IMPROVEMENTS IN FURNACES AND IN APPLIANCES CONNECTED THEREWITH FOR THE ECONOMICAL COMBUSTION OF FUEL
Year: 1874

page_text: LETTERS PATENT to Alfred de Pindray, of Novion-Porcien (Ardennes),
France, and of College Street, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVEMENTS IN FURNACES AND IN
APPLIANCES CONNECTED THEREWITH FOR THE ECONOMICAL COMBUSTION OF
FUEL."
Sealed the 10th November 1874, and dated the 14th May 1874.
PROVISIONAL SPECIFICATION left by the said Alfred de Pindray at
the Office of the Commissioners of Patents, with his Petition, on
the 14th May 1874.
I, ALFRED DE PINDRAY, of Novion-Porcien, Ardennes, France, and.
of College Street, in the County of Middlesex, Civil Enginner, do hereby>
declare the nature of the said Invention for "IMPROVEMENTS IN FURNACES!
AND IN APPLIANCES CONNECTED THEREWITH FOR THE ECONOMICAL COMBUSTION OF
FUEL," to be as follows:-
a
These improvements relate to furnaces for steam boilers for heating
retorts, soap, sugar, and other similar pans or vessels, by which
an economy in the combustion of fuel can be obtained, the furnaces'

page_text: being varied in shape and construction to suit the particular purpose or
the vessel to be heated thereby.
In carrying my Invention into effect I use brick or other refractory
material as the structure capable of withstanding the heat developed
from the kind of fuel used, and such as will best refract the rays of heat
upon or against the vessel from the fuel, which is upon bars set at an
inclination from the front to the back of the fire-place.
The central or other line of the boiler or vessel is taken and a plumb
line is dropped therefrom to a given distance, the terminal is then lifted
first to the right and then to the left to describe segments of a circle,
the limits of which are determined by the diameter or width of the
boiler or vessel's skin to form the sides, these being carried up to such a
height as to utilize the ascending products of combustion and the rays
of heat therefrom, which impinge against the 'sides, the upper parts of
which are inclined or turned in, so that the rays are refracted from these
parts also to prevent waste.
If two boilers or vessels are arranged side by side to be heated by the
products of combustion from one fire then the segments of two circles
are struck from the central points up to a given distance, the distance
between the points being connected by a sweep of a circle from a given
point in the vertical central line of the two boilers, or in some other
manner as found convenient.
In some cases I carry other vessels above to serve additional heating
vessels or as steam vessels, and I lead the flue along one or both sides
to utilize the heat of the escaping gases before they pass to the uptake
or chimney, the flue or flues being increased in diameter or size to permit.
of the free passage of the gases on their way to the chimney, the
increasing diameter or size of the flue or flues being in due proportion.
"
The plumb line measurement can be dispensed with, and the brick-
work can be built up to given distances from the boiler skin to give a
corresponding size or shape of opening or passage or an increasing
size of space
or passage the smoke and products of combustion
to pass through a chamber for a reserve of hot gas in flame is arranged.
between the main and the return flue, in which the gases developed.
by the heat can mix and be rendered more available for giving off
the heat contained in them. The bars of the furnace are of great
depth at their mid-section parts and very thin at their lower edges, the

page_text: tops being proportionately thick and with vertical partition pieces
between the sides to regulate the distance of one bar from the next, the
bars resting upon end frames with an opening for the passage of air as a
back fire draught.
When constructing furnaces for heating circular or other shaped pans
I build the flue or flues leading from the fire to the chimney of gradually
increasing width or height, or increasing in both width and height, and
I arrange the bars at an angle as before, the angle and the openings
between the bars and in the back end support being in proportion to suit
the entry of air from the ash-pit, according to the nature of the fuel
burnt.
In some cases the flue or flues may be in circular or spiral form, rising,
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred de Pindray in the Great Seal Patent Office
on the 14th November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
DE PINDRAY, of Novion-Porcien (Ardennes), France, and of Collego
Street, in the County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Letters Patent, bearing date the Fourteenth day of May, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors;
give and grant unto me, the said Alfred de Pindray, Her special licence
that I, the said Alfred de Pindray, my executors, administrators, and
assigns, or such others as I, the said Alfred de Pindray, 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 APPLIANCES CONNECTED THEREWITH FOR THE ECONOMICAL COM-
BUSTION OF FUEL,” upon the condition (amongst others) that I, the said
Alfred de Pindray, my executors or administrators, by an instrument in
i

page_text: 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 Alfred de Pindray, 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, that is to say :-
These improvements relate to furnaces for steam boilers for heating 1
retorts, soap, sugar, and other similar pans or vessels, by which an
economy in the combustion of fuel can be obtained, the furnaces being
varied in shape and construction to suit the particular purpose or the
vessel to be heated thereby.
In carrying my Invention into effect I use brick or other refractory 1
material as the structure capable of withstanding the heat developed
from the kind of fuel used, and such as will best refract the rays of heat
upon or against the vessel from the fuel, which is upon bars set at an
inclination from the front to the back of the fire-place.
The central or other line of the boiler or vessel is taken and a plumb 2
line is dropped therefrom to a given distance, the terminal is then lifted
first to the right and then to the left to describe segments of a circle,
the limits of which are determined by the diameter or width of the
boiler or vessel's skin to form the sides, these being carried up to such a
height as to utilize the ascending products of combustion and the rays 2
of heat therefrom, which impinge against the sides, the upper parts of
which are inclined or turn, so that the rays are refracted from these
parts also to prevent waste.
A boiler set in flues built in accordance with this part of my Invention
is shown in Figures 1 and 2 of the annexed Drawings. A is the boiler 30
of the ordinary return flue kind, and B, the brickwork of the setting.
The boiler is supported at its front end upon a bar or casting C at the.
mouth of the furnace, and at about its centre and rear end upon short
metal or fire-brick blocks D, D. The side flues E, E, as shown in
Figure 2, are very narrow and their faces are carried up at a distance of 35
Bay 4 inches from the sides and bottom of the boiler to the requisite

