CERTAIN IMPROVEMENTS IN FURNACES
Year: 1866

page_text: LETTERS PATENT to John Aiken Salmon, of Liverpool, in the County
of Lancaster, Engineer, for the Invention of "CERTAIN IMPROVEMENTS IN
FURNACES."
Sealed the 5th January 1867, and dated the 6th July 1866.
PROVISIONAL SPECIFICATION left by the said John Aiken Salmon at the
Office of the Commissioners of Patents, with his Petition, on the 6th
July 1866.
I, JOHN AIKEN SALMON, of Liverpool, in the County of Lancaster, Engineer,
do hereby declare the nature of the said Invention for "CERTAIN IMPROVE-
MENTS IN FURNACES," to be as follows:-
My Invention is designed for the purpose of effecting the more perfect
combustion of gases evolved from the fuel in furnaces, and the improvements
consist in extending the space of the furnace beyond the fire-bars, such exten-
sion forming the upper surface of a hollow receiver for fuel, which is fed into
the same through the "ash-pit" and beneath the ordinary fire-bars, the bridge
of the furnace being placed at a short distance from the point where the
extended furnace terminates. This extended portion of the furnace becoming
excessively heated by the fuel it contains effects a thorough combustion of
the gases evolved from the fuel on the ordinary fire-bars as such gases are
passing over the same into the flue.
A second part of the improvements consists in applying furnaces to boilers
where there is no internal space for the same. I construct outside the boiler a

page_text: semicircular jacket, the space formed between the inside of the jacket and the
outer surface of the boiler being employed for the purpose of containing fuel,
which is fed into the same through apertures formed therein on each side of
the boiler; the fuel as it is fed into the furnace through these apertures falls
on to ridges or steps, which have the effect of gradually allowing such fuel
as it is reduced to ashes to fall and accumulate upon a grid at the bottom,
whence it is withdrawn through a door provided for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Aiken Salmon in the Great Seal Patent Office on the
5th January 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
AIKEN SALMON, of Liverpool, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of July, in the year of our Lord One
thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said John Aiken Salmon, Her special license that I, the said John Aiken
Salmon, my executors, administrators, and assigns, or such others as I, the
said John Aiken Salmon, 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 " CERTAIN
IMPROVEMENTS IN FURNACES," upon the condition (amongst others) that I, the
said John Aiken Salmon, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, 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 John Aiken Salmon, do hereby declare
the nature of the 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 and accompanying Drawings (that is to say):-
My Invention is designed for the purpose of effecting the more perfect

page_text: combustion of gasses evolved from the fuel in furnaces, and the improvements
consist in extending the space of the furnace beyond the fire-bars, such exten-
sion forming the upper surface of a hollow receiver for fuel, which is fed into
the same through the "ash-pit" and beneath the ordinary fire-bars, the bridge
of the furnace being placed at a short distance from the point where the
extended furnace terminates. The extended portion of the furnace becoming
excessively heated by the fuel it contains effects a thorough combustion of the
gasses evolved from the fuel on the ordinary fire-fire-bars as such gasses are
passing over the same into the flue.
A second part of the improvements consist in applying furnaces to boilers
where there is no internal space for the same. I construct outside the boiler
a semicircular jacket, the space formed between the inside of the jacket and
the outer surface of the boiler being employed for the purpose of containing
fuel, which is fed into the same through apertures formed therein on each
side of the boiler; the fuel as it is fed into the furnace through these apertures
falls on to ridges or steps, which have the effect of gradually allowing such
fuel as it is reduced to ashes to fall and accumulates upon a grid at the bottom,
whence it is withdrawn through a door provided for the purpose.
In order that the Invention may be better understood and explained in
detail, I have hereunto attached a Sheet of Drawings made upon a scale of
about three-quarters of an inch to the foot; similar letters of reference being
marked upon corresponding parts on all the Figures alike.
Fig. 1 represents a longitudinal section of a boiler furnace, shewing the
heating plates applied thereto for effecting the thorough combustion of gasses
passing over the same from the furnace; Fig. 2 represents an end sectional
view taken through the line A, B, of Fig. 1; Fig. 3 represents a front vertical
section of the furnaces of a two-flued boiler; this view represents a heating plate
having a convex surface in contradistinction to the flat-surface heating plate
shewn in Fig. 2; Fig. 4 represents another arrangement and modification of
the heating plates or chamber, in which a deflector against which the gasses
impinge is employed; and Fig. 5 represents an arrangement of furnace con-
structed outside the boiler plates which is to be employed for generating steam
in conjunction with the internal furnace and flue of the same boiler.
In Figs. 1, 2, and 8, a, a, is the outer shell of the boiler, and 6, 6, are the
flues of the same, where the fire-bars of the furnace c terminates a slanting
platform or table d composed of fire-clay slabs is provided, which extends
some distance in the flue, and at the termination of which the circular or
curved bridge e is placed; these slabs & may be constructed so as to form a
flat slanting table, as seen in Fig. 2; or the may assume a curved shape so

page_text: as to form a convex table or platform, as seen in Fig. 8; in either case they
terminate in an abutment against the bridge e near the bottom of the flue, the
intervening space f being left open as an air passage through the bridge. The
bottom or under portion of the flue enclosed by the fire-clay slabs is lined
with tiles g, this space h being enclosed by the sliding door i, which is con-
nected by means of the rod and chain k with the furnace door in such a
manner that when the furnace door is opened the sliding door i is simul-
taneously drawn back so as to admit air into the space h, which passes through
the channel into the flue. Thus when the furnace is in action the slabs or
plates d, by fuel being supplied to the space h, becomes excessively heated,
which heat being constantly emitted effects a thorough combustion of the
gasses evolved from the fuel on the ordinary fire-bars as such gasses are
passing over the heating plates into the flue.
In Fig. 4 another modification of plates and chamber is shewn for effecting
thorough combustion; the plate or slab d projects some distance from and on
a line with the fire-bars, and about midway in the space h formed between
the termination of this slab and the bridge e a hollow bridge or deflector m is
situated, the under fire being fed into the space h through the door i in the
manner before described, which amalgamates with the fire of the ordinary
furnace; thus when the gasses evolved from the furnace are passing off into the
flue they impinge upon the heated deflector m, becoming thereby slightly
retarded so as to be longer subjected to the heating plates or slabs and bright
fire d in the chamber h, the effect of which is to give a sufficient and thorough
combustion before passing into the flue; Fig. 5 represents the application of
outside furnaces to boilers for the purpose of effecting a quick generation of
steam; the outer surface of the boiler is provided with a jacket n, the space o
formed between the inside of the jacket and the outer surface of the boiler
being employed for the purpose of containing fuel, which is fed into the same
through the ventilating doors or apertures p, p, formed on each side of the
outer flue of the boiler. The fuel as it is fed into the furnace through these
apertures falls on to the ridges or step 2, 2, which gradually allow such fuel
as it is consumed to fall and accumulate upon the grid in the space s at the
bottom, whence it is withdrawn through a door supplied with ventilators
provided at the bottom.
Having now described the nature of the said Invention, together with the
method of carrying the same into practical effect, I wish it to be distinctly
understood that I claim the slabs or heating plates marked b, together with
the arrangement of under furnace for heating the same; also the general
arrangement, construction, and adaptation of the several parts composing the

page_text: furnace of steam boilers, as herein-before described, set forth, and fully
illustrated in the Drawings attached.
In witness whereof, I, the said John Aiken Salmon, have hereunto
set my hand and seal, this First day of January, in the year of our
Lord One thousand eight hundred and sixty-seven.
JOHN AIKEN SALMON. (L.S.)