Improvements in Centrifugal Machines for Separating Liquids.
Year: 1893

page_text: Date of Application, 14th. Mar., 1893
Complete Specification Left, 14th Dec., 1893-Accepted, 20th Jan., 1894
PROVISIONAL DI MOT
Improvements in Centrifugal Machines for Separating Liquids.
communication from FRIEDRICH LUDLOFF, of Kaiserin Augusta Allee 24,
Berlin, in the Empire of Germany, Manufacturer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
ollows:-
:-
Centrifugal machines as hitherto used for the separation of cream from milk or
f the lighter substances from fluid mixtures have generally the fluid mixture
ntroduced into the drum of the centrifugal machine in a constant stream and the
separated substances are likewise carried off continuously. In all such machines
there must be a fixed relation between the speed of rotation and the speed with
which the milk or other. Huid mixture is introduced into the drum. For instance if
the milk-this word "milk" is hereinafter used to apply to all fluids separated in
the centrifugal machine-is introduced and it is desired to take off cream and skim
milk at a rate of say 200 quarts per hour, the drum has to be driven at a speed of
say 4000 revolutions per minute in order to get all available cream out of the milk.
If the speed of rotation slackens the cream will not be perfectly separated from the
This
milk, and if the speed of rotation is increased unnecessary work will be done.
leads to a serious difficulty especially in cases in which the centrifugal machines are
driven. by hand. Various systems of speed indicators have been employed, but
they have not been of any appreciable use because in many cases the attendant
employed to operate the machine will slacken the speed as soon as he considers
himself unobserved, and besides there is often difficulty in making an unskilled
attendant understand the use of a speed indicator. Morcover if-as in large dairies
-several machines are driven by motive power the unavoidable differences in the
tightness or tension of the driving belts will cause differences in speed which even
if perceived by the engine-driver could not be regulated without first stopping, the
whole of the machines driven by the same motor.
This invention consists in an apparatus which will automatically regulate the
flow of milk in such a way that a slackening of the speed of rotation necessarily
causes a slackening of the flow of the milk and within practical limits makes the
speed with which the milk' passes through the drum of the separator proportional
to the speed with which the separator is driven.
In its simplest shape this apparatus cousists of a cylindrical box fixed on the top
of the separator drum and in the centre of the lid of this box is a hole of suitable
size, hereinafter referred to as "the central hole."
At or near the bottom of the cylindrical wall of the box are one or more other
holes hereinafter termed the circumferential hole or holes.
Outside and preferably concentric with the central hole in the lid there are other
holes hereinafter referred to as concentric holes though the nature of the invention
is not influenced if the last mentioned holes are connected with the central hole or
if the central hole is so large that its outer edge is as far removed from the axis of
rotation as the outer edge of the concentric holes. The concentric holes or the
combined' central and concentric holes may be of any convenient shape.
The apparatus acts as follows,-
The milk delivered from a preferably central supply-tube or nozzle in a constan
1 the contral hole into the box. As soon as it touches the bottom

page_text: of the box it is caused to rotate with the box which as already stated is fixed to
the rotating drum and the centrifugal action causes it to rise up against the
cylindrical wall of the box and to assume the shape of a hollow cylinder-or, more
strictly speaking, of a hollow paraboloid.
If the size or number of the circumferential hole or holes be properly proportioned
at a certain speed of rotation only a certain and fixed quantity of milk per unit of
time will be able to pass through them into the drum. As soon as the speed
slackens the pressure with which the milk is forced through the circumferential
holes will be correspondingly reduced and less milk will enter the drum. However
the supply being constant more milk will accumulate around the sides of the box or
in other words the inner cylindrical or approximately cylindrical surface of the
milk in the box will be contracted until the surface reaches the outer edge of the
concentric holes. Then the milk will flow over this edge and will be projected out-
wards where it can be collected in a suitable vessel and can be afterwards returned
to the vessel containing the unseparated milk.
The general action of the before described system is evident. The speed of the
centrifugal machine can be varied within practical limits ad libitum, but no more
milk can be introduced into the machine than can be thoroughly separated at the
particular speed at which it may be running. If therefore an attendant be set to
turn a machine fitted with the before described apparatus the quantity of cream
and skim milk produced after a given time will show whether he has worked
satisfactorily or not, and in no case will the separation be badly done, the only result
of laziness or inaccuracy on the part of the attendant in operating the machine
being a smaller production of the separated fluids in the unit of time.
