An Improved Stove for Heating Purposes and also for Producing Electricity.
Year: 1891

page_text: Date of Application, 6th May, 1891
Complete Specification Left, 4th Feb. 1892-Accepted, 5th Mar., 1892
PROVISIONAL SPECIFICATION.
An Improved Stove for Heating Purposes and also for Producing
Electricity.
I, PAUL GIRAUD, of Chantilly, Oise, France, Doctor, do hereby declare the
nature of this invention to be as follows:-
The thermo-electric stove forming the object of my invention serves, as its name
indicates, both for the production of heat and of electricity to be used either for
lighting or for any other purpose. One of the principal features of my invention
consists therefore in the combination of a stove and of a thermo-electric battery
surrounding such stove and which utilizes part of its heat, the remainder of the
heat serving for heating purposes. The employment of a stove as a generator of
heat enables me to utilize for heating purposes the whole of the heat which is
usually lost in thermo-electric batteries, whence I obtain complete utilization of
the fuel consumed and consequently great economy. This utilization is rendered
all the more perfect by employing a slow combustion stove, of the form known as
portable stoves; this stove further offers, in the present instance, the primordial
advantage of having an absolutely regular combustion which ensures the hot joints
of the battery being kept at a constant temperature, thus effecting a regular
production of electricity.
In my invention the thermo-electric battery surrounds the outside of the stove,
the cold joints being towards the exterior and cooled by a current of air, and the
hot joints being towards the interior and heated by conductivity and radiation.
The elements of the battery are neither in contact with the fuel nor the products
of combustion, which circumstance together with a special arrangement of the
elements, avoids all deterioration and ensures an almost indefinite duration to the
battery.
The stove consists of two entirely distinct parts, an interior space constituting
the stove properly so called, and an annular space which surrounds the former
and encloses the thermo-electric battery. The whole rests on a base plate
mounted on wheels, which permit the apparatus to be shifted from place to
place.
The inner space consists of three parts;
1st. A conical cast iron basin of which the bottom is formed by a movable grid
and which rests on a cylindrical part of cast iron carried by the base, and in which
openings are formed for the passage of the ash tray and the grid.
2nd. Of a cylindrical cast iron part with ribs or rings, and which like the basin
is to hold the incandescent coal or fuel. A horizontal flange situated below the
flue for the escape of the gases, prevents the products of combustion from passing
directly to the chimney. By reason of its ribs or wings the cylindrical part acts,
so to speak, as a heat retainer, so as to diffuse the heat regularly over the whole
internal surface of the elements of the battery.
3rd. Of a sheet metal tube serving as a receiver of the non-incandescent fuel,
and situated above the winged cylindrical part.
The products of combustion pass to the outside of the winged piece, circulate
between the tube and a second tube concentric to the former, and then escape by
the flue.
The second tube ascends to the same height as the first tube, and, as well
as the latter, is at its upper end secured to a top annular basin of cast iron,
of which the object is to receive a packing of sand for the cover or lid of the
stove.
The annular space in which the elements of the battery are situated is limited

page_text: inside by the second tube above referred to, and outside by the cylindrical sheet
iron casing, both of which rest upon a circular flange or gallery formed in one with
the cylindrical part resting on the base, such flange which is pierced with holes
supporting the elements of the battery.
Finally a perforated cast iron part serves to close the top of the annular
space.
The elements which are formed of an absolutely homogeneous and constant alloy
having antimony for its base, are of special form; plates or blades connect the
elements and are made of German silver containing a well defined proportion of pure
nickel and of ferro-nickel. Each element is supported by a tail piece which not only
permits of easy insulation, but prevents the alloy from escaping should a thin edge
of the latter become fuzed.
The elements are placed side by side right round and throughout the height of
the furnace, their rear ends being situated against the second tube mentioned, which
by conductivity transmits the heat of the stove to them. The clements are on the
contrary cooled exteriorly by a current of air which, after entering by openings
formed in the base, passes by the openings in the circular gallery above referred
to, and through the open spaces left round each element, and finally escapes, after
becoming heated, by the opening in the perforated cover closing the annular space.
This circulation of air occurs over all the faces of the portion of the elements
which ought to be cooled including the exterior face, for there is a certain clearance
left between such exterior face and the sheet iron casing. To assist the cooling
such casing is blackened inside and outside.
This casing instead of being of sheet iron might be of any other metal, for
example, of copper, etc. It may be solid or perforated and either smooth or
provided with any system of projections or wings to assist the cooling; finally it
may be formed with double walls for a circulating water jacket.
