Year: 1886

page_text: [Partly communicated from abroad by CARL GUSTAF WITTENSTRÖM, of Motala,
EDWARD FAUSTMAN and PETTER OSTBERG, Civil Engineers, of Stockholm,
all in the Kingdom of Sweden.]
I THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
Civil Engineer do hereby declare the nature of this invention to be as follows:-
This Invention has for its object improvements in Bessemer converters and in the
manufacture of castings thereby.
In manufacturing castings direct from a Bessemer converter I have found many
draw-backs and inconveniences in the usual converter; and by a series of experiments
I have arrived at an apparatus admirably suitable for the purpose and which may be
said to be a combination of a Bessemer converter and a Martins furnace. I have
also found great advantage in combining with the converter a casting appliance by
which I am able to pour the metal from the bottom instead of over a lip; thus
preventing slag from running along with the metal into the moulds and obtaining
other advantages.
Experiments even on a large scale have several times been made of first blowing the
pig iron in the usual way in a Bessemer converter and then running the metal produced
into a Siemens-Martin-furnace, but as far as I am aware all such experiments have
proved failures economically and have been abandoned the advantage of the treatment
in the second furnace not justifying the very great expense of maintaining the
requisite high temperature in the Siemens Martins furnace and other heavy expenses
connected with such an arrangement.

page_text: I so form and arrange the converter that after the blow is completed the metal
can be retained and a gas flame kept playing over the surface of the metal and whilst
the metal is still in the converter I treat it and make additions to it as when working
with a Martins furnace. Finally I draw out the metal into the moulds by means of
my casting appliance in which is a valve which is lifted to allow the metal to flow.
In producing small castings I have not found it advantageous to use converters of
greater capacity than from five to ten cwts. In such small converters, if of the
usual shape, a great part of the metal is thrown out of the converter during the blow.
To prevent this other users of small converters have changed the shape by increasing
the height of the converter. This way of overcoming the difficulty would not answer
my purpose, when the metal has to be treated afterwards as in a Martins furnace,
because the metal would be spread over too large a surface and have too little depth.
My way of overcoming the outblow without increasing the height of the converter
is by giving the converter a bent shape, so that the metal is thrown against the upper
part of the converter during the blow, falls back, and is not thrown out of the converter.
Another purpose of this bent shape is to make the bath deeper, when to retain the
metal after the blow; for this same purpose I give to the converter an almost
rectangular section.
As for the proper treatment of the metal afterwards the converter must have a
larger mouth than desirable during the blow, I use a detachable mouth piece.
My improved invention is shown by the drawings annexed.
Figure 1 shows in front elevation the framing supporting the converter whilst the
converter itself with its tuyere box is represented in section on the line A. B in
Figure 6.
Figure 2 is a plan, with a portion of the converter in section as above.
Figure 2 shows the rest of the converter in section on the line O. P. in Figure 3.
Figure 3 is a longitudinal and vertical section of the converter and frame in
position for casting.
Figure is a transverse section on the line QR. in Figure 6.
Figure 5 shows the underside of the tuyere box.
Figure 6 is a longitudinal and vertical section of the converter in position for
blowing.
a. a. are standards carrying in bearings the hollow cranked frame b the part b¹ of
which contains the tuyere box. At c. air under pressure is admitted for the blow
and afterward a mixture of gas and air can be supplied through the tuyeres to
maintain a flame over the metal.
d is the casing of the converter, it is lined in the usual way; and at e. e the
tuyeres are provided. f is the mouth piece which is applied to contract the exit
aperture whilst blowing it is lined with refractory material and is held in its place by
studs and cottars. g is the casting appliance which is in like manner fixed at the
mouth of the converter when required. It resembles one half of a casting ladle it is
lined in a similar manner and has a pouring hole at the bottom at which a valve gl
is provided. This valve consists of a metal stem with refracted material moulded
upon it as is usual with the valves of casting ladles. 92 is a lever for operating the
valve.
The working is conducted in the following manner :-
After placing the converter in a suitable position, melted pig iron is run into it and
the mouth piece being attached the air blast let on. The converter is then erected
to the position shown by Figure 6 and the blow conducted in the ordinary manner of
Bessemer practice. When the blow is over, the converter is turned down until the
line L. M in Figure 3 (representing the surface of the metal) is horizontal. The air
blast is then turned off and the mouthpiece removed. Thereupon a properly mixed
supply of gas and air of lower pressure than the air blast is let on so as to maintain

