阅读说明：本技术 在防爆类型防爆封壳中的保护壳体 (Protective housing in explosion-proof enclosure of explosion-proof type ) 是由 E·孔德鲁斯 B·林巴赫尔 J·施密特 H·维尔茨 于 2020-02-14 设计创作，主要内容包括：根据本发明创造了一种在防爆类型防爆封壳中的保护壳体(10)。该壳体(10)优选关联有至少一个用于降低爆炸压力的装置(19,36,38,39)。壳体(10)具有带有第一密封面(13)的第一壳体部件(11)和带有第二密封面(14)的第二壳体部件(12),其中,在壳体(10)的防爆封闭的状态中弹性的密封件(32)弹性变形地保持在第一密封面(13)与第二密封面(14)之间且由此在壳体(10)的内部中爆炸的情况中防点燃击穿地封闭在第一密封面(13)与第二密封面(14)之间的空间(26)。根据本发明的防点燃击穿的组件可替代在例如遮盖件的表面与壳体部件的表面之间的扁平缝隙,该扁平缝隙要求相对较窄的制造公差的遵循。(According to the invention, a protective housing (10) in an explosion-proof enclosure of the explosion-proof type is created. The housing (10) is preferably associated with at least one device (19,36,38,39) for reducing the explosion pressure. The housing (10) has a first housing part (11) with a first sealing surface (13) and a second housing part (12) with a second sealing surface (14), wherein in the explosion-proof closed state of the housing (10) an elastic sealing element (32) is held between the first sealing surface (13) and the second sealing surface (14) in an elastically deformed manner, and thus in the event of an explosion in the interior of the housing (10) the space (26) between the first sealing surface (13) and the second sealing surface (14) is closed in an ignition-proof manner. The ignition flashover protection arrangement according to the invention can replace a flat gap between, for example, the surface of the cover part and the surface of the housing part, which requires compliance with relatively narrow manufacturing tolerances.)

1. Protective housing (10) in an explosion-proof type explosion-proof enclosure, wherein the housing (10) preferably has associated therewith at least one device (19,36,38,39) for reducing the explosion pressure, wherein the housing (10) has a first housing part (11) with a first sealing surface (13) and a second housing part (12) with a second sealing surface (14), wherein-in the explosion-proof closed state of the housing (10) -an elastic sealing body (32,47) is held between the first sealing surface (13) and the second sealing surface (14) in an elastically deformed manner and thereby seals off a space (26) between the first sealing surface (13) and the second sealing surface (14) in an explosion-proof manner in the interior of the housing (10), wherein the elastically deformed sealing body (32), 47) is free of passing gaps.

2. Housing (10) according to one of the preceding claims, characterized in that the connection between the first housing part (11) and the second housing part (12) can be undone without losses.

3. Housing (10) according to one of the preceding claims, characterized in that the first housing part (11) surrounds an access opening (22) or defines an access opening (22), the access opening (22) being closed by means of the second housing part (12).

4. Housing (10) according to claim 3, characterized in that it has at least two inlet openings (22), wherein the separation point (26) between the first housing part (11) and the second housing part (12) is closed in a manner that prevents ignition flashovers by means of a sealing body (32) that is elastically deformed between the first sealing surface (13) and the second sealing surface (14).

5. The housing (10) according to any one of the preceding claims, wherein the first housing part (11) is tub-shaped, box-shaped or frame-shaped, and wherein the second housing part (12) is a wall part, in particular a cover (12), a base or a side wall part.

6. Housing (10) according to one of the preceding claims, characterized in that for closing the housing (10) the sealing body (32) is arranged at or on the first sealing surface (13) or the second sealing surface (14) and subsequently the first sealing surface (13) and the second sealing surface (14) are pressed against each other for elastic deformation of the sealing body (32).

7. The housing (10) according to any one of the preceding claims, wherein the sealing body (32) has a closed cell material.

8. The housing (10) according to one of the preceding claims, characterized in that the sealing body (32) has an unoriented fiber body, the pores (34) of which are at least partially closed by means of an elastomer (35) in such a way that passage paths for gases through the cross section of the sealing body (32) are avoided.

