IMPROVEMENTS IN THE PROCESS OF AND ARRANGEMENTS AND MACHINERY FOR TREATING EXCRETA, HOUSE REFUSE, AND SEWAGE SLUDGE TO OBTAIN MANURE AND OTHER PRODUCTS THEREFROM
Year: 1876

page_text: LETTERS PATENT to John Howard Kidd, of Wrexham, in the County of
Denbigh, Engineer, for the Invention of "IMPROVEMENTS IN THE PROCESS OF
AND ARRANGEMENTS AND MACHINERY FOR TREATING EXCRETA, HOUSE REFUSE,
AND SEWAGE SLUDGE TO OBTAIN MANURE AND OTHER PRODUCTS THEREFROM."
Sealed the 7th July 1876, and dated the 19th January 1876.
PROVISIONAL SPECIFICATION left by the said John Howard Kidd at the
Office of the Commissioners of Patents on the 19th January 1876.
JOHN HOWARD KIDD, of Wrexham, in the County of Denbigh, Engineer.
"IMPROVEMENTS IN THE PROCESS OF AND ARRANGEMENTS AND MACHINERY FOR
TREATING EXCRETA, HOUSE REFUSE, AND SEWAGE SLUDGE TO OBTAIN MANURE
AND OTHER PRODUCTS THEREFROM."
My improved prccess consists in collecting the excreta, house refuse, and cinders
or ashes separately, so that the cinders or ashes or other matters are not mixed
with excreta or urine, the cinders suitable for fuel and other matters being saparated
by riddling, my process so far being the same as that known as the "Roch-
dale system." Then the fine asli obtained from the sifting process is mixed
with the excreta in a tank and sulphuric acid is added, and the mixture is then
allowed to stand for about twelve hours. It is then taken out and fed to a drying
machine by preference that herein-after described, whereby it is passed along
troughs by mechanical means while being subjected to the action of the heat of a
furnace until the material is dried, and it is delivered from the machine ready
(when cooled) to be placed in sacks for the market.
The furnac for heating the drying apparatus is supplied with fuel (by preference)
from the combustable cinders separated by the sifting process so that the material
to be operated upon furnishes the fuel required by the process, and the sulphur
given off from the fuel (in which there is an excess) combines with and retains
inore or less of the ammonia contained in the excreta under proc-ss of treatment,
while any free ammonia which escapes past the drying troughs along with the gases
in the flue is made to pass over or in contact with flint or other suitable material
kept moist by the spray of sulphuric acid, so that such free ammonia is collected in
the form of a sulphate of ammonia. Sewage sludge is treated in like manner, the

page_text: sludge being first drained from moisture as perfectly as possible in the ordinary
manner.
My improved drying machine consists of a series of open troughs, the lower half
being cylindrical, each trough having a shaft in suitable bearings passing length-
way, and carries a screw formed in sections so that the material fed at one end will
be carried along by the screw to the other end, and will then descend into another
similar trough and screw below, these troughs being placed horizontal in position
parallel to and one over the other. The troughs are fixed in end frames, one end of
each trough being supported in the end frame, while the other end of the trough
rests upon a cross bearer carried by the brickwork. The flue from the furnace
passes at right angles to the troughs under the lower trough and over it, and then
under the next trough and over it, and so on, and after arriving at the upper trough
it may pass to the next series of troughs, and so on, descending. The material
after passing the first series of troughs may be elevated mechanically to the next
series, and so on, if desired.
The arrangements for carrying out my process of treatment consist of a roofed
building, the floor of which is two or three feet above the roadway so that carts
can be easily discharged and loaded. The drying machines are placed by preference
in pairs about the middle of the building, but sunk in a cellar so that the upper
cover of the machines is on a level with and forms a part of the floor of the room.
