IMPROVEMENTS IN THE METHOD OF BURNING COALS (WHETHER LARGE OR SMALL COALS), COAL DUST, COXE, COKE DUST, CHARCOAL, WOOD, AND OTHER COMBUSTIBLE SUBSTANCES, AS ALSO HYDROCARBONS AND GASES, AND IN THE ARRANGEMENT OF THE FURNACES APPLICABLE THERETO
Year: 1866

page_text: LETTERS PATENT to Thomas Joseph Leigh, of No. 7, Lansdowne Cottages,
Denmark Street, Camberwell, in the County of Surrey, Civil Engineer,
for the Invention of "IMPROVEMENTS IN THE METHOD OF BURNING COALS
(WHETHER LARGE OR SMALL COALS), COAL DUST, COXE, COKE DUST, CHARCOAL,
WOOD, AND OTHER COMBUSTIBLE SUBSTANCES, AS ALSO HYDROCARBONS AND
GASES, AND IN THE ARRANGEMENT OF THE FURNACES APPLICABLE THERETO."
Sealed the 7th December 1866, and dated the 12th June 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Joseph Leigh at
the Office of the Commissioners of Patents, with his Petition, on the
12th June 1866.
I, THOMAS JOSEPH LEIGH, of No. 7, Lansdowne Cottages, Denmark Street,
Camberwell, in the County of Surrey, Civil Engineer, do hereby declare the
nature of the said Invention 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 THE FURNACES APPLICABLE THERETO," to be as follows:-
In the burning of coal, coke, and other descriptions of fuel the great
desideratum is to have a form of furnace and a system or method of burning
in which all the conditions necessary to complete combustion of the fuel are

page_text: combined. Such conditions are not obtainable in any of the forms of furnaces
or modes of burning at present in use, whether in those furnaces employed in
connection with boilers for the generation of steam, as stationary, locomotive,
and marine, nor in any of the various forms used in heating or melting in the
numerous branches of manufacture. In all such furnaces the air supplied is
either greatly in excess or greatly deficient of that necessary for perfect com-
bustion. If it be seriously deficient the fuel if bituminous, is partly only
distilled or sublimed into black smoke and tarry soot the former of which is
carried off by the chimney, while the latter is deposited in the flues or gas
exits, and in the case of boiler furnaces in the internal surfaces of the tubes
and other heat-transmitting surfaces of the boilers, thereby rendering them
non-conducting, and thus an additional cause of further loss of effect. If the
fuel be carbonaceous only, as coke, and anthracite, its gases are only oxidized
to the state of carbonic oxide in part, and being thus only partially fitted for
combustion in a great measure pass off by the chimney without useful effects
in heating, and if the fuel be wood or peat this last result occurs with the
distillation of various tarry and acid products, the latter of which would prove
highly distructive to boilers. If the volume of air be greatly in excess, the
heat of the furnace is reduced, and to an extent to cause imperfect com-
bustion, with results analogous to those already described, as owing to a
deficiency of air, the air so heated passing off by the chimney.
In addition to the foregoing evils and irregularities in the way of obtaining
a complete combustion of the fuel in the present various forms of furnaces,
there are, besides the difficulties, first, of bringing the gaseous products of the
fuel and the atmospheric air necessary to the combustion of the former to the
temperature requisite to insure the production of carbonio acid and water (the
ultimate products of combustion); second, of having the constituent atoms of
the gaseous products of the fuel and atmospheric air thoroughly mixed or
incorporated.
With my arrangements of furnace and mode of burning the aforesaid
difficulties are got rid of, and before explaining the nature of my Invention, I
will premise what is essential to the complete combustion of any fuel, and
consequent developement of heat.
The absolute quantity of heat produced when auy fuel is burnt depends
upon and varies with the quantity of oxygen with which the constituent
clements of the fuel combine, while the intensity of that heat increases in a
high ratio, according to the increase of rapidity and energy with which that
combination is effected, and when effected completely, so that the ultimate
products of combustion are water and carbonic acid, the constituent elements

