Improvements in and relating to an Apparatus and a Method for Causing Chemical Changes of Gases and Mixture of Gases by Dark Electric Discharges.
Year: 1894

page_text: Date of Application, 1st Dec., 1894
Complete Specification Left, 5th Feb., 1895-Accepted, 16th Mar.. 1895
PROVISIONAL SPECIFICATION.
Improvements in and relating to an Apparatus and a Method for
Causing Chemical Changes of Gases and Mixture of Gases by
Dark Electric Discharges.
We, NICOLAAS VAN DER SLEEN, Chemist, and AUGUST SCHNELLER, Engineer,
both of Alfen-Oudshoorn, in the Kingdom of Holland do hereby declare the nature
of this invention to be as follows:-
The apparatus known up to now for causing chemical changes of gases, and
mixtures of gases, as for instance for ozonising air or oxygen, have in the practical
use met with general approval, in that a continuous working was made possible by
them, and the quantity of the ozone or other gas produced by them was in fact
corresponding to the quantity of energy consumed. Therefore, the production of
ozone or other gases by means of dark electric discharges could be carried out on a
commercial scale, and with a favorable commercial result.
What, however, has not been attained up to now, is bringing, with the expense
of a given quantity of energy, the quantity of gas produced in correspondence to
the degree of concentration demanded; that is to say, it has not been possible to
produce with the expense of a given quantity of energy an equally great quantity
of ozone or other gas, if a greater degree of concentration was demanded for the
same. One has tried to obtain a greater degree of concentration by letting the gas
treated already by one apparatus pass through another or through more other
apparatus; but the quantity of ozone or other gas produced by the second, third, etc.
apparatus is far from being the same as that produced by the first apparatus,
provided, the quantity of energy consumed by the subsequent apparatus is equal to
that of the first.
According to the present invention, any desired concentration of the ozone or
other gas produced by the simultaneous application of two or more apparatus may
be obtained by inserting a cooling device between each two of the electric gas-
generating apparatus. Therefore, the oxygen, air or other gas or mixture of gas
treated, or produced, by the first appiratus, and having reached a certain degree of
concentration, is cooled, before it is allowed to enter the second apparatus; after
the concentration of the respective gas has been increased by said second
apparatus, the said gas is again cooled before allowed to enter the third apparatus,
and so on.
This procedure is to be well distinguished from that consisting in cooling the
discharging plates or poles of the apparatus, in that the said latter procedure is in
some sorts of apparatus necessary for preventing the heated dielectric from being
There is, it is true, also an extremely slight
destroyed by the electric current.
cooling of the gas gained by cooling the dielectric; but that is not the purpose of
cooling the latter. In every process of chemically changing a gas or gases by
dark electric discharges, the energy of the latter is transforined not wholly into
latent heat bound to the ozone or other gas, but part of said heat. becomes
sensible, and is communicated to the poles as well as to the air, oxygen or other
pas treated.

page_text: In cooling the poles, there is destroyed the heat imparted to the poles only;
according to the present invention, however, the heat imparted to the air, oxygen
or other gas is to be destroyed, too, before another treatment within another
apparatus can take place. Čooling the poles in apparatus without a dielectric
intermediate layer is not necessary at all, as in apparatus of that kind the heating
cannot result in a destruction by sparks getting through.
In combination with the afore described first improvement, the second
improvement consists in inserting, in apparatus without a dielectric intermediate
layer, between one pole of the apparatus and the high-tension transformer a
column of liquid as a specific resistance, for the purpose of preventing the
formation of a voltaic arc, or of sparks, thereby. It is known, that the dark
discharges may be secured by inserting a resistance of suitable height without
allowing sparks or even a voltaic arc to come into existence. There was, however,
the difficulty of keeping the said resistance approximately constant. We have
succeeded in working with a tension of 60000 volts at a distance of 50 m/m between
the poles; the resistances ought in this case to be chosen equal to 20 megohins.
