IMPROVEMENTS APPLICABLE TO FURNACES OR FIRE-PLACES FOR THE GENERA- TION OF HEAT BY THE COMBUSTION OF FUEL
Year: 1873

page_text: LETTERS PATENT to Robert Boyd, of Mount Street, Grosvenor Square,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS APPLICABLE TO FURNACES OR FIRE-PLACES FOR THE GENERA-
TION OF HEAT BY THE COMBUSTION OF FUEL." -A communication from
abroad by Isidore Farinaux, A. Fichaux, O. Girol, and Herbert
PROVISIONAL SPECIFICATION left by the said Robert Boyd at the
Office of the Commissioners of Patents, with his Petition, on the
8th September 1873.
I, ROBERT BOYD, of Mount Street, Grosvenor Square, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS APPLICABLE TO FURNACES OR FIRE-PLACES FOR
THE GENERATION OF HEAT BY THE COMBUSTION OF FUEL," to be as follows:-
The object of this. Invention is to economize the consumption of fuel
in furnaces or fire-places by burning the fuel in such a manner that the

page_text: resultant combustable gases may be more effectually consumed so that
a larger amount of heat may be generated than heretofore. To this end
the fire-place or combustion chamber is made air-tight as is also the
ash-pit. The fire-place is made much deeper than usual so that there
may be a thick mass of fuel on the fire-grate.
Air to support combustion is supplied to the fire by means of a blower
or other mechanical equivalent, and the air may be either hot or cold as
may be preferred. This current or blast of air will carry the combustible
gases in the required direction, and a further quantity of either hot or
cold air may be supplied at different points to promote the combustion of
the gases.
Dampers are adapted to the flue so that the escape of the incombustibe
gases, and the draught through the combustion chamber may be
regulated as may be required. As the air is supplied to the furnace by
means of a blower, a high chimney to promote the draught may be
dispensed with.
The Invention is applicable for heating steam boilers or for melting,
puddling, or heating iron or other metals.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Boyd in the Great Seal Patent Office on
the 7th March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BOYD, of Mount Street, Grosvenor Square, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of September, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Robert Boyd, Her
special licence that I, the said Robert Boyd, my executors, adminis-
trators, and assigns, or such others as I, the said Robert Boyd,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter

page_text: 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 APPLICABLE TO FURNACES OR FIRE-PLACES FOR THE GENERATION
OF HEAT BY THE COMBUSTION OF FUEL,” being a communication to me from
abroad by Isidore Farinaux, A. Fichaux, O. Girol, and Herbert Sartoris,
all of Lille, in the Republic of France, upon the condition (amongst
others) that I, the said Robert Boyd, 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 Robert Boyd, 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, reference being had to the Drawing hereunto
annexed and to the letters and figures marked thereon (that is to say)
The object of this Invention is to economize the consumption of fuel
in furnaces or fire-places by burning the fuel, in such a manner that the
resultant combustible gases may be more effectually consumed so that
a larger amount of heat may be generated and utilized than heretofore
To this end the fire-place or combustion chamber is made air-tight as is
also the ash-pit, so that the necessary quantity of air to support
combustion can gain admission to the gas generator only through the
openings or channels provided for the purpose. The fire-place is made
much deeper than usual so that there may be a thick mass of fuel on
the fire-grate.
Air to support combustion is supplied to the fire by means of a fan,
blower, or other mechanical equivalent, and the air may be either hot
or cold as may be preferred. This current or blast of air will carry the
combustible gases in the required direction, and a further quantity of
either hot or cold air may be supplied at different points to promote the
combustion of the gases.
Dampers are adapted to the flue so that the escape of the incombustible

