IMPROVEMENTS IN THE TREATMENT AND UTILIZATION OF SEWAGE, AND IN MEANS EMPLOYED THEREIN.
Year: 1874

page_text: .
LETTERS PATENT to Burton-Henry Vallé, of Stow-on-the-Wold, in
the County of Gloucester, for the Invention of "IMPROVEMENTS IN
THE TREATMENT AND UTILIZATION OF SEWAGE, AND IN MEANS EMPLOYED
THEREIN.
"
PROVISIONAL SPECIFICATION left by the said Burton Henry Vallé
at the Office of the Commissioners of Patents, with his Petition, on
the 3rd November 1874.
I, BURTON HENRY VALLÉ, of Stow-on-the-Wold, in the County of
Gloucester, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE TREATMENT AND UTILIZATION OF SEWAGE, AND IN MEANS
EMPLOYED THEREIN," to be as follows:-
My Invention relates to an improved treatment of sewage, whereby all
nuisance is prevented, and valuable and useful products are obtained, the
whole of the sewage being effectually utilized.
In carrying out my Invention the sewage is collected in filtering
tanks, wherein the solid, portion is separated from the liquid, and the

page_text: latter is effectually defecated and rendered fit for domestic use before
being allowed to flow into any river or other channel.
The Invention consists more particularly in treating the sewage sludge
remaining in the tanks in such a manner as to completely utilize it by
converting it into illuminating gas, and a substance capable of defe-
cating sewage, and of being used for other useful purposes, as hereafter
described.
I provide two or more series of tanks, to which the sewage is conveyed
by conduits from the outlet of main sewer, said conduits being so
arranged as to effect a gentle flow of the sewage into the tanks, and the
latter are so constructed that the sewage as it flows therein is screened
and filtered, and the solid matter retained. There are, say, two or more
tanks for each series, cach tank being divided by partition walls into a
number of compartments, through which the sewage filters as it flows.
The bottom of each compartment also consists of a filtering bed having:
an inclined permanent water-tight floor beneath, on which the effluent
water drains, and whence it flows through sluices into a suitable channel
in which it may be applied as a source of motive power for use in the
works. Over each compartment of the tanks provision is made for the
admixture. Over each compartment of the tanks provision is made for
the admixture of a small quantity of quicklime, as occasion may require,
to accelerate the subsidence of the solid matter of the sewage.
-
The sets of tanks one intended to be used alternately, that is to say,
the fresh sewage is run into the one set whilst the sludge is being
removed from the other set, and so on.
In order to remove the sewage sludge from the tanks the filtering bed
is constructed to be raised at one side by a mechanical arrangement, so
as to cause the sludge to flow through sluices into a receptacle or bed
outside the tanks, wherein it may be allowed to remain a suitable length
of time exposed to the action of the atmosphere.
Suitable works are erected in convenient proximity to the tanks for
the manufacture of the sewage sludge into illuminating gas, provision
being made for readily charging the retorts with the sewage. The
sewage sludge is propelled by machinery through one or more cylindrical
retorts placed within a suitable furnace, the ends projecting a convenient
distance beyond the exterior walls of the furnace. At the end where
the retorts are charged there is a syphon from each retort to the upper

