EA044703B1 - LOW FREQUENCY OZONE GENERATOR - Google Patents

Description

Field of technology to which the invention relates

The present invention relates to an ozone generating device capable of operating in the operating frequency range of 25-40 kHz.

The present invention also relates to a method of operating an ozone generating device at a frequency of 25-40 kHz.

The present invention also relates to a transformer assembly, such as a high power transformer configured or adapted to generate power in the 2540 kHz frequency range.

Prior Art

The effectiveness of an ozone water treatment plant depends on the ability to constantly maintain the required level of ozone in the water.

Proper removal of heavy metals from contaminated groundwater, adequate removal of colloidal solids, dissolved organic compounds, and conversion of nitrites to nitrates in aquaculture systems, as well as effective solutions to ozone water treatment problems in urban environments, depend on the ability to consistently maintain required levels of ozone in water.

The ozone generating device is preferably operated at a frequency above the human audible range, that is, in the frequency range 15-25 kHz, as disclosed, for example, in WO 2008/074767.

High frequency operation is also claimed to have the advantage of requiring lower operating voltages for a given input power compared to low frequency operation, as disclosed, for example, by Kogelschatz in Plasma Chemistry and Plasma Processing. , volume 23, (1): (1-46).

However, ozonizers operating at high frequencies do not always maintain ozone production at the required level. For example, actual ozone production, that is, the concentration of ozone released, may in some cases be below a set value or below acceptable limits.

Thus, an improved ozone generator would be preferred, and in particular, a more efficient and reliable ozone generating device capable of consistently maintaining the required level of ozone in the water being treated would be preferred.

The essence of the invention

An object of the present invention is to provide an ozone generating device capable of continuously maintaining a required level of ozone in the water being treated.

Another object of the present invention is to provide a method of operating an ozone generating device capable of continuously maintaining a required level of ozone in treated water.

Another object of the present application is to provide a transformer assembly for powering an ozone generating device capable of continuously maintaining a required level of ozone in the water being treated.

It is also an object of the present invention to provide an alternative to the prior art.

In particular, it may be considered as a further object of the present invention to provide an ozone generating device, a transformer assembly for powering the ozone generating device, and a method of operating the ozone generating device, which solves the above-mentioned problems of the prior art, being capable of operating in the operating frequency range of 25-40 kHz .

Thus, the solution to the above object and a number of other objects in the first aspect of the invention is provided by providing an ozone generating device comprising: an ozone generator unit comprising a high voltage electrode unit, first and second dielectric elements and first and second ground electrodes.

The generator block is designed or adapted to operate in the operating frequency range of 25-40 kHz.

For example, the operating frequency may be 30 to 40 kHz, such as 31 to 37 kHz.

In search of optimization in the field of ozone generation, inventors noticed that decreasing the operating frequency increased the productivity of the ozone generator.

In general, low frequency operation is not desirable since high frequency operation of the ozone generator has the benefit of lower operating voltages for a given input power.

In addition, decreasing the operating frequency increases the audible noise generated by the ozone generator unit. Indeed, ozone-generating devices preferably operate at frequencies above the human audible range.

In search of optimization in the field of ozone generation, the inventors examined the range of operating frequencies in relation to unwanted background noise generated during operation and in relation to optimal ozone production.

Thus, the inventors have determined a frequency range in which the correspondence between set point and actual ozone production is optimized for minimal audible operating disturbances.

The ozone generating device according to the first aspect of the invention may further comprise a low frequency high voltage alternating current source, such as a high power transformer or transformer assembly configured or adapted to supply 50 to

800 W at 25 to 40 kHz per ozone generator unit.

For example, a high voltage AC power supply may be configured or adapted to supply 50 to 800 W at a frequency of 30 to 40 kHz, for example, preferably 31 to 37 kHz.

The presence of a high-voltage AC power supply configured or adapted to provide power from 50 to 800 W provides an operating frequency of the ozone generator unit from 25 to 40 kHz.

The high voltage alternating current source according to the present invention may be referred to herein as a high power transformer, a transformer, or a transformer assembly.

With respect to the structure of the ozone generator unit, such as the high voltage electrode unit, the first and second dielectric elements, and the first and second ground electrodes, these relate to the structures and elements disclosed in WO 02/20398, incorporated herein by reference.

