IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL AND IN FURNACES EMPLOYED THEREFOR.
Year: 1874

page_text: LETTERS PATENT to Saint John Vincent Day, of 166, Buchanan
Street, Glasgow, in the County of Lanark, North Britain, Cou-
sulting Engineer, for the Invention of " IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL AND IN FURNACES EMPLOYED THEREFOR.".
A communication from abroad by James Henderson, of the City,
County, and State of New York, United States of America..
-
caled the 21st July 1874, and dated the 13th April 1874..
PROVISIONAL SPECIFICATION left by the said Saint John Vincent
Day at the Office of the Commissioners of Patents, with his
Petition, on the 13th April 1874.
I, SAINT JOHN VINCENT DAY, of 160, Buchanan Street, Glasgow, in
the County of Lanark, North Britain, Consulting Engineer, do hereby
declare the nature of the said Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL AND IN FURNACES EMPLOYED THEREFOR," to be
as follows, that is to say :-

page_text: geneous malleable iron, which for convenience of repairs and for charging
the reagents set forth in the Specifications filed under Letters Patent,
No. 318, A.D. 1870, granted to Alfred Vincent Newton as a communi-
cation from James Henderson, No. 1051, A.D. 1870; No. 554, A.D.
1872; and No. 2318, A.D. 1872, respectively granted to the said James
Henderson, is provided with a moveable hearth, and is used under
temperatures that will render the steel and homogeneous malleable iron
liquid, so that it may be poured from the hearth. The required
temperatures are produced by the complete combustion of the gases or
fucl, and this complete combustion is effected by measuring the quantity
of air employed in producing the combustible gases, and again by using
the precise quantity of air requisite to burn these gases into carbonic
acid.
In carrying out this first part of the Invention the hearth of the
furnace may be removed from or returned to its place by means of an
hydraulic ram or its equivalent. The moveable hearth is lined with
refractory material, such as sand, fire-clay, ganister, or a mixture of
these materials, or the materials used for making steel melting crucibles
may be employed to line it. The reagents set forth in the Specifications
filed under the Letters Patent granted to the aforesaid Alfred Vincent
Newton and to the aforesaid James Henderson are used by being spread
over the moveable hearth of the furnace, and it is preferred to cover the
refractory lining with sheet iron before charging these materials. It is
however to be understood that the use of sheet iron in this manner forms
no part of the present Invention.
When the fuel employed for generating the gas to be used in the
improved furnace is cither coke or anthracite, free or practically free
from hydrogen, a weight of air equal to that used for producing carbonic
oxide in the generator is employed for burning the carbonic oxide into
carbonic acid as the carbonic oxide passes through the flues into the
reverberatory chamber containing the moveable hearth, so that the
greatest amount of heat obtainable from the fuel is produced, an
object of importance being to prevent either an excess or a deficiency of
air, either of which reduces the temperature produced.
'
In order to ensure a constant measured delivery of the air used, both
for producing carbonic oxide and for burning the carbonic oxide into
carbonic acid, the furnace is provided with a blast apparatus consisting
by preference of two air forcing cylinders of equal capacity, the piston

page_text: or plungers of which are driven at equal speed by one steam cynnuer
direct or by an equivalent motor.
The air driven from one of the cylinders supplies the gas generator,
that from the other inflames or burns the gas issuing from the generators
to the reverberatory chamber into carbonic acid.
In place of employing two air compressing cylinders one or more such
cylinders or fans may be used, the quantities of air delivered to the gas
generators and the flues or reverberatory chamber being regulated by
passing through air meters.
If the fuel used for producing the gases contains hydrogen, the
resulting gases will require more air to burn them completely than what
is used in the generator itself, the proportion of such air being determined
by the character of the gases and according to the chemical equivalents
involved.
The improved furnace herein-before described may be fired from one-
or both ends, and may or may not be provided with air heating stoves
placed to receive the hot waste gases issuing from the furnace, the licat
of which is thereby imparted to the air; or the hot waste gases may.
escape to a chimney, in which case the air heating stoves are heated by
a gas generator separate from the furnace.
The mode of working the improved furnace is as follows:―The
moveable hearth whilst out of the furnace is charged with the materials.
used in the process of making steel or homogeneous malleable iron, in
accordance with the Specifications filed under the Letters Patent herein-
before mentioned. The hearth is then raised to its place in the furnace
by the hydraulic ram or its equivalent, and the gas and air are turned
into the furnace. When molten iron is charged upon the hearth the
reagents, as specified under the aforesaid processes, should be heated until-
they become viscid or somewhat hard, or united by heat so that they will
not be floated or displaced, when the molten metal is charged upon them.
The molten metal may be run from a cupola. The furnace is kept at.
the highest temperature until the conversion of the metal and steel or
homogeneous malleable iron is effected.
Instead of using air at the highest temperature during the whole time
of the conversion of the cast iron into cast steel or homogeneous malleable
iron, it may be used at the ordinary temperature until the metal is
A 2

