Improvements in Precipitation Tanks, and in connection with the Precipitation of Sewage and Polluted Water.
Year: 1893

page_text: Date of Application, 2nd Dec., 1893
Complete Specification Left, 2nd Oct., 1894-Accepted, 10th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Precipitation Tanks, and in connection with the
Precipitation of Sewage and Polluted Water.
I, FRANK PULLEN CANDY of 56 Nightingale Lane Balham in the County
of Surrey Sanitary Engineer do hereby declare the nature of this invention to be
as follows:
"
My invention consists first of improvements in the method of cleansing "quiescent"
precipitation tanks, that is to say tanks which are filled with the liquid to be
treated which said liquid I will speak of hereafter as "sewage" which is then
allowed a certain time for settlement and the settled sewage afterwards run off.
According to my improvement I form the tank with the bottom preferably sloping
away from the inlet or inlets of the sewage and at an opposite end of the tank or
at other convenient position or positions I form one or more gutters or recesses.
The inlet or inlets of the sewage and the bottom of the tank being so arranged
that when the clear or settled sewage has been drawn off from the tank the incoming
rush of water in filling the tank shall sweep the sludge from the said bottom into
the said gutter or recess or gutters or recesses from which the said sludge is drawn
by any suitable means for instance by a pipe or pipes preferably perforated or
slotted provided with a valve or valves and situated at or near the bottom of the
said gutter, the said pipe or pipes being connected with a sludge well or a pump
or otherwise arranged or connected so as to dispose of the withdrawn sludge in
any convenient manner or manners. The floating arm or arms or other means
for withdrawing the clear or settled sewage is arranged so that it will draw the
said settled sewage from the recess or gutter or recesses or gutters as well as from
the body of the tank. The sludge is preferably withdrawn as before mentioned
when the tank has filled with sewage and the sludge pipe or pipes can be carried
up to within a foot or so of the level of water in the tank when the same is full.
I prefer to form the inlet or inlets of the sewage into the tank in such a way
that most of the sludge shall be deposited near the aforesaid sludge gutter or
gutters and I sometimes form small gutters or corrugations in the bottom of the
tank.
.
My invention consists further of improved means of withdrawing the sludge from
precipitation tanks whether quiescent tanks or continuous flow tanks, and consists
of forming throughout the whole or practically the whole bottom of the tank a
series of gutters preferably V shaped or egg shaped in cross section each gutter
being provided at or about the bottom thereof with a pipe or pipes or its equivalent
preferably perforated or slotted and furnished with a valve or valves through
which the sludge is withdrawn, preferably when the tank is full of water, into a
sludge well or is otherwise conveniently disposed of. The sides of the said gutters
are sloped at such an angle that when the valves on the sludge pipes are opened
the sludge in the gutters shall be withdrawn without a too great admixture of
the sewage in the precipitation tank. I sometimes do not form the said sludge
gutters over the whole of the bottom of the tank for instance I may have only one
sludge gutter and I sweep or drag the sludge from the part or parts of the tank not
dealt with by the said sludge gutter or gutters into the said gutter or gutters by
means of a suitable rotating or travelling mechanical arrangement of a scraper
or scrapers or the like. I sometimes also employ a rotating or travelling scraper
or scrapers to loosen or remove the sludge from a precipitation tank having a
conical or the like bottom and in such a tank I sometimes place against or near the
sloping sides of the said bottom a perforated or slotted circular pipe or pipes or

page_text: its equivalent arrangement connected with an exit pipe or pipes from the said tank
through which sludge can be withdrawn from the tank; 1 place the said circular
pipe or pipes or like arrangement atra suitable distance or distances from the bottom
of the said conical, or the like bottom and prefer to ise it or them in connection
with an exit for the sludge from the extreme bottom of the said conical or the like
bottom of the tank.
In all cases where a perforated or slotted pipe is employed for the removal of
sludge the area of the pipe in. cross section should be equal to or greater than the
total collective area of the slot or slots or perforations in the said.pipe.
My, invention consists further of improved means methods or manners of causing
the sewage to enter continuous flow precipitation tanks and of improved arrange-
ments for withdrawing the settled sewage from such tanks and of improvements
in the general arrangements of the said tanks. According to my said improvements
when a pipe or tube or its equivalent-which I will term the down pipe-is
employed to carry the sewage down to the bottom part of the continuous flow
precipitation tank I cause the sewage to enter or to flow along the said down pipe
in such a manner that a rotating or the like motion is imparted to the Sewage within
the tube.
