A New or Improved Process and Apparatus for Purifying and Utilizing Town Sewerage.
Year: 1897

page_text: Date of Application, 31st Mar., 1897
Complete Specification Left, 23rd Dec., 1897-Accepted, 26th Mar.,
1898
German Empire.
A New or Improved Process and Apparatus for Purifying and
Utilizing Town Sewerage.
I, GUSTAVE ADOLPHE DE KATOW, of 93 & 94, Chancery Lane, in the County
of London, England, Engineer and Patent Expert, do hereby declare the nature
of this invention to be as follows:
My invention relates to a new or improved process and apparatus for purifying
aud utilizing town sewerage.
The purification of town sewerage and the utilization of the manure extracted
therefrom has not hitherto been successfully accomplished notwithstanding many
experiments undertaken in this direction.
In carrying his invention into practice the inventor proceeds by first removing
as quickly as possible the solid floating matter before it has had time to be de-
composed to some extent, that is to say before the impurities have had but a slight
action on the water and still retain to a great extent their value as manure.
According to this treatment the purification of the water must be effected as fast
as the sewerage runs into the main sower, and this is obtained by the following
process comprising four stages or operations that is to say::
I. The mechanical removal from the sewerage of all coarse particlos having
a size of about 15 mm. and hence the separation of matter having more value
for other purposes than manure, such as rags, paper, candle ends, soap, coke,
wood and the like. The separation of such material has this further advantage
that it offers no impediment to the subsequent removal of the remaining solid
matter which is converted by the operations hereinafter set forth into practically
utilizable manure.
II. The removal of sand from the water and its subsequent washing for practical
use.
III. The removal of all accessible floating matter having a size of from
4 to 6 mm. or thereabouts.
IV. The removal of all remaining accessible floating matter which before such
removal served to filtrate the water.
These four operations suffice for most purposes, but if the sewerage still requires
further treatment it is subjected to the following additional operations viz.:
V. The mechanical and chemical purification or clarification of the sewerage
by the addition of very small quantities of lime in the form of saturated lime
water (but not undissolved lime) as well as the precipitant known as peat, moss
or other vegetable fires. The water is thereby not only freed from alkalies but
the value of the precipitated matter as manure is greatly enhanced, the latter
being so porous that it can be dephlegmated or drained which could not hitherto
have been done unless enormous quantities of lime had been added. The precipi-

page_text: tates are always extracted in a pasty consistence without having to interrupt the
chemical and mechanical clarifying process.
6. The mixture of all the portions of the sewerage separuted in the manner
indicated under §§ 3, 4 and 5. In small towns the product thus obtained, which
can be used as manure by farmers, is generally heaped up, but in larger towns
and in places where there is no room for such heaps or where there is an objection
to them on sanitary grounds, they are pulverized and dried by evaporation so BS
to form therewith good and valuable manure in the form of dry and easily trans-
portable bricks or tablets which are pulverized when required for use.
By means of this process for purifying sewerage there is no need for great
reservoirs, as the mass of running liquid sewerage is cleaned as quickly as it runs
into the sewer.
The impurities of the water have not to be decomposed so soon as they arrive
in the clarifying basins and hence the following advantages are obtained:
1. The purification of the sewerage is facilitated in consequence of the impurities
being removed in a concentrated form.
2. The removed matter is highly valuable as manure. When decomposition
was allowed to take place, however, a considerable amount of manure was lost,
but as according to this treatment decomposition cannot take place in the clari-
fying basins, no manure can be lost.
3. The process can be carried on within a very small enclosure and in any
suitable place without giving rise to complaints.
4. The gradual treatment automatically carried on by machinery according
to the new process has further the advantage that one set of apparatus relieves
the other and as in the course of this gradual treatment several products are
formed these can be treated by one of the operations described.
The process is a combination and includes mechanical as well as chemical purifi-
cation, whereas hitherto either one or the other of these treatments was resorted to,
but more generally the latter.
