Year: 1886

page_text: Purposes.
I, WILLIAM CHANDLER THAYER at present of The First Avenue Hotel in the
County of Middlesex, but resident at Chicago, Illinois, United States of America,
Engineer 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 :—
My Invention relates to the combustion of carbonaceous material in all classes
of furnaces where great heat is required, and to the connection of the fire grate
and other parts hereinafter referred to; and it has for its object to produce complete
combustion of the carbonaceous material; to maintain a steady heat and pressure
in steam furnaces; to guard against undue contraction and expansion of the parts
of the furnace resulting from variance in the degree of the heat consequent upon
supplying fresh fuel to the fire; and to utilise more of the gases of the carbonaceous
material than heretofore thereby preventing the formation of smoke and doing
away with the extension smoke arch and spark arrester when applied to locomotive
furnaces and increasing the amount of heat derived from the same quantity of
material; and to the foregoing ends the invention also consists in the method
hereinafter described and specified of introducing highly heated air and super-
heated steam to the body of the burning carbonaceous material whereby the
oxygen supplied to the body of the carbonaceous material frees the carbon and
gases with which unites the oxygen liberated from the superheated steam while
the hydrogen of the thus decomposed steam is liberated and seeks its stronger
affinity the sulphur in the coal, and then unites with the free oxygen and carbon
gases so that as a result there is formed an oxyhydrogen fire.
The invention further consists in the construction and the combination of means
hereinafter particularly described, which are considered the best adapted for the
purpose of carrying out the method referred to.
Fig. 1 of the accompanying drawing shews a side elevation of one arrangement
of a furnace grate constructed according to my invention, Fig. 2 shews a
longitudinal section of the same, Fig. 3 shews a part plan and Fig. 4 shews a cross
section.
The fire grate D is composed of the bars E, formed with end journals a, which
the ham which most against the sides of the
"

page_text: furnace on angle irons or other supports, and are provided at one end on their
bottom faces with perforated ears o. These bars are also formed on opposite side
faces with vertical grooves d, preferably having their side walls bevilled, and
support the hollow arched and perforated caps E¹, which are formed with the
pendant plates e, preferably two, and having a convex lower edge as shewn in the
drawings and formed each with a vertical slot f as shewn in Figs. 10 and 11,
the walls of which are preferably bevilled so that the plates inay straddle the grate
bar and fit into the grooves & thereof to secure the cap to the bar. These caps
are preferably of the form shewn, but may be made of other forms without
deviating from that feature of my invention which has for its object to highly
heat the air and the thorough distribution thereof through the body of the
carbonaceous material.
By forming the ends of the bars higher than the middle portion an increased
quantity of oxygen is admitted and supplied to the gases evolved from the body of
the fuel in the middle of the grate, so as to effect complete combustion. In some
instances, however, especially where poorer qualities of carbonaceous material are
used, it may be necessary or desirable to supply a greater quantity of oxygen to
the middle portion of the fuel in order to effect complete combustion of the gases
and in that event the grate bars may be raised intermediate of their ends to a
point on a line or nearly in line with the raised end positions as indicated by
dotted lines in Fig. 9.
The journals of the grate bars E rest in slots b formed in the bars F. These
slots are made alternately of different depths so that there is a row of alternate
bars having their journals at a lower level than those of the other row of the
alternate bars. The caps E¹ are however so formed that their tops all lie in one
and the same plane as shewn, the caps on the deeper row of bars having their
curvature struck from centres corresponding to the centres of the journals of their
bars, while the caps on the higher row of bars have their curvature struck from
centres lying in the same horizontal plane as the other centres. By this arrangement
it will be seen that when the bars and caps are in the position shewn in Fig. 2, the
spaces between the caps on either side are comparatively small and equal, so that
the fuel cannot fall through, while when the bars are rocked on their journals so
as to assume the positions shewn at Fig. 1, the spaces between them on the one
side will be increased to such an extent that the fuel resting upon them can be
made to fall through into the ash pit, for the purpose of clearing out the furnace.
On the other hand if the bars are from time to time rocked slightly to and fro on
their journals, any ashes resting upon the caps are made to fall through into the
ash pit. Such rocking motion is imparted simultaneously to all the bars and caps
by means of ears c at one end thereof, which are pivotted to a connecting bar L,
the end of which is pivotted to a hand lever M outside the furnace, which can be
secured by a rack bar k so as to hold the grate bars and caps in any desired
position.
By the use of the arched caps E, the air is introduced into the very body of the
burning carbonaceous material and thoroughly heated before passing into the body
thereof so that there is no chilling or reduction of the temperature by cold air
currents. And by thus introducing fresh oxygen into the body of the fuel, the
requisite quantity is supplied at the proper point to combine with the gases so as to
form carbonic acid gas instead of carbonic oxide as heretofore where there has not
been sufficient oxygen to effect complete combustion.
By the form of grate I have just described the entire furnace bed can be stirred
and the ashes sifted out into the pan, and if desired the whole fire can be dumped
by a proper manipulation of the grate bars, thus dispensing with the necessity of
a separate dumping grate and the taking of the fire cinders and ashes from the
back of the fire box as in the constructions heretofore in use.
Figs. 5 to 12 shew another modification of my improved fire grate as applied by
way of example to the fire box of a locomotive engine. Fig. 5 of the drawing is a
sectional side elevation of a locomotive boiler with my invention applied thereto.

