Improvements in Apparatus for Removing, when Casting, Gases and Impurities Contained in the Metal or Alloy.
Year: 1892

page_text: Date of Application, 12th Aug., 1892-Accepted, 17th Sept., 1892
COMPLETE SPECIFICATION
Improvements in Apparatus for Removing, when Casting, Gases and
Impurities Contained in the Metal or Alloy.
I, JOHAN LEONARD SEBENIUS of Nykroppa in the Kingdom of Sweden,
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 :-
The object of this apparatus is (in accordance with the method described in the
British Patent No. 3440 of March 4, 1890) to treat a metal or an alloy in such a
way as to free it from gases and impurities contained in the same, and thus to
produce a solid and reliable material. This invention enables the casting to take
place during the rotation of the apparatus, the metal being thus exposed to the
action of centrifugal force at the very moment when it is flowing down in the
apparatus, that is to say, before it has had time to stiffen to any considerable
extent, by which means the escape of the gases, etcetera, takes place more rapidly
and completely.
The apparatus is represented on the accompanying drawing.
Figures 1 and 2 represent, in vertical and in plan and horizontal section
respectively, a rotating apparatus, supported on a vertical shaft.
Figures 3, 4, 5, 6 and 7 are details belonging to this invention.
At the top of a vertical shaft A, connected with any suitable source of motive
power, there is secured a disc B having an upright rim or frame, within which the
casting moulds are placed. As shown in Figures 1, 2, 5 and 6, these moulds are
chills c arranged systematically around funnels or channels b, each common to such
a system of chills, its outer end being in connection with the outer end of the
chills e by means of smaller channels f. The axes of the channels can either
run radially or, if desired, deviate a little from this direction. The channels bas
well as the chills c are open at the ends facing the centre of the disc B, as shown
by the drawings, but the chills may also be provided with separate air funnels.
By applying a common funnel, opening at the outer ends of the chills and lined
on the inside with some fire-proof material, it is possible to fill the chills with
the liquid metal, which, if the filling be performed directly, would otherwise
immediately destroy the chills, as the liquid metal, flowing along the walls, would
eat away and melt pieces off the latter, so that the castings would have neither the
required shape nor size, and could not be taken out of the chills. The stream of
metal, therefore, cannot be run in directly, during the rotation, through the inner
end of the chills without impinging on the inner walls of the former.
In the centre of the apparatus there is a vessel a, the so called distributor, which
receives the stream of metal flowing down from the ladle; the stream should pre-
ferably fall to one side of the axis of the rotator. The bottom of the distributor,
which is likewise fixed on the shaft A, and which thus rotates with the same speed.
as the parts hereinbefore described, is provided with several radial or almost radial
ridges, the sides of which are steep in one direction but slope gently in the other,
as shown in Figure 7. From the lower parts of the bottom sections h, thus formed,
mouth pieces k project, which are fixed at the outside of the distributor and
extend close to the inner ends of the funnels 6, the axes of which are in a straight
or almost straight line with the axes of the mouth pieces k¹. The distributor is
made of cast or sheet iron, and, at the points where it comes in contact with the
molten metal, it is lined with some fire-proof material.
When the moulds are made of metal (chills), the funnels and the channels f
should also be lined with some fire-proof material. The channels fare arranged
in the bottom plates 9, covering the outer ends of the moulds, which latter may

page_text: either be in one piece with the remainder of the mould or may be detachable there-
from, which latter arrangement is shown on the drawing.
The working of the apparatus is as follows:-
The shaft A, together with the parts fixed thereon, is caused to rotate in such a
direction that the molten metal, which is simultaneously allowed to flow down from
the ladle located above the apparatus, is caught by the steep sides of the ridges on
the bottom of the distributor a.
The metal is, consequently, at the very moment when it reaches the distributor,
exposed to the action of centrifugal force and is at once forced through the mouth-
pieces into the funnels b and from these through the channels f into the chills c.
By this means, the heaviest material that is, the molten metal, has a tendency to be
thrown away from the centre of the apparatus, in consequence of which the lighter
materials, such as gases and impurities, are driven in the opposite direction. The
gases escape through the open inner ends of the chills, which ends thus serve as
air funnels, while the solid or liquid impurities gather on the respective metal
surfaces, which are almost vertical.
As the quantity of metal flowing from the ladle is almost constant at every
revolution of the rotator, and as the distributor a is so arranged that, when it is only
so far filled that the metal does not surmount the ridges in the bottom of the
same, it must, under the same conditions, distribute the same quantities through
each mouthpiece k¹, the metal surfaces in all the chills will, therefore, constantly be
at about the same distance from the shaft of the rotator, that is to say, the chills
will always be equally filled, and the castings will thus be made simultaneously,
which is indispensable when several articles are to be cast at the same time, as
otherwise the liquid metal in the moulds first filled would be pressed out through
the openings at the inner ends of the moulds and thrown about in the space where
the rotating apparatus is, which, for better security, is placed in a pit of brick-
work.
The centrifugal force contributes not only to drive the gases and impurities out
of the metal or the alloy, but the product obtained is also particularly strong and
homogeneous.
The apparatus herein described may, of course, be modified in various ways.
For instance, the disc B may be replaced by arms, firmly connected with the
rotary shaft A, and between or on which arms the chills or moulds are fixed. The
chills c may also be replaced by sand moulds, brick-moulds or the like, which may
have each its respective funnel bor, as is the case with the chills, two or more may
be arranged around such funnel.
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. In casting apparatus for removing, during the operation, gases and impurities
from the molten metals or alloys by means of centrifugal force, and in which there
is a vessel supported on a vertical shaft, the arrangement, at the outer side of such
vessel, of fixed mouthpieces k¹, which extend in a radial or almost radial direction
close up to one end of funnels 6 lying in the same or almost in the same direction,
the other ends of which funnels open into channels f leading to moulds c resting
upon a disc B attached to the vertical shaft, or on a frame consisting of arms, with
the object of forcing the metal, flowing down in the vessel from the ladle during the
rotation of the apparatus, into the moulds, and there, owing to its greater specific
weight, to free it from gases which escape through the abovenamed air funnels, and
from impurities which accumulate in layers upon the surface of the metal or alloy
facing the shaft.
2. In apparatus of the kind described in Claim 1, the arrangement whereby the
bottom of the vessel fixed on the vertical shaft forms radial, or almost, radial,
ridges, the sides of which are steep in the direction in which the apparatus rotates
but slope gently in the opposite direction, and whereby each of the mouthpieces

page_text: leads from the lowest part of the section formed between a steep and a gently
sloping side, so that the metal may be partially exposed to the action of the
centrifugal force the moment it has descended into the vessel a so as to be
immediately forced out of the same and be distributed in equal quantities and
5 simultaneously to each of the different chills or moulds.
Dated this 11th day of August 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.