provements in or connected with Electrodes for Electrolysers.
Year: 1899

page_text: COMPLETE SPECIFICATION
Improvements in or connected with Electrodes for Electrolysers.
We, RAPHAEL EYCKEN, Manufacturer, of 18, Place Sebastopol Lille, CHARLES
LEROY, Manufacturer, of Wasquehal, and RENÉ MORITZ, Electro-Chemist, of 32,
Rue des Prêtres, Lille, all in France, 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.-
A study of the facts which exercise an influence on the yield of any electrolysing
apparatus (v. L'Industive Electrochimique 2. annee, p 35 and 49 and also
"Chemiker Zeitung," Repertorium 1898, pages 176 and 204) leads one to the
conclusion, that the maximum yield will be obtained, if the apparatus fulfils the
following conditions:
-
The electiodes should be placed as near together as possible, the current density
used should be as low as possible (and therefore the apparatus cheap), and the
products arising from the discharge of the ions should be removed from the zone
of the current as quickly as possible Consequently, the liquids should circulate
through the apparatus quickly, which promotes the depolarisation of gases,
especially if the circulation takes place in the direction in which the gases are
discharged, another consequence is, that the electrolysing apparatus will con-
tain but a small volume of liquid The liquids employed should be warm, in
order to reduce the electrical resistance of the solutions and the appliances must
therefore be capable of resisting heat Moreover, it is often desuable, in the
case of electrolysers with diaphragm, to be able to increase or reduce the pressure
on one side of the diaphragm or on the other, in order to promote the filtration
of the liquid from one pole to the other through the diaphragm, without danger of
breaking or shifting the latter.
Our invention has for its object, to provide a form of electrodes, which fulfils
these conditions
In the following description the new system of electrodes is divided into two
classes, the first of which includes electiodes which are made from materials
capable of being cast, moulded, or shaped by means of edge tools, while the

page_text: second includes electrodes made of materials which cannot be conveniently
shaped, and which must therefore retain the shape in which they are found in
commerce.
1. ELECTRODES MADE OF MATERIALS CAPABLE OF BEING CAST, MOULDED, OR
SHAPED BY MFANS OF TOOLS
The system of electrodes consists of two parts, viz. the electrode proper and
its supporting base or care. As the two parts usually form one piece, and
will only produce the desired result when used in combination, we call the whole
an electiode system
-
The supporting base or carrier represented by Fig 1 is constructed as follows:-
It consists of a plate having a smooth rim a a Above and below there are
ate, a (Figs. 1 and 2) two deep grooves, engraved into the mass of the plate.
These grooves or canals are connected by a row of furrows extending from the
top to the bottom approximately parallel to each other
These furrows may be
zigzag-shaped (r), corrugated (s), square (f), Fig. 3, o1 of other suitable shape in
Cross section, and serve to provide nanow passages for the liquids, so that they
are forced to circulate regularly and uniformly on the entire face of the plate.
and most quickly in the direction in which the gases escape
In some cases, as mentioned below, the furrows may be omitted
The supporting base may be made of various materials, including both good
and bad conductors of electricity, such as cast iron, wrought on, other metals,
clay, slate, wood or cement.
The electrode proper consists of a wine netting (Fig 1, right hand side, q)
(Fig 2, 3, 4 & 7. g) or of corrugated or perforated sheet iron or sheet steel, which
in case the supporting base consists of a good conductor, is simply laid in the
interior of the plate, and in case the supporting base consists of a bad conductor,
has a metallic prolongation adapted to serve as electic contacts or terminals
If certain kinds of wie netting with thick wefts are employed, the furrows
may be omitted, because thick weft wires leave interstices serving the same
purpose (Fig 7), the same is the case if perforated conugated sheet metal is
used
The electrodes may be made so that they can work with both faces For this
purpose each side of the supporting plate has a smooth rim, canals and funows
(Figs 4 and 12) The two canals or grooves which conespond to each other on
the two sides, have the same inlet and outlet
In order to simplify the construction and reduce the weight, the carrier or
plate may be reduced to a cast on 11m or fiame a which encloses a piece of
corrugated sheet metal r serving to replace the furrows (Fig 5).
