IM- PROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND MALLEABLE IRON FROM CAST IRON, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN
Year: 1868

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND MALLEABLE IRON FROM
CAST IRON, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN."―A
communication from abroad by Francis Ellershausen, of Ottawa, in
the Dominion of Canada, Metallurgist.
Sealed the 29th May 1868, and dated the 3rd April 1868.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with bis Petition,
on the 3rd April 1868. --
I, JOHN HENRY JOHNSON, of 147, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND
MALLEABLE IRON FROM CAST IRON, AND IN THE APPARATUS OR MEANS EMPLOYED
THEREIN," a communication to me from abroad by Francis Ellers-
hausen, of Ottawa, in the Dominion of Canada, Metallurgist, to be as
follows:-
This Invention relates to a peculiar process for manufacturing cast
steel and malleable iron direct from cast iron, and to certain peculiar

page_text: constructions and arrangements of apparatus to be employed for that
purpose.
The peculiar process whereby cast iron is converted into cast steel or
malleable iron consists essentially in the use of oxides of iron in a form
possessing a considerable extent of surface, such for example, as spongy
iron as it comes from the puddling furnace, or which I prefer sheet iron
or iron curlings somewhat similar to the beech shavings used in vinegar
generators, this curled sheet iron is placed in a vessel or receptacle
called the converter, which is capable of being brought into communi-
cation with a furnace in order to bring the sheet iron curlings to a
white heat, which temperature is maintained during a sufficient length
of time to insure complete oxidation of the metal. When this is
accomplished the communication with the furnace is shut off, and a
quantity of molten cast irou is poured into the converter so as to unite
with the oxide of iron.
The great object in this process is to expose as large a surface as
possible of oxide of iron to the fluid cast iron, so as to effect a rapid and
simultaneous combustion throughout the entire mass which increases
the temperature to such a degree as to cause the conversion to be
completed whilst the metal is in a fluid state. Before the cast iron
is introduced into the convertor decarbonizing and purifying or steel
improving agents, such for example, as oxide of manganese, may be
strewn or deposited in the interstices of the sheet-iron curlings or its
substitutes in order to facilitate the combustion and purification. The
subsidence of the combustion will indicate that the conversion is
completed, when the metal may be run off and the process repeated.
According to one arrangement of apparatus for carrying out or
applying the peculiar process herein-before described, a converting
vessel or chamber is constructed upon the upper portion of a furnace,
which may be of any convenient size and form and be provided with
blast pipe and fire-bars. The convertor is divided from the said furnace
internally by an arched division which forms the bottom of the convertor
and the roof of the furnace. A series of flues or passages are made
round the said division communicating with the furnace in order to
allow of the curled iron or its substitute placed in the convertor being
thoroughly heated. Each flue or passage is capable of being closed at
pleasure by a sliding stop of fire-clay, or other suitable material capped
outside with metal, which stops are held in position when closed by