page_text: of the fuel must be at a high temperature, as also the oxygen or atmospheric
air in which they are burnt.
From the foregoing it is obvious that it is only necessary to bring the
atmospheric air or oxygen, and coustituent elements of the fuel together in
such a manner that a large surface should be exposed to their mutual action,
giving guarantee of a complete mixture of the atoms of the fuel with the
oxygen or atmospheric air, and this too at a temperature equivalent to a
white heat, when combustion will be certain and complete, producing a
temperature unparallelled by any system of burning or form of furnace
hitherto in use.
By my Invention I effect these objects, and the nature of it is to burn
coals (whether large or small coals), coal dust, coke, coke dust, charcoal,
wood, and other combustible substances, as also hydrocarbons and gases, on
and in a stratum or bed of molten iron, through which I force atmospheric air
or oxygen, or atmospheric air and steam, or any vapour which evolves oxygen,
and in order to do this I use a chamber or generator made of iron or other
material lined with fire-bricks, or other refractory substances, which chamber
or generator is closed in or arched over with a dome or other means, to
prevent the escape of the flames or loss of heat, except in the direction
required, where a rectangular aperture is provided, the lower edge of which
corresponds to or is analagous to the bridge in ordinary furnaces. On the
sole of this chamber or generator I introduce the stratum or bed of molten
iron (crude or pig iron as being the cheapest), and by means of one or more
tuyeres in the lower part or bottom of the chamber I force the atmospheric
air or oxygen up through the molten iron and fuel, also into the lower part,
and at one or more points between the level of the bottom or sole of the
chamber or generator and the top or dome I insert jet pipes, through which I
introduce steam at intervals, or in conjunction with the atmospheric air, or
not at all, as occasion may require, or the nature of the fuel to be burnt
will permit.
By this my Invention of burning fuel on and in a stratum or bed of molten
iron, and forcing atmospheric air or oxygen, or atmospheric air or oxygen in
conjunction with steam through the molten iron and fuel, I claim that I bring
the atmospheric air or oxygen and constituent elements of the fuel together
in such a manner that a large surface is exposed to their mutual action,,
giving guarantee to a complete mixture of the atoms of the fuel with the
oxygen or atmospheric air, and this too at a white heat, which insures not.
only immediate and perfect combustion of the gases or gaseous products of
the fuel, but that the solid portion of the fuel or carbon when such is used

page_text: cannot exist at such a heat in the presence of oxygen or atmospheric air
without rapid and perfect combustion.
I claim further that by this my system of burning fuel I can utilize the
small or fine coal (which hitherto has been left in the coal pits as worthless),
and with the same advantages or economical results as round or large coal of
the same quality, as it is obvious that with my system of burning there are
no fire-bars through which the fine coals will fall into an ash-pit and be
wasted, nor can it possibly cake or coke, as from the violent ebulition of the
molten iron it is being continuously broken up, exposing its incandescent
particles to the action of the oxygen of the air forced through the tuyeres.
It is equally obvious that by this system of burning where solid fuel is used,
such as coal, coke, and anthracite, the waste is reduced to that which has no
combustible property in it, viz., the ash.
The rapidity, energy, and completeness with which combustion goes on in
the chamber or generator under the aforesaid system of burning fuel produces
intense local heat in the chamber, and to utilize and apply this heat
economically I introduce steam, the decomposition of which moderates the
intensity of the combustion, and from being, under the circumstances, in
contact with highly ignited carbon or carbonaceous substances, produces
by such decomposition a mixture of bydrogen, carbonic oxide, and carbonic
acid gases, but in consequence of the great heat always present, very little,
if any of the latter gas is produced. The heat thus absorbed by the gases
liberated can be applied where required, either in the body of the furnace, or
under the boiler, or for whatever purpose needed. So that there is no loss of
heat, only a transmission of it from the generator, where it is not wanted, to
the furnace where it is applied.
I claim further that by so introducing steam to utilize the surplus heat in
the chamber or generator, I obtain a large amount of free hydrogen, which
has three times the heating power of any other gas, and weight for weight,
has three times the heating power of solid carbon. And in applying my
system or Invention of burning fuel to steam boilers for the generation of
steam to be used in steam engines, an economy can be effected in making
use of or introducing the waste steam from the engine into the chamber or
generator, where it will be converted into combustible gases, as herein-before
described. In supplying or feeding the chamber or generator with fuel, the
same can be done by means of a hopper with a funnel opening into the side
or top of the chamber or generator, fitted with an air-tight valve. The
fuel can be delivered into this hopper by any suitable arrangement of
mechanism, which governs the supply in proportion to the air forced in, and

