A Process for Electric Heating and Furnace, for Realizing same.
Year: 1898

page_text: A Process for Electric Heating and Furnace, for Realizing same.
I, ALBERT ROUFAUT, of Loupy-le-Petit, Department of Meuse, France, Inventor,
do hereby declare the nature of this invention to be as follows:-
The present invention concerns a heating process utilizing the heat produced by
the electric arc, in such a way that the substance to be heated, solid or liquid,
is brought inevitably to the requisite temperature previously determinate for the
purpose to be attained.
This is a new result in industry.
The generic furnace employed for realizing my process may be considered as
being divided into two distinct chambers, rather according to their function than
to their construction.
In one of these chambers, that may be called furnace, the electric arc shoots
out, in the other, or heating chamber, the substance to be heated is placed.
To bring this substance to a rigorously temperature previously determined I
utilize either the calorific radiations of the arc, or the reverberation of the fire
proof walls employed for this furnace, or the combination of these two calorific
effects; in any case, the walls of the furnace form such a heat storing reservoir
that the slight variations of the intensity of the current-generating apparatuses,
have practically no influence upon the regularity of the temperature of the
furnace.
All things being equal, expense of energy, voltage, intensity, number and dimen-
sions of the electrodes the nature of these electrodes in the same furnace, the
temperature in the furnace decreases according as the point in consideration in
the heating chamber is more remote from the hearth; consequently at a determinate
point of the furnace, I can place any substance, to bring it to the temperature
corresponding with this point; moreover, at this very point I can obtain another
determinate temperature, which can nevertheless be regulated at will, by changing
the working order, of the furnace by a modification of the voltage, intensity,
dimension, number or nature of the electrodes or also of the volume or shape of
the chambers.
The fireproof materials forming the walls of the furnace, may be ready for the
definitive use, the wear and the changes of nature, which are inherent in this
use, being foreseen, or. these materials can be constituted in such a way that they
can undergo a completory formation, modification or constitution produced by
the actions or reactions of the gas evolving by the voltaic are between the electrodes,
into the composition of which substances of a suitable nature will have been
introduced. These substances may be of any kind, if the evolving gas is no
utilized. Should we wish to utilize the physical or chemical action of this gas
upon the heated bodies, the nature of the electrodes will vary according to need.
Their mode of advance according to the combustion is realized according to neces-
sity, and their isolation from the walls of the furnace is ensured according to

page_text: convenience to avoid the short circuits; finally, the currents utilized are of any
kind whatever.
The shape of the chambers of the furnace, the constitution of this furnace in
one or more parts, easy to be removed, repaired and changed, the number of the
ares, the grouping and the nature of the electrodes, depend upon the nature of
the substance to be treated, and with solid bodies upon their shapes and dimensions.
This process of heating with the furnace is highly suited for the heating of
metals for the purpose of soldering, forging, tempering, brazing, re-heating and
the like. It not only allows them to be brought to the temperature strictly
necessary for the execution of the work, but also: 1) removes the pernicious
influence which the intense light, produced by the arc, exercises upon the operator's
sight. 2) adulterates the chemical composition and the molecular structure of the
metal only quantitatively and thus avoids all misfits due to the presence of prejudicial
gas, carburants, oxidants and the like. The metals at work are protected, if
necessary, from the direct radiation of the arc, and from the immediate contact
of the gas evolved from it, either by a fire-proof bridge, or by a movable screen,
or by deviating the gas to the outside. Here we have, especially for the soldering,
a new manufacturing result which may be added to the above described ones, for
besides the fact that the parts to be soldered can be brought to a temperature
strictly determinate, the operator being sheltered against the wearisome light of
the arc, they are at the same time treated in such a way that the causes of misfits
produced by the difficulties of soldering are considerably diminished. These
causes are: 1) the presence of injurious gas. 2) contact of alien bodies, (coal,
ashes, iron drosses and the like) 3) an insufficient heating and 4) an over-heating
which burns the metal.
In case of soldering, the parts to be soldered, when once put in contact, are
pressed, hammered or driven forcibly one against the other by any means whatever
and with an apparatus, either independent of the furnace or adapted to it, reserving
to myself the right of using plates, welding pastes or powders now in the trade
for soldering.
The point for the site of the materials to be treated, is always judiciously
chosen, so that they may be brought to the temperature strictly necessary.
According to the shapes and proportions of these materials, they are placed in
the heating chamber, either totally or partly; or even, the part to be treated may
form the bottom of this chamber, the depth of which is strictly determined by the
temperature to be attained; the local part to be heated is only then exposed to
the heat of the furnace.
The heating may be localized on a narrow strip, up to the temperature necessary
for soldering.
Small objects like rings or meshes may be soldered by series proceeding by a
continuous advancing either of the furnace or of the objects.
The local heating is also suitable for long solderings, for instance, that of a
boiler tube, with a single arc, or a series of arcs, according to the soldering line.
When the object have thicker dimensions or offer a greater extent of surface,
such as boilers, I can place a furnace on each side of the objects to be soldered,
whichever be the shape of the soldering line.
I make either the furnace movable, or the object itself, so as to proceed in
a continuous or intermittent wav, at will.
Means identical with those described above are applied to the soldering of
metal framings, as also of sheet-iron in general, so as to suppress the riveting.
In the same furnace, one or more arcs can act upon several parts at once.
For the heating of fragile pieces, as for instance, watch springs these are
arranged on an endless chain, having a continuous movement and passing into
the heating chamber, at the point corresponding with the desired temperature,
between the branches of a screen formed of a material contributing to the heating;
on leaving the furnace, these springs fall into an oil-bath.
The annealing of numerous objects is done by this process, either in a con-

