Improvements in Supplying Atmospheric Air to Combustion Chambers or Flues of Steam Boilers and other Furnaces.
Year: 1886

page_text: Improvements in Supplying Atmospheric Air to Combustion
Chambers or Flues of Steam Boilers and other Furnaces.
I, ROBERT JOHNSON of 816 Ashton Old Road Openshaw, near Manchester, in
the County of Lancaster Thread Manufacturer do hereby declare the nature of my
invention for IMPROVEMENTS IN SUPPLYING ATMOSPHERIC AIR TO COMBUSTION
CHAMBERS OR FLUES OF STEAM BOILERS AND OTHER FURNACES, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
i
This invention consists in the combination with a boiler, and with its combustion
flue or chamber, or any other form of furnace, of air inlet pipes, with regulator
admission valves in the front of the boiler, both above the crown of the inner flue,
and also on the lower side of the inner flue, and also in the combination with a
boiler and with its combustion flue or chamber or any other form of furnace, of air
inlet pipes, those above the crown of the inner Hue entering at a distance beyond
the bridge but as close as possible to the crown of the flue, and those below the fire
grate in the lower side of the inner flue going through the bridge, and ending in
an air distributor, the top of which is fixed below the level of the upper side of the
grate bars in the furnace and near to the bridge.
t
The termination or delivery end of these upper and lower inlet air pipes, is in
the combustion chamber or flue, and so fixed that the upper one is considerably in
advance of the lower one; the lower inlet air pipe being of larger dimensions than
the upper inlet air pipe.
By this invention is obtained a perfect and thorough combustion of the coal or
other fuel used, and of the gasses and smoke produced therefrom, thereby effecting
a saving in the cost of fuel, and preventing the emission of smoke.
The method adopted may be explained as follows:-Atmospheric air is con-
ducted from the exterior of the boiler, through suitable pipes of iron, copper, or
other material, into the combustion chamber or flue of the steam boiler or other
furnace.
On the front or outer side of these inlet air pipes, or at any other more convenient
place, a regulator valve of the louvre, slide, shutter, or any other convenient form,
is fixed, to regulate the admission of air, so as to suit the various and varying
requirements of the boiler, as its demands are affected by fog, bad or good coal,
rain, or other causes.

page_text: The inlet air pipes are conducted from the exterior of the boiler, preferably from
the front end, convenient to the firing doors, and may run through the water
in the boiler, through the firing flues-through the ash or cinder space-through
the economizer-through the side or bottom smoke flues, as may be found most
convenient, so that the termination or delivery of these air inlet pipes are in the
combustion chamber or flue, beyond, or past the bridge at the back or end of
furnace fire grate.
The upper inlet air pipes, going through the water in the boiler, terminate, and
deliver the air, as near as possible to the crown of the combustion chamber or flue,
but considerably beyond the point or points where the lower inlet air pipes
discharge their contents.
The lower inlet air pipes, going through the bridge, on the lower side of the
furnace flue or cinder receptacle, terminate with an air distributor, of a fan-tail,
conical, or other form of spreader, as may be found most convenient, and the upper
side of this air distributor, is placed below the level of the upper surface of the
grate bars in the furnace, and beyond or past the bridge; the end of this air
spreader, diffuser or distributor, is perforated with holes on all sides.
The air inlet pipes may be placed in any position, or in any number, to suit the
various circumstances of size, position, and locality, but their relative positions
must be maintained as before described.
The air distributor, or spreader, at the termination of the lower inlet air pipe, is
made so that it is easily detachable, in order to facilitate renewal and repairs.
In order that my invention may be readily understood, I now describe the
accompanying sheet of drawings, with reference to the several figures and letters
marked thereon, similar letters referring to similar parts, through the several views.
Fig. 1 shows longitudinal section of an ordinary single-flue steam boiler, a. being
the outer shell, b. the shell of the inner flue or furnace, and combustion flue.
The crown of the inner flue is pierced as shown, at k. and a junction made with
the upper inlet air pipe ;; which is shown carried through the water space, to the
front of the boiler, where at m. n. a regulator valve, of suitable design, is placed,
that as shown on drawing, being a circular, ordinary "Hit" and "Miss" regulator,
to control the admission of air.
1. are suspenders for carrying freely, the upper inlet pipe j.
In the inner tube or flue, is shown the ordinary fire-bars and grate, with an
ordinary bridge c; on the lower side of the tube or flue, and resting upon it, is
shown the lower inlet air pipe d; this pipe, at its front end, is enlarged at e: and
at o. p. a regulator valve of suitable design, is placed, that as shown on drawing,
being an ordinary "Hit and Miss" regulator, for controlling the admission of air.
A lug, or projection, as shown at q. is carried forward, so as to secure, by bolts,
rivets, set screws, or other means, the pipe in position; the sides are carried down
so as to form a straight surface for cleaning out the ashes, as shown on Fig. 3.
The end of pipe d: is enlarged near the bridge, as shown on drawing, at a to
receive the end of the air distributor f: which, after passing through the bridge c.
fits into the socket at e. as shown, the joint being made airtight by a ring of
asbestos, or other packing.
After passing through the bridge a. the air distributor f: is enlarged as shown
at g: and the end is perforated on all sides, with holes of suitable sizes, as may be
found best adapted for diffusing or spreading the air into the combustion chamber;
the highest air exit hole must be below the line of the top of the fire grate bars, as
ייד

page_text: Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
The combination with a Steam Boiler, and with its Combustion Flue or Chamber,
or with any other kind of Furnace, the arrangement herein before described, of
Inlet Air Pipes, having regulating or controlling valves, for the admission of air;
the placing of these inlet air pipes, so as to discharge the air at the upper and also
at the lower sides of the combustion flue or chamber, in the relative positions
therein, beyond or past the bridge, as described; the upper inlet air pipes dis-
charging the air, near the crown of the combustion Blue or chamber, and considerably
in advance of the lower inlet air pipes, which discharge the air near to the bridge,
and below the level of the upper surface of the fire-bars in the furnace, substantially
as herein before described and illustrated.