Improvements in Apparatus employed in Treating Sewage.
Year: 1890

page_text: Date of Application, 30th Jan., 1890
Complete Specification Left, 24th Nov., 1890-Accepted, 10th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus employed in Treating Sewage.
I WILLIAM WARNER of Traffic Street Works Nottingham in the County of
Nottinghamshire Civil Engineer do hereby declare the nature of this invention to be
as follows:-
The object of the present invention is to increase the efficiency of treating sewage
where the system of precipitation by aid of chemicals is employed.
Chemicals employed to cause precipitation of sludge contained in sewage are mixed
with water or crude sewage in metal vessels to such consistence that the mixture
will run & thoroughly amalgamate with the sewage flowing into the precipitation
tanks.
Some difficulty is experienced in getting the exact quantity of chemicals into the
mixer and in such condition that it will readily mix with the liquid; there is also
some difficulty in obtaining a regular supply of mixed chemicals in their proper
proportions to the quantity of sewage. Filter presses are generally employed for
treating the sludge after precipitation, and they consist of a frame supporting a
number of loose plates, having the main end attached to the frame and the other end
movable.
Filtering cloths are hung over the surface of the plates through which a greater
portion of the liquid is filtered, the surfaces of the plates are practically flat, having
corrugations to allow a free passage for filtered liquid.
In casting these plates they are liable to fracture owing to the edge being of greater
thickness, and the strength of the metal is reduced.
They are also sometimes broken by unequal pressure during the operation of
pressing sludge. These presses are usually closed by screws and hand wheels or a
piston actuated by air or water pressure.
My invention consists in constructing a chemical mixing vessel with a conical
bottom having a vertical shaft with screw propeller blades working inside the conical
part. Thus the chemicals, either lime, ferezone, or other material which in itself
has a tendency to precipitate is propelled upwards and a thorough mixing with the
liquid is performed.
A horizontal shaft with suitable gearing erected on top of the vessel is employed
to drive the propeller, which also drives a pair of horizontal rollers, having a hopper
fixed over them to hold the chemical material. The same shaft gives motion to a
slide which assists the material into the rollers. One of the rollers is adjustable and
the gearing is arranged so that the material is fed into the mixing vessel in regulated
quantities.
By this arrangement the chemicals are also ground and finished in better condition
to mix with the liquid.
The supply of liquid to the mixer may be regulated by ordinary valves.
In order to avoid fracture when casting filter press plates and to make them of
greater strength, I have them made with concave and convex sides forming what
are known as buckle or bellied plates the joint surface round the edge remaining
fat. When the press is closed the loose plates have their hollow or concave sides
all in one direction, and the main and movable sides follow so that the sludge cakes
produced have one hollow side and the other bellied.
Studs may be used in suitable positions to hold the filtering cloths upon the
surfaces of the plates and further assist their strength.
The movable end is closed and opened by a rack and pinion or if a piston is used,
he cylinder is cast with ports to convey the pressure from a four way cock, the
barrel of which also forms part of the same casting.

page_text: Thus the arrangements for opening and closing the press are simple and efficient.
To ensure true holes in the filtering cloths, where the studs pass through they may
be cut by a punch similar to those employed in cutting gun wads.
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WILLIAM WAKNEK.
COMPLETE SPECIFICATION
Improvements in Apparatus employed in Treating Sewage.
1 WILLIAM WARNER of Traffic Street Works, Nottingham in the County of
Nottinghamshire, Civil Engineer do bereby 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:-
The object of the present invention is to increase the efficiency of treating sewage,
where the system of precipitation by aid of chemicals is employed.
Chemicals employed to cause precipitation of sludge contained in sewage are mixed
with water or crude sewage in metal vessels, to such consistence that the mixture
will run and thoroughly amalgamate with the sewage flowing into the precipitation
tanks.
Some difficulty is experienced in getting the exact quantity of chemicals into
the mixer and in such condition that it will readily mix with the liquid, there is also
some difficulty in obtaining a regular supply of mixed chemicals in their proper
proportions to the quantity of sewage.
