Note: Descriptions are shown in the official language in which they were submitted.
- ~06~ 3
The present invention relates to production process
of ozone and more specifically to high frequency ozonizers~
Ozone is a very important product having a wide
range of applieation in various branches of industry. For ex-
ample, ozone can be used for purification of potable water and
industrial effluents, for removal of nitrogen oxide and other
toxie gases from environment. Ozone can also be used in various
branches of chemical production, for example in chemical pro--
duction processes based on organic and non organic chemical,
in metallurgy etc.
Known in the art installations for synthesis of ozone
comprise a dielectric in the discharge gap thereof and in
accordance with the type of system used for cooling the di-
electric, these installations are subdivided into installations
without intensive cooling of the dielectric, preferably having
an air-cooled dielectric, and into installations having an in-
tensive liquid cooling system. The installations without an
intensive liquid cooling are intended for operation at fre-
quencies of 50 - 60 Hz and the working capacity of such ozon-
izers is comparatively low~ The installations having an in-
tensive li~uid cooling system for the dielectric are capable
of operating at increased frequencies of about 1000 Hz have a
higher working capacity which can be further increased in
proportion to the frequencyO
Known in the art are a number of embodiments of ozon-
izers having a liquid cooling system for both electrodes.
Said ozonizers have a common housing comprising co-
axially arranged tubular metal low voltage and high voltage
eleetrodes~ The eonjugate surfaces of said electrodes coated
with a dieleetric form a discharge gap, the electric dis-
charge and the ozone generating reaction taking place in said
gap. The low voltage electrodes are cooled with a through
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8~3
flow of a cooling liquid, which flows in a zone formed by the
housing and the low voltage electrode. The high voltage elec-
trodes are cooled with a through flow of gas or liquid into the
tubular æones of the electrodes from the input manifold, being
then discharged from said zones into the output manifold, which
is analogous to said input manifold, providing the supply of
the cooling liquid does not cause short circuit between the
low voltage and high voltage electrodes.
The main disadvantage of this embodiment of an ozon-
izer is complexity of replacement of faulty electrodes.
Another embodiment is an 020nizer comprising a hous-
ing with a low voltage and a high voltage electrodes coaxially
arranged therein.
The low voltage electrode consists of a metal pipe,
a dielectric attached to the inner surface of said pipe and a
metal tubular casing. The space for~ed by the casing and the
metal pipe is provided with metal corrugations.
The high voltage electrode is closed from one end
and is rigidly secured in the high voltage insulator. The zone
formed by the conjugate surfaces those of the dielectric of the
low voltage electrode and of the metal surface of the hi~h vol-
tage electrode form a discharge gap, the reaction of ozone
generating taking place therein.
The low voltage electrode is cooled by a liquid
which flows in the zone formed by the casing of the electrode
and the housing of the ozonizer. Heat from the dielectric to
the casing is removed through a metal pipe secured on the di-
electric and also through the metal corrugations~ The casing of
the high voltage electrode as well as the housing are fastened
between the covers of the ozonizer.
The high voltage electrode has no through direct-
flow cooling. The inflow of the cooling liquid into the zone
843
of the electrode i9 provided through a special pipe arranged
along the axis of the electrode. The ozonizer i5 cooled by oil,
supplied to the electrodes by a special pump.
It should be noted that the above system provides
inadequate cooling of the dielectric resulting from the fact
that the heat from said dielectric is discharged through metal
corrugations, the surface of heat-dissipation of said corruga-
tions being small since the metal pipe secured on the dielectric
has no direct contact with the cooling liquid.
The intensity of cooling of the high voltage elec-
trode is also inadequate owing to a low flow velocity of the
cooling liquid along the surface of the electrode which liquid
is oil rather than water.
Known in the art is another embodiment of a high
frequency ozonizer, wherein saveral ozonizing elements consist-
ing of a glass low voltage and a mekal high voltage tubular elec-
trodes are secured in a common metal casing. The conjugate
surfaces of these electrodes form a discharge gap, the ozone
generating reaction taking place therein at the moment of elec-
tric discharge.
