Improvements in Apparatus for use in the Purification of Sewage and Polluted Water.
Year: 1897

page_text: Date of Application, 22nd Jan., 1897
Complete Specification Left, 22nd Oct., 1897-Accepted, 8th Jan., 1898
Improvements in Apparatus for use in 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 consists firstly in improvements in precipitation or settling tanks,
secondly in improvements in apparatus for opening and closing valves in connection
with filter beds tanks or other sewage plant or appliance and thirdly in improvements
relating to the cleaning of filters.
The sewage or polluted water I will hereafter speak of as sewage.
In carrying out the first part of my invention I construct a settling tank having
the sides sloping towards a point which is preferably at or about the centre of the
tank, for instance with a circular tank the bottom part of the tank would be in shape
approximately an inverted cone; I further construct or place across the tank a
division which extends down within the said sloping sides and divides the tank into
two parts but leaves a passage at the bottom so that the sewage can pass underneath
the said division into the other compartment; I provide from the bottom part of the
tank one or more conduits by means of which the sludge or deposit can be extracted
from the bottom part of the tank in a well known manner, for instance in the manner
illustrated in Figs. 5 and 6 of Letters Patent No. 18216 of A.D. 1892 granted to me.
In working the tank the sewage flows in on one side of the aforesaid division, the
top of which reaches above the water level of the tank, is caused to flow downwards
by the divisional wall passes under the said wall and flows upwards through the other
part of the tank and escapes in a purified condition from the top.
Owing to there being a flow of sewage within the sloping sides of the tank the
sludge or deposit, instead of being deposited upon the whole surface of the sloping
sides where it is extremely difficult of proper removal, is naturally carried into
the quiet part underneath the divisional wall from whence its thorough removal is
easily accomplished, furthermore owing to the sewage being caused to flow by the
said division through the bottom part of the tank a true filtering action of the sewage
takes place in the lower part of the tank through a concentrated body of settling
suspended matter already in the tank, by means of which action better results are
obtained. A still further advantage is that owing to the bottom part of the tank
being utilized, the tank itself can be constructed of a considerably less depth while
a greater slope can be given to the sides than in circular tanks with conical
bottoms heretofore constructed.
When I wish to provide mechanical means for dislodging any matter from
the said sloping sides of the said tank may use apparatus similar to that
described with reference to Figures 8 and 9 of Letters Patent No. 23155
of A.D. 1893 granted to me, or I may use a scraper consisting of one or more rods or
the like pivoted at or about a point constituting the apex of the cone of which the
said sloping sides form a part, the said rod or rods, which may have scraping
appendages thereon being carried up sufficiently high to enable an attendant to

page_text: move the same round the tank or part thereof, this said method is applicable to tanks
which have not the divisional wall herein described.
In carrying out the second part of my invention I provide a shaft, furnished with
cams or other mechanism, which I cause to rotate and by the rotation of the said
shaft cause to open and close valves which control either the inlet or outlet or both
of sewage to a filter bed, tank or other sewage plant or appliance.
I prefer to cause the said shaft to rotate by means of a water wheel driven by the
flow of sewage but may use other means, when I use the said water wheel I cause
the shaft to revolve at the desired speed by means of intermediate gearing.
As an example of a method for causing the rotating shaft to actuate valves in
connection with filter beds which I desire to aerate at certain intervals, I will presume
there are four filter beds which I desire to continually fill and empty, I provide eight
cams on the said revolving shaft these cams actuating eight valves, four inlet valves
to and four outlet valves from the filters the cams being set at such angles to each
other that when the inlet valve to a filter is closed the outlet valve from that filter
shall be opened and at the same time the inlet valve to another filter shall be opened
and the outlet valve therefrom closed, and so on; one revolution of the shaft
completing one cycle of changes to the said beds.
The mechanism applied to the revolving shaft may vary considerably according
both to the results required and the exact details employed to achieve those results.