page_text: to the description or nature of fuel used. The chamber or generator will
also require to be modified to suit the character of fuel used; as, for instance,
coke and anthracite coal, or carbinacous coals will require one arrangement of
the chamber or generator, fatty or bituminous coals another, hydrocarbons
another; and the general character of those modifications of the generator
consists in using one or more diaphragms or partitions made of any refractory
materials or substances, such diaphragms or partitions being fixed in the
interior of the chamber or generator opposite and parallel to the aperture or
bridge, and partially separating the chamber or generator into two or more
compartments. I say partially, because in some cases, depending on the fuel
used, the compartment furthest from the aperture or bridge is formed by a
partition or diaphragm extending from within a short distance of the top or
dome of the chamber downwards, and dipping slightly into the molten iron;
this compartment may be called the fuel compartment (and is more or less
capacious, according to the fuel used), where the fuel is decomposed, and its
constituents combined with oxygen, or atmospheric air highly heated (having
been forced through the molten iron), pass over the top of this partition, and
then downwards, striking upon the molten iron and particles of incandescent
carbon, giving an opportunity for any carbonic acid gas (if such should come
over from the fuel compartment) being recarbonized and fitted for combustion,
as it in conjunction with the other gaseous products of the fuel pass over the
bridge into the body of the furnace, or under the boiler, as the case may be.
When the fuel is bituminous, a second or third partition may be required,
with this difference, that the second partition or diaphragm inserted descends
from the interior of the dome to within a short distance of the molten iron;
if a third is required it rises out of the molten iron to within a short distanco
of the dome, or midway between the position of the bridge and the dome, the
gaseous products passing over the tops of the first partition, downwards
between the first and second, striking against the molten iron and incan-
descent carbon, passes under the second, over the third, thence downwards
between the third partition and the wall of the chamber, and finally through
the aperture or bridge into the body of the furnace. By these partitions the
gaseous products are delayed in their progress to the bridge, that they may
be thoroughly fitted for the process of combustion by allowing such gases to
become perfectly oxidized where it is necessary, and that they may become as
rich as possible by the accession on their route of hydrogen, carburetted
bydrogen, and carbonic oxide, these latter derived from the decomposition of
the steam over the ignited carbon.
Without departing from the nature of my Invention, I can perform what

page_text: has been herein-before described by blowing or forcing air through the molten
iron through tuyeres in the side of the generator or chamber, placed either
borizontally or inclined at an angle with the surface of the molten iron or
metal, or through tuyeres descending from the dome or top of the chamber
into the molten iron, or down through the fuel into the molten iron. Nor
am I to be understood as confining myself to any particular form or shape for
the chamber or generator, as the purposes to which the heat generated is to
be applied will more or less govern the shape or form the chamber is to be, as
also its dimensions or size.
I claim further that this chamber or generator and mode of burning fuel is
applicable to puddling furnaces, glass furnaces, furnaces for cupelling, oxidizing
lead and other metals, drying stoves, and for the general purposes of beating
or melting in the arts and manufactures, as also and in an eminent degree
to boilers of all kinds, whether marine, locomotive, or stationary, and with
very great.economy in fuel and boiler space.
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
11th December 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JOSEPH'LEIGH, of No. 7, Lansdowne Cottages, Denmark Street, Camberwell,
in the County of Surrey, Civil Engineer, send greeting.
WHEREAS 'Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of June, in the year of our Lord One
thousand eight hundred and sixty-six, in the twenty-ninth 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
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 THE FURNACES APPLICABLE
THERETO," upon the condition (amongst others) that I, the said Thomas

page_text: Joseph Leigh, 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 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 thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to say:―
My Invention consists in burning coals (whether large or small coals)
coal dust, coke, coke dust, charcoal, wood, and other combustible substances,
as also hydrocarbons and gases on and in a stratum, bed, or bath of molten
iron or metal, through which I force atmospheric air, or oxygen, or atmo-
spheric air and steam, or any vapour which evolves oxygen; and in order to
do this I employ a chamber or generator, which may be made of iron or
other material lined with fire-bricks or other refractory substances, which
chamber or generator is closed in or arched over with a dome or other means
to prevent the escape of the flames or loss of heat except in the direction
required where an aperture is provided, the lower edge of which corresponds
to or is analagous to the bridge in ordinary furnaces.
In the accompanying Drawings the same letters refer to similar parts in
each Figure.
Figure 1, Sheet 1, is a vertical section of one of my chambers or gene-
rators; Figure 2 is a sectional plan; and Figuro 8 is a front view of
same. A is the iron casing; B, the refractory brick, clay, or ganister lining;
C is the stratum, bed, or bath of molten iron or metal; D, the aperture
through which the flames pass, and which may lead on to the bed of a
puddling furnace, heating furnace, or melting furnace, or to the body of any
form of reverberatory furnace; E is the bridge; F is a partition, diaphragm,
or hanging bridge which descends from the crown or top of the chamber to
within a few inches of the surface of the molten iron or metal; G is a hopper
for containing the fuel, and may be made of any convenient capacity; H is a
cover or lid fitting air-tight into the rim of the hopper, the rim being made in
such a manner that it can be filled with sand or other like material. The lid
or cover can be easily opened or shut when required by means of the handle J,
the lid being counterweighted by the ball K attached to a chain passing over
the pulley L on the standard M. The dotted lines shew the position of the

