IMPROVEMENTS IN EFFECTING THE COMBUSTION OF FUEL IN THE FURNACES, OF STEAM BOILERS AND THE FIRE-PLACES OF STOVES, AND OF GAS IN GAS J
Year: 1865

page_text: LETTERS PATENT to Frank Clarke Hills, of the Chemical Works, Dept-
ford, in the County of Kent, Manufacturing Chemist, for the Invention
of IMPROVEMENTS IN EFFECTING THE COMBUSTION OF FUEL IN THE FURNACES,
OF STEAM BOILERS AND THE FIRE-PLACES OF STOVES, AND OF GAS IN GAS
J
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills at:
"
the Office of the Commissioners of Patents, with bis Petition, on the
4th February 1865.
I, FRANK CLARKE HILLS, of the Chemical Works; Deptford, in the County
of Kent, Manufacturing Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN EFFECTING THE COMBUSTION OF FUEL IN THE
FURNACES OF STEAM BOILERS AND THE FIRE-PLACES OF STOVES, AND OF GAS IN GAS
BURNERS, AND IN APPARATUS CONNECTED THEREWITH," to be as follows:-
My Invention has for its object the application of heated air instead of air.
at ordinary temperatures to the ash-pits or ash-pans belonging to the furnaces
of steam boilers and to the fire-places of stoves, and also to gas burners. For
this purpose the external air is heated in its passage to the said ash-pits or
ash-paus, or gas burners, by that which is in most cases waste heat.
When my Invention is applied to a locomotive steam engine the smoke box
of the said engine should be prolonged, and the air to be heated is passed
j

page_text: either between and around a number of tubes (which may be extensions of
the ordinary boiler tubes) through which the volatile products of combustion
pass on their way to the chimpey (the said air being separated by a diaphragm
from the waste heat escaping to the chimney), or the said air is passed through
tubes or chambers between and around which the products of combustion pass
on their way to the chimney, the air heated in either way being conveyed by
a pipe or flue from the smoke box to the ash-pit of the furnace, which said
ash-pit is kept closed except at the part communicating with the said pipe or
flue. By either arrangement the air used for supporting combustion will be
heated before it enters the ash-pit, and a saving of fuel will be effected.
In applying my Invention to the boilers and furnaces of marine or of
stationary engines the apparatus by means of which the external air is heated
on its passage to the hot-air flue leading to the ash-pits of the furnaces will
be varied according to the particular construction of the boiler to which the
said apparatus is to be applied. Where the heat to which the fire-bars are
expose is great I make them of cast or wrought iron, preferably of a V or
taper shape in cross section, and with a longitudinal channel or space of a
section corresponding with that of the said bars, and I fill the said channel or
space with fire-bricks, or fire-tiles, or fire-clay.
the
In applying my Invention to stoves I construct the stove with a double
case, the inner case containing the fire, and the outer case surrounding and
being of greater depth than the said inner case, so as to form the ash-pan,
said outer case being of such a diameter as to leave a small space between it
and the inner case. Air is admitted through an aperture or through apertures
in the outer case above the fire-place, and such air passing through the space
between the interior of the outer case and the exterior of the inner case enters
the ash-pan in a heated state.
In applying my Invention to gas burners I furnish the gas burner with two
glasses fixed one outside the other. The inside glass should be about twice
the height of the outside one, which should be of such a diameter as to leave
a small space between it and the inside glass. The said outside glass should
be fitted into or upon an air-tight gallery or support so as to prevent the
access of air to the burner except through the passage between the two
glasses, the inner glass being mounted on an open gallery or support at a
higher level in order to allow the heated air to pass under its lower rim and
up to the burner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frank Clarke Hills in the Great Seal Patent Office on the
4th August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FHANK
CLARKE HILLS, of the Chemical Works, Deptford, in the County of Kent,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of February, in the year of our Lord.
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Frank Clarke Hills, Her special licence that I, the said Frank Clarke
Hills, my executors, administrators, and assigns, or such others as 1, the said
Frank Clarke Hills, 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
EFFECTING THE COMBUSTION OF FUEL IN THE FURNACES OF STEAM BOILERS AND THE
FIRE-PLACES OF STOVES, AND OF GAS IN GAS BURNERS, AND IN APPARATUS CONNECTED
THEREWITH," upon the condition (amongst others) that I, the said Frank
Clarke Hills, my executors or administrators, by an instrument in writing.
under my, or their, or of 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frank Clarke Hills, do hereby declare
the nature of the 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, that is to say:-
My Invention has for its object the application of heated air instead: of air
at ordinary temperatures to the ash-pits or ash-pans belonging to the furnaces
of steam boilers and to the fire-places of stoves, and also to gas burners. For
this purpose the external air is heated in its passage to the said aslı-pits or
ash-pans, or gas burners, by that which is in inost cases. waste heat.
When my Invention is applied to a locomotive steain-engine the smoke box.
of the said engine: should be prolonged, and the air to be heated is passed.

