Improvements in Furnaces of Steam Boilers.
Year: 1895

page_text: Date of Application, 6th Sept., 1895
Complete Specification Left, 14th Apr.. 1896-Accepted, 2nd May, 1896
και οι αρμονιστή και θεμι, του
Complete Specification Left, 14th Apr.. 1896 Accepted. 2nd May. 1896
PROVISIONAL SPECIFICATION.
Improvements in Furnaces of Steam Boilers.
JOHN STEEL DIXON SHANKS, 42 Brougham Street, Belfast Mechanical
Engineer, THOMAS HARRISON, Craigwood House, Co. Down, Barrister-at-Law,
JOHN MACCORMAC, 91, King Street Belfast, Merchant, do hereby declare the
nature of this invention to be as follows :—
To provide a means in furnaces of steam boilers for the more complete
combustion of the fuel used, and to burn or consume the smoke and other volatile
matter produced by the combustion of the fuel, and we effect these objects by
means of the arrangements as follows. We employ a number of steam jets, one or
more being directed by nozzles underneath the fire bars, and one or more into a
pipe or trough of cast iron or other suitable material, and which pipe or trough
extends from the back or bridge end of furnace to any desired distance from the
frout, preferably to the middle fire-bar bearer. This pipe or trough opens into a
box of cast iron or other suitable material, which is built into the bridge of furnace
and extends the full length of same, and beyond two walls of fire brick or other
refractory material, built up behind the bridge and separated from each other a
distance of about nine inches. These walls have every alternate brick left out,
thus providing vents for the passage of gas from the fires.
The cast iron box has vents in its upper surface or lid placed in front of each of
the brick walls, and the end beyond the second wall has a moveable hinged door or
flap which can be opened or closed at will from the front of boiler by a rod
connected by a crank on end of door pivot and carried to front of boiler. The
pipe or trough before described is so placed that the upper portion is raised above
the surface of the fire bars for the purpose of heating the air which passes through
it and the before described cast iron box. The upper side of pipe or trough is so
arranged as to take a number of the ordinary fire bars to form a cover for same.
The under side of pipe or trough is so deep as to be well beneath the under side of
fire bars. The bottom of pipe has openings covered by moveable slides, so that
any cinders from the furnace getting into the pipe or trough may be dropped into
the ashpit. Resting on sides of bridge is an arch of fire clay blocks having a
space or chamber next furnace next furnace plate for the purpose of receiving a
current of steam and air supplied through the before mentioned pipe or trough.
This current when superheated, emerges from a series of holes at the back of
arch. We employ where intense combustion of the fuel is desired, a closed front
of metal to that part of furnace beneath the bars and having a hole at bottom of
same fitted with a pipe extending some distance into the ashpit and having on side
next fire-bars one or more vents, the end being open.
A strong jet of steam is projected into the month of this pipe producing a strong
volume of air and steam beneath the fire bars.
We use an automatic valve, connected with the steam supply to jet pipes, and so
arranged that when the fire door is fully opened, the valve is opened to its full
extent thus supplying the full strength of steam jets when fresh fuel is being
applied to furnaces.
The action of this combination is, First. The steam jets directed beneath the
fire bars urge the fires to a more speedy and complete combustion. Second. The
combined current of steam and air passes through the pipe and box before

page_text: described, and through the chamber in arch and impinges against the volume of
smoke and gases from the fires and against the large surface of highly heated
bricks of the arch and perforated walls before described. The result is, perfect
combustion of the gases and smoke.
D
1 .
1005
Improvements in Furnaces of Steam Boilers.
We, JOHN STEEL DIXON SHANKS, 42 Brougham Street, Belfast, Mechanical
Engineer, THOMAS HARRISON, Craigwood House, Co. Down, Barrister-at-Law,
JOHN MACCORMAC, 91 King Street, Belfast, Merchant, 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:-
To provide a means in furnaces of steam boilers for the more complete
combustion of the fuel used and to burn or consume the smoke and other volatile
matter produced by the combustion of the fuel, and we effect these objects by
means of the arrangements which we shall describe referring to the accompanying
drawings.
Fig. 1 is a longitudinal and Fig. 2 is a transverse section of parts of a boiler fire
and flue near the bridge.
Fig. 3 is a sectional plan on 3-3 the fire bars being removed.
Fig. 4 is a section of an automatic steam valve hereinafter referred to.
We employ a number of steam jets sonie as A, directed underneath the fire bars,
and one such as B, or it may be more, into a box C which is built into the
bridge D of the furnace and preferably has an extension C¹ terminating between
two walls E F of firebrick or other refractory material, built up behind the bridge
and separated from each other at a little distance. These walls E F have
alternate bricks left out to give passage for the combustion gases.
The box C has an upwardly inclined divergent passage terminating in a slit c or
it might be a number of holes, and the extension C, when such is used, has a
similar passage terminating with a slit or set of holes c¹ so that air drawn into C
through a perforated plate G by the injector action of the steam and heated in its
passage along the ash pit and through C and C¹, is directed in a thin stream or in
numerous separate streams among the combustion gases which pass over the bridge
so as to effect their more complete combustion.
Resting on the sides of the bridge D is a hollow arch H of fire clay forming a
space or chamber receiving a supply of air drawn through perforated plates K by
the injector action of steam jets. Currents of heated air mingled with steam
issue from slits or holes to mingle with the combustion gases.
We use an automatic valve shewn in Fig. 4 connected with the steam supply to
the jet pipes, and so arranged that when the fire door is fully opened, the valve is
opened to its full extent thus supplying the full strength of steam jets when fresh
fuel is being applied to the furnaces.
The valve V is formed at the end of a plunger which works through packing
and is connected by a lever L to a piston P which works in an oil cylinder and is
urged upwards by a spring S. Through the piston passes a hollow screw T which
can be adjusted so as to throttle more or less openings to the space above the
piston. On the fire door is fixed an inclined nose N, which, when the fire door is
opened to supply fresh fuel to the fire, presses down the piston P causing the oil
to pass from below it through holes in the piston covered by a valve X to the

page_text: space above it. By this movement the spring S is compressed and the valve V is
fully opened. When the fire door is closed the spring S expands raising the
piston P and closing the valve V, but this action takes place slowly as the passage
for the oil from above the piston to the space below is throttled by the screw T.
C
The action of the apparatus above described is as follows: First, the steam jets
directed beneath the fire bars urge the fire to a more speedy and complete
combustion. Secondly, the heated currents of steam and air issuing from c c and
impinge against and mingle with the smoke and combustion gases and these
acting in conjunction with the large surface of highly heated bricks of the arch H
and perforated walls E F cause complete combustion of the gases and prevent
evolution of smoke.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a boiler furnace the combination of a box under the bridge and a hollow
arch over the bridge, both provided with inlets and steam injectors and with
outlets for the heated mixture of steam and air among the combustion gases,
substantially as and for the purpose set forth.
2. In combination with the box and hollow arch above referred to a pair of
open work partitions in the flue and an extension of the box for delivery of heated
steam and air to the gases between the partitions, substantially as described.
3. In combination with the apparatus set forth in Claim 1 an automatic valve
operated by the fire door, substantially as and for the purpose set forth.
Dated this 14th day of April 1896.
ABEL & IMRAY,
Agents for the Applicants.