IMPROVEMENTS IN THE MANU- FACTURE OF STEEL AND MALLEABLE CAST IRON, AND IN APPARATUS TO BE USED IN SUCH MANUFACTURE
Year: 1864

page_text: LETTERS PATENT to Frederic Yates, of Birmingham, in the County of
Warwick, Engineer, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF STEEL AND MALLEABLE CAST IRON, AND IN APPARATUS TO BE USED
IN SUCH MANUFACTURE."
Sealed the 2nd May 1865, and dated the 4th November 1864.
PROVISIONAL SPECIFICATION left by the said Frederic Yates at the
Office of the Commissioners of Patents, with his Petition, on the 4th
November 1864.
I, FREDERIC YATES, of Birmingham, in the County of Warwick, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF STEEL AND MALLEABLE CAST IRON, AND IN APPARATUS TO BE
USED IN SUCH MANUFACTURE," to be as follows:-
These improvements consist in the application of a combination of highly
heated steam and highly heated atmospheric air to heated pig or cast iron, for
the
purpose of partially or wholly decarbonizing it, so as to produce.crude stee!
or malleable cast iron. I also employ this process to reduce hard or brittle
steel to a lower temper; in fact it is applicable in all cases where it is
required to extract carbon out of iron or steel.
The improvements consist further in a new form of apparatus in which the
operation is to be performed, the said apparatus or furnace being so arranged
that it can be heated either by gaseous or solid fuel, the former being preferred

page_text: as being more economical. This apparatus may also be employed in the
cementation of steel by the old process in place of the furnace now in use.
The apparatus is composed of one or more clay or metal retorts or vessels of
any convenient form and dimensions, and provided with mouthpieces similar
to a gas retort, and capable of holding one or more tons of cast iron. These
retorts or vessels are furnished with moveable doors or covers at either end
for the convenience of charging and discharging the iron therefrom. For
steel making I prefer to place the retorts horizontally, but for making
malleable cast iron articles it is as convenient to place them vertically, but
I do not confine myself in either case to either the one position or the other.
At one end of the vessel or retort one or more small pipes or tubes furnished
with stopcocks or valves are attached for the purpose of admitting the steam
the
and air, and at the other end are placed similar tubes for conveying away
vapours after they have passed over, under, and around the iron under opera-
tion. The retorts when lying horizontally are placed in a reverberatory furnace,
which by preference is heated with gaseous fuel created by two gas generators,
one placed at either end of the furnace. The heated gases pass into the furnace
at right angles to the length of the retorts, and are there burnt. The flames
pass along from the ends to the middle of the furnace, completely enveloping
the retorts or vessels; they then pass out at the bottom or floor of the furnace
into a chamber beneath, and here heat the steam and air, which are passed
through iron or other pipes or tubes, or the steam and air may be heated in any
other convenient manner. The hot flame and products of combustion also com-
municate heat to a small steam generator for creating the necessary steam for
the process or for driving a small fan, and then pass off into the chimney or
stack. The air can either be supplied from a blower, such as a bellows or fan
or an exhauster, or can be sucked in with and by the steam by a similar arrange-
ment to that sometimes employed in the refining of lead for the extraction of
the silver therein contained. Where the vessels or retorts are placed vertically,
I still by preference use gas for heating them, placing the steam and air-
heating pipes and the steam generator in such a manner in the flues that they
are always heated by the surplus flame and hot products of combustion before
they ultimately pass into the chimney. The process may also be carried on
with a heat produced from ordinary fuel. Five retorts, each holding about
two tons, is the number I prefer to put into one furnace. After the furnace
and the retorts or vessels are at a sufficiently high temperature, I charge the
retorts with about two tons of thin bars of the purest cast iron, but other cast
iron, or articles made of cast iron, and which have been cast in chills or iron
moulds, may be operated upon. I place theso in the retorts in such a manner

