IMPROVEMENTS IN THE CONSTRUCTION OF BOILER FURNACES FOR ECONOMIZING FUEL AND PREVENTION OF SMOKE."
Year: 1878

page_text: LETTERS PATENT to Francis William Ashton, of Manchester, in the County of
Lancaster, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
BOILER FURNACES FOR ECONOMIZING FUEL AND PREVENTION OF SMOKE."
PROVISIONAL SPECIFICATION left by the said Francis William Ashton at
the Office of the Commissioners of Patents on the 10th October 1878.
FRANCIS WILLIAM ASHTON, of Manchester, in the County of Lancaster.
"IM-
PROVEMENTS IN THE CONSTRUCTION OF BOILER FURNACES FOR ECONOMIZING FUEL
AND PREVENTION OF SMOKE."
.
This Invention relates to improvements upon the subject matter of Letters Patent
granted to me, dated April 16th, A.D. 1878, No. 1508.
The portion of the furnace behind the fire-bars I construct as described in the
Specification of my said Letters Patent above referred to, and I arrange the fire-
bars in a slope equal to an inclination of from two and a half to three inches for
each foot of their length, so that the height of the front opening above the same
is only about one-third to one-quarter of the diameter of the flue, and the fuel will
have a slight tendency to gravitate towards the rear end of the fire-bars.
The "dead plate" which forms the continuation of the fire-bars I place only
about half in the flue, the other half projecting beyond the front end of the boiler
and forming the bottom of a hopper through which the fuel is supplied.
The front of the hopper (opposite to the opening above the fire-bars) is a door
sufficiently large to admit a rake for pushing the fuel forwards on to the bars. This
door is at all other times kept closed and the hopper is kept full of fuel so that no
air enters the furnace excepting what passes between the fire-bars.
Below the bars I put a framed rake, the teeth of which project upwards between
the bars, and I give this rake an intermittent motion by which the fuel is gradually
-

page_text: worked along the bars towards the chamber at the back, and the passage for the air
between the bars is kept open and clean.
"
If preferred any suitable form of "mechanical stoker may be employed for
pushing the fuel forwards either continuously or intermittently, the objects of the
Invention being to feed the fire in such a manner that the green fuel will be coked
on passing the mouth of the furnace, the gases generated being consumed on their
passage over the rest of the fire; this object being obtained by reducing the opening
as before stated and keeping the same always choked or closed with fuel so that no
air shall enter the furnace excepting such as passes between the fire-bars or under
the flat arch at the rear end of the same, as described in the Specification of my
former Letters Patent herein-before referred to.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis William Ashton in the Great Seal Patent Office on the 10th
April 1879.
FRANCIS WILLIAM ASHTON, of Manchester, in the County of Lancaster. "IM-
PROVEMENTS IN THE CONSTRUCTION OF BOILER FURNACES FOR ECONOMIZING FUEL,
AND PREVENTION OF SMOKE."
This Invention relates to improvements upon the subject matter of Letters Patent
granted to me, dated April 10th, 1878, No. 1508, the object of my present
Invention being to render the furnace self supplying and to cause the carrying
forward of the fuel to be automatic, regular, and certain.
Such being the nature and object of my said Invention, I will now proceed to describe
in detail the manner in which the same is to be or may be performed or carried
into practical effect; and in order that the same may be clearly understood,
have annexed hereunto a Sheet of Drawings illustrative thereof, and have marked
the same with figures and letters of reference corresponding with those in the
following explanation thereof:-
Fig. 1 in the annexed Drawing represents a longitudinal section of part of a
boiler showing the furnace and its improved apparatus, and Fig. 2 is an end view
of the boiler showing the adaptation of my improved apparatus to one of the.
furnaces.
. a, a, is part of the shell of the boiler; b, b, the flues; and c, c, the fire-bars.
The portion of the furnace behind the fire-bars I construct as described in the
Specification of my said Letters Patent above referred to, and I arrange the fire-
bars c, c, on a slope equal to an inclination of, say, from two to four inches for each
foot of their length, so that the height of the front opening above the same is only
about one-third to one-quarter of the diameter of the flue, and the fuel will have a
slight.tendency to gravitate towards the rear end of the fire-bars.
The "dead plate" d, d, which forms the continuation of the fire-bars I place only
partially in the flue, the part dx projecting beyond the front end of the boiler
being hinged and forming a portion of the hopper e, e, through which the fuel is
supplied.
The front of the hopper e, e, (opposite to the opening above the fire-bars) is a
door (or doors) ff, to admit a rake for pushing the fuel forwards on to the bars.
This door is at all other times kept closed, and the hopper 6, 6, is kept full so
that no current of air enters the furnace excepting what passes between the fire-
bars c, c.
There it a second hinged plate g, g, which when raised into the dotted position
closes the bottom of the hopper. These two hinged plates d* and g are connected
together by a link h, h, and two short levers i, i, so that they work simultaneously,
a hand lever k, k, being provided for operating the same. The furnace door may
also be provided with a projection which causes these plates to be thrown into the
dotted position as the furnace door is opened.
In front of the flues below the furnace door is a transverse shaft L, l, near one
end of which are two spur wheels m, m³, (one larger in diameter than the other).
The smaller wheel m is geared direct with a spur wheel n, n, keyed on the driving
shaft o, o, on which is also keyed the fast pulley p, p. The larger wheel m¹ is
geared by means of a carrier wheel q, q, with a small spur wheel n¹ fixed to or
cast with the boss of the pulley r, r, which runs loosely on the drawing shaft. It
will be evident therefore that when the driving strap is on the fast pulley P. p, it
will drive the shaft o, o, in one direction, and when it is on the loose pulley r, r,
it will drive it in the opposite direction and at a slower speed.
On the shaft o, o,
aro keyed two excentrics 8, 8, working in clips t, t, to which levers u, u, (above the
hopper) are connected by links v, v. To the ends of the levers u, u, are connected
pushers w, w, which as the levers rise and fall force the fuel down the hoppers e, e.

