AN IMPROVED BOILER FURNACE AND METHOD OF BURNING COAL IN FURNACES
Year: 1873

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Sutton, in the
County of Surrey, for the Invention of "AN IMPROVED BOILER FURNACE
AND METHOD OF BURNING COAL IN FURNACES."- A communication from
abroad by Levi Stevens, of Washington, in the United States of
America
1
COMPLETE SPECIFICATION filed by the said George Tomlinson Bous,
field at the Office of the Commissioners of Patents, with his Pctition
and Declaration, on the 3rd November 1873, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Sutton, in the County of Surrey, send
greeting.
WHEREAS I am in possession of an Invention for "AN IMPROVED
BOILER FURNACE AND METHOD OF BURNING COAL IN FURNACES," and have
petitioned Her most Excellent Majesty Queen Victoria to grant unto
me, my executors, administrators, and assigns, Her Royal Letters

page_text: and terminating at their lower ends in nozzles which discharge into
openings e in the lower ends of the tubes D, and forward through the
nozzles a into the flues E. Annular spaces for the admission of air are
left around the nozzles a where they enter the flues E, and around the
ends of the pipes G where they enter the vertical tubes D as shewn.
H, H, are pipes through which steam from the boiler is conducted into the
rear ends of the superheaters.
The operation of the apparatus is as follows:-While combustion is
going on upon the grate A fresh coal is introduced into the fire-box or
chamber, and allowed to remain on the plate or hearth B where it is
roasted or coked by the heat of the fire on the adjacent grate without
being ignited thereby, so that a large amount of gas is generated or
evolved from the coal. The steam after passing through the super-
heaters and being raised to a very high temperature, thereby passes down
through the pipes H and blows forward in strong jets through the lower
ends of the tubes D and through the nozzles a into the flues E. The
steam jets produce a strong current or blast down through the tubes, and
inward around the nozzles a and pipes H into the flues E, the con-
sequence of which is that the gas generated from the coal on the hearth
is drawn down through the tubes D and combined with the superheated
steam, and with the atmospheric air entering the annular spaces, and
then the mixture of steam, gas, and air, conducted by the flues E into
the ash-pit C below the fire-grate. From the ash-pit the compound vapours
ascend through the fire-grate and are consumed with the coke thereon,
the coal on the hearth being pushed back upon the grate to burn as fast
as it is roasted, or until it ceases to give off a free supply of gas. The
jets of superheated steam not only raise the temperature of the gas and
air when it combines with them, but also forces them forward with such
rapidity as to maintain a considerable pressure in the ash-pit and fire
chamber.

page_text: It will of course be understood that although the smoke pipe may be
omitted provision will still be made for allowing the flames and heat to
pass through the flues or over other extensive heating surface as
usual.
By means of the above described apparatus roasting the coal and then
combining the gas therefrom with superheated steam and atmospheric
air, and burning the combined gas, steam, and air, with the coke, I
utilize the coal to the best possible advantage, and maintain a very high
and uniform temperature in the fire-box.
The apparatus shewn in the Drawing and described above is especially
adapted for use in the fire-boxes of the common boilers now in use, as it
may be inserted without any change or alteration except the removal of
the grate bars.
It is obvious that the apparatus may be varied in form and size as
circumstances may require, and the arrrangement of the different parts
may also be changed. For example, instead of the hearth being at the
front of the grate it may be arranged lengthwise either in the middle or
on one or both sides of the grate, it being only necessary that the coal
thereon shall be subject to the heat of the fire on the grate, and free
from danger of ignition thereby.
Instead of the two side superheaters a single one may be used in any
suitable situation in the fire chamber.
Instead of introducing the combustible vapour into the ash-pit the
grate bars may be made hollow, perforated, and mounted in a hollow
frame through which the vapour may be introduced into them, so as to
issue through the perforations. This arrangement is shewn in Figures
3, 4, 5, and 6, in which A represents the hollow perforated grate bars, K
the hollow frame in which they are supported, and L a hollow bar
through which the vapour is introduced into the frame, whence it passes
through openings g into the ends of the grate bars. In this instance the
bar L is arranged lengthwise in the middle of the grate, and has a flat
closed top which forms the hearth upon which to roast the fresh coal.
As before stated my apparatus may be varied in many respects, the
essential points being that the coal shall be roasted and the steam super-
heated by the fire on the grate, and that the coal, gas, and superheated
steam shall be combined with atmospheric air and introduced into the

page_text: terial.
CLAIM.
1. A boiler furnace for the production of steam constructed without
smoke pipes or smoke stacks as a means of draft in aid of the process of
combustion, when constructed substantially as herein shewn and
described.
2. The herein described apparatus consisting of a hearth upon which
the coal is roasted, a steam superheater and conductors so arranged as to
combine the coal, gas, superheated steam, and atmospheric air, and
introduce them into the fire chamber, substantially as described.
3. The combination of the grate A, hearth B, ash-pit C, tubes G,
nozzles a, substantially as herein shewn and described.
4. The hollow perforated grate bars A in combination with the hollow
frame or its equivalent.
In witness whereof, I, the said George Tomlinson Bousfield, have
hereunto set my hand and seal, this Thirtieth day of October,
in the year of our Lord One thousand eight hundred and
seventy-three.