IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1882

page_text: LETTERS PATENT to James Moss Bennett of Glasgow in the County of:
Lanark, North Britain, Metallurgist, for an invention of "IMPROVEMENTS IN
THE MANUFACTURE OF IRON AND STEEL,"
PROVISIONAL SPECIFICATION left by the said James Moss Bennett at the
Office of the Commissioners of Patents on the 14th July 1882.
JAMES MOSS BENNETT, of Glasgow, in the County of Lanark, North Britain,
Metallurgist, "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
"
This invention which relates to Improvements in the manufacture of Iron and
Steel has reference to the production of malleable iron direct from the Blast
Furnace and Cast Steel also direct from the Blast Furnace.
In manufacturing malleable or wrought iron according to this invention the
Blast Furnace is charged from the top in the usual way and opened and closed
by means of a charging cone and the Furnace is otherwise so constructed at the
upper part that none of the gases or other products of the operations which take
place in the furnace can pass or be led off thereat, but are all discharged through
an opening or openings at the lower part of the furnace.
•
In order to produce malleable iron from the Blast Furnace two conditions are
essential to be observed namely, (First) that there shall be in the Furnace a
quantity of carbon which by its combustion shall be sufficient to maintain the
necessary heat and to effect the reduction of the ores but which (Secondly) shall
be less than the quantity of carbon usually present in a Blast Furnace, the excess
of which in the ordinary practice carburizes the metal.
According to this Invention the ores of iron are reduced without liquefaction
of the metal and the metal descends to the lower part of the Furnace in a plastic
sponge-like condition, the Furnace itself being made in the form of a conic
frustum the larger diameter of the frustum being at the bottom.-One or more
openings or passages lead from the lower part of the Furnace to one or more
reverberatory balling chambers and through these openings or passages the

page_text: plastic metal either exudes or is drawn out into the balling chamber or chambers
wherein it is made up into balls after the manner practised in puddling or balling
Furnaces, the balls being taken thence to the shingling hammer or squeezers
whereby they are formed into blooms or "uses."
In making Cast Steel according to this Invention the Furnace is constructed
like that hereinbefore described excepting that the Furnace is not necessarily in
the shape of a conic Frustum but may be more or less like that of an ordinary
close-top Blast Furnace or Cupola.-The iron ores in this case are reduced and
melted but with a less quantity of carbon than is employed in an ordinary Blast
Furnace; the quantity of carbon used being sufficient to reduce and melt the ores 1
and to carburize the metal to about the extent necessary to produce cast steel of
any required degree of carburization. The Blast Furnace used in this case as in
the preceding case is provided with one or more openings or passages leading to
one or more receptacles from which samples are taken to ascertain if the metal be.
carburized to the required extent. If the metal contains too much carbon a 1
quantity of malleable scrap iron is thrown into it to reduce the carburization to
the requisite point, if on the other hand the quantity of the carbon in the metal is
too low then Cast Iron scrap is added to the metal in the receptacle to raise the
carburization to the desired point.
In making either malleable iron or cast steel in the manner hereinbefore
described the Blast Furnaces are provided with vertical rows of twyers extending
from the top to nearly the bottom of the Furnace each twyer having a valve or
stop-cock to shut it in or out of action as required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Moss Bennett in the Great Seal Patent Office on the
12th January 1883.
JAMES MOSS BENNETT, of Glasgow, in the County of Lanark, North Britain,
Metallurgist. "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL."
My said Invention which relates to Improvements in the manufacture of Iron
and Steel has reference to the production of malleable iron direct from the Blast
Furnace and Cast Steel also direct from the Blast Furnace.
In manufacturing malleable or wrought iron according to this Invention the
Blast Furnace is charged from the top in the usual way and opened and closed
by means of a charging cone and the Furnace is otherwise so constructed at the
upper part that none of the gases or other products of the operations which take
place in the furnace can pass. or be led off therent, but are all discharged through
an opening or openings at the lower part of the furnace.
In order to produce malleable iron from the Blast Furnace two conditions are
essential to be observed namely (First) that there shall be in the Furnace a
quantity of carbon which by its combustion shall be sufficient to maintain the
necessary heat and to effect the reduction of the ores but which (Secondly) shall
be less than the quantity of carbon usually present in a Blast Furnace, the excess
of which in the ordinary practice carburizes the metal.
According to this Invention the ores of iron are reduced without lequefaction of
the metal and the metal descends to the lower part of the Furnace in a plastic
sponge-like condition, the furnace itself being made in the form of a conic frustrum
the larger diameter of the frustrum being at the bottom.-One or more openings
or passages lead from the lower part of the Furnace to one or more reverberatory
balling chambers and through these openings or passages the plastic metal either
exudes or is drawn out into the balling chamber or chambers wherein it is made
up into balls after the manner practised in puddling or balling Furnaces, the balls
being taken thence to the shingling hammer or squeezers whereby they are formed
into blooms or "uses."
In making Cast steel according to this Invention the Furnace is constructed like
that hereinbefore described excepting that the Furnace is not necessarily in the
shape of a conic Frustrum but may be more or less like that of an ordinary close-
top Blast Furnace or Cupola-The iron ores in this case are reduced and melted
but with a less quantity of carbon than is employed in an ordinary Blast Furnace;
the quantity of carbon used being sufficient to reduce and melt the ores and to
carburize the metal to about the extent necessary to produce cast steel of any
required degree of carburization.-The Blast Furnace used in this case as in the
preceding case is provided with one or more openings or passages leading to one or
more receptacles from which samples are taken to ascertain if the metal be
carburized to the required extent. If the metal contains too much carbon, a
quantity of malleable scrap iron is thrown into it to reduce the carburization to
the requisite point, if on the other hand the quantity of the carbon in the metal is
too low, then Cast Iron scrap is added to the metal in the receptacle to raise the
carburization to the desired point.
In making either malleable iron or cast steel in the manner hereinbefore
described, the Blast Furnaces are provided with vertical rows of twyers extending.
from the top to nearly the bottom of the Furnace each twyer having a valve .or
stop-cock to shut it in or out of action as required.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode or manner in or under which the

