A New Process for Producing Oxygen Gas.
Year: 1891

page_text: Belgium).
Date of Application (in United Kingdom), 19th Feb.; 1891
Complete Specification Left, 22nd July, 1891-Accepted, 29th Aug., 1891
Date of Application (in United Kingdom), 19th Feb., 1891
Complete Specification Left, 22nd July, 1891-Accepted, 29th Aug., 1891
PROVISIONAL SPECIFICATION.
A New Process for Producing Oxygen Gas.
I FERDINAND FANTA of 85 and 87 Gresham Street in the City of London
Consulting Engineer do hereby declare the nature of this invention to be as
follows:
The object of this invention is to provide new and improved means of producing
a continuous and cheap supply of oxygen in large quantities, and more especially
to render the process practical and reliable in making it independent of delicate
chemical reactions which only take place at certain temperatures.
The only process employed at present for producing oxygen on a large scale,
consists in heating barita or oxide of barium over which a current of air is passed
thus oxidating the material. When the barita has thus been oxidated, the heat is
still more increased, and the tubes or retorts containing the material are submitted
to a vacuum, whereby the oxygen is made free and may be stored in a gasholder
or similar vessel for this purpose.
This process however, presents grave inconveniences in practice in consequence
of the extreme difficulty to maintain the right temperature, both during the
oxidating and deoxidating periods, and unless these temperatures be closely watched
and so maintained, the generation is greatly impaired if not entirely stopped.
On the other hand, the material in the retorts or tubes, has great tendency to
adhere to same through its caking inside the tubes, and in this way the passage of
the air is more and more impeded as the plant is being used, so that after a very
short time both tubes and material must be replaced.
The barita is, moreover,
expensive, and not obtainable in all markets.
A number of other means have been of late years described by chemists in their
books, and among these the most reliable would seem to be based on the property
of certain minerals to absorb the oxygen contained in the atmospheric air.
The process subject of this Specification is, on the contrary, based on the well
known fact which has been indicated years ago by Prof. Bloxam, Prof. Herman
Kolber, Prof. Schützenberger, etc. that manganates of soda or of potash, when
treated in a current of steam, give up part of their oxygen, leaving a residue of
oxides of manganese and caustic soda or potash.
Taking this fact into consideration in connection with the equally well known
principle that oxides of manganese when treated in contact with alkalies and air,
are capable of absorbing the oxygen of the air in forming (in consequence of the
presence of free nitrogen) manganates and nitrogen, I devise an apparatus by means
of which currents of steam and of air are alternately passed over manganate of
soda and the residue respectively.
The process and the combination referred to have been clearly pointed out in
works on chemistry and I do not claim any part of same.
I find however that although the reactions do take place singly, as indicated
above, these principles do not by themselves allow of an uninterrupted and
commercial supply of oxygen gas in consequence :-

page_text: 1, of the caking of the material in the tubes.
2, of the condensing of the steam when passed over the said material in the
colder tubes.
3, of the expansion and contraction of the tubes resulting from the rapid changes
of temperature.
Having thus explained the principle on which my invention is based, and the
inconveniences to which this principle leads in practice, I will now proceed to
show how I overcome same, and specify the means I employ in order to obtain this
object.
,
In the first instance I prepare the manganate in such a way as to render its
caking impossible, in other words I render it non-fusible. I attain. this in heating
this manganate to a comparatively high degree, and generally until it is in a state
of complete fusion. I then break this mass to minute pieces, and add to it a
suitable quantity of caustic soda or potash, and submit this mixture to heat. I
reduce the mass, when cold, to a granular state. The material is now ready for
insertion and will not fuse nor cake in the tubes, but will readily give up its oxygen
when heated in a suitable current of steam. This manganate which, through the
passage of steam, and through heat, is reduced to a sesqui oxide of manganese and
caustic soda, is now regenerated by the passage of air, in consequence of which the
sesqui oxide of manganese under the influence of heat, in the presence of nitrogen,
is transformed into manganate of soda and nitrogen, whilst the oxidation of the
sesqui oxide has taken place in the tubes.