With this arrangement there is obtained between the poles an extremely intensive
field of discharge, there being no sparks or voltaic arcs whatever. Making such
resistances from wire is practically as well as commercially near to impossibility.
Making the said resistances from any other solid material is hindered from the
fact, that the very few materials existing are absolutely unreliable with regard to
their constancy. We, therefore, manufacture resistances of the required kind by
the use of distilled water, glycerine or alcoholic solutions, these being liquors of
good constancy. Resistances of this kind have proved well from a practical as
well as from a commercial point of view. The liquors in question are contained
in glass-tubes connected at one end with the transformer, and at the other end with
one pole of the discharging parts.
In carrying our invention into practice, we cause the air, oxygen or other gas
treated within the first apparatus to flow through a large number of pipes, cooled
by water, cold air or the like and arranged between the said first and the second
apparatus. Similar pipes are arranged also between the second and the third
apparatus, and so on; and we may employ pipes of any requisite length, so as to
make the cooling as energetic as desired. The said pipes, as a matter of course,
may be replaced by any other suitable device, delivering the same effect, and
affording the same advantages. The partition-walls between the electric apparatus
proper and the said cooling devices are connected all to one end of the secondary
coil of the transformer, the other end of which is connected to one end of the
columns of liquid aforementioned. Betwcon cach two of the partition-walls there
are arranged, rectangularly thereto, a number of vertical pole-plates soparated from
each other, and connected each with a separate column of liquid, the connection being
made with the other end of the latter (one end being connected with the transformer,
as above explained).
The height of the column of liquid is dependent partly on the sort of liquor used,
partly on the resistance requisite for the respective form of construction of the
apparatus; said latter resistance is in its turn dependent on the distance between
the poles or pole-plates of the apparatus.
Dated this 29th day of November 1894

page_text: Improvements in and relating to an Apparatus and a Method for
Causing Chemical Changes of Gases and Mixtures of Gases by
Dark Electric Discharges.
We, NICOLAAS VAN DER SLEEN, Chemist, and AUGUST SCHNELLER, Engineer,
both of Alfen-Oudshoorn, in the Kingdom of Holland, 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 stateinent:-
The apparatus known up to now for causing chemical changes of gases, and
mixtures of gases, as for instance for ozonizing air or oxygen, have in the practical
use met with general approval, in that a continuous working was made possible by
them, and the quantity of the ozone or other gas produced by them was in fact
corresponding to the quantity of energy consumed. Therefore, the production of
ozone or other gases by means of dark electric discharges could be carried out on a
commercial scale, and with a favorable commercial result.
What, however, has not been attained up to now, is bringing, with the expense
of a given quantity of energy, the quantity of gas produced in correspondence to
the degree of concentration demanded, that is to say, it has not been possible to
produce with the expense of a given quantity of energy an equally great quantity
of ozone or other gas, if a greater degree of concentration was demanded for the
same. One has tried to obtain a greater degree of concentration by letting the gas
treated already by one apparatus pass through another or through more other
apparatus; but the quantity of ozone or other gas produced by the second, third, etc.
apparatus is far from being the same as that produced by the first apparatus,
provided, the quantity of energy consumed by the consequent apparatus is equal to
that of the first.
According to the present invention, any desired concentration of the ozone or
other gas produced by the simultaneous application of two or more apparatus may
be obtained by inserting a cooling device between each two of the electric gas-
generating apparatus. Therefore, the oxygen, air or other gas or mixture of gas
treated, or produced, by the first apparatus, and having reached a certain degree of
concentration, is cooled, before it is allowed to enter the second apparatus; after
the concentration of the respective gas has been increased by said second
apparatus, the said gas is again cooled before allowed to enter the third apparatus,
and so on.
