IMPROVE- MENTS IN FILTERING APPARATUS to be as follows:―
Year: 1884

page_text: I, JOHN FREDERICK COOKE FARQUHAR of 24 Long Acre in the County of
Middlesex Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN FILTERING APPARATUS to be as follows:―
"
In the Specification of a former Patent granted to me and to Walter Oldham on
the 25th day of August 1882 N° 4072 was described a filtering apparatus in which
the filter bed was at the bottom of an upright cylindrical vessel and in which the
upper surface of the filter bed was continuously scraped by a scraper made to
project from the underside of a disc or head at the lower end of a vertical hollow
shaft which was carried up through the centre of the filter vessel. The disc or
head was slightly smaller in diameter than the interior of the cylindrical' vessel and
the refuse scraped off the filter bed passed up the inclined cutter and so to the
upper surface of the head and rested above it whilst the liquid to be filtered was
supplied on to the cleansed surface of the filter bed through the hollow spindle into
which it was supplied directly either by a pump or otherwise.
The object of my improvements is more especially to adapt apparatus of this
kind to filter liquids which have solid impurities of comparatively large size mixed
with them.
•
For this purpose in place of supplying the liquid to be filtered directly to the
hollow spindle I supply it to the upper part of the cylindrical filter vessel and
I make perforations in the central hollow spindle through which the liquid may
pass down through the spindle to the underside of the cutter plate and so on to the
filter bed.
These perforations I surround with wire gauze-the gauze keeps back the larger
impurities and prevents them from entering the spindle-it may be kept free from.
clogging by means of a stationary brush held up to it.
•
By this arrangement two operations are performed at once viz: that of a settling
bed and of a filter. The cylindrical vessel above the cutter plate acts as a settling
vessel to allow the heavy matters in suspension to deposit on to the top of the
cutter plate whilst the thinner liquid only passes through the hollow spindle on to
the filter bed. In this way fewer impurities pass on to the filter bed and the filter
bed is saved from being cut up by having heavy matters thrown on to it
consequently the filter bed will not only act more efficiently but will also last for å
longer time.
Dated th: 19th 1001

page_text: COMPLETE SPECIFICATION.
I JOHN FREDERICK COOKE FARQUHAR of 24 Long Acre in the County of
Middlesex Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN FILTERING APPARATUS" and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
Statement:
5
In the Specification of a former Patent granted to me and to Walter Oldham on
the 25th day of August 1882 No 4072 was described a filtering apparatus in which
the filter bed was at the bottom of an upright cylindrical vessel and in which the
upper surface of the filter bed was continuously scraped by an inclined cutter made
to project from the underside of a disc or head at the lower end of a vertical 1
hollow shaft which was carried up through the centre of the filter vessel.-The
disc or head was slightly smaller in diameter than the interior of the cylindrical
vessel and the refuse scraped off the filter bed passed up the inclined cutter and so
to the upper surface of the head and rested above it whilst the liquid to be filtered
was supplied on to the cleaned surface of the filter bed through the hollow spindle 1
into which it was supplied directly either by a pump or otherwise.
The object of my improvements is more especially to adapt apparatus of this
kind to filter liquids which have solid impurities of comparatively large size mixed
with them.
For this purpose in place of supplying the liquid to be filtered directly to the 2
hollow spindle I supply it to the upper part of the cylindrical. filter vessel and
I make perforations in the central hollow spindle through which the liquid may
pass down through the spindle to the underside of the cutter plate and so on to the
filter bed.
These perforations I surround with wire gauze, the gauze keeps back the larger
impurities and prevents them from entering the spindle—it may be kept free from
clogging by means of a stationary brush held up to it.
By this arrangement two operations are performed at once viz; that of a settling
bed and of a filter. The cylindrical vessel above the cutter plate acts as a settling
vessel to allow the heavy matters in suspension to deposit on to the top of the
cutter plate whilst the thinner liquid only passes through the hollow spindle on to
the filter bed. In this way fewer impurities pass on to the filter bed and the filter
bed is saved from being cut up by having heavy matters thrown on to it-
*consequently the filter bed will not only act more efficiently but will also last for a
longer time.
The drawing annexed shows a vertical section of filtering apparatus constructed
as above described.
A is an upright cylindrical vessel at the bottom of which is a filter bed B-C is
the hollow disc or head at the lower end of a vertical shaft D which as described
in the specification above mentioned can be rotated and also gradually lowered as
the filtering operation goes on. A radial passage is also as described in that
specification formed through the hollow'dise so that all refuse scraped up from off
the upper surface of the filter bed by an inclined cutter fixed along one side of the
slit may pass up the inclined cutter through the radial passage and so on to the
upper surface of the disc. E is a tube rising up from the centre of the hollow disc
or head and surrounding the lower part of the vertical shaft D.
"F is a perforated rose or head from which a tube G descends into the tube E-
the rose may be supported by arms H from the sides of the vessel A. The rose is
below the top of the vessel A. and liquid to be filtered passes from the vessel

page_text: through the perforated rose and down through the hollow tube E surrounding the
spindle and so into the interior of the hollow disc or head C from which it passes
through perforations in the bottom onto the surface of the filter bed. I'I are
brushes carried by arms from the boss of the toothed wheel J by which a slow
revolving motion is given as heretofore to the shaft D-the brushes are therefore
caused to sweep over the surface of the perforated rose and so keep the perforations
from becoming clogged. Or in place of this the rose might revolve with the tube E
and be held up to stationary brushes.
K is a plate fixed across the vessel A at a distance above the surface of the filter
bed the tube E and spindle D pass down through the centre of this plate. L is a
manhole in the side of the vessel A through which materials forming the filter bed
can be taken out and renewed-M are knives or blades which are kept from
revolving by chains N as shown-they rest upon the top of the disc or head and
prevent the refuse which comes up through the radial opening in this head from
piling up and obstructing the passage through the opening-O is a cock by which
thick sludge settling on to the plate K can be drawn off from the upper com-
partment of the vessel A.
The liquid to be filtered is delivered into the top of the vessel A through a spout
in such a manner that the stream is not directed on to the rose head-the heavier
matters then settle down on to the plate K whilst the clearer liquid passes through
the rose F to the surface of the filter bed as above explained-P is the outlet for
the filtered liquid.
In the drawing the disc or head is shown as being held up in a position to allow
of the manhole L being opened and the filter bed emptied out and renewed.
When however the filtering operation is being carried on the disc or head is lowered
down to the surface of the filter bed so that the scraper which it carries may
continuously scrape over the upper surface of this bed.
=
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 :-
First. In filtering apparatus in which the surface of the filter bed is covered
over by a disc or head that carries a scraper to scrape and clean the surface of the
filter bed as the operation of filtering goes on making the upper part of the vessel
which contains the filter to form a settling tank in which large solid matters may
settle from the liquid to be filtered whilst the clearer liquid is drawn from the
upper part of the tank on to the surface of the filter led through the axis of the
head or through a tube surrounding it substantially as described.
Second. The construction of filtering apparatus substantially as herein before
described and illustrated in the drawing annexed.
AT
T
3004