page_text: that between each of the bars or pieces there shall be space left for the steam
and air to have free access to all the surfaces of the bars or pieces. I then
close and lute up the doors or covers at the ends, and when the iron bars or
pieces are at a sufficiently high temperature I open the cocks and allow a
stream of the highly heated steam and air to pass into the retort or vessel
and amongst the iron, keeping up the temperature of the retorts all the while
at an equable degree. The gaseous products pass away through the tubes
or pipes at the opposite end of the retorts or vessels; the induction and
eduction of the steam and air being regulated by the stopcocks aforesaid.
After the process has been carried on for about 24 hours, more or less, trial
pieces are taken from time to time out of the retorts or vessels, and the temper
observed until it is ascertained that the whole mass has been reduced to the
desired state of decarbonization. When slightly cooled down the covers or
doors of the retorts or vessels are removed, and the crude steel taken out and
another charge put in. The fresh bars, if thought advisable, may be pre-
viously heated to rodness in the chamber below the hearth of the furnaces.
From 36 to 48 hours usually suffices to produce the crude steel required, but
if malleable cast iron be under treatment, the time may vary from 12 hours
to 8 days, according to the size of the articles operated upon. When the
retort or vessel is placed vertically the same mode of manipulation is observed.
The crude steel thus made is now broken up, examined, and selected accord-
ing to temper, when, according to circumstances, it is re-melted or sold in its
then state. If re-melted, I prefer to do this in my gas reverberatory furnace
(Patent dated Jan 25th, 1860, No. 185), but it can also be done in pots in
the usual way.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederic Yates in the Great Seal Patent Office on the
4th May 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
YATES, of Birmingham, in the County of Warwick, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of November, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Frederic Yates, Her special license that I, the said Frederic Yates,

page_text: my executors, administrators, and assigns, or such others as I, the said
Frederic Yates, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term 'therein expressed, should and lawfully might make, use,
éxercise, and vend, within the United Kingdom of Great Britain and Ireland,
thie Channel Islands,. and. Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF STEEL AND MALLEABLE CAST IRON, AND IN APPARATUS TO BE
USED IN SUCH MANUFACTURE," upon the condition (amongst others) that I, the said
Frederic Yates, by an instrument 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 Frederic Yates, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, 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):-
This Invention of "Improvements in the Manufacture of Steel and
Malleable Cast Iron, and in Apparatus to be used in such Manufacture'
consists, first, in the application of a combination of higbly heated steam and
highly heated atmospheric air to heated pig or cast iron, for the purpose of
partially or wholly decarbonizing it, so as to produce crude steel or malleable
cast iron. I also employ this process to reduce hard or brittle steel to a lower
temper; in fact it is applicable in all cases where it is required to extract
carbon out of iron or steel.
The Invention consists further in a new form of apparatus in which the
operation is to be performed. This apparatus or furnace is shewn in the
accompanying Drawings, and is so arranged that it can be heated either by
gaseous or solid fuel, the former being preferred as being more economical.
This apparatus may also be employed in the cementation of steel by the old
process in place of the furnace now in use.
Fig. 1 is a plan view of my improved apparatus; Fig. 2 is a longitudinal
section of the same taken in the line A, B, of Fig. 1; and Fig. 3 is a trans-
verse section taken in the line C, D, of Fig. 1.
The apparatus is composed of any convenient number of clay or metal
retorts or vessels a, a, a, of any suitable form, and are capable of holding ono
or more tons of cast iron; these retorts or vessels a, a, aro furnished with

