IMPROVEMENTS IN FURNACES, AND IN EFFECTING THE COM- BUSTION OF FUEL THEREIN
Year: 1867

page_text: Sealed the 2nd June 1868, and dated the 5th December 1867.
PROVISIONAL SPECIFICATION left by the said Thomas Joseph Leigh
at the Office of the Commissioners of Patents, with his Petition, on the
5th December 1867.
I, THOMAS JOSEPH LEIGH, of Laurence Pountney Lane, Cannon Street,
in the City of London, Civil Engineer, do hereby declare the nature of the
said lyvention for "IMPROVEMENTS IN FURNACES, AND IN EFFECTING THE COM-
BUSTION OF FUEL THEREIN," to be as follows:-
Letters Patent were granted to me on the 12th June, 1866, No. 1594, for
Improvements in the Method of Burning Coals (whether Large or Small
Coals), Coal Dust, Coke Dust, Charcoal, Wood, and other Combustible
Substances, as also Hydrocarbons and Gases, and in the Arrangement of
Furnaces applicable thereto." In my Specification of said Patent I described
a method of burning such combustibles on and in a stratum bed or bath of
molten iron or other metal, and various arrangements of furnaces applicable
[Price 6d.]

page_text: thereto, and the present application for Letters Patent has reference to certain
modifications and improvements therein.
I form a chamber lined with fire-brick or other refractory substance, which
chamber is closed in or arched over except at two places on opposite sides
where apertures are formed, the one for supplying fuel and the other for the
exit of the flames; this latter aperture leads to the bed of a puddling,
heating, or melting furnace, or to the working chamber of any reverberatory
furnace, cupola, or blast furnace, or around the sides or through the tubes of
a boiler where the heat is utilized. The chamber is formed with a partition
diaphragm or hanging bridge, which descends from the crown or roof of the
chamber to a certain distance from the bottom. Molten slag, or molten glass,
or molten metal covered by molten slag or glass occupies the bottom of the
chamber to a level of a few inches below the partition or diaphragm: the
chamber is thus separated into two compartments communicating with one
another through the passage between the lower side of the diaphragm and
the surface of the molten matter. The side of the first or feeding compart-
ment is either vertical or inclined, and through this side I introduce a
blast of air from a fan or other blowing apparatus; this may enter one by
tuyere, but I prefer to make it enter by numerous small tuyeres at suitable
levels. At the top of this compartment I place a fuel hopper, where by
suitable mechanism the fuel is passed as required for combustion into a shoot,
and made to fall upon an inclined metal plate, and thence into the chamber.
A stream of cold air is made to play upon the surface of the inclined plate so
as to keep it cool and assist the descent of the fuel into the feeding compart-
ment; the fuel in descending through the compartment is mixed with the air
entering by the Luyeres, and being kindled a continuous sheet of flame is thus
made to pass over the surface of the molten matter into the other compart-
ment of the chamber where it issues to the furnace with which it is connected.
I prefer to use heated air for the lower row of tuycres, as it tends to keep the
bed or bath of molten matter fluid, which renders combustion complete.
When coke in lumps, or anthracite coal, peat, wood, or charcoal is used as
fuel the hopper and mechanism for feeding may be dispensed with and the
furnace fed by hand through a small door in the feeding compartment. As
the ash or refuse of the fuel fuses into a slag after the furnace has been
working some time the level of the molten matter is raised; I therefore
provide a tapping hole at a proper level so that I can draw off a little of the
slag from time to time.
The construction of furnace and method of burning fuel which have
described is applicable to all the operations in the arts and manufactures where

page_text: high temperatures are required, such as for melting metals, smelting ores,
generating steam, evaporating liquids, or for the manufacture of glass,
porcelain, and earthenware.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Joseph Leigh in the Great Seal Patent Office
on the 4th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JOSEPH LEIGH, of Lawrence Pountney Lane, Cannon Street, in the City of
London, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of December, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Joseph Leigh, Her special licence that I, the said
Thomas Joseph Leigh, my executors, administrators, and assigns, or such
others as I, the said Thomas Joseph Leigh, 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 FURNACES, AND IN EFFECTING THE COM-
BUSTION OF FUEL THEREIN," upon the condition (amongst others) that I, the
said Thomas Joseph Leigh, my executors or administrators, by an instru-
ment 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 Thomas Joseph Leigh, 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:-
On the 12th June 1866, No. 1594, Letters Patent were granted to me
for Improvements in the Method of Burning Coals (whether Large or Small
Coals), Coal Dust, Coke, Coke Dust, Charcoal, Wood, and other Combustible
Substances, as also Hydrocarbons and Gases, and in the Arrangement of