page_text: Fig. 6 is an end view of the grate bars with the air distributing caps applied
thereto. Fig. 7 is a side view thereof. Fig. 8 is a side view of one of the slotted
side supporting bars for the grate bars. Fig. 9 is a perspective of one of the grate
bars having the caps detached. Fig. 10 is a perspective view of one of the air
distributing caps. Fig. 11 is a cross section through the same.
A designates the fire box provided with the water tubes B communicating at
both ends with the side water spaces of the furnace above which tubes is the
table C formed of slabs of firebrick or any suitable refractory material.
The journals of the grate bars E rest in this case in the forked ends of the
bifurcated arms H, which are pivotted to the angle irons G as shewn.in Figs. 5
and 6 and are oscillated by a forked arm I to which the lower ends of the
bifurcated arms are pivotted and which is reciprocated by a lever M pivotted to its
end and extending up into the engine cab, the said lever at its upper end engaging
with a rack bar K, to which it may be locked to hold the lever in any desired
adjusted position. By reciprocating the arm I, the grate bars will be raised and
lowered in alternation so as to sift the ashes from the bed of the fire into the pan
below. The ears c to the bars E are alternately long and short as shewn in
Figs. 5 and 7 and are pivotted to an undulating bar L, the short ears being pivotted
to the raised portion of the bar and the long ears to the depressed position so that
when said bar is reciprocated by the lever M¹ pivotted to its end and extended
up into the engine cab, the said bars will be rocked and the caps E¹ thrown first
in one direction and then in the other direction and forming accurately spaces of
greater width at one time between the grate bars attached to one set of bifurcated
arms and then between the ears of the adjacent sets of bifurcated arms.
illustration, when rocked in one direction, the widest space will be between the
bars of the adjacent sets of arms as shewn in Fig. 7, and when thrown to the other
extreme the widest space would be between the bars of the arms at the right of
the Figure. This rocking of the bars also sifts the ashes from the fire bed; and
by alternately changing the location of the widest spaces between the bars a freer
draught is given and the oxygen supplied at such points as it will be most effective
in producing combustion of the gases.
For
The grate bars can be locked in an upright or inclined position by engaging the
lever M with the rack bar K¹. The levers M and M² will preferably be fulcrumed
on a bracket N, secured to a suitable part of the engine as shewn in Fig. 5.
In combination with the above described construction of furnace I also employ
an improved system of combined air and steam blast admitted above the fire
grate, the construction of which is shewn in Fig. 5 and in enlarged detail at
Figs. 12 to 15.
The superheated steam used in effecting the complete combustion of the fuel is
brought upon the steam dome v through a pipe b, which runs through the water or
steam space m, to the soda fountain n, from whence a pipe o provided with a valve p
runs to a point below the furnace door as indicated in Fig. 5 where it enters an
opening g, therefor and is provided with one or more injector nozzles 7, the end of
which has one or more horizontal slits s, through which the steam will issue in a
broad thin sheet over and onto the body of the burning carbonaceous material."
The steam nozzles are enclosed in caps g having slits corresponding to those of
the steam nozzles, and having openings outside the fire box through which the air
can enter. Thus the steam issuing from the nozzles induces currents of air
through the surrounding cap, which issues in intimate admixture with the steam
through the slit of the cap, forming a broad thin jet of combined steam and air as
indicated in dotted lines at Fig. 12 which enters into combustion with the gases
evolved from the fuel on the grate and effects their complete combustion or
conversion as before described.
The caps g may receive a supply of compressed air from a compressed air
reservoir instead of drawing in the air at atmospheric pressure by which arrange-
ment the blast can be started on lighting the fire, before the necessary steam supply
VERR

