Improvements in Heating Liquids by Electricity.
Year: 1893

page_text: Date of Application, 14th June, -1893
(Complete Specification Left, 14th Mar., -1894-Accepted, 5th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Heating Liquids by Electricity.
I, ARNOLD BEAUMONT WOAKES of 78, Harley Street, London, W. Aural
Surgeon, do hereby declare the nature of this invention to be as follows:-
This invention relates, first, to improvements in the heating of water and other
liquids by electricity by the method described in the Specification of former
Letters Patent granted to me dated the 6th day of January 1892, No. 259 wherein
the liquid itself is made the resisting medium to the passage of the current for the
purpose of utilizing the electrical energy for heating the liquid. It also relates to
improvements in the heating of liquids by the passage of a current through .an
insulated conductor embedded in the tube or immersed in the liquid and not
through the liquid itself.
The first improvement relates to the heating of water or other liquid in bulk, in
a containing vessel, and the improvement is based on the fact that the conductivity
of a liquid greatly increases as its temperature approaches the boiling point. The
improvement consists in causing the current to traverse a relatively small portion
of the whole mass of liquid which is more or less confined so as to remain
unchanged by internal circulation of the liquid, the dissemination of heat
throughout the mass being produced by conduction and the passage through the
mass of steam generated in the confined space. By this means, the relatively
small mass of liquid traversed by the current is quickly raised nearly to boiling
point, so that the full strength of the current passes almost from the very com-
mencement whereas were free circulation of the liquid permitted its resistance
This
would only diminish as the temperature of the whole mass became raised.
result can be attained by enclosing the electrodes in a chamber situated at or
Dear the bottom of the containing vessel and open only at top to the mass of
liquid, or by making the electrodes themselves, or one of them, the enclosing
chamber, in which case they may either be placed concentrically, with
intervening annular space or the two electrodes may form two opposite sides of
the enclosing chamber. Platinum, wire, gauze, or foil, or hard carbon plates
rods or tubes may be employed as the electrodes in these respective cases.
an
A further advantage of limiting the sphere of action of the current is that as
soon as the whole mass begins to boil a marked fall of current occurs, probably in
consequence of the electrodes being to a certain extent insulated by steam which is
unable to escape freely from between them.
Another improvement consists in providing an adjustable insulating partition
which may be interposed to a greater or less extent between the electrodes for the
purpose of regulating their effective area and consequently the amount of current
passing, so that the liquid can be heated to any desired degree and be maintained
at that temperature for an indefinite period.
The next improvement relates to the heating of a liquid in the act of drawing it
off, instead of in bulk, and consists in an arrangement whereby the temperature at
which the liquid may be drawn off may be raised by merely varying its rate of
flow. For this purpose the heater is in the form of a tube which may either
contain both the electrodes or may itself constitute one of the electrodes, or which
may contain the insulated conductor when the liquid does not itself form the resisting

page_text: medium to the electric current. In the former case the tube if itself the one
electrode, may be of platinum or hard carbon and the contained electrode or
electrodes, as the case may be, may be in the form of carbon rods or platinum foil,
gauze, or spiral coils. Platinum electrodes are preferable to carbon especially when
placed in close proximity to one another, on account of the tendency of the carbon
to disintegrate. In either case the tube is in communication with the source of
supply of the liquid under the control of a tap by which the rapidity of flow and
consequently the amount of heating of the liquid may be regulated and the liquid
may pass through the tube in either an ascending or descending column, the
arrangement in either case when the liquid forms the medium of resistance being
such that no switch is required, the circuit being broken by the cessation of the
supply of the liquid which forms the electrical connection between the electrodes.
When the liquid flows in the upward direction through the heater, the draw-off
nozzle is arranged to act as a syphon so as to empty the heater when the supply of
liquid is shut off, an air inlet being provided in the plug of the tap to permit of
this siphon action.