page_text: deprived of the whole or nearly all of its carbon, and then the tempo-
rature may be increased by the use of heated air.
When perfect combustion is effected by the means herein-before
referred to the temperature of the furnace will be sufficient to render
the metal liquid enough to be run from the furnace without the use of
heated air, but the furnace cannot be worked as fast as with the use of
heated air.
Metal partly refined in the Bessemer converter, from which the
phosphoros and sulphur not removed by the Bessemer process, may be
purified by the reagents. I employ especially fluorides and oxides, as set
forth in the Specifications aforesaid, using preferably fluorspar and
titaniferous iron ore in the proportions of about 40 parts by weight of
fluorspar to 100 parts by weight of titaniferous iron ore. The Bessemer
metal may be charged from the converter either at the third period of
the Bessemer process, which is known as being "after the boil," at
which time the carbon is reduced to about one per cent., or at the " end of
the blowing," when nearly all the carbon is removed. The proportions
of the reagents will depend upon the quantities of carbon and phosphorus
in the metal. If for example the carbon present is one per cent. and
phosphorus one per cent., the amount of fluorspar and titaniferous iron
oro will be about 2 to 3 hundredweights of the mixture to one ton of
steel, and if the carbon is all removed the proportions of the mixture
may be about one-quarter to three-eighths of an inch in depth upon the
hearth of the furnace when the phosphorus present is under one per
cent., and the layer of metal is about 1.5 inches deep. Or instead of
using the metal from the Bessemer converter, old or scrap wrought iron
may be melted in a cupola, or in the furnace herein-before described, or
in any other suitable furnace, either with or without cast iron, and then
run into the furnace prepared, as herein-before described, with fluorides
and oxides to purify the metal, either into steel, or as suitable for con-
version into steel. The proportions of the fluorides and oxides is
determined by the quantity of carbon and impurities in the metal. If
the carbon and impurities in the metal are greater than one per cent. of
carbon and one per cent. of phosphorus, the proportions of fluorides and
oxides should be about the same as are given in the aforesaid Specifi-
cation, No. 1051, A.D. 1870, and if the impurities are simply silicon,
phosphorus, and sulphur, the proportions are the same as those herein-
before mentioned for treating Bessemer metal which is decarbonised.

page_text: The furnace used for melting the old or scrap wrought iron may be either
the Bessemer high-pressure cupola or the furnace herein-before described.
It is preferred to use about one-third of the whole charge of molten grey
foundry pig iron before charging the wrought iron, and then to add the
wrought iron at a white heat in about the proportion of one-half of
the whole charge, and after the iron is all melted, and to ensure its
being thereby liquid, it is prefered to add about 16 per cent. by
weight of liquid grey pig iron, and then to tap the metal into another
furnace similar to the improved furnace herein-before described, provided
with fluor spar and oxides to remove the impuritics.
Spiegeleisen or ferro-manganeso may be used for recarbonisation of the
purified iron, or the steely property may be given by the other methods
herein-before described.
The second part of this Invention consists in the use of two
reverberatory furnaces for the production of cast steel and, homogeneous
malleable iron, in one of which the conversion of cast iron into steel or
malleable iron by the processes herein-before referred to is effected at
the temperature of a boiling puddling furnace, which, produces iron in a
state in which it cannot be run or poured from the furnace. The
furnace in which this conversion takes place is provided with a moveable
hearth similar to that described in the first part of this Invention, and
when the process of conversion of the cast iron into steel or malleable
iron is complete, and whilst the metal is at the highest temperature the
hearth and the contained metal are removed to another reverberatory
furnace in which higher temperatures are maintained, and which will
melt the steel or malleable iron, so that it will be liquid enough to be
run from the furnace into ingots which will be in a fit condition to be
hammered or rolled. The furnace with the higher température is made
with a space to receive the moveable hearth from the other furnace
which is put in its place by the hydraulic ram heroin-before referred
to. The steel or malleable iron which is preferably about 1½ inches
deep upon the hearth is then exposed (with a covering of cinder or
silicious slag) to the action of the higher temperature of this furnace
until the metal is in the condition to be run or poured from the
hearth.
The furnace with the higher temperature may be a Siemens' gas
regenerative steel melting furnace with the ordinary bottom left out, and
constructed so as to receive the moveable bottom from the furnace with