The low voltage electrodes are cooled directly witha ~low of liquid, preferably water, flowing in the zone formed
by the casing of the ozonizer and by the surfaces of the elec-
trodes. The high voltage tubular electrodes having varying
cross-section are mounted in manifolds, through which the cool-
ing liquid is supplied and removed. The coolant, which may be
water, is supplied to the manifolds and remo~ed from said mani-
folds through long pipelines made of a dielectric material. The
manifolds are secured to the bottom of the ozonizer casing by
means of cylinder-shaped gas chambers.
We must point out the complexity of centering the
many high voltage electrodes in the ozonizer relative to the
~89~3
low voltage electrodes, said centering being required to provide
for an even discharge gap along the whole length of the ozoniz-
ing element, because the electrodes are secured in the mani~olds,
thus demanding for centering the manifolds relative to the ozon-
izer casing. Besides, the dismantling of the ozonizer for re-
pair or for replacing the dielectr:ic is a rather complicated
procedure.
The object of the invention is to provide a high-
frequency high capacity ozonizer having metal electrodes coated
with a dielectric, which could be easily dismantled into a high
voltage and a low voltage units, which feature considerably
simplifies the mounting and dismantling of the ozonizer for
preventive inspection and repair.
This and other objects are achieved in a high fre-
quency ozonizer having a housing and coaxially arranged therein
tubular low voltage and high voltage electrodes, the conjugate
surfaces of which form a discharge gap, in the zone of which at
least one of said electrodes is coated with a dielectric, the
high voltage electrode being secured in the housing by means of
a high voltage insulator and cooled with a cooling liquid sup-
plied into the inner zone of said electrode through a pipe arran-
ged along the axis of the housing, according to the present in-
vention, the high voltage electrode is embodied as a detacha~ls
element, consisting of two parts, one of which is disposed in
the high voltage insulator, whereas the other is butted with the
first part and is made from a metal coated with a dielectric or
from a dielectric, and which is arranged in the discharge gap
and provided with a centering device from the free end side
thereof.
In the high frequency ozonizer according to the in-
vention, the centering device is preferably embodied as an end
cup covering one end pipe used for supplying the liquid cooling
~8~L3
the high voltage electrode, and, a stop, having a clamp covering
the free end of the other part of the high voltage electrode and
having a nut screwed thereon, which rests upon a centering thrust
journal, one end of the high voltage electrode being mounted on
said thrust journal, thereby providing for centering of the
high voltage electrode along the axis of the low voltage elec-
trode. The ends of the low voltage electrode ~ust be rounded.
This feature makes it possible to avoid edge effects and dielec-
tric break-down.
In accordance with an embodiment, there is provided
a high frequency tubular ozonizer having a metal cylindrical
housing with coupling flanges on both sides thereof, said flan-
ges having branch pipes for supplying and discharging a cool-
ant, at least one ozonizing element in said housing and com-
prising a low voltage tubular electrode cooled with a flow of
coolant, a high voltage electrode coaxially disposed in said
low voltage electrode and comprising a pipe of two parts, one
of said parts ~eing metal and being coated with a dielectric,
the other of said parts comprising a metal flow outlet, said
tubular parts being arranged to abut each other, the opposing
surfaces of the pipes of the low voltage and the high voltage
electrodes forming a discharge gap wherein the ozone-generating
chemical reaction takes place at the moment of electric dis-
charge, a metal pipe inside the high voltage electrode and along
the axis thereof, said pipe having openings at each end thereof
for admitting cooling liquid into the zone of the high voltage
electrode and having an end cap with a positioning stop and a
clamp at the same end for fastening the high voltage electrode:
a hollow cylinder-shaped high voltage insulator for insulation
of the high voltage electrode from the low voltage electrode,
said insulator having a ring-shaped bead in the middle portion
thereof, a metal tubular t-piece for fastening said flow out-
6~843
let of said high voltage electrode in the zone of said high vol-
tage electrode, said pipe being rigidly fastened to a free oppo-
site end of the t-piece, a branch pipe for supplyin~ the cool-
ing liquid and being rigidly secured to abut said pipe, in a
zone of the pipe of the t-piece there is provided a branch pipe
through which the liquid cooling the high voltage electrode is
discharged;a cylinder-shaped cup having flanges on both sides
thereof for attaching flanges of said cup to said flange of the
housing, a cavity in the butt end of said flange of the cup for
fastening a branch pipe to supply ozonized gas, the other flange
having an opening arranged along the axis of said cup, said
opening and said cavity having the shape and dimensions of said
bead of the high voltage insulator: a metal cap having an open-
ing along the axis thereof, the shape and dimensions of said
opening being those of the bead o~ said high voltage insulator,
the cylindrical metal base rigidly fastened to the free end
of said housing having the bottom from one side thereof and a
flange from another side thereof, the butt end of said flange
having an opening for fastening a branch pipe to discharge the
ozonized gas.
