Process and Apparatus for Removing Dirt from Milk.
Year: 1898

page_text: Date of Application, 9th Nov., 1898-Accepted, 17th Dec., 1898
COMPLETE SPECIFICATION.
Process and Apparatus for Removing Dirt from Milk.
I, HUGO CARL PLAUT, of Eppendorfer Lanstrasse, 100, Hamburg, Germany,
Doctor of Philosophy and Medicine, 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:-
It is generally known that milk as brought to market contains a considerable
quantity of dirt. It has also been proved that the greater the quantity of dirt
contained in the milk the more quickly does it go bad, and that such milk can only
be sterilized with great difficulty, if at all. Now, since it is obvious that, in spite
of the greatest cleanliness, impurities can still enter into the milk during milking
the milk must be subjected before use to a process of purification in order to remove
therefrom the dirt which injuriously affects its keeping qualities.
Attempts have recently been made to effect this object by subjecting the milk
to centrifugal action, but this method entails considerable disadvantages, and even
milk which has been subjected to centrifugal action is not free from dirt. More-
over in treating the milk by centrifugal action the cream is separated and cannot
be returned to the milk with complete uniformity, whereby the emulsive
capacity of the milk suffers and the milk is rendered much more
difficult to digest. The centrifugal treatment has also the disadvan-
tage that the milk must be heated to about 30-35° C., which heating is extremely
injurious when the milk is to be used as an article of food for infants.
Now this invention relates to a process by which the particles of dirt contained
in the milk are removed with certainty without the milk suffering from the treat-
ment; and it also relates to apparatus for carrying out the process.
The apparatus is illustrated in the accompanying drawings in which Fig. 1 is
a vertical section and Fig. 2 a horizontal section thereof.
The apparatus comprises a vessel a which is provided at about the middle of
its height with an aperture b, and with a second aperture situated about 5 milli-
metres above the bottom. The diameter of the first aperture is about 0'04 (decimal
nought four) of the height of the vessel, whilst the diameter of the aperture c is
about 10 millimetres. The aperture is conveniently closed by means of a rubber
plug or stopper d the inner end of which is flush with the inside of the wall of the
vessel. The lower aperture is preferably closed by means of a squeeze cock which
is fitted over the flexible tube y that forms an extension of the tubular union f.
The milk from which the dirt is to be removed is allowed to remain undisturbed
for about forty minutes in the vessel a, whereby the particles of dirt are allowed
to sink to the bottom by reason of their greater specific gravity. The cream and
fat milk is then run through the upper aperture 6 into a vessel placed underneath
and then that part of the milk which is not so rich in fat is run through the lower
aperture into a vessel placed underneath, the arrangement being such that the
particles of dirt remain behind at the bottom below the aperture c.
With the hereinabove described arrangement of apertures, the milk can be
emoved from the vessel without loss of fat and free from particles of dirt. With-
ut such an arrangement either a part of the cream will remain behind in the dirt
r more or less dirt will be carried over:

page_text: The advantages of the removal of the dirt from the milk consist not only in
that the milk becomes more appetizing, but the milk also acquires a more favour-
able bacteriological condition.
**
29
Fresh milk freed from dirt will keep longer in the incubating state. It also
contains fewer germs, and if simply boiled it will keep longer than boiled dirty
milk and by boiling for about three quarters of an hour in a Soxhlet apparatus,,
it can be rendered perfectly free from germs, and even after boiling for a quarter
of an hour it will keep longer than boiled dirty milk.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. Removing dirt from milk by allowing the milk to remain undisturbed in a
vessel (say for about forty minutes) until the particles of dirt have sunk to the
bottom by reason of their greater specific gravity, and then, for the purpose of
ayoiding a loss of fat and the carrying over of particles of dirt, drawing off, at a
medium height, the milk which is rich in fat and afterwards drawing off at a less
height the milk which is poor in fat as set forth.
2. Means or apparatus for carrying out the process set forth in Claim 1, com-
prising a vessel a having two outlet apertures b and c, one large and the other
small, of which the former or larger one is situated at about half the height of the
vessel whilst the latter or smaller aperture is arranged at a less height above the
bottom.
T: 0th law of Varoma 1908
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.