page_text: height, so that they in fact follow the contour of the 'boiler's shell,
whatever form that may be, and cause the gases from the furnace F to
envelop the boiler in a very effective manner for the evaporization of
the water and the generation of steam. These flues terminate at their
rear ends in an expansion chamber G, in which the gases from the
furnace can thoroughly mix and be rendered more available for giving
off the heat contained in them, the gases passing from the expansion
chamber G and through the ordinary return tubes or flues H to the,
uptake I in the usual manner. The bars of the furnace are of great
> depth at their mid-section parts and very thin at their lower edges, the
tops being proportionately thick; and with vertical partition pieces K
between the sides to regulate the distance of one bar from the next, tho
bars resting upon end frames L with openings M in them for the passago
of air as a back fire draught. These deep bars may be fitted to the
furnaces of marine and other boilers, in fact to any furnace, whether for
licating retorts, ovens, or in any case where perfect combustion is
required.
A plan of the furnace F, fire-bars J, and end frame L, showing the
back air openings M, is shown in Figure 3.
If two boilers or vessels are arranged side by side to be heated by the
products of combustion from one fire, then the segments of two circles
are struck from the central points up to given distances, the distance
between the points being connected by a straight line or a sweep of a
circle from a given point in the vertical central line of the two boilers,
or in some other manner as found convenient.
'
In some cases I carry other vessels above to serve as steam vessels,
and in which the steam can be superheated if desired, and I can lead
the flue along one or both sides to utilize the heat of the escaping gases
before they pass to the uptake or chimney, the flue or flues being
increased in diameter or size from the fire-box or fire-place end to the
chimney end to permit of the full expansion of the gases, if any, that
may be on their way to the chimney, the increasing diameter or size of
the flue or flues being in proportion to the expansion of the gases.
Two boilers for generating steam fitted with an upper vessel and set.
in flues in accordance with this part of my Invention are shown in

page_text: Figure 4 shows a side elevation of one of these boilers with the
furnace F and flues E in section; Figure 5, a plan of same with the
upper flues shown in section; whilst Figures 6 and 7 are sections taken.
in the lines X, X, and Y, Y, respectively.
These boilers are supported in their flues in a similar manner to that a
shown in Figure 1, viz., on a bar or casting at the furnace end and on
short blocks at their centres and rear ends, as will be plainly seen. The
lower flue E, E, in this case is carried much higher up, in fact encircles
the lower vessels A, the under side of the arch of the flue terminating
slightly above the bottom of the upper vessel A¹. This flue at its rear.
end enters an expansion or gas mixing chamber G, as in Figure 1, from
which it rises and passes along one side of the upper vessel A¹ to the
front, and back again along the other side on its way to the chimney
stack. It will be seen that this flue from the point where it leaves the.
expansion chamber to the chimney gradually increases in sectional area,
this increase being in proportion to the decrease of the heat in the
escaping gases, which increases their velocity and has the effect of
drawing in through the furnace the necessary quantity of air to cause
perfect combustion of the fuel to take place within it.
The furnace, fire-bars, and back end plate are all similar to that shown
in Figure 1, the great depth of the bars effectively warming the air, so
that by the time it has travelled from the lower. to the upper edges of
them it passes into the furnace at a very high temperature.
The plumb line measurement can be dispensed with and the brick-
work can be built up to given distances from the boiler skin to give a
corresponding size or shape of opening or passage or an increasing size
of space or passage for the smoke and products of combustion to pass.
through to give room for the expansion of the gases therein.
When constructing furnaces for heating circular or other shaped pans.
I build the flue or flues leading from the fire to the chimney of gradually
increasing width or height, or increasing in both width and height, and
I arrange the bars at an angle as before, the angle and the openings
between the bars and in the end supports being in proportion to suit
the entry of air from the ash-pit, according to the nature of the fuel
burnt.
And, having now described the nature of my said Invention and.in

page_text: what manner the same is to be performed, I declare that I claim as my-
improvements,
The construction of furnaces, in the manner shown, in or by which
a less consumption of fuel effects the utilization of a larger amount of
heat than heretofore, as described, the temperature of the air being by
this Invention carried to a degree which permits it to rise with the
carbon in close or intimate combination, which being in the pro-
portionately necessary quantity, the phenomenon of the heat resulting
from the light transforms the molecules of solid carbon into carbonic
acid.
Secondly. I claim the construction or formation of furnace flues of
increasing area, from the rear of the flue outside the boiler to the
chimney shaft or stack, so that the products of combustion in their
travel can expand in a chamber and the contained gases be developed,
these being utilized in the return flue of ordinary boilers for throwing
off their heat therein prior to entering the uptake, as set forth and
shown.
Thirdly. I claim the construction and employment of bars, wedge-
shaped, in cross section and of at least 20 inches in depth at mid-section,
by which the air entering between them becomes heated effectively
prior to entering the furnace, in which the full caloric power of the air
is developed in combination with the products of combustion from the
fuel, as and for the purposes set forth.
In witness whereof, I, the said Alfred de Pindray, have hereunto set.
my hand and seal, this Fourteenth day of November, One thousand
eight hundred and seventy-four.
ATDTD TAT
מנזוזת
ATT
ALFRED DE PINDRAY. (L.S.)