Improvements in Apparatus for the Electrolysis of Chlorides and other Salts.
Year: 1893

page_text: Date of Application, 27th ept., 1893
Complete Specification Left, 27th June, 1894-Accepted, 18th Aug.,
1894
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for the Electrolysis of Chlorides and
other Salts.
We, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of Lancaster,
Chemical Engineer, and THOMAS BIRD, of Cressington, near Liverpool, in the
same county, Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to an improved construction of apparatus for use in
decomposing chlorides, iodides, bromides, nitrates and other salts, and adapted to
operate on the principle of that described and claimed in the Specification filed in
pursuance of our application for Letters Patent No. 18,871, A.D. 1892; the
primary object of the present invention being to render such apparatus more
compact.
According to one mode of carrying out our invention, the apparatus, which is
vertical, comprises a set of submerged electrodes (anodes or cathodes), and another
set of exposed electrodes (cathodes or anodes). The cell is preferably built up of
sections which for the major part are repetitions of pieces of the same shape and are
fastened together by bolts. Some of the sections may be of cast iron and others of
slate. The exposed electrodes and their diaphragms are gripped between the
various sections. The anodes are coupled in parallel, and the cathodes likewise.
In apparatus constructed according to our preferred method, the parts are
arranged in the following order :-First there is a plate of cast iron bounding a
space in which the product collected; the opposite side of this space being
bounded by a vertical electrode, against which is placed a permeable diaphragm.
The next chamber, which, like all the chambers or compartments, is rectangular,
contains the electrolyte; the top, bottom, front and back being formed of slate or
equivalent material. The submerged electrode may extend through an orifice in
the top. There are also provided suitable apertures for the admission of the
electrolyte and the escape of the gaseous product. On the opposite side of this
chamber is another diaphragm and electrode, and then another space enclosed
within a frame of cast iron or other suitable metal or substance. The opposite side
of this space is bounded by an electrode and diaphragm followed by another cell for
the electrolyte and submerged electrode, and so on. The required number of
electrodes having been thus assembled, the last electrode being exposed and the last
but one submerged, the apparatus is completed by the addition of a side frame or
plate similar to that first described. The complete apparatus thus embodies
numerous compartments containing the electrolyte and submerged electrodes, and
the same number plus one of compartments or collecting chambers wherein the
product is obtained from parallel electrodes; the several compartments being
arranged alternately.
When the product is obtained in the form of solution, it is not allowed to
accumulate but is permitted to escape from the bottoms of the compartments
through branch-pipes to a main drain-pipe.
In the collecting chambers or spaces there may be sprays or jets of water disposed
in such a manner as to impinge against and to wash the exposed faces of the
electrodes; or the said chambers may be supplied with steam or with air or other
gas.
The apparatus may, however, contain only one compartment for the electrolyte
and two collecting chambers, one of each side of that compartment. Under these
circumstances, there would be two cast iron side plates, one slate section, two

page_text: exposed electrodes, a diaphragm adjacent to or combined, with each of these
electrodes, and one submerged electrode.
According to an alternative mode of carrying out our invention, none of the
electrodes are submerged, the order of arrangement being as follows:-A hollow
plate containing a collecting space, an exposed anode, a diaphragm, the electrolyte,
a diaphragm, an exposed cathode, a collecting space, an exposed cathode, a dia-
phragm, the electrolyte, a diaphragm, an exposed anode, a collecting space, an
exposed anode, a diaphragm, the electrolyte, and so on; the apparatus ending with
an exposed anode and a second hollow plate. But it will be understood that so long
as two exposed anodes alternate with two exposed cathodes in the central part of
the apparatus, it is immaterial whether the electrodes at the ends of the apparatus
be anodes or cathodes. Or, the apparatus need only consist of two hollow side
plates, an exposed anode and its diaphragm, an exposed cathode and its diaphragm,
and a compartment for the electrolyte between the diaphragms.
Dated the 27th day of September 1893.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Apparatus for the Electrolysis of Chlorides and
other Salts.
We, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of Lancaster,
Chemical Engineer, and THOMAS BIRD, of Cressington, near Liverpool, in the
same county, Electrical Engineer, 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 relates to an improved construction of apparatus for use in
decomposing chlorides, iodides, bromides, nitrates and other salts, and adapted to
operate on the principle of that described and claimed in the Specification to our
Letters Patent No. 18,871, A.D. 1892; the primary objects of the present invention
being to render such apparatus less expensive to construct, more convenient to
manipulate and more compact.
In the accompanying drawings,
Fig. 1 is a vertical section of a cell constructed in accordance with this
invention.
Fig. 2 is a horizontal section on the line a a.
Fig. 3 is a vertical section showing an alternative form of apparatus.
Fig. 4 is a horizontal section on the line y y.
Fig. 5 is a detail view drawn to an enlarged scale representing our improved form
of exposed carbon anode.
According to the mode of carrying out our invention illustrated in Figs. 1 and 2,
the apparatus, which is arranged vertically, comprises a set of submerged
electrodes A (anodes or cathodes), and another set of exposed or bare electrodes B
(cathodes or anodes). The cell is preferably built up of sections C C C¹ and e e¹
ee which for the major part are repetitions of pieces of the same shape and are
fastened together by bolts. The sections C* CC, when the electrodes are
connected in parallel, as shown in Fig. 1, may be of cast iron or other metal or
conducting material, and the sections e e¹ ee³ of slate, glass or other non-conducting
material. H and H are the conductors for the electric current. The exposed
electrodes B and their diaphragms B¹ are gripped between the various sections.
The electrodes may, however, be connected in series, each anode (except the one
coupled to the leading main conductor) being connected to the cathodes pertaining
to the next preceding anode, in which case it is necessary to make the pieces C* C C¹
of non-conducting material.

page_text: The parts are preferably arranged in the following order :-First there is a.
plate C bounding a space D in which the product is collected; the opposite side
of this space being bounded by a vertical electrode B, against which is placed a
permeable diaphragm B¹. The next chamber E, which, like all the chambers or
compartments, is here shown as rectangular, is enclosed by one of the sections e ele² e
and contains the electrolyte F. The submerged electrode A may extend through
an orifice in the top e, as illustrated. There are also provided suitable apertures.
for the admission of the electrolyte and the escape of the gaseous product. One of
these apertures is shown by a dotted line in Fig. 1. On the opposite side of this:
chamber is another diaphragm B¹ and electrode B, and then another space D
enclosed within a frame C. The opposite side of this space is bounded by an.
electrode B and diaphragm B₁ followed by another cell E for the electrolyte F and
submerged electrode A and so on. The required number of electrodes having been.
thus assembled, the last electrode being exposed or bare and the last but one.
submerged in the electrolyte, the apparatus is completed by the addition of a
side plate C similar to the said plate C*. The complete apparatus thus
embodies numerous compartments E containing the electrolyte F and submerged.
electrodes A, and the same number plus one of compartments or collecting
chambers D wherein the product is obtained from parallel exposed or bare-
electrodes B; the several compartments E and D being arranged alternately.
When the product is obtained in the form of solution, it is not allowed to
accumulate, but is permitted to escape from the bottoms of the compartments D.
through branch-pipes d to a main drain-pipe D'.
In the collecting chambers or spaces D there may be sprays or jets G of water
disposed in such a manner as to impinge against and to wash the exposed faces.
of the electrodes B; or the said chamber D may be supplied with steam or
with air or other gas.
The apparatus may, however, contain only one compartment E for the electro-
lyte F and two collecting chambers D, one on each side of that compartment..
Under these circumstances, there would be two side plates C* and C₁, one
section e e e e³, two exposed electrodes B, a diaphragm B adjacent to or combined.
with each of these electrodes, and one submerged electrode A.
The direction of the current may be reversed, the electrodes B then becoming
exposed or bare anodes and the electrodes A submerged cathodes. Under these
circumstances, the apparatus may be employed, by way of example, for decom-
posing sulphate of ammonia. Ammonia would be given off from the submerged
cathodes in gaseous form; sulphuric acid being yielded at and constantly washed
down from the exposed anodes. The anodes should then be of platinum wire
gauze, or of serrated, perforated or grooved carbon. If heat be applied to the
decomposing cells, the quantity of ammonia gas given off is considerably increased..