This procedure is to be well distinguished from that consisting in cooling the
discharging plates or poles of the apparatus, in that the said latter procedure is in
some sorts of apparatus necessary for preventing the heated dielectric from being
destroyed by the electric current. There is, it is true, also an extremely slight
cooling of the gas gained by cooling the dielectric; but that is not the purpose of
cooling the latter. In every process of cheinically changing a gas or gases by
dark electric discharges, the energy of the latter is transformed not wholly into
latent heat bound to the ozone or other gas, but part of said heat becomes
sensible, and is communicated to the poles as well as to the air, oxygen or other
gas treated.
In cooling the poles, there is destroyed the heat imparted to the poles only
according to the present invention, however, the heat imparted to the air, oxygen

page_text: or other gas, is to be destroyed, too, before another treatment within another
apparatus can take place. Cooling the poles in apparatus without a dielectric
intermediate layer is not necessary at all, as in apparatus of that kind the heating
cannot result in a destruction by sparks getting through.
In combination with the afore described first improvement, the second improvement
consists in inserting, in apparatus without a dielectric intermediate layer, between
one pole of the apparatus and the high-tension transformer a column of liquid as a
specific resistance, for the purpose of preventing the formation of a voltaic arc, or
of sparks, thereby. It is known, that the dark discharges may be secured by
inserting a resistance of suitable height, without allowing sparks or even a voltaic
arc to come into existence. There was, however, the difficulty of keeping the said
resistance approximately constant. We have succeeded in working with a tension
of 60000 volts at a distance of 50 /m between the poles; the resistance ought in
this case to be chosen equal to 20 megohms. With this arrangement, there is
obtained between the poles an extremely intensive field of discharge, there being
no sparks or voltaic arcs whatever. Making such resistances from wire is practically
as well as commercially near to impossibility. Making the said resistances from
any other solid material is hindered from the fact, that the very few apparently
suitable materials existing are absolutely unreliable with regard to their constancy.
We, therefore, manufacture resistances of the required kind by the use of distilled
water, glycerine or alcoholic solutions, these being liquors of good constancy.
Resistances of this kind have proved well from a practical as well as from a
commercial point of view. The liquors in question are contained in glass-tubes
connected at one end with the transformer, and at the other end with one pole of
the di charging parts.
In order to make our invention more clear, we refer to the accompanying
drawings, in which similar letters denote similar parts throughout the several views,
and in which:
Fig. 1 is a perspective view of the whole apparatus,
Fig. 2 is a horizontal section through the right hand portion of the lower part of
the apparatus ;
Fig. 3 is a vertical longitudinal section through the left hand portion of the lower
part of the apparatus ;
Fig. 4 is a vertical cross-section taken on line 6-7 of Fig. 3; and
Fig. 5 is a vertical cross-section through the whole apparatus.
The apparatus is constructed as follows:
A longish casing a having at one end an inlet-pipe b for the gas or gases to be
treated, and at the other end an outlet-pipe b¹ for the gas or gases treated is by
means of partition-walls al divided into a number of chambers cc c²... c (Figs. 2
& 3). Said partition-walls are perforated, and the second and third, the fourth
and fifth, and the sixth and seventh, are connected by parallel tubes d serving as
passages for the gas on its way from one discharging-chamber to the next following
one. Each of the chambers containing said tubes d is communicating with a pipe c
leading water into said chambers, and with a pipe leading that water again off.
The said pipes d are, therefore, constantly cooled whilst the gas passes through
thein.
The discharging-plates f contained within the chambers c¹ c c c are hung in
vertical position to frames g fixed to the lower ends of rods held by the lid or
cover of casing a (compare Figs. 2, 3 & 5). Each of said discharging-plates is
connected to the metallic foot or base i of a glass-tube k (Figs. 1 & 5) containing
the liquor forming the specific resistance afore mentioned. There are in each of
the discharging-chambers six plates f, it is true, and but three tubes k above each
of said chambers; the failing-tubes, however, have been left away for the sake of
distinctness. The several wires running from each set of the tubes to each set of
the discharging-plates are united to a cable led along the respective rod h.