9. Housing (10) according to one of the preceding claims, characterized in that the ratio of the length of the space (26) between the first sealing surface (13) and the second sealing surface (14) filled by means of the sealing body (32) to the width (W) of the space (26) between the first sealing surface (13) and the second sealing surface (14) is greater than 100.

10. Housing (10) according to one of the preceding claims, characterized in that a spacer (33) is arranged between the first sealing surface (13) and the second sealing surface (14), the spacer (33) determining a minimum spacing between the first sealing surface (13) and the second sealing surface (14).

11. The housing (10) according to one of the preceding claims, characterized in that the first housing part (11) and/or the second housing part (12) has a preferably elongated structure (30), in particular a groove (30), wherein the sealing body (32) is contained in the structure (30), in particular the groove (30), or is arranged running alongside the structure (33), or wherein the sealing body (32) constitutes a flat seal.

12. The housing (10) according to any one of the preceding claims, characterised in that the means (19,36,38,39) for reducing the explosion pressure have an open-pored material.

13. The housing (10) according to any one of the preceding claims, characterised in that the device (19) for explosion pressure reduction has a pressure relief body (20) which is arranged in an opening of the housing (10) to the surroundings of the housing (10).

14. Housing (10) according to one of the preceding claims, characterized in that the means (36, 38,39) for explosion pressure reduction have an open-pored material which is not ignition-resistant.

15. Housing (10) according to one of the preceding claims, characterized in that the second housing part (12) has a further second sealing surface (45) and the housing (10) has a third housing part (41a,41b) with a third sealing surface (46), wherein-in the explosion-proof closed state of the housing (10) -a further elastic sealing body (47) is held elastically deformed between the further second sealing surface (45) and the third sealing surface (46) and thereby closes the space between the further second sealing surface (45) and the third sealing surface (46) against ignition flashover in the event of an explosion in the interior space (23) of the housing (10).

Technical Field

The present invention relates to a protective casing in an explosion-proof enclosure of the explosion-proof type.

Background

Housings constructed in accordance with explosion-proof type explosion-proof enclosures (sometimes also referred to as explosion-proof type pressure-proof enclosures) are known from the prior art. The housing allows the accumulation of an explosive gas mixture within the housing and its explosion by an ignition spark (formed by an electrically operated device in the housing). Depending on the type of protection, it is also possible for gases or particles to penetrate through the gap from the inside of the housing to the outside in the event of an explosion, where an explosive atmosphere may be present. However, depending on the type of explosion protection, it must be excluded that the gas is heated to such an extent or that the particles are heated or glowing to such an extent that the explosive atmosphere outside the housing can be ignited.

DE 102010016782 Al describes a pressure relief device for explosion-proof (sometimes referred to as pressure-proof) enclosures. The pressure relief device is provided for arrangement in the housing part and reduces the size of the pressure peaks formed even when reactions in the form of explosions in the interior space occur in such a way that the gases formed can flow out of the housing quickly and easily through the pressure relief device.

DE 3436300C 2 discloses a device housing with an explosion-proof chamber. The housing has a jacket as a first housing part and a cover as a second housing part. The sheath and the cover have flanges to facilitate establishing a flanged connection between the sheath and the cover. Through which gaps between the flanges through which gas or particles can penetrate from the interior of the housing towards the exterior in the event of an explosion are allowed. The gap is however dimensioned such that the gas ignited in the cavity of the housing is sufficiently cooled before it leaves the housing through the gap between the flanges. A seal may be disposed between the flanges to facilitate preventing ingress of moisture into the housing.

DE 2617965B 2 discloses a housing, referred to as explosion-proof, having a lower housing part and an upper housing part. The two parts constitute an intermediate space, which is called a gap space. A seal is arranged between the upper housing part and the lower housing part at the gap space. The sealing element is used together with the spring element for joining the lower housing part to the upper housing part. The spring element is arranged in the intermediate space. The intermediate space is cast with a casting resin. It is pointed out that the explosion-proof housing is obtained by casting the gap with a casting resin, which is of seamless design.

DE 102007003009 Al describes a method for producing a fluid-tight housing and a fluid-tight housing. The housing has a base part and a cover in the form of a plate and a seal arranged between the mutually facing airfoils of the base part and the cover for fluid-tightly sealing the interior space of the housing. The base part and the cover are fixed to one another with a bias, so that the elastic seal is deformed. It is therefore excluded that the gas reaches the ignition source in the fluid-tight housing from the surroundings of the housing.

DE 102013111374 Al discloses an explosion-proof assembly for electrical and/or electronic components. The assembly has a carrier and a closure body. The cover body defines at least one receiving cavity for a structural element. Between the cover body and the carrier, a resilient coupling element is arranged, which completely surrounds the opening in the cover body. When the cover body and the carrier are connected by means of a force-fitting and/or form-fitting connection, the coupling element between the cover body and the carrier is thereby elastically deformed. The explosion-proof assembly is intended to fulfill the requirements as defined for the cast capsule (Ex-m) or the explosion-proof capsule (Ex-d). In the case of a cast enclosure (Ex-m), the explosive atmosphere is vented from the interior space of the housing.

DE 1801062 a discloses an explosion-proof housing consisting of steel plate parts which are connected by welding.

For contacting the electrically operated components in the housing of the explosion-proof enclosure of the protective type, the housing part can have a receiving opening for receiving a line or a line bushing (sometimes also referred to as a lead). An Ex gap (ignition-resistant gap) can be formed between the opening and the sleeve, which can be formed as a cylindrical or threaded gap.

Disclosure of Invention

The object of the invention is to provide an improved solution for the housing of a protective explosion-proof enclosure.

This object is achieved with a protective housing according to claim 1:

the protective housing (also referred to below merely as housing) in an explosion-proof enclosure of the explosion-proof type according to the invention has a first housing part with a first sealing surface and a second housing part with a second sealing surface. Preferably, the housing has associated with it a device for reducing the explosion pressure. The elastic sealing element is held between the first sealing surface and the second sealing surface in an elastically deformable manner and thus seals the space between the first sealing surface and the second sealing surface against ignition flashovers in the event of an explosion in the housing interior.

The seal itself is gap-free (durchgangsspaltfrei) and is therefore impermeable to the explosive gas. No paths, pores (Poren) or other channels are guided through the sealing body through gaps which, in the event of an explosion, allow gas (likewise gas which has not been cooled to the ignition temperature of the atmosphere) to pass through the sealing body. This does not mean that the seal or the assembly of seals between the sealing surfaces must be diffusion-tight (also sometimes referred to as diffusion-tight).

By means of the elastically deformable sealing body, the separation point (Trennstelle, also sometimes referred to as a separation line) between the first housing part and the second housing part is likewise closed at least to such an extent in the event of an explosion that the potentially remaining explosive gas entering the gap leading through the separation point is cooled to such an extent that it cannot ignite the explosive atmosphere outside the housing. The non-passable gap property (durchgapsspaltfreiheiit) of the sealing body exceeds the requirement for insulation against ignition breakdown at the separation site, since the gap (if present in general) is closed further in the sealing body than is necessary for the ignition breakdown resistance.

In the protective housing according to the invention, for example, a flat gap (as is provided in the prior art between the housing body and the cover in the case of pressure housings of explosion-proof "explosion-proof enclosures") is therefore replaced as proposed according to the invention by an assembly of an elastic sealing body between two sealing surfaces. In the prior art, when a flat gap between the cover part and the housing body is defined, in the embodiment according to the invention the space between the sealing body and the first housing part is at least so narrow that it is protected against an ignition flashover and the space between the sealing body and the second housing part is at least so narrow that it is protected against an ignition flashover. The gap which may remain between the sealing body and the first housing part and between the sealing body and the second housing part meets the requirements for an Ex gap which is resistant to ignition flashover (for example, standard EN 6079-1) in view of gap width and gap length. It is therefore not necessary to comply with narrow manufacturing tolerances, as is necessary for the production of the separating point between the cover and the housing body, which forms a flat gap.

