Improvements in the Manufacture of Oxygen.
Year: 1890

page_text: Date of Application, 9th Oct., 1890
Complete Specification Left, 10th Aug., 1891-Accepted, 9th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Oxygen.
I, JOHN CHARLES LAWSON of 6, Newman's Row Holborn London, Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in the manufacture of oxygen, and has for
its object to produce at a low cost a continuous supply of a gas containing about
95% of pure oxygen. According to my invention I extract the oxygen from air
which has been previously subjected to the action of electricity, and hence contains
a certain amount of ozone. This ozonification is effected by passing a current of
air, freed by suitable chemicals from its impurities and subsequently dried by
means of sulphuric acid or otherwise, through a pipe leading to an apparatus in
which the ozone is generated and which will be hereinafter called the generator.
This generator consists of a box containing a number of superposed plates of
non conducting material such as vulcanite, mica, glass, or the like, these plates
being coated with shellac or other non conducting varnish.
On each plate is fixed a sheet of metal foil preferably tin, which is finely
perforated by means of a pointed instrument in such a manner, that the edges of
the metal surrounding the perforations, are forced upwards, so as to form a series
of pointed conical projections above the plate. The various plates are separated
from one another at suitable intervals by glass rods or fillets. These metal plates
are connected to the terminals of a series of induction coils, arranged in such a
manner, that should any sparks produced by overheating render one of these coils
useless, the said coil could be isolated from the others, without interfering with the
regularity and continuity of the operation.
The primary coil of this induction coil, is connected to the terminals of a dynamo
electric machine producing alternate currents. A current of air which is forced
into the generator comes into contact with the glass plates, which divide it, and
cause the various portions thereof, to pass over these plates, through the flood of
electric sparks, produced at the apices of the perforated conical projections above
mentioned, thus producing a continuous current of electrified or ozonified air, from
which the oxygen is subsequently extracted in the manner hereinafter set forth.
To extract this oxygen, I utilise the properties possessed by certain bodies of
absorbing oxygen under the action of heat, and of surrendering the same under the
subsequent action of steam. Various compounds have been heretofore used for a
similar purpose, such as baryta, a mixture of caustic soda and bioxide of manganese
and others, but they have not been treated in the manner required to cause them
to act continuously and evenly, that is to say of surrendering as nearly as possible
the whole of the oxygen which they had absorbed in the first instance, the result
being that a continuous flow of oxygen could not be obtained, but that inter-
missions occurred which rendered the process tedious, and expensive.
I am also aware that apparatus have been constructed on a large scale for the
purpose of carrying out these processes with a view to supply oxygen for com-
mercial purposes, but although they have been so far successful, their imperfections
and intermittency have prevented the cost price of oxygen from descending below
a certain limit, which is yet far too high to permit of its general application to
purposes connected with arts and manufactures. Now one of the essential features
of my invention, is to prepare and treat the substances destined to absorb the
oxygen, from the electrified or ozonified air, prepared preferably in the manner
above set forth, or in any other manner, and to so arrange and combine the
apparatus, in which the extraction of the gas is effected, that a continuous flow of
oxygen may be produced at a cost price which is far below that of oxygen manu-
factured according to other similar processes.

