US3296116A

US3296116A - Apparatus for producing ozone

Info

Publication number: US3296116A
Application number: US264251A
Authority: US
Inventors: Leviel Roger
Original assignee: Degremont SA
Current assignee: Suez International SAS
Priority date: 1962-03-28
Filing date: 1963-03-11
Publication date: 1967-01-03
Anticipated expiration: 1984-01-03
Also published as: CH415570A; BE629724A; DE1260448B; GB1023864A; ES286289A1; FR1326514A

Description

Jan; 3, 1967 R. LEVIEL 3,295,116

APPARATUS FOR PRODUCING OZONE Filed March 11, 1963 OOOOOO INVENTOR Roger Leviei ATTORNEY 3,296,116 APPARATUS FOR PRODUCING OZONE Roger: tLeviel, Suresnes, France, assignor to Degremont The present invention relates to apparatus for producing ozone.

Differing types of apparatus for producing ozone are known, which consist, for" example, of a receptacle of metal or glass, containing a liquid such as water, the said receptacle containing the apparatus for producing ozone which comprises a tubular electrode made, for example,

of metalior a plastic material, concentrically surrounded by a dielectric; such as a glass or ceramic tube; the liquid, such as water, acts as an exterior electrode while the tubular electrode acts as the interior electrode; the ozonization chamber being the annular space disposed between the interior electrode and the dielectric which surrounds it concentrically.

It is :also known to provide the connection of the intei rior: electrode of an apparatus for producing ozone to a current inlet terminal from a high voltage transformer, for example, throughthe intermediary of a fusible circuit breaker. in the case of an overload. of current, and of a contactisuch, for example, as a pressure elastic contact.

The known types of apparatus for :producing ozone, however, present a certain number of disadvantages in that the interior tubular electrode and the dielectric which surrounds it are of relatively large dimensions, the effect of which is to make the ozone producing apparatus expensive, if one takes into account the fact that the quantity of ozone produced is proportionate to the volume of the zone of electric discharge obtained and which usually produces between 1.5 to 2 g. :of ozone per hour for 100 cm? of volume of the zone traversed by the electric discharge.

. In addition, the providing of the connection of the electrodei to a transformer through the intermediary of contacts and of fusible circuit breakers in case of overload also represents an increase in costs which does not appear justified in view of the evidence that the cases of interruption of the dielectric are very rare if the apparatus is well conceived and if, in particular, the dielectric is not compressed. so as to oppose its free expansion.

An object of thepresent invention is the provision of improved apparatus for producing ozone which is better "suited to thejrequirements of general use than the apparatuspfor producing ozone heretofore known, particularly in thatthe present invention permits the mounting of a large number of electrodes in parallel, which permits lowering the ratio of the volume of the metal to the volume of the discharge of an electrode producing ozone. This has the effect of greatly lowering the net cost of such apparatus and also permits elimination of the placement of contacts corresponding to each of the interior electrodes and providing each with a circuit breaker. This results in rather complicated equipment in previously proposed apparatus and an. increased net cost for ozone producing apparatus. Finally, the present invention does away with the necessity of compressing the dielectric in the joints, which resultsin avoiding the breaking of the dielectric.

The present invention has as its principal object providing an ozoneproducing apparatus comprising metal electrodessuitably mounted in parallel, each surrounded .by a dielectric, for example, of glass or ceramic, and immersed. in a liquid medium which preferably constitutes the exterior electrode and which is contained in a vessel.

United States Patent Patented Jan. 3, 1967 These metallic electrodes thus constitute the interior electrodes and the space provided between each of the interior electrodes and the dielectric which surrounds it concentrically, constitutes the ozonization chamber. This apparatus, according to the present invention, includes a collector, preferably made of metal, connected to a source of current of high voltage, for example, by a current inlet terminal to which the interior electrodes are connected in a removable manner.

According to a preferred embodiment of the invention, the electrically conducting collector which supports the interior electrodes also simultaneously acts to conduct the air to be ozonized to the interior electrodes.

