Improvements in Furnace Shells, Flues, and Mechanical Stoking Apparatus for Steam Boilers.
Year: 1893

page_text: Date of Application, 13th Mar., 1893
Complete Specification Left, 12th Dec., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Furnace Shells, Flues, and Mechanical Stoking
Apparatus for Steam Boilers.
I, GEORGE SINCLAIR, of Albion Boiler Works, Leith, in the County of
Mid Lothian, North Britain, Boiler Maker, do hereby declare the nature of this
invention to be as follows, that is to say :-
My said invention has for its object to improve the construction of furnace shells
and flues of steam boilers, and of mechanical stoking apparatus therefor.
My improvements in the furnace shells or flues are applicable whether these parts
are made without or with encircling corrugations, I however prefer to make them
with a few corrugations with plain cylindrical parts between, and with the bottom
parts of the furnace shells or flues uncorrugated. For the purpose of making
satisfactory joints between the ends of the furnace shells and flues and the end plates
or the tube plates of the boilers, and in order to render the application of
strengthening rings unnecessary, I have the plates of which I form the furnace
shells or flues rolled with an increased thickness at the edge or edges and for a
suitable distance inwards from the edge or edges. The thickened border thus
formed may be tapered from the outer edge inwards, or it may be formed of a
uniform increased thickness for some distance inwards. When a furnace shell or
flue is formed out of the improved plates, and the thickened border is flanged
out, an extremely strong joint can be formed with it without any additional ring, or
covering plate.
In my improved mechanical stoking apparatus a hopper for the fuel is, as usual,
fixed above the outside of the furnace front. Below the hopper, there is a middle
door giving access to the interior of the furnace, and at the sides of this door there
are spaces in which pushing boxes are arranged to move inwards and outwards to
push inwards into the furnace fuel which drops from the hopper when they move
outwards. The pushing boxes are moved by levers extending up within the boxes
from below, the extent of movement imparted being regulated by adjusting screws
in the fronts of the boxes. The levers have their lower parts like forks and they
rest on fulcrum pins from which they can be easily lifted whenever it may be wished
to remove the pushing boxes. The lower ends of the levers are actuated from
mechanism which also gives a reciprocating motion to the fire bars, this mechanism
consisting of a rotating crank shaft driven in any convenient way, and carried across
the front of the furnace in suitable bearings. The front ends of the fire bars are
connected to a transverse front bearer or bar which receives motion from the crank
shaft by means of two connecting rods, the connections being adjustable to allow of
the extent of the movement imparted being regulated. The connecting rods may
be jointed to eye bolts which are adjustable in the front bearer by means of screw
nuts; or the connecting rods may pass through holes in the front bearer and have
adjustable screw nuts on their inner ends and ferrules and screw nuts on them on
the outside of the bearer. Every alternate fire bar has imparted to it a shorter
movement than that of the other bars, being moved by means of a projection on its
under side acted on by a channel-shaped bar moving with the front bar, and the
channel of which is wider than the projections of the bars. The inner ends of the
fire bars are supported on a transverse bearer resting on brackets fixed to the sides
of the furnace.
The levers which work the pushing boxes are acted on by pins fixed in the
connecting rods which work the fire bars. The middle door is hinged at its bottom

page_text: and can be opened outwards; and then by withdrawing a slide at the bottom of the
hopper, fuel may be allowed to drop on the inner side of the door to be pushed into
the furnace by hand by means of a rake or other instrument, when it is wished to
supply more fuel to the furnace, than what is being supplied mechanically. Further
for the purpose of stoking by hand, the pushing boxes may be removed, and slides
at the bottom of the hopper may be adjusted to allow fuel to drop into the pusher-
box spaces to be fed in by means of a rake or other instrument.
For the purpose of supplying air in a more or less heated state above the fire
bars a cast iron plate is provided on the inner side of the furnace front and over the
upper part of the furnace mouth, this plate being perforated and the interior being
occupied by perforated or grooved firebrick pieces, and provision being made for
the entrance of air above the plate above the middle door.
