IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES
Year: 1878

page_text: LETTERS PATENT to James Fortescue Flannery, of 9, Fenchurch Street, in the
City of London, Consulting Engineer, for the Invention of "IMPROVEMENTS
IN STEAM BOILER AND OTHER FURNACES."
Sealed the 21st February 1879, and dated the 5th September 1878.
PROVISIONAL SPECIFICATION left by the said James Fortescue Flannery at
the Office of the Commissioners of Patents on the 5th September 1878.
"f
JAMES FORTESCUE FLANNERY, of 9, Fenchurch Street, in the City of London,
Consulting Engineer. IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES."
My Invention of improvements in steam boiler and other furnaces has reference
more especially to the furnaces of marine and other steam boilers, and its objects
are to accelerate to the greatest possible extent the generation of steam, to diminish
the consumption of fuel in proportion to the quantity of water evaporated, and to
increase the facilities for practically effecting these results.
The amount of fuel consumed upon each square foot of grate surface per hour is
as a test imperfect and comparatively valueless. Power in the form of carburetted
gases may be rapidly developed, but unless it is as rapidly utilized by the com-
bination of these gases with the duo admixture of oxygen a portion is entirely lost.
Great rapidity of combustion has consequently hitherto been attended with a great
loss of power,
and in some cases so enormous as to nearly neutralize the advantages,
the loss in inutilized gases being nearly equivalent to the time occupied in their
generation independently of the absolute waste of fuel. Such is the case, and must
inevitably be so when this accelerated combustion is obtained by means of chimney
draught.
Artificial draught produced by fans, steam jet blowers, and other means has
been employed with more or less advantage to accelerate combustion, but when the
blast is discharged underneath the grates of furnaces, the usual mode, it inevitably
involves the rapid destruction of the fire-bars.

page_text: Again, atmospheric air has been introduced with more or less advantage, in some
cases behind, and in others over the fire, in order that the oxygen contained therein
may enter into combination with the carburetted gases given off by the fuel; but
it is obvious that this will afford no aid in accelerating the combustion of the fuel
itself, which is also and additionally necessary in order to attain to the greatest
possible extent the rapid generation of heat. On the contrary, if a larger quantity
of air be thus supplied than will admit of the combustion of the oxygen contained
therein with the carburetted gases set free, in combustion it would to a certain
extent prove not only useless but detrimental. The object to be gained therefore
is the greatest possible rapidity in the decomposition of the fuel and at the same
time to give such an amount of oxygen, and so distributed as shall be best calcu-
lated to ensure its perfect combination with the carburetted gases given off in
process of decomposition of the fuel, in order that perfect combustion or the nearest
attainable approach thereto may be effected. This result is attained by means of
my Invention which I will now proceed to describe.
I employ artificial blast in quantity and power sufficient to ensure the most rapid
combustion compatible with the power to utilize all the products of such com-
bustion which may be required in the development of heat.
I convey the blast to the fire through hollow perforated grate bars, and where
necessary, in order to more effectually preserve the bars by ensuring the greatest
strength of blast at the ends furthest from their mouths (these being the parts
exposed to the greatest heat), or for the more equal or better distribution of blast
to all parts of the furnace, and in cases where great length of fire-grate renders it
desirable to make the fire-bars in two lengths, or for other purposes where it may
be expedient, I cause the blast to enter the bars at the back of the furnace instead
of (or in addition to, as the case may be) conveying it through the bars from front
to back as hitherto done.
When the fire-bars are made in two lengthis the blast may be conveyed in two
separate currents by a branch blast pipe to the main delivery tube or other suitable
means to each of the blast chambers, which respectively appertain to each length of
fire-bars; the blast for the front bars may enter them at the ends nearest the fire-
door, and that for the back bars at the ends nearest the bridge.
I also convey a portion of the blast to the entrance of the flue immediately over
the bridge, and in addition thereto another portion over the incandescent fuel
either by jets from a chamber over the fire-door, into which chamber such portion of
the blast may enter, or by other means, such as one or more fire-bars (hollow and
perforated at the sides and near to the tops) elevated above the fire in order that
by these combined arrangements the blast shall be so distributed as to ensure the
most complete combination of the gases attainable, for the purpose of effecting
perfect combustion or the nearest possible approach thereto.