page_text: lid or cover when partially open as also that of the handle. The funnel or
lower part of the hopper opening into the chamber or generator is enlarged
into a cylindrical drum N, in which is made to revolve a spindle or shaft O,
with radial arms or feathers upon it; these arms or feathers extend the
whole width of the drum, and in their radial direction fit to the inside of the
drum and completely close the throat or funnel, but so as to revolve easily.
On the end of the spindle is a pulley P, around which passes a belt P¹ to
give motion to the feathers or radial arms whereby the fuel is delivered into the
chamber or generator; Q' is the air main (fitted with stop-cock R) leading
from the fanner or blast cylinder; Q, Q, Q, are pipes from the main to the
tuyeres, and Q, Q³, are the tuyeres; S is a slag hole by which the sand and
other impurities (not combustible) in the fuel are run off in the form of slag
as occasion may require; S' is a fire-clay plug, and S is a door for more
securely retaining the plug in position; T is the tap hole by which the iron or
inetal is run off when the furnace is not required; T¹ is a fire-clay plug; T' is
a door for more securely retaining the plug in position; T³ is a feed hole in
the side of the chamber for charging the molten metals or coke and pieces
of metal, the latter to be melted down as in a cupola or finery to form the bed
or bath of molten metal; V, V, V, are steam pipes; G' is the fuel.
Having now described the chamber or generator, and the several parts
belonging thereto, I will describe its action, confining my remarks in so doing
to Figures 1, 2, and 3. The hopper G being supplied with fuel G' and
molten iron or metal introduced through the fuel hole T, the fanner or
blast engine is then started, and at the same time motion is given to the
radial arms in the cylindrical drum, whereby the fuel is gradually thrown
down upon the surface of the molten iron or other metal, when it is imme-
diately decomposed by the heat from the molten metal, and its gases are
forced by the pressure of the blast on and into the mass of molten metal by
which the constituent elements of the fuel and the blast are heated to a high
degree of temperature, mixing and passing through and over the molten
metal and under the bottom of the diaphragm or banging bridge F, rise in the
chamber in a sheet of flame, passing through the aperture D, over the bridge
E, to be employed in puddling, heating, melting, or generating steam, as may
be required. The rapidity, energy, and completeness with which combustion
goes on in the chamber or generator under the aforesaid system of burning fuel
produces intense local heat in the chamber; and to utilise and apply this heat
economically I introduce steam as occasion may require by the pipes V, V, V,
the decomposition of which moderates the intensity of the combustion, and
from being under the circumstances in contact with highly iguited carbon or

page_text: carbonaceous substances produces by such decomposition a mixture of hydrogen,
carbonic oxide, and a little carbonic acid gas; the heat thus absorbed by the
gases liberated can be applied, when required, either in the body of the furnace
or under the boiler, or for whatever purpose needed, so that there is no loss
of heat, only a transmission of it from the generator where it is not wanted to
the furnace where it is applied. I also have the quality of the flame entirely
under my control, whicb, chemically is of the greatest importance, particularly
in refining and puddling iron or steel, besides the additional advantage of
being able by my arrangement to bring the gases into the furnace or place
where the heat is required at a high temperature, thereby securing at the
working point the maximum of heat which enables me to melt large masses
of cast or puddled steel at one operation and without crucibles. Further,
from the nature of my process of burning fuel, I can (where coal is used as
the fuel) completely trap the sulphur and other impurities that may be in the
coal, by means of a suitable slag in connection with the bath or bed of molten
iron or metal in the generator, and so where my system is used to a puddling
furnace I can withold all gases or fumes from passing over the bridge that
may prove injurious or noxious to the iron or other metal under treatment.
In the present forms of puddling furnaces where pit coal is used as fuel, the
sulphur passes over the iron under the process of being puddled as sulphuretted
bydrogen, and must necessarily not only delay the ultimate purification of the
iron but tend to render it inferior in quality, while by my process of burning
you can turn on to the iron (under treatment) a strong decarburising flame,
a carburising blast, or an intense oxidising blast, or neutral flame, at will
retaining (by means of the slag above alluded to) in the fuel chamber or gene-
rator all noxious fumes and gases. My Invention also enables me to utilise
the small or fine coal and with the same advantages or economical results as
with round or large coal of the same quality. In fact it would be to the
advantage of my system if the coals were small or fine, and to this end in
place of the spindle with the radial arms or feathers revolving in the cylindrical
drum a pair of crushing rollers might be arranged at the base of the hopper
to perform the office of crushing the coals and feeding them into the chamber
or generator.
The chamber or generator may sometimes require to be modified more or
less from the form or arrangement as shewn in Figures No. 1, 2, & 3, Sheet
1, to suit the character of the fuel used with the view to a more perfect com-
bustion of the constituents of the same, as for instance, coke and anthracite
coal or carbonaceous coals may require one arrangement of the chamber or
generator, fatty or bituminous coals another, bydrocarbons another, and the

