Improvements in Centrifugal Separators.
Year: 1894

page_text: Date of Application. 18th Sept., 1894-Accepted, 20th Oct., 1894
COMPLETE SPECIFICATION,
Improvements in Centrifugal Separators.
I, OSSIAN JOHAN ROBERT STRÖM, of No. 19 Storgatan, Stockholm, 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:--
In centrifugal cream separators constructed as heretofore, it is not only the most
pure skimmed milk, that is to say, the milk layer next to the wall of the centrifugal
drum, that escapes through the milk outlet from the drum, but a great effluence
also takes place from the imperfectly separated layers nearer the axis of the drum
particularly from the parts in the vicinity of the milk discharge pipe. This
effluence takes place very easily, as the particles in the last mentioned layers are,
in addition to the flow or suction towards the discharge pipe, driven outwards and
towards the said pipe by the centrifugal force, while the particles in the extreme
layer, arrive at and into the discharge pipe only owing to the flow or suction.
Therefore it is evident, that in the main only those particles in the extreme layer
which are next to the milk discharge pipe, escape through the same, so that only a
part of the perfectly separated milk is discharged, which must cause a decrease of
the skimming capacity of the apparatus.
The object of this invention is to effect a flow of the entire outer or extreme
milk layer towards the milk discharge pipe. This is obtained by providing certain
arrangements in the centrifugal dram, which offers a resistance to the passage of
the imperfectly separated particles, which resistance increases towards the said pipe
in the direction along the rotatory axis af the drum.
In the accompanying drawing I have shown these arrangements applied to a
cylindrical centrifugal drum with a vertical axis, although they may be used as
advantageously in other drums.
The arrangement in question consists of a number of flat dises a or parts of
discs which are provided at their centres with circular openings b and superposed
with spaces between them and arranged so that their centres coincide with the
central line of the centrifugal drum. The discs a are supported by a suitable
frame C, and provided with elevations, ridges or figures in relief of any desired
shape indicated in Figures 2 and 3 by the lines d, which are oblique with respect
to the direction of motion of the liquid particles toward the periphery of the drum,
so as to create a resistance to the said motion. In order to obtain a current of the
liquid through the entire extreme layer, this resistance decreases in proportion as
the distance from the mouth of the discharge pipe increases, counted along the
rotatory axis of the drum, consequently in the drum represented, in the drawing in
which the discharge pipe is located at the top or lid, the resistance decreases in
proportion as the lower part of the drum is approached. This can be effected for
instance by causing the longitudinal directions of the said elevations to coincide
gradually with the direction of motion of the particles or by reducing the number
of such elevations in proportion as the bottom of the drum is approached, or,
preferably, in the manner shown in Figure 1, by reducing the width of the disc
rings continually downwards while preserving the same direction of the elevations
on all the disc rings.
It is evident, that the described arrangement may be applied to other centrifugal
apparatus than these designed for skimming milk.

page_text: 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 :-
In centrifugal apparatus which are provided with disc rings located per-
pendicularly to the rotatory axis of the drum, the arrangement in which the disc
rings or parts thereof placed at a small distance from each other, are provided
with elevations ridges or the like projecting from their surfaces offering a resistance
to the motion of the liquid particles outwards, which resistance increases taken
along the rotatory axis in a direction towards the outlet for the heavier liquid, with
the object of effecting a flow through the whole of the heavier liquid layer towards
the outlet of the latter.
Dated this 18th day of September 1894
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.