Improvements in Smoke-consuming Apparatus for Boiler and other Furnaces.
Year: 1892

page_text: Complete Specification Left, 7th Oct., 1892-Accepted, 25th Mar., 19
COMPLETE SPECIFICATION.
Improvements in Smoke-consuming Apparatus for Boiler and other
Furnaces.
I, WESLEY SMITH of Toledo in the County of Lucas and State of Ohio,
United States of America, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention has for its object to promote the combustion of fuel in fire-boxes
or furnaces, and particularly the fire-boxes of steam boilers, either stationary or
locomotive.
The invention consists in the combination with a furnace or fire-box, an air-
compresser, and a conduit arranged to conduct compressed air to the fire-box and
to subject said air to heat, of another conduit, arranged to conduct external air at
ordinary atmospheric pressure to the fire-box, the last-mentioned conduit being
arranged to subject the air passing through it to heat and conduct such heated air to
the point where the compressed air is delivered by the compressed air conduit,
the arrangement being such that the jet of compressed. air acts somewhat on the
principle of a jet of steam in an injector to induce a flow of air under ordinary
pressure, the result being the supplying of a large volume of heated air to the
fire-box. The invention also consists in certain improvements relating to the con-
struction and arrangement of the apparatus involved, all of which I will now
proceed to describe and claim.
Of the accompanying drawings, forming part of this Specification:
Figure 1 represents a side elevation and partial section of a locomotive provided
with apparatus embodying my invention.
Figure 2 represents a section on line 2-2, Figure 1.
Figure 2A represents a section on line 2-2, Figure 2.
Figure 3 represents a rear elevation of the fire-box of the locomotive shown in
Figure 1.
Figure 4 represents a section on line 4-4, Figure 1.
Figure 5 represents a longitudinal section of the fire-box and a portion of the
boiler.
Figure 6 represents a longitudinal section of the fire-box and casing of a
stationary boiler, the boiler being shown in elevation.
Figure 7 represents an end view of the casing of the fire-box and boiler shown
in Figure 6.
The same letters of reference indicate the same parts in all the figures.
I have shown my invention, in Figures 1, 2, 3, 4 and 5, applied to the fire-box
of a locomotive, and I will first describe said appliance with reference to said
figures.
a represents the furnace or fire-box, which is or may be of the usual general
construction.

page_text: b represents an air-pump or compresser, which may be of any suitable construc-
tion, and supported at any suitable point, said pump being here shown as provided
with an air inlet 61. represents a conduit for compressed air, extending from
the compresser b, and communicating with the interior of the fire-box, so that the
air which is compressed and set in motion by the pump 6 will enter the fire-box to
promote the combustion of the fuel. The compressed air conduit is arranged so
that it will subject the air within it to heat before the air is delivered to the fire-
box, so that the compressed air enters the fire-box in a heated condition. Any
suitable means may be used to heat the air, and, for the purposes of my invention,
it may be assumed that the conduit passes through a portion of the fire-box,
although I prefer to provide a casing on the exterior of the fire-box, through
which the compressed air conduit passes, said casing being arranged to receive heat
from the fire box, either by radiation from the wall against which the casing is
placed, or through flues connecting the interior of the casing 63 with the
interior of the fire-box, as shown in Figure 5. When the casing b³ is employed, I
prefer to bolt or rivet it securely to one of the walls of the fire-box, by means of
flanges formed on said casing, and to extend the conduit back and forth through
the casing in a suitable number of return bends, as, indicated in dotted lines in
Figure 3, for the purpose of giving the conduit a sufficient exposure to the heat.
The conduit be terminates at its delivering end in a nozzle, which is arranged to
deliver a jet of compressed air to the fire-box, said nozzle being preferably of the
form shown in Figure, 24, and arranged within the tapering or conical nozzle.c
which forms the delivering end of the secondary air conduit which will be presently,
described, said nozzles c and 6 resembling in their relative arrangement and form
an injector, the jet of compressed air delivered by the nozzle & inducing a flow of
air through the nozzle c and through the secondary conduit.
In Figures 1 and 2, I have shown the conduit 6 as divided at 66, one division
communicating with the casing 6* at one end, and the other with the casing 63 at the
other end of the fire-box, so that compressed air is supplied simultaneously at both
ends of the fire-box. In Figures 2 and 3, I show each compressed air conduit as
provided with a series of nozzles b', so that air is delivered to the fire-box from each
of the conduits in a series of jets or blasts. The supply of compressed air delivered
by each nozzle may be regulated by means of a screw-threaded spindle 6', shown in
Figure 2A.
For the purpose of supplying a large volume of heated air and of utilizing the
force of the compressed air to induce a current of air at ordinary atmospheric
pressure into the furnace, I provide a secondary air conduit, which, as already
stated, terminates in a nozzle c, receiving the compressed air nozzle 6. In the
construction shown in Figures 1, 2, 3 and 4, the secondary conduit comprises a
tube c', surrounding the smoke-pipe of the locomotive, and adapted to receive
air, through perforations or other suitable openings inside the tube; a jacket or
casing, partly surrounding the smoke-arch of the locomotive, and suitably
attached to the boiler or its casing; and pipes cc, extending from said jacket,
at opposite sides of the boiler, to the nozzles c, there being as many of the
latter as there are compressed air nozzles . The tube c', jacket c, pipes c³
and nozzles c constitute a conduit which receives air around the smoke-stack,
and conducts it downwardly along the heated surface of the smoke-stack, over
the heated surface of the smoke-arch and along the sides of the boiler, so that
each nozzle c delivers a supply of heated air to the space surrounding the
delivering ends of the compressed air nozzles 65. The jets of compressed air
delivered by the nozzles & induce a rapid flow of air from the said secondary
conduit, so that each nozzle c delivers to the fire-box a large volume of air which
results from a commingling of the compressed air furnished by the compressed air,
conduit and the air furnished by the secondary conduit, the entire volume being
highly heated.
It will be seen that, in the construction above described, the air is heated without
materially drawing on the resources of the fire-box, the air in the secondary

