An Improved Stoker for Steam Generator and other Furnaces.
Year: 1893

page_text: Date of Application, 5th July, 1893
Complete Specification Left, 2nd Feb., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
An Improved Stoker for Steam Generator and other Furnaces.
BRIERLEY DENHAM HEALEY of Higher Walton, Preston, in the County of
Lancaster, Civil Engineer, do hereby declare the nature of this invention to be as
follows :-
:-
This invention has reference to an arrangement of stoking gear which is suitable
for steam generator furnaces, and for other furnaces of various kinds, wherever a
regularity of 'feed is required, and where it is desired to prevent smoke.
In carrying this invention into effect I use by preference an odd number of bars,
both for the feeding part and the firegrate part of the stoker, and in a grate with
say 37 bars in each part, 18 are made so as to move continuously, whilst 19 remain
stationary on permanent bearers.
The outer end of the feeding part of stoker is carried by a trough casting, and
from thence the feeding bars slope down towards the firegrate part, to which it is
attached at or near the point where power is applied for driving the stoker, and
each bar has a knuckle joint to allow of altering the angle of slope.
The motion imparted to the moving bars is obtained from a cam shaft, or from a
pair of eccentrics which carry a cross bar, and operating at or about the point.
where the feeding bars join the firegrate bars, so that the feeding and forwarding
motion proceeds simultaneously.
The speed of travel imparted to the material upon the bars is of a differential
nature, being the greatest at or near the cam or cross bar attachment, and reducing
gradually from that point towards the outer ends of both sets of bars, where there
is only a reciprocating motion of the bars.
The bars are fair with each other on the upper surface when the cam or
eccentrics are set forward or backward, and therefore the moving bars are elevated
above and depressed below the fixed bars during each revolution of the shaft,
which ensures a steady forwarding motion of the fuel.
In very wide grates one half of the cam shaft may be set forward when the
other half is set backward. At the front end of the stoker is a hopper with a
regulating slide, or an arrangement for lowering the sloping bars at the outer end.
The bars in the feeding part of the stoker are set close together, and the air
spaces between the firegrate part stop a few inches short of the ends. Beyond the
bridge there is a gap for the clinkers and below the bridge one or two airtight doors
for withdrawal of clinkers.
The stoker may be driven by changewheel gear, or wormwheel gear, actuated by
an eccentric on shaft overhead, or by a special motor, any of which may be
combined with a catch wheel and palls.
Dated this Fourth day of July 1893

page_text: An Improved Stoker for Steam Generator and other Furnaces,
I, BRIERLEY DENHAM HEALEY of Higher Walton, Preston in the County of
Lancaster, Civil Engineer, 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:-
This invention has reference to an arrangement of stoking gear which is suitable
for steam generator furnaces and for other furnaces of various kinds, wherever a
regularity of feed is required and where it is desired to prevent smoke.
In carrying this invention into effect I use by preference an odd number of bars,
both for the feeding part and the firegrate part of the stoker, and in a grate with
say 37 bars in each part, 18 are made so as to move continuously whilst 19 remain
stationary on permanent bearers, or 19 bars may be made so as to move continually
whilst 18 remain stationary.
The outer end of the feeding part of the stoker is carried by a trough casting,
and thence the feeding bars slope down towards the fire grate part, to which it is
attached at or near the point where power is applied for driving the stoker and
each bar has a knuckle joint to allow of altering the angle of slope.
The motion imparted to the moving bars is obtained from a cam shaft, or from a
pair of eccentrics which carry a cross bar, and operating at or about the point
where the feeding bars join the firegrate bars, so that the feeding and forwarding
motion proceeds simultaneously.
The speed of travel imparted to the material upon the bars is of a differential
nature, being the greatest at or near the cam or cross bar attachment, and reducing
gradually from that point towards the outer ends of both sets of bars, where there
is only a reciprocating motion of the bars.
The bars are fair with each other on the upper surface when the cam or
eccentrics are set forward or backward, and therefore the moving bars are elevated
above and depressed below the fixed bars during each revolution of the shaft,
which arrangement ensures a steady forwarding motion of the fuel.
In very wide grates one half of the cam shaft may be set forward when the
other half is set backward. At the front end of the stoker is a hopper with a
regulating slide, or an arrangement for lowering the sloping bars at the outer end.
The bars in the feeding part of the stoker are set close together, and the air
spaces between the firegrate part stop a few inches short of the ends. Beyond the
bridge there is a gap for the clinkers and below the bridge one or two airtight doors
for the withdrawal of clinkers.
The stoker may be driven by change wheel gear, or wormwheel gear, actuated by
an eccentric on shaft overhead or by a special motor any of which may be combined
with catchwheel and palls.
And in order that this invention may be better understood I have appended
hereto a sheet of drawings. The letters of reference marked thereon when shewn
on two or more of the figures refer to the same or corresponding parts.
Figure 1 is a longitudinal section and Figure 2 is a transverse section, shewing
the application of the improved stoking gear herein described to a steam generator
of the Lancashire type, and which is equally applicable with a very slight modifi-
cation to generators on the water tube system.
Figure 3 is a longitudinal section and Figure 4 is a transverse section, shewing
the application of the improved stoking gear herein described to a steam generator
either of the Lancashire type or the marine type fitted with stoking doors instead
of the outside hopper, which arrangement provides for an intermittent supply of
steam.