To carry out the new process partly improved new contrivances, in so far as thoy
have been found suitable for the purpose in view, and partly novel and special
apparatus are used.
In the first stage or operation all clods having a size larger than 15 m/m are
removed from the sewerage by the mechanism hereunder set forth.
In the sewer or canal through which the sewerage enters there is arranged
an arched grating, the bars of which are fixed at intervals of 15 m/m, so that
the sewerage may pass through the same. Each couple of adjoining bars are
connected and rivetted together by means of intermediate pieces. These couples
are arranged loosely in the canal in close proximity one to the other and "are
subsequently fixed by set screws, so as to form a strong connection carried by
iron rails at the top and at the bottom in such a manner that the different bars
of the grating may be removed and replaced by new ones whenever required. In
front of the grating is arranged a shaft provided with double arms and a comb
the flexible steel arms or teeth of which enter the intervals between the bars.
This shaft is rotated by the main shaft common to all the apparatus, preferably
with the aid of a screw gear, so that its arms may rise, as soon as their combs
pass through the intervals between the bars, the various clods held back by tho
grating. At the end of the bars is arranged a hinged circular sheet iron apron
forming the continuation of the saine, so that the stuff raised may be lifted to the
required height. To this apron is rivetted a scraping board. When the comb
aforesaid has reached the extreme end of the apron the scraping is effected by
means of suitable brushes fixed to an oscillating pendulum. If this pendulum,
which is actuated by the first mentioned shaft, an excentric, a weighted lover and
a chain passing round a roller carried by suitable uprights, was unable to act, the
comb would raise, as it rotates the brushes with the pendulum. After the comb
has passed under the brushes, the latter fall back by gravity into their working
position. The combed up stuff is thrown upon a slant table and is removed there-

page_text: from by an endless travelling band; such material as rags, paper, soap, candle
ends, cork, wood &c., being picked up by hand and thrown into baskets while the
remainder is automatically carried off by a travelling band into a waggon or the
like. After its passage through the grating, the water is freed from all solid
substances of a larger size than 15 m/m which it contained. Amongst theso
substances sand plays a very important part and is removed at the following opera.
tion.
II. The sand is treated by the following appliances the proper working of which
has been tested in experimental works.
The sandy particles carried away into the canal have a tendency to accumulate
and settle on a movable bottom arranged slightly below the hottom of the canal
proper, a suitable pit being dug under this movable bottom. The particles of
sand remain thus longer in suspension and are carried away by the stream of
water and deposited in greater quantity on the movable bottom than down in the
sand pit. At first the sewer or canal behind the grating maintains its sectional
area, the water runs slowly and the sand has time to deposit. Hinged iron plates
form the movable bottom, their ends overlapping one another. At the end of
each plate is arranged a transverse rail about 5.10 m. high and the whole iron
bottom surface is about 10 cm. below the usual canal bottom so that the sand,
hemmed in by the said cross rail at the top, is bound to settle down. Below the
iron bottom plates is constructed a walled sand pit, the walls of which taper down-
ward after the manner of a hopper. The sand settles at the top on the bottom plates
aforesaid and as these are deeper than the ordinary canal bottom, the water
flushes constantly the different layers of sand and cleans them. From time to
time one of these plates is dronned down by the aid of chains and is raised again
after the sand has fallen therefrom into the sand pit. This work is done by the
same operative who attends to the first set of apparatus. The sand is removed
by a hoisting apparatus into a suitable truck or waggon.
III. In the third stage of the process the sewerage ridden from coarse material
and sand is freed from the average fixed substances having a size of 5 to 6 m/m.
The apparatus used for this purpose resembles that described under I, the bars
of the circular grating built in the sewer or canal are tapered in such a manner
that the intervals between these bars on the side through which the water enters
are from 5 to 6 m/m wide while on the other side they reach a width of about
10 m/m; this arrangement has for its object to prevent the grate from being
obstructed. The comb used in this case consists of a number of steel plates toothed
like a saw the teeth of which are twisted at the top to strengthen the same. This
middle grate. operates automatically and serves to relieve the appliance which
operates first being used to carry out the fourth stage of the process.
