Improvements in and relating to Filter Presses and similar Filtering Apparatus.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Filter Presses and similar Filtering
Apparatus.
I, JOHN WILSON, 10, Ronald Street, Glasgow, in the County of Lanark,
Analytical Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention which relates to filter-presses and similar filtering apparatus
has for its object the provision of means for periodically removing the deposit
formed upon the surface of the filtering medium in cases where such deposit
is of such a nature as to prevent filtration before it has acquired sufficient depth
to be removed in the form of cakes by the ordinary methods.
To that end I form the plates, or plates and frames square or rectangular shaped,
with the channels for the admission of the unfiltered liquor, lixiviating water,
steam, etcetera running through adjoining snugs as commonly done in some ordi-
nary types of filterpresses. To each plate or plate and frame according to the par-
ticular design of press adopted I attach a roller or rollers one at the top and the
other at the bottom parallel to the upper and lower edges of the plates and in
such fashion that a roll of filtercloth or other filtering medium can be wound
from one end of the press to the other leaving the filtercloth over the filtering
surfaces of the plates precisely as they are where separate cloths are used for each
plate. Revolving brushes are provided contiguous to the bottom rollers so that
in the passage of the cloth thercover it is brushed free from any deposit adhering.
Scrapers and jets of water are also provided to facilitate this operation.
filtercloth is wound backwards or forwards or continually forward when the two
ends are joined together, according to the gearing provided for that purpose on
the two ends of the press.
The
As the process of cleaning the cloths is one that is performed while filtration
is stopped and the plates or plates and frames must be equally distant from each
other during the winding of the cloth means are provided for opening out the
platos or plates and frames the requisite distance expeditiously and with a
minimum of manual labour. Upon the edges of each plate and frame and at
suitable positions are cast round projections, the projections upon each adjacent
plate and frame being connected by metal hoops the length of which regulates
the extent to which the plates and frames are opened out. Upon the end plate
being drawn back each plate and frame is drawn out successively, the distance
between each plate and frame being equal and sufficient to allow of the filtercloth
being wound as described. To draw out the back plate either I form a cylinder
in the back frame with a piston and piston rod working therein the motive power
being either air or water under pressure, or I use a screw working in a boss
within the back frame this boss being connected to a wheel into which gears a
pinion turned by means of a handle.
In a filterpress where plates only are used the plates are constructed suitably

page_text: and both upper and under rollers are attached thereto but when frames are also
used in conjunction with plates the upper rollers are attached to the frames and
the under rollers to the plates respectively.
Improvements in and relating to Filter Presses and similar Filtering
Apparatus.
I, JOHN WILSON, late of 10, Ronald Street, but now of 1, Hill Street, Garnethill,
Glasgow, in the County of Lanark, North Britain, Analytical Chemist, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention which relates to filter-presses and similar filtering apparatus has
for its object the provision of means for periodically removing the deposit formed
upon the surface of the filtering medium is particularly applicable to filter-presses
where the deposit is of such a nature as to prevent filtration before it has acquired
sufficient depth to be removed in the form of cakes by the ordinary methods.
To that end I form the plates, or plates and frames, of square or rectangular
configuration, with the channels for the admission of the unfiltered liquor, lixi-
viating water steam running through adjoining snugs as is commonly done in
some ordinary types of filter-presses.
To each plate or plate and frame according to the particular design of press
adopted I attach a roller or rollers, one at the top and the other at the bottom,
parallel to the upper and lower edges of the plates, and in such manner that a
roll of filtercloth or other filtering medium can be wound from one end of the
press to the other, leaving the filtercloth over the filtering surfaces of the plates,
precisely as is the case where separate cloths are used for each plate. Revolving
brushes are provided contiguous to the bottom rollers, so that in the passage of
the cloth thereover, it is brushed free from any deposit adhering. Fixed scrapers
and jets of water are also provided to facilitate this operation. The filtercloth is
wound backwards or forwards, or continually forward, when the two ends are
joined together according to the gearing provided for that purpose on the two
ends of the press.
As the process of cleaning the cloths is one that is performed while filtration
is stopped and the plates or plates and frames must be equidistant from each other
during the winding of the cloth, means are provided for opening out the plates
er plates and frames the requisite distance expeditiously, and with a minimum
amount of manual labour.
Upon the edges of each plate and frame and at suitable positions are cast round
projections, the projection upon each adjacent plate and frame being connected
by metal hoops, the length of which regulates the extent to which the plates and
frames are opened out. Upon the end plate being drawn back, each plate and
frame is drawn out successively, the distance between each plate and frame being
equal and sufficient to allow of the filter-cloth being wound as described. To
draw out the back plate either I form a cylinder in the back frame with a piston
and piston rod working therein, the motive power being either air or water under
pressure, or I use a screw working in a boss within the back frame, this boss
being connected to a wheel into which gears a pinion turned by means of a handle.
