Improvements in Furnaces.
Year: 1894

page_text: Date of Application, 20th Feb., 1894-Accepted, 26th Jan., 1895
COMPLETE SPECIFICATION.
[Communicated from abroad by SAMUEL PAXSON HUTCHINSON. of 2116, Park
Avenue, Conveyancer, and S. LLOYD WIEGAND, of 146, South Sixth Street,
Mechanical Engineer, both in the City and County of Philadelphia, State of
Pennsylvania, U.S.A.]
Improvements in Furnaces.
I, WALLACE FAIRWEATHER, C.E., of 62 Saint Vincent Street in the City of
Glasgow, Chartered Patent Agent do hereby declare the nature of this invention
and in what manner the same is to be performed, as communicated to me to be
particularly described and ascertained in and by the following statement :-
This invention relates to furnaces wherein fuel is burned with air, or air and
steam, and is usefully applicable to the purposes of generating steam and other
heating effects, but is more especially useful for steam generation, because it
protects the fuel in combustion, from such reduction of temperature at the place,
and time of reducing it to a gaseous condition by proximity to the comparatively
low temperature of the steam boiler, or other steam generating vessels.
The objects of this invention are to render the process of gas generation and
combustion continuous, and more completely regulable to suit varying requirements
of work, by protecting it from interruption during the introduction of fuel, and the
removal of incombustible residuum, to facilitate the cleaning of the fires, and to more
durably and economically construct such furnaces, in the portion for protecting the
solid fuel from reduction of temperature.
The nature of this invention to secure these desiderata consists in a system of
construction of such furnaces as illustrated in the accompanying drawing, and fully
hereinafter described.
Referring to the drawing:
Figure 1, shows a central vertical section of an upright cylindric furnace
embodying this invention.
Figures 2, and 3, respectively, show lengthwise and transverse vertical sections
of rectangular forms of such furnaces.
Figure 4, shows a lengthwise vertical section of a furnace embodying this
invention adapted to use in limited spaces, such as render access to more than one
side inconvenient or impracticable.
Figure 5 shows an enlarged perspective view of a deflecting tile, used in the
construction of the gas out-let flue and,
Figures 6 and 7, show enlarged views of an interlocking mechanism for controlling
the fuel doors.
1, represents the ash pit, 3, stationary grate bars, 4, a moving segmental section
of grate, arranged to disintegrate clinkers and drop them into the ash pit. The
seginental part 4 as shewn at Figure 1 has an arm 5 entering the upper end of a
cylinder 5 through a neck 5 and being connected to a piston piece 53 within
the cylinder. The lower end of the cylinder 5' has a bevel wheel 5* formed on it
with which is geared a bevel wheel 5 on a spindle 5%, and on turning the spindle 56
the segmental part 4 is caused to rotate and clear the opening formed by the ends
of the fire bars 3 as shewn at Fig. 1, sufficient to allow clinker to pass through
to the hearth 2.
The segmental portion of the grate 4 in Figures 2, 3 and 4 is in these forms of
the furnace of cylindric shape and is operated by vibrating or oscillating it upon
its axis to disintegrate clinkers and discharge ashes from the fuel to the ash pit.
6, is a moving circular chamber fixed to the spindle 56 and turning with it and

