IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR TREATING STREET SWEEPINGS, URINE, AND OTHER REFUSE OF TOWNS, THE APPARATUS BEING ALSO PARTly Applicable to other ANALOGOUS PURPOSES
Year: 1876

page_text: LETTERS PATENT to Alfred Fryer, of Wilmslow, in the County of Chester,
for the Invention of " IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR
TREATING STREET SWEEPINGS, URINE, AND OTHER REFUSE OF TOWNS, THE
APPARATUS BEING ALSO PARTly Applicable to other ANALOGOUS PURPOSES”
PROVISIONAL SPECIFICATION left by the said Alfred Fryer at the Office of
the Commissioners of Patents on the 11th February 1870.
"IMPROVEMENTS IN
ALFRED FRYER, of Wilmslow, in the County of Chester.
THE METHOD OF AND APPARATUS FOR TREATING STREET SWEEPINGS, URINE, AND
OTHER REFUSE OF TOWNS, THE APPARATUS BEING ALSO PARTLY APPLICABLE TO
OTHER ANALOGOUS PURPOSES."
My improved apparatus consists, in the first place, of an improved form of kiln
for carbonizing street sweepings. The kilns at present in use for carbonizing
purposes are either quite unsuited to admit the heterogeneous mass of which these
are composed by reason of the smallness of their carbonizing chambers (a condition
essential to their success in carbonizing cheaply), or they have costly moving parts
liable to rapid deterioration from accidental stoppage of the machinery, and from
the fact that all the heat used is transmitted through their enclosing surfaces, while
few, if any, apply the heat directly to the materials to be carbonized.
My improved kiln is heated by means of a furnace which I prefer to place at its
side, to provide with fire-bars suitable for burning cinders, sloping sharply from
the back towards the door, while at the back, and above the furnace, I place a
hopper for the supply of fuel suitably closed.
In order to enable this furnace more readily to consume such refuse fuel I prefer
to fit it with close ash-pit doors, while I force air into the ash-pit, and thence
through the fuel, by means of a fan or other suitable apparatus (but in some cases I
make use of an ordinary chimney draught, taking care however to regulate the
supply of air). This arrangement permits me to regulate the quantity of air
passing through the furnace, and I so regulate the air in relation to the thickness
of the mass of incandescent fuel that the oxygen supplied is all, or almost all,
consumed in the furnace, and I prefer that it should be insufficient to burn the
carbon wholly into carbonic acid. The products of combustion thus formed, which
contain little or no free oxygen, I then lead into the kiln itself. This I prefer to
make rectangular in horizontal section, but larger above, where the street sweepings

page_text: enter it damp and bulky, than at the bottom, where they leave it dry and
carbonized.
The top may, if desired, be closed by a removable cover; the bottom is closed by
a slide, which when withdrawn permits the contents of the kiln to drop through it
by their own weight. The products of combustion enter this kiln at the side near
the bottom and leave it also by preference on one side near the top.
It is obvious that if the kiln were quite full of street sweepings or other matter
to be carbonized it would be difficult for the products of combustion to force their
way through. To overcome this difficulty I arrange a sort of inverted gutter
(which I prefer to make of netal) spirally around the interior walls of the kiln in
such a way as to lead from the point at which the products of combustion enter to
that at which they leave the kiln. This inverted gutter, passing around and
around the interior of the kiln, forms a sort of ledge which throws the sweepings
or other materials in the kiln from side to side as they pass downwards to a
considerable extent holds them up and prevents them from becoming compacted
into a solid mass, and also tends to turn them over so as to expose fresh surfaces to
the heated gases or the heated side of the gutter. As the lower side of the
inverted gutter is open the heated gases are free to come into direct contact with
the sweepings or other material to be carbonized, while as all the available oxygen
has already been utilized they can only drive off the water and distil off the
hydrogen compounds, and cannot carry off the carbon. Thus they effect the
carbonization partly by coming into direct contact with the material to be
carbonized and partly by heating the side of the inverted gutter with which that
material is in contact.
The gases passing out of the kiln consist, to a large extent, of carbonic oxide
and of hydrogen compounds, and I usually mix these with a further supply of air
and pass them through another furnace so that they may be burnt and made to
yield an additional supply of heat, while at the same time any odour which may
have been present in them will be destroyed.
In some cases, however, I simply pass these gases through a red-hot chamber
for the purpose of destroying the odour instead of passing them through the
furnace.
