Improvements in the Open Hearth Method or Process of Manufacturing Iron and Steel and in Furnaces Employed therein.
Year: 1887

page_text: Date of Application, 30th Sept., 1887
Complete Specification Left, 2nd July, 1888
Complete Specification Accepted, 3rd Aug., 1888
PROVISIONAL SPECIFICATION.
"
Improvements in the Open Hearth Method or Process of
Manufacturing Iron and Steel and in Furnaces Employed
therein.
I, GEORGE HATTON, of Hagley in the County of Worcester, iron and steel
manufacturer, do hereby declare the nature of this invention to be as follows :—
In describing my invention it will be convenient to first describe generally a furnace
which forms part of the invention and which is employed in the improved method or
process of manufacture about to be described herein. This furnace is formed on the
open hearth" principle, but has two distinct hearths within the one chamber. Tho
furnace is so arranged that it may be turned over, and the hearths are so arranged
therein that while one of them is at the bottom of the chamber the other is upside
down at the top forming the roof, or is otherwise in such position within the chamber
as to be clear above any metal within the lower hearth, and that when the furnace is
turned over sufficiently in the proper direction the positions of the hearths will be
changed so as to bring the upper one into the position formerly occupied by the lower,
and the lower one into the position formerly occupied by the upper or into a position
corresponding thereto. This furnace is open at each end to the ports communicating
with the regenerators, and is heated by gas in the usual manner of the open-hearth
process. The hearths are provided with suitable doors and with pouring spouts, one
of which latter is placed in position in relation to each hearth, respectively, to be
above the working level of the metal when the hearth to which it is applied is in its
usual working position at the lower side of the chamber, instead of placing such spouts,
as is usual in the case of a tapping spout of an ordinary open hearth furnace, in
position to run the metal off the horizontal, or approximately horizontal, bottom of the
hearth. The furnace is constructed and carried in bearings for the purpose of enabling
it to be turned, and in such a manner as to be readily removable for relining and
repair.
In using phosphoric pig iron in the open-hearth process, according to this invention,
I employ a furnace of the above description, having one of the hearths acid lined and

page_text: .
the other basic lined, with suitable insulating material dividing the linings from one
another; and I first treat the metal in the acid lined hearth and rake out the bulk of
the silicious slag, formed during the process of desiliconising, through the pouring
spout of such chamber by first turning the furnace in the direction and degree to
lower the spout sufficiently to admit thereof; and then turn the furnace in the opposite
direction thus transferring the metal into the basic lined hearth by bringing such
hearth into the position previously occupied by the acid lined hearth, and the metal is
then treated in the usual manner for the elimination of the phosphorus, after which it
is ready for casting. The metal is poured out into the ladle as required through the
spout of the hearth in which its treatment is completed, by turning the furnace
sufficiently in the necessary direction.
By employing a furnaco of the above description, having an acid and also a basic
lined hearth, pig iron higher in silicon than it has hitherto been desirable to use may
be conveniently employed.
When it is desired to produce high carbon steel, or when for any reason it is
desired to complete the treatment of the metal in an acid lined hearth, after treatment
in the basic lined hearth, the metal is transferred from the basic to the acid lined
hearth (by again turning the furnace) where it is treated in the manner usual in such
a lined hearth, and then poured out through the spout of such hearth; but, previously
to such transference to the acid lined hearth, the basic phosphoric slag is raked or
poured out through the spout of the basic lined hearth in the inanner described for the
removal of the slag from the acid lined hearth.
When it is desired to employ only an acid or only a basic process, the furnace is
lined entirely with an acid or basic lining as the case may be, and whether so lined, or
in the manner previously described, the advantage of the employment of such a
furnace results in being able to pour out the metal at the precise moment desired, and
also in such quantity as may be desired, as a portion only may be poured out and the
remainder retained indefinitely. When the furnace or converter is to be employed
.simply on account of its convenience for pouring out the metal it is not, of course,
essential to form two hearths in the chamber; as one will suffice, and such a furnace,
having one hearth only, forms for this purpose one of the features of this invention;
but an advantage arises in the employment of two hearths, even when both are
similarly lined, at any rate when they alternately answer the purpose of a roof for
each other, as each when turned down for use as a hearth may be readily repaired
between the heats, thus enabling the furnace to be employed for a larger number of
heats than usual before removal for relining is necessary.
The furnace is conveniently made of a cylindrical, or approximately cylindrical,
shape narrowed in at its ends, with the hearths opposite to one another within the
chamber, and is mounted on rollers to enable it to be easily turned on its axis; and
when so constructed the openings through the ends are formed central to the axis of
the furnace so that the furnace may be turned without in any degree affecting the
free passage of gases and heat therethrough. When one of the hearths is required to
be acid lined and the other basic lined, the acid lining may consist of silica in the
usual forms and the basic lining of prepared dolomite or other suitable material, the
two materials being separated with the usual chrome ore, or carbon insulating joint.
When the furnace is constructed in this manner a half revolution thereof will, of
course, reverse the position of the hearths, the upper one in each case acting as the
roof to the lower.
Dated the 29th-day-of Santambon 1047

