IMPROVED FURNACE ARRANGEMENTS TO PREVENT SMOKE AND ECONOMIZE FUEL
Year: 1862

page_text: LETTERS PATENT to John Fleming Allan, of the Firm of Allan and
M Ruer, Ironfounders, of Glasgow, in the County of Lanark, North
Britain, for the Invention of "IMPROVED FURNACE ARRANGEMENTS TO
PREVENT SMOKE AND ECONOMIZE FUEL."
Sealed the 9th December 1862, and dated the 16th June 1862.
PROVISIONAL SPECIFICATION left by the said John Fleming Allan at the
Office of the Commissioners of Patents, .with his Petition, on the 16th
June 1862.
I, JOHN FLEMING ALLAN, of the Firm of Allan and McRuer, Ironfounders,
of Glasgow, in the County of Lanark, North Britain, do hereby declare the
nature of the said Invention of "IMPROVED FURNACE ARRANGEMENTS TO PREVENT
SMOKE AND ECONOMIZE FUEL," to be as follows, that is to say:-
This Invention has. for object to prevent smoke and économise fuel in
connection with furnaces, such as are used with steam boilers. In carrying
out the improved arrangements according to one modification suitable in the
case of a boiler with an external furnace, the furnace bars are, by preference,
disposed entirely, or for the most part, forward of the boiler, the flue there-
from proceeding backwards under the boiler. To prevent or consume the
smoke, a sheet of air, or a series of currents of air, considerably heated, is
made to pass horizontally, or nearly so, above the fire, and immediately in
contact with the inner end of the furnace roof or flue, and with the boiler

page_text: bottom; and this heated air causes an increased combustion and generation of
heat immediately in contact with the boiler bottom, and whilst preventing
smoke, at the same time effects an increased production of steam from a given
amount of fuel. For the purpose of heating the air and causing its injection
as described, it is preferred to cover the furnace, or to line its roof, or a large
portion of it, with a kind of double shell, the space between the top and
bottom of which is open at the front end to admit air. This air passes over
the bottom shell, forming the actual roof of the furnace, and taking up heat
therefrom enters at the inner end in a highly heated state. The bottom shell
of this air passage or gill becomes intensely heated by the direct radiation
from the fire, and to cause a more complete communication of the heat to the
air, this bottom shell is, by preference, formed or cast with a number of pins
or projecting points, against which the air impinges in passing. The same
end may be obtained by forming the gill with ribs, dividing the space into
narrow, and by preference, tortuous passages, or the pins may be enlarged
into hollow cones, cups, or such like indentations, with their concavities open
to the fire. In the case of boilers with internal flues, the furnace, with its
warm-air gill, may be disposed outside and in front of the flue end, or it may
be arranged wholly within the flue or boiler, the fire in that case commencing
to act on the roof of the flue just beyond the inner end of the warm air gill.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Fleming Allan in the Great Seal Patent Office on the
15th December 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
FLEMING ALLAN, of the Firm of Allan and M Ruer, Ironfounders, of Glasgow,
in the County of Lanark, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of June, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Fleming Allan, Her special licence, that I, the said John Fleming
Allan, my executors, administrators, and assigns, or such others as I, the said
John Fleming Allan, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,

page_text: the Channel Islands, and Isle of Man, an Invention for "IMPROVED FURNACE
ARRANGEMENTS TO PREVENT SMOKE AND ECONOMISE FUEL," upon the condition
(amongst others) that I, the said John Fleming Allan, my executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed; and cause
the same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Fleming Allan, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:-
My said Invention has for object to prevent smoke and economise fuel in
connection with furnaces, such as are used with steam boilers. And in order
that my said Invention, and the manner of performing the same, may be
properly understood, I have hereunto appended a Sheet of explanatory
Drawings, showing the application of my Invention, by way of example, to
two varieties of steam boiler furnace, and to be referred to in particularly
describing my improved arrangements. The same reference letters are used
to mark the same or like parts in all the Figures. In carrying out the
improved arrangements, according to one modification, suitable in the case of
a boiler with an external furnace, such, for example, as is represented in front
elevation in Figure 1 of the Drawings, and in longitudinal vertical section
in Figure 2, the furnace bars A are, by preference, disposed entirely, or for
the most part forward of the boiler B, the flue C therefrom proceeding
backwards under the boiler. To prevent or consume the smoke, a sheet of
air, or a series of currents of air, considerably heated, is made to pass hori-
zontally, or nearly so, above the fire, and immediately in contact with the
inner end of the furnace roof and with the boiler bottom; and this heated
air causes an increased combustion and generation of heat immediately in
contact with the boiler bottom; and whilst preventing smoke, at the same
time effects an increased production of steam from a given amount of fuel.
For the purpose of heating the air and causing its injection as described,
the furnace D is covered, or its roof, or a large portion thereof, is lined
with a kind of double shell, E, F, the space between the top and bottom
of which is open at the front or outer end to admit air. This air passes
over the bottom shell E, forming the actual roof of the furnace D, and
taking up heat therefrom, enters at the inner end in a highly heated state.

page_text: The bottom shell E of this air passage or gill E, F, becomes intensely heated
by the direct radiation from the fire, and to cause a more complete com-
munication of its heat to the air, this bottom shell E.is, by preference, formed
or cast with a number of pins or projecting points G, against which the air
impinges in passing. The same end may be obtained by forming the gill with
ribs, dividing the space into narrow, and by preference, tortuous passages, or
the pins G may be enlarged into hollow cones, cups, or such like indentations,
with their concavities open to the fire. In the case of a boiler with an internal
flue, such as is represented in front end elevation in Figure 3, and in
Jongitudinal vertical section in Figure 4, the furnace D, with its warm air
gill E, F, G, may be disposed completely outside and in front of the flue end,
or it may project more or less, as shewn in these Figures. Or, again, it may
be arranged wholly within the flue or boiler, the warm air gill being still made
to extend inwards considerably over the fire, and the fire in that case com-
mencing to act on the roof of the flue just beyond the inner end of the gill.
. Having thus particularly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated, and that I do
not claim generally the causing of air to be heated and admitted into the
furnace, but that what I believe to be novel and original and claim as the
Invention secured to me by the herein-before in part recited Letters Patent
is, the using of improved furnace arrangements substantially such as are
herein-before described, and more particularly the causing of the warm air
gill to project considerably over the fire, to receive the direct radiant heat
thereof, and to insure the highly heating of the air.
In witness whereof, I, the said John Fleming Allan, have hereunto
set my hand and seal, this Thirteenth day of December, in the year of
our Lord One thousand eight hundred and sixty-two.
JOHN F. ALLAN. (L.S.)