page_text: As shewn at the enlarged sectional view at Fig. 15, the steam is led through a zig
zag or coiled pipe o' situated closely against the fire box and this coil is enclosed by
a box t open at bottom, fixed against the fire box, so that the air supply passing up
through the box to the caps g also becomes heated to a considerable degree before
combining with the.steam issuing from the nozzles before described.
5
By introducing the heated air into and through the body of the carbonaceous
material as herein before indicated and directing the superheated steam over the
body of the burning fuel in a broad thin sheet, the requisite amount of oxygen is
supplied in a heated state to take up the carbon gases and the liberated hydrogen of
the decomposed steam is caused to unite with the sulphur of the carbonaceous fuel 1
and then to unite with the carbon gases so as to effect complete consumption of the
gases and thus prevent the formation of smoke.
Surface combustion has heretofore been tried by various methods but I find that
unless great care was exercised much valuable combustible gas passed off uncon-
sumed although it was supposed that combustion was nearly complete because 1
the product was invisible.
My experience applied to various carbonaceous materials and particularly to
bitumenous coal and lignite is that by my method of distributing the heated air
throughout the entire body of the carbonaceous material and bringing the air and
steam and evolved gases into intimate contact with each other, steam is decomposed
and complete combustion effected and the formation of smoke and sparks prevented.
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
1. The within described method of producing complete combustion in burning
carbonaceous material, consisting in passing heated air into and throughout the
body of the fuel and injecting superheated steam with or without admixture of air
in a broad thin sheet over and onto the surface of the fuel whereby the gases are
intimately united and the formation of smoke prevented.
2. The within described method of producing complete combustion in burning
carbonaceous material, consisting in passing heated air into hollow spaces formed
in the body of the fuel and then discharging it into the same and injecting steam
in a broad thin sheet together with air over and onto the surface of the fuel
whereby the gases are intimately united and the formation of smoke prevented.
3. The combination with a furnace of a grate provided with arched perforated
caps or air distributors, substantially as described.
4. The combination with a furnace of a grate provided with rocking bars having
arched perforated caps or air distributors connected therewith, substantially as
described.
5. The combination with a furnace of a grate composed of a series of rocking
bars provided with arched perforated caps arranged in different planes, substantially
as described.
6. In a furnace grate arranging a series of rocking grate bars and arched per-
forated caps thereon in such manner that while the tops of the caps all lie in one
plane, the journals of the grate bars lie in different planes.
7. The combination with a furnace of a grate composed of a series of rocking
bara provided with arched air distributors and connected with an undulating bar
by pivotal connections whereby the bars may be rocked and the air distributors
moved to alternately increase and lessen the space between them, substantially as
described.
8. The combination of the rocking bars provided with the arched air distributors,
the bifurcated arms supporting the said bars, and the bar to which they are con-
nected for oscillating the same, substantially as described.
9. The combination of the rocking bars provided with arched air distributors,
the slotted bars through which the journals of the grate bars pass, the bifurcated

page_text: arms in which the grate bars have their bearings, and the bar to which the arms
are connected for oscillating the same substantially as described.
10. The combination of the rocking grate bars provided with the arched air
distributors, the bar having a pivotal connection with the grate bars to rock the
same, the bifurcated arms in which the grate bars have their bearings, and the bar
to which said bifurcated arms are pivotted for oscillating the same, substantially as
described.
11. The rocking grate bar having its upper surface formed of different planes, in
combination with the arched air distributors connected thereto, substantially as
described.
12. The rocking grate bar having vertical grooves formed in its sides, in com-
bination with the arched perforated caps provided with slotted plates straddling
the bar and fitting the grooves thereof, substantially as described.
13. The use in combination with a furnace of apparatus for supplying a flat
broad jet of combined steam and air over the fuel, consisting of a steam nozzle
having a horizontal slit through the steam issues, and surrounded by a cap into
which air is drawn or forced, and which has a horizontal slit corresponding in
position to the slit of the steam nozzle.
14. The combination of the apparatus for discharging combined steam and air in
a broad thin jet over the fuel in a furnace such as is is referred to in the preceding
claim, with a furnace grate having arched perforated caps or air distributors, such
as are herein before referred to.