Improved Electrolytic Apparatus, more particularly applicable for Manufacturing Caustic Soda and other Products from Salt, but also applicable to other purposes.
Year: 1891

page_text: Date of Application, 24th Nov., 1891
Complete Specification Left, 23rd Sept., 1892-Accepted, 19th Nov., 1892
PROVISIONAL SPECIFICATION.
Improved Electrolytic Apparatus, more particularly applicable for
Manufacturing Caustic Soda and other Products from Salt, but
also applicable to other purposes.
I, GODFREY BAMBERG, of No. 22 Walbrook, in the City of London, Chemist,
do hereby declare the nature of this invention to be as follows:-
My invention relates to electrolytic apparatus in which there are produced from
the electrolyte different substances at the cathode and anode which it is desired
to keep separate from each other. Such apparatus have for this purpose been
constructed with a porous partition dividing the electrolytic tank into two separate
compartments, one of which contains the anode and the other the cathode, whereby
while the gases generated in each of the compartments are effectually separated
from each other, the liquids are made to communicate with each other sufficiently
through the porous partition to allow of the passage of the electric current from
the one compartment to the other. Such porous partitions offer however several
disadvantages, such as by causing a considerable resistance to the passage of the
current. According to my present invention I obviate the disadvantages of such
a construction by the following arrangement. I provide in the electrolytic tank a
partition which is made so as, at top, to divide the tank into two separate
compartments, while passages are made to extend down each side of the partition
and to communicate with each other at bottom through the partition. The upper
ends of these passages being made to terminate a certain distance below the level
of the liquid, it will be seen that while the liquid charges in the two compartments
are allowed to freely communicate with each other through such passages, thus
allowing of the free passage of the electric current, the gases that collect in the
upper parts of the two compartments are effectually separated from each other,
and can be led off separately to wherever required. I prefer to construct the
partition with its communicating passages by forming on each side of the central
partition which extends down from the top of the tank to near the bottom thereof,
two side partitions extending from the bottom of the tank to a certain height
below the level of the electrolyte, a certain space being made to intervene between
the central partition and two side partitions to form the said passage.
This construction is applicable more particularly to the manufacture of caustic
soda from common salt, the electrolytic action, as is well known, causing hydrogen
to be given off from the salt solution at the cathode, while chlorine is given off at
In order to
the anode, the electrolyte being thus converted into caustic soda.
prevent the gaseous and some of the liquid products of the electrolysis from being
conveyed through the communicating passage from the one compartment to the
other, I prefer to fill the passage with some loosely piled suitable material that
will absorb or neutralize any such gases or liquid products that may tend to
descend, and I prefer to employ for this purpose lime, which will take up the
chlorine, forming chloride of lime, which, when a certain degree of strength has
been attained, can be removed through a door at the end of the tank, and be replaced
by a fresh charge of lime, the liquid in the tank having previously been withdrawn
sufficiently to bring the level thereof below the tops of the side partitions.
Pipes are provided at the tops of the compartments to convey away the
hydrogen from the cathode and the chlorine from the anode. The nascent hydrogen
may also, if it be so desired, be converted into water by placing near the cathode
in any convenient manner, any known material used for that purpose by chemists
The electrodes may
to impart the necessary oxygen or other combining matter.
be insulated above the level of the outer diaphragms in certain cases when desirable.

page_text: The sides of each compartment may have a tray for salt crystals for solution as
the electrolyte is weakened by the decomposition, inasmuch as the caustic soda
produced, though in solution, will yet permit the solution to take up more salt, a
saturated solution of one salt being able to dissolve a quantity of another salt.
Instead of trays may be used permeable bags filled with salt, made of material not
acted on by the solution. By this means it is possible to obtain a more concentrated
solution of caustic soda than when the continuous inlet of salt solution and outflow
of soda method alone is employed. It is of course advisable to have the partitions
either made of, or coated with any suitable material not acted on by caustic
soda or chlorine. They may be either of porous or of impermeable material.
Instead of employing a single electrolytic tank divided into two compartments
by partitions arranged as described, I, in some cases employ two separate tanks,
one containing the anode and the other the cathode, which tanks are connected
together at a point below the level of the electrolyte by a passage which is. formed
as an inverted siphon, and which may be charged with the solid materials above
mentioned.
Dated this 23rd day of November 1891.
ABEL & IMRAY,,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Electrolytic Apparatus, more particularly applicable for
Manufacturing Caustic Soda and other Products from Salt, but
also applicable to other purposes.
'
I, GODFREY BAMBERG, of No. 22 Walbrook, in the City of London, Chemist,
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 :-
My invention relates to electrolytic apparatus in which there are produced from
the electrolyte different substances at the cathode and anode, which it is desired to
keep separate from each other.
Such apparatus have for this purpose been constructed with a porous partition
dividing the electrolytic tank into two separate compartments, one of which
contains the anode and the other the cathode, whereby, while the gases generated
in each of the compartments are effectually separated from each other, the liquids
are made to communicate with each other sufficiently through the porous partition
to allow of the passage of the electric current from the one compartment to the
other. Such porous partitions offer, however, several disadvantages, such as
causing a considerable resistance to the passage of the current. According to my
present invention obviate the disadvantages of such a construction by the
following arrangement. I provide in the electrolytic tank a partition which is
made so as, at top, to divide the tank into two separate compartments, while passages
are made to extend down each side of the partition and to communicate with each
other at bottom through the partition. The upper ends of these passages being
made to terminate a certain distance below the level of the liquid, it will be seen
that while the liquid charges in the two compartments are allowed to freely
communicate with each other through such passages, thus allowing of the free
passage of the electric current, the gases that collect in the upper parts of the
two compartments are effectually separated from each other, and can be led off
separately to wherever required. I prefer to construct the partition with its
communicating passages by forming on each side of the central partition which
extends down from the top of the tank to near the bottom thereof, two side
partitions extending from the bottom of the tank to a certain height below the
level of the electrolyte, a certain space being made to intervene between the
central partition and two side partitions to form the said passage.

