Improvements in and in the Construction of Fire-bridges for Steam Generator and other Furnaces.
Year: 1899

page_text: Date of Application, 14th Sept., 1899
Complete Specification Left, 13th June, 1900-Accepted, 14th July, 1900
Improvements in and in the Construction of Fire-bridges for Steam
Generator and other Furnaces.
I, ERNEST RALPH OLDHAM, of 8, Shaw Road, Heaton Chapel, in the County of
Lancaster, Boilermaker, do hereby declare the nature of this invention to be as
follows:
-
My said invention relates to improvements in and in the construction of fire-
bridges for steam generator and other furnaces, and has for its object to provide
a bridge which can be readily secured in and removed from the furnace flue,
such removable bridge being also designed to act as a smoke consumer.
In carrying my invention into effect, instead of building up the bridge of the
flue from fire-brick as is usual, I provide a cast metal bridge which is of a semi-
circular formation viewed from the front. The top of this removable metallic
bridge extends backwards for a sufficient distance, a suitable chamber or air
heating box being formed below the top and behind the front of the bridge.
The front of the bridge is formed with one or more air inlets or apertures
through which the air enters to the chamber leaving the same by an outlet or
outlets formed in the top of the bridge. The top of the bridge carries a hollow
slope which constitutes an additional air heating chamber this slope being pre-
ferably formed separate from the bridge and arranged to rest thereon.
The said hollow slope is formed with an air outlet or outlets for the delivery up
of the air as will be understood.
To secure my improved bridge in the furnace flue I may bolt the same to
suitable brackets and I may form the front of the bridge with a perforated ledge
on which the end of the fire bars would rest.
When my improved bridge is put to work, air enters the bridge through the
aperture formed in the same below the level of the furnace bars, and passes up
wards to the hollow slope. In passing through the bridge and slope the air
becomes very highly heated, so that when it issues from the slope to mix with
the unconsumed products passing over the bridge, complete combustion is
set up.
A bridge such as I have described can be removed and replaced with the
utmost facility its use saving the time and labour expended in taking down and
erecting the ordinary brick bridge.
Doted this 13th day of September.

page_text: İmprovements in and in the Construction of Fire-bridges for Steam
Generator and other Furnaces.
I, ERNEST RALPH OLDHAM, of 8, Shaw Road, Heaton Chapel, in the County of
Lancaster, Boilermaker, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement and accompanying drawings:-
My said invention relates to improvements in and in the construction of fire-
bridges, for steam generator, and other furnaces, and has for its object, to pro-
vide a bridge which can be readily secured in or removed from, the furnace flue,
such removable bridge being also designed to act as a smoke consumer.
My said invention will be clearly understood from a perusal of the following
description, in which, reference is made to the annexed two sheets of illustrative
drawings.
In the said drawings.
On Sheet 1.
Fig. 1 shows a front view of a hollow movable fire bridge, constructed in
accordance with my invention, in position in a furnace fluc.
Fig. 2 is an end view of the bridge, together with a removable hollow
slope forming part of my improvements.
Fig. 3 is a plan of Fig. 1.
Fig. 4 shows the removable hollow slope in plan view.
Fig. 5 is an inverted plan view of Fig. 4.
On Sheet 2.
Fig. 6 is a sectional view showing the application of my improved bridge to
one of the flues of an ordinary Lancashire boiler.
In carrying my invention into effect, instead of building up the bridge of the
flue from fire-brick, as is usual, I provide a metallic bridge a which (when
applied to a cylindrical flue) is of semi-circular formation, viewed from the
front, as clearly shown in Fig. 1. This bridge a which is preferably so arranged
as to be readily removable is cast or otherwise formed from metal
The top 6 of the removable metallic bridge a extends backwards for a sufficient
distance, a suitable chamber or air heating box or space e, being formed below the
top, and behind the front of the bridge. Instead of a single chamber or space c,
two or more chambers may be formed, or the space c might be divided into two
or more compartments.
The front of the bridge is formed with one or more air inlets or apertures 7,
through which the air enters to the chamber c, leaving the same by an outlet
or outlets f, formed in the top of the bridge. The top of the bridge a carries
a hollow slope g, which is preferably formed separate from the bridge and
arranged to rest thercon.
The hollow slope g may be divided into two or more compartments g¹, g,
these compartments constituting additional air heating chambers for the air
passing upwards through the hollow bridge a, the air, in a highly heated state,
being delivered from the said slope through the outlets g³, g
In order to secure the slope in position on the hollow bridge the latter is
formed with ridges or projections a¹, a³, between which the slope bears, a set
screw a³ jambing and holding the slope when in position.
To regulate the air supply passing through the aperture d formed in the
bridge a, I may employ an adjustable ledge h, this ledge, if desired, also serving

page_text: to sustain the ends of the row of fire bars j adjoining the front of the bridge.
This adjustable ledge is clearly shown in Figs. 1 and 2.
In applying my improved smoke burner to a steam generator or furnace, the
hollow bridge is passed into the flue, and secured in position by means of set
screws or the like i, i, which bear against the plates of the flue, the hollow slope
being thereafter introduced, and arranged upon the bridge, whereupon the fire
bars may be fixed and the furnace is ready for work.
Any other suitable method of readily securing the fire bridge a in the furnace
flue may however be adopted.
When my improved bridge is at work, air enters the bridge a through the
aperture formed in the same, the air being drawn below the level of the
furnace bars, and passing upwards to the hollow slope (see Fig. 6). In passing
through the bridge and slope the air becomes very highly heated, this highly
heated air, on issuing from the slope, serving to promote combustion so that
dense smoke passing to the bridge is to a great extent consumed.
A bridge such as I have described can be removed and replaced, as required,
with the utmost facility, its use saving the time and labour expended in taking
down and erecting the ordinary brick bridge.
An important advantage, of my improved removable smoke burning bridge,
lies in the fact that its use entails no cutting of the shell or alterations of the
fittings or working conditions of the generator to which it is applied.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim, is:-
The improved movable fire-bridge, for steam generator and like furnaces,
consisting of a part. a formed with an air chamber or space, or it might be air
chambers, and provided with a slope such as g, and with or without means for
regulating or controlling the admission or delivery of air to or from the bridge,
substantially as herein described.
Dated this 19th dore of Tune 1000