IMPROVEMENTS IN APPARATUS OR MEANS FOR IMPROVING AND SUPPORTING COMBUSTION, APPLICABLE TO STEAM BOILER FURNACES." AND SUPPORTING COMBUSTION, APPLICABLE TO STEAM BOILER FURNACES."
Year: 1871

page_text: LETTERS PATENT to Henry Edward Mines, of Cheltenham, in the
County of Gloucester, Engineer, and Philip Charles Evans, of
Brimscombe, in the same County, Cloth Manufacturer, for the
Invention of "IMPROVEMENTS IN APPARATUS OR MEANS FOR IMPROVING
AND SUPPORTING COMBUSTION, APPLICABLE TO STEAM BOILER FURNACES."
AND SUPPORTING COMBUSTION, APPLICABLE TO STEAM BOILER FURNACES."
PROVISIONAL SPECIFICATION left by the said Henry Edward Mines
and Philip Charles Evans at the Office of the Commissioners of
Patents, with their Petition, on the 15th February 1871.
We, HENRY EDWARD MINES, of Cheltenham, in the County of
Gloucester, Engineer, and PHILIP CHARLES EVANS, of Brimscombe, in
the same County, Cloth Manufacturer, do hereby declare the nature of
our said Invention for "IMPROVEMENTS IN APPARATUS OR MEANS FOR IM-
PROVING AND SUPPORTING COMBUSTION, APPLICABLE TO STEAM BOILER FURNACES,"
to be as follows:-
:-
This Invention relates to a peculiar arrangement for supplying heated
air to the fires of steam boiler furnaces, whereby economy of fuel and

page_text: prevention of smoke are effected. For this purpose an air supplying
iron pipe or tube is placed in the upper part of one of two lateral outside
flues so as to form the arch or top thereof, which top has hitherto been
made of solid brickwork, the air entering such tube from the front end
of the boiler. This tube communicates with a cast iron hot air chamber
at the back of the boiler, and the air entering therein becomes highly
heated; this hot air then passes off through another tube similar to the
first, situate in the upper part of the opposite outside flue and com-
municating with the ash-pit. The cast iron hot air chamber should be
of a length equal to about the diameter of the boiler, and sufficiently
high to reach from the level of the bottom of the boiler to the top of
the centre flues of the boiler. The upper part of the hot air chamber is
to be of an arched form, and bear against the end of the boiler, thereby
forming the arch usually composed of brickwork for directing the flames
from the internal flue or flues into the bottom or side flues. A hinged
trapdoor is formed in the back part of the dead plate nearest the fire-
bars for the admission of air into the front of the furnace from the
ash-pit, the said trapdoor being made to close down when the fire-door
is opened and to open slightly when the fire-door is closed by means
of a lever attached to the dead plate, and worked from the fire-door
itself. By this arrangement the heated air before referred to may be
supplied to the front of the furnace, or that end of the fire-bars nearest
the fire-door, the ash-pit being closed in front or provided with valves
to admit more or less cold air as may be found desirable.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Henry Edward Mines and Philip Charles Evans in
the Great Seal Patent Office on the 15th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
EDWARD MINES, of Cheltenham, in the County of Gloucester, Engineer,
and PHILIP CHARLES EVANS, of Brimscome, in the same County, Cloth 3
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of February, in the year
of our Lord One thousand eight hundred and seventy-one, in the 34th
year of Her reign, did, for Herself, Her heirs and successors, give and a

page_text: grant unto us, the said Henry Edward Mines and Philip Charles Evans,
Her special license that we, the said Henry Edward Mines and Philip
Charles Evans, our executors, administrators, and assigns, or such others
as we, the said Henry Edward Mines and Philip Charles Evans, our
executors, administrators, or 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 "IMPROVEMENTS
IN APPARATUS OR MEANS FOR IMPROVING AND SUPPORTING COMBUSTION, APPLICABLE
TO STEAM BOILER FURNACES," upon the condition (amongst others) that we,
the said Henry Edward Mines and Philip Charles Evans, our executors
or administrators, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, 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 we, the said Henry Edward Mines and Philip
Charles Evans, do hereby declare the nature of our 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 accompanying Drawings and to the letters and figures
marked thereon, (that is to say) :-
Our said Invention relates to a peculiar arrangement for supplying
heated air to the fires of steam boiler furnaces, whereby economy of fuel
and prevention of smoke are effected. For this purpose an air supplying
iron pipe or tube is placed in the upper part of one of two lateral outside
flues so as to form the arch or top thereof, which top has hitherto been
made of solid brickwork, the air entering such tube from the front end
of the boiler. This tube communicates with a cast iron hot air chamber
at the back of the boiler, and the air entering therein becomes highly
heated; this hot air then passes off through another tube similar to the
first, situate in the same position of the opposite outside flue and com-
municating with the ash-pit. The cast-iron hot-air chamber should be of
a length equal to about the diameter of the boiler and sufficiently high
to reach from the level of the bottom of the boiler to the top of the
internal or centre flues of the boiler. The upper part of the hot air