Dated this Eleventh day of March 1893.
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Furnace Shells, Flues, and Mechanical Stoking
Apparatus for Steam Boilers.
I, GEORGE SINCLAIR, of Albion Boiler Works, Leith, in the County of
Mid Lothian, North Britain, Boiler Maker, 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, that is to say :-
My said invention has for its object to improve the construction of furnace shells
and Hues of steam boilers, and of mechanical stoking apparatus therefor.
My improvements in the furnace shells or flues are applicable whether these parts
are made without or with encircling corrugations, I however prefer to make them
with a few corrugations with plain cylindrical parts between, and with the bottom
parts of the furnace shells or flues uncorrugated. One improvement consists in
haring the plates, of which I form the furnace shells or flues, rolled with an
increased thickness at the edge or edges, and for a suitable distance inwards from
the edge or edges where the joint is formed with the tube plate or end plate.
The invention also comprises improved mechanical stoking apparatus in which a
hopper for the fuel is, as usual, fixed above the outside of the furnace front.
Below the hopper there is a middle door giving access to the interior of the furnace
and at the sides of this door there are spaces in which pushing boxes are arranged
to move inwards and outwards to push inwards into the furnace fuel which drops
from the hopper when they move outwards the hopper being fitted with slides to
regulate the amount of dropping coal. The pushing boxes are actuated by
mechanisin hereinafter described. The front ends of alternate fire bars are
connected to a transverse front bearer or bar with is actuated by mechanism to give
a reciprocating motion to these bars, and a similar but shorter movement is given
to the other bars. For the purpose of supplying air in a more or less heated state
above the fire bars a castiron plate is provided on the inner side of the furnace
front and over the upper part of the furnace mouth this plate being perforated
and the interior being occupied by perforated or grooved firebrick pieces, and
provision being made for the entrance of air above the plate abvoe the
middle door.
And in order that my said invention and the manner of performing the same
may be properly understood I bereunto append two sheets of explanatory drawings,
to be hereinafter referred to, and showing parts, sufficient for explanation, of steam
boilers as made or fitted with my improvements.
Figure, 1, on Sheet, 1, of the drawings is a longitudinal vertical section of a
part of a boiler made with my improvements.

page_text: Figures, 2, and, 3, are enlarged views of one modification of my improved joints,
Figures, 4, and, 5, being similar views of a second modification.
Figure, 6, on Sheet, 2, is an end elevation of a boiler fitted with my improved
mechanical stoker, the stoker being shown partly in section. Figure, 7, is a
vertical section as at right angles to Figure, 6.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
In carrying out my invention I prefer, as shown in Figure, 1, on Sheet, 1, of the
drawings, to make the furnace shell or flue, A, of the boiler with a few corru-
gations, A 1, with plain cylindrical parts, A 2, between, and with the bottom part
uncorrugated. For the purpose of making satisfactory joints between the ends
of the furnace shell A, and the end plate, B, or the tube plate (not shown) of
the boiler, and in order to render the application of strengthening rings unnecessary,
I bave the plates of which 1 form the furnace shell, rolled with an increased thick-
ness at the edge, and for a suitable distance inwards from the edge. The thickened
border, thus formed, may be tapered from the outer edge inwards as shown in
Figures, 2, and, 3, or it may be formed of a uniform increased thickness for some
distance inwards as shown in Figures, 4, and, 5. When a furnace shell, A, is formed
out of the improved plates, and the thickened border is flanged out an extremely
strong joint can be formed with it without any additional ring or covering plate.