page_text: Another essential feature of my invention, is making use of such electrified
or ozonified air, for the extraction of oxygen, instead of common air as hitherto
practised. I will now describe the preparation of the compound which I use for
alternately absorbing and surrendering the oxygen. I dissolve six ounces of
caustic soda in one pint of water, and I place the solution in an iron vessel, adding
thereto four ounces of powdered manganese. While the mixture is being properly
stirred, whereupon heat is applied to the vessel, I subsequently add to the mixture
six parts of caustic soda, and four parts of powdered manganese, supplementing
afterwards this addition by three and half ounces of manganate of soda while a
gentle heat is maintained throughout until the mixture boils, when I further add
four and half parts or ounces, of a mixture containing seven parts of chlorate of
potash and from one and half of two ounces of powdered manganese.
I ΠΟΛΥ
increase the heat while preventing the mass from boiling over, and I diligently stir,
until the whole has assumed a fluid consistence. When this is attained the mass is
evaporated to siccity and transferred to another iron vessel, subjected to a bright
red heat for a period of an hour and a half or thereabouts. The product obtained
should be thick and adhesive to the touch, of a dark green colour, and intensely
alkaline to the taste. During the above treatment the mass successively assumes
a black, a green, a dull red, a bright red, and finally a dark green colour when
viewed in small quantities. The above oxygen absorbing compound is now
placed in the cross tubes of two or more retorts, constructed in the following
manner.
Within an outer cylindrical casing is arranged an inner tube or casing, traversed
by a series of cross tubes or pipes, arranged at suitable intervals by the side of one
another. The inner tube is connected to the outer casing by means of radial arms
or in any other suitable manner.
The retort is connected at one end with a pipe leading to the air supply pipe
through which the electrified air is forced in the said retort by means of a fan
or blower, the former pipe communicating with a steam pipe, which is furnished
as well as the supply pipe beforesaid with a suitable valve. The other end of the
retort is furnished with an outlet for the nitrogen, and with an oxygen supply
pipe leading to one or more scrubbers, through which the oxygen, is freed from
any impurity it may contain, and washed, the latter passing finally into a gasometer
or holder. The above retort is connected to another adjoining retort, by a branch
pipe, this second retort, being likewise connected by an outlet pipe with the oxygen
supply pipe, and also furnished with an outlet for the nitrogen and a pipe for the
steam. The operation is carried on alternately in the first and in the second
retort which are both heated in such a manner, that a constant flow of oxygen
is discharged through the oxygen supply pipe either from one or the other retort,
and without the occurrence of any intermission.
The electrified or ozonified air above mentioned is freed from its oxygen in the
retort, while its nitrogen escapes through the outlet provided therefor. When
as much oxygen as possible has been absorbed by the compound in the retort,
(which is determined by test papers, indicating the presence of ozone in the
retort,) the supply of electrified air to this retort is closed, and opened for the
other retort, where the absorption now takes place. While this absorption is
proceeding in the second retort, steam has been admitted into the first retort,
and has caused the compound to surrender its oxygen, which is discharged through
the oxygen supply pipe. The course of the process is such, that as soon as the
first retort has discharged all its oxygen, the absorption is complete in the second
retort; and the supply of electrified air is now reversed from the second to the
first retort and so on. The opening and closing of the various valves may be
effected automatically by means of any suitable mechanism.
Dated this 8th day of October 1890.
RAYNER & CASSELL,
37, Chancery Lane, W.C., Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Oxygen.
I JOHN CHARLES LAWSON of 6 Newman's Row, Holborn, London, Engineer,
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 :-
This invention for improvements in the manufacture of oxygen has for its object
to separate the oxygen contained in atmospheric air from the other constituents by
means of a continuous process and at a considerably less cost than heretofore and
consists essentially in passing ozonised air through a compound capable of readily
absorbing free oxygen and of giving it off again when heated and acted upon by a
current of steam.
One arrangement of carrying this invention into practical effect is illustrated in
the annexed sheet of drawings in which
Fig. 1 is a diagrammatic view shewing the whole process and
Fig. 2 is a front elevation of the heating furnace showing the method of
connecting the air and steam inlet pipes and the nitrogen and oxygen outlet pipes
to the retorts so that the process can be rendered continuous and
Fig. 3 is a side elevation of the same.
The apparatus consists essentially as shown in Fig. 1 of a fan or suitable air
pump a driven from any suitable source of power and drawing in air from the
atmosphere and discharging it into a pipe 6, of an ozone generator e having an inlet
connected to the air pipe and an outlet to a pipe d, of an alternating current
dynamo electric generator driven from the source of power and supplying electric
current to the induction apparatus or secondary generator, of the electrical
induction apparatus or secondary generator for supplying a high potential current
to the ozone generator c, of the retort e connected at one end to the ozone pipe d
and to a steam supply pipe and at the other end to a nitrogen pipe g and oxygen
pipe h, the pipes d, f, g, h being each provided with a suitable cock, of a furnace i
for heating the retort e, of the scrubber or washer / connected to the oxygen pipe h
and to a pipe m, and of an oxygen reservoir n connected to the pipe m.
3
The ozone generator e contains a number of glass or other insulating plates
arranged parallel to one another in the case c and the air forced into the apparatus
by the fan or pump a is caused to pass evenly between these plates by means of a
perforated plate. The plates o are varnished with suitable insulating varnish and
are coated on their upper sides with tin or other metallic foil which is perforated
so as to allow any air underneath the foil to escape readily when the plates are
heated by the passage of the current and to roughen the surface and thus facilitate
the electric discharge. The metallic foils on the plates are alternately connected
to two conductors leading to the terminals of the high potential circuit of the
induction apparatus whose low potential circuit is connected to the terminals of the
dynamo electric generator.
The retort e in the furnace is filled with a compound capable of readily
absorbing free oxygen from the air and of giving it up again under the action of
heat and a current of steam, such as commercial manganate of soda which may be
mixed with oxide of copper.
The operation is as follows:
P
2
The furnace is lighted and the retort e evenly heated, the cock
of the ozone
pipe d and the cock g of the nitrogen pipe g are closed and the cock of the oxygen
pipe is opened; steam is then turned on by means of the cock o in the steam pipeƒ
and is absorbed by the heated compound in the retort e; the compound giving off
a portion of its oxygen which passes by the tube through the scrubber or
washer e, where it is purified, to the gas holder or reservoir n. When no more
oxygen is given off, the steam is turned off and the retort if necessary further

page_text: heated to drive off the excess of moisture; and afterwards the cocks o and r being
shut, the cocks p and q are opened, the dynamo electric generator is operated and
the electric current turned on to the induction apparatus and a high potential
current thus passed to the ozone generator e; the fan is then put in operation and
passes a current of air through the ozone generator e, where a portion of the
oxygen is converted into ozone; and by the pipe the ozonised air is conveyed to
the retort e, where a portion of the oxygen of the ozonised air is absorbed by the
heated compound in the retort, and nitrogen mixed with more or less, oxygen given
off by the pipe When the compound has absorbed sufficient oxygen or is
saturated, the cocks and y are closed, and the cocks o and opened and the
absorbed oxygen driven off as before, the operations being repeated indefinitely.
If desired the steam may be superheated.
A suitable arrangement of retorts for rendering the process continuous, is shown
in Figs. 2 and 3, in which by suitably operating the steam cocks o, ozone cocks p,
nitrogen cocks and oxygen cocks, one vertical set of retorts is caused to give
off oxygen whilst a second set is being dried, a third set is absorbing oxygen and
the fourth set idle, these sets being interchangeable at pleasure so that oxygen is
always being given off by one or more sets.
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
In the manufacture of oxygen, oxydising a compound capable of readily
absorbing free oxygen and of again giving it up, by means of a current of
ozonised air substantially as described.
Dated this 10th day of August 1891.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.