IMPROVEMENTS IN HEATING STOVES OR FURNACES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Maurice Chapman Hull at the
Office of the Commissioners of Patents, with his Petition, on the
21st April 1870..
I, MAURICE CHAPMAN HULL, of the City and State of New York,
United States of America, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN HEATING STOVES OR FURNACES," to be as.
follows:-
:-
My stove or furnace is adapted especially to burning bituminous coal,.
and the improvement is available either in a stove to stand in a room or in
a furnace to be set in brickwork to heat air passing between the brickwork
and such furnace and led off by pipes into the parts of the building.
to be warmed. I make use of an ordinary metal fire pot with grate bars..
The upper part of this pot is enlarged by a ring-shaped flange, above.
which is a conical ring, and the air space between the two opens by.
jets to the fire to supply air above the fuel, and by an opening with
or without a slide or damper to the external air to regulate the draught
admitted. The combustion chamber is above the fire and formed by
a casing that usually is larger than the fire pot. Within this combustion
chamber are smoke flue pipes that are open at their upper ends and
connect at their lower ends with a horizontal flue that runs partially
around the combustion chamber or fire pot, so that the products of

page_text: combustion passing from the fire up into the combustion chamber have
to descend through these pipes before going off by the horizontal flue
to the chimney. These smoke flue pipes in the combustion chamber
are more or less numerous, and may be perpendicular, or of a compound
rising, curved, or ram's horn shape, discharging into a flue leading to
the chimney, and a damper is provided near the chimney pipe to allow.a
direct draft in kindling the fire. The draught if too strong can be checked
by a slide to admit cold air into the chimney pipe. This stove when
made of a size suitable for a hot air furnace for setting in brickwork
or surrounding with a metal case is to be provided with air pipes
running vertically or nearly so through the combustion chamber, and
passing through the flange around the fire pot and through the top
plate of the combustion or radiating chamber, so that the air to be
heated circulates freely through these as well as around the fire pot
and exterior of the combustion chamber. A hopper or magazine to
contain coal may be provided above the fire to feed the fire as the coal
is consumed.
The combustion chamber in some stoves can be made cylindrical
or else with a central dome having a flange with and below which the
air pipes before-named are cast, and the smoke flues in that case will
rise in the outer portion of the combustion chamber, the same being of a
cylindrical shape.
. . .
In stoves there are often doors or frames containing mica and forming
windows; the mica becomes smoky and black, especially from kindling and
when soft coal is employed. One feature of my Invention is the protection
of the mica from discoloration, and consists in a finely perforated metal
plate or septum between the mica and the fire, leaving a space between
the mica and the perforated plate for air, and into this space the external
atmosphere is admitted through small openings from a hollow space
or tube made in the door or frame that carries the mica, and this pipe
has an external opening as well as the jet holes, so that the air becomes
warmed in passing through the metal frame, and by passing into the
fire from the air space behind the mica carries the smoke entirely away
from the mica.