In some cases it may be found advantageous not to fix the regulating apparatus
on the drum of the separator itself, and in such a case the box is driven by suitable
gearing at a speed proportioned to but preferably slightly less than that of the
separator proper. If this is done the circumferential holes may be placed at or near
the upper edge of the box and the concentric hole or holes near the centre of the
bottom and each provided with a short tube. As the speed increases the milk will
rise up against the circular wall of the box and more milk will overflow and pass to
the separator. When the speed of rotation slackens more milk will run through
the concentric hole into a suitable vessel or be directly returned to the unseparated
milk reservoir or supply.
In one form of the apparatus there may be employed a box containing a second
box with the central hole at the top and with other holes at or near the bottom of
the circular wall the last mentioned holes being wide enough to allow any desired
quantity of milk to pass. The holes which in the foregoing examples are referred
to as "circumferential," in this construction are situated near the outer edge of the
bottom of the box. They are of uniform width and their number is proportioned
to the output of the machine. Below the lid of the box is fixed an inwardly-
projecting flange or ridge which defines the thickness of the hollow cylinder of milk
formed by the centrifugal force inside the box. All the milk that flows over the
flange from a temporary or continuous slackening of the speed of rotation can pass
out of openings in the top of the box.
The before described apparatus may be modified without departing from the
spirit of the invention for example the box may be of other than cylindrical form.
Dated this 14th day of March 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.

page_text: 5
Improvements in Centr
A communication from FRIEDRICH LudloffF, of Kaiserin Augusta Allee 24,
Berlin, in the Empire of Germany, Manufacturer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 relates to means for automatically regulating the supply of liquid
to a centrifugal separating machine; and it consists in the novel construction and
combination of the parts hereinafter fully described.
In the drawings:
Figure 1 is a vertical section through a centrifugal separating machine and its
automatic supply regulator, and shows also means for revolving the said parts.
Figure 2 is a vertical section of a modified form of regulator secured to the top
of a separator drum, and drawn to a larger scale.
Figure 3 is a vertical section similar to Figure 2, but showing another
modification in the construction of the regulator.
Figures 4, 5 and 6 are plan views showing three modifications in the arrange-
ment of the apertures in the top plates of the regulators.
Figure 7 is a vertical section of a separator and a regulator, similar to Figure 1,
but the construction of the regulator is modified and it is detached from the
separator.
The centrifugal separator may be of any approved construction adapted to
separate substances of different specific gravity. In illustrating the application of
the automatic regulator a simple form of separator has been shown which is
adapted to separate milk into cream and skim-milk, but the use of the regulator is
not confined to this form of separator, nor to the separation of milk, nor to the
devices shown for revolving it.
A is the separator drum secured on the vertical shaft a which is journalled in
the frame A¹ and is provided with a driving pulley a¹.
This device consists of a
B is an operating device for revolving the shaft a.
belt pulley b mounted on a shaft 6' which is journalled in the frame B'. A handle C
projects from one of the arms of the pulley b so that it may be turned by hand.
C is a belt pulley secured on a shaft c journalled in the lower part of the
frame B¹.
D is a belt which passes around the belt pulleys b and C¹ and d is a device for
keeping the belt taut.
Another belt pulley D₁ is secured on the shaft c and d is a belt which passes
around the pulleys D' and a' so that the drum A may be revolved rapidly by
turning the handle C.
When the
drum is revolved very rapidly its contents form a hollow paraboloid inside it, the
10 skim-milk being driven to the periphery of the drum and the cream remaining
The milk is let into the separator drum A from the supply pipe E.
nearer its centre.
.
E' is a collecting pipe for removing the skim-milk, and e¹ is a collecting pipe for
removing the cream. The lower end of the pipe E' communicates with a cylinder F
which is secured to the frame A', and fis au outlet pipe projecting from the
45 bottom of the cylinder F and adapted to discharge the skim-milk into the
receptacle F¹.
The lower end of the cream collecting pipe e¹ communicates with a chamber G
in the said cylinder F, and g is an outlet pipe projecting from the bottom of th
chamber G and adapted to discharge the cream into the receptacle G¹.

page_text: In a centrifugal separator of this description the supply of milk from the supply
pipe E is constant, and it is found that the separation is best effected when the
drum is driven at a certain speed, say of 4000 revolutions a minute. If this speed
is decreased all the available cream will not be separated from the skim-milk, and
if the speed is increased unnecessary work will be done.
It is difficult to revolve
the drum at one uniform high velocity, more especially when its driving is effected
by a hand-operated device."
In carrying out the present invention the supply of milk from the supply pipe to
the drum is automatically varied and controlled by the speed of the drum itself, so
that no irregularity in the work of the machine is caused by fluctuations in its
speed.
