Improvements in the Manufacture of Steel, and in Gas Furnaces therefor.
Year: 1899

page_text: Date of Application, 18th Apr., 1899
Complete Specification Left, 16th Jan., 1900-Accepted, 24th Feb., 1900
PROVISIONAL SPECIFICATION,
Improvements in the Manufacture of Steel, and in Gas Furnaces
therefor.
I, ALEXANDRE TROPENAS, of 6, Rue d'Erlanger, Paris, France, Engineer, do
hereby declare the nature of my said invention to be as follows:-
I am aware that several patents have been taken out for furnaces used in the
manufacture of steel, uniting in the same construction, the principles of the open
hearth furnace and those of the Bessemer converter.
"
I am the patentee of a pneumatic process which is generally known as the
Tropenas process and which is fully described in my British Patent
Number 7,625, A.D. 1891, in which the decarburization of metal is obtained by
the blowing of air at low pressure, through a set of tuyeres above the surface
of the metallic bath, and the temperature within the converter is increased by
the admission of extra air through a second row of tuyeres.
The object of my present invention is to apply this improved process of blow-
ing, to an open hearth furnace, that can be worked, turned, or tilted to any angle
desired, and to be able to use in such improved furnace, hematite or common pig
iron, with high percentage of silicon, with or without scrap containing (or not)
sulphur and phosphorus; also to use pig iron by itself for the composition of
the full charge without any addition of iron ore.
I wish it to be understood that I do not claim in this patent any novelty for
the process of blowing, per se, neither do I claim any novelty for an open hearth
furnace which can be turned or tilted, but it is the application of my known
process to a furnace of the open hearth type and the particular arrangement and
combination of parts and appliances in the construction of such a furnace which
constitutes the essential features of my present invention.
In carrying out my invention, I use a rotary furnace ovoid in shape, on the
middle of which I fix a cylindrical or other shape receiver projecting outside of
the body of the furnace. The projecting receiver which I also call a crucible,
receives a charge of metal which may be previously melted in a cupola or blast
furnace or the melting may be effected within the furnace itself.
The metal is decarburized in the receiver by means of compressed air at low
pressure, generated by a Roots' or other form of blower or blowing engine, and
when the decarburization is finished I tilt the furnace around its horizontal axis.
The bath comes then in the opposite part of the furnace which acts then as an
ordinary open hearth furnace.
Having succintly indicated the working of the furnace I will now give a full
description of its different parts.
The ovoid body of the furnace is formed of an iron or steel shell, the ends or
trunnions of which rest on standards. provided with friction rolls. In turning
or tilting the furnace I employ any of the known methods which may be suitable
for the purpose.
The crucible receiving the molten metal is formed of a metallic shell having a
evlidrical or other convenient shape, made of wrought iron or steel which is
bolted or otherwise secured onto the body of the furnace.

page_text: The body of the furnace and crucible which receive the molten metal are lined
inside with refractory materials, but silicious or neutral material is employed in
the crucible and the parts next to it which come in contact with silicious slag
during decarburization. The other parts of the body of the furnace, which after
decarburization of the metal and when the furnace has been tilted come in contact
with the steel and the slag, are lined with refractory materials basic or neutral.
The lining of the crucible in which decarburization of the metal takes place
being worn out quicker than the lining of the body of the furnace, the crucible
and its shell can be removed and replaced by another between two charges with-
out stopping the furnace. The shell of the crucible being fixed on the shell of
the body of the furnace by bolts and cotters or other convenient means so that the
crucible and its shell can be expeditiously liberated and exchanged.
The lining of the crucible is made so as to form a projection inside the general
lining of the body of the furnace. This projection is made to keep the scrap.
lime, etc. from slipping into the crucible while charging or during the operation
of blowing for the decarburization of the metal.
An inclined hole is made through this projection so as to allow the slag or
metal which might be projected behind, in case of an abnormal blowing, to return
into the crucible.
The ends of the furnace are open so as to allow passages to convey into the
body of the furnace air and gas from the regenerating chambers which are dis-
posed as in an ordinary open hearth furnace.
The gas is made in an ordinary gas producer.
The passages for air and gas are built with refractory bricks inside of metallic
tubes, the ends of these tubes being cylindrical on the outside and penetrating
partly into the open ends of the furnace so as to receive a stuffing-box, which
prevents escape of gas or communication with the outside.
The top part of these tubes is bent to a right angle and can be removed so as
to be replaced when the end of the passages or burners are worn out, without
stopping the furnace.