A convenient way of effecting this is to place a short length of tube closed at
the end and of a somewhat smaller diameter than the down pipe, for instance about
two thirds of its diameter, within the said down pipe and preferably at the top
part thereof, the said short length of down pipe having a slot or opening or slots
or openings in its side. The sewage flows first into the short length of pipe and
issues from the said slot or opening or slots or openings into the down pipe in such
a manner as to cause a rotating motion of the sewage in the down pipe, or I
sometimes cause the sewage to enter the down pipe through a slot or opening or
slots or openings in the said down pipe in such a manner that the rotating motion
aforesaid of the sewage within the down pipe is produced; or I cause the sewage to
enter the said down pipe through a smaller pipe going inside it and bent or curved
in such a manner as to cause the said rotating motion of the sewage, or I sometimes
place inside the down pipe a suitable coil or curl of metal or other suitable
material which will cause the sewage flowing down the pipe to assume, a rotary
motion; or obtain the required rotating or the like motion in other ways.
A further part of my said improvements consists in causing the sewage to enter
at or near the bottom of the precipitation tank from a division or divisions- or
pussage or passages as hereafter described the said division or passage or divisions
or passages may extend the whole length of one or more sides or for a part of the
length of one or more sides of the tank if the said tank be a rectangular one; or if
the said tank be a circular one the said division or passage or divisions or passages
may extend along the whole or a part of the circumference or there may be more
than one division or passage suitably arranged at intervals along the circumference
of the tank. If the tank be built in brick or concrete the wall of the division' or
passage may be built of the same materials or it may be formed of wood or of any
other suitable material or materials. I sometimes instead of forming the divisional
wall straight at the side nearest the wall of the tank form it in a succession of
curves and I sometimes form the passage or passages of a number of pipes for
instance earthenware socket pipes, placed side by side or in other suitable position.
The sewage enters the division or passage or divisions or passages from the sewage
pipe or carrier in such manner that an eddying, rotating or agitating motion of
the sewage is set up in the said division or passage or divisions or passages, for
example I cause the sewage to enter it or them from a pipe or carrier running
alongside, through a series of openings and down a slope or at such an angle as will
produce the required result or sometimes employ the means hereinbefore
mentioned; when I employ a division or passage or divisions or passages as
aforesaid to convey the sewage to the bottom of the tank, I preferably cause the
exit of sewage from the said division or divisions or passage or passages to be
parallel or nearly so with the bottom of the tank or parallel or nearly so with the
A

page_text: water level and also preferably cause the sewage to exit from the said division or
passage or divisions or passages into the tank in a thin spread out stream and I
arrange the said exit or exits from the said division or passage or divisions or
passages in such a manner as to effect this.
If the division or passage be formed by erecting a wall, a slot or opening or slots
or openings or pigeon holes or the like is or are left or formed for the exit of the
sewage into the tank at the bottom of the said division or passage, the said opening
or openings being preferably a short distance from the bottom of the tank, if the
said passage for the sewage be formed by employing a pipe or pipes a suitable
arrangement is or may be placed at or in connection with the bottom of the pipe
so as to spread the sewage as before described, for instance the pipe or pipes may
be connected with a distributing channel, or a bend or its equivalent placed on the
end of the pipe or pipes which bend I sometimes form with a flattened and elongated
mouth.
Heretofore when a pipe has been used to convey the sewage to the bottom of a
precipitation tank the exit from the pipe has been either towards the top of the
tank or towards the bottom thereof and the said pipe has been carried out to about
the centre of the tank, according to a part of my invention I employ one or more
than one pipe and do not ring it to about the centre of the tank but simply
carry it or them down the side of the tank the exit of sewage being towards.
the opposite side of the tank and preferably in a thin spread out stream as before
described.
The sewage after passing down the beforementioned division or passage or
divisions or passages rises in an upward direction through the said tank and over-
flows into a trough or troughs suitably arranged placed in or across the tank, the
said troughs are so placed as to cause the rise or flow of the sewage and working of
the tank to be as uniform as possible.