In order that my invention may be properly understood and readily carried into

page_text: effect have hereunto appended three explanatory sheets of drawings, in the
several figures of which corresponding parts are marked with the same letters of
reference.
Fig. 1 is a longitudinal elevation of my improved filterpress shewing the course
of the filtercloth, (the plates being opened out for that purpose), closing up, and
tightening up the plates and frames as hereafter more fully referred to.
Fig. is a plan of the bed plate upon which the filterpress stands, shewing the
brushes for brushing the cloth, also a mechanical form of opening out, closing
up, and tightening up the plates and frames, which have been removed, and is an
alternative method to that shewn in Fig. 1.
Fig. 3 is an elevation of one of the plates, of which there are seven, together
with a fixed front plate and a moveable back plate, showing the under roller
attached thereto, combined with a section of the bed-plate and one of the revolving
brushes.
Fig. 4 is a cross-section of the plate, with a roller and brush in situ shewing
the method of grooving the surface thereof.
Fig. 5 is an end elevation of part of two plates and one frame, shewing the
form of the lower corners of the plates when a scraper is used in addition to a
revolving brush as shown in section, or without a revolving brush as not shown.
Fig. 6, is an elevation of one of the frames shewing the upper roller attached
thereto.
Fig. 7 is a horizontal section of a frame shewing the vertical bars or grooves.
Figs. 8, and 9, are respectively part views, drawn to an enlarged scale, illustrat-
ing the method of mechanically drawing out the plates and frames, shewing the
position of the links when the plates are open, vide Fig. 8, and closed vide Fig. 9.
Figs. 10 and 11, are elevation and plan respectively of a third alternative
method to be employed for opening out, closing up, and tightening up the plates
and frames.
Fig. 12 is a part elevation, corresponding to Figs. 10 and 11, illustrating how
the end plate of filterpress is withdrawn.
The plates and franies are constructed as shewn in Figs. 3 and 6, the main inlet
channel for the liquor to be treated being formed as at a, and the channel for
water, steam or air as at b. To the entrance or end of the channel a, is attached
two T pipes, a, a², Fig. 1. To the outer flange of a', is connected the inlet
valve or cock (not shown on the drawing) for the unfiltered liquid and to the two
branches of a, are connected respectively suitable valves or cocks, (not shown on
the drawings also) one of which is used for running off the contents of the filter-
press prior to opening out, and the other for running off the waste water used in
washing the cloth.
To the upper edges of the frames and to the lower edges of the plates, I attach
small brackets c, d, 2, 3, respectively which in turn hold in position the upper
roller, and lower roller d'. These brackets may be cast along with the plate
or frame respectively, the means of holding the rollers being adapted suitably
thereto.
To the bedplate g, I attach two brackets e, e¹, which accomodate the two nipping
rollers ff. Figs. 1, and 2. These rollers are kept in close contact by means of
the small screws h, h. A pair of additional rollers and Fig. 1, are provided,
the former pair, being attached to the legs of the fixed head of the filter and the
latter to the bed-plate g.
The filter cloth, is passed over the rollers d, d', d, 3, and through the nipping
rollers f, f, as shewn in Fig. 1, and upon the wheel f², being rotated by the;
pinion 3, Fig. 2, in the direction shewn by the arrows in Fig. 1, the cloth j, is
drawn through the press.
In some cases it may be found desirable to assist the nipping rollers f, and f¹,
in drawing the filter cloth through the press. To this end auxiliary help may be
obtained by causing the upper rollers d, and lower rollers d', to be rotated inde-
pendently of the said nipping rollers.

page_text: To the bed plate y, is fixed a number of small bearings k, which accomodate
revolving brushes k¹."
These brushes are actuated in one direction and that contrary to the direction
in which the cloth j, travels by means of the small pulleys &, and the position of
the brushes is such that they come into sufficient contact with the cloth j, when
passing over the bottom rollers d', and when the plates and frames are opened out
the necessary distances as shown in Fig. 1. Power for driving the brushes and
turning the rollers f, f', is communicated by means of the pulley ³, or in place
of this pulley a handle may be utilised, where the employment of manual labour
would be necessary or more suitable.
In order to open out the plates and frames equidistantly and expeditiously I
have them cast as shewn in Figs. 1, 3, and 6, with round projections m, upon
their edges. These projections are connected together by means of the small
hoops, links or rings p, which are of such size or dimension that upon the back
plater, being drawn back cach plate and frame is drawn out in succession such
distance as the size of the hoops will permit as illustrated in Figs. 8, and 9.