In the body of the furnace are two openings fitted with doors for charging the
furnace. Another opening or mouth is provided for the exhaust of the gases
generated during decarburization before the furnace has been tilted. This same
opening or mouth, after the metal has been decarburized, is utilized also for the
evacuation of slag when the furnace has been tilted. This opening or mouth is
also utilized for pouring the steel into the ladle when the operation is completely
finished.
On the face of the receiver or crucible are placed two rows of tuyeres issuing
from two air boxes. The bottom box is connected by an articulated pipe to a
Root's or other form of blower or blowing engine.
The two air boxes communicate with each other by means of a connecting pipe
which is fitted with a valve to allow this communication or to suppress it at
any moment of the operation.
Having now described the different parts of the furnace I will describe a full
operation and explain the advantages of my improvements and invention.
The furnace having been previously heated and placed with the crucible in a
vertical position I pour through the opening or mouth previously described a
charge of molten metal previously melted in a cupola or blast furnace. At the
same time I charge through the openings in the body of the furnace, the doors
of which have been opened, the wrought iron or steel scrap. This scrap is placed
on each side of the crucible containing the bolten metal, then I shut the doors
of the openings, or sometimes I introduce the charge of metal into the furnace
before melting, for this purpose the furnace would be turned so that the charge
may be placed in the body of the furnace. When the metal has become melted
the furnace is turned back into its original position, which brings the crucible
to the bottom to receive the molten charge.

page_text: I rectify, if necessary, the position of the furnace so as to bring the surface
of the bath of molten metal to the level of the bottom part of the bottom tuyeres.
I then turn on the blast. The air comes only through the bottom tuyeres, the
communication between the air boxes being shut. I keep blowing, through the
bottom tuyeres only, until the flame, showing the combustion of carbon appears
outside through the opening or mouth. When the combustion of carbon is well
pronounced 1 open gradually the valve placed on the pipe connecting the air box
of the bottom row of tuyeres with air box of the top row of tuyeres so as to allow
a portion of air to come into the furnace through the top tuyeres while the
bottom tuyeres are kept blowing. The bottom tuyeres acting as fining (or
refining) tuyeres, and oxidizing the silicon, maganese and carbon of the iron, the
oxidation of carbon produces carbonic acid gas (C.02) and oxide of carbon (C.0.).
This last gas (C.O.) escaping from the metallic bath meets the air coming front
the top tuyeres and is transformed into carbonic acid gas (C.0.) thus increasing
not only the temperature of metallic bath, but also the temperature of all parts
of the furnace, especially the parts near to the crucible where the scrap stands.
The bottom tuyeres are of a circular section, the top tuyeres are of a flattened
section.
During the blowing, the bottom tuyeres are maintained at the surface of the
bath or above it, but they are never at any moment of the blowing, below the
surface of the metallic bath.
These tuyeres are disposed either parallel or symmetrical to the middle tuyere
so as to prevent any gyrating motion of the bath through the friction or pressure
of the jets of air. This mode of grouping the tuyeres, their position at or above
the surface of the metallic bath and the low pressure of air used, unite together
to prevent the rising, churning or agitation of the bath and also prevent the
projection of slag or metal which would quickly destroy the lining, would cover
the scrap and would interfere with the good progress of the operation, and the
quality of the steel produced.
When the scrap is placed on each side of the crucible containing the molten
metal, it is exposed during the blowing to an intense heat and absorbs a portion
of this heat developed by the gases emitted by the metallic bath, thus utilizing
a portion of the heat of this gas which otherwise would have been completely lost
in the atmosphere without any advantage for the following operation.
When the decarburization of the metal contained in the crucible is sufficient,
the furnace is moved slightly so as to disengage the bottom tuyeres from the
slag which has been formed on the surface of the metallic bath, and the blast is
stopped. The furnace is then tilted, when the bath of metal leaves the crucible
and comes in the ovoid part, the scrap slips during the rotation of the furnace
until it is mixed with the molten metal. During the operation of blowing the
communication between the regenerator chambers and the chimney is shut, so
as to prevent the cooling of the regenerators and the introduction into them of
gases emitted by the decarburization of the molten metal. When the furnace
is in this position the opening or mouth is shut with the door provided for the
purpose and the gas and air valves are opened: the producer gas is put into action
and the furnace is, from that moment, managed exactly as an ordinary open
hearth furnace. Lime is added into the furnace if necessary. When the slag
is to be taken out the furnace is inclined until the slag can run out through the
opening or mouth previously referred to. Ferro-manganese, silicon, etc. are
added in the ordinary way, test pieces are taken, as is done in the usual practice
of open hearth process, and the steel is poured into the ladle, through the same
opening or mouth.
The proportion of metal and scrap may be varied almost to any requirement.
With crucibles made in readiness of different capacities the charge of molten
metal can be increased or decreased at will. When the sizes of crucible iş
decreased, the room for the scrap is increased, and vice versa.
When the charge has to be of metal only, or when the scrap is in very small

page_text: proportion, I vary the shape of the crucible which sometimes may be rectangular
in section. The space then left on each side of crucible is smaller than it is when
the crucible is made circular in section and the space is utilized to place the lime
necessary to get rid of the phosphorus, in case phosphoric iron is used, or the
final addition, in case hematite iron is used, in any case these materials are heated
during the blowing. When lime is introduced after the tilting of the furnace,
it slips into the bath, but remains near the ends of the furnace, thus allowing
the evacuation of a good portion of silicious slag standing in the middle of the
bath to be taken out through the opening or mouth, before it gets mixed with
the lime, thereby saving a certain quantity of lime.
From the foregoing description it will be seen that the complete operation is
divided into two periods. In the first period, the decarburization by compressed
air is effected in considerably less time than it would be in an ordinary open
hearth furnace. In the second period the melting of scrap will also take much
less time than it would in an ordinary open hearth furnace owing to the fact that
the portion of the charge which has gone through the operation of decarburiza-
tion is already at a high temperature and that the scrap has been heated during
the process of decarburization. The consequence will be that in this improved
furnace the time for one complete operation will be reduced considerably, com-
pared with the time now required in an ordinary open hearth furnace.
Total 1711.
1000
Improvements in the Manufacture of Steel, and in Gas Furnaces
therefor.
I, ALEXANDRE TROPENAS, of 6, Rue d'Erlanger, Paris, France, Engineer, do
hereby declare the nature of my said invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the follow-
ing statement:―
I am aware that several patents have been taken out for furnaces used in the
manufacture of steel, uniting in the same construction the principles of the open
hearth furnace and those of the Bessemer converter.
"
I am the patentee of a pneumatic process which is generally known as the
Tropenas process and which is fully described in my British Patent
Number 7,025, A.D. 1891, in which the decarburization of metal is obtained by
the blowing of air at low pressure, through a set of buyeres above the surface
of the metallic bath, and the temperature within the converter is increased by
the admission of extra air through a second row of tuyeres.
The object of my present invention is to apply this improved process of blow-
mg, to an open hearth furnace, that can be worked, turned, or tilted to any angle
desired, and to be able to use in such improved furnace hematite or common pig
iron, with high percentage of silicon, with or without scrap containing (or not)
sulphur and phosphorus, also to use pig iron by itself for the composition of
The full charge without any addition of iron ore.
My invention provides for the treatment of pig metal by both the converter
and open hearth processes within the same chamber, furnace, or piece of
apparatus, but respectively in different sections or areas thereof, which may have
respectively, as required, acid or basic linings, or a neutral lining throughout.
Thus in the converter operation the pig metal may in the way ordinarily practised

page_text: be desiliconized or dephosphorized, and in ither case decarburized according to
the character of the pig metal used. While in the open hearth operation the
bath previously treated in the converter operation may be operated upon in the
usual manner of open hearth process, with the addition of scrap or hematite iron
or other constituents desired in the product to be finally obtained. These two
operations within the same furnace or piece of apparatus may even be practised
in the reverse order to that above suggested were the particular grade of pig
metal be considered to require it.
Where pig metal is of such character as to require the elimination of both
silicon and phosphorus, it it practically requisite that the metal be desiliconized
and decarburized in a converter operation and subsequently dephosphorized in an
open hearth.
Practical difficulties, well understood and therefore quite
unnecessary to be recited here, exist to the performance of these two operations
while the bath is contained in either a converter, crucible, or an open hearth
furnace. A type of furnace vessel or crucible, adapted in shape, general
characteristics, and mode of operation to the proper performaned of the converter
operation for desiliconizing and decarburizing is not adapted to the proper
performance of the open hearth operation of dephosphorizing and deoxidising, for
reasons well known and recognized by those skilled in the art Hence, in the
manufacture of steel from pig metal containing both silicon and phosphorus in
large quantities, it has been proposed to desiliconize in an ordinary converter and
then transfer the bath by pouring or transit through a trough or run-way to an
entirely distinct and separate open hearth furnace where the phosphorus is
eliminated by the addition of lime, and then such materials as are desired may be
added to the molten mass upon the hearth of the furnace. This manner of
procedure has been practised to some extent, but it is uneconomical, not only in
the matter of fuel and output of steel, but in the elements of time and
construction of plant, and is otherwise objectionable.