page_text: Improvements in the Open Hearth Method or Process of Manu-
facturing Iron and Steel and in Furnaces Employed therein.
I, GEORGE HATTON, of Hagley in the County of Worcester, Iron and Steel Manu-
facturer 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:-
In describing my invention it will be convenient to first describe the furnace which
forms part of my invention and which is employed in the improved method or process
of manufacture about to be described.
open hearth" principle,
This furnace, which is constructed and worked on the "
and is not intended to be used with blast as a Bessemer Converter, when constructed
as shown in Figures 1 and 2, (Figure 1 being a longitudinal elevation and half
section, and Figure 2 the transverse sectional elevation) is provided with two distinct
hearths A and B within one chamber, so arranged that when one hearth, as for
instance the hearth A, is in the bottom position as shewn in Figure 2, the other
hearth B is at the top forming for the time being the roof of the furnace, this
arrangement being of course exactly reversed when the hearth B is in the bottom
position; the furnace is mounted on rollers or wheels C rotating in fixed bearings D,
sucli rollers or wheels supporting the, furnace on the circular pathways E attached to
the furnace By means of steam or other suitable power and with gearing attached
to the axles of the wheels C, or by any suitable mechanical arrangement, (such
gearing not being shewn in the drawings) the furnace may be turned over in either
direction and in this way the position of the hearths can be changed bringing the
upper one into the position formerly occupied by the lower one and the lower one into
the position formerly occupied by the upper one, the furnace may also be entirely
removed for lining and repairs and if desirable a duplicate furnace mounted upon the
rollers or wheels in its place.
The furnace is open at each end. to the ports F, F, communicating with the
regenerators G, G, and by preference is heated by gas in the ordinary way, though
under some circumstances it may be heated by "coal firing."
The hearths are provided with suitable doors H, H, and with pouring spouts J
and K one of which latter is placed in position in relation to each hearth respectively
to be above the working level of the metal when the hearth to which it is. applied is
in its usual working position at the lower side of the chamber, instead of placing
such spouts, as is usual in the case of a tapping spout of an ordinary "open hearth
furnace, in a position to run the metal off the horizontal or approximately horizontal
bottom of the hearth.
In using phosphoric pig iron in the open hearth process according to this invention
I employ a furnace of the foregoing description, having the hearth A lined with
"Acid-" material-and the hearth B lined with "Basic" material, with a layer of

