IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR TREATING THE REFUSE OF TOWNS
Year: 1878

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 THE REFUSE OF TOWNS."
Sealed the 9th August 1878, and dated the 19th February 1878.
"
IMPROVEMENTS IN
PROVISIONAL SPECIFICATION left by the said Alfred Fryer at the Office of
the Commissioners of Patents on the 19th February 1878.
ALFRED FRYER, of Wilmslow, in the County of Chester.
THE METHOD OF AND APPARATUS FOR TREATING THE REFUSE OF TOWNS."
My Invention relates-
First. To improved methods of and apparatus for preparing refuse material for
treatment in the special furnaces patented by me the 5th of August 1876, No. 3125.
Secondly. To improved methods of treating the material in these furnaces and in
the evaporating apparatus connected therewith.
Thirdly. To improved methods of and apparatus for treating the "pail contents"
before they enter the evaporating apparatus.
And, Fourthly. To an improved method of and apparatus for treating the semi-
solid matter which issues therefrom.
First. The material which is brought to the special furnaces devised by me for
treating the refuse of towns, and patented by me on the 5th of August 1876,
No. 3125, often contains large quantities of small ash entirely exhausted of com-
bustible material. This ash not only will not itself burn, but in consequence of its
fine state of subdivision it much impedes the passage of air through the mass of
material in the furnace. The amount of work done by the furnace is thus con-
siderably diminished, while at the same time the temperature of the products of
combustion is lowered, and consequently the useful effect to be produced by them is
lessened. In order to avoid these evil consequences it is desirable to screen the material
before it passes into these furnaces, and thus to separate the fine ash from the other
material.

page_text: My improved method of effecting this screening consists in forming a rectangular
chamber, to opposite sides of which I attach a series of bars, the axes of which are
parallel, and their sides tapering in forin, somewhat like the teeth,of a comb. These
bars project outwards from the side to which they are attached, but have a down-
ward inclination so that any material not falling through the bars rolls down them
to their lower ends, whence it falls on to another set of bars projecting from the
opposite side of the chamber at a lower level and inclined in the opposite direction
which the set first described overlaps. This second set in like manner delivers on
to a third set which is fixed below and parallel to the first set, and so on until the
material has been sufficiently screened. Below each set of bars is fixed a diaphragm,
preferably of sheet metal, which catches the material which drops through
(between) the bars, and being inclined in the opposite direction to them guides it
outside the chamber. Thus the fine material is delivered outside the chamber on
each side of it while that which has not passed through the bars drops to the bottom
of the chamber.
It will be observed that there are no moving parts about this screen, it is only
necessary to throw the material to be heated into it at the top, and it will be
discharged properly screened at the bottom.
Secondly. In order that the liquid undergoing evaporation or concentration
should be rendered or preserved slightly acid, and prevented from parting with its
volatile alkali, it is desirable as explained in the Specification of my said Patent,
that sulphurous acid should be mingled with the gases which effect the evaporation.
In certain cases the necessary supply of this acid may be obtained from the fuel,
but in most cases it is necessary to provide for the supply of a greater quantity of
the acid than would be naturally present in the products of combustion. I provide
this additional supply of sulphurous acid by adding from time to time to the material
being passed into the furnaces for treatment a small quantity of iron pyrytes, by
preference using what is technically called "smalls." The pyrytes gradually parts
with its sulphur in the form of sulphurous acid, which mixes with the other
products of combustion, and adds to the heat of the furnace. It is obvious that
pyrytes required to supply the sulphurous acid to the liquid undergoing concentra-
tion might be burnt in a furnace other than the special one described by me.
Thirdly. This part of my Invention consists of an apparatus, the object of which
is to separate the solid and fibrous substances from the other portions of the "pail
contents," to dispense with manipulation, to prevent odour during the mixing process,
and to furnish the vessel supplying the concentrating apparatus with liquids, pasty
material, and paper reduced to a thin homogeneous pulp.
This part of my Invention consists of a vessel (constructed preferably of iron) for
the reception of the "pail contents." The vessel is furnished with agitators usually
moved by steam power, and these churn or mix the "pail contents" together. The
vessel is usually closed except at the points needful for feeding and discharge.
When in operation the vessel is kept full, and the addition of each portion of "pail
contents" displaces an equal portion of churned material, which having been passed
through a strainer to separate the solids and fibrous substances, is conducted to the
vessel supplying the evaporating apparatus.
Fourthly. The material discharged from the evaporating or concentrating
apparatus is still in a semi-solid state. In order to reduce it still further in bulk
and to deliver it in a solid and practically dry state, I make use of another machine
which I call a "poudretteur."
This apparatus consists of a fixed cylinder placed horizontally or in a slightly
inclined position, through the axis of which runs a revolving shaft driven by
suitable gearing outside the cylinder, and fitted with arms arranged spirally upon
it, and revolving with it. The ends of the cylinder are fitted with covers, through
one of which heated air or gases (mixed with a suitable proportion of sulphurous
acid gas) is admitted into the upper part of the cylinder, and through the other of
which these gases are drawn away by a chimney or other suitable draught. I
prefer to draw the gases through the cylinder rather than to force them, as by the