page_text: either between and around a number of tubes (which may be extensions of
the ordinary boiler tubes) through which the volatile products of combustion
pass on their way to the chimney (the said air being separated by a diaphragm
from the waste heat escaping to the chimney), or the said air is passed through
tubes or chambers between and around which the products of combustion
pass on their way to the chimney, the air heated in either way being conveyed
by a pipe or flue from the smoke box to the ash-pit of the furnace, which said
ash-pit is kept c'osed except at the part communicating with the said pipe or
flue. By either arrangement the air used for supporting combustion will be
heated before it enters the ash-pit, and a saving of fuel will be effected.
In applying my Invention to the boilers and furnaces of marine or of
stationary engines the apparatus by means of which the external air is heated
on its passage to the hot-air flue leading to the ash-pits of the furnaces will
be varied according to the particular construction of the boiler to which the
said apparatus is to be applied. Where the heat to which the fire-bars are
exposed is great I make them of cast or wrought iron, preferably of a V or
taper shape in cross section, and with a longitudinal channel or space of a
section corresponding with that of the said bars, and I fill the said channel or
space with fire-bricks, or fire-tiles, or fire-clay.
In applying my Invention to stoves I construct the stove with a double
case, the inner case containing the fire, and the outer case surrounding and
being of greater depth than the said inner case, so as to form the ash-pan, the
said outer case being of such a diameter as to leave a small space between it
and the inner case. Air is admitted through an aperture or through apertures
in the outer case above the fire-place, and such air passing through the space
between the interior of the outer case and the exterior of the inner case enters
the closed ash-pan in a heated state.
In applying my Invention to gas burners I furnish the gas burner with two
glasses fixed one outside the other. The inside glass should be about twice the
height of the outside one, which should be of such a diameter as to leave a
small space between it and the inside glass. The said outside glass should be
fitted into or upon an air-tight gallery or support so as to prevent the access
of air to the burner except through the passage between the two glasses, the
inner glass being mounted on an open gallery or support at a higher level
in order to allow the heated air to pass under its lower rim and up to the
burner.
Having thus described the nature of my Invention, I will proceed to describe
the manner in which the same is to be performed, reference being had to the
accompanying Drawings, and to the figures and letters marked thereon, with

