IMPROVEMENTS IN THE MANUFACTURE OF SUGAR, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by William Miller at the Office of
the Commissioners of Patents, with his Petition, on the 2nd March
1864.
I, WILLIAM MILLER, of No. 66, High St., Hull, in the County of York-
shire, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF SUGAR, AND IN THE APPARATUS EMPLOYED THEREIN,"
to be as follows:-
The Invention has for its object an improved method of evaporating
saccharine solutions at temperatures below those at which they boil under the
ordinary pressure of the atmosphere, at the same time that the saccharine
solutions never come in contact with metallic or other surfaces heated by fire
or high-pressure steam, nor are subjected to any temperature which cannot be
regulated to or below that of boiling water or 212° Fahrenheit. The Invention
has reference to one for which Letters Patent have been granted to me, dated
26 February 1862, and numbered 525, and consists of a cylinder composed
of curved blades, arranged like the floats of a water wheel, only overlapping
each other considerably so as to increase the evaporating surface. This
cylinder is made to revolve in the saccharine solution to be evaporated at the

page_text: rate of from 20 to 60 revolutions per minute or more, according to the
diminished diameter of the cylinder, the front or outermost curve of the
cylinder dipping first into the solution, and this only in a slight degree, say,
from half to one inch, so as to avoid pressure of the fluid, and diminish the
power requisite to make the cylinder revolve quickly, which becomes a matter
of great importance, as the solution of sugar is thereby kept in constant
agitation, the portion remaining at the bottom of the pan being brought to
the surface, and in fact every particle of the solution of sugar brought
successively in contact with the heated surface. As the cylinder revolves the
blades take up thin films of the liquid, and expose them to the air, the quick
revolution of the cylinder vastly promoting the evaporation apparently thro'
the agency of centrifugal force, at the same time that the curved form of the
blades carries air into the solution, and further aids in carrying off the vapor.
The saccharine solution is contained in a pan having large flat or slotted tubes
passing through it so as to more than double the heating surface of the pan;
and this is another reason why the cylinder should not dip deep into the pan,
otherwise there would not be room left for the passage of these tubes; it is
likewise essential that this pan should be made very shallow, so that the whole
of the contents of the pan be kept in constant motion by the revolution of the
cylinder. This pan is surrounded by another outer casing or jacket, the lower
part of which is covered by water, and the water is heated either by direct
fire heat, or by high-pressure steam passing. into it. The jacket has an
over-flow pipe to carry off condensed water, and a pipe open to the atmosphere
so as to prevent pressure or the heat ever rising above 212° Fahrenheit. For
the colonies the cylinder may be allowed to revolve freely exposed to the
atmosphere, and if possible to a current of air; but where it is desirable to
get rid of the steam arising from the revolving cylinder, the latter should be
covered with a hood, leaving an opening in front of the pan. To the top
of the hood a fan is to be attached, the revolution of which drawing the air
through an opening left in front of the pan, and against the blades of the
revolving cylinder, will carry off the steam to any convenient outlet, and
augment the evaporation.
Another part of my Invention consists in an improved apparatus for
dissolving or washing the sugar. Ordinarily this is effected by blowing the
sugar up by means of high-pressure steam passed through holes in a coil of
pipe, whereby the sugar becomes injured by direct contact with the steam.
Instead of this I make use of cylindrical shaped pans, having a coil of pipe
with a condense cock passing round the lower part of the side of the pan,
but sufficiently high up that the sugar when thrown into the bottom of the

page_text: pan does not come in contact with the heated pipe except when it is in
solution. To effect the solution of the sugar I also make use of an agitator
in the form of a cross, having cutting knives attached at it, and another cross
with flat blades to keep the solution in constant agitation.