CERTAIN IMPROVEMENTS IN THE PRODUCTION OF EVAPORATED MILK
Year: 1886

page_text: I, ALEXANDER HENRY REED, of Suffolk House, Laurence Pountney Hill, Cannon
Street in the County of Middlesex, Engineer do hereby declare the nature of
said invention for CERTAIN IMPROVEMENTS IN THE PRODUCTION OF EVAPORATED
MILK and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
-
This invention consists in the production of a dry granulated powder composed
of milk and sugar by first mixing the milk with cane sugar in suitable proportions
and then evaporating the mixture to dryness at a temperature below 140° Fahrenheit
under constant agitation and comminution.
The invention consists further in a new apparatus for the purpose of carrying
out the process above named, said apparatus being fully described in the following
specification and illustrated in the accompanying drawing in which, fig. 1 represents
a transverse vertical section in the plane x, x, fig. 2.
Fig. 2 is a longitudinal vertical section in the plane y, y, fig. 1.
Similar letters indicate corresponding parts.
Fresh milk is taken and mixed with cane sugar in the proportion of about 1 pound.
of sugar to each gallon of milk,, and to this mixture is further added a small quantity
of glycerine in the proportion of one or two drops of glycerine to each gallon of
milk; this mixture is then introduced into a vacuum pan, which is provided with
a stirrer and with scrapers and in which a vacuum of 26 to 29 inches of mercury
is maintained. The vacuum pan is heated by means of a water bath or otherwise
so as to keep the contents at a temperature of from 90° to 130° Fahrenheit, and at
the same time the agitators and scrapers are kept in motion, so that the mixture
is prevented from adhering to the inside walls of the vacuum pan. After the lapse
of several hours, (more or less according to the quantity of liquid in the pan), the
mixture has become reduced to a coarse dry powder, which contains all, the
properties of fresh milk, and which is ready for the market.
In the drawing the letter A designates a container to receive the fluid to be
evaporated; the container is provided with a dome A¹ extending almost the entire
length of the container and having a feed opening a and a number of glass windows,

page_text: so that the interior of the container can be inspected from without. The dome A¹
furnishes a space for the distillation to take place so that the liquid evaporates
rapidly. The distilled liquid is led from the dome by an exit pipe a¹ to which an
air pump is connected. The container is surrounded by a hot air chamber B which
contains a series of steam pipes or radiators 6 and is provided with an inlet and an
outlet pipe for the air. The air flowing through the chamber is held at a constant
temperature (below 140° for milk) so that the container cannot become overheated.
Instead of an air chamber, a water jacket or other well known means can be used
to prevent an excessive temperature. In the evaporation of milk to reduce the
same to a dry powder as well as in the evaporation in general it is very necessary
to provide means to keep the mass constantly agitated and also free the same from
the walls of the container to prevent charring.
Through the container A. extends a shaft C which is provided with bearings in
the container and in a standard C¹. A rotary motion in the direction of arrow 1
is imparted to the shaft by means of a belt and pulley-connection with a counter-
shaft C. On the shaft Care secured a series of cutters or blades D¹ having their
keen edges facing in the direction of rotation of the frame. These series of cutters
or blades extend throughout the length of the container and revolve in the same.
Upon the shaft C is loosely fitted a sleeve E, fig 2, which extends into the
container and carries a number of radiating arms e e¹ e², and at proper intervals in
the length of the shaft are loosely fitted additional sleeves E*, said sleeves carrying
corresponding arms e e¹ e². To the arms e e³ of each sleeve are attached long and
narrow plates f, which extend throughout the length of the container but do not
come in contact with the walls of the same in their revolutions. These plates f
serve as bases for the counter cutting blades F which are arranged thereon at proper
intervals to pass between the blades D¹ on the frame D. On the third arm e of
each sleeve E E* is secured a long narrow scraper G which extends throughout the
length of the container and is provided with a sharp cutting edge g that is in close
contact with the walls of the container. The sleeve E and consequently the
counter cutting blades and the scraper are rotated as shown in the drawing, in the
same direction as the shaft but at a lower rate of speed, but if desired the sleeve
may be rotated in the opposite direction. In this example the rotation of the
sleeve is effected by means of a belt and pulley connection with the counter-
shaft C. The sleeve E* at the right hand end of the drum can also be connected
by pulleys and a belt with the countershaft C³.
The scraper G removes all the material which settles on the walls of the drum,
and as it accumulates on the counterblades F is broken up by the action of the
cutting blades.
By rotating the two sets of blades and the scraper in opposite directions or at
different rates of speed, the contents of the container are kept constantly agitated
and are continually removed from the wall as they accumulate thereon and broken
up by the blades to form a dry coarse powder. When the container consists of a
hollow sphere, the scraper is made in the form of a ring to which are secured the
counter cutting blades and the frames carrying the cutter blades are also made in
ring form, such circular cutter frame rotating inside of the ring scraper.
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. The production of a dry granulated powder composed of a mixture of milk
and sugar, by mixing the milk with sugar in suitable proportions and then
evaporating the mixture to dryness in vacuo at a temperature below 140° Fahrenheit
under constant agitation and comminution.
2. The combination with the stationary container, of the series of rotating
frames D, the cutting blades D¹ thereon, the series of counter cutting blades F and
the scraper G, said cutting blades F and scraper being constructed to rotate
independently of the cutting blades D', substantially as shown and described.
•

page_text: 3. The combination with the stationary container, of the series of revolving
cutting blades D¹ the series of counter cutting blades F and the scraper G, said
blades F and scraper G being constructed to revolve independently of the cutting
blades D as shown and described.
4. The combination with the stationary container A and the rotary shaft
extending through the same, of the frame D secured thereto, the cutting blades D¹
thereon, the sleeves EE*, loosely_fitted to the shaft and rotating independently
of the shaft, the arms thereof and the counter cutting blades F and the scraper G
attached to the arms, substantially as shown and decribed.
5. The combination with the stationary container A, its dome A¹ and its jacket B,
of the series of rotary frames D, the cutting blades D¹ thereon, the series of counter
cutting blades F and the scraper G, said blades F and scraper G to revolve in an
opposite direction to the cutting blades, substantially as shown and described.
Dated this seventeenth day of August 1886.