In cases where a steam jet may be advantageously used for creating the required
amount of blast I apply one blower for every two or more adjacent bars in the
following manner, that is to say :-The tops of the bars at their mouths fit close
up to the back part of the dead plate, which is about six inches, more or less, in
width, the bottoms of the bars resting upon a similar plate. I insert vertically
division plates which slide into grooves made for the purpose in the bottom surface
of the upper horizontal plate, or dead plate, and in the top surface of the under
horizontal plate. There will be a greater or less number of these divisions, according
to the width of the grate, the number of bars (preferably two or three) contained
in each division and the width of the bars. It will thus be seen that the whole
space in front of the fire-bars, and bounded at top and bottom by the two
horizontal plates and at the back by the fire-bars, is divided into compartments,
open in front by varying in number according to circumstances (such, for instance,
the width of the grate) by the afore-mentioned vertical division plates. I then
convert each of these compartments into a blower, contracting the space gradually
a certain point equidistant, or nearly so, from the back and front ends, being the
narrowest part, whence it gradually widens back and front to each end. This is
09

page_text: accomplished by casting on the inner plane of each of the two end vertical division
plates a curved plate of the required curvature (and which will vary according to
the width), so that it shall fit close to the top and bottom horizontal plates, and
by casting a similar curved plate upon both sides of the intermediate vertical
division plates.
I may cast either the whole or some of the parts in one, and may make the
vertical division plates immovable instead of making them to slide in and out.
Into each of the compartments thus converted into blowers 1 insert a pipe
tapering to a small nozzle of proper dimensions, and communicating with the main
pipe which conveys the steam to all the blowers.
I also in order to keep the inside of the bars perfectly free from any particles of
ash or other matter that may drop into them, and to remove any difficulty which
from the nature of some of the arrangements herein described may in certain cases
bo experienced in pricking them out as well as to avoid unnecessary labor, connect
with the bottom of the longitudinal cavity in the bar an aperture or apertures of
suitable dimensions, but by preference one aperture at the end of the bar furthest
from its mouth, this aperture being of the same length as the width of the base of
longitudinal cavity.
It will be seen that outlets are thus provided through which any dust or particles
of ash that might otherwise in course of time accumulate in the cavities of the bars
may be expelled by the action of the blast.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Fortescue Flannery in the Great Seal Patent Office on the
5th March 1879.
JAMES FORTESCUE FLANNERY, of 9, Fenchurch Street, in the City of London,
Consulting Engineer. "IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES."
My Invention of "Improvements in Steam Boiler and other Furnaces " has reference
more especially to the furnaces of marine and other steam boilers, and its objects
are to accelerate to the greatest possible extent the generation of steam, to diminish
the consumption of fuel in proportion to the quantity of water evaporated, and to
increase the facilities for practically effecting these results.
The amount of fuel consumed upon each square foot of grate surface per hour is
as a test imperfect and comparatively valueless. Power in the form of carburetted
gases may be rapidly developed, but unless it is as rapidly utilized by the com-
bination of these gases with the due admixture of oxygen, a portion is entirely
lost. Great rapidity of combustion has consequently hitherto been attended with a
great loss of power, and in some cases so enormous as to nearly neutralize the
advantages, the loss in inutilized gases being nearly equivalent to the time occupied
in their generation, independently of the absolute waste of fuel. Such is the case,
and must inevitably be so when this accelerated combustion is obtained by means of
chimney draught.

page_text: Artificial blast produced by fans, steam jet blowers, and other means has been
employed with more or less advantage to accelerate combustion, but when the blast
is discharged underneath the grates of furnaces (the usual mode) it inevitably
involves the rapid destruction of the fire-bars.
