Improvements in or relating to Precipitation Tanks for the Clarification of Sewage and Impure Waters.
Year: 1895

page_text: Date of Application, 27th Feb., 1895
Complete Specification Left, 27th Nov., 1895--Accepted, 27th Feb., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Precipitation Tanks for the
Clarification of Sewage and Impure Waters.
I JOSEPH SPIERS PICKERING of Pool Bank Street Nuneaton in the County of
Warwick Surveyor do hereby declare the nature of this invention to be as
follows:-
My invention relates to improved means for clarifying or filtering sewage or
polluted water (hereafter spoken of as sewage) which has previously undergone
precipitation or deposition and consists in forming a filter, as hereafter described,
in the upper part of an upward flow precipitation tank.
even and
In carrying my invention into effect I place across the said precipitation tank
and at the upper part thereof girders or beams or supports which are firmly attached
or fixed to the sides of the said tank I then place firmly across or between these
said supports, boards or plates or blocks or woven wire or other like suitable
material either perforated or arranged with open joints or otherwise arranged so
that the sewage in the tank may pass upwards therethrough in as
equally distributed a manuer as possible, upon this said pervious floor I place
a layer of coarse gravel or pebbles then a layer or layers of finer gravel and
then a layer of sand and sometimes a further layer of gravel; the sewage after
passing through the filter is collected into overflow arms or channels placed across
the top of the filter or may pass away over a sill or sills around the sides of the
tank; the said filter is flushed out periodically by removing the sludge from the
bottom of the tank.
Dated this Twenty-sixth day of February 1895.
Improvements in or relating to Precipitation Tanks for the
Clarification of Sewage and Impure Waters.
I JOSEPH SPIERS PICKERING of Pool Bank Street Nuneaton in the County of
Warwick Surveyor 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 :-
My invention relates to improved means for clarifying or filtering sewage or
polluted water (hereafter spoken of as sewage) which has previously undergone
precipitation or deposition and consists in forming a filter as hereafter. described in
the upper part of an upward flow precipitation tank.
In carrying my invention into effect I place across the said precipitation tank
and at the upper part thereof girders or beams or supports which are firmly
attached or fixed to the sides of the said tank, I then fix across or between these
said girders or the like wooden boards or plates of iron or blocks of stoneware or
cement either perforated or laid with open joints to form a floor for the filtering
material so that the sewage in the said tank may pass therethrough. Instead of
Price 8d.1

page_text: the beforementioned materials I may use any other suitable material or materials
and I sometimes use a perforated or reticulated material such as woven wire ;
upon the floor thus formed I place a filter bed. The said floor should be built into
the walls of the said precipitation tank at the sides thereof to prevent sewage
passing between the sides of the said tank and the filtering material.
When I provide open joints between the aforesaid parts of the said Hoor I leave
a space of about a quarter of an inch between the joints and I retain the said
parts in their relative positions by means of ears formed on the said parts or by
means of pegs or the like inserted thereinbetween, when I provide perforations in
the said parts of the floor I make the said perforations about three cights of
an inch in diameter when I use iron plates I sometimes cast slots in them as long
as convenient and about a quarter of an inch wide. The said floor may be either
bolted or similarly attached to the aforesaid girders or the like or may rest upon
them and be kept in position by the weight of the filtering material.
The filter bed I form as follows On the said floor I place a layer about three
inches thick of gravel of about three quarters of an inch in diameter upon this said
layer place another layer about three inches thick of gravel of about three cights
of an inch diameter and upon this said layer 1 place a third layer of about twelve
inches thick of gravel of about one eighth of an inch diameter, I sometimes use
other filtering material than gravel and may vary the sizes of the layers of filtering
material.
The said filter bed is flushed periodically by removing the sludge from the
bottom of the said precipitation tank, and when the filtering material has become
too dirty to be cleaned by such flushing it is washed by other means and then used
again. The sewage after passing through the said filter is collected into a chaunel
or channels.
Referring to the drawings Fig. 1. is a part plan and Figs. 2 and 3 are part cross
sections therethrough taken at right angles to one another.
The same letters indicate the same parts in each of the figures.
a is the Hoor formed of wooden planks resting upon steel girders b, the said
planks being placed about a quarter of an inch apart and so kept apart by means
of pegs d, the spaces e between the said planks serving for the passage of the liquid.
fis a groove formed in the side g of the tank which said groove enables a water-
tight joint to be made by means of cement between the said floor and the wall or
walls of the tank. Referring to Fig. 2. 1. represents a layer of coarse pebbles about
three inches in thickness aud of a size sufficiently large not to pass through th
spaces e between the planks a; m is a layer about three inches in thickness of fine
pebbles resting upon the said layer 1; and n is a layer about twelve inches in
thickness of fine gravel resting upon the said layer m; p is a trough into which
the treated liquid overflows and from whence it is conducted away. The weight
of the filtering material is sufficient to keep the planks in their position when the
tank is full of liquid, but if desired augle irons can be attached to the girders as
shown at Fig. 2. in order to keep the said planks down independently of the
weight of the filtering material. The filtering matter when dirty can be cleansel
in any convenient manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. In connection with upward flow precipitation tanks provided with means for
the removal of the sludge therefrom fixed floors constructed and arranged sub-
stantially as hereinbefore described and stretching across the said precipitation
tanks at the upper part thereof and supporting beds of filtering material.
Dated this Twenty-sixth day of November 1895.
JOSEPH SPIERS PICKERING.