IMPROVED METHOD AND APPARATUS FOR "PURIFYING TOWN SEWAGE AND FOR RENDERING USEFUL THE SOLID PARTS OF SAME
Year: 1882

page_text: LETTERS PATENT to Peter Jensen of 33 Chancery Lane in the County of
Middlesex for an Invention of IMPROVED METHOD AND APPARATUS FOR
"
PURIFYING TOWN SEWAGE AND FOR RENDERING USEFUL THE SOLID PARTS
OF SAME"
A communication to him from abroad by Hermann Betche of
Magdeburg, Engineer, and by the firm of Zeppernick and Hartz of Berlin both
in the German Empire
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office
of the Commissioners of Patents on the 21st November 1882.
PETER JENSEN of 33 Chancery Lane in the County of Middlesex
"IMPROVED
METHOD AND APPARATUS FOR PURIFYING TOWN SEWAGE AND. FOR RENDERING
USEFUL THE SOLID PARTS OF SAME" (A Communication to me. from abroad by
Hermann Betche of Magdeburg, Engineer, and by the firm of Zeppernick and Hartz
of Berlin both in the German Empire)
According to this invention town sewage is treated in the first instance with the
view of separating the solid manurial constituent parts therefrom in order to
prevent the ground from being choked or glutted there with when the liquid is used
for irrigation while the solid parts are dried and treated for other uses; or the
sewage is separated in its solid and liquid parts and the latter then filtered in a
peculiar manner so as to purify it entirely and render it free from noxious parts
and suitable for running off into any natural watercourse.
The sewage from the main sewer pipe is run into a collecting reservoir or well
and is thence by means of pumps delivered into a tank in which it is mixed with a
thin solution of sulphate of alumina; it then passes to a number of centrifugal
separating and filtering machines the rotating baskets of which have double
perforated walls between which spongy material is placed, the sponge being
rendered imputrescible by treatment with iron tannate.
The liquid coming from these machines may as required be led directly onto the
land for irrigation, as the sewage is so far purified that the land cannot become
LD.

page_text: choked up. The solid parts remaining in the centrifugal machines are conveyed to
heated drying rooms and may then be utilized as manure.
But if the sewage is not to be used for irrigation but to be led away to a natural
watercourse it will after leaving the centrifugal machines require a further purifi-
cation and by the following arrangement which in contradistinction to other
heretofore used arrangements for such purpose is not only of a peculiar form but is
especially of great practical importance and advantage because by the previous
removal of the solid parts by the centrifugal machines as hereinbefore described
these solid parts do not come into the filters which latter therefore act better and
last longer and hence cause less expenditure in proportion.
From the centrifugal machines the liquid sewage is conveyed to a reservoir from
which by pumps it is passed into an air vessel and thence into the bottom part of
the filter compartments containing pieces of peat free from iron and sawdust,
The liquid sewage rising
and having upper layers of peat steeped in tar.
up through these filters gives up the greater part of its dissolved manurial substances
and passing up over the edge of the filters (which may be arranged in the form of
a round tower divided into four sector compartments) contain only small quantities
of such substances that might be injurious to a natural watercourse. But in order
also to remove these or to render them innocuous the liquid may, as it overflows
the top edge of the filter be mixed with milk of lime which issues from a pipe all
along the edge of the filter.-The overflowing liquid runs down through a filtering
medium or graduation appliance around the upper part of the filter. The milk of
lime binds the carbon dioxide contained in the sewage water, and the carbonate of
lime so produced settles in the graduating medium and the atmospheric air to
which the liquid is exposed as it runs down through the graduating medium
oxydises the other remaining gaseous parts and especially the ammonia.
From the graduation appliance the liquid runs into a secondary filter charged
with peat and arranged around the lower part of the filter tower and penetrating
this secondary filter it flows off below perfectly purified through holes in the lower
part of the circumference and runs into a channel formed all round it and charged
with Swedish iron ore so that a third or final filtration takes place therein
The filtering material in the filtering tower has to be replaced from time to time
for which purpose the compartment in question may be shut off from the delivery
pipe by means of a valve. The filtering material saturated with manure is mixed
with solid parts from the centrifugal machines dried in drying rooms and heated
above 212° F so that all substances injurious to health may be thus destroyed. The
manure obtained contains all the manure substances originally contained in the
sewage and forms an excellent manure while noxious sewage is rendered perfectly
harmless,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Jensen in the Great Seal Patent Office on the 21st May 1883.