According to a preferred form of the invention, the vessel which contains the liquid medium is made of plastic. This medium constitutes the exterior electrode in which the dielectrics are mounted in parallel, concentrically in relation to the corresponding interior electrodes.

According to the preferred mode of carrying out the invention, the interior electrodes are suspended on the aforementioned collector by means of one end thereof.

According to another advantageous arrangement of this preferred embodiment, the end of the interior electrodes through which they are suspended on the collector is suitably tapered and curved in the form of a crook to facilitate the suspension of the interior electrodes on the collector.

According to another advantageous arrangement of this preferred embodiment, the openings in the collector designed to receive the tapered curved extremities of the interior electrodes are arranged on one part, or on the total surface of the collector.

According to another advantageous arrangement of this preferred embodiment, the tensioning means, such as springs, for example, cooperate with the above-mentioned openings provided on the collector to provide for perfect suspension of the electrodes on the collector.

In addition to the principal arrangement and the pre ferred embodiments which have been described, the invention comprises still other arrangements which become evident from the following description.

The invention aims to provide improved apparatus for producing ozone which conforms in whole or in part to the preceding arrangements, in such a manner that the special elements, the apparatus, installations or assem' blies in accordance with the preceding arrangements for producing ozone conform in whole or in part with the apparatus of the present invention.

The invention may be better understood by reference to the following description which refers to the annexed drawing in which the single figure represents a schematic sectional view of an apparatus for producing ozone provided in accordance with the present invention and which is one example thereof.

It should be well understood at all times that this drawing and the corresponding descriptive parts are given only by way of example and are in no way limiting.

The apparatus for producing ozone according to the present invention comprises a vessel 1 of plastic material such as, for example, poly vinyl chloride, which contains a liquid medium 2, such, for example, as water, Whose level in the vessel may be suitably varied by means of an arrangement designated by the references 3 and 4 on the drawing, which forms the subject matter of the French application for patent filed in the name of the applicant on February 17, 1961, as Serial Number PV 853,060 for an Apparatus Producing Ozone and which is designed to vary the output of ozone.

The plastic vessel may equally well be made of metal provided it is protected on the interior against corrosion which may result from contact with the ozone.

The liquid medium should be sufficiently conducting to permit the passage of a quantity of electric energy corresponding to that required for the production of ozone and which is in the order of 20 watthours/ gram of ozone. As the operation is under very high voltage, the intensity of the electric current is Weak and it is not necessary to provide a highly conducting liquid. Natural water is generally sufficiently conductive for this but if slightly mineralized water is used, it should be acidified to increase its conductivity.

The tubes 5 which are preferably made of glass are closed at their lower extremities and are immersed in the liquid. They preferably have an interior diameter of the order of to 20 mm. In the present case, the interior diameter of the tubes 5 are 12 mm. The tubes 6, which are preferably made of a metal such as aluminum or stainless steel, are concentrically mounted in the interior of each of the tubes 5. These metallic tubes preferably have an exterior diameter of the order of 6 mm. The centering of each of the metallic tubes 6 in each of the tubes 5 may be accomplished in any known appropriate manner. The centering of the tubes 6 may be accomplished by means of a helicoidally wound ring 7, preferably made of a plastic material such as poly Vinyl chloride, which may be mounted at one or several points along the length of the height common to the tubes 5 and to the tubes 6.

According to a preferred embodiment, the glass tubes 5 as well as the metallic tubes 6 which they contain, are mounted parallel to the vertical axis of the plastic vessel 1. The metallic tubes 6 are mounted in a removable manner on the collector 10, which is preferably made of metal, and is connected to a source of current such as, for example, a high voltage transformer, through the intermediary of a terminal 11 for the inlet current. The collector 10 conducts the current to the metallic tubes 6 which constitute the interior electrodes of the ozone producing apparatus.

According to this embodiment of the invention, the interior electrodes 6 are removably connected with the electrically conducting collector 10 by suspending the electrode tubes 6 on the collector 10.

