Improvements in or relating to Boiler Furnaces.
Year: 1896

page_text: Date of Application, 10th Nov., 1896-Accepted, 6th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Boiler Furnaces.
A communication from SAMUEL PAXSON HUTCHINSON and S. LLOYD WIEGAND,
Civil and Mechanical Engineers, of 2116 Park Avenue and 1525 Lehigh Avenue,
both in Philadelphia, State of Pennsylvania, United States of America.
I, ALFRED JULIUS BOULT of 111 Hatton Garden in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
scertained in and by the following statement :-
This invention relates to furnaces for generating steam in boilers, and relates
particularly to that class of furnaces in which air or steam and air are introduced in
heated condition to the gaseous fuel evolved from the coal or like solid fuel and has
for its object the better economy of fuel and smokeless combustion thereof.
The invention consists in the method of introducing an air and steam supply,
singly or conjointly, and in a construction of furnace of easy and efficient adaptation
to steam boilers, and in protecting by perforated arches the solid fuel from
temperatures below that requisite for constant gas generating.
The construction and operation of this invention is hereinafter fully described and
shown in the accompanying drawings in which
Figure 1 shows a steam boiler in partial sectional side elevation shortened in
length and with a furnace embodying this invention applied thereto.
Figure 2 is an elevation of the same,
Figure 3 is a vertical section in the plane indicated by the dotted line xx in
Figure 1,
Figure 4 is an enlarged partial section of the furnace showing the conduits for
introducing and distributing steam and air,
Figures 5, 6 and 7 show in enlarged perspective view the bricks, of which the
channelled furnace walls and perforated arches are constructed,
Figure 8 shows in detached perspective view, the pipes for injecting and beating
air and steam to one half of the furnace.
Figure 9 shows an enlarged view of the device for controlling the admission of
air and steam to the heating apparatus.
Figure 10 shows, in enlarged section, the construction of the fitting for controlling
the distribution of air and steam to different parts of the furnace,
Figure 11 shows a vertical lengthwise sectional elevation of a steam boiler, with a
modification of this invention applied thereto,
Figure 12 shows a front elevation thereof and,
Figure 13 shows a transverse section thereof in the plane indicated by the dotted
line y y in Figure 11,
Figures 14 and 15 show two forms of the arch in plan view shown in
Figures 11 and 13.
Referring to the drawing, (in Figs. 1, 2 & 3) 1 represents the upper cylinder of
the boiler, which is of the type known as 'rider or double deck' the lower cylinder 1

page_text: of which has flues 9 extending through the entire length and is connected by necks 12
to the upper cylinder 1' in which the working water level is about in the plane of
its axis.
22 are the side walls of the setting, 3 the rear wall thereof, 4 is the front wall of
breast, 5 is the bridge wall 6 is the ash pit 7 is the flue under the cylinder 11, 8 is
the rear flue, leading from the Blue 7 to the flues 9 in the cylinder 11; 10 is the
front rising fine leading froin the front ends of the flues 9 to the returning flue 111
between the cylinders 1 and 1, which leads to the flue 12 discharging the products
of combustion into the chimney; 14 is the grate. The parts above described are
those in common use, and are here particularly referred to for facilitating the
description of the novel parts combined therewith.
The grate 14 may be of any known construction, but grates which clear
the fuel of ashes and cinders without opening the furnace, and which receive
and distribute the fuel automatically in the furnace from a magazine or hopper,
are preferable.
Below the level of the grate 14 there is formed a channel or conduit 15
(shown in Fig. 3) in the side wall 2, which may be extended into a connecting cross
channel 16, (shown in Fig. 1), at the same level below the bridge wall 5, the upper
side of the clannels 15 and 16 is covered by grooved refractory bricks 17 (shown in
enlarged view in Figure 5) so laid in courses, that the grooves 18 form vertical
channels 19 (shown in Fig. 1) extending above the fuel, and covered by grooved
bricks 20 (shown in Figure 6) so laid that the grooves or channels 21 lead
outwardly from the channels 19 into the furnace chamber 14', as shown in
Figures 1 and 3.
The channels or grooves are covered by bricks or tiles 22, (shown in Fig. 4) which
have bevelled upper surfaces 23 on which rests a perforated arch 24; formed of
grooved bricka 25, (shown in Figure 7); above the perforated arch 24 is a
chamber 26, and above this is a second perforated arch 27, formed of bricks 25
similar to those in the arch 24; the rear wall 28 of the chamber 26 is formel with
perfomations 29 in it male from bricks 20 (shown in Figure 6).
