Improvements in Electrolytic Cells.
Year: 1894

page_text: Date of Application, 4th Aug., 1894
Complete Specification Lelt, 3rd May, 1895-Accepted, 3rd Aug., 1895
Improvements in Electrolytic Cells.
A communication from ERNEST SOLVAY, of 25 Rue du Prince Albert, Brussels,
Belgium.
I, WILLIAM LLOYD WISE, of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer, and Chartered Patent Agent, do hereby declare the
nature of this invention to be as follows:-
:-
A great drawback of all electrolytic apparatus at present in use, is their small
output in relation to their surface area. This drawback is due to the resistance of
the electrolyte which reduces the intensity of the current due to a given electro-
motive force, according to a well known law. Attempts have been made to
reduce the resistance as far as possible by placing the electrodes nearer to one
another, but there are practical objections to their being placed very close together.
Now this invention has reference to the reduction of the aforesaid resistance by
the use of electrolyzing surfaces formed of very thin electrodes placed side by side,
instead of being arranged opposite to each other or face to face with intervening
spaces, as heretofore. Thus when using strips of platinum insulated on their two
sides or faces, the strips are pressed against one another like the leaves of a book,
so that only their edges serve as conducting surfaces. In this manner there may
be built up a block or slab which when seen from one side, will show an alternating
arrangement of conducting and insulating lines, constituting it may be a plane or
flat surface, and forming what is herein termed an electrolytic table, each metallic
strip of even number being connected to one pole of an electric generator and all
the odd-numbered metallic strips being connected to the other pole. If the liquid
to be electrolized he hrought upon a table or electrode of this kind, it is clear that
the resistance to be overcome by the current will be infinitesimal in comparison
with the resistance of the apparatus heretofore usually employed, and that a very
small surface area can in this way be made to do a maximum quantity of work.
The edges alone of the strips would not suffice to conduct the amount of current.
that can be absorbed by the sheet of liquid. The total cross section of each strip
however acts towards this object, and may be determined so as not to produce any
appreciable heating effect, but the edge alone of each strip acts in the electrolysis
proper so that the said edge may be made of platinum, whilst the remainder of the
strip can be made of a cheaper metal. The strips may be replaced by mere
threads or wires in cases where such threads or wires are of sufficient cross section
to carry the current in any particular arrangement of apparatus employed, and
which arrangement may be varied indefinitely.
As electrolysis effected by means of the edge portions of conducting strips such
as described, takes place with great intensity, the liquid employed must be quickly
renewed. For this purpose the liquid is caused to How over the electrolytic table
at a speed suitable for producing the maximum output. With this object, the table
may be more or less inclined, and the liquid allowed to flow over the same by
gravity in a thin stream. Or mechanical means may be provided for producing a
rapid circulation of the liquid over the table. When the electrolyzing surfaces are
enclosed or are of tubular form the liquid may be subjected to pressure, but in most
casca, particularly in cases where the electrolytic table is free or exposed, it is
preferred to employ centrifugal action in order to produce rapidity of circulation

page_text: and a thin sheet of liquid. For this purpose it will be sufficient to mount the table
upon a shaft and to cause it to revolve at a suitable speed according to the viscosity
of the liquid being treated. There may also be employed if necessary, besides
centrifugal action, special means for facilitating the rapidity of the circulation and
the thinness of the sheet of liquid. Thus the liquid may be heated to render it
more fluid, and a special preparation of the electrolyzing surface may be adopted
consisting in slightly graining or roughening the said surface with the object of
diminishing capillary or surface adhesion.
It is to be understood that this invention is not limited to the use of plane or flat
electrolytic surfaces constructed as herein described the term << electrolytic table
being herein used by way of example only. Thus the thin conducting strips may
be arranged side by side in other forms, for example in cylindrical form in order to
constitute electrolyzing tubes. Again the thickness of the insulating material may
be reduced to a minimum by coating the strips with varnish; or thin strips of
insulating material such as caoutchouc, glass, paraffin, mica and the like may be
inserted between the strips. The conducting strips may also be fixed in place by
any suitable means and without the interposition of any insulating substance, but
in such a case, it is obvious that it would be better to cause their entire surface to
act electrolytically. Thus all arrangements which produce the juxtaposition of a
large number of conducting strips, or in which the strips are placed very close to
one another, so that an intense electrolytic action is produced, is regarded as
coming within the scope of this invention. Furthermore, in the case of the table,
the surface need not constitute a perfect plane. For the purpose of effecting
certain results, the conducting strips may project to a very slight extent beyond the
edge of the insulating material or the latter may be arrangel to form slight
projections or ribs.
