IMPROVEMENTS IN PURIFYING AND UTILISING SEWAGE AND IMPURE OR WASTE WATERS
Year: 1885

page_text: Waste Waters.
We HERMANN WAGENER, Councillor of State, and Professor ALEXANDER
MÜLLER, Doctor of Philosophy both of the City of Berlin in the Empire of
Germany do hereby declare the nature of our Invention for "IMPROVEMENTS IN
PURIFYING AND UTILISING SEWAGE AND IMPURE OR WASTE WATERS to be as
follows:-
This invention relates to improvements in purifying and utilising sewage and
impure or waste waters.
.
In order to carry our invention into effect we first free the sewage or other
water from the sludge and if there is an opportunity of employing the resulting
fluid for irregating purposes the precipitation of the sludge can be effected by
means of hydrate of lime H, Ca O2 or slaked lime simply and the resulting liquid
let off to be employed for such said irregating purposes.
In order to effect this we cause the sewage or other waste fluid or semi fluid to
pass over several wire filtering cloths and finally over a felt cloth. The wire and
felt filtering cloths employed are endless cloths and the entire mechanism is
arranged in similar manner to that employed in the manufacture of paper.
The wire filtering cloths are so arranged that the sewage or other fluid passes
first over a cloth with wide meshes and from thence over cloths with continuously
decreased width of the meshes, the meshes decreasing in size from 5 millimetre
to 11th millimeter. By means of the filtering cloths of wire fabric we attain the
filtration and also a sorting of the sludge which said sludge can also be employed
direct as manure although we have found it more advantageous to utilize. the
purified fluid and the sludge separated out of the same by subjecting them to a
technical process described later on in this said specification.
The filtered or defecated water is mixed with a small quantity of slaked lime, is
thus rendered alkaline and then fed into a suitable vacuum apparatus which
consists of a large closed vessel or receptacle from which the air is exhausted by
means of a suitable air pump or its equivalent. In this said vessel we arrange two
or more rows or series of superposed flat disk like vessels or receptacles. The
filtered matter flows downwards and passes by means of an overflow pipe from
one of the said dish like vessels into a like vessel situate beneath the said vessel or
receptacle.

page_text: Sulphuric acid SO, of about 25 per cent strength passes through the second row
or series of vessels in like direction as above mentioned id: est: downwards.
The Vacuum in the apparatus vessel or receptacle causes a rapid evaporation or
volatilization of the ammonia contained in the material or matter operated on which
said ammonia is immediately absorbed by the sulphuric acid so that an absolute
vacuum is always present for the ammonia and so that a special heating of the
apparatus is not necessary for the entire evaporation of the ammonia.
The abovementioned lime sludge and also the various kinds of slush or sludge
from the filtering cloths and the felt cloths are according to the component parts of
the same treated for obtaining the fats or grease, fatty acids, fibrous matter (hairs,
feathers, flax, cotton, paper and wood fibres) phosphoric acid and nitrogen contained
in the same.
The succession of the operations depends on the composition or component parts
of the kind of slush or sludge to be treated. As a rule we commence with the
operation for obtaining the fats by one of the known methods of extraction whilst
on the other hand the fatty acids are previously made free.
The fibres are cleansed by washing the same with water, acid and lye or oxy-
chloride of lime-Those parts of the same which cannot be utilised for making
fabriks, felt, paper, card board or papier maché is worked up for obtaining
ammonia or manure or both.
The sludge which has been deprived of the fibrous matter fats and fatty acids is
precipitated by means of lime, alumina, ferric salts or other suitable matter and
treated for the manufacture of manure.
The nitrogenous refuse from the previous operations is placed in dry condition
in a closed gas generator and transformed into gas whereby steam mixed with air
is forced into the said generator by means of a suitable steam blower or injector.
The material must be arranged in a high or thick layer so that the upper part is
subjected to the process of distillation before consumption can take place. The
steam which is mixed with the air acts in such manner on the said material that
the entire nitrogen volatilises or passes off in the form of ammonia.
The gases passing off are cooled and then lead through a layer of coke from
above which sulphuric acid flows down so as to absorb the ammonia.
The said gases can now be employed for illuminating or heating purposes-The
condensed tar is led back into the generator for combustion unless it is found
advisable to employ the samo for other technical purposes.
The remaining ashes and the silt or precipitate from the clarifying process can
be employed direct as manure or after the same have been treated with acids
suitable for recovering the large percentage of phosphoric acid contained in the
same,

