IMPROVEMENTS IN THE METHOD OF TREATING TOWNS REFUSE AND FURNACE AND APPARATUS THEREFOR
Year: 1884

page_text: BRIERLEY DENHAM HEALEY of 37 Victoria Street Liverpool in the County of
Lancaster Civil Engineer and BENJAMIN HOWARTH THWAITE of St Neots in the
County of Hantingdon a Director of the Municipal Appliances Company Limited
do hereby declare the nature of our invention for IMPROVEMENTS IN THE METHOD
OF TREATING TOWNS REFUSE AND FURNACE AND APPARATUS THEREFOR to be as
follows:-
According to our invention the refuse is burnt in a reverberatory furnace and
the resulting clinkers are ground in a mill in which the light dust is separated from
the heavy gravel by wind blast.
The refuse is charged into the back end of the furnace about two or three feet
below the upper or road level the lower part of the charging opening being level
with the bottom of the refuse pit. The drying zone of the furnace leading from
the charging opening to the back end of the firebars is formed at an angle of about
30° or say 1 in 2 and the firebars are set at an inclination of about 5° or say
1 in 10.
The firebars are of cast steel or cast iron tapered in section similar to coal screen
bars and they have distance pieces cast thereon about one foot apart so as to keep
the bars about three eights of an inch apart at the top side. The reverberatory
arch of the furnace is built with grooved and tongued bricks, and the charging hole
lintel is placed so as to prevent the nose of this arch from being injured by the
charging tools. According to another modification the firegrate has moving fire-
bars which are moved forward altogether at regular intervals every other bar or
one half the number moving back afterwards and the other half following before
the next forward movement takes place by which means the clinkers are delivered
into a suitable receiver as the refuse is burnt.
The drawing doors are of fireclay slabs bung with chains, pulleys and balance
weights and bound together with iron bands. When more than one furnace is built
at once the intermediate down flues have each a damper which is suspended from
its upper edge so that it may be used to shut off the draught on either the right or
left side thereof.
The main roof of the furnace is arched from side to side excepting for about
three feet of the front part which is turned from the front wall up to the square

page_text: end of main arch. In another arrangement the main arch is shortened and a steam
generator is laid across the furnace which generator has a number of Field's tubes
in the lower part of the shell.
When four or more furnaces are built at once they are arranged with a central
roadway having a refuse pit on either side thereof from which pits the furnaces
are very conveniently charged and the clinker pits are formed to the extreme right
and left.
In building furnaces below the general level of the ground the clinker pits are
provided with hydraulic lifts having differential rams. The greater area of the
ram is acted upon for raising the loaded table and the smaller area for lowering
the empty clinker wagon or barrow. Tappets are attached thereto which actuate
a fourway valve and ensure the stopping of the table at the top and bottom.
The grinding mill used for crushing the clinkers and separating the light dust
therefrom has two or three pairs of horizontal rolls as required centred and speeded
to suit the material operated upon and is provided with a wind blast below the
lowest pair of rolls by which means the light dust is blown into a suitable receiver
whilst the gravel is collected in one or more sizes as may be desired with or without
the use of screens.
When the gases passing from the furnace contain a large amount of sulphur or
ammonia a steam jet arrangement is applied in which superheated steam is mixed
therewith and the mixed gases are afterwards condensed before reaching the
chimney by which means the strength of the obnoxious fumes is considerably
reduced.

page_text: BRIERLEY DENHAM HEALEY of Liverpool in the County of Lancaster Civil
Engineer and BENJAMIN HOWARTH THWAITE of St Neots in the County of
Huntingdon a Director of the Municipal Appliances Company Limited do hereby
declare the nature of our invention for IMPROVEMENTS IN THE METHOD OF
TREATING TOWNS REFUSE AND FURNACE AND APPARATUS THEREFOR and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
According to our invention the refuse is burnt in a reverberatory furnace and
the resulting clinkers are ground in a mill in which the light dust is separated from
the heavy gravel by wind blast.
The refuse is charged into the back end of the furnace at a depth of two or three
feet below the upper or road level. The lower part of the charging opening is level
with the bottom of the refuse pit. The drying zone of the furnace leading from the
charging opening to the back end of the firebars is formed at an angle of about 30°
and the firebars are set at an inclination of about 5°.
The firebars are of cast steel or cast iron tapered in section similar to coal screen
bars and they have distance pieces cast thereon about one foot apart so as to keep
the bars about three-eights of an inch apart at the top side. The reverberatory
arch of the furnace is built with grooved and tongued bricks, and the charging hole
lintel is placed so as to prevent the nose of this arch from being injured by the
charging tools. According to another modifacation the firegrate has moving fire-
bars which are moved forward altogether at regular intervals, every other bar or
one half the number moving back afterwards and the other half following before
the next forward movement takes place by which means the clinkers are delivered
into a suitable receiver as the refuse is burnt.
When more than one furnace is built at once the intermediate down flues have
each a damper which is suspended from its upper edge so that it may be used to
shut off the draught on either the right or left side thereof. The main roof of the
furnace is arched from side to side excepting for about three feet of the front part
which is turned from the front wall up to the square end of main arch. In another
arrangement the main arch is shortened and a steam generator is laid across the
furnace which generator has a number of Field's tubes in the lower part of the
shell.
When four or more furnaces are built at once they may be arranged with
a central roadway having the refuse pits on either side thereof, from which pits the
furnaces are very conveniently charged.
In building furnaces below the general level of the ground the clinker pits may
be provided with hydraulic lifts having differential rams. The greater area of the
ram is acted upon for raising the loaded table and the smaller area for lowering
the empty clinker wagon or barrow. Tappets are attached thereto which actuate
a'fourway valve, and ensure the stopping of the table at the top and bottom,