Filter presses are generally employed for treating the sludge after precipitation,
and they consist of a frame supporting a number of loose plates, having the main
end attached to the frame and the other end movable. Filtering cloths are hung
over the surface of the plates through which a greater portion of the liquid is filtered.
the surfaces of the plates are practically flat having corrugations to allow a free
passage for filtered liquid.
In casting these plates they are liable to fracture owing to the edge being of
greater thickness, and the strength of the metal is reduced.
They are also sometimes broken by unequal pressure during the operation of
pressing sludge.
These presses are usually closed by screws and hand wheels or a piston actuated by
air or water pressure.
My invention consists in constructing a chemical vessel with a conical bottom,
having a vertical shaft with screw propeller blades working inside the conical part.
Thus the chemicals, either lime, ferezone or other material, which in itself has a
tendency to precipitate is propelled upwards and a thorough mixing with the liquid
is performed.
A horizontal shaft with suitable gearing erected on top of the vessel is employed
to drive the propeller, which also drives a pair of horizontal rollers, baving a hopper
fixed over them to hold chemical material.
The same shaft gives motion to a slide which assists the material into the rollers.
One of the rollers is adjustible and the gearing is arranged so that the material is
fed into the mixing vessel in regulated quantities.
By this arrangement the chemicals are also ground and finished in better condition
to mix with the liquid. The supply of liquid to the mixer may be regulated by
ordinary valves.
In order to avoid fracture when casting filter press plates and to make them of
greater strength, I have them made with concave and convex sides, forming what are
known as buckle or belleyed plates, the joint surface round the edge remaining flat.
When the press is closed the loose plates have their hollow or concave sides all in
one direction and the main and movable ends follow, so that the sludge cakes
produced have one hollow side and the other belleyed.
Studs may be used in suitable positions to hold the filtering cloth upon the surface
of the plates and further assist their strength.

page_text: The movable end is closed and opened by a rack and pinion or if a piston is used,
the cylinder is cast with ports to convey the pressure from a four-way cock, the barrel
of which also forms part of the same casting.
In the accompanying sheets of drawings Figures 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
illustrate apparatus suitable for carrying my invention into practical effect.
The same letters of reference indicate the same parts of the apparatus in all the
figures.
Figure 1 represents a sectional elevation of the chemical mixing vessel and
Figure 2 represents a side view of the same part of my invention, a represents the
hopper into which chemicals are fed, b, b, are perforated and spiked slide plates,
which are moved by the lever c taking motion from the crank d. e represents two
iron rollers set in adjustable bearings parallel to each other, f end frames to support
rollers and hopper g bevil wheel for working the vertical shaft and bevil wheel for
driving it; through pullies i, i. ; represents a baffle inside the vessel, k. propeller
blades attached to the bottom of the vertical shaft. is the conical part of the vessel
and m the casing.
In working this part of my invention the chemicals used in the precipitation of
sludge contained in sewage, are fed into the hopper a and agitated by means of
the slides which prevent it caking inside the hopper, and cause a continuous
feed to the grinding rollers, e.
The rollers e may be adjusted by the set screw at and thus the chemicals
may be ground to a certain degree of fineness and regulated to suit the flow of
sewage into the precipitation tanks.
The shaft of one roller is carried over the top of the mixing vessel and supported
by bearing brackets p, p, and has fast and loose pullies i, i, which are driven by
belt, and thus the horizontal shaft Q gives motion to the roller mill and also the vertical
shaft and propeller for mixing chemicals.
The flow of water or sewage to mix with the chemicals is regulated by a cock
having inlet at r, the position of this inlet may however be altered to suit the chemicals
used.
With some materials it may be found advantageous to place it near the bottom and
the outlets may also be moved as desired.
A manhole is provided to clean out the vessel and adjust the propeller blades, and a
baffle j is fixed to prevent the flow of chemicals out of the apparatus before thorough
agitation and mixing.
•
Thus the chemicals are thoroughly mixed with liquid and in such condition that
they will amalgamate with the main flow of sewage, and a continuous supply is fed
into the sewage.
