Improvements in or relating to Steam Boiler or other Furnaces.
Year: 1897

page_text: Date of Application, 17th May, 1897
Complete Specification Left, 17th Mar., 1898—Accepted, 20th Apr., 1898
Improvements in or relating to Steam Boiler or other Furnaces.
I, EDWARD BENNIS, of Beech Hill, Bolton, in the County of Lancaster, Engineer,
do hereby declare the nature of this invention to be as follows:-.
This invention relates to furnaces for steam boilers and other structures and
it has for its object more especially certain improvements on my prior Patent
No. 19730 of 1895, whereby I am able to secure increased power and economy.
By my present invention I construct the compressed air furnace bars in the
following manner:
The bar is of a U or approximate section, the sides straight down and the
bottom flat. The front of the bar extends in practically a straight line about
15 inches beyond the point where the fire starts, but is so tapered that the front part
of this length is narrowed about 1½ inches and then so widened as to form a bell-
mouth, the whole being somewhat of a trumpet shape.
This front portion is closed by a cover which makes the front form a tube.
The part of the bar on which the fuel rests is formed of small bars which lock
one another so that no one bar can be displaced easily. The steam or air jet is
placed near the end of this bar and blows almost in a direct line to the end of the
bar.
The bars which form the surface of the bar are at the front straight, but farther
down the bar they are preferably cast, so that two bars fill up the space, the teeth
of one filling up the recess in the other, and leaving a narrow air space, thus
increasing the length of the air space while keeping it narrow and saving having
80 many separate pieces.
The air space is in fact serpentine or zig zag instead of straight. The bearers
for these bars are cast so that the bars rest on rollers and these rollers run on
ridges with spaces between and to the end of the stroke so that ashes that fall
between the bars will not obstruct the action of the rollers. The bearers are
made with the surface like the roof of a house, so that when the bars are pushed
in they run up the incline and then down at the other side and when they are
drawn out again they have to mount the ridge and run down again. The move-
ment of the bars is effected in the following manner:
Near the front under the bars I place a shaft and on this shaft I place a number
of levers so made that all the bars are pushed in together, when the shaft is moved
one way, and drawn out one by one by the action of another set of levers, which
press on pins placed on the side of the bars and catching them at varying points.
This shaft is generally moved by an eccentric, placed on the shaft that drives
the stoker, so doing away with the worm and wheel cam shaft and
cams of my former bars. This motion can be varied and in many
cases greatly improved in the following manner; I make my bearers with a con-
siderable rise upon them say % of an inch in a length of 1 inch and only a slight
fall in of an inch or thereabout. The lever then pushes the bar in and it is held
in position by the slight fall. When the return lever pushes it over this slight

page_text: fall it suddenly runs down the hill by its own weight and effectually leaves the
clinker behind.
There are arrangements upon the bar and inside to keep it free from dust and
dirt, generaly a moving plate actuated from the bar.
Dated this 15th day of May 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Tutes.
I, EDWARD BENNIS, of Beech Hill, Bolton, 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 follow-
ing statement:
This invention relates to furnaces for steam boilers and other structures and has
for its object more especially certain improvements on my prior Patent 19730 of
1895 whereby I am able to secure increased economy and power.
On the accompanying drawing,
Figure 1 is a longitudinal section of an improved fire bar;
Figure 2, an enlarged cross section on the line x-x;
Figure 3, a plan view; and
Figure 4, a longitudinal section of a main bar showing a different form of bar
on which the fuel rests;
Figure 5, plan of the same;
Figure 6, enlarged cross section on the line z z;
Figures 7 and 8, cross sections on the line y y and y¹ y¹;
Figure 9, a similar view to Figure 7 but the bearer being in section;
Figures 10 and 11 show devices for imparting a reciprocating movement to
the main bars.
The bar A A is of a U or approximate section, the sides preferably straight and
the bottom flat, from the point B to C on which the fire rests.
has holes O in it preferably at the bottom, which holes are covered by the plate 1)
This part of the bar
which also has corresponding holes in it, but so arranged that they are only open
when the bar is at the centre of its movement, thus securing a closed trough
except for a very short space of time during each movement.
The holes O in the plate D act as pushers for any small cinder or ash that falls
through from the fire and this they drop through the openings in the bar as they
pass over them, so keeping the bar itself free from obstruction. This plate is
held stationary by projections upon it FF which fit the bearer G, the main bar
moving to and fro under this plate, generally with a movement of from 2 to 4
inches, so that the holes in the bar and in the covering plate move over one another
and are open twice in each complete movement of the bar. The front of the bar
extends from 15 to 18 inches in practically a straight line beyond the point where
the fire starts from H to B, this part of the bar is made with a bell mouth H¹ and
from the narrowest part I this part of the bar widens as a cone at the rate of
about 1 inch in each foot. If, for example, the narrow part I is 2½ inches in
diameter and round, then 1 foot nearer the fire it would be 31" diameter and
round or nearly so. If the bar at I were 2 inches square then at 1 foot from I as
before the bar would be about 3" square. The bar from B to C becomes less in
depth so as to partially keep up the air pressure, as some escapes through the fire.