It is clear that the seal can additionally be used to prevent the ingress of moisture through the separation point between the first sealing surface and the second sealing surface, preferably in the absence of an explosion. The main task of this seal is, however, to keep the separation point from ignition breakdown in the event of an explosion.

Examples of further advantageous embodiments of the invention and examples of preferred features are described below:

in a preferred embodiment, the second housing part has a further second sealing surface and the housing has a third housing part with a third sealing surface, wherein in the explosion-proof closed state of the housing the further elastic sealing body is held between the further second sealing surface and the third sealing surface in an elastically deformed manner and thus in the event of an explosion in the interior of the housing the space between the further sealing surface and the third sealing surface is closed in an ignition-proof manner.

The second housing part may be an intermediate frame. One or more cover parts, which can form a third housing part of the housing, can be fastened, preferably articulated, to the intermediate frame.

Preferably, the connection (if present) between the first and second housing part and/or between the second and third housing part can be undone without damage. The connection can be established, for example, by means of a screw connection or a screw connection. Preferably, neither the first nor the second housing part and preferably also the sealing element are damaged here and/or preferably neither the second nor the third housing part and preferably also the further sealing element are damaged here. Preferably, the sealing element can be reused after opening the housing, particularly preferably for sealing a space or a separation between the first housing part and the second housing part (when the first housing part and the second housing part are again connected to one another). Alternatively or additionally, this may apply to the further seal (if present).

The first housing part can, for example, surround the opening, i.e. the housing parts individually define the opening. Alternatively, the housing part may define the opening together with the further first housing part. However, the opening can be closed by means of the second housing part. In a further embodiment, the second housing part can define an opening into the first housing part, wherein the opening can be closed by means of the third housing part.

Preferably, the opening closable by means of the second housing part or the third housing part is an access opening of the housing. The access opening is designed and determined to provide a user of the housing or of the electrical operating device contained therein with access to the interior of the housing or to an operating device arranged in the housing. Through this access opening, a user of the housing can fit the interior space of the housing to operate the device and/or to perform modifications, repairs and/or actions for operating the operating device. The access opening may be so large that a user's hand passes through the access opening. The receiving opening in the conductor insertion end (leitsunflungen) for receiving an electrical bushing, in particular an electrical conductor, or in the housing part for receiving a fluid line for introducing a fluid into or out of the housing is not to be regarded as an insertion opening in the sense of this application. Likewise, a receiving opening for receiving, for example, a handling attachment or a detector (holder, sometimes also referred to as a sensor), in particular a light detector, is not to be regarded as an access opening in the sense of this application. Likewise, openings in parts of the electrical bushing, parts of the lead-in end of the conductor, parts of the lead-in end of the fluid conduit, parts of the handling attachment or (light) probe are not considered to be access openings in the sense of this application.

Preferably, the first and second housing part and/or, if appropriate, the third housing part are provided for separating the interior space of the housing from the atmosphere surrounding the housing. The opening of the first, second and/or third housing part from the housing interior to the atmosphere surrounding the housing is closed without ignition gaps in the case of an explosion-proof closure housing.

The first housing part and/or the second housing part is particularly preferably wall-shaped, basin-shaped, frame-shaped or box-shaped, or preferably at least wall, basin or box-shaped sections, and/or the first housing part and/or the second housing part forms a section of the frame, which can be closed by means of the wall part. The first housing part can be, for example, a frame part or a part in the form of a tub or box or a section thereof, and the second housing part can be a wall part, for example a side wall part, a cover or a base or a section thereof.

In order to close the housing, the seal can be arranged at one of the first and second sealing surfaces and, if necessary, fixed in a form-fitting, force-fitting and/or material-fitting manner, and then the first and second sealing surfaces are arranged adjacent to one another or adjacent to one another for elastic deformation. Alternatively, a further sealing body can be arranged for closing the housing at one of the further second and third sealing surfaces and, if necessary, fixed in a form-fitting, force-fitting and/or material-fitting manner and then the further second and third sealing surfaces are arranged adjacent to one another or adjacent to one another for elastic deformation of the further sealing body.

