Improvements in Electro-chemical Generators.
Year: 1888

page_text: Date of Application, 24th Dec., 1888
Complete Specification Left, 21st Sept., 1889-Accepted, 16th Nov., 1889
PROVISIONAL SPECIFICATION.
[Communicated from abroad by LA SOCIÉTÉ PERREUR-LLOYD & FILS, of 118, Rue
de Vaugirard, Paris, France, Electrical Engineers.]
Improvements in Electro-chemical Generators.
I FREDERICK JOHN BROUGHAM, of 46 Lincoln's Inn Fields, in the County of
Middlesex, Managing Clerk do hereby declare the nature of this invention to be as
follows:-
This invention relates to electro chemical generators capable of producing metallic
salts on a commercial scale whilst permitting of the utilization of the electric current
produced.
In an electric generator according to this invention the solutions are by reason of
the utilization of the heat due to internal resistance, heated and concentrated to such
a degree of strength that on cooling the salts will crystallise out.
In the accompanying sheet of illustrative drawings
Fig. 1 is an elevation partly in longitudinal section of an electro chemical generator
according to this invention.
Fig. 2 is a vertical transverse section.
Figs. 3, 4 and 5 are detail views hereinafter referred to.
Figs. 6 and 7 illustrate forms of porous vessels employed.
The electric generator comprises a trough a of any suitable material that will resist
acids and may be built up of suitably shaped plates secured together in any convenient
manner.
It is formed into two independent parts vic. an upper part designed to contain the
elements and a lower part designed to receive the concentrated liquids.
The upper part is divided by glass plates into compartments each of which serves
as a cell for a distinct element.
The elements are formed as follows.
Porous plates are arranged to form cells or flat porous vessels c may be employed
the cells in either case being caused to communicate with one another.
If plates are employed they are slidden into vertical grooves formed in the walls
of the trough, a tight joint being made between the plates and the walls by any
suitable means such as cement a double bottom being provided at a suitable height.
The spaces between the plates are then caused to communicate with one another by
channels formed in the cement or mastic employed for obtaining a tight joint.
If flat vessels or cells such as c be employed they may be caused to communicate
laterally with one another by means of tubular nipples or projections c¹ formed there-
with in the process of manufacture. The porous plates or cells as the case may be
rest upon a double bottom d which serves partly divide the upper from the lower
part of the trough which lower part is hereinafter called the "reservoir."
Each element thus comprises a porous cell c in which is placed a carbon C the
thickness of which increases gradually as it extends upward and a plate F of metal
for instance iron that forms, the soluble electrode, arranged between two porous cells
as shown.
"
23
The reservoir communicates directly with that part of the trough containing.
the soluble electrodes for a purpose hereinafter mentioned. In each of the compart-
ments formed by the plates b are placed a number of cells the positive and negative
element being coupled up for quantity as it is not advantageous to couple up the
elements for tension in view of the cost of the apparatus and of losses occasioned by
by too great a tension since all the cells in a compartment communicate with one
another.
The galvanic elements are thus arranged to give a large current.

page_text: The generators are covered by plates that may be of glass or slate through which
project the carbons C and the contacts of the soluble electrodes F. The plates fare
inclined to facilitate the draught of a chimney e placed at the upper part of the
generator. This inclination has also another object when the battery is at work it
becomes heated and the water vapour formed is condensed upon the cover and absorbs
to a greater or less extent the nitrous vapours evolved forming therewith nitric acid.
This acid runs off the plates and is collected in a gutter / formed in the front wall of
the generator as shewn. This arrangement enables the nitric acid thus regenerated to
be readily collected without its becoming mixed with and altering the nature of the
metallic salts produced.
Above the generator are arranged two reservoirs R, R1, one R, containing the
depolarising solution and the other R the exciting solution. In order to charge
the generator the porous cells or vessels e are by opening suitably arranged taps placed
in communication with the reservoir R containing the depolarizing solution for instance
nitric acid, and the interior of the trough is placed in communication with the
reservoir R¹ containing the exciting solution which may be composed of a mixture of
water and acids in suitable proportions the positive element and the acid varying
according to the product it is desired to produce such as sulphates chlorides etc. of
iron, copper, zinc etc.
