AN IMPROVEMENT IN CENTRIFUGAL APPARATUS FOR. WASHING SUGAR
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by George Davies at the Office of
the Commissioners of Patents, with his Petition, on the 18th August
1867. A communication from abroad by George E. Evans, of Boston,.
Massachusetts, in the United States of America.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, and No. 87, St. Vincent Street, in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "AN IMPROVEMENT IN CENTRIFUGAL APPARATUS FOR. WASHING
SUGAR," (being a communication to me from abroad by George E. Evans, of
Boston, Massachusetts, in the United States of America,) to be as follows:-
This Invention consists in providing the ordinary centrifugal tubs used for.
washing or purifying sugars with an apparatus by means of which a wall of
dry sugar of uniform thickness concentric with the wall of the centrifugal
tub may be formed within the same for the purpose of receiving the applica-
tion of jets of water for washing or purifying the sugar, and also in the mode.
of operating such apparatus. Within a fixed cylindrical tub is placed an inner
centrifugal tub with perforated sides. The inner centrifugal tub revolves upon
a vertical spindle supported in any suitable manner.
The apparatus thus briefly described is that commonly used, and is not
claimed as new.
The original feature of this Invention is the application to the interior of
the inner centrifugal tub of a removable and adjustable cone called the "wall
former," which is usually constructed of tinned iron, although the material is

page_text: unimportant; this cone is so constructed that when in place its base shall
be upon the bottom of the inner centrifugal tub, and its diameter shall
correspond with the perpendicular axis of the centrifugal tub, and also that
there shall be a space between the bottom of the cone and the sides of the
centrifugal tub sufficient for the desired diameter of the wall of sugar to be
formed; this cone is so constructed as to be instantly and easily removable
for the purpose of fixing it in place, and at the same time rendering it readily
removable. The cone is made hollow, and provided with elastic wires or strips
of metal which grasp the central fixed cone or shaft with which centrifugal
tubs are usually provided for supporting the spindle upon which the centrifugal
tub revolves.
The improved apparatus above described is operated as follows:-The sugar
to be washed is dropped from a charger above into the centrifugal tub until
the tub is about half full, the sugar lying upon and around the wall former or
cone; power is then applied to the centrifugal tub to cause its revolution.
When the centrifugal tub is revolving teu or fifteen times a minute, with a
constantly increasing velocity, as the centrifugal action causes the sugar to
recede from the wall former or cone towards the outer circumference of the
wall former the wall former is slowly lifted vertically by means of a cord
attached to the cone passing over a pulley, while at the same time the revo-
lution of the centrifugal tub is being rapidly accelerated. The combined
centrifugal action and the action of the wall former as it is lifted upon
the sugar cause the formation of a wall of sugar of equal diameter con-
centric with the circular side of the centrifugal tub. The sides of this wall
of sugar are free from any irregularities or ridges consequent upon the
use of basket wall formers, which have sometimes been used. When the
wall former is removed the uniformity of the wall of sugar is preserved by
the centrifugal action. While the centrifugal tub, containing the wall of
sugar is rapidly rotated a jet of water from a suitable pipe is applied to the
sugar; the water passing through the sugar and escaping in consequence of
the centrifugal action through the perforated sides of the centrifugal tub
effects the complete purification of the sugar.
The Invention consists of two parts, the application of the mechanical
apparatus above described, and the mode of operating the same also above
described.