IMPROVEMENTS IN REFINING THE COLORED RAW SUGAR OF COMMERCE SO AS TO PRODUCE WHITE CRYSTALLINE SUGAR
Year: 1884

page_text: COMPLETE SPECIFICATION.
I CARL STEFFEN, Engineer of 1 Jacquingasse in the City of Vienna in the
Austro Hungarian Empire do hereby declare the nature of my Invention for
IMPROVEMENTS IN REFINING THE COLORED RAW SUGAR OF COMMERCE SO AS TO
PRODUCE WHITE CRYSTALLINE SUGAR and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My Invention relates to improvements in refining the colored raw sugar crystals
of commerce so as to produce white crystalline sugar and freo the said raw
crystalline sugar from all impure syrup. The chief novel features of my said
Invention consist therein that the said raw crystalline sugar is treated in such
manner with an aqueous saturated pure sugar solution without the employment of
steam, that the crystalls of the raw sugar form a pulp like mass of crystals without
any solid body for instance like lumps of adhering crystals.
The said pap like or pulpy mass of crystals is introduced into suitable vessels
which are connected so as to form a battery and lixiviated in the same whereby a
fixed quantity of a pure solution of sugar is forcibly introduced above each charge
of raw sugar until the said pure solution of sugar has become mixed with so much
of the impure syrup in the raw sugar that the said solution becomes of like quality
with an inferior syrup or the so called molasses.
This syrup or molasses is pressed out of the battery by the succeeding or
following solution of pure sugar whilst the raw sugar passes off with more or less
of the solution of pure sugar as a pure white sugar. By employing my process the
entire crystallized raw sugar is converted into pure white sugar crystals and into a
syrup or molasses of inferior quality without loss of the pure sugar solution
employed for the purpose of lixiviation as the pure solution of sugar employed for
separating out the impure syrup is again won with the purified crystalline sugar in
the crystalline mass.
The syrup drawn off from the lixiviating vessels is very inferior in quality and
small in quantity and is similar to the syrup generally resulting from the process of
refining raw sugar. In order to carry ny said Invention into practice the following
process can be adopted.
The raw sugar to be treated must not be in balls or lumps and should be passed
through a suitable seive.

page_text: A lixiviating battery can be employed for lixiviating the raw sugar, similar to
those employed in beet root sugar factories and known under the name of diffusion
batteries or one of the well known constructions of continuous diffusion apparatus
or diffundators can be employed.
The lixiviating fluid id. est. the pure aqueous saturated solution of sugar located
above the raw sugar can be forced or sucked through the battery; both suction and
pressure producing good results. If the fluid is sucked through the battery above
the raw sugar it is advantageous that such vessel in the battery should be open at
the upper part and a force and suction pump applied to each vessel beneath the
scive or perforated bottom, which said pump will force the solution of sugar
sucked off from the one vessel into the next following vessel of the said battery.
By means of this combination all loss of pressure resulting from the friction
created in closed vessels is avoided.
The lixiviating fluid can, according to the construction of the battery pass
through the raw sugar charge, downwards, or vice versa. As diffusion seives I
employ fine seives such as are employed in centrifugal machines.
The raw sugar is preferably introduced into the vessels of the lixiviating battery
in sifted dry form but can, if desired, be previously mixed with the syrup drawn olf
from the preceding vessel of the battery.
In both cases care must be taken to fill the vessels with like quantities of sugar.
The number of vessels forming the battery depends on the quality of the sugar but
in order to attain pure white sugar not less, than four vessels per battery should be
employed.
The ordinary temperatures are the most suitable but higher temperatures can be
employed when saturated sugar solutions are used for lixiviation.
As a general rule my process is carried out in the same manner as the well
known diffusion process so that the pure solution of sugar is always introduced into
the vessel longest in operation that is, above the raw sugar which has been sub-
jected to the process for the longest period whereas the oldest syrup is introduced
above the freshest charge of raw sugar and is allowed to escape when it is inferior
enough in quality. Ordinary raw sugar of about 95% polarizing capacity gives
off an inferior molasses after passing the 14th vessel.
The vessel longest in operation, the sugar crystals in which are now perfectly
pure, is saturated with a solution of pure sugar. Before this vessel is emptied the
solution is sucked off so that about 6 to 10% water remains in the crystalline
mass.
The white crystalline mass from this vessel of the battery is melted and worked
up into primo refined sugar or is dried and sold as crystalline sugar or the same
can be ground and introduced into commerce as ground sugar.
°
If however the pure white crystalline mass containing about 10% water, is
heated in a mashing butt to 70° Reaumur (190° Fahrenheit) or more, the mass will
become fluid, can be filled into suitable forms and allowed to crystallize. In this
inanner a perfectly solid crystalline body is attained which can be freed from any
residue of syrup by moans of a centrifugal apparatus or in other suitable manner
and so worked up into commercial ware.
If it is desired to have a fine corn the white crystalline mass can be pulverized
in a suitable gin, roller, mill or other pulverizing device before the said mass is filled
into the forms.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is
The process substantially as described in the foregoing Specification for treating
purifying and lixiviating raw crystalline sugar or the commercial raw sugar
containing colored impure syrup in lixiviating batteries or similarly operating
continuous lixiviating apparatus with a saturated solution of pure sugar so that
the raw sugar crystals do not form a crystallised lumpy body but a crystalline
---

page_text: pulpy or pap like mass saturated with syrup above which the abovenamed
lixiviating fluid is so long introduced until the said fluid attains a syrupy quality
similar to the molasses and is forced or pressed out by the pressure of the solution
of pure sugar introduced into the vessel of the battery which has at that time been
longest in operation and above the crystalline mass so that on the one hand the
crystals of the raw sugar are purified, are saturated with a solution of pure sugar.
and leave the battery in the form of a pure white crystalline pulpy or pap like
mass whilst on the other hand the impure syrup combined with the raw sugar is
separated from the same and is drawn off in the form of a molasses liko fluid.
Witnesses,
ANTHONY Steffen.
EDWIN A. BRYDGES.
CARL STEFFEN.
W. H. Beck, Agent,
115, Cannon St.