When the circuit of the generator is completed the sulphates or chlorides are
formed within the generator and nitrous vapours are evolved that are regenerated in
suitably arranged condensation towers. When the solution in these towers is at
20 degrees it is re-employed after having been concentrated with sulphuric or hydro-
chloric acid. The generator thus arranged serves to produce the electric current in
an economical way since the value of the resulting product is greater than that of the
materials used in producing the current. In the improved electric generator the heat
resulting from the internal resistance of the battery is utilized to concentrate the
solutions and to bring them to a degree of concentration such that they shall crystallize
on cooling after leaving the apparatus.
The mother liquors being again employed after being diluted with the exciting
solution. The heating of the solution has the further advantage of preventing the
formation of crystals upon the soluble electrode which may be of iron, copper, zinc,
nickel, tin &c.
By using nitric acid as a depolarizing agent the metallic salts may be obtained quito
pure. The improved generators are particularly suitable for the manufacture of the
simple or double sulphates and chlorides of iron, manganese, zine, copper, nickel, tin
&c. whether these products be directly saleable or are to be used in the manufacture
of other products as for instance the production of permanganates from the salts of
manganese. The soluble electrodes may be formed of clippings, parings and other
waste of the metals herein before mentioned.
When so formed they may be contained within receptacles of suitable material such
as asbestos that will not be attacked by the acid materials employed and provided with
perforations the clippings, parings &c. being arranged around a central electrode. The
cost of manufacture of the soluble electrodes is thereby reduced. For instance as
shewn in fig. 3 a perforated porcelain vessel may be placed between two flat porous
vessels and it will be obvious that the clippings, parings or waste metal heaped up
between the central electrode and the perforated walls kk of the vessel will be
attacked before the central electrode because they are nearer to the carbons so that
this, central electrode can be used several times. It is thus advantageous to employ
vessels filled with clippings of sheet iron, tinned sheet iron, sheet brass copper &c.
If copper be used as the soluble electrode it is not sensibly attacked in a diluted
solution of sulphuric acid but when a couple is formed (copper and sulphuric acid
solution on the one hand and carbon and nitric acid solution on the other) the amount
of copper sulphate formed is proportional to the intensity of the current and reaches
very nearly the theoretical amount.
The sulphate of copper may be subsequently obtained in a crystallized state by
merely allowing the saturated solution to cool.

page_text: Instead of copper or copper clippings, brass or brass turnings may be employed
with advantage, the acids by their action on the same producing sulphates or chlorides
as the case may be of copper and zinc which may be afterwards separated from each
other.
Thus when brass is attacked with sulphuric acid, sulphates of copper and of zinc
are formed, and on cooling, the slightly soluble sulphate of copper crystallises out
whilst the very soluble sulphate of zinc remains in solution.
The reservoir below the cells offers the advantage of enabling the electrodes to be
brought as near as desired to each other thereby enabling the internal resistance to be
reduced to a small amount whilst admitting of the use of a volume of exciting solu-
tion very much greater than that of the depolarizing solution.
It will be readily understood that since the depolarizing solution is concentrated,
and since only one third part of an equivalent of nitric acid is theoretically necessary
in order to oxidise the hydrogen evolved by the combination of one equivalent of
acid (sulphuric acid for instance) with the soluble electrode, and, since, further, this
acid is employed in a diluted state only, therefore the ratio between the volume of the
exciting and depolarizing solutions must often be considerable.
For the proper working of the apparatus, the two exciting and depolarizing
solutions should become exhausted or spent at the same time. The labor in general,
and the labor of filling and emptying the generator in particular, will thereby be
proportionally diminished.
The use of the lower reservoir also admits of the working of the apparatus in a more
regular manner, for when the acid solution is neutralized, being denser, it falls to the
bottom of the reservoir and is replaced by fresh solution which maintains a constant
attacking action.
The generator becoming heated by its own working, the chemical actions are intensi-
fied, and are facilitated in proportion as the acid solution becomes weaker, which also
contributes to the regularity of the current.