In the form of automatic regulator shown in Figure 1, 2 is a vessel secured to the
top of the drum A under the supply pipe. This vessel is provided with a bottom 3
and has one or more outlets 4 through which the milk may pass into the drum.
The outlet or outlets 4 are proportioned in area so that a certain prearranged
quantity of milk will pass through then per unit of time with a prearranged normal
speed of revolution of the vessel.
Inside the vessel 2 there is preferably a cylinder 5 provided with holes 6 at its
lower part. The holes 6 are of large area so that they do not obstruct the flow of
milk under any circumstances. The cylinder 5 may be dispensed with if desired,
but it is useful as it prevents the milk from splashing in the vessel 2.
A cover plate 7 is secured to the top of the vessel 2. This cover plate has a central
hole 8 under the supply pipe, and holes or openings 9 between the hole 8 and its
periphery. The holes 8 and 9 may be variously arranged and proportioned. In
Figure 4 the holes 9 are small and triangular; in Figure 5 the holes 9 are
circumferentially-curved slots; and in Figure 6 the openings 9 join into the centre
hole 8. In Figure 1 a plate 10 is shown a little below the top plate, and is
provided with a large central hole 11 but this plate may be dispensed with if
desired.
A stationary catch pan 12 is secured to the top of the cylinder F, or is supported
in any other approved manner. The top of the regulator vessel 2 projects through
central hole 13 in the bottom of the catch pan, which is provided with a flange.
The catch pan is also provided with an outlet pipe 14 adapted to discharge into
the overflow vessel 15.
The operation of the automatic regulator is as follows:-As the vessel 2 is
revolved rapidly with the drum A, the milk is thrown to its periphery by
centrifugal force and passes through the outlets 4 into the drum, rising to some
extent around the periphery of the said vessel. When the speed of the drum and
the regulator vessel is temporarily diminished, the milk will be forced through the
outlets 4 with less pressure, and will accumulate around the periphery of the vessel 2.
As soon as the accumulating milk overflows the edge of the hole 11 of the plate 10
it is driven off through the holes or openings 9 and falls into the catch pan 12,
whence it passes into the overflow vessel 15. The action is the same when the
plate 10 is not used but the position of the outer edges of the holes or openings 9
then determines when the overflow shall commence, and the point at which overflow
commences can be more nicely regulated by using the plate 10 having a single
large hole 11 in it.
The milk can be seen as it runs into the overflow vessel, and the operator then
knows that the machine must be turned with increased speed. The milk is
subsequently removed from the overflow vessel and poured into the supply vessel.
It is not expected that the speed of the drum and regulator vessel will ever be
much increased above the normal, but if such should be the case the operator will
notice that no milk whatever is being driven into the overflow vessel, and will not
drive the machine so fast.
Increase of speed is of no detriment to the product like diminution of speed, but
only tires the operator. The automatic regulator however guards against the evil
effects of both increase and diminution of speed.

page_text: In the modification shown in Figure 2, the bottom of the vessel 2 is concave and
nsists of a portion of the top of the drum A the outlets 4 being in the bottom 3
stead of in its sides. The inner cylinder 5 is dispensed with, and the cover-
ate 7 and the plate 10 are replaced by a single funnel-shaped plate 10¹ having a
entral hole 11. The operation of this form of the regulator is identical with the
rin shown in Figure 1.
The modification of the regulator shown in Figure 3 is exactly the same as that
hown in Figure 1 except that the cylinder 5 is left out.
In the modification shown in Figure 7 the regulator is driven separate from the
eparator drum. The separator and the mechanism for driving it are exactly the
ame as shown in Figure 1, but the separator drum shown in Figure 7 has a small
eceiver H at its top provided with holes h at its lower part inside the drum A, so
hat the milk can be driven into the drum without carrying in air with it.
In this form of the apparatus the regulator vessel 2' is supported by the frame B¹
of the operating device, and is secured on a vertical shaft I journalled in the said
frame and operatively connected with the shaft c by the intergearing bevelled
toothed wheels i i¹.
The milk supply pipe E is arranged over the regulator vessel and regulator
vessels such as hereinbefore described may be used. In the modified form of
regulator shown in Figure 7, the action is substantially the same as in the
regulators hereinbefore described, but the positions of the corresponding parts are
reversed. The vessel 2' has outlets 4' in the upper part of its periphery, and an
When the vessel 21 is revolved at its
outlet pipe 9¹ in its bottom near its centre.
prearranged normal speed, the milk rises against its periphery and passes through
the outlets 4' into the receptacle 20 and thence down the spout 21 into the
receiver H of the drum A.
