IMPROVEMENTS IN FILTERING AND PURIFYING WATER AND OTHER LIQUIDS, AND AN APPARATUS FOR THAT PURPOSE
Year: 1876

page_text: LETTERS PATENT to Francis Thomas Bond, of Gloucester, in the County of
Gloucester, Doctor of Medicine, for the Invention of "IMPROVEMENTS IN
FILTERING AND PURIFYING WATER AND OTHER LIQUIDS, AND AN APPARATUS
FOR THAT PURPOSE."
Sealed the 23rd June 1876, and dated the 18th January 1876.
PROVISIONAL SPECIFICATION left by Francis Thomas Bond at the Office of
the Commissioners of Patents, on the 18th January 1876.
FRANCIS THOMAS BOND, of Gloucester, in the County of Gloucester, Doctor of
Medicine. "IMPROVEMENTS IN FILTERING AND PURIFYING WATER AND OTHER
LIQUIDS, AND AN APPARATUS FOR THAT PURPOSE."
For the purpose of this 'Invention I construct a filter in the following way:-I
take a cylinder of metal or any other appropriate material, and of a size which is
proportionate to the quantity of liquid required to be filtered. To one rim of this
cylinder I attach by soldering or by a screw thread a hollow cone, the surface of
which is perforated after the manner of a sieve with numerous small holes; to the
other rim of the cylinder I adapt a cover having a small aperture in the centre ⚫
thereof for the insertion of a tube, and so constructed that the said cover forms an.
air-tight chamber of sufficient size to keep the whole apparatus floating level or
nearly level with the surface of the water or other liquid in which it may be
immersed. Through the aperture in the upper surface of the cover aforesaid 'I
introduce a tube of glass or metal in such a way that the lower part of it shall pass
into the interior of the apparatus and down to the extremity of the cone.
The portion of the apparatus consisting of the air chamber fits on to the
cylindrical part of the conical portion much in the same manner as the lid of a
common saucepan does, but in an overlapping way.
In order to adapt the apparatus so constructed to filtering purposes, I apply to
the outer surface of the perforated cone, which should for this purpose preferably
be shaped to an angle of sixty degrees, a piece of some fine tissue such as cambric
or muslin, or of such unsized paper as is ordinarily employed for filtering purposes,
forming such fabric or paper into a cone so as to exactly fit the conical portion of

page_text: .
the apparatus, and so binding the upper margin of the flexible cone of fabric or
paper to the cylindrical portion of the apparatus, and over the junction between
the cover and the conical part by means of thread, string, an india-rubber band, or
other convenient appliance that no liquid can pass into the interior of the
apparatus when floating, except through the filtering medium aforesaid.
.
Instead of using either a woven fabric or paper separately I prefer to combine
the two materials in the following way-I first apply a cone-shaped piece of
cambric or muslin to the outer surface of the perforated cone, then over that a cone
of paper, and over that again another cone of muslin or cambric, carefully binding
the upper part of all the cones to the cylindrical part of the vessel as before
described. To the upper end of the tube which is inserted in the cover as already
described, I attach a piece of india-rubber tubing of sufficient length to form a
syphon when the apparatus is immersed in water in a tub, bucket, or other similar
vessel, and to the other end of this piece of flexible tubing may be attached a tap
or other appliance to regulate the flow of the liquid through the syphon.
.
Into the interior of the conical portion of the apparatus I introduce before
applying the filtering fabric to the outside of it, fragments of charcoal, or of any
material which possesses the same power of determining the oxidation of organic
matters which charcoal possesses, and which renders it so suitable for purifying
water. In so doing I take care to leave a space in the material for, the insertion of
the lower part of the tube referred to above.
In order to apply for filtering purposes the apparatus thus arranged I fill a tub,
bucket, or other similar and convenient vessel with the water or other liquid to be
filtered; I then take the tube out of the cover of the apparatus, and with it the
piece of flexible tubing that is attached to it,-and. Iinimerse the rest of the:
apparatus cone downwards in the liquid, pressing it gently down on the surface of
the liquid until a sufficient amount shall have filtered into the cone to keep it
floating in steady equilibrium, I then re-introduce the tube into the aperture in the
cover, taking care in so doing that it fits so as to be air-tight.
To set the filter in action I apply_my_mouth to the free end of the flexible tube,
or to the tap which may be attached to it and gently suck water through it until it
is full, I then place it whilst full of water so that it shall bang over the edge of the
vessel containing the liquid to be filtered in such a way as to form a syphon, ie,
the part which is outside the vessel being longer than that which is inside. The
liquid then flows through the flexible tube at a rate which is determined by the
filtering power of the filtering arrangement above described, and may be received
in a vessel placed underneath for the purpose.
The filter so constructed is a complete and suitable arrangement for filtering and
purifying water or any other liquid. Where the special purifying action of charcoal
or any other similar material is not required, but it is only desired to separate
impurities mechanically suspended in a liquid, the filter may be employed without
filling the cone with such material; but where such purifying action is required as
in the case of purifying water for drinking purposes, it may be supplemented and
the water may be stored so that it may be drawn off in bulk as required by the
following arrangement I construct a cylindrical vessel of metal, glass, or other
suitable material closed at the bottom and open at the top, and of such a size as to
allow of the filter above described floating freely within it when the vessel is filled,
or nearly filled with water. The vessel so constructed I adapt to fit on the top of
another cylindrical vessel of somewhat larger diameter, in such a way that the
_expanded base of the upper cylinder shall fit on and form a cover for the top of the
lower cylinder. Near the bottom of the lower cylinder I-insert-a-tap-so-as-to-draw
off the water from the interior when required, and around the rim of this vessel on
its inside I construct a shallow shelf or gallery having a floor, and also a vertical
border on the inside rising to the level of the top of the cylinder so as to hold a
certain amount of liquid. In the upper portion of the vertical inner border of this
gallery, and at any part of it I fix a small tube, running horizontally through the
border and terminated at either end by a vertical leg, the leg which is inside the