The sealing body and/or the further sealing body can be closed, for example, annularly. The sealing body and/or the further sealing body preferably respectively surround an opening in the housing. The sealing body and/or the further sealing body can be formed from an elastomer or have an elastomer or be formed from another elastic material. For example, the sealing body and/or the further sealing body can be made of metal, in particular sheet metal. The seal may have a closed cell material or be open cell, wherein, however, all passage through the seal via the pores is blocked. The sealing body and/or the further sealing body may have a non-oriented fibre body (wirefacer), for example, made of metal fibres, the pores of which are at least partially closed by means of an elastomer, so as to avoid passages through the sealing body.

Likewise, the larger-diameter opening in the housing can be closed as provided according to the invention. The ratio of the length of the space between the first sealing surface and the second sealing surface (which may also be referred to as the separation point) which is filled by means of the elastically deformable sealing element to the width of the space between the first sealing surface and the second sealing surface with the elastically deformable sealing element arranged therebetween in order to seal the sealing element against ignition flashovers may be, for example, greater than 100. In one embodiment, the ratio of the length of the space (which may also be referred to as the separation point) between the further second sealing surface and the third sealing surface, which is filled by means of the elastically deformable sealing body, to the width of the space between the further second sealing surface and the third sealing surface with the further sealing body arranged therebetween, which is elastically deformed in order to seal against ignition flashovers, may be, for example, greater than 100. The manufacturing tolerances for producing the first and second and/or second and third housing parts, in particular for producing the first and second sealing surfaces and/or the further second and third sealing surfaces, can be less stringent than for producing components with surfaces which are intended to define a flat gap between the surfaces which is resistant to ignition flashovers.

With the seal body according to the invention, minor damage or unevenness of the sealing surface can be compensated. In contrast, the surfaces of the housing parts adjacent to one another in the prior art must meet stringent requirements with regard to integrity and flatness in order to form a flat gap between the surfaces, in order to preclude penetration of the ignitable gas mixture through the flat gap. The solution according to the invention is therefore particularly advantageous when the housing is re-closable. Since in the open state damage to the sealing surfaces or, in the prior art, to the surfaces of the flat slits which limit the protection against ignition flashovers is entirely possible.

Because of its elasticity, this seal can compensate for some damage and, despite the damage, can seal the separation point in a flashover-proof manner, whereas housings with flat slots known from the prior art and having damage at the corresponding point cannot be used and must be replaced.

A spacer is preferably arranged, which determines the minimum distance between the first sealing surface and the second sealing surface. It is thus prevented that the seal between the first sealing surface and the second sealing surface is pressed together to such an extent that the seal is damaged so strongly, for example by plastic deformation, that it is unusable for a seal that prevents a flashover or that the seal is at least not reusable in the case of a reclosure of the housing. Preferably, in the case of a connection established between the first housing part and the second housing part, the first housing part and/or the second housing part is pressed onto the spacer, so that the minimum distance is determined as the distance between the first sealing surface and the second sealing surface in the space filled by the sealing element.

In order to protect the seal, the first sealing surface and/or the second sealing surface can have a preferably elongated structure. The structure may be a groove, for example. The seal may be arranged alongside or in the structure. Alternatively, the seal may be a flat seal, which is not arranged in the groove in particular.

The elastically deformable sealing body preferably contacts the first sealing surface and the second sealing surface. Alternatively, a second sealing body is arranged, for example elastically deformable, between the elastically deformable sealing body and the first sealing surface and/or between the elastically deformable sealing body and the second sealing surface, so that the sealing bodies form a stack between the first sealing surface and the second sealing surface.

Preferably, the at least one device for explosion pressure reduction of the associated housing is set up and determined for limiting the maximum overpressure that can form as a result of an explosion in the interior of the housing to a maximum value that is less than the maximum value that would occur in the same housing without the at least one device.