page_text: The front part is generally closed by a cover, but it may be cast in one piece form-
ing a round or square tube somewhat like a trumpet, but of about the form
described.
At the front of the set of bars is a steam pipe P in which are holes or nozzles
as convenient of a suitable size, and the steam blows with great force through the
bell mouth opening, and in consequence of the scientific shape described carries
into the bar a very large volume of air and causes a considerable pressure in the bar.
The surface of the bar on which the fuel rests may be either small straight
bars R with narrow air spaces as shown in Figures 1, 2 and 3 or may be cast like
wheel teeth, as shown in Figures 4, 5 and 6, so that the teeth on one bar fill up
the teeth on the other, except a narrow space for air passage, thus increasing the
length of the air space while keeping it narrow and saving having so many
separate pieces.
Whichever of the above described bars are put in they are made to lock one
another, either by projections r, Figure 2, cast on them, or by having holes cast
in them and rods put through so that each set across the bar is as though cast
in one.
They are also made to lock lengthways by the projections K which go under
a little bar L cast or put across the main bar, and the projection M which presses
on the projection N on the bar in the next section as shown in Figure 1.
The front bearer 6 for these bars is cast with ridges c¹ having spaces or open-
ings, Figure 9, between, through which ashes can fall. The bars rest on the
roller c which roll on the surfaces of the ridges, these ridges and spaces being
at right angles to the roller axes, and ashes that fall between the bars will not
therefore obstruct the action of the rollers, as the ashes can fall down into the ash-
pit through these spaces between the bars and will not obstruct the action of the
rollers. The bearers may be made if desired with the surface like the roof of a
house, so that when the bars are pushed in they run up the incline and then down
at the other side and when they are drawn out again they have to mount the ridge
and run down again.
The movement of the bars may be effected in the following manner: -Near
the front under the bars I place a shaft Q, Figure 10, and on this shaft I place a
number of levers R¹ so made that all the bars are pushed in together when the
shaft is moved one way, and drawn out one by one by the action of another set
of levers S which press on pins s placed on the side of the bars and catching them
at varying points. This shaft is generally moved by an eccentric, placed on the
shaft that drives the stoker, so doing away with the worm and wheel cam shaft
and cams of my former bars. This motion can be varied and in many cases
greatly improved in the following manner:-
I make my bearers as shown in Figure 11 with a considerable rise upon them
say 3 of an inch in a length of 1 inch and only a slight fall in % of an inch or
thereabout. The lever R then pushes the bar in and it is held in position by the
slight fall b. When the return lever pushes it over this slight fall, it suddenly
runs down the hill by its own weight and effectually leaves the clinker behind.
This movement not being useful when the fuel is of a sticky nature 1 provide an
equivalent motion to meet such a condition, or when for other reasons it is desirable.
I place a shaft d, Figure 4, across the front of the furnace and arrange ene set
of cams e with their abutments e in line to push all the bars in together by press-
ing a suitable projection d¹ on the bar, and the other cams intended to bring the
bars out one by one, with their abutments e, so placed behind one another on the
cam shaft, as to draw each bar out one after another by pressing on a projection on
the bar, thus breaking up cunker and causing the fire gradually to move away
from the front and eventually to fall over the bar end. This arrangement of
striking abutments placed one behind the other, striking consecutively against
projections on the bars, is an equivalent arrangement for the levers striking
against the pins at varying points.

page_text: 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 improvement in furnaces, which consists in the combination of a series
of built up hollow bars having bell mouths continuation cones
and injecting
devices with propelling mechanism such as described, whereby a series of the
bars are moved forward together and each bar drawn back while those contiguous
to it are stationary, substantially as described.
2. In combination with a bar substantially as above described the cleaning device
substantially as specified.
3. In furnaces having moving grate bars operated by levers, cams, or other
equivalent device, forming the surface of the bearers on which the grate bars
rest substantially in the manner described, whereby when the bars are pushed
forward they are locked in their forward position by a slight fall or depression
on one side of the bearer, while on the return movement of the bars, they are
pushed over and released from this slight fall and run down the slope en the
other side of the bearer automatically by their own weight, effectually leaving
the clinker behind.
Dated this 16th day of March 1898.
WM. P. THOMPSON & Co.,
Patent Agents.
Of Liverpool, Manchester, Birmingham, and London.