page_text: Furnaces applicable thereto." In my Specification of said Patent. I described
a method of burning such combustibles on and in a stratum, bed, or bath of
molten iron or other metal and various arrangements of furnaces applicable
thereto, and my present Letters Patent have reference to the following
modifications and improvements therein:-
I form a chamber lined with fire-brick or other refractory substance, which
chamber is closed in or arched over except at two places on opposite sides
where apertures are formed, the one for supplying fuel and the other for the
exit of the flames; this latter aperture leads to the bed of a puddling, heating.
or melting furnace, or to the working chamber of any reverberatory furnace,
cupola or blast furnace, or around the sides or through the 'tubes of a boiler
where the heat is utilized. The chamber is formed with a partition diaphragm,
or hanging bridge which descends from the crown or roof of the chamber to
a certain distance from the bottom. Molten slag or molten glass or a bottom
or bed plate of metal covered with molten slag or glass occupies the bottom
of the chamber to a level of a few inches below the partition or diaphragm:
the chamber is thus separated into two compartments communicating with
one another through the passage between the lower side of the diaphragm
and the surface of the molten matters. The side of the first or feeding
compartment is either vertical or inclined, and through this side I introduce
a blast of air from a fan or other blowing apparatus: this may enter by one
tuyere, but I prefer to make it enter by numerous small tnyeres at suitable
levels. At the top of this compartment I place a fuel hopper, where by
suitable mechanism the fuel is passed as required for combustion into a
shoot and made to fall upon an inclined metal plate, and thence into the
chambers. A stream of cold air is made to play upon the surface of the
inclined plate so as to keep it cool. and assist the descent of the fuel into
the feeding compartment. The fuel in descending through the compartment
is mixed with the air entering by the tnyeres, and being kindled a continuous
sheet of flame is thus made to pass over the surface of the molten matter into
the other compartment of the chamber, where it issues to the furnace with
which it is connected. I prefer to use heated air for the lower row of tuyéres
as it tends to keep the bed or bath of molten matter fluid, which renders
combustion complete, but I do not confine myself to the use of heated air as
cold air might be used, though I consider heated air the more suitable for
the purpose. When coke in lumps or anthracite coal, peat, wood, or charcoal
is used as fuel the hopper and mechanism for feeding may be dispensed with
and the furnace fed by hand through a small door in the feeding compart-
ment. As the ash or refuse of the fuel fuses into a slag after the furnace has

page_text: been working some time, the level of the molten matter is raised; I therefore
provide a tapping hole at a proper level so that I can draw off a little of the
slag from time to time.
The construction of furnace and method of burning fuel which I have
described is applicable to those operations in the arts and manufactures where
high temperatures are required, such as for melting metals, smelting ores,
generating steam, evaporating liquids, or for the manufacture of glass,
porcelain, and earthenware.
DESCRIPTION OF THE DRAWINGS.
Fig. 1. Sheet 1. is a side clevation of a furnace constructed according to
my Invention Fig. 2 is a front elevation of the same; Fig. 3 is a sectional
plan; Fig. 4 is a longitudinal section: Fig. 5 is part of a transverse
section.
A, A', is a chamber lined with fire-brick or other refractory material; B is
a slit or aperture through which fuel is fed into the chamber A; C is the
aperture for the exit of the flames which may lead to the bed of a puddling.
reheating, or melting furnace, or to the working chamber of any reverberatory
furnace, cupola or blast furnace, or around the sides or through the tubes or
flues of a boiler where the heat is utilised: D is a partition, or diaphragm or
hanging bridge, dividing the chamber A, A', into two compartments A and A':
E is a bed of molten matter, which may be slag or glass, or metal covered by
molten slag or molten glass, or a solid metal bed so covered: F, F. are tuyeres
passing through the side of the chamber A, and supplied with air from a fan or
other blowing apparatus. I prefer that the air admitted to these chambers should
be heated, and this may be done by passing it through pipes in the chimney,
and conducting it by the pipe G to the tuyeres F, F, its admission to which
is regulated by valves H, H. J is a fuel hopper covered by a lid which has
a rim resting in a sand bed round the upper edge of the hopper, so that
when closed it is air-tight or nearly so, and which can be raised by the
handle J. K is a hollow cylinder having a fluted surface, the flutes running
in a slightly helical direction from end to end. The cylinder K is made to
revolve slowly by hand or by engine power communicated to it through the
gearing represented on the Drawing or other suitable mechanism.
L' is a
round bar or bolt on which a series of palls L' are strung side by side free to
vibrate thereon; these palls are heavy, and are so hung upon the bar L that
their surfaces can lean against the cylinder K, and thus prevent the fuel dust
contained in the hopper J from passing down into the feeding compartment A,
except the quantity which fills the flutes of the revolving cylinder K. M is