page_text: former arrangement I am enabled more readily to draw in cold air to mingle with
them and temper their heat if necessary.
Between each set of arms and the next a fixed bar is introduced, one end of which
is supported by the shaft carrying the arms, while the other end passes through an
opening in the cylinder itself, and is secured outside it. The cylinder is fitted with
suitable hand boles, enabling the interior to be readily examined, and any
obstruction within to be removed.
The semi-fluid material required to be further dried is admitted into this cylinder
near one of its ends.
The arms revolving within the cylinder become covered with it, and carry
portions of it up with them; they are prevented from becoming too thickly covered
by the fixed bars introduced between them which act as scrapers. The material
upon the arms, and falling from them, is exposed to the current of heated gases
passing through the cylinder. These arms dipping during part of their revolution
into the semi-liquid or pasty substance in the lower part of the cylinder, and then
rising into the heated gases above, continually present fresh surfaces of the material
to this drying agent; they are also so constructed as gradually to propel the
material within the cylinder from the end at which it enters towards the other
end; this movement may, if desired, be aided by slightly inclining the cylinder.
By the time the material has reached the far end of the cylinder it has attained the
desired degree of dryness (that is, in the state known as poudrette "), and is
allowed to fall out through an aperture which I prefer to close by a balanced valve
or door.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Fryer in the Great Seal Patent Office on the 17th August
. 1878.
ALFRED FRYER, of Wilmslow, in the County of Chester.
"IMPROVEMENTS IN THE
METHOD OF AND APPARATUS FOR TREATING THE REFUSE OF TOWNS."
My Invention relates,―
First. To improved methods of and apparatus for preparing refuse material for
treatment in the special furnaces patented by me, August 5th, 1876, No. 3125.
Secondly. To improved methods of treating the material in these furnaces, and
in the evaporating apparatus connected therewith.
Thirdly. To improved methods of and apparatus for treating the "pail contents "
before they enter the evaporating apparatus.
And, Fourthly. To improved methods of and apparatus for treating the semi-solid
matter which issues therefrom.
First. The material which is brought to the special furnaces devised by me for
treating the refuse of towns, and patented August 5th, 1876, No. 3125, often
contains large quantities of small ash, entirely exhausted of combustible material.
This ash not only will not itself burn, but in consequence of its fine state of
subdivision, it much impedes the passage of air through the mass of material in the
furnace. The amount of work done by the furnace is thus considerably diminished,
while at the same time the temperature of the products of combustion is lowered,
and consequently the useful effect to be produced by them is lessened. In order to
avoid these evil consequences it is desirable to screen the material before it passes
into these furnaces, and thus to separate the fine ash from the other material.
My improved method of effecting this screening is illustrated by Figs. 1 and 2
on the annexed Drawing, and consists in forming a rectangular chamber a, a, to
opposite sides of which b, b', I attach a series of bars c, c', c", the axes of which are
parallel, and their sides tapering in form, somewhat like the teeth of a comb, as
shown at Fig. 2. These bars project inwards from the sides b, b¹, to which they are
attached, but have a downward inclination, so that any material not falling through
the bars C, rolls down them to their lower ends, whence it falls on to another set of
bars C projecting from the opposite side b' of the chamber at a lower level, and
inclined in the opposite direction which the set first described overlaps. This
second set in like manner delivers on to a third set c¹¹, which is fixed below, and
parallel to the first set C, and so on until the material has been sufficiently screened.
Below each set of bars c, c', c¹¹, is fixed a diaphragm d, d', d", preferably of sheet
metal, which catches the material wbich drops through (between) the bars c, c, c¹¹,
and being inclined in the opposite direction to them, guides it outside the chamber
through the openings e, e³, e, made in the sides b, 61, of the chamber. Thus the fine
material is delivered outside the chamber a, a, on each side of it, while that which
has not passed through the bars c, c¹, cl, drops to the bottom of the chamber.
It will be observed that there are no moving parts about this screen, it is only
necessary to throw the material to be treated into it at the top, and it will be dis-
charged properly screened at the bottom.
Secondly. In order that the liquid undergoing evaporation or concentration
should be rendered or preserved slightly acid, and prevented from parting with its
volatile alkali, it is desirable, as explained in the Specification of my said Patent,
that sulphurous acid should be mingled with the gases which effect the evaporation.
In certain cases the necessary supply of this acid may be obtained from the fuel,
but in most cases it is necessary to provide for the supply of a greater quantity of
the said acid than would be actually present in the products of combustion. I
provide this additional supply of sulphurous acid by adding from time to time to
the material being passed into the furnace for treatment, a small quantity of iron
pyrites, by preference using what is technically called "smalls."
The pyrites

page_text: gradually parts with its sulpher in the form of sulphurous acid, which mixes
with the other products of combustion, and adds to the heat of the furnace.
It is obvious that pyrites required to supply the sulphurous acid to the liquid
undergoing concentration might be burnt in a furnace other than the special one
described by me.
Thirdly. This part of my Invention consists of an apparatus (so simple as not to
require Drawings to make its construction clearly understood), the object of which
is to separate the solid and fibrous substances from the other portions of the "pail
contents," to dispense with manipulation, to prevent odour during the mixing
process, and to furnish the vessel supplying the concentrating apparatus with
liquids, pasty material, and paper reduced to a thin homogeneous pulp.
This part of my Invention consists of a vessel (constructed preferably of iron) for
the reception of the "pail contents." This vessel may be of any convenient form,
and is provided with openings for the admission and discharge of the pail contents,
and is also furnished with a man-hole or tight-shutting lid, by means of which the
interior can be examined, and solid or fibrous matter withdrawn from it. The
vessel is furnished with suitable agitators, usually moved by steain power, and these
churn or mix the "pail contents" together. The vessel is usually closed, except at
the points needful for feeding and discharge. The inlet opening is usually made in
the lower part of the vessel, but to it is attached a funnel which rises some distance
above the top of the vessel.
The outlet opening may either be made in the top of the vessel, or may be made
near the bottom, and furnished with a pipe outside rising to or above the top, and
it is also furnished with a strainer. Thus, when in operation, the vessel is kept
full, since the feeding funnel and the outlet pipe both rise above it, and the addition
of each portion of pail contents displace an equal portion of churned material, which,
having been passed through a strainer to separate the solids and fibrous substances,
is conducted to the vessel supplying the evaporating apparatus. By this arrange-
ment, the inlet and outlet pipes form traps which prevent the pail contents under-
going agitation from being exposed to the air.
The vessel in addition to the outlet already described is usually furnished with a
cock or plug in the bottom, by means of which it can be emptied of its liquid
contents when required.
Fourthly. The material discharged from the evaporating or concentrating
apparatus is still in a semi-solid state. In order to reduce it still further in bulk,
and to deliver it in a solid and practically dry state, I make use of another machine
which I call a "pondretteur," and which may also be described without the
assistance of Drawings.
This apparatus consists of a fixed cylinder (placed horizontally or in a slightly
inclined position), through the axes of which runs a revolving shaft driven by
suitable gearing outside the cylinder, and fitted with arms arranged spirally upon it
and revolving with it. The ends of the cylinder are fitted with covers, through one
of which heated air or gases (mixed with a suitable proportion of sulphurous acid.
gas) is admitted into the upper part of the cylinder, and through the other of
which these gases are drawn away by a chimney or other suitable draught; I prefer
to draw the gases through the cylinder rather than to force them, as by the former
arrangement I am enabled more readily to draw in cold air to mingle with them
and temper their heat if necessary.
Between each set of arms and the next a fixed bar is introduced, one end of
which is supported by the shaft carrying the arms, while the other end passes
through an opening in the cylinder itself and is secured outside it. The cylinder is
fitted with suitable hand-holes, enabling the interior to be readily examined, and
any obstruction within to be removed.
The semi-fluid material required to be further dried is admitted into this cylinder
near one of its ends.
The arms revolving within the cylinder become covered with it, and carry

page_text: portions of it up with them; they are prevented from becoming too thickly covered
by the fixed bars introduced between them which act as scrapers. The material
upon the arins and falling from them, is exposed to the current of heated gases
passing through the cylinder. These arms dipping during part of their revolution
into the semi-liquid or pasty substance in the lower part of the cylinder, and then
rising into the heated gases above, continually present fresh surfaces of the material
to this drying agent; they are also so constructed as gradually to propel the
material within the cylinder from the end at which it enters towards the other end;
this movement may, if desired, be aided by slightly inclining the cylinder.
By the time the material has reached the far end of the cylinder, it has attained
the desired degree of dryness (that is, in the state known as "pondrette "), and is
allowed to fall out through an aperture which I prefer to close by a balanced valve
or door.
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 wish it to be understood that I claim as my Invention,—
First. The method herein described of screening the refuse material for the
purpose of preparing it for treatment in the special furnaces herein-before referred
to.
Secondly. The peculiar construction of screening apparatus herein-before de-
scribed, and illustrated by Figs. 1 and 2 on the annexed Drawings.
Thirdly. The method herein described of supplying sulphurous acid to the liquid
refuse material whilst undergoing concentration by the addition thereto of iron
pyrites.
Fourthly. The construction and use of the apparatus herein-before described for
mixing and agitating the "pail contents," and separating solid and fibrous sub-
stances therefrom.
And, Fifthly. The construction and use of the apparatus herein-before described
as the "poudretteur," for the purpose of reducing the semi-solid concentrated refuse
material to the solid and practically dry state known as "poudrette.".
In witness whereof, the said Alfred Fryer, have hereunto set my hand and
seal, this Sixteenth day of August, in the year of our Lord One thousand
eight hundred and seventy-eight.
Witnessed by
JOHN HUGHES,
Clerk to Geo. Davies, C.E.,
Patent Office,
4, St. Anns Sq.,
Manchester.
ALFRED FRYER. (L.S.)