page_text: tinuous way, as with iron-wires, or in an intermittent way, for loose parts; the
localization or concentration of the heating also enables me to soften an object
on a small surface, for instance a stamping knife.
L. DUVINAGE,
Patent Agent,
S, Rue des Princes, Brussels.
I, ALBERT ROUFAUT, of Loupy le Petit, Department of Meuse, France, Inventor,
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 follow-
ing statement:-
The object of this invention is to provide means, in which the electric are will
be utilized to raise any desired substances or materials to the required previously
determined heat accommodated to the desired purpose.
And in order that this my invention may be the more readily understood and
carried into practical effect, reference is hereby made to the accompanying illus-
trative drawings, in which:
Fig. 1 shows the general form of carrying out my invention;
Fig. 2 shows a furnace more specially designed for reheating or soldering metal
bands or the like;
Fig. 3 shows the form of furnace serving to solder the longitudinal ends of
boiler-tubes or the like;
Fig. 4 shows a furnace adapted for soldering bottom-plates to boilers;
Fig. 5 shows an arrangement in which one arc may act on a plurality of tubes
or the like.
Figs. 6 & 7 are a side elevation and a cross section respectively of a furnace for
treating thin springblades or strips or the like.
Fig. 8 is a plan view of same with the upper part thereof removed.
Referring to the drawings and particularly to Fig. 1, the improved electric
furnace is composed of two distinct chambers or compartments, one of which or A
represents the fire-place or hearth, while the other or B is the heating chamber
and serves to receive the substances to be heated. In order to raise such substances
to the required, predetermined heat, may utilize either direct radiations of the
electric arc produced in chamber A, or a more or less proximate contact of burnt
products, or the reverberation of the fire-proof walls of the furnace, or the com-
bination of these various effects: the fire-proof walls of the furnace constitute a
suitable heat storage means and serve to compensate any variations in intensity
due to the current producing apparatus.
Regardless to the expenditure of energy, intensity, the number and dimensions
of electrodes, the nature of such electrodes, the degree of heat in a furnace similar
to that shown in Fig. 1, will be in direct proportion to the distance between the
determinate point in the heating chamber B and the hearth or fire-place; conse-
quently any substance placed at m n (Fig. 1) will be raised, to a heat corre-
sponding to this point of chamber B; furthermore at this point m n I may obtain
another degree of heat which may be controlled as desired by varying the conditions
of the furnace by a modification of the intensity, arrangement and size, the num-
ber or nature of electrodes employed, or the form and capacity of the chambers,

page_text: The electrodes employed may be of any composition if the gases evolved between
the electrodes are not utilized. But if the physical or chemical actions of such
gases on the substances to be heated are to be utilized, the nature of the electrodes
is to be varied correspondingly. The movement of the electrodes in accordance
with the combustion thereof may be obtained in any preferred manner, and the
electrodes properly insulated from the walls of the furnace to avoid short circuits;
furthermore I may employ any electric currents.
The shape of the chambers, the construction of the furnace of one or more easily
removable parts, the number of electric arcs, the arrangement and nature of the
electrodes depend upon the nature of the substances under treatment, and more
particularly for solid bodies, upon the form and dimensions thereof.
The improved furnace is particularly convenient for reheating, annealing,
soldering, forging, hardening, and brazing metals, which may be readily raised to
the required degree of heat; said furnace furthermore protects the operator from
the injurious influence of the intensive light produced by the electric are, and
avoids the usual deteriorations in quality of the metals under treatment, due to the
production of injurious gases; said metals may be protected from the direct
radiations of the electric arc or arcs and the proximate contact with the produced
gases by a fire-proof bridge, or a movable screen, as required.
If it is desired to join two metal parts the same are pressed, hammered or united
by any preferred means after being raised to a suitable heat within the furnace,
and such mechanical means or devices may be independent from the furnace or
form part of same, and the operation may be further facilitated by means of
welding powder or the like.
With the furnace shown in Fig. 1 of the accompanying drawings, the point mn,
where the body to be heated is to be placed, will be previously determined, so
that said body be raised to the necessary heat. Furthermore said body may be
entirely or partially introduced into the heating chamber B, in accordance with
the form and dimensions thereof, or it may form the end of said chamber, as in
Fig. 1.
In the furnace shown in Fig. 2, the heating action will be localized upon a
narrow band until the required heat is obtained for soldering or welding. Chain-
links or like small articles may be soldered in series, by running the same through
the furnace or moving the latter along the links.
The local heating is further convenient for long shuts or seams, as it is required
in boiler-tubes, (Fig. 3), in which case I may employ one or more electric arcs
as desired.
If the parts to be soldered are of greater dimensions or surfaces, I may arrange
a furnace on each side of said parts, as in Fig. 4 of the accompanying drawings.
Such furnaces may be very advantageously employed for uniting the various
parts of iron frames or the like, whereby the usual means for securing such parts
together may be dispensed with; to this end the furnaces may be arranged movably
as required.
The furnace may be further arranged and constructed so that one electric arc
acts on a plurality of parts; one electric arc may heat three tubes as in Fig. 5.
The furnace shown in Figs. 6, 7 and 8 of the accompanying drawings is particu-
larly arranged for heating metal strips, such as springs or the like, said strips
being arranged on an endless chain extending over two rollers a a' and running
through the furnace, that is, the heating chamber B which may be formed by a U-
shaped part of carbon or like material; after the heating action said strips are
preferably dropped into an oil-bath (not shown).
As it is evident that many changes in the construction and relative arrangement
of parts may be resorted to without departing from the spirit and scope of my
invention, I would have it understood that I do not restrict myself to the particular
construction and arrangement of parts shown in the accompanying drawings, but
that such changes and equivalents may be substituted therefor.

page_text: Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:-
1. A new or improved method of heating by electric arcs, the heat of which
may be controlled by any well known means, said arc being produced within a
furnace divided into two chambers; one of which constitutes the hearth or fire-
place, and furnishes heat to the second chamber, within which and at a deter-
minate point thereof a more or less high degree of heat is thus produced, so that
substances placed at a proper point be raised to a predeterminate heat, the walls
of the furnace serving to regulate the heating action.
2. For heating metals for any desired purpose, the method and furnace claimed
in 1, in combination with a suitable fire-bridge or screen, arranged between the
electric arc and the metal to be heated and allowing the latter to be protected from
direct radiations of said electric arc and direct action of injurious gases.
3. The means and method claimed in 1 and 2 for soldering or welding within
a furnace, protecting the operator from the light produced by electric ares and
avoiding the contact between the metals to be soldered or welded and any foreign
substances, such as coal, ashes, clinkers or the like, as well as gases adapted to
interfere with the soldering or welding operation or deteriorate the quality of
metals.
4. The means herein set forth in conjunction with a furnace of the class
described, the rear end of the heating chamber of which is formed to produce a
local heating of the metals under treatment, and terminated at a point which is
more or less distant from the electric arc in accordance with the heat to be obtained,
so that the other portions of the metal may be outside the furnace and cannot be
altered by the action of the heat, the furnace being provided with any required
number of suitably arranged arcs in accordance with the form or surface of the
part to be heated.
5. A furnace of the class described, of varying forms and having any required
number of electric arcs, produced between suitable electrodes, in which furnace
the parts to be heated are protected from the contact with the evolved gases,
deviating such gases by means of suitable screens or forcing the same outwards,
or said parts are submitted to the actions or reactions of such gases to obtain a
determinate result, or the actions and reactions of such gases may be utilized for
influencing the composition, molecular modification or reformation of the walls
of the furnace, all substantially as set forth.
11.
T1000
J. P. BAYLY,
18, Fulham Place, London, W.,
Agent for the Applicant.