Figure 3 represents a square type filter press plate and Figure 4 represents a
section on line A. B of Figure 3 shewing a concave and convex side forming a buckle
or belleyed plate, the surfaces a are made perfectly true, so that a tight joint may
be formed round the edges of each plate, when working in position in the filter press,
such joint may be inade with rubber or other jointing material or with the filtering
cloths, the distance between b and c is the amount of buckle given to the plates, which
may be varied in making the pattern to suit the strength required in the plates. A
section on line C. D. would also be like Figure 4 with exception in the position of
studs e which are used to further assist the strength; but they do not form part of my
invention.
The Figures 5 and 6 represent a round or circular type plate buckled the letters
thereon denote the same parts as in Figures 3 and 4.
It will be seen that the edges of the plates have a greater thickness of metal
than the body or corrugated part and therefore in casting them the edge will
take longer to cool and during that time the corrugated or centre part of the
plate will rise or fall in accordance with the varying temperature from 6 to c.
Thus the metal will not be strained so much and not so liable to fracture as in flat
filter press plates. If the press plates are made an equal thickness and the edges have
no tendency to cool quicker, any variation by exposure the hot casting in the

page_text: moulding box would cause unequal contraction and a risk of fracture, which is
relieved by the buckle in press plates made in accordance with my invention.
Figure 7 represents a filter press in elevation shewing six plates in section and the
remaining plates on the outside edge all in position in which they are used. The
general construction is similar to other filter presses in use and the frame and standards
may be of any ordinary type; but this part of my invention relates to plates buckled
or belleyed placed in a filter press.
In the same figure my improved cylinder is shown for moving the end plate z.
When the sewage sludge is fed into the press an unequal pressure is caused at times
upon the sides of the press plates by the passages becoming partially blocked with
rags string and other material contained in sewage sludge and ordinary press plates
are broken by unequal pressure.
When a press is closed containing my improved plates they have their hollow sides
in one direction as shewn at a, a, a, a, a, a, Figure 7 or they may be placed the
reverse way as shewn at Figure 8, the direction of the buckle may face the flow of
sludge into the press or not.
In either position the plates are stronger and much more durable than flat filter
press plates.
Figure 8 represents part of a filter press with rack and pinion arrangement for
opening and closing the end plate.
The rack is attached to the movable end of the filter press at f. The pinion c is
supported upon the spindle d and the guide wheel e is fixed to take the pressure
against the rack, and guide it truly when moving backwards and forwards, this
arrangement may be used when compressed air, water or steam is not available.
Figure 9 represents a plan of the cylinder used for moving the end plate of press
and Figure 10 represents a section of same, with piston inside, also shewing the
ports or channel for passing compressed air, water or steam, a is the entrance for
airports leading to each end of the cylinder c four-way plug valve d dial
plate with set screws for adjustment. e, piston ƒ handle and pointer to work piston.
g exhaust port from cylinder.
Cylinders with pistons have been used for moving end plates of filter presses, but
the arrangements for conveying pressure upon the piston are pipes attached to
each end of the cylinder, my improvements consist in having ports cast with the
cylinder and also the casing forming the outside of a four-way cock or valve, and thus no
pipes are required to convey the pressure to each end of the cylinder and no additional
plug valve cock is required, which makes this part of my invention more compact and
efficient.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. In the process of treating sewage and the like by precipitation, having a
chemical mixing vessel with arrangements for grinding and regulating the supply
of chemicals in accordance with the flow of sewage, as substantially hereinbefore
described and for the purposes set forth.
2. In the process of treating sewage and the like by precipitation a press or
presses with filter plates having buckle or belleyed sides as substantially hereinbefore
described and for the purposes set forth.
3. In the process of treating sewage and the like by precipitation, a rack and
pinion for moving the end plate as described and for the purposes set forth.
4. In the process of treating sewage and the like by precipitation, a cylinder
and piston for moving the end plate as described and for the purposes set forth.
Dated this 15th day of November 1890.
WILLIAM WARNER.