page_text: having an opening 7 in the side which in one position registers with an opening 8,
in the bottom or hearth 2 of the ash pit 1, against which the chamber 6, fits
closely, and in another position closes the opening 8, and prevents air currents
entering through the opening 7, when in register with an opening 9, in a case 38,
common to Figures 1 and 3 surrounding and fitting closely to the chamber 6, so
that when the opening 7, is turned upward, ashes and cinders or any other residuum
from the fuel, fall into the chamber 6, and only so much air as is contained in the
chamber 6 enters the ash pit 1, through the opening 8, and when the chamber 6 is
turned with the opening 7, downward, it is emptied of the ashes or like matter
through the opening and refilled with air.
An air injector 10, which may be operated by steam or compressed air or by
both, is connected with the ash pit, so as to introduce a regulable supply of air, or
air and steam or aqueous vapor to the ash pit 1.
11, is a furnace chamber, which is formed or lined with refractory material, and
is provided with air heating channels 39, leading from the ash pit, and conducting
air therefrom, and delivering it in heated condition above the fuel in the
chamber through apertures 12, in the manner described in U.S. Letters Patent
serially numbered 436,483 dated February 21, 1893, and grauted to Samuel P.
Hutchinson.
13, are charging funnels, or chutes, for introducing fuel.
As shown Figures 1 and 4, the chutes 13, are each provided with an outer
dour 14, and an inner valve 15, which by an interlocking mechanism 16, hereinafter
more particularly described can only be opened alternately, and thus prevent air
currents passing in, or gas out of the chutes 13. As shown in Figure 3, a constant
supply of fuel maintained in the chutes 13, serves to exclude air.
Above the furnace chamber 11 is a perforated partition or screen, shaped as a
dome 17, of refractory material, the lower concave surface of which deflects and
concentrates heat on the central body of fuel in the chamber 11, maintaining the
fuel in constant condition for free evolution of gases, as it combines with the air, or
air and aqueous vapor, introduced into the ash pit.
As shown in Figures 1, 3 and 4, a series of refractory tiles 18, are placed above
the dome 17; one of these tiles is shown in enlarged perspective in Figure 5, these
tiles are formed with downward projections 19, near the sides and ends, and have
the corners 20 so shaped as to leave openings between them when placed in position
over the dome 17, and are so placed relatively to the apertures 21, on the dome 17
as to obstruct radiation of heat, from the fuel through the apertures 21, in the
dome 17, but to permit the escape of gases through the apertures 21.
In Figure 2, instead of a perforated dome for concentrating heat on the fuel, an
imperforate dome 22, is substituted, and the discharge of gas to the flue 23 is
through perforations 24 in the partition 25, of refractory material, beyond which,
with an intervening space 26, is another similar partition 27, having perforations 28,
none of which should register with the perforations 24, in the partition 25, a like
effect is thus produced on the fuel, but not so uniformly, when the combustion is
urged to its greatest capacity.
The interlocking mechanism 16, applied to the doors 14 and valves 15, is indicated
in dotted lines in Figures 1 and 4, is shown in enlarged view in Figure 6, and in an
equivalent form in Figure 7.
As depicted in Figure 6, a lever 28 turning on a pivot 29, and having on its ends
segments 30 which fit against notches or flat facets 31 in cylinders 32, which turn
with the arbors of the doors 14 and valve 15; in each of the segments 30 is a
notch 33, which when opposite the cylinder 32, permit it to turn; the notches 33
are so located in relation to each other and the cylinders 32, that one cylinder 32
must be locked by a segment 30, with its connected door or valve closed before the
other cylinder 32 can enter the notch 33, and permit the connected door or valve
to open.
The equivalent form of interlocking mechanism, shown in Figure 7, consists of
a cylinder 34, fastened to the arbor of the door 14, a similar cylinder 35, fastened

page_text: to the arbor of the valve 15, and a sliding bar 36, supported in guides 37, and of
such length that one end of the bar must engage in a notch in the cylinder 34
or 35, before the opposite end of it can be disengaged from the notch in the other
cylinder.
The form of furnace depicted in Figure 4, is with inclined front walls, and a step
shaped grate so that it can be fed with fuel from the front side only.
The operation of gas generation, as conducted in this furnace, is similar to that
stated in the Letters Patent No. 492,020 hereinbefore referred to, the several
improvements embodied in this invention facilitating the continuous working of the
process.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me,
I declare that what I claim is :-
1. In a gas producing furnace, a concave dome arranged to deflect and concentrate
heat upon the fuel in transit on the grate, a fuel supporting grate constructed and
arranged to move the fuel from the entrance to a discharging aperture and an air-
tight ash pit in combination with a disintegrating mechanism, arranged substantially
as shown to discharge clinkers and fuel residuum without ingress of air draft,
substantially as set forth.
2. In a gas producing furnace an air-tight ash pit with a regulating air admitting
mechanism, a fuel supporting grate a furnace lining provided with air heating
conduits, arranged as described to deliver heated air above the fuel, and a deflecting
dome, arranged to concentrate heat on the fuel, in combination with a partition
having gas discharge apertures leading outward from the furnace to a flue, and a
deflecting refractory screen or screens in said flue opposite such gas discharge
apertures arranged to operate as and for the purpose set forth.
3. In a gas producing furnace an enclosed air-tight ash pit, means of introducing
air thereto in regulated quantities, and an ash and cinder discharging aperture in
said ash pit, in combination with a vessel, moving in contact with the edges of said
aperture, constructed and arranged to alternately receive cinders and ashes through
said aperture, and to close said aperture, and when closed discharge such ashes and
cinders substantially as set forth.
4. In an enclosed gas producing furnace, a fuel support, a perforated concave
reflecting dome, arranged to concentrate heat upon the fuel, in combination with
refractory covers located near the reflecting dome, and arranged to obstruct
radiation of heat through the aperture and permit egress of gas through said
apertures substantially as set forth.
5. In a gas producing furnace, an enclosed furnace chamber lined with refractory
materials, air heating channels through said lining, arranged to receive air from an
enclosed ash pit and a fuel supporting grate, in combination with fuel supplying
conduits, each provided with two or more valves or doors, arranged to open and
close alternately, and restrict ingress and egress of air through said fuel supplying
conduits substantially as set forth.
6. In a gas producing furnace an enclosed air-tight ash pit, a deflecting dome 17,
and a stationary inclined grate arranged to receive fuel near the wall or walls of
said furnace and conduct such fuel toward the focus of the deflecting dome 17, in
combination with a moving convex segmental grate, arranged to gyrate or
reciprocate in contiguity with said stationary grate and receive fuel and cinders
therefrom and disintegrate and discharge clinkers into the ash pit, substantially as
set forth.
Dated this 17th day of February 1894.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.