page_text: a tapping hole through which the fused ash or earthy impurities of the fuel
can be drawn off from time to time when its level rises above that of the tap
hole. N is an inclined plate on which the fuel falls from the cylinder K:
O is a pipe fitted with a regulating valve by which a current of cold air enters
the chamber O¹, escaping from it over the upper edge of the plate N, blowing
through a narrow slit over the upper surface of the same, and finally passing
with the fuel through the aperture B: the object of this blast is to keep the
plate N cool, and to assist the fuel in its descent into the feeding compart-
ment A. P is a door faced with refractory material by which access can be
obtained when necessary to the bed of the chamber A for cleaning or repairs:
Qis an air casing surrounding the cylinder K supplied with cold air from
the air chamber O¹ by the pipes Q, Q. I prefer to make the trunnions of
the cylinder K hollow, and to convey the cold blast also through it so that
the various parts of the feeding apparatus can be kept cool, and thereby the
generation of gas and the caking or coking of fuel in the hopper prevented.
G', G', are plugs for clearing the tuyeres.
The action of the apparatus is as follows:--The hopper J being supplied
with fuel and the lid or cover shut close, the chamber A is supplied with a
quantity of burning fuel, preferably in a state of incandescence through a
small door R at the side thereof; the blast is then gently turned on through
the tuveres F, F, so that the fuel burns freely and heats the lining of the
chamber A fuel is also admitted through another side door R until the
chamber A is filled to that level, and the whole of the fuel is brought to a
high state of ignition. A charge of cast iron broken small is then introduced
through the door R along with a small quantity of chalk, or lime, or other fluxing
matter to assist in forming slag; the blast is then increased so that the iron
and slag are fused, and this is continued till the slag begins to flow through
the tap hole M, or instead of using iron or running a slag in the furnace,
slag may be supplied in small pieces through the door R¹, or a composition
of sand, lime, and such like maiter, mixed up with a little moisture and made
into balls or lumps can be introduced after being thoroughly dried. or broken
glass may be added or common red ore. When the metal or slag is fused
and the fuel originally introduced is nearly consumed, the feeding apparatus
is put into action, and the fuel passing down between the cylinder K and the
palls L, L', falls on to the inclined plate N, and is injected into the chamber A,
little however passing into the compartment A'. The fuel in descending
through the chamber A is mixed with the air entering by the tuyeres F, F,
and a continuous sheet of flame is thus made to pass over the surface of the
molten matter into the compartment A¹, whence it issues to the furnace with

page_text: which it may be connected. After the furnace is put into operation I
introduce from time to time a flux to assist in fusing the ash and other earthy
impurities in the fuel; lime, limestone. chalk, or oyster shells answer this
purpose. After the furnace has been working some time, should the slag
become tough and tenacious or inclined to be hard or chill, a little alkali may
be added, or other suitable matter for making it more fluid or a little fresh
slag. The material to flux the ash and carthy impurities of the fuel may be
introduced through the door R or into the hopper with the fuel in propor-
tionate quantity and mixed throughout it. The action of the furnace is con-
trolled by means of the valves which admit the air and by change pulleys or
other mechanism for adjusting the speed of the feeding apparatus. In order
that no carbonic oxide or other inflammable gas or particles of fuel may
escape without receiving their full supply of oxygen or air, a pipe or air box S
fitted with a valve S admits air from the hot air pipe. G through several
tuyeres S', S', S', at the top of the compartment A', so as to meet the gases or
other inflammable. matters as they rise in the uptake.
Sheet 2, Figs. 1, 2, 3, represent respectively front and side elevations and
a section of a combustion chamber similar to that above described, except
that in place of the fluted cylinder and palls a pair of rollers T, T, are used
for the supply of the fuel; these rollers are geared together, and the distance
between them is adjusted by set screws. The other letters mark parts
corresponding to those described with reference to Sheet 1.
Fig. 1, Sheet 3, is a longitudinal section, and Fig. 2 is a transverse section
through the fire-box of a locomotive arranged according to my Invention.
The bottom of the box is closed by a plate U fitted with a manhole P, and
faced with refractory material. In this case, instead of using blowing
apparatus for producing a blast through the tuyeres F. F, the ordinary steam
blast in the funnel acts upon them by vacuum impulse, and the quantity of air
is regulated by a valve or slide F. The air chamber 01 and casing Q are
supplied by air entering through numerous apertures by the like vacuum
impulse. On first lighting the fire the tuyeres can be supplied from a fan or
other blowing apparatus.
Fig. 3, Sheet 3, is a longitudinal section through a marine boiler with a
furnace arranged according to my Invention, and Fig. 4 is part front elevation
and part transverse section. I prefer to mount the combustion chamber on
rollers, as represented in the Drawing, so that I can run it into the fire-box
and secure it there. For long voyages duplicate apparatus could be provided,
so that while one set is in action the other might be repaired. For boilers of

page_text: other forms apparatus of similar character can be applied, and the details of
construction may be varied to suit particular circumstances.
Having thus described the nature of my Invention, and in what manner
the same is to be performed, I would have it understood that I do not limit
myself to the details represented in the Drawings, nor do I claim the use of
such details per se or apart from the objects and purposes of my said Invention
as herein-before described.
In witness whereof, I, the said Thomas Joseph Leigh, have hereunto
set my hand and seal, this Twenty-ninth day of May, in the year of our
Lord One thousand eight hundred and sixty-eight.
Witness,
RP. COCKER,
21, Cockspur Street,
Charing Cross.
T. J. LEIGH. (L.S.)