EP3630304A1

EP3630304A1 - Flame arrester

Info

Publication number: EP3630304A1
Application number: EP18728557.2A
Authority: EP
Inventors: Thorsten Arnhold; Clife HERMANOWSKI
Original assignee: R Stahl Schaltgeraete GmbH
Current assignee: R Stahl Schaltgeraete GmbH
Priority date: 2017-06-01
Filing date: 2018-05-24
Publication date: 2020-04-08
Also published as: RU2019140350A; DE102017112162A1; CN110891654B; RU2751623C2; US20200179735A1; CN110891654A; RU2019140350A3; WO2018219764A1

Abstract

A flame arrester (10) according to the invention comprises two part-bodies (12, 14), which consist of different wire fabric layers (11, 13) and are connected to one another by an intermediate layer (15) of particularly coarse-meshed wire fabric. The coarse-meshed wire fabric preferably consists of a thick wire. Both the wire diameter and the mesh width of this intermediate layer (15) are preferably much greater than the mesh widths and wire diameters of the wires used for the part-bodies (12, 14). The pressure relief body (10) according to the invention combines a high degree of mechanical stability with a great flame arresting capability and at the same time very low flow resistance.

Description

Fire protection filters

The invention relates to a flameproof filter, in particular a flameproof filter for use as a pressure relief body in explosion-proof enclosures of the type of protection Ex-d.

From DE 10 2014 116 149 AI a Flammenschutz- filter is known, which has a greater number of wire mesh layers of different mesh size and wire thickness and preferably ^¬ also different orientation. Due to the changing mesh size and the angular offset of the individual layers against each other arise labyrinthine passages on the one hand verhin ^¬ a flameout and on the other hand offer good gas permeability. The individual layers are connected to each other, for example, by sintering. It turns out, however, that such flameproof filters are more centrally flowed through in the middle of pulsed pressure load, as they can occur as a result of occurring in a housing explosions than in near-edge zones.

It is an object of the invention to provide a flameproof filter with improved flowability.

This object is achieved with the flameproof filter according to claim 1:

The flameproof filter according to the invention has a number of wire fabric layers whose mesh size does not exceed a limit value d _max . The number of wire ^¬ fabric layers is anyhow greater than two, preferably these are five or more layers that define labyrinthine pores. The Flammenschutz- inventive filter comprises at least two such in each case by an on ^¬ number formed of wire gauze layers partial body, between which an intermediate layer having a mesh attached ^¬ arranged is larger than the largest mesh width lying within the specified mesh size range the two part bodies. Arranged between the two part bodies intermediate layer forms a pressure distribution ^¬ layer that permits transverse to the main flow direction, for example radially directed flow, thereby resulting in the intermediate layer to a pressure equalization. The pressure compensation can lead to a better surface utilization of the pressure relief body and thus to a Vermin ^¬ tion of the flow resistance in particular at a pulse-like pressure load. This will reduce pressure peaks more effectively than before.

[0006] Due to the fixed connection of the two partial bodies with the intermediate layer and also a particularly stable pressure relief ^¬ body is obtained, which may be formed over a large area.

The wire fabric layers preferably have wires whose diameter is within a fixed wire diameter range D, whose upper limit d _{max is} exceeded by any of the wires of the wire fabric layers of the two body parts. However, the intermediate layer preferably has wires with a diameter d _z , which is greater than the largest lying within the wire diameter range D ^{diammes ¬} ser d _max . Preferably, additionally or alternatively, the mesh width m _{z of} the intermediate layer is at least 1.5 times as great as the largest mesh width m _max lying in the mesh width region M. Each of the two measures mentioned leads to a low resistance to cross flows the intermediate layer and thus to a good homogenization of the pressure in the intermediate layer. Of the pressure wave forth ^¬ touching flow is so widened in the intermediate position so that is in the direction of flow R wärtige partial body downstream passageway to a larger area used, as would be the case without an intermediate layer.

The intermediate layer can be formed both as a fabric and as a grid of crossing wires or by an equivalent structure. Essential is the possibility of the formation of cross flows.

Further details of advantageous embodiments of the invention are the subject of subclaims and the drawings and the associated description. Show it:

FIG. 1 shows the flameproofing filter according to the invention in a schematic cross-sectional representation,

FIG. 2 shows a detail from the cross section of the flameproof filter according to FIG. 1,

3 and 4 are diagrams for illustrating the mesh sizes and wire diameter in the flameproof filter according to Figures 1 and 2,

5 shows a detail of the flameproof filter according to FIG. 1, in a perspective exploded view, FIG.