page_text: means of holdfast screws in order that they may not be forced out by
the pressure of the molten metal in the convertor. Loose blocks or
doors are provided for affording ready access to the interior of the said
flues or passages and to the seats of the sliding stops for repairs; the
bottom of the convertor is hollowed or dished slightly in order that
in the event of any of the metal in the act of oxidising becoming fluid
it may receive the saino. A moveable hood or cap is fitted on to the top
of the convertor of the same form and diameter at the base as the interior
of the convertor, but tapering towards the mouth which is curved to onc
side and is in connection with a chimney shaft.
According to another modification of apparatus a removeable cast iron
flue serves to convey the flame and heat from the furnace to the convertor
which convertor is supported on pillars or columns on the furnace roof,
the said flue being placed over the aperture of the furnace when required
for use and removed again when not wanted. A. flap door or false bottom
is hinged to the bottom of the convertor, and when this door is open
the interior of the convertor is in immediate contact with the flame from
the furnace which is carried up through the circular removeable fluc.
A lateral discharge aperture for the molten metal is formed at or near
the hottom of the convertor, and upon the top of the convertor there
is fitted by hinges or otherwise a cap or hood of the form herein-before
described with reference to the first modification. In converting cast
iron into cast steel by the aid of either of the herein-before described
apparatus curled sheet iron is placed in the convertor, the hood is then
applied and connected with the chimney and the sliding stops or
removeable flue are adjusted. Fire is then raised in the furnace beneath
until the sheet iron curlings or substitutes therefor in the convertor are
brought to a white heat, and so maintained until complete oxidation
has taken place. The sliding stops are then closed or the circular flue
is removed, the door or flap (if used) is closed against the bottom of the
convertor and the top or hood is turned over. A sufficient quantity of
molten cast iron is then poured into the convertor to unite with the
oxide of iron causing rapid combustion throughout the mass and effecting
conversion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 3rd October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letiers Patent, bearing date the Third day of April, in the year
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her. reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my exccutors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or 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 "In-
PROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND MALLEABLE IRON FROM
CAST IRON, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN, a communi-
cation from abroad by Francis Ellershausen, of Ottawa, in the Dominion
of Canada, Metallurgist, upon the condition (amongst others) that I, the
said John Henry Johnson, my executors or administrators, by an instru-
ment in writing under my hand and seal, 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 John Henry Johnson, 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, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon, that
is to say:-
The said Invention relates to a peculiar process for manufacturing cast
steel and malleable iron direct from cast iron, and to certain peculiar

page_text: constructions and arrangements of apparatus to be employed for that
purpose.
The peculiar process whereby cast iron is converted into cast steel or
malleable iron consists essentially in the use of oxides of iron in a form
possessing a considerable extent of surface, such for example, as spongy
iron as it comes from the puddling furnace, or which I prefer sheet iron
or iron curlings somewhat similar to the beech shavings used in vinegar
generators, this curled sheet iron is placed in a vessel or receptacle called
the convertor which is capable of being brought into communication with
a furnace in order to bring the sheet iron curlings to a white heat,
which temperature is maintained during a suflicient length of time to
ensure complete oxidation of the metal. When this is accomplished the
communication with the furnace is shut off, and a quantity of molten
cast iron is poured into the convertor so as to unite with the oxide
of iron.
The great object in this process is to expose as large a surface as
possible of oxide of iron to the fluid cast iron so as to effect a rapid
and simultaneous combustion throughout the entire mass, which
increases the temperature to such a degree as to cause the conversion
to be completed whilst the metal is in a fluid state. Before the
cast iron is introduced into the convertor decarbonizing and purifying
or steel improving agents, such for example, as oxide of manganese,
may be strewn or deposited in the interstices of the slicet iron curlings
or its substitutes in order to facilitate the combustion and purifi-
cation. The subsidence of the combustion will indicate that the
conversion is completed, when the metal may be run off and the
process repeated.
According to one arrangement of apparatus for carrying out or
applying the peculiar process herein-before described, a converting
vessel or chamber is constructed upon the upper portion of a furnace
which may be of any convenient size and form, and be provided with
blast pipe and fire-bars. The convertor is divided from the said furnace
internally by an arched division, which forms the bottom of the con-
vertor and the roof of the furnace. A series of flues or passages are
made round the said division communicating with the furnace in
order to allow of the curled iron or its substitute placed in the convertor
being thoroughly heated. Each flue or passage is capable of being
closed at pleasure by a sliding stop of fire-clay, or other suitable material

