Improvements in the Purification of Sewage and Water, and Apparatus for use therein.
Year: 1893

page_text: Date of Application, 15th Sept., 1893
Complete Specification Left, 15th June, 1894-Accepted, 15th Nov., 1894
Improvements in the Purification of Sewage and Water, and
Apparatus for use therein.
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 to he
as follows:
My invention consists in part of the improvements hereinafter described in filters.
When I form the filter bed of two or more layers of different kinds or sizes of
filtering materials I in some cases separate the layers by means of a diaphragm or
diaphragms consisting of suitable perforated or reticulated or porous material
so arranged that it or they will not interfere with or impede the working or
cleansing of the filter bed.
My invention consists further of the improvements hereinafter described in
apparatus by means of which a stream of fluid precipitating matter is caused to
pass into water flowing through pipes on its way to a precipitating tank or to a filter
bed and is especially suitable when the water in the said pipes is under pressure.
According to my said improvements I connect together two vessels capable of
being closed water tight and of about equal capacity and I connect the said vessels
together and to the water pipe by means of tubes provided with stop-cocks or by
other convenient means whereby communication between the two vessels and
between them and the water pipe may be readily opened and closed one of the said
vessels (which I term the air vessel) is provided with stop-cocks or stoppers at its
upper and lower part and the other of the said vessels (which I term the precipitant
vessel) has an opening at the upper part capable of being closed water tight by
means of a stopper or otherwise and is or may be provided with a stop-cock or
stopper at the lower part. When the apparatus is to be used the communications
between the said vessels and water pipe are closed and any water which they may
contain is removed or allowed to run out. The precipitant vessel is then charged
with the required precipitant in a liquid form and closed the stopcocks of the air
vessel if open are also closed and the means of communication between the
two vessels is opened. The said apparatus is then ready for action and is brought
into action by opening the communications between the said vessels and the water
pipe a portion of the water in which pipe enters the air vessel and drives the air
therein into the precipitant vessel displacing the precipitant therein which is
thereby caused to pass into the water flowing through the said pipe. Or I may
force the liquid precipitant into the water in the said pipe by means of air
compressed in other ways.
My invention consists further of the improvements hereinafter described in the
purification of sewage and polluted waters by precipitation.
I add fresh "sludge" to the sewage or polluted water flowing into the
precipitation tank.
My said improvements consist further in providing for removal of the sludge
from the bottoms of precipitating tanks especially of upward How precipitation
tanks by means of a pipe or pipes or a conduit or conduits with perforations slots
or openings therein the sectional area of each of which pipe or conduit is nearly or
quite equal to or greater than the collective area of the whole of the perforations
therein. I prefer to arrange outwardly opening valves in or near the ends of the
said pipes within the said tank to provide for cleansing of the said pipes by flushing.
The perforations in the said pipes may be furnished with bell shaped or conical
shaped mouths or may be of other suitable shape.

page_text: I sometimes employ one or more perforated or slotted pipes as before mentioned
pivoted or arranged so that it or they can be rotated or moved by a suitable
mechanical contrivance the said pipe or pipes being rotated or moved when they are
employed for drawing the sludge from the precipitation tank.
Dated this Eleventh day of September 1893.
Improvements in the Purification of Sewage and Water, and
Apparatus for use therein.
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 in part of the improvements hereinafter described in filters
consisting of two comparatively shallow layers of different kinds or sizes of filtering
materials the object of my said improvements being to cause the relative positions
of the said layers to be maintained while the filters are being cleansed by upward
flow of water through them. According to this part of my invention I separate
the layers of filtering material by means of a diaphragm consisting of suitable
perforated or reticulated material.
Figure 1 of the accompanying drawings is a vertical section of a portion of a
filter to which my said improvements are applied. Referring to the said figure
a is a portion of the filter case. b is a portion of the layer of fine filtering material
and c is a portion of the layer of coarse filtering material. d is a portion of the
diaphragm separating the said layers which diaphragm may consist of any
perforated or reticulated material of sufficient strength for the purpose and which
is sufficiently open to permit of free passage of water through it and which is not
readily corroded by the action of water. Copper wire gauze of twelve meshes to
the linear inch is suitable. The said diaphragm is retained in position by means of
a ring of metal or other suitable material e secured to a flange projecting from
the innerside of the filter case by means of screws one of which is shown at g.
