any to
assist in the reduction of the oxide produced in the process or the tuyeres D may
be used to assist in the process of refinement by projecting on to the surface of
the fluid metal currents of air or steam and in order that the tuyere pipes D
may thus act effectually on the metal I prefer to use air or steam of a con-
siderably higher pressure than is generally employed so that the jets may
penetrate the covering of fluid oxide and act powerfully on the fluid metal. In
this particular modification of the finery furnace it will not be necessary to turn
on the blast of air or steam through the pipes C before the metal is run into
the hearth because they are situated above the surface of it and consequently
the fluid metal cannot enter them. The metal which is let into the furnace at
each charge should rise a little higher than the under side of the projecting
covering pieces. A* so that when a blast of air or steam is forced into the
spaces B it will depress the surface of the metal therein until it sinks below the
level of the pieces A* beneath which the gaseous matters will rush in a broad
sheet acting on an extended surface of metal which will in part be carried
with it and produce a considerable agitation and circulation of the metal and
thus present all parts of it in turn to the decarbonizing action of the blast.
Whenever the crude metal so treated has passed into the condition of steel or
of malleable iron, the blasts of air or steam may be discontinued and the fluid
metal may be left to repose for a short period until the workman judges that its
temperature is suitable to produce a sound or solid ingot of metal he will then
proceed to tap out the malleable metal into suitable moulds, after which he may
run in a fresh charge of crude metal to be treated in-like manner.

page_text: The
For the process of decarbonizing and refinement of the iron without the
use of additional fuel for that purpose I construct a box or chamber of brick
firestone or iron lined with loam or other slow conductor of heat.
chamber should be closed except at one end where there is a raised outlet for
the escape of the air or steam and aeriform matters produced. At the opposite
end the cover rises so as to form a space for the admission of the air or steam
above the surface of the metal. The metal in a fluid state is run into the box
or chamber which may be previously heated so as to fill it up to the cover and.
at least a few inches up the raised parts the air or steam is then forced into.
the space above the surface of the metal which will be displaced therefrom
and allow the air or steam to find its way along the cover of the chamber and
pass up through the metal in the raised outlet where it will escape and where
the slag formed in the process will also be carried. The cover may be flat or
corrugated or it may have projecting ribs with or without perforations to
obstruct the too easy passage of the air.
In order that this part of my said Invention may be fully understood I have
shown three modifications of apparatus on the Sheet of Drawings hereunto an-
nexed suitable for carrying into practical operation this part of my said Invention.
Figure 9 is a longitudinal section and Figure 10 a cross section of a rectangular:
box or chamber to be used for this purpose. E is the outer casing of iron
lined with fire-brick or other suitable refractory substance F is a compartment
closed air-tight at the top and into which air or steam or a mixture of air and
steam may be conducted by means of the pipe G. At the opposite end of the
apparatus there is a raised outlet H from which the flame and gaseous products
may escape. Fluid crude iron is to be run or poured into the apparatus .until
it rises a few inches above the roof or cover I the blast may then be let into
the compartment F the effect of which will be to disturb the level of the fluid
metal by depressing that portion which occupies the compartment F and raising
the level of the metal in the outlet passage H. As soon, however as the:
metal is lowered to the level of the cover I the air or steam under pressure
will rush in a broad sheet along the surface of the molten iron and bubble up
through the metal in the outlet passage H a rapid circulation will thus be
produced and every part of the metal will thus in turn come under the influence
of the air or steam forced into the compartment F and become refined and
decarbonized to the desired extent. The slags or scoria produced in the.
process will float on the surface of the metal in the outlet passage H. At J
there is a.tapping hole stopped with loam through which the metal may be
run off into suitable moulds as soon as it has acquired by the process the proper
degree of refinement and malleability. It will be observed that in this form of.