IV. This stage or operation being of paramount importance requires some pre-
liminary explanation:
The finest particles of solid substances contained in the sewerage were hitherto
left therein, for two reasons, 1, because it had not been found possible to remove
them by mechanical means from large quantities of sewerage and 2, because when
the water was subsequently purifyed by chemical means these substances were
supposed to act as precipitants which, after the addition of the chemical precipitant,
were to sink to the bottom with the precipitate formed by the latter, thus in-
creasing the quantity of such precipitates which carried down with them even
the finest particles of solid substances.
Experiments have proven however, that such supposition was erroneous.
The floating, particles in question do not act as precipitants but require the use
of precipitates to make them sink which, they being heavier, do more rapidly
than the finer particles, but they do not carry the latter away with them as assumed,
Moreover the fatty matters
but pass to the greatest extent in advance of the same.
contained in the water cannot be made to sink with the aid of precipitants but
remain on the surface: These considerations have led to the decision that when-

page_text: ever possible all accessible substances should be removed by mechanical means.
Before their removal the finest particles will be utilized in another manner aud
will serve as filtering means to suck up still finer particles.
To carry on this purifying operation, appliances of special construction are
used being provided with very fine openings which must not be obstructed so as
not to interfere with the continuity of the operation.
All experiments tried in this direction with sieves & perforated metal sheets
whether arranged over straight surfaces or drums have proved fruitless. The
meshes and the perforatious are soon obstructed, the cleaning is very difficult
and even water under pressure has been found of no avail to remove such ob-
structions.
The appliances hereinafter described, which havo on the contrary produced
a most satisfactory result, consist of two or more light frames of forged iron
having the same size in height and width as the sewer or canal. These frames
are covered with wires fixed like the chords of a harp and leave throughout their
length free openings 1 m/m or less in width. The whole surface which is opposed
to the flow of sewerage is smooth; free and straight and can be readily cleaned.
The two frames are arranged at a distance of about 1 metre in the canal and are
held by suitable guides obliquely to the direction of the water.
The dirt contained in the sewerage adheres to the wires and forms a filtering
layer which retains even the finest floating particles. When this appliance has
become so thick as not to allow the passage of the necessary quantity of water,
the first frame, provided on both sides with racks, is raised by means of a suitable
gear. On its way up the filtering mud is removed by a circular brush and is
thrown on a travelling baud. A slowly rotating roller likewise wiped by the
brush is arranged between the frame and the travelling band. When the rack
has run through, the frame remains standing still. The same gear is now used to
bring it back along its guides into its former position in the canal and is wiped
by the above brush on its return. While one of the frames is thus raised the
other frame behind the same catches the fine particles and filters the water. The
circular brush of each frame is only temporarily at work and rotates freely in
the air for the rest of the time during which it cleans itself, the brushes remaining
thus clean and stiff. This mechanical cleaning process can thus be carried on
almost to perfection by sufficiently increasing the number of frames and reducing
the size of the openings and it only consumes a few minutes that is to say only
just enough time not to retard the speed of the water running through the
apparatus. When the sewerage is cleaned but a short time after its appearance,
so that the decomposition of the solid particles has not yet cominanced and if no
injurious chemical refuse is mixed thereto, this mechanical cleaning process is
sufficient to allow the cleaned water to run into open rivers. But if such is not
the case the fifth stage of the general process that is to say a subsequent chemical
and mechanical purification must be resorted to.