The at least one device for explosion pressure reduction may have a pressure relief body which is arranged in or at the opening of the housing to the surroundings of the housing in order to facilitate the exit of gas from the interior of the housing for the purpose of unloading in the event of an explosion. Such pressure relief bodies are designed in a protective explosion-proof enclosure (Exd, EN 6079-1 (standard)) in order to prevent ignition flashovers.

Alternatively or additionally, the at least one device for explosion pressure reduction may have means for preventing gas from escaping from the housing, which may however absorb thermal and/or kinetic energy from the explosion in order to limit the maximum overpressure caused by the explosion.

The means for reducing the explosion pressure preferably have an open-pored material. The open-porous material, due to its large surface area, effectively cools the gas in order to reduce the maximum explosion pressure. The open-pored material can be, for example, a fibrous material, for example a metal fibrous material, for example fibers processed to form a textile (Gewebe), a nonwoven (Gelege) or a felt (Filz), or a wadding (schultung) consisting of a free-flowing (rieself ä higem) material.

The at least one device for reducing the explosion pressure is at least designed and determined to reduce an explosion pressure (overpressure above atmospheric pressure) of several bars, in particular greater than or equal to 10 bars, which would occur if the at least one device were not arranged in the remaining, unmodified housing, to an overpressure of, for example, less than or equal to 1 bar. The inventors have realised that when such a device is arranged for reducing the explosion pressure, the following possibilities are opened: even in the case of housings with an internal volume of 1 liter or more, or even 1000 liters or more, an elastic sealing body is used for the arrangement of the separation point, which is sealed off against ignition flashover, between the two housing parts, wherein in the prior art, for example, a flat gap against ignition flashover is provided in a defined manner or is already provided by the two housing parts. The first sealing surface and the second sealing surface, together with the elastically deformable sealing body arranged therebetween, can therefore replace the gap that prevents ignition flashover, which in the prior art is limited on the one hand by the first sealing surface and on the other hand by the second sealing surface. In one embodiment of the invention, the flat gap delimited by the first sealing surface on the one hand and by the second sealing surface on the other hand is replaced by a spark-through-proof or narrower gap between the first sealing surface and the sealing body or a narrower gap between the second sealing surface and the sealing body.

Drawings

Further advantageous embodiments and features result from the following description, the dependent claims and the drawings:

exemplarily and schematically:

FIG. 1 shows a perspective view of an embodiment of a protective enclosure according to the present invention of a protective-type explosion-proof enclosure;

figure 2 shows a perspective view of the first housing part of the protective housing shown in figure 1,

figure 3 shows a perspective view of the cover of the protective housing shown in figure 1,

fig. 4 shows a perspective view of a sealing ring, which can be arranged between the covering part and the first housing part as shown in fig. 1,

figure 5 shows a cross-sectional illustration through a sealing ring with a part of the enlarged illustration,

figure 6 shows a schematic side view of a view into the interior of a protective casing according to the invention,

figure 7 shows a partial sectional illustration through the separation between the first housing part and the cover part of the housing according to figure 1,

figure 8 shows a partial cross-sectional illustration through the separation between the first housing part and the second housing part of the protective housing according to the invention,

figure 9a shows an example sealing body of another embodiment of the housing according to the invention,

figure 9b shows a cross-section through an embodiment with a sealing body according to figure 9a,

figure 10a shows an embodiment of a housing according to the invention in a perspective view according to yet another embodiment,

figure 10b shows the housing according to figure 10a with the cover element open,

FIG. 10c shows a partial view through a cross section of the housing according to FIG. 10a, and

fig. 10d shows an enlarged detail of the view according to fig. 10 c.

Detailed Description

The protective housing 10 according to the invention (also referred to below simply as housing) preferably satisfies the protection type "explosion-proof enclosure". The requirements for a housing of this protective type are described, for example, in standard EN 60079-1 (Ex-d) or in corresponding other standards (for example in the united states). For a housing according to this type of protection, it is established that the housing withstands the pressure of an explosion of the explosive mixture in the interior of the housing and must prevent the explosion from being transmitted to the explosive atmosphere surrounding the housing.