page_text: conduit being heated entirely by the waste heat from the fire-box, while the air in the
compressed air conduit may be heated either by waste heat or by a comparatively
small portion of the direct heat from the fire-box, diverted into the casings b
When the casings 6 and the flue 6 connecting the same with the interior of the
fire-box are employed, I prefer to connect each casing with one or more of the
nozzles c, by means of one or more short tubes d (Figure 3), said connections
causing an upward draft through the casings, and drawing sufficient quantities of
the heated gases and products of combustion from the fire-box through the flues 6*
into the casings 6 to ensure the heating of the air in the portions of the compressed
air conduits in said casings, it being understood that the products of combustion
that enter the casings 6 will pass through the connections d to the nozzles c and
back into the fire-box.
In Figures 6 and 7, I show a stationary fire-box a', arranged in suitable relation
to a stationary boiler e. In this case the compressed air is supplied by a com-
presser b, which is connected by a pipe 6 with one or more nozzles 6, arranged to
deliver compressed air to the fire-box, said nozzles entering the front wall of the
fire-box. The compressed air conduit & passes through the boiler casing, so that it
is subjected to the heat from the fire-box and from the boiler, the compressed air
being thus thoroughly heated before it reaches the nozzles 6. In this case, the
secondary air conduit is composed of a pipe c', which is open to the atmosphere
at 10 outside of the casing of the boiler, and passes through the said casing, and
along through the flue or passage through which the heat passes, through the fire-
box to the chimney, and preferably over the fire-box, as shown in Figure 6, said
pipe terminating in one or more nozzles or outlets c", arranged to deliver air at the
delivering ends of the compressed air nozzles . The conduit c is preferably
provided with two or more return bends, as shown at c", in order to give said
conduit a greater area of surface exposed to the heat.
It will be seen that, in this embodiment of my invention, there is no difference.
in principle from that previously described, the action being essentially the same in
both forms.
In Figure 6, I have shown, in the bridge-wall as at the rear of the fire-box, a
chamber a, which receives heated compressed air through a branch pipe a
connected with the compressed air conduit, the compressed air entering the
chamber as being delivered to the fire-box through orifices a³ in the bridge-wall.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1st. The combination with a furnace or fire-box, of an air compresser, a conduit
connecting said compresser with the interior of the fire-box, and a secondary air
conduit arranged to conduct external air to the delivering end of the compressed
air conduit, said secondary conduit being arranged to subject the air passing
through it to heat, as set forth.
2nd. The combination with a furnace or fire-box, of an air compresser, a conduit
connecting said compresser with the interior of the fire-box and arranged to subject
the air passing through it to heat, and a secondary air conduit adapted to conduct.
external air to the delivering end of the compressed air conduit and arranged to
subject the air passing through it to heat, as set forth.
3rd. The combination with a fire-box or furnace, of an injector comprising an
inner and an outer nozzle; air conduits connected with said nozzles and arranged
to heat the air passing through them, and an air compresser connected with the
conduit communicating with the inner nozzle, as set forth.
Dated this 7th day of October 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.