Figure 6 wire fabric layers of the flameproof filter of Figure 1 to 5, in a separate perspective exploded view, and

Figure 7 shows the flameproof filter of Figure 1 in a housing wall, in a schematic cross-sectional view upon impact of a pressure wave. In Figure 1, a pressure relief ^¬ body 10 is schematically illustrated, which is attachable, for example, in or on egg ^¬ ner housing wall of an explosion-proof housing to allow rapid pressure equalization between the housing interior and the environment. The pressure relief body 10 has a first number of

Wire cloth layers 11, which form a first part body 12. There is a further number of wire fabric layers 13, which are materially connected to one another and form a second part body 14. The wire fabric layers which are in each case interconnected in the two partial bodies 12, 14 are preferably connected, for example, by edge welding, but in particular by sintering, so that an unmanageable multiplicity of connection points distributed over the surface of the wire fabric layers 11, 13 exist.

Between the two porous part bodies 12, 14, an intermediate layer 15 is arranged, preferably as

Wire fabric layer is formed and the further preferably preferably stoffschlüs ^¬ sig is connected to the two partial bodies 12, 14, for example by sintering. In this case, the partial bodies 12, 14 with the intermediate layer 15 form a single sintered body. In addition, the pressure relief body 10 may be provided at its two perpendicular to the flow direction R flat sides with wire fabric layers 16, 17, for example, consist of a Drahtge ^¬ webe, which coincides with the intermediate layer 15 or its mesh size and the wire diameter the same conditions subject as the intermediate layer 15.

Figure 2 illustrates an enlarged Aus ^{¬ section} II, which detects the intermediate layer 15, the body part 12 and the top layer 16. As shown somewhat exaggerated in FIG. 2, the diameter d _{z of} the wire 18 is the Interlayer 15 significantly larger than each wire diameter in the body part 12 (Figure 4). In any case, the partial body 12 contains more than two, preferably many, wire mesh ^layers 11, which preferably occupy the entire cross-section of the partial body 12 over the whole area. The diameter d of the present in the wire mesh layers 11 wires 19 are shown in FIG 4 in a wire diameter range D, up to a Maximaldurchmes ^¬ ser d _max ranges from a minimum diameter d _m i _n. The lower wire diameter limit d _m i _n is about 0.1 mm while the upper limit d _max is preferably at most 1 mm. The wire diameter d _z of the wire 18 of the intermediate layer 15 is set outside this through knife coater ^¬ D realm. Preferably, the diameter d _{z of} the wire 18 of the intermediate layer 15 is at least 1.5 times as large as the largest diameter d _{max of} the diameter region D. The same applies to the wire 20 of the cover layer 16.

In the intermediate layer 15, the wire diameter of the individual wires can vary quite. It is true, however, that at least having the distance between the two partial ^¬ bodies 12, 14 defining wires, such as the wire 18 has a diameter d _z of the outside diameter D range.

[0020] Similarly, the ratios with respect to the Ma ^¬ mesh size m in the portion of body 12 and in the intermediate layer 15. The mesh size m of the supporting fabric layers 11 lies in the portion of body 12 in the mesh width region M of a minimum mesh size m _m i _n to to a maximum mesh size m _{max is} enough. The minimum mesh size m _m i _n is in the range tenth millimeter while the maximum Ma ^¬ mesh size m _max in the range of a millimeter is located. The Ma ^¬ mesh size m _for the intermediate layer is greater than the maximum occurring in that part of body 12 Maschenwiete m _max, preferably ^¬ example at least 1.5 times as large. For the part body 14 preferably apply corresponding conditions. However, the number of wire fabric layers 11 may differ from the number of wire fabric layers 13 in the partial bodies 12, 14.

[0022] Figure 5 illustrates the structure of the Druckentlas ^¬ tung body 10 in a partial exploded view. As can be seen, the wire fabric layers 11 and 13 of the partial bodies 12 and 14 adjoin the intermediate layer 15 on both flat sides thereof. These can, as already apparent from Figure 2, be made with different wire thicknesses and also have different Aus ^¬ directions. In addition to different wire thicknesses, the individual layers of the partial bodies 12 and 14 each have at least preferably different mesh sizes m. While the individual layers of the body part 12, 14 m mesh sizes that lie in a mesh size range M, the mesh size is m _for the intermediate layer 15 au ^¬ ßerhalb this mesh size range M.