The proposed invention is further explained by an
example of an embodiment of said invention with reference to
the accompanying drawings, in which:
Figure 1 shows a longitudinal section of the
proposed high frequency ozonizer com-
prising one ozonizing element, accord-
ing to the invention,
Figure 2 shows a scheme of coupling the uniele~ent
ozonizers with the help of pipelines
to form a multielement installation
of the proposed high frequency ozon-
izer, lateral view, according to the
~4)8~3
invention;
Figure 3 shows a scheme of coupling the uni-
element ozonizers with the help of a
pipeline to form a multielement in-
stallation of the proposed high fre-
quency ozonizer, top view, according
to the invention;
Figure 4 shows a scheme of a high frequency ozon-
izer comprising seven ozonizing elements
in a common housing, lateral view, accord-
ing to the invention,
Figure 5 shows a scheme of a high frequency ozon-
izer comprising seven ozonizing elements,
lateral view, àccording to the invention;
~igure 6 shows a diagram of output of the ozonizer
(g.dm 2 hour 1~ versus concentration of
ozone (volume %) depending on consump-
tion~of oxygen, according to the invention.
The high frequency ozonizer according to the invention
can be embodied as one ozonizing element shown in Fig. 1. Pnother
embodiment of a high frequency ozonizer, comprising three 020n-
izing elements, connected by means of common pipelines is shown
in Figs. 2,3. Still another embodiment of a high frequency
ozonizer comprising seven ozonizing elements in a common cylin-
d~ical housing is shown in Figs. 4, 5.
~owever, it should be noted, that the number of the
ozonizing elements can be increased or decreased depending o~
the required output, whereas the arrangement of the elements and
the shape of the housing can be arbitrary.
Each ozonizing element of the high frequéncy ozonizer
consists of high voltage and low voltage units covering a group
8~3
of details operating at high or low voltage, said units being
separated with a high voltage insulator 1 (Fig. 1)~
The low voltage unit of the ozonizing element comprises
a cylindrical housing 2, a metal cylindrical low voltage electro-
de 3 having rounded ends 4, the surface of which electrode fac-
ing the high voltage electrode 5 can be coated with a dielec-
tric. The rounding of the profile of ends 4 of the low voltage
electrode 3 is required to exclude dielectric break-down and
to eliminate edge effects. The housing 2 and the electrode 3
are welded to coupling flanges 6 and 7. The zone between the
high voltage electrode 5 and the low voltage electrode 3 is
the discharge gap 8, the electric discharge taking place there-
in.
Along the perimeter of the coupling flanges 6 and 7
there are provided openings (said openings are not shown in
Fig.l), accommodating fixing bolts 9 and 10, and also ring
grooves 11 and 12 accommodating ozone-resistant cover gaskets,
whereas the butt ends of said flanges are provided with bored-
out cavities 15, 16, wherein the branch pipes 17 and 18 are
sealed and secured, said branch pipes being used for admission
and discharge of liquid cooling the low voltage electrode 3.
The low voltage unit has a cylindrical metal base 19 from the
side thereof which is fastened to the coupling flange 7 with the
help of flange 20, with holes being provided along the perimeter
of flange 20 (not shown in Fig. 1) for bolts 10, whereas the
butt end is provided with an opening for securing the branch
pipe 21 through which the ozonized gas is discharged~ The
surface of flange 20 facing the coupling flange 7 of the hous-
ing 2 has a ring projection 22 intended to mate through the
ozone-resistant gasket 14 with the respective groove 12 of the
coupling flange 7. Inside the base 19 there is secured a cen-
tering journal 23 made from an insulating and ozone-resistant
-- 8 --
~36~989~3
material and having a recess 24 along the axis of the high vol-
tage electrode 5 for centering the high voltage electrode 5.