The third part of my invention relates to an improved means for cleaning filter
beds and is especially applicable to filter beds composed of rather coarse material say
for instance pea gravel, the filter bed should be circular in plan. I provide inside
the said filter bed one or more horizontal or approximately horizontal arms attached
to a vertical shaft which shaft is placed in the centre of the filter bed or approximately
so, and so arranged by means of a screw thread or otherwise, that upon the said shaft
being revolved the aforesaid horizontal arms shall be both revolved and gradually
lowered down through the filtering material and upon reversing the motion the said
arm or arms shall be raised up through the said material; I form the said arm or
arms and preferably also the said shaft or part thereof hollow and pierce the said arm
or arms with a number of holes or with a slot, I connect the said arm or arms with a
supply of water, or with air under pressure or with other suitable fluid so that the
said fluid shall be discharged from the said arm or arms into and against the filtering
material during the aforesaid movement of the said arm or arms and thus effectively
aid the cleaning scouring or freeing action of the said apparatus upon the matter
retained by the said filtering material, which said matter can then be flushed out of
the bed.
CT
1007
F. PULLEN CANDY.
COMPLETE SPECIFICATION.
Improvements in Apparatus for use in the Purification of Sewage
and Polluted Water.
1, FRANK PULLEN CANDY of Ivy Bank Ashley Road Bowdon in the County of
Cheshire, Sanitary Engineer 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 consists firstly in improvements in precipitation or settling tanks
secondly in improvements in apparatus for opening and closing valves in connection
with filter beds tanks and the like, and thirdly in improvements relating to the
cleaning of filters.

page_text: The sewage or polluted water I will hereafter speak of as sewage.
In carrying out the first part of my invention I construct a settling tank having
the sides sloping towards a point which is preferably at or about the centre of the
bottom of the tank, for instance with a circular tank the bottom part of the tank
would be in shape approximately an inverted cone; I further construct or place across
the tank a division the top of which projects above the water level of the tank and
which extends down within the said sloping sides and divides the tank into two parts
but leaves a passage at the bottom of the tank so that the sewage can pass under-
neath the said division from one part of the tank into the other part the passage
should not of course be so small as to cause the sewage to flow therethrough at such
a rate as to disturb the sewage in the said other part. I preferably provide from the
bottom part of the tank one or more conduits by means of which the sludge or
deposit can be extracted from the bottom part of the tank in a well known manner,
for instance in the manner illustrated in Figures 5 and 6 of Letters Patent No 18216
of A.D. 1892 granted to me.
In working the tank the sewage flows in on one side of the aforesaid division,
is caused by the divisional wall to flow downwards, passes under the said wall
and flows upwards through the other part of the tank from whence it escapes in
a purified condition. As a modification I may carry the said divisional wall
down to the bottom of the tank and provide one or more passages for the flow of
sewage through the said wall, in this case if sludge removal arrangement be desired
there should be one such provided to each part of the divided bottom of the
tank.
Owing to there being a flow of sewage within the sloping sides of the tank, the
sludge or deposit, instead of being deposited upou the whole surface of the sloping
sides where without mechanical arrangements it is extremely difficult of proper
removal, is carried into the quiet part underneath the divisional wall or passages
therethrough, from whence its thorough removal is easily accomplished; furthermore
owing to the sewage being caused to flow by the said division through the constricted
bottom part of the tank a true filtering action of the sewage takes place in the lower
part of the tank through a concentrated body of settling suspended matter, by means
of which action better results are obtained: a still further advantage is that owing
to the bottom part of the tank being utilized, the tank itself can be constructed of a
considerably less depth while a greater slope can be given to the sides than in circular
tanks with conical bottoms as heretofore usually constructed.
