Improvements in connection with the Purification of Sewage and Polluted Water.
Year: 1897

page_text: Date of Application, 27th May, 1897
Complete Specification Left 28th Feb. 1898-Accepted 27th May 1898
Date of Application, 27th May, 1897
Complete Specification Left 28th Feb. 1898-Accepted 27th May 1898
PROVISIONAL SPECIFICATION.
Improvements in connection with the Purification of Sewage and
Polluted Water.
I, FRANK PULLEN CANDY, of Ivy Bank, Ashley Road, Bowdon, in the County
of Cheshire, Sanitary Engineer, do hereby declare the nature of this invention to
be as follows:-
My invention relates to new or improved methods for aerating filter beds, for
spreading or delivering the liquid to be filtered upon the filter bed and for remov-
ing sludge or deposit from a tank.
In order to aerate filter beds I preferably work them in pairs and I provide
mechanism whereby the feed liquid is automatically shut off from one bed and
turned on to another bed and an outlet valve or valves for the discharge of liquid
is opened from one bed and closed from another bed. The mechanism to each bed
consists of a float or floats which is in communication with the inlet and outlet
valves to the filter, the float being in a chamber or vessel to which the water from
the filter (preferably after filtration) has acess and which mechanism is so arranged
that when the filter is full of water to a required height the float rises and actuates
the valves; the filters being worked in pairs the float and valves to each pair
would be attached to a pivoted lever so that the alternate motion of each float
would give the necessary motion to the valves. I provide for a practically instan-
taneous rise of the float; for instance I may attach a float or floats to a pull up
valve one of which floats is submerged when the motion is required to be given to
the valves, the float or floats being arranged to be not sufficient of themselves to
open the pull up valve, and at the proper time I cause liquid to flow under the
said valve so as to reduce the pressure of water thereon whereupon the float or floats
shall open the said valve and rise up through, the liquid thereby operating the
aforesaid lever and valves; in this case the outlet from the filter bed would be
preferably through the said pull up valve; or I may keep the float down by a
catch arranged to release the Hoat when there is a certain depth of water thereover
or I may obtain the required result in other ways. Or I may employ a pivoted
lever at one side of which is attached a vessel and at the other side a weight
which shall be sufficient when the vessel is empty to cause the lever to fall with
the weighted side down, but when the vessel contains a certain amount of liquid
it shall cause the lever to fall with the vessel side down, I provide an outlet tap
or valve as hereafter described to the vessel, an overflow from one filter fills the
vessel and so moves the lever, return motion of the lever being accomplished by the
emptying of the said vessel which emptying is effected by an overflow from another
filter causing the tap or valve on the vessel to open, the tap being arranged to
close or be closed after the vessel is empty; the motion of the lever actuates inlet
and outlet valves. Or I may employ one mechanism to open and close the inlet
valves to a pair of filters and a separate mechanism to open and close the outlet
valves to a pair of filters; the inlet mechanism may consist of a pivoted trough
or the like having floats attached thereto by the rising of which on the filling of

page_text: the filter beds the trough is alternately tipped up and down and so discharges the
liquid alternately into either filter, the liquid flowing into the trough at or about
the pivot thereof; the mechanism to open and close the outlets to the filters is
actuated by the inflow of liquid into or the filling of the filter which is empty
and may be achieved by the operation of rising floats or falling vessels or otherwise.
Instead of actuating the inlet and outlet valves by the filling or emptying of the
filters I may actuate them by a flow of liquid from a store or supply causing a
float or floats to rise or causing a vessel or vessels to fall.
When it is preferable that the rate of flow of discharge of a filter bed shall be
as even as possible during the period of discharge I provide means whereby the
decreased pressure of water on the outlet as the filter bed empties is compensated,
for instance I may attach a float to a valve or valves on the discharge pipe so
arranged that as the head of water decreases the valve shall be correspondingly
opened; I may employ a similar arrangement to obtain other desired rates of
discharge or inlet at various periods of the working.
When I wish to provide a valve which can be opened or closed with very little
power I form it as a tube or rod which to close an orifice descends upon the same
and is raised therefrom to open the orifice, the said tube or rod extending almost up
to or beyond the top water level; I sometimes arrange that when I employ a tube
may allow liquid to flow away into or exit from the top thereof.
In order to spread or deliver water on a filter bed I employ a conduit movable
up and down over the filter bed through or from which conduit the liquid is
delivered upon the filter bed and I move the said conduit by means of a water wheel
the rotation of which, through a suitable mechanism, causes the conduit to travel
up or down the filter, the reversal of motion of travel of the conduit being obtained
by delivering the liquid working the said wheel to alternate sides of the wheel the
said change of delivery being achieved by the engagement of the conduit at the
ends of its travel with an arrangement controlling the delivery of the liquid to
the water wheel or by other means. Or I sometimes connect the conduits of two
or more filters together by a suitable arrangement the part on which the conduits
run being sloping so that one or more conduits sufficiently full of water and
working shall travel by gravity down over the filter bed or beds and pull a conduit
or conduits sufficiently empty of water and not working up one or more filter beds,
this or these conduits in their turn being filled and set working and the other
conduit or conduits being emptied and stopped working and thus the travel of
the conduits reversed; the conduits may be fed through a syphon from a trough.
In order to remove sludge or deposit from a tank I provide a conduit furnished
with valves or their equivalents the conduit having a discharge outlet (preferably
also controlled by a tap or the like) for the sludge, the said valves may be either
spaced or practically continuous and are so arranged that one (or more) may be
opened at a time whereby a comparatively large orifice is obtained and correspond-
ingly large matter may be removed, I preferably build a division across the inlet
end of a precipitation or settling tank thereby forming a preliminary settling
chamber in which I place one or more of the said conduits.
Dated this Twants fifth Int of War 1907
Improvements in connection with the Purification of Sewage-and
Polluted Water.
I, FRANK PULLEN CANDY, of Ivy Bank, Ashley Road, Bowdon, in the County 5
of Chester, Sanitary Engineer, do hereby declare the nature of this invention

page_text: 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 new or improved apparatus or methods for causing filter
beds to be automatically aerated, and for spreading or delivering the liquid to
be filtered upon the filter bed whereby also aeration is obtained. The sewage or
polluted water I will speak of as sewage.
•
When I require to work a filter bed so that it is filled and then emptied for
aeration,
I preferably work them in pairs I provide mechanism whereby the feed liquid is
automatically shut off from one bed and turned on to another bed and an outlet
valve or valves for the discharge of liquid is opened from one bed and closed from
another bed.
If desired I may use more than one pair of beds the inlets and outlets of which
are so cross connected and arranged that the liquid is allowed to rest in the bed
a certain time instead of being immediately drawn off.
The mechanism to each bed consists of a float or floats which is in communica-
tion with the inlet and outlet valves to the filter, the float being in a chamber or
vessel to which the water from the filter (preferably after filtration) has acess and
which mechanism is so arranged that when the filter is full of water to a required
height the float rises and actuates the valves; the filter beds being worked in
pairs the float and valves to each pair would be attached to a pivoted lever so that
the alternate motion of each float would give the necessary motion to the valves.
I provide for a practically instantaneous rise of the float; for instance I may
attach a float or floats to a pull up valve one of which floats is submerged when
the motion is required to be given to the valves and at the proper time I cause
liquid to flow under the said valve so as to reduce the pressure of water thereon
whereupon the float or floats shall open the said valve and rise up through the
liquid thereby operating the aforesaid lever and valves; in this case the outlet
from the filter bed would be preferably through the said pull up valve; or I may
keep the float down by a catch arranged to release the float when there is a certain
depth of water thereover or I may obtain the required result in other ways.
Fig. 1 illustrates in sectional elevation a suitable mechanism as before described.
1 is a vessel receiving the sewage to be filtered, from 1 are two outlet pipes 2, 3
which convey the sewage to two filters; valves 4, 5, connected to the lever 8 (which
is pivoted at 25) by means of flexible wires 6, 7, control the discharge from the
pipes 2 and 3 into the filters. Rods 9, 10 are attached to each side of the lever
and have on their other ends valves 11, 12, which control the discharge of the
filtered sewage from the beds through pipes 13, 14, on each of the said rods are two
floats 15, 16, and, 17, 18; the filters into which the sewage from pipes 2, and 3,
passes discharge respectively into the chambers 19, and 20, through the pipes 21,
and 22, so that as the sewage rises in the filters it will correspondingly rise in the
chambers 19, 20. The adjustable weight 23 is connected by the arm 24 to the
lever 8. I preferably provide means for adjusting the length of the rods 9 and 10
and for regulating the position of the floats; the valves 11, and 12 have guides 26,
and 27 and I hinge the said rods at their connection with the said lever and the
said valves. The floats 15 and 17, which are semi-discs, are not sufficient of
themselves to open the valves 11 and 12, but the floats 15, 16 and 17; 18 are
sufficient to open the valves but would. not raise them and move over the lever
without the arrangement now to be described-viz. the discharge pipes 13, 14 have
their outlet ends carried up as shown and small draining holes 28, 29 are provided.
The bottom of the filters should be slightly above the outlet ends of the pipes 13, 14.
The working in connection with a pair of "lateral filters" as described in
Letters Patent No. 27513 of A.D. 1896 granted to me would be as follows (see
Fig. 1). The sewage delivered to the vessel, 1, flows through the pipe 2 into one of
the filters and a portion after passing through the filter enters the chamber 19
through the pipe 21; when the sewage has risen to the required height in the
filter the filtered sewage has also risen sufficiently high up the float 16 to slightly

page_text: open the valve 11, it (the filtered sewage) then flows into the discharge pipe 13 and
by rising up in it reduces the downward pressure on the valve 11 but the upward
pressure of the floats 15 and 16 not being reduced the floats rise up through the
sewage and change over the lever thus closing the valves 4 and 12 and opening
the valves 5 and 11, whereby the filter which has just filled is allowed to empty 5
and the other filter (which has been previously emptied and is aerating) is set to
work again; and so on. Instead of the vessel 1 with valves as arranged I may
attach a trough or the like to the lever S into which trough the sewage is delivered
and from which it flows into either filter bed according to which end of the trough
is the lower, and instead of the method of the turned up outlet pipes 13 and 14 I 1
may deliver the filtered sewage suddenly into the chambers 19 and 20 by means of
a syphon or other equivalent arrangement so that the suddenly large inflow of
liquid into the said chambers shall cause the floats to rise and change over the
levers.
I may provide to the inlet or outlet discharge of a filter bed a valve or valves
seperate from or independent of the valves which are opened or closed automati-
cally by suitable mechanism so that by means of the said independent valve or
valves the rate of flow of liquid into or from the filter bed may be conveniently
regulated without disturbing the mechanism for example, referring to Fig. 1 I
may place valves on the pipes 2, 3, and 21, 22: and when it is preferable that the
rate of flow of discharge of a filter bed shall be as even as possible during the
period of discharge I provide means whereby the decreased pressure of water on
the outlet as the filter bed empties is compensated; for instance I may attach a
float to a valve or valves on the discharge pipe so arranged that as the head of
water decreases the valve shall be correspondingly opened.
Fig. 2 illustrates a suitable mechanism for attaining this result 30 is a com-
.partment in connection with the filter 31 in which compartment is a float 32,
attached to which is a chain 33 which passes over pulleys, 34, and is attached at
its other end to the disc or reel 35 which is capable of rotation on a shaft 36, on
the disc 35 is a smaller disc 37 to which a chain 38 is attached at its one end the
other end being attached to the lever 39 which operates a valve 40, the filter is
shown full of liquid and the valve 40 at its least opened position; as the liquid is
let out of the filter the float 32 descends correspondingly with the liquid and
causes the discs 35 and 37 to rotate and so the lever 39 is raised and the valve 40
opened to correspond with the decreased head of liquid in the filter; the weight 41
causes the lever to fall down as the float 32 rises when the bed is being filled. In
order to spread or deliver water on a rectangular filter bed I employ a conduit
movable up and down over the filter bed through or from which conduit the liquid
is delivered upon the filter bed and I move the said conduit by means of a water
wheel the rotation of which through a suitable mechanism causes the conduit to
travel up or down the filter the reversal of motion of travel of the conduit being
obtained by delivery the liquid working the said wheel to alternate sides of the
wheel the said change of delivery being achieved by the engagement of the conduit
at the ends of its travel with an arrangement controlling the delivery of the liquid to
the water wheel or by other means.
Fig. 3 illustrates in sectional elevation a suitable mechanism for the purpose:
42 is the sewage feed trough, 43 a syphon delivering sewage on to the water
wheel 44 which is keyed to the shaft 45 running in bearings 46 attached to the
hopper 47 of the spreading conduit 48, the syphon is pivoted at 49 to the support 50
attached to the spreading conduit, the said conduit being carried by four wheels,
of which two the driving wheels 51 can be seen, the wheels are keyed to a shaft 52
having bearings in the carriages 53, the wheels run on the rails 54, motion is
imparted to the driving wheels through a chain 55 gearing into toothed wheels 56
and 57 the former being on the water wheel shaft and the latter on the driving
wheels shaft, motion is thus imparted to the whole apparatus over the surface of
the filter 58; the sewage from the water wheel flows through the hopper 47 into
the conduit 48 from whence it is delivered through orifices on to the filter. When

page_text: the apparatus reaches the end of its travel in one direction the discharge end of
the syphon 43 strikes against a projecting arm which moves it over to the other
side of the water wheel and so reverses the direction of travel of the apparatus.
The water wheel is of course arranged to work in either direction and the buckets
should have small draining orifices. The necessary valves for charging the
syphon 43 are not shown the level of the sewage in the feed trough should not
be allowed to fall to the inlet end of the syphon.
