IMPROVEMENTS IN TREATING BESSEMER METAL IN ORDER TO PRODUCE COMPACT INGOTS FREE FROM RED SHORTNESS, AND IN APPARATUS THEREFOR.
Year: 1881

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN TREATING BESSEMER
METAL IN ORDER TO PRODUCE COMPACT INGOTS FREE FROM RED SHORTNESS,
AND IN APPARATUS THEREFOR.' A communication from abroad by Dr. Henrik
Tholander, of Forsbacka Iron Works, Sweden.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office
of the Commissioners of Patents on the 22nd June 1881.
PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex. " IMPROVE-
MENTS IN TREATING BESSEMER-METAL IN ORDER TO PRODUCE COMPACT INGOTS
FREE FROM RED SHORTNESS, AND IN APPARATUS THEREFOR." (A communication
from abroad by Dr. Henrik Tholander, of Forsbacka Iron Works, Sweden.)
It is of particular importance in the Bessemer manufacture to produce ingots
both compact and free from bubbles. By means of strong working and stretching
by way of hammering or rolling after welding, one may certainly improve the
metal in porous ingots, but it cannot be converted into such a high class article as
if the ingots had been free from pores or air holes from the beginning. This
treatment, however, occasions great expense. When castings are to be produced
which are not to be subjected to further treatment before being finished, it is of
course of a still more palpable advantage and importance to obtain an article free
from pores. Many endeavours have also been made for producing steel free from
pores, even with a partial success, such as the Whitworth and the terre-noire
methods. Compared with these, the following method claims to be more simple
and more direct, and thus cheaper also, both with regard to constructions and to
the mode of working. According to this Invention the molten Bessemer metal
before being poured into the mould is exposed to a vacuum, as I shall denominate
it for the sake of brevity throughout the following, although I ought to say the
minimum of atmospheric pressure, and the gases which are thereby caused to
evaporate are removed. The vacuum is to be produced in the converter itself, in
which the metal is kept for some time after the process of smelting is over before
it is emptied out of it in one of the usual ways. In the opening of the converter,
or if a so called converting chamber is used, in the upper free end thereof, an ejector
is placed, which is worked by a current or blast of air or steam of sufficient
pressure, or the converter (or the converting chamber, if such an one is used) is
closed by a cover and connected afterwards with a separate ejector, or an exhaust

page_text: or suction fan of suitable construction. In the same way as other liquids, the over
heated Bessemer metal melted into a thin fluid mass in a vacuum evaporates with
a certain violence the gases which have been absorbed by it when exposed to a
higher pressure. Although in practice for many reasons an article absolutely free
from gases cannot be produced by means of a converter vacuum, the tension of the
remaining gases is nevertheless so much lessened that they can no longer separate
themselves when after the evacuation is completed the full atmospheric pressure is
allowed to act on the metal, but remain fully dissolved therein and form no bubbles
or air holes.
Another advantage gained by the vacuum process is that the red shortness of
the Bessemer metal, as far as this is occasioned by the presence of oxidized iron in
the metal, is diminished, because the oxidized iron dissolves itself on account of the
high temperature in the converter into metallic iron and oxygen, which latter
evaporates in one or another gas formation.
. A suitable mode of carrying out this Invention is as follows:-The converting
chamber is fitted with an ejector, and has on its upper part a dish or collar of cast
iron, into which by means of a luting consisting of fine ground quartz or "chamotte
flour" (powdered brick) and clay, and by means of screw bolts, an iron ring is
pressed in air tight; this ring is fastened to a sheet iron helmet or cap which is
lined with fireproof material. Through said dish or collar, fitting as closely as
possible, the leading or guiding rod runs to a branch from a chambered interior rod,
and is made hollow in order to serve as blowing pipe in an injector, the delivery
mouth piece of which is placed in the helmet or cap covering the converting
chamber precisely in the middle above the leading rod or blowing pipe, and an air
pressure or steam pipe is connected to this when evacuation is to take place.
In order to increase the efficiency of the ejector a funnel of sheet-iron is attached
to the delivery mouth piece when evacuation is to take place. The mouth piece
may have a current of steam or air applied on its outer side to increase the
suction. The leading or guiding rod may of course also be made solid, as is the
usual way, and the ejector be attached quite apart from it to the converting
chamber or its cover. If a converting chamber is not used the ejector ought to be
fixed with a suitable luting direct to the opening of the converter.
