Improvements in Treating Sewage and in the Construction and Arrangement of Means therefor.
Year: 1889

page_text: Date of Application, 8th Mar., 1889
Specification Accepted, 13th Apr., 1889
Improvements in Treating Sewage and in the Construction and
Arrangement of Means therefor.
I HERBERT GUTHRIE of Albert Road Levenshulme Manchester in the County of
Lancaster Civil 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 relates to improvements in the treatment and purification of sewage
and has for its chief objects to reduce the area of land and the size of the works
required and consequently to reduce the first cost of such works and the subsequent
expenses of maintenance.
In carrying out my improvements I propose to divert the sewage from its direct
line of flow to the outlet whether brook stream river lake or sea as the case may be
and conduct it along a passage into which a precipitant would be introduced and then
take the sewage into a basin or tank of a particular shape. This tank which I de-
signate the Debris Tank is intended for the deposition of the larger and heavier
impurities. From the Debris Tank the sewage is conducted into a larger deeper
subterranean basin or tank also of special form. From this tank which I designate
the Precipitating Tank the liquid overflows and the precipitated matter is removed by
a pump bucket elevator or equivalent means.
And in order that my invention may be fully understood and readily carried into
effect I will describe the accompanying Sheet of Drawings reference being had to the
figures and letters marked thereon.
Figure 1 is a sectional elevation and Fig. 2 a plan of a convenient construction and
arrangement of sewage works for attaining the objects of my invention.
In these views A designates the subterranean Precipitating Tank, B the main
sewer, Ba hopper for the introduction of the precipitant, C a shut off valve or valves
to the Debris Tank, C" a shut off valve or valves to the floodway or overflow, D the
Debris Tank, E a bucket elevator, Fa screen or grid, G descent pipe or passage for
the sewage into Precipitating Tank A, H ascent pipe or passage for precipitated
sludge, I the exit passage for water, J a gutter to lead the water to filters when filters
are employed, K centrifugal or other filters and L mud or sludge pump.
The sewage and the precipitant introduced to the sewer B through the hopper B'
| flow through the valve C³ (the valve C" being closed) into the Debris Tank D which

page_text: is large enough to reduce the rate of the flow of sewage sufficiently to permit the pre-
cipitation or deposition of the larger and heavier impurities. There will however be
sufficient movement left to thoroughly mix the precipitant with the liquid sewage.
The Debris Tank D is preferably formed at the bottom in the shape of a hopper as
shown so as to facilitate the introduction of the bucket elevator the function of
which is to extract the deposited debris at any time without interrupting the constant
flow of sewage through the Tank D). At the exit end of this tank is the screen or
grating F which is preferably set obliquely as indicated in Fig. 1 so as to screen all
large floating matter which would be washed up the screen by the force of the current
and so leave the lower part of the screen free for the passage of the liquid sewage and
smaller solids. After passing the screen F the sewage flows through a passage and
descends the pipe G into the Precipitating Tank A.
The tank A is a large subterranean cavity or basin forming a sort of gigantic cess-
pool into which the sewage constantly flows and as constantly overflows the movement
towards the exit passage or cess-pool being so slow that precipitation can go on
uninterruptedly.
The Precipitating Tank may either be of the form shown or of any other suitable
shape which will cause the sludge to collect either to a point or along a line so as to
admit of the application of the pump L or a dredger or equivalent in order to withdraw
the precipitated sludge through the pipe H from the Tank A periodically as often as
may be found necessary. The barrel of the pump L is preferably made a loose fit in
the ascent pipe H so as to perinit the free passage of air to the surface of the ascent
column to act as a cushion so that when the pump is worked the sludge will readily
ascend the pump barrel without undue strain. The ascent pipe FL may be built in
brickwork or masonry or formed of metal or other suitable convenient material and
may either be placed centrally as shown or to one side or outside the tank altogether;
in the latter case a passage would have to be formed to connect the bottom of the tube
with the bottom of the tank A. With an ascent pipe such as H placed centrally in
the tank A it is a convenient arrangement to have the descent pipe G for the admission
of sewage to the Precipitating Tank placed vertically and centrally also that is to say
the smaller pipe H placed within the larger pipe Ġ and to have a deflecting or dis-
tributing ring R fixed on the pipe H at a convenient distance below the mouth of the
pipe G so as to cause the inrushing sewage to take an approximately horizontal
direction when liberated in the Tank A. The sewage being thus liberated in a very
large area its movement would necessarily be very slow and consequently precipitation
and settlement of the sludge would take place under very favourable circumstances the
waste water rising slowly and overflowing through the cess-pipe I while the solids
settle down and collect at the mouth of the ascent pipe H. It is obvious that any
other convenient mode of admitting the sewage to the Tank A might be employed
subject to the conditions and requirements above indicated.
In some cases the waste water overflowing from the Precipitating Tank A would be
sufficiently purified and could be conducted directly to the outlet; but should further
purification be necessary filtration by any of the ordinary methods may be added to
complete the process. For instance the waste water could be led through the gutter J
to centrifugal filters K or to a permanent filter bed if there should be land enough
available.
A great advantage to be obtained by the adoption of my system of sewage purifi-
cation as herein set forth is that only a small head of water say twelve inches or so
including ascending filter beds or five or six feet if descending filtration beds or
centrifugal filters were used whereby in many cases the cost of expensive pumping
machinery would be saved.
It will be readily understood that any number of Debris Tanks and Precipitating
Tanks may be employed in combination worked either by dividing the sewage each
division going through a separate system or by sending the whole or any portion
through several systems in series that is to say that the sewage may go through several
precipitating tanks overflowing from one into the other and further that the said
tanks may be either open or covered.

page_text: 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 construction use and application of a subterranean Precipitating Tank into
and out of which sewage is allowed to flow said tank being so arranged as to permit
the regular settlement and withdrawal of the precipitated sludge without interfering
with the constant working of the process substantially as herein set forth.
2. The combination with a precipitating tank, of the descent or inlet pipe or
passage so arranged as to admit the sewage at the desired level and distribute it
quietly in a horizontal direction and the ascent pipe or passage arranged substantially
as and for the purposes herein set forth.
3. The combination with a Precipitating Tank or Tanks, of a Debris Tank or
Tanks and a screen or screens substantially as and for the purposes herein set forth.
4. The combined arrangements of parts for effecting a process of sewage purifi-
cation the several operations comprising said process being performed substantially in
the manner and in the sequence herein set forth.
thin 7th dos. of M 1880
H. B. BARLOW,
17, St. Ann's Square, Manchester,
Agent for Applicant