Improvements in the Production of Ozone and in Apparatus. therefor.
Year: 1894

page_text: Date of Application, 17th Mar., 1894
Complete Specification Left, 11th Dec.. 1894-Accepted, 12th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Production of Ozone and in Apparatus.
therefor.
We, AUGUST SCHNELLER, of Aarlanderveen-Alfen, near Leyden, Engineer,
and WILLIAM JOIN WISSE, of Haarlem, in the Kingdom of Holland, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention has reference to improvements in the production of ozone and in
apparatus therefor.
a.
One method of manufacturing ozonized air by means of electricity on
commercial scale has been to cause dark or silent discharges between conducting
surfaces, the air situate between the said conducting surfaces being the only
resistance which the current had to overcome; also the ozonization of air has been
effected by supplementing the resistance of the air by means of other resistances
placed between the discharge-surfaces, e.g. glass, so as to prevent the formation of
voltaic arcs between the conducting surfaces and secure the necessary dark
discharges.
-
The latter object has been attained by surrounding one or both of the conducting
discharge wires with a glass-tube, so that the dark discharges between the
discharge-wires had to overcome the resistance of the glass-tubes as well as that of
the layers of air within and between such tubes.
Both of these methods of ozonization have the disadvantage that the production
of voltaic arc is not prevented with certainty when there are fluctuations of current
and this is of especial importance when currents of high tension are employed.
Now, it has been found by experiment, that a regular ozonization of the air by
means of currents of high tension (over 4000 volts), can only be effected by
preventing the formation of voltaic arcs by inserting a specific resistance in the
circuit between the source of the current, for example, a transformer for currents
of high tension, and the discharge-surfaces, by which means the required dark
discharges are produced between the discharge-surfaces. The said resistance acts
as a regulator to secure the production of the dark discharges between the
discharge-surfaces by reason of its restricting the quantity of current passing
through the circuit so that with a fixed distance between the discharge-surfaces.
formation of voltaic arcs cannot take place through the air situate between the
said surfaces.
We are, of course, aware that resistances are already employed in the most
varied manner in electrical apparatus for the regulation of the intensity of currents,
but so far as we are aware, no one prior to this invention has perceived the
necessity in the transformation of currents of low tension into currents of high
tension for use in the production of ozone, of regulating the quantity of current
employed so as to ensure dark discharges between the discharge-surfaces, or that
the insertion of a specific resistance in the circuit between the transformer and the
discharge-surfaces renders unnecessary the insertion of a di-electric, for example
glass between the discharging-surfaces.
The method and apparatus heretofore usually employed for the formation of
ozone, will be hereinafter more fully explained in order that the improvements
forming the subject of this application may be clearly understood.
When it was ascertained by experiment that ozonization took place during dark

page_text: discharges of electric currents, it was endeavoured to make use of this fact for
manufacturing ozone on a large scale. The process, however, could not be utilized
on a commercial scale as, in consequence of the use of a transformer, the tension of
the current naturally fluctuated with the result that not only were electric sparks
produced but voltaic arcs were readily formed, which prevented the glowing-
discharges and consequently also the formation of ozone.
As herein before staied attempts have been made to prevent the formation of
voltaic arcs between the discharge-surfaces by inserting a dielectric between them,
the said surfaces, when of wire, having for this purpose, been each surrounded by a
glass-tube. By the use of a dielectric in the manner described the formation of
voltaic arcs was obviated to a limited extent, as with careful selection of the glass
tubes, dark discharges were obtained in consequence of the great resistance of the
dielectric (glass) employed. It soon, however, became obvious that the glass tubes
were not of uniform cross section and contained cracks, cleavages or flaws, the
consequence of this irregularity in the material being easy and frequent breakage
of the tubes. Furthermore the use of these intermediate layers of dielectric
material, owing to their enormous resistance, necessitated a very great waste of
electric energy which was lost for the formation of ozone.