page_text: suitable insulating material of a neutral character separating the two linings from one
another; I first treat the metal in the "Acid" lined hearth A and pour or rake
out the bulk of the silicious slag formed during the process of desiliconising, through
the spout J by turning the furnace in the necessary direction and degree to lower the
spout sufficiently to admit thereof, and then turn the furnace in the opposite direction
thus transferring the metal into the "Basic" lined hearth B by bringing such hearth
into the position previously occupied by the "Acid" lined hearth A, and the metal
is there treated in the usual manner for the elimination of Phosphorous and when
ready for casting the metal is poured out into the ladle as required through the
spout K by turning the furnace sufficiently in the necessary direction.
"
When it is desired to produce high carbon steel, or when for any reason it is
desired to complete the treatment of the metal in an "Acid "lined hearth after treat-
ment in the "Basic" lined hearth, the metal is transferred from the "Basic to the
"Acid" lined hearth, (by again turning the furnace), where it is treated in the
manner usual in such a lined hearth, but previously to such transference to the
"Acid lined hearth, the Basic, Phosphoric slag is poured or raked out through
the spout J of the Basic lined hearth.
32
process
When it is desired to employ only an "acid" process or only a " basic "
the furnace is lined entirely with an "acid" or "basic" lining as the case may be,
and whether so lined or in the manner previously described an advantage of the
employment of such a furnace results in being able to pour out the metal at the
precise moment desired and also in such quantity as may be desired, as a portion only
may be poured out and the remainder retained indefinitely.
When the furnace is to be employed simply on account of its convenience for
pouring out metal, as for instance in the manufacture of steel or iron castings, it is
not, of course, essential to provide two hearths in the one chamber as one will suffice,
and such a furnace as shewn in Figure 3 having one hearth only and a roof con-
structed in the ordinary way, but mounted on wheels or rollers as previously described,
forms for this purpose one of the features of my invention; but an advantage arises
in the employment of two hearths even when both are similarly lined at any rate
when they alternately answer the purpose of a roof for each other, as each hearth
when turned down for use as a hearth may be readily repaired between the heats,
thus enabling the furnace to be employed for a larger number of heats than usual
before removal for relining is necessary.
The furnace is conveniently made of a cylindrical, or approximately cylindrical,
form narrowed in at its ends, with the hearths opposite to one another within the
chamber, and when so constructed the openings through the ends are formed central
to the axis of the furnace so that the furnace may be turned without in any degree
affecting the free passage of gases and heat therethrough.
When one of the hearths is required to be "Acid lined and the other "Basic"
lined, the "Acid "lining may consist of silica in the usual forms and the "Basic"
lining of prepared dolomite or other suitable material, the two materials being
separated with the usual chrome ore, or carbon insulating joint.
When the furnace is constructed in this manner a half revolution thereof will, of
course, reverse the position of the hearths, the upper one in each case acting as the
roof to the lower.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is:-
1. A furnace mounted on wheels or rollers in such a manner as to enable it to be
conveniently turned or rotated in either direction and so constructed as to contain
two hearths, one of which hearths is lined with "Acid" material and the other lined
with "Basic" material, so that while the "Acid" lined hearth is in use the "Basic
lined hearth forms the roof of the furnace, and vice versa, both hearths being provided
with spouts for pouring, substantially as herein described and shown.
2. A furnace mounted on wheels or rollers, and capable of being turned or rotated
in either direction and so constructed as to contain two hearths both of which hearths

page_text: may be lined with "acid material or both may be lined with "basic" material but
so arranged that when either of the two hearths is in use in the bottom position the
other hearth forms the roof of the furnace, both hearths being provided with spouts
for pouring substantially as herein described and shewn.
3. An open hearth furnace so constructed and mounted on wheels or rollers that it
may be rotated or turned over and at the same time the end connections to the ports
or flues at each end of the furnace remain always in the same position (irrespective
of the position of the furnace) and open for the free passage of gases through the
furnace substantially as herein described and shewn.
4. A furnace mounted on wheels or rollers containing one hearth only and with a
roof of ordinary construction as shewn in Figure 3, capable of being partially rotated
or turned sufficiently to allow of slag or metal being poured out of it at the same
time that the end connections to the ports or flues at each end of the furnace remain
always in the same position (irrespective of the position of the furnace) and open for
the free passage of gases through the furnace, substantially as herein described and
shewn.
5. In the manufacture of Iron and Steel the treatment of iron alternately by what
is known as the "Acid process" and by the "Basic process "in one furnace by means
of a furnace provided with two separate hearths one of which is "Acid" lined and
the other "Basic" lined substantially as herein described and shewn.
Dated this 30th day of June 1888.
GEORGE HATTON.