The first and second dielectric elements may be polymer layers, such as a thin layer of polymer materials, such as polytetrafluoroethylene (PTFE) sheets.

In some embodiments, the high voltage electrode assembly is located between the first and second dielectric elements.

The first and second dielectric elements may be located at a distance from the high-voltage electrode assembly in the range of 0.01 to 0.5 mm, such as 0.01 to 0.4 mm, such as 0.01 to 0.3 mm, such as 0.01 to 0.1 mm.

In some further embodiments, the first and second dielectric elements may be separated from the high voltage electrode assembly by one or more separating elements.

The first and second dielectric elements may be separated from the high voltage electrode assembly by one or more spacer elements ranging from 0.01 to 0.5 mm, such as 0.01 to 0.4 mm, such as 0.01 to 0.3 mm , for example from 0.01 to 0.1 mm.

The first and second dielectrics may be located on either side of the high voltage electrode.

In some embodiments, first and second ground electrodes with first and second dielectrics define first and second reaction chambers.

Each of the first and second reaction chambers may include an inlet channel for supplying oxygen gas or an oxygen-containing gas and an outlet channel for releasing ozone gas.

The outer surface of the first and second reaction chambers may include cooling elements, such as cooling fins.

In some embodiments, air cooling may be used alone or in combination with water cooling to improve the efficiency of the ozone generator unit.

In some other embodiments, only water cooling may be used to cool the ozone generator unit.

The high-voltage electrode can be made in the form of a metal coating on the first and/or second dielectric.

In some other embodiments, the high voltage electrode is a metal foil or metal sheet.

In some further embodiments, the first and second dielectric elements may contact the interior surface of the first and second reaction chambers.

An advantage of the above specific configuration is that the heat generated during ozone production can be dissipated more efficiently because the heat exchange between the cooled ground electrodes forming part of the first and second reaction chambers and the first and second dielectrics contacting the inner surface of the first and second reaction chambers are more efficient.

In a second aspect, the invention relates to a method of operating an ozone generating device according to the first aspect of the invention, the method including operating the ozone generating device at a frequency of 25 to 40 kHz, for example 30 to 40 kHz.

In some embodiments, according to the second aspect of the invention, operation of the ozone generating device according to the first aspect of the invention includes supplying a fluid stream containing oxygen gas to an ozone generator unit; controlling the flow of a fluid containing oxygen gas; control of the power supplied from the power supply device to the ozone generator at a frequency of 25-40 kHz, for example from 30 to 40 kHz.

In a third aspect, the invention relates to a method of operating an ozone generating device, the method comprising operating said ozone generating device at a frequency of 25-40 kHz,

- 2 044703 for example from 30 to 40 kHz.

In some embodiments of the method of operating an ozone generating device according to the third aspect of the invention, operation of the ozone generator includes: supplying a fluid stream containing oxygen gas to the ozone generator; controlling the flow of a fluid containing oxygen gas; controlling the power supplied from the power supply device to the ozone generator at a frequency of 25-40 kHz, for example from 30 to 40 kHz.

In some further embodiments of the first, second or third aspects of the invention, the operating frequency is 31 to 40 kHz, such as 32 to 35 kHz.

In a fourth aspect, the invention relates to a transformer assembly or transformer, such as a high power transformer, configured or adapted to supply electrical power in the frequency range of 25-40 kHz, for example 30 to 40 kHz.

The transformer assembly according to the fourth aspect may include a cladding-type ferrite core surrounding a primary winding and a secondary winding.

The primary winding may have less than 14 turns, and the secondary winding may have more than 107 turns. The cladding type ferrite core may have an air gap of less than 2.0 mm.

In some embodiments, the cladding-type ferrite core comprises at least two portions separated from each other by an air gap of less than 2.0 mm.

The inventors developed a high-power transformer, taking into account that the operating frequency of the ozone generator unit depends on the reactor capacitance and the inductance on the secondary side of the high-voltage transformer. The primary side inductance of the high voltage transformer and the series inductance also have some influence on the operating frequency of the ozone generator unit.

To change the operating frequency, the invention uses a transformer unit with increased inductance.

Approximately the inductance can be calculated using the following formula:

_{L =} Ν ² * μ ₀ ~ Σ(£) _G

A, where μ ₀ is a physical constant and cannot be changed.