From the said overflow trough or troughs the sewage is conducted to any desired
part or point. I sometimes place underneath the said trough or troughs a sheet or
sheets of metal of a width greater than the width of the trough the said sheet or
sheets being preferably sloped towards the bottom of the tank, the sheet or sheets
are sometimes perforated. The object of the said sheet or sheets is to prevent
particles of suspended matter from being carried over and into the said trough, the
said sheet or sheets I preferably attach to or form from the said trough or troughs
and sometimes form it or them of other material than metal. I employ the said
sheet or sheets or the equivalent in the manner or manners best calculated to effect
the desired result.
I sometimes fill the said trough of troughs partly or wholly with a filtering or
oxidizing material, such as coke, sand, iron oxile or manganese. One of the.
features of my invention is the employment of an inlet or inlets for the sewage
having exit into the tank at or near one or more of the sides thereof, combined
with more than one overflow trough or carrier for the removal of the clarified
sewage from the tank.
The precipitant should be added to the sewage before it reaches the precipitation
tank and a further part of my invention consists in an arrangement for effectually
mixing the precipitant with the sewage. I cause the sewage after the addition of
the precipitant to flow with a vertical up and down motion through a carrier or
conduit the said up and down motion of the sewage being produced by diaphragms
or divisions suitably placed across the said carrier or conduit, the said diaphragms
or divisions being pivoted or hinged so that they may be agitated by a suitable
arrangement and thereby any deposit or settlement caused to be carried away.
by the flow of sewage and also so that any increase in the flow of the sewage
can deflect the said diaphragms or divisions and thereby allow the increased flow.
to pass.
Dated this Thirtieth day of November 1892

page_text: Improvements in Precipitation Tanks, and in connection with the
Precipitation of Sewage and Polluted Water.
I FRANK PULLEN CANDY of No. 56 Nightingale Lane, Balham, in the County
of Surrey, 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 first of the improvements in the method of cleansing
quiescent" precipitation tanks that is to say tanks which are filled with the
liquid to be treated (which said liquid I will speak of hereafter as
sewage")
which is then allowed a certain time for settlement and the settled sewage after-
wards run off. According to my improvements I form the tank with the bottom
preferably sloping away from the inlet or inlets of the sewage and at an opposite
end of the tank or at other convenient position or positions I form one or more
gutters or recesses, the inlet or inlets of the sewage and the bottom of the tank
being so arranged that when the clear or settled sewage has been drawn off from
the tank the incoming rush of water in filling the tank shall sweep the sludge
from the said bottom into the said gutter or recess or gutters or recesses from which
the said sludge is drawn by any suitable means for instance by a pipe or pipes
preferably perforated or slotted provided with a valve or valves and situated at or
near the bottom of the said gutter, the said pipe or pipes being connected with a
sludge well or a pump or otherwise arranged or connected so as to dispose of the
withdrawn sludge in any convenient manner or manners. The floating arm or arms
or other means for withdrawing the clear or settled sewage is arranged so that it
will draw the said settled sewage from the recess or gutter or recesses or gutters as
well as from the body of the tank. The sludge is preferably withdrawn as before
mentioned when the tank has filled with sewage and the discharge end of the
sludge pipe or pipes can be carried up to within a foot or so of the level of water
in the tank when the same is full. I prefer to form the inlet or inlets of the sewage
into the tank in such a way that most of the sludge shall be deposited near
the aforesaid sludge gutter or gutters and I sometimes form small gutters or
corrugations in the bottom of the tank in the direction in which the incoming
sewage flows.
Figure of the accompanying drawings is a plan of a tank having an inlet
formed and arranged as hereinbefore described at one end thereof and having
one sludge gutter at the end farthest from the inlet in which gutter a perforated
pipe is arranged for withdrawal of sludge therefrom.
Figure 2 of the said drawings is a longitudinal vertical section and Figure 3 is a
transverse vertical section of the same showing the corrugations in the bottom of
the tank. The section Figure 2 is taken on the line A Figure 1 and the section
Figure 3 is taken on the line B Figure 2.
