Improvements in Furnaces for the Manufacture of Cast Steel and Homogeneous Iron.
Year: 1896

page_text: Date of Application, 2nd Jan., 1896
Complete Specification Left, 1st Oct., 1896-4ccepted, 7th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Furnaces for the Manufacture of Cast Steel and
Homogeneous Iron.
I, JOHN GJERS, of Ayresome Iron Works, Middlesbrough-on-Tees, in the County
of York, Ironmaster, do hereby declare the nature of this invention to be as
follows-
My invention has reference to the construction of a duplex furnace so arranged
with regenerators that whilst metal is being heated at a high temperature on the bed
of the one furnace the heat escaping therefrom will be utilized to melt metal in
the bed of the other furnace. Such furnaces may be constructed in various
forms; and may be used with oxide of iron linings for carrying out the manu-
facture of cast steel and homogeneous iron according to another invention of mine
in respect of which I am making separate application for Letters Patent. In this
case heat escaping from the furnace in which steel or homogeneous iron is being
produced will be utilized to simultaneously melt the crude pig iron in the other
furnace of the pair.
In the construction of my improved duplex furnaces I sometimes embody
features described in the Specification of my Patent No. 2720 of 1894 and features
of inventions relating to furnaces for which I am making application for other
Letters Patent. Thus the two furnaces arranged side by side can be provided each
with a close combustion chamber with heated air supply for surface combustion
(with or without grate and steam blast or water bottom or both) at one eud, and
with a regenerator, there being a flue or passage or passages connecting the two
furnaces at their rear ends, and the necessary arrangements for reversing, as well
understood.
COMPLETE SPECIFICATION.
Improvements in Furnaces for the Manufacture of Cast Steel and
Homogeneous Iron.
I, JOHN GJERS, of Ayresome Iron Works, Middlesbrough-on-Tees, in the
County of York, Ironmaster, 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 :-
My invention has reference to the construction of a duplex furnace so arranged
with regenerators that whilst metal is being heated at a high temperature on the
bed of the one furnace the heat escaping therefrom will be utilized to melt metal

page_text: on the bed of the other furnace. Such furnaces may be constructed in various
forms and may be used with oxide of iron linings and bottoms for carrying out
the manufacture of cast steel and homogeneous iron according to another inven-
tion of mine in respect of which I am making separate application for Letters Patent
dated 27 November 1895 No. 22727. In this case heat escaping from the furnace
in which steel or homogeneous iron is being produced will be utilized to
simultaneously melt the crude pig iron in the other furnace of the pair.
In the construction of my iniproved duplex furnaces I sometimes embody features
described in the Specification of my Patent No. 2720 of 1894 and features of
inventions relating to furnaces for which I have obtained other Letters Patent
dated 31 May 1895 No. 10815. Thus the two furnaces arranged side by side can
be provided cach with a close combustion chamber with beated air supply for
surface combustion (with or without grate and steam blast or water bottom or both)
at one end, and with a regenerator, there being a flue or passage or passages
connecting the two furnaces at their rear ends, and the necessary arrangements for
reversing, as well understood.
In the accompanying drawings,
Fig. 1 is a longitudinal vertical section through one of the furnaces and
regenerators of a duplex furnace constructed according to this invention.
Fig. 2 is a sectional plan of a complete duplex furnace, one half showing a
horizontal section through one melting furnace and its combustion chamber and the
other half showing a plan of the other furnace and a horizontal section through
the corresponding regenerator above.
Fig. 3 is a front elevation of the duplex furnace with an air reversing valve in
vertical section.
Fig. 4 is a plan of the regenerators, with adjacent parts of the furnaces.
Figs. 5 and 6 are respectively a sectional elevation and a sectional plan of a
portion of a duplex furnace adapted to be fired with gaseous fuel.
D and E are two furnaces placed at an angle side by side and each provided at its
front end with a combustion chamber F. The ends of the furnaces furthest from the
combustion chambers F are brought as close together as they conveniently can be, and
there connected by a circular flue G while the combustion chamber ends are kept at
such a distance apart as to allow of the regenerators C above them being arranged
side by side. The body of each furnace may be of any open hearth type, and the
connecting flue G may be of any suitable cross section with walls sufficiently thick
to prevent excessive loss of heat by radiation. The bottom A and lining B of each
furnace may be of oxide of iron as herein before stated, or of the acid or basic
material commonly employed, according to requirement.
The regenerators may be of any desired form, but are preferably of the
cellular type shown placed directly over the combustion chambers F and carried on
suitable columns C and girders *.
In Figs. 1 to 4 inclusive, each furnace is provided with a close combustion
chamber F having a heated air supply from the regenerator above for surface
combustion of solid fuel on a solid hearth F' as described in my said former Specification
No. 2720 of 1894. In this case, solid fuel is fed into each combustion chamber
through an opening F that is normally closed by a door F. Air for combustion
is admitted alternately to the top of each regenerator C by a reversing valve H
(Fig. 3) worked from the ground, the air passing down and up and down through the
passages of each regenerator C so as to abstract heat from the regenerator walls
and finally entering by a passage C the top of each combustion chamber in turn so
as to impinge upon the fuel therein and cause intense surface combustion thereof
to at once take place.
In order that a duplex furnace of the kind described may be worked successfully,
it should be supplied with a mild air blast, produced by a fan or equivalent means.
In the example shown, it is provided with a lan H' arranged to deliver air into a
pipe H2 connected with the casing of the reversing valve H. The tops of the two
regenerators are shown connected by a brick lined tube H3 having at its centre the