As the porous vessels are generally made of limited dimensions, the use of a lower
reservoir is especially advantageous in cases where it is necessary to couple up several
of the cells for quantity, in one compartment, in order to have generators that are
economical and applicable to industrial purposes. Now, in such cases, if no reservoir
be employed to attain the desired relation between the exciting and depolarizing
solutions, it would be necessary, either to move the electrodes further apart (as in
Fig. 4) which would increase the internal resistance; or else, to employ two soluble
electrodes for each soluble one, which would increase the local action, the number of
contacts, and the space occupied by the generator, and renders its heating more
difficult (see Fig. 5).
Further by the use of the lower reservoir porous cells or vessels of small height
may be employed, whereby the carbon electrode offers a proportionally smaller
resistance.
Dated this 24th day of December 1888.
COMPLETE SPECIFICATION.
Improvements in Electro-chemical Generators.
I, FREDERICK JOHN BROUGHAM, of 46 Lincoln's Inn Fields, in the County of
Middlesex, Managing Clerk, do hereby declare the nature of this invention (a
communication from abroad by La Société Perreur-Lloyd & Fils of Paris, France,
Electrical Engineers) and in what manner the same to be perforived to be
particularly described and ascertained in and by the following statement :-
This invention relates to electro-chemical generators capable of producing metallic
salts on a commercial scale, whilst permitting of the utilisation of the electric current
produced.
In an electric generator according to this invention the solutions, are, by reason of
the utilisation of the heat due to internal resistance, heated and concentrated to such

page_text: a degree that on cooling, the salts will crystallise out. In cases where the heat due
to the internal resistance is not sufficient for this purpose the solutions are heated by
steam and thus brought to a suitable temperature and degree of concentration.
In the accompanying sheet of illustrative drawings:
:-
Fig. 1 is an elevation, partly in longitudinal section, of an electro-chemical
generator according to this invention.
Fig. 2 is the corresponding plan, a portion being shewn without the covering plates
of glass or slate.
Fig. 3 is a vertical transverse section on the line 1-2 of Fig. 2.
Figs. 4, 5 and 6 are detail views hereinafter referred to.
Figs. 7 and 8 illustrate forms of porous vessels employed.
Figs. 9 and 10 illustrate an arrangement of generator adapted for working with
large porous vessels such as can now be made.
The electric generator comprises a trough a of any suitable material that will resist
acids; and may be built up of suitably shaped plates fitted and secured together
in any convenient manner. The trough is formed with two independent parts, viz.,
an upper part designed to contain the elements, and a lower part designed to receive
the concentrated liquids.
The upper part is divided by glass plates into compartments each of which serves
as a cell for a distinct element.
The elements are formed as follows:-
Porous plates are arranged to form cells, or flat porous vessels c may be employed,
the cells in either case being caused to communicate with one another. If plates are
employed, they are slidden into vertical grooves formed in the walls of the trough,
a tight joint being made between the plates and the walls by any suitable means a
bottom or plate being provided at a suitable height above the bottom of the reservoir.
The spaces between the plates are then caused to communicate with one another
by channels formed in the cement or mastic employed for obtaining a tight joint.
If flat vessels or cells such as c (Fig. 7 and 8) be employed, they are caused to
communicate laterally with one another by means of tubular nipples or projections e¹
formed therewith in the process of manufacture.
When the large porous vessels herein before referred to, are employed, it is suffi-
cient to place them upon the edges or borders formed in the trough, and an
arrangement of syphons adapted to be started by steam is provided to empty and to
fill them again by merely operating cocks.
The porous plates or cells, as the case may be, rest upon a bottom or plate d, which
serves to partly divide the upper from the lower part of the trough, which lower
part is hereinafter called the "reservoir."
Each element thus comprises a porous cell c in which is placed a carbon the
thickness of which increases gradually from bottom to top, and a plate F of metal for
instance iron that forms the soluble electrode which is arranged between two porous
cells as shewn.
The reservoir communicates directly with the part of the trough containing the
soluble electrodes for a purpose hereinafter mentioned.
