Improvements in Steam Boilers and Furnaces therefor.
Year: 1898

page_text: Date of Application, 29th Mar., 1898--Accepted, 4th June, 1898
COMPLETE SPECIFICATION.
Improvements in Steam Boilers and Furnaces therefor.
A communication from HENRY STANTON, Machinist, of Flushing, in the County of
Belmont and State of Ohio, United States of America.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of the improvements in
steam boiler and furnace therefor, communicated to me by Henry Stanton,
Machinist, of Flushing, in the County of Belmont and State of Ohio, and in what
manner the same are to be performed to be particularly described and ascertained
in the following statement:-
This improvement relates to that class of steam boilers in which a circular rotary
grate is employed and is designed to produce a boiler having both perfect com-
bustion and perfect circulation. To these ends the invention consists in the pecu-
liar construction hereinafter more fully described and then definitely claimed at
the end hereof.
In the accompanying drawings—
Figure 1 is a vertical central section of a boiler embodying my improvement.
Fig. 2 is a cross section of the same through the line xx, Fig. 1.
Fig. 3 is a similar section through the line y y, Fig. 1.
Figs. 4, 5 and 6 are details which will be more fully referred to hereinafter.
Referring now to the details of the drawings by numerals--1 indicates the outer
shell of the boiler having legs 2 bolted thereto at suitable intervals; 3 is the outer
wall and 4 the inner wall of the furnace, protected by fire-brick 5 at the sides,
and the perforated tiles or arch-blocks 6. The fire bricks 5 rest upon flanges 7
rivetted to the plates forming the walls 3 and 4.
The outer shell and the wall 3 are connected at bottom by the plate 8 having
turned down flanges. The inner wall 4 is in the form of a tube, inside of which
is another tube 9, and these two tubes are connected by screw plugs 10, one end of
each of which projects into the fire box or combustion chamber.
The outer wall and the boiler shell are connected in the same manner, but part
of most of the plugs in this case extend through into the smoke chamber sur-
ounding the boiler.
The inner and outer walls of the fire-box are connected at top by the annular
rown-plate 11 strengthened by the crown bar 12 and bolts 13.
Connected to the tube 9 is an upwardly inclined annular plate 9¹ to direct the
prising water over the crown-plate, which serves to keep said crown plate clean.
he annular plate 9¹ may be made of several plates, secured in any convenient
anner.
In the centre of the tube 9 is a shaft set in a step 15 mounted on a step bar 16
olted to the inner wall or tube 4, which shaft carries a screw or propeller 17 at
e bottom and a bevel-wheel 18 gearing with another bevel-wheel 19 on a shaft 20,
hich passes through a stuffing-box 21, and carries on its outer end a pulley 22,
tended to be driven from any convenient source of power.
The grate bars 23 are shown resting on two rings 24 connected by cross bars 25.
DO17

page_text: The rings rest on idlers 26, and the outer ring has bolted to it a series of castings
forming a circular rack 27, which is driven by a pinion 28 mounted on a suitable
shaft and having a flange 29 which helps to support the weight of the outer ring
with the bars and fuel.
Below the bar 16 is a distributor and mud collector 30 provided with a suitable
blow-off 31 and tubes 32 terminating in "tees" 33 which communicate with the
space between the shell and the outer wall of the fire box. Below the tees are
the blow-offs 34.
The flues shown at 35 pass through the outer wall of the fire box and combus-
tion chamber by which means the products of combustion pass into the smoke
chamber 36 formed between the shell 1 and the inner jacket 37, the upper part of
which is surrounded by an outer jacket 38. In the smoke chamber there are a
series of bricks or tiles 39 set diagonally or spirally around the boiler, forming a
series of spiral passages for the heated products of combustion. These bricks are
formed with projections 40 to rest against the studs which thus form a support for
the bricks, and as the products of combustion pass through the passages between
the bricks, they come in contact with the lower side of the same, by which means
all of the caloric that can be communicated to the water in the boiler is extracted
from the heated products of combustion, instead of passing off without doing use-
ful duty.
As a further saving of the heat generally wasted I use the second or air jacket 38
before referred to, which passes up and around the smoke stack 41 and having air
inlets 42 through which air is drawn down by a blower 43 and driven into the
annular hot air pipe 44 from whence the heated air is distributed by pipes 45 lead-
ing to the fire-box and other pipes 46 discharging into the ash-pit, and still other
pipes 47 leading to passages 48 through the bricks surrounding the inner wall 4 of
the fire-box.
The smoke stack has a series of tubes 49 passing through it, which will absorb
nearly all the heat that remains at that point in the products of combustion and will
transfer the same to the air that enters through the inlets above, which air as it
descends is still further heated by the surface of the jacket 37, so that not only
is there but little heat lost, but the air to support combustion is thoroughly heated
before it enters the ash-pit or fire-pot. Instead of tubes 49 solid plugs may be
used.
In order to get the most advantage from the products of combustion, baffle-
plates 50 are set in the smokestack so as to deflect the smoke, etc., against the
jacket 37.
Around the fire-boxes may be set suitable doors 51 for stoking purposes, but to
produce the best effect I propose to use a mechanical feeder which will spread the
fuel regularly over the grate as it revolves under said feeder.
In carrying out this part of my invention, I intend to use the apparatus shown
in my drawing, but do not limit myself to this, as the motion may be given to the
feeder or chute which spreads the coal over the fire by other constructions without
departing from the spirit of my invention. At 52 is shown a chute which is
pivoted at 53, and is provided with an arm 54 which rests against a cam 55 on a
rotary shaft 56 which carries a sprocket-wheel 57 giving motion through the drive-
chain 58 to the sprocket-wheel 59 driving a feed-wheel 60 in the hopper 61. This
cam is of such shape as to give the chute a differential feed as it moves over the
grate so as to feed the fuel substantially at the same rate over the entire surface
of the grate, whether it is delivering it at the outer or inner surface of the same.
It is obvious that if the cam were of such shape as to give the chute a regular
motion, it would feed as much fuel at the inner edge of the fire-box as at the out-
side edge, whereas if a circle is drawn around the grate at an equal distance from
the inner and outer edges of the fire box, the grate surfaces on the outside of the
circle would be nearly double that on the inside. It is therefore necessary that
the cam should be of the peculiar shape shown in the detail figure of the feeding
apparatus:-Fig. 6.