page_text: This construction is applicable more particularly to the manufacture of caustic
soda from common salt, the electrolytic action, as is well known, causing hydrogen
to be given off' from the salt solution at the cathode, while chlorine is given off at
the anode, the electrolyte being thus converted into caustic soda. In order to
prevent the gaseous and some of the liquid products of the electrolysis from being
conveyed through the communicating passage from the one compartment to the
other, I prefer to fill the passage with some loosely piled suitable material that will
absorb or neutralize any such gases or liquid products that may tend to descend,
and I prefer to employ for this purpose lime which will take up the chlorine,
forming chloride of lime, which, when a certain degree of strength has been
attained, can be removed through a door at the end of the tank, and be replaced
by a fresh charge of lime, the liquid in the tank having previously been withdrawn
sufficiently to bring the level thereof below the tops of the side partitions.
Pipes are provided at the tops of the compartments to convey away the hydrogen
from the cathode and the chlorine from the anode. The nascent hydrogen may
also, if it be so desired, be converted into water by placing near the cathode in
any convenient manner, any known material used by chemists to impart the
necessary oxygen. The electrodes may be insulated above the level of the outer
diaphragms in certain cases when desirable.
The sides of each compartment may have a tray for salt crystals for solution as
the electrolyte is weakened by the decomposition, inasmuch as the caustic soda
produced, though in solution, will yet permit the solution to take up more salt, a
saturated solution of one salt being able to dissolve a quantity of another salt.
Instead of trays may be used permeable bags filled with salt, made of material
not acted on by the solution. By this means it is possible to obtain a more con-
centrated solution of caustic soda than when the continuous inlet of salt solution
and outflow of soda method alone is employed. It is of course advisable to have the
partitions either made of, or coated with any suitable material not acted on by
caustic soda or chlorine. They may be either of porous or of impermeable
material.
Instead of employing a single electrolytic tank divided into two compartments
by partitions arranged as described, I, in some cases employ two separate tanks,
one containing the anode and the other the cathode, which tanks are connected
together at a point below the level of the electrolyte by a passage which is formed
as an inverted siphon, and which may be charged with the solid materials above
mentioned.
Fig. 1 of the accompanying drawings a vertical section of an electrolytic cell
according to my invention.
A is the anode which may be carbon and C is the cathode, which may be copper.
B is the middle partition extending down from the top but not to the bottom, and
D D' are the two side partitions extending up from the bottom but not to the
level E of the electrolyte.
Fragments of lime may be placed in the passage when the electrolyte employed
is sodium chloride for the production of caustic soda. F is a porous pocket
containing a supply of the sodium chloride. The chlorine is conducted away
from the one compartment of the cell by the pipe P and the hydrogen is conducted
away by the pipe Q. Solution of caustic soda is run off from time to time by the
pipe R.
Fig. 2 is a section shewing two separate cells communicating through an
inverted siphon pipe S, which operates as the equivalent of the passage between D, B
and D.
Although I have described a cell according to my invention as applied to the
electrolytic decomposition of sodium chloride, such a cell may obviously be applied
to the decomposition of other solutions and liquids, among which may be mentioned
sewage slightly acidulated. Also, by employing suitable refractory materials in
constructing the cell and its partitions, it may be adapted for the decomposition of
a fused electrolyte as for instance sodium chloride producing chlorine and sodium.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An electrolytic cell divided into two compartments the one containing the anode
the other the cathode, communicating with one another by a passage formed by
partitions or otherwise as an inverted siphon having its mouths below the surface
of the electrolyte liquid, substantially as and for the purpose set forth.
Dated this 23rd day of September 1892.
ABEL & IMRAY,
Agents for the Applicant.