page_text: Figure 5 is a longitudinal section and Figure 6 is a transverse section, shewing
the application of the improved stoking gear herein described to furnaces for
burning refuse fuel, the side walls of which have ledges projecting about two inches
inwards at the level of the grate bars.
Assuming that the odd number bars rest upon the bearers E and S and upon the
bridge plates F, the even number bars are operated by a cam shaft A and a quiet
forwarding motion is imparted to the fuel.
And likewise if the even number bars rest upon the bearers E and S and upon
the bridge plates F, then the odd number bars are operated by the cam shaft A.
and a similar forwarding motion is obtained.
The fuel is charged into the hopper B, which on Figure 1 is shewn with a
regulating slide R and regulating screws T for moving the slide R, so that the
depth of the fuel may be regulated as it passes towards the furnace.
A slotted casting S carries the upper end of the feeding bars C and the outer
end of the grate bars D is carried by the bridge plates F which are of any suitable
section.
The resulting clinkers fall over the bridge plates F into receivers or pockets J
from which they are withdrawn at intervals through the doorways K.
Referring to Figures 5 and 6, in practice it has been found that the side
ledges V reduce the fusing action of the fire on the walls X. Outlets O leading
from the furnace G to the heat chamber N are formed in the arch W for escape
of waste gases.
The heat from the chamber N may be taken off by flues in the side walls, or by
an overhead flue or by a chimney connection in any convenient way, without
departing from the objects comprised by this invention.
It is obvious that a portable clinker receiver somewhat as shewn in the
Specification of Patent No. 18,398 A.D. 1892 may be used instead of the pocket J
shewn on Figure 5 of the drawing appended hereto without departing from the
merits of the present invention.
The method of driving the cam shaft A does not form any part of this invention,
and many of the well-known ways of applying the necessary power can be adopted
or modified as circumstances may require.
The stoking doors U shewn on Figure 3 may be of any well known type and
fitted up in pairs or as single doors. The flap doors H and K shewn on Figure 5
are generally fitted up in pairs and provided with counterbalance weights and
levers.
The cam end of the moving bars D may rest on shaped carriers, and the
joints of such carriers being under the slotted part of the moving bars, the carriers
form a shield over the cam and keep it free from grit.
The latter arrangement of carriers allows of the renewal of the grate bars,
without interfering with the parts which rest on the cam, and which have then
become smooth by previous work.
By lowering the main bearing blocks or pedestals which carry the ends of
the cam shafts, any defective grate bar may be renewed without withdrawing
the fire.
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. The application of the herein described improved stoking gear to steam
generators substantially as herein shewn and described.
2. The combination of the ledges V in connection with the improved stoking
gear herein described and shewn on Figure 6.
3. The position and form of clinker receiver J fitted with balanced flap
doors K in combination with the improved stoking gear herein described and shewn
on Figure 5.
4. The shaped carriers on the cam shaft A of the improved stoking gear

page_text: herein described, for the purpose herein set forth and substantially as herein
.described.
5. The method of joining the feeding bars C to the grate bars D at a point
immediately over the cam A substantially as herein shewn on Figure 1.
6. The combination and arrangement of the various parts of the stoking gear 5
as aforesaid for the purposes set forth and substantially as herein shewn and
described.
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