Process for Removing Gases and Foreign Impurities from Metals or Alloys.
Year: 1890

page_text: Date of Application, 4th Mar., 1890-Accepted, 10th May, 1890
Process for Removing Gases and Foreign Impurities from Metals or
Alloys.
I, JOHAN LEONHARD SEBENIUS of 48, Sturegatan, Stockholm, in the Kingdom
of Sweden, Civil Engineer, 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 purpose, immediately after a piece of iron, steel or
other metal or alloy has been cast and while it is still in a more or less liquid or
soft state, to lessen its porosity and also to remove the flaws and foreign impurities,
such as quartz, clay and oxides, as well as to impart an augmented strength to the
" rotator,"
"with
same. These results are effected by means of an apparatus called a
a vertical shaft, on or to which rotator the chills or moulds containing the castings
are freely suspended so as to be able, when the rotator is revolved, to occupy a
more or less radial and horizontal direction, by which the centrifugal force will act
upon the particles of the cast piece or pieces with a pressure partly depending
upon the speed of rotation, and the direction of which is parallel with that of the
axis of the casting which passes through its point of suspension and its point of
gravity, whatever be the speed of rotation and whatever the position occupied by
the casting, during the rotation, the upper surface will, owing to this disposition,
rest perpendicular to the said axis and the metal can thus not flow out through
the open gits and vent-holes of the moulds, on the other hand, the gases to be
removed have free passage through the same, and, besides, the foreign matters which
When now after
may be contained in the metal will gather in the said openings.
a casting has been quickly cast, the rotator with the chills or moulds and their
contents has been put in motion, the latter, affected by the centrifugal force, tend
to occupy a direction radial to the circle of motion and more or less horizontal,
when the metallic particles, having a far greater specific weight, than the gases
and impurities are driven further out in a radial direction, rapidly invading the
space occupied by the former. After a very short time, the pure metal will occupy.
the extreme part of the mould, the impurities gather at the inner and open surface
of the ingot, and the gases have escaped from the same and through the vent-holes,
if any.
By means of this process, it has been found possible to drive out all gas and foreign
impurities, without any waste of metal, so that absolutely flawless and homogeneous
iron and steel ingots and castings of almost any description can be produced.
For effecting the centrifugation of iron, steel and other metals, which, of course,
can be performed by devices of very different kinds, the inventor has constructed
different rotators, the construction of which however, will, in principle be understood
by the annexed drawing, and the following description.
Figures 1 and 2 show, in section and plan, the rotator disposed in one manner.
Inside the pillar A, which is carefully fixed in the ground, is mounted a shaft B, on
the top of which a disc C is firmly secured. The chills F are suspended freely on the
arms D, which are, at their outer ends, shaped to a hook and supported by the disc U,
at the centre of which they are secured by a ring E. In lieu of the disc C, there
may obviously also be used swinging arms fixed to the shaft, which, besides, may
have its bearings at the top and at the bottom in the manner customary to turning
cranes or rotators. The rotator (the shaft B with the chills or moulds) is revolved by
means of a transmission pulley acting upon the shaft. The rotator is used as a ladie
crane by raising it as indicated by the dotted lines, when the casting is to be effected
from the ladles into the disconnected chills F arranged in a circle around the rotator,
and the molten metal may also be centrifugalled in the ladles.

page_text: Amongst the many different ways of carrying this process into practice, the
following may be described, by which others, more or less deviating therefrom, may
likewise be understood. Such metals as easily yield their gases are centrifugalled in
the ladles previous to the casting, in a manner easily understood from the dotted
lines.
If, on the contrary, metals are to be treated which less easily yield their gases and
foreign matters, the chills or moulds F are arranged in their places, and then one,
two or more casting ladles containing molten metals are suspended on the rotator,
diametrically one to another, whereafter the casting is speedily performed simul-
taneously from all the ladies employed. After the casting, the ladles are disconnected,
and the filled chills or moulds are suspended on the rotator lowered for this purpose,
and then raised a little by means of hydraulic pressure, or in any convenient way, so
that the chills will hang freely, whereafter the rotator is put in motion by means of
any convenient force applied to the same.
It is evident that, where cheap rotators are wanted, the hydraulic lifting apparatus
may entirely be dispensed with, and if the casting takes place directly from the
furnace into the chills or moulds, these may, by means of suitable trucks or travelling
cranes, be transported to and suspended on the rotator. If the mode of suspension of
the chills or moulds be such that the casting is not hindered thereby, it is evident that
the casting may take place even while the chills are suspended on the rotator.
The rotator and the place where the casting rotates must, as shown by the drawing,
be surrounded by a solid brickwork or a strong plate cylinder or some similar guard,
in order that the workmen may be protected in the event of any chill or mould not
being perfectly tight, but permitting the molten metal to get out. To ensure greater
security in this event, the chills or moulds should externally be provided with a strong
plate casing.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The process for removing gases or other foreign impurities from molten metals
or alloys, which consists in subjecting them, while contained in suitable ladles, moulds,
or chills, to a centrifugal motion, whereby the said metals, heing of greater specific
gravity than the impurities, will displace the latter and become more homogeneous,
substantially as described.
2. A process for displacing impurities in molten metal by centrifugal force, which
consists in suspending ladles, moulds or chills upon or near the outer extremities of
two or more arms radiating from a revolvable shaft in such manner that the said
ladles, moulds or chills will, when the apparatus is revolved, tend to assume a position
outside their axes of suspension, substantially as and for the purposes set forth.
Dated this 3rd day of March 1890.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.