Improvements in and Apparatus for Effecting Combustion of Fuel in Furnaces.
Year: 1897

page_text: Date of Application, 14th Oct., 1897
Complete Specification Left, 14th July, 1898-Accepted, 1st Oct., 1898
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for Effecting Combustion of Fuel in
Furnaces.
I, THOMAS MACALPINE of 22, Sutton Court Road, Chiswick, London, W., D.Sc.,
Consulting and Research Chemist, do hereby declare the nature of the said
invention to be as follows:-
According to this invention, fuel is projected to the back portion of the furnace
and gradually returned towards the front in such wise that the more difficultly
volatile matters and the fixed carbon may be oxidised by the air at or in the
neighbourhood of the front portion of the furnace whilst the air remains com-
paratively cool and dense. By this means the fuel can be more economically
burnt than usual and the burning gases at the front portion of the furnace are
raised to a high state of incandescence and subsequently mixing in the lighter
and more volatile matters evolved from the fresh fuel delivered to the back
portion of the furnace, effect the combustion of such matters in such a way as
to practically prevent formation of smoke.
Apparatus for carrying this invention into effect may be constructed in various
forms.
According to one arrangement, the fuel is delivered in measured quantities from
a suitable hopper or receptacle into or on to a shovel-like or other thrower, which,
by mechanical means is caused to intermittently or otherwise throw or project the
fuel so that it shall be deposited upon the more rearward portion of the grate,
which may be a travelling grate, moving constantly or intermittently from the
rearward portion towards the front of the furnace, or one having a vibratory
action, substantially as and for the purpose above indicated.
In one such arrangement there is provided at the front end of the furnace and
above the firing opening therein a fuel hopper closed at the lower end by a
measuring device comprising a hollow cylinder which is mounted to rotate and
is formed with an opening by which fuel can alternately enter and leave it the
arrangement being such that upon rotating the cylinder measured quantities
of fuel will be delivered in an intermittent manner from the hopper to the thrower.
The thrower comprises a metal plate bent to a partly circular shape and fixed
at its lower edge to a suitably supported horizontal shaft so that it can work
within a casing forming a lower extension of the fuel hopper extending down
to the dead plate of the furnace. The shaft is partly rotated, in an intermittent
manner so as to cause the thrower to turn inward and throw the fuel thereon to
the back portion of the firegrate, by a vertically movable loaded rod which is
provided with a tappet that is acted upon and lifted by a pin rotating with the
rotary measuring device and then released so as to permit the rod to suddenly
fall upon an arm projecting from the shaft and so partly rotate it and the thrower
to the desired extent, the backward movement of shaft and thrower being
effected by gravity, aided it may be by other means such as a spring. By varying
the load, which is preferably in the form of weights, on the vertical rod, the blow

page_text: imparted to the shaft can be varied to suit the character of the fuel employed.
Buffers may be provided to limit the inward and outward movements of the
thrower and prevent shock. A suitable buffer is or may be also provided to
receive the blow of the falling loaded rod. The shaft may be provided with means,
for example a hand wheel, whereby it can, when desired, be turned in such a way
as to turn the thrower outward and downward to afford access to the furnace.
The firegrate may conveniently be composed of fire bars so mounted arranged
and operated that adjacent bars are first moved backward alternately and are
then moved forward altogether so that the fuel on them is gradually moved from
the rear to the front of the furnace. The said bars may be arranged to slope
downward from the back of the furnace.
My invention can be applied in connection with steam boiler and other
furnaces.
Improvements in and Apparatus for Effecting Combustion of Fuel in
Furnaces.
1, THOMAS MACALPINE, of 22, Sutton Court Road, Chiswick, Doglor of Science
and Consulting and Research Chemist, do hereby declare the nature of this inven-
tion, and in what manner the same is to be performed to be particularly described
and ascertained, in and by the following statement:--
According to this invention fuel is projected to the back portion of the furnace
'and is caused to be gradually returned by mechanical means to the front in such
wise that the more volatile matters and the fixed carbon may be oxidised by the
air, at or near the front portion of the furnace where the air remains comparatively
cool and dense. By this means the fuel can be more economically burnt and the
burning gases at the front part of the furnace are raised to a high state of incan-
descence, and are thus subsequently mixed with the lighter and more volatile
matters evolved from the fresh fuel delivered to the back part of the furnace,
whereby combustion is effected in such manner as to practically prevent the
formation of smoke.
Apparatus for carrying my invention into effect may be constructed of various
forms and arrangements according to the types of furnaces to which the inven-
tion is to be applied, and I will by way of example now describe an application
of my invention to a common type of steam boiler furnace from which any person
skilled in the art will obtain such information as will enable the construction
to be altered to suit other furnaces. In the accompanying drawings Fig. 1 is a
longitudinal section Fig. 2 a front view and Fig. 3 a side view shewing
diagrammatically an application to a steam boiler furnace.
At the front end of the furnace A, above the firing opening, I provide a fuel
hopper B, closed at the lower end by a measuring device, consisting of a hollow
cylinder C, carried by a shaft 1), capable of rotation in bearings I, fixed to the
front plate A', of the boiler. The cylinder C, has a portion of its cylindrical
wall cut away throughout its length as at Fig. 1-so that during its rotation
it will receive a measured quantity of fuel from the hopper B, and deliver same
below the hopper,