The flue from each furnace after passing the drying. troughs ascends and then passes
on a level with the lengthway of building below the floor, the upper cover of
the flue being made of iron plates to form the floor upon which ashes are placed to
dry. Parallel to and on each side of the building a shallow tank is formed, and it
is in these tanks that the excreta, ashes, and sulphuric acid are mixed and allowed
to stand. The mixed excreta and ashes are taken by train waggon to the floor or
cover of the drying machine and are there fed to its hoppers or troughs. The
dried material is discharged from the troughs and is elevated by screws in a cylinder
or trough, or by other mechanical elevators, to a hopper for filling it into the sacks
for the market. The cinders and ashes are sifted by mechanical riddles worked by
steam power at the side of the mixing and drying room, and the fine ashes for
mixing with the excreta are brought by screws and cylinders from the sifter over
the drying flues ready for mixing. The free ammonia is collected by means of trays
or sieves having flints upon them placed one over the other in the vertical part of
the flue from each drying machine, these trays allowing the flue gases to pass
through and in contact with the trays or sieves of flints moistened by spray of
sulphuric acid which flows from a cistern down a pipe over the trays or sieves.
In draining and partly drying sewage sludge I prefer to place it on filter beds in
a roofed building with a space or flue above and one below the filter bed, and I
connect the space or flue over the filter bed with a chimney so that a current of air
will pass along over the surface of the sludge upon the filter bed to help to dry it.
When
In some cases I make the space and side under the filter bed air-tight, and
exhaust this space partly by a steam jet or other means, the partial vacuum thus
formed assisting to draw the moisture from the sludge upon the filter bed.
sufficiently dry it is treated in the same manner as excreta, as herein-before
explained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed by
the said John Howard Kidd in the Great Seal Patent Office on the 13th July
1876.
JOHN HOWARD KIDD, of Wrexhamn, in the County of Denbigh, Engineer. 50
"IMPROVEMENTS IN THE PROCESS OF AND ARRANGEMENTS AND MACHINERY FOR
TREATING EXCRETA, HOUSE REFUSE, AND SEWAGE SLUDGE TO OBTAIN MANURE AND
OTHER PRODUCTS THEREFROM."

page_text: "
My improved process consists in collecting the excreta, house refuse, and cinders
or ashes separately, so that the cinders or ashes, or either matter are not mixed
with the excreta or urine, which is collected in pails, and will be herein-after
referred to as the pail contents. The cinders suitable for fuel and other matters
are separated by riddling, my process so far being the same as that known as the
"Rochdale system." The fine ashes obtained by the sifting process are mixed with
the excreta or pail contents in about equal proportions by weight, more or less,
according to the quantity of liquid to be absorbed by the ashes, and about 20lbs.
of sulphuric acid (the vitriol of commerce) is sprinkled over and mixed with each
ton of the mixture, which is then allowed to stand for about twelve hours, and it
is then taken and fed to a drying machine, by preference that herein-after described,
whereby it is passed along troughs while being subjected to the action of the heat
of a furnace until the material is sufficiently dry, and it is then delivered from the
machine ready when cooled to be placed into sacks for the market.
By another method the excreta or pail contents are subjected to the action of
heat in an evaporating furnace pan or receptacle, such heat being sufficiently great
(say 500 degrees Fah.) when passing into the flue or chimney as to destroy the
noxious gasos or effluvia given off in the process of evaporation, which process is
continued until from 50 to 75 per cent. of the liquid portion of the pail contents is
evaporated. The remaining products of the process of evaporation are mixed
with sufficient fine ashes as above explained to absorb the liquid left, and about
20lbs. of sulphuric acid (vitriol of commerce) is sprinkled over cach ton of the
mixture, which after standing for about twelve hours, more or less, is passed
through the drying machine as before explained. Before subjecting the pail
contents to the evaporating process about one hundred pounds weight to the ton of
a cheap sulphate of lime or gypsum, such as the refuse from potteries known as
pot mould," containing say about forty per cent. of sulphuric acid, is added and
mixed with the pail contents, which will retain a large portion of the free
ammonia which might otherwise pass off with the heated guses in the process of
evaporation. To obtain a concentrated manure I take the manure or dried
material first obtained by either of the above processes and mix such dried
material with about an equal weight of fresh pail contents or of pail contents
which have been subjected to the evaporating process, and I pass the mixture
through the drying machine, and the products thus obtained may be again mixed
with an equal weight of fresh pail contents or pail contents which have been
partly evaporated and again dried by the machine, and so on as aften as desired,
the material thus obtained being dried concentrated excreta with but little ash.
