Improvements in Moving Fire Bars for Cleaning Furnaces, and Means for Perfecting Combustion and Consuming Smoke.
Year: 1894

page_text: Date of Application, 20th June, 1894
Con plete Specification Left, 20th Mar., 1895-Accepted, 15th Jure, 1895
Improvements in Moving Fire Bars for Cleaning Furnaces, and
Means for Perfecting Combustion and Consuming Smoke.
I, JAMES WILLIAM CLARIDGE 79 Gracechurch Street London E.C. Engineer
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in & connected with fire bars more
particularly for those for use in steam boilers & of the class to which motion is
imparted either by a lever worked by hand or worked from a motion shaft & by
which the grate is kept clean for the admission of air amongst the fuel. This
invention further relates to means whereby I let in any desired quantity of air
outside the boiler & carry it along to the back of the grate, heating it in its passage
in order to more effectually consume the smoke.
For this purpose I make the grate like an ordinary one & the bars run the full
length. I support the bars on a cross shaft or shafts & with or without the
bearers already found on the boiler. On the shaft is set cams in such a way
that by the movement of a lever connected to the before mentioned shaft or
shafts raise which bars I desire up into the fire while leaving the others
standing. prefer to raise the alternate ones only while holding firmly down
the others so that they cannot lift. guide the moving bars at each end of the
grate so that they will keep their proper position & can if desirable lower the bars
in the back movement of the shaft.
The grate being thus kept clean 1 employ two tubes running along & level with
the same for the passage of air through them. This air is taken in from the front
& let out at or near the bridge & by the use of a small jet of steam can force a
greater quantity of air through than would pass by the natural draught or 1 can
fit doors in the front of the tubes or use any other ineans for varying the quantity
of air carried through.
Dated this 19th day of June 1894.
Improvements in Moving Fire Bars for Cleaning Furnaces, and
Means for Perfecting Combustion and Consuming Smoke.
I, JAMES WILLIAM CLARIDGE of 79 Gracechurch Street London E.C.
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 and accompanying drawing:
My invention relates to improvements in and connected with fire bars whereby
they may be cleaned mechanically and a more perfect combustion be obtained

page_text: than in those of ordinary construction. Further to improvements in furnace
grates whereby forced or induced draught may be supplied to the grate hot or the
bars kept cool as desired.
It consists in an arrangement whereby every alternate fire bar is lifted vertically
both ends together and without lateral movement, being afterwards lowered again
in a line approximately parallel to the grate for the purpose of breaking up
clinker and admitting air amongst the fuel. Also to two hollow bars held down
and preferably running along the sides of the furnace with main body at the same
level as the grate bars into which air, steam or water is forced or exhausted, being
afterwards sprayed out underneath into the ashpit and rising from thence to
the fire.
1 generally construct the furnace grate so that every other bar is fixed at each
end, called the fixed bars, and the next bars called moving bars are lifted
vertically both ends at same time between guides and approximately parallel to
line of grate and afterwards lowered again. For this purpose the said fixed
hollow bars carry two cross shafts which are connected together. On these cross
shafts are cams, generally same length and set at the same angle, which gear
loosely with the undersides of the moving bars. When the cross shafts are
reciprocated by a lever, worked either intermittently or continuously the moving
bars are lifted and lowered again us before mentioned. To effect. this object the
moving bars are preferably shinped with two books on their undersides, both hooks
on same bar turned one way. These houks engage with the cams on the cross
shafts, when I require to lower the moving bars. The fixed bars are held down
by projections on the end guide plates. In this system of construction one of the
ute plates is made removable so that the bars may be disengaged readily from
The shafts. Links, chains or a similar device may be used to engage the shafts
with the bars and being tied together be capable of disconnection from the bars by
one motion of a red from the front. The hollow side bars are perforated on their
undersides so that the currents issuing from them may lead into the ashpit,
afterwards rising to the grate bars. Portions of the hot air supply may be taken
from the ashpit to the top frcut and back of fire through the dead-plate, fornace
front and bridge. The hollow bars may be of any suitable section plain, ribbed
or corrugated and rise above and below the level of the grate as long as the
moving bars vertically clear them. The hollow bars are formed to lead under
dend plate to outside of boiler. The grate bars need not be plain on their top
sites, but he ribbed transversely to facilitate air admission.
Figure 1, of the accompanying drawings shews a longitudinal section of a
furnace grate constructed neconding to my invention. Figure 2 shews a plan.
Figure 3, a cross section taken on the line a-6 of Figure 2. Figure a front
view.
In these figures the bars A. are supported by the cross shafts B. The motion
of the lever C. lifts the moving bars into the position shewn by Cotted line a, as in
Figures and 3, vertically between end guide plates D and D', by means of
cams On the removal of D, the bars may be disengaged from the cam shaft
and taken from the furnace. The link L' connects the two shafts together and a
rod L, the link to the lever C. When the lever is raised the bars descend to their
original position, the cams acting on the hooks H H. The guide plate Dis
fastened to the dead plate E. The fixed bars are held by projections F Fas
shown in Figures 1 and 2. O is the pipe conveying a stent jet or jets from the
boiler to the nozzles O, leading into the hollow sile bars M as shewn in Figures 1,
2. 3 and 4, but instead of employing a steam jet or jets, a blower or exhauster may
be used for giving the required air supply to the hollow side bars M. The arrows
shewn in Figure 3 indicate the direction that the currents would take from the side
tubular bars in entering the ashpit.
Figure 5 shews another system of construction of cam shaft 13 and bar A where
the shaft B is shewn in section but having a groove B' formed therein by means
of which the bar. A is caused or cuabled to lift, and Figure 6 shews the alternate

