The Middlebury register. [volume] (Middlebury, Vt.) 1850-1882, 1873-11-18


rests the lime and other impurities, aud
the purified juice strains out between the
frames at their planes of Junction, and
flows thence to closed iron vessc con-
nected by pipes with waits situated 10 the
tower at the top OF the building. by
turning a jet Of steam Into this vessel The
juice is forced up through these pipe. in
to the watts, whence it uudergoes b further
process Of publication by liitcring
through bone.dust.
The filter is 10 the form of cylinder,
divided by partitions into several cham
bers which are all conducted by system
of pipes. The juice is made to pass
through two of these compartments in
succession, and the arrangement ofpipes
is such that any one Of them may be dis
connected from the system without break
ing the connection among the others.
Thus as each division Of boHe-dust be.
comes saturated with impurity it may be
disconnected, cmptied, and fresh charge
added without interrupting the continue
ty Of the filtering process which is going
On through the other chambers There
are six Of these chambers or separate
filters, and each one will run six hours
before it becomes necessary to renew
its charge of bone-dust.
At this stage of the process the juice
contains about 10 per cent. Of saccha-
rinc matter. The next step is one of
concentration
The juice passes from the bone.dust
filters into boilers where its volume is re.
duced by boiling, and is then passed a
second and last time through the filter,
by which the last particles of foreign
matter are extracted The color of the
juice is now pale gold. The remainder
Of the process is one Of boiling down."
by which the percentage Of water is pro.
gressively reduced, until the sugar crys.
talizes, when the syrup is expelled by
mechanical action, and pure sugar is pro.
cured. In the operation of extracting
the saccharine juice and its publication,
the steps thus far described may be DIES.
ignated as the mecnaDical ones of the
process The soluble substances extract
ed from the beet are not saccharine sole.
ly. One constant element which is also
found is common salt-the proportion
varying with different parcels of ocets.
Traces of other soluble salts may also be
found. Although the relative quantity
of these is minute, it is still necessary to
eliminate them before the final boiling !;
and this is done by the introduction at
different stages of the mechanical purii.
cation of different chemical reagents.
The detail OF the use of these will de.
pend on the preliminary analysis of the
raw material under treatment. Up to
the present stage of the process, also, in.
dicatiops Of the course and success of its
operation are afforded by the colors sue.
cessively assumed by the juice. At
tached to most of the apparatus described
are thermometers arranged to indicate
the temperature of the juice at different
stages.
The saccharometer-a apparatus that
indicates the percentage OF sugar in its
solutlons-gives the quality of these at
any moment In practice, all of these
things are in use. The degree of heat to
be given at the several steps Of the pro.
cess may vary with the different read.
ings of the saccharomster aud the color
Of the juice. The particular form OF
sugar to be ultimately produced from a
given quantity Of juice may, in some
cases, depend on these observations. 1t
will be correctly inferred that the practi.
cal management of works of this class
demands an antecedcnt training, and that
the degree Of success attending their op.
erations will be found intimately depend.
ent on the judgment and practical knowl-
edge with which these re directed.
We have followed the juice to the
stage Of its final publication. The liquid
now consists Of saccharine matter and
water-,including under the first term the
pure sugar, together with the inseperable
coloring matter which ultimately remains
in the syrup. From its second fltering
the juice constantly passes into the first
vacuum boiler, in which vacuum equal
to six inches Of pressure-that is, equal
to six inch column Of mcrcury-is
maintained and in this it is kept at
temperature sufficient for ebulition. Tue
use of vacuum boilers is to produce ebu.
lition at successfully lower temperatures,
for otherwise the sugar would become
dark. From the first vacuum boiler the
juice, now the consistence of thin syrup,
passes into second, in which vacuum
equal to 26 inches is maintained Here
it remains until the saccharometer indi.
Gates that it is concentrated TO 40 per
cent. Of sugar; the remaining GO per
cent. is water. Hence the thick syrup
liquid passes into the last boiler-a large
copper globe, in which are set thick
glass windows admitting the operator to
view the process going Oh within. In
this boiler the vacuum is maintained at
% inches-producipg ebulition at TEN.
perature of 63 degrees (Rean), and dur
ing this boiling crystalization begins.
The color of the entire mass is now rath.
or darker than that of the golden syrup
of the re6neries The operator Judges
the progress of the boiling by the ap-
pearance of the semi-fuid, drawing small
portions Of it from time to time upon a
plate of glass, and observing the degree
and character Of the capitalization.
When the formation Of pure sugar crys-
tails is complete, the mass is drawn off
into large iron buckets, aud allowed to
stand for some six hours to cool off 1t
is then put into
THE CENTRIFUGAL MACHINES.
These are iron vessels some four feet in
diameter, which revolve at the enormous
velocity Of 1900 revolutions per minute.
The semi.huid mixture of sugar and
syrup is emptied into one of these, and it
is set in motion, as a high velocity is at.
tanned, the viscous charge is forced by
centrifugal force to lay itself like a
coat of plaster against the sides of the