page_text: regulated as may be required. As the air is supplied to the furnace
under pressure by means of a blower or other equivalent device, a high
chimney to promote the draught may be dispensed with.
The Invention is applicable to furnaces for heating steam boilers or
for melting, puddling, or heating iron or other metals.
The generation of heat for those purposes is usually effected upon
open grates to which air is freely admitted, large quantities of combustible
gases and smoke thus escape up the chimney and are lost or wasted.
This mode of combustion only admits of utilizing a small portion of the
heat, the quantity varying with the particular form of the furnace and
other circumstances.
Many plans have been heretofore proposed for effecting a more
complete utilization of the heat evolved from the fuel either by
modifying the construction or form of the grate or fire-place, or by
adapting to the furnace a system of smoke consuming apparatus, or by
injecting into the flame above the fire-bars or under the fire-bars a jet
of steam or air, or by producing in gas generating apparatus combustible
gases, such as carburetted hydrogen or carbonic oxide which would be
conducted from the generator along suitable close channels, so that the
combustion of the gases would be allowed to take place only under the
boiler which it is desired to heat. Although this latter mode of
producing heat from the combustion of fuel is the preferable and most
rational one, the gas generator has heretofore always been separate or
distinct from the boiler, so that a certain portion of the heat evolved
from the fuel inevitably becomes lost by radiation before it reaches the
boiler. It is for this reason that the gas generator with the apparatus
for forcing in the air is (according to the present Invention) placed
beneath the boiler (in the case of boilers heated externally) or inside the
steam generator in the cases of tubular boilers or boilers heated by a
fire placed within them. The same may be said of reverberatory
furnaces. When the air is forced in and through the fuel or among the
gases it produces the combustion of the gases in the space above the gas
generator, and directs the flame towards the opposite end of the boiler
at the same time that it preserves the sheet iron from the possibly
injurious action of the blast. In fact the combustion of the gases is
completely effected by blowing in hot air at the upper part of the sides
of the gas generator, and also behind the bridge so as to mingle with
the gases.
.

page_text: ранулно
to a long cylindrical boiler provided with two large water tubes, and
shewing the arrangement of gas generator and suitable valves for
regulating the admission of the air.
Fig. 1, Sheet I., is a longitudinal vertical section of the apparatus
complete; Fig. 2, Sheet I., is a transverse vertical section, one half of
the apparatus being shewn in elevation.
The steam generator A is fixed in any convenient manner and is by
preference heated externally as shewn in the Drawings at Figures 1 and 2.
The two hot water tubes A¹, A", are supported at their outer ends by
the front plate D in which are also made the fire-doors E, E³, of the
furnace which on being opened are made to act upon a register, whereby
a communication is temporarily opened between the end of the gas
generator and the chimney. A second door F and F' shuts in as closely
as possible all the lower part of the fire-place, and the bottom edge of
this door is on a level with the upper surface of the grate bars G. These
latter doors are used when it is necessary to clean the grate bars and
remove the clinkers therefrom. It will be seen therefore that a thick or
deep mass of fuel or coal is operated upon, and that the fire-place or
grate is converted into a gas generator and simply acts in that capacity.
The lower plate of the grate G forms a horizontal joint with the front
plate D, and hermetically closes in the ash-pit and part beneath the
grate bars. A door H is made in this front plate for the convenience of
cleaning out the ash-pit, and an elbow tube L conducts air under
pressure from the conduit S to the space below the grate into which
space it is forced by a fan or blower.
It will now be understood that the space or chamber indicated in the
Drawing, Fig. 1, by B is the gas generator, upon the grate of which a
mass of coal of from sixteen to twenty-four inches in thickness is
charged. The air which is forced in under the grate bars (the quantity
of which is regulated by the valve V) is intended first, to decompose the
fuel by passing through the mass (while in a state of ignition), and
thereby produce the gas which with the air is transformed in the first
place into incombustible carbonic acid gas (C, O₁); then by passing
through the upper layer of coal while in a state of combustion, this
carbonic acid (C, O.) seizes a second atom of carbon and becomes
converted into C³, 0%, or 2, C, O, which is carbonic oxide, an essentially

page_text: combustible gas; secondly, the air passes along the passages a, b, c, d,
in order to raise its temperature by coming in contact with the heated
sides of the gas generating fire-place, and escapes through a number of
holes made in the sides of these passages as at a¹, 6', and also at the
back of the fire-bridge as at c, d, f. The upper part of the front plate D
carries a twyere or upper air pipe K which is provided with a valvo M
through which the air is drawn in and mixes with the gases which are
given off above the grate bars. The injection of the air admits these
gases, effects their combustion, and directs the flame towards the end of
the generator. This cold air laps round the water tubes with the flame
and at the same time counteracts the effects, which would be otherwise
produced by the blast from the twyeres being made to strongly impinge
on the iron. By this means the iron is preserved from the too great
intensity of the heat. This being admitted, when the boiler is intended
to be set to work, the lower door H of the plate D is opened wide as are
also the firing doors E and E¹, the doors F and F¹ being left closed;
then after opening the register the fire is lighted. The two doors E
and E¹ may then be closed until it is required to supply the fire-place
with more coal. When the pressure of steam in the boiler admits of the
engine being set to work, the fan or blower which forces in the air may
be put in motion. The air is then drawn in and forced through the
upper twyere in quantities which are regulated by the valves V and M,
so that the combustion may be as complete as possible. It also passes
along the air passages and escapes from the sides through the openings
made therein and from the slits behind the bridge. By this means the
most complete decomposition of the coal into combustible gases is
produced, and the most economical combustion of these gases is effected.
I have described above the mode of applying the gas generating
fire-place to a steam boiler provided with hot water tubes and heated
externally.
The Invention is equally applicable to boilers having one or more
internal fire-places, that is, fire-places arranged within the body of the
boiler. In this instance the grate must be reduced in size about one
half, and lowered to such an extent as its width will admit. The sides
are protected by lumps made of fire-clay or other refractory substance,
and air passages are constructed in these fire-lumps. The bridge is also
constructed of refractory material and is closed below thegrate. The
first door of the furnace also shuts with a close joint below the level of