page_text: capped outside with metal, which stops are held in position when closed
by means of hold fast screws in order that they may not be forced out
by the pressure of the molten metal in the convertor. Loose blocks
or doors are provided for affording ready access to the interior of the
said flues or passages and to the seats of the sliding stops for repairs;
the bottom of the convertor is hollowed or dished slightly in order
that in the event of any of the metal in the act of oxidising becoming
fluid it may receive the same. A moveable hood or cap is fitted
on to the top of the convertor of the same form and diameter at
the base as the interior of the convertor, but tapering towards the
mouth which is curved to one side and is in connection with a chimney
shaft.
According to another modification of apparatus a removeable cast-iron
fluc serves to convey the flame and heat from the furnace to the con-
vertor, which couvertor is supported on pillars or columns on the furnace
roof, the said flue being placed over the aperture of the furnace when
required for use and removed again when not wanted. A flap door or
false bottom is hinged to the bottom of the convertor, and when this door
is open the interior of the convertor is in immediate contact with the flame
from the furnace which is carried up through the circular removeable
flue.
A lateral discharge aperture for the molten metal is formed at
or near the bottom of the convertor, and upon the top of the convertor
there is fitted by hinges, or otherwise, a cap or hood of the form herein-
before described with reference to the first modification. In converting
cast iron into cast steel by the aid of either of the hercin-before described
apparatus, curled sheet iron is placed in the convertor, after which the
hood is applied and connected with the chimney and the sliding stops or
removeable fluc are adjusted. Fire is then raised in the furnace beneath
until the sheet iron curlings or substitutes therefor in the convertor are
brought to a white heat, and so maintained till complete oxidation
has taken place. The sliding stops are then closed, or the circular
flue is removed, the door or flap (if used) is close against the bottom
of the convertor and the top or hood is turned over. A sufficient quantity
of molten cast iron is then poured into the convertor to unite with the
oxide of iron causing rapid combustion throughout the mass and effecting
conversion.
And in order that the said Invention may be fully understood, I
shall now proceed more particularly to describe the same, and for that

page_text: purpose shall refer to the several Figures on the annexed Sheets of
Drawings, the same letters of reference indicating corresponding parts in
all the l'igures.
Figure 1 on Sheet 1 of the Drawings represents a side elevation of one
arrangement of the improved furnace and convertor; Figure 2 is a
vertical section of the same, and Figure 3 is a plan of the convertor with
the cap or hood removed.
« is the furnace; b, the fire-grate; e, a fan blast pipe underneath the
fire-bars; the convertor is placed directly over the furnace a, as shewn
in Figure 2 separated from it however by the arched roof E. In order
to heat the curled sheet iron rolls which are placed in the interior of the
convertor, four or more flues C, C', are arranged for the purpose of
allowing the flame and heat to proceed from the furnace into tho
convertor ff, f, are stoppers made of refractory material, and so
arranged as to slide in and out, opening and closing the flues in doing
so, as shown in Figure 2 where the flue C is shewn open, and the
flue C¹ closed; these stoppers are provided with hold fast screws J, J,
to prevent any movement of the stoppers when the pressure of the liquid
metal in the convertor is acting against them on the inside. In order
to enable the operator to gain access to the flues, and also to repair any
damage with cement in the corners n, loose blocks mare so arranged
as to afford access to that part. a, b, are metal caps attached to the
outer ends of the stoppers f, f. The bottom of the convertor is
curved or dished in the manner shown at o, so that in the event of any
of the metal in the act of oxidising becoming fluid it will be retained;
is the discharging spout for running off the molten converted metal;
m is a hood or cap piece herein-after more fully referred to having an
open contracted mouth at ¹.
Figure 1 on Sheet 2 of the Drawings represents a side elevation of
another modification of furnace and convertor; Figure 2 is a vertical
section of the same, and Figure 3 is a plan.
a is the furnace of any convenient size or form, provided with fire-
bars b, b, ash-pit c, feeding door d, for the admission of fucl and blast
pipe e of the usual form. On the top of this furnace is placed the
convertor constructed of brick with an external boiler plate casing
to strengthen the same as in the first modification; it may be supported
on pillars g', g, resting on the top of the furnace; is a removeable
flue for the purpose of conveying the flame or heat from the furnace to