V. Before the mechanically cleaned water enters the two basins wherein it is
treated the precipitant is added thereto. In these basins are arranged rows of
hoods through the centre of which passes a pipe. The water which is divided by
each row into as many streams as there are hoods in the row ascends and finds
no other outlet than an opening provided at the top between each two adjoining
hoods. The central pipe of each row receives the clean water and raises it to the
above outlet. The scum or sediment deposited on the hoods acts again as a filtering
medium and slides off when it has accumulated in sufficient quantity in order to
fall in a bucket whence it is brought to the surface by a dredging engine and is
discharged into suitable trucks or wagons. Amongst the precipitants used a
very small quantity of lime is added in the form of saturated lime water, so as to
merely utilize the hydrate of lime. This small addition of lime water is rendered
necessary in consequence of the above described mechanical purification and of
the use of other precipitants which consist mainly of ground peat or of the paper
pulp extracted from the said purification and specially treated. By the uso of

page_text: these precipitants very good precipitates are obtained and as they are porous
they can be subsequently dephlegmated or drained. It is obvious that according
to the particular nature of the sewerage other precipitants may be used.
VI. In conclusion, all the residual matters are mixed together. When as
aforesaid the manure cannot be stored in heaps all the residual matters extracted
during the 3rd, 4th and fifth operation aforesaid are mixed together, reduced
into powder and dried in a contrifugal machine or in a filter press according to
the nature of the product; ashes being added thereto if needed. The stuff is after-
wards made into cakes tablets or bricks and is dried in the open air or by heat
when it is packed in this form or that of a powder into sacks which are sent off
wherever required as manure.
A New or Improved Process and Apparatus for Purifying and
Utilizing Town Sewerage.
I, GUSTAVE ADOLPHE DE KATOW, late of 93 & 94, Chancery Lane, and now of ?,
Featherstone Buildings, Holborn, Engineer, Linguist and Patent Expert, 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 a new or improved process and plant for purifying and
utilizing town sowerage and consists in removing the matter contained in the water
as soon and as rapidly as possible, so that the decomposition of such matter has
not yet or only slightly set in.
By such quick removal of the matter, the obvious advantage obtained is that
the chemical action of the impurities upon the water is still very slight and that
they retain. their value as a fertilizer.
To attain this purpose it is necessary that the purification of the water be carried
on as soon as it reaches the main sewer, and this is effected by the method em-
bodying the four or six following different steps or stages.
First. A mechanical cleaning of the refuse water from all coarse bodies up to
about 15 millimeters in size, coupled wth an easily effected separation of all matter
that may advantageously be used for other purposes, as for instance rags, paper,
candle pieces, soap, cork, wood, etc. The separation of these bodies is likewise
effected for the purpose of preventing them from becoming prejudicial to the
separation of the remaining matter which are principally formed into fertilizer
or manure during the following operations.
Second. The separation of the water from sand and the cleaning of this sand.
Third. The separation of all tangible lumps or bodies up to a size of 4 to 5
millimeters.
Fourth. The separation. of all remaining floating bodies, which however before
being removed from the water,.serve to filter the same.
These four steps answer the purpose in many instances. If however, a higher
degree of purity of the water is desired, the two following steps are embodied
in the process, viz. :-
Fifth. A chemical and mechanical cleaning of the water by adding thereto
the precipitating means until the said water assumes a flaky state when it is con-

page_text: veyed into one or more settling tanks or basins containing clarifyers whereon
these flakes are deposited and from which they drop down by gravity to the deepest
part of the basins whence they are removed by a dredging engine, while the clear
water runs from the top of each clarifyer into a discharge pipe.
Sixth. The mixing of all refuse, soparated by the operations specified
sub. 3, 4 and 5. In smaller cities, this matter, which is used as a fertilizer or
manure without any further operation, and is directly removed for agricultural
purposes, is piled up in compact heaps. In larger cities, or in such places where
there is no room for piling up the heaps or where this cannot be done for sanitary
reasons, the refuse is mixed and at the same time disintegrated and dried, and
in this way a highly valuable fertilizer in the form of bricks is obtained, which
is pulverized when used as a manure.
In my method of purifying the refuse water, any collection of this water in
large basins is avoided, because the water is purified as it arrives in the plant.