page_text: end of a vertical condenser, the syphon being connected with each in an
oblique or diagonal direction to admit of its being readily cleansed if
required. This syphon is the only passage for the escape of the steam
and gases from the retort, into the condenser, from whence the gases
pass through another syphon into a cylindrical refrigerator, and thence
through a purifier, after which the gas passes into a gasometer fit for
use. One end of the retort is open to admit a fireproof shaft having a
spiral line of teeth, and also for connecting a tube and receiving the
sewage sludge, and the other or opposite end is closed.
At a suitable distance from the charging end of the retort in front of
it is placed a metal frame, in which is fixed a hollow cylinder partly
open at one end and closed at the other in a direct line with the retort,
and also a metal tube of sufficient length is connected with the cylinder
and the mouth or open end of the retort, so that when the tube is
charged with sewage sludge no external air can enter the retort at that
end, nor any gas can escape therefrom, which is safely effected by a
valve apparatus within the cylinder at that end of it which connects
with the tube. Within the cylinder there is a revolving shaft placed
axially therein, and provided with radial arms or blades arranged spirally
thereon. At the closed end of the cylinder furthest from the furnace
this cylinder is surmounted by another of the same diameter, open at
both ends, one of which joins a corresponding opening in the upper side
of the horizontal cylinder, thus forming one continuous right-angled
cylinder. In this vertical cylinder a similar revolving shaft is fitted,
provision being made for kneading the sewage sludge prior to its entry
in the horizontal cylinder.
The sewage sludge enters the upper end of the vertical cylinder, and
by the revolution of the shafts it is propelled through the tubes into the
retort. From the end of the horizontal cylinder connected with the tube
and connected with the horizontal revolving shaft thereon there is a
metal shaft in the line of the retort axis to the mouth of the retort,.
which is prolonged by means of a fireproof shaft prepared for the purpose,
which passes axially through the retort to the closed end thereof, and
which shaft is made to revolve in a certain ratio to the revolving shafts
within the cylinder.
Along that length of the shaft within the tube from the cylinder to

page_text: propulsion of the sewage sludge into the retort. Along the shaft within
the retort there are a number of sharp or cutting radial projections or
blades also disposed spirally, which break up the carbon or charcoal and
move it onward and discharge it into a vertical tube near the closed end
of the retort. This tube leads from an opening of the retort, and is |
provided at the upper and lower ends with moveable covers or sliding
plates, both of which are connected with the revolving shaft in the
retort, and the machinery is so arranged that at certain intervals of time
the shaft in revolving opens one of the covers or plates, and at the same
moment closes the other, by which means the carbon or charcoal is
discharged from the retort without allowing any gas to escape at that
end of the retort, which end with the perpendicular tube and machinery
connected therewith are enclosed in an air-tight chamber of sufficient
capacity to contain a convenient quantity of the carbon or charcoal
discharged from the retorts. Within the chamber and under the per-
pendicular tube there is a spreader which distributes the charcoal as it
falls from the tube over the floor of the chamber, provision being made
for readily removing it from thence when required.
Instead of a fireproof shaft running the whole length of the retort the
carbon or charcoal can be moved forward to be discharged by means of a
hollow cylinder or tube, one end of which is open and connected with
the centre of that end of the retort which in this case has a circular
opening of the diameter of the tube which is within the air-tight
chamber, and the other end of the cylinder, which is closed, is supported
by a frame within the chamber. Midway in the tube there is a vertical
plate which divides the tube into two partitions, that one nearest the
retort having a fireproof shaft in the axial line of the tube, along
which there are a number of movable jointed knives, which are arranged
spirally, and the other partition furthest from the retort is for the
purpose of a stuffing box to prevent the admission of any air into the
retort, or the escape of any gas therefrom. The end of the fireproof
shaft nearest the retort has a sharp spiral penetrating point, and the end
furthest from the retort is connected by a metal axle, which extends
through the centre of the covered or extreme end of the tube, and thence
through the side wall of the chamber, where it is connected with the
motor which makes it revolve, and at the same time move in the axial
line of the retort towards the charging end thereof, and back to its
former position, whereby the carbon or charcoal is discharged into the