Two or more outlet mouthpieces may be used where a strong current must be
maintained, rather than to increase the delivery opening of a single ejector in a
corresponding degree. On tapping out the Besseiner-metal, even if made absolutely
free from gases before the tapping takes place, bubbles may be therein produced,
if air is pressed down into the ingots by the stream of metal, which is the more the
case the higher the fall is in the open air, and the quicker the metal runs out from
the tap hole. This air oxydizes the iron, and the iron thus oxydised mixing with
carbonic iron turns into carbonic-acid, which certainly may evaporate, while the
metal remains liquid in the mould, but which otherwise, at least to a certain
extent, remains collecting together in bubbles in the blooms. In order to avoid
this inconvenience it is advisable to adopt the method used in many places in
regard to Bessemer-metal, viz., to place a funnel or a basin over cach mould, close
beneath the converting chamber, in which the metal is first poured, and from
whence it runs down into the mould with decreased speed. This basin should so
completely cover the opening of the mould that space is only left sufficient for
allowing the gases to escape which are in the mould when it is filled up, because
the mould will in this way be kept filled with gases consisting chiefly of carbonic
acid formed by the burning of the black-lead, birch bark, smoke, or something of
the sort, wherewith the moulds are generally covered; or else they are such as
evaporate from the metal, be it to a small amount after the evacuation, wherefore
it is evident that no air can be pressed down by the metal stream, but only gases
to which the Bessemer-metal is indifferent, and which when they get down into
the metal are not absorbed, but immediately rise to its surface.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Jensen in the Great Seal Patent Office on the 22nd December
1881.
PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex. "IMPROVE-
MENTS IN TREATING BESSEMER METAL IN ORDER TO PRODUCE COMPACT INGOTS
FREE FROM RED SHORTNESS, AND IN APPARATUS THEREFOR.' (A communication
from abroad by Dr. Henrik Tholander, of Forsbacka Iron Works, Sweden.)
It is of particular importance in the Bessemer manufacture to produce ingots
both compact and free from bubbles. By means of strong working, and stretching
by way of hammering or rolling after welding, one may certainly improve the
metal in porous ingots, but it cannot be converted into such a high class article as
if the ingots had been free from pores or air holes from the beginning; such
treatment moreover occasions great expense. When castings are to be produced
which are not to be subjected to further treatment before being finished, it is of
course of a still more palpable advantage and importance to obtain an article free
from pores. Many endeavours have also been made for producing steel free from
pores, even with a partial success, such as the Whitworth and the terre-noire's
methods. Compared with these the following method claims to be more simple
and more direct, and thus cheaper, also both with regard to the constructions of
the apparatus and to the mode of working-According to this Invention the
molten Bessemer-metal before being poured into the mould is exposed to a vacuum,
as I shall denominate it for the sake of brevity throughout the following, although
I ought to say the minimum of atmospheric pressure or the partial vacuum and
the gases which are thereby caused to evaporate are removed. The vacuum is to
be produced in the converter itself, in which the metal is kept for some time after
the process of smelting is over, before it is emptied out of it in one of the usual
ways. In the opening of the converter, or if a so called converting chamber is
used, in the upper free end thereof an ejector is placed, which is worked by a fan,
or by steam of sufficient pressure; or the converter (or the converting chamber if
such a one is used) is closed by a cover, and connected afterwards with a separate
cjector or an exhaust or suction fan of suitable construction. In the same way as
other liquids the overheated Bessemer metal melted into a thin fluid mass in a
vacuum evaporates with a certain violence the gases which have been absorbed by
it when exposed to a higher pressure. Although in practice for many reasons an
article absolutely free from gases cannot be produced by means of a converter
vacuum, the tension of the remaining gases is nevertheless so much lessened that
they can no longer separate themselves when after the evacuation is completed the
full atmospheric pressure is allowed to act on the metal, but remain fully dissolved
therein and form no bubbles or air holes.
Another advantage gained by the vacuum process is that the redshortness of
the Bessemer metal, as far as this is occasioned by the presence of oxydized iron in
the metal, is diminished, because the oxydized iron dissolves itself on account of the
high temperature in the converter into metallic iron and oxygen, which latter
evaporates in one or another gas formation.