Consequently the decomposition of the impurities in the water is stopped when
the water reaches the cleaning plant, and I hereby obtain the following advan-
tages:
1. The cleaning of the water by chemicals is greatly facilitated and but a small
quantity of precipitant suffices therefor, as all the coarse bodies and particles
have been previously removed at a small cost, and as they contain no chemicals
they have a higher fertilizing value.
2. The process can be carried out in a very limited space and at any desired
place, without giving cause for complaint.
3. The gradual operations as embodied in my process, are performed automati-
cally by machines, one machine relieving the other.
The mechanical means used for carrying my new method into practice are
illustrated in the annexed drawings, forming a part of this Specification, and
wherein :
Fig. 1 shows a plant for the mechanical purification of refuse water.
Figs. 2, 3 and 4 show the several mechanical means on a larger scale.
Fig. 5 shows chemical and mechanical cleaning appliances, which are used
in connection with the plant illustrated in Fig. 1, if the mechanically cleaned
water should still require a chemical treatment.
In the first step of my method all bodies larger than 15 millimeters are
removed from the water. The means used for this purpose are illustrated in
Figs. 1 and 2.
In the sewer A the curved grate a is so placed that the water flowing_through
the sewer in the direction of the arrow must pass through the grate. The bars
of this grate are at a distance of 15 millimeters from each other and they are not
connected by cross bars running the full width of the sewer, but each couple of
bars are kept together by connecting pieces. They are loosely placed in the sewer
one besides the other and then assembled by suitable set screws.
I thus obtain a solid grate, the bars resting at both ends in suitable supports,
while if necessary the bars may be readily removed and replaced. Before the
gpate is arranged the rotary shaft with double arms C C and comb e, the
elastic teeth of which engage in the grate openings.
The shaft derives its rotary motion from the shaft B common to all devices,
preferably by means of a worm gear as shown, so that the teeth of the comb c,
passing between the grate openings, move all matter retained thero upward. At
the upper end of the grate is arranged a hinged shell a forming an extension
of the grate, and adapted to enable the combs e to raise the matter sufficiently
for its further convoyance. A discharge table d is rivetted to this shell a', and
when the comb c has reached the end of the shell, the adhering matter is removed
by means of a brush e connected to the pendulum E.
This pendulum is set in motion by the shaft by means of the eccentric f, the
weighted lever F and the chain i passing over the roller h, arranged in the sup-

page_text: port H. If through any cause this pendulum should not operate, the comb will
raise the brush which is loosely suspended in the pendulum as shown in the
drawing. As soon as the pendulum and its brush have operated they will drop
again by gravity into operative position while the comb continues to rotate.
The matter brought up by the comb is deposited upon the inclined table d
and thus slides on an endless travelling belt. Articles such as rags, paper, soap,
cork etc., are removed by hand and thrown into baskets, the rest being automati-
cally removed into a car or similar device for further conveyance.
The water is thus released of the coarse objects and passed through the grate a
charged with all further impurities of a size less than 15 millimeters. Among
these impurities sand is found in rather considerable quantity, and this sand is
removed in the second operation.
This operation is based upon the following principle, the correctness of which
has been demonstrated by experiments. The particles of sand carried along by
the water have a tendency to collect on the bottom, if same is slightly lower than
the normal bottom of the sewer, rather than in a so called sand trap of considerable
depth interposed in the sewer. In the latter case the particles of sand remain
floating longer, are carried forward by the current of water and settle more on
the bottom of the sewer behind than in the sand trap.
"The channel A behind the grate a is continued in straight line and of uniform
dimension. The water flows slowly through the channel, so that the sand can
settle. At this place, the bottom of the channel is formed by hinged metal
plates k, (eight of these plates being shown in Fig. 1), the ends of which overlap
each other as shown. At one end of each of these plates is arranged a cross rail k¹
of about 5 to 10 centimeters in height, and the whole length of the bottom formed
by the series of plates is about 10 centimeters below the normal bottom of the
channel, so that the sand which is moreover retained by the cross rails ¹ will
settle upon these plates.
