Improvements in Steam Boiler or other Furnaces.
Year: 1889

page_text: Date of Application, 22nd May, 1889
Complete Specification Left, 12th Feb., 1890-Accepted, 5th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Steam Boiler or other Furnaces.
I, THOMAS HENDERSON of 40 Castle Street Liverpool in the County of Lancaster,
Engineer do hereby declare the nature of this invention to be as follows:-
This invention has for its object the improvement of my well known system of
fire bars patented by me in patents Nos. 2509 of 1872, 3812 of 1876, 800 of 1880
and 3458 of 1884.
The improvements herein set forth are also applicable in part to other systems of
fire bars. The object of the present invention is to enable one to more easily clean
out these and other fire bars. It is found sometimes with these self acting fire bars
that when a new hand takes charge of them, he is apt to stoke away very hard to the
far end of the bars, and as a result he sometimes gets an absolutely impenetrable
mass of clinker at the end of the furnace.
Now in order to avoid this and other evils and enable the furnace to be more
casily cleaned out, I form a second set of bars beyond the first, say about two or three
feet long with very narrow air spaces fixed at the back to a revolvable cross pièce.
The ends of these bars, under ordinary circumstances, meet the ends of the fire bars,
and the clinker, by the action of my self-cleaning fire bars, is brought on to these
secondary bars. After a time when these bars get tolerably full of clinker they are
released by pulling a handle out of a notch. The ends of the bars all fall down and
launch the clinker into the ash pit. The ordinary pendent door, which I have usually
had in the ash pit, in this case is done away with. In some cases, however,
especially with forced draught it is desirable to clean out in front instead of at
the rear.
In this case instead of having a pivoted set of fire bars, I have a pivoted
dead-plate perforated or otherwise. This dead-plate, by the action of a bell-crank
and handle worked from the outside, is turned on its axis and the clinker thereon
is precipitated into the air chamber close to the door.
This is especially useful in the case of forced draught. In either case the action is
practically the same, a continuation of the fire bars either made all in one piece or
rigilly fixed to a cross piece but formed of separate bars is held in position by a
notched bar or its equivalent. It is reversed by either letting the notched har go free,
in which case the weight of the clinker causes the frame of bars to fall, or the
notched bar handle is pushed in, reversing the set of bars or dead-plate and causing
in either case the load to be precipitated into the air chamber below. It is obvious
that the secondary bars or the dead-plate can be pivoted in the centre or at one end
as desired. Where the secondary bars or dead plate is in front, however, I prefer
to pivot it near the centre. Where they are at the rear I prefer to pivot it at the
back end.
D
COMPLETE SPECIFICATION.
Improvements in Steam Boiler or other Furnaces.
I, THOMAS HENDERSON of 40 Castle Street, Liverpool, 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 to cleaning appliances for steam boiler or other furnaces, and
more especially to certain improvements in my system of self-cleaning fire bars which

page_text: was patented by me under Patents Nos. 250972, 381270, 80080, 34588¹. These
improvements are, however, also applicable in part to other arrangements or
systems of fire bars.
It is found that an inexperienced hand when working with these self-cleaning fire
bars is apt to throw too much fuel to the back end of the bars, and there thus results
a large accumulation of clinker at the rear end of the furnace. Now the object of
this invention is to afford facilities for dealing with the clinker and for removing,
from time to time as desired, any accumulation of the same, whether such accumu-
lation has occurred through carelessness or inexperience, or in the ordinary course.
of working.
My system of self-cleaning fire bars as hitherto publicly used by me may be
briefly described as follows, reference being had to the accompanying drawings,
which also illustrate the improvements forming the present invention, and in which,
Figure 1 is a longitudinal section through the furnace, taken on line a a
Figure 2.
Figure 2 is a sectional plan on line y y Figure 1, a portion of the dead plate being
broken away to show the actuating mechanism.
Figure 3 is a view similar to Figure 1, showing a slightly modified arrangement.
Figure 4 is a longitudinal section through the furnace, taken on line z Figure 5,
and showing another way of carrying the invention into effect.
Figure 5 is a sectional plan of the mechanism shown in Figure 4, parts being
broken away, and other parts removed.
Figure 6 is a view similar to the left hand portion of Figure 4 showing a slightly
modified arrangement.
Referring first more especially to Figures 1 and 2:-
A is the furnace. B is the main driving shaft, located in front of the furnace, and
provided with a crank or eccentric b. C is an adjustable strap working on said
eccentric, and connected by a link C with the actuating fire bar C. The latter
engages the flange or bail D¹ of the actuating shaft D in such a manner as to oscillate
the same during its reciprocation. At each end of its stroke, the bail D' engages the
corresponding end of a recess d formed on the lower edge of each of the alternate
fire bars E, so that the latter, are moved to and fro intermittently. A second bail ])²
on the shaft D engages a projecting piece f on each of the alternate fire bars F',
and imparts an alternate rising and falling movement to the forward ends of the
same, synchronously with the oscillation of the shaft D. The effect of the combined
movements imparted to the bars E and I is to feed the fuel, with the clinker, steadily
towards the rear ends of the bars. On reaching the rear ends of the bars, the clinker
drops on to a dead plate G having small or no air spaces, such dead plate being formed
by widened rearward extensions of the alternate bars F', as may be seen in Figures 1
and 2. This dead plate partakes of the to and fro movement of the bars F, and
the clinker being thus brought, at each alternate stroke of the bars F, against the
ends of the bars E, it is gradually pushed rearwards over the dead plate and falls
into the space H at the rear of the ashpit H. h is a hinged door which may be
opened by a chain h', and through which the clinker may be drawn into the
ashpit and removed from time to time. J is the dead plate usually found at the front
of a boiler furnace.
66
The apparatus described in detail herein before is old and well known, and forms
no part of my present invention, which consists briefly in providing, at either end
of the furnace according to the direction of travel of the clinker-a movable dead
plate or a series of movable fire bars, having small or no air spaces, such device
(hereinafter called a clinker plate ") being so mounted and arranged in combination
with an operating device worked from the front of the furnace (or from other
convenient point), that it may be tilted from time to time as desired, in order to
discharge the clinker into the ashpit, H', or into its extension, the space H.
. In the arrangements shown in Figures 1 to 3, the fire bars E F feed the clinke
front to rear of the furnace, and the clinker plate. K is therefore placed at the
he bars, its upper surface being in continuation of the upper surface of the