The heat generated by this second furnace I employ to generate a supply of
steam (for driving the fan by means of which the air is forced through the kiln), or
for evaporating or concentrating urine, or for any other purpose.
The carbonized street sweepings form, on leaving the kiln, a kind of charcoal,
which is used in a manner well-known for mixing with sewage, and more especially
where the forces and urine are collected separate from other refuse matter for
mixing with these in order to deodorise them and prevent them from fermenting
and becoming offensive, and when thus treated these matters have a considerable
manurial value. Since, however, the urine consists to a very large extent of water,
which may be removed by evaporation, and since the residue, after such evaporation,
will form a stronger and more concentrated manure, better able from its greater
concentration and portability to bear the expense of carriage, I prefer to collect as
much as possible of the urine separately from the faces, and to concentrate it by
means of the heat generated in the second furnace already spoken of. This
concentration I effect sometimes by taking the products of combustion from this
furnace and conveying them through a revolving cylinder (of the type known
amongst sugar manufacturers as a concretor cylinder) furnished internally with thin
sheets of metal forming spiral or volute blades. The urine to be concentrated
enters this cylinder at one end and leaves it at the other. As the cylinder revolves
the urine becomes spread over the whole of the surface of the interior of the
cylinder, and the volute blades and the hot gases passing over these wetted surfaces
rapidly take up moisture and effect concentration in the manner well known
without unduly heating the urine itself. The gases may be carried through this
cylinder by any ordinary form of natural or artificial draught. Sometimes I effect
the concentration by means of a boiler heated by the second furnace.

page_text: In this boiler, which I feed with urine or water, I raise steam to a high pressure.
Part of this steam I employ for driving the fan, the concretor cylinder, or any
other mechanical purpose (taking care that when urine is used the steam is
condensed after being used by the engines, so that any unpleasant or injurious
vapours or odours which may arise with the steam do not pass into the air), and
the remainder I employ in heating one or more vessels, which I also use for
concentrating urine. Where I employ more than one such vessel I arrange the
various vessels in such a way that the steam at high pressure from the boiler heats
the first pan boiling at a lower pressure, and is condensed on metal surfaces within
it and thence drawn off as condensed water, the steam from the first pan heats the
second in like manner, which boils at a still lower pressure, and so on, while the
steam and vapour from the last pan may, if in any way unpleasant, be condensed
so that no vapour shall pass from the apparatus into the air. One or more of theso
vessels may be boiled under a lower pressure than that of the atmosphere, in
which case the vacuum will be maintained by means of a condenser and air pump,
or in any ordinary way.
The urine will most conveniently be admitted in the first instance into the boiler
or into the vessel boiling under the highest pressure, thence be forced by the higher
pressure into the steam heated vessel boiling under the next lower pressure, and so
on, the most concentrated material eventually being drawn from the vessel boiling
at the lowest temperature.
Sometimes I use the heat of the second furnace for heating urine and foccal
matter in a closed vessel to such a temperature as shall decompose the urea and
other nitrogenous compounds. Decomposition having been thus effected the
valuable matter in the shape of ammonia can more readily be separated from the
other ingredients by distillation or other convenient means.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Fryer in the Great Seal Patent Office on the 10th August
1876.
ALFRED FRYER, of Wilmslow, in the County of Chester. "IMPROVEMENTS IN
THE METHOD OF AND APPARATUS FOR TREATING STREET SWEEPINGS, URINE, AND
OTHER REFUSE OF TOWNS, THE APPARATUS BEING ALSO PARTLY APPLICABLE TO
OTHER ANALOGOUS PURPOSES."
My improved apparatus consists, in the first place, of an improved form of kiln
for carbonizing street sweepings or other refuse matter. The kilns at present in use
for carbonizing purposes are either quite unsuited to admit the heterogeneous mass
of which these are composed by reason of the smallness of their carbonizing
chambers (a condition essential to their success in carbonizing cheaply), or they have
costly moving parts liable to rapid deterioration from accidental stoppage of the
machinery, and from the fact that all the heat used is transmitted through their
enclosing surfaces, while few, if any, apply the heat directly to the materials to be
carbonized.
In the annexed Drawings Fig. 1 is a longitudinal section, taken vertically_through
the line A, A, Fig. 2 is a vertical section through the line B, B, and Fig. 3 a
vertical section through the line C, C, of my improved kiln, as arranged for
carbonizing street sweepings or other refuse matter.