In each of the compartments formed by the plates are placed a number of cells,
the positive and negative elements being coupled up for quantity, as it is not
advantageous to multiply the number of elements in tension in view of the cost of
the apparatus, and of the losses occasioned by too great a tension, since all the cells
in a compartment communicate with one another. The elements are thus arranged to
give a large current.
Also all the vessels or cells in the same trough can be coupled up for quantity
and the large current of low tension obtained can be transformed on leaving the
apparatus into a small current of high tension.
The generators are covered by plates that may be of glass or slate through
which project the carbons C and the contacts of the soluble electrodes F.
The plates are inclined to facilitate the draught of a chimney e placed at the
upper part of the generator. This inclination has also another object; when the

page_text: battery or generator is at work it becomes heated, and the water vapor formed is
condensed upon the cover and absorbs to a greater or less extent the nitrous vapors
evolved from the cells e forming there with nitric acid. This acid runs off the plates
and is collected in a gutter formed in the front wall of the generator as
shewn. This arrangement enables the nitric acid thus regenerated, to be readily
collected, without its becoming mixed with and altering the nature of the metallic
salts produced.
Above the generator are arranged two reservoirs R, R¹ one (R) containing the
depolarising solution, and the other (R) the exciting solution. In order to charge
the generator, the porous cells or vessels care, by opening suitably arranged taps,
placed in communication with the reservoir R containing the depolarising solution
and the trough is placed in communication with the reservoir R¹ containing the
exciting solution which may be composed of a mixture of water and acids in suitable
proportions the positive element and the acid varying according to the products it.
is desired to produce such as sulphates, chlorides &c. of iron, copper, zinc etc.
When the circuit of the generator is completed, the sulphates or chlorides are
formed within the generator and nitrous vapors are evolved that are regenerated in
When the solution in these towers is at
suitably arranged condensation towers.
20 degrees, it is re-employed after having been concentrated or strengthened with
sulphuric or hydrochloric acid.
The generator thus arranged serves to produce the electric current in an economical
way, for the following reasons:-
1. It enables the salts formed by the combination of the acids and metallic bases
within the apparatus to be collected at a minimum cost, these salts crystallizing as
soon as they leave the generator. The total value of the acids and the bases employed
being considerably less than the value of the salts produced by their combination in
the generator, and the cost of the concentration and crystallization of the solutions
being almost nil, the sale of the same covers, the cost of buying the original materials
as well as the cost of labour &c. The electric current is consequently obtained as a
bye-product.
2. The depolarizer employed in the generator hereinbefore described is really the
oxygen of the air. The nitric acid employed as a depolariser, is decomposed into
nitric oxide and oxygen. The oxygen combines with the hydrogen disengaged on
the carbon and forms water. The nitric oxide forms, in contact with the air, hypo-
nitric acid which is drawn into the condensing towers through which water trickles,
and the hyponitric acid is re-converted into nitric acid which can be used over again.
These condensing towers act on the principle of Gay-Lussac towers used in sulphuric
acid works.
From the foregoing description it will be understood that the cycle of operations,
by which metallic salts are manufactured in the manner described whilst affording
an electric current, without other expense than that of the acid and base employed,
the nitric acid being theoretically entirely regenerated, comprises :-
--
A. Attack of a soluble electrode by sulphuric, hydrochloric &c. acid.
B. Oxidation of the hydrogen evolved by the nitric acid with which the porous
vessel containing a carbon or other unattackable electrode is charged.
C. Oxidation in the presence of air, of the nitrous products evolved, and regene-
ration of the nitric acid by contact with the water which trickles through the
condensing towers, in a direction opposite to that of the gas.
D. Crystallization of the salts formed in the reservoir of the trough, the solution
being brought to the desired degree of concentration by the heat evolved in the
generator and due to the internal resistance.
E. Recharging of the generator with the acidulated water on the one hand, and
the regenerated nitric acid on the other, this acid being concentrated or strengthened
by means of a suitable proportion of sulphuric acid.
In the electric generator herein described the heat, resulting from the internal
resistance thereof, is utilized to concentrate the solutions and to bring them to a
degree of concentration such that they will crystallize on cooling after leaving the

page_text: apparatus, the mother-liquors being again employed in the generator after being diluted
with the exciting solution. The heating of the solution has the further advantage of
preventing the formation of crystals upon the soluble electrode which may be of iron,
copper, zinc, nickel, tin brass &c. as desired.
