Improvements in Filter-presses and in Cloths therefor.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Filter-presses and in Cloths therefor.
I, JOHN CUNINGHAME MONTGOMERIE, of Dalmore, Stair, in the County of Ayr,
Scotland, Justice of the Peace, do hereby declare the nature of this invention
to be as follows; --
This invention relates to filter-presses and consists in various improvements
in the details of their construction, whereby their manipulation is facilitated
and their efficiency increased.
When washing materials-as, for instance, gold and silver ores-in a filter-
press, I have observed a tendency for the wash-water to pass between the inner
and smooth surfaces of the frames and the material under treatment; the quantity
of wash-water required to effect the operation being, in consequence, largely
augmented. In order to prevent leakage of this character, I form the inner sur-
faces of the frames with transverse grooves or corrugations, whereby the wash-
water is caused to pass through the mass of the material instead of around its
sides. When air is passed through the filter-press to dry the material before the
latter is discharged, the grooved or corrugated surfaces of the frames have the
same effect, and cause the air to permeate more thoroughly the mass of material.
It is not necessary to cleanse the grooves between each charge; because, assuming
the same kind of material to remain under treatment, the fresh charge makes a
good joint with any material that may be left in the grooves from the previous
charge.
In order to secure good joints and prevent leakage, the cleansing of the faces
of the filter-plates, distance frames and filter-cloths is a matter of importance.
For the expeditious and effective accomplishment of this object, I employ what
may be termed an air-brush," or nozzle whence a jet of high pressure air issues
and impinges against the various surfaces to be cleansed.
A filter-press of the improved kind above described may be employed in the
extraction, with the aid of charcoal, of the precious metals from solutions con-
taining the same. Where ordinary percolating filters are employed for this pur-
pose, much difficulty has been met with, owing to their becoming choked with
slime and fine sand. In applying a filter-press for the purpose, I charge the
press under pressure with charcoal in a finely granulated state mixed with the
liquid containing the precious metals to be extracted; the liquid from which the
precious metals are to be extracted being then passed through the charcoal.
The working pressure of the press is regulated and adapted to the rate of extrac-
tion deemed desirable.
In working filter-presses, I have also found that considerable leakage takes
place through the cloth joints owing to capilliary attraction; such leakage being
increased by the pressure used in charging the press, and washing the material
therein.
To prevent this waste, I coat the edges and sides of the cloths with vulcanized
rubber or similar composition, so that a solid piece of rubber may lie outside the

page_text: edges of the cloth and extend inwards as far as the catch on the face of the plates,
where the plates grip when pressure is applied to close the press for work.
In order to prevent the stretching of the edges of the filter-cloth, I introduce
brass or other suitable wire into the said edges during the process of weaving the
I also
cloth, and I afterwards coat these portions with the vulcanized rubber.
prefer to cement the edges of the cloths whether vulcanized or not, to the edges
of the plates, thus preventing their becoming displaced and time being lost in
their adjustment. The filter-cloth may be provided with perforations which, on
the cloth being folded over the filter-plate, engage with pins on the edge of the
latter.
By the foregoing method of treating filter-cloths, a practically tight joint is
obtained, and all waste of the liquid treated or of the wash-water is avoided.
In practice I prefer to interpose between the corrugated face of the filter plate
and the cloth, a 16 inch mesh sieve instead of the usual perforated plate.
To prevent the clogging of the cloths with mud or other matter, I wash the
material in the press, the first charge from one side and the next charge in the
opposite direction, and so on alternately. The same mode of procedure is adopted
to prevent the clogging of the cloths when passing auriferous solutions through
charcoal with a view to the extraction of the precious metals, the mud being in
a great measure arrested by the filter-cloth and prevented from permeating the
charcoal. The mud so retained is subsequently washed out of the filter-cloth
upon the direction of flow being reversed. In this way, the filter-cloths and the
charcoal are always kept fairly clean, and the necessity for frequently removing
the cloths for washing is avoided, the quantity of charcoal required is diminished,
and a great saving in time and labour is effected.
