A New or Improved System of Purifying Sewage or other Liquids by Aerated Filtration, and Apparatus therefor.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
A New or Improved System of Purifying Sewage or other Liquids by
Aerated Filtration, and Apparatus therefor.
I, ROBERT BAPTISTE DUNCAN, of Neville Street, in the City and County of
Newcastle-upon-Tyne, Secretary of The North Eastern Sanitary Inspection
Association, do hereby declare the nature of this invention to be as follows:-
My invention relates to aerated filtration with special reference to sewage,
but applicable to impure water or other liquids, by micro-organisms and I propose
to call it "The Aerobic Filter." It is adapted also for water works and for
domestic use the apparatus consisting of a series of sections the area and cap-
abilities of which may be indefinitely multiplied.
Impure water and other liquids may be purified by micro-organisms, whose
vitality is dependent upon oxygen. To cultivate and accommodate these micro-
organisms a bed of any fine sharp granular material (e.g. crushed' clinkers,
coke breeze, burnt ballast gravel, sand &c.) is necessary. The deeper and finer
the bed the greater the purification, if the bed is kept regularly and well aired
throughout which may, and has been, secured by intermittent use, but this
involves an expensive installation occupying large areas of ground.
To aerate a liquid while passing through a filter so that the filter may be used
continuously is the object of this invention.
The filter, constructed of any number of sections, is divided into layers, the
liquid passing in fine streams from one layer to another through successive spaces
of air thus absorbing oxygen which enables the micro-organisms in the succeeding
layer to work continuously.
1007
T. J. DANSON, F.I.P.A.,
Agent for Applicant, Newcastle-upon-Tyne.
A New or Improved System of Purifying Sewage or other Liquids by
Aerated Filtration, and Apparatus therefor.
I, ROBERT BAPTISTE DUNCAN, of Neville Street, in the City and County of
Newcastle-upon-Tyne, Engineer, do hereby declare the nature of-this invention
037

page_text: 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 modifications in the kind of filter invented by Walter
Mardon Ducat, for which Letters Patent No. 654 of 1897 have been granted
to him.
The filter (constructed of any number of sections) is divided into layers, the
liquid passing in fine streams from one layer to another, through successive
spaces of air, thus absorbing oxygen which enables the nitrifying organisms in
the succeeding layer to work continuously.
5
In applying it to sewage the latter, in its crude state, is preferably first passed!
through a covered tank or cesspool, arranged so as to secure bacterial action,
reduction, and liquefaction, the effluent therefrom being subjected to further
bacterial action, reduction, and nitrification in the filter.
The porosity and total depth of the filtering material (crushed "clinker,"
coke "breeze," burnt ballast sand, gravel, &c.) determine the quality of a bacterial 1
effluent, so that any desired degree of purification may be secured.
The filter may be arranged as illustrated by the accompanying drawings, or,
in an alternative form, may be arranged in steps where that would best suit
local conditions. The sides or ends (or both) of the boxes will be "louvred "
for the aeration of the filtering material. The liquid is divided into fine streams 2
by perforated or slotted bed plates, forming the bottoms of the boxes, which may
be each a separate casting or plate, or be formed of bars of iron, hardwood, or
the like, separate or in groups, set on edge. The tank into which the liquid
first flows, has no "louvres" and is arranged so as to secure even distribution of
the liquid over the filtering material beneath. The liquid enters by a pipe or 2
pipes or other channel arranged to distribute it over a thin layer of coarse gravel
or the like, laid on the bottom which is formed of perforated or slotted plates.
DESCRIPTION OF DRAWINGS.
Fig. 1 is a plan of one section of the filter, the left hand portion shewing
the skeleton frame, the centre and part to the right hand shewing the perforated
or slotted plates in position but without the filtering material, and the remaining
portion shewing the filtering material upon the perforated or slotted plates.
Fig. 2 is an end elevation and Fig. 3 a vertical section through the filter.
Four filtering boxes are shewn, but the number may be increased according
to the requirements of liquid treated.
The frame consists of vertical columns A, (placed on a concrete foundation)
to which are secured horizontal bars B, to carry the tank C, and the four
boxes D1, D2, D3, D4. The perforated or slotted plates E, are of any convenient
sizes (3' 0"x1' 0" x 1/4th" with 3/16" spaces or slots), stiffened by ribs where
necessary, and resting upon transverse bars F across the frame.
The liquid to be treated enters the tank C, by the channel pipe G, (or two
or more pipes may be used with perforations or slots) and passing into the first
filtering box 1) is oxygenised as it falls in fine streams through the air
spaces S1, S2, S3, and reaching the concrete bed is gathered into the channel H.
and flows away by the pipe G₁ any overflow being discharged through the
pipe G².
The sides or ends, or both, of the boxes are formed with "louvred " openings 0,
to admit air into the filtering material as an additional supply to the nitrifying
organisms working in the boxes.
In very cold climates or in severe frosts, the liquid may be protected from
freezing by admitting steam into pipes laid inside the boxes or by other suitable
means.
.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
. I claim is:-
\
First. For the purification of sewage or other liquid by bacterial agency, a

page_text: continuous filter in which the sewage or other liquid is received in a tank and
distributed over a thin bed of gravel or the like laid upon the perforated or
slotted bed plates or their equivalent thin bars set on edge and percolates in
fine streams into and through a series of boxes, also having perforated or slotted
bed plates, or thin bars set on edge with spaces between, upon which is placed
the filtering material containing the nitrifying organisms, the sewage or liquid
being aerated by contact with atmospheric air, in a series of empty spaces between
the boxes, by which the organisms are kept supplied with oxygen, the filtering
material in the boxes being also aerated by "fourred" openings admitting air,
substantially as described.
+
Second. For the purification of sewage or other liquid by bacterial agency, the
continuous filter (one section of which is shewn) comprising the following parts
in combination, viz:-A frame A, B, set on a concrete foundation supporting a
receiving and distributing tank C, the boxes D1, D2, D3, D (with empty
spaces S1, S2, S3, between) and "louvred " sides or ends, or both, carrying filtering
material upon perforated or slotted plates E, (or their equivalent thin bars)
forming the bottoms of said boxes; the inlet pipe G, the gathering channel II,
in the concrete bed, the outlet pipe G1, and overflow pipe G2; the whole arranged,
constructed, and operating, substantially with the objects set forth, as described
and illustrated by Figs. 1, 2, and 3 of the drawings herewith.
Dated this 19th day of August 1898.
T. J. DANSON, F. C. Inst. P. A.,
Agent for Applicant, Newcastle-upon-Tyne.