An Improved Smoke Consuming Apparatus for Steam Boiler Furnaces.
Year: 1898

page_text: Date of Application, 15th Dec., 1898
Complete Specification Left, 21st Jan., 1899-Accepted, 22nd Apr., 1899
PROVISIONAL SPECIFICATION.
An Improved Smoke Consuming Apparatus for Steam Boiler
Furnaces.
I, WILLIAM ARTHUR GRANGER, of 102, Brooke Road, Stoke Newington,
London, N., Engineer, do hereby declare the nature of this invention to be as
follows:-
-
My invention relates to an improved apparatus for consuming or burning
the smoke which is ordinarily produced in the furnaces of steam boilers and it
is based on the principle of maintaining the furnace gases at a high temperature
for some little time after they leave the fuel and of injecting among them several
small streams of highly heated air.
Hitherto devices for accomplishing these ends have more or less failed owing
(1) to the furnace gases becoming chilled before the smoke has had sufficient
time to burn away into flame (2) to an insufficient length & time of contact
between the smoke and the heated air (3) to insufficient heating of the air or to
a lack of its positive & definite supply & (4) to the orifices from which it issues
becoming choked with cinders &c.
Now to remedy these defects I construct my improved smoke consumer (as
applied to Lancashire, Cornish and externally fired boilers, for which types it
is more especially suitable) in the following manner viz-Behind the bridge and
near the level of the furnace crown I fix a mass of firebrick (or other refractory
material) preferably of an arched shape and extending several feet backward from
the bridge and preferably inclining downwards as it recedes therefrom.
This arch is placed on hollow vertical supports resting on or forming part of a
plate or the like put across the lower portion of the boiler flue and the space
beneath the plate is arranged to form an air chamber into which air is forced
by means of a steam jet blower which may run from the ashpit mouth through
the base of the bridge into the chamber. The air thus forced into the chamber
passes through the hollow vertical supports into passages made in the fire brick
arch and ultimately issues from orifices chiefly in the under side thereof thus
forming a number of air jets projected downwards among the smoke and fur-
nace gases; and as these orifices are considerably above the fire level and point
more or less in a downward direction they cannot become choked with cinders &c.
It will be understood that the brick arch and supports become highly heated
by reason of the furnace gases continuously passing along them and conse-
quently the air supply from the steam jet blower in passing through their
interiors must be raised to a high temperature before issuing from the orifices
-and further that as the furnace gases pass mainly under the brick arch
immediately after crossing the bridge and travel along its full length they are
maintained at a high temperature during that travel and the chilling action due
to contact with the flue or other comparatively cool surfaces is avoided.
The surface of the arch may be roughened or have projections upon it so that
the stream of gases may be broken up.
As an alternative arrangement I sometimes suspend the brick arch or support
it upon cross bearers in the flue and deliver the air supply direct to the interior
of the arch by means of a steam jet blower running from the boiler front
through the furnace.

page_text: I
In order to still further maintain the temperature of the furnace gases
generally provide a second mass of fire brick (or other refractory material) placed
behind the bridge & preferably on the beforementioned plate which forms the
roof of the air chamber. This fire brick, which may be of any appropriate
shape, forms a second reservoir of heat and a second protection of the furnace
gases from chilling action and it extends backwards from the bridge to about
the same distance as the brick arch and the two are so arranged that the greater
part of the furnace gases after crossing the bridge must pass between them
and thus be kept thoroughly hot during that passage. The length of travel
being several feet gives an ample space of time for the hot air to mingle with
the smoke and to cause it to be burnt up in a state of flame.
A portion of the air from the chamber may be allowed to escape through
perforations in the before named plate and holes or spaces in the bottom fire
brick and thus issue in upward jets among the furnace gases. In the event
of these bottom orifices becoming choked with cinders &c. the air jets in the
upper brick arch will still continue to act and will discharge larger volumes
than before owing to the lower orifices being stopped and ceasing to draw on
the air chamber.
It is obvious that a fire clay tube of more or less circular section and having
suitable air inlets and outlets could be substituted for the two masses of fire
brick but the constructive and fixing difficulties would be greater.
With regard to types of boiler other than those already named, it is merely
necessary to modify the size and shape of the fire brick and connections in
accordance with the varying shapes and sizes of the furnaces to be treated but
in loco-type and vertical boilers there is usually insufficient space for the full
action of my apparatus.
An Improved Smoke Consuming Apparatus for Steam Boiler
Furnaces.
I, WILLIAM ARTHUR GRANGER, of 102, Brooke Road, Stoke Newington,
London, N., Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to an improved apparatus for consuming or burning
the smoke which is ordinarily produced in the furnaces of steam boilers and it
is based on the principle of maintaining the furnace gases at a high temperature
for some little time after they leave the fuel and of injecting among them several
small streams of highly heated air.
Hitherto devices for accomplishing these ends have more or less failed owing
(1) to the furnace gases becoming chilled before the smoke has had sufficient
time to burn away into flame (2) to an insufficient length and time of contact
between the smoke and the heated air (3) to insufficient heating of the air or to
a lack of its positive & definite supply and (4) to the orifices from which it issues
becoming choked with cinders &c.
Now to remedy these defects I construct my improved smoke consumer (as
applied to Lancashire, Cornish and externally fired boilers, for which types it
is more especially suitable) in the following manner viz.-Behind the bridge
and near the level of the furnace crown. I fix a. mass of fire brick
(or other refractory material) preferably of an arched shape extend-

page_text: ing several feet backwards from the bridge and preferably inclining
downward as it recedes therefrom. This arch is placed on hollow
vertical supports resting on or forming part of a plate or the like put across the
lower portion of the boiler flue and the space beneath this plate is arranged to
form an air chamber into which air is forced by means of a steam jet blower
which may run from the ashpit mouth through the base of the bridge into the
chamber. The air thus forced into the chamber passes through the hollow
vertical supports into passages made in or behind the fire brick arch and ulti-
mately issues from orifices chiefly in the under side thereof, thus forming a
number of air jets projected downwards among the smoke and furnace gases-
and as these orifices are considerably above the fire level and point more or less
in a downward direction, they cannot become choked with cinders &c. It will
be understood that the brick arch and supports become highly heated by
reason of the furnace gases continuously passing along them and consequently
the air supply from the steam jet blower in passing through their interiors must
be raised to a high temperature before issuing from the orifices and further
that as the furnace gases pass mainly under the brick arch immediately after
crossing the bridge and travel along its full length they are maintained at a high
temperature during that travel and the chilling action due to contact with the
flue or other comparatively cool surfaces is avoided. The surface of the arch
may be roughened or have projections upon it so that the stream of gases may be
broken up.
As an alternative arrangement I sometimes suspend the brick arch or support
it upon cross bearers in the flue and deliver the air supply direct to the interior
of the arch by means of a steam jet blower running from the boiler front
through the furnace.
In order to still further maintain the temperature of the furnace gases I
generally provide a second mass of fire brick (or other refractory material) placed
behind the bridge and preferably on the beforementioned plate which forms the
roof of the air chamber. This fire brick which may be of any appropriate
shape, forms a second reservoir of heat and a second protection of the furnace
gases from chilling action and it extends backwards from the bridge to about
the same distance as the brick arch and the two are so arranged that the greater
part of the furnace gases after crossing the bridge must pass between them
and thus be kept thoroughly hot during that passage. The length of travel
being several feet gives an ample space of time for the hot air to mingle with
the smoke and cause it to be burnt up in a state of flame. A portion of the air
from the chamber may be allowed to escape through perforations in the before
named plate and holes or spaces in the bottom fire brick and thus issue in upward
jets among the furnace gases. In the event of these bottom orifices becoming
choked with cinders &c., the air jets from the upper fire brick will still continue
to act and will discharge larger volumes than before owing to the lower orifices
being stopped and ceasing to draw on the air chamber.
It is obvious that a fire clay tube of more or less circular section and having
suitable air inlets and outlets could be substituted for the two masses of fire
brick but the constructive and fixing difficulties would be greater.
With regard to types of boiler other than those already named it is merely
necessary to modify the size and shape of the fire brick and connections in
accordance with the varying shapes and sizes of the furnaces to be treated but
in loco-type and vertical boilers there is usually insufficient space for the full
application of my apparatus.
In the accompanying drawings Fig. 1 is a longitudinal section of part of the
flue of a Lancashire boiler with my improved smoke consuming apparatus shown
therein; Fig. 2 a cross section of the same on the line A B; Fig. 3 a similar
view showing a modified method of supporting the brick arch specially suitable
for boilers having Galloway tubes; and Fig. 4 shows the application of my

page_text: apparatus to a Babcock boiler. The same reference letters indicate like parts
in all the figures.
In Figs. 1 and 2, B B is the fire brick arch shown as consisting of segments
of fire brick held in an arched iron frame CC which rests on the long hollow
strips M M supported on the vertical pieces D D. These latter may form part
of the plate EE (which merely rests on the sides of the flue) on the under side
of which is the air chamber F supplied with air by the steam jet blower G. The
course of the air supply from the chamber to the inside H of the iron arch is
shown by the arrows N, and it then issues through holes or spaces J in the fire
brick among the smoke as soon as the latter has crossed the bridge I.
The front of the iron arch may be faced with fire brick R to protect it from
the flames. The lower mass of fire brick is shown shaped as an inverted arch K
with orifices L from which a supply of air from the chamber may issue.
For convenience of getting the various parts in position without taking down
the bridge, the vertical supports may be made in two or more lengths and be
merely socketed together as shown at P and similarly the crescent shaped air
chamber may be made separate from the plate E and be bolted to it after they
are both in the flue.
In Fig. 3 one or more vertical supports D are fixed centrally in the flue in-
stead of near the sides and the iron arch with the fire brick is mounted on its
top. The right and left hand parts of the arch may be made separate and be
bolted together when in the flue.
This modification is specially suitable for boilers having Galloway tubes near
the bridge.
In Fig. 4 the masses of fire brick B and B¹ are placed in the positions shown
and they may be built across to the side walls of the furnace and supported on
cross bearers. Air is supplied through passages in the side walls or to B¹ through
the back of the furnace from the ash pit, one or more steam jet blowers providing
the supply which ultimately issues from holes J.
may often
In cases where boilers are under forced draught the steam jet blower
be dispensed with and the air supply may then pass direct from the ashpit to
the chamber, a suitable valve or the like being provided to regulate the volume
of air supplied. When so preferred this valve can be connected with the fire
door in such manner as to open it more widely when the fire door is closed after
firing and similarly the steam jet of the blower G may be so connected.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
(1) In Lancashire, Cornish and externally-fired boilers the employment of a
mass of fire brick or the like placed behind and above the bridge and having
orifices in its under side for the issue of heated air, substantially for the purpose
herein set forth.
(2) In Lancashire, Cornish and externally fired boilers the combination of a
mass of fire brick or the like placed above the bridge and having orifices in its
under side for the issue of heated air;-and a steam jet blower or blowers (whether
independent or forming part of a forced draught arrangement) for the purpose
of delivering streams of air near the bridge for the purpose herein set forth.
(3) The general arrangement and combination of parts constituting my im-
proved smoke consuming apparatus as herein described.
T
that day of January 1899.