The bridge wall 5 is built up solidly above the openings 21 to the top of the
arch 24 forming the rear wall of the furnace chamber 14¹.
In the chamber 26 is formed a channel 30, with walls and top of refractory
material, resting upon the arch 24, opon at the front end, and to the apertures 31
beneath it in the arch 24, but closed at the rear end.
A steam pipe 32 leads from the upper part of the boiler 1 as shown in Figure 1
and separately in enlarged view in Figure 10, and is provided with a valve 33, and
controlled by a pressure regulator 35, connected therewith by levers 36 and 37 and
a link 33, which is adjustable in lengthwise position on the levers 37 and 36, so that
the ratio of opening and closing of the valve 32, as actuated by fluid in the
regulator 35, can be varied.
The pipe 32 extends forward from the valve 33 and is branched to each side, (as
shown in Fig. 2,) terminating in stop valves 39, and jet tubes 40; the jet tubes 40
are placed centrally in front of air funnels 41; so that steam jets, from the tubes 40
inject air into the funnels 41; on each of the jet tubes 40 is a screw thread 42 (as
shown in the enlarged detached sectional view in Fig. 10,) on which is fitted a screw
threaded disc or stopper 43 which by screwing upon the jet acts as a means of
regulating the admission of air to the funnels 41.
From the necks of the funnels 41, tubes 44 extend into the flue 11, and are
connected by return bends 45, with pipes 46, that extend to a three branched
fitting or T 47, (shown in Figs. 1 and 8,) the front opening of which extends
through the breast wall 4, and is closed by a plug 48; from the side branch of
the T 47, a T fitting 49 located in the breast wall 4 extends downward to the
pipe fitting 50, having the front branch closed by a plug 51 and the rear branch
connected by a pipe 52 to the channel 15.
Through the plugs 51 are fitted stems 53, (shown in Fig. 8,) bearing valve plugs
on the inner ends which fit seats in the ends of the pipe 60 in the fitting 50, by

page_text: which the flow of air from the T fittings 50 to the pipes 52 and channels 15 and 16
is adjusted.
In the pipe 49 is a branch or T fitting 55 from the side branch of which a pipe 56
extends in the breast wall 4 to a T fitting 57 the front end of which is plugged and
provided with a stem 58 and valve 59 and the rear end is connected by a pipe 60,
with the channel 30 in the chamber 26; by means of the stem 58 and valve 59, the
flow of air and steam to the chamber 30, shown in Figs. 1, 3 & 4, (and thence to
the centre of the furnace through the opening 31) is adjusted and controlled.
In operating this furnace the fuel is kindled in the furnace chamber 141 in the
usual manner, and when steam has been raised in the boiler, and the arch 24 highly
heated, a smail amount of steam is injected, froin the jet tubes 40, into the air
funnels 41 and the discs 43 adjusted to limit the volume of the air injected, so that
the air with the steam, flowing through the pipes 44, 46, 49, 52 and 56 and 60,
with the channels 15 and 16, will not injuriously reduce the temperature of the
tiles or brick 17, 20 and 25, and enters the furnace chamber at such temperature as
to combine with the carbon of the fuel, and form increased volumes of combustible
gas, and burns such gas with great calorific effect.
The draft of the Blue 12 may he regulated in the usual manner by a connected
automatic regulator and damper, independently of the regulator controlling the
steam and air injectors.
Referring to Figures 11, 12, 13, and 15 of the drawing 61 represents the
boiler; 62 the ash-pit; 63 is the door for closing the ash-pit; 64 is the grate,
having a dead plate 64 at the front end thereof; 67 is a bridge wall, beyond the
inclined shelf 64, containing a chamber 68; the hollow bridge wall 67 has
numerous small perforations 671 in the upper side receiving air from air tubes 70,
from the front, to heat the air and deliver it to the hollow bridge wall; 71 are
tubes or channels for receiving air and delivering it to the vertical heating
channels 72 (shown in Fig. 11), in the side walls of the furnace below the arch 73,
the arch 73 is closed or imperforate at the front portion and has several series of
openings 73 of gradually increasing size towards the rear, and a larger aperture 72
close to the bridge wall 67, a tube 76' with small perforations 762 is placed below
the dead plate 64 in the ash-pit 62 and a tube 78 is connected from the boiler 61
to the perforated tube 76; from which steam is discharged in minute jets below the
dead plate 64 whence it passes forward and rises between the grates 64 into the
fuel of the dend plate.
