Improvements in the Treatment of Sewage, and in Apparatus therefor.
Year: 1895

page_text: Date of Application, 8th Nov., 1895
Complete Specification Left, 25th Feb., 1896-Accepted, 25th Apr., 1896
. PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Sewage, and in Apparatus
therefor.
We, DONALD CAMERON of No. 1 Sylvan Road, Pennsylvania, Exeter, Civil
Engineer, and FREDERICK JAMES COMMIN of No. 7 Bedford Circus, Exeter,
Fellow of the Institute of Surveyors, do hereby declare the nature of this invention
to be as follows:-
This invention relates to the treatment of sewage and to apparatus therefor,
and has for its principal object to deal with crude sewage bacteriologically and
bring it into such a condition of solution and liquefaction that it can be treated
by filtration or irrigation, or in any other suitable way.
By this invention further it is possible to get rid of the sludge difficulty because
the solid portion of crude sewage is entirely thrown into solution.
In the systems now employed the crude sewage is first treated chemically so
that the solid matter is to a great extent precipitated and it is only the liquid
part which is treated by filtration or otherwise.
treated
By this invention the chemical treatment is entirely dispensed with and further
the expense of dealing with the precipitated matter is also obviated. In previous
systems it has been considered of advantage that there should be contact of
sewage matter with the air. In the treatment of sewage according to our invention
it is of the utmost importance that the chamber in which the bacteriological action
takes place should be dark and also that means should be provided for preventing
contact with the air. This want of contact with the air can be arranged by
providing a closed cover to the tank or vessel or in certain cases by having no
cover but by utilizing the formation of scum which occurs when sewage
according to this invention. In carrying out this invention we provide or con-
struct a tank of concrete, brick or other suitable material preferably, shallow
compared to its other dimensions. In order to ensure exclusion of air we make
the cover air-tight and the man-hole solid and air-tight. It may be found
desirable to have a valve in the man-hole to allow at times of the escape of gas'
should the fermentation or bacteriological action take place too rapidly.
inlet pipe and outlet pipe into the tank should be preferably trapped. The inlet
pipe should be so arranged that it discharges into the tank some two or three
inches below the normal surface of the water so as to avoid breaking the scum
which forms. For the same reason the outlet pipe should be from the top of
the tank but trapped and carried down below the surface so that the floating
matter is retained in the tank. The bottom of the tank may be provided with
a small channel or it may be dished so that the mineral or other insoluble matter
may be collected there and taken out as required.
The
We have found by experiment that the tank should be of a capacity to hold
about 20 gallons per bead of population but we do not bind ourselves to this.
After such a tank has been for 2 or 3 days in operation a brown scum forms at the
top and eventually becomes 2 or 3 inches in thickness. This scum is formed by
bacteriological action and rises in particles from the bottom of the tank; gas
forining at the bottom and carrying these small particles with it to the top of the
tank. After such a tank has been in operation for 2 or 3 days the effluent is.
satisfactory and is in a condition to be further treated by any other means such for
example as a coke-breeze filter.