When it is desired to separate from each other the evolved gascous products of
electrolysis or even in other cases, an electrolyzing surface constructed as herein
described may be combined with a cover or hood, such as hereinafter described,
which requires only that the electrolytic strips shall not be so closely arranged as
when such cover is not used, and that the distance between the strips shall become
appreciable. The cover is formed with a series of longitudinal grooves which
constitute an inverted furrow or channel over the edge of each conducting strip.
The gases are given off vertically, that given off by each edge being collected.
without mingling with that given off from the adjacent edges, in the inverted
furrow or channel provided over such edge. All the even-numbered furrows
communicate with a cominon collecting channel, and all the odd-numbered furrows
communicate with another common collecting channel so that each gas can be
conducted off separately. With an electrolytic table having a considerable surface,
the cross sectional area of a single groove would not be sufficient to permit of the
discharge through a single orifice at the end, of the volume of gas which would be
collected in such groove. In this case the system of collectors is arranged to form
a number of stages of discharge; the grooves discharge into small channels, these
into larger channels, and these latter into main collectors, the whole being arranged
to branch off in such a manner as to provide at all parts, a passage of sufficient
cross section to lead off the gas at such part whilst forming one with the cover.
This general arrangement is very simple and allows of the electrolytic surface
being readily inspected and cleaned as there is only a single part to be lifted in
order to lay bare the whole interior of the apparatus whilst working, and only one
joint to be remade in order to resume working.
In a modified construction of cover, the tops of the grooves are formed of
insulating material, but the walls may be made conducting, or be covered with
conducting strips in such a manner as to constitute a complete cell, in which case
the conducting strips which formed part of the table in the arrangement first herein
described may be dispensed with. The table then ceases to act electrolytically and
serves only as a support for the sheet of liquid on which the grooved cover provided
with electrolyzing strips then acts. In this construction there are two strips of

page_text: similar polarity in each groove, each strip being very close to a strip of opposite
polarity in the next adjacent groove.
In all the arrangements hereinbefore described, it has been assumed that thin
sheets of liquid are used circulating in general at a high speed, but it will be
readily understood that the electrodes or electrolyzing surfaces may be used for the
electrolysis of sheets of liquid that are comparatively thick and have a compara-
tively slow circulation or which may even flow intermittently instead of continuously.
In such a case it is sufficient to make the grooves in the cover a little leeper, so
that they then become small inverted troughs having conducting walls composed of
thin adjacent strips immersed in the liquid to be electrolysed. It is however of
small importance whether the troughs are completely separated at their upper parts
for collecting the gases separately, if there be any, or whether they inter-communi-
cate freely so as to collect only a mixture of the said gases. In the latter case the
arrangement resolves itself into the insulated strips herein before described, which
act with their entire surface.
When the strips offer an appreciable resistance it is advantagecus to cause the
liquid to flow in a contrary direction to that of the current.
An electrolytic table such as herein described, is, for certain purposes very
suitable for use with alternating currents, which is an important advantage by
reason of the greater simplicity of the dynamos employed.
Dated this 4th day of August 1894.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
A communication from ERNEST SOLVAY, of 25 Rue du Prince Albert, Brussels,
Belgium.
I, WILLIAM LLOYD WISE, of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer. and Chartered Patent Agent, 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 great drawback of all electrolytic apparatus at present in use, is their small
output in relation to their surface area. This drawback is due to the resistance of
the electrolyte which reduces the intensity of the current due to a given electro-
motive force, according to a well known law. Attempts have been made to reduce
the resistance as far as possible by placing the electrodes nearer to one another,
but there are practical objections to their being placed very close together.
Now this invention has reference to the reduction of the aforesaid resistance by
the use of electrolysing surfaces formed of very thin electrodes placed side by side,
instead of being arranged opposite to each other or face to face with intervening
spaces, as heretofore. Thus when using strips of platinum insulated on their two
sides or faces, the strips are pressed against one another like the leaves of a book,
so that only their edges serve as conducting surfaces. In this manner there may be
built up a block or slab which, when seen from one side, will show an alternating
arrangement of conducting and insulating lines, constituting it may be a plane or
flat surface, and forming what is herein termed an electrolytic table, each metallic
strip of even number being adapted to be connected to one pole of an electric
generator and all the odd-numbered metallic strips being adapted to be connected
to the other pole. If the liquid to be electrolized be brought upon a table or
electrode of this kind, it is clear that the resistance to be overcome by the current
will be infinitesimal in comparison with the resistance of the apparatus heretofore

page_text: usually employed, and that a very small surface area can in this way be made to do
a maximum quantity of work. The edges alone of the strips would not suffice to
conduct the amount of current that can be absorbed by the sheet of liquid. The
total cross section of each strip however acts towards this object, and may be
determined so as not to produce any appreciable heating effect, but the edge alone
of each strip acts in the electrolysis proper so that the said edge may be made of
platinum, whilst the remainder of the strip can be made of a cheaper metal. The
strips may be replaced by mere threads or wires in cases where such threads or
wires are of sufficient cross section to carry the current used in any particular
arrangement of apparatus employed, and which arrangement may be varied
indefinitely.
