Improvements in Electrolytic Apparatus.
Year: 1894

page_text: Date of Application, 22nd May, 1894-Accepted, 23rd June, 1894
COMPLETE SPECIFICATION.
Improvements in Electrolytic Apparatus.
I, THOMAS CRANEY, of 624 Harrison Street, in the City of Bay City, County of
Bay, State of Michigan, United States of America, Manufacturer, 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 electrolytic apparatus adapted for the commercial
exploitation of the process of electrolysis of salts, especially the chlorides, such as
chloride of sodium and the object of my invention is particularly to make a durable,
economical and effective apparatus in which the operation can be carried on
continuously.
To this end my invention consists in the improved construction and arrangement
of an electrolytic cell, and in the combination of several cells to form a large plant
adapted to meet various contingencies when in operation, all as more fully herein-
after described.
In the drawings,
Fig. 1 is a diagram plan view of an electrolytic plant composed of four cells and
embodying my improvements.
Fig.
is a longitudinal, central, cross-section of one of the cells shown in Fig. 1.
Fig. 3 is a cross section on line in Fig. 1.
Fig. 4 is an enlarged, vertical section through one of the anodes, and
Fig. 5 is a section showing some details of construction.
In the drawings, I have shown an apparatus comprising four cells, each of which
is constructed as follows::
A is a large iron tank preferably of boiler iron and supported upon cross bars B
by hangers C from suitable overhead beams D.
The tank is electrically insulated in any suitable manner, such as by passing the
hangers C through insulating bushings a in the beams.
The tank is divided by a diaphragm into an anode compartment. E occupying the
upper portion of the tank and a cathode compartment F occupying the space in the
tank below the diaphragm."
The diaphragm forms a complete vessel and consists of porous material G which
constitutes the diaphragm proper, and of a vessel shaped frame or screen through
which the liquid can pass, but which is adapted to hold the material of which the
diaphragm is made. The frame can be made of open work in any manner to form
a soreen, but I preferably use iron wire screen H and support it at intervals by
cross iron bars H, which are secured to the edges of the tank by bolts or rivets b.
As shown more particularly in section Fig. 5 the bars H' are flattened at the ends
and washers c are placed upon the bolts to hold the edges of the screen away from
the edges of the tank and thus form an opening d for the escape of the gas from
she cathode compartment.
The diaphragm proper I make of asbestos, which I preferably use in the form of
o-called asbestos sheet placed on the inside of the supporting frame in several

page_text: али
vur Juua ULURC
50
AVETU
lining.
The frame and lining thus form an inner porous anode vessel in the tank, and a
particular feature is that the frame has outwardly inclined sides and a sloping
bottom, the object of which will be explained hereinafter.
The opening d may be left open for the escape of the gas or it may be covered
and pipes placed in the cover if it is desired to collect the gas for use.
The anode compartment is closed on top by a cover J, which is provided with
openings in which the anodes K are secured and project into the compartment
below.
These anodes I preferably form of gas carbon inclosed in tubular supports L of
earthenware open at the bottom and with a wire connection leading into the top.
As shown in the detail in Fig. 4 I preferably take a solid piece of gas carbon e
to which is cast a metallic head f of lead or other suitable material. The gas
carbon e projects into the support L. and powdered carbon el is packed around it,
while the upper end is hermetically sealed into the top of the support by plaster of
Paris.g or other cement placed around it, and the wire terminal is soldered into the
lead f.
The gaseous products of decomposition from the anode compartment escape
through specially provided exit pipes M which lead from the cover over the sides
of the tank into mains M', which pass underneath the cells and receive the individual
pipes from the anode compartments of every cell and carry the gas to an exhaust
fan M. In this manner air is drawn into the anode compartments through the
cracks or leaks around the cover and other places which may not be closed quite
air tight and this inward suction prevents the escape of any gas from the anode
compartments and thus the decomposition of chlorides of sodium may be carried
on without there being even a trace of the noxious chlorine gas in the surrounding
air.
The tubular support of the anode projects to near the bottom of the anode
compartment which is covered with a layer of broken pieces of gas carbon N
distributed over the whole surface of the diaphragm. At the extreme edges,
however, I preferably use a row of brick or large chunks of gas carbon N¹ laid
upon the diaphragm for the purpose of preventing the edges of the diaphragm from
being accidentally disturbed.
The carbou on the bottom of the anode compartment forms the anode by being
in contact with the carbon in the tubes L, it holds the lower ends of the tubes in
place against accidental displacement and tends to exclude the gaseous products of
decomposition from entering into the tubes.
This preserves the mechanical continuity of the anode which might in time
become destroyed by the corrosive action of chlorine, and as a further safeguard
I place perforations in the tubular supports L above the line of the liquid whereby
any gas formed in the tubes can escape into the anode compartment without danger
of forcing its way to the top and corroding the metallic conductor.
The anode compartment of each tank is provided with a valve controlled supply
pipe O and an overflow pipe 01 placed at opposite ends of the compartment.
In using my apparatus for the electrolysis of common salt a constant supply of
fresh brine is preferably allowed to flow into the anode compartment and thus a
saturated solution is constantly maintained therein, while the overflow pipe maintains
the liquid at a fixed height in the compartment and produces a flow of the liquid
through the tank.
The advantage of having a constant feed is that most of the chlorine gas is
thereby carried off in solution and the quantity of the product in the cathode
compartment is naturally increased by maintaining the liquid in the anode com-
partment at its full strength.
The overflow from the anode compartment may be freed from the chlorine gas,
and if required, saturated with fresh salt, and then used again.
"
The cathode compartment of the cell is provided with a valve controlled feed

