IMPROVEMENTS IN-THE MELTING AND CASTING OF STEEL, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1866

page_text: LETTERS PATENT to George Henry Benson,. of Staleybridge, in the
County of Chester, Engineer, and William George Valentin, of the Royal
College of Chemistry, Chemist, for the Invention of "IMPROVEMENTS IN
PROVISIONAL SPECIFICATION left by the said George Henry Benson
and William George Valentin at the Office of the Commissioners of
Patents, with their Petition, on the 9th October 1866.
We, GEORGE HENRY BENSON, of Staleybridge, in the County of Chester,
Engineer, and WILLIAM. GEORGE VALENTIN, of the Royal College of Chemistry,
Chemist, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN-THE MELTING AND CASTING OF STEEL, AND IN THE APPARATUS EMPLOYED THEREIN,"
to be as follows:-
Our Invention relates to an improved mode of and apparatus for melting
steel.
In order to melt steel, soft or hard, a very high temperature is required.
For this purpose we propose to employ a furnace of such a form and shape.as.
to-confine and concentrate the heat to the best advantage. We prefer to use.

page_text: a kind of low cupola furnace of round, oval-shaped, or any such form as may
be found most conducive to produce a great heating effect. We also propose
to heat the furnace by means of gaseous fuel.
The gases obtainable from a gas generator, consisting of carbonic oxide,
hydrogen, and hydrocarbons, together with nitrogen and some carbonic acid,
possess a considerably high temperature, and their heating effect may even be
increased by passing them through heating stoves such as are now generally
employed for obtaining hot blast; they may, in fact, be raised to the very highest
temperature short of melting malleable iron if necessary. It is a well
understood law that carbonic oxide gas produces its greatest heating effect
when burnt to carbonic acid; that in fact more than twice the heating
effect is produced from that produced when carbon is burnt to carbonic
oxide. With these combustible gases possessing already a very high
temperature we propose to mix a blast of air heated like the gases to
acquire a high temperature in such a manner as to produce as nearly as
possible complete combustion, and consequently to yield the very highest heating
effect attainable. By means of a concentric tuyere or tuyeres we are able to
effect a thorough intermixture of the combustible gases with the atmospheric
blast which is requisite to burn and consume them properly. Such a thorough
mixing is absolutely necessary before the gascous fuel is made to act upon
the steel and to expend its heat upon it on account of the large quantity of
nitrogen from the atmospheric blast, which being a non-combustible gas acts
as a diluent upon the combustible gases. We prefer to arrange the gas
tuyere or tuyeres already referred to in one, two, or more rows or tiers nearly
all round the cupola, oval-shaped, or other furnace, so as to fill the furnace
completely with an intense flame. The tuyere or tuyeres are placed some
little way back and made to discharge the gases and blast into a small fire-
brick chamber running all round the outer side of the furnace, and being
merely divided into separate little chambers by division walls sufficiently
thick to support the next higher series of chambers, thus allowing as much
space for the diffusion and mixing of the gases and blast as possible. The
nozzles of the tuyeres we also prefer to have made oval-shaped or rectangular,
or some such appropriate shape to fit the mixing chambers, and to leave as
little space as possible between the several sheets of flame issuing from the
tuyeres. The flame which issues from the concentric tuyeres is made to
converge into one common centre upon the piled up steel. We prefer to
carry off the products of combustion in such a manner as to break as little as
possible the current and the direction imparted to the flame by the gas
tuyeres. Before allowing these highly heated products of combustion to pass

page_text: off into the chimney we propose to utilize them further for heating the hot-
blast stoves.
Soft steel containing a lesser per-centage of combined carbon may also
be melted down in the steel furnace together with a certain amount of good
pig iron, when it will be found to melt more readily, and by the subsequent
addition of iron scales or black oxide of manganese in such quantities only as
to remove a certain amount of carbon and to convert the iron into steel a
good and uniform steel may be obtained. By tapping the metal when in a
fluid state and running it into ingots and castings, and by combining the
contents of several furnaces and tapping one after another, castings of con-
siderable size and weight may be made.
Instead of the low cupola furnace above described we sometimes propose to
employ a reverberatory furnace of peculiar construction. This furnace con-
sists of a shallow hearth with an inclined surface or bed, on which is placed
the steel to be melted. The heated gases are made to play on the steel, and
as it melts it will run down the inclind bed into a shallow basin or ladle
below, and will be kept liquid by the spent heat passing over it from the
anterior part of the furnace. Sometimes we prefer to employ a further tuyere
or tuyeres for supplying heal to this basin or ladle, in order to keep the steel
in a thoroughly molten state in this basin, which may be mounted on a
centre, so that it can be tipped when it is required to run out the molten
steel, or if preferred the basin may be stationary and tapped in the usual
manner
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Henry Benson and William George Valentin in the
Great Seal Patent Office on the 9th April 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
HENRY BENSON, of Staleybridge, in the County of Chester, Engineer, and
WILLIAM GEORGE VALENTIN, of the Royal College of Chemistry, Chemist, send
grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Ninth day of October, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said George Henry Benson and William George Valentin, Her special licence
that we the said George Henry Benson and William George Valentin, our
executors, administrators, and assigns, or such others as we, the said George