In case this heat is not sufficient, steam may be used as hereinbefore mentioned
which condenses in the trough.
By this invention therefore, metallic sulphates, chlorides, etc. can be produced on
a commercial scale, whilst a current of electricity is obtained as a bye-product.
By using nitric acid as a depolarizing agent the metallic salts may be obtained
quite pure.
The improved generators are particularly suitable for the manufacture of the simple
or double sulphates and chlorides of iron, manganese, zinc, copper, nickel, tin, &c.,
whether these products be directly saleable, or are to be used in the manufacture of
other products as for instance the production of permanganates from the salts of
manganese.
The soluble electrodes may be formed of clippings parings and other waste of the
metals herein before mentioned. When so formed they may be contained within
receptacles of suitable material such as asbestos that will not be attacked by the acids
employed or solutions produced, or within any other receptacles made of unattackable
material, and provided with perforations, which allow of the clippings, parings &c.
being arranged around a central electrode. The cost of manufacture of the soluble
electrodes is thereby considerably reduced. For instance, as shown in Fig. 4, a perfo-
rated porcelain vessel may be placed between two flat porous vessels, and it will be
obvious that the clippings, parings or waste metal heaped up between the central
electrode a and the perforated walls K K of the vessel, will be attacked before the
central electrode, because they are nearer to the carbons, so that this central electrode
can be used several times. It is thus advantageous to employ vessels filled with
clippings of sheet iron, tinned sheet iron, sheet brass, copper &c.
Copper may be advantageously used as the soluble electrode. Copper is not
sensibly attacked in a diluted solution of sulphuric acid, but when a couple is formed
(copper and sulphuric acid solution on the one hand, and carbon and nitric acid
solution on the other) the amount of copper sulphate formed will be proportional to
the intensity of the current and reaches very nearly the theoretical amount.
working with copper as the soluble electrode constitutes a new method of manu-
facturing sulphate of copper, which is very advantageous from an economical point
of view.
This
The sulphate of copper may be subsequently obtained in a crystallized state by
merely allowing the solution which is concentrated and heated as herein before described,
to cool.
Instead of sheet copper or copper turnings, sheet brass, or brass turnings, may be
employed with advantage, the acids by their action on the same, producing sulphates
or chlorides as the case may be of copper and zinc which may be afterwards separated
from each other. Thus when brass is attacked with sulphuric acid, sulphates of
copper and of zinc are formed, and on cooling, the slightly soluble sulphate of
copper will crystallize out whilst the very soluble sulphate of zinc will remain in
solution.
As shown in Figs. 5 and 9 the reservoir is situated below the active surfaces of
the elements. This reservoir offers the advantage of enabling the electrodes to be
brought as near as desired to each other, whilst admitting of the use of a volume of
exciting solution very much greater than that of the depolarizing solution.
It will be readily understood that since the depolarizing solution is concentrated,
and since only one third part of an equivalent of nitric acid is theoretically necessary
in order to oxidise the hydrogen evolved by the combination of one equivalent of acid
(sulphuric acid for instance) with the soluble electrode, and, since, furthermore, this
acid is employed in a diluted state only, therefore the ratio between the volumes of the
exciting and depolarizing solutions must often be considerable.
Therefore for the proper working of the apparatus, the exciting and depolarizing

page_text: solutions should become exhausted or spent at the same time. The manual labor in
general, and the labor of filling and emptying the generator, in particular, will then
he proportionally diminished.
The employment of a lower reservoir such as benables this object to be attained,
for it enables the electrodes to be brought near together and the internal resistance
thereby reduced to the lowest possible minimum.
The use of the lower reservoir also admits of the working of the apparatus in a
more regular manner for when the acid solution has become neutralized, being denser,
it sinks to the bottom of the reservoir and is replaced by fresh solution which maintains
a constant attacking action.
The generator becoming heated by its own working, the chemical actions are
intensified, and are facilitated in proportion as the acid solution becomes weaker,
which also contributes to the regularity of the current.