page_text: a flame of very high temperature within the converter. The metal may now be
treated in any desirable way. The slag or part of the slag may be raked out,
samples may be taken, pig iron or wrought iron scrap may be added for regulating
the temper, ferromanganese, ferro silicon, aluminium pig or other physics may be
added and the bath may be allowed sufficient time for settling and letting the gases
go off, owing to the continuous flame no cooling takes place.
When the metal is such as desired the flame may be taken off for an instant for the
purpose of attaching the casting appliance 7 and it is then immediately turned on
again. The converter is then turned into the position shown in Figure 3 and the
casting is commenced the line J. K. then representing the surface of the metal in the
bath.

page_text: Improvements in Bessemer Converters and in the Manufacture of
Castings thereby.
I, THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster,
Civil Engineer, (which invention has been partly communicated to me from abroad
by Carl Gustaf Wittenström of Motala, Edward Faustman and Petter Ostberg Civil
Engineers, of Stockholm, all in the Kingdom of Sweden) 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 has for its object improvements in Bessemer converters and in the
manufacture of castings thereby.
In manufacturing castings direct from a Bessemer converter I have found many
drawbacks and inconveniences in the usual converter; and by a series of experiments
I have arrived at an apparatus admirably suited for the purpose and which may be
said to be a combination of a Bessemer converter and a Martin's furnace. I have
also found great advantage in combining with the converter a casting appliance by
which I am able to pour the metal from the bottom instead of over a lip; thus
preventing slag from running along with the metal into the moulds and obtaining
other advantages.
Experiments even on a large scale have several times been made of first blowing the
pig iron in the usual way in a Bessemer converter and then running the metal produced
into a Siemens-Martins furnace, but as far as I am aware all such experiments have
proved failures economically and have been abandoned the advantage of the treatment
in the second furnace not justifying the very great expense of maintaining the
requisite high temperature in the Siemens Martins furnace and other heavy expenses
connected with such an arrangement.
I so form and arrange the converter that after the blow is completed the metal
can be retained and a gas flame kept playing over the surface of the metal and whilst
the metal is still in the converter I treat it and make additions to it as when working
with a Martins furnace. Finally I draw out the metal into the moulds by means of
my casting appliance in which is a valve which is lifted to allow the metal to flow.
In producing small castings I have not found it advantageous to use converters of
greater capacity than from five to ten cwts. In such small converters, if of the usual
shape, a great part of the metal is thrown out of the converter during the blow. To
prevent this other users of small converters have changed the shape by increasing the
height of the converter. This way of overcoming the difficulty would not answer
my purpose, when the metal has to be treated afterwards as in a Martin's furnace,
because the metal would be spread over too large a surface and have too little depth.
My way of overcoming the outblow without increasing the height of the converter
is by giving the converter a bent shape, so that the metal is thrown against the upper

