Improvements in or connected with Apparatus for the Electrolytic Decomposition of Liquids.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Apparatus for the Electrolytic
Decomposition of Liquids.
We GEORGE BELL and GEORGE WILLIAM BELL, both of 97 Newsham Drive,
Newsham Park, Liverpool, in the County of Lancaster, Mechanical and Chemical
Engineers, do hereby declare the nature of this invention to be as follows:-
This invention has reference to apparatus by which brine or a saturated solution.
of common salt is decomposed into its two constituents, namely, sodium or sodium
compound and chlorine, and it has for its object more particularly so to construct
apparatus of this kind, and so to carry on the manufacture of such substances
electrolytically, that, Firstly:-The battery shall not become polarized at the
cathode: Secondly:-The resistance of the partition used between the anode and
cathode is reduced as far as possible: Thirdly:-The resistance of the liquor to
the passage of the current through, shall be small; and Fourthly:-The resistance
of the anode to the current is rendered as small as possible.
Although, as stated, the invention is not restricted to the manufacture of sodium
compounds and chlorine from solution of common salt, or brine, still at the same
time it is to be understood, that it may be applied more or less in the decomposition.
of the solutions or liquids which differ materially from common salt, and also in
part in combination with other electrolytic systems.
The type of electrolytic apparatus to which this invention has special reference,
is that in which mercury is used as the cathode, into which sodium ions formed
passes, and is transferred to the liquor above, where it is oxidized by the water
forming caustic soda; and in some forms to apparatus into which the cathodes
and anodes are disposed one above the other, and the current of electricity flows
upwards from the anodes to the cathode above. In this latter kind of apparatus
according to the present invention, the apparatus is divided into three parts. The
lower one of these is the anode chamber wherein the brine is decomposed. The
second is a cathode chamber in which caustic alkali, i.e. caustic soda, is formed.
And the third above that is a chamber in which the gas given off in the anode
chamber, viz.: chlorine, is collected and in which also access is had to the anodes
in the lowermost chamber of the cells above. These three chambers are separated
from one another by diaphragms. The anode chamber is separated from the top
chamber of the cell below it by a metal insulated diaphragm, whilst the anode
chamber aud cathode chambers are separated by a porous diaphragm, on which
mercury is held. And above, this cathode chamber is separated from the gas
collecting chamber also by a metallic diaphragm. All these diaphragms are made
of a suitable metal, or other suitable material. In one arrangement having the
general characteristics above described, the three chambers are shallow in relation
o their diameter or width, and these sets of three are arranged in multiple, one,
wo, or more above one another, and therefore constitute a pile of batteries or
uperposed chambers.
The porous diaphragm may be made of any suitable material such as will suit
he well known nature of mercury; that is, which will be retained upon its surface
without liability of letting any of it go through the pores or apertures.
The chambers herein described are conveniently made of metal, the inner surface
hereof, in contact with. which gases or liquids may come, and which may become

page_text: corroded, being coated with some suitable material as rubber solution, cement,
chonite, brickwork, or any other suitable material.
Tubes by which the chlorine from the lower chamber is conducted to the upper
one are provided, and these serve also as supports to the porous diaphragm, they
being attached at their upper ends to the upper metal diaphragm and at the lower
end to the porous diaphragm, or parts or provisions which support same.
According to a further part of this invention, the brine used is kept in a
concentrated state by introducing salt into a separate vessel which is connected
with the various brine chambers of the cells, and through which the liquor from
the anode chambers circulates or is circulated; and the chlorine contained in such
liquor is driven off in this vessel by heating it, say by waste heat from any
available sources. The circulation between the various chambers and this vessel
is suitably effected by a pump or by other means; and the introduction of the
saturated brine close under the diaphragm into the cells is directed towards the
anodes to expediate the process. By thus driving off the chlorine, secondary
reactions of the chlorine in the brine upon the sodium, at the porous diaphragm,
upon the mercury and soda contained therein are avoided, and the efficiency
generally, correspondingly increased. The means by which this delivery and
discharge of brine is effected is by pipes suitably arranged, and provided with
cocks and passages as may be deemed suitable or advisable.