My invention consists further of the improvements hereinafter described in
apparatus by means of which a stream of fluid precipitating matter is caused to
pass into water flowing under pressure through pipes on its way to a precipitation
or settling tank or to a filter bed.
Figure 2 of the accompanying drawings is a side elevation of apparatus for the
said purpose constructed and arranged according to this part of my invention and
shown applied to a water pipe. hi are two water tight vessels of about equal
capacity connected together by means of a pipe and respectively connected to the
water pipe by means of pipes I m. The said vessels and the pipes j l m are
provided with stop cocks marked respectively h² i¹ i² ³ j¹ l' m² the purpose of
which is hereinafter described and the vessel i is also provided with a gauge glass i*.
The direction in which water passes through the pipe & is indicated by the arrow.
The said apparatus is used and acts as follows;-
Assuming that the stopcocks are all closed and that the vessels hi are both void
the stopcocks are first opened and the vessel i is then charged with the required
liquid precipitant by pouring it into the funnel shaped mouth of the stopcock 3.
When the said vessel has been fully charged the stop cocks i¹³ are closed and the
apparatus is ready for action and may be set in action by opening the stop
cocks jm the effect of which is to permit water from the pipe to pass into the
vessel the air in which vessel is displaced by the water so eutering it and caused
to pass into the vessel i permitting the precipitant therein to pass by the pipe i

page_text: into the water in the pipe k. By adjustment of the stopcocks 'm' the rate of flow
of the precipitant may be regulated as required relatively to the volume of water
passing through the pipe k. In adjusting the said stop cocks 1 m³ it is desirable
that both of them be opened or closed to the same extent.
When the whole of the precipitant has passed out of the vessel the stop cock j
is closed and the apparatus may be prepared for recharging by closing the
stop cocks and opening the stop cocks 2 whereby the water which has
entered the vessel is allowed to run out. The object of the stopcock 2 is to
admit of ready removal of the contents of the vessel i when desirable.
ways.
In some cases I force the liquid precipitant into water flowing under pressure to
a precipitation or settling tank or to a filter by means of air compressed in other
For instance in works where a steam engine or other motor is used a pump
or air compressor connected to the upper part of the vessel i may be arranged to be
worked by such motor. It being desirable to maintain in the vessel i a constant or
steady pressure of air somewhat greater than the pressure of the water in the
pipe & the said vessel when supplied with air by a pump or compressor should be
furnished with a valve arranged to open when the pressure is higher than necessary
and the supply of air to the said vessel should be sufficient to keep the said valve
constantly open.
My invention consists further of the improvements hereinafter described in the
purification of sewage and polluted water by precipitation. According to this part
of my invention I add freshly precipitated sludge to the sewage or water to he
purified Howing into the precipitation tank. The sludge thus added assists in
carrying down the coagulum which is produced in the precipitation tank by the
action of the precipitants and thus accelerates precipitation. I prefer to add
the sludge to the stream of sewage or water just before it enters the tank and I
add the precipitant to the sewage or water after adding the sludge thereto. The
sludge may be added in the proportion of about fifty to one hundred grains of thin
wet" sludge (as usually obtained from a precipitation tank) to each gallon of
sewage but greater or less proportions of sludge may be added according to the
character of the sewage.
"
My said improvements consist further in providing for removal of the sludge
from the bottoms of precipitation tanks by means of perforated or slotted pipes
pivotted or otherwise arranged so that they can be rotated or moved over the
bottoms of the said tanks by a suitable mechanical contrivance the said pipe or
pipes being so moved when removal of the sludge froin the said tanks is required.
Figure 3 of the accompanying drawings is a vertical section of a precipitation
tauk provided with a perforated sludge removal pipe pivotted at one end the
arrangement being that which I prefer for circular tanks. is the perforated pipe
the perforations in which are marked n' n'. o is a pipe laid in the bottom of the
tank and carried up on the outerside thereof and provided with a valve of the exit
of which pipe is below the water level of the tank. The inner end of the pipe
communicates with the pipe o and is jointed thereto in such a manner as to admit.
of the former being turned on its joint so that it may be moved over all parts of
the bottom of the tank by means of a rotatory shaft the foot of which is affixed
to the inner end of the said pipe n. The upper end of the shaft p works in
bearings carried by a standard supported by a beam or girder crossing the tank
which beam or girder also supports another standard in which standards
mounted a horizontal shaft t geared to the shaft p by means of bevil wheels pl
and provided with a winch. This arrangement is used and acts as follows.
