IMPROVEMENTS IN THE CON- VERSION OF CAST IRON INTO STEEL OR WROUGHT IRON, AND IN THE APPARATUS EMPLOYED THEREIN.
Year: 1872

page_text: LETTERS PATENT to Robert Elsdon, of Brockham, in the County of
Surrey, Engineer, for the Invention of "IMPROVEMENTS IN THE CON-
VERSION OF CAST IRON INTO STEEL OR WROUGHT IRON, AND IN THE APPARATUS
EMPLOYED THEREIN.
"
Sealed the 20th August 1872, and dated the 22nd February 1872.
PROVISIONAL SPECIFICATION. left by the said Robert Elsdon at the
Office of the Commissioners of Patents, with his Petition, on the
22nd February 1872.
I, ROBERT ELSDON, of Brockham, in the County of Surrey, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE CONVERSION OF CAST IRON INTO STEEL OR WROUGHT IRON, AND IN THE
APPARATUS EMPLOYED THEREIN," to be as follows:-
My improvements relate to those processes of manufacturing steel
or wrought iron wherein cast iron in a molten state is treated with a
decarbonising and purifying material such as nitrate or chlorate of soda,
nitrate or chlorate of potash, or other analogous substances.

page_text: My Invention consists, firstly, in causing the gases generated by the
decomposition of the salts employed to act upon the liquid metal in a
more uniform manner than has been effected heretofore, and this I
propose to effect by applying the salts above the surface of the molten
metal in the converter instead of beneath, in such manner that the gases
generated shall act downwards, and thereby be caused to operate more
fully upon the metal under treatment.
2ndly. In a peculiar construction, adaptation, and arrangement of
apparatus for carrying my process into effect. To this end I employ a
curved or syphon shaped converter, mounted on an axis and capable of
being revolved thereon to any desired extent. Over one branch of the
converter when it is charged with the molten cast iron I cause the
before-mentioned salts in a measured quantity contained in a vessel,
which may be partially or wholly filled therewith, to be quickly placed
and securely retained in position until they are converted into gas, which
gas acts downwards upon the metal, and passing through it effects the
desired chemical changes & carrics off the impuritics, finally escaping
by the other branch of the converter.
By an arrangement of chimnies and a suitable gas or other heating
furnace in connection with the converter, I am enabled to apply heat to
the said converter at any desired part of the operation by mercly turning
it on its axis so as to place it in communication with the furnace in such
manner that it becomes for the time being the bed or sole of such
furnace; for example, before allowing the charge of metal to flow from
the melting cupola, or other melting or smelting furnace into the con-
verter, I heat up the latter so as to prevent the cooling of the charge
on contact therewith before the salts are applied; also, if required, I
apply heat by the same means to the converted metal before casting the
same into ingots. In order to prevent the too sudden action of the salt
upon the molten cast iron I sometimes interpose between them a layer of
small pieces of steel or other suitable substance, by preference as free
from carbon as may be convenient.
The removal of the converted metal from the converter may be effected
either by turning it down into a suitable position to pour the metal·
therefrom, or by means of a tap hole in the ordinary way.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Elsdon in the Great Seal Patent Office on
the 22nd August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
ELSDON, of Brockham, in the County of Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of February, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert Elsdon, Her special
licence, that I, the said Robert Elsdon, my executors, administrators,
and assigns, or such others as I, the said Robert Elsdon, 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, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
VERSION OF CAST IRON INTO STEEL OR WROUGHT IRON, AND IN THE APParatus
EMPLOYED THEREIN," upon the condition (amongst others) that I, the said
Robert Elsdon, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, 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 Robert Elsdon, do hereby declare
the nature of my 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 accompanying
Drawing:-
My improvements relate to those processes of manufacturing steel
or wrought iron wherein cast iron in a molten state is treated with
a decarbonizing and purifying material, such as nitrate or chlorate of
soda, nitrate or chlorate of potash, or other analogous substances.
My Invention consists, firstly, in causing the gasses generated by the
decomposition of the salts employed to act upon the liquid metal in a
more uniform and perfect manner than heretofore, and in order to effect
this I apply the salts above the surface of the molten metal in the
.