page_text: f
lower temperature, which may be a reverberatory furnace of the ordinary
construction using solid fuel, or it may be a furnace for using gas and
air either at the ordinary temperature, or heated air arranged similar to
those described in the first part of this Invention. Or the steel melting
furnace may be provided with Whitwell's fire-brick air heating stoves
placed at each end of the furnace, and arranged to receive the waste
heated products of combustion after being used over the hearth of the
furnace.
The third part of this Invention relates to an improved method of
giving the steely property to wrought iron to form cast steel or
homogeneous malleable iron in large quantities in reverberatory furnaces,
which for convenience of charging the materials for giving the steely
property is preferably provided with a moveable hearth similar to that
herein-before described under the first head of this Invention.
In carrying out this part of the Invention it is preferred to use a
reverberatory gas furnace similar to those described under the first and
second heads of this Invention; or furnaces using air under high or great
pressure may be employed. The hearth or bottom whilst out of the furnace
is charged with the agents for giving the steely property, which may be
powdered charcoal with the oxide or carbonate of manganese, or charcoal
with chrome iron ore, or carbonate of manganese with wolfram, these
agents being used in exactly the same proportions that would be required
to give the steely property to wrought iron to make cast steel or
homogeneous malleable iron when applied together in crucibles. These
agents are thoroughly mixed and spread over the bottom of the furnace
and are covered with the wrought iron to be melted, which may be in
flat bars or of miscellaneous shapes. The steely property giving agents
may be covered with sheet iron, and the wrought iron charged upon the
shect or plate iron. The furnace hearth is then put in its place in the
furnace and the heat applied to melt the iron; by the time the iron
melts the steely property giving agents will have become prepared to
act upon the metal and perform the part usually obtained from them
when used in crucibles to make cast steel and homogeneous malleable
iron, the metal thus produced will be of superior quality to that
ordinarily made in reverberatory furnaces by use of spiegel eisen, and cost
less than if made with spiegel eisen.
If preferred the process of giving the steely property by use of
carbonate of manganese and wolfram can be effected in any suitable

page_text: furnace without a moveable bottom, as these substances will not ignite
before being covered with the sheet or bar iron as charcoal does when
placed in a furnace. This method of converting wrought iron into casț
steel and homogeneous malleable iron is of great use in connection with
the patent processes hercin-before referred to when applied in furnaces
constructed as described under the first and second parts of this Inven-
tion. When applying these agents in this way they are evenly charged
upon the hearth and covered with a sheet or plate of iron, and the
chemical reagents of the aforesaid processes are charged upon the sheet
or plate iron. When the reactions of the process are completed and the
resulting malleable iron settles upon the sheet iron, the sheet iron also
melts and becomes a part of the charge, and the agents for giving the
steely property being liberated rise up through the metal and become
incorporated with it, and cause it to become cast steel or homogeneous
mallcable iron in the condition to be run or poured from the hearth into
ingots.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Saint John Vincent Day in the Great Seal Patent
Office on the 12th October 1874.
"
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAINT
JOHN VINCENT DAY, of 166, Buchanan Street, Glasgow, in the County
of Lanark, North Britain, Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her
Letters Patent, bearing date the Thirteenth day of April, in the year
of our Lord One thousand eight hundred and seventy-four, in the
37th year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Saint John Vincent Day, Her
special license that I, the said Saint John Vincent Day, my executors,
administrators, and assigns, or such others as I, the said Saint John
Vincent Day, 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 In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL AND IN