The sheet metal projects into the cast iron (Fig 5), the canals for the liquid
are formed in the rim (Fig 6), and the liquid gets into the zone of the current
though small holes (h), and passes out in the same manner. The construction
18 the same at the top and at the bottom One-sided electrodes may be con-
atructed in a similar mannei
The following examples will show, what materials may be employed
The liquid attacks neither cast non or wrought iron In this case the
supporting base is of cast on, and the electrodes proper of wrought non wne
netting or of perforated conugated on or steel plate
A few screws serve to establish contact between the cast non plate and the
sheet on o wie netting The electic terminals are on the cast iron plate
It is necessary to use electrodes of precious metals, such as platinum
According to the nature of the liquid the supporting base consists of cast non
faced with ebonite, or enamel, slate, clay, wood, and is covered with a wue netting
of platinum. The ends of the platinum wues on the wne netting are all com-
municating with an external conductor which carries the electic terminals In
this manner the weight of the platinum is reduced to a minimum.
If the liquids are to be heated by the electrolysing apparatus itself, electrodes

page_text: Fig 15, in which a and b represents a carbon electrode, e a diaphragm, d and e a
metallic electrode (the whole approximately in natural size). The distance k
between the electiodes is only the thickness of the diaphragm.
The enculation of the liquid is so arranged, that the liquid situated in the
electrically active zone has a very small volume and circulates as rapidly as may
be desired, its speed being approximately equal at every point of the electrode,
Consequently, the renewal of the liquid is absolutely rational, and the podnets
of discharge of the ions cannot accumulate at one point: on the contrary, the
said products are led off very quickly, and the secondary electiolysis of the same
18 diminished, thus increasing the efficiency
4 As the cnculation of the liquid takes place rapidly in the same direction in
which the gases escape, the depolarisation of gas is promoted and thereby the
electric resistance reduced
6 Electrolysing apparatus formed by means of these electrodes contains as
few joints as possible, all these joints or connections can be made externally and
easily, in consequence of which it is impossible, especially with unbreakable
diaphragms, that liquid will flow accidentally from one pole to the other.
7. After the electiolyse has been set in action, both sides of the diaphragm are
held in position by the electrodes on its entire face, the pressure may be increased
or reduced on either side in order to promote filtration without danger of break-
ing or shifting the diaphragm
8 The cost of production of electrolysers, especially those which are arranged
in batteries, and made with light double faced electrodes, is reduced to a
minimum, and it is possible to work with very low current density, while ensuring
commercial success. In some cases, for instance the electrolysis of alkali-chloride
with carbon anodes, the carbon is not attacked, consequently no carbonic acid
will get into the chlorine Carbonic acid is always very injurious in the manu-
facture of hypochlorite.
9 Owing to the special arrangement of the carbon-electrodes, especially when
working with high current density, small, cheap, and easily replaceable carbons
may be employed.
J
10 These electrodes are very durable, and may therefore be handled by work-
men who have no special training.
APPLICATIONS
For the electrolysis of alkali-chlorides cheap and efficient electiolysers which
requie but little space may be built up in the manne illustrated by Fig. 12,
that is to say, by pressing together a kathode a of cast iron and non we netting,
a diaphragm d, a double-faced carbon-anode c, a diaphragm d, a double-faced
cast on kathode with wire netting b, a diaphragm 7, a carbon anode, a dia-
phragm ete in the order represented by the drawing The negative connections
are made on the cast on fiame of the kathode, and the positive connections on
the heads of the thick carbon 1ods.
For this application electrodes may be made having upwards of two square
meters of active surface
Electrodes may be employed which contain a pipe coil embedded in the casting.
in order to heat the liquids when they are in the apparatus, or liquids may be
caused to cuculate through the apparatus which have been heated previously by
suitable means.
A reduction of pressure may be produced on the negative side, in order that the
positive liquid may filter into the negative liquid. In this case no hypochlorite
and no chlorate will be formed.
