Improvements in Electrolytic Apparatus for Decomposing Chloride of Sodium or Potassium in Solution, and for Leading Away the Products of Decomposition.
Year: 1893

page_text: Date of Application, 14th Mar., 1893
Complete Specification Left, 30th Aug., 1893-Accepted, 4th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electrolytic Apparatus for Decomposing Chloride
of Sodium or Potassium in Solution, and for Leading Away the
Products of Decomposition.
I TREVENEN JAMES HOLLAND of Mount Ephraim House, Tunbridge Wells,
Colonel C.B., Retired List H.M. Army do hereby declare the nature of this
invention to be as follows:-
This invention relates to a further development of the invention for which Letters
Patent were granted to James C. Richardson and Col. T. J. Holland, dated
February 12th 1890, No. 2297.
The object of the present invention is directed mainly to rendering the apparatus
continuous, or practically continuous, in its operation.
To this end, a tank of slate or other suitable material, divided transversely or
longitudinally into any convenient number of compartments, by partitions arranged
after the manner explained in the Specification of the Patent above mentioned, is
provided with double sides, between which are channels or chambers extending
along on either side of the tank.
These chambers, which may, if desired, be divided longitudinally by horizontal
divisions, communicate with the compartments of the electrolytic tank through
suitably arranged apertures.
A supply of solution to be electrolysed is admitted through the chamber com-
municating with the anode compartments, while the caustic liquor is drawn off by a
chamber or channel in communication with the cathode compartments, near the
bottom of the tank.
The gases liberated at the electrodes escape also into chambers or channels com-
municating with the space above the level of the solution in each compartment of
the tank. The channels for conducting off the gases may be divided from the
channels supplying the electrolyte and carrying off the liquor produced by the
electrolysis, or the same channels may be used for both gas and solution, where
there is no fear of recombination. For instance, in the case of the electrolysis of
chloride of sodium solution, the chlorine gas liberated at the anode may pass into
the upper part of the channel through which the solution is supplied, the said
channel being furnished with apertures to the anode compartments, both above and
below the level of the solution. A channel communicating with the cathode
compartments, both above and below the level of the solution, would serve to carry
off the hydrogen gas liberated at the negative electrode, and the caustic soda
liquor.
These channels or chambers within the tank are easily and inexpensively
contrived at the time the tank is being made, and, by their means, the products of
decomposition can be constantly drawn off as the electrolysis proceeds, while fresh
solution is introduced to maintain the proper level.
During the process of the electrolysis, it is found that the lower portions of the
carbon anodes are eaten away, and, by degrees, become shorter, and further removed
from the negative electrodes. In order to provide a ready means for making up or
reducing the distance between the electrodes, after the eating away or disintegration
has proceeded some time, it is proposed that the bar carrying the anode should be
suspended by long bolts which can be let down by unscrewing nuts thereto outside
the compartments. To protect the metal carrying the carbon anodes within the
:

