IMPROVEMENTS IN AND RELATING ΤΟ STEAM-BOILER AND FURNACES
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
OTHER
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN AND RELATING ΤΟ STEAM-BOILER AND
FURNACES." A communication from abroad by David Sinton; of Cincinnati,
Ohio, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the Commissioners of Patents on the 11th November 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN AND RELATING TO STEAM-
BOILER AND OTHER FURNACES." [A communication from abroad by David Sinton,
of Cincinnati, Ohio, United States of America.]
This Invention relates to improvements in and connected with steam, boiler or
other furnaces, and is of such a nature that I am thereby enabled to transform an
ordinary furnace into one that will cause such a complete combustion of the fuel as
to prevent the emission of smoke.
In order to accomplish the above result, it is necessary first to remove the grises
of the burning fuel from contact with the boiler for such a distance and in such a
manner that they will have their temperature elevated to a very high degree;
second, to introduce into these gases atmospheric air in such heated condition and
in such quantities and diffusion as will produce a perfect chemical combination
and combustion.
My said Invention is carried into practice as follows, that is to say :-
In the furnace at or near the rear end of the fire-chamber I construct a tunnel,
the arch of which reaches the boiler and descends in steps from front to rear. The
arch may have any number of descending steps, or it may be smooth.and inclined;
but I prefer the stepped arch, as herein stated. The upper portion of the arch
must encircle the boiler on both sides until it reaches its semi-horizontal diameter.
or closure. The grate-bars of the fire chamber may descend slightly from front to
rear, or they may be level, and they should be shorter than those ordinarily used,
and with no dead-plate in front. From the end of the grate-bars the base of the
tunnel is built solid, either gradually ascending or level, while its arch descends by
steps from front to rear, and thus the exit of the tunnel can be more or less con-
tracted, according as the requirements of each furnace may demand. Atmospheric

page_text: air is admitted through the fire-doors by merely opening and closing them from
time to time, and to such an extent as may be necessary. The fire-chamber under
the boiler should be large, with sufficient dimensions to provide for the proper
expansion of the heat and gases evolved from the tunnel, and to prevent any
injurious concentration of heat on the boiler a bridge-wall is dispensed with. In
case the flues in the boiler fail to properly arrest the too rapid transit of hent, an
arch should be constructed at the rear end of the boiler, leaving underneath only
such space as is necessary for this purpose, and consistent with the sufficient draft
of the furnace; but such arch is always beneficial under a cylindrical boiler.
While it is preferred to give the base of the tunnel or hearth a slight upward
inclination from the grate, on account of the more perfect action thereby secured,
the base may be made level, and good results secured thereby.
The arch forms the top of the tunnel, and is constructed partly over the fire-
chamber, and the remainder over the solid base of the tunnel, so that when there
are three steps, the front end of the centre step is immediately over the rear end of
the fire-chainber-grate.
After the first, and immediately preceding each subsequent firing, the incan-
descent coals on the grate should be pushed back into the tunnel, until it is nearly
filled.
To facilitate the removal of clinkers, the solid base of the tunnel should be kept
covered with ashes.
By these arrangements a constant supply of incandescent coals is maintained,
the diffusion and heat of the air and gases are amply provided for, and the draft of
the furnace is so improved that the strength of its current under the boiler is
sufficient to overcome all the checks and hindrances of the stepped arch, the
incandescent coals in the tunnel, the enlargement of the flue-chamber under the
boiler beyond the tunnel, and the further impediment of an arch under the rear
end of a boiler, as before stated, thus causing that slowness of current which is
essential to such chemical combinations of the air and gases as will produce perfect
combustion and economizo fuel. The result of this is that under all ordinary
circumstances of subsequent firings, including the opening of the fire-doors, no
smoke is emitted from the furnace.
By the admission of the atmospheric air, which is heavier than the hydrogen
and lighter than the carbonic oxide, through the door, it is caused to mingle with
them both, thus producing a compound of the three, which passes under the broken
or inclined arch, and through the incandescent coals. By the arch the compound
is caused to roll or curl upon itself, and the constituent elements are thereby
thoroughly mixed.
The heat here produced rises from about 300° to 1400° or 1500° Fahrenheit, and
causes a complete combustion of all the combustible gases, which takes place under
the rear end of the arch, and in a long flue or chamber beneath the boiler.
combustion is facilitated by the absence of the usual bridge-wall
This
The aforesaid arch at the rear end of the chamber or flue is designed to control
the flow of the gases or vapors through the chamber.