When I wish to provide mechanical means for dislodging any matter from the sides
of the said tank I may use apparatus as described with reference to Figures 8 and 9
of Letters Patent No. 23155 of A.D. 1893 granted to me or I may use a scraper
consisting of one or more pivoted rods or the like, the said rod or rods which may
have scraping appendages thereon being carried up sufficiently high to enable an
attendant to move the same round the tank or part thereof and so dislodge the
deposit from the sides of the tank; this said method is applicable to tanks which
have not the divisional wall as herein described.
Figure 1 of the accompanying drawing illustrates the tank, in cross section,
provided with a pivoted scraper.
1 is the inlet of sewage into the tank 2 the sloping sides of the tank, 3 the
divisional wall carried upon a girder, 4 an overflow cill extending around the
circumference of that part of the tank up which the sewage rises, 5 is the channel to
conduct the treated sewage away, 6 is the water level of the tank; no method of
withdrawing the sludge is illustrated, the arrows indicate the flow of the sewage :
7, 8 and 9 are parts of the pivoted scraper, 7 is a member pivoted at 8 to the girder
which supports the divisional wall, 9 is a member attached to 7, the upper end of 9
terminates in a handle, a strip of rubber 10 of good quality about 6" wide and about
one eighth of an inch thick at one side and about one quarter of an inch thick at the
other side is attached to 9, this rubber touches the wall so that when the scraper is
moved round the tank by means of the handle end the deposit on the wall is
scraped off and falls to the bottom of the tank; as the divisional wall 3 prevents

page_text: L
the scraper from travelling right round the tank I provide a similar scraper for the
other part of the tank; when the tank is large and 9 heavy I preferably also
provide a support 11 pivoted at 12; the members 7 and 9 I may form of angle
iron.
In carrying out the second part of my invention I provide a shaft furnished with
cams or other mechanism which I cause to rotate and by the rotation of the said
shaft cause to open and close valves which control either the inlet or outlet or
both of sewage to a filter bed, tank or other sewage plant or appliance. I cause
the said shaft to rotate by means of a water wheel or turbine or other motor rotated
by the flow of sewage. I cause the shaft to revolve at the desired speed by means of
intermediate gearing when the said motor would otherwise cause the said shaft to
revolve too rapidly if connected direct.
Figure 2 represents in sectional elevation apparatus for opening and closing the inlet
and outlet valves to four filters which it is desired to work as follows, allow (in turn or
rotation) each bed to fill with sewage, then remain full a certain time, then empty of
sewage and remain empty a certain time; then fill again and so on.
In this case
sewage will be at one time flowing into one bed and flowing out of another bed, the
other beds will either be resting with sewage in them or resting empty of sewage.
In Figure 2 I have only shown the principal parts of the arrangement; bearings and
such parts as are well known to persons skilled in the construction of such apparatus
I have not shown.
13 is the conduit delivering sewage on to the water wheel 14, 15 is the shaft
of the water wheel, 16 a worm thereon and 17 a worm wheel into which 16 gears and
causes it to rotate at the required speed, 18 is the shaft or axle of 17 rotating
therewith, 19 are eight cams on the shaft 18 which cams in their rotation cause to
open and close the inlet valves 20 which command the mouths of pipes 21 leading
sewage to the four filters, and also to open and close the weighted valves 22
which command the mouths of pipes 23 conveying treated sewage from the four
filters, 24 are rods attached to the various valves which rods have roller covered
pins thereon with which the cams engage and so lift up the valves, the weight
of the valves causing them to drop when the cams release themselves therefrom.
The said roller covered pins I preferably bolt to the said rods so that their (the
pins) position can be adjusted or if required removed so as to throw any filter out of
work. The outlet valve of the end of the series is shown opening and the inlet
valve of the next set to it is shown full open, the other valves are closed.
sewage from the water wheel runs into the trough 25 to which the inlet pipes 21
are attached, the rods from the outlet valves pass through tubes in the trough 25.
I preferably place the apparatus in a chamber outside the filter, the various pipes
being connected therefrom to the filters.