page_text: moveable doors or covers 6 and 6' at each end for the convenience of charging
and discharging the iron therefrom. For steel making I prefer to place the
retorts horizontally, as shewn in the Drawings, but for making malleable cast-
iron articles, it will be found as convenient to place them vertically, but I do
not confine myself in either case to either the one position or the other. At
the end of the vessels or retorts a, a, there is a chamber formed in the cover
by means of the vertical perforated plate or partition c; into this chamber air
is admitted from the pipe d, which is provided with a stopcock or valve d'.
Steam is also admitted to the chamber through a pipe e, also provided with a
stopcock or valve. At the other end of the retorts are placed similar tubes d"
for conveying away the vapours after they have passed over, under, and around
the iron under operation in the retorts a. The retorts when lying horizontally
are placed in a reverberatory furnace f, which by preference is heated with
gaseous fuel created by two gas generators, one placed at either end of the fur-
nace. The heated gases pass from the generators through the flues f¹, f', into,
the furnace at right angles to the length of the retorts a, and are there burnt.
The flames pass along from the ends to the middle of the furnace, and com-
pletely envelope the retorts or vessels a, after which the gases and heated
vapours pass out at the bottom or floor of the furnace through the openings ƒª
into a chamber g beneath, and heat the steam and air pipes h and h¹. It will
be seen on referring to Fig. 1 that these pipes are arranged in a serpentine.
form, and consist of two sets; one set h is for heating the air which passes
in, as indicated by the arrow h³, and the other set h' is for heating the steam,
which is conducted from any conveniently placed steam generator into the
pipes h', as indicated by the arrow h³ in Fig. 1. The hot flame and products
of combustion then escape from the chamber g through the flues i,.i, which
conduct them to a small steam generator, by heating which the necessary
steam is generated for the converting process or for actuating an engine for.
driving a small fan to force the air through the pipes d and d". The gases
then pass off into the chimney or stack in the usual manner.. .The air can
either be supplied from a blower, such as a bellows or fan or from an exhauster,
or it can be sucked in with and by the rush of the steam from the pipe e by a
similar arrangement to that sometimes employed in the refining of lead for.
the extraction of the silver therein contained. Where the vessels or retorts
are placed vertically, I still by preference use gas for heating. them, placing
the steam and air-heating pipes and the steam generator in such a manner in
the flues that they are always heated by the surplus flame and gaseous
products of combustion before they ultimately pass into the chimney.. The
process may also be carried on with a heat produced from ordinary fuel.

page_text: Five retorts, each holding about two tons, is the number I prefer to put into
one furnace.
After the furnace f and the retorts or vessels a, a, are at a sufficiently high
temperature I charge the retorts with about two tons of thin bars of the purest
cast iron, but other cast iron, or articles made of cast iron, and which have
been cast in chills or iron moulds, may be operated upon. I place this metal
in the retorts in such a manner that between each of the bars or pieces there
shall be space left for the steam and air to have free access to all the surfaces
of the bars or pieces. I then close and lute up the doors or covers b, b¹,
at the ends, and when the iron bars or pieces are at a sufficiently high
temperature, I open the cocks d¹ and e', and allow a stream of the highly
heated steam and air to pass into the retort or vessel through the perforated
plate c, whereby the steam and air are mixed and divided into thin streams or
jets, and are made to pass over the surface of the heated iron, care being
taken to keep up the temperature of the retorts all the while at an equable
degree. The mixed gases after acting on the heated iron pass away through
the tubes or pipes d¹¹ at the opposite end of the retorts or vessels, the
induction and eduction of the steam and air being regulated by the stopcocks
aforesaid. After the process has been carried on for about twenty-four hours
(more or less) trial pieces are to be taken from time to time out of the retorts
or vessels, and carefully examined to ascertain the progress of the converting
operation. When the whole mass of heated iron has been reduced to the
desired state of decarbonization, it may be slightly cooled down, and the
covers or doors 6, 61, of the retorts or vessels may then be removed, and
the crude steel taken out and another charge put in the retorts. The fresh
bars if thought advisable may be previously heated to redness in the chamber g
below the hearth of the furnace. From thirty-six to forty-eight hours usually
suffices to produce the crude steel required, but if malleable cast iron bo
under treatment, the time may vary from twelve hours to eight days, according
to the size of the articles to be operated upon. When the retorts or vessels
are placed vertically the same mode of manipulation is observed. The crude
steel thus made is now broken up, examined, and selected according to
temper, when according to circumstances it is re-melted or sold in its then
state. If re-melted, I prefer to do this in my gas reverberatory furnace
(Patent dated January Twenty-fifth, One thousand eight hundred and sixty,
No. 185), but it can also be done in pots or crucibles in the usual way.
Having now described my Invention of "Improvements in the Manufacture
of Steel and Malleable Cast Iron, and in the Apparatus to be used in such
Manufacture," and having explained the manner of carrying the same into

page_text: effect, I claim as the Invention secured to me by Letters Patent as aforesaid
the mode herein set forth of decarbonizing cast iron.
I also claim the arrangement or construction of the furnace or apparatus
herein-before described, or any mere modification, whereby the decarbonization
of cast iron may be effected in the manner above set forth.
In witness whereof, I, the said Frederic Yates, have hereunto set my
hand and seal, the First day of May, in the year of our Lord One
thousand eight hundred and sixty-five.
FRED°. YATES. (L.S.)