mprovements in Electroly the Processes, and Apparatus therefor.
Year: 1896

page_text: mprovements in Electroly the Processes, and Apparatus therefor.
I, GIOVANNI BATTISTA BALDO, Professor of the Real Superior School,
Trieste, Austria, 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 relates to improvements in electrolytic processes and apparatus
therefor.
The apparatus I employ is illustrated in the accompanying drawing in which
Fig. 1 is a cross section of a cell.
Fig. 2 is a longitudinal section.
Fig. 3 is a sectional plan on line -x, Fig. 1.
Fig. 4 is an elevation on a larger scale broken in several places to show the two
porous vessels hereafter referred to.
Figs. 5 and 6 are sections on enlarged scale of the walls of such porous vessels.
Fig. 7 is a cross section of a modified form of cell, and
Fig. 8 is a section on an enlarged scale of the wall of the porous vessel of such
cell.
The apparatus is adapted for carrying out the process for obtaining caustic soda
hydrogen and chlorine by electrolysis of sea water described in the Complete
Specification filed under an application for Letters Patent No. 18406 of 1895, and
forms also an electrolytic apparatus for the separation of the magnesium and
calcium in the form of oxides from the electrolytes and the sulphuric acid
and hydrochloric acid developed during the process.
The cell, Figs. 1, 2, 3 and 4 consists of an outer vessel c in which is supported a
porous vessel b-e forming the cathode, inside of which is a second porous vessel a-d
containing the anodes which are of carbon or other suitable material. The
contents of the vessel c may be drawn off through a pipe i, and the contents of
the vessels b-e and a-d through pipes g, h, respectively. The vessel c has an
inlet pipe m for liquid and an outlet pipe for the gases, and the vessel a―d has
an inlet 7 for liquid and an outlet n for the gases. The vessel a-d is closed by a
cover, and the vessel c by a flange to attached to or forming part of the
vessel b-e.
The vessel be consists of an open or skeleton framework 6 of earthenware or
like material which is covered with linen el surrounded in turn by
layer of
asbestos board or the like e of about one millimetre in thickness which again is
surrounded and is in contact with an openwork metal sheet such as close wire
netting
The vessel a-d consists of an earthenware framework a covered with a layer of
linen d, a layer of asbestos board d, and a further layer of linen d.
The apparatus when electrolysing sea water for instance, may be supplied with
sea water in the space u of vessel a-d, and in the space o of the vessel b-e, while
the space t of the vessel c may contain fresh water. Upon a current being passed
through the apparatus the sea water in the two spaces u and o is decomposed,
magnesium and calcium oxides being precipitated in the space o while the sodium
passing through the porous vessel ad from space u and through the porous vessel
and cathode b-e is decomposed and forms filtered caustic soda when it reaches the
space t of the vessel c. Chlorine gas is given off at the anodes f, and hydrogen
at the cathode be, the gases escaping through the pipes n, q, and being collected

page_text: if desired. The liquid remaining in the space u contains free sulphuric acid
produced by the decomposition of the sulphates of the sea water, undecomposed
chloride of sodium, and some undecomposed sulphate of magnesium and other
sulphates. This liquid may be distilled, the first three quarters being rejected and
the last quarter collected, the dense residue remaining being heated to redness
while the vapour passing off may be collected as hydrochloric acid which may be
added to that previously distilled.
If sea water be left in space o and in place of sea water in the anode space u
water acidulated with sulphuric acid is used, sulphuric acid and chlorine gas only
are obtained in the space u, the space o collecting the magnesium and calcium
oxides and the space the caustic soda as before." When caustic soda is to be
obtained from sea water without collecting the magnesium and calcium, the
apparatus shown in Figs. 7 and 8 may be employed. The chauge here consists in
omitting the vessel b-e and using only the porous vessel here marked v which
consists of the earthenware framework a covered with a layer of linen v¹, asbestos
board II, and wire netting or the like II, which enables it to form the cathode.
The vessel so formed has an inlet and an outlet u. By filling the vessel with sea
water when placed in another vessel containing fresh water such as a vessel cin
Fig. 1, caustic will be formed in such latter vessel, hydrogen given off, and chlorine
will be given off at the anodes f.
Cells constructed as above described will be found to possess a minimum of
internal resistance compared with many of the cells at present in use.
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. Apparatus for the electrolysis of sea water having porous vessels in one of
which the caustic soda is formed, and in the other the magnesium and calcium
oxides deposited, substantially as described.
2. In apparatus for electrolytic processes the construction of the combined
cathode and porous vessel substantially as and for the purpose described.
3. In apparatus for electrolytic processes the construction of the porous vessel
forming the chamber for the anodes substantially as and for the purpose described.
4. The improved process for electrolysing sea water and obtaining chlorine,
hydrochloric or sulphuric acid, magnesium and calcium, caustic soda and hydrogen,
substantially as described.
Dated the 6th day of March 1896.
PHILIP M. JUSTICE,
55 & 56 Chancery Lane, London, Chartered Patent Agent,
For the Applicant.