Improvements relating to the Application of Depolarizers in Electrolysis.
Year: 1891

page_text: Date of Application, 13th Nov., 1891
Complete Specification Left, 13th Sept., 1892-Accepted, 15th Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements relating to the Application of Depolarizers in
Electrolysis.
I, JAMES CHARLES RICHARDSON, of 23 Claremont Square, Clerkenwell, in
the County of Middlesex, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:-
The object of this invention is to maintain the depolarizing action of a
compound, such as an insoluble oxide, next the cathode in electrolytic work.
In the case of employing metallic oxides as depolarizers which are reduced or
partly reduced by hydrogen at the cathode, it is necessary to stop the electrolytic
action while fresh, or "live," depolarizer is being introduced.
To avoid the intermittence caused by this method, my plan is to so arrange the
cathode that the depolarizer may be introduced next it regularly, by causing either
the cathode itself, or the depolarizer upon it to move (without causing undue
agitation--a precaution necessary in certain cases), so that the depolarizer at one
stage of its progress through the electrolyte will be partly or wholly reduced, and
at another will be renewed or replenished; and this plan may be conveniently
described by imagining a travelling broad band constituting the cathode (of any
desired construction and surface) upon which as it enters the electrolyte a
depolarizer is introduced, and as it emerges from the electrolyte the depolarizing
properties are wholly or partly exhausted, or, instead of the cathode itself being
caused to move through the electrolyte, the depolarizer may be caused to move
over the cathode by suitable means, at one point being active and another
more or less inactive-it being gradually reduced in its progress over the
cathode.
This plan may be referred to in connection with the Patent No. 2296, 1890,
granted to myself and Col. T. J. Holland, C.B., in which oxide of copper is
employed in the electrolysis of salt; the oxide of copper in this case being
introduced next the cathode at one point, and the reduced copper removed for
re-oxidation, or re-oxidised without actual removal from the cathode, at another,
the regular depolarizing action thus allowing the electrolytic action to go on
continuously, as, for example, in decomposing common salt, the salt solution would
be admitted continuously, the electric current, depolarizer, and draw-off of caustic
soda solution, being so arranged as to work automatically.
Dated this 13th day of November 1891.
JAMES CHARLES RICHARDSON.
COMPLETE SPECIFICATION.
Improvements relating to the Application of Depolarizers in
Electrolysis.
I, JAMES CHARLES RICHARDSON, of 23 Claremont Square, Clerkenwell,
London, 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:--
In electrical decomposition of solutions, where a depolariser is employed, after
the manner explained in the Specification of the British Letters Patent granted
to myself and Col. Trevenon James Holland, dated 12th February 1890, No. 2296,
it is necessary from time to time to stop the process of electrolysis for renewal of
the depolarising agent.

page_text: The object of the present invention is to render the electrolysis more continuous,
and to avoid the interruptions which perforce occur while the reduced or spent
depolariser is being removed and replaced by fresh.
According to my invention, I introduce the depolariser, which will be an
insoluble metallic oxide, in a more or less finely divided state, continually, or at
regular intervals, into the electrolytic tank, where it falls onto a travelling apron,
which conveys it slowly from one end of the tank to the other, arriving thither in
a reduced condition, ready for removal by means of an elevator.
In the accompanying drawing, I have shewn an electrolytic tank, suitable for
decomposing a solution of salt, illustrating my invention:-
Fig. 1 is a plan view, and Figure 2 is a longitudinal section.
A is the body of the tank, of slate or other suitable material. a is a cover of the
same width as the tank, but somewhat less in length, so as to leave a space
uncovered at either end. bb' are solid partitions extending from side to side of
the tank, and from the cover downwards into the solution, to about three quarters
the depth of the tank, so as to make an enclosed compartment for the anodes B
immersed in the solution. The anodes are made of pieces of retort carbon,
secured by casting into bars of lead, or other suitable material supported from the
cover a.
The cathode or negative electrode is situated in the bottom of the tank, below
the level of the lowest edge of the partitions bbl.
In the drawing, C is the cathode, as well as the travelling apron for traversing
the depolariser through the solution in contact with itself.
The travelling apron C consists of an endless band of suitable sheet metal, of
a width nearly equal to the breadth of the tank. This endless band is strained
over two rolls cc, mounted in bearings in the tank. The shaft of the roller c
extends through the side of the tank, where there is a stuffing box to prevent the
escape of the solution, and terminates in a pulley to which rotation is communicated
to advance the apron at a slow pace in any convenient manner. d d' d² are rollers
which serve to support the band and keep it tight at the middle of its length.
62 are terminals for making electrical connection with the anodes, and is a
terminal for making connection, by the aid of the contact strip or brush c³, with
the cathode.
E is a hopper containing the depolarising agent, and e is a feed roller, which,
by its rotation, continually discharges small quantities down the shoot e¹, which
delivers onto the apron C.
The speed of travel of the apron C is regulated so that any given portion of
depolariser, on completing its passage through the tank, falls from the apron in a
condition as fully reduced or spent as possible, so that when it is removed by
the elevator F, there may be little or no depolarising porperties left in it. f is a
tray into which the spent depolariser falls from the apron, and into which the
elevator F dips.
The tank. is provided with inlet and outlet pipes for the solution etc., but, as
these form no part of the present improvements, there is no need to refer to
them.
The elevator F may consist of an endless chain of buckets, as illustrated in the
drawing.
From the foregoing it will be seen that the depolariser is constantly being
renewed as fast as it is removed in a reduced condition. Thus, it will be un-
necessary to stop the electrolytic process, as has hitherto been necessary, while the
reduced depolariser is removed and reoxidised in the usual way.
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 1
claim is :-
The employment in connection with the decomposition of solutions by
electrolysis, of a depolariser constantly supplied in a live or active condition.

page_text: and removed in a reduced or spent state, in the manner and for the purpose above
explained.
1800
NEWTON & SON,
Agents for the Applicant.