My invention provides for the treatment of such pig metal, or any other such
metal, as might be considered adapted to the purpose by both such required
processes in one enclosed space chamber, or crea, one portion of which is in
effect and in fact a converter provided with its necessary adjuncts, and another
portion an open hearth furnace with its adjuncts, provision being made for
delivery of the bath after treatment in the converter portion of the apparatus to
the open hearth furnace portion. The two interior superficial portions of the
inclosed area which respectively constitute the converter and open hearth furnace
are in juxta-position, and after the completion of the operation in one, the metal
is caused to run into the other. This I may accomplish by changing the relative
levels of the two portions of the apparatus or interior space, so that the molten
bath already treated in one will flow over into the other. By this mode of pro-
cedure the available heat of one operation is conserved within the space and
utilized for the assistance of the second by reason of the high temperature to which
the entire interior space and its confining walls are raised. I am thus enabled to
perform the two requisite converter and open hearth operations and preserve the
theoretical economies of both operations considered as a whole. To accomplish
this the casing or structure within which are provided the two portions of its
area which constitute respectively the converter and open hearth, is so con-
structed and mounted as to have a rocking or tilting movement or a rotary or
partial rotative movement whereby the molten bath already treated in the con-
verter is at once and within the same heated area caused to run into the open
hearth portion, where the open hearth operation, whatever it may be, is completed.
It is, of course, quite immaterial what the specific construction may be, and what
the special shape or contour interiorly and exteriorly is, provided the apparatus
is capable of performing the functions indicated. The specific construction and
shape which I consider the best now known to me are hereinafter set forth in
detail.

page_text: blowing converters by which I obtain a higher temperature on the surface of
the bath and above it than is otherwise practicable." This style of converter
or mode of operating it becomes of special importance in my present invention,
because the high heat developed and not absorbed in the bath is conserved within
the apparatus, and by its use I am enabled to perform the operations contemplated
by the present invention with greater dconomy that would otherwise be feasible.
A feature of the present invention is, therefore, the employment of such a con-
verter so operated in combination with the open hearth furnace, both arranged
upon or within the walls inclosing the single area, in which the heat of each
operation is utilized in whole or in part to asssist the other.
Another feature of my invention that may be practised or made available by
the use of the special apparatus hereinafter described, or other apparatus having
like characteristics or similar mode of behaviour, is a process wherein the heat of
one operation, say the converter operation, is not only utilized for heating the
interior space of the apparatus and its inclosing walls or lining, but also such
material as may be used in the second or open hearth operation, either for
effecting the proper chemical changes or reactions in the bath or as added con
stituents of the bath affecting the physical characteristics or composition of the
final product. To this end a way is provided whereby such materials may be
placed within the inclosed space in proper juxtaposition to the converter, thereby
becoming highly heated, and then by the action of the apparatus already
indicated be delivered along with the molten bath to the open hearth furnace.
The invention also comprises a way of evacuating the silicious slag of
converter operation before the open hearth operation is commenced, or at any
time desired, and also other details, all as is hereinafter described.
the
Referring now more in detail to the construction of apparatus and mode of
operation of the invention, but with the desire that it be clearly understood that
the details of construction, as well as contour, of the apparatus may be varied by
those skilled in the art without departing from my invention, in the accom-
panying drawings;-
The nature of my invention will be better understood on reference to the
accompanying three sheets of drawings, in which
Figure 1 is a vertical_longitudinal section on the line E F of Figure 2,
and on the lines E F, G H, of Figure 3.
Figure 2 a horizontal section on the line I J of Figure 1 and 3.
Figure 3 is a vertical transverse section on the lines ABCD) of Figure 1.
Figure 4 a horizontal section on the line KL of Figure 3.
Figure 5 a detail transverse section of the combined converter and open hearth
furnace on the line MN of Figure 6.
Figure 6 a similar vertical longitudinal section on the line OP of Figure 5.
Figures 7 and 8 show the combined converter and open hearth furnace in a
different position, in which the bath occupies the floor of the open hearth furnace,
and aro respectively transverse sections on the line Z W of Figure 8 and X Y of
Figure 7.
Figures 9 and 10 are views similar to Figures 5 and 6, showing a different
form of the converter part of the apparatus, Figure 9 being a section on the
line QR of Figure 10, and Figure 10 a section on the line ST of Figure 9.