Again, atmospheric air has been introduced with more or less advantage, in some
cases behind and in others over the fire, in order that the oxygen contained therein
may enter into combination with the carburetted gases given off by the fuel; but it
is obvious that this will afford no aid in accelerating the combustion of the fuel
itself, which is also and additionally necessary in order to attain to the greatest
possible extent the rapid generation of heat. On the contrary, if a larger quantity
of air be thus supplied than will admit of the combination of the oxygen con-
tained therein with the carburetted gases set free in combustion, it would to a
certain extent prove not only useless but detrimental. The object to be gained
therefore is the greatest possible rapidity in the decomposition of the fuel, and at
the same time to give such an amount of oxygen and so distributed as shall be
best calculated to ensure its perfect combination with the carburetted gases given
off in process of decomposition of the fuel, in order that perfect combustion, or the
nearest possible approach thereto, may be effected. This result is attained by means
of my Invention, which I will now proceed to describe.
I employ artificial blast in quantity and power sufficient to ensure the most rapid
combustion compatible with the power to utilize all the products of such com-
bustion which may be required in the development of heat.
I convey the blast to the fire through hollow perforated grate-bars, and where
necessary, in order to more effectually preserve the bars by ensuring the greatest
strength of blast at their ends furthest from their mouths (these being the parts
exposed to the greatest heat), or for the more equal or better distribution of blast
to all parts of the funace, and in cases where great length of fire-grate renders it
desirable to make the fire-bars in two lengths, or for other purposes when it may
be expedient, I cause the blast to enter the bars at the back of the furnace, instead
of or in addition to (as the case may be) conveying it through the bars from front
to back, as hitherto done.
Figure 3 of the accompanying Drawings (subsequently described) shows a grate
composed of bars in two lengths, the blast for the front bars entering them at
the ends nearest to the fire-door, and entering the back bars at the ends nearest the
bridge.
In addition to the blast which is thus supplied to the fuel to accelerate com-
bustion I also take a portion (and which varies according to the construction of the
boiler and furnace, and also in proportion to the speed at which the carburetted
gases, and which would otherwise escape combination with oxygen, are given off in
combustion), either through the bars themselves or through pipes independently
of them, to a chamber at the back of the furnace, whence it escapes for the purpose
of mingling with the gases before described as given off by the fuel in com-
bustion.
A hollow bridge may constitute the chamber, from which the blast may be
conveyed into the bars at their back ends, as already indicated, as well as admitting
a portion into the flue behind the fire, and by means of which the blast will acquire
a considerable amount of heat.
I also for the same purpose take a portion of the blast over the surface of the
furnace, either by increasing the height of one or more of the fire-bars to a point
above the surface of the incandescent fuel, and by means of perforated side holes
near the top of such bar or bars let the blast escape, and be distributed over the
surface of the fire in such proportions as may be most suitable in each particular
case, and according to the celerity of decomposition of fuel; or I may convey it
into a chamber over the fire-door, escaping thence over the furnace through per-
forations.
It will be observed that the air before it reaches the point of contact with the
carburetted gases acquires a considerable degree of heat.

page_text: I In cases where a steam jet may be advantageously used for creating the required
amount of blast, I apply one blower for every two or more adjacent bars in the
following manner, that is to say:-The tops of the bars at their mouths fit close up
to tho back part of the dead plate, which is about six inches (more or less) in width,
the bottoms of the bars resting upon a similar plate. I insert vertically division
plates, which slide into grooves made for the purpose in the bottom surface of the
upper horizontal plate (or dend plate) and in the top surface of the lower horizontal
plate. There will be a greater or less number of these vertical division plates,
according to the width of the grate, the number of bars (preferably two or three)
contained in each division, and the width of the bars. It will thus be seen that the
whole space in front of the fire-bars, and bounded at top and bottom by the two
horizontal plates, and at the back by the fire-bars, is divided into compartments
open in front, and varying in number, according to circumstances (such, for instance,
as the width of the grate), by the afore-mentioned vertical division plates. I then
convert each of these compartments into a blower by contracting the space
gradually, a certain point equidistant, or nearly so, from the back and front ends,
being the narrowest part, whence it gradually widens back and front to each end.
This is accomplished by casting on the inner plane of each of the two end vertical
division plates a curved plate of the required curvature (and which will vary
according to the width), so that it shall fit close to the top and bottom horizontal
plates, and by casting a similar curved plate upon both sides of the intermediate
vertical division plates.