Or I sometimes connect the conduits of two or more filters together by a suitable
arrangement, the part on which the conduits run being sloping so that one or
more conduits sufficiently full of water and working shall travel by gravity down
over the filter bed or beds and pull a conduit or conduits sufficiently empty of
water and not working up one or more filter beds, this or these in their turn being
filled and set working and the other conduit or conduits being emptied and stopped
working and thus the travel of the conduit reversed; the conduits may be fed
through a syphon from a trough.
Fig. 4 in plan and Fig. 5 in elevation as shown, illustrate such an arrangement.
For instance I construct a filter bed 59 say 20 feet long and 20 feet or more wide
and along one of its sides, I form a sufficiently deep feed channel 60 (similar to
that shown in Fig. 3) for the syphon 61 to work in and supply liquid to a spreading
conduit 62 of large diameter, say twelve or eighteen inches, which is supported
above the surface of the bed by wheels and carriages 63 running on rails 64 (similar
to that shown in Fig. 3); the syphon which should have a water seal 65 at each
end and be provided with charging valves 66 delivers sewage into and is attached
to the said large conduit 62 the apertures for the discharge of the sewage from
which are situated at the bottom therof; the rails 64 are laid at a good slope say
one in five, there are two slopes to the bed that is to say the rails starting from each
end of the filter would come together in the centre of the bed at a height about
two feet above their level at the ends of the filter, as shown in Fig. 5 at the middle
of the said feed channel 60 the supply 67 of sewage is connected to it and in the
feed channel on each side of the supply is a valve 68 so that the sewage may be
turned into either half of the feed channel, the valves take the form of drop
shutters and they are connected together by a chain which passes over a pully 69
supported above them by a horizontal shaft one part of which projects over the
filters and has a cranked handle 70 on its end so that when the said handle is
moved from side to side it shall alternately open and shut the valves 68 controlling
the delivery of sewage to each half of the said feed channel; there is a spreading
conduit with its syphon and carriages to each slope of the rails and the one spread-
ing conduit is connected to the other by two light flexible ropes 71 passing over
pullys 72 at the centre of the filter so that when one spreading conduit is at the
top of the slope the other conduit is at the bottom. In working, one conduit is
set at the top and the other at the bottom the sewage is then let into the feed
channel that supplies the conduit which is at the top; as the syphon delivers
sewage into the spreading conduit quicker then the apertures therein will
discharge it, the said conduit becomes full of sewage and then by its superior
weight runs down the incline pulling the other empty conduit up, which when it
reaches the top strikes by an arm 73 attached thereto the aforesaid crank 70 and
thus changes the position of the valves supplying the feed channels so that the
sewage runs into the feed channel supplying the spreading conduit which has
been pulled to the top of the incline and is shut off from the other conduit where-
upon as soon as the spreading conduit at the top is full and the one at the bottom
It is necessary
empty the former runs down and pulls the other up and so on.
that friction be reduced as much as possible in the working wherefore I employ
ball bearings for the wheels and make the apparatus as light as possible.
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. Apparatus for automatically changing the delivery to and discharge from

page_text: filters of liquid, consisting of floats caused alternately to rise through an accumula-
tion of liquid and so actuate a lever or its equivalent to which valves or changers
controlling the said delivery and discharge of liquid are attached.
2. For automatically changing the delivery to and discharge from filters of
liquid, apparatus substantially as described.
3. For automatically changing the delivery to and discharge from filters of
liquid, apparatus substantially illustrated with reference to Fig. 1.
4. In combination with filters the working of which is controlled by automatic
mechanism secondary valves or their equivalents placed between the automatically
controlled valves feeding the filters and the actual discharge of the liquid into the
filters.
5. In combination with filters the working of which is controlled by automatic
mechanism, secondary valves, or their equivalent, regulating the speed of the
discharge from the filters through the automatically regulated valves.
6. In combination with filters the working of which is controlled by automatic
mechanism a valve or valves worked by the fall of the liquid in the filter to auto-
matically regulate the discharge from the filters to an even rate of outflow.
7. In combination with filters the working of which is controlled by automatic
mechanism the arrangement substantially as illustrated and described with
reference to Fig. 2, to automatically regulate the discharge from the filter.
8. A water wheel carried by a conduit arranged to deliver liquid over the surface
of a filter bed, the water wheel being fed from a supply of the liquid to be
filtered the revolution of the said water wheel causing the whole apparatus to
travel to and fro over the filter bed arrangements being provided to cause the
apparatus to travel back again when it has arrived at the end of its travel in each
direction.
9. Automatic apparatus for delivering water to filter beds substantially as
described and illustrated with reference to Fig. 3.
10. Automatic apparatus for delivering water to filter beds consisting of two or
more spreading conduits running on slopes and connected so that the running
down of the one full of liquid shall pull up the other empty one, the whole arranged
and combined substantially as described.
Dated this Twenty-fifth day of February 1897.