According to this embodiment, the metallic tubes '6 are suspended on the collector 10 by means of their upper extremity, which may be bent 180 to form a crook 8 whose extremity is preferably tapered, and may be inserted in the openings 9 provided on the surface of the collector 10.

An arrangement for tensioning, such as springs 12, assures the tightening of the connection of the metallic tubes 6 onto the collector 10 when the tapered extremity of these tubes which are curved in the form of a crook Iare inserted in the openings 9 provided on the collecting The opening provided at the extremity of the electrodes 6 which is suspended on the collector 10 by insertion in the openings 9, is narrowed in such a way as to introduce a pressure drop, that is to say, a difference in the pressure of the air, in order to assure that the total air flow may be equally distributed in the different electrodes. This drop of pressure is between 3 and 20 millibars.

This means of removably connecting the interior electrodes 6 with the collector 10 which has just been described, constitutes only one preferred means of suspension; and it may be easily understood that this means of suspension is given only as an example, and that the electrodes 6 may be fastened to the collector 10 in any appropriate manner, for example, as by screwing in to the corresponding holes provided in the collector, or by any other suitable joining.

The operation of the apparatus for producing ozone according to the present invention is as follows:

Air, previously dried in any appropriate manner, is introduced into the apparatus by conduit 13 for the entry of dry air. According to a particularly advantageous way of using the invention, the electrically conducting collector 10 is provided in the form of a hollow tube which constitutes a branch of the conduit 13 for the entry of dry air, so that the air introduced into the apparatus through the conduit 13 passes first across the collector 10 and then to the electrodes 6 through suspension openings 9 provided on the collector 10. Such an arrangement has the advantage of uniting in a single element the collector for conducting electricity to the electrodes 6, the conduit for entry of air towards the electrodes 6, and the mechanism for carrying the electrodes contained in the ozone producing apparatus. Such an arrangement results in a perceptible lowering of the cost of the apparatus due to the simplicity of such an arrangement.

Cooling water is introduced in the vessel 1 through a perforated metallic tube 14. The cooling water flows from the vessel through a siphon arrangement which includes the siphon tubes 3, through the outflow column 20 for the cooling Water 4 and the outlet 15. This arrangement constitutes the means for regulating the quantity of ozone produced by variation of the wet surface of the exterior tubes 5 as described in the French patent application No. PV 853,060 mentioned above.

The numeral 16 designates the ground plate of the conducting liquid medium 2.

The liquid medium 2, such as water, which the vessel 1 contains, is put under alternating voltage increased by the collector 10 and the tubes 6, which collector is joined to a high voltage transformer not shown, through the intermediary of the inlet current terminal 11, in such a manner that the electric flow develops in the annular space 17 provided between the exterior diameter of the tube 6 and the interior diameter of the tube 5 in any known manner, the other terminal of the transformer being grounded at the same time as the ground plate 16.

It is advantageous to cover the liquid medium 2, such as water, with a layer of oil 18 which constitutes an efiicient insulator to avoid diffusion of moisture to the contact of the electrodes.

The ozone producing apparatus, according to this invention, functions equally well under pressure or under vacuum.

In the case where the apparatus functions under pressure, the air may be advantageously circulated in a direction such that the ozonized air product flows through the collector 10, then through the conduit 13, to avoid all leakage of the ozone.

In the case where the apparatus functions under vacuum, there is advantage in choosing the direction of circulation of the air in such a manner that in case of a leakage, the humid air which may penetrate into the apparatus does not come in contact with the electric discharges. In particular, to avoid the possibility of a leakage at the joint of the vessel 1, the air is introduced through conduit 13, the collector 10 which constitutes a branch of the conduit 13, and the tubular electrodes 6; the air escapes through the pipe .19 situated above the vessel 1, in the direction indicated by the arrow A, contrary to that which occurs when the apparatus functions under pressure.