page_text: perpendicular tube, the covers of which are opened and closed alter-
nately, as before described.
In the partition of the tube in which the fireproof shaft works there is
an opening in the lower side thereof near the vertical plate, and com-
municating with a vertical tube having movable covers or plates, which
alternately open and close similar to those before described for the
purpose of allowing the escape of the carbon or charcoal which is carried
with the fireproof shaft in its return into the tube, by which means the
same result is attained.
The gas works are so arranged that coal gas may first be mado in the
ordinary way, the resulting coke being used for the purpose of heating
the sewage sludge retorts, so that no smoke or other nuisance injurious
to health may arise from the whole process. The coal gas is passed
through a sewage gas purifier before entering the holder, whereby the
quality of the gas is rendered identical with that of the sewage gas which
is supplied to the same holder to mix with the coal gas.
The residue in the sewage sludge retorts is of value, inasmuch as it
possesses the property of defecating sewage, as before mentioned, and in
case the whole of the sewage sludge should not be required for the
manufacture of gas it can be used for agricultural purposes, its transport
being effected without nuisance by the application of the said defecating
substance, or the sewage sludge can be manufactured into bricks for
building purposes by the admixture of a small proportion of clay with
the filtering substance used in the tanks. Or the sewage sludge may be
made into cement of good quality by the admixture of lime and a
neutralizing substance prepared at the works.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Burton Henry Vallé in the Great Seal Patent
Office on the 3rd May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BURTON
HENRY VALLÉ, of Stow-on-the-Wold, in the County of Gloucester, send

page_text: '
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Burton Henry Vallé,
Her special licence that I, the said Burton Henry Vallé, my
executors, administrators, and assigns, or such others as I, the said
Burton Henry Vallé, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN THE TREATMENT AND UTILIZA-
TION OF SEWAGE, AND IN MEANS EMPLOYED THEREIN," upon the condition
(amongst others) that I, the said Burton Henry Vallé, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Burton Henry Vallé, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the two Sheets
of Drawings hereunto annexed, and to the letters and figures marked
thercon, that is to say :-
My Invention relates to an improved treatment of sewage whereby
valuable and useful products are obtained, the whole of the sewage
being effectually utilized and all nuisance is avoided.
In carrying out my Invention the sewage is collected in filtering
tanks wherein the solid portion is separated from the liquid, and the
latter is effectually defecated and rendered fit for domestic use before
being allowed to flow into any river or other channel.
The Invention consists more particularly in treating the sewage sludge
remaining in the tanks in such a manner that it is completely utilized
by converting it into illuminating gas, and a substance capable of
defecating sewage, and of being used for other useful purposes as herein-
after described.

page_text: And in order that my Invention may be more readily understood,
I will describe it with reference to the accompanying Drawings in which
I have illustrated the principal apparatus I employ in carrying the
Invention into effect.
Figure 1 represents a plan view of one series of filtering tanks; Figure 2,
a longitudinal sectional elevation, and Figure 3, a transverse section of the
same on lines 1, 1, 2, 2, respectively; Figure 4 shows a plan, and
Figure 5, an elevation of the apparatus used for converting the solid
matters retained in the said filtering tanks into illuminating gas.
I provide two or more series of filtering tanks, each series constructed
in brick or stone, and arranged as shown in Figures 1, 2, 3, to which the
sewage is conveyed from the outlet of main sewer, in such manner as to
effect a gentle flow of the sewage into the tanks, and the latter are so
constructed that the sewage as it flows therein is screened and filtered,
and the solid matter retained. The series of tanks are intended to bo
used alternately, that is to say, the fresh sewage is run into the one set,
while the sludge remaining after filtration is being removed from the
other set, and so on. Each series is composed of any convenient number
of tanks or compartments (two or more) A, A', A², A³, A', each tank or
compartment being divided from the adjacent ones by partition walls B,
the upper part B' of cach partition wall being constructed to filter and
allow the supernatant portion of the sewage to flow through into the
next tank, for which purpose the tanks or compartments and partition
walls are constructed at successively lower levels, as shown. The
bottom of each compartment also consists of a filtering bed C supported
at a convenient distance above an inclined permanent water-tight
floor D on to which the effluent water drains, and whence it flows through
sluices a into an inclined channel E common to all the tanks or com-
partments of the series. In this channel E there may be a number of
filtering banks E¹ (of the same materials hereafter mentioned for
filters B' and C) for still further purifying the water as it flows down
this channel. The filters B₁ of the partition walls are composed of a
mixture of the carbon or charcoal residue (obtained by the distillation of
the sewage sludge in retorts as hereafter described), sand, and earth
which is filled in between narrow walls b, b', provided with apertures
for the passage of the sewage, a thin vertical layer of coarse gravel being
interposed between the filtering mixture and the wall to retain the
mixture. The filter beds C are composed of the same mixture upon a