The gas is led away and subsequently condensed in the usual manner. The carbon
anode we prefer is shown in Fig. 5. The carbon plate A* is made with numerous.
serrations a. In order to avoid injury to the carbon plate, a recess (such as shown
in the sections C C C in Figs. 3 and 4) would be formed in the section Cx or C
or C for holding that plate against its diaphragm, the latter only being subjected
to the full pressure exerted by the bolts when the sections of the cell are secured
together. Water is admitted at a¹ (Fig. 5) either continuously or from time to
time, and runs down between the carbon A* and the diaphragm A', thus permitting
the electric current to flow easily, and washing away the product from the exposed.
or bare anode.
In effecting the decomposition of certain salts, such for example as sodium nitrate
and potassium iodide, we employ apparatus constructed according to the alternative
mode of carrying out our invention shown in Figs. 3 and 4, all the electrodes being
exposed or bare.
The order of arrangement is as follows:-A hollow plate C³ enclosing a collecting
space Dx, an exposed anode A*, preferably serrated, as illustrated, but which may
be perforated or grooved, a diaphragm A', a section e e e e containing the

page_text: electrolyte F, a diaphragm B, an exposed wire gauze (or perforated metal plate)
cathode B, a section C enclosing a collecting space D, an exposed wire gauze (or
perforated metal plate) cathode B, a diaphragm B₁, a section e e e e containing
the electrolyte F, a diaphragm A', an exposed serrated (or perforated or grooved)
carbon anode A*, a section C enclosing a collecting space D. an exposed serrated
(or perforated or grooved) carbon anode A*, a diaphragm A', a section e e¹ e² e
containing the electrolyte F, and so on; the apparatus ending with an exposed
serrated (or perforated or grooved) carbon anode A* and a second hollow plate C.
But it will be understood that so long. as two exposed serrated (or perforated
or grooved) carbon anodes A* alternate with two exposed wire gauze (or
perforated metal plate) cathodes B in the central part of the apparatus, it is
immaterial whether the electrodes at the ends of the apparatus be anodes A*
or cathodes B.
The chambers D communicate through branch-pipes d with the drain-pipe D'.
The gaseous or volatile product obtained in the chambers Dx is led away through
pipes K and treated in any suitable manner. The pipes E are for the admission
of the electrolyte. When the acid radical is volatile, as in the case of nitrates or
bromides, heat may be applied to aid in expelling the acid in the form of gas or
vapour. Liquid resulting from condensation or filtration is conducted from the
chambers D through branch-pipes d' to a main drain-pipe D³.
The apparatus, however, need only comprise two hollow side plates C³ and C',
an exposed serrated (or perforated or grooved) carbon anode A* and its dia-
phragm A', an exposed wire gauze (or perforated metal plate) cathode B and
its diaphragm B', and a compartment E for the electrolyte F between the
diaphragms A and B'.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we claim :-
1. For use in the manufacture of an alkali or cation or derivative product by
electrolysis, a cell constructed substantially as described with reference to Figs. 1
and 2 of the accompanying drawings, and comprising a submerged electrode or
electrodes and a corresponding number of exposed or bare electrodes.
2. For use in the manufacture of an alkali or cation or derivative product by
electrolysis, a cell comprising numerous compartments containing the electrolyte
and submerged electrodes and a corresponding number of compartments or collecting
chambers wherein the product is obtained from parallel exposed or bare electrodes,
the several compartments being arranged alternately, substantially as herein
described.
3. For use in the manufacture of an alkali or cation or derivative product by
electrolysis, a cell constructed substantially as described with reference to Figs. 3
and 4 of the accompanying drawings and in which none of the electrodes are
submerged in the electrolyte.
4. For use in the manufacture of an alkali or cation or derivative product by
electrolysis, a cell comprising numerous compartments containing the electrolyte
and a corresponding number of compartments or collecting chambers wherein the
product is obtained from parallel exposed or bare electrodes, the several collecting
chambers being arranged alternately with the compartments containing the electro-
lyte, and the anode collecting chambers alternately with the cathode collecting
chambers, substantially as herein described.
Dated the 15th dow of Tune 1001