When it is required to remove sludge from the bottom of the tank the valve o' is
opened and the shaft is slowly rotated the outer end of the perforated pipe n
being thereby carried round over the whole surface of the bottom of the tank.
The pressure of water in the tank causes the sludge to enter the perforations n' n¹
in the pipen and to pass through it into and through the pipe o by which the sludge
is conducted to the required place or receptacle. When the thick sludge has been
removed the valve o' is closed.
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page_text: For the removal of sludge from the bottoms of rectangular tanks I prefer to so
arrange the perforated or slotted pipes that they may be moved from side to side
or from end to end of the said tanks. A convenient arrangement for this purpose
is illustrated in Figures 4, 5 and 6 of the accompanying drawings Figure 4 being
a plan of the said arrangement. Figure 5 a vertical longitudinal section taken on
the line A Figure 4 and Figure 6 a vertical transverse section taken on the
line B Figure 5. In the following description the same letters and figures of
reference indicate the same parts in all the said figures.
ụ is the tank, is the perforated pipe which is sppported by wheels on
rails set in the bottom of the tank. To the said pipe is connected a
vertical pipe provided with cocks the upper end of which pipe e is within
a trough y secured in the tank and has secured to it a bucket forming a water
seal and is supported by wheels which rest on the upper edge of one side of
the said trough.
is a windlass mounted on a platform and connected to the
perforated pipe e by means of a wire rope connected to eyes e² on the pipe e
and passing round guide pulleys 3 fixed in the walls of the tank. This apparatus
is used and acts as follows-When it is required to remove sludge from the bottom
of the tank the cocks are opened and the pipe is drawn over the bottom of
the tank from end to end thereof by turning the windlass . The sludge which is
forced into the pipe by the pressure of the water in the tank rises in the pipe
and passes therefrom into the bucket and overflows into the trough y from which
it is conducted by a pipe y'. While the apparatus is at rest the cocks are
kept closed.
Before the said cocks are first opened the part of the pipe between
them is filled with water through the cock which is afterwards kept closed.
The object of the sealing bucket is to ensure that the syphon action of the said
pipe may be retained while the tank is being cleaned.
1:
In order to ensure satisfactory working of the apparatus it is important that the
sectional area of the perforated pipes and of the pipes in connection therewith be
equal to or greater than the collective area of the perforations through which the
sludge passes into the said pipes.
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 I claim
First. The means hereinbefore described and illustrated in Figure 1 of the
accompanying drawings for maintaining the relative positions of the layers of
filtering material in filters consisting of two shallow layers of filtering material the
upper layer being of fine material and the lower one of coarse material that is to
say the arrangement between the said layers of a diaphragm consisting of suitable
perforated or reticulated material.
Secondly. Apparatus constructed and arranged substantially as hereinbefore
described with reference to Figure 2 of the accompanying drawings for supplying
a liquid precipitant to water flowing under pressure to a precipitation tank or to a
filter that is to say apparatus in which the precipitant is caused to pass into the
water by means of air forced by the pressure of the water into a vessel containing
the said precipitant.
Thirdly. Apparatus whereby a liquid precipitant is caused to pass into water
Howing under pressure to a precipitation tank or to a filter by means of air forced
into a vessel containing the said precipitant substantially as hereinbefore described.
Fourthly. The addition as and for the purpose herein before described of
freshly precipitated sludge to sewage or water to be purified by the action of
precipitants also added thereto.
Fiithly. The improvements herein before described in apparatus for effecting
removal of sludge from precipitation tanks which improvements consist essentially
in so mounting perforated or slotted pipes in the said tanks that they may be moved
over the bottoms thereof for the purpose of receiving the sludge deposited thereon
which sludge passes into the said pipes through the perforations or slots therein.
Sixthly. The arrangement in a precipitation tank of a perforated or slotted

page_text: pipe substantially as hereinbefore described and illustrated in Figure 3 of the
accompanying drawings for effecting removal of sludge from the said tank.
Seventhly. The arrangement in a precipitation tank of a perforated or slotted
pipe substantially as herein before described and illustrated in Figures 4, 5 and 6
of the accompanying drawings for effecting removal of sludge from the said tank.
Dated the 15th day of June 1894.
W. T. WHITEMAN,
Agent for the Applicant.