page_text: general character of such modifications of the generator are shewn in
Figures No. 4, 5, & 6, Sheet 1, which represent sectional elevations of the
chamber.
In Figure 4 the chamber is shewn with a partition or diaphragm F
partially separating the chamber into two compartments Z and Z. Z being
properly the fuel compartment, while Z' may be looked upon as more properly
the combustion compartment and gas mixing space, this arrangement of
chamber will suit for anthracite or stone coals and coke.
Figure 5 shews the chamber partially separated into three compartments
by means of the diaphragm F¹ and hanging bridge F, and Figure 6 shews
the chamber partially separated into four compartments by the diaphragms
F, F, and banging bridge F, and is, as also Figure 5, best suited for fatty
or bituminous coals. In these several arrangements the compartment Z is
to be always made more or less spacious according to the fuel used, where
the latter undergoes decomposition and its constituents combine with the
oxygen of the blast, thence passing (as in Figure 4) over the top of the
diaphragm F and thence downwards, striking upon and deflecting from the
surface of molten iron or metal in Z', thereby giving opportunity for the con-
stituent gases of the fuel, and atinospheric air or oxygen, being thoroughly
mixed and heated so as to insure combustion before passing over the bridge
E; the blast is here shewn forced up through the molten iron or metal and
the fuel. In Figure 5 the gases rise from compartment Z, pass over the
top of diaphragm F¹ thence downwards into Z impinging upon the molten
'iron or metal and the particles of incandescent fuel, thence between the sur-
face of the molten iron and bottom or lower edge of the banging bridge F,
thence upwards into Z' completing the process of mixing and thoroughly
Leating up as in the case of Figure 4. In Figure 6, the gases have a still
longer course to pursue before passing through the aperture D into the body
of the furnace or under the boiler as the case may be. By these partitions
or diaphragms and hanging bridge or bridges, the gaseous products of the
fuel are delayed in their progress to the bridge E, and passage D, that they
may be thoroughly fitted for the process of combustion by the accession on
their route of bydrogen, carburetted bydrogen, and carbonic oxide, these
latter derived from the decomposition of the steam let into the chamber by
the pipes V, V, V, over and in contact with the incandescent carbon which
lies more or less upon the surface of the molten iron or other metal in each
of the compartments having (from the disturbance and motion of the iron
caused by the blast) gradually worked its way into each of the compartments
from the first or fuel compartment Z.