When the vessel 2¹ is revolved at its prearranged normal speed no milk passes
down the pipe 9¹ but when its speed and that of the separator drum A. is diminished
a portion of the milk passes down the pipe 9¹ into the catch pan 12' whence it
passes into the overflow vessel 151 by way of the pipe 14¹.
In each form or modification of the regulator the revolving vessel 2 or 2' is
provided with two separate outlets or series of outlets, and one outlet is arranged
nearer to its centre or axis than the other outlet. The outlet or outlets more
remote from the centre of the regulator vessel deliver the milk to the revolving
separator drum, and the outlets nearer to its centre serve for the discharge of the
surplus milk when the speed of the separator drum and the regulator vessel falls
below the prearranged normal speed at which they are designed to work.
The regulator is most conveniently arranged when attached to the top of the
separator drum as shown in Figure 1, but when arranged separate from the said
drum it may be driven at a different speed from the drum. The regulator is
connected with the drum so that the speeds of the regulator and drum are
constantly in the same proportion, and so that a fluctuation of the speed of the
drum is attended by a similar fluctuation in the speed of the regulator.
Having now particularly described and ascertained the nature of the said inven-
5 tion as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is :-
1. The method of regulating the supply of liquid to a centrifugal separator
which consists in subjecting the supply liquid to centrifugal force before it enters
the separator the said centrifugal force being arranged to be constantly in pro-
50 portion to the centrifugal force developed in the separator and operating to
automatically reduce the supply of liquid to the separator when the speed of the
separator is diminished substantially as described and illustrated in the accom
panying drawings.
2. The combination with a centrifugal separator, of a centrifugal suppl
55 regulator, and driving mechanism operating the separator and the regulator at th
same proportionate speeds whereby the supply of liquid is automatically rendere

page_text: proportionate to the speed of the separator substantially as described and illustrated
in the accompanying drawings.
3. The combination with a centrifugal separator, and driving mechanism for
revolving it; of a centrifugal supply regulator secured to the said separator and
operating to automatically reduce the supply of liquid to the separator when the
speed of the separator is diminished substantially as described and illustrated in
the accompanying drawings.
4. In an automatic supply regulator for a centrifugal separator the combination
with a revoluble vessel provided with two outlets arranged at different distances
from its axis of a catch pan arranged around the outlet nearer the axis of the
vessel and adapted to receive the surplus supply liquid when the speed of the said
vessel is diminished substantially as described and illustrated in the accompanying
drawings.
5. In an automatic supply regulator for a centrifugal separator the combination
with a revoluble vessel provided with an outlet at its lower part near its periphery
for the passage of the liquid to the separator and a second outlet at its upper part
between the first said outlet and the axis of the vessel; of a catch pan arranged
around the second said outlet and adapted to receive the surplus supply liquid when
the speed of the said vessel is diminished substantially as described and illustrated
in the accompanying drawings.
6. In an automatic supply regulator for a centrifugal separator, the combination
with a revoluble vessel provided with an outlet at its lower part near its periphery,
a second outlet at its upper part nearer the axis of the vessel than the first said
outlet, and an internal vessel provided with openings at its lower part; of a catch
pan for receiving the surplus liquid which passes through the second said outlet
when the speed of the vessel is diminished substantially as described and illustrated
in the accompanying drawings.
7. In an automutic supply regulator for a centrifugal separator the combination
with a revoluble vessel provided with an outlet at the lower part of its periphery a
cover plate provided with a central inlet hole for the liquid and outlets between
the said central hole and its periphery of a catch pan for receiving the surplus
liquid when the speed of the vessel is diminished substantially as described and
illustrated in the accompanying drawings.
;
8. The combination with the revoluble vessel 2 provided with an outlet 4 at its
periphery the internal cylinder provided with holes 6 the cover plate provided with
a central hole 8 and outlets between the hole 8 and its periphery and the plate 10
secured in the vessel below the cover plate and provided with the outlet hole 11;
of a catch pan encircling the said vessel and adapted to receive the surplus liquid
driven through the outlets 11 and 9 substantially as and for the purpose described
and illustrated in the accompanying drawings.
9. An automatic supply regulator for a centrifugal separator comprising in its
construction a revoluble vessel provided with a central opening for the entrance of
the supply liquid and two separate outlets through which the said liquid is dis-
charged by centrifugal force one of the said outlets being arranged nearer the axis
of the said vessel than the other said outlet the outlet more remote from the axis
operating to permit the passage of the liquid into the separator and the outlet
nearer the axis operating to permit the discharge of surplus liquid from the said
vessel without entering the separator.
Dated this 13th day of December 1893.
W. P. THOMPSON & BOULT,
London, Nottingham, Liverpool, and Manchester,
Agents for the Applicant.