A further improvement in electrolytic apparatus consists in conveying the
alkali solution (caustic soda liquor) from the uppermost cathode chamber into
that of the second and the succeeding chambers in succession, thereby causing the
liquor when discharged from the lower one, to be in a more or less concentrated
state, a constant quantity however remains in each cell it becoming more
concentrated as it descends. The apertures or pipes by which this flow is effected
are so arranged that the liquor is discharged onto the surface or near the mercury,
so causing an agitation thereof, and thereby a more rapid action thereof and
enhancing the efficiency somewhat.
To enable access to be had to the anodes for repair or otherwise, the chamber in
which the anode holders are disposed and fastened is provided with manholes,
which can be readily taken off and put ou, and these chambers are made of such a
size that a man can get in to examine, and, if necessary, to release and replace
in position these anodes and their fittings.
By this invention, not only is a high efficiency afforded, but at the same time, a
comparatively small cell capacity is needed for obtaining a given output of
material; and thereby great advantage is afforded in the commercial carrying out
of this electrolytic production of alkali and chlorine, in as much as the area
occupied, on account of this efficiency, and on account also of the vertical or pile
arrangement of the cells is relatively small.
According to a modification under this invention, the porous diaphragm is not
horizontally disposed but stands at an inclination say in annular form, and is held
in position by a porous cover, which will prevent the escape of mercury, but will
not form much resistance, to their passage of gases or current. The top of this
annular diaphragm would be open and connected with the gas chamber diaphragm
above, and the space within it would contain the auode, supported or carried by an
earthenware holder substantially similarly to the case above described. The water
in this case would be contained in the space outside the conical diaphragm, and the
brine would be admitted to the interior thereof. In this case, the general
construction of the cells would have the appearance of consisting of two
chambers, viz., a gas chamber and a liquid chamber; while the anode chamber
would be within the cathode chamber or space.
The various improvements in apparatus herein described, are not necessarily
used in combination hereunder, but one or more of them might be used separately,
or in conjunction in connection with other electrolytic apparatus which may differ
materially in general design and characteristics from the apparatus herein described,
and the improvements also as regards the circulation and dechlorination of the

page_text: brine, and the concentration of liquor and other improvements herein specified,
may similarly be employed, in any other electrolytic process having for its object
the decomposition of brine for the production of alkali and chlorine.
Dated this 30th day of October 1895.
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicants' Patent Agents:
Improvements in or connected with Apparatus for the Electrolytic
Decomposition of Liquids.
We, GEORGE BELL and GEORGe William BeLL, both of 97 Newsham
Drive, Newsham Park, Liverpool, in the County of Lancaster, Mechanical and
Chemical 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 :-
This invention has reference to apparatus by which brine or a saturated
solution of common salt is decomposed into its two constituents, namely, sodium
or sodium compound and chlorine.
It is also, however, applicable more or less to the decomposition of the solutions
or liquids which differ materially from common salt, and also in part in
combination with other electrolytic systerus.
The type of electrolytic apparatus to which this invention has special reference
is that in which mercury is used as the cathode, into which the sodium or basic
ions formed pass, and are transferred to the liquor above, where they are oxidized
by the water forming caustic soda; and in which the cathodes and anodes are
disposed one above the other, and the current of electricity flows upwards from
the anedes to the cathode above. In this latter kind of apparatus according to the
present invention, the apparatus is divided into three parts. The lower one of these
is the anode chamber wherein the brine is decomposed. The second is a cathode
chamber in which caustic alkali, i.c. caustic soda, is formed. And the third above
that is a chamber or space into which the gas given off in the anode chamber,
viz., chlorine, is collected, arid in which also in some cases access is had to the
anodes in the lowermost chamber of the cells above. These three chambers or
parts are separated from one another by diaphragms. The anode chamber is
separated from the top chamber of the cell below it by a metal insulated
diaphragm, whilst the anode chamber and cathode chambers are separated by a
porcus or suitable diaphragm, on which mercury is held. And above, this cathode
chamber is separated from the gas collecting chamber also by a metallic
diaphragm. All these diaphragms are made of a suitable metal, or other suitable
material. In one arrangement having the general characteristics above described,
the three chambers are shallow in relation to their diameter or width, and these
sets of three are arranged in multiple, one, two or more above one another, and
therefore constitute a pile of batteries or superposed chambers.