page_text: Henry Benson and William. George Valentin, our 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, éxercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands; and Isle of Man, an Invention
for "IMPROVEMENTS IN THE MELTING AND CASTING OF STEEL, AND IN THE APPARATUS
EMPLOYED THEREIN," upon the condition (amongst others) that we, the said
George Henry Benson and William George Valentin, our executors or admi-
nistrators, by an instrument in writing under our, or their, or one of our or
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the saine 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 we, the said George Henry Benson and William
George Valentin, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to the
Drawings hereunto annexed, and to the letters and figures marked thereon
(that is to say):-
1
Our Invention relates to an improved mode of and apparatus for melting
steel.
In order to obtain a very high temperature, such as is required for
melting steel, soft or hard, we propose to employ a furnace of such a form and
shape as to confine and concentrate the heat to the best advantage, so that "a
very intense heat may be obtained. We prefer to use a kind of low cupola
furnace of round, oval, or any such form as may be found most conductive to
produce a great heating effect.
In the accompanying Drawings, Fig. 1, Sheet I., is a longitudinal vertical
section of a cupola furnace constructed and arranged according to our
improvements; Fig. 2 is a sectional plan view of the same.
a, a, is the hearth of the furnace, which is made in the shape of a basin;
this basin we sometimes prefer to surround by a bank or inclined sides, on
which the steel, or some of it, may be placed in order to be partially melted
before it is charged into the basin. We also propose in order to obtain a
very high temperature to heat the furnace by means of gaseous fuel, which
may be obtained from any suitable gas generator, and which is known to
consist chiefly of carbonic oxide, hydrogen, and hydrocarbon gases, together
with nitrogen and some carbonic acid. If these gases are brought direct
from the generator they will possess a considerably high temperature, and

page_text: their heating effect may even be increased by passing them through heating-
stoves such as are now generally employed for obtaining hot blast; they
may, in fact, if necessary be raised to the very highest temperature short of
melting malleable iron. It is a well understood law that carbonic oxide gas
produces its greatest heating effect when burnt to carbonic acid, and that in
fact more than twice the heating effect is obtained by this means than from
the heat produced when carbon is burnt to carbonic oxide. Common coal gas
or gases obtainable from other carbonaceous matter by distillation may also
be used in place of the combustible gases, obtained from gas generators in the
ordinary manner. Gases which are produced by passing steam over ignited
carbonaceous matter, such as charcoal or coke contained in a close apparatus
or retort which is heated from the outside, may also be used. The mixture of
combustible gases thus obtained is free from the non-combustible nitrogen,
and contains principally hydrogen and carbonic oxide, together with more or
less carbonic acid, and is known under the term of water gas. The heating
effect which these combustible gases are capable of producing is far greater
than that produced by the combustion of the generator gases, in the pro-
duction of which atmospheric air was employed, and which therefore contain
about three-fifths of non-combustible nitrogen gas. We propose to employ
water gas in addition to the generator gases, and according to The greater or
lesser amounts of water gas which we mix to burn with the generator gases
we are enabled to obtain a' considerably increased temperature in the furnace.
In all these cases the amount of atmospheric blast must be regulated in pro-
portion to the quality or chemical composition of the gas, as is well under-
stood. With these combustible gases (possessing already a very high tem-
perature) we propose to mix a blast of air under pressure heated in heating
stoves so as to acquire a high temperature, and in such a manner as to
produce as nearly as possible complete combustion, and consequently to yield
the very highest heating effect atiainable under the circumstances and with the
gases and atmospheric blast which we employ. By means of concentric tuyeres
of such like construction as is shewn in the Drawings, and by the use of a
mixing chamber or chambers as described hereafter, we are able to effect a
thorough combination of the combustible gases with the atmospheric blast
Such a thorough
which is requisite to burn and consume them properly.
mixing is absolutely necessary before the gaseous fuel can be made to act
upon the steel and to expend its heat upon it, owing to the large quantity of
nitrogen introduced by the atmospheric blast used in the gas generator, and
which nitrogen being a non-combustible gas acts as a diluent upon the com-
-bustible gases, and consequently reduces the heating power.