Figure 11 is a horizontal section of the converter on the line UV of Figure 9.
The same letters refer to similar parts throughout the several views.
In carrying out my invention I use a rotary furnace, that may be ovoid in
shape, on the centre of which I fix a cylindrical or other shape receiver projecting
outside of the body of the furnace as shown in the drawings. The projecting
receiver, which I also call a crucible, and which is in fact a converter, receives a
charge of metal which may be previously melted in a cupola or in a blast furnace,
or the melting may be effected within the furnace itself.
The metal is decarburized and desiliconized in the receiver or converter by
means of compressed air at low pressure, generated by a Root's or other form of

page_text: blower, or by a blowing engine, and when the decarburization and desiliconization
The bath
is practically finished I tilt the furnace around its horizontal axis.
passes then into the opposite part of the furnace, which acts as an ordinary open
hearth furnace.
The ovoid body of the furnace is formed of an iron or steel shell a (Figures 1.
2, and 3), the ends or trunnions of which rest on standards b. b. provided with
friction rolls c, c. In turning or tilting the furnace I employ any one of the
known methods which may be suitable for the purpose, and such, for instance, as
those commonly employed for the rocking of ordinary converters.
The crucible receiving the molten metal is formed of a metallic shell, e. having
a cylindrical or other convenient shape made of wrought iron or steel. which
is bolted or otherwise secured to the body of the furnace.
The crucible or converter which receives the molten metal may be lined with
appropriate silicious or neutral material, and preferably also the parts next to it
which may come in contact with the silicious slag during desiliconization and
decarburization. These parts lined with silicious or neutral materials are shown
in the drawings with ordinary hatching. Figures 1 to 3 and 5 to 10. The other
parts, which after decarburization and desiliconizing of the metal, and when the
furnace has been tilted as shown in Figures 7 and 8, come in contact with the
steel and the slag, may be lined with suitable basic or neutral material, shown in
Figures 1 to 3 and 5 to 10 by dotted hatching.
The lining of the crucible in which decarburization and desiliconization of
the metal takes place wearing out quicker than the lining of the body of the
furnace, the crucible and its shell can bd removed and replaced by another
hetween two charges without stopping the operation of the furnace. The shell of
the crucible being fixed on the shell of the body of the furnace by bolts and
cotters or other convenient means, so that the crucible and its shell can be expe-
ditiously removed and another put in its place.
The lining of the crucible is made so as to form a projection d inside the
general lining of the body of the furnace, as shown in Figs. 1. 2. and 10. This
projection is made to keep the scrap, lime, etc.. from slipping into the crucible
while charging or during the operation of blowing for the desiliconizing and
decarburization of the metal.
An inclined hole, r. is made through this projection so as to allow the slag or
metal, which might rise above and behind it, in case of an abnormal blowing, to
return into the crucible.
The ends of the furnace are open so as to allow the passages f. g to convey
into the body of the furnace air and gas from the regenerating chambers h, i,
which are disposed as in an ordinary open hearth furnace.
The gas is made in an ordinary gas producer, which, having no particular
feature of novelty, is not shown in the drawing.
The passages f, g, for air and gas. are preferably built with refractory bricks
inside of metallic tubes, the ends of these tubes being cylindrical on the outside,
and penetrating partly into the open ends of the furnace so as to receive a
stuffing-box a, which prevents escape of gas or communication with the outside.
The top part of these tubes is bent to a right angle, and can he removed so as
to be replaced when the ends of the passages or burners, f, g, are worn out,
without stopping the operation of the furnace.
In the body of the furnace are two openings, j. j. fitted with doors for charging
the furnace. Another opening. k. is provided for the exhaust of the gases gene-
rated during desiliconisation and decarburization when the furnace occupies the
position of Figs. 5 and 6. This same opening is utilized also for the evacuation
of slag when the furnace is in position shown in Figs. 7 and 8, and for pouring
the steel into the ladle when the operation is completely finished.
On the face of the receiver or crucible e, are placed two rows of tuveres, o, p.
issuing from two air boxes. 1, m. The bottom box, 1, is connected by an articu-
lated pipe. n. (Fig. 3.) to a Root's or other form of blower, or to a blowing engine,

page_text: The two air boxes, l, m, communicate with each other by means of a con-
necting pipe, which is fitted with a valve to allow this communication or to sup-
press it at any moment of the operation. To avoid complication, this valve is
not shown in the drawings.
