AN IMPROVED METHOD OF AND APPARATUS FOR PROMOTING THE COMBUSTION OF FUEL IN FURNACES
Year: 1874

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "AN IMPROVED METHOD OF AND APPARATUS FOR
PROMOTING THE COMBUSTION OF FUEL IN FURNACES."-A communication
from abroad by Gustavus A. Jasper, of Boston, Massachusetts,
United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 19th September 1874.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "AN IMPROVED METHOD OF AND APPARATUS
FOR PROMOTING THE COMBUSTION OF FUEL IN FURNACES," a communication, to
be as follows :—
The said Invention relates to throwing into burning fuel a powerful
draught of air loaded with water subdivided mechanically.

page_text: I prefer to use the well known Harrison's boiler, which consists of
cast-iron spheres with the usual passages for hot air, smoke, and gases,
the smoke and other products of combustion passing out through a
passage into a flue. A door is provided for communicating with the
smoke chamber. The boiler rests upon a cross beam.
The foregoing parts may be constructed in any ordinary manner in
which furnaces are built, my Invention not having any special relation to
steam boiler furnaces, and much less to the form or situation of the boiler.
The openings between the grate bars should be made much narrower
than in ordinary grates, for although improved results are obtained by
applying my Invention to fires of ordinary sized coal the best results are
obtained when the coal is reduced to a coarse powder.
In practical operation in furnaces anthracite coal screenings only are
generally burned, the grate bars being one quarter of an inch apart.
A fan blower is provided for forcing air through a pipe and branch:
pipes into the ash box beneath the. grate bars. Where two furnaces are
used there intervenes between each of the pipes and the fan blower a
large common pipe. The draught created by the fan is in each furnaco
regulated by a valve. A water pipe leads from a tank in the upper part
of the building above the furnace; its purpose is to combine a small
quantity of water with the fresh air forced into the furnace through the
first mentioned pipe, and when this pipe is divided into two branch
pipes the stream of water is divided into two streams by entering another
pipe, and thence flowing through small pipes into each of the branch
pipes, where it is broken into numerous jets by striking against discs
attached to nozzles.
Above each of the openings of the branch pipes in the ash box about
half way between the orifice and the grate bars is a metallic disc,
preferably perforated, supported by a bar set in the brickwork, which
breaks up and evenly distributes below the grate the current of air
entering from the pipe in order that the fire may burn evenly over all
parts of the grate. This current of air brings with it and further divides
and distributes the jets of water thrown off from the disc.
In practice the above described apparatus may be applied for forcing
air and water into several furnaces in one room, using onc blower and
one main pipe from the water tank, the blower being made to force air

page_text: into several pairs of branch pipes, one pair for each furnace, and each of
these pipes being provided with a pipe for a water supply.
In locomotives and other engines where it is not convenient to supply
water by its fall from a tank it may be forced into the air passage by a
small pump, the water being broken up by striking against discs on the
nozzles of the discharge pipes. The air may also be carried into the
furnace by other contrivances than the one described, provided the
draught is made of the requisite force. It is obvious also that where
there is a large grate surface in the furnace some device similar to the
aforesaid disc should be employed to evenly distribute the air through
all parts of the grate to prevent the fire from burning in holes.
Where bituminous coal is to be burned a blast of air must be intro-
duced into the fire chamber above and across the surface of the burning
coal, and regulated by a proper damper, so that fresh air may be supplied
to ignite and consume within the furnace gases and smoke which would
otherwise escape from such coals.
Regulating valves are arranged to communicate respectively with the
ash box and fire chamber, and consist of a tube and a mica lid weighted,
but the weight is important only as attached to the ash box valve. The
latter valve is so weighted that it is forced outward when the blast is too
strong, and the valve for regulating the draft of air can be adjusted
accordingly.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 19th March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of September, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence

page_text: that I, the said William Robert Lake, my executors, administrators, and
assigns, or such others as I, the said William Robert Lake, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for " AN
IMPROVED METHOD OF AND APPARATUS FOR PROMOTING THE COMBUSTION OF FUEL IN
FURNACES," a communication to me from abroad by Gustavus A. Jasper,
of Boston, Massachusetts, United States of America, upon the condition
(amongst others) that I, the said William Robert Lake, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawing forming a part of this Specification :-
The said Invention relates to throwing into burning fuel a powerful
draught of air loaded with water, subdivided mechanically.
The Drawing represents a steam boiler furnace to which this Invention
is applied.
Figure 1 is a side view of the brick casing in which the furnace and
boiler are enclosed; Figure 2 is a side view of the same, with a part of
the casing broken away to give in sectional elevation details of the said
Invention; Figure 3 is a plan (taken below the line x, x¹, of Figure 2,
the last-named Figure being on the line x, xa, of; Figure 3. The plan
represents the Invention as applied to two furnaces.
Figures 4 and 5 are views in detail of valves used in the said furnace.
Figure 6 shews a grate bar.
A is the brickwork of the furnace; B is the boiler; C is the furnace
chamber; D is the ash box; E is the furnace chamber door; F, the ash