page_text: part of the converter during the blow, falls back, and is not thrown out of the converter.
Another purpose of this bent shape is to make the bath deeper, when to retain the
metal after the blow; for this same purpose I give to the converter an almost
rectangular section.
As for the proper treatment of the metal afterwards the converter must have a
larger mouth than desirable during the blow, I use a detachable mouth piece.
My improved invention is shown by the drawings left with my provisional speci-
fication.
Figure 1 shows in front elevation the framing supporting the converter whilst the
converter itself with its tuyero box is represented in section on the line A B in
Figure 6.
Figure 2 is a plan, with a portion of the converter in section as above.
Figure 2 shows the rest of the converter in section on the line OP in Figure 3.
Figure 3 is a longitudinal and vertical section of the converter and frame in
position for casting.
Figure 4 is a transverse section on the line QR in Figure 6.
Figure 5 shows the underside of the tuyere box.
Figure 6 is a longitudinal and vertical section of the converter in position for
blowing.
a a are standards carrying in bearings the hollow cranked frame 6 the part 1 of
which contains the tuyere box. At c air under pressure is admitted for the blow
and afterward a mixture of gas and air can be supplied through the tuyeres to
maintain a flame over the metal.
d is the casing of the converter, it is lined in the usual way; and at e, e the
tuyeres are provided. This converter it will be seen is rectangular in cross section;
the sections increase progressively in area from the bottom or tuyere and to about the
middle and they decrease in area progressively from the middle to the mouth. The
body also is abruptly bent near the middle. This form provides ample capacity for
retaining the metal when the converter is tipped with the tuyeres, raised sufficiently
high out of the metal. It is also well adapted to admit of the metal being con-
veniently worked and the slag skimmed from its surface over the straight horizontal
lip. is the mouth piece which is applied to contract the exit aperture whilst
blowing it is lined with refractory material and is held in its place by studs and
cottars. 9 is the casting-appliance which is in like manner fixed at the mouth of the
converter when required. It resembles one half of a casting ladle it is lined in a
similar manner and has a pouring hole at the bottom at which a valve g¹ is provided.
This valve consists of a metal stem with refracted material moulded upon it as is
usual with the valves of casting ladles. ' is a lever for operating the valve.
The working is conducted in the following manner :-
After placing the converter in a suitable position, melted pig iron is run into it and
the mouth piece being attached the air blast let on. The converter is then erected
to the position shown by Figure 6 and the blow conducted in the ordinary manner of
Bessemer practice. When the blow is over, the converter is turned down until the
line L M in Figure 3 (representing the surface of the metal) is horizontal. The air
blast is then turned off and the mouthpiece f removed. Thereupon a properly mixed
supply of gas and air of lower pressure than the air blast is let on so as to maintain
a flame of very high temperature within the converter. The metal may now be
treated in any desirable way. The slag or part of the slag may be raked out,
samples may be taken, pig iron or wrought iron scrap may be added for regulating
the temper, ferromanganese, ferro-silicon, aluminium pig or other physics may be
added and the bath may be allowed sufficient time for settling and letting the gases go
off, owing to the continuous flame no cooling takes place.

page_text: When the metal is such as desired the flame may be taken off for an instant for
the purpose of attaching the casting appliance g and it is then immediately turned on
again. The converter is then turned into the position shown in Figure 3 and the
casting is commenced the line J K then representing the surface of the metal in
the bath.
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. The process in the manufacture of castings direct from the converter consisting
in blowing the metal in the converter, then retaining it in the converter with a gas
flame playing over the surface whilst suitable additions are made and finally when
the metal is in a fit state drawing off the metal from beneath the surface by means
of a casting appliance upon the converter, all substantially as described.
2. A converter substantially as described with its cross sections increasing pro-
gressively in area from the bottom or tuyere end to about the middle and decreasing
progressively in area from the middle to the mouth and with the body as shown
abruptly bent near the middle.
3. A converter substantially as described and represented by the annexed drawings.
4. The combination substantially as described of a converter having a mouth which
gives free access to the metal admitting of its being skimmed and worked after
blowing and a moveable mouth piece which being in place during the blow contracts
or shelters the mouth and prevents undue loss of heat in this operation as herein set
forth.
5. The combination of a converter and a casting appliance substantially as described
and such that the metal having been worked and brought to a fit state after blowing
may be drawn off into moulds from beneath the surface of the metal in the converter
as herein set forth.
00 11
T 1
1007
CARPMAEL & Co.,
Agents for the Applicant.