66
The furnace for heating the drying apparatus or evaporating pan is supplied
with fuel (by preference) from the combustable cinders separated by the sifting
process, so that the material to be operated upon (by being collected separately)
furnishes the fuel required by the process, and the sulphur given off from the fuel
combines with and retains more or less of the ammonia contained in the excreta or
pail contents under process of treatment, while any free ammonia which escapes
past the drying troughs along with the gases into the flue is made to pass over or
in contact with flint or other suitable material kept moist by the spray of sulphuric
acid (the vitriol of commerce) so that such free ammonia is collected in the form of
sulphate of ammonia.
Sewage sludge by my improved process is first drained as perfectly as possible,
and may have sulphuric acid (vitriol of commerce) mixed with it, say about 25lbs.
to the ton, then allowed to stand say twelve hours and passed through the drying
machine heated by any suitable fuel.
Sewage sludge which has been dried as above described may be mixed with fresh
drained sludge, which will facilitate the drying, the moisture being thus spread
over a larger bulk of material is more readily acted upon and taken away by the
heat and heated gases.
My improved drying machine consists of a series of open troughs, the lower half

page_text: being cylindrical, each trough having a shaft in suitable bearings passing length-
way, and carries a screw formed in sections so that the material fed at one end
will be carried along by the screw to the other end, and will then descend into
another similar trough and screw below these troughs, being placed horizontal in
position parallel to and one over the other. The troughs are fixed in end frames,
ene end of each trough being supported in the end frame while the other end of
the trough rests upon a cross bearer carried by the brickwork. The furnace in
some cases must be under each series of troughs, and in others (especially where
there is good draught) at one side, and the flue from the furnace in the latter case
may pass the troughs at right angles under the lower trough and over it, and then
under the next trough and over it, and so on, and after arriving at the upper
trough it may pass to the next series of troughs, and so on descending, or the heat
flue may be divided so that one portion of the heated gases will pass to and from
each set of troughs separately. The heat or heated gases, after acting upon steam
· boilers, may be conducted by flues to the drying cylinders. The material, after
passing through the first series of troughs, may be elevated by mechanical means,
such as a screw in an inclined pipe or cylinder to the next series of troughs.
My improved drying machine and the arrangements for carrying out my process
of treatment will be more particularly described by reference to the accompanying
two Sheets of Drawings.
.
'
Fig. 1 is a sectional elevation across the troughs of my improved drying
machine; Fig. 2 is a sectional elevation in the lengthway of the troughs; and
Fig. 3 is a plan section through the lower set of troughs. a are the walls for
enclosing the troughs, furnaces, and flues. Two sets of troughs b are shown, they
are secured at one end in iron frames c, and rest at the other end upon a cross
bar & built in the walls. The troughs and surrounding flues are entirely closed
from the external air by suitable covers at the ends. The furnaces in the arrange-
The furnace door (e),
ment illustrated are directly under each set of troughs.
dead plate (el), and fire-bars (e), are shown in Fig. 2. The top of the furnace is
formed by a brick arch in which a series of holes fare formed, passing into vertical
flues on each side of the troughs. In the sides of the partition between the side
flues and the two lowest troughs there are holes f¹ to admit heat and allow
moisture or gases to escape to the flue. On the right of Figure 1 the section is taken
through the flues as they pass directly from the furnace to the chimney; on the left
side of Fig. 1 the section is taken through the flues and those passages arranged
to take away the moisture and gases from each trough without coming in contact
with the under side of the other troughs. a¹ are fire-brick slabs which extend
between the walls on each side of the troughs; g are passages to take away the
vapour or gases from the troughs to the flues; fare the flues to the chimney;
h is a flat top which forms a drying floor. The material to be operated upon is fed
into a hopper at b, and the rotation of the screw shaft causes the material to
traverse along the troughs until it arrives at the end, when it drops to the trough
below, and so on, being finally delivered from the lowest cylinder at b. I prefer to
make the shafts i for the screws square in cross section, and to put on the screw
in sections, each forming one turn. The shafts of each set of troughs are geared
together, as shown, one of the screw shafts having a worm wheel i¹ upon its end
into which gears a worm on a cross shaft in suitable bearings, the shaft being
driven by a belt, as shown. The speed at which the screws are to be rotated will
depend upon their pitch, and the quantity of heat available, and the quantity of
moisture to be driven off. If the material comes out too dry the speed is increased,
if too moist the speed is diminished. The material is fed into the hopper so as to
keep the trough full up to a level with the under side of a boss part of the
screws.