page_text: the convertor. This flue is circular in form, of cast iron, and placed over
the aperture of the furnace; when it is required to pass the flame or heat
through the convertor, this flue is removed from under the convertor
when it is required to close the door; i, i, is a flap door or false bottom
attached to the lower side of the convertor by the hinge k, this door is
also lined on the inside with fire-brick; when this door is open the whole
interior area of the convertor is in immediate contact with the flame
from the furnace carried through the flue which is then in place for
that purpose; is an aperture for the discharge of the molten metal
from the convertor when the same is ready for withdrawal; m is the
hood or cap piece of metal of the peculiar form shewn in the Drawings,
circular at the base, and of the same internal diameter as that of the
convertor; it is attached to the top of the convertor by a hinge or other
suitable fastening, so arranged as to permit of its being elevated or turned
back when required. This cap picec terminates in a reduced diameter
at for the purpose of connection with a chimney shaft to carry off the
products of combustion.
With the foregoing brief description of the apparatus for carrying the
Invention into effect, I will now proceed to describe, the process or
modus operandi by which the cast iron is converted into cast steel or
malleable iron, but before doing so will make the following general
remarks. On the principle that carbon cannot exist at a white heat in
the presence of oxygen without combustion ensuing, and also that the
combustion will proceed with a rapidity dependant on the extent of
surface exposed to the united action of the carbon and oxygen with an
increase of temperature, the Invention or discovery has been made that
by the use of certain mechanical appliances in conjunction with the
foregoing cast iron may be readily converted into cast steel or into
malleable iron, and which may be accomplished in the following manner
with greater economy both in time and expense, and at the same time
yielding a superior description of steel or malleable iron.
These results are brought about in the following manner:-Sheet iron
is curled in a similar manner to the beech shavings used in vinegar
generators, and is placed in the interior of the convertor, this vessel
is open at the top but is provided with means for the upward passage
of the flame from the furnace a through the interior of the convertor;
the cover m is then put in place and connected with the chimney, the
flucs or passages C, C, (Sheet 1), or the lower door i (Sheet 2) are

page_text: opened, and the flue in the latter arrangement put in place. Fire is
then introduced into the furnace «, and the temperature raised to such a
degree as to bring the sheet iron curlings in the convertor to a white
heat, and continued for a suflicient length of time to ensure the complete
oxidation of the same. When this is accomplished the flue (if
employed) is removed and the door i closed, and the top cover m' is
turned over, or the stops ", ', in the arrangement on Sheet 1 are
pushed in so as to close the passages C, C. A sufficient quantity of
molten cast iron is then poured into the top of the convertor to unite
with the oxide of iron as may be required. It will be evident from the
manner in which the sheet iron curlings afterwards converted into an
oxide of iron were originally placed in the convertor, that a large surface
of oxide of iron is exposed within a comparatively small space to contact
with the incoming molten cast iron uniting the particles of each in close
conjunction, causing a rapid combustion throughout the entire mass,
which increases the temperature to such a degree as to effect the con-
version while the metal is in a fluid state. In place of the sheet iron
curlings other oxides may be used if they possess the desired extent of
surface, for instance, spongy iron as it comes from the puddling furnace.
In cither of the above cases before the cast iron is introduced into the
convertor decarbonizing and purifying or steel improving agents, such
for instance, as oxide of manganese may be strewn or deposited in the
interstices of the sheet iron curlings, or its substitutes, in order to
facilitate the combustion and purification. When the conversion is
completed, which can be easily determined by the subsidence of the
combustion, the metal is drawn off through the tap or discharge spout 4,
and the process is repeated. The quantity of metal to be operated
ou during each conversion may range from one half of a ton io ten
tons.
Having now described and particularly ascertained the nature of
the said Invention, and the manner in which the same is or may
be used or carried into effect, I would observe in conclusion that
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,

page_text: Second. The combination of furnace, converting vessel, and diaphragm
or separating arch E, with the flues and stoppers arranged and operating
substantially as and for the purpose herein-before described and
illustrated on Sheet 1 of the Drawings hereunto annexed.
Third. The combination of furnace, converting vessel, and removeable
flue arranged and operating substantially as and for the purpose herein-
before described and illustrated on Sheet 2 of the Drawings hereunto
annexed.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Seventeenth day of
September, One thousand eight hundred and sixty-eight.
J. HENRY JOHNSON. (L.S.)