For the combustion of the smoke and gases, a heat of from 1400° to 1000°
Fahrenheit is required. The space on the boiler which is covered by the arch must
therefore be sufficiently long for the compound of gases passing through the
incandescent coal to attain the temperature named. The hearth or bottom of the
tunnel must be solid, so that no air can enter the bottom. The entire bottom of
the furnace, including the forward portion of the tunnel or chamber, or in other
words the hearth must be level, or substantially so, in order that the coals may be
pushed back reading from the grate. The gases after passing down through the
incandescent coal must find an exit, or an explosion will occur. A passage or
throat provided under the rear end of the arch is large enough for this purpose, and
the gases pass into the flue or passage under the boiler at a very bigh degree of
temperature, and in said flue the final combustion takes place.

page_text: 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
10th May 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. IMPROVEMENTS IN AND RELATING TO STEAM-
BOILER AND OTHER FURNACES." A communication from abroad by David Sinton,
of Cincinnati, Ohio, United States of America.
This Invention relates to improvements in and connected with steam boiler or
other furnaces, and is of such a nature that I am thereby enabled to transform an
ordinary furnace into one that will cause such a complete combustion of the fuel
as to prevent the emission of smoke.
In order to accomplish the above result, it is necessary first to remove the gases
of the burning fuel from contact with the boiler for such a distance and in such a
manner that they will have their temperature elevated to a very high degree; and,
secondly, to introduce into these gases atmospheric air in such a heated condition,
in such quantities, and so diffused as to produce a perfect chemical combination and
combustion.
My said Invention is carried into practice as follows, that is to say-In the
furnace at or near the rear end of the firo chamber I construct a tunnel, the arch of
which reaches the boiler and descends in steps from front to rear, as shewn in the
accompanying Drawing. The arch may have any number of descending steps, or
it may be smooth and inclined; but I prefer the stepped arch. The upper portion
of the arch must encircle the boiler on both sides until it reaches its horizontal
diameter or closure. The grate-bars of the fire chamber may descend slightly from
front to rear, or they may be level, and they should be shorter than those
ordinarily used, and with no dead-plate in front. From the end of the grate-bars
the base of the tunnel is built solid, either gradually ascending or level, while its
arch descends by steps from front to rear, and thus the exit of the tunnel can be
more or less contracted, according as the requirements of each furnace may demand.
Atmospheric air is admitted in graduated or regulated quantities through the fire-
doors by merely opening and closing them from time to time, and to such an extent
as may be necessary. The fire-chamber under the boiler should be large, and of
such dimensions as to provide for the proper expansion of the heat and gases evolved
from the tunnel, and to prevent any injurious concentration of heat on the boiler a
bridge wall is dispensed with. In case the flues in the boiler fail to properly arrest
the heat due to its too rapid passago through the same, an arch should be con-
structed at the rear end of the boiler, leaving underneath it only such space as is
necessary for this purpose, and consistent with the sufficient draught of the furnace;
but such arch is always beneficial under a cylindrical boiler.
In the accompanying Drawing,
Figure 1 is a vertical longitudinal section of my furnace and a portion of a
boiler, and
Figure 2 is a transverse section of the same.
Figure 3 is a vertical longitudinal section of the said furnace, shewing the rear
arch beneath the boiler.
A represents a portion of the boiler, and B the front arch. This arch B with
the three descending steps C, D, and E, forms the top of the tunnel, and is
constructed partly over the fire-chamber F, and the remainder over the solid base
of the tunnel, so that the front end of the step D is immediately over the rear end
of the fire-chamber grate, and the remainder of the arch B is over the solid base of
the tunnel; G is the ash-pit; H, the ash-pit door; I, the fire door; J, the grate;
and K, the tunnel; L is the arch at the rear of the boiler.
While it is preferred to give the base of the tunnel or hearth a slight upward

page_text: inclination from the grate, as shown in the Drawing, on account of the more perfect
action thereby secured, the base may be made level, and good results secured
thereby.
After the first, and immediately preceding each subsequent firing, the incandescent
coals on the grate should be pushed back into the tunnel until it is nearly
filled.