The process is, as will be seen, a continuous one and may be repeated almost
indefinitely.
The manganate which I make use of and prepare, as described before, may be
obtained either by oxidation by air of a sesqui oxide of, manganese, or by an
admixture of peroxide of manganese and of chlorate of potash, or by any other
known process.
To obviate the inconveniences referred to above under 2 and 3, I construct a
furnace in which I insert not only a double series of tubes containing the material
(one of each of these series is under the influence of steam whilst the other series
of tubes is under the influence of air,) but I also provide this furnace with two
appliances very similar to each other, one of which I use for the purpose of, over-
heating the current of air, and the other one of which I employ to overheat the
current of steam, previous to their being admitted into the tubes.
In this way I maintain the whole system at the same temperature and I moreover
greatly facilitate the reaction by decomposing the steam into its component elements
before it reaches the manganate, and prevent the moisture which would be caused
by the condensing of the steam, from counteracting, or destroying the effectiveness
of the caustic soda.
Dated this 10th day of Februa 1891
COMPLETE SPECIFICATION.
A New Process for Producing Oxygen Gas.
I, FERDINAND, FANTA Consulting Engineer of 85 and 87 Gresham Street in
the City of London, 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 object of the present invention is to provide new and improved means of
'producing a continuous and cheap supply, of oxygen, in large quantities, to render
the production practical and reliable, and more especially to make same independent
of delicate chemical reactions..
The only process employed at present for producing oxygen on a large scale,
consists in heating barita or oxide of, barium, whilst passing over same a current of

page_text: air thus oxidating the material. When this barita has been oxidated, the heat is
still more increased and the tubes or retorts containing the material are submitted
to a vacuum, whereby the oxygen is made free and may be stored in a gas holder
or similar vessel provided for the purpose.
The inconveniences appertaining to this mode of operating are self evident, since
it is not only difficult to regulate the temperatures, but also because at such high
temperatures the material freely cakes and adheres to the retorts containing it, thus
intercepting the passage of air and considerably reducing the oxidating power of
same.
Several other means for obtaining oxygen from the atmospheric air have been
advocated; but have never been adopted commercially, in consequence of the facility
with which the material cakes, adheres to the retorts, and in fact renders the
continuation of the working impossible.
The process subject of the present Specification is based on the principle that
manganates of soda when heated, and intimately mixed with a current of steam,
give up a certain amount of their oxygen, thus becoming reduced to sesqui oxides
of manganese, and that such residue may be regenerated by heating the material
in the presence of a current of air thus again forming manganates.
22
This principle, which forms the basis of the process known as the "Tessier du
Motay process, has however not met with any success in consequence of the
material melting and caking in the retorts, thus preventing the passage of air, and
preventing same from oxidating as it should this material in all its parts.
This melting and caking of the material is further brought on by the moisture
introduced into the retorts, not only by the steam, but also by the dampness of the
atmospheric air, which latter in entering the tubes becomes condensed therein in
consequence of the differences of temperature, viz.: when the material is over-
heated the rapid creation of steam caused by the moisture of the air acts as a
reducing agent, whilst when the material is colder than it should be, the moisture
of the air passed over same gradually renders same soft, resulting in the baking or
caking of same.
The same inconvenience also occurs when steam is introduced into the retorts,
thus rendering the process unreliable and greatly impeding if not stopping the
production of oxygen altogether.
To avoid these difficulties and in, order. to make the process reliable and
continuous, the material viz. manganate of soda employed according to the present
invention is, previous to its insertion into the tubes, treated in a special manner for
the purpose of rendering it granular and non-fusible; and to attain this object it is
prepared in the same way and under the same circumstances, as those under, which
it will eventually have to be acted upon during the process of production of oxygen
as hereinafter described.
