An Improved Arch for Promoting the Combustion in the Furnaces of Locomotives and the like.
Year: 1898

page_text: Date of Application, 23rd May. 1898-Accepted, 11th Feb., 1899
COMPLETE SPECIFICATION.
An Improved Arch for Promoting the Combustion in the Furnaces of
Locomotives and the like.
I, ALFRED FRANK HACK, of Greville Street, Prahran, in the Colony of Victoria,
Bricklayer, 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:-
:-
By the use of this invention, combustion is improved, smoke is prevented, sparks
are arrested, flames and gases entering the boiler tubes are cleaner (that is carry
less soot and impurity) dragging" of fire is reduced, and the fuel is therefore
used in a more economical manner than in using any arches of furnaces known to
me. In carrying out this invention a specially useful combustion chamber over
part of the fire bars, is produced next to the rear tube plate further details of which
will appear hereafter; and in locomotives particularly I find this chamber to be
nost advantageous.
I have shown the invention in the attached drawings and will describe it by
reference thereto. Figure 1 is a plan view of the arch in section on the line 4 4
in Figure 3, Figure 2 is an elevation of the back of the arch from within the furnace
or fire box, in section on line 5, 5 Figure 3. Figure 3 is a vertical middle section
transversely to Figure 2. The arch I use consists of two main parts, the upper-
most being substantially vertical, and resting on the lower which is substantially
oblique. The uppermost part shown by vertical wall A, with thickened base A¹
reaches the-top Y of the fire box, and occupies the central portion of the width
thereof, that is to say a clear passage B is left at each side of said upper part.
It is through these passages that all the flames and heated gases from the fire
beneath pass. The lower part of the arch is the bridge C concave below and convex
above, and extends obliquely from the rear end (opposite the furnace door X) to
the front end V. The said front end meets the wall of the fire box below the
bottom boiler tube Z in the case of a locomotive or like boiler. The bridge is sup-
ported by suitable means such as an iron bar D on each side resting on studs E
projecting from the side wall W of the fire-box. The bridge of the arch is thicker
preferably than the uppermost part A, the material used being firebrick, or like
refractory substance with thin fire clay joints. In the use of this invention, a
great part of the flame and gases will rise towards the aforesaid upper wall A,
but after nearing or striking the same they become diverted to the passages B.
Incidentally wall A becomes highly heated." Where any stay head as T is in the
way of the bricking, the latter is cut so as to receive the head, and allow the brick
to fit solidly against the fire box. With regard to the other details of this inven-
tion I locate the studs (in the case of a locomotive) so as to have the iron bars D
at such an inclination as to be in a line with a point usually a few inches above
the fire box door top. These carrier bricks which form the arched bridge are
placed on end and at each corner of the bridge front I provide holes F, for the
removal of dirt from the upper surface.
In order to support the lower part A¹ of the wall A I make one of the brick

page_text: courses G of longer bricks than the courses in front thereof, and usually provide
a supporting ring course G¹ at the rear of course G. These details G and G are
liable however to modifications.
It will be observed from Figure 3 that the whole front of the arched bridge
does not rest against the front of the firebox, but that only the upper part of the
front does so, leaving a fissure or space H, adjacent to the lower part of said front.
If this space were not left there would be acute angled corners to the bricks and
these acute angles would entail extra labor as they would soon break away and the
arch be injured accordingly. Variations in the details may be made without
departing from the scope of my claims as the precise arrangements of the bricks
and the form of the built up parts indicated may be departed from without affecting
the essentials namely a combustion chamber as J the entire width of the fire box
and then at its rear end having a central wall of less width rising to the roof, and
dividing the fire box into two combustion chambers, the frontal chamber J and
the rearward one I the communication of heated gases and flames to the former from
the latter being by way of the side passages or flues B.
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:
1. A fire box arch having an inclined arched bridge extending the full width
of the fire box, and supporting upon its rear end a central vertical wall of lesser
width, whereby two combustion chamber I, J are formed connected by passages
or flues B substantially as set forth.
2. A fire box arch having an inclined arched bridge extending the full width
of the fire box, a part only of the bridge front touching the tube plate and a space H
being left between the tube plate and the lower part of said bridge front sub-
.stantially as set forth.
3. In a fire box an upper combustion chamber, having as its base a bridge the
full width of the fire box, and having as its rear a central wall of less width
extending from the firebox top to the rear of the said bridge, so as to leave side
passages between the said combustion chamber and the chamber containing the
firebars substantially as set forth.
4. The combination of the several parts, C, D, E, F, and G with a wall A reaching
to the fire box roof substantially as set forth.
Dated this 23rd day of May 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.