page_text: apparatus the process of forcing air or steam through the molten mass may he
discontinued and resumed when desired by means of a valve on the pipe G
there being no tuyeres below the surface of the metal to become stopped up by
a cessation of the blast. The workman may therefore discontinue the process
from time to time and test the quality of the metal by dipping out a small
sample with a ladle from the outlet. H he may also allow the metal when
refined to remain for a short time, in the chamber in order to cool a little and
thus enable him to form a sounder ingot or casting. I have before mentioned
that the too easy passage of the air may be prevented by a perforated screen
which will have the effect of more completely dividing the current and diffusing
it throughout the metal. The mode of constructing apparatus for this purpose
will be better understood by reference to Figure 11 which is a longitudinal
section and Figure 12 which is a cross section of an apparatus similar to the
one herein lastly described except that there is a perforated fire lump or
perforated stone bridge at K which prevents the air or steam forced into the
space L from passing along the roof M without first passing through the
perforations which acts as tuyeres and distribute the blast in jets which rise
up through the metal and collect under the roof until the metal is displaced
therefrom sufficiently to allow the air or steam to force its way beneath the
bridge N and rise up and escape through the outlet passage O. It will be
observed that in this form of outlet passage there is a tendency for the air or.
steam to escape upwards in contact with the brickwork instead of passing up
through the body of the metal I therefore form in some cases a projecting
part so as to throw off the air or steam and cause it to rise through the fluid
metal. This modification will be better understood by reference to the longi-
tudinal section Figure 13 where P is the projecting part referred to. Many
other modifications of this apparatus may be made and used with more or less
advantage the main object being to cause currents of air or steam to be forced
through and in contact with molten iron without the use of tuyeres or nozzles
situated below the surface of the fluid metal and thus enable the process to be
stopped and resumed when required.
Another mode by which I decarbonize or partially decarbonize iron in its
fluid state without additional fuel is to run the crude metal into a chamber
constructed of or lined with fire-bricks or other slow conductor of heat and
then direct jets of air or steam on its surface so to act on the metal and its
impurities. I prefer to use numerous jets with such force as to remove the
slag from the surface and cause a rapid circulation of the fluid metal.
The mode by which this part of my said Invention is carried into practical
operation is represented on the Sheet of Drawings hereunto annexed at

page_text: Figure 14 which is a vertical section thereof and at Figure 15 which is a plan
of the same. Qis a chamber composed of fire-bricks or other suitable refrac-
tory substance it is of a square or rectangular form. On one side of it the
wall is in part arched over as shewn at R and on the opposite side there is a
series of tuyere or jet pipes S inclined at a somewhat acute angle to the sur-
face of the fluid metal which may be run into the apparatus from a blast
furnace or re-melting furnace until it rises up nearly to the level of the
tuyeres. I prefer for the purposes of this part of my said Invention to used a
blast of from ten to twenty pounds pressure to the square inch or even of a
greater pressure in order that the surface of the fluid metal may be ploughed
up or deeply indented by the force of the blast and the fluid iron be made to
circulate rapidly and be dashed against the under side of the arched pro-
jection R which will prevent its being thrown out of the chamber. The
refinement of the crude iron may thus be carried on until it is converted into
malleable steel or into malleable iron while still retaining the fluid state and
be in that condition run or poured from a tap hole in the lower part of the
vessel into suitable moulds and thereby form ingots of metal capable at once
of being hammed or rolled into rods plates or bars. In lieu of the square or
rectangular form of apparatus herein lastly described a circular chamber may
be used a vertical section of which is shewn at Figure 16 and a plan of the
same at Figure 17 of the annexed Sheet of Drawings the outer wall T over-
hangs its base on the interior so as to form a sort of basin at the bottom of
the apparatus around the upper part of this basin are situated several tuyeres
U which direct the blast on to the fluid metal at such an angle as to disturb it
as much as possible and cause it to circulate rapidly the force of the blast
being (as in the former case) sufficiently powerful to penetrate the mass of.
metal and scatter it in splashes about the interior of the apparatus and bring
it in contact with the scoria or slag floating on the surface of the mass. When.
the process is completed the malleable metal may be drawn from the basin by
the unstopping of a tap hole and be formed into ingots suitable for hammering
or rolling or it may be cast in suitable moulds into any required article or
form by the process of founding.
When the decarbonization and refining of iron is.effected by either of the
modes herein mentioned or by any other method in which jets of steam or air
are supplied to fluid iron for that purpose and in which the metal is kept in a
fluid state until the completion of the process I force on to or into such fluid
metal carburetted gases or introduce therein fluid or solid carbonaceous sub-
stances in sufficient quantity to combine with any oxide of iron that may exist
in or interfere with the malleability of the metal. For this purpose I use an
'

page_text: air pump or blast engine and I connect it with a gasometer containing car-
buretted hydrogen gas which I force through the same tuyeres or passages
into the fluid metal as I had previously used for the passage of air or steam
in order that such gases may unite with any oxygen existing in or among the
particles of metal and effect a separation thereof. Or in lieu of forcing in such
gaseous matter I put into the converting vessel or chamber a pole or mass of
wood which I force down below the surface of the fluid mictal until the car-
bonaceous gases which are emitted therefrom have united with or removed
any excess of oxygen from the metal.
Towards the completion of the process of decarbonization and refinement of
the metal it will be found that a portion of the iron is converted into an oxide
I therefore put into the crucible or chamber any suitable carbonaceous matter
such as charcoal anthracite coal or a carbonate of iron that is rich in carbon.
in order to reduce the oxides existing in the crucibles or chambers and thus
add to the weight of the charge of metal obtained. Or in lieu of putting char-
coal into the crucible or vessel with the metal I put charcoal into a cylinder
or other shaped vessel and when it is in a state of combustion I pass air or
steam or a mixture of both through the ignited fuel and from thence into the
fluid metal under operation the gaseous products having become highly
heated before coming into contact with the metal and here I would observe
that the vapours thus forced into the metal may be made to have a carbonizing
or decarbonizing effect according to the properties in which the constituents
of the different gaseous vapours predominate and whereby I am enabled to
produce malleable iron or steel as may be desired. In the refinement of iron
by means of jets of air or steam in crucibles or vessels I sometimes assist the
process of decarbonization by putting into such vessels or crucibles some scales
of iron or other iron oxides or iron ore part of which becomes reduced to the
metallic state and thus adds to the quantity of metal while it assists the
decarbonizing process.
In order that the mode by which the carbonaceous vapours of charcoal
are forced into the fluid iron may be understood I have shown on the Sheet
of Drawings hereunto annexed an apparatus to be used for that purpose
Figure 18 being a vertical section and Figure 19 a plan of the same
the outer shell of the vessel is made of plate iron having a lining of
fire-brick V at the top is a man-hole W for the introduction of charcoal
and capable of being secured as nearly air-tight as may be. A pipe X is used
for the conveyance of a blast into the vessel among the fuel and another pipe
Y for the conveyance of the carbonic acid or carbonic oxide vapours into the
converting vessel so that whenever it may be desired the blast of air or steam

