CS252410B1 - Lightweight filter to reduce explosion-proof overpressure - Google Patents

Abstract

The solution concerns the problem of short-circuit resistance of electrical equipment in an explosion-proof enclosure. The relief filter simply reduces the overpressure in the explosion-proof enclosure in the event of an internal short-circuit below the value of the mechanical resistance of the enclosure and reduces the temperature of the short-circuit fumes below the ignition temperature of the surrounding flammable mixture of gases, vapors or dusts. The relief filter can be used in electrical equipment in an explosion-proof enclosure in areas with a risk of explosion of gases, vapors or dusts, i.e. in the chemical industry or in mines.

Description

The invention solves short-circuit resistance of enclosures of non-explosive enclosure with electrical equipment at internal short-circuit and electric arc development, prevents distortion of the enclosed enclosure due to temperature and pressure, hot exhaust to the surrounding space and ignition of surrounding explosive gas and vapor arrays.

Problems occur in particular in non-explosive lozenges and knowledgeable internal lenses, such as 0.3 n and nanfilms.

The closest known solution operates on the principle of swirling the short-circuited hot products on Z-shaped metal lamellas folded in a row behind or behind, reducing the exhaust pressure and cooling it.

The simpler principle is based on the application of the lightening filter of the present invention, which consists in inserting into the filter of the filter two cooling blocks composed of metal plates separated from each other by an air feed of not more than 0.5, which provides an outlet heat from the hot fumes produced by the internal short circuit and the development of an electric arc in the non-explosive lining, and by a layer of sand separating the two cooling blocks from each other and serving! to trap hot solids in short circuit products.

The effect of the invention is to simplify the solution of the problem of temperature and pressure increase within the non-explosive lining during internal short-circuiting, and to eliminate the destructive effects of β ignition of the surrounding angels of flammable gases and vapors. The design of the filter according to the invention allows cost reduction to non-explosive devices and ensures safe operation.

The device according to the invention is shown in Fig. 1, in which the relief filter body 1, made of cast iron or an aluminum alloy 42, is shown in the front view. block 2 and es melted from pleats of material 11 331 · 1, in which it is not secured between the pleats msx · up to 0,5 not secured by nallies protruding relative to each other by 180 °, second cooling block 3 assembled similarly and sand layer 4 to catch Both blocks 2 and 3 and the sand layer 4 are inserted into the body 1 so as to stand in the way of the passage of the hot products, ensuring their cooling and trapping of the solid particles while preventing the pressure build-up inside the non-explosive enclosure above the strength limit. The entrance to the first cooling block 2 is limited by a metal plate 5 so that the edges of the floats are not in the water by direct arc action at short-circuit. downwards so as not to stir up dust deposited on non-explosive enclosures ·

Fig. 3 shows the arrangement of the individual floats of the first cooling block 2 from the hot exhaust gas inlet side of the filter.

On the one hand, the filter body 11 is identical in its attachment dimensions to that of the non-explosive enclosure and forms a complete non-explosive enclosure.

The relief filter acts at the time of short circuit from arcing to switch-off of the electrical device by a protective device or fuse. The function of the relief filter is that hot short products within the non-explosive enclosure are blown overpressure via the least resistance through the filter. where the temperature drops below 1000 Λϊ, then layer 4 of sand, where solid particles are caught and further cooled, and then the second cooling block 3, where the temperature of the exhaust gases is lowered below the ignition temperature of the mixture of gases and vapors explosion proof ·

The size of the cooling blocks corresponds to the amount of heat given by the short-circuit time and the magnitude of the short-circuit current when the arc develops, the thickness of the sand layer corresponds to the overpressure inside the nonexplosive enclosure.

Claims (1)

OBJECT OF THE INVENTION Relief filter for reducing overpressure in an enclosed enclosure • electrical device · at an internal short circuit · electric arc development, characterized in that it releases from the body (1) into which the first cooling block (2) and the second cooling block (3) are inserted ) _} oon, made of metal, pleated, separated by air «drunk not more than 0,5 inches» and sand (4) in sand, between these blocks · 1 drawing