IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PROMOTING THE ECONOMICAL CONSUMPTION OF FUEL IN THE FURNACES OF STEAM GENERATORS
Year: 1878

page_text: LETTERS PATENT to Francis Erskine, of Manchester, in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN THE METHOD OF AND
APPARATUS FOR PROMOTING THE ECONOMICAL CONSUMPTION OF FUEL IN THE
FURNACES OF STEAM GENERATORS."
Sealed the 13th August 1878, and dated the 15th February 1878.
PROVISIONAL SPECIFICATION left by the said Francis Erskine at the Office
of the Commissioners of Patents on the 15th February 1878.
1
FRANCIS ERSKINE, of Manchester, in the County of Lancaster, Engineer. "Iм-
PROVEMENTS IN THE METHOD OF AND APPARATUS FOR PROMOTING THE ECONOMICAL
CONSUMPTION OF FUEL IN THE FURNACES OF STEAM GENERATORS."
My Invention relates in the first place to the fire-grates of steam generators, and
consists in the employment of interlocking discs threaded upon shafts, to which a
revolving motion can be imparted to sustain the fuel and to carry it forwards.
The said shafts are mounted in suitable bearings, and are provided with suitable
gearing for effecting their rotation. I prefer to employ worms and worm wheels
for the said purpose.
The said gearing and the bearings are shielded by side
plates.
The portion of each shaft upon which the discs are threaded is square in cross
section, or is otherwise formed to cause each disc to revolve with the shaft.
The shafts are arranged to be parallel one with another, or thereabouts, and
to be at such a distance apart as that the discs on one shaft interlock with the
discs on the next shaft or shafts, that is to say, the discs on one shaft enter the
spaces between the discs on another shaft.
The peripheries of the discs may be plain, or be serrated or grooved so as to
take hold of the fuel
The gearing is so arranged
can be caused to revolve in one
towards one end of the grate.
spaces between the discs."
as that whenever desirable the whole of the discs.
direction, and thereby to carry or propel the fuel.
Air to supply the combustion flows through the

page_text: A second part of my Invention relates to the supply of air at required intervals
to mingle with the products of combustion flowing over the bridge. I employ a
hollow perforated or split bridge, or by preference two bridges, and I employ jets
of steam to induct a current of air to meet the said products of combustion.
In the arrangement which I prefer, I employ two bridges, the front bridge being
constructed over an air passage, which is provided with a hinged hanging door.
Steam is conveyed to a steam nozzle or to two or more steam nozzles, and means
are provided for admitting or shutting off the steam when required. When the
steam is turned on, the jets of steam issuing from the nozzles cause a current of
air to flow through the opening into the space between the two bridges, and to flow
upwards and mingle with the products of combustion. The said current of air
finds admittance by opening the aforesaid hanging door. When the steam is
shut off the said door closes.
In some cases each steam nozzle may discharge into a separate aperture leading
to the front, top, or back of the bridge, and if not considered to be necessary, the
said hanging door may be dispensed with.
In practice I prefer to turn on the steam at the time of "fireing " the furnace,
and to shut it off after a suitable interval of time.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis Erskine in the Great Seal Patent Office on the 15th August
1878..
"
FRANCIS ERSKINE, of Manchester, in the County of Lancaster, Engineer. “IM-
PROVEMENTS IN THE METHODS OF AND APPARATUS FOR PROMOTING THE ECONOMICAL
CONSUMPTION OF FUEL IN THE FURNACES OF STEAM GENERATORS."
1."
My Invention relates in the first place to the fire-grates of steam generators, and
consists in the employment (instead of the ordinary fire-bars) of interlocking discs
threaded upon shafts to which a revolving motion can be imparted to sustain the
fuel and to carry it forwards, » 21
.
70
10
A second part of my Invention relates to the supply of air at required intervals
to mingle with the products of combustion: flowing over the bridge. "I employ a
hollow perforated or split bridge (or by preference two bridges); and I have a jet
or jets of steam to induct a current of air. to meet the said products of combustion
so as to ensure the more perfect combustion of the fuel and to prevent smoke.
1
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
I 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, :.
1:
' 1. ..

page_text: Fig. 1 in the annexed Drawing is a longitudinal section taken vertically through
a boiler furnace constructed according to my Invention.
Fig. 2 is a similar section taken horizontally.
Fig. 3 is a transverse section and Fig. 4 is an end view of the boiler.
a, a, is the boiler flue and b, b, are the interlocking discs threaded upon transverse
shafts c, c.
The said shafts are mounted in suitable bearings, and are provided
with suitable gearing for effecting their rotation. I prefer to employ worms d, d,
and wheels e, e, for the said purpose. The said gearing and the bearings are shielded
by covering plates f, f.
The portion of each shaft c, c, upon which the discs b, b, are threaded, is square
in cross section, or is otherwise formed to cause each disc to revolve with the
shaft.
The shafts are arranged to be parallel one with another, or thereabouts, and
are mounted at such a distance apart as that the discs on one shaft interlock with
the disc on the next shaft or shafts, that is to say, the discs on one shaft enter the
spaces between the discs on another shaft, as seen at Figs. 1 and 2.
The peripheries of the discs may be plain or be serrated or grooved so as to take
hold of the fuel.
The gearing is so arranged as that whenever desirable the whole of the discs can
be caused to revolve in the direction of the arrow, and thereby to carry or propel
the fuel towards the back end of the grate. When it is required to clean out the
furnace the discs may be caused to revolve in the reverse direction, so as to throw
the fuel forward towards the furnace doors. Air to supply combustion flows through
the spaces between the discs.
I prefer to employ two bridges g, g, and h, h, the front bridge g, g, being con-
structed over an air passage i, i, which may be open or provided with a hinged
hanging door k, k. Steam is conveyed by a pipe l, l, to a steam nozzle, or two or
more steam nozzles m, m, and means are provided for admitting or shutting off the
steam when required. When the steam is turned on, the jets of steam issuing from
the nozzles m, m, cause a current of air to flow through the opening i, i, into the
space between the two bridges g and h, and to flow upwards and mingle with the
products of combustion. The said current of air finds admittance by opening the
aforesaid hanging door k, k. When the steam is shut off the said door closes.
In some cases each steam nozzle may discharge into a separate aperture leading
to the front, top, or back of the bridge, and if not considered to be necessary, the
said hanging door may be dispensed with.
In practice I prefer to turn on the steam at the time of "fireing" the furnace,
and to shut it off after a suitable interval of time.
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,-
First. The use or employment of interlocking discs threaded upon revolving
shafts in place of fire-bars, substantially as herein-before described, and illustrated
by the Drawings annexed.
And, Secondly. I claim the employment of a jet or jets of steam at or near the
bridge, for the purpose of inducing a current of air to produce combustion, sub-
stantially in the manner herein-after described and illustrated.
In witness whereof, I, the said Francis Erskine, have hereunto set my hand
and seal, this Thirteenth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.