It results from the foregoing that whatever may be the method of operation, an ozone producing apparatus is obtained with advantages over the prior apparatus which is so evident that it is unnecessary to present further explanations.

The ozone producing apparatus, according to the invention, provides, in addition to those already mentioned, real advantages as compared to the apparatus for producing ozone previously known, notably:

1. An increase in the rate of production of ozone is accomplished, taking into account the fact that the quantity of ozone produced is proportional to the volume measured at the electric discharge and that this increases the quantity of ozone produced, according to the present invention. In lowering the volume ratio of the metal used 20 PrQYidQ the electrodes to the volume measured at the discharge; a reduction in the cost price of the ozone producing apparatus made in conformity with the present invention .;in relation to that of apparatus for producing ozone previously known, is realized in a ratio of 1 to 4. This reduction in the cost price is obtained by the arrangement of the series of metallic tubes of small diameter and of small thickness, which on the one hand increases the measured volume at the electric discharge, and on the other hand results in a lower cost price to that of tubes previously. used as interior electrodes whose diameter may be 4 to 8 times larger than that of the metallic tubes used according to the present invention.

2. Access to the interior electrodes as well as replacement of these .is permitted considerably easier than in thexgforms of apparatus previously known due to the mounting of these electrodes on the apparatus by a simple suspension to the: collector.

3. A more positive operation of the ozone producing apparatus is assured, which was not the case for the previouslyll known forms of. apparatus since in the previously proposed apparatus, rupture of one of the dielectrics has thevelfect of flooding not only the corresponding interior electrode but also the other electrodes which have not ruptured, .while in the apparatus according to the present invention, the. deterioration of one of the dielectrics has no influence on the functioning of the other electrodes,

and the deterioration may be remedied at the deteriorationwpointin question either by replacement of the deteriorated electrode or by its simple removal and closing the opening 9 of the collector 10 to which it was joined,

\ which. permits proceeding with the production of ozone,

and which avoids the risks of leakage of ozone.

The invention is not limited only to the modes of application or to the methods of accomplishing the various parts which have been more particularly explained; it encompasses, on the contrary, all variations, and in I particular. those which have been mentioned previously 3 and still others which come withinthe knowledge of one skilled in this subject matter, all coming within the framework and in the spirit of the invention.

Whatis claimed is: 1. In :an apparatus for producing ozone which. includes a: source uof voltage, hollow metal interior electrodes suitably mounted in parallel, and a plurality of dielectric elements each surrounding each of said metal electrodes,

and defining a space therebetween constituting the ozonization chamber, the improvements comprising:

an electrically conducting hollow collector for the passageof gas therethrough, said hollow collector being attached to each. of said hollow electrodes for the passage of gas therethrough, said hollow electrodes being connected to said source of voltage through said collector;

means to create a gas pressure drop between said hollow collector and each of said hollow electrodes, said means including a narrow restricted portion adjacent the juncture of said hollow collector and said hollow electrodes; both said collector and said electrodes having relatively. large cross-sectional areas compared with said narrow restricted portion; and

means. to flexibly and resiliently separate and support each 11 of said surrounding dielectric elements from each of said hollow electrodes so that relative movement between said hollow electrodes and said dielectric elements is permitted upon temperature variations.

2.11Aniapparatusdn accordance with claim 1, wherein said: collector constitutes: a tubular inlet.

3. Apparatus according to claim 1 wherein said interior hollow electrodes are suspended from said collector by one end of each said interior electrode entering a corresponding opening in said collector.

4. Apparatus according to claim 1 wherein one end of each said interior electrodes is curved in the form of a crook and said end enters a corresponding opening in the top surfaces of said collector.

5. Apparatus according to claim 1 wherein said means to create a gas pressure drop comprises a restricting tapered portion at the end of sach said electrode which enters the collector for said attachment thereto.

6. Apparatus according to claim 4 wherein the curved end of each said electrode is tapered to constitute said means to create a gas pressure drop.