page_text: reversing valve H by means of which the waste products of combustion are directed
on the one side to the chimney H', while the air for combustion is directed on the
other side into the top of the other regenerator. If desired, the products of com-
bustion, may be brought down in a tube to the ground and there connected to a
separate chimney or chimney flue.
The action of the furnace is as follows:-The flame and hot gases from one com-
bustion chamber F in passing into the corresponding furnace, melt the material
lying upon the furnace bed, the hot gases passing off at the other end through the
connecting flue G and entering the other furnace where they are utilized to heat and
melt previously introduced crude pig iron, this heiting and melting of the crude pig
iron taking place during the time that the charge in the first furnace is being
converted into finished steel. The products of combustion pass through the second
combustion chamber F, in which the solid fuel has been previously allowed to burn
low, and through the regenerator C above, which they heat, and finally pass out
through the chimney H.
After the flow of the hot gases has gone on in one direction for a sufficient length
of time to cool down one regenerator and heat up the other, the fire having been
allowed to burn low in the conibustion chamber that is for the time being in use the
reversing valve H is turned over by suitable gear, worked from the ground, and the
direction of the flow of the gases thereby reversed, the fire in the other combustion
chamber having been just previously made up with fresh fuel. This reversing always
takes place when the crude pig iron has been brought to the melting stage, or
nearly so, in one furnace and the finished steel has been tapped from the other
furnace.
In the modified construction of duplex furnace shown in Figs. 5 and 6, each
combustion chamber F is provided at its forward end with a number of passages I
through which producer or other combustible gas can be admitted to the combustion
chamber from an underground gas flue I provided with a gas regulating valve 1².
The gas passages I are inclined upward and rearward as shown so that the issuing
gas will be brought into intimate contact with the heated air coming down from the
regenerator above in a manner suitable for effecting its rapid combustion in the
combustion chamber F.
When the hot gases have passed in one direction a sufficient length of time for
reversing to become necessary, the gas regulating valve I commanding the com-
bustion chamber which has been in active operation, is closed, the reversing valve H
turned over, and the gas regulating valve of the other combustion chamber opened.
Although I have shown the two connected furnaces arranged at a small angle side by
side, it will be evident various relative positions may be adopted in practice according
to convenience so long as there be at the front end of each furnace a combustion
chamber, and the rear ends of the two furnaces are connected together in such wise
that they may be worked substantially in the manner and for the purpose I have
hereinabove described.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A duplex furnace comprising two furnaces each having a combustion chamber
at its front end, a flue connecting together the rear ends of the said two furnaces, and
regenerators in communication with the respective combustion chambers, the arrange-
ment being such that whilst metal is being heated at a high temperature on the bed
of the one furnace the heat escaping therefrom can pass through the connecting flue
into the rear end of and be utilized to melt metal on the bed of the other furnace,
substantially as herein described with reference to the drawings annexed.
2. My improved duplex furnace constructed arranged and operating substantially
as hereinbefore described with reference to and shown in Figs. 1 to 4 inclusive, or
modified according to Figs. 5 and 6 of the drawings annexed.

page_text: 3. For the manufacture of cast steel or homogeneous iron, the use of a duplex
furnace with mild air blast substantially as described.
Dated this 1st day of October 1896.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.