Improvements in Apparatus for use in Electrolysis, more especially intended for use in the Electrolysis of Zinc Chloride.
Year: 1896

page_text: Date of Application, 15th Dec., 1896
Complete Specification Left, 15th Sept., 1897-Accepted, 30th Oct., 1897
Improvements in Apparatus for use in Electrolysis, more especially
intended for use in the Electrolysis of Zinc Chloride.
We FERDINAND HURTER Ph.D. Chemist and the UNITED ALKALI COMPANY
LIMITED both of G Exchange Buildings Liverpool in the County of Lancaster
do hereby declare the nature of this Invention to be as follows:-
This Invention relates to apparatus for use in electrolysis particularly for the
electrolytic decomposition of solutions of metallic salts, the metals of which are
readily fusible and can thus be separated by their fusibility from the cathode on
which they have been deposited and is specially applicable to the production of
metallic zinc and chlorine gas from solutions of zinc chloride.
According to this Invention the tank is preferably constructed of wood or slate
by bolting together any suitable number of frames, placed in between each frame
a suitable diaphragm, the frames being made or arranged so that the tank consists
of a number of compartments alternately open and closed at the top. The open
compartments receive the negative electrodes or cathodes, and the closed compart-
ments receive the positive electrodes or anodes. We prefer to make the d
compartments of the tank, anode compartments. The end frames of each tank
are closed by end plates of wood, slate, or the like.
According to this Invention the cathodes consist of a number of cylinders of
iron, or other suitable metal, which does not readily form an alloy with the metal
to be deposited. These cylinders are preferably made of tubes closed at the bottom
by somi globular or rounded ends so that no sharp corners are presented. Both
ends are provided with pivots upon which the tubes can be rotated. These cathodes
are placed vertically, or approximately so, in the cathode compartments, their
lower pivots fitting into corresponding footsteps at the bottoms of the compart-
In each compartment a series of such cylinders can be placed beween the
diaphragms, which are sufficiently far apart to admit of the cylinders rotating
after they have been covered with the metallic deposit.
The pivots at the upper end of the cylinders may fit into a metal support and be
provided with suitable gearing such as bevel wheels or small driving pulleys to
enable the cylinders to be rotated.
The electric current may be conveyed to the cathodes by means of brushes or
by means of mercury cups fastened to the upper ends of the pivots. The whole of
the mechanism must be so arranged that the cathodes can readily be detached,
removed and replaced.
It is not necessary to rotate the cathodes completely. A reciprocating or to
and fro rotatory motion, through say one quarter turn, is sufficient. We may
effect this movement by attaching to each cathode. a crank and connecting all the
cranks appertaining to each series of cathodes to a rod so that the reciprocating
motion of the rod causes the series of cathodes to have the to and fro movement
imparted thereto. These cranks may be simply strong pins projecting from the
25

page_text: cathode so as to be easily removed. With cathodes thus operated the current
may be conveyed to the upper pivot by attaching thereto a flexible leading wire.
In order that the whole of the upper surface of the tank may be
free for the necessary mechanism for operating the cathodes, the carbon
anodes can be inserted at the sides of the anode compartments, and
the current be conveyed to the carbon ends projecting from the sides
of the compartments in any suitable manner. The upper part of the anode
compartments receives the chlorine or other gas evolved and is provided with an
exit pipe, also preferably passed in at the side. Openings for circulating the
liquid to be electrolysed, for introducing fresh liquid and for withdrawing the
exhausted liquid are provided at the sides or at the bottom of the respective
compartments.
When the cathodes have received a sufficiently thick deposit of the metal, they
are withdrawn from the tank, washed, dried, and plunged into a molten bath of
the same metal as that which has been deposited upon them, this bath being
sufficiently deep to permit the cathodes to be wholly submerged, so that all the
metal may be removed therefrom by fusion.
Dated this 15th dow of December 1800.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improvements in Apparatus for use in Electrolysis more especially
intended for use in the Electrolysis of Zinc Chloride.
We, FERDINAND HURTER, Ph.D., Chemist and the UNITED ALKALI COMPANY
LIMITED, both of G Exchange Buildings, Liverpool, in the County of Lancaster
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 apparatus for use in electrolysis, particularly for the
electrolytic decomposition of solutions of metallic salts, the metals of which are
readily fusible and can thus be separated, by reason of their fusibility, from the
cathode on which they have been deposited, and is specially applicable to the
production of metallic zinc and chlorine gas from solutions of zinc chloride.
According to this invention the tank is preferably constructed of wood or slate,
by bolting together any suitable number of frames, placing between each frame a
suitable diaphragm, the frames being made, or arranged, so that the tank consists
of a number of compartments alternately open and closed at the top. The open
compartments receive the negative electrodes, or cathodes, and the closed compart-
ments receive the positive electrodes, or anodes. We prefer to make the end
compartments of the tank, anode compartments. The end frames of each tank
are closed by end plates of wood, slate, or the like.
According to this invention' the cathodes consist of a number of cylinders of
iron, or other suitable metal, which does not readily form an alloy with the metal
to be deposited. These cylinders are preferably made of tubes closed at the bottom
by semi-globular, or rounded, ends so that no sharp corners are presented. Both
ends are provided with pivots upon which the tubes can be rotated. These cathodes
are placed vertically, or approximately so, in the cathode compartments, their
lower pivots fitting into corresponding footsteps at the bottoms of the compartments.
In each compartment a series of such cylinders can be placed between the

