IMPROVE- MENTS IN FURNACES TO STEAM GENERATORS
Year: 1883

page_text: LETTERS PATENT to Charles Denton Abel of N° 28 Southampton Buildings
Chancery Lane in the County of Middlesex for an Invention of " IMPROVE-
MENTS IN FURNACES TO STEAM GENERATORS" communicated to him from
Abroad by Joseph Ferrando of Genoa in the Kingdom of Italy
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at
the Office of the Commissioners of Patents on the 18th August 1883.
,
"
CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane in the
county of Middlesex "IMPROVEMENTS IN FURNACES TO STEAM GENERATORS
[communicated to him from Abroad by Joseph Ferrando of Genoa in the Kingdom
of Italy]
This invention has reference to furnaces for steam generators having firebars
constructed with downward extensions which are generally made to dip into water,
and which are used more particularly for burning pulverulent combustible matter,
the bars being placed very close together and the air supply being forced in under
pressure.
In such furnaces, as heretofore constructed, the said deep bars have been
arranged longitudinally, and this has the disadvantages, firstly, of allowing the air
to pass between them and through the fuel in a very slanting direction towards
the fire-bridge, whereby a considerable quantity of the fine fuel was carried off
without being burnt; secondly, when using the bars in cylindrical fireboxes, such
as those of cornish boilers, only the middle bars could be made to dip into the
water, and those at the sides not only became rapidly deteriorated, but were soon
blocked up with fuel, and thus rendered the action of the furnace very imperfect.
According to the present improvements, these inconveniences are obviated, by
placing the deep fire-bars in a transverse direction, whereby firstly, the air
ascending between them is made to pass up more or less vertically through the
fuel before being deflected by the draught towards the fire-bridge, and thus the
particles of fuel carried up by the air currents have time to become burnt before
they can pass off to the fire bridge. Secondly, all the bars can be constructed of
uniform depth and be made to dip to the same extent into the water: In this
ID 11

page_text: arrangement, in order to allow free access of air to all the bars, holes aro made
through the web or lower part of the bar, so that the air can pass right through all
the bars.
In applying this arrangement of the furnace bars to internal or external furnaces
for steam boilers, the casing or pan which encloses the lower parts of the bars, and
which contains water, is according to one arrangement, extended somewhat beyond
the brickwork and is there made to communicate with a pipe through which both
the air supply for the furnace and the water supply for the pan are introduced,
the air being propelled either by a steam jet from the boiler, or otherwise.
According to another arrangement, the firegrate is placed in a firebrick chamber
external to the boiler but communicating with the flues thereof by a tubular firebrick
extension. The chamber is constructed with a double arch, having air passages
between the two arches, into which the air required for combustion enters through
side holes at bottom, and whence, after having become heated by the furnace heat, it
it is made to pass through a pipe at top into the injector apparatus by which it
is propelled into the furnace. Instead of employing a double arch for the chamber,
a single firebrick arch may be used, having air passages formed therein or
surrounded by a rectangular casing of brickwork or metal through which the air
supply is made to circulate.
When there are two or more furnaces to the steam boiler, they are connected by
pipes for supplying the water to the pans and for conveying the air supply.
The same construction as above described is also applicable to boilers having
upper cylindrical water chambers connected to a lower steam generator of the kind
known as the "Ten-Brink" Boiler, in which a cylindrical water chamber has a flue
passing transversely and obliquely through it, in which is ordinarily situated an
inclined firegrate. According to the present invention, this grate is removed and
the flames from the external furnace are made to pass first through such Bue, and
then round the outer surface of the generator. Or, according to another arrangement
of the above construction, the "Ten-Brink " generator is entirely removed, and the
abovo described construction of furnace with immersed fire-bars is introduced in its
place.
According to another arrangement, the said furnace is enclosed in a metallic
chamber or firebox surrounded by a water-space that communicates by branch
pipes with the upper water chambers of the boiler.
