IMPROVEMENTS IN FILTERS
Year: 1871

page_text: LETTERS PATENT to William Henry Moore, of 11, High Street,
Denmark Hill, in the County of Surrey, for the Invention of
"IMPROVEMENTS IN FILTERS."
Scaled the 21st November 1871, and dated the 19th August 1871.
PROVISIONAL SPECIFICATION left by the said William Henry Moore
at the Office of the Commissioners of Patents, with his Petition,
on the 19th August 1871.
I, WILLIAM HENRY MOORE, of 11, High Street, Denmark Hill, in the
County of Surrey, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FILTERS," to be as follows:-
This Invention has for its object the construction of filters in such a
manner that they shall be self-cleansing without any special operation,
and in the ordinary course of drawing water. For this purpose I arrange
that the filter is connected with the service pipe, which is attached to
the bottom of the filter on one side, and the water passing through and
out at the opposite side to the ordinary tap for drawing water, the water
then ascends upwards through a block of carbon or other filtering
media, and is conveyed through a pipe into the filtered water chamber,
ready to be drawn off. The aperture through which the water is admitted
is of small dimensions so that the water does not pass too rapidly, thereby
ensuring more perfect filtration. The filtered water chamber in this

page_text: "
two nozzles a¹ and a³, at which are connected respectively the supply
pipe and the draw off cock for unfiltered water. a³ is a third nozzlo
upon the vessel a to receive the tap for drawing off the filtered water
for use from time to time as it may be required. In the Figure theso
nozzles aro represented in such positions that they may be clearly 5
scent, but it will be more convenient in many cases to arrange them
in the positions indicated in Figure 2, which is a horizontal section of
the filter taken on the line 1, 1, in Figure 1. b is a carbon block
forming the filtering bed through which the water is compelled to pass;
this block is set in Portland cement c, and in the cement glass tubes 1
c', c', closed at the upper end and open below are bedded; they form
air vessels to lessen concussion when the draw off cock at a³ is suddenly
closed. d is a bottom to the filter, it is held in its place watertight by
cement e is a slate set in cement at a short distance over the carbon
block 6; it has two holes e' and e' through it. The hole e' is small, 1
and by it the water passes upwards; its size is such as to prevent the
filtration being unduly rapid, and consequently imperfectly performed.
The other hole e' is large for the return of the water to cleanse the
filtering bed. A valve e** is fitted to this hole, which prevents the
upward passage of the water through it. I prefer to form the valvo 2
of a piece of sheet india-rubber secured by a rivet on one side, and
prevented from falling more than a short distance away from the hole
it covers. A similar valve may be fitted to the hole e' to prevent the
filtering material being worn away by the jet of water, which other-
wise would descend upon it each time when the draw off tap at a³ is 2
opened.
-
Over the partition e is a chamber ƒ, into which the filtered water
enters, and air is also contained in this chamber. This chamber is
secured in its place by cement, and as the pressure within it rises the
water ascends the pipe g, which is fixed securely in a hole in the top g
of the chamber and flows into the filtered water cistern h. The pipe g
descends some distance below the top of the chamber f, so that a con-
siderable quantity of air at all times remains in this chamber. The
lower end of the pipe g is contracted to a small aperture, so that whilst
it provides a slow escape for the filtered water it does not prevent the 3
pressure in the chamber being maintained nearly on an equality
with that of the supply. i is a ball valve, which closes the pipe 9 when
the cistern his full; k is a loose cover to the filter.

page_text: Figure 3 shews a filter also constructed according to my Invention,
but differing in some respects from that shewn by the previous Figures.
It contains a filter bed, consisting of loose materials, such as charcoal,
sand, and gravel materials, now commonly used in filters. The filter
bed is enclosed between two porous or perforated slabs k, k, fixed with
cement. The upper part of the filter case forms the closo air chamber,
and a pipe attached at the nozzle a³ at the lower part of this air
chamber passes to a separate filtered water cistern, the supply to which
is regulated by a ball cock. Whilst this ball cock is open the pressure
in the air chamber is limited to that due to the column in the pipe,
and if this be high it will be sufficient in itself to give an efficient
return flow, but in any case when the ball cock closes the full pressure
of the supply becomes available. The filter shewn at Figure 3 may also
be used without a filtered water cistern, a tap to draw off the filtered
water being then inserted at the nozzle a³. A supply of air to the
filter may be ensured by an air pump dipping into the mouth of the
supply pipe within the supply cistern.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I do
not confine myself to the details described, and in particular the shape
of the filter, and the materials of which the filter bed and the case of
the filter are formed may be varied; but I claim the construction of
filters, substantially as described, so that filtration is performed, and
filtered water retained under pressure, and so that when the pressure
of the supply is from time to time relieved by opening a draw off tap a
backward flow of such filtered water takes place through the filtering
bed, which by such means is cleansed.
In witness whereof, I, the said William Henry Moore, have here-
unto set my hand and seal, this Sixteenth day of February, in
the year of our Lord One thousand eight hundred and seventy-