page_text: converter instead of beneath, in such manner that the gasses generated
shall act downwards, and thereby be caused to operate more fully upon
the metal under treatment.
Secondly. In a peculiar construction, adaptation, and arrangement
of apparatus for carrying my process into effect. To this end I employ
a curved or syphon shaped converter mounted on an axis and capable
of being revolved thereon to any desired extent. Over one branch of
the converter when it is charged with the molten cast iron I cause the
before-mentioned salts in a measured quantity contained in a vessel,
which may be partially or wholly filled therewith, to be quickly placed
and securely retained in position until they are converted into gas, which
gas acts downwards upon the metal, and passing through it effects
the desired chemical changes and carries off the impurities, finally
escaping by the other branch of the converter.
By an arrangement of chimnies and a suitable gas or other heating
furnace in connection with the convertor, I am enabled to apply heat
to the said converter at any desired part of the operation by merely
turning it on its axis, so as to place it in communication with the
furnace in such manner that it becomes for the time being the bed or
sole of such furnace; for example, before allowing the charge of metal
to flow from the melting cupola or other melting or smelting furnace
into the converter, I heat up the latter so as to prevent the cooling
of the charge on contact therewith before the salts are applied; also,
if required, I apply heat by the same means to the converted metal
before casting the same into ingots. In order to prevent the too sudden
action of the salt upon the molten cast iron I sometimes interpose
between them a layer of small pieces of steel or other suitable substance,
by preference as free from carbon as may be convenient.
The removal of the converted metal from the converter may be
effected either by turning it down into a suitable position to pour the
metal therefrom or by means of a tap hole in the ordinary way.
Figure 1 is a side elevation of the apparatus; Figure 2 a longitudinal
section, Figure 3 a plan, and Figure 4 an end elevation of the same.
A is the converter, which I prefer to be of the syphon shape and
oblong section shown, but any other suitable form may be employed. It
is composed of a casing of wrought or cast iron, with a lining of fire-clay,
ganister, or other refractory materials. The converter is carried upon
the axis B supported in bearings in the side frames C, C, which latter

page_text: ог
support also certain other parts of the apparatus, so as to make it as
much as possible self-contained. D is the vessel open at bottom con-
taining the salts intended to act upon the molten metal in the converter;
this vessel slides over the surface of the plate E, so as to be brought
over the chamber F to receive the charge of salts therefrom, and then
suddenly slid over the mouth of the converter when the "blow
converting operation is to be performed. The chamber F forms a
measure in which the salts are gauged prior to their being forced into
the vessel D by the piston G, which is operated by the racks and
pinions H, H. The cross head I connected to the frames C, C, by
strong columns J, J, resisting not only the pressure of the piston G
on the salts in the vessel D, but also the force of their explosion, when
the vessel D is brought into communication with the converter. The
vessel D containing the salts is slid with the requisite suddenness over
the mouth of the converter by means of a heavy weight K. connected
with it by the levers L and links M, which is allowed to fall when
released by the trigger M, the vessel D being returned over the chamber
F by means of a lever O applied to the axis P. Q is a chimney in
connection with the longer branch of the converter, and which forms the
exit for the gasses during the "blow" or converting process. It will
now be understood that the charge of cast iron may be conveyed direct
from the cupola or other melting furnace into the converter, which
thus becomes a means of measuring the said charge. A proportionate
quantity of salts having been measured into the vessel D, if desired a
layer of small pieces of steel or other suitable substance having been
first placed in the measuring chamber to prevent the too sudden action
of the salt upon the molten metal as already described, it is slid suddenly
over the mouth of the converter and if needful clamped thereto, when
the salts come in contact with the molten metal the "blow" takes place
and the gasses forcing their way downwards through the metal or forcing
it up into the longer branch of the converter finally escape through it
to the chimney Q. Projecting ribs may be formed in the converter
such as R, R, in the most suitable positions and forms, so as to retard
and baffle the gasses and metal, and prevent the too sudden escape of the
former through or past the latter. If desired the charge of metal may
be treated with a second or any required number of charges of salt
before "pouring "into the ingot mould S or reheating furnace I. If
desired the converter can be put into communication with the furnace.T
or other source of heat for the purposes before described by merely

page_text: turning it on its axis into the position shown in dotted lines, the piece V
being adapted to slide into position to complete the connection between
the furnace and the longer branch of the converter, while the shorter
When it
branch thereof becomes connected with the chimney U.
is desired to pour or remove the converted metal the longer branch of
the converter is tilted still lower down, the chimney U being turned
out of the way by the screw and wheel W to admit thereof, or a tap
hole in the bottom of the converter may be used if preferred. The
converter is moved on its axis as required by means of gearing such
as the sectors X and pinions Y, or in any other convenient manner and
counterbalanced by the weights Z.
Having now described the nature of my said Invention, and the
manner in which the same is to be or may be performed, I would have
it understood that I do not confine myself to the precise details of
apparatus shown and described, as they may be varied without departing
from my Invention; but what I claim is,―
Firstly. Applying decarbonizing and purifying materials, such as
those described above, the surface of the molten metal, to be converted
instead of beneath, substantially as and for the purposes described.
Secondly. The apparatus consisting of the converter A, the moveable
vessel D, measuring chamber F, and chimnies Q and U constructed,
arranged and applied substantially as described and shown.
Thirdly. The converter A so arranged and adapted as to receive and
measure the charge of metal direct from the melting cupola or furnace
and to serve either as a converter or as a reheating chamber, substan-
tially as described and shown.
Fourthly. The moveable vessel D for conveying the salts to the con-
verter in connection with the measuring chamber F arranged and operated
substantially as described and shown.
In witness whereof, I, the said Robert Elsdon, have hereunto
set my hand and seal, this Twenty-first day of August One
thousand eight hundred and seventy-two.
ROBERT ELSDON. (L.S.)