page_text: bar A which is in like manuer caused or enabled to desceud by the same movement
of lever. On this plan the hooks will hold the fixed bars also, the shaft B being
in this position formed quite circular.
Figure 7 is another system of construction shewn partly in section where the
bars A have studs G Ginstead of books H H engaging with links II' connected
by the rod J which is held firmly outside the furnace and yet permits of the lift
of the bars. To draw the bars down again as in this form of coustruction
chains K K connect the links to the shafts. When it is desired to remove the
bar on this plan the rod J is pushed inwards to untie the links 11' from the
studs G G The shafts B are rotated for lifting and lowering the bars A in
similar manner to that shewn and described by means of the connecting rod L' and
connections as shown in Figure 1.
Figure 8 partly in section refers to another system of cam C and bar A with
double pairs of hooks H H on same bar which is shewn in its lifted position.
Figure 9 shews the cam shaft B inserted in the bar A. and instead of using the
link Las in Figure 1 to connect the two shafts B B together one of the bars
shown as Ain Figure 10 may serve the same purpose by being made to have a
longitudinal motion instead of a vertical one. This is effected by connections
continued to the outside of the furnace to give this required motion. The cam
with this particular bar A" is then vertical as shewn in Figure 10 and due to
the rotative action given to the shaft by the longitudinal motion of the bar A"
the other bars are lifted and lowered as desired by the cam C' and slot B¹ in the
sane shaft B as shewn in Figure 9. I need not, or wish to, confine myself to
the above or exact details, as it is obvious that other modifications may be made
without departing from the spirit of the invention, for instance-more than two
cross shafts may be employed and each bar divided in its length or one half the
bars be made to lift and the others lower as shown in Figures 5 and 6, but
wish it to be understood I lay no claim to firebars which are rocked or tilted
from the centre or ends or to those with end movement, nor do I lay claim to plain
straight tubes conveying air to back of bridge.
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. Constructing furnace grates with fire bars supported by cross shafts which
when reciprocated both ends of the same bar are lifted and lowered vertically and
simultaneously between end guides and approximately parallel to the line of grate,
substantially as and for the purposes described.
2. Constructing furnace grates worked mechanically so that certain of the
fire-bars are held rigidly down while the others are lifted and lowered both ends
vertically and simultaneously by means of cams or the like on cross shafts between
end guides and approximately parallel to line of grate substantially as and for the
purposes described.
3. In furnaces constructed and operating as set forth in Claims 1, and 2, pro-
viding a fire bar with hooks set the same way to engage with cans on reciprocating
cross shafts substantially as and for the purposes described.
4. In furnaces constructed and operating as set forth in Claims 1 and 2, providing
a fire bar with studs to engage with links and chains attached to reciprocating
cross shafts substantially as and for the purposes described.
5. In furnace grates constructed and operating as in manner set forth in Claims 1
and 2 means whereby the bars may be disengaged from the cam shaft and replaced
substantially as and for the purposes described.
6. In furnace grates two hollow bars or tubes situated in the wings of furnaces,
level or approximately level with the fire grate as a means for conducting forced
or induced air, steam or water through and to the ash pit and thence towards and
over the fire in diffused currents or spray substantially as and for the purposes
described.

page_text: 7. In furnace grates the combination of hollow bars or tubes as set forth in
Claim G with moving grates substantially as and for the purposes described.
8. In furnace grates the combination and arrangement of parts substantially as
described and set forth in the accompanying drawings.
Dated this 20th day of March 1895.
J. W. CLARIDGE.