Referring to the said figures a is the tank is the sludge gutter formed in the
bottom thereof which is slightly inclined downward toward the said gutter.
c is the
inlet passage to which the sewage to be precipitated is conveyed by a conduit d and
channel e the said inlet terminating at the higher end of the bottom of the tank.
fis the perforated or slotted pipe in the sludge gutter which pipe is arranged
slightly above the bottom of the said gutter and is carried up and passed through
the wall of the tank at " and is provided at some convenient part with a valve
The said valve and the arrangement for withdrawal of supernatant water after
precipitation are not shown in the drawings. As herein before stated a floating arm
arranged to act in the gutter b may be used for the purpose or any other ordinary

page_text: Contrivance is suitable. 9, 9 (see Figure 3) are the corrugations in the vottom
of the tank.
The arrangement hereinbefore described acts as follows. When a charge of
sewage or liquid has-been precipitated in the tank and the supernatant water has
been drawn off and a fresh supply of liquid to be precipitated is admitted to the
tank the stream of liquid entering by the passage c drives off the precipitate which
has been left on the bottom of the tank and deposits it in the gutter b.
When
the tank has been filled with the fresh supply of liquid to be precipitated the valve
in the pipe fis opened and the pressure of the said liquid causes the sludge or
precipitate in the gutter to enter the perforations in the said pipe and to pass
through it out of the tank. When the thick sludge has been thus removed the
valve in the pipe is closed. The bottom of the tank may be flat instead of
corrugated as illustrated in Figure 3.
My invention consists further of improved means of withdrawing the sludge from
precipitation tanks whether quiescent tanks or continuous flow tanks, and consists
of forming throughout the whole or practically the whole bottom of the tank
a series of gutters preferably V shaped or egg shaped in cross section each gutter
being provided at or about the bottom thereof with a pipe or pipes or its equivalent
preferably perforated or slotted and furnished with a valve or valves through which
the sludge is withdrawn, preferably when the tank is full of water, into a sludge well
or is otherwise conveniently disposed of. The sides of the said gutters are sloped
at such an angle that when the valves on the sludge pipes are opened the sludge in
the gutters shall be withdrawn without a too great admixture of the sewage in the
precipitation tank. Figure 4 of the accompanying drawings is a section of a
portion of a tank the bottom of which is thus formed. In the said Figure 4
and the other figures of the accompanying drawings the tanks are marked a
and the pipes through which the sludge passes out are marked, as in
Figures 1 and 2.
I sometimes do not form the said sludge gutters over the whole of the bottom of
the tank for instance I may have only one sludge gutter and I sweep or drag the
sludge from the part or parts of the tank not dealt with by the said sludge gutter
or gutters into the said gutter or gutters by means of a suitable rotating or
travelling mechanical arrangement of a scraper or scrapers or the like. A tank.
having three gutters or trenches formed transversely in its bottom and having a
travelling scraper mounted therein is illustrated in Figures 5, 6 and 7 of the
accompanying drawings, Figure 5 being a plan Figure 6 a longitudinal section
taken on the line C Figure 5 and Figure 7 a transverse section on the line D
Figure 6.
Referring to the said figures bbb are the gutters or trenches in the lower parts
of which perforated pipes may be arranged as and for the purpose hereinbefor
described. is the blade or acting part of the scraper which may be formed of
wood or other suitable material and is secured to a support which may consist of an
iron girder having trunnions jj formed at its ends which work in bearings formed
in carriages mounted on rails set in the bottom of the tank. The part of
the scraper is connected at ' ' and h²h to chains m m passing round pulleys m' m¹
secured to the walls of the tank and around chain wheels m² m² on a shaft m
carrying a worm wheel m with which gears a worm provided with a crank or
handle m by actuating which the scraper may be drawn from end to end of the
tank as required. When the scraper is being drawn in the direction indicated by
the arrow in Figure 6 the part of the scraper is retained in the position illustrated
by bearing against projections formed on the faces of the carriages k k but
when the scraper is being drawn in the reverse direction the part i is free to turn
on its trunnions consequently the said parth takes an inclined position its lower edge
being then above the bottom of the tank. In order that the acting part of the
scraper may be drawn close up to the end walls of the tank when desirable recesses
may be formed in the said walls for the ends of the carriages kk to pass into.
prefer to secure flaps of india rubber to the sides and lowermost edge of the.

page_text: acting part or blade ofrthe scraper in order that it may thoroughly remove the
precipitate from the bottom of the tank and I prefer to make the bottom of
the tank inclined slightly downward in the direction in which the scraper is drawn
to remove the precipitate as illustrated in Figure 6.
I sometimes also employ a rotating or travelling scraper or scrapers to loosen
or remove the sludge from a precipitation tank having a conical or the like bottom
i.e. a bottom inclined from the sides towards the middle of the tank. Figures 8
and 9 of the accompanying drawings illustrate an arrangement of a rotary scraper
in a tank having a conical bottom Figure 8 being a plan of a tank to which the
said arrangement is applied and Figure 9 a vertical section of a portion of the
said tank. Referring to the said figures n is a rotatory shaft mounted in the tank
and is a blade secured to the said shaft by means of arms ³n by the rotation
of which blade in the direction indicated by the arrow in Figure 8 the precipitate
is removed from the upper part of the conical bottom of the tank and pushed
downward. The shaft may be rotated by hand or otherwise either continuously
or intermittently by means of any ordinary arrangement of mechanism suitable
for the purpose.
Figure 10 of the accompanying drawings illustrates an arrangement of travelling
scrapers in a rectangular tank the bottom of which is inclined towards the middle
the tank being shown in transverse section. Referring to the said figure o o are
the scrapers which are secured to a carriage consisting of a frame p mounted on
wheels pp resting on rails supported by bearers 7. The said carriage is
drawn from end to end of the tank for the purpose of removing sludge from the
inclined bottom thereof by means of chains and chain wheels as in the case of the
travelling scraper illustrated in Figures 5, 6 and 7 of the accompanying drawings
or by any other convenient arrangement.
In a tank having a conical or the like bottom I sometimes place against or near
the sloping sides of the said bottom a perforated or slotted circular pipe or pipes
or its equivalent arrangement connected with an exit pipe or pipes from the said
tank through which sludge can be withdrawn from the tank. I place the said
circular pipe or pipes or like arrangement at a suitable distance or distances from
the bottom of the said conical or the like bottom and prefer to use it or them in
connection with an exit for the sludge from the extreme bottom of the said conical
or the like bottom of the tank.
Figure 11 of the accompanying drawings is a central vertical section and
Figure 12 is a plan of the lower part of a conical bottomed precipitation tank
having circular sludge removal pipes arranged therein and connected with a pipe
by which sludge is withdrawn from the extreme bottom of the tank r r being the
said circular pipes and the pipe to which they are connected.
lu all cases where a perforated or slotted pipe is employed for the purpose
hereinbefore described the sectional area of the pipe should be equal to or greater
than the total collective area of the slot or slots or perforations in the said pipe.
My. invention consists further of improved means methods or manners of causing
the sewage to enter continuous flow precipitation tanks and of improved arrange-
ments for withdrawing the settled sewage from such tanks and of improvements
in the general arrangements of the said tanks. According to my said improvements
when a pipe or tube or its equivalent (which I will term the down pipe) is
employed to carry the sewage down to the bottom part of the continuous flow
precipitation tank I cause the sewage to enter or to flow along the said down pipe
in such a manner that a rotating or the like motion is imparted to the sewage
within the tube.
A convenient way of effecting this is to place a short length of tube closed at
the end and of a somewhat smaller diameter than the down pipe for instance about
two thirds of its diameter within the said down pipe and preferably at the top part
thereof the said .short length of down pipe having a slot or opening or slots or
openings in its side. The sewage flows first into the short length of pipe and
issues. from, the said slot or opening or slots or openings into the down pipe in

page_text: such a manner as to cause a rotating motion of the sewage in the down p.pe.
I sometimes cause the sewage to enter the down pipe through a slot, or opening or
slots or openings. in-the-said down pipe in such a manner that the rotating motion
aforesaid of the sewage within the down pipe is produced. Or I cause the sewage
to enter the sad down pipe through a smaller pipe going inside it and bent or
curved in such a manner as to cause the said rotating motion of the sewage. Or
I sometimes place inside the down pipe a suitable coil or curl of metal or other
suitable material which will cause the sewage flowing down the pipe to assume a
rotary motion or I obtain the required rotating or the like motion in other ways.
The several arrangements hereinbefore described for causing rotatory motion of
the sewage while passing through the down pipe are illustrated in Figures 13, 14,
15, 16, 17, 18, 19 and 20 of the accompanying drawings in all of which figures the
down pipe is markeds and the means for producing rotatory motion of the sewage
within it is marked t and the direction in which the sewage enters and passes down
the pipes is indicated by arrows.
The arrangement in which the sewage enters the down pipe through an inlet
consisting of a short length of tube closed at its end and having a slot or opening
in its side is illustrated partly in vertical section in Figure 13 and in transverse
section (taken on the line E Figure 13) in Figure 14 the closure at the end of the
inlet being marked s' and the opening from which the sewage passes into the down
pipe being marked s². The arrangement in which the sewage enters the down pipe
through an opening in it in such a manner as to produce rotatory motion is
illustrated in elevation in Figure 15 and in transverse section (taken on the line F
Figure 15) in Figure 16. The arrangement in which the sewage enters the down
pipe through a smaller pipe going inside it is illustrated partly in vertical section
in Figure 17 and in plan in Figure 18. The arrangement in which the rotary
motion of the sewage is produced by a coil or curl of metal within the down pipe
is illustrated in Figures 19. and 20 Figure 19 being an elevation partly in section.
and Figure 20 a plan of the said arrangement.
:
A further part of my said improvements consists in causing the sewage to enter
at or near the bottom of the precipitation tauk from a pipe or pipes a suitable
arrangement being placed at or in connection with the bottom of the pipe so as to
spread the sewage out in a thin stream. For instance the pipe or pipes may be
connected with a distributing channel or its equivalent placed on the end of the
pipe or pipes.
Figure 21 of the accompanying drawings is a plan and Figure 22' a central.
vertical section of a precipitation tank to which the sewage is conducted by a
pipe u communicating at its lowermost end with an annular distributing channel
formed by a plate or plates of metal or other suitable material secured in an
inclined position to the lower part of the inner side of the wall of the tank.
v
.
Figure 23 is a plan and Figure 24 a central vertical section of a precipitation
tank provided with two distributing channels one being formed and arranged and
connected with the sewage supply pipe as in Figures 21 and 22 and the other
consisting of an annular trough formed of sheet metal or other suitable material w
and supported in an inverted position within the lower part of the tank with the
hollow of which trough the exit end of a sewage supply pipe u¹ communicates.
In both the arrangements herein before described the sewage after passing into
the tank rises therein and overflows into a trough or troughs suitably arranged
placed in or across the tank, the said troughs being so placed as to cause the rise
or flow of the sewage and the working of the tank to be as uniform as possible.
From the said overflow trough or troughs the sewage is conducted to any desired
part or point. 1 sometimes place underneath the said trough or troughs a sheet
or sheets of metal of a width greater than the width of the trough the said sheet
or sheets being preferably sloped towards the bottom of the tank. The sheet or
sheets are sometimes perforated. The object of the said sheet or sheets is to
prevent particles of suspended matter from being carried over and into the said
trough. The said. sheet or sheets.I. preferably attach to or form.from, the, said

page_text: trangh or troughs and sometimes form it or them of other material than metal..
I employ the said sheet or sheets or the equivalent in the manner or manners
best calculated to effect the desired result.
Figure 25 is a plan and Figure 26 a central vertical section of a precipitation
tank provided with distributing channels consisting of inverted troughs & arranged
transversely in the lower part of the tank with which troughs sewage supply
pipes communicate. yy are outflow troughs at the upper part of the tank
which troughs communicate with a channel formed around the tank which channel
receives the effluent water.
The precipitant should be added to the sewage before it reaches the precipitation
tank and a further part of my invention consists in an arrangement for effectually
mixing the precipitant with the sewage. I cause the sewage after the addition of
the precipitant to flow with a vertical up and down motion through a carrier or
conduit the said up and down motion of the sewage being produced by diaphragms
or divisions suitably placed across the said carrier or conduit, the said diaphragms
or divisions being pivoted or hinged so that they may be agitated by a suitable
arrangement and thereby any deposit or settlement caused to be carried away by
the flow of the sewage and also so that any increase in the flow of the sewage can
deflect the said diaphragms or divisions and thereby allow the increased flow
to pass.
