In- PROVEMENTS IN APPARATUS FOR DRYING SUGAR
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
17th May 1869.-A communication from abroad by Alexander
Herbst, of Moscow, in the Empire of Russia.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
No. 8, Southampton Buildings, Chancery Lane, London, Consulting
Engineer, do hereby declare the nature of the said Invention for "In-
PROVEMENTS IN APPARATUS FOR DRYING SUGAR," a communication, to be as
follows:-
The time for drying sugar loaves in the ordinary manner is from 8 to
12 days, but with my improved apparatus this time is reduced to 24
hours, and the product is much clearer and more compact than that
dried by the old method. These favorable results are obtained by
producing complete currents of heated air in the loaves themselves.
In practising my Invention the sugar loaves are dried in forms. A
tube of cast iron is placed in a drying room, which can be heated and
cooled; the sugar loaves in the forms are placed under the tubes in
such a manner that the points of the forms fit in openings in the tube.

page_text: By means of a screw the loaves are pressed against the tube. The con-
nection of the form points with the tube is made tight by small india-
rubber hoppers. The tubes are connected with an air pump, which is
worked after all the forms are filled with loaves. This pump forces the
air through a heating apparatus in the tube, and thence through the
sugar loaves. The air is heated before entering the tube to 45° or 50°
Réaumur, and to prevent the cooling of the air by its passing through
the loaves the air in the drying room must be kept at a temperature of
45° or 50°.
The air heating apparatus consists of a cylinder with tubes like a
multitubular boiler, the air passes through the tubes, and its temperature
is raised to any degree. The latter can be regulated by the aid of a
thermometer placed at the point where the air comes from the heating
apparatus passing through the tube.
In some cases it is advisable to conduct the air before it enters the
heating apparatus above a layer of chloride of calcium for drying it; but
find by many experiments that the loaves are dryel in 24 hours
without conducting the air above chloride of calcium. As soon as the
heated air passes into the points of the former it is separated into many
currents and goes through the crystals of the sugar, absorbing the
moisture and escaping at the bottom of the loaves. When the syrup has
dropped off the sugar loaves are taken out of the forms and placed at
their base. The forms are placed near the sugar loaves with their points
below. In a few hours the inner sides of the forms are dried, mean-
while the syrup in the points of the loaves is dissolved, and a crust is
forined on the outer surfaces of the loaves. The loaves can only be taken
ont of the forms when the syrup in the points is about of the whole
}
mass of syrup in the loaf; if this is not the case the surplus syrup must.
be removed. This fore drying is necessary, as the omission of it would
cause the sugar to adhere to the inner sides of the forms, and the taking
out of the loaves would be very difficult. After the fore drying process
is ended the sugar loaves are put in the forms. It must be observed
that the loaves are put in at their former positions, therefore it is
desirable to mark the base of the loaves and the under rim of the
form before they are taken out. As soon as the loaves are all put in
they are prepared for drying with the heated air currents.
The drying apparatus may be modified by providing the cast-iron
tube with a flange at the openings. The loaves are placed with their

page_text: basc upon this flange, which has the same diameter as the base of the
loaves. Between the base of the sugar loaf and the flange is placed a
ring of india-rubber to make a tight joint. An air pump draws the air
from the tubes and produces in the loaves a vacuum, and the hot air in
the drying room enters the points of the loaves and dries the sugar in the
same manner as hercin-before described.