page_text: The hopper casing is continued downwards at B¹ and its lower open front portion
is (at times), closed by a curved plate E, which I term a "thrower," this thrower E,
is pivotted at its lower edge to a horizontal shaft E' carried by bearing brackets E³,
from the boiler plate A¹ the thrower is calculated to receive the charge of fuel
from the measuring drum C, and to project the said fuel to the back of the
furnace A. To produce this action the thrower shaft E¹, has keyed thereto at
one end an arm E, Figs. 2 and 3, and this arm is acted upon by the impact of
a vertically moveable rod F, loaded by weights F, and guided by bearing
brackets F, F2, the loaded rod F, is raised by means of a crank or disc pin G,
carried upon the shaft D, of the measuring drum C, which shaft is revolved as
required by any convenient or suitable means. The pin G, in its revolution acts
against a cam or tappet piece H, fixed on the rod F, the rod being lifted as the
pin G, revolves and allowed to fall to actuate the thrower E, and project the fuel
into the furnace. A suitable buffer is or may be provided to receive the
impact between the end of the rod F, and the arm E, and
an elastic
buffer F, may be provided between the weights F" and the bearing bracket Fa
Although it is not necessary to illustrate same in the drawing the thrower is
or may be arranged so that it should tend to fall by gravity from its momentary
position in dotted lines at Fig. 1, to its full line position, or this tendency of
motion may be produced by springs suitably arranged. Means should be pro-
vided to prevent the thrower from normally descending below the full line
position Fig. 1, such as a supporting bar J, carried in brackets J¹, and such
means (as the bar J,) should be made readily removeable so that the thrower may
be turned when required into the lower position shown by dotted lines at E³, so
that access may be had to the furnace. This movement of the thrower may be
effected by the removal of the supporting bar J, and the placing of a handle or
wheel on the square end Ex of the shaft E thereby throwing down the thrower..
In order to cause the fuel to be gradually moved forwards from the back of the
furnace, I may provide a travelling grate of any known construction or the grate
may be composed of fire bars K, so mounted arranged and operated, that the
adjacent bars are moved backwards and forwards and the fuel on them caused to
travel from the rear to the front of the furnace. The said bars are then arranged
to slope down as shewn and may be operated by a mechanically rocked shaft L.
In the position the mechanism is shewn at Fig. 3, the mouth of the measuring
drum C, is upwards and the drum is filled from the hopper, the thrower E, is in
its normal position, and the pin G, is just commencing to lift the rod F. At
Fig. 1, the motion is more advanced the rod F, has been lifted through a part
of its travel and the thrower E, is in position to receive the charge of fuel. The
apparatus should be so timed that upon the charge having been delivered from
the drum C, on to the thrower E, that the pin G, should be released the rod F, which
would descend and project the fuel to the back of the furnace. By varying the
load on the rod F, the blow imparted thereby can be varied to suit the character
of the fuel employed.
Having now particularly described and ascertained the nature of this
invention, and in what manner the same is to be performed. I declare that what
I claim is: —
1. In furnaces, mechanical means whereby a quantity of fuel is measured and
delivered from a hopper on to or into a plate or container, mechanical means by
which the plate or container is caused to project the fuel to the back of the furnace
and a mechanically operating grate by which the fuel is gradually carried to the
front of the furnace whereby the said fuel is more economically burnt and the
formation of smoke prevented, substantially as set forth.
2. In. furnaces, the combination of a fuel hopper a rotating drum to deliver
measured quantities of the fuel from the hopper, a pivotted curved plate to receive the
5 fuel from the drum, a vertically weighted rod to act by impact on an arm of the
thrower and cause the latter to project the fuel to the back of the furnace, a crank

page_text: pin on the shaft of the measuring drum to co-act with a tappet piece on the
weighted rod to raise and release the latter and a grate adapted to mechanically
carry the fuel to the front of the furnace, substantially as described.
3. The particular arrangement and combination of parts composing the im-
proved mechanism for feeding furnaces substantially as and for the purposes
described with reference to the accompanying drawings.
Dated this 14th day of July 1900
FREDERIC PRINCE,
37, Cursitor Street, Chancery Lane, London, Agent for Applicant.