And having thus described the nature of this Invention in a general way, I will
proceed to describe the manner in which it is or may be carried into effect with
reference to the accompanying Drawings.
Figure 1 is a vertical section through a converting chamber constructed

page_text: same.
according to this invention; Figure 2 is a plan, and Figure 3 an end elevation of
The converting chamber A is fitted with an ejector B, and has on its upper
part a dish or collar a of cast iron, into which by means of a luting consisting of
fine ground quartz or "chamotte flour," powerded brick, and clay, and by means of
screw bolts b, the iron ring c is pressed in airtight; this ring c is fastened to a
sheet iron helmet or cap d, which is lined with fire-proof material. Through said
dish or collar a, and fitting as closely as possible, the leading or guiding rod e rung
to a branch from the chambered interior rod f, and is made hollow in order to
serve as blowing-pipe in an ejector, the delivery mouth-piece g of which is placed
in the helmet or cap d covering the converting chamber precisely in the middle
above the leading rod or blowing pipe, and an air pressure or steam pipe is, when
evacuation is to take place, connected to the cross pipe h.
In order to increase the efficacy of the ejector a funnel of sheet iron is attached
to the delivery mouth piece when evacuation is to take place. Figure 4 shows on
a diminished scale the converting chamber with the funnel attached to the
converter in the proper position when the evacuation takes place. The mouth
piece g may, as shown in the modification at Figure 5, have a nozzle k for a
current of steam or air applied on its outer side to increase the suction. The
leading or guiding rod e may of course also be made solid, as is the usual way, and
the ejector be attached quite apart from it to the converting-chamber or its cover,
as shown at Figures 6 and 8, or in some other way. If a couverting-chamber is not
used the ejector ought to be fixed with a suitable luting direct to the opening of
the converter, as shown at Figures 7 and 10; Figure 9 shows an ejector
arrangement of the same type as Figure 8. Two or more outward mouth pieces g may
thus be used with advantage where a strong current must be maintained, rather
than to increase the delivery opening of a single ejector in a corresponding degree.
On tapping out the Bessemer metal, even if made absolutely free from gases before
the tapping takes place, bubbles may be therein produced if air is pressed down
into the ingots by being carried down by the stream of metal, which is the more
the case the higher the fall is in the open air and the quicker the metal runs out
from the tap bole. This air oxydizes the iron, and the iron thus oxydized mixing
with carbonic iron turns into carbonic acid, which certainly may evaporate while
the metal remains liquid in the mould, but which otherwise, at least to a certain
extent, remains collecting together in bubbles in the ingots or blooms. In order to
avoid this inconvenience it is advisable to adopt the method used in many places
in regard to Bessemer metal, viz., to place a funnel or a basin over each mould
close beneath the converting chamber in which the metal is first poured, and from
whence it runs down into the mould with decreased speed. This basin should so
completely cover the opening of the mould that space is only left sufficient for
allowing the gases to escape which are in the mould when it is filled up, because
the mould will in this way be kept filled with gases consisting chiefly of carbonic
acid, formed by the burning of the black lead, birch bark, smoke, or something of
the sort wherewith the moulds are generally covered, or else they are such as
evaporate from the metal may be to a small extent after the evacuation, wherefore
it is evident that no air can be pressed down by the metal stream, but only gases
to which the Bessemer metal is indifferent, and which when they get down into
the metal are not absorbed but immediately rise to its surface.
And having thus described and ascertained the nature of this Invention, and
in what manner it is carried into effect as communicated to me, I declare that I
claim,―
First. The mode of treating Bessemer metal in order to attain compactness and
freedom from redshortness, according to which it is exposed to a partial vacuum
in its molten state in the converter by the application of ejectors or air pumps or
other exhausting apparatus, substantially as described, and whether a converting
chamber is used at the tapping or not.

page_text: Second. The combination of parts forming the improved apparatus for treating
Bessemer metal, substantially as described and shown.
In witness whereof, I, the said Peter Jensen, have hereunto set my hand
and seal, this Twentyfirst day of December, in the year of our Lord
One thousand eight bundred and eighty one.
D
CTXTזיזז
'
ΓΙΑΤ
P. JENSEN
(L.S.)