I may cast either the whole or some of these parts in one, and may make the
vertical division plates immovable instead of making them to slide in and out; or
I may form the blast chamber, common to two or more bars, by casting the chamber
and its bars in one piece. Into each of the compartments thus converted into
blowers I insert a pipe tapering to a small nozzle of proper dimensions and com-
municating with the main pipe which convoys the steam to all the blowers.
I also, in order to keep the inside of the bars perfectly free from any particles of
ash or other matter that may drop into them, and to remove any difficulty which
from the nature of some of the arrangements herein described may in certain
cases be experienced in pricking them out, as well as to avoid unnecessary labor,
connect with the bottom of the longitudinal cavity in the bar an aperture or
apertures of any suitable form and size, but by preference one aperture at the end
of the bar furthest from its mouth, this aperture being of the same length as the
width of the base of the longitudinal cavity. It will be seen that outlets are thus
provided, through which any dust or particles of ash that might otherwise in course
of time accumulate in the cavities of the bars may be expelled by the action of the
blast.
The accompanying Drawings represent several arrangements for carrying out my
Invention.
In Figure 1, G is the blast pipe; A is the blast chamber; B, the bar; C, the
bridge; D, a flue in the bridge, taking a current of air to the back of the bridge;
E, hollow perforated blast chamber over the fire-door; F, closed ash-pit.
In Figure 2 (Sheet 2) A, A, are blast chambers; B, B, fire-bars in two lengths;
G, one of the blast pipes; and in Figure 3 (Sheet 1) A, A, are the blast chambers;
B, B, the fire-bars; C, the bridge; D, a flue in the bridge for the escape of a
current of air; E, perforated blast chamber extending over or around the fire-door;
F, closed ash-pit; G, G, blast pipes.
Instead of special blast pipes for this purpose, as shown, I sometimes convey the
blast to the inner chamber from the outer chamber by making each alternate hollow
fire-bar without side perforations and connecting it at either end respectively to the
two chambers; a certain portion of the blast is thus supplied to the inner chamber,
and thence to the perforated fire-bars communicating therewith.
Figures (Sheet 2), 5, and 6 (Sheet 3), represent an arrangement of my In-
vention for producing a blast with a jet of steam. A is the steam pipe leading to
the horizontal steam chamber or reservoir B; C, C³, C³, C³, C, C³, C, C7, C³, are

page_text: the nozzles or pipes for conveying the steam to the blowers; D is the dead plate;
E, the lower horizontal plato; F, F', to F7, are the vertical division plates,
separating and converting into blowers the space between the two horizontal plates
D and E; G, G¹, to Gs, are the hollow perforated fire-bars; and H, H¹, to H¹³, are
the apertures in the lower part of each hollow bar for clearing them.
Figure 7 (Sheet 2) is a larger view of the hollow fire-bars."
Figure 8 (Sheet 1) shows the blast chamber, common to two bars, cast in one
piece with the bars.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my "Improvements in Steam
Boiler and other Furnaces,"
First. The combination and adaptation of arrangements, substantially as herein-
before described, to be used with blowers, whereby such an amount of atmospheric
air is supplied as is adequate to produce a very rapid decomposition of fuel, and is
at the same time so distributed as to promote the perfect combination of oxygen
with the carburetted gases given off in the process of such decomposition, in order
to ensure perfect, or as nearly as possible perfect combustion.
Second. The conveyance (where necessary or desirable), of either the whole or a
portion of the blast to the back of the furnace, substantially as horein-beforo
described, in order that it may enter the hollow fire-bars at the ends furthest from
the fire door.
Third. The conveyance, substantially as herein-before described, of blast in two
separate currents to each of the blast chambers which respectively appertain to
each length of fire-bars in cases where such bars are made in two lengths.
Fourth. The adaptation to or combination with the hollow grate bars of furnaces S
of steam jet blowers, substantially as herein-before described.
Fifth. The forming of an aperture or apertures in the lower part of the hollow
bars of furnaces and communicating with the longitudinal cavity in such bars,
through which any particles of ash or other matter that may enter such bars may
be ejected, substantially as herein-before described.
In witness whereof, I, the said James Fortescue Flannery, have hereunto set
my hand and seal, this First day of March, One thousand eight hundred
and seventy-nine.
JAMES FORTESCUE FLANNERY. (L.S.)