page_text: horizontal layer of gravel, the whole being placed between upper and
lower filtering floors c, c¹, constructed of oak with cast and wrought-iron
girders, and provided with apertures c² for the passage of the liquid
sewage, the upper floor c being made double with friction rollers between
to enable the upper half of the floor to slide longitudinally upon the
lower half, for the purpose of making their apertures coincide or not as
required. This, movement is effected by means of a gearing chain wheel
and capstan. The thickness of filters B¹ and the depth of filtering
beds C, and the number of filtering compartments A depends upon the
quality of the sewage to be filtered, and must be determined by the
result of analysis of the effluent water at the outfall channel.
In order to remove the sludge remaining in the tanks A after filtration.
of the sewage the upper floor c is constructed to be raised at one side
(the apertures having been previously closed) so as to cause the sludge
to flow through sluices d and spouts d' into a receptacle or bed G, outside
the tanks, wherein it may be allowed to remain exposed for a short time
to the action of the atmosphere until sufficiently dry for conveyance
where required.
The raising of the upper floor of the filtering beds may be effected by
means of chains attached to hooks bolted to the lower half of floor c,
and passing through slots in the upper half to admit of the sliding move-
ment before mentioned. The chains from cither end pass over guide
pulleys to two independent shafts, as shown in Figure 3. This arrange-
ment admits of the floor being raised at the end furthest from the
sluices d by revolving one of the shafts, and also, as occasion may
require, of being raised at both ends by the simultaneous revolution of
the two shafts sufficiently for the purpose of renewing the filtering bed.
The sluices d are opened and closed by means of a rack and pinion.
The sewage, which it is preferred should be kept separate from the
rainfall drainage, is first received from the sewer in a tank F, which
may be termed an intercepting or settling tank, whence the sewage is
conveyed by a conduit F¹ to the one or other series of filtering tanks A,
the flow of the sewage being controlled by valves or sluices e. The
floor of the intercepting tank F has a downward slope from one side of
the tank to the other, where two pumps fare placed for emptying the
intercepting tank F when required, the one serving to pump the fluid part of
the sewage into the conduit F', and the other to raise the sludge deposited
.

page_text: into a trough g, by which it is conveyed to a tank / provided with a
layer of stones and coarse gravel through which the watery part drains,
and is conveyed by a channel i to the upper end of the channel E, the
solid matter remaining being removed to the sludge bed G. The bottom
or floor of this sludge bed, and likewise the bed of the channels are so
constructed as to prevent any sewage from percolating through them.
The sewage flows from the sewer into the intercepting tank, and it
may either be pumped up into conduit F' or where the level of the
locality will admit of tanks "A being constructed in the ground the
sewage may flow into the conduit F¹, and thence into the filtering tanks.
k, k, are gratings.
A small quantity of quickļime is supplied to the intercepting tank, as
occasion may require, to accelerate the subsidence of the solid matter of
the sewage. The lime is placed in a trough (not shown), to which a
sufficient quantity of sewage is admitted from the sewer. In the
trough is a shaft provided with blades, and operated by any suitable
motive power to agitate and mix up the. lime with the sewage, which
is then allowed to flow through spouts into the intercepting tank.
Suitable works, of which a portion is shown in Figures 4 and 5, are
erected in convenient proximity to the tanks for the manufacture of the
sewage sludge into illuminating gas, provision being made as hereafter
described for readily charging the retorts, of which there may be one or
more with the sewage. H is one of these retorts. It is of cylindrical
shape, and is placed within a suitable furnace I, the ends of the retort
projecting a convenient distance beyond the exterior walls of the fur-
nace. The charging end of the retort is open, and the opposite end is
closed. To the charging end is connected the open end of a hollow
cylinder K closed at the other end, and supported on a frame K². This
cylinder is of the same diameter as the retort of which it forms a con-
tinuation. K is a vertical cylinder or hopper by which the sewage
sludge is fed into the cylinder K through an opening in its top side.
The frame K' is made moveable, in order that the cylinder K may be
readily disconnected and removed to give access to the interior of the
retort. The retort H and cylinder K are traversed from end to end by
a longitudinal revolving shaft / placed axially therein, and provided with
blades arranged spirally thereon. That part of the shaft which is within
the retort H must be made of a material capable of withstanding the
great heat in the retort, and I propose to make it either of cerium or
'