This arrangement is illustrated in Figures 27 and 28 of the accompanying
drawings, Figure 27 being a longitudinal section and Figure 28 a transverse section
of a sewage conduit having pivotted or hinged diaphragms mounted therein. The
said conduit being marked 2 and the diaphragms 3. As shown in Figure 28 the
said diaphragms are supported by the engagement of pins 4, 4 at their upper ends
with bearings 5, 5 set in the walls of the conduit and the said diaphragms are each
provided with a handle 6 by means of which they may be swung to and fro in their
bearings for the purpose of stirring up and dislodging any sediment which may
accumulate in the hollows of the curved parts of the conduit 2. The diaphragms
or baffles 3 should be of such weight and be mounted at such a height that although
their position will not be materially altered by the stream of sewage normally
flowing through the conduit 2 yet when the level of the said stream is considerably
raised (as when storm water is passing) the said diaphragms or baffles will be
deflected by and yield to the said stream thus allowing it freer passage.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that I
claim;-
First. Arrangements whereby the inflow of liquid to a precipitation tank is
caused to effect the collection in one part of the tank of precipitate deposited on
the bottom thereof substantially as herein before described and illustrated in
Figures 1, 2 and 3 of the accompanying drawings.
Secondly. The combination of a perforated or slotted pipe with a gutter or
trench formed in the bottom of a precipitation tank for the purpose of effecting
removal of precipitate therefrom substantially as herein before described and
illustrated in Figures 1, 2 and 3 of the accompanying drawings.
Thirdly. Forming channels in the bottom of a precipitation tank provided with
arrangements of the kind referred to in my first claim substantially as illustrated in
Figure 3 of the accompanying drawings and for the purpose described.
Fourthly. The construction of the bottoms of precipitation tanks substantially as
hereinbefore described and illustrated in Figure 4 of the accompanying drawings
and the combination therewith of perforated or slotted pipes substantially as
illustrated in the said figure for the purpose of removing precipitate from the said
tanks.
Fifthly. The combination with a precipitation tank having a gutter or trench or
gutters or trenches formed at a part or parts of the bottom thereof of a scraper so
mounted and arranged as to be capable of being drawn over the bottom of the tank
:

page_text: by means of which scraper the precipitate in the bottom of the tank may be
collected and pushed into the said trench or trenches substantially as hereinbefore
described and illustrated in Figures 5, 6 and 7 of the accompanying drawings.
Sixthly. The combination with a precipitation tank having a conical bottom or
a bottom inclined from the sides towards the middle of a scraper or scrapers for
dislodging precipitate from the inclined part or parts of the bottom or the higher
portions of the said inclined part or parts substantially as hereinbefore described.
Seventhly. The arrangement illustrated in Figures 8 and 9 of the accompanying
drawings for dislodging precipitate from the higher part or parts of the bottom of a
precipitation tank having a conical or partly conical bottom.
Eighthly. The arrangement illustrated in Figure 10 of the accompanying
drawings for dislodging precipitate from the higher part or parts of the bottom of
a precipitation tank having a bottom inclined from the sides towards the middle.
Ninthly. Arrangements by which rotatory motion of sewage passing through a
pipe or conduit on its way to a precipitation tank is produced substantially as
hereinbefore described.
Tenthly. The several arrangements illustrated in Figures 13 to 20 both inclusive
of the accompanying drawings for producing rotatory motion of sewage passing to
a precipitation tank.
Eleventhly. The construction at the lower part of an upward flow precipitation
tank of an inverted channel or trough or inverted channels or troughs for
distributing the sewage entering the said tank the sewage being conveyed to the
said channels or troughs from the side or sides of the said tank substantially as
hereinbefore described and illustrated in the accompanying drawings.
Twelfthly. The arrangement illustrated in Figures 21 and 22 of the accom-
panying drawings for distributing sewage entering an upward flow precipitation.
tank.
Thirteenthly. The arrangement illustrated in Figures 23 and 24 of the accom-
panying drawings for distributing sewage entering an upward flow precipitation
tank.
tank.
Fourteenthly. The arrangement illustrated in Figures 25 and 26 of the accom-
panying drawings for distributing sewage entering'an upward flow precipitation
Fifteenthly. The arrangement in a conduit through which sewage passes
to a precipitation tank of diaphragms or baffles so mounted as to be capable of
yielding when the level of the sewage in the said conduit is abnormally high
substantially as hereinbefore described and illustrated in Figures 27 and 28 of the
accompanying drawings.
Dated the Twenty-eighth day of September 1894.