page_text: with the first part of the said Invention. The bottom A of the furnace,
shewn by these Figures, is movable, not only for convenience of repairs,
but also for the purpose of charging the furnace with the reagents
necessary for the removal of impurities, such as silicon, sulphur,
phosphorus, and carbon from the crude iron being converted into cast
steel or homogeneous malleable iron in the said furnace. The reagents
employed are those set forth in the Specification filed under Letters
Patent No. 318, A.D. 1870, granted to Alfred Vincent Newton, as a
communication from the said James Henderson, and which consist of
titaniferous iron or titaniferous iron ores in conjunction with fluor spar,
the latter of which substances is rendered plastic by being mixed with
starch, gum water, or other mucilaginous substance, and in that con-
dition applied to the sides and sole of the movable bottom A and dried
thereon, whilst the titaniferous iron or titaniferous iron ore is admixed
with the crude iron and melted, previous to being run into the rever-
beratory furnace, wherein the reactions of the fluor spar and titaniferous
iron take place, as set forth in the aforesaid Specification.
In lieu of these reagents the movable bottom A of the furnace may
be lined with the reagents set forth in the Specification filed under
Letters Patent No. 1051, A.D. 1870, granted to the said James
Henderson, and which consists of a combination of fluor spar or fluorides
with oxides, theso reagents being so employed as to ensure the simul-
taneous reaction of the fluorides and oxides on the crude iron, and so
remove silicon, sulphur, phosphorus, and carbon therefrom.
The reagents set forth in the Specification filed under Letters Patent
No. 554, A.D. 1872, granted to the said James Henderson, may also be
employed to line or cover the interior of the movable bottom A, in
manufacturing cast steel or homogeneous malleable iron under this
Invention. These reagents consist of fluor spar, or artificial fluorides of
calcium, fluo-silicate of lime, cryolite, or the fluorides of sodium and
aluminum, in combination with other substances which are capable of
evolving oxygen and acids to act upon the metallic base of the fluorides
or fluo-silicate of lime, and so liberate the fluorine, which reacts with
the impuritics contained in the crude iron being operated upon, as set
forth in the said Specification.
The reagents, consisting of fluo-silicate of lime in admixture with
oxides of iron annloved under the Lottons Patant No 0210
1070 מ

page_text: granted to the said. James Henderson (for the removal of silicon, sulphur,
phosphorus, and carbon from crude iron), may also be applied in the
production of iron and steel under this Invention to the interior of the
movable bottom A of the reverberatory furnace shewn at Figures 1, 2, 3,
and 4, Sheet 1 of the Drawings, which furnace is used under such
temperatures as will render the cast steel and homogeneous malleable
iron liquid, so that it may be poured from the hearth of the movable
bottom A. The required temperatures are produced by the complete
combustion of the gases or fuel, and this complete combustion is effected
by measuring the quantity of air employed in producing the combustible
gases or carbonic oxide, and again by using the precise quantity of air
requisite to burn or convert these gases into carbonic acid.
The hearth or bottom A of the furnace is movable vertically by being
mounted on a table or platform B fixed to the upper end of an hydraulic
ram C, or it may be connected with other equivalent raising and lowering
mechanism, such for example, as racks and pinions, screws, ropes, or
chains, and the bottom A is provided with wheels or rollers a, which
run on rails b, when the bottom is at the position shewn in dotted lines
at Figure 1, Sheet 1, by which means the bottom may be run out from
and returned to its position underneath the reverberatory chamber D of
the furnace. Bevilled or inclined surfaces c are formed at opposite ends
of the movable bottom A, which, to prevent leakage when the bottom is
at its raised position, bear at one end of the hearth against a corres-
pondingly inclined surface made in the brickwork of the furnace, and at
the other end against the inclined side of a hollow water bridge or
channel E, as shewn at Figure 1. The inclined surfaces c may be made
of fire-clay or other suitable refractory material, or they may be made of
hollow cast iron with water circulating through them. The sides of the
furnace may also be made of hollow cast iron with water circulating in
the space so formed. The movable hearth or bottom A. is provided with
a lining d of refractory material, such as sand, fire-clay, ganister, or a
mixture of these materials, or the materials used for making. steel,
melting crucibles may be employed to line it. The reagents herein-
before set forth are used by being spread over the movable hearth or
bottom A, for which purpose the hearth is lowered (by allowing the
water to escape from the cylinder F), and run out from below the
reverberatory chamber D, and it is preferred to cover the refractory
lining d of the hearth with sheet iron before charging the reagents. It