Now our present improvements in the production of ozone obviate the necessity
of inserting glass between the discharge-surfaces in ozonization apparatus by the
employment of one or more specific resistances between the source of current and
the discharge-surfaces.
It is advantageous to employ for the discharge-surfaces, perforated plates, sieves,
or wires arranged parallel or cross-wise to one another.
In the accompanying drawings,
Figs. 1 and 2 are sectional views at right angles to each other, showing an
arrangement of apparatus that has been found to give satisfactory results in
practice.
From one terminal of the source of current, for example, the closed transformer t,
a conductor leads to a resistance w of say 1-5 megohm which consequently, with a
tension of 15,000 volts, only itself allows 001 ampere to pass, and thus in con-
junction with the resistance of the fixed air space between the discharge-surfaces,
allows only of the passage of so small a current that a continuous voltaic are cannot
be produced between the said discharge-surfaces.
From this resistance to a conductor leads to the discharge-surfaces e, e¹, e³.
which are made of perforated sheet metal and are arranged at a predetermined
distance of say 14 cm. from the perforated sheets of metal i,, which are arranged
parallel thereto and are connected to the other terminal of the transformer by the
conductor .
...
There is in this case a single resistance w for the common conductor . There
may, however, and this will specially recommend itself in order to work in, a
practical manner, be separate resistances for the several conductors and discharge
surfaces. Such an arrangement is represented in Figs. 3 and 4 of the drawings
which are respectively a cross section of the apparatus and a plan with the cover
removed. From the transformer t the conductor leads by means of the wires *,
1,14.
to the separate resistances to.. with which the wires ... are connected
and which may be arranged in tubes of insulating material such for example as
glass. At the lower end of each resistance w¹ is secured a conducting body or
plug p which is brought into intimate connection with the resistance w', so that the
several plugs p... serve as discharge-surfaces, whilst the perforated sheet of
metal n forms the opposite discharge-surface. Through the holes n'... of this
sheet of metal passes the air from between the glass tubes which, as shown, are
arranged parallel to each other and so as to leave between them spaces V. The
air consequently passes in the most diverse directions through the space traversed
by the dark discharge.
In this construction the resistances W₁ are arranged separately for each of the
discharge-surfaces p and this arrangement possesses the advantage that the ozone-

page_text: apparatus is capable of sustaining a considerably greater density of current than
formerly, without fear of formation of electric arcs. More ozone or concentrated
ozonized air can, therefore, be produced in a given time than would otherwise be
the case.
This separation of the resistances can, of course, be effected with the arrangement
represented in Figs. 1 and 2; and, of course, resistances may be placed in direct
connection with each of the discharge-surfaces.
Instead of the glass tubes shown in Figs. 3 and 4, a modified construction with
separate glass-strips between the resistances may be employed.
Instead of the ozonization of ordinary air, pure oxygen, or another gas containing
oxygen may, of course, be transformed into ozone in apparatus constructed as
described.
Improvements in the Production of Ozone and in Apparatus
thèrefor.
We, AUGUST SCHNELLER, of Aarlanderveen-Alfen, near Leyden, Engineer,
and WILLIAM JOHN WISSE, of Haarlem, in the Kingdom of Holland, 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 has reference to improvements in the production of ozone and in
apparatus therefor.
One method of manufacturing ozonized air by means of electricity on a commercial
scale has been to cause dark or silent discharges between conducting or discharging
surfaces, the air situate between the said discharging surfaces being the only
resistance which the current had to overcome. Also the ozonization of air has
been effected by supplementing the resistance of the air by means of other
resistances for example, glass, placed between the discharge surfaces so as to
prevent the formation of voltaic arcs between the conducting surfaces and secure
the necessary silent discharges.
The latter object has been attained by surrounding one or both of the conducting
or discharging wires with a glass-tube, so that the silent discharges between the
said wires had to overcome the resistance of the glass tubes as well as that of the
layers of air within and between such tubes.