Fig. 4 is a longitudinal elevation in section; Fig. 5 is a cross section; and Fig. 6
is a plan section, or a plan with part of the upper cover removed, of a furnace
suitable for carrying out my improved process, where the excreta or pail contents

page_text: are first partly evaporated. a is a furnace which communicates by holes in its
crown archway with the space or flue over the pan or receptacle for the excreta or
pail contents. There are three parallel longitudinal walls 6 which carry fire-brick
slabs bedded in cement, and over these and breaking joints are other slabs laid in
cement, The side walls and these bottoms c form two receptacles to hold the pail
contents. Iron pans may be placed upon the walls to form the receptacle instead
of forming them in brickwork. The receptacle is covered by slabs jointed in
coment, and the gases and heat from the furnace will thus pass over the surface and
thence to the flue or chimney. There may be an exhausting steam jet g at the
bottom of the chimney to draw off the gases where the natural draught of the
chimney (a¹) is insufficient. The pail contents may be emptied into the pans or
receptacles at the holes in the covers covered by conical stoppers d, and the contents
of the pans or receptacles are withdrawn when sufficient of the liquid part has
been evaporated at one or more holes closed by a block e and clay, or by a door;
f is a door through which rakes may be inserted to clear out the pan when
required.
a, the
The
Fig. 7 is a longitudinal section; Fig. 8, a plan; Fig. 9, a cross sectional elevation;
and Fig. 10, a partial cross section of the building and arrangements and machinery
for carrying out my improved process of treating excreta and house refuse.
walls of a roofed building, the floor of which is preferred two or three feet above
the roadway, so that carts may be easily discharged and loaded. The drying
machines bare placed by preference in pairs; the furnaces opposite each other
about the middle of a building, but sunk in a cellar, so that the upper cover of
the machines is on a level with and forms a part of the floor of the room.
flue from the drying machines passes on a level in the lengthway of the building
below the floor in flues (c) to the flue c¹ leading to the chimney, the upper cover (c)
of the flue being made of iron plates to form the floor upon which the ashes are
placed to dry. Parallel to and on one side of the building are formed the recep-
tacles for the pail contents. These are made by spreading ashes on the floor and
making banks of ashes round to retain the pail contents when placed therein;
there is sufficient of the pail contents more ashes are thrown over, and sulphuric
acid (vitriol of commerce) is sprinkled over the mass; the ashes and pail contents
are then well mixed and allowed to stand.
when
The mixed ashes and pail contents may be taken by a tram waggon to the floor
or cover of the drying machine, and there fed to its hoppers or troughs. The dried
material when discharged from the troughs may be elevated by screws in inclined
and horizontal cylinders or troughs, or by other mechanical ineans to a hopper for
filling it into sacks for the market, or on to the upper floor to be mixed with fresh
pail contents to form a concentrated manure in the same manner as ashes and pail
contents are first mixed, as herein-before described. The cinders or ashes are sifted
by riddles worked by steam power as well understood, and the fine ashes may be
brought by screws and inclined and horizontal cylinders from the cinder sifter over
the drying floors as required. The furnaces for evaporating the pail contents may
be placed at x, or they may be arranged to discharge their contents on to the mixing
floor. The engine may be placed at w driving the shafting v for giving motion to
the drying machines, and to the riddles and crushing mills and other machinery
requiring motion. The free ammonia is collected by means of trays or sieves
having pieces of flint upon them, these trays or sieves are placed in the flues or
in the chimney by preference one over the other. The trays or sieves might
extend over half the area of the chimney, and be fixed alternately to come close
to the opposite sides of the chimney, leaving spaces for the gases to pass between
the trays which would compel the gases to pass under and over the trays or
sieves, the latter being preferred. The flints on the trays or sieves are kept moist
by the spray of sulphuric acid (vitriol of commerce), which flows from a cistern
down a pipe over the trays or sieves.