page_text: Figure 7, Sheet 1, is a front elevation of the lower part of the chamber
or generator, shewing the position of the tuyeres in Figures 4, 5, and 6.
My Invention is also applicable for heating steam boilers and other
vessels; Fig. 8 is a vertical section through the fire-box of a locomotive
shewing the application of my system. In this arrangement I dispense with
the fire brick, fire clay, or other refractory material in the diaphragm or
hanging bridge, and introduce in its stead a water box F, divided into
three compartments by the plates f, f, for the purpose of producing a more
rapid circulation of the water at the part F, and allowing a more ready
escape for the steam generated; W is a valve with a handle and counter-
weight fitted to a pipe W' by which the products of combustion or gases
from the fuel pass off when the blast is not in operation. The induced cur-
rents through the tuyeres produced by the steam blast in the funnel, will be
found quite sufficient to produce perfect combustion of the fuel by my
system; Q is a valve or slide for closing the mouth of the tujeres the
moment the blast is turned off, or for regulating the quantity of air passed in.
Fig. 9 is a cross section through the fire-box in the center line of the water
diaphragm or hanging bridge, looking towards the tuyeres, four of which
are shewn, as also the slag holes.
In the case of locomotive or other boilers or vessels to which my Invention
may be applied, the molten metal can be provided by lighting a coke fire on
the sole or hearth of the chamber mixed with pieces of metal. The tuyeres
can be connected with a fan blast which can be urged by a small portable
engine and boiler, or one of Schele's steam fans, the metal will be run down
in about half to three quarters of an hour during which time the water in the
boiler will be heated up by the waste heat from the chamber or generator, and
by the time the iron or other metal is melted, steam will be up in the boiler, so
that the fuel used to run down the iron or metal will have also heated up the
furnace and raised steam to start working. The portable engine, boiler,
and fan can be dispensed with until next morning again. In the case of a
large depot where a number of engines are to have their fires lighted a
cupola sufficiently large could be used for running down metal sufficient for
all the engines, the metal to be poured into the fuel chamber or generator
of each engine through the feed hole T3 by means of a ladle.
Fig. 10, Sheet 2, is a sectional elevation through a marine boiler,
shewing the application of the chamber or generator; Fig. 11 is part
elevation and section of front of boiler shewing two furnaces, the chamber or
generator is made to roll into the space (occupied in the present system
the fire bars and ash-pit) and to fit by bolts or otherwise close up to the

page_text: front of the boiler. On board steam ships on long voyages, duplicate boxes,
chambers, or generators, could be provided, so that one sett may be always
in repair, ready for any emergency. The valve W, worked by the handle
W, opens into the uptake, and is for the same purpose as the valve W in
the locomotive arrangement. On board steamboats a fan blast, blowing
cylinders, or air current, induced by steam or otherwise, may be used to
supply the air of ignition.
Having now described the nature of my Invention, and in what manner
the same is to be performed, I wish it to be understood that what I claim
is,-
First, 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, on and in a stratum, bed, or bath of molten
iron or other metal.
Second, the arrangement of the furnaces applicable to this method of
burning as exemplified by the Drawings herein-before described.
Third, I claim that I can perform what has been herein-before described,
without departing from the nature of my Invention, by blowing or forcing
air by means of fanners, blowing cylinders, or by induced currents or
otherwise through the molten iron or other metal, through tuyeres in the sides
of the chamber or generator, placed either horizontally or inclined at an angle
with the surface of the molten iron or other metal, or through tuyeres
descending from the dome or top of the chamber or generator into the molten
iron or other metal, or by blowing or forcing air by induced currents or other-
wise down through the fuel into the molten iron or other metal. Nor am
I to be understood as confining myself to the particular forms or shapes of
the apparatus as shewn in the Drawings herein-before referred to, nor to
the exact position of the diaphragm or bridge, nor to the particular form or
materials of which the tuyeres may be made, nor to the particular angle or
position, nor part of the furnace at which they may be introduced.
Fourthly, I claim the advantage of being able (when it is desirable to do
so, as when my furnace is applied to the purposes of puddling or refining
iron) to trap or retain the sulphur and other impurities of the coal, that may
prove injurious or noxious to the iron or other metal under treatment.
Fifthly, I claim the advantage of being able (when my furnace is applied
to the purposes of puddling) to direct at will on to the iron or other metal
under treatment a strong decarburising flame, a carburising blast or an
intense oxidising blast, as also a neutral flame.
Sixthly, I claim the advantage of being able to burn coal dust and small

page_text: coal, with the same advantages, in thermal effect as round or large coal
will afford, and utilise all the small and fine coal which at present is left in
the coal pits as valueless.
Seventhly, I claim the advantage of being able to secure intense heats
enabling me to melt large masses of cast or puddled steel at one operation
and without crucibles.
Eighthly, claim that my chamber or generator or furnace can be applied
to all purposes of heating or melting metals or alloys or amalgam of metals,
also to boilers and other vessels for generating steam or evaporating, to
puddling furnaces, glass furnaces, furnaces for cupelling and oxidising lead
and other metals, and to a great variety of chemical and other operations
in the arts and manufactures.
In witness whereof, I, the said Thomas Joseph Leigh, have hereunto
set my hand, and scal, the Eleventh day of December, in the
year of our Lord One thousand eight hundred and sixty-six.
THOMAS JOSEPH LEIGH. (L.B.)