Improvements in Mechanical Stokers for Steam-boiler Furnaces.
Year: 1890

page_text: Date of Application, 28th Feb., 1890
Complete Specification Left, 28th Nov., 1890-Accepted; 3rd Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Mechanical Stokers for Steam-boiler Furnaces.
1, JAMES PROCTOR of Hammerton Street Iron Works Burnley in the County of
Lancaster Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates principally to mechanical stokers for steam boiler furnaces
wherein the coal or fuel is pushed upon or on to moving or self-cleaning fire bars.
When the coal or fuel is simply pushed onto one end of the fire bars I use the
following arrangement.
Beneath the open bottom of the coal hopper I mount a tile or slab of fire clay (or
by preference a number of bricks or sections) enclosed between metal plates, or in a
metal shoe.
I arch the metal plates, or the shoe, at the centre to follow the form of the crown
of the furnace, or I otherwise raise the central part thereof in order to obtain more
heating surface of fire clay, and I prefer to make the fire clay extend about six inches
(or more) further into the furnace than the metal plates or shoe.
I cause this cam so constructed to move to and fro, beneath the supply of coal, in
the direction of the fire bars, and as the coal falls upon the ram it is carried forward
by the inward stroke thereof, but at the return stroke the weight of the rest of the
coal behind prevents that which has been so carried inwards from returning and as the
ram recedes this coal will fall over its inner edge and will be scattered or spread upon
the fire for a distance corresponding with its traverse.
Beneath this ram or moving tile and below the fire door is a plaie preferably gridded
or perforated which moves in and out on the dead plate and over the gap between it
and the front ends of the fire-bars.
Part of the coal or fuel falls over the edge of the ram as above stated upon this
gridded plate and part upon the fire bars.
The object of this gridded plate is to agitate the incandescent fuel, keeping it loose
and open, so that the air can have free access thereto and intensify the combustion ;
it also assists the bars in pushing the fire forwards.
I actuate this gridded plate by levers mounted on the ram-box and moved by a
connecting rod and an excentric upon a driving shaft in front of the furnace. I may
connect the ram to the same lever, and I prefer so to arrange this reciprocating
mechanism that the length of traverse of the ram and the gridded plate may be varied,
and also the relative speeds of the motion of the said ram and plate.
Sometimes instead of the fire brick or tile ram as above described I may employ a
long arched or metal plate filling as nearly as practicable that part of the flue in
which it works, and beneath the inner end of this plate is a slab, slabs or bricks of
fire clay.
A reciprocating motion of about two or three feet is given to this plate which thus
distributes the coal or fuel over a greater area of the fire.
This motion will be obtained by a rack and pinion.
I check the supply of coal or fuel on the moving plate or ram by a weighted or
spring flap or equivalent device.
In some cases I make the fire clay slab, slabs or bricks stationary in the bottom of
the ram box and mount two or more rams to move over the said fire clay slab, slabs or
bricks whereby the coal or fuel is pushed on to the gridded plate above described.
As I insert the fire brick slab or tile from the outside, it can be easily removed and
replaced.
The effect of using these tiles bricks or slabs is that in consequence of their being
placed within the furnace they attain an incandescent heat, and the fuel before falling
therefrom is considerably heated, and on falling off readily ignites.

page_text: In some cases where the coal is thrown on the fire I fix the moving grid on the
plate which is attached to the fire bars and moves over the "dead plate.'
The fire door in this case rests upon this grid and moves to and fro therewith, being
mounted on a pivot at the top.
Dated this 27th day of February 1890
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Mechanical Stokers for Steam-boiler Furnaces.
I JAMES PROCTOR of Hammerton Street Iron Works Burnley in the County of
Lancaster 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 relates principally to mechanical stokers for steam boiler furnaces
wherein the coal or fuel is pushed upon or on to moving or self cleaning fire-bars in
contradistinction to its being thrown or jerked on to the fire bars.
My invention will be readily understood from the following description on reference
to the annexed two sheets of drawings, of which Fig. 1 is a vertical longitudinal section
of the front end of a steam boiler fitted with my improved mechanical stoker, and
Fig. 2 is a partial front elevation and Fig. 3 is a sectional elevation and Figs. 4 and 5
(Sheet 1) and 6 and 7 (Sheet 2) are sectional views showing modifications hereafter
described.
a is the front end of the boiler flue and b is the coal hopper.
Below the open bottom of the coal hopper band within the mouth of the flue a I
mount a tile or slab c of fire clay (or a number of bricks or sections) enclosed between
two metal plates d and d¹ or in a metal shoe.
The lower plate d¹ may be hung from the upper plate d and can be adjusted thereto
so as to grip the slab c by means of a set screw e.
I prefer to arch the metal plates d d² (or the shoe) as shown at Fig. 2, to follow
the form of the crown of the furnace; or I otherwise raise the central part thereof
(for example as shown at Fig. 5) in order to obtain more heating surface of fire clay
and better access to the fire for hand firing and other purposes and I prefer to make
the fire clay extend about six inches (or more) further into the furnace than the metal
plates or shoe.
This tile with the plates or shoe forms a carrier to receive the fuel from the open
mouth of the hopper and carry it forwards and distribute it on to the fire bars of the
furnace as hereafter described. It is mounted on antifriction wheels or rollers f and
is capable of moving to and fro (from about three to twelve inches) beneath the
supply of fuel in the direction of the fire bars g and as the coal rests upon the carrier
(which forms the bottom of the hopper) it is carried forwards by the inward motion
thereof whilst the coal above in the hopper 6 falls by its own gravity to fill up the
space of that which is carried forward; but on the return movement, the weight of
the rest of the rest of the coal behind prevents that which has been so carried forward
from returning, and as the carrier recedes, this coal will fall by its own gravity over
the inner edge of the tile c and will be deposited or spread upon the fire for a
distance corresponding with its traverse, thus forming what may be termed a gravi-
tating feed.
As the carrier advances again it skims or pushes this fuel which has been coked
forward and as it returns again it deposits a fresh supply of fuel in the place thereof,
so that the carrier not only supplies the fuel but also assists the fire bars in carrying
the same towards the bridge, and thereby keeping the fire in a loose and spongy
condition which state is the most favorable for combustion.
Beneath this carrier or moving tile c and below the fire door x is a plate g*
preferably gridded or perforated which moves in and out on the dead plate i and over