page_text: COMPLETE SPECIFICATION.
Improvements in Purifying and Utilizing Sewage and Impure'
or Waste Waters.
We HERMANN WAGENER, Councillor of State and Professor ALEXANDER
MÜLLER, Doctor of Philosophy, both of the City of Berlin in the Empire of,
Germany do hereby declare the nature of our Invention for IMPROVEMENTS IN,
PURIFYING AND UTILIZING SEWAGE AND IMPURE OR WASTE WATERS and in what
manner the same is to be performed, to be particularly described and ascertained in,
and by the following statement:-
Our invention relates to improvements in purifying and utilizing sewage and
impure or waste waters.
In order to carry our invention into effect we first free the sewage or other water
from the sludge and if there is an opportunity of employing the resulting fluid
from irrigating purposes the precipitation of the sludge can be effected by means of
hydrate of lime H, Ca O₂ or slaked lime simply and the resulting liquid let off to
be employed for such said irrigating purposes, or we cause the sewage or other
waste Huid or semi-fluid to pass over sinall wire filtering cloths and finally over a
felt cloth.
The wire and felt filtering cloths employed are endless cloths and the entire
mechanism is arranged in similar manner to that employed in the manufacture of
paper.
The wire filtering cloths are so arranged that the sewage or other fluid passes
first over a cloth with wide meshes and from thence over cloths with continuously
decreased width of meshes, the meshes decreasing in size from five millimetre to
one tenth millimetre.
"
ני
By means of the filtering cloths of wire fabric we attain the filtration and also "
a sorting of the sludge which said sludge can also be employed direct as manure
although we have found it more advantageous to utilize the purified fluid and the
sludge separated out of the same by subjecting them to a technical process described
later on in this said specification.
The filtered or defecated matter is mixed with a small quantity of slaked lime,
is thus rendered alkaline and then fed into a suitable vacuum apparatus.
Figure 1 is a vertical section.
"
2 is a section at right angles to Figure 1, and
"
3 is a plan of the apparatus which consists of a large closed vessel or;
receptacle A in which said vessel or receptacle two or more rows or series of
superposed shallow dish like vessels or receptacles of sheet iron are arranged which-
are supported by angle iron or in some other suitable manner.
:

page_text: The vessels or receptacles a¹ to a³ are each provided with an overflow pipe which
is in each vessel or receptacle placed at the opposite end to the overflow pipe of
the vessel above, so that the filtered matter flowing through the pipe c into the first
shallow dish like vessel or receptacle a¹ has to pass from one of the said vessel to
the other in order to flow into the second vessel or receptacle a² and from here
through the whole length of the same to the next vessel or receptacle a³ and so on
until the filtered matter finally passing out of the vessel or receptacle a³ is collected
in the lower part or base / of the receptacle A formed by the partition and can
be led off by the pipe i.
In this receptacle A a second row or series of similar but smaller dish like vessels
or. receptacles 61 to 6s is arranged, the overflow pipes d' to 8 of which are also
situated at opposite sides to each other. These vessels or receptacles are supplied
by the tube h with sulphuric acid SO, of about twenty five per cent strength which
can be led off through the pipe f and any overflowing sulphuric acid is collected
in the smaller space of the receptacle A which said space is formed by the
partition Z.
The outlet pipes c¹ to c and d to d³ are provided with appropriate hoods. The
vessel or receptacle A is provided with a tube g which is connected to a vacuum
apparatus in order to evacuate the vessel or receptacle A whereby the process is
carried out without special heating, although at the same time a rapid evaporization
of the ammonia is effected.
The process to be carried out by the apparatus and the operation of the same
will be readily understood.
The filtered alkaline matter is fed into the vessel or receptacle A in which a high
vacuum is maintained so as to facilitate the rapid evaporization or volatilization of
the ammonia contained in the matter or material operated on, on its long passage
through the series of vessels or receptacles, which said ammonia will be immediately
absorbed by the sulphuric acid which by means of a similar arrangement of
analogous vessels or receptacles, is also compelled to offer the largest possible
surface, consequently a sulphuric acid solution of ammonia will pass off through
the pipe and the filtered matter which has been freed from the aminonia it
contained, will flow off through the pipe or tube i. These pipes faud i may be
connected by air pumps and the process accelerated by suction.
At the beginning of this specification it was stated that the sewage or waste
waters were freed from the sludge by means of filtration and that the various parts
of the slush or sludge were separated by suitable filtering cloths according to the
component parts of the same as required for obtaining the fats or grease, fatty acids,
fibrous matter (hairs, feathers, flax, cotton, paper and wood fibres) phosphoric acid
and nitrogen contained in the same.
The succession of the operations depends on the composition or component parts
of the kinds of slush or sludge to be treated. As a rule I commence with the
operation for obtaining the fats by one of the known methods of extraction whilst
on the other hand the fatty acids are previously made free.
The fibres are cleansed by washing the same with water acid and lye or
oxychloride of lime. Those parts of the same which cannot be utilized for making
fabrics, felt, paper, cardboard or papier maché is worked up for obtaining ammonia
or manure or both. The sludge which has been deprived of the fibrous matter,
fats and fatty acids is precipitated by means of lime, alumina, ferric salts or other
suitable matter and treated for the manufacture of manure.
Those parts of the said sludge, which do not permit of any other commercial
utilization are besides being treated in the above described manner, also subjected
to further treatinent for obtaining the ammonia id est. by converting the sludge
into gas in the apparatus shown in a vertical section in Figure 4 and in plan in
Figure 5.