Both of these methods of ozonization have the disadvantage that the production
of voltaic arcs is not prevented with certainty when there are fluctuations of current
or of electro motive force and this is of especial importance when currents of high
tension are employed.
Now, it has been found by experiment, that a regular ozonization of the air by
means of currents of high tension (over 4000 volts), can only be effected by
preventing the formation of voltaic arcs by inserting a suitable resistance in the
circuit between the source of the current, for example a transformer for currents
of high tension, and the discharge surfaces by which means the required silent
discharges are produced between the said discharge surfaces.
The said resistance acts as a regulator to secure the production of the silent
discharges between the discharge surfaces by reason of its restricting the quantity
of current passing through the circuit so that with a fixed distance between the

page_text: discharge surfaces, formation of voltaic arcs cannot take place through the air
situate between the said surfaces.
We are of course aware that resistances are already employed in the most varied
manner in electrical apparatus for the regulation of the intensity of currents, but
so far as we are aware, no one prior to this invention has perceived the necessity in
the transformation of currents of low tension into currents of high tension for use
in the production of ozone, of regulating the quantity of current employed so as
to ensure silent discharges between the discharge-surfaces or that the insertion of a
suitable resistance in the circuit between the transformer and the discharge-surfaces,
renders unnecessary the insertion of a dielectric, for example glass between the
said discharge surfaces.
The method and apparatus heretofore usually employed for the formation of
ozone, will be hereinafter more fully explained in order that the improvements
forming the subject of this application may be clearly understood.
When it was ascertained by experiment that ozonization took place during silent
discharges of electric currents, efforts were made to utilise this fact for manufacturing
. ozone on a large scale. The process however could not be utilized on a commercial
scale, as in consequence of the use of a transformer, the tension of the current
naturally fluctuated, with the result that not only were electric sparks produced,
but voltaic arcs were readily formed, which prevented the silent discharges and
consequently also the formation of ozone.
As herein before stated attempts have been made to prevent the formation of
voltaic arcs between the discharge-surfaces by inserting a dielectric between them
the said surfaces when of wire, having for this purpose, been each surrounded by
a glass tube. By the use of a dielectric in the manner described, the formation of
voltaic arcs was obviated to a limited extent, as by careful selection of the glass-
tubes, silent discharges were obtained in consequence of the great resistance of the
dielectric glass employed. It soon however, became obvious that the glass-tubes
were not of uniform cross section, and that they contained cracks, cleavages, or
flaws, the consequence of this irregularity in the material being easy and frequent
breakage of the tubes. Furthermore the use of these intermediate layers of
dielectric material, owing to their enormous resistance, necessitated a very great
waste of electric energy which was lost for the formation of ozone.
Now our present improvements in the production of ozone obviate the necessity
of inserting glass between the discharge surfaces in ozonization-apparatus, by the
employment of one or more suitable resistances between the source of current and
the discharge surfaces.
It is advantageous to employ for the discharge-surfaces, perforated plates, or
wires arranged parallel or to one another, or woven, as in sieves so as to be crosswise
to cach another.
In the drawings filed with our Provisional Specification,
Figs. 1 and 2 are sectional views at right angles to each other, showing an
arrangement of apparatus that has been found to give satisfactory results in
practice.
From one terminal of the source of current, for example, the closed transformer t,
a conductor leads to a resistance w of say 1-5 megokin which consequently, with
a tension of 15,000 volts, only itself allows 001 ampere to pass, and thus in
conjunction with the resistance of the fixed air space between the discharge-
surfaces, allows only of the passage of so small a current that a continuous voltaic
are cannot be produced between the said discharge-surfaces.
From this resistance w a conductor / leads to the discharge-surfaces e, e¹, e³..
which are made of perforated sheet-metal and are arranged at a predetermined
which are
distance of, say 14 cm. from the perforated sheets of metal i, 1, 3,
arranged parallel thereto and are connected to the other terminal of the transformer
by the conductor P.