page_text: same is or may be used or practically carried into effect, reference being had to the
accompanying Drawings and to the letters and Figures marked thereon that is
to say:-
Figure 1, is a part vertical section and part elevation of a Blast Furnace for
manufacturing malleable or wrought iron constructed according to my present
invention.
Figure 2, is a part plan and part horizontal section of the same,
Figure 3, is a part section and elevation of the same taken on a line at right
angles to that on which Figure 1, is taken.
Figures 4, and 5, are respectively elevation and plan of a detached portion of
the apparatus.
Figures 6, 7, and 8, are views corresponding respectively to Figures 1, 2, and 3,
of a Blast Furnace for manufacturing Cast Steel constructed according to and
constituting part of my present invention.
With reference to Sheet 1, of the accompanying drawings, the Blast Furnace is
charged from the top by the cover a, being raised from off the charging-hopper b,
which is effected by the action of the counter-weighted lever c, from whose
bifurcations d, it is suspended by connecting links working at their upper ends in
slots in said bifurcations. The materials to be treated within the furnace, are then
charged into the hopper b, and the cover a, lowered into its normal' position, a sand
joint is or may then be made around its joint with the hopper b, as is usual in
close topped Blast Furnaces, to prevent the upward escape of gas. The charge then
contained within the hopper b, is lowered into the Furnace by the cone e, being
lowered by means of the counter-weighted lever f, from whose end it is suspended
by the connecting-link g, whose upper end works preferably in a horizontal slot
within the lever f, and which passes through a gland and stuffing-box h, provided
on the cover a.- -The gases and products of the operations which take place within
the furnace, being unable to escape at the upper part of the same, pass down through
the materials in the furnace and out through the openings A, (of which there are
three in the Furnace represented on Sheet 1, of the accompanying drawings) and
are forced therethrough by the hot-air blast which is led into the furnace by the
several rows of twyers as represented at . The gaseous products after passing
through the openings A, are deflected by the arch B, formed in the roof of the
reverberatory balling chambers C, upon the pasty or spongy iron contained
therein. The gaseous products then pass off through the flues D, and may be led
to a chimney or to condensers or to any other apparatus.
In the production of malleable iron, the two conditions necessary to be observed
are, firstly, that there shall be such a quantity of carbon in the Furnace as shall
by its combustion be sufficient to maintain the necessary heat and effect the
reduction of the ores, and, secondly, that such qauntity of carbon will be less than
that usually present in a Blast Furnace, the excess of which carbon usually
carburizes the metal.
According to this Invention the ores of iron are or may be reduced without
liquefaction and the reduced iron descends in a sponge-like condition to the lower
part of the furnace upon the hearth E, in place of being liquefied and highly
carburized as in the case of a Blast Furnace, working in the usual manner, that is
to say with the Blast and gases ascending through the furnace, I preferably
construct the hearth as a flat conical form as shewn. The plastic metal produced
as described either exudes or is drawn out into the balling chambers C, the latter
being effected by "rabbling" tools being worked through the chamber openings F,
or through the openings G, which are provided for the insertion of tools for that
especial purpose. In the drawing out of this metal the advantages of the flat
conically-formed hearth are obvious as it causes the metal to fall by its own weight
towards the openings A, leading into the balling chambers C.-The metal is then
within the chambers C, is formed into balls after the manner usually practised in
puddling or balling Furnaces and which are or may be then taken to the shingling
hammer or squeezers whereby they are formed into "blooms" or "uses,"
"