page_text: is however to be understood that the use of sheet iron in this manner
forms no part of the present Invention.
The combustible gases employed in converting the crude iron in the
reverberatory chamber D into cast steel or homogeneous malleable iron.
enter the flues G from any suitable gas producer by the opening at H.
From the flue G the combustible gases pass upwards through the flues
or apertures f, wherein they are impinged upon and admixed with
atmospheric air preferably heated to from 1400 to 2000 degrees
Fahrenheit. The gases are thereby inflamed or ignited, and passing
over the bridge I enter the reverberatory chamber D, wherein they act
upon the crude iron, the products of combustion being thereafter con-
veyed away from the furnace by the flue J. The heated air passes into
each flue or passage f from twyers g, which communicate at their lower
ends with pipes / connected to a pipe i leading from the air heating
stove or apparatus shewn in part at Figure 1, and which consists
of a flue K, through which combustible gases are conveyed from a gas
generator to the entrance flue L of a Whitwell's or other air heating
stove. M is the hot air flue or passage leading from the stove, and
through which the heated air is conducted to the pipe i. A valve,
preferably a water valve o, is employed to close the entrance to the
pipe, whilst the combustible gases are passing through the stove
wherein they are admixed with a quantity of air sufficient to inflamo
and consume them.
When Whitwell's fire-brick stoves are used the combustible gases heat
the refractory lining of the stove, which, being effected to a sufficient
degree, the gases are shut off and air passed over the refractory lining,
and becoming highly heated, is thereafter passed through the flue M,
pipes and h, and twyers g into the gas flues f, whereat the air and gas
are inflamed and pass through the reverberatory chamber D, as herein-
before described.
When a uniform temperature of the furnace is required a single iron
air heating stove giving temperatures of from 1000 to 1200 degrees
Fahrenheit may be used, or Whitwell's stoves applied in pairs, so that
whilst one is being heated the other is heating the air, may be employed.
Or a single Whitwell stove may be used when the pig iron is to bo
converted into malleable iron without the use of heated air, in which
latter case the stove is being heated whilst the conversion of the pig iron
is being so effected.

page_text: When the conversion of the pig iron into malleable iron has been
effected air is conducted through the stove, and by this means heated air
is provided to inflame the gases and raise the temperature of the furnace
sufficiently to render the metal contained therein liquid enough to be run
from the hearth as cast steel or homogeneous malleable iron. It is
preferred however to use one iron or two Whitwell's air heating stoves
to maintain a uniform temperature throughout the process, when one
furnace and a single set of twyers are used, as shewn at Figure 1, Sheet 1,
to convert the crude iron into cast steel or homogeneous malleable iron.
A pipe is provided in conjunction with each row of flues or passages f,
and the said pipes may each be formed with an annular space around
them, in which water may be made to circulate. Various proportions of
the gas flucs or passages ƒ relatively with the air twyers and with the
hearth space of the furnace may be adopted. The following proportions
give good results, namely, 36 of the air twyers 9 of 1 inch diameter,
situate in a like number of gas flues or passages f, about 4 inches
the space occupied by the movable hearth A being approximately 9 feet
wide by 7 feet long. These relative dimensions of the twyers g and gas
flucs or passages are approximately such as to admit of the passage
through the twyers g of 1000 cubic feet of atmospheric air heated to
1600 degrees Fahrenheit during the time that the carbonic oxide or
combustible gases produced from coke by the use of 1000 cubic feet of
atmospheric air is passing through the flues f.
square,
The air to be heated as well as that employed in generating the
carbonic oxide is previously measured at 50 degrees Fahrenheit, and
at pound pressure per square inch by apparatus herein-after set
forth. It is however to be understood that the Inventor does not
confine himself to the proportions herein-before given, as the size of the
air twyers may be increased or diminished according to the temperature
or pressure of the air passing through them as is well understood.
The air twyers g, instead of being arranged as shown on the Drawings,
may be placed lower in the gas flues f, and the said gas flues may also
be made deeper, whereby a more intimate admixture of the air and gas
is ensured in the flues or passages.
When the fuel employed in generating the combustible gases is either
coke or anthracite, free or practically free from hydrogen, the greatest
amount of heat obtainable from the fuel is produced by conducting

