Improved Method of and Apparatus for Decarbonizing Iron.
Year: 1892

page_text: Date of Application, 25th Oct., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
Improved Method of and Apparatus for Decarbonizing Iron.
We, WILLIAM AUGUSTUS BALDWIN, and FREDERICK GRIDLEY WHEELER,
of 49 West 14th Street, in the City of New York, County and State of New
York, United States of America, Gentlemen, do hereby declare the nature of this
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to an improved method and apparatus for decarbonizing
iron and liberating the impurities contained therein for the purpose of rendering
such iron in a condition to be re-carbonized by fluxing therewith a suitable
re-carbonizing agent such as spiegeleisen, so as to convert the same into malleable
or wrought iron or into steel.
Heretofore atmospheric air has been introduced into the molten mass in the form
of a powerful blast by the use of heavy and expensive machinery so as to force
the particles of the metal apart and present the same to the action of the oxidizing
agent, while the silicon, carbon, and other combustible agents are intended to be
brought into that intimate contact with the oxidizing agent which is essential to
insure a complete and uniform combustion by producing both at the surface and in
the body of the metal violent air currents which increase the agitation of the mass
so that the eliminated impurities are mixed and forced by the currents so as to he
returned repeatedly to the mouth of the tuyeres and there exposed to the action of
the blast and driven back into the body of the metal.
Heretofore the blast has been introduced into the vessel upward vertically
through the mass of molten iron. The blast has also been introduced horizontally
into the mass has been introduced at an angle so as to be discharged violently
upon the surface of the mass. It has been introduced tangentially into the mass or
bath, and it has been introduced at an angle upon the surface of the mass and the
angle of the tuyere or inlet adapted to be changed so as to vary the places of
contact and project the currents uniformly over the surface of the bath.
This invention differs from all of these methods in that the currents or current
are introduced from opposite sides of the vessel and projected upon the mass at or
beneath the upper and lower surfaces respectively and at different angles so as to
impart a horizontal and a gyratory motion to the molten mass and to bring every
particle of the same to the action of the air currents as they are introduced at the
tuyeres.
In order to enable those skilled in the art to which this invention appertains to
practise the same we have illustrated in Fig. 1 in the accompanying drawings, a
vertical, central sectional view of a converter such as usually employed, with the
improved means of projecting the blast or currents, and in Fig. 2 we have illustrated
a cross-sectional view of the same, taken in the plane indicated by the dotted
line - on Fig. 1, and
Fig. 3 is a cross-sectional view of a modification.
Referring by letter to the said drawing :-
A indicates a receptacle for the molten mass commonly known as the converter.
This converter is lined with refractory material to enable it to withstand the heat
of the metal, and may be of any ordinary or approved construction. This vessel or
converter which is designed to receive the molten iron from the cupola or any
known melting furnace, is provided in one of its lower sides with a suitable number
of tuyere holes a, there being three shown in the present illustration although we
may employ more or less.
These tuvere holes which are provided with tuyere tubes b, of suitable material,
are arranged in an upwardly oblique or inclined position so that the currents

page_text: introduced through the same will act upon the upper side or slightly below the
surface of the molten mass in an angular manner.
On the opposite side of the vessel or converter we provide similar.tuyere holes
and tuyeres, but instead of inclining them upwardly, we incline them downwardly
or in an opposite direction and have them enter the interior of the vessel at a less
altitude.
These tuyere tubes c, are designed to direct the blast into the body of the mass
and slightly above the bottom so that the blast is simultaneously introduced in the
mass in opposite directions or at different angles upon or slightly below the upper
and lower surfaces respectively so as to produce a thorough agitation of the particles
of the metal and the impurities therein and liberate the latter.
B indicates the wind-box or pipe which leads from the blast operating mechanism
and has its inlet controlled by a suitable valve d. This wind pipe may be of a
spiral form although we have illustrated the same as a broken spiral having its ends
securely capped, as by such construction we are enabled to get better results by
more effectively utilizing the force of the blast. This air pipe may be connected
with the outer ends of the tuyere tubes in the usual manner.
In the illustration of the apparatus we have shown the tuyere tubes on one side
of the vessel arranged upon an angle of about 20 degrees while those on the
opposite side are arranged at an angle of about 40 degrees, although we do not
wish to confine ourselves to such angles, as shown, as they may be varied if
desired.
In operation when the molten metal has been placed in a vessel and the air blast
turned on, the air currents will take the courses indicated by the arrows so as to
impart a whirling or gyratory motion to the mass and thoroughly agitate every
particle of the metal and rapidly eliminate all of the impurities.
In the modification illustrated in Fig. 3 of the drawings, we have shown the
tuyere tubes slightly deflected from diametrical points in opposite directions so that
the currents will be directed upwardly on one side of the mass and downwardly
on the other side and also at a slight angle to the right and left respectively thus
giving to the molten mass a double action.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The method described of converting crude iron into malleable iron or steel,
consisting in violently agitating or imparting a gyratory motion to a molten mass
by simultaneously projecting air currents upon the molten mass from one side of
the vessel upwardly at an angle thereto, and from the opposite side of the vessel
into the mass and downwardly at an angle, substantially as specified.
2. The combination with a suitable vessel adapted to hold molten metal, having
tuyeres entering the interior from one side and upwardly at an angle, and tuyeres
entering from the opposite side and downwardly at an angle, of a suitable air box
or pipe connected with the tuyeres, substantially as specified.
3. The combination with a suitable vessel adapted to hold molten iron, of tuyeres
entering the vessel from one side and arranged upwardly at an angle tuyeres
entering the opposite side of the vessel and arranged downwardly at an angle,and
the air pipe of a broken spiral form connected with the tuyeres, substantially as
specified.
4. The combination with a converter vessel, of tuyeres in opporite sides thereof,
said tuyeres entering the opposite sides at different angles to a horontal plane, and
a suitable air pipe connected with the tuyeres, substantially as spec.fied.
Dated this 25th day of October 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicants.