RU2275324C1 - Device for production of ozone in the electrical discharge - Google Patents

Abstract

FIELD: equipment for production of ozone; devices for production of ozone at the ozone plants.

SUBSTANCE: the invention is pertaining to the field of equipment for production of ozone, mainly, to the designs of the electric discharge chambers of the ozone plants, in particular, to the device for production of ozone in the electrical discharges. The device contains the dielectric barrier, the inducing electrode and the discharge electrodes electrically connected among themselves. The inducing electrode and the dielectric barrier represent the cuttings of a cylindrical cable electrically connected to each other. The discharge electrodes are made in the form of the non-insulated cylindrical conductors, which diameter is equal to the diameter of the cylindrical cable. The cable cuttings and the discharge electrodes are arranged back-to-back in the staggered order. The offered invention ensures simplification of manufacture of the device for production of ozone, reduction of its linear overall dimensions, increased reliability of operation.

EFFECT: the invention ensures simplification of manufacture of the device for production of ozone, reduction of its linear overall dimensions, increased reliability of operation.

2 dwg

Description

The invention relates to the field of creating ozone generators, namely, to the design of electric discharge chambers of ozonizers designed to produce ozone from oxygen or a mixture containing oxygen.

Ozonizers are widely known in which ozone is obtained by treating oxygen-containing gases with an electric discharge in a chamber equipped with electrically conductive surfaces - electrodes located in parallel through a small gap from each other, to which an alternating high voltage is applied; a dielectric material (dielectric barrier) is attached to the inner surface of the electrodes [1]. The synthesis of ozone in such devices is due to the volume-barrier discharge in the gas gap.

The main disadvantage of these devices is the failure of the dielectric barrier, the most vulnerable element of the ozonizer chamber. In addition to the effects of ozone, the barrier experiences destruction caused by both microdischarges of the barrier discharge and directly by the electric field. The combined effect of these factors leads to the release of the dielectric barrier, resulting in a short circuit between the electrodes. The initial destruction of the barrier is due to the high-temperature action of microdischarge channels. Especially such a process intensifies when the barrier discharge is localized. The main reason for localization in the barrier discharge is the formation of spots with increased conductivity on the surface of the barrier. Such spots arise both due to humidity, contamination of the treated gas, and due to products accompanying ozone synthesis. These spots have a high capacity with an electrode, which is located on the other side of the barrier. As a result, a discharge occurs from another electrode to the spot. The larger the area of the spot and correspondingly higher its capacity, the more intense the discharge. The discharge site is localized by the location of the spot on the barrier. Due to localization and increased intensity, the discharge through the spot quickly destroys the dielectric barrier.

The closest in technical essence to the claimed device is a device selected as a prototype, containing a dielectric barrier, on one side of which there is one inducing electrode, and on the other a set of uniformly distributed discharge electrodes made in the form of metal strips [2]. In this case, an electric discharge occurs on the surface of the barrier and is supported by the bias current flowing through the barrier between the discharge electrodes and the induction electrode. According to [3], a surface barrier discharge has some characteristics, that is, physical properties inherent only to it, distinguishing it from a volume-barrier discharge: for example, the spectral range of radiation falling in the near ultraviolet region and a lesser degree of contraction of microdischarge channels. The first difference helps to increase the efficiency of ozonation. And the second difference is to reduce the likelihood of localization of discharge processes and, as a result, to increase the life of the ozonizer chamber.

However, in the prototype [1], as in analogues [2], the manufacture of a dielectric barrier is of great difficulty in creating ozone generators. These are tight tolerances on the uniformity of the barrier, the absence of air inclusions between the electrodes and the barrier, which is technologically difficult. This applies to both plate and tubular versions of ozonizers. With the lamellar type of ozonizers, edge effects have a great influence on reliability and dimensions. With tubular execution, one of the linear dimensions is reduced by more than π times, taking into account the flanges for the plate version.

In view of this, serious structural and technological difficulties are encountered in the manufacture of electric discharge elements, leading to defects and, as a result, to a decrease in the life and reliability of ozone generators.

The technical result of the invention is to simplify the manufacture of the device, reducing its linear dimension and increasing the reliability.

This technical result is achieved by the fact that in the device for producing ozone containing a dielectric barrier, an inducing electrode and discharge electrodes electrically connected to each other, the induction electrode and a dielectric barrier are pieces of a cylindrical cable electrically connected to each other, and the discharge electrodes are made in the form non-insulated cylindrical conductors, the diameter of which is equal to the diameter of the cylindrical cable, with cable lengths and discharge electrodes located staggered to each other.

The use of a cable as a dielectric barrier and an inducing electrode can significantly simplify the manufacturing technology of ozone generators. Automation of cable manufacture and control guarantees high reliability when used as electric discharge elements. A wide variety of cable products allows in each case to achieve the necessary indicators and parameters for ozone generators. In addition, it becomes possible to have different geometry of the cross-section of the ozonization chamber due to the adjustable location in space of the cable segments and uninsulated conductors. This reduces the linear dimension of the ozone generator.

Figure 1 schematically shows an ozone generator; in Fig. 2, section A-A of Fig. 1, a case is presented where the section of the ozonizer chamber is square, i.e. the number of columns is equal to the number of rows (in our case, Figs. 1 and 2 in each column and row are three pieces of insulated cable and three pieces of uninsulated conductor).

The ozonizer consists of pieces of insulated cable of circular cross-section 1 and pieces of non-insulated round conductor 2. The diameters of cable 1 and conductor 2 are the same and are staggered relative to each other.

The cross-sectional shape of the ozonizer chamber can be varied. The most technological and easily implemented is a rectangular shape. Giving the necessary shape to the cross-section of the camera and its conservation is ensured by means of a housing 3 made of dielectric material. To ensure the conclusion of the ends of segments 1 and 2, in order to connect them to a source of alternating high-voltage voltage (not shown in FIG. 1), two covers 4 are used, which simultaneously provide sealing of the ozonizer chamber. For the supply and output of ozonated gas, two nozzles 5 and 6 are used. Figure 1 shows the active zone of the ozonation chamber, and figure 2 shows its cross section. In this zone, segments 1 and 2 are located close to each other. Further, before the output from the chamber, the segments diverge relative to each other in order to reduce the influence of edge effects. Obviously, other versions of the conclusions of segments 1 and 2 are possible.

The ozone generator operates as follows. A predetermined ozonated gas flow enters through the nozzle 5 into the ozonizer chamber. Then it passes into the discharge gaps formed by the surfaces of the segments of cables 1 and conductors 2 (these are the gaps between the surfaces of the cylinders when they are placed close to each other). When applying a high alternating voltage to the terminals of the ozone generator, one of which connects all segments of insulated cables 1, and the other connects all segments of bare wires 2, sliding discharges occur in the core along the cylindrical surface of the cable segments and ozone is synthesized. Then the ozone-gas mixture leaves the discharge gaps of the active zone of the chamber and is fed through the nozzle 6 to the ozone treatment object. The number of discharge zones on each cable segment is determined by the number of lines of contact with the segments of uninsulated conductor. Due to the checkerboard rotation of figure 2, for the lengths of cables located inside the section of the ozonizer chamber, the number of such lines is four, and for the extreme segments is three and for the corner - two.

The total number of discharge zones is determined by the formula

,

,

here a is the number of rows, b is the number of columns. The largest number of discharge zones for the same number of segments will be for a square section and is equal to

,

,

where n = a = b is the number of rad or columns of the cross section of the discharge chamber.

The same conclusion is true to ensure a minimum linear size. Figure 2 presents the cross section of the ozonizer chamber square shape corresponding to the best option.

The implementation in the ozone generator of the most critical element of the dielectric barrier of the cable segments allows you to increase the life of the proposed device. Such cables are widely produced by industry, their production and quality control are automated, which is a guarantee of their high reliability.

In laboratory conditions, a number of ozonization chambers were created based on the PPI-U brand cable. The core insulation of such a cable is made of polyimide-fluoroplastic film grade PMF-S-352 and a thickness of 0.23 mm. Ozone generators with such cameras operated at various frequencies with voltages up to 4 kV with a specific ozone productivity of 200 g / kW. None of the chambers failed and the duration of continuous operation of ozone generators was at least 4000 hours.

Information sources

1. V.V. Lunin, M.P. Popovich, S.N. Tkachenko. Physical chemistry of ozone. - M: Publishing House of Moscow State University, 1998, p. 63-67.

2. Masuda S. Industrual Applications of Electrostatics // Journal of Electrostatics. 1981. V / S. P.1-14.

3. Kalinin A.V., Kozlov M.V., Panyushkin V.V. An experimental study of the characteristics of a high-frequency surface discharge // Izv. USSR Academy of Sciences. Energy 1993. T.4, p. 44-51.

Claims (1)

A device for producing ozone containing a dielectric barrier, an induction electrode and discharge electrodes electrically connected to each other, characterized in that the induction electrode and dielectric barrier are pieces of a cylindrical cable electrically connected to each other, and the discharge electrodes are made in the form of uninsulated cylindrical conductors, the diameter of which is equal to the diameter of the cylindrical cable, with cable lengths and discharge electrodes located close to each other in a checkerboard pattern order.

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