page_text: dead plate G and at any suitable inclination thereto. The clinker plate K is, in
this instance, formed of a series of fire bars k, with small air spaces, and it occupies
almost two thirds of the width of the furnace, the spaces at each side of the clinker
plate being occupied by side pieces and fixed bars. The clinker plate K is
adapted to turn about its rear end, as may be seen from Figures 1-3, in each of
which the clinker plate is shown in its tilted or open position. The bars k, forming
the movable clinker plate K, are mounted upon a rotatable shaft in such a
manner as to move therewith as a whole, being preferably threaded upon a square
portion of the shaft, as shown. L is a depending toothed sector, fixed on the
shaft and gearing with a worm L. The worm L' is fixed on a shaft L2 lving
along the bottom or side of the ashpit and mounted in bearings L. The shaft L³
is provided, at the front end of the furnace, with a hand wheel Lt, by which it may
be turned, and the clinker plate tilted, as desired.
In Figure 3, the shaft is shown provided with a depending arm in lieu of a
toothed sector. This arm may be worked to and fro from the front of the furnace
by a push and pull rod or by a chain. The rod is provided with a suitable
device, such as a notch in the lower edge of the rod and a corresponding detent 73
on the front of the furnace, by means of which the clinker plate may be retained in
its normal or elevated position. By simply knocking the front end of the rod 1
upwards, the clinker plate is tilted by gravity and discharges the clinker into the
space H, or enables it to be drawn thereinto by means of a rake.
it
The clinker plate K may be extended rearwards to any convenient distance, and
may be pivoted at any suitable point between its front and rear ends. In boilers
of the marine type, having furnaces at both ends with a common combustion chamber
between the adjacent ends of the furnaces, the clinker plates K of two opposite
furnaces may be extended inwards until they meet, and thus a continuous grate
surface is formed from one end of the boiler to the other.
In the arrangements shown in Figures 4 to 6, which are specially applicable to
furnaces working with a forced or artificial draught, the ordinary action of the
bars E F is reversed, so that the fuel and clinker are fed from rear to front of the
furnace, an arrangement not I believe publicly known at the date of this application.
The bars are operated in a substantially similar manner to that described with
reference to Figures 1 to 3. The reversed action is obtained by reversing the
position of the actuating shaft 1), as shown in Figure 4, and the said shaft may,
instead of being connected to its operating crank by a link C¹ and actuating bar C³,
be connected thereto by a link e¹ and depending arm & as shown, the arm being
attached rigidly to the shaft D). The dead plate G is no longer needed, and a fire
bridge G is substituted therefor, the fuel being thrown well back towards said
bridge. The usual dead plate J is replaced by a movable clinked plate M; whose
upper surface is on a level with or a short distance below the level of the bars E F.
In Figures 4 and 5 this plate M is shown in the form of a flat plate provided with
narrow elongated slots or air spaces and it is pivoted at or about its centre as at m.
Its under side is fitted with a depending arm m³, on to which a socketed bar may
be fixed for the purpose of tilting the plate. Or the arm m¹ may be made long
enough to serve itself as an operating handle. Any suitable catch device or counter-
balance may be employed to retain the plate M in its normal position.
In Figure 6 the clinker plate M is shown pivoted at its front edge as at m² and
provided with an arm m³ and a counterbalance ms, which holds the plate always in
its elevated position. The plate may be tipped by simply drawing forward the
balance weight.
When the clinker plate is located at the front end of the furnace, the hinged door h
at the rear end of the ashpit is unnecessary as the clinker is discharged directly
into the front portion of the ashpit and can be very quickly removed, which is an
advantage when a forced draught is employed.
It will be obvious that other arrangements of mechanism, not shown in the
drawings, could be employed for operating the clinker plates. Also these plates
could be employed with many other arrangements of fire bars, self-cleaning or

page_text: otherwise, the clinker being automatically fed or simply pushed or drawn by hand,
on to the plates, the main object of the latter being to afford a ready means of
discharging the clinker into the ash-pit or other similar space below the level of the
bars.
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 arrangement within a boiler or other furnace of a tipping clinker plate
forming a continuation of the fire bars at either end of the furnace and adapted to
receive the clinker from the said bars, and also to discharge such clinker into the
space below the bars each time it is tipped by means of suitable mechanism operated
or released from the front end of the furnace or from other convenient point,
substantially as described.
2. The arrangement, within a steam boiler or other furnace, of a system of self-
cleaning fire bars substantially as described, adapted to feed the fuel and clinker
from the rear portion of the furnace towards the front thereof, in combination with
arrangements for quickly discharging or removing said clinker after it has reached
the tail end of the fire bars, substantially as described.
בד
111 1
1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.