The
The mechanism applied to the revolving shaft may vary considerably according
both to the exact motions required and the details employed to achieve the same.
It will be evident that I may use the revolving shaft for various combinations as may.
be desired, connected with the opening and closing of valves; for instance to open
and close valves controlling only the inlet or only the outlet of sewage to or from a
filter or tank and it will be evident that I may employ other mechanical arrangements
than cams to actuate the valves from the revolving shaft, and that I may use more
than one shaft and that I may use more than one cam to actuate one valve. When I
wish to obtain a quick and sudden opening of a valve I may give the revolving shaft
an alternately revolving motion by employing a toothed wheel without its full
complement of teeth gearing into a toothed wheel with its full complement of teeth
the latter wheel being keyed on the said shaft and the former wheel or tooth driven
by the water wheel, in this case I provide a ratchet and pawl on the said shaft to prevent
the same from being turned round the wrong way by the weight of the valves.
I sometimes do not turn the whole of the sewage to be dealt with on to the water
wheel or other revolving motor but only a part thereof, and thereby regulate the
speed of the wheel or shaft.
The third part of my invention relates to an improved means for cleaning filter

page_text: beds and is especially applicable to filter beds composed of rather coarse material say
for instance pea gravel, the filter bed should be circular in plan. I provide inside
the said filter bed one or more horizontal or approximately horizontal arms attached
to a vertical shaft which shaft is placed in the centre of the filter bed or approximately
so and so arranged by means of a screw thread or otherwise that upon the said shaft
being revolved the aforesaid horizontal arm or arms shall be both revolved and
gradually lowered down through the filtering material and upon reversing the motion
the said arm or arms shall be raised up through the said material.
I may form the said arm or arms and preferably also the said shaft or part thereof
hollow and pierce the said arm or arms with a number of holes or with a slot, I
connect the said arm or arms with a supply of water or with air under pressure so
that the same shall be discharged from the said arm or arms during the aforesaid
movement thereof, into and against the filtering material & thus effectively aid the
cleaning, scouring, or freeing action of the said arm or arms upon the matter retained
by the said filtering material during its working, which said matter can then be
flushed out of the bed. Figure 3 shows in section such a filter constructed of iron.
26 is the casing, 27 the bottom, 28 a perforated false bottom 29 the filtering material,
30 the shaft screwed at the upper part, having handles 31 for rotating the same,
and provided with a stirring blade 32, 33 and 34 are bearings for the shaft 33 having
a female thread cut therein; 35 and 36 are the inlet and outlet for the sewage; the
filtration is preferably upwards and the flushing downwards. 37 is an air or water
tiglit revolving joint connected to the flexible tube 38 and conveying air or water
under pressure down the hollow shaft into and out of the hollow perforated stirring
blade.
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. The combination of a settling tank having the sides thereof sloping towards a
point at the bottom of the said tank, and a divisional wall across the said tank, sub-
stantially as and for the purposes described.
2. The construction and arrangement of a settling tank substantially as described
and illustrated in Figure 1.
3. For cleaning or scraping the sides of a settling tank a pivoted scraper or scrapers
adapted to be moved round the tank substantially as described and illustrated.
4. A revolving shaft or shafts actuating the valve or valves controlling the inlet
and (or) outlet of liquid to one or more filters or tanks which said shaft or shafts has
or have its or their motion imparted by the revolution of a water wheel or motor
driven by the liquid treated or to be treated substantially as described.
5. For cleaning a filter bed one or more horizontal stirring arms attached to a
vertical shaft provided with a screw thread whereby upon rotation of the said shaft
the said arm or arms is or are also rotated and moved downwards or upwards through
the filtering material substantially as described.
6. For cleaning a filter bed one or more horizontal revolvable arms attached to a
vertical screwed shaft and connected with air or water under pressure so that the
same can be passed into the filtering material, substantially as described.
Dated this 20th day of October 1897
F. PULLEN CANDY.