Improvements in the Furnaces of Steam-boilers.
Year: 1886

page_text: Date of Application, 10th June, 1886.
Complete Left, 8th Mar., 1887.
Complete Accepted, 7th Apr., 1887.
PROVISIONAL SPECIFICATION.
Improvements in the Furnaces of Steam-boilers.
We ROBERT CHAPMAN, of Exley Head, Keighley in the County of York, Black-
smith, and THOMAS LITTLE MURRAY of Ingrow near Keighley aforesaid, Mechanic, do
hereby declare the nature of our said invention for IMPROVEMENTS IN THE FURNACES
OF STEAM-BOILERS, to be as follows:-
This invention relates to novel and useful improvements in the furnaces of steam-
boilers, and its object is to admit the whole, or a portion, of the draft at the back of
the fire, thus causing the unconsumed gases to circulate in the fire-box; and also
causing the fuel at the back of the fire to burn with more energy, and therefore
develop a greater heat consequently the combustable gasses passing out of the fire-box
are in a large measure consumed and fuel thereby economised.
To carry out our invention we form an opening, or openings, under the fire-bars at
the back, and a corresponding opening, or openings, above the fire-bars; the said
opening, or openings, being in communication with each other the draft passes under
the fire-bars through such openings into the back of the fire. Suitable dampers may
be fitted to control the draft.
T1006
DRACUP & NOWELL,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Furnaces of Steam-boilers.
We ROBERT CHAPMAN, of Exley Head, Keighley in the County of York, Black-
smith, and THOMAS LITTLE MURRAY, of Ingrow near Keighley aforesaid, Mechanic
do hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to novel and useful improvements in the furnaces of steam-
boilers, particularly applicable to boilers in which a fire-brick bridge is employed at
the back of the furnace; and the object of the said invention is to admit the whole,
or a portion of the draft at the back of the fire, thus causing the unconsumed gases to
circulate in the fire-box, and the fuel at the back of the fire also burns with more
energy, consequently a greater heat is developed and the combustable gases passing
out of the fire-box are in a large measure consumed, thereby economising fuel and
preventing smoke.
To carry out our invention we construct the fire-brick bridge with an opening or
passage under the fire-bars, and corresponding openings or passages above the
fire-bars, the said openings above and below the fire-bars are in communication with
each other, and the draft or supply of air passes under the fire-bars through such
openings into the back of the fire or furnace.
In order to more particularly describe our invention reference is to be had to the
accompanying drawing forming a part of this specification in which similar letters of
reference indicate corresponding parts in all the figures.
Figure 1, represents a perspective elevation of a boiler, the plates at the side of
which are broken away, disclosing a section of the internal fire-box and flue provided
with a fire-brick bridge constructed in accordance with our invention. Figure 2, is a
transverse section of the fire-box showing a front view of the said bridge. Figure 3,
is a section of the same, the broken line 1, 2, in the former figure denoting the line of
section.
A passage or opening A, is formed in the bridge B, beneath the firebars C, the
bar 1, over the opening is provided to support the brickwork above. The said
opening communicates with the vertical passage E, which branches into the three a
openings F, above the firebars.
The draft or current of air is heated during its passage beneath the fire-bars C, in
which state it passes through the opening A, up the passage E, and out of the

page_text: openings F, into the furnace or fire-box G, and impinging against the back of the fire
circulates through the fire-box, thereby creating an intense heat at the back of such
fire-box which causes a more perfect combustion of the fuel and prevents smoke.
Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed we declare what we claim is:
In a steam boiler, the construction and arrangement of openings or passages in the
bridge of the furnace adapted to direct the draft or current of air to the back of the
fire, substantially as herein shown and described.