Improvements in or applicable to Centrifugal Machines for Separating Liquids.
Year: 1896

page_text: Date of Application, 21st Aug., 1896-Accepted, 28th Sept., 1856
COMPLETE SPECIFICATION.
Improvements in or applicable to Centrifugal Machines for
Separating Liquids.
We, CARL ALRIK HULT, of 48, Flemminggatan, Stockholm, and OSCAR
WALFRID HULT, of Aronsberg, nenr Stockholm, both in the Kingdom of Sweden,
Engineers, do hereby declare the nature of this invention and in what manner the
sanie is to be performed, to be particularly described and ascertained in and.
by the following statement :-
Our invention relates to centrifugal machines of the kind having in the revolving
drun a screw or worm concentric with the rotary shaft and following the wall of
the drum, the said screw or worm causing the liquid mass subjected to centrifugal
action, to move in a spiral course along the shaft. With the spiral as arranged
hitherto, the path traversed by the liquid has been considerably longer at the
periphery than nearer the centre, which obviously had a prejudicial effect upon the
work of the centrifugal machine.
The object of our invention is to remove this objection by considerably
lengthening the path traversed by the liquid as it approaches the centro.
According to our invention we corrugate the worm so as to give it the shape
shewn in the annexed drawing, in which the drum and the worm are represented
in section. The worm a is made from a straight or nearly straight strip of sheet
metal which is corrugated in such a way that the flutes or corrugations become
deeper towards the one edge of the strip. The strip will thus be contracted at
one end so as to obtain a circular shape, it being thus possible to adapt the
contraction, when corrugating, so thint the spiral will just fit in the drum. The
pitch will depend upon how close the convolutions of the spiral are to be placed
and can thus also be accurately determined. Towards the inner edge of the worm
the flutes project deeper and deeper into each other, but outwardly there is a free
space between the convolutions of the worm. Owing to the fact that the flutes or
corrugations project deeper and deoper into each other towards the centre of the
drum they gradually lengthen the path traversed by the liquid so that the said
path will be about the same leugth at the inner edge of the worm as at the outer
edge along the wall of the drum. The flutes may be laid perpendicularly or
obliquely across the strip.
Having now particularly described and ascertained the nature of our said invon-
tion and in what manner the same is to be performed, we declare that what we-
clain is:-
1. In a centrifugal machine provided with a screw or worm located in the drum
concentrically with the drum shaft, causing the revolving liquid mass to move in a
spiral direction along the shaft, corrugating or fluting the screw or worm
perpendicularly or obliquely in such a way that the corrugations or flutes are
deeper and deeper as they approach the centre of the drum and project deeper and
deeper into each other in the said direction, in order that the screw or worm
corrugated or fluted in this way may afford the liquid a path along the inuer edge
of about the same length as that along the outer edge, substantially as herein-
before described.

page_text: 2. The improvements in centrifugal machines herein before described with
reference to the accompanying drawing.
Dated the 21st day of August 1896.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.