page_text: In order to carry out this operation the sludge is first dried and then placed in a
gas generator B which is lined with a layer of fire bricks m, where the gasification
takes place, the combination being accelerated by a steam injector.
The increased temperature, caused by the combustion of the steam mixed with
air, causes the greater part of the nitrogen in the organic matter contained in the
sludge to be separated in the form of ammonia. The generator should be filled so
high that the carbonic acid is as far as possible reduced to carbonic oxide. The
products of combustion which contain ammonia pass from the generator B through
the tube into the condensor C which is of ordinary construction and are there
cooled down to such an extent that the tarry products and ammonia water are
separated out and can be led off through the cock p which latter is provided with
a syphon trap.
The uncondensed gases are led through the tube q to a scrubber D where they
are thoroughly washed by water which is supplied and finely divided by means of
an appropriate rose. The ammonia is absorbed by the water which is led off
through the tube 8. The last particles of volatile ammonia pass from the
scrubber D through the tube r into a second scrubber E where they are thoroughly
washed with a weakened solution of sulphuric acid which is led off through the
pipe t.
The products of combustion are led off by the pipe u and may be utilized for
heating purposes. The said gases which are now free from ammonia can be
employed for illuminating or heating purposes. The condensed tar is led back into
the generator for combustion unless it is found advisable to employ the same for
other technical purposes.
The ashes remaining in the generator give an excellent manure, which may be
used either in this state or after previously being treated with an acid. The great
amount of phosphorous which this manure contains, makes it specially valuable for
such said purpose.
The apparatus shown in Figures 1 to 3 may also be subjected to a modification
in such manner that instead of the receptacle with the vessels a¹ to a³ cylinders
may be used and in place of the shallow receptacles, layers of coke or stones may
be employed, upon and over which the filtrate or the acid (the latter naturally by
itself) can flow in order to offer the advantages of the largest possible surface.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed we declare that what
we claim is
1. The process for extracting the ammonia and the matter for the formation of
the same from the filtrate or sludge or slush of sewage and other waste waters,
which process is characterised by,
a) the treatment of the filtered, alkaline filtrate in a vacuum apparatus by means
of an aqueous solution of sulphuric acid or
b) the gasification of the dried sludge and the employment of a combined air and
steam blast, the washing of the ammonia with a weakened solution of sulphuric
acid in specially provided scrubbers which takes place after the products of
gasification have passed a series of condensers substantially as described in the
foregoing specification.
2. The apparatus, by means of which the process described in claim 1 is carried
into effect consisting of,
a) the receptacle A which is evacuated by means of the tube g, which said
receptacle is provided with a number or series of flat or shallow dish like vessels a¹
to a for the reception of the filtrate and a number of other smaller vessels or
receptacles d¹ to d³ for the aqueous solution of sulphuric acid all of which said
vessels or receptacles are so arranged, that the fluids which are led into the upper

page_text: vessels or receptacles have to pass through overflow pipes situate at opposite ends
to each other in order to reach the next lower vessel or receptacle.
b) the generator B in which the gasification of the sludge by the aid of the
,steam blower or injector n is effected which said gas then passes off through
the pipe o into the condensers C and from thence to the scrubbers D and E from
which the fluid containing the ammonia can be led off by means of the pipes or
tubes p 8 and t substantially as described in the foregoing specification and shown
in the accompanying drawings.