An Improved Method of Filtration for Water, Sewage, and other Liquids.
Year: 1894

page_text: Date of Application, 17th Oct., 1894
Complete Specification Left, 15th July, 1895-Accepted, 12th Oct,
1895
PROVISIONAL SPECIFICATION.
An Improved Method of Filtration for Water, Sewage, and other
Liquids.
We, WALTER JOHN LOMAX and CHARLES JAMES LOMAX, both of 11 Fold
Street, Bolton in the County of Lancaster, Surveyors, do hereby declare the.
nature of our said invention to be as follows:-'
This invention relates to an improved method of filtration for water, sewage, and
other liquids, and is designed to improve the admission of liquids to filter beds and
the aeration of the same. This we carry into effect by covering the area of the
filter with any kind of paper or fibre matting, felting, canvas, netting, or any kind
of perforated metal, paper gauze, timber, earthenware, or wickerwork, basketwork,
wire netting, or similar materials; the object of which is to obtain a complete covering
of the surface of the filter with liquid. By the use, automatically or otherwise, of
syphons suitable valves, tipping vessels, and the like to obtain an intermittent and
instantaneous distribution of the water or liquid over the whole surface of the filter
and a more perfect aeration of the filter bed. By covering the surface of the filter
with spar, pea gravel, limestone chippings, granite chippings, or small materials as
a protection to the sand surface if required during the admission of water or other
liquids.
Dated the 15th October 1894.
EDMUND CHADWICK, F.J.C.P.A.,
Agent.
An Improved Method of Filtration of Water, Sewage, and other
Liquids.
We WALTER JOHN LOMAX and CHARLES JAMES LOMAX, both of 11 Fold
Street, Bolton, in the County of Lancaster, Surveyors, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement and
accompanying drawings :-
Our said invention refers to an improved method of filtering waters, sewage and
other impure liquids, in such a manner as to provide for the repeated oxygenation
or aeration of the filter bed, and in means for the complete distribution of the
liquid to be filtered over the whole surface of the filter bed without disturbance of
the filtering medium.
The following description of the invention will be easily understood by referring
to the accompanying sheet of drawings in which Fig. 1 shows a portion of a plan
view of our improved filter bed while Fig. 2 is a portion of a cross section.
The filter bed A is composed of suitable materials or of successive layers of
suitable materials or substances such as are or may be used for filtration purposes.
As a rule however the top
The composition of the bed is no part of our invention.
layer of filtering material is usually covered with a thickness of sand or other fine.
רנ...'

page_text: material and to prevent the disturbance of this top layer we might cover the surface
with spar, gravel, limestone or granite chippings or other similar material and with
fibrous or paper matting, felting, canvas, netting, or perforated metal, paper gauze,
timber earthenware or wickerwork to prevent the sand or other upper surface of
the filter bed from being disturbed by the recurring inflows of liquid which take
place under our invention and also to secure the complete and equal covering of
the filter bed surface. The filter bed A is surrounded by a wall and at one end of
the filter bed is a trough or receptacle B which is supplied with liquid to be
filtered by a pipe C. Within the trough B is a number of appliances D arranged
automatically to discharge the contents of the trough B upon the filter bed A at
the times when the liquid in the trough B has reached a fixed height. These
periodically discharging appliances D might be of any suitable nature. For
example they might be tipping vessels or valves but in the drawings they are
intended to represent syphons arranged to be brought simultaneously into action
by the connecting air pipe D'. In any case whether the appliance consists of a
valve or tipping vessel or syphon or other contrivance (the special appliance being
no part of our invention) the result is intended in all cases to be the same viz. that
when the liquid in the trough B has reached a certain height, the appliances D
come into action and simultaneously discharge the liquid in the trough through the
pipes E upon the filter bed. When the trough has been thus emptied the
appliances D resume their normal condition or positions until the required height
of liquid in the trough is again reached. The liquid thus discharged upon the
filter bed A filters downward and escapes by the outlet channel F.
To prevent
the periodical rushes of liquid from disturbing the surface of the filter bed, we
provide troughs G sunk level with the filter bed and in line with the discharge
pipes E. A strip of canvas H, is also secured on each side of each trough G
and extends for a short distance say for about two feet on each side or the
trough G. The inrushes of liquid thus flow into the trough G from which
they overflow upon the filter bed the canvas borders. H preventing disturbance
of the bed close to the troughs G. When the filter bed is thus flooded,
the liquid sinks slowly down through the filter bed and escapes, finally leaving the
surface of the filter bed exposed to the atmosphere which enters and permeates the
filter bed thoroughly oxygenating the same and thereby greatly increasing its
efficiency. Each flushing of the filter bed is thus followed by exposure to the action
of the atmosphere and these successive flushes and exposures to oxygenation
maintain the filter bed in a high state of efficiency.
Although we prefer automatic action of the appliances D as described this is not
an essential of our invention as we might operate the flooding conduits manually but
we prefer automatic action.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. Subjecting a filter bed for filtering water, sewage and impure liquids, to
periodic and successive exposures to the atmosphere so as to aerate or oxygenate
the filter bed for the purposes by the means and substantially as described and
shown.
2. Admitting the liquid to be filtered to the filter bed by periodic flushes and
allowing the admitted liquid to sink away and leave the surface of the filter bed
exposed to the atmosphere before the next influx of liquid takes place by the means
and substantially as described and shown.
3. The combination of a filter bed with a trough such as B provided with a
number of automatically operating appliances D by the action of which the
contents of the trough upon reaching a certain height are discharged upon
the filter bed in separate and successive flushes the surface of the filter bed being
allowed to become exposed to the action of the atmosphere between each influx of
liquid for the purposes and substantially as described and illustrated.

page_text: 4. Covering the surface of a filter bed of the indicated nature with fibrous
matting, felting, canvas, netting or perforated sheet metal, paper gauze, timber,
earthenware, wickerwork or other suitable material so as to effect equal and
complete distribution of the liquid to be filtered over the surface of the filter bed
and also to protect the said surface from being disturbed by the periodic flushes of
liquid substantially as described and as indicated.
Dated the 13th day of July 1895.
EDMUND CHADWICK, F.I.C.P.A.,
Agent.