IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES
Year: 1854

page_text: LETTERS PATENT to Robert Galloway, of Lambeth, in the County of
Surrey, Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF FURNACES."
Sealed the 12th September 1854, and dated the 22nd April 1854.
PROVISIONAL SPECIFICATION left by the said Robert Galloway at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
April 1854.
I, ROBERT GALLOWAY, of Lambeth, in the County of Surrey, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF FURNACES" to be as follows:-
My Invention consists in the employment of a tube, which I place below
the furnace bars, and carry into the bridge under the further end of the furnace
bars; I then bend this tube upwards, carry it to the top of the bridge, and
narrow it off at top; I then fit thereon a hollow metal mouth-piece, and carry
it up a greater or less distance above the brickwork of the bridge, according
to the size of the furnace. I make this mouth-piece to be readily removeable,
so that in cleaning out the flues it may be lifted out of the mouth of the tube,
and thus offer no impediment. I am aware that hollow bridges have been
already proposed; I do not therefore intend to claim them; but what I consider
new and as of my Invention is, the admitting of air by a pipe or pipes under
the furnace bars into the top of the bridge through a moveable metal mouth-
piece.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Galloway in the Great Seal Patent Office on the
21st October 1854.1
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
GALLOWAY, of Lambeth, in the County of Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria; by Her Letters
Patent, bearing date the Twenty-second day of April, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Robert Galloway, Her special licence that I, the said Robert Galloway, my
executors, administrators, and assigns, or such others as I, the said Robert
Galloway, 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, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CONSTRUC-
TION OF FURNACES," upon the condition (amongst others) that I, the said Robert
Galloway, by an instrument in writing under my hand and seal, should par-
ticularly 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 Robert Galloway, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say:
My Invention consists in the employment of a tube, which I place below
the furnace bars, and carry into the bridge under the further end of the furnace
bars; .I then bend this tube upwards, carry it to the top of_the_bridge-and
narrow it off at top; I then-fit-thereon-a-hollow metal mouth-piece, and carry
it up a greater or less distance above the brickwork of the bridge, according
to the size of the furnace. I make this mouth-piece to be readily removeable,
so that on cleaning out the flues it may be lifted out of the mouth of the tube,
and thus offer no impediment. I am aware that hollow bridges have been
already proposed; I do not therefore intend to claim them; but what I consider
new and as of my Invention is, the admitting of air by a pipe or pipes under
the furnace bars into the bridge, and through the top of the bridge into the
fire, through a moveable-metal-mouth-piece-or-valve.----

page_text: Figure 1 of the Drawings annexed is a sectional elevation, and Figure 2.a
longitudinal section of a Cornish boiler, having a furnace constructed according
to my Invention. A is the boiler, and B the fire-grate; C is the air tube, which
is formed by placing a plate of iron D, a few inches above the bottom of the
ash pit, and extending the whole length and breadth of it. This plate is air-tight
at the sides and bridge end, and forms the bottom of the ash pit, on which the
ashes, &c., fall from the fire-grate. E; E', is the bridge, which is made hollow,
as shewn in Figure 2; the front part E, or that which is nearest the fire being
built perpendicular, and the back part E' at an angle, leaving a hollow space
F between them, which forms a continuation of the air tube C, and is of suffi-
cient dimensions to admit of the movement of the parts by which the mouth-
piece or valve is worked, as herein-after mentioned. G is the mouth-piece or
valve, which is of an angular form, and is supported on two or more hooks H
(one only of which is seen in the Drawings), built into the brickwork of the
back part E' of the bridge. I is a lever fixed to the mouth-piece G; and J is
a rod with a handle, under the control of the engine man, connected to the
lever I, and by means of which the mouth-piece or valve G can be brought to
any desired position, so as to close wholly or partially the outlet from the hollow
of the bridge, as may be required. The rod J is formed with a rack near its
outer end, to enable it to be held by the catch K. in any position to which it
may have been moved. The arrangement described is also applicable to other
forms of boilers where the contraction of the space over the fire bridge is not
considered; but in cases where sufficient room is required for a man to pass
over the bridge, I form a portion of the front of the bridge of metal, and
attach it to the fixed part of the bridge, so that it may be readily removeable;
the valve then works against the top edge of this metal part instead of against
the corner of the fire lump at the top of the bridge.
Figure 3 is a sectional elevation, and Figure 4 a longitudinal section of a
still, copper, or boiler, having a furnace constructed according to this arrange-
ment; Figures 5, 6, and 7 are respectively a front elevation, a cross section,
and a plan of the mouth-piece which is fitted to the front of the bridge,
detached; and Figures 8 and 9 are a back elevation and a cross section of the
valve detached. A is the copper, still, or boiler; and B, the fire-grate; C is
the air tube; and E, E', the bridge, as before described; F is the mouth-piece,
which is fitted to the front part of the bridge E, and supported in position by
the projecting piece a, a, and the end pieces b, b, which latter come against the
sides of the furnace. G is the valve, which is supported by the hooks H, built
into the brickwork of the back part of the bridge E', and is worked by the
rod and lever J, I, as in the arrangement before described. The lever I is

page_text: secured to the valve by bolts c, and a flap d is fixed to the back of the valve to
prevent ashes, &c., from choking it. By removing the mouthpiece F and
unscrewing the bolts c, so as to free the valve, and then lifting out the valve,
ample space will be given above the fire bridge.
In the arrangements described, the air admitted to the furnace through the
tube C is entirely independent of that passing to the fire through the ash pit,
and hence the power of the chimney draught will not be diminished, whatever
may be the position of the valve G. The air admitted through the hollow
bridge will also be heated in its passage, by impinging against the front part E
of the bridge, which is exposed to the full heat of the fire. The advantage of
the valve at the top of the bridge is, that it controls the force and quantity of
the air admitted by it. In no two furnaces will the draught be the same.
When the draught is very sharp the valve requires to be only slightly open, for
if open too much, the quantity of air passing cools the brickwork below the
required temperature, and will not then consume the smoke, not having suffi-
cient force to mix with it, or rise above the top of the bridge. When the
draught is slow the valve requires to be opened a greater distance, to obtain
the proper quantity of air, which then passes in with less speed, and does not
cool the brickwork so quickly; in either case the valve is not required to be
open longer than two or three minutes, to bring the furnace to the proper
condition. When too much air is admitted at the bridge, the furnace will give
out as much smoke as when a solid bridge is used; it is therefore imperative
to have the power of regulating the supply.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim as my
Invention is, the admitting of air to furnaces by a pipe or pipes under the
furnace bars into the bridge, and through the top of the bridge into the fire,
by a moveable metal mouth-piece or valve, as herein-before described.
In witness whereof, I, the said Robert Galloway, have hereunto set my
hand and seal, this Twentieth day of October, One thousand eight
hundred and fifty-four.
R. GALLOWAY. (L.S.)