IMPROVEMENTS IN PUDDLING IRON AND STEEL, AND IN THE MACHINERY OR APPARATUS AND FURNACES EMPLOYED THEREIN
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN PUDDLING IRON AND STEEL, AND IN THE MACHINERY
OR APPARATUS AND FURNACES EMPLOYED THEREIN."-A communication
from abroad by Charles Pernot, of Paris, in the Republic of France,
Manager.
Sealed the 13th March 1874, and dated the 31st December 1873.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 31st December 1873.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PUDDLING IRON AND STEEL, AND IN THE
MACHINERY OR APPARATUS AND FURNACES EMPLOYED THEREIN," a communication
to me from abroad by Charles Pernot, of Paris, in the Republic of
France, Manager, to be as follows:-
1
This Invention relates to puddling furnaces having an inclined rotatory
hearth, for which Provisional Protection was granted to me August 27th

page_text: First. In the employment of a current of water, air, or steam, or
damp sand, or other damp or moist substances around the hearth of the
furnace for the purpose of preserving the hearth during the operation of
puddling. When water is used a conduit or sheet metal casing is
employed surrounding tho trough of the hearth, within which conduit
or between which casing and the external surface of the hearth the
water circulates and is constantly renewed. The quantity of water is
increased or diminished as required, according to the temperature to be
obtained at the various stages of the operation. A jet of water from a
pipe in the works provided with a cock may be employed to distributo
the necessary quantity as required. A free current is in any case
preferred to a current under pressure, as the former admits of the free
escape without danger of the steam produced, which might impede the
circulation.
Secondly. In the employment of a blast or forced draught for the
purpose of maintaining a plenum or internal pressure greater than the
pressure of the external atmosphere, and producing practically a joint
between the rotatory hearth and the walls of the furnace in order to
exclude the external air, the admission of which involves loss of heat.
This arrangement dispenses with the necessity for a tight joint, but a
joint of sand or other material may be employed in addition if
required.
Thirdly. In heating the furnace with gas. The gases required for
this purpose may be obtained from any suitable generator, and their use
renders practicable the manufacture of cast steel with the improved
furnace.
Fourthly. In the employment of a movable hearth of large dimen-
sions which admits of the treating of charges of say 1 ton and upwards,
or of any weight whatever, in combination with a furnace having two
or more doors for the purpose of facilitating the working of the balls.
The trough of the hearth is made of a size proportionate to the charges
to be operated upon.

page_text: Fifthly. In the employment of a double furnace, that is to say, two
furnaces coupled together or superposed, one of which, provided with a
rotatory hearth, is termed the "laboratory," and serves for the formation
of the wrought iron, and the other, which may be either fixed or mov-
able, is termed the "welding furnace," and is intended for the finishing
of the iron and the formation of the balls. The two furnaces may be
arranged in any suitable position with relation to each other, and may
be heated by gas. This arrangement of double furnace admits of
wrought iron and steel being produced continuously. In the "labora-
tory" the iron is brought to nature, and it is then carried to the
'welding furnace" in which the balls are made.
66
The hearth of the furnaces may have either a continuous rotatory
motion in one direction or a reciprocating rotatory motion in both
directions during the operations.
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 30th June 1874.
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 Letters
Patent, bearing date the Thirty-first day of December, in the year of
our Lord One thousand eight hundred and seventy-three, in the 37th
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 executors, administrators,
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 "IMPROVEMENTS
IN PUDDLING IRON AND STEEL, AND IN THE MACHINERY OR APPARATUS EMPLOYED
THEREIN," a communication to me from abroad by Charles Pernot, of

page_text: erves for the formation of the wrought iron; the other, which may be
ither fixed or movable, and is termed the "welding furnace," being
ntended for the finishing of the iron and the formation of the balls.
The latter furnace may be arranged with respect to the former either at
he fire-grate or the flue end of the same, or above it. This arrange-
nent is illustrated in Figures 4, 5, and 6 of the accompanying
Drawing.
The great difficulty which is experienced in maintaining the hearth in
the case of puddling furnaces in general, especially those in which large
charges are treated, has led the communicator of this Invention to seek
to discover a means of preserving the hearth from running during the
operation of puddling. The arrangement employed for this purpose
according to this Invention is illustrated in Figures 1, 2, and 3.
Figure 1 is a longitudinal section of the furnace taken through its
centre; Figure 2 is a horizontal section taken along the line 1-2; and
Figure 3 is a transverse section taken along the line 3-4 (Figure 1). It
consists of a current A of water, air, or steam, or damp sand, or other
humid substances surrounding the hearth C of the furnace. In the case
of water a sheet metal casing or conduit is employed, which admits of
the water circulating and being constantly renewed. At the various
stages of the operation the quantity of water introduced is increased or
diminished, according to the requirements of the temperature to be
obtained. A free current is preferred to a current under pressure, as
the steam which is formed may then escape freely and without danger, ·
whilst in the case of water under pressure the formation of steam has a
tendency to prevent the admission of the water, and a liability would
ensue of the furnace being stopped and of the hearth being burnt,
thereby necessitating the renewal of the latter. A jet of water from a
pipe in the works admits of the necessary quantity being distributed by
means of a cock to suit the requirements of the operation.
Second. Use of a blast which among other advantages admits of an
internal pressure being obtained, whereby the necessity for a tight.

page_text: "
In the case of a double furnace, that is to say one composed as shewn
in Figures 4 and 5 of a furnace D designated the "laboratory" and an
auxiliary furnace E termed the "welding furnace," the licarths of both
furnaces may be movable, or the "laboratory" alone may be movable
and the "welding furnace fixed. The relative position of these
furnaces may also be varied, one being arranged at the right or left hand
side of the other or one above the other, as found most convenient. In
either case these furnaces may be heated with gas. The arrangement of
the double furnace admits of wrought iron or steel being produced in a
continuous manner. The iron is brought to nature in the "laboratory "
D. whence it is conducted into the "welding furnace." where the balls
J. HENRY JOHNSON. (L.S.)