IMPROVEMENTS IN FILTERS FOR WATER AND AIR
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Janes Livesey at the Office of the
Commissioners of Patents on the 15th March 1877.
JAMES LIVESEY, of No. 9), Victoria Chambers, Westminster, in the County of
Middlesex. "IMPROVEMENTS IN FILTERS FOR WATER AND AIR."
My Invention relates to the construction of filters for water, in which the filtering
materials are aerated and ready access is given for cleansing or renewal, and to
means of filtering the air supplied to apartinents by ventilating tubes by sifting
from it the impurities suspended in it.
For a water filter I employ an upright vessel, preferably cylindrical in shape,
divided by two horizontal partitions into three compartments.
In the higher
partition there is a central hole sufficiently large to give access to the compartment
below, which hole is plugged by a block of porous stone or compressed charcoal.
The water to be filtered is supplied to the highest compartment, and one or
more air pipes extend through the highest partition and thence up above the level of
the water supplied.
Instead of pipes one or more air passages may be formed in the walls of the
vessel, or the whole upper compartment may be made of the form of a basin with
its upper lip resting on the top edge of the filter, there being passage for air in the
annular space between the basin and the filter wall. As the air which passes
through the pipes or passages mentioned above has the effect of aerating the filtering
materials, as I will hereafter explain, I prefer to provide the mouths of the air
passages with plugs of loose cotton for the purpose of keeping back the organic
matters suspended in the air that might otherwise pass with it to the filtering
materials. The lower partition is perforated and has one or more raised hollow
ribs or prominences, also perforated, projecting upwards from its general surface.
On this partition are laid the loose filtering materials of such kinds as are usually
employed.
The partition itself may be flat with corrugated cakes of compressed carbon or
other filtering material placed on it, and the partition itself may be dispensed with,
such cakes themselves effecting the necessary separation of the chambers. The
lowest compartment receives the filtered water and is provided with an outlet pipe
with a cock, valve, or plug.
The action of the filter is as follows:-Water supplied to the uppermost compart-
ment percolates through the porous plug and then through the filtering materials in

page_text: the middle compartment and the partition on which they rest into the lowest
compartment, displacing the air contained in it, which air finds its way through the
perforations in the raised parts of the lowest partition or of the porous cakes, and
rises through the filtering materials, finally escaping by the air passages from the
middle compartiment. When a quantity of the filtered water is drawn off, the
supply through the porous plug above being very much retarded, air enters by
the passages into the middle compartment and follows the water down through
the filtering material into the space in the lowest compartment left void of water
by its withdrawal. The air so entering is in its turn caused by the downward
percolation of water to rise again through the filtering materials, which are thus
more or less acrated every time water is withdrawn from the filter.
Filters arranged to act in the manner just described may be placed in tanks,
in which case the uppermost compartment is dispensed with, the water of the
tank constituting the supply that percolates through the porous plug; but in this
case also, I provide air pipes or passages extending above the water level for the
purpose above stated.
In order to obtain in filters a great length of filtering chamber, I prefer to place
the filtering materials in a pipe which, in order to economise space, may be turned
into a spiral or zig-zag formi, plugs being provided at the bends for giving access to
the several convolutions; or instead of a zig-zag pipe, the filtering chamber may
consist of annular spaces between concentric cylinders, so arranged that the water
has to pass to and fro in these spaces in zig-zags. In employing filters of this kind
I prefer to make the water supply enter in a jet the orifice of the filter chamber so
as to take with it air for the purpose of aerating the filtering materials, or I cause
the supply water to flow with considerable velocity along a pipe to which there is a
lateral air supply.
For the purpose of filtering the air supplied to an apartment by a vertical
ventilating tube, I hang within the tube a conical or taper bag mado of porous
fabric, the mouth of the bag being stretched by a hoop which rests at the top of the
ventilating tube while the apex of the bag hangs freely below. By this arrange-
ment I am enabled to obtain an extended porous surface for the passage of the air,
and the bag can with facility be removed for cleansing, and replaced.
A bag such as I have described may be stretched on a light wire frame and
inserted in the tube, and this arrangement may be used when the ventilating tube
is not vertical.