Improved Apparatus for the Extraction of Sludge from Settling Tanks.
Year: 1895

page_text: Date of Application, 9th Oct., 1895
Complete Specification Left, 9th July, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improved Apparatus for the Extraction of Sludge from Settling
Tanks.
We WILLIAM STUBBS Borough Engineer, and WILLIAM HENRY PRESCOTT
Assistant Engineer, both of the Municipal Offices Darwen, in the County of
Lancaster, do hereby declare the nature of this invention to be as follows:-
The principal object of this invention is the extraction of the sludge fron
settling tanks employed in the chemical treatment of sewage for the parification
thereof, but it is equally applicable t other analogous processes where it is
desirable to extract sludge or semi-fluid precipitant from water or other supernatant
liquid.
The invention is designed to be applied to settling tanks of an oblong form, and
consists principally of a series of scrapers attached at or near each end to two
endless chains, passing round sprocket wheels or toothed pulleys mounted one at or
near each end of the tank upon axles or shifts placed transversely across the tank,
at such a height above the bottom, that as the chains travel the scrapers are drawn
along the bottom of the tank from one end to the other, where they pass round the
wheels or pulleys and return over the top, the upper part of the chains being
supported by carrier pulleys or rollers to prevent it from "sagging."
A very slow revolving motion is given (preferably by a wheel or turbine driven
by the effluent water or liquid) to the axles or shafts of the sprocket wheels (or
one of them) so as to give a very slow creeping motion to the series of scrapers
which will remove the sludge, as it becomes precipitated or settles towards the
bottom of the tank, without any appreciable disturbance of the supernatant water
or liquid, and so as not to interfere in any way with the settlement of the sludge or
other precipitate or heavier portion.
At the delivery end of the tank the sludge as it is pushed forwards by the
scrapers falls into a
"sump" in which works a revolving screw which carries it to
the delivery aperture or outlet, which is provide with a suitable valve.
The sewage or other turbid liquid enters the tank through small holes in a
partition at one end, and the supernatant water or clear liquid escapes slowly over
a sill at the other end, whilst the flocculent matter is gradually precipitated and
carried off in the form of sludge as before described.
Dated this 8th day of October 1895.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Apparatus for the Extraction of Sludge from Settling
Tanks.
We WILLIAM STUBBS, Borough Engineer, and WILLIAM HENRY PRESCOTT,
Assistant Engineer, both of the Municipal Offices, Darwen, in the County of
Lancaster, 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 :-
The principal object of this invention is the extraction of the sludge from settling

page_text: tanks employed in the chemical treatment of sewage for the purification thereof,
but it is equally applicable to other analogous processes where it is desirable to
extract sludge or semi-fluid precipitant from water or other supernatant liquid.
'The nature of our invention and the manuer in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the four sheets of drawings hereunto annexed and the following explauation
thereof.
Sheets 1 and 2 of the drawings represent a vertical longitudinal section of the
two ends of a settling tank with our invention shown as applied thereto, and
Sheets 3 and 4 represent a plan view of the same.
The invention is designed to be applied to settling tanks of an oblong or
rectangular form as shown at a, and consists principally of a series of scrapers b
attached at or near each end to two endless chains c passing round sprocket wheels
or toothed pulleys d mounted one at or near each end of the tank a upon short
axles or shafts e placed transversely across the tank a at such a height above the
bottom that as the chains c travel the scrapers are drawu along the bottom of the
tank from one end to the other where they pass round the wheels or pulleys d and
return over the top, the upper part of the chains c being supported by carrier
pulleys or rollers e¹ to prevent them from "sagging."
A very slow revolving motion is given (preferably by a wheel or turbine f driven
by the effluent water or liquid) to the axles or shafts of the sprocket wheels d (or
one of them) at the driving end of the tank the water wheelf being so connected
to the sprocket wheels d (by worm gearing g or otherwise) as to give a very slow
creeping motion to the series of scrapers b which will remove the sludge as it
becomes precipitated or settles towards the bottom of the tank without any
appreciable disturbance of the supernatant water or liquid and so as not to
interfere in any way with the settlement of the sludge or other precipitate or
heavier portion.
At the delivery end of the tank the sludge as it is pushed forwards by the
scrapers falls into a sump h in which may work a revolving screw i which carries it
to the delivery aperture or outlet, which is provided with suitable means for
effecting the extraction or exit of the sludge.
The sewage or other turbid liquid enters the tank through small holes in a
partition a at one end of the tank a and the supernatant water or clear liquid
escapes slowly over a sill + at the other end, whilst the flocculent matter is
gradually precipitated and carried off in the form of sludge as before described.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
The combination with sludge settling tanks of a series of scrapers or push plates
attached to endless chains travelling over pulleys or sprocket wheels which are
arranged near the bottom of the said tanks, and whereby a continuous slow motion
is given to such scrapers or push plates along the bottom of the tank from the
feeding end to the overflow or delivery end and back again over the top of the
pulleys or sprocket wheels substantially as herein before described and illustrated
by the drawings annexed.
Dated this 8th day of July 1896.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.