page_text: The openings F, of the chambers C, are closed when necessary by the doors H,
which are in connection with and are acted upon by the counter-weighted lever 1,
and the openings G, from the lower part of the furnace are closed by the doors J,
which may be similarly operated or operate by any other suitable means. The
reverberatory balling chambers are preferably constructed wholly of fire-brick and
are framed up in the usual manner of furnaces by the iron plates K, framing
pieces L and tie-bolts M.
Over the top and down the sides of the opening A, from the lower part of the
furnace, I place the water-bridge N, through whose tubes j, a constant stream of
water is circulated the necessary connections for this purpose being provided as is.
well understood in Iron works.-The hereinbefore mentioned twyers i, are each
formed as represented more particularly at Figures 4, and 5, of the accompanying
drawings in which they are each provided with a stop-cock O, forming the
connection between the blast pipe P, and the twyers i at their outer ends are
each preferably provided with a small window Q, of mica or any other suitable
material to enable the operator to inspect the action of the Furnace more
satisfactorily. The pipes P, as represented on the accompanying drawing are three
in number and are each connected with the large blast-pipe R, encircling the
furnace and which is carried on brackets S, and is in direct communication with
the blast heaters. The three lowest rows of twyers i, are constructed as water-
twyers as represented at T, and a constant stream of water is circulated around
the same, the necessary connections being provided for that purpose.
With reference to Sheet 2, of the accompanying drawings, it will be obvious that
the Furnace there represented is charged in a manner corresponding to that Furnace
hereinbefore described but the shape of the upper part of the same may (as shewn)
differ from it, inasmuch as the Furnace represented at Figures 6, 7, and 8, is at its
upper part constructed more or less like an ordinary close-top Blast Furnace or
cupola.
In manufacturing Cast Steel, the iron ores are reduced and melted with a less
quantity of carbon than is employed in an ordinary Blast Furnace; the quantity of
carbon being sufficient to reduce and melt the ores and carburize the metal to
about the extent necessary to produce Cast Steel of the required degree of
carburization.
The Blast furnace represented on Sheet 2, as in that represented on Sheet 1, is
provided with the openings A, leading to the chambers C, to which the molten
metal is run from the hearth k, by tapping it at l, and placing one end of a
moveable curved channel piece (not shewn on the Drawings) thereinto, the other
end thereof being passed in the chamber opening F, which being on a lower level
allows the metal to run freely. Samples may be taken from these chambers C, to
ascertain whether the metal is carburized to the required extent, and malleable
scrap iron or Cast iron scrap is added as may be found necessary respectively to
reduce or increase the carburization of the metal. The hearth k, is formed with a
receiver or crucible m, in contradistinction to the hearth E, hereinbefore described
with reference to Sheet 1, of the accompanying drawings-From this receiver or
crucible the metal is tapped off at 7, and the slag is tapped off at n, the latter of
which may be left open continually or closed temporarily by a clay stopping or by
any of the well known means and the metal tapping 7, is similarly conducted.-
The liquid metal in the chamber C, may, if it be carburized to the proper extent
corresponding to any particular quality of metal, be at once cast from the
chamber C, or its degree of carburization may if necessary be increased therein by
adding scrap cast iron thereto; or if the metal coming from the blast furnace be
too highly carburized, the proportion of carbon is reduced by adding scrap wrought
iron thereto. As is obvious the general details of the Furnace represented on
Sheet 2, are similar to those of Sheet 1.
In constructing the Furnaces herein before described it is necessary to carry the
upper part or shaft of the Furnace upon columns o, as shewn in which case the
mantle-plates p, are built thereinto to rest upon the top of the said columns,

page_text: "
"
By means of the several sets of twyers I am enabled to force oxygen or
atmospheric air into the furnace at any point and thus to regulate or vary the
working of the furnace when, through any cause such as scaffolding or
hanging" in the furnace, the working becomes irregular or when it is necessary
to vary the working of the furnace in order to produce iron or steel of different
degrees of carburization.
66
Having now described and particularly ascertained the nature of my said
Invention and the system, mode or manner in or under which the same is or may
be carried into practical effect, I would observe in conclusion that I do not limit
. myself to the precise form or detail of the Furnaces herein before described with
reference to the accompanying drawings as I may vary the same in many ways
without departing from the nature of my said Invention for instance I may construct
a Furnace with one or more reverberatory or balling chambers; but what I consider
to be novel and original and therefore claim as the Invention secured to me by the
herein before in part recited Letters Patent is:-
First. The manufacture of Malleable Iron and Steel in the manner hereinbefore
described that is to say in a Blast furnace wherein the whole of the gaseous as
well as the liquid and more or less solid portions resulting from the operations
are led off or taken out through openings below the twyers in the bottom of the
said Blast Furnaces, substantially as herein set forth and shewn upon the
accompanying drawings.
Second. The providing of Blast Furnaces with vertical rows of twyers as herein
set forth and shewn upon the accompanying drawings for the purpose of admitting
blast to or turning it off from any part of the column of materials in the furnace.
Third. Combining with the Improved Blast Furnace reverberatory chambers
wherein the charge of wrought iron is balled or wherein the requisite degree of
carburization of the steel is effected by adding scrap iron to the charge as
hereinbefore described.
In witness whereof the said James Moss Bennett have hereunto set my
hand and seal this Fifth day of December in the year of Our Lord One
thousand eight hundred and eighty two.