IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF IRON AND STEEL BY THE APPLICATION OF A COMBINED REVERBERATORY AND BESSEMER FURNACE
Year: 1877

page_text: LETTERS PATENT to Alfred Longsdon, of Queen Victoria Street, in the City
of London, Engineer, for the Invention of "IMPROVEMENTS IN FURNACES FOR
THE MANUFACTURE OF IRON AND STEEL BY THE APPLICATION OF A COMBINED
REVERBERATORY AND BESSEMER FURNACE" A communication from abroad
by Alfred Krupp, of Essen, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Alfred Longsdon at the
Office of the Commissioners of Patents on the 28th December 1877.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, Engineer.
"IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF IRON AND STEEL BY
THE APPLICATION OF A COMBINED REVERBERATORY AND BESSEMER FURNACE."
(A communication from abroad by Alfred Krupp, of Essen, in the Empire of
Germany.)
The object of this Invention is to apply one and the same furnace as a reverbe-
ratory and Bessemer furnace, so that when in one position it may be used as &
reverberatory furnace; and when in another position as a Bessemer furnace,
whereby the charge may be treated as in a reverberatory furnace, or have air blown
through it as in a Bessemer furnace; the operations may be carried on alternately
as desired.
A convenient way to carry the Invention into effect of combining a reverberatory
furnace with a Bessemer furnace is as follows:-The body proper of the furnace can
revolve on its longitudinal axis, and is provided with Bessemer twyeres on one
narrow side of its oval section. A Siemens' regenerator may be used for re-heating,
but any other arrangement for re-heating may be used.
When the furnace is in a horizontal position the heating gases flow alternately on
one side of the furnace from apertures of the regenerator chambers into orifices of
the apparatus proper, and after having passed through the same they pass off
through openings on the opposite side of the apparatus, and there re-enter the
regenerator chambers on that side,

page_text: When the furnace is turned into a vertical position the inlet valve of the blast is
open by an eccentric during this rotation, and air is admitted into the twyere
chambers by a pipe, and then through twyeres into the fluid metal. The body of
the furnace is sustained by or rests on rings, which rest on friction rollers, one of the
said rollers and the ring forming the pinion and wheel, whereby the furnace is
rotated. The supporting and driving portions of the apparatus being combined in
this way, the wheels are well geared, even should the furnace twist, and the large
tooth wheel get out of truth. The axle of the pinion roller carries a worm
wheel at its other end in gear with worm driven from any suitable prime
mover.
Charging and discharging of the furnace are effected through a mouth opposite
the twyeres; this mouth is closed by door during heating. The furnace proper is
mounted on a carriage, so that it can be easily replaced by another, in case of
necessity, without putting the generator or other fire out of work. The re-heating
of the charge takes place on a flat hearth, and no part of the charge is left in the
apparatus after tapping, as is the case ordinarily when a very flat fixed hearth with
tapping hole is used.
When the apparatus is in a vertical position the Bessemer process can proceed
without injury to the regenerator chambers, as they are shut off from the furnace
proper by the openings thereto being closed through the position of the
furnace.
The above-described combined reverberatory and Bessemer furnace enables the
Bessemer process to be worked with such sorts of pig iron, the working of which is
too cold in an ordinary Bessemer converter, especially with the much cheaper white
pig iron and pig iron purified according to what is known as Krupp's "
method.
"
By the use, too, of furnaces constructed according to this Invention, large
quantities of steel and wrought iron scraps can be added to the pig iron and a
"dead" melted metal is obtained; by re-heating the metal again after the Bessemer
process has taken place, the physical properties are improved, and the chemical pro-
perties can also be improved by any desired additions, and all this is attained in
and by the same apparatus, re-heating the charge or blowing air through it alter-
nately at will. The white pig iron, for instance, melted in any other furnace, is
charged in to the apparatus when in the upright position through the mouth, then it
is first superheated, and in the apparatus, when upright, turned into Bessemer metal.
Then the charge is re-heated in the apparatus placed horizontally, scraps being added
at will, thus obtaining a "dead" melted metal, and by means of suitable additions
the ordinary Bessemer metal is improved to a higher quality.