.
There is in this case a single resistance w for the common conductor . There
may, however, and this will specially recommend itself in order to work in a

page_text: practical manner, be separate resistances for the several conductors and discharge-
surfaces. Such an arrangement is represented in Figs. 3 and 4 of the said drawings
and which are respectively a cross section of the apparatus and a plan, with the
cover removed. From the transformer t, the conductor / leads, by means of the
wires 1, 1, 1, . . . . to the separate resistances W₁ which may be arranged in
tubes of insulating material such for example as glass. At the lower end of each
resistance W' is secured a conducting body or plug p which is brought into intimate
connection with the resistance W' so that the several plugs p
serve as
discharge-surfaces whilst the perforated sheet n of metal or woven wire forms the
opposite discharge-surface. Through the holes n¹. . . of this sheet of metal or
woven wire passes the air from between the glass-tubes or bars which serve to keep
the discharge surfaces or electrodes at equal distances from and parallel to each
other and so as to leave between them spaces V. The air consequently passes
through the space traversed by the silent discharge.
In this construction the resistances Ware arranged separately for each of the
discharge-surfaces p and this arrangement possesses the advantage that the ozonising
apparatus is capable of sustaining a considerably greater density of current than
formerly, without fear of formation of electric arcs. More ozone or concentrated
ozonised air can, therefore, be produced in a given time than would otherwise be
the case, especially when the air is also either before or during its passage through
the apparatus, dried purified and cooled.
Instead of the glass-tubes shown in Figs. 3 and 4, the construction may be
modified by the use in lieu of such tubes, of separate strips of glass or other
non-conducting material arranged between the resistances either vertically, or
horizontally or in an inclined position.
Fig. 5 of the accompanying drawings shows in vertical section, a further modified
construction of ozonising apparatus according to this invention and which has
been found to give very satisfactory results in practice. In this arrangement the
separate resistances
connected with the conductor are arranged outside the
ozonising chamber a, and the wires connecting them and the conductor with
the discharge surfaces e, e¹, e² etc. and i, i, respectively located inside the said
chamber, are led through holes in the top and bottom of the chamber as shown.
If the said discharge surfaces are formed of metallic webs, the air to be treated is
caused to enter at b and flow through a perforated plate e and after traversing the
chamber, is allowed to escape through an opening d. The air may, if desired, be
led through several ozonizing apparatus in succession.
The separation of the resistances can, of course, be effected with the arrangement
represented in Figs. 1 & 2; and, of course, resistances may be placed in direct
connection with each of the discharge-surfaces either inside or outside of the
ozonising apparatus.
Instead of the ozonization of ordinary air, pure oxygen or another gas containing
oxygen may, of course, be transformed into ozone in apparatus constructed as
described.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :--
1. The herein described method of ozonizing oxygen or gas containing oxygen
by passing the gas or mixture of gases directly between discharge surfaces separated
only by the gas or gases to be treated and connected with the poles or terminals of
au electric generator, such as a transformer, capable of producing a current of high
tension, and placing a resistance or resistances in the electric circuit between the
transformer and one or both of the discharge surfaces to prevent the production of
voltaic arcs and to ensure direct silent discharges between the said discharge
surfaces as set forth.
2. For operating in the manner referred to, the combination of unprotected
discharge surfaces, a transformer, and a resistance or resistances arranged in the

page_text: circuit between the said transformer and one or both of the said discharge surfaces,.
substantially as described.
3. In apparatus of the kind referred to in the preceding claim, the use as
discharge surfaces of sheets of perforated metal or woven wire or of wires stretched
parallel or crosswise to each other as described.
4. The improved apparatus for the formation of ozone, constructed and arranged
as hereinbefore described with reference to and shown in Figs. 1 & 2; in Figs. 3 & 4
K of the dusminga
Dated this 11th day of December 1894.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.