In working a filter-press provided with a feeding channel arranged along the
top of the filter-plates, great difficulty is experienced, on opening the plates, in
preventing the material falling between the filter-plates and the filter cloth. To
obviate this inconvenience, I form on the lug of the feeding channel a recess
or pocket into which a flap on the filter-cloth is inserted.
Various devices have been resorted to with the object of making a tight joint
between the channels of the plates and the frames, but all have proved more or
less faulty and troublesome. According to my improved method of construction,
I fit over the channel-lug a cloth hood provided with holes to match the channel
holes; and I saturate the cloth surrounding the holes with india-rubber to the
extent of the grip of the lug on the cloth; the cloth being made ½ inch larger
than the hole so that the rubber may cover the edge of the cloth, and thus prevent
The rubber is
the liquid being forced out through the pores of the cloth.
vulcanised after it is applied to the cloth.
2004
1, JOHN CUNINGHAME MONTGOMERIE, of Dalmore, Stair, in the County of Ayr,
Scotland, Justice of the Peace, do hereby declare the nature of this invention

page_text: and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:
This invention relates to filter-presses and consists in various improvements
in the details of their construction, whereby their manipulation is facilitated
and their efficiency increased.
my
In the accompanying drawings, Figs. 1 and 2 are respectively a face view and
a transverse section of a filter-frame constructed according to invention.
Figs. 3 and 4 are respectively a face view and a transverse section of the filter-
plate. Figs. 5 and 6 are views of filter cloths prepared according to my improved
method. Figs. 7 and 8 are views of the face and end respectively of the upper
portion of a filter-frame showing the feeding channel. Figs. 9 and 10 are similar
views of a filter-plate showing the lug of the feeding channel formed with a recess
for the reception of a flap on the filter-cloth. Fig. 11 is an enlarged transverse
section taken on the line - in Fig. 7. Fig. 12 is an enlarged transverse
section on the line y-y in Fig. 9. Fig. 13 is a face view and Fig. 14 a trans-
verse section of the cloth hood applied to the lug of the feeding channel of the
filter-plate. Fig. 15 is a view of the upper portion of a filter-cloth furnished
with a flap for insertion in a recess or pocket formed in the filter plate.
When washing materials-as, for instance, gold and silver ores-in a filter-
press, I have observed a tendency for the wash-water to pass between the inner
and smooth surfaces of the frames and the material under treatment; the quantity
of wash-water required to effect the operation being, in consequence, largely
augmented. In order to prevent leakage of this character, I form the inner sur-
faces of the frames A with grooves or corrugations a, same being arranged parallel
with the faces of the frame and transverse to the general direction of flow of the
liquid; whereby the wash-water is caused to pass through the mass of the material
instead of around its sides. When air is passed through the filter-press to dry
the material before the latter is discharged, the grooved or corrugated surfaces a
of the frames have the same effect, and cause the air to permeate more thoroughly
the mass of material. It is not necessary to cleanse the grooves between each
charge; because, assuming the same kind of material to remain under treatment,
the fresh charge makes a good joint with any material that may be left in the
grooves from the previous charge.
In order to secure good joints and prevent leakage, the cleansing of the faces
of the filter-plates distance frames and filter-cloths is a matter of importance.
For the expeditious and effective accomplishment of this object, I employ what
may be termed an "air-brush," or nozzle whence a jet of high pressure air issues
and impinges against the various surfaces to be cleansed.
In working filter-presses, I have also found that considerable leakage takes
place through the cloth joints owing to capillary attraction; such leakage being
increased by the pressure used in charging the press, and washing the material
therein.
To prevent this waste, I coat the edges and sides of the cloth b with vulcanized
rubber c or similar composition, so that a solid piece of rubber may lie outside the
edges of the cloth and extend inwards so far as the catch on the face of the plates,
where the plates grip when pressure is applied to close the press for work.