A combined reverberatory and Bessemer furnace may be used, similar to an
ordinary Bessemer converter, but flattened, and with a broad opening or mouth
through which the apparatus is heated by the injection of pulverized coal, such as
is now known as Crampton's system, or other arrangements for the supply of
powdered fuel may be used, or the system known as Siemens' for his rotators may
be used. Supply of blast and movement of the converter as before. Air enters by
a pipe into a series of twyere chambers extending over the full width of the con-
verter and from there into the twyeres. Sometimes a narrower mouth is employed
and double bottom; then when the Bessemer process takes place both bottoms
receive (separated from one another) air through both converter trunnions; but in
turning the apparatus into the horizontal position for re-heating the charge, the air
in the lower bottom is self-actingly replaced by lighting gas injected under pressure
by steam. The upper bottom receives air as before, but now it is used for com-
bustion of the gas, or it may be that the flame would not strike back into the
bottom if a single one were employed, and the lighted gas were injected directly
through the twyere blast.
When the annaratus is heated the burnt gases escape by a flue.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Longsdon in the Great Seal Patent Office on the 28th June
1878.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, Engineer.
"IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF IRON AND STEEL BY
THE APPLICATION OF A COMBINED REVERBERATORY AND BESSEMER FURNACE"
(A. communication from abroad by Alfred Krupp, of Essen, in the Empire of
Germany.)
The object of this Invention is to apply one and the same furnace as a reverbe-
ratory and Bessemer furnace, so that when in one position it may be used as a
reverberatory furnace, and when in another position as a Bessemer furnace,
whereby the charge may be treated as in a reverberatory furnace, or have air blown
through it as in a Bessemer furnace, the operations may be carried on alternately as
desired.
A convenient way to carry the Invention into effect is as follows:-The body
proper of the furnace can revolve on its longitudinal axis, and is provided with
Bessemer tuyeres on one narrow side of its oval section. A Siemens' regenerator
may be used for re-heating, but any other arrangement for re-heating may be
employed.
When the furnace is in a horizontal position the heating gases flow alternately on
one side of the furnace from apertures of the regenerator chambers into orifices of
the apparatus proper, and after having passed through the same they pass off through
openings on the same or opposite side of the apparatus, and there re-enter the
regenerator chambers on that side.
When the furnace is turned into a vertical position the inlet valve of the blast is
opened by an eccentric during this rotation, and air is admitted into the tuyere
chambers by a pipe, and then through tuyeres into the fluid metal. The body of the
furnace is sustained by or rests on rings which rest on friction rollers, one of the said
rollers and the ring forming the pinion and wheel, whereby the furnace is rotated. The
supporting and driving portions of the apparatus being combined in this way, the
wheels are well geared, even should the furnace twist and the large toothed wheel
get out of truth. The axle of the pinion roller carries a worm wheel at its other
end in gear with worm driven from any suitable prime mover, or motion may be
transmitted thereupon by spur wheel or other gearing.
Charging and discharging of the furnace are effected through a mouth opposite
the tuyeres; this mouth is closed by door during heating. The furnace proper is
mounted on a carriage, so that it can be easily replaced by another in case of
necessity, without putting the generator or other fire out of work. The re-heating
of the charge takes place on a flat hearth, and no part of the charge is left in the
apparatus after tapping, as is the case ordinarily when a very flat fixed hearth with
tapping hole is used.
When the apparatus is in a vertical position, the Bessemer process can proceed
without injury to the regenerator chambers, as they are shut off from the furnace
proper by the openings thereto being closed through the position of the furnace or
by special doors.
On the accompanying Sheets of Drawings I have shown apparatus suitable for
carrying this Invention into effect.
Figures 1 and 3, Sheet 1, and Figures 6, 7, and 8, Sheet 3, show the apparatus in
the position required for the Bessemer part of the process; and Figure 2, Sheet 1,
Figures 4 and 5, Sheet II., and Figures 9, 10, 11, Sheet III., show the same
apparatus in the position required for the re-heating part of the process. As before
stated the heating of the furnace may be effected by a gas regenerator furnace as
supposed in this case, or by any other suitable heating appliance.
Figures 6 and 7, Sheet III., and Figures 1 and 3, Sheet I., are respectively vertical
longitudinal section and vertical transverse section through the furnace, constructed

page_text: and adapted for this process; and Figure 8, Sheet III., is an outside end view of the
apparatus proper, and a section through line M, L, Figure 6, as regards the parts
below the same.
Figures 9, 10, and 11, Sheet III., are respectively vertical longitudinal section,
vertical transverse section, and horizontal longitudinal section through the apparatus
proper.
The body a of the furnace or converter, Sheet III., is at its ends provided with
hollow pivots b and c, which rest on friction rollers d, and are held down against
them by the weight of the apparatus itself, and by a cap and tie bolts as shewn.