page_text: the grate through which the air is introduced. The operation of the
parts arranged in this manner is the same as in the arrangement shewn
in Figures 1 and 2, and above described.
Fig. 3, Sheet II., is an end elevation of a boiler with the gas generator
arranged within the body of the boiler in the manner just referred to;
Fig. 4 is a longitudinal vertical section taken in the line m, n, of Fig. 3,
of so much of the boiler and gas generator as is necessary to explain the
present improvements; Fig. 5 is a transverse vertical section of the
same taken in the line A, B, of Fig. 4, and Fig. 6, which latter is a
sectional plan view of the apparatus taken in the line C, D, of Fig. 4.
The part marked A in Fig. 4 is the gas generator, and the part marked B
is the ash-pit. A large pipe or tube 7 brings air under pressure from a
fan or blowing apparatus conveniently placed for the purpose, and
supplies such air through the branch pipe / to a box i (Figures 4 and 5)
extending across the upper part of the gas chamber, and provided with
a number of holes through which the air issues and commingles with
the combustible gases evolved from the fuel; j is the fire-door through
which the generator is from time to time supplied with fuel, and k is the
lower door by opening which access can be obtained to the grate bars 1, 1,
when they require cleaning. The ash-pit B is hermetically closed by.
means of the door m as in the former instance, and no air can be
admitted thereto except through the passages specially provided for the
purpose as will be hereafter explained.
The fire-bridge n is constructed of fire-brick or fire-lumps, and behind
it is placed the superheater o for heating the hair before it is allowed to
escape into and mingle with the gases. This superheater is made of
cast iron or other suitable substance, and is divided internally by a
number of vertical partitions in such a manner that the air passage is
diverted and made sinuous or serpentine. A longitudinal vertical section
of this superheater taken in the line E, F, of Fig 6, is shewn at Fig. 7,
in which the arrows indicate the direction in which the air circulates,
and when it is raised to a high temperature part of it escapes through
the slits or openings a, b, c, into the midst of the gases which are
evolved from the thick mass of fuel, and another part passes out through
similar openings at the back of the fire-bridge. The air which is
supplied to the ash-pit B for the purpose of being forced through the
body of fuel on the grate bars, passes under pressure from the air tube g
into the lower air box p (Figures 4 and 5) from whence a portion of it

page_text: escapes through the slits or openings p', p', into the ash-pit, and from
thence up through the fuel. Another portion of the air passes along the
pipe to the superheater o behind the fire-bridge, and from this
superheater the air when sufficiently heated escapes and mingles with
the gases as already explained. This form of superheater may if desired
be adapted to the furnaces or gas generators of boilers, such as that
shewn at Figures 1 and 2, and may be placed in any convenient position
to take up and utilize the waste heat.
I would here remark that gas generators and fuel economizers such as
those above described may be adapted with advantage to puddling and
reverberatory furnaces in place of the fire-places usually employed.
Having now described the Invention which has been communicated
to me by my foreign correspondents, and having explained the manner
of carrying the same into effect, I claim as the Invention secured to me
by Letters Patent as aforesaid, adapting to steam boilers or to puddling
and other furnaces or fire-places gas generators constructed, arranged,
and operated as herein set forth for the generation of heat by the
combustion of fuel in the manner shewn and described.
In witness whereof I, the said Robert Boyd, have hereunto set
my hand and seal, the Sixth day of March, in the year of our
Lord One thousand eight hundred and seventy-four.
DAD DAVD