In Figure 6, the preferably unequal Winkelaus ^¬ direction of three layers 11 of the body part 12 is illustrated ^¬ light. In each layer, the wire mesh consists of mutually parallel warp wires and a number of these crossing parallel weft wires. Although different shapes are also possible, the partial body 12 is round in the present exemplary embodiment, so that the individual layers 11 are circular disks with respect to a central axis 21. To this center axis 21, the individual layers are each rotated by an angle ß against each other, so that, for example, weft wires superposed La ^¬ gene 11 are each rotated by this angle ß against each other. This results in a pattern of distribution over the area and different in each contact plane. points of contact at which the individual layers are materially connected to one another in the sintering process. The wires of one layer cover the meshes of other layers, resulting in a porous body with multiple angled non-straight through pores.

[0024] Figure 7 illustrates the function of the printing t ^¬ lastungskörpers 10 at a take place in an internal space 22 of a housing explosion. In the housing wall 23 of the pressure relief body 10 is arranged to allow a quick pressure equalization from the interior 22, starting in the environment.

In Figure 7, such an explosion 24 is illustrated in the vicinity of the housing wall 23, wherein the spreading of the spherical compression shock pressure wave 25 is illustrated at different times by three circular arcs. At an early date to 25 exceeds the pressure ^¬ wave to the pressure relief body 10. Accordingly, hot gases pass through the partial body 12 and meet at the time ti on the intermediate layer 15. This is the first time a large-scale cross-flow possible, bringing the pressure surge, like arrows 26, 27 indicate, with respect to the central axis ^¬ 21 propagate radially outward. The spreading pressure wave penetrates the second part of the body 14 on a wide front, as shown in Figure 7 by the lower curvature of the pressure wave symbolizing circular arc t _{2 is} illustrated. Thus, the pressure relief body is penetrated on an enlarged surface. The flow concentrates less in the middle range and the total flow resistance decreases.

A flameproofing filter 10 according to the invention has two partial body parts 12, 14 consisting of different wire fabric layers 11, 13, which are interconnected by an intermediate rule position 15 are made of particularly coarse-meshed wire mesh ^¬ connected. The coarse-mesh wire mesh is preferential ^¬, of a thick wire. Both wire diameter and the mesh size of this intermediate layer 15 are preferably ^¬ significantly larger than the mesh sizes and wire diameter of the wires used for the part body 12, 14.

[0027] The pressure relief body 10 according to the invention combines high mechanical stability with high flame transmission safety and at the same time very low Strö ^¬ flow resistance.

Reference sign:

Claims

Claims:

1. flameproof filter (10), consisting of:

a number of fabric layers (11, 13) whose mesh sizes (m) are set in a mesh size range (M), and

at least one intermediate layer (15) whose meshes wide ^¬ (m _z) greater than the maximum, within the time ^¬ specified mesh size range (M) lying mesh ^¬ wide (m _max) is fixed.

2. Flameproof filter according to claim 1, characterized in that the wire fabric layers (11, 13) wires (19), whose diameter (d) in a fixed wire diameter range (D).

3. Flameproof filter according to claim 1, characterized in that the intermediate layer (15) has wires (18) with a diameter (d _z ) which is greater than the largest within the wire diameter range (D) lying diameter (d _max ) ,

4. Flammenschutzfilter according to any one of the preceding claims, characterized in that the mesh ^{¬ width} (m _z ) of the intermediate ^layer (15) is at least 1.5 times as large as the largest, in the mesh-Be ^¬ rich (M) lying mesh size (m _max ).

5. flameproof filter according to one of the preceding claims, characterized in that the ^{diam ¬} ser (d _z ) of the wires (18) in the intermediate layer (15) we ^¬ least 1.5 times as large as the largest inner ^¬ half the wire diameter range (D) lying

Diameter (d _max ).

6. Flameproof filter according to one of the preceding claims, characterized in that the intermediate ^¬ position (15) formed cross-flow channels defining is.

7. Flame protection filter according to one of the preceding claims, characterized in that the Drahtgewe ^¬ coverings (11, 13) alternately larger and smaller, within the mesh width range (M) lying Ma ^¬ mesh widths (m).

8. Flame-proof filter according to one of the preceding claims, characterized in that the Drahtgewe ^¬ bellows (11, 13) alternately larger and smaller, within the wire diameter range (D) lying wire diameter (d).

9. Flame protection filter according to one of the preceding claims, characterized in that aufeinanderfol ^¬ ing wire fabric layers (11, 13) have different Ori ^¬ entierungen.

10. fire protection filters according to any one of the preceding claims, characterized in that the wire-turn ^¬ coverings (11, 13) and the intermediate layer (15) of the ^¬ are cohesively connected miteinan.