The mechanical dimensions of the transformer assembly are limited by the size of the ozone generator unit. In addition, the ferrite core in the transformer assembly also has predetermined dimensions that cannot be changed.

In practice, in accordance with the above formula, this means that no changes in Σ( ⁱ / _Ae ) (geometric constant of the core) and A _e (core area) are possible. μ _e is the constant of the material used, which in this state of the art is ferrite.

The solution according to the invention is to change N (the number of turns of the primary winding) and G (the air gap of the core).

However, the limitation on the mechanical size of the generator unit means that there is no room to increase the number of turns in the transformer secondary without reducing the number of turns in the primary. The solution according to the invention was to change the number of turns in the primary winding, for example by reducing it by a certain number, for example by reducing it by 1, 2, 3, 4 or 5 turns from the value currently used in transformer assemblies with working frequency -45 kHz, which is, for example, approximately 14 turns. This left enough room to change the number of turns of the secondary windings, for example by increasing it by a certain number, for example by increasing it by 1, 2, 3, 4 or 5 turns from the value currently used in transformer assemblies, with an operating frequency of - 45 kHz, which is, for example, approximately 107.

Reducing the gap in the transformer increases the magnetic flux in the core. Lowering the frequency increases the magnetic flux, which leads to increased losses in the core. On the other hand, lowering the frequency reduces the number of changes in flow direction. This, on the contrary, reduces losses. Thus, the gap was changed, for example reduced by 0.25, 0.5, 0.75, 1, 1.1, 1.2 mm from the value currently used in transformer units with an operating frequency of -45 kHz, component, for example, approximately 2.1-2.2 mm.

Thus, in some embodiments, the invention relates to a transformer assembly comprising a cladding-type ferrite core surrounding a primary winding and a secondary winding, wherein the number of turns of the primary winding is less than 14 and the number of turns of the secondary winding is greater than 107, wherein the cladding-type ferrite core has an air the gap is less than 2 mm.

By reducing the gap and increasing the number of turns in the secondary winding and reducing the number of turns in the primary winding, the operating frequency was lowered from -45 kHz to -30 kHz.

This change may slightly increase operating temperature. However, the increase in operating temperature can be reduced through improved cooling solutions.

Each of the first, second, third, and other aspects and embodiments of the present invention may be combined with any other aspects and embodiments. These and other aspects of the invention will be apparent and explained by consideration of the embodiments disclosed below.

List of drawing figures

The ozone generator, the method of operation of the ozone generator and the transformer assembly according to the invention will now be described in more detail with reference to the accompanying drawings. The drawings illustrate one mode of implementing the present invention and are not to be construed as limiting with respect to other possible embodiments falling within the scope of the appended claims.

In fig. 1 shows a cross-section of an ozone generator assembly in accordance with some embodiments of the invention.

In fig. 2 shows a cross-section of an ozone generator assembly in accordance with some other embodiments of the invention.

In fig. Figure 3 shows a graph of operating frequency versus weighted audible noise and the relationship between set value and actual ozone production value.

In fig. 4 is an exploded view of a transformer assembly in accordance with some embodiments of the invention.

In fig. 5 is a perspective view of a transformer assembly according to some embodiments of the invention.

In fig. 6 is a flow diagram of a method of operating an ozone generator in accordance with some embodiments of the invention.

Information confirming the possibility of implementing the invention

In fig. 1 shows an ozone generator assembly 27 comprising a first PTFE sheet 23 and a second PTFE sheet 24 surrounding a high voltage electrode 16.

The first and second reaction chambers in which ozone is generated are limited by the first PTFE sheet 23 and the second PTFE sheet 24 on one side and the inner surface of the housing or the ground electrodes 14 and 15, respectively. Oxygen gas enters the ozone generator unit 27 through inlet channels 19 and 20 and is subjected to corona discharge in the first and second reaction chambers, resulting in the formation of ozone gas, which exits through ozone outlet channels 21 and 22, respectively. The housing or ground electrodes 14 and 15 are cooled by water cooling flowing in water cooling chambers 11 and 13. Water cooling chambers 11 and 13 are formed by recesses on the outer surface of the grounding electrodes 14 and 15, closed by covers 10 and 12.