The boiler may be of any of the usual forms; that shown in the drawing is of
the kind known as the return tubular but other forms may be employed.
To use the furnace, a fire is started so as to cover the entire grate, in the usual
manner with kindling, then coal is added at the front in the dead plate, and as this
ignites it is steadily pushed towards the rear; as the coal is supplied; the heat is
deflected by the imperforate portion of the arch 73 upon the new fuel, and the
hydro-carbon vapors, passing from such fuel in consequence of the heat deflected
upon it combines with the hot air jets from the perforations in the side walls, and
forins combustible gas, which passing further forward meet the combustible gases
arising from the fuel on the grate 64 partially consumed, and divested of much of
its hydro-carbon gases, (as it passes rearward), so that when the fuel has reached
the rear of the furnace, all of the volatile hydro-carbons are exhausted and converted
into gases, and have passed through the graduated series of openings 73 and the
large terminal openings 72 in the arch 72 and burned with the air that is mingled
with it from the rear apertures in the side walls of the furnace. The gases rise
through the larger opening at the rear of the arch and pass over the perforated
bridge wall 67 where they mingle with the highly heated air and effect a smokeless
thorough combustion with a commensurate evolution of heat.
The combustion of fuel in this form of apparatus can be smokelessly conducted
without the aid of steam in the pipe 761, and with some fuels to some extent without
using steam in the pipe 76'; but the capacity for combustion of fuel, without
producing smoke is greater when steam is thus employed.

page_text: The gas and products of combustion thus thoroughly consumed, pass under the
boiler and return through the flues in the usual course or direction, and throughout
the operation, no smoke is generated and carbon is not precipitated on the boiler
or furnace.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents and in what manner
the same is to be performed I declare that what I claim is;-
1. In a steam boiler furnace, a fuel chamber having walls of refractory material
containing air inlets connected with a heated air and steain supply, a perforated
arch covering said fuel chamber, a second chainber above said fuel chamber also
covered by a perforated arch, in combination with a central conduit in said second
chamber arranged to discharge previously heated steam and air into the central
portion of the fuel chamber, as set forth and described.
2. In a steam boiler furnace, the combination of steam jets, automatically
regulated steam supply connected therewith air inlet funnels provided with air
flow regulating discs tubes and return bends and pipes located in the flue of a
connected boiler furnace pipes protected from radiation in the breast of the furnace
connecting said tubes and return bends with the channels for distributing heated
air and steam in the furnace and valves arranged to adjust the relative flow of heated
air and steam to the different parts of said furnace, substantially as set forth.
3. In a steam generating furnace and arch, placed above the fuel chamber of the
furnace, a grate, having a dead plate at the front end, below said fuel chamber, series
of openings of gradually increasing size in said arch, a large discharging aperture
through the rear of said arch, channels in the sides of said furnaces, means of heating
air and discharging the same above the fuel in the fuel chamber in combination with
a perforated heating bridge wall, arranged substantially as and for the purpose set
forth.
4. In a steam generating furnace, an arch, placed above the fuel chamber of the
furnace, a grate, having a dead plate at the front end below said fuel chamber, series
of openings of gradually increasing size in said arch, a large discharging aperture
through the rear of said arch, channels in the sides of said furnaces, means of heating
air and discharging the same above the fuel in the fuel chamber, in combination with
a perforated heating bridge wall, and means of supplying heated air thereto,
arranged substantially as and for the purpose set forth.
5. In a steam generating furnace, an arch, placed above the fuel chamber of the
furnace, a grate, having a dead plate at the front end, below said fuel chamber; series
of openings gradually increasing in size toward the rear in said arch, a large
discharging aperture through the rear of said arch, channels in the sides of said
furnace, means of heating air, and discharging the same above the fuel in the fuel
chamber, in combination with a perforated steam and air heating bridge wall,
arranged substantially as and for the purpose set forth.
6. In a steam generating furnace an arch, placed above the fuel chamber of the
furnace, a grate, having a dead plate at the front end, below said fuel chamber,
series of openings of gradually increasing size in said arch, a large discharging
aperture through the rear of said arch, channels in the sides of said furnace, means
of heating air and discharging the saine above the fuel chamber through said
channels, in combination with a perforated heating bridge wall and means of
supplying steam and heated air thereto arranged substantially as and for the purpose
set forth.
1000
BOULT & WADE,
Agents for the Applicant.