In order moreover to avoid any changes of temperature, both during the time
when air or when steam is being passed over the material, and with the object of
avoiding the inconveniences of condensing the moisture suspended both in the air
and in the steam, and brought about mainly by the difference of temperature
between such material in the air or the steam, the present invention provides.for an
apparatus by means of which the material, as well as the air and the steam, are
submitted to the same heat and kept at the same temperature, previously to either
the steam or the air as the case may be coming into contact with the material..
The manganate of soda or potash which I use for inserting into the retorts or
producing tubes is prepared as follows
The manganate is carefully mixed with a small quantity of water in which about
5% in weight of caustic soda has been dissolved until a thick paste is obtained;
and this mixing is best done mechanically by any well known means to assure
perfect, homogeneity. This, paste is next, submitted to, slow heat, for evaporation
under occasional stirring. When evaporated the material, which having been
heated in a shallow evaporating pan takes the form of a tablet, is then when col!
reduced to small fragments; it is hereafter in this reduced granular state submitted

page_text: to considerable heat, when it will be absolutely porous and will readily allow the
oxidating air and the de-oxidating steam to penetrate into its pores, and will neither
fuse nor cake even at a very high temperature, and not unless such temperature by
far exceeds that under which it has thus been prepared.
I
In order to further maintain the temperatures constant throughout the process,
and also in order to obtain a continuous and uninterrupted supply of oxygen,
provide an apparatus mainly composed of a furnace in which are inserted a heating
appliance for the air, a superheater of steam, and two independent series of tubes
or retorts containing the prepared material. In this way one of the series is
traversed by superheated steam, the effect of which is to de-oxidate the manganate
of soda in reducing it to sesqui oxide of manganese, in giving up oxygen which is
collected in a gasholder after having passed through a cooling apparatus, and also
through a washing appliance, whilst the second series is simultaneously traversed
by heated air for the purpose of regenerating or re-oxidating the sesqui oxide of
manganese contained therein, same being the result of a previous operation.
It will be seen from the above, that if a continuous stream of superheated steam
and a continuous supply of heated air be kept up, and if steam is applied to one of
the series whilst air is applied to the other and vice versa continuously, an
uninterrupted and continuous supply of oxygen will be obtained without any
possible change of temperature, in consequence of the steam, the air, and the
material heating appliances being all contained in the same furnace and under the
influence of the same heat.
The process is thus rendered continuous and may be repeated indefinitely.
The superheating of the steam has not only the advantage of assimilating the
temperatures but also of decomposing same into its component elements, thus
greatly facilitating the de-oxidating process.
Although the proportions of caustic soda used in the preparation of the material
are indicated above as accurately as possible, I do not bind myself to same exactly,
nor do I restrict myself to a particular way of preparing the material in all its
details; but I have found by a series of experiments that the mode as specified is
most, suitable.
Having now particularly described the nature of my invention, and the means
which I employ in the process for the production of oxygen subject of the present
Specification, I claim :—
1. The preparation and use of material specially prepared and rendered non-
fusible for the production of oxygen substantially as described.
2. The combination and use in connection with material prepared mainly as
described and claimed in Claim 1. of steam and air as de-oxidating and oxidating
agents of such material for the purpose of such production of oxygen substantially
as described.
3. The combination and use of steam and air alternately for the purpose set forth
and claimed in Claim 2, both steam and air being heated previously to their being
used for such purpose substantially as described.
4. The use of superheated steam in the production of oxygen substantially as
described.
5. The construction and use of two sets or series of generating tubes
simultaneously traversed one by steam whilst the other is so traversed by air and
vice versa alternately for the purposes set forth substantially as described.
6. The construction and combination of a double set of generating tubes for the
purpose set forth and claimed in Claim 5, and combination with a heating apparatus
for the air, and a superheater for the steam the whole substantially as described.
Dated this Twenty-second day of July Eighteen hundred and ninete_one