Between the inner surface of the ground electrodes 14 and 15 and the first PTFE sheet 23 and the second PTFE sheet 24 are stainless steel mesh or sheet 25 and 26. Stainless steel mesh or sheet 25 and 26 are corona effect promoting structures that promote discharge between the electrodes.

Between the grounding electrodes 14 and 15 there are support rings 17 and 18 made of PTFE.

PTFE back-up rings can act as spacers to form reaction chambers between the ground electrodes and the high voltage electrode.

In fig. 2 shows an ozone generator assembly 45 comprising a first PTFE sheet 43 and a second PTFE sheet 44 surrounding a high voltage electrode 36.

The first and second reaction chambers in which ozone is generated are limited by the first PTFE sheet 43 and the second PTFE sheet 44 on one side and the inner surface of the housing or ground electrodes 34 and 35, respectively. Oxygen gas enters the ozone generator unit 45 through input passages 39 and 40 and is subjected to corona discharge in the first and second reaction chambers, resulting in the formation of ozone gas, which exits through ozone output passages 41 and 42, respectively.

The housing or ground electrodes 34 and 35 are cooled by water cooling flowing in water cooling chambers 31 and 33. Water cooling chambers 31 and 33 are formed by recesses on the outer surface of the grounding electrodes 34 and 35, closed by covers 30 and 32.

Between the grounding electrodes 34 and 35 there are support rings 37 and 38 made of PTFE.

The ozone generator unit 45 includes first and second PTFE sheets 43 and 44 in contact with the inner surface of the first and second reaction chambers, that is, with the inner surface of the ground electrodes 34 and 35.

This configuration provides improved and efficient cooling of the PTFE sheets in contact with the inner surface of the ground electrodes, which are externally cooled by water.

In fig. Figure 3 shows a graph relating operating frequency to weighted audible noise, as well as the relationship between actual value and ozone production set point.

The X-axis represents the operating frequency, in Hz, of the ozone generator according to the first aspect of the invention

- 4 044703 nia.

The Y1 axis represents the weighted audible noise reduction in dBA.

Line 1 is a dataset of ozone generators operating at different frequencies with respect to noise reduction.

It can be seen that increasing the frequency from 10 to 30 kHz leads to a significant reduction in noise, that is, up to -32.5 dBa. A further increase to 40 kHz provides a further reduction to -37.5 dBA. An additional increase in operating frequency does not result in a significant reduction in the audible noise produced by the ozone generator.

The Y ₂ axis represents the relationship between the actual ozone production value and the set ozone production value O _av /O _sv at an ozone concentration of 200 g O ₃ /nm ³ , at 2 bar and 100% ozone production capacity.

The value of 100 on the Y2 axis represents the condition where the set value corresponds to the actual value, so for a set value of 200 g O ₃ /norm.m ³ , the actual value of ozone produced is 200 g O ₃ /norm. m ³ . Values below 100 correspond to conditions where the set point is higher than actual ozone production, i.e. Less ozone is produced compared to the set value.

Values above 100 correspond to conditions where the set point is lower than actual ozone production, i.e. more ozone is produced compared to the set value.

Line 2 shows the correspondence between set values and actual values depending on the operating frequency.

It can be observed that the higher the operating frequency, the worse the agreement between the set value and the actual value of ozone produced.

Indeed, at high frequencies, for example at 60 kHz, the corresponding value of 90 means that at a given value of 200 g O ₃ /norm.m ³ only 180 g O _{3 /norm.m} ³ are produced.

Reducing the operating frequency improves the agreement between the set point and the actual ozone produced.

For example, for an operating frequency of 30 kHz, the corresponding value of 102 means that at a given value of 200 g O ₃ /norm.m ^3, 204 g O ₃ /norm.m ³ are produced.

Within acceptable limits, deviations between the set and actual values, i.e. 100 +/- 2, it was unexpectedly found that the operating frequency of 30 to 40 kHz provides the lowest audible noise, i.e. the highest reduction in dBA, i.e. from - 32.5 dBa to - 37.5 dBa.

Thus, the inventors designed the ozone generator to operate at a frequency of 30 to 40 kHz.

In fig. 4, a transformer assembly 5 according to some embodiments of the invention comprises a ferrite core having two parts 3 and 6 separated by a spacer 7 for clearance, and primary and secondary windings 4 and 8.

In fig. 5 shows a perspective view of the transformer unit 5 of the transformer, shown in disassembled form in FIG. 4.