If it is desued to obtain hydrogen and oxygen by using caustic soda liquor as
an electrolyte, the apparatus is made from cast iron electrodes provided with
iron we netting, which serve both as anode and as kathode (Fig 13) Dia-
phragms are inserted between the electrodes
If it is desired to obtain the same gases by using sulphuric acid as an

page_text: are employed, the plates of which can be heated by steam. This is effected by
means of a pipe coil embedded in the mass of the plate, or by means of hollow
electrode-plates, according to the nature of the electrode system In the case of
metals the plate is cast in a mould containing a pipe coil made of a metal having
a higher melting point than the metal of the plate. Figs 1 and 2 show such
a pipe coil 1, 1, while m and indicate the inlet and outlet openings of the
steam The connections with the steam conduit are made of bad conductors of
electricity, in order that no electricity may be wasted through the steam conduït,
2. THE MATERIALS ARE NOT SUITABLE FOR CASTING OR MOULDING OR SHAPING
BY MEANS OF CUTTING TOOLS, SUCH AS CARBONS.
Electric carbons are found in commerce in the shape of round or prismatic
rods of various dimensions, but hither to neither in the shape of large plates, nor
in the shape of wine netting Consequently we must adapt our electrolysing
apparatus for using the commercial form of carbon
We have retained our arrangement with supporting base and electrode proper
Figs 8 and 9 represent such a carbon electrode together with its supporting base.
The supporting base consists of a fiame 2, 2, of wood, which may be impreg-
nated to increase its resistance, ou of cast iron or wrought non faced with ebonite,
or of enamelled metal, earthenware, cement, clay, slate, or other material, thot
may be suitable for each particular case This hollow frame has its outside armed
with metal to prevent it from falling to pieces
"
At the top this fiame has a series of holes, through which pass the carbon
1ods serving to conduct the current to the electiode proper A tight joint is made
by means of putty or asbestos packing, to prevent the escape of gas or liquid
between the carbon rods and the frame.
The sides of the frame have openings 4 and 5, for the admission and discharge
of the liquid
The thick carbon rods 1 do not reach to the bottom of the frame, but leave a
clearance space 6. in front of which is situated the inlet tube (4)
Right and left (in the case of a double-faced electiode), or on one side (in the
case of a one-sided electrode) are applied the electrodes proper which consist of a
series of thin carbon rods 10 of 1ound, polygonal or other suitable cross section,
and which are in contact with the thick carbon 1ods These thin carbon rods
do not extend to the top of the frame, but leave a clearance (7, 7) in which
accumulates the liquid before it is discharged.
The thin carbon rods are kept in contact with the thick rods by means of
strips (9, 9. 9) made of asbestos fabric.
The regularly shaped carbon 1ods may be replaced wholly or partly by less
regular lumps of carbon, for instance waste pieces of arc lamp carbons 'This
electrode may also be replaced by electiodes made from materials capable of being
cast, moulded or shaped by means of edge tools, but the system of electrodes
described above is better.
Instead of a flat shape for the electiode as described above, a cylindrical,
prismatic or other shape may be employed Figs 10 and 11 represent such an
electrode, a being a smooth or plain pait. c the collector and 6 the furrowed or
grooved pait, on which lies the wire netting
The advantages of these electrodes are as follows .–
1. These electrodes may serve for producing very simple electrolysing apparatus
for it 18 sufficient to press two electrodes one upon the other to obtain a simple
electrolyser If it is deaned, to obtain an electrolvser with diaphragm, it 19
sufficient to press two electrodes against a diaphragm enclosed in a U shaped
frame The said frame has for its object to prevent the escape of liquids or
gases and to protect the diaphragm from pressure
2 The electrically active part of the electrode is placed as near as possible
to the diaphragm or to the opposite electrode, consequently the waste of current
due to internal resistance is reduced to a minimum. This will be seen from

page_text: electrolyte, carbon electrodes are used as anode and as kathode
pressed upon diaphragms (Fig. 14).
These are
The two end electrodes a, a are one-sided. We have successfully used these
electrodes also for removing non fiom solutions of alumina-sulphate, the non
being precipitated upon insoluble electrodes and subsequently again dissolved
by acid.