page_text: diaphragms, which are sufficiently far apart to admit of the cylinders rotating
after they have been covered with the metallic deposit.
The pivots at the upper end of the cylinders may fit into a metal support and be
provided with suitable gearing, such as bevel wheels, or small driving pulleys, to
enable the cylinders to be rotated, or with means by which a reciprocating rotary
motion can be imparted thereto.
The electric current may be conveyed to the cathodes by any suitable means
such as by means of brushes, by means of mercury-cups fastened to the upper ends
of the pivots. The whole of the mechanism must be so arranged that the cathodes
can readily be detached, removed and replaced.
It is not necessary to rotate the cathodes completely. A reciprocating, or to and
fro, rotary motion, through say one quarter turn, is sufficient. We may effect this
movement by attaching to each cathode a crank and connecting all the crauks,
appertaining to each series of cathodes, to a rod so that the reciprocating motion
of the rod causes the series of cathodes to have the to and fro movement imparted
thereto. These cranks may be simply strong pins projecting from the cathodes
so as to be easily removed. With cathodes thus operated the electric current may
be conveyed to the upper pivot by attaching thereto a flexible leading wire.
In order that the whole of the upper surface of the tank may be free for the
necessary mechanism for operating the cathodes, the carbon anodes can be inserted
at the sides of the anode compartments, and the electric current be conveyed to the
carbon ends projecting from the sides of the compartments in any suitable manner.
The upper part of the anode compartments receives the chlorine, or other gas,
evolved, and is provided with an exit pipe, also preferably passed in at the
side. Openings for circulating the liquid to be electrolysed, for introducing fresh
liquid, and for withdrawing the exhausted liquid, are provided at the sides, or
at the bottom, of the respective compartments.
The accompanying drawing represents an arrangement of apparatus according
to this invention but we do not limit ourselves to the precise details illustrated.
Figure 1 is a horizontal section of a cell,
Figure 2 represents one frame carrying anodes,
Figure 3 represents another frame for cathodes,
Figure 4 shews, in sectional elevation, the manner in which the several frames
are joined together.
Figure 5 shews in plan the means for moving the cathodes.
Corresponding parts are lettered alike in all the figures.
Figure 1 represents a complete tank made by bolting together seven separato
frames, namely four anode frames A, A, A, A, and three cathode frames B, B, B.
Between each of the adjacent frames A and B is inserted a diaphragm C, which
may consist of parchment, or of nitro parchment, or of a thin' plate of porous porce-
lain let into rebates provided for the purpose in the frames A and cemented therein.
The tank is completed by end-plates DD, and the whole is held together by a
number of bolts d passing through the several frames and end-plates. The tank
thus made is therefore composed of a number of compartments, the compart-
ments A being closed at the top as shewn in Figure 4, and the compartments B
being open at top.
The frames A are built of four pieces of stout timber or of slate, or the like,
and have at the upper end side-boards II attached (Figures 2 and 4). Thus the
frames A with their diaphragms C form completely closed compartments. The
side-hoards H must reach below the surface of the solution with which the tank
is filled as indicated in Figure 4, where the line at e indicates the surface of the
solution.
Each frame A carries a number of carbon rods EEE; the exterior ends of
which project beyond the frames A and are electrically connected together by
lead blocks I which have been cast round the carbon rods. The several lead
blocks are connected up electrically by a copper tape G which conveys the current
from a suitable generator to the carbons.

page_text: The frames B consist of only three pieces of timber slate or the like and serve
to receive the cathodes I. When fixed between the anode frames A, these frames B
form the cathode compartments of the tank.
The cathodes I are preferably made of wrought iron tubes, welded up at their
ends into semi-globular form and provided with pivots on which they can turn or
revolve. The lower pivots rest on an iron plate K (Figure 3) over which is fastened
a piece of hard wood L, through which are bored the holes in which the pivots
move. The piece of wood L is tapered off as shewn in Figure 4 so that it is easy
to place the cathode pivots into their holes. The upper pivots of the cathodes
nass through the plate M and are in electrical contact therewith.
The cathodes I in the arrangements shewn have a reciprocating rotary movement
through a little more than one quarter turn conveyed to them by the reciprocating
motion of the iron bar N Figures 3 and 5, and the pins n which pass through the
cathodes, I. The iron bar N is connected to the crank O and the several cranks
of the several rows of cathodes may all be connected by another bar, so that by
one single motor the whole of the cathodes of a large tank may be operated. The
mechanism is carried by metal brackets PP fastened on to the frame B. These
brackets are all connected to the negative terminal of the electric generator as
indicated in Figure 3.
.
Thus the electric current passes through the lead blocks F into the carbons E,
thence into the solution with which the tank is filled, say zinc chloride, then
through the porous partitions or diaphragms C, to the cathodes I and leaves the
tank through the plato M and brackets P.
Chlorine is generated at the anodes and collects in the spaces (Q Figure 4)
above the surface of the liquor from whence it is conducted by suitable pipes (not
shewn in drawing) to be utilised elsewhere.
The solution in the anode compartment does not require changing often, but
for convenience of filling and emptying supply pipes are fitted to the bottom of
the anode frames A.
As the solution in the cathode compartments B requires rapid changing, or
circulating these compartments are provided with inlet pipes at the bottom and
outlet pipes at the top. These are not shewn in the drawings.
After the cathodes have received a sufficiently thick deposit of metal, they are
withdrawn from the tank, washed, dried, and plunged into a molten bath of tho
same metal as that which has been deposited upon them, this bath being sufficiently
deep to permit the cathodes to be wholly submerged, so that all the metal may be
removed therefrom by fusion.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
In apparatus for use in electrolysis more especially for the electrolysis of zinc
chloride solutions, cathodes capable of turning round or partly rounil a vertical
axis and placed between carbon anodes and diaphragms in a tank constructed of
separable frames substantially as herein before described and illustrated in
Figures 1, 2, 3, 4 and 5 of the accompanying drawings.
Dated this 15th day of September 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.