In applying the improved firegrate to steam boiler that are subject to oscillations,
such as inarine boilers, the pan or tank containing water into which the bars dip is
divided into several compartiments by partitions reaching up to a certain height,
the fire-bars being formed with slits at the points where they intersect with the
partitions, so that these fit into the slits.
By this means the dashing about of the water in the pan to any inconvenient
extent is prevented.
The partitions may have holes at bottom so that the water can flow from one
compartment into the other, or the compartments may be entirely separate, cach
compartment being fed by a separate pipo.
According to another improvement, instead of causing the deep bars to dip into
water, they are subjected to the action of moist steam or other vapor which may
be introduced through a perforated pipe placed in the pan for the water; or the
latter may have a small quantity of water supplied to it which is evaporated by
the heat of a steam pipe. With this arrangement, sufficient space would be:
allowed between the bottoms of the bars and the level of the water to allow the
air supply to pass, and the fire bars need in this case not be provided with the
before-mentioned, holes for the air to pass through.
According to another arrangement, a spray of water is caused to play upon the
bars instead of steam or vapor.
When furnaces are used with a forced air supply and closed ash pit, considerable
inconvenience arises when the fire-door is opened, owing to the gaseous pressure
necessarily existing in the furnace causing the flames to be forced out more or less

page_text: through the fire-door. According to the present invention this inconvenience is
overcome by providing within the furnace close to the fire-door a plate having no
fuel upon it and provided with openings that can be closed by a slide.
When the
fire door is closed, the openings are closed and the. air supply from the ash pit.
passes entirely through the fuel, but when the fire door is opened, the. apertures
of the plate are also opened, and a body of air, in rushing up through them from
the ash pit and out of the door, prevents the flames from striking outwards.
According to another arrangement, for preventing the flames from striking out
as described, there is provided in the uptake of the boiler a steam ejector or other
suitable known suction apparatus, which, in being put into operation on opening
the furnace door, neutralises the excess of pressure in the furnace.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abol in the Patent Office on the 18th February
1884.
"
CHARLES DENTON ABEL of No 28 Southampton Buildings Chancery Lane in
the county of Middlesex "IMPROVEMENTS IN FURNACES TO STEAM GENERATORS'
A communication to me from abroad by Joseph Ferrando of Genoa in the Kingdom
of Italy.
This invention has reference to furnaces for steam generators, having firebars
constructed with downward extensions, which are generally made to dip into
water, and which are used more particularly for burning pulverulent combustible
inattor, the bars being placed very close together and the air supply being forced
in under pressure.
In such furnaces, as heretofore constructed, the said deep bars have been
arranged longitudinally, and this has the disadvantages, firstly, of allowing the air
to pass between them and through the fuel in a very slanting direction towards
the fire bridge, whereby a considerable quantity of the fine fuel was carried off
without being burnt; secondly, when using the bars in cylindrical fireboxes, such
as those of Cornish boilers, only the middle bars could be made to dip into the
water, and those at the sides not only became rapidly deteriorated, but were
soon blocked up with fuel, and thus rendered the action of tho furnace very
imperfect. According to the present invention, these inconveniences are obviated,
by placing the deep fire-bars in a transverse direction, whereby firstly, the air
ascending between them is made to pass up more or less vertically through the
fuel before being deflected by the draught towards the fire-bridge, and thus tho
particles of fuel carried up by the air currents have time to become burnt before
they can pass off to the fire bridge. Secondly, all the bars can be constructed of
uniformn depth, and be made to dip to the same extent into the water. In this
arrangement, in order to allow free access of air to all the bars, holos are made
through the web or lower part of the bar, so that the air can pass right through
all the bars.