page_text: chamber is to be of an arched form and bear against the end of the
boiler, thereby forming the arch usually composed of brickwork for
directing the flames from the internal flue or flues into the bottom or
side flues. A hinged trapdoor is formed in the back part of the dead plate
nearest the fire-bars for the admission of air into the front of the furnace
from the ash-pit, the said trapdoor being made to close down when the
fire-door is opened and to open slightly when the fire-door is closed by
means of a lever attached to the dead plate and worked from the fire-
door itself. By this arrangement the heated air before referred to may
be supplied to the front of the furnace, or that end of the fire-bars
nearest the fire-door, the ash-pit being closed in front or provided with
valves to admit more or less cold air as may be found desirable.
And in order that our said Invention may be fully understood we shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawing,
the same letters of reference indicating corresponding parts in all the
Figures.
Figure 1 of our Drawings represents a side elevation of a Cornish
boiler fitted with our improved arrangements for supplying the furnaces
with hot air. Figure 2 is a plan of the air tubes and hot air chamber
detached from the boiler. Figure 3 is an elevation of the front end
of the boiler shewing the communication of the air pipes with the ash-
pits. Figure 4 is a transverse vertical section of the boiler, air pipes,
and side flues. Figure 5 is a detached elevation of one half of the hot
air chamber, and Figure 6 is an enlarged sectional view of the hinged
trapdoor in the dead plate and mode of working the same.
The fire front, ash-pit, lid, and all other parts are so constructed
that no air can enter to supply the fire other than in the manner
which we shall now proceed more particularly to describe. The air
tubes A, A¹, are by preference (as applied to horizontal boilers) made
of such a form as shall best expose the largest external area to the
face of the heated gases circulating in the flues, and also form an arch
for the top of the flues B, B', on which the superincumbent materials
may rest, thus saving brickwork. The atmospheric air enters at a large
mouth piece near the boiler front and thence passes along the tube A,
which runs parallel to the boiler directly above and forming the top
of the flue B until attaining the opposite end of the boiler, here the
tube A discharges the air into a large rectangular hot air chamber C

page_text: placed directly opposite the boiler tube or tubes (or in an egg ended
boiler opposite the centre flue) that is, in such a position that the flames
and gases from the furnace may impinge directly against the front
plate forming one side of this end chamber which is made as wide as
the tubes or flues of the boiler. The front plate of this chamber should
be so made as to be readily removed where burnt out. This chamber,
which may if desired be made of clay, is subdivided by plates a which
cause the air to circulate back and forwards in the chamber, each
passage connecting such sub-chamber being of equal area to the cross
section of the side air tubes A, A¹. This end chamber C is arch
shaped at the top, thus avoiding the necessity for brickwork and
forming a passage for the gases to enter the under or side flues B, B¹.
On leaving the end chamber C the air returns on the opposite side of
the boiler by the air tube A³, until it again reaches the front of tho
boiler, whence it is conveyed preferably by circular pipes to a pipe D,
running horizontally at right angles to the boiler, and for convenience
below the ground line; from this pipe D two discharge nozzles E, E,
entering for convenience through the ash-pit door, deliver the heated
air under the dead plate, which is close to the fire-grate. If desired
an extra pipe with expanded mouth at the back end of the boiler may
be laid under the arch shaped side tube, or along the top of the boiler,
whereby increased heat may be obtained. This dead plate, as shewn in
Figure 6, is provided with a lid or hinged trapdoor F which the
fire-door when shut causes (through the action of the rod G and
lever H) to open, thus effecting an entrance for the heated air to the
fire. When the fire-door is opened the lid F in the dead plate closes,
allowing a clear space for charging the fire or withdrawing clinkers.
The discharge nozzles E are mounted on hinges I, I, in such a manner
that the ashes can be easily cleared from the ash-pit when the nozzles
are turned back, as shewn in dotted lines in Figure 1, but if preferred
the pipes communicating with the nozzles E may be made to descend
from above the firc-doors in lieu of being connected with a pipe D sunk
below the ground, as shewn in the Drawings, in this case the hinging of
the nozzles will be obviated, as no obstruction to the removal of the
ashes will be presented.
Having now described and particularly ascertained the nature of our
said Invention, and the manner in which the same is or may be used or
carried into effect, we would observe in conclusion that what we consider

page_text: to be novel and original, and therefore claim as the Invention secured
to us by the herein-before in part recited Letters Patent is,—
First. The peculiar combination of air pipes A, A¹, hot air chamber C,
and nozzles E for supplying hot air to the furnaces of steam generators,
as herein-before described and illustrated by our Drawings.
Second. The so constructing and placing the air pipes A, A¹, as that
they shall constitute or form the tops of the flues, as herein-before
described and illustrated by our Drawings.
5
Third. The application and use of the trapdoor or lid in the dead
plate opened and closed by the fire-door, substantially as and for the 1
purpose herein-before described and illustrated by our Drawings.
In witness whereof, I, the said Philip Charles Evans, on behalf of
myself and of the said Henry Edward Mines, have to this our
Specification, set my hand and seal, this Twelfth day of August
One thousand eight hundred and seventy-one.
PHILIP CHARLES EVANS. (L.S.)