page_text: respect to which said Drawings I would premise that the parts in section are
coloured red, and that the details, which are not shown, are of the ordinary
kind, and constitute no part of my Invention.
Figure 1 represents a longitudinal section (taken on the line t, Figure 2)
of certain portions of a locomotive engine to which is applied one of the
arrangements of apparatus for heating the air used for the support of com-
bustion according to my Invention; and Figure 2 is a transverse section
(taken on the line u, Figure 1) of the smoke box of the said engine and the
parts in connection therewith; Figures 3 and 4 represent,in full size, portions
of the apparatus as herein-after referred to. The same letters indicate the
same parts.
In Figures 1, 2, 3, and 4, A is the boiler of the engine, and B is the smoke
box, which is prolonged at C, the parts B and C being separated by the front
plate D of the sinoke box and the inclined diaphragm E; b, b, are tubes
which form continuations of the ordinary boiler tubes a, a, and are connected
therewith by being driven on the ferrules b', 6', as shewn in Figures 3 and 4,
which represent in longitudinal section and end elevation (partly in section)
respectively one of the ferrules and the ends of the tubes a and b, which it
serves to connect; the other ends of the tubes are fixed by ferrules in tho
usual way. F, F, are sheets or plates of metal which, together with the front
and back plates of the smoke box, form an air-tight passage communicating
at its lower end with a flue G, which is fixed low enough to clear the machinery
under the boiler,and communicates with the ash-pit H, which is closed except
at the part which opens into the said flue; I is the ash-pan, into which a
little water may be admitted in any convenient way in order to keep the ashes
damp, and thus cool the fire-bars and prevent them from clinkering; or
instead of admitting water into the ash-pit asmall jet of waste steam from the
cylinders may be admitted into the said ash-pit for the purpose specified. Kis
the induction pipe; L'is the blast pipe; and L is the breeches pipe com-
municating with the eduction ports.
The action of the apparatus is as follows:-The volatile products of com-
bustion pass from the tubes a through the tubes into the prolonged part c of
the smoke box, whence they escape by the chimney, as shown by red arrows z.
The air to be used for the support of combustion enters the part B of the
smoke box by apertures M, M, formed in the top thereof,and passing between
and around the tubes b, b, passes through the flue G and enters the closed
ash-pit H, as shown by blue arrows y.
Figures 5, 6, 7, and 8 represent another arrangement of apparatus applied
to a locomotive for heating the air used for the support of combustion, Figure 5

page_text: being a longitudinal section (taken on the line v, Figure 6) of part of a loco-
motive to which the said apparatus is applied, Figure 6 being a transverse
section (taken on the line w, Figure 5) of the same; Figure 7 a plan of the
smoke box and the air-heating tubes herein-after referred to; and Figure S
front elevation of the said tubes. The same letters indicate the same parts in
Figures 5, 6, 7, and S. This arrangement is especially applicable to loco-
motives in which the arrangement of the cylinders and valves is such as to
leave no space for the hot-air flue between them.
A is the boiler of the engine, and a, a, are the boiler tubes; B is the smoke
box, the upper part of which has a rectangular opening at b, b, to allow of the
insertion of a frame C (shown separately in Figure 8), in which is fixed, by
brazing or otherwise, a series of tubes c, c. The upper part of the frame C is
provided with a flange c', which is screwed tightly upon the smoke box B by
screw bolts c², c²; c³, c³, are hooks by means of which the said frame can be
lifted out of the smoke box when it is required to have access to the boiler
'tubes. The lower part of the said frame is formed with a slightly-inclined
rim c4, which fits tightly into a rim forming an opening of a corresponding
shape in the hot-air chamber D. This chamber communicates with a flue
E1, E2. The part E' of the said flue occupies the available space between the
front of the smoke box and the buffer bar F of the engine, and the part E² is
fixed low enough to clear the machinery under the boiler, and leads into the
ash-pitof the furnace in the manner herein-before described with respect to
the flue G, Figures 1 and 2. G is the induction pipe, and H is the blast
pipe, which passes through a circular aperture d formed in the hot-air chamber
D, and is bolted on to the steam bridge I which conveys the steam from the
eduction ports of the cylinders to the said pipe, it being necessary, both in this
arrangement and in that first described, to place the blast pipe and chimney
in the forward part of the smoke box in order to make room for the air-heating
tubes. The flue E', E2, is covered with "lagging" in order to prevent loss of
beat by radiation.
The action of the apparatus is as follows:-The volatile products of com-
bustion pass from the boiler tubes a, a, between and around the tubes c,c, and
escape by the chimney, as shown by red arrows z. The air to be used for the
support of combustion passes through and is heated by the tubes c, c, and
enters the hot-air chamber D), whence it is conveyed to the ash-pit of the
furnace by the flue E1, E2, its course being indicated by blue arrows y. In
this arrangement,as well as in that first described, care must be taken that
the air-heating pipes and the chamber or the frame in which they are placed
are so fitted as to prevent the volatile products of combustion either from