Wires connected all to one wire m (Fig. 1) are hanging down into the liquor

page_text: contained within the tubes k. Said wire m is connected to one end of the secondary
coil of the transformer n; the other end of said coil is connected by means of the
wire o to each of the partition-walls al whereby the circuit is completed. The dark
or silent discharges will, thus, take place between the discharging-plates f of each
chamber, and the partition-walls forming the same, and the gas or gases flowing
through between the said plates f from one partition-wall to the other will thus be
caused to undergo the action of the electric discharges so as to be chemically
changed in the desired way.
The gas to be treated enters the apparatus through pipe b, and flows first into the
fore-chamber c, from which it is distributed by the first partition-wall a' (Fig. 2).
After being electrically treated within the first discharging-chamber c', the gas now
more or less hot is led through the first cooling-chamber c², or through the pipes d
of the same respectively; and, after having been cooled down to its former
temperature (or, perhaps, even to a lower one), the gas is entering the second
discharging-chamber. Owing to the low temperature, the ozonisation or the like
of the gas will now be repeated with exactly the same effect, i.e. the degree of
concentration will be doubled. When the gas has passed all the discharging-
chambers (four in the present case), the degree of concentration will be the fourfold
of what it was in the first chamber.
We wish it to be understood, that the number of the discharging- as well as of
the cooling-chambers employed may be chosen as desired, or according to the degree
of concentration demanded; and that, further, the cooling-devices used may be of
any desired construction. If there are used the cooling-devices shown in the
drawing, the number and length of the pipes may be as desired.
Having thus particularly described and ascertained the nature of our said inven
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The method of causing chemical changes of gases, or mixtures of gases, by
dark or silent electric discharges, consisting in subjecting the gas two or more times
to the electrical treatment, and in cooling the gas between each two consecutive
electrical treatments, for the purpose as described.
2. As a means for causing chemical changes of gases or mixtures of gases, by
dark or silent electrical discharges, the combination with two or more electrical
discharging apparatus, of cooling-devices arranged so as to alternate with said
electrical discharging-apparatus, for the purpose as described.
3. In an apparatus for causing chemical changes of gases, or mixtures of gases,
by dark or silent electric discharges, the combination with two or more electrical
discharging-chambers, of cooling-chambers arranged so as to alternate with said
electric discharging-chambers, for the purpose as described.
4. As a means for causing chemical changes of gases, or mixtures of gases, by
dark or silent electric discharges, the combination with two or more electrical
discharging apparatus containing each a number of separated plates connected each
to a separate specific resistance formed by liquor, of cooling devices arranged so as
to alternate with said electrical discharging-apparatus, for the purpose as described.
5. As a means for causing chemical changes of gases, or mixtures of gases, by
dark or silent electric discharges, the combination with two or more electrical
discharging-apparatus, of cooling-devices arranged so as to alternate with said
electrical discharging-apparatus, and containing each a number of pipes adapted to
lead the gas from one of the said apparatus to the next following one, for the
purpose as described.
6. As a means for causing chemical changes of gases, or nixtures of gases, by
dark or silent electric discharges, the combination with two or more electrical
discharging apparatus containing each a number of separated plates connected each
to a separate specific resistance formed by liquor, of cooling devices containing
each a number of pipes adapted to lead the gas from one of the said apparatus to
the next following one, for the purpose as described.

page_text: 7. In an apparatus for causing chemical changes of gases, or mixtures of gases
by dark or silent. electric discharges, the combination with two or more electrical
discharging chambers cc có c²°. containing each a number of separated
discharging-plates of connected each to a separate specific resistance formed by
liquor, of cooling-chambers c² c c... arranged so as to alternate with said electrical
discharging-chambers, and containing each a number of pipes d adapted to lead the
gas from one of the said discharging chambers to the next following one,
substantially as described.
NICOLAAS VAN DER SLEEN,
AUGUST SCHNELLER,
By Geo. H. Rayner,
37, Chancery Lane, London, Agent for the Applicants.