Besides, the low voltage unit has a cylinder-shaped
cup 25, made from a metal or from an insulating and ozone-resist-
ant material. The cup 25 is provided with flanges 26 and 27,
along the perimeter of which there are provided openings 28
acco~nodating the fixing bolts 9 cmd 29. The surface of ~lange
27 facing the coupling flange 6 of housing 2 is provided with
a ring projection 30, which mates the respective groove 11 of
the coupling flange 6 via an ozone resistant gasket 13. The
butt end of flange 27 of cup 25 is provided with a bored cavity
31 for sealing and securing branch pipe 32, oxygen or a gas
containing oxygen being admitted through said pipe. The cup is
closed with a cover 33 with the help of bolts 29 arranged along
the perimeter of said cover. The cover 33 and the flange 26
along the axis thereof have openings 34 and 35, wherein the high
voltage insulator 1 together with the high voltage unit rigidly
fastened to the free side of cup 25 with the help of the ring
bead 36 and through the ozone-resistant cover gasket 37.
The high voltage units has a tubular detachable
high voltage electrode comprising two parts, one of which 5 is
made of metal with a dielectric coating 38, for example sili-
cate enamel (or a dielectric, for example glass) and is dis-
posed in the high voltage insulator 1 and is provided from one
side thereof with a ring bead 40, the high voltage electrode
5 being butted through an ozone-resistant covèr gasket 41 to
said bead, whereas from the other side the cap 39 is provided
with a thread 42 for coupling with a tee 43. The metal tubu-
lar T~piece 43 is provided on the inner surfaces of opposite
ends thereof with a thread for securing a cap 39 from one side
and for securing a pipe 44 from another side, which pipe is used
to supply the cooling liquid into the zone of the high voltage
electrode 5, whereas along the outer surface of the T-piece 43
and from the end of said piece whereto said pipe is fastened,
there i5 provided a thread, by means of which a branch pipe 47,
through which the cooling liquid is supplied into the pipe, is
fastened with the help of a nut 45 and is sealed with the help
of a gas}cet 46. The lateral pipe of the T-piece is provided
with a cavity for fastening and sealing of branch pipe 48, through
which the cooling Liquid is discharged from the high voltage
electrode~
In the middle portion thereof the T-piece is provided
with a clamp 49, a wire for supply of electric current being
connected to said clamp.
The cap 39 with the help of said bead 40 from one side
thereof and with the help of a metal washer 50 and the T-piece
43 screwed on the cap 39 from the other side thereof is rigidly
fastened in the high voltage insulator 1.
The metal pipe 44 is provided with a thread and with
openings 51 for discharging the cooling liquid into the zone of
the high voltage electrode 5 at one end thereof, whereas the
opposite end of said pipe 4~ is closed with a cap 52. The cap
52 is provided with a stop 53 with a thread 54. The stop 53 has
a clamp 55 and an ozone-resistant gasket washer 56, both put free
on said stop, and a nut 57 screwed on said stop, with the help
of which nut the high voltage electrode 5 is sealed by means of
an ozone-resistant gasket 58 and is rigidly joined to the other
part thereof, i~e., with the cap 39.
The stop 53 and the nut 57 are fitted into a recess 24
provided in the centering journal 23 resulting in coaxial arrange-
ment of the high voltage electrode 5 and the low voltage elec-
trode 3, i.e., resulting in centering of the electrodes.
To increase the output of the ozonizer the ozonizing
element~ are coupled to form high frequency multitubular ozoni-
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64;18~3
zers as follows.
For example, several unielement ozonizers can be cou-
pled directly through pipelines used for cooling liquid and gas.
An example of such coupling of thre~ ozonizers is shown in FigO
2,3.
The liquid cooling the high voltage electrodes 5 is
supplied and distributed through branch pipes 47 connected with
a pipeline 60, said pipeline being common for all the ozonizers,
whereas said liquid is discharged through branch pipes 48 con-
nected to a common pipeline 61, providing the pipelines are
made of a dielectric material. The arrangement of the pipe-
lines 60 and 61 and coupling thereof with respective branch
pipes 47, 48 of the ozonizers do not impede dismantliny of the
high voltage units.