When an insulated conductor is used as the medium of resistance for the electric
current the same tubular form of heater may be employed, but in this case a switch
would be necessary to control the flow of the current, and this may either be
separate or combined with the tap so that the liquid and the electric current are
turned on and off simultaneously by one motion and the syphon action above
referred to is unnecessary in this case. The advantage of this tubular form of
heater for heating a flowing column of liquid is that only the exact amount of
liquid required need be heated and the dimensions of the heater are so restricted
that there is little loss of heat by conduction and radiation..
Dated this 14th day of June 1893.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Heating Liquids by Electricity.
I, ARNOLD BEAUMONT WOAKES, of 78, Harley Street, London, W., Aurai
Surgeon, 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 relates, first, to improvements in the heating of water and other
liquids by electricity by the method described in the Specification of former Letters
Patent granted to me, dated the 6th day of January 1892, No. 259, wherein the
liquid itself is made the resisting medium to the passage of the current for the
purpose of utilizing the electrical energy for heating the liquid. It also relates to
improvements in the heating of liquids by the passage of a current through an
insulated conductor embedded in the tube or immersed in the liquid and not through
the liquid itself.
The first improvement relates to the heating of water or other liquid in bulk in a
containing vessel, and the improvement is based on the fact that the conductivity
of a liquid greatly increases as its temperature approaches the boiling point. The
improvement consists in causing the current to traverse a relatively small portion of
the whole mass of liquid which is more or less confined so as to remain unchanged
by internal circulation of the liquid, the dissemination of heat throughout the mass
being produced by conduction and the passage throughout the mass of steam
generated in the confined space. By this means the relatively small mass of liquid
traversed by the current is quickly raised nearly to boiling point so that the full

page_text: strength of the current passes almost from the very commencement (since liquids
near the boiling point conduct nearly three times as well as the same liquids when
cold) whereas were free circulation of the liquid permitted, its resistance would only
diminish as the temperature of the whole mass became raised.
This result can be attained by enclosing the electrodes in a chamber situated at
or near the bottom of the containing vessel and open only at the top to the mass of
the liquid, or by making the electrodes themselves, or one of them, the enclosing
chamber, in which case they may either be placed concentrically with an intervening
annular space, or the two electrodes may form two opposite sides of the enclosing
chamber. Platinum in the form of wire, gauze, or foil, or hard carbon plates, rods,
or tubes, or any suitable combination of the two, may be employed as the electrodes
in these respective cases.
When the electrodes are placed close together, say from 16th to 8ths inch apart,
the full strength of the current passes from the commencement, no matter in what
position the electrodes are placed in the liquid this being due to the fact that the
water enclosed in the narrow space between the electrodes is raised to near the
boiling point almost instantly. A further advantage of limiting the sphere of
action of the current is that as soon as the whole mass of liquid contained in the
vessel begins to boil, the current falls automatically to rd or one quarter of the full
strength, practically sufficient current passing only to maintain the liquid boiling,
or, in other words, sufficient current passing to generate sufficient steam and
electrolytic gases in the space between the electrodes to more or less insulate the
electrodes from one another. This automatic fall of current when boiling occurs is
present to a greater or less extent in all forms of electrodes but it is very marked
when there is no free circulation of the liquid in the space between the electrodes,
so that the steam generated therein cannot easily escape.
In the accompanying drawings, forming part of this Specification, various
examples of this mode of heating water are illustrated.
-
Figure 1 shews a vertical section of a concentric arrangement of electrodes,
a being a central electrode surrounded by an annular electrode b, the two being
separated by the annular space c, c, which communicates above with the interior of
the vessel d but is closed below by the insulating material e. The space c being
thus closed below, the water is unable to circulate from below upwards through
the space c, and consequently it becomes almost instantly raised to nearly boiling,
but as soon as the whole bulk of the water in the vessel d attains the boiling
temperature the steam generated between the electrodes cannot escape freely and
they become more or less insulated from one another so that a corresponding fall of
current occurs. The vessel itself may be made of glass, porcelain, or other
suitable material, the outer electrode b being fixed water-tight into the neck of the
vessel by being bedded in a flexible cement, such as india-rubber solution, shewn
at f. 9 is a rod insulated from, and passing through, both electrodes and through
the neck of the vessel, to keep the electrodes in position, the ends of the rod
projecting in order to engage in bayonet slots in a socket in which the neck of the
vessel is received, in order to support the vessel and make connection between
the electrodes and the electric circuit. For this purpose the lower ends of the
electrodes a, b, are received in central and annular sockets in an insulating block i
contained in the pedestal p supporting the socket h, and are respectively pressed,
the electrode a by a sliding contact rod j and the electrode 6 by a ring k pressed
upwards by springs k' and guided by rods k to one of which one of the conducting
wires is attached whilst the other is connected directly or through a safety fuse to
the central rod j. The latter is raised and lowered by a switch lever l, in order
to make or break the circuit with the electrode a. The long arm of the switch
lever is formed by a spring 1, and a latch (not shewn) is provided to maintain the
contact with the electrode a.
Figure 2 represents another form of the apparatus wherein the vessel is mounted
on legs and is provided with a different form and arrangement of the electrodes
which are formed by two discs of carbon a and b, placed one above the other with

page_text: the space c intervening into which the water enters and where the heating takes
place, the electrodes being contained within the neck of the vessel with the body
of which the space c communicates at the edges of the discs. The electrodes are
separated by the insulating material e, the disc a being attached to a stem a', while
the disc b is attached to an annular boss b' through which the stem a¹ passes and
wherein it is secured by a nut m and insulating washer m', whilst the electrode b is
bedded on insulating material and clamped to the bottom of the vessel by a nut
or collar n the nuts screwing on threaded metal ferrules soldered on the electro-
plated stems a¹ of the carbons. Electrical connection may be made by any
suitable means, for instance by springs o, o', one terminal pressing against collar n
which is in contact with b, while the other terminal presses against m, the union of
the two parts of the socket being maintained by a bayonet joint.
Other forms of electrodes will answer the purpose equally well, either in platinum
or carbon, or a combination of the two, suitable for either a continuous or alternating
current.
Instead of the electrodes being fixed in the vessel, they may be attached to a
handle and dipped to the bottom of the vessel, the one electrode forming the
chamber in which the small mass of water to be traversed by the current is
confined.
Figure 3 represents a concentric arrangement of electrodes attached to a handle,
a being the inner electrode and the outer electrode. The latter is a tube
perforated with holes g to admit the water and let the steam escape, the two
electrodes being separated by the insulating material e, e.
The electrodes should be close together, say from th to about ths inch, and of
small superficial area, say about or 1 square inch, according to the quantity
of current available or desirable to employ.
In most cases the electrodes a and b in Figures 1, 2, and 3, may be made of tubes
or plates of platinum foil or gauze, instead of carbon. In other cases two coils of
platiuum wire on an insulating plate or rod may be used, or two plates of platinum
foil properly supported on an insulating material may be made to form a very
convenient arrangement.
Figures 4 and 5 are horizontal cross-sections representing an arrangement in
which an adjustable insulating partition is interposed, to a greater or less extent,
between the electrodes, for the purpose of regulating their effective area and con-
sequently the amount of current passing, so that the liquid may be heated to any
desired degree and be maintained at that temperature for an indefinite period.
a and b represent the two electrodes in the form of strips fitted into vertical grooves
within an enclosing chamber formed on the side of the vessel, the electrodes facing
each other and being separated by the intervening space c which communicates by
perforations g with the interior of the vessel. ris a partition or strip of insulating
material adapted to fit in guide grooves and to be slid up or down in the space c
so as to insulate the electrodes more or less from each other as required.
The next improvement relates to the heating of a liquid in the act of drawing it
off, instead of in bulk whereby the temperature at which the liquid is required may
be regulated by varying its rate of flow. For this purpose the heater is in the
form of a tube, preferably the nozzles of a draw-off cock, as shewn in longitudinal
section in Figure 6 and in cross-section in Figure 7. This heater should be con-
structed entirely of an insulating material, such as porcelain or ebonite, the
electrodes a, b, being formed of two plates of platinum foil backed up by pieces of
obonitet fitted in slots in opposite sides of the tube or nozzles and pressed water-
tight against seats in the slots by binding screws u, in metal rings v encircling the
Dozzle 8, each piece of foil being folded back at one end over its backing strip t, or
otherwise adapted to make contact with the respective wires of the circuit. The
circuit is completed between the electrodes by the water flowing through the bore c
of the nozzle under the control of a tap. If the water be allowed to run slowly, it
will come out heated to boiling, or nearly so, and if rapidly, it will come out cold.