page_text: We prefer to arrange the gas tuyeres already referred to in one, two, or
more rows or tiers nearly all round the cupola, oval-shaped, or other furnace, as
shewn at b, b, b', b', Figs. 1 and 2, Sheet I., so as to fill the furnace completely
with an intense flame. The tnyeres are placed some little way back, and made
to discharge the gases and blast into a small fire-brick chamber b running all
round the furnace. This chamber is divided into separate little chambers by
division walls sufficiently thick to support the next higher series of chambers,
thus allowing as much space for the diffusion and mixing of the gases and
blast as possible. The nozzles of the tuyeres we also prefer to have made
oval-shaped, or rectangular, or some such appropriate shape to fit the mixing
chambers and to leave as little space as possible between the several sheets of
flame when issuing from the tuyeres and mixing chambers into the interior of
the furnace. The flames which issue from the concentric tuyeres may be
made to converge, and be concentrated upon the piled up steel, or to strike
at an angle tangential to a circle struck from the centre of the furnace, as
shewn in the plan view.
An essential feature of our arrangements for producing great heat in order
to melt steel consists as we have already shown in promoting as much as
possible complete and thorough combustion of the gases. Owing to the
thorough control which we have over the mixing of the gases and blast, as
well as owing to the pressure under which we can force the flame down upon
the metal, the steel can be melted without materially altering its quality and
without much loss from oxidation and waste in the shape of slags. We wish
it, however, to be understood that although we prefer for the purposes set
forth the use of concentric tuyeres, as described, for mixing combustible gases
with atmospheric blast, we do not confine ourselves thereto, as the com-
bustible gases can be mixed with blast in various other ways. If complete
and thorough combustion be effected, and regularity and facility of controlling
the flame be secured, any convenient arrangement of apparatus for so doing
may be employed.
We prefer to carry off the products of combustion in such a manner
as to break as little as possible the current and the direction imparted to the
flame by the gas tuyeres, and this will be facilitated by the arrangement of
the tuyeres shewn in the Drawing. Before allowing these lighly heated.
products of combustion to pass off into the chimney we propose to utilize
them further for heating the hot blast stoves; to this end they are conducted
along the flue c into a chamber d, in which are arranged serpentine air
pipes e, e, so that the air in its passages may be heated by the waste gases in
the chamber d before it reaches the tuyeres. Soft steel containing a lesser

page_text: per-centage of combined carbon, may also be melted down in the steel furnace
together with a certain amount of good pig iron, by the addition of which it
will melt more readily, and by the subsequent addition of iron scales or black
oxide of manganese or other suitable substance (in such quantites only as to
remove a certain amount of carbon and to convert the iron into steel) a good
and uniform steel may be obtained. By tapping the basin- a the metal when
in a fluid state may be run into ingots and castings, and by combining the
contents of several furnaces and tapping one after another, castings of
considerable size and weight may be made.
Instead of the low cupola furnace above described, we sometimes propose
to employ a reverberatory furnace of peculiar construction, such as that shewn
at Figures 3 and 4, Sheet II., in which Fig. 3. is a longitudinal vertical
section of our improved furnace; Fig. 4 is a sectional plan, and Fig. 5 a
cross sectional view of the same. This furnace consists of a shallow hearth a
with an inclined bank or bed a. on which is placed the steel to be melted.
The heated gases from the tuyeres b, b. are made to play on the steel, and in
combination therewith we sometimes employ lateral tuyeres, as shown in the
Drawing. As the steel melts under this blast it will run down the inclined
hed or bank into the shallow basin or ladle a below, and will be kept liquid by
The waste
the heat passing over it from the anterior part of the furnace.
gases on leaving the furnace pass in the direction of the arrows down the
exit opening e into the chamber d, in which are placed a serpertine arrange-
ment of pipes to conduct the atmospheric blast to the tuyeres, as in the
former instance. Sometimes we prefer to employ a further tnyere or tnyeres
for supplying heat to this basin or ladle in order to keep the steel in a
thoroughly molten state, as shewn at b¹, Fig. 4; this basin may if desired
be mounted on a centre, so that it can be tipped when it is required to run
out the molten steel, or if preferred the basin may be stationary and tapped
in the usual manner as in the former instance.
Having now described our Invention of "Improvements in the Melting
and Casting of Steel, and in the Apparatus employed therein," and having
explained the manner of carrying the same into effect, we would observe that
it has hitherto been impracticable to melt down steel in large masses in
consequence of the impossibility of concentrating on the steel to be melted a
heat of sufficient intensity.
We therefore claim as the Invention secured to us by Letters Patent as
aforesaid, melting steel in large masses by means of an intense and concentrated
heat produced by the thorough combustion of gaseous fuel and heated
atmospheric blast under pressure, as herein set forth.

page_text: Second, we claim the supplying the gases and blast in such a manner that
we are enabled to control and modify their action and regulate the process of
melting so as not to injuriously affect the quality and character of the steel,
and to prevent material loss from oxidation during the process of melting
down, as herein set forth.
Third, we claim the general construction and arrangement of apparatus
herein shewn and described whereby we are enabled to produce an intense
and concentrated heat capable of melting large masses of steel, and also to
control the action of the gases and blast during such melting.
In witness whereof, we, the said George Henry Benson and William
George Valentin, have hereunto set our hands and seals, the 28th
day of March, in the year of our Lord One thousand eight hundred
and sixty-seven.
G. HENRY BENSON. (L.S.)
W. GEO. VALENTIN. (L.s.)