IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND MALLEABLE IRON FROM CAST IRON AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
30th March 1868.-A communication from abroad by Francis
Ellershausen, of Ottawa, in the Dominion of Canada, Metallurgist.....
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 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 Ellershausen,
of Ottawa, in the Dominion of Canada, Metallurgist, to be as follows,
that is to say :-
This Invention relates to a mode or method of manufacturing cast
steel and malleable iron direct from cast iron, and to a peculiar
construction and arrangement of apparatus to be employed for that
purpose.
According to this Invention a furnace of any convenient size and
form provided with a blast pipe, on the top of which furnace is placed a
converter constructed of brick and cased in boiler plate externally for
the sake of strength. A circular cast-iron flue conveys the flame and

page_text: heat to the converter, 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 converter, and
when this door is open the interior of the converter 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 converter, and upon the
top of the converter there is fitted by hinges or otherwise a cap or hood
of a circular form at the base and of the same internal diameter as that
of the converter, but tapers towards the mouth which is curved to one
side and is in connection with a chimney shaft. In converting cast iron
into cast steel by the aid of this apparatus, curled sheet iron is placed
in the converter, which is open at the top but is provided with a
perforated bottom for the passage of the flame. The hood is then
applied and connected with the chimney, & the moveable flue
adjusted in its place. Fire is then raised in the furnace beneath until
the sheet-iron curlings in the converter are brought to a white heat, and
so maintained till complete oxidation has taken place. The circular flue
is then removed, the door or flap is closed against the bottom of the
converter, and the top or hood is turned over. A sufficient quantity of
molten cast iron is then poured into the converter to unite with the
oxide of iron, the sheet iron curlings exposing a large surface of oxide
of iron to contact with the cast iron, the particles of each uniting closely
and causing rapid combustion throughout the 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. In lieu of sheet-iron
curlings other oxides may be used possessing the same extent of
surface, as, for example, spongy iron as it comes from the puddling
furnace. Before the cast iron is introduced into the converter
decarbonizing and purifying agents, such as oxide of manganese and
the like, may be deposited in the interstices of the sheet-iron curlings or
their substitutes.