The liquid cooling the low voltage electrodes 3 is
supplied and distributed through branch pipes 18 connected to a
common pipeline 62, whereas said liquid is discharged through
branch pipes 17 connected to a com~on pipeline 65.
To ensure an even flow of liquid and gas through the
unielement ozonizers the inlet branch pipes 18, 32, 57 must be
provided with respective built-in diaphragms 660 High voltage
is fed to each ozonizing element separately through a fuse or
through a circuit breaker (not shown in Fig. 4), which cuts the
high voltage off in case of dielectric break down. Figs. 4, 5
show one more example of embodiment of an ozonizer comprising
seven ozonizing elements 67 in a common housing 68. The housing
68 by means of flanges 69 and fixing bolts (not shown in Fig. 4)
is connected with a common base 70 and a common cup 71. The
centering journals 23 are arranged along the axis of separate
ozonizing elements on the bottom of base 70. The cup is closed
with a cover 72 having openings ~not shown in Fig. 4) for fasten-
iny the high voltage insulators 1 of separate ozonizing elements,
~6~8~3
fixed on the cover 72 with special fixing washers 73 with the
help of bolts (not shown in Fig.4 ).
The low voltage electrodes are cooled with water sup-
plied through a branch pipe 74 into a ring-shaped manifold 75
having diaphragms 76 providing for even distribution of the flow
of water, which is admitted to base 68 and is discharged there-
from through a branch pipe 17.
T~e high voltage electrodes are cooled with water in-
coming through long pipelines made from a dielectric material
to a ring-shaped manifold 77, also made from a dielectric mater-
ial and from said manifold the water flows along branch pipes
47 into the zone of high voltage electrodes 5, said branch pipes
having built-in diaphràgms 76 proviaing for even distribution
of water. The water is discharged from the high voltage elec-
trodes through branch pipes 4~ into a ring-shaped manifold 78
connected to a long pipeline made from a dielectric material.
Oxygen or a gas containing oxygen is supplied through the branch
pipe 32 to a ring-shaped manifold 79, said manifold having the
diaphragms 76, through which manifold the water flows into the
discharge gap of the ozonizing elements and is discharged
through the branch pipe 21 disposed in the base 70.
If the installation comprises three ozonizers coupled
directly, the high voltage is supplied as described above. The
cup can be made not only from a metal but also from a di-elec-
tric. The high voltage unit can also be fastened directly to
the cover 72 of the cup 71, because in this case the high vol-
tage insulators are not required. The embodiment of the high
frequency ozonizer provides for dismantling thereof for pro-
tective inspection and repair of units or for replacing-the
high voltage electrode 5 if said electrode is rendered inoper-
able.
1Ci 6~84~3
The di~mantling of the ozoniz~r is eEfected by discon-
necting the branch pipes 47 and 48 from the pipelines used for
supplying a liquid to cool the high voltage electrode, by dis-
connecting the high voltage electrode from the clamp 49, screw-
ing off the bolts and removing the high voltage unlt together
with the insulator 1, after which procedure the high voltage
electrode 5 becomes easily accessible for preventive inspection.
In case of a breakdown or other defects the high vol-
tage electrode S can be replaced. The replacement is effected
by unscrewing the nut 57, and removing first the clamp 55 then
the electrode 5. To assemble the high voltage electrode 5 the
same steps must be taken in reverse order, said procedure pro-
viding for a simultaneous self-centering of said high voltage
electrode owing to the fact that .the throw-out stop 53 enters
the recess 24 of the centering journal 23. If badly damaged,
the high voltage unit can be replaced by another unit.
In the first example describing a multitubular high
frequenc~ ozone-producing installation comprising three uniele-
ment ozonizers coupled by common pipelines the procedures for
dismantling and mounting of said ozonizers for preventive in-
spection and repair coincide with those described above.
In the second example describing installations compris-
ing seven ozonizing elements in a common housing the procedure
of repair and replacing separate inoperable units is as follows.