page_text: platinum, that within cylinder K being of iron. The vertical cylinder
or hopper K¹ is also provided with a shaft having knives or blades for
the purpose of kneading the sludge before it enters the horizontal
cylinder K. The sewage sludge enters the upper end of the vertical
cylinder, and by the revolution of the shafts it is conveyed into the
retort. When the cylinder K is charged with sludge no air can enter
the retort, neither can any gas escape therefrom. The rate at which
the sludge is conveyed into and passed through the retort will depend
on the state of the sludge, and the heat of the furnace. The blade
within cylinder K is a continuous spiral for conveying the sludge into
the retort, but within the latter they are short cutting blades, also dis-
posed spirally, which break up the carbon or charcoal residue, and move
it onward, and discharge it into a vertical tube m near the closed end of
the retort. This tube leads from an opening in the bottom of the retort,
and may be closed at the upper and lower ends by a movable cover or
plate, the two being coupled together, so that when one is opened the
other is closed. The upper one is so geared with the shaft that at
certain intervals it will be closed, and the lower one opened to discharge
the carbon or charcoal contained in the tube without allowing any gas
to escape. This end of the retort with the perpendicular tube and
machinery connected therewith are enclosed in an air-tight chamber L
of sufficient capacity to contain a convenient quantity of the carbon or
charcoal discharged from the retort. The covers may be mounted on
horizontal axes, and the gearing may consist of a train of cog wheels and
pinions driven by the shaft l, and operating a small crank arm jointed by a
link to the connecting rod to which a balance weight is attached to
operate the covers as above mentioned, which takes place whenever a
blank part of one of the wheels comes opposite the pinion of the crank
arm, and so releases the latter. Within the chamber L and under the
perpendicular tube there is a spreader which is rapidly rotated by
gearing from shaft to distribute the charcoal as it falls from the tube
over the floor of the chamber.
The steam and gases from the retort escape through a syphon M near
the charging end of the retort which leads to the upper end of a con-
denser N containing water into which the syphon dips. The gases pass
thence through another syphon O connected to top of condenser and
leading to a drier P, in the upper portion of which is a purifier R through
which the gas rises and passes off by a pipe S to a gas holder fit for use.

page_text: The purifier is composed of a number of perforated shelves, on which
there is placed a thin layer of the charcoal residue from the retorts and
lime, and the lower part of the apparatus (the drier) is filled with the
same mixture. T is a tank receiving the overflow from the condenser
by a pipe n which dips into a vessel containing water; p is another pipe
leading from the top of the purifier, by which the quality of the gas
therein may be tested.
Instead of a shaft running the whole length of the retort the carbon
or charcoal can be moved forward to be discharged by means of a hollow
cylinder or tube, onc end of which is open and connected with the
centre of that end of the retort which in this case has a circular opening
of the diameter of the tube which is within the air-tight chamber, and
the other end of the cylinder which is closed is supported by a frame
within the chamber. Midway in the tube there is a vertical plate which
divides the tube into two compartments, that one nearest the retort
having a shaft in the axial line of the tube along which there are a
number of moveable jointed knives which are arranged spirally, and the
other compartment furthest from the retort is for the purpose of a
stuffing box to prevent the admission of any air into the retort or the
escape of any gas therefrom. The end of this shaft nearest the retort
has a sharp spiral penetrating point, and the end furthest from the retort
is connected by a metal axle which extends through the centre of the
covered or extreme end of the tube, and thence through the side walls
of the chamber where it is connected with the motive power which
makes it revolve and at the same time move in the axial line of the
retort toward the charging end thereof and back to its former position,
whereby the carbon or charcoal is discharged into the perpendicular
tube, the covers of which are opened and closed alternately, as before
described.
In the portion of the tube in which the shaft works there is an
opening in the lower side thereof near the vertical plate and communi-
cating with a vertical tube having moveable covers which alternately
open and close similar to those before described for the purpose of
allowing the escape of the carbon or charcoal which is carried with the
fireproof shaft in its return into the tube, by which means the same
result is attained. Or the shaft in the retort may be dispensed with if
the sewage sludge be dried or broken into small pieces before dis-
tillation in the retorts. In this case the length of the retorts within the

