RU2448778C1 - Electric filter with self-centering corona-forming elements - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to electric cleaning of gases of suspended solid and fluid particles in heat power engineering, chemical industry, production of construction materials, metallurgy, etc. Proposed filter consists of casing, precipitation and corona-forming electrodes and electrode shakers. Corona-forming electrodes has different-length-and-cross-section-needles. Note here that long needles have smaller cross-section than that of short needles.

EFFECT: higher quality of gas cleaning due to better centering.

2 cl, 3 dwg

Description

The invention relates to the electrical cleaning of gases from suspended solid and (or) liquid particles in various industries, in particular in the power industry, chemical industry, building materials industry, metallurgy, etc.

Known electrostatic precipitator (EF), consisting of precipitation and wire corona electrodes (Uzhov V.N. Industrial gas purification by electrostatic precipitators. P.177. - M .: Chemistry 1962.) The disadvantages of this electrostatic precipitator are insufficient gas purification. This is due to the gradual deviation of the corona elements from the central position due to the constant striking by the shaking mechanisms during the regeneration of the electrode surface.

Also known is an electrostatic precipitator (Uzhov VN Industrial gas purification by electrostatic precipitators. Page 178. - M .: Chemistry 1962.) This electrostatic precipitator contains tape-needle corona electrodes having the same needle sizes.

The disadvantages of this electrostatic precipitator are also the gradual misalignment of the electrode system due to the action of shaking mechanisms. This reduces the degree of gas purification by electrostatic precipitators during their long-term operation.

Closest to the proposed invention in terms of technical nature, the technical problem to be solved and the totality of common essential features is the element of the corona electrode of the electrostatic precipitator (Patent No. 2229939) (prototype), in which corona needles with a small radius of curvature are used.

However, both the above analogues and the prototype do not solve the problem of improving the alignment of the electrode system both during commissioning of the EF and during its long-term operation.

The technical problem of the present invention and the technical result achieved by solving it consist in increasing the degree of purification of the EF gases by improving the alignment of the electrode system both during the commissioning of the EF and during its long-term operation.

The specified technical result is achieved in that the corona elements have needles of different lengths and cross-sections, and longer needles have a smaller cross section than the cross section of short needles.

In addition, the electrostatic precipitator with self-centering corona elements is characterized in that the corona elements have pairs of twin needles of different heights and cross-sections, the distance between twin needles is 5 ... 10 mm, and the distance between the centers of the pairs of twin needles is 20 ... 90 mm.

These features are significant and interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The distance between twin needles, up to 60 mm, is due to the fact that when it increases, the needles in pairs will start to function independently and will not be able to track the alignment of the electrode system. The minimum distance between the pairs of needles is not strict and may vary slightly depending on the manufacturing conditions of the corona element.

The distance between the pairs of needles is caused on the lower side by the need to exclude the mutual screening of the needles, and on the greater hand, by the need to exclude a significant decrease in the corona current.

The possibility of carrying out the invention, characterized by the above set of features, as well as the possibility of realizing the purpose of the invention can be confirmed by the description of a design variant of the device made in accordance with the invention, the essence of which is illustrated by graphic materials.

Figure 1 shows a side view of the corona element.

Figure 2 shows a perspective view of the same element.

Figure 3 shows a fragment of the proposed electrostatic precipitator and its functioning when the alignment appears in the electrostatic precipitator.

Designation of positions in the drawings:

1 - a long needle;

2 - a short needle;

3 - housing of the corona element;

4 - precipitation electrode (shown conditionally);

5 - place of misalignment of the electrode system;

U _CR - breakdown voltage in the electrostatic precipitator installed during commissioning of the electrostatic precipitator.

The functioning of the proposed electrostatic precipitator is as follows. When the electrostatic precipitator is supplied with power from a high voltage source, a corona discharge is ignited on the tops of long needles. As the supply voltage increases, the corona current increases and the electrostatic precipitator operates at a certain operating voltage U _pr installed during commissioning of the electrostatic precipitator. During prolonged use of the electrostatic precipitator, the electrode system is somewhat misaligned for a number of reasons: off-center shock of the hammers of the shaking mechanisms, thermal deformation, random mechanical deformation during inspection or repair of the electrostatic precipitator, etc. In this case, the breakdown gap in some places of the electrostatic precipitator is reduced and becomes similar to that shown in Fig. .3. Then, in a reduced gap, breakdowns will occur and a long thin needle will be shortened due to the action of arc discharges, and corona will occur with a short thickened needle, while the piercing gap will be maintained at the same level. As a result, the supply voltage will remain at the level of U _ol , which will allow to maintain the degree of gas purification at the level specified during commissioning of the electrostatic precipitator.

The present invention is industrially applicable, since its manufacture does not require special equipment and new technologies.

The design of the device "Electrofilter with self-centering corona elements" described in this example and shown in graphic materials is not the only one possible to achieve the above technical result and does not exclude other variants of its manufacture containing a combination of features included in an independent claim.

In addition, in particular cases of implementing the invention, the corona elements can be made in other variants containing a combination of features included in an independent claim.

For example, the supporting part of the corona element can be made of a cylindrical wire of small diameter (2 ... 3 mm), and thin needles are attached to the wire. In this case, the role of thickened needles will be played by the cylindrical wire itself.

Claims (2)

1. An electrostatic precipitator with self-centering corona elements, consisting of a housing, precipitation and corona electrodes and electrode shaking mechanisms, characterized in that the corona elements have needles of different lengths and cross-sections, with longer needles having a cross section smaller than the cross section of short needles. 2. An electrostatic precipitator with self-centering corona elements according to claim 1, characterized in that the corona elements have pairs of twin needles of different heights and cross-sections, the distance between twin needles is 5 ... 60 mm, and the distance between the centers of the pairs of twin needles is 20 ... 90 mm.

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