By varying its rate of flow between these limits, by means of the tap, any desired

page_text: degree of heat may be obtained. The water may be supplied from a tank, or from
the main, and in the latter case the heaters should be connected with the supply
pipe by an insulating tube of sufficient length to avoid any local action upon the
metal pipes.
Figures 8 and 9 shew a side view and cross-section of a similar form of heater-
in which the electrodes a, b, are cemented to backing strips of insulating material t
screwed water-tight against flats formed on the body of the tap so that the
electrodes enclose the passage c between them, as before.
Figures 10 and 11 shew similar heaters in which the water is heated when
flowing in the downward and upward directions respectively. When the liquid
flows in the upward direction through the heater, as in Figure 11, the draw-off
nozzle is arranged to act as a syphon to empty the heater when the supply is shut
off, an air inlet being provided either in the plug of the stop cock or by means of
a rising tube w to permit this syphonic action so that in all these tubular forms of
draw-off heater no switch is required, since the current passes only so long as the.
circuit is completed by the water between the electrodes.
The water traversed by the current in passing between the electrodes becomes.
charged with oxygen, and in certain cases when the electrodes are in sufficiently
close proximity, any living organisms or other good conducting particles contained
in the water may be destroyed by the heat derived from the current when they
pass between and short circuit, or partially short circuit, the electrodes.
Figure 12 shews a heater in which an insulated conductor is used as the medium.
of resistance for the current. is the double spiral resistance coil wound and
enamelled on to an insulating rod enclosed in the rising part of a draw-off nozzle s-
and connected with the circuit by spring contacts, as shewn, the resistance depending
on the amount of current to be used. In this case a switch is necessary to control
the flow of the current and this switch is combined with the stop cock so that the
liquid and the electric current are turned on and off simultaneously by one motion.
y, y, are the spring contacts of the switch bearing against an extension z of the-
plug of the tap, having conducting and insulating segments by which the circuit is
completed and broken as the tap is turned on and off.
The advantage of the tubular forms of heater above described, for heating a
flowing column of liquid is that only the exact amount of liquid required need be
heated and the dimensions of the heater are so restricted that there is little loss of
heat by conduction and radiation. The above described heaters are principally
intended for use in houses supplied with current for electric lighting.
Having now particularly described and ascertained the nature of the said inven--
tion, and in what manner the same is to be perfornied, I declare that what I
claim is :-
1. An electric heater for liquids, wherein the electrodes are arranged at the
lower part of the containing vessel, and a small portion of the liquid forming the
resisting medium for the current is so confined between them, that whilst commu-
nicating with the bulk of the liquid above, it cannot circulate freely and becomes.
heated nearly to boiling point before the mass of the liquid is heated, as and for
the purpose specified.
2. In an electric heater for liquids, wherein a portion of the liquid forming the
resisting medium for the current is confined between the electrodes, as described,
the means of regulating the amount of current passing, which consists of an
adjustable partition introduced between the electrodes so as to insulate them, more-
or less, from each other and so vary their effective area as specified.
3. An electric water heater wherein the water, forming the resisting medium for
the current, completes the circuit between the electrodes only when in a state of
flow, such heater consisting essentially of electrodes a passage for the water to
establish connection between them, and a means of regulating the rate of flow,
and consequently the temperature to which the water is heated, substantially as.
specified.

page_text: 4. An electric water heater, consisting of an insulated conductor within a tube
or passage for the water, in combination with a means of simultaneously arresting
the flow of the water and of the electric current, as specified.
Dated this 14th day of March 1894-
A. B. WOAKES,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.