As the porous vessels are generally made of limited dimensions, the use of a lower
reservoir is especially advantageous in cases where it is necessary to couple up several
cells for quantity in one compartment, in order to have generators that are economical
and applicable to industrial purposes. Now, in such cases, if no reservoir be
employed to attain the desired ratio between the exciting and depolarizing solutions,
it would be necessary, either to move the electrodes further apart (as in Fig. 5) which
would increase the internal resistance; or else, to employ two soluble electrodes for
each insoluble one (see Fig. 6) which would increase the local action the number of
contacts or connections and the space occupied by the generator, and would render the
heating of the generator more difficult. By the use of the lower reservoir, also,
porous cells or vessels of small height may be employed, whereby the carbon electrode
offers a proportionally smaller resistance."
Figs. 9 and 10 illustrate the arrangement it is considered advantageous to employ
with large porous receptacles.
In these Figs. a is the trough which may be of lava and which has formed at its
lower part, the reservoir b. The elements are composed of carbons (having contacts h
and arranged within the porous vessels d and soluble electrodes whose contacts are
shown at j. The trough a is closed by a cover e; the porous vessels d are emptied
by suction produced by means of a Giffard's ejector or by any other equivalent
apparatus, through tubes g having cocks fone for each vessel. The lower reservoir bis
also provided with a discharge cock k. m is the condensation trench, and t is a steam
pipe.
Between the improved generator and accumulators which may be arranged to
be charged thereby day and night (in an analogous manner to that in which the gas
from the gas retorts fill a gasometer) or between the generator and the place where
the electricity is to be utilized there may be placed electrolytic troughs for refining
copper obtained from old brass &c. or other source. This refining operation, depending
on the decomposition of the sulphate of copper, which is reformed continuously
within the troughs will consume very little power, and will only entail a small cost as
the same
workmen who perform the manipulations necessary for maintaining
the generators in action, can also without inconvenience atttend to the refining
operations. This refining renders possible the recovery of the precious metals
contained in some kinds of commercial copper, whilst at the same time admitting of
the production of an electrolytic copper of considerable value.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The construction with movable materials, of electro-chemical generators
allowing of the establishment on the spot and complete in all parts, apparatus for
giving exactly and during a determined period, the quantity of electrical energy
required.
2. The employment in an electro-chemical generator of the kind referred to of a
reservoir placed below the soluble electrodes, and communicating with the space

page_text: which they occupy, this reservoir giving two results:-1. a concentrated solution of
low conductivity or an exhausted solution is automatically replaced by a fresh active
solution of greater conductivity and 2 the power of reducing to a minimum the
internal resistance, whilst enabling the desired relation to be given to the volumes
of the exciting and depolarizing solutions as herein before described.
3. The novel application in electro-chemical generators and in batteries in general,
of carbons of reduced section substantially as hereinbefore described and shewn.
4. The combination of an electro-chemical generator constructed as hereinbefore
described with apparatus for the absorption of nitrous gases.
5. The regeneration or simply the absorption, at the expense of the oxygen of
the air, and in the presence of water, of the nitric acid employed as a depolarizing
agent in electro-chemical generators, batteries &c. and the application of the principle
of Gay-Lussac employed in sulphuric acid works to fix the last traces of nitrous
vapors substantially as described.
6. The herein before described cycle of operations by means of which metallic
salts may be economically manufactured whilst obtaining the electric current as a
bye-product.
7. The employment of soluble electrodes formed of clippings, cuttings, waste, of
iron, manganese, zinc, copper, nickel, tin, brass, tinned iron and other metals and
alloys enclosed in bags of asbestos or other unattackable material, or held between
perforated plates substantially as described.
8. The utilization of the heat resulting from the internal resistance of a battery,
for concentrating the solutions up to such a degree. that they will crystallize on
leaving the apparatus.
9. The heating by steam, of the solutions of primary batteries substantially as set
forth for the purpose mentioned.
10. The use of an electrolytic refining trough arranged between the electric
generator and the place to which the current is conveyed to be utilized as for
instance in the form of light, power, or heat.
Dated this 21st day of September 1889.
F. J. BROUGHAM.