page_text: compartments, it may be coated with ozokerite, or similar material, not acted upon
by chlorine.
Dated this 11th don of March 1893
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electrolytic Apparatus for Decomposing Chloride
of Sodium or Potassium in Solution, and for Leading Away the
Products of Decomposition.
I TREVENEN JAMES HOLLAND of Mount Ephraim House, Tunbridge Wells,
Colonel C.B. Retired List H.M. Army do hereby declare the nature of this inven-
tion 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 a further development of the invention for which
Letters Patent,were granted to James C. Richardson and Col. T. J. Holland dated
February 12th 1890, No. 2297.
The object of the present invention is directed mainly to rendering the apparatus
continuous, or practically continuous in its operation.
To this end, a tank of slate, or other suitable material, divided transversely or
longitudinally into any convenient number of compartments by partitions arranged
after the manner explained in the Specification of the Patent above mentioned, is
provided with double sides, between which are channels or chambers extending
along on either side of the tank.
These chambers, which may (if it is desired to feed in the electrolyte and
withdraw the alkali, when formed; on the same side of the tank) be divided
longitudinally by horizontal divisions, communicate with the compartments of the
electrolytic tank through suitably arranged apertures.
A supply of solution to be electrolysed is admitted through the chamber
communicating with the anode compartments, while the caustic liquor is drawn off
by a chamber or channel in communication with the cathode compartments near the
bottom of the tank.
:
The gases liberated at the electrodes escape also into chambers or channels
communicating with the space above the level of the solution in each compartment
of the tank.
A tank embodying the present improvements is illustrated in the accompanying
drawing, wherein Fig. 1 is a longitudinal section, Fig. 2 a transverse section on
the line of Fig. 1; Fig. 3 is a plan view, Fig. 4 is a transverse section on the
line y y of Fig. 1; and Fig. 5 is a similar view, merely intended to indicate a
modified form of the negative electrode.
A is the tank, of slate or other suitable material, divided into any convenient
number of compartments or cells by transverse partitions extending downwards into
the solution to be electrolysed.
a are the anode cells, which are shown covered; b are the cathode cells, which
are shown not covered."
The cells a communicate by holes c arranged above the level of the solution
(see Fig. 2), with a closed outside chamber C, which extends the whole length of
the tank. This chamber C serves to lead away the gas given off at the positive
electrode, or anode, during the progress of the electrolytic decomposition. The
anode chambers obtain a supply of fresh solution of chloride of sodium or potassium
through holes c¹, a little below the level of the solution in the tank, from a chambe
or channel C¹ (see Fig. 2) running the entire length of the tank.
The products of electrolysis, which are formed at the cathode, and have a
downward tendency, so as to stratify at the bottom of the tank, are led off by a

page_text: aperture or apertures d communicating with the passage D, which leads to any
suitable receptacle.
In many cases, the supply of fresh solution to the anode cells, and the removal
of the gas formed therein, may be effected through one and the same passage,
and in that case, there are two holes in the passage at different levels, one above
the level of the solution, for the removal of the gas, the other just below the
level, for admitting a fresh supply of liquid.
The cathode passage D will be as before explained.
In the electrolysis of chloride of sodium solution, the fresh supply may be derived
in the following manner :-
The chamber C¹ may be charged with common salt, which will be taken up by
the solution, as it becomes weaker during the progress of the decomposition, and
water may be added to maintain the level of the solution. In this way, a saturated
solution may be maintained.
In the accompanying drawing, I have illustrated means whereby the electrodes
may be raised or lowered in the solution, as required, for adjusting the distance
between those of opposite polarity, which
circumstances.
18
a
convenience
under
some
For suspending the anodes, screws are employed attached thereto, and passing
through the covers of the anode chambers. Threaded nuts upon the screws above
the covers hold the anodes at the proper height in a manner easily understood.
The cathodes have lugs thereon, pierced with a series of holes one over the other,
the suspension of the cathodes being effected at any convenient level by pins
engaging with the edges of the tank and with the holes in the lugs aforesaid.
The chambers or passages communicating with the anode and cathode cells, are
by preference built in one structure with the tank, so as to effect an economy in the
construction.
In the accompanying drawing, the passages are formed by providing double sides
upon a single base for the whole structure, covers or horizontal divisions for the
spaces between the double sides being provided as required.
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:
1. A tank to be used in the electrical decomposition of chloride of sodium or
potassium in solution, having any convenient number of anode and cathode cells
formed by dividing the tank transversely by non-porous partitions extending
downwards from the covers of the anode cells to a depth somewhat below the level
of the electrodes, and having passages communicating respectively with the said
cells, for removing the products of decomposition and supplying fresh electrolyte,
substantially as herein described with reference to the accompanying drawing.
2. The use, in the electrical decomposition of chloride of sodium or potassium in
solution, of a tank constructed substantially as described in the first claim hereof.
Dated the 92nd dow of August 1893.
NEWTON & SON,
Agents for the Applicant.