IMPROVEMENTS IN MEANS, APPARATUS, OR ARRANGEMENTS FOR STORING AND SUPPLYING HEAT FOR HEATING RAILWAY AND OTHER CARRIAGES, AND FOR OTHER PURPOSES, MORE PARTICULARLY APPLICABLE TO FOOT AND BED WARMERS, AND TO OTHER PORTABLE HEATERS."
Year: 1881

page_text: LETTERS PATENT to Francis William Webb, of Crewe, in the County of
Chester, Mechanical Engineer, Joseph Reddrop, and Martin Hugh Foye, of the
same Place, Analytical Chemists, for an Invention of "IMPROVEMENTS IN
MEANS, APPARATUS, OR ARRANGEMENTS FOR STORING AND SUPPLYING HEAT
FOR HEATING RAILWAY AND OTHER CARRIAGES, AND FOR OTHER PURPOSES,
MORE PARTICULARLY APPLICABLE TO FOOT AND BED WARMERS, AND TO
OTHER PORTABLE HEATERS."
PROVISIONAL SPECIFICATION left by the said Francis William Webb,
Joseph Reddrop, and Martin Hugh Foye at the Office of the Commissioners
of Patents on the 20th July 1881.
FRANCIS WILLIAM WEBB, of Crewe, in the County of Chester, Mechanical
Engineer, JOSEPH REDDROP, and MARTIN HUGH FOYE, of the same Place, Analytical
Chemists. "IMPROVEMENTS IN MEANS, APPARATUS, OR ARRANGEMENTS FOR
STORING AND SUPPLYING HEAT FOR HEATING RAILWAY AND OTHER CARRIAGES,
AND FOR OTHER PURPOSES, MORE PARTICULARLY APPLICABLE TO FOOT AND BED
WARMERS, AND TO OTHER PORTABLE HEATERS."
This Invention relates to improvements upon those means of heating described
in the Specification of a Patent granted to W. R. Lake, No. 4180, dated the
15th October 1879, whereby the latent heat of the fusion of crystallized acetate of
soda (amongst other substances) is proposed to be used for heating purposes.
Water has been principally used hitherto as a medium for heating railway
carriages and other purposes, but acetate of soda has considerable advantage over
water, owing to the fact that acetate of soda fuses or melts in its water of
crystallization at about 58 degrees centigrade, whereby a large quantity of heat is
absorbed or stored, which is again liberated or given out on cooling when it returns
to its primary crystalline state.
In the use of acetate of soda a great obstacle presents itself, as when a quantity

page_text: of it is completely liquefied by heat, and is then allowed to cool to the ordinary
temperature, it does not solidify in the crystalline form which it had before
liquefaction, but instead assumes a pasty condition, in which state in contains and
retains a large amount of heat latent or undeveloped.
While in this pasty state it is somewhat unstable, as a blow on the containing
case, or a sudden jerk, or the mere contact with it of the smallest crystal of the
ordinary variety is sufficient to start the change from the pasty to its primary
condition, and so determine and produce the evolution of the undeveloped heat.
The principal object of these improvements is to provide means which will
prevent the formation during the cooling of the liquefied acetate of soda of the pasty
condition above mentioned, and the consequent loss of heating effect.
The material employed is placed and enclosed in hollow metallic cases of the
ordinary form of foot warmers used for hot water, or the case is of other form or
shape to suit the purpose required.
We place in each case the crystallized acetate of soda and water, that is, from 97
to 99 per cent. by weight of the mixture is crystallized acetate of soda, the remaining
three or one per cent. being water.
If the anhydrous salt be used then a larger proportion of water is added, so that
between 33 and 30 per cent. of the mixture is anhydrous salt, and between 67 and
70 per cent. by weight of the mixture is water.
Combined with these mixtures we arrange means for producing agitation,
vibration, or concussion in the materials, which arrangements are or may be
actuated to produce the desired effect by the notion of the railway or other carriage
or otherwise.
For the purpose of agitation, vibration, or concussion we use two or more balls
of iron or other suitable material of any suitable diameter placed inside the vessels
or cases.
With the mixture described the arrangements for producing agitation or con-
cussion, and the motion or vibration of the train or vehicle, the salt, on cooling
passes from the liquid state into the ordinary crystalline condition, and consequently
there is obtained in heating effect not only the sensible heat, but also the whole of
the latent heat of fusion.
For heating appartments or for other heating purposes, where there is no vibration,
a different arrangement is necessary.
It has already been observed that when acetate of soda has cooled down into the
first or pasty condition, the further developement of its latent heat may be effected
by mere contact with a crystal of ordinary variety.
-
We practically apply this principle in the following manner :-
To the case containing the acetate of soda or mixture (say, it is a case similar
to those used for foot warmers with hot water) we attach a small tube which
may be arranged to form a convenient handle at one end of the case, or two of
these tubes may be used bent and made to come together to form the handle, both
ends of the tubes communicating with the interior of the case.
One or both of the tubes is or may be charged with crystals of the ordinary
variety of acetate of soda, but we prefer to fill the tube or tubes somewhat tightly
with a piece of cotton wick (similar to ordinary oil lainp wicks) or other suitable
porous materials which have been previously soaked in acetate of soda heated to
about 90° centigrade, and finally brought into contact with a crystal of the ordinary
variety.
The cotton wick tends to prevent convection currents when the acetate of soda
is liquefied and the case is laid down flat.
With this arrangement it is necessary that the case be so heated (preferably in a
vertical position with the handle exposed to the air) that the tube containing the
acetate of soda does not rise to a temperature exceeding 58° centigrade.
When the case is allowed to cool (as when used for heating purposes) the crystals
in the handle, which have been kept by the above precautions below the temperature
of 58° centigrade, cause the heated acetate of soda in the case when cooling to