page_text: through the twyers 9 and mixing with the gases a weight of air or
oxygen equal to that used in producing carbonic oxide in the generator,
as herein-before described, an object of importance being to prevent
cither an excess or a deficiency of air, either of which reduces the
temperature produced.
In order to ensure a constant measured delivery of the air used both
for producing carbonic oxide in the generator and for burning the
carbonic oxide into carbonic acid, the furnace is provided with a blast
apparatus (not shewn on the Drawings, but) which consists by preference
of two air forcing cylinders of equal capacity, the pistons or plungers of
which are driven at equal speeds by one steam cylinder direct, or by an
equivalent motor.
The air driven from one of the cylinders supplies the gas generator,
that from the other cylinder inflames or burns the gases issuing from
the generator to the reverberatory furnace through the flues or passages f
into carbonic acid.
In place of using two air compressing cylinders, one or more than two
such cylinders or fans may be used, the quantities of air delivered to the
gas generator and the twyers being thus regulated by passing through
air meters placed ono in cach of the pipes leading to the gas producer
and to the twyers g.
If the fuel used for producing the gases contains hydrogen, the
resulting gases will require more air to burn them completely than is
used in the generator itself, the proportion of such increase of air being
determined by the character of the gases and according to the chemical
equivalents involved.
The furnace hercin-before described and shown at Figures 1, 2, 3,
and 4, Sheet 1, of the Drawings, may in lieu of being fired at one end
be provided with duplicate arrangements of flues and twyers similar to
those shewn, in which case the furnace is fired at both ends, and it may
or may not also be provided with air heating stoves placed to receive the
hot waste gases issuing from the furnace, the heat of which is thereby
imparted to the air, or the hot waste gases may escape through a flue to
a chimney, in which case the air heating stoves are heated by gas
generated separately from the furnace.
The mode of working the improved reverberatory gas furnace now
under reference is as follows:-The movable licarth A whilst out of the

page_text: furnace is charged with the reagents used under any of the processes of
making cast steel and homogeneous malleable iron in accordance with
the Specifications filed under the Letters Patent herein-before referred
to. If it is desired to produce the cast steel or homogeneous malleable
iron from pig iron, not previously melted in a cupola or melting furnace,
under the modes set forth in the said Specifications No. 1051, A.D. 1870,
No. 554, A.D. 1872, and No. 2318, A.D. 1872, the pig iron in the
proportions relatively with the reagents set forth in these aforesaid
Specifications, or in other suitable proportions, according to the nature
of the pig iron employed, is at the same time also charged into the
hearth A, which being effected the hearth is run in over the hydraulic
cylinder E and raised to its position in the furnaces by the hydraulic
ram C. The gas and air are then directed into the furnace and the heat
generated by the combustion thereof liberates the reagents, which
remove the impurities from the iron in the form of vapour, or slag,
or both.
When operating with pig iron proviously melted in a cupola or melting
furnace the reagents to be employed are placed on and around the
interior of the hearth A, when the hearth is out of the furnace, the
hearth is then returned to its raised position, and the reagents heated
until they become viscid or somewhat hard or united by heat, so that
when the molten metal is charged upon them they will not be floated or
displaced. It is preferred to run the molten metal from a cupola or
melting furnace situate at L (Figures 2 and 3, Sheet 1), into the
reverberatory furnace through the opening or doorway at M, in amount
sufficient to cover the hearth A to a depth of about 1.5 inches. Tho
reverberatory furnace is kept at the highest temperature until the con-
version of the metal into cast steel or homogeneous malleable iron is
effected, which with average qualities of molten No. 4 pig iron will be
in from 1 to 2 hours, after which the metal may be run or poured from
the movable hearth through the spout N, Figure 4, when the hearth is
either at its raised or lowest position.
Instead of using air at the highest temperature during the whole time
of the conversion of the cast-iron into cast steel or homogeneous
malleable iron, the air may be used at the ordinary temperature until
the metal is deprived of the whole or nearly all of its carbon, and then
the temperature may be increased by the use of heated air.

