IMPROVEMENTS IN FURNACES APPLICABLE TO MARINE AND OTHER STEAM BOILERS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I JOSEPH SAWYER of 63 Alma Street, New North Road in the County of
Middlesex, Engineer do hereby declare the nature of my Invention for
IMPROVEMENTS IN FURNACES APPLICABLE TO MARINE AND OTHER STEAM BOILERS
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 Furnaces for Marine and other Steam boilers and has
for its object to supply a given quantity of atmospheric air in order to obtain the
necessary amount of oxygen to secure perfect or nearly perfect combustion.
In carrying out my Invention I fix a cast iron bottom dead plate which projects
about 9 inches outside or beyond the front of the boiler, and above this I fix a
top dead plate leaving a space of from 3 to 5 inches between the top and bottom
dead plates. These dead plates are bolted or rivetted to the front of the boiler
The furnace bars may be of wrought or cast iron. The front ends of the bars rest
on the lower dead plate, and the back ends of the bars rest on a plate which is cut
away to allow the air to enter and is bolted to the upright plate at the back of the
furnace. Another plate projects from the bridge a few inches, over the ends of the
bars and the space thus obtained between the fire bar ends and the top plate above
it allows a certain quantity of beated air to enter the furnace and combine with
the carbonic exide at or near the bridge in order to render the combustion more
complete. The upper surfaces of the fire bars are notched at intervals of a few
inches with angular curved or rectangular notches. The front ends of the bars are
arranged and fitted in such a manner that.
1 Every alternate bar is fixed and the intermediate bars moveable longitudinally.
2ndly Every alternate bar is moveable in one direction longitudinally and the
intermediate bars are moveable in an opposite direction longitudinally.
3rd Every bar is independently moveable in either direction longitudinally, by
means of a separate appliance. And in order that my said Invention may be
clearly understood reference is hereby made to the accompanying drawings, in
which similar letters of reference indicate corresponding parts in the several
figures.
a is the furnace,
Fig. 1 is a sectional elevation of a portion of a marine boiler.
b the fire bars, c the bridge d d the centres on which the bell crank levers work,

page_text: The bars bare moved by means of the levers k to and fro', but are not caused to
rise & fall. The levers are moved by manual power at suitable intervals. The
motion of the bars, with the assistance of the notches 6' 6' formed in the upper
surface, effectually causes the removal of all clinkers & scoria, by the shearing
action of the bars, which completely break up any obstruction arising between
the bars.
Fig. 2 is a front view of a portion of a marine boiler with one of the furnaces
fitted with my improvements.
I sometimes fit every bar with a separate & independent lever, in order that the
stoker may, at suitable intervals, move the bars in succession; whereby the bars
are kept free for the passage of the air,
The passage is provided to allow a certain quantity of air to enter & become
heated, & on its entry into the furnace at f¹ it mixes with the products of combus-
tion & supplies the necessary oxygen to any carbonic oxide which may be passing
to the flue, and completes its combustion.
A door g is fitted in front of the two dead plates. A number of feathers or
division plates g₁ are provided, suspended from, & fitted to, or cast with, the
upper dead plate; between which streams of heated air g' are passed when smoke
is seen to arise from the fuel. The amount of air is controlled by the door g. I
also place an air valve h in the fire door to admit a small quantity of air above
the fuel, when fresh fuel has been supplied.
It will be seen that 'my improvements comprise & provide for four sources of
air supply; 1 through the bars, 2ndly at the back end of the bars next to the
bridge, 3 through the door g & passages g³, & 4thly through the ordinary door
valve h.
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. The formation of fire bars with angular curved, or rectangular notches for the
purpose of shearing and breaking up the clinkers and scoria, substantially as herein-
before described and shewn on the drawings.
: 2. The method and means of moving the fire bars longitudinally for the purpose
of utilising the notched bars in removing clinkers, and scoria, substantially as
herein before described and shewn on the drawings.
3. The method and means of admitting air at each end of the fire.bars by the
passage and door g substantially as herein before described and shewn on the
drawings.
4. The combination of the several and respective parts together forming my
improvements in furnaces applicable to marine and other steam boilers, herein
before described and shewn on the drawing, or any mere modification thereof.
Dated K L 1001