Improvements in Galvanic Elements.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Galvanic Elements.
I CARL WILHELM ADOLF HERTEL of 16, Beuth Strasse, Berlin, in the
German Empire, Manufacturer, 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:-
The galvanic elements hitherto known have several defects, of which the most
serious are their small power when durable or their short durability where their
action is more powerful and in the latter case the long time required for regenerating
the element. Besides this, powerful elements, especially such as Bunsen elements,
those containing chromic acid solutions etc., produce such strong exhalations that
the placement of batteries in inhabited rooms is excluded.
The object of my improvements in galvanic elements is the production of an
element of great power in which the regeneration is effected in a comparatively
short time and which works free from smell and costs very little to maintain it in
continual activity.
These advantages are obtained by the combination of zinc, copper and carbon
and depolarising substances in a particular manner and by the employment of an
exciting liquid hitherto not used for this purpose; and by certain improvements in
the formation of the electrodes.
On the drawing appended hereunto,
Fig. 1 is a view of the element with the exciting substances omitted.
Fig. 2 is a section of an element ready for use.
Fig. 3 a plan of Fig. 2.
Fig. 4 shows the connection of the conducting wire with the zinc electrode.
Figs. 5 and 6 the closure of the element by a rubber cover and a slate
respectively.
Into the glass vessel A, as shewn by Figs. 1 and 2, a carbon cylinder B, open
at the bottom is placed, the bottom end being closed by a copper lid b, the rim of
which is formed with strips a prolonged upwards, one of which is extended above
the vessel and serves for fixing the pole clip c. The strips a are at some distance
from the walls of the cylinders A and B, about mid way between them. The
carbon cylinder B with the armature described is placed into the vessel A after
the bottom of the latter has been covered with a layer of small pieces of retort
carbon or graphite so that the upper edge of the cylinder B is level with that of
the vessel A. After this the annular space between the carbon cylinder B and
glass vessel A is also filled with small pieces of retort carbon, and while strewing
these in, oxide of copper mixed with an addition of sub-oxide of copper is also
screwed in, so that the strips a are completely embedded in the mixture.
Into the carbon cylinder B, a second carbon cylinder C formed with a bottom is
placed, the outside diameter of the cylinder being smaller than the inside diameter
of the cylinder B, so that an annular space is left between them. In the carbon
cylinder C the zinc electrode D is suspended on a glass rod d¹ in such a manner
that between the bottom end of the zinc electrode and the bottom of the carbon
cylinder a space is left.
The zinc electrode D is formed of a zinc plate spirally rolled up or bent in zig-
ag form, which contains perforations for the circulation of the exciting liquid and
others for the reception of insulating glass rods. It is connected to the conducting
vire e in the manner shewn by Figs. 2 and 4 and insulated from the walls of the
carbon cylinder C, by means of glass rods f, which pass through the zinc electrode D
nd project beyond its outside. For keeping the glass rods fin position, india
D

page_text: rubber rings f, Fig. 3 are placed upon the glass rols between the convolutions or
folds of the zinc electrode. This arrangement assures the retention of the glass
rods also when the zinc electrode wears away and the holes through which the
rods pass become somewhat enlarged, as no wear or change of the rubber rings
takes place.
For closing the element either a cap of elastic rubber formed with an opening
for the conducting wire, as shewn by Fig. 5, or a solid cover h made of slate or
other suitable material can be used. In the latter case, the cover is made with an
opening for the carbon cylinder C to pass through.
After the various parts have been put together, the annular space between the
cylinder B and vessel A, filled with a mixture of granular retort carbon and oxide
of copper with sub-oxide of copper, is charged with the exciting liquid consisting of
a solution of caustic potash, and the inner cylinder C after insertion of the zinc
electrode D and the annular space between cylinders B and C are likewise filled
with the same solution. The potash solution is suitably prepared in the proportion
of 2 to 3, that is to say, one pound of caustic potash to one and a half pounds of
water, while the quantity of sub-oxide of copper is about 10 per cent. of that of the
oxide of copper, the quantity of the latter mixed with the granular retort carbon
being about one eighth part of the weight of the caustic potash used for the
solution.
It is not absolutely necessary that the outer vessel A be made of glass, but it
may also consist of iron or other suitable metal, in which case the clip c may be
fixed directly to the vessel A.
The objects of filling the space between the vessel A and cylinder B with
granulated retort carbon mixed with oxide and sub-oxide of copper are to obtain
great efficiency of the element and to reduce as much as possible the polarisation
taking place while the element is used, and to replace the used up oxide of copper
by the transformation of suboxide of copper into oxide of copper which is effected
by the action of the element, and in this way to obtain not only a momentary but
a continual regeneration of the element, that is to say, one repeated as often as
desired. As soon as the element herein before described is put out of activity, the
exciting liquor is regenerated, for which only a few minutes of rest are required,
without any decrease of the original power of the element becoming sensible even
after repeated regeneration.
The
The chemical process during the activity of the element may be explained as
follows: After the circuit is closed, decomposition of the water commences.
positive current passes from the zine through the liquid to the copper or carbon ;
in the same direction the particles of hydrogen also travel. In doing so they
encounter the oxide of copper and in consequence of the strong reducing action of
the nascent hydrogen the oxide of copper is reduced to sub-oxide of copper
eventually even to metallic copper. The carriers of the negative electricity, the
particles of oxygen, travel in the opposite direction from the strips of copper to the
zinc. When these particles of oxygen meet with the sub-oxide of copper or metallic
copper, they oxidise these again and form oxide of copper.
By suspending the zinc electrode in the manner hereinbefore described in a
separate carbon cylinder C, the electrolytic precipitate of zinc mud is deposited in
this cylinder, which can be readily removed for cleaning without disturbing the
depolarising substances contained in the space between the vessel A and cylinder B.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
1. The arrangement or combination of parts and substances of a galvanic element
substantially as herein before described and illustrated by the drawings.
2. The arrangement of a galvanic element in which the conducting strips (a) of
the copper bottom (6) of the carbon electrode (B) are completely embedded in a
depolarising mixture and the zinc electrode (D) is placed into a second carbon

page_text: cylinder (C) formed with a bottom which is in conductive contact with said copper
bottom (6), substantially as hereinbefore described and for the purposes set forth.
3. In galvanic elements the use or arrangement of a zinc electrode formed of a
zinc plate provided with perforations and spirally wound or bent in zig-zag form,
which is suspended in the carbon cylinder by a glass rod and insulated from said
cylinder by means of other glass rods passing cross-wise through the zinc electrode
and projecting beyond it, substantially as hereinbefore described and illustrated by
the drawings.
4. In a zinc electrode arranged as hereinbefore described and claimed in the
preceding claim, the arrangement of india rubber rings surrounding the glass rods
and placed between the convolutions or folds of the zinc plate substantially as
hereinbefore described and for the purpose set forth.
Dated this 14th day of Iul. 1002
R. J. URQUHART,
57, Barton Arcade, Manchester, and 5, Clayton Square, Liverpool,
Consulting Engineer and Patent Agent.