The porous material on which the mercury is held may be made of any suitable
sul stance such as will suit the well known nature of mercury; that is, which
will retain it upon its surface without liability of letting any of it go through
the pores or apertures.
The chambers herein describe are conveniently made of metal, the inner
surface whereof, in contact with which gases or liquids may come, and which may
become corroded, being coated with some suitable material as rubber solution,
cement, ebonite, brickwork, or any other suitable material.
Tubes, by which the chlorine or other gas from the lower chamber is conducted

page_text: to the upper one, are provided; and these serve also as supports to the porous
diaphragm, they being attached at their upper ends to the upper metal diaphragm,
and at the lower end to the porous diaphragm, or parts or provisions which
support same.
According to a further part of this invention, the brine used is kept in a
concentrated state by introducing salt into a separate vessel which is connected
with the various brine chambers of the cells, and through which the liquor from
the anode chambers circulates or is circulated. The circulation between the
various chambers and this vessel is suitably effected by a pump, or by other
means; and the introduction of the saturated brine into the cells is directed
towards the anodes to expedite the process. The means by which this delivery
and discharge of brine is effected is by pipes suitably arranged, and provided
with cocks and passages as may be deemed suitable or advisable.
A further improvement in electrolytic apparatus consists in conveying the alkali
solution (caustic soda liquor) from the uppermost cathode chamber into that of the
second and the succeeding chambers in succession, thereby causing the liquor when
discharged from the lower one, to be in a more or less concentrated state, a
constant quantity however remains in each cell, it becoming more concentrated as
it descends. The apertures or pipes by which this flow is effected are so arranged
that the liquor is discharged on to the surface of or near the mercury, so causing
an agitation thereof, and a more rapid action of the process, and enhancing the
efficiency thereof somewhat.
To enable access to be had to the anodes for repair or otherwise, the chamber in
which the anode holders or carriers are disposed and fastened is provided with
manholes, which can be readily taken off and put on, and these chambers are made
of such a size that a man can get in to examine, and if necessary, to release and
replace in position these anodes and their fittings.
By this invention, not only is a high efficiency afforded, but at the same time a
comparatively small cell capacity is needed for obtaining a given output of
material; and thereby great advantage is afforded in the commercial carrying out
of this electrolytic production of alkali and chlorine, inasmuch as the area
occupied, on account of this efficiency, and on account also of the vertical or pile
arrangement of the cells, is relatively small.
In the drawings annexed to this specification an electrolytic apparatus illustrative
of this invention is given. In them, Figure 1 is an elevation partly in section, and
Figure 2 is a plan.
Referring now to the drawings, a is the lower or anode chamber wherein this
liquid is decomposed; e is the cathode chamber in which the alkali is formed; and
is the uppermost chamber in and by which access to the chambers a and e is had,
and into which the gas given off in a passes. The whole of these parts of the
electrolytic apparatus shown is made of cast iron.
bare the anodes. They are made of suitable material, say carbon, electrically
in connection with the bottom plate c of the chamber a; and they are hollow with
open sides, and have roofs over them, with a chimney or outlet 6² for the escape
of chlorine (or other gas) which is produced within them. The anodes must be
such that ample area in contact with the liquid being decomposed, for a given
amount of current supplied through them, is provided. The current to the anodes
passes by the conductor x, the plate c, and the bolts p³. This construction of
anode, however, forms no part of this specification, it being the subject of a
separate and subsequent application; and, therefore, per se, no claim is made to it
bereunder.