The apparatus is turned into the required positions by wheel gearing e at the end
of the pivot b, the said gearing being actuated from a steam engine f, the fly wheel
g of which is provided with a brake.
The charge contained in the furnace is when in the position shewn in Figures 9,
10, and 11, Sheet III., heated by the two openings 1, 1, (which openings during the
Bessemer part of the process are closed by means of doors q, shewn in position on
Figure 6, Sheet III.; m is the throat or exit opening of the converter'; this opening
is closed by a door or cover r, Figure 11, during the re-beating part of the process;
the opening m serves for charging and discharging the apparatus; or an opening 2,
as shewn in dotted lines in Figure 7, may be applied for discharging, in order to
keep back all the slag.
The blast in the Bessemer part of the process enters from the pipe h, Figure 6,
Sheet III., by a self-acting valve in the upper part thereof in the usual manner,
passing through the pivot c into the pipe i, and thence to the three branch pipes ¿¹
and tuyeres k
The openings 1, Figs. 9, 10, and 11, Sheet III., in the re-heating part of the
process receive the heating gases from the corresponding openings o in the head n
of the regenerator furnace. The openings o are closed by doors p, Figures 10 and 8,
Sheet III., during the Bessemer part of the process, and the heat from the gas
furnace is thus shut off during that time.
The furnaces may be arranged in couples with one common gas-heating furnace,
as indicated on Figure 8, where the space marked a' on the right of the centre
line is supposed to be occupied by a furnace similar to a on the left; the heat
for the furnace at a' comes from the opening o¹. In such an arrangement an
alternate working may be applied, one Bessemer apparatus being at work while the
lining of the other is cooling down and being repaired.
The above-described combined reverberatory and Bessemer furnace enables the
Bessemer process to be worked with such sorts of pig iron, the working of which is
too cold in an ordinary Bessemer converter, especially with the much cheaper white
pig iron and pig iron purified according to what is known as "Krupp's" method.
By the use too of furnaces constructed according to this Invention, large quantities
of steel and wrought iron scraps can be added to the pig iron, and a "dead" melted
metal is obtained by re-heating the metal again after the Bessemer process has
taken place; the physical properties are improved, and as the chemical properties
can also be improved by any desired additions; and all this is attained in and by
the same apparatus re-heating the charge or blowing air through it alternately at
will. The white pig iron, for instance, melted in any other furnace, is charged
into the apparatus a when in the horizontal position through the mouth m, then it
is first superheated, and in the apparatus when upright, as shewn in Figures 6, 7,
and 8, Sheet III., turned into Bessemer metal. Then the charge is re-heated in the
apparatus placed horizontally, as shewn in Figures 9, 10, and 11, Sheet III.,
scraps being added at will, thus obtaining a "dead" melted metal, and by means
of suitable additions the ordinary Bessemer metal is improved to a higher
quality.
A combined reverberatory and Bessemer furnace may be used similar to an
ordinary Bessemer converter, but flattened, and with a broad opening or mouth
through which the apparatus is heated by the injection of pulverized coal, such as
is now known as Crampton's system, or other arrangements for the supply of

page_text: powdered fuel may be used, or the system known as Siemens' for his rotators may
be used, supply of blast and movement of the converter being effected as before.
Air enters by a pipe into a series of tuyere chambers, extending over the full width
of the converter, and from there into the tuyeres. Sometimes a narrower mouth is
employed and double bottoms, then when the Bessemer process takes place both
bottoms receive (separated from one another) air through both converter trunnions,
but in turning the apparatus into the horizontal position for re-heating the charge
of the air in the lower bottom is self-actingly replaced by lighting gas injected under
pressure by steam. The upper bottom receives air as before, but now it is used for
combustion of the gas, or it may be that the flame would not strike back into the
bottom if a single one were employed and the lighted gas were injected directly
through the tuyere blast.
When the apparatus is heated the burnt gases escape by a flue.
And having thus described and ascertained the nature of this Invention, I declare
that I claim,
Firstly. The application of apparatus consisting of a combined reverberatory and
Bessemer furnace for alternately heating the charge and blowing air through it,
substantially as set forth.
Secondly. The construction and application of apparatus operating as herein
described and shewn, consisting of an oval Bessemer converter, which can
turn on its longitudinal axis, and which is provided on one narrow side with
Bessemer tuyeres, and on the other narrow side with opening for the admission
of heat.
In witness whereof, I, the said Alfred Longsdon, have hereunto set my
hand and seal, this Seventeenth day of June, in the year of our Lord
One thousand eight hundred and seventy-eight.
ALFRED LONGSDON. (L.S.)