h
The accompanying drawings shew how this invention may be applied to boilers
and furnaces of various forms, In the several figures, corresponding parts are
marked by similar letters. Fig. 1 is a side view and fig. 2 a transverse section to
an enlarged scale of one of the fire bars f, which is made of considerable depth to
reach down into the water, and has through it large holes g g for free passage of
air through the range of bars constituting the fire grate. Eig. 3 is a part longitu-
dinal section, Fig. 4 is a transverse section, and fig. 5 is a sectional plan, shewing
one mode of applying a fire-grate, consisting of transverse bars F, to a boiler of
the Cornish type, the fire place being in this arrangement in an external structure
at the end of the boiler. The bars f dip into the water of the tank d, and the air
draught is promoted by an injector e, supplied with steam.by a pipe / regulated by
a valve c. The structure of the fire place may be built in solid brickwork, or it
may be made double, as shown with an air space b between the inner firebrick
lining and the outer inasonry, and thus the air for supplying the fire, entering at a,
is, in the first place, heated by passing through the space b. This space may be
cased in by metal plates instead of brick work. Figs. 6, 7 and 8 show the fireplace
and tank arranged within the fire flue of the boiler. Figs. 9, 10 and 11 shew the
application of the transverse bars to a cylindrical boiler. Figs. 12, 13 and 14 shew
the application to a boiler with generator having inclined flue tube through it.
Figs. 15, 16 and 17 shew its application to a generator with internal fire,
communicating with two cylindrical parts above; and figs 18, 19 and 20 shew the
transverse bars forming a fire place for two cylindrical boilers above it. When.
boilers are subject to oscillations, as on ship-board, the water tank should be
divided by partitions into several compartiments, as shown in figs. 21, 22 and 23,

page_text: and to an enlarged scale in figs 24 and 25. There may be small passages at the
bottoms of the partitions, so that the general level of the liquid may be maintained
in all the compartments of the tank.
Instead of causing the deep bars to dip into water, they are subjected to the
action of moist steam or other vapor which may be introduced through a perforated
pipe placed in the pan for the water; or the latter may have a small quantity of
water supplied to it which is evaporated by the heat of a steam pipe. With this
arrangement, sufficient space would be allowed between the bottoms of the bars
and the level of the water to allow the air supply to pass, and the fire bars need
not in this case be provided with the holes g for the air to pass through.
According to another arrangement, a spray of water is caused to play upen the
bars instead of steam or vapor.
When furnaces are used with a forced air supply and closed ash pit, considerable
inconvenience arises when the fire door is opened, owing to the gaseous pressure,
necessarily existing in the furnace, causing the flames to be forced out more or less
through the fire door. According to the present invention, this inconvenience is
obviated by providing within the furnace, close to the fire door, a plate having no
fuel upon it and provided with openings that can be closed by a slide. Fig. 26 is
a plan and fig. 27 is a section of a plate with slide for this purpose, which is shewn
in its place in figs. 21, 23, 24 and 25.
When the fire door is closed, the openings are closed, and the air supply from
the ash pit passes entirely through the fuel, but when the fire door is opened, the
apertures of the plate are also opened, and a body of air, in rushing up through
them from the ashpit, and out of the door, prevents the flames from striking
outwards. According to another arrangement, for preventing the flames from
striking out as described, there is provided, in the uptake of the boiler, a steam
ejector or other suitable known suction apparatus, which, in being put into
operation on opening the furnace door, neutralises the excess of pressure in the
furnace.
Having thus described the nature of this invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
I claim :-
First Constructing the fire grate of a steam generator of deep transverse bars
dipping into water, and having through them holes for passage of air, substantially
as herein described.
Second: In combination with a fire grate consisting of deep transverse bars
dipping in water, a double cased fire box with space between the casings for heating
the air supplied to the fire, substantially as herein described with reference to
figs 3, 4 and 5.
Third: For the firegrate of steam boilers subject to oscillation, the use, in
combination with deep transverse fire-bars, of a partitioned tank containing water
into which the fire bars dip, substantially as herein described with reference to
figs. 21, 22, 23, and 24.
Fourth: In steam boiler furnaces having forced draught, the use of a grated
dead plate for preventing flame from being blown out at the door when it is
opened, in combination with a slide closing the dead plate when the fire door is
closed, substantially as herein described with reference to figs. 21, 23, 24, 25, 26
and 27.
In witness whereof I the said Charles Denton Abel have hereunto set my hand
and seal this Eighteenth day of February in the year of our Lord, one thousand
eicht hundred and eighty four
CHAS. D ABEL (L.S.)