Improvements in Washing and Cleaning Raw Sugar.
Year: 1890

page_text: Date of Application, 5th Apr., 1890
Complete Specification Left, 3rd Jan., 1891-Accepted, 28th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Washing and Cleaning Raw Sugar.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
from abroad by Moriz Weinrich, of St. Louis, Missouri, United States of America,
Gentleman,) to be as follows:-
My invention relates to the cleaning of raw-sugar by washing off all the
molasses coating the sugar crystals in such a way that nothing of the crystallized
sugar is dissolved, and while on the one hand, a well purified sugar is obtained,
on the other hand a low molasses is also obtained.
To attain this object, I proceed in the following way:
The raw-sugar is mixed intimately with a certain amount of hot concentrated
syrup, and with ten to thirty per cent. of its weight, of an indifferent light and
porous material, as for instance, comminuted cork, corn-cobs, corn-stalks, bagasse,
straw, or saw-dust, or any other suitable vegetable matter, or wood-char, corn-cob-
char, or bone-char.
This mixture (which ought to have about the concentration of what is known in
art as 66
masse-cuite," when it is put into a centrifugal machine) is now allowed to
run into vessels having the shape, and being connected among themselves, like a
diffusion-battery."
This battery communicates with a tank, standing 30 to 40 feet above it, and con-
taining concentrated white liquor. This tank is always connected with that vessel
in which the cleaning or washing of the raw-sugar is the most advanced, so that
the white liquor takes off only the last impurities from the sugar crystals.
From this vessel the syrup passes over and through a number of other vessels
(and it may become by passing from one vessel to the other, advantageously heated
up by a so-called "calorisator" like the juice passing through a diffusion-battery)
until it is completely charged with impurities, and has the composition of a low
molasses. In this way a continuous and economical working can be attained similar
to that in a "diffusion-battery."
As soon as the sugar in the vessel, connected with the white liquor tank, is
sufficiently washed, is disconnected, and this tank now connected with the next
or following vessel. The molasses is drawn off continuously from the last filled
vessel. The disconnected vessel containing the clean sugar is emptied into a
melting-pan, the sugar melted and drawn off, and the indifferent material taken out
and used at once again.
This indifferent light and porous material enables and facilitates greatly the
washing of the crystals by the passing syrup making the whole mass spongy, and
thus preventing the sugar from hardening and packing together; a faultiness which
if existing would make the whole process impracticable.
The addition of such material to raw-sugar destined to become washed, is
therefore of about equal advantage with other methods of raw-sugar washing
carried out for instance in open vessels without pressure, or in centrifugal
machine.
My improved process can be worked with cold syrup: but I generally prefer hot
concentrated syrup as it accelerates the working.
Dated this 5th day of April 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Washing and Cleaning Raw Sugar.
I, GEORGE FREDERICK REDFERN, of the firm of G. F: Redfern & Co., the
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
from abroad by Moriz Weinrich, of St. Louis, Missouri, United States of
America, Sugar Expert), and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
is
My invention relates to the cleaning of raw sugar or of masse cuite by washing
off all the molasses coating the sugar crystals in such a way that nothing of the
crystallized sugar is dissolved, and that on the one hand a well purified sugar
obtained, and on the other hand a low molasses is also obtained. To attain this
object I proceed in the following way:
The raw sugar is mixed intimately with a certain amount of concentrated syrup,
hot or cold, and with 8 to 30 per cent. of its weight of an indifferent, light and
porous material, as for instance, comminuted cork, corn cobs, wood, bagasse, wood-
char, bone char or any other suitable matter. The size of this material ought to
be about to of an inch in diameter and as equal as possible.
The added percentage varies according to the grain and quality of the treated
sugar, and according to the specific gravity of the mixing material.
66
This mixture, (which ought to have about the concentration of what is known in
art as masse-cuite,"
," when it is put into a centrifugal machine) is now allowed to
run into vessels or cells having the shape and being connected among themselves
like a diffusion battery.
Each of these cells has to be provided with a perforated top-plate made of
The centre of
wrought or cast iron, and of the same diameter as the cell itself.
this plate is removable, and taken out during the filling of the cell. The plate is
equipped with proper guides. During the washing process it lies loose on top of
the mass, the object being to hold the mass down, preventing the passing syrup
from separating the mixing material from the sugar, and forming channels in the
mass.
This battery communicates with a tank standing 40 to 80 feet above it, and
containing concentrated white liquor or clairee. This tank is always connected
with that vessel in which the cleaning or washing of the raw sugar is the most
advanced, so that the white liquor takes off only the last impurities from the sugar
crystals.
.
From this vessel the syrup passes over and through one or more of the other
vessels (and in case that hot syrup is used, it may become, by passing from one cell
to the other, advantageously heated up by a so-called "calorisator," like the juice
passing through a diffusion-battery), until it is completely charged with impurities
and has the composition of a low molasses.
The process can be carried out with the same advantage in such a way that the
raw-sugar mixed with the indifferent material, but without any syrup, is put first
in the cells and the syrup then allowed to run over the mixture and take up by and
by the impurities. In this way, a continuous and economical washing can be
obtained similar to that in a diffusion-battery.
From the last filled cell, is drawn off, first a certain amount of molasses and pu
aside for other purposes; then so much of the remaining and somewhat bette
syrup is drawn off as will be necessary to mix with the sugar for one of th
following cells. This done the cell is connected with the other or following cell
which was filled in the meantime, and at which the same procedure now begins.
In some cases, especially if the treated sugar is of low quality and the molasse
drawn off of very tough nature, I prefer to accelerate the passing of the syrup b
forming a vacuum under the false bottom of the cell, by means of an air pump a
*practised frequently in the sugar industry.

page_text: As soon as the sugar in the vessel or cell connected with the white liquor tank is
sufficiently washed, it is disconnected and this tank now connected with the next or
following cell.
The white liquor remaining in the cell can be drawn off and pumped back into
the tank above.
In case that the thus cleaned crystals are destined to be remelted, the whole
mass is put in a melting pan, the sugar melted, and the solution separated from the
indifferent material which is then again used at once.
If the sugar is to go into direct consumption, then the whole mass is taken out
of the cell and passed through some sifting apparatus, which separates the crystals
from the indifferent material, and which may be constructed in such a way that it
will simultaneously dry the sugar.
The indifferent, light and porous material enables and facilitates greatly the
washing of the crystals by the passing syrup, making the whole mass spongy and
elastic, and thus preventing the sugar from hardening and packing together, a
faultiness which, if existing, would make the whole process impracticable.
The process can be worked also to the same advantage without applying any
pressure in the cells, especially if very large cells holding from 30,000 pounds to
40,000 pounds of sugar are used.
In this case it is best and cheapest to have the cells open on top, but they (as
also the closed cells) have to be provided with perforated top plates. That kind of
syrup running off which is destined to traverse another cell, has to be pumped over
to it.
The addition of such indifferent material to raw sugar destined to become washed
in centrifugal machines, is also of great advantage, especially if the sugar be of
low quality and fine grain, as it accelerates the passing of the washing solutions,
and prevents the small crystals from being pressed through the meshes of the
sieve.
My method can be applied with equal advantage to masse-cuite, and in this case
the addition of any syrup to the mass is unnecessary.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
The described method of cleaning and washing of raw sugar or masse-cuite,
mixed with an indifferent, light and porous material, consisting in treating such
mixture by means of syrups under pressure in closed vessels connected to a battery
or in some other apparatus.
Dated the 3rd day of January 1891.
3rd day of January 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.