Improvements in Apparatus for Electrolytically Producing Soda and Chlorine.
Year: 1893

page_text: Date of Application, 5th Dec., 1893-Accepted, 13th Jan., 1894
COMPLETE SPECIFICATION.
[Communicated from abroad by THE UNION CHEMICAL COMpany, of
29, Broadway, New York, United States of America.]
Improvements in Apparatus for Electrolytically Producing Soda
and Chlorine.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co. Patent
Agents, 45 Southampton. Buildings, in the County of Middlesex, 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:-
The invention relates to an apparatus for electrolytically producing soda and
chlorine by electrolyzing an aqueous solution of sodium chloride to produce
chlorine and soda, withdrawing the chlorine from the body of the solution and
allowing the soda to accumulate, by its own gravity, at the bottom of a containing
vessel.
In the drawings,
Fig. 1 is a vertical section of the complete apparatus, on the line 11 of Fig. 2..
Fig. 2 is a cross section on the line 22 of Fig. 1.
Figs. 3 and 4 show methods of holding the carbon electrodes in place.
Fig. 5 shows the mode of impreguating, with paraffine, the bodies which hold
the carbon electrodes in place.
Fig. 6 shows the mode of adjusting the joint between the electrodes and the
supporting pin.
Similar letters of reference indicate like parts.
A is the containing vessel of iron, having a flanged collar, B, which supports
brackets, C.. D is a bell of earthenware, supported on brackets C. It may be
made in two pieces, E and F, jointed together. It is closed above by a dome, G,
in which is the outlet pipe, H, for the chlorine, which connects with any suitable
form of pump or exhauster. Also in dome H is the tubular opening, I, surrounded
by flange J. K is a bell-shaped cover for opening I. Brine is introduced into the
apparatus through opening I.. In the bottom of vessel A is an outlet pipe, M,
above which is a layer of wire gauze, N, and above the gauze is a steel plate, O.
On plate O is the conical support, P, of earthenware, above which is the flanged
disk Q, also of earthenware. The pipe R passes through the wall of vessel A,
and communicates with the space inside of disk Q. The pipe R and the space
within disk is filled with insulating material, such as a mixture of paraffine and
gutta-percha. In the disk Q are openings, above each of which is disposed a
vertical bar, S, of gas carbon. These bars are supported by pins, T, also of
carbon, which are inserted in the bottom of bars S and also in the apertures of
disk Q. The carbon pins T are impregnated with paraffine, and are connected by
a wire, U, in multiple arc relation. Said wire U extends through the space
between disk Q and support P, and through the tube R. Bars S are therefore at
the anodes of the cell.. Vessel A is at the cathode, and is connected to the other
terminal of the source of current by means of the binding post V., Vessel A is
filled with a, solution of sodium chloride above the level of the lower edge of
bell D. Current is established, and the exhauster or pump communicating with
pipe H is started. The liquid is then electrolyzed, chlorine being produced
at the anodes and drawn out of the liquid, in gaseous form, through pipe H.
Caustic soda, also, produced, forms at the inner surface of vessel A, and
descending, by gravity, along the sides thereof, filters through gauze N and
escapes at pipe M.

page_text: In order to protect the joint between the anodes S and the holder Q, I construct
said joint in the following manner: In one end of each electrode S is a tapered
opening into which is driven the carbon pin T. Each pin enters the holder Q.
The portion of the electrode S which surrounds the pin T is impregnated with
paraffine, and the pin itself is similarly impregnated thus a very tight joint is
made, which is packed by paraffine, so that, in practice, it is impossible for the
liquid electrolyte to introduce itself in the joint, or for salts to form in or about
the same.
In order further to protect the joint, it is surrounded with an
envelope, W, of insulating material, such as paraffine or glass, as indicated in
Fig. 3. The glass is applied in a fused or molten state, so that it runs in between
the support Q and electrode S, and cements one firmly to the other. Glass is
preferred, because it is not attackable by any ordinary acids or other substances.
in the cell. Instead of making the support of earthenware, it may be made of
glass and fused at the joint with the carbon electrode, and also carried up around
said joint, as shown in Fig. 4.
In Fig. 5 is shown a mode of impregnating the carbon pins T with paraffine or
other insulating material. They are placed in an iron vessel, a, having heads, b
and c
In head is a pipe, d, connecting with an air compressor. The pins being
placed in a, the vessel is filled with melted paraffine nearly to the top, and is
supported over a grate or other source of heat sufficient to melt and keep the
paraffine liquid. During the heating, and while the paraffine is liquid, air is forced
into vessel a at a pressure of about three hundred pounds per square inch. This
pressure, acting upon the upper surface of the liquid, forces it into all the pores
of the carbon, and thus the carbon becomes completely impregnated with
paraffine.
Fig. 6 illustrates the mode of adjusting the resistance at the joint between the
electrode S and pin T to any desired degree. One terminal of battery e is con-
nected to the rod S, the other end to a clamp,, applied to the pin T. In circuit with
the battery is an ammeter, g. The strength of current thus passed through S
and T should be equal to that which it is desired to pass through the electrode in
the cell in which the electrode is to be used. is a voltmeter in multiple arc
relation to battery e. This voltmeter measures the difference of potential between
the clamp and the upper end of electrode S; hence, if the strength of current be
kept constant, this difference will vary with the resistance, and this resistance will
depend upon the closeness of the joint between S and T; so that, by carefully
driving the pin T into S, the resistance at the joint may be reduced to any desired
amount, and the fact when that desired amount is obtained may be determined from
the voltmeter h. In practice, the electrodes S may be bodies of carbon from two
to three feet in length and some four inches in thickness. The pins T are about
one inch thick and nine inches long.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed as communicated to me by
my foreign correspondents, I declare that what I claim is
1. The apparatus for electrolytically producing soda and chlorine, constructed
substantially as herein before described.
2. The construction and arrangement of the carbon electrode S, in combination
with the pin T and a holder or support.
3. The carbon electrode S and conical pin T inserted therein, both parts at the
joint being impregnated with paraffine or similar material, a holder or support
receiving said pin, and an envelope of glass or other insulating substance
surrounding said joint.
1000
Dated this 6th day of December 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.