page_text: In order to prevent the chute from being burnt out I propose to make it hollow
as shown in the enlarged detail Fig. 6, so. that a current of water may pass through
it, which will enter at one of the hollow pivots indicated at 53 and out of the other.
This water may pass into the boiler as feed water if desired. In order to prevent
the passage of the heated gases from the fire passing up and out under the feeder,
I attach an apron 62 to the back of the same which rises and falls with it and thus
keeps the opening tolerably tight.
In making my boiler I propose to use plugs like those shown, but do not limit
myself to this particular form. The plugs are made with either one or two
enlarged parts 10' which are screw-threaded to be screwed into the two adjacent
parts and then the outer edge (which is undercut for that purpose) is rivetted
down.
The tubes forming the flues 35 are screw-threaded for their whole length, and
after being screwed in are rivetted over on both ends.
The crown-bars are sustained by stay bolts 63 which extend up through the
top of the boiler.
When in operation and motion being given to the different parts by connection
with any suitable source of power, the grate is caused to revolve and the chute to
vibrate across the same, which will feed the fuel in a zigzag line over the same,
which if continued would leave some parts of the grate partially uncovered, to
avoid which the gearing should be so arranged that on the next revolution of the
grate the points of the zigzag line of feed should come between the points of the
zigzag line of the feed of the previous revolution of the grate, and thus the feed of
fuel would be substantially even over the grate.
66
tees"
A complete and perfect circulation of the water is kept up by the use of the
screw or propeller 17, for it draws down the water through the central passage
and drives part of it through the pipes 32 and "tees" 33 into the space between
the outer wall 3 of the fire-box and the shell 1, where it is spread by the
and afterwards rises up to be again drawn down as before. The other part of the
water passes up between the tubes 4 and 9 and over the top of the crown sheet, to
be drawn down again as before. It will be noticed that there are no opposing
currents in this boiler, all the water in the main part of the boiler being bound to
travel in the same direction.
From the peculiar arrangement and construction of this boiler, it will be found
that a perfect feed of the fuel, a perfect combustion of the same, and a perfect cir-
culation of the water have been obtained, and that all of the caloric in the heated
products of combustion that it is possible to be saved is made use of in my boiler
and furnace.
Having now particularly described and ascertained the nature of my invention,
as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is:-
-
1. The combination in a boiler, of a central passage and a screw working therein
to induce forced circulation, substantially as described.
2. The combination in a boiler, of two concentric water chambers and a concen-
tric grate between them, with a central water passage and a screw working therein
arranged to draw water from the centre passage and force it into the concentric
chambers, substantially as described.
3. The combination in a boiler, of two concentric water chambers, a concentric
grate and fire-box between them, said fire-box being lined with fire-brick and pro-
vided with a perforated arch-brick dividing the flame space, substantially as
described.
4. The combination in a circular boiler, of a smoke passage, a series of bricks
set therein arranged to make spiral passageways for the products of combustion,
and a series of supports for said bricks extending horizontally from the boiler,
substantially as described.
5. The combination with a boiler having an annular fire-box of an outside smoke

page_text: passage, an air chamber surrounding the same, passages carrying air to the inner
part of the annular fire-box, and means for drawing down the air from said air
chamber and forcing it into the air passages, substantially as described.
6. The combination with a boiler and furnace, of a smokestack, an air jacket
surrounding the same and a series of heat-absorbing devices passing through the
smokestack and projecting into the air passage, substantially as described.
7. In combination with the fire and water chambers of a a boiler, studs having an
enlarged threaded portion near their centres and adapted to be screwed into the
boiler sheets and then rivetted against the same, substantially as described.
8. The combination in a boiler, of a smoke passage, a series of absorbing studs
projecting therein, and a series of fire-bricks resting on said studs, arranged to
form spiral passages for the products of combustion, substantially as described.
9. The combination with a circular rotary grate, of a fuel feeder and means for
giving said feeder a faster motion over the inner half of the grate than over the
outer half of the same, substantially as described.
10. The combination with a circular rotary grate of a fuel feeder, arranged to
move over said grate, and a revolving cam operating said feeder, and arranged to
move the feeder faster over the inner half of the grate than on the outer half of
the same, substantially as described.
11. The combination in a boiler furnace, of a fire-box having a brick lining,
with an arch-brick resting upon said lining, and having an inclined upper sur-
face whose upper edge rises above the flues running through the side of the boiler,
substantially as described.
12. In a furnace feeding apparatus, a vibrating chute provided with an apron
to close the opening under the chute, substantially as described.
BOULT & WADE.
Agents for the Applicant.
BOULT & WADE.
Agents for the Applicant.