The chamber a is made up substantially of the ring of cast iron forming its
sides, the lower metal plate c, and the lower plate or bottom to the chamber e.
The outer ring a has outer flanges by which it is bolted to the chambers next it,
above and below (and these chambers similarly are provided with external flanges
for enabling them and the whole pile to be fastened up together); and it also has
an internal flange d to which the plate c is attached by studs or bolts. By this

page_text: с
construction it will be seen the plate e with its anodes 6 can be taken away and
lowered down into the chamber i, or the plate can be removed and access had to
the mercury and its suspending material, for repair, renewal, inspection, &c., and
again placed in position and fastened up, with facility.
The cathode chamber e comprises the outer ring of metal forming its sides, the
lower metal skeleton plate or frame f, and the upper metal plate h, while between
these plates the tubes k extend. The lower plate is of a skeleton form, consisting
of a peripheral ring, and rings within them, to which the lower flanges of the
tubes are attached; while ribs or bars run across the spaces between the outer
rim and these inner rings, and connect them together. Thus the whole thing
constitutes a skeleton frame or plate, and the open spaces in it are closed or filled
in with a thin porous material, l, such as porous china, carthenware, closely woven
asbestos cloth, or other similar or equivalent material, by which the mercury used
as the cathode in the apparatus is suspended upon the surface of the brine in a.
These porons suspending plates or parts I will be secured to the underside of the
frame by any suitable known means. The mercury in this chamber forms the
cathode, and the electric current is carried off by the conductor y, which is
connected with it.
The upper chamber of the three is made much deeper than the other two,
a and e; ie. it is made deep enough to enable a man to enter it and work within it,
such as to unscrew or screw up the nuts or bolts used to fasten the plate to the
internal flange d, or the nuts k¹ of the tubes k, or the bolts and nuts which are used
to fasten the edge of the plate h to the internal flange of the ring to the side of the
chamber e.
On the other hand, the chamber a is made as shallow as possible (say
about 6 inches), consistent with a sufficiency of anode and liquid area to render
the distance between the anode and cathode as short as possible, so as to keep the
resistance to the electric current low. To enable an entrance to be had to the
chambers i, manholes m, with covers, are provided in them.
As will be seen by the drawings, these three sets of chambers a, e, i, are
arranged in multiple one above another, in a pile. The number of the sets that
would be so employed one upon another, depending largely upon practical con-
siderations, and the circumstances and conditions of applications and use. Under
some circumstances where only a few sets of such chambers are used, and the
weight of the whole or bulk of the apparatus is such that it can be lifted safely
fron above by suitable hoisting machinery, so that access to any part of the
apparatus could be had by lifting up that portion which is above by the hoisting
machinery, then, in such a case, the size of the chambers i may be modified and be
made no deeper than a or e.
e,
of one set
The alkaline liquor is, as stated, passed from one cathode chamber
of chambers, to another; and in the apparatus shown it is conducted by a number
of pipes, n, suitably distributed, which connect the upper part of the upper of the
pair of chambers, which they couple, with the lower part of the lower chamber of
the pair. Thus the level of the liquor in these chambers e is regulated by the
level of the aperture connecting them with the upper ends of the pipes n, and the
overflow from one chamber passes by gravity to the lower part of the chamber e
next beneath it; and so, from the top of the pile or apparatus to the bottom, the
liquor flows through the succeeding chambers e, it being as it is supplied to the
uppermost chamber water or weak alkaline liquor, and becoming stronger and
stronger as it passes through the successive cathode chambers, leaving the
lowermost as a more or less strong solution.
