IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES OR FIREPLACES
Year: 1879

page_text: LETTERS PATENT to James Thom Graham, of Glasgow, in the Counties of
Lanark and Renfrew, North Britain, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF FURNACES OR FIREPLACES."
Sealed the 27th December 1880, and dated the 7th October 1879.
PROVISIONAL SPECIFICATION left by the said James Thom Graham at the
Office of the Commissioners of Patents on the 7th October 1879.
JAMES THOM GRAHAM, of Glasgow, in the Counties of Lanark and Renfrew,
North Britain. IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES OR FIRE-
PLACES."
"
This Invention, which relates to improvements in furnaces or fireplaces, has for
its object to effect economy in fuel, burning of the smoke, and the gaseous
matters produced, thereby effecting a more perfect combustion of the fuel.
The Invention is applicable to furnaces and fireplaces generally, that is to say,
to furnaces for generating steam, for metallurgical, chemical, pottery, glass, and
other analogous furnaces, as well as for domestic fire-places, stoves, and cooking
ranges.
The improvements consist in constructing the fireplace or fuel chamber of the
furnace with an inclined or perpendicular set or sets of fire-bars forming the front
side or sides of the chamber or chambers in which the fuel is burnt. The lower
part of the chamber or chambers is also fitted with fire-bars in the ordinary
manner, and a portion or portions of the lower part of the vertical or inclined fire-
bars is or are made moveable independently of the other portions of such fire-bars,
thereby affording facility for the laying in, lighting, and pricking the fire until
it is sufficiently burnt up to admit of its igniting the cold or green fuel charged
above it in or at the upper part of the chamber, this upper part of the chamber
being fitted with one or more openings and doors for closing the same, which are
opened when the fuel is charged thereinto and afterwards shut down.
The essentially novel features in the furnace constituting this present Invention
are the making of the fuel chamber or chambers, or the upper part thereof, closed
in at the top, the providing of it (or them) with one, two, or more flues, whereby

page_text: the gases and other unburnt matter produced at or in the upper part of the
chamber or chambers are either led off and discharged into the burning fuel below
or into any other chamber or receptacle, wherein they are ignited and burnt.
The furnace is provided with a bridge having one or more tubes or flues passing
therethrough, thus forming additional communication between the fuel chamber
and the flue or combustion chamber. These tubes or openings have a damper for
the purpose of opening and closing them when required. The lower fire-bars are
of such a length as to admit of the spent hot ashes and clinkers being pushed off
them into the lower part of the combustion chamber or flue, wherein they remain
until their heat is exhausted in performing useful work in the furnace.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Thom Graham in the Great Seal Patent Office on the
3rd April 1880.
JAMES THOM GRAHAM, of Glasgow, in the Counties of Lanark and Renfrew,
North Britain. "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES OR FIRE-
PLACES."
My said Invention relates to improvements in furnaces or fire places, and has
for its object to burn the smoke and the gaseous matters produced, thereby
effecting a more perfect combustion and consequently economy of the fuel.
My said Invention is applicable to furnaces and fire places generally, that is to
say, to furnaces for generating steam, for metallurgical, chemical, pottery, glass,
and other analogous furnaces, as well as for domestic fire places, stoves, and cooking
ranges.
According to my Invention the fire place or fuel chamber of the furnace is
constructed with an inclined or perpendicular set or sets of fire bars forming the
front side or sides of the chamber or chambers in which the fuel is burnt, or forming
part of such front side. The lower part of the chamber or chambers is also fitted
with fire bars in the ordinary manner, and a portion or portions of the lower part
of the vertical front side or sides is or are made moveable independently of the
other portions of such fire bars, thereby affording facility for the laying in, lighting,
and pricking the fire until it is sufficiently burnt up to admit of its igniting the
cold or green fuel charged above it in or at the upper part of the chamber, this
upper part of the chamber being fitted with one or more openings and doors for
closing the same, which are opened when the fuel is charged thereinto, and after-
wards shut down.
The fuel chamber or chambers, or the upper part thereof, is or are closed in at
the top, and provided with one, two, or more flues opening from the upper part to
the lower part thereof, whereby the gases and other unburnt matter produced at
or in the upper part of the chamber or chambers are led off and discharged into
the burning fuel below.
The furnace is provided with a bridge having one or more tubes or flues passing
therethrough, thus forming additional communication between the fuel chamber
and the flue or combustion chamber. These tubes or openings have a damper for
the purpose of opening and closing them when required. The lower fire bars are
of such a length as to admit of the spent hot ashes and clinkers being pushed off
them into the lower part of the combustion chamber or flue, wherein they remain
until their heat is exhausted in performing useful work in the furnace.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to
the accompanying Drawings, and to the letters and figures marked thereon, that is
to say :-
Figure 1 represents in vertical section, and Figure 2 in front elevation partly
in section a boiler furnace constructed or arranged according to my Invention.
The furnace or fuel chamber A is constructed with its front side of fire bars B
resting upon bearers b, b. The lower part of the chamber is fitted with fire bars
C in the ordinary manner. The lower part of the front of the furnace is closed by
a casing D open to the lower part of the fire, and provided with a door d for
communicating with the fire place for laying in, lighting, or stirring the fire. The
upper part of the fuel chamber is closed, and thereat there are formed casings E
and a door e, the latter being for charging in green_fuel to the furnace when the
fire is started, and the casings E opening into flues F which lead into the casing D,
and consequently from the part of the fuel chamber containing the green fuel to

page_text: the part containing the incandescent fuel.
G is a hanging bridge having tubes or
flues g passing through it, the said flues g being provided each with a damper g².
The said bridge leaves a passage at g³ to the flue of the boiler.
The fire bars C are continued beyond the bridge G, and beyond them is a
chamber or pit H into which the spent ashes may be pushed from the said bars,
where they give off any heat which may still remain in them. They may be
removed by the doors h, h, which close the ashpit, or by a door at the side of the
said pit H.
In starting the fire the door at d is opened, and when the fire is sufficiently
strong to ignite green fuel fed above it by the door e the door d is closed, and
green fuel is fed in by the door e. The smoke and gaseous products of combustion
from the green fuel then pass down the flues F, as shewn by the arrows in
Figure 1, and are discharged into the burning fuel below, by which they are
burnt. The heat from the fire passes by the passage at g³ and by the openings g.
the dampers of which latter may be opened or closed to regulate the draught by
means of a handle g*. A door or flap i may be provided to cover the bars B when
desired. This flap i is shewn in Figure 1. It will be evident without further
illustration that my Invention may be applied to furnaces and fireplaces generally,
the said furnaces or fireplaces being closed at top and provided with flues for
conducting the gases and unburnt matter produced by the green fuel being led off
and discharged into the live fuel beneath.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the system, mode, or manner in or under which the same is or may be
used or practically carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the herein before in part recited Letters Patent is,―
The hereinbefore described improvements in the construction of furnaces or
fire places, that is to say, constructing such furnaces or fireplaces with a fuel
chamber closed at top and provided with means for conducting the gases or
unburnt matter from the green fuel to the burning fuel below, essentially as
herein before described and illustrated in the accompanying Drawing.
In witness whereof, I, the said James Thom Graham, have hereunto set my
hand and seal, this Twenty fifth day of March, in the year of our Lord
One thousand eight hundred and eiglity.
JAMES THOM GRAHAM. (L.S.)