As electrolysis effected by means of the edge portions of conducting strips such
as described, takes place with great intensity, the liquid employed must be quickly
renewed. For this purpose the liquid is caused to flow over the electrolytic table
at a speed suitable for producing the maximum output. With this object, the table
may be more or less inclined, and the liquid allowed to flow over the same by gravity
in a thin stream. Or mechanical means may be provided for producing a rapid
circulation of the liquid over the table. When the electrolyzing surfaces are
enclosed, or are of tubular form, the liquid may be subjected to pressure, but in
most cases, particularly in cases where the electrolytic table is free or exposed, it is
preferred to employ centrifugal action in order to produce rapidity of circulation
and a thin sheet of liquid. For this purpose it will be sufficient to mount the table
upon a shaft and to cause it to revolve at a suitable speed according to the viscosity
of the liquid being treated.
In the accompanying drawings,
Fig. 1 is a central vertical section, partly in elevation, and Fig. 2 a part plan,
showing one electrolytic apparatus constructed according to this invention.
1 are the thin sheet metal electrodes insulated from each other and arranged
close together withiu an annular recess in a holder 2 so as to form an electrolytic
table of annular shape and having a flat upper surface composed of alternately
arranged conducting and non-conducting lines. In Fig. 1 and in the right hand
half of Fig. 2, the electrodes consist of thin flat metal strips arranged radially, each
alternate strip being electrically connected at one end to an inner conducting ring 3
and the remaining strips being similarly connected to an outer conducting ring 4.
At the left hand side of Fig. 2, the electrodes 1 are in the form of thin sheet metal
strips insulated from each other and arranged concentrically with each other and
with inner and outer conducting rings 3 and 4. The electrolytic table thus formed
is arranged within a fixed annular casing 5 having a trough 6 and discharge pipe 7,
and is carried by a vertical shaft 8 mounted in bearings 9 in a support 10.
shaft is provided with a belt pulley 11, and with insulated metal contact rings 12, 12"
that are connected with the conducting rings 3 and 4 respectively and against which
bear brushes 13, 13ª connected with the poles of an electric generator, the
arrangen:ent being such that the electrolytic table can be rotated at a high rate of
speed so that the electrolyte delivered from a supply pipe 14 over a delivery
cone 14 will be caused to travel rapidly over the table in the form of a thin
sheet.
The
There may also be employed if necessary, besides centrifugal action, special
means for facilitating the rapidity of the circulation and the thinness of the sheet
of liquid. Thus the liquid may be bcated to render it more fluid, and a special
preparation of the electrolyzing surface may be adopted consisting in slightly
graining or roughening the said surface with the object of diminishing capillary or
surface adhesion.
"
It is to be understood that this invention is not limited to the use of plane or
flat electrolytic surfaces constructed as herein described, the term " electrolytic
table being herein used by way of example only. Thus the thin conducting strips
may be arranged side by side in other forms, for example in cylindrical form in
order to constitute electrolyzing tubes. Again the thickness of the insulating

page_text: material may be reduced to a minimum by coating the strips with varnish; or thin
strips of insulating material such as caoutchouc, glass, paraffiu, mica and the like
may be inserted between the strips. The conducting strips may also be fixed in
plare by any suitable means and without the interposition of any insulating
substance, but in such a case, it is obvious that it would be better to cause their
entire surface to act electrolytically. Thus all arrangements which produce the
juxtaposition of a large number of conducting strips, insulated laterally from each
other or in which the strips, separated by insulating material, are placed very close
to one another, so that an intense electrolytic action is produced, are regarded a-
coming within the scope of this invention. Furthermore, in the case of the table,
the surface need not constitute a perfect plane. For the purpose of effecting certain
results, the conducting strips may project to a very slight extent beyond the edge
of the insulating material, or the latter may be arranged to form slight projections
or ribs.