In order to prevent the stretching of the edges of the filter-cloth, I introduce
brass or other suitable wire d into the said edges during the process of weaving
the cloth, and I afterwards coat these portions with the vulcanized rubber. I
also prefer to cement the edges of the cloths, whether vulcanized or not, to the
edges of the plates, thus preventing their becoming displaced and time lost in
their adjustment. The filter-cloth may be provided with perforations e e which,
on the cloth being folded over the filter-plate, engage with pins f f on the edge
of the latter.
By the foregoing method of treating filter cloths, a practically tight joint is
obtained, and all waste of the liquid treated or of the wash-water is avoided.

page_text: In working a filter-press provided with a feeding channel arranged along the
top of the filter-plates, great difficulty is experienced, on opening the plates, in
preventing the material falling between the filter-plates and the filter-cloth. To
obviate this inconvenience, I form on the lug g of the feeding channel a recess
or pocket gl in which a flap c¹ on the upper edge of the filter-cloth is inserted.
Various devices have also been resorted to with the object of making a tight
joint between the channels of the plates and of the frames, but all have proved
more or less faulty and troublesome. According to my improved method of con-
struction, I fit over the channel lug g of the plate a cloth hood h provided with
holes to match the channel holes; and I saturate the cloth surrounding the
holes with india-rubber h² to the extent of the grip of the lug on the cloth; the
holes in the cloth hood being preferably made 1/8th inch larger than the channel
hole so that the rubber may cover the edge of the cloth, and thus prevent the
liquid being forced out through the pores of the cloth. The rubber is vulcanized
after it is applied to the cloth. The hood his perforated at to engage with.
pins ff on the lug of the filter-plate.
In practice I prefer to interpose between the corrugated face of the filter-plate
and the cloth, a 16th inch mesh sieve instead of the usual perforated plate. I
have not, however, considered it necessary to illustrate this sieve, as its applica-
tion will be readily understood by those familiar with the construction and work-
ing of filter-presses.
Το prevent the clogging of the cloths with mud or other matter, I wash the
material in the press, the first charge from one side and the next charge in the
opposite direction, and so on alternately. In this way, the filter-cloths are always
kept fairly clean, and the necessity for frequently removing the cloths for wash-
ing is avoided, great saving in time and labour resulting.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I claim :-
1. For employment in a filter-press, a filter-frame constructed substantially as
herein described and having its inner surfaces formed with grooves or corruga-
tions parallel with the faces of the frames and transverse to the general direction
of flow of the liquid, whereby the wash-water or other medium is caused to
traverse the mass of material under treatment, instead of flowing across the surface
of the frame.
2. For employment in a filter-press, a double folding or single filter-cloth having
edges coated with vulcanized rubber or similar water-tight composition, substan-
tially as set forth.
3. For employment in a filter-press, a filter-cloth having brass or other suit-
able wire woven into its edges, these parts being then coated with vulcanized
rubber or similar composition, substantially as and for the purposes set forth.
4. In a filter-press provided with a feed-channel on the top of the filter-plates,
the herein described means for preventing the ingress of the material between
the filter-plate and the cloth, same consisting in forming a recess or pocket in
the filter-plate into which a flap on the filter-cloth is inserted.
5. For employment in a filter-press provided with a feed-channel on the top of
the filter-plates, a filter-plate having a recess or pocket, such as g', formed at
or about the junction of the lug of the feed-channel with the plate, substantially
as and for the purpose specified.
6. For employment in a filter-press provided with a feed-channel on the top
of the filter-plates, a filter-cloth having a flap, such as c, extending from the
upper edge of the cloth, substantially as and for the purpose specified.
7. In a filter-press provided with a feed-channel on the top or sides of the
filter-plates, the herein described means for effecting a tight joint between the
feed-channels pertaining to the plates and frames, same consisting in a channel-
lug furnished with a cloth hood having holes corresponding with the holes in the

page_text: lugs; the cloth surrounding the edges of the holes in the hood being coated with
india-rubber to the extent of the grip of the lug on the cloth, substantially as and
for the purpose specified.
For the Appпcant,
G. G. M. HARDINGHAM.
Chartered Patent Agent, Clun House, Surrey Street, London, W.C.