In fig. 6 is a flow diagram of a method of operating an ozone generator 9 of an ozone generating device in accordance with the first aspect of the invention, the method including operating the ozone generating device at a frequency of 25 to 40 kHz, for example 30 to 40 kHz.

The operation of an ozone generator includes the following:

S1 supplies the ozone generator with a fluid stream containing oxygen gas;

S2 controls the flow of a fluid containing oxygen gas;

S3 controls the power supplied from the power supply to the ozone generator at a frequency of 25 to 40 kHz, for example 30 to 40 kHz.

Although the present invention has been disclosed in connection with these embodiments, it should not be construed as in any way limited to the examples presented. The scope of the present invention is defined by the accompanying claims. In the context of the claims, the terms containing or containing do not exclude other possible elements or steps. In addition, mention of features or reference to features in the singular (indefinite articles a or an in the original text of the application in English) should not be construed as excluding plurality. The use of item numbers in the claims in relation to elements shown in the drawings should also not be construed as limiting the scope of the invention. In addition, individual features given in different claims can be effectively combined, and the inclusion of these features in different claims does not exclude the fact that a combination of features is impossible and ineffective.

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Claims (15)

CLAIM 1. An ozone generating device containing an ozone generator block (27, 45) containing a high voltage electrode block (16, 36); a first dielectric element (23, 43) and a second dielectric element (24, 44); a first ground electrode (14, 34) and a second ground electrode (15, 35); wherein said high-voltage electrode block (16, 36) is located between said first dielectric element and said second dielectric element, said generator block being configured to operate in an operating frequency range of 30 to 40 kHz; low-frequency high-voltage alternating current source, which is a transformer unit capable of supplying from 50 to 800 W with a frequency of 30 to 40 kHz to the ozone generator unit. 2. The ozone generating device according to any one of the preceding claims, wherein said first and second dielectric elements are located at a distance from said high voltage electrode unit in the range of 0.01 to 0.1 mm, for example 0.01 to 0.075 mm. 3. The ozone generating device according to any one of the preceding claims, wherein said first and second dielectric elements are separated from said high voltage electrode assembly by one or more separating elements. 4. The ozone generating device according to any one of the preceding claims, wherein said first and second dielectrics are located on both sides of said high voltage electrode. 5. The ozone generating device of any one of the preceding claims, wherein said first and second ground electrodes with said first and second dielectrics define the first and second reaction chambers. 6. The ozone generating device according to any one of the preceding claims, wherein said high voltage electrode is formed as a metal coating on said first and said second dielectrics. 7. The ozone generating device according to any one of claims 1 to 5, wherein said high voltage electrode is a metal foil or a metal sheet. 8. The ozone generating device according to any one of the preceding claims, wherein each of said first and second reaction chambers comprises at least an inlet channel (19, 20, 39, 40) for supplying oxygen gas or an oxygen-containing gas and at least , output channel (21, 22, 41, 42) for releasing ozone gas. 9. The ozone generating device according to any one of the preceding claims, wherein the outer surface of the first and second chambers includes cooling elements such as cooling fins. 10. The ozone generating device according to any one of the preceding claims, wherein said first and second dielectric elements are in contact with an inner surface of said first and second reaction chambers. 11. The ozone generating device according to any one of the preceding claims, wherein said transformer assembly is a transformer. 12. The ozone generating device according to any one of the preceding claims, wherein said transformer assembly is a transformer comprising a cladding type ferrite core surrounding a primary winding and a secondary winding, wherein the number of turns of said primary winding is less than 14 and the number of turns of said secondary winding is more than 107, wherein said cladding-type ferrite core has an air gap of less than 2 mm. 13. The method of operating an ozone generating device according to any one of claims 1 to 12, comprising operating said ozone generator at a frequency of 30 to 40 kHz. 14. The method of operating an ozone generating device according to claim 13, wherein said operation comprises supplying a stream of fluid containing oxygen gas to said ozone generating device; controlling said flow of fluid containing oxygen gas; controlling the power supplied from the power supply device to said ozone generator at a frequency of 30 to 40 kHz. 15. The method of operating an ozone generating device according to claim 13 or 14, wherein said frequency is a frequency of 31 to 40 kHz, for example a frequency of 32 to 35 kHz. -