page_text: furnace would be made shorter and the furnace narrowed accordingly,
the remaining machinery of either the other methods herein described
being made suitable for charging the sewage sludge into the retorts and
extracting the carbon or charcoal therefrom.
The drying of the sludge may be effected in an air-tight chamber, on
the floor of which there are several iron partitions placed vertically and
longitudinally from the entrance door of one side of the chamber to the
opposite side thereof which make several compartments into which the
sludge is put. Under the floor of the chamber there is a furnace to heat
the same. In the centre of the top or roof of the chamber there is an
opening in which a bent pipe is inserted, and the other end of the pipe
is connected with the upper end of the condenser, similar to the syphons
connected with the retorts. Prior to the sewage sludge being removed
from the chamber the furnace is allowed to sufficiently cool so that no
more vapor may be generated in the chamber.
In the bent pipe near the end which joins the roof of the drying
chamber there is a valve, and any gas which may be in the chamber
can be expelled by an exhauster and then the valve closed. The sludge
is then removed and broken up into the required pieces.
I prefer to make coal gas in the ordinary way in a separate set of
retorts and to use the resulting coke for heating the sewage sludge
retorts, the coal gas being either used separately or mixed with the
sewage gas, in which case it would be passed through a purifier like
that before described before entering the holder to mix with the sewage
gas.
The residue in the sewage sludge retorts possesses the property of
defecating sewage, as before mentioned, and in case the whole of the
sewage sludge should not be required for the manufacture of gas it can
'be used for agricultural purposes, its transport being effected without
giving rise to any nuisance by the application of the said defecating
substance; or the sewage sludge can be manufactured into bricks for
building purposes by the admixture with the sludge of the filtering
mixture after use in the filtering tanks and of the carbon residue from
the retorts, and a small proportion of carth, sand, and clay, the pro-
portion of these various materials depending upon the quality of the
sludge. The bricks are burnt in the ordinary way.

page_text: Having described the nature of the said Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,-
First. The manufacture of illuminating gas from sewage sludge by the
improved process or treatment and means, substantially as herein set
forth. I also claim the mixing the gas so obtained with coal gas for
consumption, as specified.
Second. The production of a substance having defecating and filtering
properties by the distillation of sewage sludge in retorts, as herein
described, and the employment thereof either alone or mixed with other
substances, substantially as and for the various purposes herein set
forth.
Third. The construction and arrangement of the filtering tanks for
filtering the sewage, and the means of removing the sludge therefrom,
substantially as herein shown and described.
.
Fourth. The combination of machinery and parts used for charging
the retort with sludge and withdrawing the deposit from the retorts
without allowing the gas to escape, substantially as herein set forth.
Fifth. The manufacture of clay suitable for bricks by a mixture of a
small proportion of natural clay with the sewage sludge, and the filtering
mixture used in the filtering tanks, as specified.
In witness whereof, I, the said Burton Henry Vallé, have here-
unto set my hand and seal, this Thirtieth day of April, in the
year of our Lord One thousand eight hundred and seventy-five.
Ima
T VATTY