Having now described the different parts of the furnace, I will describe a full
operation of the apparatus.
the
When
The furnace having been previously heated, I place it in a position shown in
Figs. 5 and 6. I pour through opening into the crucible or converter e, a charge
of molten metal. At the same time may charge through openings j, j, wrought
iron or steel scrap or other desired material. This scrap is placed as shown
(Figs. 5 and 6) on each side of the crucible containing the molten metal. I then
shut the doors of the openings j, j. Sometimes I introduce the charge of metal
into the furnace before melting. For this purpose the furnace would be turned
into the position shown in Figs. 7 and 8. When the metal has become melted,
the furnace is turned into the position shown by Figs. 5 and 6, which brings the
crucible to the bottom to receive the molten charge. I rectify, if necessary,
position of the furnace so as to bring the surface of the bath of molten metal to
the level of the bottom part of the bottom tuyeres o. I then turn on the blast.
The air comes only through tuyeres o, the communication between the air boxes m
and being closed. I keep blowing through tuyeres o only, until the flame,
showing the combustion of carbon, appears outside through opening k.
the combustion of carbon is well pronounced, I open gradually the valve placed
on the pipe connecting the air box 7 of the bottom row of tuyveres o with air
box m of the top row of tuyeres p, so as to allow a portion of air to come into
the furnace through tuyeres p, while the tuyeres o are kept blowing. The bottom
tuyeres o acting as fining (or refining) tuyeres, and oxidizing the silicon, man-
ganese, and carbon of the iron, the oxidation of carbon produces carbonic acid
gas (C0) and oxide of carbon (CO). This last gas (CO) escaping from the
metallic bath meets the air coming from the top tuyeres p, and is transformed
into carbonic acid gas (CO2), thus increasing not only the temperature of the
metallic bath. but also the temperature of all parts of the furnace, especially the
parts near to the crucible where the scrap stands. The bottom tuyeres o are of a
circular section, while the top tuyeres p are of a flattened section, as shown in
Figs. 6 and 10. During the blowing the bottom tuyeres o are maintained at the
surface of the bath or above it, but they are never, at any moment of the blowing,
below the surface of the metallic bath.
In the plan view these tuyeres are disposed as shown in Fig. 9, i.e.. they are
either parallel or symmetrical to the middle tuyere, so as to prevent any gyrating
motion of the bath through the friction or pressure of the jets of air. This mode
of grouping the tuyeres, their position at or above the surface of the metallic
bath and the low pressure of air used, act together to prevent the rising, churning
or agitation of the bath, and also prevent the projection of silicate, slag,
or metal, which would quickly destroy the basic lining outside of the converter.
would cover the scrap. and interfere with the good progress of the operation and
the quality of the steel produced.
The scrap placed as shown in Figs. 5 and 6 is exposed during the blowing to
an intense heat. It absorbs a portion of this heat developed by the gases emitted
by the metallic bath. thus utilising a portion of the heat of these gases. When
the decarburization and desiliconizing of the metal contained in the crucible is
sufficient, the furnace is moved slightly so as to disengage the bottom tuyeres
from the slag which has been formed on the surface of the metallic bath, and
the blast is stopped. The furnace is then tilted to the position shown in Figs. 7
and 8. The bath of metal leaves the crucible and comes in the ovoid part. The
scrap slins during the rotation of the furnace until it is mixed with the molten
metal. Figs. 7 and S. During the operation of blowing the communication
between the regenerator chambers and the chimney may be closed, so as to
prevent the cooling of the regenerators and the introduction into them of gases

page_text: emitted by the decarburization of the molten metal. When the furnace is in
position of Figs. 7 and 8, the opening k is shut with the door provided for the
purpose, and the gas and air valves are opened, the producer gas is put into
action, and the furnace is, from that moment, managed exactly as an ordinary
open hearth furnace. Lime is added into the furnace, if required, for dephos-
phorization. Whenever slag is to be taken out the furnace is inclined until the
slag can run out by opening k. Ferro-manganese, silicon &c., may be added in
the ordinary way, test pieces are taken, as it is done in the usual practice of open
hearth process, and the steel is poured into the ladle through opening k. The
proportion of metal and scrap may be varied almost to any requirement. With
crucibles made in readiness of different capacities, the charge of molten metal
may be increased or decreased at will. When the size of crucible is decreased
the room for the scrap is increased, and vice versa. When the charge has to be
of pig iron only, or when the scrap is in very small proportion, I may vary the
shape of the crucible, which sometimes may be rectangular in section as in
Figs. 9, 10, and 11. The space then left on each side of the crucible is smaller
than it is in Figs. 1, 6, and 8, and this space may be utilised to place the lime
necessary to get rid of the phosphorus in case phosphoric iron is used, or the final
addition in case hematite iron is used. In any case such materials are heated
during the blowing operation in the converter. When the lime is so introduced
it slips into the bath after the tilting of the furnace, but remains near the ends
of the furnace, thus allowing the evacuation of most of the silicious slag stand-
ing in the middle of the bath to be taken out by opening k, before it gets mixed
with the lime, thereby saving a certain quantity of lime.
