IMPROVED APPARATUS APPLICABLE TO THE EVAPORATION OF SAC- CHARINE LIQUIDS, AND FOR THE CONCENTRATION OF HEAT FOR OTHER PURPOSES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by George Davies at the Office of
the Commissioners of Patents, with his Petition, on the 23rd February
1859. A communication from Augustus Jouan, residing at San
Francisco, California.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County
of Middlesex, and No. 28, St. Enoch Square, in the City of Glasgow,
Civil Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVED APPARATUS APPLICABLE TO THE EVAPORATION OF SAC-
CHARINE LIQUIDS, AND FOR THE CONCENTRATION OF HEAT FOR OTHER PURPOSES," (a
communication from Augustus Jouan, residing at San Francisco, California),
to be as follows:-
This apparatus is applicable principally to the ordinary pans employed for
boiling sugar, and consists in the application of a floating cover thereto, of a
peculiar novel construction. The exterior or upper form of this cover is
convex, or nearly hemispherical, with a tube projecting upwards therefrom, and
the lower or interior surface is of a concave, conical, or funnel shaped form.
The lower edges of these two parts are united or joined together, and they
are each furnished at the upper part with a hole, in which is inserted a tube,
the two tubes being situated one within the other, and having an interval or
space between them. The outer tube is made slightly conical at the top, so
as to reduce its diameter to about that of the inner tube, and the tubes are
there united or joined together.
There is a small hole near the top of the outer tube to allow of the expan-
sion of the air between the tubes and inside the hollow cover when heated. The

page_text: base of the cover is made circular, or of other form, so as nearly to fit the
interior of the pan. At the top of the tubes (which is open) is placed a
moveable sieve, designed for detaining the grosser parts of the liquid at the
earlier part of the operation, and beneath this on the neck of the outer tube is
a larger sieve of an annular form. The cover is furnished with screw rods
passing through screwed bushes, for the purpose of plunging and holding the
cover below the surface of the liquid. This apparatus has the advantage of
causing an extraordinary degree of evaporation, and of aiding the filtering
operation, and above all of concentrating the syrup to the degree of perfect
crystallization under a comparatively low temperature; operating in the latter
respect similarly to the vacuum pan, crystallization is made perfect, and the
operation is performed with a great economy of fuel, time, and labor, and a
very small quantity of molasses is formed when compared with other modes of
boiling sugar.in an open pan.
Direct heat may be applied to the pan, but steam heat is considered pre-
ferable.
A hollow floating cover like that above described or with some modifications
may be employed with advantage for other purposes than sugar boiling, as it is
evident that the Invention is susceptible of being used in the manufacture of
various substances and articles requiring the concentration of heat.