As regards the other conduits for brine, chlorine, and hydrogen, the latter is
carried off from the chambers e by a main o connected with such chambers by
branches o; and the chlorine is carried off from the chambers i by a main p
connected to the said chambers by branches p'. The brine is circulated through
the chambers a by force (say a pump), it being introduced by inlet pipes q, and
carried away from the chambers i, into which it passes by way of the pipes k, by
the pipes q. The pipes 7 lead from a brine tank or vessel in which the brine is

page_text: kept at full strength (i.e. a saturated solution of salt) by introducing common salt,
and the pipes q lead to it; thus the liquor being electrolysed is always at full
strength, and the power required for the decomposition of the salt in this respect
consequently kept as small as possible, and the electrolyte having a closed cir-
culation through the saturator and cell, no chlorine which may be in solution therein
is carried away or lost; also by this circulation, coupled with the arrangement and
construction described by which the electrolyte exists on and circulates over the
under and upper plates forming the roof and floor to the cathode chamber e, the
temperature of caustic liquor in e is prevented from becoming excessively high
owing to the carrying off of the heat by the electrolyte. Further, by the
construction and arrangement described, viz., by the tubes k, through which the
gases pass to the chamber 1, and up which the electrolyte is carried, the depth of
electrolyte that is employed, and the head or pressure of same, in relation to the
head of caustic liquor, plus the weight or head of mercury in the cathode
chamber e, are such that the pressure of these latter liquids on the porous bottom
is completely counterbalanced by the upward pressure of electrolyte on its underside,
and thereby enabling thin or weak material for the suspension of the mercury upon
the surface of the electrolyte to be used, and thereby reducing the resistance of
such suspending material to the passage of the current or basic ions to the mercury.
As a modification of this construction by which this same effect is obtained, instead
of obtaining this balancing head or pressure by having an internal level of electrolyte
as specified, such level may be obtained by having a tube or tubes or receptacles
outside the chambers and connected therewith, in which the electrolyte will be
caused to stand at the point or level required.
The interior surfaces of the chamber a, except the porous material, are covered
with a suitable insulating material; and all the current is caused to pass to the
solution being electrolysed by way of the carbon of the anodes 6 (the inner surface
of the plate con which they rest being covered with the insulating material) to the
cathode, viz. the mercury. This insulation is represented in the drawings by the
thick line on the surface of the parts. The chambers i are also similarly covered
internally with insulating material, in the case of the liquid to be electrolysed
being carried up within the chambers i; and all the bolts, Hanges and connections
are insulated so as to completely isolate one chamber from one another. The surfaces
within the chambers not covered with an insulating material, and which are subject
to the action of corrosive gases, vapours, and liquids, should be covered with a
material which is capable of resisting the action of such gases.
In the operation of the apparatus (assuming the different chambers to be charged
with liquors, and the whole apparatus to be in action), the electric current passes
through the plate c to the interior of the hollow anodes b, and the salt in the
solution in a, in contact with the carbons within the anodes, is decomposed. The
chlorine liberated at these surfaces rises up naturally to the roof b¹ of the anodes,
and passes away therefrom by the funnel 6, into the interior of the tubes k; and
through these it passes up into the chamber i. The ions of sodium formed at the
same time in the anodes pass by their open sides out into the solution around them,
and towards the cathode, the mercury; and in their passage thence, they have first
to pass through the pores of the porous floors / which suspend the mercury upon the
surface of the liquid in a. The sodium thus entering the mercury at once forms
an amalgam therewith and, owing to its being less dense than the metallic mercury,
it (the amalgam) ascends through it and rises on the upper surface. Here it comes
into contact with water in the chamber e and is decomposed, the base being
converted to caustic soda, with the liberation of hydrogen.
This liquor, as it descends from one set of chambers e to another, as stated,
becomes stronger, and leaving the lowermost chamber e of the apparatus at the
required degree of strength, is conveyed away and concentrated by heat for the
production of dry or solid caustic soda in the usual way; or it may be treated in
any other required manner, or used in any required condition or state.