Fig. 11 is a longitudinal clevation in section; Fig. 12, a plan, and Fig. 13, a

page_text: cross section showing a building and the arrangement of tanks, filter and drying
beds, and machinery for carrying out my improved process of treating sewage
sludge; a are the settling tanks into which the sewage enters at a¹, and the water
is drained off after depositing its sediment at a². The filter beds b and drying floor
care placed in a roofed building which is between the settling tanks. There are
openings or doors (e) in the side walls of the building through which the sewage
sludge can be passed from the tanks (a) to the filter beds (b), which are formed
with a metal grid surface having sand and then gravel underneath. The walls and
sides of the filter beds are made as air-tight as possible with cement, and there is a
cavity along the centre of each filter bed below the gravel, and there is a pipe
between this cavity and the exterior of the filter bed having its outlet over the
settling tank, which outlet can be closed by a tap. This tap allows the water to
pass from the bed of the filter to the tank. Each filter bed is divided into separate
lengths or sections, and each section has a separate pipe or tap.
To assist in removing the moisture after the material has been drained on the
filter bed for a few hours, each section of the filter bed has a communication
between the cavity under it by a branch pipe with a main pipe, there being a tap
between the branch, and the main pipe has a partial vacuum formed in it by a
steam jet or by any other well known means, so that when the tap in the branch
pipe is open and that on the branch pipe going to the settling tank is closed, there
will be a partial vacuum formed under that section of the filter bed which will
assist in abstracting the moisture from the sludge. This sludge when sufficiently
drained is placed upon the drying "floor c, under which the flues f pass from the
boilers and drying machine to the chimney f¹. Through the room for the filters
and drying floors a current of air passes into the chimney f¹, and when required
the current may be increased by means of a steam jet at f, or by other well known
mechanical means; g is the machine for drying the sludge after it has been exposed
on the drying floors c, which is on the same level as the top of the machine,
which is in a building having a room below the level of the drying floor; fx is a
flue from the steam boilers passing to the drying cylinders in which flues at the
entrance to and exit from the drying cylinders g¹ there is a swivel damper or valve
g so that the draught or quantity of heat and gases passing the drying cylinders
may be regulated, the surplus heat and gases passing through a flue f² going under
the machine.
I have now particularly described the nature of my Invention and the mode of
carrying it into effect and claim as my Invention,--
Firstly. The system or mode of treating excreta and house refuse to obtain
manure therefrom, whereby the house refuse collected separately from the excreta
is sifted, and the cinders are used in the furnace for the drying process substantially,
as herein-before described.
Secondly. The system or mode of treating excreta or pail contents collected
separately from the cinders or house refuse by heat to evaporate a part of the
liquid, the heat when leaving the evaporating pan being sufficient to destroy the
noxious gases and effluvia, substantially as herein-before described and illustrated
by the Drawings.
Thirdly. The system or mode of making concentrated manure substantially as
herein-before described.
Fourthly. The combination and arrangement of mechanism for drying mixed
excreta ashes or other suitable material, and for drying sewage sludge and other
like materials formed by open cylinders or troughs, or partly open or partly closed
cylinders or troughs having rotating shafts carrying screws or parts of screws for
propelling the material through the troughs, substantially as herein-before described
and illustrated by the Drawings.
Fifthly. The system or mode of arresting and collecting in the flues the ammonia
passing from the drying machine or machines along with the products of combustion
to the chimney, substantially as herein-before described.

page_text: Sixthly. The arrangement of the building machinery and flues for carrying
out my improved process of treating excreta and house refuse, as herein-before
described and illustrated by the Drawings.
Seventhly. The arrangement of the building machinery and flues, settling tanks,
and filter beds, and the system or mode of forming vacuums under such filter beds,
substantially as herein-before described and illustrated by the Drawings.
In witness whereof, I, the said John Howard Kidd, have hereunto set my
hand and seal, this Twelfth day of July, in the year of our Lord One
thousand eight hundred and seventy-six.
TATT
JOHN HOWARD KIDD. (L.S.)