They are also so arranged one below the other that upon the closing together of
the plates they do not come in contact and prevent the plates so meeting as will
be better understood reference being had to Fig. 1.
.
As the drawing out of the plates and frames is an operation requiring a certain
amount of power and it is desirable to minimise the manual attendance necessary,
I adopt either of three methods of performing this, one of which is shown in
Fig. 1, one in plan in Fig. 2, and the other in Figs. 10, and 11. In Fig. 1, I
form a cylinder s¹, in the back frame or gauntress s. Within this cylinder works
a piston and piston rod and to the end of the piston rod is attached a ring s
This ring works within a suitable projection, on the back plate r.
Water or
air under pressure is admitted to the cylinder by either of the cocks s', the waste
water or air escaping by the cocks . The side bars n are provided with straps
at t, in which a key and cotter 1,, are inserted and which serve to keep tight
the plates and frames during the process of filtration after the piston within the
cylinder has pushed the plates, as close as the power employed will allow.
In Fig. 2, a screw y is provided which works within the boss v. To this boss
is attached the spur wheel 2 which in turn is actuated by the pinion and
handle. By the aid of the smaller wheel which is rigidly attached to the
wheel, and the use of a crow bar the plates, can be given the extra pressure
necessary to keep them tight.
In Figs. 10 and 11, the process of drawing the eud plate r, backwards and
forwards is the same as shewn in Fig. 1, but in the final tightening up a different
devies is adopted. The piston rod projects through the back cover at 6; and along
with the cylinder s¹, and gauntress s is cast two strong arms $7. Into these arms
by means of the pins is connected the cross-bar which accomodates. the
screw 10. The end of this screw presses upon the end of the piston rod at 6 and
serves to finally tighten up the plates and frames as seen in Fig. 11. In slacking
back the screw 10 as soon as the screw clears the end of piston rod one of th
pins may be removed and the cross-bar s swung round so as to clear the piston
rod. As in some instances it is desirable to scrape off the deposit on the cloth
before the brushes come into play I provide for that in the manner shewn in
Fig. 5 the projections which I attach to the bottom of the plates are formed
in the manner, and shape shewn with a slit c. Into this slit is inserted a
scraper which may be formed of any suitable material and may or may not
be faced with indiarubber. These scrapers may be kept in suitable contact with
the cloth in a variety of well known methods, one only of which is shewn.
To facilitate the removal of the deposit from the cloth by the brushes I provide
a series of pipes perforated with small holes and running between each plate as
shewn in Figs. 1 and 2. Water or steam may be forced into these pipes and
according to the position of the perforated holes projected on to the most suitable
points of the cloths while the brushes are revolving.

page_text: As for the purpose of better cleaning the cloths it is advisable to use low pres-
sures I form the plates as shewn in section in Fig. 4. The projections which form
the grooves are horizontal formed of suitable depth and distance from each other.
By this means a larger proportion of the area of the cloth is free from the metal
of the plate and the winding of the cloth may be stopped at such points as will
ensure the cloth resting on different successive points after each cleaning.
In the frames as shewn in Figs. 6 and 7, I form a series of vertical bars or
divisions. When water, steam, or air, is applied at the back of the cloths these
bars tend to assist the loosening of the deposit prior to its final removal by the
brushes, besides serving to counteract the effect of the 'bulges which are neces-
sarily formed in the cloth by the horizontal ribs on the plates.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
-
1. A filterpress constructed and arranged to operate substantially as described
with reference to the accompanying drawings.
2. In a filterpress the method and means of cleaning the filtercloth which may
be in a roll or joined together to form an endless band, by causing its interstices
to be brought into contact with revolving brushes rotated in an opposite direction
to the travel of the cloth while being drawn through the press during the sus-
pension of filtration substantially as described and shewn on the drawings.
3. In a filterpress the arrangement of rollers to the top of the frames and the
bottom of the plates in order to carry the filtercloth and imparted with an inde-
pendent rotation or not substantially as and for the purposes set forth.
4. In a filterpress the arrangement of revolving brushes for the periodic clean-
ing of the filtercloth substantially as and for the purposes set forth.
5. In a filterpress the provision of scrapers as an alternative or auxiliary method
of cleaning the filtercloth substantially as and for the purposes set forth.
6. In a filterpress the arrangement of projections on the edges of the plates and
frames in combination with moveable hoops or links substantially as and for the
purposes set forth.
7. In a filterpress the combination of an hydraulic cylinder in the back frame
with a swinging screw for the proper closing up and withdrawal of the sections
of the plates and frames substantially as and for the purposes set forth.
Dated this 10th day of Nov 1899
JOSEPH HENRY PEARSON,
Applicant's Agent.