In Figure, 6, and, 7, ou Sheet, 4, of the drawings showing my improved
mechanical stoking apparatus, a hopper, C, for the fuel is, as usual, fixed above
the outside of each furnace front, A 3. Below the hopper, C, there is a middle
door, D, giving access to the interior of the furnace and at the sides of this door
there are spaces in which pushing boxes, E, are arranged to move inwards and
outwards to push inwards into the furnace fuel which drops from the hopper when
they move outwards. The pushing boxes, E, are moved by levers, E 1, extending
up within the boxes from below, the levers being actuated to strike transverse
rollers or rods, E 2, fixed near the backs of the boxes and to strike screws, E 3,
fixed (opposite to the rods) in the fronts of the boxes, the extent of the movement
imparted to the boxes being regulated by adjusting the said screws.
levers E 1, have their lower parts like forks and they rest on fulcrum pins, F, in
brackets, F 1, fixed to the bottom of the boxes, E, from which they can be easily
lifted whenever it may be wished to remove the pushing boxes. The lower ends of
the levers, E 1, are actuated from mechanism which also gives a reciprocating
motion to the fire bars, G, this mechanism consisting of a rotating crank shaft, H,
driven by a ratchet, H 1, and ratchet wheel, H 2, on the end of the shaft which is
carried across the front, A 3, of the furnace in suitable bearings, H 3. The front
ends of alternate fire bars, G, are connected to a transverse front bearer or bar, G 1,
which has its end rollers, G 2, running on guides and receives motion from the
crank shaft, H, by means of two connecting rods, J, jointed to eye bolts, J 1, which
are adjustable in the front bearer, G 1, by means of screw nuts, J2; or the con-
necting rods, J, might pass through holes in the front bearer, G 1, and have
adjustable screw nuts on their inner ends and ferrules and screw nuts on them at
the outside of the bearer. Every alternate fire bar, G3, has imparted to it a
shorter movement than that of the other bars, G, being moved by means of a pro-
jection, G 4, on its under side acted on by a transverse channel-shaped bar, G 5,
fixed to the other bar, G. The inner ends of the fire bars, G, and G 3, are
supported on a transverse bearer, K.
The
The levers, E 1, which work the pushing boxes E, are acted on by pins, L, fixed
in the connecting rods, J, which work the fire bars. The middle door, D, is hinged
at its bottom and can be opened outwards; and then by withdrawing a slide, M, at
the bottom of the hopper, C, fuel may be allowed to drop on the inner side of the
door, to be pushed into the furnace by hand by means of a rake or other instrument,
when it is wished to supply more fuel to the furnace than what is being supplied
mechanically. Further for the purpose of stoking by hand, the pushing boxes, E,
may be removed, and the slides, M 1, at the bottom of the hopper, C, may be

page_text: adjusted to allow fuel to drop into the pusher-box spaces to be fed in by means of a
rake or other instrument.
For the purpose of supplying air in a more or less heated state at the top of the
furnace mouth a castiron plate or flange, N, is provided at the sides of each
hopper, C, and communicating with a space, N 1, between the inner side of the
hopper and the boiler front, this plate being perforated at the sides and the inner
part of the space, N 1, being occupied by perforated or grooved firebrick pieces, P.
Some air is also admitted immediately over the fire bars (as in my former arrange-
ment shown in my Patent Specification No. 380882) through perforated or grooved
firebrick pieces, Q.
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. Forming furnace shells or flues of steam boilers of plates having an increased
thickness at the edge which is flanged and rivetted to the end plate of the boiler
substantially as and for the purposes hereinbefore described.
2. The construction arrangement and combination of parts constituting the
improved mechanical stoking apparatus for steam boilers substantially as herein-
before described with reference to Figures, 6, and, 7, of the accompanying
'drawings.
3. In mechanical stoking apparatus for steam boilers, the improved combination
of the pushing boxes and their actuating and adjusting parts with the mechanism
by which the fire bars are moved substantially as hereinbefore described with
reference to Figures, 6, and, 7, of the accompanying drawings.
4. In mechanical stoking apparatus for steam boilers, the combination of the fire
bars with the means by which they are made to reciprocate to different extents
substantially as hereinbefore described with reference to Figures, 6, and, 7, of the
accompanying drawings.
5. In mechanical stoking apparatus for steam boilers providing for the admission
of air at the top of the furnace mouth through or between grooved firebrick pieces
substantially as hereinbefore described.
Dated this Eleventh day of December 1893.
EDMUND HUNT,
Applicant's Agent.