page_text: shelf reaching nearly to the floor, and that which is outside it passing down into
the main body of the cylinder, and being a little longer than the other leg so as to
form a syphon; I then fill the shelf or gallery with fragments of charcoal or other
material suitable for purifying water. In that portion of the expanded bottom of
the upper vessel which forms the cover of the lower vessel, I make a hole of
sufficient size to admit the lower extremity of the tube attached to the floating
.filter.
To set to work the apparatus thus constructed I. fill the upper cylindrical vessel
(after placing it upon the lower vessel) with water nearly to the top, I then
introduce into the water the floating filter in the way described above, and after
filling the flexible tube attached to it with water so as to start the syphon action
I introduce the lower end of the tube through the small hole aforesaid into the
gallery of the lower vessel, so that the water shall pass directly from the floating
filter into this gallery, and thus come in contact with the charcoal or other
material which the gallery contains. So soon as the water in the gallery rises to
the level of the horizontal portion of the small syphon tube which is fixed in its
free margin, a syphon action is established and the whole of the water in the
gallery runs off from the charcoal or other purifying material into the main body
of the lower vessel, leaving the gallery to be filled again from the filter. By this
means the purifying material is repeatedly and at. short intervals brought into
contact with air which enters the vessel through the hole in the cover, and its
purifying action on the water which permeates it is intensified and perpetuated.
The advantages of this filter are as follows:-
1°. The separation of impurities which are merely mechanically suspended in the
water, and the purification by oxidation of organic impurities which are dissolved
in the water processes which are essentially distinct in themselves are performed
by it separately, the latter after the former instead of at the same time, as is
sought to be effected in most of the filters ordinarily in use. Hence the purifying
material cannot become clogged with mechanically entangled impurities, and thus
speedily lose its power as is the case in filters of the ordinary construction, especially
those which filter by downward action.
2°. As all the impurities accumulate on the outside of the filter its state can be
seen at once, by simply lifting it out of the water, and the accumulated impurities
can in most cases easily be removed by a sponge, piece of linen, camel's air pencil,
or other similar appliances.
3°. As the filter is a floating one it draws its supply of water from the upper
stratum of the water which has to be filtered, so that whilst it is acting those
impurities which are merely mechanically suspended in the water are in process of
settling to the bottom of the vessel.
4°. The floating filter may be used without the double vessel above described by
immersing it in any ordinary domestic vessel as a container of the water to be
filtered, or it may be introduced into a water butt, cistern, or tank.
5°. The addition of the arrangement by means of which the water after passing
through the charcoal or other purifying material in the floating filter is again
subjected to the purifying action of that which is contained in the shelf in the
lower part of the double vessel, in the intermittent way described greatly increases
the purifying nature of the process.