The liquor is delivered into the different chambers e at points, or in such a

page_text: manner, as to cause the flow or streams thereof to act upon the surface of the
mercury, and thereby expedite the process of transferrence of the oxide of the
base provided at its surface to the alkaline liquor, and so the whole action and
process.
The chlorine is conducted away from the chambers i by the pipes p, and utilized
in the manufacture of bleaching powder in the usual way, or for any other
purpose.
The hydrogen passes down pipe o, and can be utilized for heating purposes or in
any other serviceable manner.
It has been stated that the invention is applicable in whole or in part to the
decomposition of substances other than chloride of sodium, in respect of which its
(the invention's) application has been chiefly or substantially wholly specified;.
generally, such substances are solutions of alkaline or earthy alkaline bases, such..
as potash, ammonia, magnesia, alumina, and the like, either for the purpose of
separating the base from the salt, or with the object of obtaining another saline
solution; in the former case, the amalgam formed is decomposed by water, and in
the latter, by a suitable acid. Also, soluble lead solutions may be treated to form
hydrates and carbonates of lead, or white lead; in this case the mercury is
dispensed with.
In the case of the apparatus being employed in the production of the salts or
compounds of lead referred to, the anodes 6 would be of lead and sodium chloride,
or sodium nitrate in the form of a solution would be used in the anode chamber a;
while water would be used in the cathode chambers e, the porous plates 1 being
alone used to separate these liquids, i.e. without the mercury above specified. The
iron forming the shell of the cathode chamber e and the pipes k, constitute the
cathode in these cases.
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 is :-
1
1. The herein described improvement in apparatus for the electrolytic decom-
position of liquids or substances as referred to, namely, an apparatus comprising
plurality of sets of chambers, one upon the other, each set consisting of an anode
chamber, a cathode chamber, and a chamber or space above the anode chamber and
connected therewith; for the purposes set forth.
2. An apparatus for the electrolytic decomposition of liquids or substances as
referred to, comprising a plurality of sets of chambers a, e, and i, constituting
anode, cathode, and intermediate chambers, respectively, arranged one upon
another as a pile; substantially as described.
3. In apparatus for the electrolytic decomposition of liquids or substances as
referred to, wherein mercury is employed and serves to transfer the base from the
substance being electrolytically decomposed, to the liquid solution being formed,
and such liquor is passed through a number of chambers or vessels in series,
effecting the expedition of the removal of the salt formed at the upper surface of
the mercury, by directing or causing the flow of such liquor into the said
chambers or vessels towards or on to the surface of mercury; substantially as
described.
4. An electrolytic apparatus for the electrolytic decomposition of liquids or
substances as referred to, comprising a plurality of sets of chambers, such as
specified, one upon the other in a pile; each pair of cathode chambers being
connected together, and the alkali solution caused thereby to be conveyed
through the successive chambers in series; substantially as and for the purposes
described.
5. In electrolytic apparatus for the electrolytic decomposition of liquids or
substances as referred to, the combination of a lower anode chamber, and a cathode
chamber above, such anode chamber having tubes or conduits carried up into or
through the cathode chamber, by which gases generated in the anode chamber

page_text: below are conveyed away from the plates or material suspending the mercury
cathode, and froin such anode chamber generally; substantially as described.
6. In electrolytic apparatus for the electrolytic decomposition of liquids or
substances as referred to, the improvement described consisting of a lower anode
chamber in which the electrolyte is contained, and a cathode chamber directly,
above same containing a mercury cathode suspended upon the electrolyte below by
porous material, and water or liquor thereon, and having the head or pressure of
such electrolyte in or acting upon the underside of such porous material in the
anode chamber, substantially as and for the purposes described.
7. Electrolytic apparatus for the electrolytic decomposition of liquids or
substances as referred to, having parts arranged and constructed and adapted to
operate as set forth with reference to and shown in the drawings, for the purposes
described.
Dated the 30th day of July 1896.
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicants' Agents.