My improved kiln A, A, is heated by means of a furnace or furnaces B, B, which
I prefer to place at its side, and to provide with fire-bars C, C, suitable for burning
cinders, sloping sharply from the back towards the door (see Fig. 3), while at the
back, and above the furnace, I place a hopper D for the supply of fuel.
In order to enable this furnace more readily to consume such refuse fuel, I prefer
to fit it with close ash-pit doors E, while I force air into the ash-pit, and thence

page_text: through the fuel, by means of a fan or other suitable apparatus (but in some cases I
make use of an ordinary chimney draught, taking care however to regulate tho
supply of air). This arrangement permits me to regulate the quantity of air passing
through the furnaces B, B, and I so regulate the air in relation to the thickness of
the mass of incandescent fuel that the oxygen supplied is all or almost all consumed
in the furnace, and I prefer that it should be insufficient to burn the carbon wholly
into carbonic acid. The gaseous products of combustion thus formed, which con-
tain little or no free oxygen, I then lead into the kiln A itself. This I prefer to
make rectangular, in horizontal section, but larger above, where the street sweepings
enter it damp and bulky, than at the bottom, where they live it dry and car-
bonized.
The top may, if desired, be closed by a removable cover, the bottom is closed by a
slide at F, which when withdrawn permits the contents of the kiln to drop through
it by their own weight. The gaseous products of combustion from the furnaces
enter this kiln A at the side, near the bottom, through the passage G, and leave it
also by preference on one side, near the top, as at H, Fig. 2.
It is obvious that if the kiln were quite full of street sweepings or other matter
to be carbonized it would be difficult for the gaseous products of combustion to
force their way through. To overcome this difficulty, I arrange a sort of inverted
gutter I, I, (which I prefer to make of metal) spirally around the interior walls of
the kiln in such a way as to lead from the point at which the products of combus-
tion enter to that at which they leave the kiln. This inverted gutter, passing
around and around the interior of the kiln, forms a sort of ledge, which throws the
sweepings or other materials in the kiln from side to side as they pass downwards,
to a considerable extent holds them up, and prevents them from coming compacted
into a solid mass, and also tends to turn them over so as to expose fresh surfaces
to the heated gasses, or the heated side of the gutter. As the lower side of the
inverted gutter I is open the heated gases are free to come into direct contact with
the sweepings or other material to be carbonized, while as all the available oxygen
has already been utilized they can only drive off the water and distil off the
hydrogen compounds and cannot carry off the carbon. Thus they effect the car-
bonization, partly by coming into direct contact with the material to be carbonized
and partly by heating the side of the inverted gutter I with which that material is
in contact.
The gases passing out of the kiln consist to a large extent of carbonic oxide, and
of hydrogen compounds, and I usually mix these with a further supply of air and
pass them through another furnace, so that they may be burnt and made to yield
an additional supply of heat, while at the same time any odour which may have
been present in them will be destroyed.
In some cases, however, I simply pass these gases through a red hot chamber for
the purpose of destroying the odour instead of passing them through the furnace.
The heat generated by this second furnace I employ to generate a supply of
steam (for driving the fan by means of which the air is forced through the kiln) or
for evaporating or concentrating urine, or for any other purpose.
The carbonized street sweepings form, on leaving the kiln, a kind of charcoal,
which is used in a manner well known for mixing with sewage, and more especially
where the fæces and urine are collected separate from other refuse matter for mixing
with these in order to deodorise them and prevent them from fernenting and
becoming offensive, and when thus treated these matters have a considerable
manurial value. Since, however, the urine consists to a very large extent of water
which may be removed by evaporation, and since the residue after such evaporation
will form a stronger and more concentrated manure, better able from its greater
concentration and portability to bear the expense of carriage, I prefer to collect as
much as possible of the urine separately from the forces, and to concentrate it by
means of the heat generated in the second furnace already spoken of. This concen-
tration I effect sometimes by taking the products of combustion from this furnace,
and conveying them through a revolving cylinder (of the type known amongst

page_text: sugar manufacturers as a "concretor cylinder"), furnished internally with thin
sheets of metal, forming spiral or volute blades. The urine to be concentrated
enters this cylinder at one end and leaves it at the other. As the cylinder revolves
the urine becomes spread over the whole of the surface of the interior of the
cylinder, and the volute blades and the hot gases passing over these wetted surfaces
rapidly take up moisture and effect concentration in the manner well known,
without unduly heating the urine itself. The gases may be carried through this
cylinder by any ordinary form of natural or artificial draught. Sometimes I effect
the concentration by means of a boiler heated by the second furnace.