page_text: pipe P through which pure water or a solution of the liquid flows into the com-
partment in sufficient quantity to discharge the product by displacement, through
a discharge pipe Q. In case of several cells being connected, the cathode
compartment of the first cell need only be provided with a feed pipe P, and that
of the last cell only with a discharge pipe Q, and the product is carried from one
cathode compartment into the next by means of suitable communicating pipes,
which I preferably arrange in the manner shown and wherein R R are main
communicating pipes arranged at both ends of the tanks and communicating with
each cathode compartment through valved branches S, and valves T are placed in
the main pipes between each two tanks.
To prevent short circuiting the pipes R R³ are partly made of sections of tubing
of rubber or other insulating material.
With this construction it will be seen that by a proper manipulating of the
different valves, the cathode compartments may be connected for the flow of the
liquid in series through the compartment while at the same time in case of needed
repairs or for any other reason, one or more of the tanks may be cut out without
interfering with the working of the other in combination.
The main leads V V through which the current is furnished are preferably
arranged overhead with feeders W W leading from them to the anodes and to the
cathodes, the latter of which are represented by the metallic support of the
diaphragm and by the metallic tank to which the feeders may be connected.
An important feature of my invention is the frame which supports the diaphragm
proper, it has the form of a vessel without any vertical walls. The object is to
hold the lining of asbestos in position by making the walls at a suitable inclination,
and my invention broadly comprises the idea of making the porous vessel or
diaphragm entirely of incompact material. What I mean by incompact, is
material of granular pulpous or fibrous condition, such as sand, cotton, pulpous or
fibrous asbestos, or material which is transformed into this condition when
used in a liquid, such as asbestos sheet which becomes pulpous when used as a
diaphragm.
Heretofore the porous vessel was either entirely formed of a solid material, such
as the porous earthenware vessels or of incompact material filled in between solid
supports or forming only a portion of the walls of the vessel.
Considering that the incompact materials spoken of are generally preferable as
diaphragms to the use of compact or solid diaphragms on account of their having
less electrical resistance the advantage of my construction is obvious. I not only
get the benefit of having the incompact material form the entire walls of the vessel,
but as the material itself forms the inner walls of the vessel or diaphragm, the anode
can be placed directly in contact therewith, and by making the supporting frame the
cathode, I contrive to have a cell in which the anode and cathode are co-extensive
with the diaphragm and are only separated from each other by the incompact
material, and thus the electrical resistance is decreased to a minimum.
The specific way in which I have presented my invention has several advantages,
thus it will be seen that by using vessels of small height with large area the
diaphragm and the electrodes are of large area in proportion to the contents of the
vessels and thus a large output is obtained.
The walls of the frame may be arranged at any suitable incline, either straight or
curved, by curving them however, interior corners are avoided.
The bottom may be flat, but I prefer to make it slope towards the middle so
as to make the inclines less abrupt and prevent the gas from collecting on the
underside.
The layer of broken pieces of gas carbon firmly hold the material which forms
the diaphragm in position against the screen, it also forms an inner compartment
for the liquid which is in contact with it throughout. The screen may be of a
suitable fine mesh to hold the material of the diaphragm from passing through it,
but I prefer using coarser screen and cover it with some fabric such as one or more
sheets of cotton.

page_text: - Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
<claim is :
The electrolytio annaratus as shown and described
Dated this 4th day of April 1894.
THOMAS CRANEY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents. for the Applicant.