An Improved Process for the Production of Condensed Milk.
Year: 1899

page_text: Date of Application, 23rd Dec., 1899
Complete Specification Left, 24th Sept., 1900-Accepted, 8th Dec., 1900
PROVISIONAL SPECIFICATION.
An Improved Process for the Production of Condensed Milk.
I, AUGUST GÜRBER, University Assistant at the Physiological Institute of
Würzburg, in the Empire of Germany, do hereby declare the nature of this
invention to be as follows:-
--
For the carrying out of the process for the production of condensed milk, the
skimmed milk is brought from the separator into a turbine where it is congealed
until a sufficient degree of concentration is attained.
The refrigeration, which takes place from the centre towards the circumference,
is produced by immersing from above into the turbine a container in which is a
refrigerating substance corresponding in shape to the final paraboloid of fluidity
which the milk in the turbine takes when the maximum speed is reached.
The refrigerating container is provided with suitable vertical ribs, and is fed
with a cold solution of salt or in a similar way. As soon as this substance is
introduced, the milk at the surface begins to congeal slowly and the frozen parts
are driven against the sides of the turbine where they form a solution which
becomes continually more concentrated.
The concentrated milk can then be drawn off from the periphery by means of
a conduit having its outlet in the axle of the turbine, thereby producing a con-
tinuous flow, whilst the ice remainng in the turbine can be melted by a quick
jet of steam and discharged through an outlet from the turbine, which will then
be ready to receive a fresh supply of milk.
An Improved Process for the Production of Condensed Milk.
I, AUGUST GÜRBER, Assistant at the Physiological Institute of the University
of Wuerzburg, Bavaria, in the Empire of Germany, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
The product hitherto known to the trade as condensed milk has the disadvan

page_text: •
tage of greatly altering its taste, a circumstance which must be attributed to the
method of condensing by evaporation, employed in the manufacture of that
product. Another disadvantage lies in the fact that owing to the milk being
boiled down to only a comparatively slight degree of consistency, it does not
keep in good condition, so that it is necessary to make a considerable addition
of cane sugar to preserve it. For rearing infants, therefore, who require an
addition of sugar varying according to their stage of lactation this condensed
milk is not at all suitable.
By the present method a condensed milk is prepared not by evaporation, but
on an entirely new principle. It is well known that an aqueous solution of solid
substances becomes thoroughly frozen if the temperature be lowered to a suffi-
cient extent, in any suitable way.
If this freezing process be effected in a centrifugal machine while rotating,
the detached particles are thrown out according to their specific gravity, flying
towards the circumference where they form a solution, which is, say 5 to 6 times
stronger than the original solution, while the water becomes gradually frozen
towards the axis of the centrifugal machine. My invention consist in the
application of this principle to the manufacture of condensed milk. In carrying
my invention into effect the milk is first skimmed in any suitable way (prefer-
ably in a centrifugal separator) and the skimmed milk is then put into a centri-
fugal apparatus, where it is frozen (during rotation) until a sufficient degree of
concentration is attained. The milk is then again mixed with the cream, after
having been separated from the frozen particles of water.
The refrigeration and subsequent separation may be conveniently conducted as
follows: The refrigeration is preferably applied from inside the centrifugal
apparatus and may be produced by immersing from above into the the centrifugal
apparatus a refrigerator corresponding in shape to the final paraboloid of fluidity
which the milk in the apparatus assumes when the maximum of speed is reached.
The refrigerator is provided with suitable vertical ribs, for providing greater
refrigerating surface or it may be in the form of a coil or worm. It is fed with
a solution of cold brine or any other suitable refrigerating medium. As soon
as the refrigerator is introduced the liquid nearest to the refrigerating surface
begins to freeze slowly, and the heavier particles are driven by the centrifugal
action against the sides of the apparatus where they form a solution which becomes
continually more concentrated. The concentrated milk can be drawn off from
the periphery by means of conduits having their outlet in the axle of the centri-
fugal machine, thereby producing a continuous flow. The ice remaining in the
apparatus can be melted by passing a jet of steam into the apparatus, and after
the water has been removed, a fresh supply of milk can be introduced. In order
to produce a greater concentration, the process may be repeated. The milk
condensed in this manner may be diluted with water to its original volume and
still have the taste of fresh milk without exhibiting the sweet but to many
people disagreeable taste of the condensed milk hitherto in use.
This new
condensed milk preserves its good taste without the addition of sugar owing to
its not having been heated to a high degree in order to obtain the desired
consistency.
For purpose of rearing infants however, it may be mixed with sugar in any
desired proportion.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In the manufacture of condensed milk, subjecting skimmed milk to a
combined freezing and centrifugal action, substantially as and for the purpose
described.
2/. The method or process of producing condensed milk, which consists in
separating the cream from the milk and in then submitting the skimmed milk

page_text: whilst in a rotating centrifugal machine to a freezing action, and finally mixing
the separated parts of the milk with the cream, all substantially as herein
described.
Dated this 24th day of September 1900.
S. S. BROMHEAD,
Agent for Applicant, 33, Cannon Street, London, E.C.