From the foregoing description it will be seen that the complete operation is
divided into two periods. In the nrst period the decarburization and desilicon-
ization by compressed air is effected in considerably less time than it would be
n an ordinary open hearth furnace. In the second period the melting of scrap
will also take much less time than it would in an ordinary open hearth furnace,
owing to the fact that the portion of the charge which has gone through the
operation of decarburization and desiliconizing is already at a high temperature,
and that the scrap has been heated during the process of decarburization and
desiliconizing. The consequence will be that in this improved furnace, the time
for one complete operation will be reduced considerably compared with the time
now required in an ordinary open hearth furnace.
I wish it to be understood that I do not claim in this patent any novelty for
the process of blowing, per se, neither do I claim any novelty for an open hearth
furnace which can be turned or tilted, but it is the application of my known
process to a furnace of the open hearth type, and the particular arrangement and
combination of parts and appliances in the construction of such a furnace, which
constitutes the essential features of my present invention.
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. An apparatus comprising within its inclosed space or interior part, two
separate and distinct portions, both shaped and adapted to be used at will, one
as a crucible or converter, and the other as an open hearth furnace, and provided
with means whereby the metal bath in one such portion may be transferred to
the other at will, substantially as and for the purposes set forth.
2. An open hearth furnace and crucible or converter combined in a single
structure, and being respectively parts of a single inclosed space, and equipped
and adapted to be separately operated as an open hearth furnace and converter
respectively, such structure being adapted to be rocked or tilted to cause the
material or bath in the converter to run into the open hearth furnace, and vice
versa, substantially as and for the purposes set forth.

page_text: 3. A structure constituting an open hearth furnace, provided with the usual
equipment or adjuncts of such a furnace, having mounted thereon a crucible or
converter at one side of the floor of the open hearth furnace, opening into the
inclosed space, and having the usual or proper equipment or adjuncts of a con-
verter, the structure being so constructed and mounted as to be capable of a
rocking or tilting movement that will cause the molten bath in the converter to
flow into the open hearth furnace substantially as set forth.
4. A closed structure comprising an open hearth furnace, with the necessary
or usual equipment, having mounted at one side of the floor thereof, and opening
into the inclosed space, a removably attached crucible, constituting a converter,
which is provided with tuyeres and blowing apparatus; such structure being so
made and mounted as to be capable of being rocked or tilted to run the contents
of the crucible upon the floor of the open hearth furnace.
5, An elongated hollow structure, one portion of the interior of which
constitutes the suitable floor of an open hearth furnace, open hearth burners
arranged in the ends of the structure in suitable relation to the floor thereof, and
an interior extension or recess in the side of the structure, constituting a crucible
or converter having tuyeres and blowing apparatus; the structure being so made
and mounted as to be capable of being tilted or rocked axially to raise tho
converter, then at the bottom of the structure to flow its contents into the open
hearth furnace, which, by such rocking action, becomes the bottom of the
structure.
6. A hollow structure, one portion of the interior of which constitutes the
floor of an open hearth furnace, open hearth burners arranged at the ends of the
structure in suitable relation to such floor, a projecting crucible or converter
opening into the hollow structure and mounted thereon at one side of the floor
of the open hearth furnace and an opening () in the wall of the structure on
the other side of the structure; the structure being so mounted as to be capable
of being rocked to discharge the contents of the converter upon the floor of the
furnace.
7. A hollow structure, one portion of the interior of which constitutes the
floor of an open hearth furnace, open hearth burners arranged at the ends of the
structure in suitable relation to such floor, a projecting crucible or converter
opening into the hollow structure, and mounted thereon at one side of the floor
of the open hearth furnace and an opening (k) in the wall of the structure on
the other side of the structure, and one or more openings (2) in the wall of the
structure between the converter and the first-named opening, the structure being
so mounted as to be capable of being rocked to discharge the contents of the
converter upon the floor of the furnace.