Underneath these plates is the receptacle K, made of brick work, the walls
of which incline toward each other in funnel shape. The sand settles upon the
plates as explained, and as same are arranged slightly below the bottoni of the
channel, the water will flow continuously over the several layers of sand and
clean it.
From time to time the plates are tilted our after the other by means of the
chains passed over the pulleys L, and again raised into position after the sand,
settled on the plate, has dropped into the receptacle K. The sand is removed
from the pit K by a suitable dredge X.
In the third step, the water already released from the coarse objects and sand,
is freed from the bodies larger than 5 to 6 millimeters.
The apparatus employed for this purpose is essentially similar to the one used
for the first operation. but the bars of the grate are formed so as to present
passages from 5 to 6 millimeters at the front, but widening to about 10 millimeters
at the back of the bars, in order to prevent a clogging up of the passages. In
this device the combe is not formed as in number oue of separate teeth but of
sheets of steel, equipped with saw like leeth, each tooth being twisted so as to
increase its strength.
This device can be allowed to operate without any attendance.
The fourth step in my method is of special importance and requires some
explanatory remarks.
Hitherto the fine bodies floating in the refuse water were allowed to remain
therein, in the first place because in large quantities of water their removal by
mechanical means was not practicable, and in the second place because in case the
water was submitted to a subsequent chemical cleaning, these bodies were con-
sidered to provide additional means for forming the sediment after the precipitant
had been brought into the water, in so far as these bodies will settle with the
sediment formed by such precipitant and thus increase the sediment, which was
supposed to carry along the finest matter with it.

page_text: Repeated experiments have shown this theory to be incorrect. The swimming
objects do not constitute precipitants but they require a precipitant. With such
precipitant they will obviously settle quicker than the finer matter because they
are heavier, but they do not carry such finer matter along, as was generally
assumed, but leave same for the greater part floating. As to fatty matter grease
and the like no precipitant will cause them to settle.
It is therefore reasonable to assume that as far as possible all tangible bodies
should be removed by mechanical clarification. These fine bodies should however
be caused to cooperate in a different way i.e. by using them as filters for the
absorbtion of still finer matter.
In order to effect a purification as specified, special arrangements are required
with very fine passages whereby the great danger of clogging is avoided, so that
the continuous operation be not interrupted under any circumstances. All experi-
ments made with sieves or perforated sheets, either of straight surface or of drum
form have not yielded satisfactory results. The mashes and perforations become
clogged up very soon, the cleaning is very difficult, even flooding with water under
pressure being not adequate. With the apparatus which I am now proceeding
to describe, very fine results have been obtained.
The apparatus consists of two or more iron frames M (Figs. 1, 3 and 4) corres-
ponding in height and width to the dimensions of the sewer. The frames are
equipped with metal wires in the manner of a harp, and in this way passages of
1 millimeter or if necessary still smaller are obtained.
In order to obtain a uniform tension of the wires, each couple of wires, is
tightened by a tension screw.
The whole surface presented to the refuse water is perfectly smooth, free and
straight, and can therefore be casily cleaned. The two frames are placed in the
sewer in guide rails m (Fig. 3) at a distance of about 1 meter and oblique to the
current of the water.
The dirt in the water will settle before the wires and thus form a filter layer
that will retain the finest floating bodies. If the layer has become so thick and
compact, that the normal passage of water becomes obstructed, the foremost
frame is raised by throwing into gear a mechanical hoisting device. For this
purpose the frame is equipped at both sides with a rack m¹. During its upward
movement the frame is cleansed by the circular brush n, and the dirt is thrown
on the endless apron N. The slowly rotating roll o, also cleaned by the brush,
closes the space between the frame and the endless apron N. As soon as the
frame is moved to its highest point, it is held in a stationary position by the
counterweight. By releasing such counterweight the frame is then gradually
lowered on its inclined guide into the sewer, and is once more cleaned by the
brush during this downward movement.