PETER JENSEN of 33 Chancery Lane in the County of Middlesex " IMPROVED
METHOD AND APPARATUS FOR PURIFYING TOWN SEWAGE AND FOR RENDERING
USEFUL THE SOLID PARTS OF SAME (A communication to me from abroad. by
Hermann Betche of Magdeburg Engineer and by the Firm of Zeppernick and Hartz
of Berlin both in the German Empire)
According to this Invention town sewage is treated in the first instance with the
view of separating the solid manurial constituent parts therefrom in order to
prevent the ground from being choked or glutted therewith when the liquid is used
for irrigation while the solid parts are dried and breated for other uses, or the
sewage is separated in its solid and liquid parts and the latter then filtered in a
peculiar manner so as to purify it entirely and render it free from noxious parts
and suitable for running off into any natural watercourse. And in order that this
Invention may be fully understood I will now describe the same with reference to
the accompanying drawings of which Figure 1 is a vertical section through sewage
works arranged and operating according to this Invention and Figure 2 a plan of
sane Figure 3 is a vertical transverse section through a centrifugal apparatus
employed in this process Figure 4 a plan and Figure 5 a perspective view of a part
of the apparatus.
The sewage from the main sewer pipe A¹ is run into a collecting reservoir or
well A and is thence by means of pumps B delivered into a tank C in which it is
mixed with a thin solution of sulphate of alumina, it then passes by a pipe D to
a number of centrifugal separating and filtering machines E which are illustrated
separately by Figures 3, 4 and 5 and the rotating baskets e of which have two or
more perforated walls such as e e2 and Figure 3 between which spongy
material is placed, the sponge being rendered imputrescible by treatment with iron
tannate.
The liquid coming from these machines may as required be lead directly on to
the land for irrigation, as the sewage is so far purified that the land cannot become
choked up. The solid parts remaining in the centrifugal machines are conveyed to
heated drying rooms F and may then be utilized as manure:
In filtering the sewage waters by means of the above described centrifugal
apparatus, the precipitated matters deposited on the inner wall e¹ of the centrifugal
apparatus in a comparatively speaking, short time forin an impermeable layer
which prevents all further filtering and consequently has to be removed. Now for
the purpose of being enabled to effect the removal of this layer during the rotation
of the centrifugal apparatus, and thus to attain continuous working a kind of
scrapers are provided in the centrifugal apparatus which "drag" along the inner
wall of the centrifugal apparatus rotating with the centrifugal apparatus either at
a higher or a lower speed.
On a hollow shaft a (Figure 3) with a driving pulley b is mounted the filter
basket e. Through the hollow shaft a passes the spindle c likewise provided with
a driving pulley d which just above the bottom of the basket, carries the inlet
cone f, on this, arms are arranged in pairs say as shown in the drawing two
pairs g, g and h, h¹ whose ends are forked (Figures 4 and 5) so as to receive and
guide the scrapers V. these form a narrow hollow body (Figure 5) open in front and
obliquely rising towards the rear; the thin wall i of the same is properly speaking
the scraper, and may advantageously be constructed of thin elastic metal plate.
On the inner wall k are provided the lugs Ɩ, by which the scrapers loosely take

page_text: into the forked slots of the arms g, g¹ nnd h, h' so that the scrapers can avoid
irregularities, such for instance as untrue revolution of the filter basket or of the
arms, or adapt themselves to the same. The scrapers and the basket e of the
centrifugal apparatus revolve at different velocities so that the former either race
or lag behind and thus have a motion relatively to the walls. of the basket,
travelling along the same, thus scraping off the mud that deposited receiving the
same in their interior. The continually following mud creeps up along the rear
wall of the scrapers and is discharged from the opening m at the top, it is caught
by the guard-plate n and flows away by the pipe o.