page_text: and oxides, as herein-before set forth to purify the metal either into
steel, or as suitable for conversion into steel. The proportions of the
fluorides and oxides employed under this mode is determined by the
quantity of carbon and impurities in the metal. If the carbon and
impurities in the metal are greater than 1 per cent. of carbon and 1 per
cent. of phosphorus, the proportions of fluorides and oxides should bo
about the same as are given in the aforesaid Specification, No. 1051,
A.D. 1870, and if the impurities are simply silicon, phosphorus, and
sulphur, the proportions of the fluorides and oxides are the same as
those herein-before mentioned for treating Bessemer metal which is
decarbonised.
It is preferred in working with old or scrap wrought iron to use about
1% of the whole charge of molten grey foundry pig iron before charging
the wrought iron, and then to add the wrought iron at a white heat in
about the proportion of one-half of the whole charge, and after the iron
is all melted, and to ensure its being thereby liquid it is preferred to add
about 16 per cent. by weight of liquid grey pig iron, and then to tap
the metal into another reverberatory gas furnace constructed with a
movable bottom and otherwise similar to the furnace illustrated at
Figures 1, 2, 3, and 4, Sheet 1, on the hearth, of which other furnace
fluor spar or fluorides and oxides are spread to remove the impuritics
from the molten metal being converted into cast steel or homogeneous
malleable iron.
It is generally preferred in producing cast steel or homogeneous
malleable iron under any of the modes hercin-before described to
cmploy a sufficient quantity of the chemical re-agents to ensure the
removal of all the carbon and afterwards to recarbonise the purified
product with spiegel eisen or ferro-manganese, or the stccly property
may be given to the product by other methods herein-after described
under the third head of this Invention.
Figure 5, Sheet 1 of the Drawings, is a vertical section; Figure 0,
a plan; and Figure 7, an elevation of the end marked A, Figure 5,
of a modified arrangement of the improved reverberatory gas furnace
herein before described in reference to Figures 1, 2, 3, and 4, Sheet 1,
and which may be employed in converting cast or crudo iron alone,
or in combination with old or scrap wrought iron into cast steel, or
homogeneous malleable iron, in any of the modes herein-before set
forth in reference to the said first arrangement of reverberatory gas

page_text: The heated air employed in inflaming the combustible gases is
regulated as to quantity relatively with the air employed in generating
the combustible gases in the manner herein-before described in reference
to the first arrangement of improved reverberatory gas furnaces as
constructed in accordance with this Invention; and the number of gas 5
flues F and twyers d, and also the dimensions of these flues and twyers
are regulated by the area of the movable hearth I, and as regards the
twyers d by the temperature of the air passing through them..
The air twyers d may, or may not, have an annular space around
them for the circulation of water, and they may be made of iron, of 1
platinum, or of fire-clay, or a mixture of fire-clay and plumbago, or of
other suitable material.
The reverberatory furnace may now under reference, as well as the
furnace herein-before described in reference to Figures 1, 2, 3, and 4,
Sheet 1 of the Drawings, is or may be provided with a damper in the 1
flue, through which the waste products of combustion are conveyed
away from the reverberatory chambers D and H in order to regulate
the amount of combustible gases in these chambers.
The movable bottom I of the furnace, shewn at Figures 5, 6, and 7,
Sheet 1, may also be so arranged as to be capable of turning round in 2
order to expose the coldest end of the hearth to the hottest part of the
furnace. To effect this when a rectangular bottom is employed, it is
lowered so as to clear the parts of the furnace into which it fits, and
thereafter turned round, the lower part of a chamber below the furnace
being made of a size sufficiently large to enable the turning to be
effected without removing the bottom from under the reverberatory
chamber; or the bottom may be made circular and turned round with-
out being lowered. In either case it is preferred to turn the bottom at
intervals of 30 minutes.
The second part of this Invention consists in the use of two 3
reverberatory furnaces for the production of cast steel and homogeneous
.malleable iron, in one of which furnaces the conversion of the cast iron
-into steel or malleable iron, by the processes herein-before described is
effected at the temperature of a boiling or puddling furnace, which
produces iron in such a state that it can not be run or poured from the 3
hearth of the furnace. The furnace in which this conversion takes
place is provided with a movable hearth similar to that herein-before
"