page_text: which ordinarily passes direct from the blast engine or steam boiler may by
means of suitable valves be diverted from its direct course and be made to
pass through the mass of ignited fuel and be conveyed from thence into
the fluid metal.
The third part of my said Invention consists in forming masses of refined
iron or steel of a suitable form or configuration for hammering or rolling or
for other purposes by forming the vessel or chamber in which the iron is
refined or partially refined by air or steam of such form and dimensions as
will admit of the metal being retained therein after the process of refinement
until it is sufficiently solidified to be removed therefrom the decarbonizing
vessel serving as the mould for giving the desired form to the mass and thus
saving the labour of pouring the refined metal into a separate mould and at
the same time avoiding the unsoundness sometimes caused by pouring the
metal into a separate mould. When however I refine the metal in vessels
unsuited by their form for the formation of the ingot or article desired I
construct an ingot mould having a runner or gate communicating with the
bottom of the mould and extending upwards to the top of it so that the mould
is filled from its lower end the metal rising upwards until it is filled. When
the mould is of iron the runners should be lined with loam to prevent the
metal from becoming solidified therein before the ingot is completed but I
sometimes form such ingot mould of porous fire clay fire stone or other slow
conductor of heat so that the metal will retain its fluidity sufficiently long to
allow much of the gaseous matters to escape which would otherwise render
the casting cellular. In order that this mode of forming ingots of malleable
steel or malleable iron that has been converted direct from crude fluid iron
may be fully understood I have shewn on the Sheet of Drawings hereunto
annexed an elevation at Figure 20 one half of an iron ingot mould and a
plan of the entire mould at Figure 21. 1 is the passage down which the
fluid metal is poured and 2 is the main body of the ingot the passage or
runner 1 is lined up with loam so as to prevent the chilling of the metal
therein. The two halves of the mould are secured together by bolts passing
through the lugs 3 which retain the parts in position during the casting
process after which the bolts are unscrewed and the ingot removed from the
mould. Ingots cast of this metal are sometimes found to be cellular and I
will now explain how the tendency to this defect in cast ingots may be also
lessened or removed by forming the mould as nearly air-tight as possible. It
should be placed so that an opening in the lower part of the mould will dip
into the fluid metal a partial vacuum is then to be formed in the mould by
opening a cock which communicates with a previouly exhausted vessel and

page_text: by means of which the air occupying the mould will be removed and the fluid
metál caused by atmospheric pressure to fill the mould the metal rising
upwards into the vacuous space without producing that admixture of air
which results from pouring in the metal from above while the lessened
pressure of the air above the surface of the metal will assist in the disengage-
ment of any gaseous matters contained therein. A mould suitable for forming
ingots in this manner is represented in vertical section at Figure 22 on the
annexed Sheet of Drawings where 4 is the mould having an exhaust pipe and
cock 5 in connection with its upper end and a short piece of fire clay pipe 6
fixed into the lower end of it. A gutter down which the metal is allowed to
flow from the decarbonizing vessel or chamber is shown at 7 having a hollow
or recess at its lower end in which the metal collects and in which the fire
clay pipe is inserted so that whenever the molten metal rises high enough to
cover the lower end of the pipe 6 the cock leading to the exhausted vessel
may be opened when the fluid metal will rise up and fill the mould without
having been divided by the air as in the act of falling into a mould as usual
and whereby the tendency to form air bubbles by the falling current of fluid
metal is avoided.
In witness whereof I the said Henry Bessemer have hereunto set my
hand and seal this Fifteenth day of September in the year of our
Lord One thousand eight hundred and fifty-six.
Witness,
B. GOBEY
4 Old Square Lincoln's Inn.
HENRY BESSEMER. (L.s.)