In the arrangement of stove above described the products of combustion may
pass more or less directly to the chimney, and it follows that the upper parts of
the battery are less heated than the lower parts and generate a less intense current
than the latter. The utilization of the fuel will consequently be better and the
output of electricity will be increased if the hot gases remain longer within the
space between the two tubes referred to, and are obliged to rise to the upper part
of the stove. I obtain this result by interposing between the two tubes an
additional tube serving as a baffle.
In this arrangement the products of combustion arriving outside the winged
piece ascend between the inner tube and the additional tube, which may be of
sheet iron or of cast iron, then pass by openings formed at the upper part of
this additional tube, descend in the space between the additional tube and the
outer tube, and escape by the flue after having given up the greater part of
their heat.
The horizontal flange of the winged piece, which in the first arrangement
prevents the products of combustion passing directly to the chimney will of course
be abolished as the additional tube will now serve the same purpose, and in a much
more efficient manner.
Beyond the advantages above indicated the additional tube avoids accidental
sudden increases of heat at the level of the part containing the incandescent fuel,
and which might occasion the fusing of the elements.
It is evident that without in any way changing the principle of my invention
instead of employing a fuel such as coke, coal or anthracite in my stove, I may
just as readily employ a liquid or gaseous fuel; the stove may be heated by gas or
by liquid hydrocarbons by simply removing the grid and introducing suitable
combustion apparatus in its place.
Dated this 6th day of Me 1901
ALLISON BROS.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Stove for Heating Purposes and also for Producing
Electricity.
I, PAUL GIRAUD, of Chantilly, Oise, France, Doctor, do hereby declare the
nature of this invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The thermo-electric stove forming the object of my invention serves, as its name
indicates, both for the production of heat and of electricity to be used either for
lighting or for any other purpose. One of the principal features of my invention
consists therefore in the combination of a stove and of a thermo-electric battery
surrounding such stove and which utilizes part of its heat, the remainder of the
heat serving for heating purposes.
The employment of a stove as a generator of heat enables me to utilize for
heating purposes the whole of the heat which is usually lost in thermo-electric
batteries, whence I obtain complete utilization of the fuel consumed and con-
sequently great economy. This utilization is rendered all the more perfect by
employing a slow combustion stove, of the form known as portable stoves; this
stove further offers, in the present instance, the primordial advantage of having
an absolutely regular combustion which ensures the hot joints of the battery being
kept at a constant temperature, thus effecting a regular production of electricity.
In my invention the thermo-electric battery surrounds the outside of the stove,
the cold joints being towards the exterior and cooled by a current of air, and the
hot joints being towards the interior and heated by conductivity and radiation.
The elements of the battery are neither in contact with the fuel nor the products
of combustion, which circumstance together with a special arrangement of the.
elements, avoids all deterioration and ensures an almost indefinite duration to the
battery.
The annexed drawing shows an example of a portable thermo-electric stove
constructed according to my invention,
Fig. 1 being a vertical section thereof, and Fig. 2 a horizontal section on a
larger scale, on the line Y-Z of Fig. 1.
The stove consists of two entirely distinct parts, an interior space A constituting
the stove properly so called, and an annular space B, which surrounds the former
and encloses the thermo-electric battery. The whole rests on a base plate a
preferably mounted on wheels b, b, and c, which permit the apparatus to be shifted
from place to place.
The inner space A consists of three parts:
First. A conical cast iron basin e of which the bottom is formed by a
movable grid, and which rests on a cylindrical part of cast iron d carried by the
base a and in which openings are formed for the passage of the ash tray and the
grid.
Second. Of a cylindrical cast iron part g with ribs or wings, and which like the
basin e is to hold the incandescent coal or fuel. A horizontal flange situated
below the flue o for the escape of the gases, prevents the products of combustion
from passing directly to the chimney. By reason of its ribs or wings the part g
acts, so to speak, as a heat retainer, so as to diffuse the heat regularly over the
whole internal surface of the elements of the battery.
Third. Of a sheet metal tube h serving as a receiver of the non-incandescent
fuel.
circulate
The products of combustion pass to the outside of the winged piece 9,
between the tube h and a second tube i concentric to the former, and then escape by
the flue o.
The tube i ascends to the same height as the tube h, and, as well as the latter, is
at its upper end secured to an annular basin of cast iron, of which the object is to
receive a packing of sand for the cover or lid of the stove.

page_text: The space B in which the elements of the battery are situated is limited inside
by the tube, and outside by the cylindrical sheet iron casing 1, both of which rest
upon a circular flange formed in one with the cylindrical part d; this flange,
which is pierced with holes c¹, supports the elements, which are further applied
against the exterior surface of the tube i. Finally a perforated cast iron part m
serves to close the top of the space B.
The elements which are preferably formed of an absolutely homogeneous and
constant alloy having antimony for its base, and which have a special form and
composition, are connected together by plates or blades s of pure nickel or other
material. Each of the elements is supported by a socket or cup t which not only
permits of easy insulation, but prevents the alloy from escaping should a thin edge
of the latter become fuzed.
