The Hawaiian star. [volume] (Honolulu [Oahu]) 1893-1912, 1899-03-23
FOR SUGAR MANUFACTURE
or SACCHARINE
JUICES
New Process for obtaining Clear Juice
Does Away With Former Clumsy
Methods and Avoids Cloudiness.

In the manufacture of sugar, says
Kuhlow's, the separation of extremely
fine impurities, present in the form of
powder or slime, is connected with
special difficulties The efforts made to
keep back these impurities by means
of liberation, have not enabled manu-
| facturers to be certain of obtaining
/ clear Juice and ever and anon they
have found themselves compelled to
recur to the ancient process of avail
ing themselves of the surface action of
boneblaCk.
The further attempt to get a better
working by thickening the cloth filters
| by means of the deposition of finely
| divided substances, mechanically bro
ken up, had only been partially success
| full, inasmuch as the filters do not be-
come effectual until the thickening of
| the mass to be filtered has proceeded
so far as to render high pressure nee
essary for the filtration. AS sam
! pie of this may be instanced the SoX-
/ hlet process.
The new process succeeds, even where
| the fltering substance is of a light
| spongy nature, and consequently re-
/ uuires only slight liberation pressure
| in keeping back the whole of the me-
/ chanical impurities, even the shines,
/ which during the filtration behave
/ like liquids and consequently pass
/ through the pores.
This is due to reasons similar TO
those which secure the great effective
ness of the boneblack but the new pro-
cess is distinguished by the important
difference that layers of only few
millimetres thickness are sufficient,
while in the case of boneblaCk the
| liquid to be filtered has to undergo a
passage of several metres in length
through to purifying medium. Even
liquids added to the juice i'm sort of
| emulsion are effeCtually separated
where the new process is used.
The process is specifically distlng-
uished by the use, as filtering media,
or nsOluble compounds, chemically
precipitated, but not produced in the
Juice itself; compounds for instance,
such as are obtained as waste pro-
! ducts in certain chemical industries, of
which the carbonate of lime thrown
down in the manufacture of caustic
soda may be named as an example.
The new process must not be con-
founded with that of adding, on the
third saturation the residua from the
filtration of the first saturation. The
two processes are radically distinct.
In the latter case the fine slime of the
third saturation is mixed with the
coarse residua of the filtration of the
first saturation, which are strongly
contaminated by organic substances,
and are only added with the object of
attracting the fine slime of the third
saturation, and so rendering possible
the filtration of the latter.
The new process may be carried out
in the following manner: given
quantity of the filtering medium is
made into batter with water or juice,
and the mixture passes through a fill
ter press or similar apparatus for fill
tering. The first filtrate, which may
possibly still have a cloudy appear
ance, is again put into the liquid to be
| filtered. Heating the liquid in most
cases gives better results, but the new
process, as compared with others, e. g.
| the SoXhlet above mentioned. also
| gives clear filtrates with cold juice.
If cloudiness should result after the
! filter has been used a long time, in con-
! sequence of a weakening of the effect
of the filtering medium, a fresh guam
tity of the latter must be supplied to
the filter as directed, and this can be
repeated until the filtering apparatus
is almost completely full.