First of all, the high voltage supply wire must be
disconnected (not shown in Fig. 1). This step is followed by
disconnecting the branch pipes 47, 48 from -the ring-shaped mani-
folds 77 which are manifolds for supplying and discharging the
water cooling the hiyh voltage electrodeS 5.Then the bolts ~not
shown in Fig. 1) fixed with washers 73 must be screwed off fol~
lowed by removal of the high voltage uni-t. After the inspection
or replacement of the high voltage unit, the ozonizer is mount
ed following the same procedure in a reverse order. So, the
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843
procedure of dismantling and mounting of the ozonizer for pre-
ventive inspection and repair i5 very simple and requires little
time, whereas the ozonizers having a through direct-flow cooliny
o~ the electrodes re~uire time not only for dismantling the
whole installation but also for removing the manifolds and the
electrodes while the procedure of mounting said ozonizers re-
quires centering of each electrode.
The high frequency ozonizer operates as follows.
Prior to feeding the electric current, a liquid
cooling the electrodes, for example water, is supplied to the
ozonizer. The water is fed to the housing of.the low voltage
electrode directly from the tap water supply through the branch
pipe 18 and is discharged through the branch pipe 17. The water
is fed to the high voltage electrode through the branch pipe
~7 and is discharged from said electrode through the branch
pipe 48 which branch pipe is connected to long pipe lines made
from a dielectric material, provided the electric resistance of
the column of water flowing through these pipe lines~is high
enough to exclude energy losses through water.
Then oxygen or an oxygen containing gas is fed to the
ozonizer through the branch pipe 32. Having passed in parallel
through the ozonizers, the ozonizer gas is discharged through
the common pipe line 65. Then the electric current is supplied
to each:~ozonizing element separately provided the increase of
voltage is gradual.
The pipelines 60, 61 are made from a dielectric,
which feature ensures sufficient electric resistance between
the high voltage electrodes of individual ozonizers for dis-
connecting faulty high voltage ozonizers.
In an ozonizer comprising seven ozonizing elements in
one housing, the water cooling the low voltage electrodes is
supplied through the common branch pipe 74, and is discharged
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~al6~ 3
therefrom through the common branch pipe 17. Water ~or cooling
the high voltage electrodes is supplied through the ring-shaped
manifold 78, provided said electrodes are made from a di-electric
material.
Oxygen or a gas containing oxygen enters the installa-
tion through the branch pipe 32 and is discharged through the
branch pipe 21. After that electric current is fed to each high
voltage electrode 5 provided the voltage increase is gradual.
A~ the manifolds 77, 78 are made of a dielectrie material, each
of the high voltage electrodes can be disconneeted in case of
a break-down.
To stop the installation operation the same steps
should be taken in a reverse order.
An ozonizer comprising only one ozonizing element and
having a 2 mm wide discharge gap, the temperature of water cool-
ing the electrodes being 25C, was operating being fed with alter-
nating current at a frequency of 1500 hz and 6 kW voltage. Fig.
6 shows output of said ozonizer (curve A) (in g.dm. 2 hour 1)
and concentration of ozone ~curve B) (in volume % O3) versus
consumption of oxygen. (in 1 hr). The shape o~ the curves shows
that inerease in oxygen consumption causes increase in the ozon-
izer output and decrease of ozone concentration. At a compara-
tively low consumption of gas when the ozone concentration drops
only to 2.5% the output of the ozonizer is rather high, amount-
ing to 15 g.dm. 2 hour 1, the power eonsumption for producing
ozone being 8.3 kwhr.kg 1.
The provided data are not related to the highest pos-
sible output of the ozonizer, because these data are obtained at
a eomparatively low eonsumptionlof gas amounting to only S60 l/hr.
at which con~umption the concentration of ozone produced is ra-
ther high and amounts to 2.5%. An increase of gas consumption
aimed at decrease of concentration of oæone, for example down
to 1%, results in substantial increase of the output of the
ozonizer and reduces energy consumption.
In this way the proposed ozonizer differs from all
prior art oæonizers by simplicity of dismantling for repair,
high operational reliability and high output.
A combination of the above features ensures consider-
able economic efficiency of large-scale high capacity commercial
ozone-producing installations.
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