page_text: The grinding mill used for crushing the clinkers and separating the light dust
therefrom has two or three pairs of horizontal rolls as required centred and speeded
to suit the material operated upon. It is provided with a wind blast below the
lowest pair of rolls by which means the light dust is blown into a suitable receiver
whilst the gravel is collected in one or more sizes as may be desired with or without
the use of screens.
When the gases passing from the furnace contain a large amount of sulphur or
ammonia a steam jet arrangement is applied in which superheated steam is mixed
therewith and the mixed gases are afterwards condensed before reaching the
chimney by which means the strength of the obnoxious fumes is considerably
reduced.
And in order that our Invention may be understood we will now describe it with
reference to the two sheets of Drawings accompanying this specification like
reference numbers being used to denote the same or similar parts where repeated
on the various diagrams.
Figure 1 is a longitudinal section of the furnace, figure 2 is a section on line A. B,
and figure 3 is a section on line C. D. on figure 1. Figure 4 is an elevation of the
hydraulic lift for clinker pit. Figure 5 is a section of the grinding mill and figure 6
is an elevation of one end of same indicating the method of gearing. Figures 7
& 8 indicate the corrugated sheet iron portion of the condensing apparatus.
The refuse is deposited in the pit 1 from which it is charged into the drying
zone 2 and afterwards passed down to the grate 3. The reverberatory arch 4 is
built of grooved and tongued bricks, and when the furnace is at full heat this arch
is red hot. The charging hole lintel 16 protects the nose 17 of the reverberatory
arch 4 from injury during the charging. The products of combustion pass down
the flues 8 and through the side branches 9 to the main flue 5. The upper road
level 6 is on or about the same level as the top of the furnace, and this allows of
shorter inclines in forming the approach roads than hitherto. Special charing
openings 7 for bulky articles which have to be burnt may be provided when
required. The drawing doors 10 may be of fireclay slabs bound with iron and
hung in any well known manner. The floor of ashpit 11 is on same level as the
clinkering floor 14 in front of the furnace. Iron Binders 12 are built in the walls as
indicated and secured with tie bolts. The fire bars rest at front end on door cill
and at back end on bearer 13. The steam generator is indicated by dotted lines 15.
The dampers 18 in downflues 8 swing to either side having a rod attached thereto
with lever in front of furnace.
"
In using moving firebars the mechanism is similar to that commonly known as
"Viccars but the motion is reversed so as to deliver the clinkers at the front end
into a receiver. The receiver may be encased within the front line of furnace and
be hopper shaped with balanced flaps to prevent an undue inrush of cold air to the
furnace.
The hydraulic clinker lift has a cylinder 19, differential ram 20, cross head 21,
pulleys 22 and chains leading over the head wheels 23 to the carriage 24. A four-
way valve is attached by pipes to each end of cylinder and to the pressure and
waste mains. Suitable levers and tappets are provided for starting and stopping
the carriage.
The clinker grinding mill is shewn on figures 5 and 6 with two pairs of rolls 25
and 26. The upper pair 25 is geared to the lower pair 26, by wheels 27 and 28
shewn in elevation on figure 6 of different speeds and each pair of rolls is geared at
the other end by wheels of equal pitch. The wind blast enters at 29 and plays
upon the crushed material in a thin stream 30, driving the dust in the direction 31.
It is obvious that instead of the wind blast a strong chimney draught or steam
exhaust apparatus is equally effective.
In order to further render the gases resulting from the combustion of the refuse
as innoxuous as possible, we make use of a special system of condensation by which
we recover the ammonia and other gases which are condensable at atmospheric
pressure. To effect this condensation, we make use of the following arrangement

page_text: and apparatus, at a point in the chimney flue, as near its connection with the said
furnace as practicable, we insert a steam blower through which we inject super-
heated steam, which mixes with the waste gases, aiding their dissolution and
increasing the draught of the furnace. In the chimney flue and between the
chimney and the said furnace we construct the condenser apparatus, for which
purpose we make use of corrugated sheets, 32 placed one over the other in zig-zag
form nearly horizontally and in such a way as to compel the waste gases 33 to pass
and repass under and over the corrugated sheets before they can enter the chimney.
We cause water to flow on to the top or highest sheet which gravitates to those
beneath it, through perforations equally and numerously distributed in the corru-
gations; this shower-like fall of water thoroughly cleanses the gases and removes
the ammonia and other pungent elements from them. The water from the con-
denser flows into a receptacle 34 from which we pump it again and again to the
upper part of the condenser until it becomes sufficiently strong ammoniacally for
We do not confine ourselves to the exact form of condenser described.
use.
Having now described and ascertained the nature of our Invention and explained
the best means we are acquainted with of performing the same, we wish it to be
understood that we do not restrict ourselves to the precise details shewn on the
accompanying drawings but we claim as our Invention
First. The use of a furnace for burning towns refuse constructed with the
charging hole and refuse pit below the top level of furnace substantially as herein
shewn and described.
Second. The improved methods of building the arches with or without a steam
generator, and of constructing the firegrate for said furnace substantially as herein
shewn and described.
Third. The use of a steam jet and condensing apparatus for treating the products
of combustion substantially as herein shewn and described.
Fourth. The use of the hydraulic clinker lift and of the clinker grinding mill
substantially as herein shewn and described.