To facilitate the removal of clinkers the solid base of the tunnel should be kept
covered with ashes.
By these arrangements a constant supply of incandescent coals is maintained, the
diffusion and heating of the air and gases are amply provided for, and the draught
of the furnace is so improved that the strength of its current under the boiler is
sufficient to overcome all the checks and hindrances of the stepped arch, the
incandescent coals in the tunnel, the enlargement of the flue chamber under the
boiler beyond the tunnel, and the further impediment of an arch under the rear
end of the boiler, as above stated, thus causing that slowness of current which is
essential to effect such chemical combinations of the air and gases as will produce
perfect combustion and economize fuel. The result is that under all ordinary
circumstances of subsequent firings, including the opening of the fire doors, no smoke
is emitted from the furnace.
In operating the furnace the fire is built on the grate-bars, and after it is fairly
burning the incandescent coals are pushed back under the arch into the tunnel, as
shown, and fresh fuel is placed on the grate. The partial combustion which takes
place in the chamber F produces hydrogen gas and carbonic oxide gas. Hydrogen-
gas being very light rises to the top of the chamber, while the carbonic oxide being
very heavy remains in the bottom of the said chamber.
By the admission of atmospheric air, which is heavier than the hydrogen and
lighter than the carbonic oxide, through the door I, it is caused to mingle with
them both, thus producing a compound of the three, which passes under the stepped
or inclined arch and through the incandescent coals in the tunnel K. By means
of the arch the compound is caused to roll or curl upon itself, and the constituent
elements are thereby thoroughly mixed. The heat here produced rises from about
300° Fahrenheit to 1400° or 1500° Fahrenheit, and causes a complete combustion
of all of the combustible gases which takes place under the rear end of the arch and
in the long flue or chamber beneath the boiler. This combustion is facilitated by
the absence of the usual bridge wall.
The aforesaid arch L at the rear end of the chamber or flue is designed to
control the flow of the gases or vapors through the same.
For the combustion of the smoke and gases a heat of from 1400° to 1600° Fahrenheit
is required. The space on the bottom of the boiler which is covered by the arch
must therefore be sufficiently long for the compound of gases passing through the
incandescent coal to attain the temperature named. The hearth or bottom of the
tunnel must be solid, so that no air can enter the bottom. The entire bottom of
the furnace including the forward portion of the tunnel or chamber, or, in other
words, the hearth, must be level, or substantially so, in order that the coals may be
pushed back readily from the grate. The gases after passing down through the
incandescent coal must find an exit or an explosion would occur. The passage or
throat provided under the rear end of the arch is large enough for this purpose,
and the gases pass into the flue or passage under the boiler at a very bigb
degree of temperature, and in the said flue the final combustion takes place.
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 am aware that a descending arch located beneath the boiler in the fire-
chamber is not new; also that boiler furnaces have been constructed without
bridge-walls; also that air has been admitted to a furnace above the grate-bars;
but these features have not been combined and arranged in such a manner as to
produce a practical smoke-consuming furnace, and I claim,―
First. In a boiler-furnace the combination of a substantially horizontal grate, a

page_text: smooth ascending hearth or tunnel bottom extending upward from the rear end of
the said grate, as shown, and a downwardly-extending arch located immediately
beneath the boiler, partly above the rear end of the grate and partly over the
forward end of the hearth or tunnel bottom, as above set forth and for the purpose
specified.
Second. In a smoke-consuming boiler-furnace the combination of a substantially
horizontal grate, a backwardly extending tunnel having its bottom or hearth flush
with the rear end of the said grate, a downwardly-extending arch located beneath
the boiler above the rear end of the grato and the forward end of the tunnel-bottom
or hearth, and means for admitting air above the grate at the front of the furnace,
substantially as above set forth.
Third. The combination of the boiler, the fire chamber F, the inclined arch,
located as described, the grato J, the ash-pit G, and the flue M extended backward
beneath the boiler without having a bridge wall therein, as above set forth and
for the purposes specified.
Fourth. The combination of the boiler, the downwardly-inclined arch immediately
beneath the said boiler, the grate, the tunnel, having the smooth bottom in line with
the said grate, the passage or flue M, the arch L at the rear of the said passage or
flue, and means for admitting air in graduated quantities above the grate, all
substantially as above set forth and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Tenth day of May, in the year of our Lord One
thousand eight hundred and eighty one.