An Improved Method, Means, or Process of Producing Caustic Soda and Chlorine Gas or Caustic Potash and Chlorine Gas by the Electrolysis of Common Salt in Solution or Chloride of Potassium in Solution.
Year: 1894

page_text: Date of Application, 16th June, 1894-Accepted, 28th July, 1894
COMPLETE SPECIFICATION.
An Improved Method, Means, or Process of Producing Caustic Soda
and Chlorine Gas or Caustic Potash and Chlorine Gas by the
Electrolysis of Common Salt in Solution or Chloride of Potassium
in Solution.
I, THOMAS DRAKE, of New Street, Huddersfield, in the County of York,
Solicitor, 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 :-
My invention consists in a new method or means of producing caustic soda and
chlorine gas or caustic potash and chlorine gas by the action of electricity on
common salt in solution or chloride of potassium in solution.
For the purpose of carrying out my invention I use an electrolytic cell containing
two chambers, I also employ a porous pot, surrounded with wire, wire-gauze or
perforated sheet metal of the nature and in the manner hereinafter described
together with electric currents.
In order that the nature and object of my invention may be more fully understood
and put into practical operation I will make reference to the annexed sheet of
drawings wherein Fig. 1 illustrates an arrangement of vessels and an electrolytic
cell the latter resting upon a pedestal A. The cell is composed of an outer vessel B-
made of cast iron. A porous pot C is placed within the cast iron vessel,
leaving a space between the inner walls of the outer vessel B and the porous
pot C.
This porous pot contains two or more carbons cast to a disc of lead D which
forms the lid of the said porous pot, which lid is the anode of the cell C. The
outerside of the porous pot must be closely and firmly wrapped with a very fine
wire, wire-gauze or finely perforated sheet of gold, silver, copper, brass, zinc, iron,
or platinum, or other metal of suitable electrical conductivity as shewn at
letter T.
After the porous pot has been thus covered with the metal described, the said
pot is immersed in a salt of mercury say-nitrate of mercury-for the purpose of
coating the wire, wire-gauze or perforated sheet of metal above described. E is
the cathode and it is connected to the wire, wire-gauze or perforated sheet of metal
surrounding the porous pot as above described as shewn by the letter E and
also in detail in Fig. 2. The space F formed between the outer vessel B and the
inner vessel C is filled with water to the height of the overflow pipe P.
After the introduction of water into the space F the tap H of vessel I (which
is filled with a strong solution of common salt or strong solution of chloride of
potassium) is opened allowing the liquor therein to flow into the anode side of the
cell until it rises to the overflow J when the liquor falls into the depositing tank or
vessel K.
In the process of manufacture, the supernatant liquor in vessel K flows over
through pipe L into vessel M which when full is forced or pumped back into the
upper vessel 1 and thus the circulation of the liquor is continued. The vessel N is o
charged with water and flows through pipe O into the space F until the water rises
to the level of the overflow pipe P when it passes into the vessel Q which when
full is forced or pumped back into the vessel Ñ and so the circulation of the liquor
continues. The electric current produced by a dynamo being now connected to
the two poles of the cell, the electrolysis commences and the brine or the solution
of chloride of potassium in the inner cell C decomposes and chlorine gas passes off
by pipe R whilst sodium or potassium is received or combines with the wire, wire-

page_text: gauze or perforated sheet of metal surrounding the porous pot C. The action of
the flow of water through pipe O is to oxidise the sodium to soda with liberation
of hydrogen, or potassium to potash the said water being discharged through
pipe P. This process may be continued until the solution of caustic soda or
caustic potash attains any desired gravity or strength.
I would here observe that for covering the porous pot C I give preference to
fine copper gauze treated with a salt of mercury.
The mercury sustains no chemical waste by the action or process herein
described, at the same time it is not absolutely necessary to employ mercury in
as much as an inferior result can be obtained without its use. I would also
observe that the chamber of the porous pot above the overflow pipe J should be
coated or charged inside and outside with paraffin or other like substance to
destroy its porosity, as also should the bottom of the pot on the outside bringing
the paraffin in contact with the wire, wire-gauze or perforated sheet of metal.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed and carried out, I
would remark that I do not confine nor limit myself to the shape or configuration
of any of the vessels or cells.herein mentioned, but what I do claim is :-
Firstly. The manufacture of caustic soda and chlorine gas or caustic potash and
chlorine gas by having the cell C wrapped or surrounded with fine wire, wire-gauze
or perforated sheet of gold, silver, copper, brass, zinc, platinum, or other metal of
suitable electrical conductivity arranged and operated in the manner and by the
means herein described and shewn in the drawings.
Secondly. In manufacturing caustic soda and chlorine gas or caustic potash and
chlorine gas, the use therein of a cell namely the cell wrapped or surrounded
with any of the metals in the manner as herein mentioned; immersed or treated
with a salt of mercury for purposes described herein.
Thirdly. In manufacturing caustic soda and chlorine gas or caustic potash and
chlorine gas, the use or employment of water within space F formed between the
two vessels B and C for purposes described.
Fourthly. In manufacturing caustic soda and chlorine gas or caustic potash and
chlorine gas, the connecting of the cathode E directly to the wire, wire-gauze or
perforated sheet metal T wrapped around the porous pot C substantially as shewn
and described.
Fifthly. I claim the porous pot C closely and firmly wrapped or surrounded with
a very fine wire, wire-gauze or finely perforated sheet of gold, silver, copper, brass,
zinc, iron, platinum or other metal of suitable electrical conductivity treated or not
treated with mercury.
Dated this 12th day of June 1894
TASKER & CROSSLEY,
Halifax, Agents.