Improvements in Furnaces.
Year: 1888

page_text: Improvements in Furnaces.
1 GEORGE FRANCIS GALLAGHER, of 118, Fulton Avenue, Rochester, in the County
of Monroe, in the State of New York, United States of America, Manufacturer, do
hereby declare the nature of my invention for IMPROVEMENTS IN FURNACES, 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 that class of furnaces which have for their object the entire
consumption of all the products of combustion and consists in certain improvements in
that special class in which the draft is downwards through the fuel and grate bars.
In the drawings,
Figure 1, is a vertical longitudinal section of the improved furnace shown in
connection with a boiler.
Figure 2, is a partial front view of the same, and
Figure 3, is a horizontal section taken in the line a, a, of figure 2.
Referring to the drawings,
a is the boiler, under the front end of which is located the furnace, of which 6 is the
fire-box, the ash-pit, and 6 the grate-bars. The bridge-wall cas will be seen, is
solid above the grate-bars thus closing in the fire-box at the rear and has an opening c¹
in its lower portion leading from the ash-pit.
d is the door of the fire box with damper d¹ and e e are the ash-pit doors with their
dampers e¹ e¹.
To the construction thus far described as a basis, and for which no novelty is
claimed it is proposed to add the improved features constituting the present invention
thus producing a most effective apparatus for the purpose described.
Accordingly, by preference, two chainbers or passages f and g are arranged above
the grate-bars, the higher chamber commencing at the front of the furnace on the
left hand side with the door f in the front wall of the furnace by which the draft
through this passage can be regulated.
This passage extends back along the side wall of the fire-box, thence across the rear
wall and forward along the other side wall with the opening leading in to the
fire-box at the front. A damper is placed in the door f. The other chamber or
passage commences at the door g' with damper 93 on the right hand side and
extends back just over the grate bars along the right hand side wall of the ash-pit ;
thence across the rear wall and forward along the other side wall with the opening g
(see figure 1) leading into the fire-box at the front.

page_text: In this connection it may be stated that while only two of these passages are
shown, the entire side and rear walls of the fire. box could be lined with a series
of them, or the passages could extend only along the side walls, in which event,
each separate chamber would have a return passage to conduct the air to the rear of
the fire-box and return it to the front to be discharged into the fire-box at that
point as in the construction shown in the drawing.
The operation of this improved furnace is substantially as follows:-
Without the chambers or passages fand g the draft would be admitted through the
door d¹ of the fire box and would pass down through the fuel and grate-bars into the
ash-pit and from thence through opening c² in its heated state through the flues of
the boiler. With the improved construction the door d and its damper dare closed
and the side doors f¹ and g¹ are opened which admits a current of air to the
chambers and g. This air becomes super-heated in its passage around the fire-box
and is discharged at the front and drawn in this condition down through the fuel
and grate-bars. Being super-heated as before stated it causes a complete con-
sumption of all the products of combustion thus effecting the purpose desired.
Knowledge is had of the use of the hollow grate-bars through which the draft is
conducted and also of a construction by means of which the draft is conducted up
through a chamber at the back of the fire-box and discharged into the same at that
point for its passage through the fuel and grate-bars in a downward direction; but in
the present improved construction the air is conducted to the rear of the fire-box and
returned and discharged into the same in a super-heated state at the front through
passages located in the fire-box above the grate-bars. In this manner the super-heated
air being discharged into the fire-box at its front causes an intensely heated and
uniform draft down through all parts of the fuel and grate-bars which results in a
much greater and more thorough consumption of the products of combustion than in
the furnaces now in use, where the draft passes down through the fuel and grate-bars.
This form of furnace is obviously adapted for other purposes than that of steam
generating. With this improved construction the super-heated air will necessarily
pass slowly through the furnace but will cause a correspondingly intenser heat in the
fire-box as the air already super-heated will be more or less confined thereby causing a
greater, but much slower combustion.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1-A furnace for steam generating and other purposes consisting essentially of a
fire-box with closed side and rear walls, an ash-pit with an opening for the discharge
of the products of combustion and air passages or chambers located in the fire-box
above the grate-bars and adapted to conduct air from the outside to the rear of the fire-
box and thence to the front of the same, where it is discharged in a superheated state
for its downward passage through the fuel and grate bars.
2-A furnace for steam generating and other purposes consisting of the fire-box b
with closed side and rear walls, the ash-pit b₁ with rear opening c¹, the grate-bars 6,2
and the chambers or passages fand g located above the grate-bars and passing in
opposite directions around the side and rear walls of the fire-box having openings in the
furnace front for the admission of air, and discharge openings and g² in the front
of the fire-box, all operating substantially as and for the purpose stated.
Dated this 16th day of October 1888