8. A hollow structure, provided at its ends with burners, and a portion of
the interior of which forms the floor of an ordinary open hearth furnace, arranged
in suitable relation to the burners, a converter mounted upon the structure,
forming part thereof, and opening thereinto at one side of the said floor, and
of less width than the length of the structure, and a raised ledge, as d, sur-
rounding the mouth of the converter, the structure being so made and mounted
as to be capable of being rocked to run the contents of the converter upon the
floor of the open hearth furnace.
9. A hollow structure provided at its ends with burners, and a portion of the
interior of which forms the floor of an ordinary open hearth furnace arranged
in suitable relation to the burners, a converter mounted upon the structure,
forming part thereof, and opening thereinto at one side of the said floor, and
of less width than the length of the structure and a raised ledge, as d, sur-
rounding the mouth of the converter, and having ducts or passages in it through
which any fluid material escaping from the converter may return thereto, the
structure being so made and mounted as to be capable of being rocked to run
the contents of the converter upon the floor of the open hearth furnace.

page_text: 10. The combination of a hollow structure, a portion of the interior of which
forms the floor of an open hearth furnace, and which is provided with proper
burners at its ends in suitable relation to such floor of a couverter, attached to
the side of the structure opening thereinto, and provided with a system of tuyeres
and blowers of the general character described. and operating in the manner set
forth, the structure being so made and mounted as to be capable of being rocked
to discharge the contents of the converter upon the floor of the furnace.
11. An open hearth furnace and a converter comprising portions of the same
structure, and whose interior surfaces are part of the interior space of said
structure of a system of tuyeres, and blowers, such as described substantially as
and for the purpose set forth.
12 The herein described improvement in the art of manufacturing steel,
which consists in so associating an open hearth furnace and a converter that the
heat from the operation of either of them is conserved in the inclosed space
common to both of them, and the available temperature of one operation utilized
in the other, substantially as set forth.
13. The herein described improvement in the art of manufacturing steel,
which consists in so associating an open hearth furnace and a converter that the
heat from the operation of the converter is conserved in the inclosed space
common to both of them, heating the material to be added to the bath in the
open hearth operation while such material is disposed in said common space, and
aiter the completion of the operation in the converter, transferring the bath
therein and the material so heated to the floor of the open hearth furnace.
14. The improvements in the process of manufacturing steel from pig
metal, which consists in treating successively, in two distinct, separate, and inde-
pendent operations, any kind of pig metal, high or low in silicon, sulphur,
phosphorus, and carbon, with or without the addition of ores, scrap, lime, or the
like, according to circumstances, by the two methods known under the generio
names of the converter and open hearth processes, carrying on the operation in
two vessels entirely distinct from and independent of each other, as regards their
mode of action and of working, though contained in the same apparatus, cach
vessel in fact working in the exact conditions of the class of apparatus to which
it belongs, but at the same time so connected with the other and contained in
the same apparatus or furnace, that the surplus heat of each of these distinct
operations can be made available for specific purposes of carrying on the other.
15. A rotary furnace of the character set forth, fitted with a converter
specially for the decarburization of iron, the possibility of replacing this con-
verter, the lining of which is worn out quicker than the lining of the furnace,
without stopping the furnace; also the possibility of replacing the ends of the gas
and air passages or burners, f, g, without stopping the furnace.
16. In a rotary furnace of the character set forth, the disposition shown in
Fig. 10 which allows, when phosphoric iron is treated alone or with a small
proportion of scrap, of the lime or other material being treated by the gases
emitted during the decarburization, and the location of the lime being such that
when the furnace is tilted in position of Figs. 7 and 8 it does not fall on the
middle of the bath, but towards each end, thus allowing the evacuation of a great
portion of the silicious slag, before the floating lime gets mixed with all the slag
and comes near to opening k, thus saving a quantity of lime and accelerating the
operation of dephosphorization.
17. In a rotary furnace of the character described, the utilization of a portion
of the temperature developed during the decarburization of the iron, for the heat-
ing of scrap, lime for dephosphorization, or other materials generally added to
the charge, thus allowing, after decarburization, of the introduction into the
charge of the materials previously heated in the furnace itself.
18. In a rotary furnace of the character described, the disposition, form, and
shape of the furnace, allowing to place the scrap, lime, and other materials in
proximity to the crucible or converter where the decarburization is effected; these

page_text: materials being charged in a heap, protecting the ends of the furnace where the
passages f, g, come in, and preventing their obstruction with slag and metal in
case of an abnormal operation of blowing.
D
1000
R. HEBER RADFORD,
Agent for the Applicant.