page_text: Below the bars I put a framed rake, the teeth of which project upwards between
the bars, and I give this rake an intermittent to-and-fro motion by which the fuel
is gradually worked along the bars towards the chamber at the back, and the
passage for the air between the bars is kept open and clean.
This rake is constructed as follows:-x, x, is a carriage to which are pivotted two
rows of teeth z, z. The carriage, o, travels on two bars 1, 1, and is drawn to and
fro alternately by the chains 2, 2. When the carriage moves slowly in the direction
of the arrow (the strap being on the pulley 2, r,) the teeth remain upright and carry
the fuel forwards, but as soon as the carriage arrives at or near the end of the bars
it comes against a stop 3, 3, pulling the rod 4, 4, in the same direction, and by means
of a link 5, 5, at its forward end causes the partial revolution of the shaft 6, 6, at
the upper end of which are attached two arms 7, 7, one of which comes against a
projection on the slide 8, 8, of the strap fork and causes it to put the strap on to the
pulley P, P, reversing the motion and bringing the rakes back at a quicker speed.
At the same time the teeth fall over by their own weight, or a projection from the
lower end of the rake teeth z, z, comes against a stop which throws the teeth 2, 3,
into the position drawn in dotted lines, with their points below the surface of the
.bars, so that they do not act as the rake moves towards the furnace doors.
If preferred the rake teeth may be fixed on square bars and be thrown over into
the dotted position by a short lever on the end of one of the square bars coming
against a projection from the bridge frame or other fixed point. When the rake
carriage, a, has arrived at the position shown at Fig. 1 it comes against another
stop 10, 10, and draws the bar 4, 4, in the reverse direction, thus causing the strap
fork to put the strap on to the pulley r, r, and so on alternately, and at the same
time the rake teeth z, z, by coming into contact with the cranked bar 11, 11, will
be brought to their upright position ready for advancing. When the strap fork is
moved into its central position (as shown at Fig. 2) the shaft o, o, is not driven at
all. If preferred any other suitable form of "mechanical stoker" may be employed
for pushing the fuel forwards either continuously or intermittently, the objects of
the Invention being to feed the fire in such a manner that the green fuel will be
coked on passing the mouth of the furnace, the gases generated being consumed on
their passage over the rest of the fire, this object being obtained by reducing the
opening as before stated and keeping the same always choked or closed with fuel so
that no air shall enter the furnace excepting such as passes between the fire-bars
or under the flat arch at the rear end of the same, as described in the Specification
of my former Letters Patent herein-before referred to.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I wish it to be understood that I claim as my Invention the arrangement
of apparatus herein-before described, and illustrated by the annexed Drawings,
or any mere imitation or modification constructed and operating in substantially the
same or a similar manner.
In witness whereof, I, the said Francis William Ashton, have hereunto set
iny hand and seal, this Eighth day of April, in the year of our Lord One
thousand eight hundred and seventy-nine.