Heating Liquids by Electricity.
Year: 1893

page_text: Date of Application, 31st Jan., 1893
Complete Specification Left, 9th June, 1893-Accepted, 5th Aug., 1893
PROVISIONAL SPECIFICATION.
Heating Liquids by Electricity.
LESLIE BRADLEY MILLER and MAURICE WALTER WOODS both of 2 Grays
Inn Road, Holborn, London W.C. Electrical Engineers, do hereby declare the
nature of this invention to be as follows:-
Our invention relates to apparatus for efficiently and conveniently utilizing the
heat given out by an incandescent lamp for heating liquids.
.
The form of electric heater that we find most convenient for use is a cylindrical
vessel of metal or other suitable material having a bottom recessed to a depth
sufficient to nearly or quite enclose the lamp or burner (hereinafter referred to as
the lamp). The outside diameter of the vessel is only a little larger than that of
the recess, so that a small quantity of water will fill up this narrow space
as far as the top and become rapidly heated if the vessel be filled no higher. The
recessed bottom should preferably be made by spinning or otherwise without any
joint liable to melt and the junction with the outer case made at the bottom so that
it will be covered by the water as long as any remaine.
To prevent loss of heat from the mouth of the recess by reflection from the inside
and also to enclose the air we make use of a reflector fitting closely round the
narrow portion of the lamp. This reflector also prevents the cap (if any) and the
lampholder from overheating.
The lamp and holder are conveniently attached to the base of the vessel so that
it can be tilted or carried about with the lamp inside it and its contents poured out
and the vessel refilled without removing the lamp. For making electrical connec-
tion to the lamp we prefer to make use of a socket on the base from which a flexible
cord can be readily detached.
In some cases we make use of a lamp having two or more filaments so that the
whole can be used for raising the temperature quickly and a portion only to
maintain it. This reduction can conveniently be effected by means of an auto-
matic switch operating by the unequal expansion of two metals. when heated.
Regulation of the hent may also be arrived at by the use of two or more separate
lamps in separate motallic envelopes or otherwise, controlled by switches.
Instead of applying the heat from below we may use a lamp mounted on a long
stem so that the liquid may be stirred with the lamp as with a glass rod. For
mechanical protection the vacuum glass coutaining the filament may be enclosed in
a tube of thin metal or an outer glass envelope and the pot lid may be so constructed
with a hole in it that the tube may be pushed through this holo more or less into
the contents of the vessel or the lamp and its envelope may be permanently attached
to the pot lid.
In order to prolong the life of the lamp it is preferable not to run the filament at
a high incandescence although it is advantageous to be able to see if the current is
on or "off" by merely inspecting the apparatus from a distanco.
"
Dated this 31st day of January 1893.

page_text: COMPLETE SPECIFICATION.
Heating Liquids by Electricity.
We, LESLIE BRADLEY MILLer and MaurICE WALTER WOODS, both of
2 Grays Inn Road, in the County of London, Electrical Engineers, 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:
Our invention relates to apparatus for conveniently and efficiently utilizing the
heat given out by an incandescent electric lamp for heating liquids.
A convenient arrangement of apparatus for this purpose, according to this
invention comprises a vessel of suitable material for example metal, having its
bottom recessed to a depth sufficient to enclose or nearly enclose the incandescont
lamp. The outside diameter of the vessel may advantageously be made only a
little larger than that of the recessed bottom portion so that a small quantity of
water will fill the narrow space formed between the two as far as the top, and
become rapidly heated if the vessel be filled no higher. The recessed bottom
portion which may be of metal, is preferably made by spinning or otherwise so as
to be without any joint liable to melt, and the junction with the outer case
should be made at the bottom so that it will be covered by the water as long as any
remains.
To lessen or prevent loss of heat through the mouth of the recessed bottom
portion of the vessel by reflection from the inside thereof, and also to enclose the
air, we use a reflector arranged to fit closely around the narrow portion of the lamp.
This reflector also serves to prevent the cap of the lamp (if one be used) and the
lamp holder from becoming overbeated.
The lamp and its holder may conveniently be attached to a base to which the
vessel may also be secured so that the vessel can be tilted or carried about with
the lamp inside it, and its contents poured out and the vessel refilled without
removing the vessel from the lamp.
In some cases we use a lamp having two or more filaments so that the whole of
the filamonts can be used for raising the temperature of water quickly, and one
or some of them used for maintaining such temperature. This reduction in the
number of filaments used can be conveniently effected by menus of a suitable switch.
The heat may also be regulated by the use of two or more separate lamps arranged
in separate metallic cnvelopes or in an envelope common to them and controlled by
switches.
Instead of applying the heat from below, it may be applied from above. In this
case the glass receiver containing the lamp filament or filaments is enclosed in a
tube that may be of thin metal, or of glass, and the lid of the vessel is constructed
with a hole so that the tube may be pushed through this hole more or less into the
contents of the vessel, or the lamp and its envelope may be permanently attached
to the vessel.
In order to prolong the life of the lamp it is advantageous not to run the lamp at
a high incandescence, although it is advantageous, to be ablo, to see if the current is
or "off" by merely inspecting the apparatus from a distance, to obtain a
light of one or two candles from the apparatus.
on
In the accompanying drawings,
Fig. 1 shows partly in vertical section and partly in elevation, an apparatus for
heating liquids according to this invention.
1 is a vessel of sheet metal, shaped in the example shown to resemble a jug. It
is constructed with a deeply recessed bottom 2 that forms with the outer wall of
the vessel a narrow annular space 3 for the liquid to be hoated. 4 is a portable
hollow stand or support formed with opening 4ª and to which the bottom of the
vessel is secured in any convenient manner. In the example shown it is hold in

page_text: place by the bent upper ends 4 of clips, the lower portions of which are
pivoted at 4 to the underside of the top portion of the stand. 4° are screws by
which the clips are normally held in place. 5 is an incandescent electric lamp
removably connected in any convenient manner, as for instance by a bayonet joint
as shown, to a lamp holder 6 carried by a base 7 secured within the stand 4. The
terminals of the lanıp are connected in any convenient manner with conductors
that are led through the socket 8 and are insulated to form a flexible cord 9 the
outer ends of the conductors terminating in spring contacts 10, 10" that are
adapted to be connected to a wall or other suitable socket or to a switch, provided
with corresponding contacts in connection with an electric generator. 11 is a
reflector consisting of a piece of tin plate placed between the bottom of the vessel 1
and its support 4. This reflector, which is formed with a central aperture through
which the lower part of the lamp 5 extends, is arranged to practically close the
lower end of the air space within the recessed bottom 2 of the vessel and thus
serves to lessen or prevent the free escape of air and heat therefrom and entrance
of cold air thereto; it also serves to keep the lamp holder cool by intercepting
radiant heat from the lamp, but nevertheless the lower glass portion of the lamp
permits of the passage of sufficient light, which can be seen through the
openings 4, to show at a distance, when the lamp is burning, as well as to enable
the apparatus to be safely handled in a dark room.
Fig. 2 is a similar view to Fig. 1 illustrating a modification in which the stand 4
consists of a hollow casting of truncated conical shape externally so that liquid
falling thereon will flow off without entering it. The lamp 5 in this example is an
-end loop lamp having its flattened lower end or base Atted into a slot in the
reflector 11, and the upper end stendied by a strip 5" of asbestos arranged between
it and the bottom 2 of the vessel. 6 is a short tube of insulating material, for
example slate, carrying the connections for placing the terminals of the lamp in
connection with the conductors forming the cord 9. This tube may be closed at
the bottom by a plate 12 of mica that permits of the passage of light from the
lamp and which may be held in place by an annular sheet 13 of tinned iron secured
it may be to the tube 8 by bolts one of which is shown. The lower edge of the
stand 4 is formed with notches 4" so that the light of the lamp that passes through
the mica plate 12 can be readily seen.
Fig. 3 illustrates an arrangement similar to that shown in Fig. 1 excepting that
the vessel 1 is in the form of a kettle, which may be detachably connected to the
stand 4 by bent clips 4 ench of which is secured to the said stand 4 and normally
bears upon a wire or bead 1* soldered to the exterior of the vessel. The two
wires or bonds 1* are so arranged that a gap 1 is left botween their adjacent ends
ns shown in Fig. 3ª through which the upper bent ends of the clips 4º can pass
when placing the kettle in position, after which by partly turning the kettle round,
the clips are caused to bear upon the wires or beads and hold the kettle securely
in place, the connection resembling a bayonet joint.
The vossel 1 in each of the preceding oxamples may advantageously be separated
from the stand 4, when of metal, by material that is a bad conductor of heat.
For this purpose a strip or washer 1 of asbestos may be placed between the
bottom of the vessel and the stand as shown in Fig. 2, or between the bottom of
the vessel and the reflector 11 as shown in Fig. 3. Or the vessel may be supported
upon pins or projections on the top of the stand 4.
Fig. 4 is a vertical section, partly in elevation; and,
Fig. 5 is a plan, illustrating another construction of heating apparatus according
to this invention. In this case the incandescent lamp 5 is inserted from above into
a metal tube or envelope 2 that is fitted with a cup or cover 13 to which the
lamp holder 6 is secured, and is supported centrally within the vessel 1 by a bent
perforated metal ring 14 resting upon the bottom of the said vessel. The vessel is
5 provided with a perforated lid made in two parts 15, 15" whereof the former is
pivoted to the vessel at 16, and the latter is pivoted to the former at 17 so that it

page_text: can be turned upward without disturbing either the part 15 or the incandescent
lamp, when it is desired to pour out the contents of the vessel.
Each of the apparatus hereinbefore described may, as shown be provided with a
handle 18 by which it can be easily carried from place to place as may be
desired.
Figs. 6 and 7 are respectively a side elevation and a cross section on the line xx
Fig. 6, of an electric heating apparatus according to this invention in which
provision is made for regulating the quantity of heat produced in any given
time.
In this case the vessel 1, which may be made stationary and be provided with a
draw off cook 19, is constructed with a number of horizontally arranged metal
tubes 2 that traverse the interior of the vessel so as to be surrounded by the
liquid to be heated and each of which is provided with an incandescent lamp.
Each lamp is supported in place by rings 5 of material such as asbestos and is
held against a piece 5° of similar material by a plate 20 fixed to one side of the
vessel and through a slot in which the flattened projecting end of the lamp passes.
The terminals of each lamp are connected by conductors 21, 21" to fixed contact
pieces that can be electrically connected with or disconnected from supply
conductors 22 22 by a switch 23 of any suitable construction. The said supply
conductors and switches may be carried by a suitable insulating support 24 fixed to
one side of the vessel as shown.
As will be obvious heating apparatus according to this invention can be
constructed in various forms.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
1. Heating liquid by means of the radiant heat of an incandescent electric
lamp arranged within a receptacle or chamber surrounded by the liquid to be
heated substantially as herein described.
2. Apparatus for heating liquids by electricity, comprising a vessel provided
with an inner receptacle or chamber arranged to be surrounded by the liquid to be
heated, and an incandescent electric lamp located within the said receptacle or
chamber substantially as herein described.
3. Apparatus for heating liquids by an incandescent electric lamp, so constructed
as to perinit of light from the lamp passing to the exterior thereof substantially
as herein described for the purpose specified.
4. Apparatus for heating liquids by electricity, constructed, arranged and
operating substantially as hereinboforo described with reference respectively to
and shown in Fig. 1, or modified according to Fig. 3; in Fig. 2; in Figs. 4 and 5 ;
and in Figs. 6 and 7 of the accompanying drawings.
Tlated this 9th day of June 1893.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.