The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1880-11-27
How Sugar is Refined.


plantations, may be of interest, says the
american NaagfactareT and Exporter, to
those not familiar with the methods now
employed in Boston refneries, so favora-
bly, known by their products wherever
shipped, aud SO remuneratiVe to their
owners.
The melting process, which is tho first
in order for refining sugar, is carried on 10
a melting room, SO called, now mostly sep
arate from the main establishment, in q
building by itself, on account of the un-
cleanliness Of the process. Here the hogs
heads aud other packages are brokenopen
and emptied by machinery into melting
pan, together with the sugary water OBJ
tanned by cleansing the empty hogsheads
by steam. This melting pan contains from
four to six hogsheads Of sugar, aud has
connected with it revolving horizontal
or vertical shaft with stirrer knives for
byavS1g up the Jumps Of sugar. Here,
with water and steam, the sugar, which
Varies in quality, is melted to consistency
ofabout 3O' Baume, aud drawn of through
sieve till all coarse impurities, such as
nails, chips, etc., are removed. 1t is then
raised by means of a large pump to the
upper floor Of the clarifying house, where
it is received into the clariiyers or "blow
ups"
The clarifying process is now entered
upon, the CHARTERS or "blow ups" being
large shallow pans about ten feet in diam.
eter aud six feet high, having at the bot
tom three or four inch copper coil
through which the steam circulates. Here
the liquor is gradually heated up to a tenn
perature Of about 1902 To 2l0o Fahr., and
to density Of 200 to 800 Baume. Ali
moist sugars contain more or less ascdity,
and on these lime is used Dry sugars,
especially Manillas aud all lower grades of
East Indian sugars, containing too much
lime, are treated with sulphurous gas or
an acid to neutralize the same. Alum is
sometimes used to good advantage. In all
cases the liquor, before it is filtered, should
have an excess of lime in it to prevent it
from fcrmenting. On the lower grades Of
sugar, bullock's blood, either fresh or dried,
is used, The albumen of the blood begins
to coagulate at about 140o Fahr., forming
a net throughout the liquid, which gradu-
ally rises, as the heat increases, to the
surface, carrying with it all the lighter
impurities, and leaving all the heavier ones
at the bottom. Between the thick scum
on the top Of the liquid and the impurities
at the bottom Of the "blow up clear
liquid will be seen, which is drawn off and
finds its way to the bag filters, on the next
floor below.
The fltering process now begins. The
liquid from the clarifier or "blow up"
passes through bag filters, which arrest all
floating impurities in the liquid. These
filters differ in size in different establish
men,s, but where ten years ago abouta hun.
dred bags were put into single filter, they
now put from four to eight hundred. The
filters are constructed as follows At the
the top is a large tank for receiving the
liquid from the clarifer above, the bottom
Of which is perforated with multitude Of
loies, TO which as many bags are attached
beneath, to receive the liquid from the
tank, and are double, that is to say, bag
made of cotton cloth, FIVE feet long and
about two feet wide, is introduced into a
strong bag made of fax, six feet long aud
only six inches wide, and brass bell
shaped thimble, larger end downward, is
inserted into the neck of the inner bag,
and both inner and outer bags are tied to
it, both constituting one bag. These dou-
BILE bags are fastened to the bottom of the
tank by means of a screw 10 the smaller
end Of the thimble Of each. The tank
holding all the bags on the bottom stands
over another tank, which surrounds the
bags and receives the liquor at its base as
it percolates through the bags. This com
binatiou of flteriug bags with upper and
lower tanks constitutes the "bag filter, as
it is named, and by means Of it large
amount Of 6ltcriug surface is obtained in
u small space. The filtration is rapid, il
the preceding clarifying process has been
perfect.
From tho bag filters the liquid runs into
the receiving tanks on the floor below, and
consists Of the raw sugar in liquid sta te
freed Of its coarse impurities, yet still re-
tanning many Objectionable ingredients
which will prevent the equalization of
the sugar and others which will impair the
quality Of the refined product These
impurities arc gum, lime, salts, mineral
substances, and coloring matter, which
have TO be removed BY means of charcoal
filters.
Charcoal has the power to abstract and
retain the organic coioring matter and i'm
purities Of the liquor, and thus to assist
the granuhtion of crystals, increase the
amount Of sugar, and Improve It's quality.
Charcoal filters are now mostly built ten
feet in diameter by twenty feet in height,
each to hold about 80, 900 pounds Of char
coal burnt bones). They are constructed
with a perforated bottom, composed of
separate pieces, SO as to be removed aud
cleansed occasionally, and made to rest on
wooden blocks so MS TO leave space six
inches in depth between the perforated or
false bottom and the lower bottom Of the
filter A fltering cloth or blanket is
spread over the perforated bottom to pre-.
vent the filtered juice, in running through,
from carrying any Of the bone black ol
the charcoal with it. The filters now used
have mostly closed tops aud man holes ou
the side, at the bottom, aud on the top
for the purpose of filing aud emptying
them when necessary. 10 secure good
filtration care must be taken To pack the
charcoal uniiornly throughout the Glter
otherwise channels viii be formed through
(which the liquor will 6nd It's way easily
ovsrtaxing part Of the charcoal ant
leaving other portions unused The oh
jeet Of these filters is TO remove the yege
table eploring matter FROM the sugar llquo
aud any excess Of lime which may hav,
been supplied it during elari6catiou, ais,
all mineral salts originally existing in III,
cane or added to the liquor on is wa,
from the clari6ors to the charcoal filters
1t viii be readily seen that this process /
Il Of the greatest importance to the sugar re
finer, US almost ali impurities, especiali,
gumniy substances, iu the sugar liquo
will hinder the granulation of the crystal