These electrodes are suitable also for organic oxidation and reduction. The
composition of the apparatus in that case varies according to the nature of the
liquids We generally employ carbon electrodes as anodes, but sometimes also
platinum electiodes, the supporting base being of earthenware and the electrode
proper of platinum wie netting, and as kathodes we employ platinum electrodes
01 cast on electrodes with on 01 nickel wire netting.
In the diawings:-
Fig 1 18 a face view of an electiode belonging to the first category, paitly with
and partly without the wne netting (9)
Fig. 2 18 a vertical section corresponding to Fig 1
Fig. 3 18 a horizontal section of the same kind of electrode showing various
shapes of fallows r, 5, t.
Fig. 4 is a horizontal section of a double-faced electrode provided with grooves
and we netting on both sides.
Fig. 3 18 a horizontal section of an electiode consisting of a rectangular east
iron frame enclosing a piece of coniugated sheet metal
Fig 618 a partial face view of the electrode shown in Fig 5
Fig. 7 is a partial section of an electrode similar to Fig 3, but on a laiger
Bcale.
Fig. 7b represents an electrode with thick we netting and without furrows
Fig. 8 is a vertical section of a double-faced electrode belonging to the second
category and showing the thick carbon 1ods
Fig. 9 is a face view of the same, a portion of the electrode propei (consisting
of thin carbon rods) having been removed.
Fig. 10 is a horizontal section of an electrode of the fist category, in the shape
of a hollow cylinder.
Fig. 11 is a partial vertical section of the same
Fig 12 is a horizontal section of an electrolyse suitable for the decomposition
of alkali-chlorides, a and b representing electrodes of cast on and we netting,
c double-faced carbon electrodes, d diaphragm.
Fig. 13 is a section of an electrolyse composed of single-faced non elec-
trodes a, a (ot cast on and wire netting), double-faced non electrodes b and
diaphragm d.
Fig 14 18 a horizontal section of an electrolyser composed of single-faced
carbon electrodes a, double-faced carbon electrodes b and diaphragm d
Fig 15 18 a partial section approximately in natural size of an electrolysei
composed of a carbon electrode a, b, a metallic electrode de, and a diaphragm c.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that
what we claim 18:-
1. An electrode or system of electrodes (Figs. 1 to 7) composed of two per-
manently connected parts, riz : a supporting base or electrode carrier and an
electrode proper, the supporting base consisting of a suitably fullowed plate made
of a matei al capable of being cast, moulded or shaped by means of cutting tools,
while the electiode proper consists of wie netting or perforated conugated sheet
metal; canals or grooves being provided for conducting the liquids into the said
furrows which seive to reduce the layer of liquid to a minimum, to bring the
electiode in close proximity to the diaphragm or to the opposite electrode, and
to cause a regular and unitoim enculation of the liquid over the entire face of
the electrode from the bottom to the top, to promote the escape of gases and to

page_text: accelerate the separation of the products resulting from the discharge of the
Jons, and a Pipe
coil being embedded in the casting, in order to heat the liquids
n the electiolyser.
2 An electrode or system of electiodles (as indicated by Figs 8 and 9) made of
materials not suitable for transformation by casting moulding on shaping, such
as carbon, and composed of two permanently connected parts, us a supporting
base or electrode canner and an electrode proper, the supporting base consisting
of a frame in which are fixed thick carbon 1ods, while the electrode proper con-
sists of thinner carbon rods pressed against the thick rods, and a series of canals
o ducts being formed between the two for the purposes specified above, sub-
stantially as described
3. The modification of the two systems of electioles specified by Claims 1
and 2 by making the electrodes of cylindrical, prismatic, or other analogous
shape
4. Electrolysing apparatus built up from electrodes of the types specified by
Claims 1, 2 and 3, by pressing them together, with or without the addition of
diaphragms substantially as described
5. Electrodes and electrolysers constructed and adapted to operate substantially
as described and illustrated by the drawings.
Dated this did day of November 1899.
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London.
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London.