page_text: assume the ordinary crystalline form, which change is attended with the develope-
ment of the whole of the latent heat of fusion.
Should the handle of the case, as above described, become over-heated, and fail
to determine or cause the requisite change, the result is or may be brought about
by a smart blow from a hammer or other instrument upon the outside of the case
after the contents have somewhat cooled. The change which thus takes place in
the case is transmitted to the contents of the handle, which are thus again rendered
effective for the next operation.
With the above described improvements a given bulk of acetate of soda absorbs
when heated and gives out when cooling from four to five times as much beat as
the same bulk of water heated to the same temperature, say, 100° centigrade. It
may be explained that when the salt cools down to 58° centigrade or thereabouts,
the solidification sets in and a constant temperature is maintained for a considerable
time.
The cases containing the mixture are hermetically scaled, and after cooling are
re-heated, by preference, by placing them in boiling water for a short time.
It may be observed that crystallized acetate of soda may be heated in closed
vessels to about 123° centigrade without decomposition.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Francis William Webb, Joseph Reddrop, and Martin Hugh Foye
in the Great Seal Patent Office on the 21st December 1881.
"
FRANCIS WILLIAM WEBB, of Crewe, in the County of Chester, Mechanical
Engineer, JOSEPH REDDROP, and MARTIN HUGH FOYE, of the same Place, Analytical
Chemists. IMPROVEMENTS IN MEANS, APPARATUS, OR ARRANGEMENTS FOR
STORING AND SUPPLYING HEAT FOR HEATING RAILWAY AND OTHER CARRIAGES,
AND FOR OTHER PURPOSES, MORE PARTICULARLY APPLICABLE TO FOOT AND BED
WARMERS, AND TO OTHER PORTABLE HEATERS."
This Invention relates to improvements upon those means of heating described
in the Specification of a Patent granted to W. R. Lake, No. 4180, dated the
15th October 1879, whereby the latent heat of the fusion of crystallized acetate of
soda (amongst other substances) is proposed to be used for heating purposes.
Water has been principally used hitherto as a medium for heating railway
carriages, and for other heating purposes, but acetate of soda has considerable
advantage over water, owing to the fact that acetate of soda fuses or melts in its
water of crystallization at about 58 degrees centigrade, whereby a large quantity of
heat is absorbed or stored, which is again liberated or given out on cooling when it
returns to its primary crystalline state.
In the use of acetate of soda a great obstacle presents itself, as when a quantity
of it is completely liquefied by heat and is then allowed to cool to the ordinary
temperature, it does not solidify in the crystalline form which it had before
liquefaction, but, instead, assumes a pasty condition, in which state it contains and
retains a large amount of heat latent or undeveloped.
While in this pasty state it is somewhat unstable, as a blow on the containing
case, or a sudden jerk, or the mere contact with it of the smallest crystal of the
ordinary variety is sufficient to start the change from the pasty to its primary
condition, and so determine and produce the evolution of the undeveloped heat.
The principal object of these improvements is to provide means which will
prevent the formation, during the cooling of the liquefied acetate of soda, of the
pasty condition above mentioned, and the consequent loss of heating effect.
The material employed is placed and enclosed in hollow metallic cases of the
ordinary form of foot warmers used for hot water, or the case is of other form or
shape to suit the purpose required.
We place in cach case the crystallized acetate of soda and water, that is, from
97 to 99 per cent. by weight of the mixture is crystallized acetate of soda, the
remaining three or one per cent. being water.
If the anhydrous salt be used then a larger proportion of water is added, so that
between 33 and 30 per cent. by weight of the mixture is anhydrous salt, and
between 67 and 70 per cent. by weight of the mixture is water.
Combined with these mixtures we arrange means for producing agitation,
vibration, or concussion in the materials, which arrangements are or may be
actuated to produce the desired effect by the motion of the railway or other
carriage or otherwise.
For the purpose of agitation, vibration, or concussion we use one, two, or more
balls of iron or other suitable material of any suitable diameter placed inside the
vessels or cases.
With the mixture described the arrangements for producing agitation or con-
cussion, and the motion or vibration of the train or vehicle, the salt on cooling
passes from the liquid state into the ordinary crystalline condition, and consequently