During the time that one of the frames is raised, the other one will remain
operative and catch the fine matter and filter the water. It is remarked, that the
circular brush n of cach frame is only operative during the raising and lowering
of the corresponding frame; during the balance of time it rotates freely. During
this time it will clean itself automatically, and in this way the bristles remain
dry and stiff.
By means of this apparatus the mechanical purification of the water can be
brought to a high degree of perfection, especially by increasing the number of
frames or by making the passages between the wires still narrower. This mechani-
cal purification is effected in a few minutes and does not take more time than
required by the refuse water for passing through the apparatus without decreasing
its speed.
If the purification of the refuse water is effected soon after its formation and
if no injurious chemical refuse is contained in the water, the mechanical purification
hereinbefore described, will be entirely sufficient and the water may be safely
admitted into the open streams. If, however, this is not the case, the water is
submitted to the fifth chemical mechanical purification.

page_text: Precipitating means are added to the mechanically purified water, before it is
admitted into the tanks P and Q in which are located the clarifyers p and q.
These clarifyers to which I lay no claim whatsoever and which may be replaced
by any other equivalent arrangement consist of a central tube or stems placed
vortically in the upper part of the tank, closed at its lower end and provided with
a number of holes. Just above the water line, a horizontal discharge pipe is
connected to this vertical tube or stem. A series of shades provided with perforated
central collars are passed over the tubes, the perforations of the collar registering
with the holes in the vertical tube s. It is obvious that the efficiency of these
clarifyers will be in a direct ratio with the number of shades. The water will now
riso between these plates and find no other exit than the holes r. The sediment
will thereby settle on the shades and act there as a filter, and when this sediment
has obtained a certain weight it will slide down the plate and drop into the mud
receptacle provided at the bottom of each basin. The purified water enters
into the central stems and runs out through the pipes t.
The sediment collected in the receptacles is continuously removed by
dredges and dropped into suitable cars provided for this purpose.
The character of the precipitants used depends upon the nature of the refuse
water.
The sixth step in my process constitutes the mixture of the several refuse
matters obtained.
If, the piling up of compact heaps should not be possible, all the refuse matter
obtained by the steps described sub. 3, 4 and 5 are mixed, disintegrated and
pressed dry by means of centrifugal or filter presses in accordance with the nature
of the product, and if necessary with the addition of ashes. The cakes in tho
form of bricks are sold in this shape or pulverized.
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. A plant for purifying refuse water by mechanical means whereby the several
apparatus are placed one behind the other in the sewer so that the water is purified
without any material interruption of its current, substantially as described and
shown.
2: A method for purifying refuse water by mechanical means consisting of the
following steps, first removal of the large bodies down to about 15 millimeters;
second removal and cleansing of the sand; third removal of the bodies down to
about 4 to 6 millimeters; fourth removal of all other impurities floating in the
water, substantially as and for the purpose described and set forth.
3. In a plant of the class described, the combination of a grate located in the
sower in an oblique position with a rotary comb, removing the impurities from the
grate and discharging same on an endless blanket, substantially as and for
the purpose described and set forth.
4. In an apparatus of the class described, the combination of a rotary comb
with a swinging brush for cleaning said comb, substantially as and for the purpose
described and set forth.
5. In a plant for purifying refuse water, a sand trap, consisting of receptacle
provided below the sower and a series of swinging iron plates, located alightly
lower than the bottom of the sewer, substantially as and for the
described
purpose
and set forth.
6. In a plant for the purifying refuse water, the combination of a frame
provided with metal wire strings, placed in an inclined position in the sewer, with
means for raising and lowering said frame and a rotary brush for removing the
dirt from said frame, substantially as and for the purpose described and set forth.
7. In a plant for purifying refuse water, the combination of a basin in which
the smallest impurities are precipitated by means of a chemical precipitant, with
B

page_text: means for continuously removing the sediment from such basin, substantially
and for the purpose described and sot forth.
AS
GUSTAVE ADOLPHE DE KATOW,
7, Featherstone Buildings, Holborn, London, W.C.