Improvements in Apparatus for the Production of Silent Electric Discharges.
Year: 1899

page_text: Improvements in Apparatus for the Production of Silent Electric
Discharges.
I, MARIUS OTTO, of 9, Boulevard St. Denis, Paris, France, Doctor of
Physical Sciences, 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;
In the Specification of Letters Patent previously granted to me and num-
bered 11010 of 1897, I described an apparatus for the production in a continuous
manner of diffused electric discharges. I indicated the advantages possessed by
this apparatus, especially in the preparation of ozone, over known apparatus, in
which, in order to prevent the formation of arcs, short-circuits, and luminous
discharges between electrodes of opposite signs, it is necessary to have recourse
to the employment of fixed dielectrics for separating the said electrodes.
In my aforesaid specification, I pointed out that the characteristic principle
of the invention therein described consisted in a relative arrangement of the elec-
trodes of opposite signs such that the discharge could take place only during
intervals of time sufficiently short to prevent the formation of short circuits and
to break automatically any arcs that might be formed. I pointed out also that
one of the simplest means of producing the successive startings and interrup-
tions of the discharges between the various points of the surfaces of the opposing
electrodes..consisted in moving them relatively to one another--either by giving
both sets a continuous movement, or by giving only one half of them a continuous
displacement relatively to the other half of opposite sign. I also described various
means by which this principle might be carried into practice.
Now this present invention relates to apparatus for attaining the same object
as the apparatus with movable electrodes described in my aforesaid specification_
that is to say, the bontinuous production of diffused electric discharges in the
apparatus.
The fundamental principle-that is to say, the gradual and successive start-
ings..and interruptions of the discharges between the various opposing points of
the electrodes of the apparatus-remains unchanged, but the means of practically
realizing the same that I employ in the apparatus that I am about to describe,
are different..
For the production of the gradual and successive startings and interruptions
of the discharge, I arrange movable separating discs between the fixed electrodes.
These separating discs are divided into sectors such that their passage between
the opposing faces of the electrodes successively allows the discharge to take place,
or on the contrary renders the discharge impossible.
It will be readily understood that if the electrodes of opposite signs are suffi-
ciently far apart that normally, unless the surrounding gaseous medium be heated,

page_text: the discharge cannot occur between them, although the discharge would become
possible if a conducting disc of suitable thickness were interposed, it will be suffi-
cient in order to bring about the gradual and successive startings and interrup-
tions of the discharge to cause a conducting disc with alternate full sectors and
open sectors to move betweeen the electrodes so arranged at a distance. On the
other hand if the electrodes of opposite signs are normally so close together as to
permit the discharge to take place between them, the gradual and successive start-
ings and interruptions can be produced by the passage between these electrodes
of an insulating disc of suitable thickness with alternate full sectors and open
sectors.
I have shown, by way of example, in the accompanying drawings, apparatus
for producing electric discharges constructed in accordance with these principles
and capable of being utilized in the industrial preparation of ozone and other
gases.
Fig. 1 is a longitudinal section and Fig. 2 an end elevation of an apparatus for
interrupting and starting the discharges in which the electrodes of opposite signs p
and n are sufficiently far apart to render all direct occurrence of the discharge be-
tween the points of these electrodes impossible. The apparatus comprises a cast
iron box b divided into a certain number of similar compartments by partitions c
cach having a central orifice d for the circulation of the gas.
Each compartment has two electrodes p and n fixed respectively to the two
partitions of the compartment, the two end electrodes being fixed to the inner sides
of the end walls of the box b.
Two metallic conductors f, r, are arranged in corresponding insulating sleeves ĝ,
h. The electrodes are connected by a wire e to the conductor f and the elec-
trodes n by a wire to the conductor r the current being taken from the ex-
tremities of the conductors f, r, by means of binding screws k.
The electrodes (of which one is shown in detail in Fig. 5, which is a cross
section according to the line A B of Fig. 1) may, for instance, each be com-
posed of metallic sectors provided with points u connected at their upper parts by
a ring, the disc as a whole being fixed to an insulating disc m which is itself fixed
to the partition c. Instead of points u, there can be arranged on the metallic
sectors P and a bevelled blades, which may be considered as points placed infinitely
near together along radii as shown at vin a portion of Fig. 5 or along arcs as
shown at in another portion of the same figure.
On the shaft a of the apparatus are mounted, midway between the electrodes p
and n, separating discs (Fig. 4). These discs consist of a conducting plate
having alternately full sectors i and open sectors y. The number of the full
sectors is equal to the number of the point sectors of the electrodes. The sectors y,
instead of being entirely open, can be provided with a very thin sheet of insulating
material; in this way each disc i makes a more complete baffle for the circulation
of the air or the oxygen, which enters through the orifice o, to be collected as
ozone at s.
The discs being rotated by the shaft a the discharge passes between the points
of the electrodes p and n so long as the full sectors of the discs are between
these points; but as soon as an open sector y comes between them, the discharge
is interrupted.
In the example shown in Fig. 3, the electrodes and are normally suffi-
ciently close together to enable the discharge to pass between their points without
the interposition of a conductor. In this case the discs i are consequently com-
posed of insulating plates having alternate full sectors and open sectors the open-
ings of which can be covered with a very thin conducting sheet.
It is obvious that the details of construction, such as the number, the shape,
and the relative dimensions of the electrodes, and the arrangement of their con-
ducting surface, may vary, and that such variations may result in corresponding
modifications in the details of the movable separating discs i.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:
The hereinbefore described improved apparatus for the continuous production
of diffused electric discharges, on the principle of successive startings and inter-
ruptions indicated in my aforesaid specification in which the successive and gradual
startings and interruptions of the discharges are caused by the arrangement, be-
tween the fixed electrodes, of movable separating discs having alternately con-
ducting and insulating sectors, or more generally, having alternate sectors such
that whilst one sector allows the discharge to pass between the electrodes before
which it moves the following sector interrupts this discharge and thus automati-
cally prevents the dangerous short-circuits that might otherwise occur.
Dated this 30th dow of March 1800
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant