RU2363653C1 - Device for producing ozone using pulsed barrier discharge - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to devices for producing ozone from wet air. The device for producing ozone using pulsed barrier discharge contains a discharge chamber with high voltage, dielectric-coated and grounded electrodes, high voltage pulse source, containing a driving pulse generator, charging device, the outputs of which are connected to corresponding inputs of one or several modules, containing a storage capacitor, controlled pulsed switch, shorted by a pulse capacitor, and the primary coil of a pulse transformer, mounted on a separate closed part of a magnetic core with or without clearance. The high voltage coil of the pulse transformer is connected to high voltage and grounded electrodes respectively.

EFFECT: design of a simple, cheap and easier to use ozone generator while increasing its reliability, ozone output and reducing specific energy consumption.

4 cl, 3 dwg

Description

The invention relates to devices for producing ozone from dry air and can be used in various fields of the national economy, for example, in the field of purification of drinking and waste water, in pulp and paper, food, pharmaceutical, chemical and other industries.

The created high-voltage pulsed generators for ozone electrosynthesis using pulsed corona discharge and pulsed barrier discharge turned out to be more competitive with conventional alternating current ozone generators with a frequency of 50 Hz and higher frequency (400-4000 Hz). The generation of ozone by means of pulsed discharges is promising because of the possibility of decreasing the specific energy consumption when producing ozone.

A device of an electric transformer is known that converts electric current, voltage or resistance from one value to another (A.K. Losev, 1971, Linear radio circuits, Moscow, Higher School), consisting of one primary and one or several secondary windings inductively connected between by myself.

The ozone generators with a dielectric barrier are widely known (see AS SU No. 941276, IPC СВВ 13/11, dated 07/07/1982; SU No. 1774585, IPC С01В 13/11, dated 05/15/1994; SU No. 17753535, IPC С01В 13/11 , dated November 15, 1992) containing a high-voltage pulse generator and a working chamber connected to it with electrodes, one of which is covered with a dielectric layer.

A device for ionizing gas using a barrier discharge (see US patent No. 5554344, IPC СВВ 13/11, 09/10/96), consisting of internal and external concentric metal electrodes and a grounded shield with a glass dielectric tube located between them. Working gas is passed between the dielectric and the grounded shield. The electrodes and the grounded shield are designed so that cooling of the working chamber is achieved.

A device is known for generating powerful current pulses in a low-impedance load (see patent RU No. 2153762, IPC Н03К 3/53 Н02Р 13/06, dated July 27, 2000), comprising a transformer with a load in the secondary winding, a bi-directional controllable switch, an alternating voltage source, and a device control, moreover, a charge device, a capacitor and a second bi-directional controlled key are introduced, the capacitor connected through a second bi-directional controlled key to a part or to all turns of the primary winding of the transformer, and through the device poison - to a source of alternating voltage.

A device for producing ozone is known (see patent RU No. 2119446, IPC СВВ 13/11, dated 09/27/1998), consisting of a housing with an inlet for introducing dry air or oxygen and an outlet for supplying air or oxygen to the outside with the obtained ozone, at least one pair of corona and non-corona electrodes, mutually isolated and located opposite each other, is installed inside the housing in the gas passage, and a source of short high-voltage pulses of positive polarity with a duration of up to 1 is installed outside the housing 000 ns, the output terminals of which are connected to the electrodes in the agreed polarity, moreover, the non-corona electrode or at least its part in contact with the discharge is made of aluminum, or an aluminum alloy, or of an electrically conductive alloy with thermal conductivity above 50 W / (m · deg) .

Moreover, the source of short high voltage pulses provides an average specific power of the corona discharge of more than 50 W / l, the repetition frequency of high voltage pulses is more than 500 Hz, the ratio of the amplitude of high voltage pulses to the amplitude of the residual DC voltage on the electrodes between the pulses is 1.5-3.

This device is technically difficult to implement and has a small operational resource, since it requires the use of fast high-current high-voltage pulse switches for its operation, for switching high-voltage pulses with a rise front of less than 1 μs. In addition, aluminum alloys have insufficient corrosion resistance in an acidic environment, which inevitably forms during the synthesis of ozone.

The closest in technical essence and the achieved result is an ozonizer (see AC SU No. 1370072, IPC С01 В13 / 11, from 1988), containing an ozone generator, a controlled pulse generator, including a rectifier, a thyristor high-frequency inverter, an inverter control system, a switching element and an energy storage element in the form of a capacitor through which a controlled pulse generator is connected to the primary winding of a pulse transformer, the ozone generator is included in the secondary winding of which.

The ozonizer operates in resonance mode, which is ensured by the presence in the secondary winding of a pulse transformer of a resonant frequency sensor connected in series with the ozone generator. The discharge time of the storage element is several microseconds, which is due to the presence of a switching thyristor, so the rise time (front) of the pulse in the secondary winding of the pulse transformer is ≥1 μs.

In the known invention, the rise front pulses are determined by the opening time of the switching thyristor, and such a power source has obvious drawbacks when it is used to supply a barrier discharge, due to the fact that the main energy consumption of the barrier discharge falls on the pulse front, when the thyristor is not yet completely open, and the voltage drop (which determines the amount of energy loss) on it is significant, which leads to a decrease in the energy efficiency of this construction of the known circuit.

As well as the significant difficulty of scaling it, requiring a radical change in the elemental base when switching to large power levels.

The technical result of the invention is the creation of a simple, cheap, easy to use and easily scalable ozone generator while increasing the high reliability of the device, increasing the output of ozone and reducing specific energy consumption.

Ample opportunities are achieved in that in a device for generating ozone by means of a pulsed barrier discharge containing a discharge chamber with inlet and outlet openings, inside which high-voltage electrodes coated with a dielectric and grounded electrodes are placed, moreover, a high voltage pulse source containing control pulse generator, charger, the outputs of which are connected to the corresponding inputs of one or more modules, including a drive a capacitor controlled by a pulse switch shorted by a pulse capacitor and the primary winding of a pulse transformer located on a separate closed part of the magnetic circuit with or without a gap, and the high voltage winding of the pulse transformer, covering all parts of the magnetic circuit belonging to all modules, is connected respectively to high voltage and grounded electrodes .

The controlled pulse switches are implemented on IGBTs (bipolar transistors with insulated gate), or on field-effect or bipolar transistors with connected reverse diodes.

The controlled pulse keys of the modules are opened and closed synchronously with each other using a single external control pulse generator.

The high-voltage electrode is made in the form of a column of metal powder or of metal chips placed in a quartz tube.

The essence of the invention is that a technical solution is proposed that makes it easy to increase the output current of a pulse transformer without affecting the remaining parameters of the pulse due to the modular construction of the electrical circuit of the pulse generator. The proposed solution allows, using standard modules with given parameters, to arbitrarily increase the output pulse power and, therefore, the ozonizer performance by adding the required number of modules, without switching to a new element base.

To manufacture an arbitrarily productive ozone generator, reliable and inexpensive serial IGBTs, as well as field-effect or bipolar transistors with connected reverse diodes, can now be used as pulse keys of the underlying modules.

The use of high-voltage electrodes, which are a quartz tube filled with metal powder or metal chips, can improve the reliability of the ozonizer and reduce the accuracy requirements for maintaining the interelectrode gap due to the concentration of the electric field on the surface of the particles of metal powder or chips.

Comparison of the proposed solution with the known technical solutions shows that it has a new set of essential features that, together with the known features, can successfully achieve the goal.

Figure 1 shows the functional diagram of the proposed technical solution, figure 2 and 3, respectively, the implementation of the electronic key on the field effect transistor with parallel inverse diodes and IGBT (Isolated Gate Bipolar Transistor).

A device for generating ozone using a pulsed barrier discharge contains:

1 - discharge chamber;

2, 3 - inlet and outlet openings of the discharge chamber;

4 - high-voltage electrode made of metal powder or chips, placed in a quartz tube;

5 - dielectric (quartz tube);

6 - grounded electrode;

7 - a source of high voltage pulses;

8 - module;

9 - charger;

10 - storage capacitor;

11 - controlled impulse key;

12 - pulse capacitor;

13 ^1-n - primary windings of a pulse transformer;

14 - secondary high-voltage winding of a pulse transformer;

15 - IGBT (Insulated Gate Bipolar Transistor);

16 - field effect transistor;

17 - bipolar transistor (not shown);

18 - reverse diode;

19 - a generator of control pulses;

20 - high voltage pulse transformer;

21 - a separate element of the magnetic circuit belonging to this module;

22 - electrode system;

23 - network voltage;

The operation of the device is as follows.

In the discharge chamber 1 with inlet 2 and outlet 3 there is an electrode system 22 made of high voltage electrodes 4 and grounded electrodes 6, which are metal tubes that can be cooled by water or air. Inside the grounded tubes 6, high-voltage electrodes 4 are coaxially located, which are quartz tubes 5 filled with chips or stainless steel powder or other ozone-resistant material.

A source of voltage pulses 7 is connected to the high-voltage electrodes 4 of the discharge chamber 1, containing a charger 9 connected to an alternating voltage of the supply network 23 (for example, a rectifier of the mains voltage), charging one or more storage capacitors 10 and a high-voltage pulse transformer 20. Pulse transformer 20 can have one 13 ¹ or several independent primary windings 13 ⁿ , each of which is wound on a separate closed magnetic circuit 21 with or without a gap. The secondary high-voltage winding 14 passes through all the magnetic circuits with the primary windings 13 ⁿ and, thus, the voltage on the secondary high-voltage winding 14 increases not only in proportion to the ratio of the turns in the primary 13 ⁿ and secondary winding 14, but also in proportion to the number of primary 13 ⁿ windings.

In series with each primary winding 13 ^n, a controlled pulse switch 11 is installed, which opens and closes at specified times, shorted by a pulse capacitor 12. As such a key, IGBT 15, bipolar 17 or field 16 transistors shorted by a reverse diode 18 can be used. Primary winding 13 ⁿ through a controlled pulse switch 11 is connected to the storage capacitors 10. When opening the controlled pulse switch 11, the storage capacitor 10 is discharged through the primary winding 13 ⁿ . Moreover, the current during the entire opening time of the controlled pulse switch 11 through the primary winding 13 ⁿ increases. Along with the increase in current, the energy stored in the inductance of the primary winding 13 ⁿ grows. At the moment of closing the controlled pulse switch 11, this energy starts charging the pulse capacitor 12, shorting the controlled pulse switch 11, and after a certain time specified by the value of the effective inductance of the primary winding 13n and the value of the pulse capacitor 12, is charged to a maximum voltage that can exceed the voltage by storage capacitor 10 several times. Then, the pulse capacitor 12 is discharged through the primary winding 13 ⁿ . In the remaining primary windings 13 ^{n, the} described process proceeds synchronously. The process of synchronous charging and discharging pulse capacitors 12 through the primary windings 13 ⁿ generates a voltage pulse on the secondary high-voltage winding 14, leading to the ignition of the barrier discharge in the discharge chamber 1 of the ozonizer and energy dissipation in this discharge.

The proposed technical solution has the following advantages: the pulse front is not related to the key opening time and, as a result, the main energy release in the barrier discharge, which falls in time exactly to the pulse front, is separated in time from the moment of opening and closing of the controlled pulse switch 11, t. e. with moments of maximum energy loss in a controlled pulse switch 11. Thus, energy losses in a controlled pulse switch 11 are minimized. In addition, this circuit makes it possible to easily scale it without changing the used elemental base by adding in this way new primary windings 13 ⁿ with simultaneous a decrease in the number of turns in the secondary high-voltage winding 14.

And the use of high-voltage electrodes 4, which are quartz tubes 5, filled with chips or powder from stainless steel or other ozone-resistant material, can improve the reliability of the ozonizer and reduce the accuracy requirements for maintaining the interelectrode gap due to the concentration of the electric field on the surface of the particles of metal powder or chips.

The technical and economic effect of the invention allows to significantly increase the reliability of the ozonizer, increase ozone output, reduce specific energy consumption by creating a simple, cheap, easy to use and easily scalable generator of short high voltage pulses.

Claims (4)

1. A device for generating ozone by means of a pulsed barrier discharge, comprising a discharge chamber with inlet and outlet openings, inside which are placed high-voltage electrodes coated with a dielectric, and grounded electrodes, and a high voltage pulse source containing a control pulse generator and a charging pulse is installed outside the discharge chamber a device whose outputs are connected to the corresponding inputs of one or more modules, including: storage capacitor controlled by a pulse a key shorted by a pulse capacitor and a primary winding of a pulse transformer placed on a separate closed part of the magnetic circuit with or without a gap, and the high voltage winding of the pulse transformer, covering all parts of the magnetic circuit belonging to all modules, is connected, respectively, to high voltage and grounded electrodes. 2. The device for generating ozone using a pulse barrier discharge according to claim 1, characterized in that the controlled pulse switches are implemented on IGBT, either on field or bipolar transistors with connected reverse diodes. 3. The device for generating ozone using a pulse barrier discharge according to claim 1, characterized in that the controlled pulse keys of the modules are opened and closed synchronously with each other using a single external control pulse generator. 4. A device for generating ozone using a pulsed barrier discharge according to claim 1, characterized in that the high-voltage electrode is made in the form of a column of metal powder or of metal chips placed in a quartz tube.

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