In this boiler, which I feed with urine or water, I raise steain to a high pressure.
Part of this steam I employ for driving the fan, the concretor cylinder, or any other
mechanical purpose (taking care that when urine is used the steam is condensed
after being used by the engines, so that any unpleasant or injurious vapours or
odours which may arise with the steam do not pass into the air), and the remainder
I employ in heating one or more vessels, which I also use for concentrating urine.
When I employ more than one such vessel I arrange the various vessels in such a
way that the steam at high pressure from the boiler heats the first pan, boiling at a
lower pressure, and is condensed on metal surfaces within it, and thence drawn off
as condensed water; the steam from the first pan heats the second in like manner,
which boils at a still lower pressure, and so on, while the steam and vapour from
the last pan may, if in any way unpleasant, be condensed so that no vapour shall
pass from the apparatus into the air. One or more of these vessels may be boiled
under a lower pressure than that of the atmosphere, in which case the vacuum will
be maintained by means of a condenser and air pump, or in any ordinary way.
The urine will most conveniently be admitted in the first instance into the boiler
or the vessel boiling under the highest pressure, thence be forced by the higher
pressure into the steam heated vessel boiling under the next lower pressure, and so
on, the most concentrated material eventually being drawn from the vessel boiling
at the lowest temperature.
Sometimes I use the heat of this second furnace for heating urine and foccal
matter in a closed vessel to such a temperature as shall decompose the urea and
other nitrogenous compounds. Decomposition having thus been effected, the
valuable matter, in the shape of ammonia, can more readily be separated from the
other ingredients by distillation or other convenient means.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I would remark in conclusion that I claim as my Invention,-
First. The novel method of treating street sweepings, urine, and other refuse
matter, substantially as hercin-before described.
Secondly. I claim the general arrangement of furnace and charring, or carbonizing
kiln, as described and illustrated, for the purpose of charring street sweepings, refuse
of towns, and other analogous material.
Thirdly. I claim the use of a furnace constructed substantially as above de-
scribed, with the fire-bars sloping sharply towards the clearing door, and fed by a
hopper above (or nearly above) the upper end of the bars, for the purpose of con-
suming cinders or other refuse material as fuel.
Fourthly. I claim the use in a charring kiln of an inverted gutter, constructed
substantially as described, for the purpose of ensuring the free circulation of the
heating gases, whilst allowing them to come freely into direct contact with the
material to be carbonized.
Fifthly. I claim the combination with a charring kiln (in which the materials are
carbonized partly by means of deoxygenised gases coming into direct contact with
them) of a second furnace in which the gases escaping from the kiln may be more
perfectly burnt, deprived of their odour, thoroughly disinfected, and made to yield a
further supply of heat, substantially as herein-before described.
Sixthly. I claim the combination of a revolving cylinder, constructed and heated

page_text: substantially as above described (and used for the purpose of concentrating urine)
with a charring kiln and second furnace, substantially as described.
Seventhly. I claim the use of a revolving cylinder (constructed substantially as
above described) for the purpose of concentrating urine or similar fluids at a low
temperature, by bringing the gaseous products of combustion into direct contact
therewith.
Eightly. I claim the use of several vessels, boiling at different temperatures, for
the concentration of urine, so arranged that the steam from the first (boiling at the
highest temperature) may be condensed on metal surfaces within the second
(boiling at the next highest temperature) which it thus heats, whilst the steam from
the second vessel in like manner serves to heat a third, and so on, together with the
prevention of unpleasant or injurious odours or gases from the process of concen-
tration by the condensation of the vapours evolved in the process.
Ninthly. I claim the treatment of urine, focal matter, or other analogous material
in a closed vessel, and under pressure, in order to raise it to a temperature higher
than its natural boiling point, for the purpose of decomposing the urea and other
nitrogeneous compounds so as to cause the rapid evolution of ammonia, and to allow
it to be readily collected.
In witness whereof, I, the said Alfred Fryer, have hereunto set my hand and
scal, this Eighth day of August One thousand eight hundred and seventy-
ALFRED FRYER. (L.S.)