page_text: By this invention crude sewage can be treated for long periods and there is at
the end of such time practically no sludge at all in the tank.
We have also tried baffle plates in the tank these plates being made of wood;
but up to the present we have not found that such baffle plates add to the
bacteriological action.
Dated this oft
'
100K
•
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Sewage, and in Apparatus
therefor.
We, DONALD CAMERON of No. 1 Sylvan Road, Pennsylvania, Exeter, Civil
Engineer, and FREDERICK JAMES COMMIN of No. 7 Bedford Circus, Exeter,
Fellow of the Institute of Surveyors, 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 :-
This invention relates to the treatment of sewage and to apparatus therefor,
and has for its principal object to deal with crude sewage bacteriologically and
bring it into such a condition of solution and liquefaction that it can be treated
by filtration or irrigation, or in any other suitable way.
By this invention further it is possible to get rid of the sludge difficulty because
the soluble solid portion of crude sewage is thrown into solution.
In the systems now employed the crude sewage is first treated chemically so
that the solid matter is to a great extent precipitated and it is only the liquid part
which is treated by filtration or otherwise.
By this invention the chemical treatment is entirely dispensed with and further
the expense of dealing with the precipitated matter is also obviated. In previous
systems it has been considered of advantage that there should be contact of sewage
matter with the air. In the treatment of sewage according to our invention it is
of the utmost importance that the chamber in which the bacteriological action
takes place should be dark and also that means should be provided for preventing
contact with the air. This want of contact with the air can be arranged by
providing a closed cover to the tank or vessel or in certain cases by having no
cover but by utilising the formation of scum which occurs when sewage is treated
according to this invention.
In carrying out this invention we provide or construct the tank of cement-
concrete, brick or other suitable material preferably shallow compared to its other
dimensions. In order to ensure exclusion of air we make the cover air-tight and
the man-hole solid and air-tight. It may be found desirable to have a valve in
the man-hole to allow at times of the escape of gas should the fermentation or
bacteriological action take place too rapidly. The inlet pipe and outlet pipe into
the tank should be preferably trapped. The inlet pipe should be so arranged that
it discharges into the tank in such a way as to avoid breaking the scum which
forms and this can be effected by carrying the pipe some distance below the normal
surface of the water. For the same reason the outlet pipe should be so arranged
that the floating matter or scum is retained in the tank and this can be effected by
having the outlet pipe at the upper part of the tank but carried down below the
surface of the water. The bottom of the tank may be provided with a small
channel or it may be dished or it may be inclined and have a sump at one end so
that the mineral or other insoluble matter may be collected there and be taken out
as required.
We have found by experiment that the tank should be of a capacity to hold

page_text: After the
about 20 gallons per head of population but we do not bind ourselves to this.
After such a tank has been in operation for 2 or 3 days a brown seum begins to
form at the top and eventually becomes 2 or 3 inches thick. This scum is for.ned
by bacteriological action and rises in particles from the bottom of the tank; gas
forming in and carrying these sinall particles to the top of the tank.
tank has been in operation sufficiently long for this scum to commence forming the
effluent is so free from matter in suspension that it is in a condition to be further
treated by any other means such for example as coke-breeze filters, or for irrigation
or discharging into rivers and tidal waters.
By this invention crude sewage can be treated for long periods without
practically any sludge at all forming in the tank.
The accompanying drawings represent a tank suitable for carrying out our
invention. In practice we generally construct the tanks in pairs so that whenever
the working of either tank of the pair has to be temporarily stopped for any purpose
the other tank is available for continuing the work. The drawings show only one
tank of a pair, the centre line between the two being at x-x. Figure 1 is a
horizontal section of the tank and Figure 2 a longitudinal section. Figures 3
and 4 are transverse sections on the lines A B and C D respectively of Figure 1.
a is the tank constructed of any suitable material but we recommend cement-
concrete. It is shallow in comparison with its other dimensions. b is the tank
cover which is made air-tight. c is the man-hole in this cover also made air-tight.
d is the inlet to the tank; it is shown as trapped and provided with an inspection
eye and cover at e. It discharges into the tank some distance below the normal
water level as shown so as to avoid breaking the scum which forms in the tank.
fis the outlet from the tank; it is at the upper part of the tank but is carried
down below the surface as shown so that the floating matter or scum is retained
undisturbed in the tank. The outlet is represented as discharging on to a table g
surrounded by a low weir h; this ensures that the effluent will spread in a thin
film over the weir which is of great assistance in purification. The bottom of the
tank is shown as inclined towards one end where there is a sump j in which mineral
or other insoluble matter will collect and from which it can be removed from time
to time. It is not absolutely necessary for the tank to have an air tight cover as
above described because the dark scum which forms serves to keep both light and
air from the sewage, but we consider it important to provide the cover.
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
1. For the bacteriological treatment of sewage, a tank having an outlet so
arranged that it discharges the effluent without disturbing the scum or floating
matter, substantially as and for the purpose set forth.
2. For the bacteriological treatment of sewage, a tank having an inlet which
delivers the sewage thereto without disturbing the scum or floating matter and
an outlet which discharges the effluent also without disturbing the scun or floating
matter, substantially as and for the purpose set forth.
3. For the bacteriological treatment of sewage, a tank having an air-tight cover,
an inlet which delivers the sewage to the tank without disturbing the scum or
floating matter, and an outlet which discharges the effinent also without disturbing
the scum or floating matter, substantially as and for the purpose set forth.
4. The improved apparatus hereinbefore described and shown in the accom-
panying drawings for the bacteriological treatinent of sewage.
072
CL100G
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.