page_text: box door. The boiler shewn is the well known “Harrison's boiler,"
which consists of cast-iron spheres, with the usual passages for hot air,
smoke, and gases. G is the usual smoke chamber, the smoke passing
out through a passage S into the flue not shown; S' is a door commu-
nicating with a smoke chamber. The boiler rests upon a cross beam P.
The foregoing parts may be constructed as shown, or in any ordinary
manner in which furnaces are built.
a is the grate. The openings between the bars should be made much
narrower than in ordinary grates, for although improved results are
obtained by applying my Invention to fires of ordinary sized coal the
best results are obtained when the coal is reduced to a coarse powder.
In practical operation in furnaces to which this Invention has been
applied anthracite coal screenings only are generally burned, the grate
bars being one quarter of an inch apart.
H is a fan blower forcing air through the pipe I and branch pipes I', I',
into the ash box beneath the grate bars. In the apparatus shewn, there
being two furnaces, there intervenes between the pipes I and the fan
blower a large common pipe, as shewn. The draught created by the
fan is in each furnace regulated by a valve c.
K is a water pipe leading from a tank in the upper part of the
building above the furnace; its purpose is to combine a small amount
of water with the fresh air forced into the furnace through the pipe I,
and as the pipe I is divided in the apparatus shewn into two branch
pipes I and I¹ the stream of water is accordingly divided into two
streams by entering the pipe K, and thence flowing through small
pipes pinto each of the pipes I', where it is broken into numerous jets
by striking against discs o, o, attached to the nozzles of the pipes p, p, as
shewn.
Above each of the openings of the branch pipes I¹ in the ash box;
about half way between the orifice and the grate bars, is a metallic disc m
(preferably perforated) supported by a bar n set in the brickwork, as
shown, and which breaks up and evenly distributes below the grate the
current of air entering from the pipe in order that the fire may burn evenly
over all parts of the grate. This current of air brings with it and further
divides and distributes the jets of water thrown off from the disc o, and
the effect of the combined atmospheric air and water passing into the

page_text: coal which, where powdered anthracite is used, should be evenly spread
over the grate to the depth of from two to three inches, is to produce a
practically perfect combustion.
In practice the above described apparatus may be applied for. forcing
air and water into several furnaces in one room, using one blower and
one main pipe from the water tank, the blower being made to force air
into several pairs of branch pipes I', I', one pair for each furnace, and.
each of these pipes I¹ being provided with a pipe p for a water supply.
Good results have been obtained with draughts varying in force within
considerably wide limits, but the best results have been with a blower of
a size and speed to supply about one hundred and twenty-five cubic feet
of atmospheric air per minute to each square foot of grate. The nozzles
of the pipes p that have been used have had a diameter of one thirty-
second of an inch, the pressure being sufficient to break up the streams
of water against the discs o, and to load the air with as much or nearly
as much water mechanically subdivided as it will carry. There is a
cock e in the main pipe K to regulate the supply of water, but I
have also at times when the atmosphere has been dry admitted an
additional stream of water directly into the main blower pipe near the
fan, and it is obvious that the water may be supplied in any way which
will permit the air about to enter the fuel to take up sufficient water in
a mechanically divided condition; for instance, in locomotives and other
engines, where it is not convenient to supply water by its fall from a
tank, it may be forced into the air passage by a small pump, the water
being broken up by striking against discs on the nozzles of the discharge
pipes, and the air may be carried into the furnace by other contrivances
than the one described, provided the draught is made of the requisite
force. It is obvious also that where there is a large grate in the furnace
some device similar to the disc m should be employed to evenly dis-
tribute the air through all parts of the grate to keep the fire from a
burning in holes.
I am aware that steam in combination with air has heretofore been
passed through burning coal for the purpose of assisting in the combus-
tion and otherwise, and make no claim to such use of steam and air;
but there are objections attending the use of steam and air which do not
exist when water is used in the state of minute particles, one serious
objection being that steam takes up much more space than the water at
the expense of nure air.

page_text: An advantage attending the use of water mechanically subdivided and
introduced as I have described is, that the watery particles when they
strike the burning coals there burst into steam and break the coals open
by the force of the explosion, thereby multiplying the surface of the
fuel.
The apparatus shown in the Drawing is designed more especially for
promoting the combustion of powdered anthracite coal. Where buti-
minous coal is to be burned a blast of air must be introduced into the
fire chamber above and across the surface of the burning coal and
› regulated by a proper damper, so that fresh air may be supplied to ignite
and consume within the furnace gases and smoke which would other-
wise escape from such coals; and in burning soft coal I have found
that when the air supplied above the coal is loaded with water and sent
in across the coal from 12 to 18 inches above it by a blast an advantage
3 is gained nearly equal to the advantage resulting from feeding the firc
from below, as above described.
The apparatus required for introducing the auxiliary blast of air and
water is not shown, but is substantially like the apparatus shown below
the grate. The best effect however is obtained by introducing the blast
both sides of the furnace chamber, as distinguished from the front
and back.
upon
V and V¹ are regulating valves; they communicate respectively with
the ash box and fire chamber, and consist, as shown in Figures 4 and 5,
of a tube and a mica lid weighted, but the weight is important only as
attached to the ash box valve. The latter valve is so weighted that it is
forced outward when the blast is too strong, and the valve c can be
adjusted accordingly. Through the valve V' the condition of the fire
may be observed, and it can thus be determined whether the draught is
sufficient, and whether there is the proper supply of water.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim,-
First. The method of promoting the combustion of fuel in furnaces
by combining water in a mechanically divided state with a blast of air,
as above described.

page_text: Second. The combination with a furnace of the blast pipe I', water
pipe p, and distributing disc or discs, as above described and for the
purpose specified:
:>
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Nineteenth day of March, in
the year of our Lord One thousand eight hundred and seventy-
five
Witness,
HENRY JAMES NOONE.
WM. ROBT. LAKE. (L.S.)