The elements are placed side by side right round and throughout the height of
the furnace, their sockets t being situated against the tube i, which by conductivity
transmits the heat of the store to them through a layer of material which is not
acted upon by heat and which serves to insulate the elements electrically while at
the same time it holds their sockets t against the tube i; this insulating layer of
material is composed of asbestos board impregnated with silicate of soda. Further
a paste composed of asbestos and silicate of soda is interposed between each of the
elements and its socket t; washers or rings of silicated asbestos board are also
placed between the horizontal rows of sockets t, and, by means of the same
material, the different vertical rows are also insulated.
The elements are on the contrary cooled exteriorly by a current of air, which,
after entering by openings formed in the base a, passes by the openings in the
circular flange d', and through the open spaces round each element, and finally
escapes, after being heated, by the openings in the cover m.
This circulation of air occurs over all the faces of the portion of the elements
which ought to be cooled, including the exterior vertical face, for there is a certain
clearance left between such face and the sheet iron casing 1. To assist the cooling
such casing is blackened inside and outside.
This casing, instead of being of sheet iron, might be of any other metal, for
example, of copper, etc. It may be solid or perforated and either smooth or
provided with any system of projections or wings to assist the cooling; it may
further be formed with double walls for the circulation of water or other liquid or
fluid; and finally it might be omitted entirely.
In the arrangement of stove above described and which is illustrated in Figs. 1
and 2 of the drawings, the products of combustion may pass more or less directly
to the chimney; it follows that the upper parts of the battery are less heated than
the lower parts and generate a less intense current than the latter. The utili-
zation of the fuel will consequently be better and the output of electricity will be
increased if the hot gases remain longer within the space between the tubes h
and i, and are obliged to rise to the upper part of the stove. I obtain this
result by interposing between the tubes and i an additional tube serving as a
baffle.
In this arrangement, which is illustrated in Fig. 3 of the drawing, the products
of combustion arriving outside the winged piece g, ascend between the tube hand
the additional tube q, which may be of sheet iron, cast iron, etc., then pass by
openings p formed at the upper part of this tube descend in the space between
the tubes and i, and escape by the flue o after having given up the greater part
of their heat.
The horizontal flange of the winged piece g, which in the first arrangement
prevents the gases passing directly to the chimney, will of course be abolished, as
the additional tube 7 will now serve the same purpose, and in a much more
efficient manner.
Beyond the advantages above indicated, this additional tube avoids accidental
sudden increases of heat at the level of the part containing the incandescent fuel,
and which might occasion the fuzing of the clements.

page_text: It is evident that without in any way changing the principle of my invention,
instead of employing a solid fuel such as coke, coal or anthracite, in my stove, I
may just as readily employ a liquid or gaseous fuel; thus the stove shown in the
drawings may be heated by gas or by liquid hydrocarbons, by simply removing the
grid and introducing suitable combustion apparatus in its place.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. A thermo-electric stove composed of a chamber of any suitable form in which
any suitable combustible is burned, and of thermo-electric battery elements
arranged around such chamber so as to be heated on their inner part whilst they
are cooled on their outer part by an air current or otherwise; by which means the
heat developed by combustion serves both to heat the space in which the stove is
situated and to produce electric energy.
2. The interposition of one or two annular spaces between the chamber in which
the combustible is burned and the series of thermo-electric battery elements, such
annular spaces being included between the walls and or between the walls h, i,
and and through which the hot gases travel, with the object of avoiding the
deterioration which the clements might undergo if they were fixed to the wall / of
the combustion chamber; the additional wall, when it is employed, being pierced
with openings at its upper part, so that the hot gases ascend against the inner
face of such wall and descend against its outer face on their passage to the
chimney.
3. An outer casing of metal or other material surrounding the series of
elements which constitute the thermo-electric battery, and arranged so as to ensure
the cooling of the outer part of such elements either by a current of air entering by
openings situated towards the lower end of the annular space which it limits and
leaving by openings situated towards its upper end, or by means of a circulation of
water or other liquid or fluid in this wall, which is then made hollow; the said
wall being capable of being abolished to simplify the apparatus, leaving the
elements simply exposed to the contact of the outer air.
4. The electric insulation of the thermo-electric elements by means of a material
capable of also resisting the action of heat, and specially by means of asbestos and
of silicate of soda as described.
5. The arrangement and the combination of parts constituting the thermo-
electric stove, substantially as described and as shown in Figs. 1 and 2, and in
Fig. 3 of the drawings.
Dated this 4th day of February 1892.
ALLISON BROS.,
Agents for the Applicant.