page_text: escaping into the air (except through the chimney) or from mingling with the
current of heated air used for the support of combustion.
In applying my Invention to the boilers and furnaces of marine orstationary
engines the apparatus by means of which the atmospheric air is heated on its
way to the ash-pits of the furnaces must be varied according to the particular
construction of the boiler to which the said apparatus is to be applied. The
general conditions to be observed are heating the air used for the support of
combustion by passing it between and around or through tubes or chambers
upon the interior or exterior surfaces of which the volatile products of com-
bustion are caused to impinge on their way to the chimney, the air so heated
being conveyed by a flue or pipe to the ash-pit of the furnace, which said
ash-pit is to be closed except at the part communicating with the said flue,
care being taken in the fitting and arrangements of the various parts for the
reason herein-before mentioned.
As the general arrangement to be adopted will be understood from tho
Drawings herein-before referred to, I do not think it necessary further to
describe or illustrate this part of my Invention.
Where the heat to which the fire-bars are exposed is great they may be
made of cast or wrought iron, preferably of av or taper shape in cross section,
aud with a longitudinal channel or space of a section corresponding to that
of the said bars, the said channel or space being filled with fire-brick, or
fire-tiles or fire-clay.
In applying my Invention to stoves I construct the stove with a double
case, the inner case containing the fire, and the outer case surrounding and
being of greater depth than the said inner case, so as to form the ash-pan, the
said outer case being of such a diameter as to leave a small space between it
and the inner case. Air is admitted through an aperture or through apertures
in the outer case above the fire-place, and such air passing through the space
between the interior of the outer case and the exterior of the inner case enters
theash-pan (which is closed except at the annular opening between the outer
and inner cases) in a heated state.
In applying my Invention to gas burners I furnish each burner with two
chimney glasses placed one outside the other. The inside chimneyglass should
be about twice the height of the outside one, which should be of such a
diameter as to leave a small space between it and the inside glass, so as to
limit the draught of the inside chimney glass to the desired extent so that
only a sufficient quantity of air for the combustion of the gas is heated, for if
too much air is allowed to pass between the two glasses it will not be suf-
ficiently heated for the purpose. The space required between the two glasses

page_text: will depend in a great measure upon the difference of height between them.
What I have found to answer well in practice is to allow a space of about
or of an inch between the two glasses, the inner one being three or four
inches higher than the outside one. The outside glass should fitted into or
upon an air-tight gallery or support so as to prevent access of air to theburner
except through the annular space between the two glasses, the inner glass
being mounted on an open or perforated gallery or support at a higher level
in order to allow the heated air which descends between the two glasses to
pass under the lower rim of the inside glass and up to the burner. The
openings in the gallery which supports the inside chimney glass are also tobe
limited so as not to allow more heated air to pass than is just sufficient to
effect the perfect combustion of the gas.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I do not
limit myself to the precise details herein-beforedescribed and illustratedinthe
accompanying Drawings, as the same may be varied without departing from
the nature of my said Invention; but I claim as my Invention,-
Firstly, the adaptation and application to steam boilers and their furnaces
of apparatus for the purpose of heating atmospheric air by means of what is
ordinarily waste heat,and introducing such air in a heated state into theclosed
ash-pits of such furnaces in the manner herein-before described.
Secondly, the construction of stoves in the manner described for thepurpose
of effecting the combustion of fuel in the fire-places thereof by the use of
heated air introduced into the closed ash pits of such stoves.
And, lastly, effecting the combustion of gas by means of heated air, heated
and limited in its quantity, as generally described.
In witness whereof, I, the said Frank Clarke Hills have hereunto set
my hand and seal, this Twenty-sixth day of July, in the year of our
Lord One thousand eight hundred and sixty-five.
Witness,
H. H. MURDOCH,
7, Staple Inn.
F. C. HILI.S. (L.S.)