page_text: there is obtained in heating effect not only the sensible heat, but also the whole of
the latent heat of fusion.
For heating appartments or for other heating purposes where there is no vibration
a different arrangement is necessary.
It has already been observed that when acetate of soda has cooled down into the
first or pasty condition, the further developeinent of its latent heat may be
effected by mere contact with a crystal of ordinary acetate of soda which has not
been heated.
We practically apply this principle in the following manner :-
To the case containing the acetate of soda or mixture (say, it is a case similar to
those used for foot warmers with hot water) we attach a small tube, which may be
arranged to form a convenient handle at one end of the case; or two of these
tubes may be used bent and made to come together to form the handle, one or both
ends of the bores of these tubes communicating with the interior of the case.
One or both of the tubes is or may be charged with crystals of the ordinary
acetate of soda, but we prefer to fill the tube or tubes somewhat tightly with a
piece of cotton wick (similar to ordinary oil lamp wicks) or other suitable porous
materials which have been previously soaked in acetate of soda heated to about
90° centigrade, and finally brought into contact with a crystal of the ordinary
acetate of soda which has not been heated.
The cotton wick tends to prevent convection currents in the tube when the
acetate of soda in the connected case is liquefied and the case is laid down flat.
With this arrangement it is necessary that the case be so heated (preferably in a
vertical position with the handle exposed to the air) that the tube containing the
acetate of soda does not rise to a temperate exceeding 58 centigrade.
When the case is allowed to cool (as when used for heating purposes) the crystals
in the handle which have been kept by the above precautions below the tempera-
ture of 58° centigrade, cause the heated acetate of soda in the case when cooling to
assume the ordinary crystalline form, which change is attended with the develope-
ment of the whole of the latent heat of fusion.
Should the handle of the case, as above described, become overheated and fail to
determine or cause the requisite change, the result is or may be brought about by
a smart blow from a hammer or other instrument upon the outside of the case after
the contents have somewhat cooled. The change which thus takes place in the case
is transmitted to the contents of the handle, which are thus again rendered effective
for the next operation.
With the above described improvements a given bulk of acetate of soda absorbs
when treated, and gives out when cooling, from four to five times as much heat as
the same bulk of water heated to the same temperature, say, 100° centigrade.
It may be explained that when the salt cools down to 58° centigrade or there-
abouts the solidification sets in, and a constant temperature is maintained for a
considerable time.
The cases containing the mixture are hermetically sealed, and after cooling are
re-heated, by preference, by placing them in boiling water for a short time.
It may be observed that crystallised acetate of soda may be beated in closed
vessels to about 123° centigrade without decomposition.
We have now particularly described the nature of our said Invention, and the
modes of carrying the same into effect, and claim as our Invention,--
Firstly. The combination of water with acetate of soda, crystallized or anhydrous,
substantially as and for the purpose herein before described.
Secondly. The combination with cases or vessels charged with acetate of soda
and water of a metallic ball or balls or other equivalent mechanical means or
arrangements for producing percussion or vibration, and transmitting the same to
the chemical mixture, substantially as and for the purpose herein before described.
Thirdly. The combination with a case or vessel charged with acetate of soda,
and in communication therewith of a separate reservoir charged with crystallized
acetate of soda arranged within or without the case or vessel, so as to retain the

page_text: acetate of soda contained in the separate reservoir in its ordinary crystallized state
as when below the temperature of fifty eight degrees centigrade, substantially as
and for the purpose herein before described.
Fourthly. The use and combination with cases or vessels charged with acetate of
soda of cotton wick or any other suitable porous material which has been saturated
in liquefied acetate of soda, and then converted to the ordinary crystalline state,
substantially as and for the purpose herein before described.
In witness whereof, we, the said Francis William Webb, Joseph Reddrop,
and Martin Hugh Foye, have hereunto set our hands and seals, this Twentieth
day of December, in the year of our Lord One thousand eight hundred
and eighty one.
FRANCIS WILLIAM WEBB. (L.S.)
JOSEPH REDDROP.
MARTIN HUGH FOYE.
(L.S.)
(L.S.)