When it is desired to separate from each other the evolved gaseous products of
electrolysis, or even in other cases, an electrolyzing surface constructed as herein
described may be combined with a cover or hood, such as hereinafter described,
which requires only that the electrolytic strips shall not be so closely arranged a-
when such cover is not used, and that the distance between the strips shall becom
appreciable. The cover is formed with a series of longitudinal grooves whic
constitute an inverted furrow or channel over the edge of each conducting strip.
The gases are given off vertically, that given off by each edge being collected.
without mingling with that given off from the adjacent edges, in the inverted furrow
or channel provided over such edge. All the even-numbered furrows communicate
with a common collecting channel, and all the odd-numbered furrows communicate
with another common collecting channel so that each gas can be conducted off
separately. With an electrolytic table having a considerable surface, the cross
sectional area of a single groove would not be sufficient to permit of the discharge
through a single orifice at the end, of the volume of gas which would be collected
in such groove.
In this case the system of collectors is arranged to form a number
of stages of discharge; the grooves discharge into small channels, these into larger
channels and these latter into main collectors, the whole being arranged to branch
off in such a manner as to provide at all parts, a passage of sufficient cross section
to lead off the gas at such part whilst forming one with the cover.
This general
arrangement is very simple and allows of the electrolytic surface being readily
inspected and cleaned, as there is only a single part to be lifted in order to lay bare
the whole interior of the apparatus whilst working, and only one joint to be remade
in order to resume working.
In a modified construction of cover, the tops of the grooves are formed of
insulating material, but the walls may be made conducting, or be covered with
conducting strips in such a manner as to constitute a complete cell in which case
the conducting strips which formed part of the table in the arrangement first herein
described, may be dispensed with. The table then ceases to act electrolytically,
and serves only as a support for the sheet of liquid on which the grooved cover
provided with electrolyzing strips then acts. In this construction there are two
strips of similar polarity in each groove, each strip being very close to a strip of
opposite polarity in the next adjacent groove.
In all the arrangements hereinbefore described, it has been assumed that thin
sheets of liquid are used circulating in general at a high speed, but it will be readily
understood that the electrodes or electrolyzing surfaces may be used for the
electrolysis of sheets of liquid that are comparatively thick and have a comparatively
slow circulation, or which may even flow intermittently instead of continuously.
In such a case it is sufficient to make the grooves in the cover a little deeper, so
that they then become small inverted troughs having conducting walls composed of
thin adjacent strips immersed in the liquid to be electrolysed. It is however of
small importance whether the troughs are completely separated at their upper parts
for collecting the gases separately, if there be auy, or whether they inter-communicate

page_text: freely so as to collect only a mixture of the said gases. In the latter case the
arrangement resolves itself into the insulated strips herein before described, which
act with their entire surface.
When the strips offer an appreciable resistance, it is advantageous to cause the
liquid to flow in a contrary direction to that of the current.
An electrolytic table such as herein described is, for certain purposes very suitable
for use with alternating currents, which is an important advantage by reason of the
greater simplicity of the dynamos then employed.
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. In an electrolytic cell, an electrolysing body composed of a number of juxtaposed
thin strips threads or wires of conducting material insulated from each other
and grouped together so as to form intense electrolyzing bodies, substantially as
herein described.
2. In an electrolytic cell, a flat or curved open or closed electrolyzing surface,
formed by the edges of a number of insulated and juxtaposed thin conducting
strips arranged to constitute an electrolytic table substantially as hercin described.
3. In an electrolytic cell provided with an electrolyzing surface or table such as
berein referred to, causing the electrolyte to flow or circulate rapidly in the form
of a thin sheet over the said surface or table by the action of a mechanical device
or by the action of gravity, pressure or centrifugal force, with or without the aid of
beat, substantially as hereinbefore described for the purpose specified.
4. In an electrolytic cell, an electrolyzing table of the kind herein referred to,
baving a grained or roughened surface for the purpose of diminishing capillary or
surface adhesion and so facilitate the rapid flow of the electrolyte in the form of a
thin sheet over the said surface.
5. In an electrolytic cell, the combination with a flat electrolyzing surface or
table of the kind specified in Claims 1 and 2, of a grooved cover adapted to
separate and collect the gaseous products of electrolysis substantially as herein
described.
6. In an electrolytic cell, a surface or table for supporting the electrolyte in
place and a cover arranged above said surface or table and formed with grooves the
sides of which are formed of or provided with conducting material arranged to form
an inverted electrolyzing surface or table of the kind herein explained, substantially
as herein described for the purpose specified.
. גיז
1
1002
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent, Agent.