7. Apparatus accord-ing to claim 1 further comprising a vessel made of plastic material, said vessel being adapted to contain a liquid medium acting as an exterior electrode surrounding said plurality of dielectric elements.

8. Apparatus for producing ozone comprising a vessel, said vessel being adapted to contain a liquid medium acting as an exterior electrode; a plurality of dielectric tubes closed at their lower ends and open at their upper ends extending into and adapted to be surrounded by said liquid medium, said open ends adapted to extend above the uppermost level of said liquid medium when in said vessel; an electrically conducting tubular collector mounted in the upper portion of said vessel and above the open ends of said dielectric tubes, said tubular collector constituting an air inlet; means for connecting said collector to a source of high voltage; a plurality of tubular interior electrodes removably connected to said collector and extending downwardly into said dielectric tubes, the space between said interior electrodes and the dielectric tubes which surround them concentrically constituting ozonization chambers so that air to be ozonized can pass through said collector into said interior electrodes and thence to said ozonization chambers, the junction of said tubular hollow electrodes and said collector being restricted so as to induce a pressure drop in fluid passing from said hollow collector to said hollow electrodes which have relatively large cross-sectional areas compared to said restriction; and means to resiliently support said dielectric tubes within said vessel from said tubular interior electrodes.

9. Apparatus according to claim 8 wherein the upper end of each said electrode is bent in the form of a crook and enters a corresponding opening in the top surface of said collector.

10. Apparatus according to claim 9 wherein the upper end of said electrode entering the collector is tapered to form said restriction.

References Cited by the Examiner UNITED STATES PATENTS 986,194 3/1911 Meeker et a1 204-321 X 987,902 3/ 19 11 Meeker 204321 1,035,489 8/1912 Steynis 204-321 FOREIGN PATENTS 67,176 12/ 1914 Australia. 1,096,338 l/196l Germany.

JOHN H. MACK, Primary Examiner.

G. KAPLAN, Assistant Examiner.

Claims

1. IN AN APPARATUS FOR PRODUCING OZONE WHICH INCLUDES A SOURCE OF VOLTAGE, HOLLOW METAL INTERIOR ELECTRODES SUITABLY MOUNTED IN PARALLEL, AND A PLURALITY OF DIELECTRIC ELEMENTS EACH SURROUNDING EACH OF SAID METAL ELECTRODES, AND DEFINING A SPACE THEREBETWEEN CONSTITUTING THE OZONIZATION CHAMBER, THE IMPROVEMENTS COMPRISING: AN ELECTRICALLY CONDUCTING HOLLOW COLLECTOR FOR THE PASSAGE OF GAS ATHERETHROUGH, SAID HOLLOW COLLECTOR BEING ATTACHED TO EACH OF SAID HOLLOW ELECTRODES FOR THE PASSAGE OF GAS THERETHROUGH, SAID HOLLOW ELECTRODES BEING CONNECTED TO SAID SOURCE OF VOLTAGE THROUGH SAID COLLECTOR; MEANS TO CREATE A GAS PRESSURE DROP BETWEEN SAID HOLLOW COLLECTOR AND EACH OF SAID HOLLOW ELECTRODES, SAID MEANS INCLUDING A NARROW RESTRICTED PORTION ADJACENT THE JUNCTURE OF SAID HOLLOW COLLECTOR AND SAID HOLLOW ELECTRODES, BOTH SAID COLLECTOR AND SAID ELECTRODES HAVING RELATIVELY LARGE CROSS-SECTIONAL AREAS COMPARED WITH SAID NARROW RESTRICTED PORTION; AND MEANS TO FLEXIBLY AND RESILIENTLY SEPARATE AND SUPPORT EACH OF SAID SURROUNDING DIELECTRIC ELEMENTS FROM EACH OF SAID HOLLOW ELECTRODES SO THAT RELATIVE MOVEMENT BETWEEN SAID HOLLOW ELECTRODES AND SAID DIELECTRIC ELEMENTS IS PERMITTED UPON TEMPERATURE VARIATIONS.