IMPROVEMENTS IN FILTERS FOR SACCHARINE JUICES, SYRUPS, AND OTHER LIQUIDS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
of the Commissioners of Patents on the 11th August 1883. Communicated
to him from abroad by Alfred Perret of Roye, Somme, in the French
republic
CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane in the
county of Middlesex "IMPROVEMENTS IN FILTERS FOR SACCHARINE JUICES,
SYRUPS, AND OTHER LIQUIDS [communicated to him from abroad by Alfred
Perret of Roye, Somme, in the French republic]
The present invention relates to the use for filtering liquids, more particularly
saccharine juices or syrups, of sponges or spongy material or materials such as
loose textile fabrics, cotton and other vegetable fibre, pumice stone, asbestos, hair,
spun glass fibrous metal, and the like, which will retain the solid impurities
contained in liquids passing through them, by molecular or capillary attraction
and by simple adhesion, instead of solely by the ordinary filtering action such as
heretofore employed, where the filtering medium is of such close texture as to
prevent the impurities passing through.
For this purpose, according to one arrangement, a long horizontal vessel or vat
of rectangular transverse section is divided by loose perforated or permeable
partitions into a number of compartments. Each partition is attached to a
transverse bar at top, resting with its ends on endless pitch chains on each side of
the vat, passing round pitch wheels at the ends, by turning which by a crank
handle, motion can be imparted to the chains and consequently to the bars.
The compartments between the partitions are filled with the spongy or fibrous
filtering material, which may consist either of loops of loosely woven material, or
of hanks of fibre, connected at one point by the partitions, or it may consist of
fibres arranged in brush form, or it may be simply sponges; or again, it may
consist of pieces of pumice-stone, enclosed in a perforated casing or netting.
The liquid to be filtered being introduced through a pipe provided with a
regulating cock at one end of the vat or tank, is made to flow slowly consecutively
through the several compartments, whereby the greater portion of the solid
impurities will be retained by the filtering materials in the first compartments,
while the remaining portions will be gradually retained in the following com-
partments, the liquid flowing off from the last compartment through a discharge
pipe.

page_text: When the filtering material of the first compartment has become charged to a
certain extent with impurities, the flow of liquid is stopped for a time, and the
said filtering material with the corresponding moveable partition is removed.
The whole of the partitions with their filtering material are then moved one step
forward in the tank, by means of the endless chains, so that the second com-
partment now becomes the first, and so on, and after treating the filtering material
removed from the first compartment, so as to free it entirely from the accumulated
deposit, it is replaced in the last compartment together with the perforated
partition, and the filtering process is again proceeded with. If it be desired not
to interrupt the filtering process during the above operation, two or more such
apparatus can be employed in combination, the liquid being made to pass through
the one while the other is being cleansed.
The partitions, which may be made of perforated sheet metal, may be placed in
a slightly oblique position in the tank, so as to ensure that the edges thereof shall
fit closely against the sides of the tank. In some cases, it may be found advan-
tageous to combine with the filtering medium, a certain quantity of charcoal
powder, which will be removed by the cleansing operation and then renewed.
Instead of arranging the apparatus horizontally as described, it may be arranged
vertically or inclined, so as to utilise the filtering vats now employed in sugar
factories or refineries, the partitions being, in this case, horizontal with the filtering
material below them. The liquid -may, in -this-case, be made to flow either from
the top downwards, or from below upwards. The filtering material would then
-be removed from time to time. through apertures in the partitions, provided with
covers.
The apparatus may also be of circular or conical form, as in filters now used in
Bugar refineries.
In the first described arrangement, the cleansing of the filtering material may
be effected in the filtering tank itself, the whole of the compartments being cleansed
simultaneously instead of in rotation, as described.
In this case, there are fixed temporarily on the top of the tank standards carrying
rails, the partitions, together with the filtering material attached thereto, being
raised up out of the tank and suspended from the said rails, so that the liquid can
drain from the filtering material into the tank; this liquid is then removed from
the tank to be subsequently filtered again, and the tank is filled with cleansing
liquid, into which the partitions with their filtering material are then plunged, so
as to cleanse them. The tank is then again emptied and refilled with a second
charge of cleansing liquid, and so on repeatedly if required. The cleansing being
completed the partitions are again drained and are then replaced in the tank, and
the filtering process is resumed.
A convenient form of partition for such filtering apparatus consists of a frame-
work of angle iron, to which horizontal iron bars are attached, with spaces between,
forming a grating to which the filtering material is attached.
Handles are provided at the top and bottom of the partition for convenience of
manipulation.