page_text: described and shewn on Sheet 1, of the Drawings, and when the process
of conversion of the cast iron into steel or malleable iron is complete,
and whilst the metal is at the highest temperature the hearth and the
contained metal are lowered on to the rails as at b, Figure 1, Sheet 1, of
the Drawings, and removed to another reverberatory furnace in which
higher temperatures are maintained and which will melt the steel or
malleable iron, so that it will be liquid enough to be run from the
furnace into ingots, which will be in a fit condition to be hammered or
rolled. The furnace wherein the higher temperatures are maintained is
made with a space under the reverberatory chamber to receive the hearth
from the furnace in which the cast, pig, or crude iron is first treated, and
which is raised to its position in the latter furnace by an hydraulic ram or
equivalent mechanism in the manner herein-before described. The
steel or malleable iron which is preferably about 1.5 inches deep upon
the hearth is then exposed (with a covering of cinder or silicious slag) to
the action of the higher temperatures of the said latter furnace until
the metal is in the condition to be run or poured from the hearth into
ingot moulds. The furnace with lower temperatures may be á
reverberatory furnace of the ordinary construction using solid fuel, or it
may be a furnace for using gas and air either at the ordinary temperature
or for using heated air, and arranged similar to either of the reverberatory
gas furnaces herein-before described and shewn at Figures 1, 2, 34, and
5, 6, and 7, Sheet 1, of the Drawings.
The furnace with the higher temperatures may be a Siemen's gas
regenerative steel melting furnace with the ordinary bottom left out,
and constructed to receive the movable bottom from the furnace with
lower temperatures, as shewn in vertical section at A, Figure 8, Sheet 1
of the Drawings. Or in lieu of using a Sicmen's furnace a steel melting
furnace provided with Whitwell's fire-brick air licating stoves. at each
end as indicated at A in vertical section at Figure 1, and in horizontal
section on the line a, b, Figure 1, at Figure 2, Sheet 2 of the Drawings
may be employed. The stoves A are arranged to receive the waste
heated products of combustion after passing through the reverberatory
chamber B with which they communicate by flucs C, in each of which
a damper D is placed as shown. Air twyers a and gas flucs and F
are placed at each end of the reverberatory furnace, by which micans the
currents of heat may be reversed as desired as in a Sicmen's furnace.
When air is being heated by passing through one of the stoves at A

page_text: communication between that stove and its flue C is shut off by the
damper D, whilst the damper of the other flue is raised to allow the
heated waste products of combustion to pass through the air heating
stove in connection therewith, which stove is thereby heated and imparts
its heat to the air passed through it when the currents through the t
reverberatory furnace are again reversed. From each stove at A the
heated air passes into a pipe E, thence through branch pipes a¹ to the
air twyers a, on issuing from which the air is admixed with the gas in
the flues and inflames it. The upper ends of the flues b are covered
by movable slabs G formed with openings d therein, through which 1
the inflamed gas passes upwards into the flues C. The slabs G are
adjusted in the flues C so as to be slid or pushed over the upper ends of
the flues 6 when the heated waste products of combustion are passing
over them to the stoves at A, as shown more particularly at the right-
hand end of Figure 2, Sheet 2, whereby the said products are prevented 1
from passing thereinto. Spiegel eisen or ferro-manganese may be used to
give the steely property to the metal so treated in the manner well
understood.
The third part of the said Invention relates to an improved method of
giving the steely property to wrought iron to form cast steel or homo- 2
geneous malleable iron in large quantities in reverberatory furnaces,
which for convenience of charging the materials for giving the steely
property are preferably provided with movable bottoms or hearths con-
structed and operated substantially similar to the movable bottom or
hearth herein-before described in reference to the first hicad of the said
Invention.
In carrying out this part of the Invention it is preferred to uso a
reverberatory gas furnace constructed similar to the furnaces herein-
before described and shewn in reference to the first and second heads
of the Invention, and illustrated on Sheets 1 and 2 of the Drawings, or a
other furnaces using air under high or great pressure may be employed.
The hearth or bottom whilst out of the furnace is charged with the
agents for giving the steely property, which may be powdered charcoal
with the oxide or carbonate of manganese, or charcoal with chrome
iron ore, or carbonate of manganese with wolfram, these agents being a
used in the same proportions that would be required to give the
steely property to wrought iron to make cast steel or homogeneous
malleable iron when applied together in crucibles. The agents are

page_text: Sixth. Giving the steely property to cast steel and homogeneous
malleable iron in the manner herein-before described in reference to the
third part of this Invention.
In witness whereof, I, the said Saint John Vincent Day, have
hereunto set my hand and seal, this Tenth day of October One
thousand eight hundred and seventy-four.
ST. JOHN VINCENT DAY. (L.S.)