page_text: the gap between it and the front ends of the fire-bars g (see Fig. 1); part of the coal
or fuel falls over the edge of the tile c as above stated upon this gridded plate g* and
part upon the fire bars.
The object of this gridded plate gx is to agitate the incandescent fuel, keeping it
loose and open so that the air can have free access thereto and intensify the com-
bustion; it also assits the bars in pushing the fire forwards.
The fire door & may move with the gridded plate g* or it may be fixed to the front
of the furnace.
In some cases I find it preferable in order to increase the combustion of the fuel at
each side of the moving carrier de to fix a hinged grid 9* above the plate g* as
shown at Fig. 2 and Fig. 3 (detached sectional view) openings being made in the
front plate of the furnace to be closed partially or entirely as required by the small
doors g², hinged at g*.
These hinged grids g¹ may also be moved slightly at each inward motion of the
gridded plate gx to prevent the fuel from collecting and coking together round the
sides of the carrier.
Or a brick or tile may be placed at each side of the latter as shown at g³,
Fig. 4, instead of the grids gl and a small ram or pusher go, may be caused to
move inwards and outwards with, or by, the central carrier over each of these bricks
or tiles 9³.
These rams go, as well as preventing the agglomeration of the coal at the sides of
the central carrier also serve to assist the feeding of the fuel to the sides of the
furnace in case the supply furnished by the central carrier is not sufficient.
Or the plates d, d may be made to carry side bricks or tiles 97, 98 (see Fig. 5
Sheet 1 and Fig. 6, Sheet 2) which will have the same effects as the arrangements
last described.
I may actuate the gridded plate gx by rocking levers moved by a connecting rod
and an excentric upon a suitable driving shaft in front of the furnace, and I may
also connect the carrier to the same levers.
I prefer however to actuate the carrier and the gridded plate by a modified
form of an invention for which I applied for Letters Patent No. 10300 on the
3rd of July 1890.
I actuate the carrier by levers r, r¹ fixed on or cast to a rocking shaft o̟ carried by
the side plates q' forming part of the ram box.
These levers r, are actuated by means of slotted levers p, p¹ caused to rock
by crank pins o, o¹ and plates n, n¹ driven by a transverse shaft m worm wheel s
and worm t on the vertical shaft t¹ which is driven by any convenient means.
By keying the plates n, n' upon a feather on the shaft m either of the crank
pins o, or can be moved out of gear with its lever por pl as desired. The
fixed screws ✶✶hold the plates n, n' in working position by being set in the
grooves in the edges of the said plates (see Fig. 2).
The gridded plate g* is connected to the plate d by an arm or bracket w which is
slotted at w and adjustable so that the lengths of traverse of the ram or carrier and
of the gridded plate gx can be varied with regard to each other.
Fig. 7. Sheet 2 shows another method of actuating the carrier, the levers are
pivotted to the side plates q¹ and each is moved by an eccentric q2 on the shaft q
which is driven direct by the worm wheels and worm t on the shaft t'.
It will be observed that as in all cases I insert the fire bricks or slabs from the
outside they can be easily removed and replaced.
The effect of using these fire bricks or slabs is that in consequence of their being
placed within the furnace they attain an incandescent heat and the fuel before falling
therefrom is considerably heated and even ignited.
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 :-
First. In combination with the open mouth of the fuel hopper, an arched or stepped

page_text: carrier or fire clay slab moving to and fro beneath the said mouth and carrying the
fuel forward into the furnace and depositing the same upon the moving fire bars
substantially as hereinbefore described and illustrated by the drawings annexed.
Secondly. The combination with a feeding or distributing and coking apparatus, of
a plate, preferably gridded, or equivalent device, moving to and fro beneath the said
apparatus and over the dead plate and fire bar ends substantially as and for the
purposes hereinbefore described.
Dated this 27th day of November 1890.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant