Improvements relating to Reheating certain kinds of Solid Bodies, more particularly for use in connection with Foot Warmers or Receptacles with which such bodies are employed, and in such Foot Warmers or Receptacles.
Year: 1891

page_text: Date of Application, 22nd Oct., 1891
Complete Specification Left; 16th July, 1892-Accepted, 20th Aug. 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Reheating certain kinds of Solid Bodies,
more particularly for use in connection with Foot Warmers or
Receptacles with which such bodies are employed, and in such
Foot Warmers or Receptacles.
A communication from LA SOCIÉTÉ ANONYME POUR LE TRAVAIL ÉLECTRIQUE
DES MÉTAUX, of 16, Rue Drouot, Paris, in the Republic of France,
Manufacturers.
1, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street, Man-
chester, both in. the County of Lancaster and 323 High Holborn in the County
of Middlesex,. Civil Engineer, do hereby declare the nature of this invention to
be as follows::—
This invention has essentially for its object the application of steam and
electricity for re-heating, by fusion, solid bodies which give.off heat when passing
again from a liquid condition to a solid one, and which are used for filling the
heating vessels employed for warming railway or other carriages.
Among the
different solid bodies which produce this effect, acetate of soda is the one which
up to the present has been most generally employed.
Acetate of soda foot. warmers have hitherto been composed of a simple
metal case containing this substance and they have always been reheated from
the exterior either by immersing, them in hot water, or by being placed in
stoves into which steam was passed. The results obtained by these methods of
reheating were too unsatisfactory for them to ever come into regular application.
The foot warmers became cold at the end of a very short short space of time,
which result was. attributed to the phenomenon of superfusion; after having
remained cold for a certain time, they became re-heated spontaneously either owing
to the jarring or to shocks, or in some cases-owing to the influence of ill defined
causes, and it was then stated that the superfusion had ceased and that the normal
crystallisation. was being produced.
As a result of experiments which have been made with this material it is
found;-
1. That the state of superfusion of the acetate of soda which, forms an obstacle
to the release of the heat obtained on cooling, is produced by the effect of a certain
crystallisation of the first system, when, after having been highly heated, the mass
of acetate of soda, in cooling, naturally arrives at about 70 degrees centigrade.
2. That the state of superfusion. is avoided when cooling if the mass of acetate
o soda has not been heated even. during a prolonged time to a temperature higher
than 68 to 70 degrees centigrade at the maximum.
3. That the constancy of the heat given off is owing to the fact that, at about
58 degrees centigrade, the mass of acetate of Foda tends to crystallise, giving off
a sensible. heat; according to a second. system different to the first one above
mentioned.
4. That the object to be attained is to perfectly avoid, with certainty, the first
kind of crystallisation and to produce on the contrary the formation of crystals
under the second system, either by obtaining them directly, or by transformation
of the crystals of the first system.
5. That, in order to. practically apply these principles to the re-heating of acetate

page_text: This foot-warmer is of the usual pattern of foot warmers used on railways.
It is of copper or any other suitable metal, and it contains about 10 kilogrammes
of acetate of soda. In the interior of this foot-warmer, there is a copper worm
which is bent in the mass of acetate of soda in such a manner as to act on it
rapidly in all parts by the creation of a number of points of contact distant onc
from another, as has been before stated, by not more than one or two centimetres.
The object of this arrangement is-
(1) To melt entirely and not partially this substance, and
(2) To diminish considerably the necessary time for producing the complete
fusion.
The steam entering by one end of the worm escapes by its other extremity
without mixing with the substance, and the inlet orifice of this tube is arranged
in such a way as to allow of the re-heating of the foot-warmers by means of any
suitable steam heater, such, for instance, as those already in use by all the railway
companies.
This worm may, however, be replaced by any other arrangement of tubes
fulfilling the same object, for instance, such as shall be shown for the foot-warmer
with a double heating apparatus to be described later on.
In order to facilitate the division of the heat over the surface of this foot
warmer, metal wings attached to the surface penetrate into the melted substance
and act as collectors of heat. Without these collectors, in fact, it would be
probable that the heat would be concentrated in the interior of the mass without it
being possible for it to be given off therefrom in consequence of various circum-
stances, such as the superfusion or a partial solidification, whereby the foot-warmer
would be felt to be getting cool, although containing a large quantity of available
caloric.
These collectors may as well serve in assisting to re-heat the mass of acetate of
soda when this re-heating is produced by immersion in hot water, they serve, in

page_text: mass to be melted.
The utility of these collectors is, therefore, incontestable.
2. ELECTRICAL. RHEOSTAT FOOT-WARMER.
The general form of this foot-warmer is also similar to that of all foot-warmers
in current use.
It is filled with any
It is of copper or any other suitable metal.
suitable solid substance, such as acetate of sods, the cooling of which can be
utilised for warming purposes.
This foot-warmer contains in its interior a
rheostat, that is to say, a metallic mass arranged in such a way as to receive the
electric current and to be heated under its influence, and to distribute its heat
throughout the entire mass to be melted. The arrangement of this rheostat may
be very varied, but it must always fulfil the two following conditions
-
1. Its electrical resistance must be pretty considerable so that the current shall
produce heat, and
2. It must always be capable, owing to the multiplicity of its points of contact,
of treating the whole of the mass to be melted simultaneously in all its parts. In
order to fulfil the first condition, any suitable kind of conducting metal and alloy
may be used, and, in order to fulfil the second condition, metallic sheets or threads,
bent and coiled upon themselves in any suitable manner, may be used.
A metallic sheet is rolled on a series of insulating bars and winds about in
the whole mass to be heated.
The dimensions of the rheostat are such that the top of the metallic sheet stands
above the melted mass.
This arrangement has for its object to utilise the rheostats in the same way as the
heat collectors mentioned above.
3. FOOT-WARMER SUITABLE FOR RE-HEATING BY STEAM OR BY
ELECTRICITY.
This foot warmer is a combination of the two first, which have just been described.
The method of re-heating is a double one; it may be, as desired, re-heated by
steam, seeing it is provided with a worm of a form suitable for the object in view,
or be re-heated electrically, as the group of tubes, which it contains, is itself arranged
so as to form a rheostat, that is to say, a group specially composed of conducting
metal or alloy, but presenting sufficient resistance so that the passage of the current
effects the release of heat. There can thus be employed, for the same apparatus,
either steam or electricity, according as one or the other is at disposal.
In order to treat the entire mass, the fusion can be performed in various ways.
Whilst the arrangement of a tubular boiler has been described, any other grouping
may be employed. Besides which there may be applied to this foot-warmer any
of the arrangements of which mention was made for the two first ones.
The worm may be made of any suitable metal; in order, however, that it may
form a rheostat, it is sufficient if it be merely insulated electrically at its two ends
from the case of the foot-warmer itself.
Dated this 21st day of October 1891.
WM. P. THOMPSON & Co.
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
1.22-
Improvements relating to Reheating certain kinds of Solid Bodies,
more particularly for use in connection with Foot Warmers or
Receptacles with which such bodies are employed, and in such
Foot Warmers or Receptacles.
A communication from LA SOCIÉTÉ ANONYME pour le TravAIL ÉLECTRIQUE
DES MÉTAUX, of 16, Rue Drouot, Paris, in the Republic of France,
Manufacturers.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool and 6 Bank Street,
Manchester both in the County of Lancaster and 323 High Holborn in the
County of Middlesex, Civil Engineer, 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 :-
This invention has essentially for its object the application of steam and
electricity for re-heating, by fusion, solid bodies which give off heat when passing
again from a liquid condition to a solid one, and which are used for filling the
heating vessels employed for warming railway or other carriages. Among the
different solid bodies which produce this effect, acetate of soda is the one which,
up to the present, has been most generally employed.
Acetate of soda foot warmers have hitherto been composed of a simple metal
case containing this substance, and they have always been reheated from the
exterior either by immersing them in hot water, or by placing them in stoves into
which steam was passed. The results obtained by these methods of re-heating
were too unsatisfactory ever to come into regular application. The foot warmers
became cold at the end of a very short space of time, which result was attributed
to the phenomenon of superfusion; after having remained cold for a certain time,
they became re-heated spontaneously either owing to jarring or to shocks, or, in
some cases, owing to the influence of ill defined causes, and it was then stated
that the superfusion had ceased and that the normal crystallisation was being
produced.
As a result of experiments which have been made with this material, it is
found :-
1. That the state of superfusion of the acetate of soda, which forms an obstacle
to the release of the heat obtained on cooling, is produced by the effect of a
certain crystallisation of the first system, when, after having been highly heated,
the mass of acetate of soda, in cooling, naturally arrives at about 70 degrees
centigrade.
2. That the state of superfusion is avoided when cooling if the mass of acetate
of soda has not been heated even during a prolonged time to a temperature higher
than 68 to 70 degrees centigrade at the maximum.
3. That the constancy of the heat given off is owing to the fact that, at about
58 degrees centigrade, the mass of acetate of soda tends to crystallise, giving off a
sensible heat, according to a second system different to the first one above
mentioned.
4. That the object to be attained is to perfectly avoid with certainty the first
kind of crystallisation, and to produce, on the contrary, the formation of crystals
under the second system, either by obtaining them directly, or by transformation
of the crystals of the first system.
5. That, in order to practically apply these principles to the re-heating of
acetate of soda foot warmers, that is to say, in such a way that their cooling shali
be absolutely regular during several consecutive hours, it is necessary,
sufficient, not to re-heat them above a temperature varying from 68 to 70 degrees
centigrade.
and

page_text: By the processes and arrangements which will be described, the means are
supplied of regulating, in a precise and certain manner, the temperature to be
given to the mass to be re-heated, and in particular of solving the two following
problems:
1. To melt, in a very short time and completely a certain quantity of acetate of
soda, or of other similar salt by means of fusing mediums, which may be either a
current of steam, or an electric current, so that the conductors of heat need not
attack the substance to be melted, on a thickness of more than one or two
centimetres; and
2. To sustain, by means of collectors inserted, on the one hand into the substance,
and, on the other hand, in communication with the external case, the latent heat
contained in this mass, in order to transform it into Rensible heat which is
maintained during the longest possible duration.
Finally, the problem which is to be solved is to melt, in a very short time, a
total mass of acetate of soda or other suitable material, by treating it simul-
taneously at a very large number of points without leaving any part of the mass
untreated, and to obtain in its entirety this heat, not only by the effect of ordinary
cooling down, but also by means of collectors which can constantly collect the beat
in the interior in order to bring it to the upper part of the case.
This problem has been solved entirely by means of three methods of construction
of heaters or foot warmers. They will now be described.
In order that the invention may be the more easily understood, reference will be
made to the accompanying drawings:-
WARMER FOR RE-HEATING BY STEAM.
Figure 1 represents a longitudinal section of a foot warmer suitable for use in
railway carriages.
Figure 2 is a sectional plan.
Figure 3, an end view of the same,
Figure 4 is a transverse section along the line A. B of Figure 1.
This foot warmer is of copper or any other suitable metal, and contains about
10 kilogrammes of acetate of soda.
BB are plugs for filling or emptying the foot warmer.
C is a protective covering of wood.
DD are handles for handling it.
In the interior of this foot warmer, there is a copper worm A which is bent in
the mass of acetate of soda in such a manner as to act on it rapidly in all parts
by the creation of a number of points of contact distant one from another, as has
been before stated, by not more than one or two centimetres.
The object of this arrangement is :-
(1) To melt entirely and not partially this substance; and
(2) To diminish considerably the necessary time for producing the complete
fusion.
The steam entering by one end of the worm a escapes by its other extremity a
without mixing with the substance, and the inlet orifice of this tube a is arranged
in such a way as to allow of the re-heating of the foot warmers by means of any
suitable steam heater such, for instance, as those already in use by all the railway
companies.
This worm may, however, be replaced by any other arrangement of tubes
fulfilling the same object, for instance, such as shall be shown for the foot warmer
with a double heating apparatus to be described later.
In order to facilitate the division of the heat over the surface of this foot
warmer, metal wings A, attached to the surface, penetrate into the melted
substance and act as collectors of heat. Without these collectors, in fact, it would
be probable that the heat would be concentrated in the interior of the mass without

page_text: it being possible for it to be given off therefrom in consequence of various circum-
stances, such as the superfusion or a partial solidification, whereby the foot warmer
would he felt to be getting cool, although containing a large quantity of available
caloric.
These collectors may as well serve in assisting to re-heat- the mass of acetate of
soda when this re-heating is produced by immersion in hot water, they serve in
such case as conductors for bringing the heat more rapidly to the centre of the
mass to be melted.
The utility of these collectors is, therefore. incontestable.
Figures 5, 6 and 7 in the accompanying drawings represent, by way of example,
the general form of this foot warmer, which is similar to all foot warmers in
current use, showing the same in longitudinal sectional elevation, in sectional plan.
and in cross section, respectively.
It is of copper or any other suitable metal. It is filled with any suitable solid
substance, such as acetate of soda, the cooling of which can be utilised for warming
purposes. This foot warmer contains in its interior a rheostat, that is to say, a
metallic mass arranged in such a way as to receive the electric current and to be
heated under its influence, and to distribute its heat throughout the entire mass to
be melted. The arrangement of this rheostat may be very varied, but it must
always fulfil the two following conditions:-
1. Its electrical resistance must be pretty considerable so that the current shall
produce heat, and secondly it must always be capable, owing to the multiplicity
of its points of contact, of treating the whole of the mass to be melted simul-
taneously in all its parts. In order to fulfil the first condition, any suitable kind
of conducting metal and alloy may be used, and in order to fulfil the second
condition metallic sheets or threads bent and coiled upon themselves in
any suitable
manner may be used.
The apparatus shown in the accompanying drawings is composed of a metallic
sheet A rolled on a series of insulating bars B and winding about in the whole
mass to be heated. The divisions C are designed to produce the same effect as
the wings A in Figures 1 and 2.
The dimensions of the rheostat are such that the top of the metallic sheet
stands above the melted mass. This arrangement has for its object to utilise the
rheostats in the same way as the heat collectors mentioned above.
3. FOOT WARMER SUITABLE FOR RE-HEATING BY STEAM OR BY
ELECTRICITY.
This foot warmer is represented as a specimen in horizontal section in Figure

page_text: The worm may be made of any suitable metal, in order however that it may
form a rheostat it is sufficient if it be merely insulated electrically at its two ends
from the case of the foot warmer itself.
The entrance of the steam takes place as previously by the plug a opening into
a chamber F into which all the tubes A' abut, and the exit takes place by the
plug a' communicating with an analogous chamber F¹; B being as previously a
plug for the introduction of the acetate of soda into the heating vessels and C the
protecting pieces. A¹ A¹ are diaphragms or wings which play the same part as.
that which has been previously indicated.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I wish it to be understood that the shapes, dimensions,.
proportions and accessory parts of the apparatus employed in carrying out this
invention may be varied to suit circumstances, and the materials used in the.
make may also be varied as may be judged desirable, but I declare that what I
claim is :-
1. The application, for re-heating heating vessels, and other receptacles of the
same kind, acting by means of acetate of soda, of a circulation of steam in such
receptacles by means of worms, of metals or alloys, which are completely stopped
and arranged in such manner as to allow the steam which they conduct to rapidly
communicate all its heat to all the points of the mass to be melted, so that it will
be melted entirely and not partially and the time necessary for producing this
fusion be considerably diminished, owing to the multiplicity of points of contact,
substantially as hereinbefore described.
2. The process for completely collecting, and without the liberation being
interrupted by reason of superfusion, partial solidification or other cause, all the
heat produced by the solidification of the mass after fusion, such process being
characterised by the arrangement of metallic conducting collectors or wings
connected with the surface of the receptacle and plunged up to the centre of the
melted matter, substantially as herein before described and shown.
3. The application of electricity to re-heating heating vessels and other
receptacles of any shape and substance, containing substances which liberate heat
whilst solidifying after fusion, such application being carried out by the employ-
ment, for such purpose, of rheostats of various shapes, of metal or any other
substance, having a sufficient electrical resistance to cause a considerable liberation
of heat on the passage of the current, these rheostats in all cases being arranged
in such manner as to allow of a circulation of the electric current, the producer of
heat, throughout all parts of the mass to be melted, these same rheostats being
capable of being utilised as collectors of heat by making them emerge from the.
melted body into the upper part of the receptacle, substantially as hereinbefore
described and shown.
4. The combination, allowing, as desired, the application of either steam or
electricity, with the same apparatus under the conditions indicated above, so as to
produce the effect of successive re-heating, substantially as hereinbefore described
and shown.
5. The arrangement of apparatus permitting the application of either heat or
electricity, as desired, for producing the re-heating of the heating vessels, acting.
by means of acetate of soda, substantially as herein before described and shown.
Dated this 15th day of July 1892.
WM. P. THOMPSON & Co.,
Agents for the Applicant.