To avoid that the scrapers be pressed against the wall of the filter by
centrifugal force during rotation, and be in this manner carried away by the
same, the counterweights are provided. These are adjustably fixed on the
levers having their fulcra in the upper arms g and h respectively and are jointed
to the scrapers V₁
The counterweights p are so put in equipoise with the scrapers V that the latter
only just touch the inner walls of the filtering basket during rotation Instead of
counterweights springs may be employed, or the scraper may be made without
special counterweight if the outer or upper part of the scraper is made heavy
enough for the centrifugal force to press it against the inner wall of the basket.
If the liquid part of the sewage after the centrifugal filtering treatment is not
to be used for irrigation but to be lead away to a natural watercourse it will after
leaving the centrifugal machine require a further purification and by the following
arrangement which in contradistinction to other heretofore used arrangements for
--such purpose-is not only-of a peculiar form but is especially-of great-practical-
importance and advantage because by the previous removal of the solid parts by
the centrifugal machines as herein before described these solid parts do not come
into the filters which latter therefore act better and last longer, and hence cause less
expenditure in proportion.
From the centrifugal machines E the liquid sewage is by passages G conveyed to
a reservoir H from which by pumps I it is passed into an air vessel K and thence
by a delivery pipe L' into the bottom part of filter compartiments M, containing
peices of peat free from iron, and sawdust and having upper layers of peat steeped
in tar. The liquid sewage rising up through these filters gives up the greater part of
its dissolved manurial substances and passing up over the edge of the filters (which
may be arranged in the form of a round tower divided into four sector
compartments) contain only small quantities of such substances that might be
injurious to a nateral watercourse. But in order also to remove these or to render
them innocuous the liquid may as it overflows the top edge of the filter be mixed
with milk of lime which is supplied by a pump N from slake-troughs and
issues from a pipe P all along the edge of the filter. The overflowing liquid runs
down through a filtering medium or graduation appliance Q around the upper part
of the filter. The milk of lime binds the carbon dioxide contained in the sewage
water, and the carbonate of lime so produced settles in the graduating medium Q
and the atmospheric air to which the liquid is exposed as it runs down through
the graduating medium Q oxydises the other remaining gaseous parts and
especially the ammonia.
From the graduation appliance Q the liquid runs into a secondary filter R
charged with peat and arranged around the lower part of the filter tower M, and
penetrating this secondary filter it flows off below perfectly purified through
holes in the lower part of the circumference and runs into a channel S formed all
round it and charged with Swedish iron ore so that a third or final filtration takes
place therein,
The filtering material in the filtering tower has to be replaced from time to
time for which purpose the compartment in question may be shut off from the
delivery pipe L by means of a valve L. The filtering material saturated with
manure is mixed with solid parts from the centrifugal machines, dried in drying
rooms and heated above 2125 F so that all substances injurious to health may bo

page_text: thus destroyed The manure obtained contains all the manure substances originally
contained in the sewage and forms an excellent manure while noxious sewage is
rendered perfectly harmless.
I claim as the Invention communicated to me.
First. The combination of parts forming the improved centrifugal machine E
having a ring filter basket with two or more perforated walls and a scraper
for the purpose of separating liquid from solid parts while the latter are
continuously removed all substantially as described with reference to Figures 3, 4
and 5.
Second-The combination of apparatus for purifying town sewage consisting
in the centrifugal machine E, the filter compartments M which receive the liquid
from the machine E, and the filter Q which causes the oxidation of the ammonia
in the liquid mixed with lime while the latter mixture overflows the edge of M
substantially as described with reference to Figures 1 and 2.
Tbird The combination of apparatus for purifying town sewage consisting in
the centrifugal machine E, the filter M, the filter Q, the secondary filter R
which is charged with peat and the channel S containing iron ore from which
the purified liquid passes off, substantially as described with reference to
Figures 1 and 2.
In witness whereof I the said Peter Jensen have hereunto set my hand and
seal this Twentyfirst day of May in the year of our Lord one thousand
aight hundred and eighty three