In the embodiment, the housing 10 according to the invention, as shown by way of example in fig. 1, has a first housing part in the form of a tub or box with a base (covered in fig. 1), which first housing part 11 is closed with a cover 12 forming a second housing part. The housing parts 11,12 are preferably metal parts, for example made of aluminum, in particular an aluminum alloy, steel or gray cast iron. The first sealing surface 13 and the second sealing surface 14 of the first housing part 11 or of the second housing part 12 are preferably made of metal, for example aluminum, in particular an aluminum alloy, steel or gray cast iron.

The first housing part 11 and/or the cover part 12 can have receiving openings for bushings, such as a conduit bushing and an electrical bushing 15, or receiving openings for receiving an operating element 16 or an indicator or communication device 16. In the exemplary embodiment shown, an electrical bushing 15 for supplying operating devices in the interior of the housing with electrical power, an operating device 16 and a display unit 17 are arranged in an opening of the first housing part.

Furthermore, the first housing part 11 has a receiving opening in the side wall 18, which is closed by means of a pressure relief device 19. The pressure relief device 19 has a pressure relief body 20 which allows a gas exchange between the interior of the housing 10 and the external surroundings 21 via the receiving opening and the pressure relief device 19. However, depending on the protective explosion-proof enclosure, the gap through the pressure relief body 20 is designed (in particular so long and so narrow) such that, in the event of an explosion, the gases or particles escaping outward through the pressure relief body 20 cool to such an extent that they cannot ignite the flammable atmosphere outside the housing 10. Therefore, the gap is said to be ignition breakdown resistant.

The pressure relief device 19 can be screwed into a receiving opening in the side wall 18 of the first housing part 11, wherein it is ensured that the gap, the thread gap, between the first housing part 11 and the pressure relief device 19 is ignition-proof. Likewise, the other bushings and the associated components (such as the actuating device and the signal generator) together with the receiving openings in the housing in which they are arranged define gaps which prevent ignition flashovers.

The first housing part 11 has an access opening 22 to a chamber 23 in the housing 10 (see fig. 2). The access opening 22 is surrounded by a flange 24. The access opening 22 to the chamber 23 in the first housing part 11 is closed by means of the cover 12. For closing, the cover 12 is screwed to the first housing part 11 in the illustrated embodiment. Other connection possibilities are conceivable in principle, for example a snap-on connection. The chamber 23 contains at least one electrically operated device 25 which can generate a spark. The housing 10 according to the invention preferably limits an internal volume of at least 1 cubic decimeter, particularly preferably at least 4 cubic decimeters. Embodiments may in particular have an internal volume of at least 10 cubic decimeters. According to the invention, a housing with a housing volume of, for example, 2000 liters can likewise be created. The housing 10 according to the invention therefore preferably has a relatively large internal volume, which can contain a correspondingly large amount of combustible gas mixture. The circumference (closed length) of the separation point 26 between the first housing part 11 and the covering part 12 can likewise be correspondingly large.

The sealing surface 13 (first sealing surface) of the first housing part 11 is arranged in the assembly of a device for tightening, for example a bore (Bohrung)27 for receiving a threaded bolt with an external thread. Fig. 2 shows the housing 10 according to the invention according to the example of fig. 1 with the first housing part 11 open.

The cover 12, which is shown in fig. 3 in an inwardly oriented view, has an assembly of mating means for screwing the cover and the first housing part (for example, holes 28 for receiving threaded bolts). Within the assembly, a groove may be disposed in the face of the closed housing 10 facing the flange 24. The groove 30 can however also be dispensed with, so that the second housing part 12 has a step-free surface in the region of the sealing surface 14 (second sealing surface) of the cover part 12. Alternatively or additionally to the groove 30 in the cover 12, a groove closed along the periphery can be machined into the surface of the flange 24 of the first housing part 11. The peripheral shape of the illustrated slot is rectangular, conforming to the shape of the access opening 22. However, the peripheral shape can likewise be designed otherwise, in particular in accordance with the shape of the otherwise shaped housing 10 and/or the access opening 22. The groove 30 has a groove base 31 which constitutes the second sealing surface 14.

Fig. 4 shows a rectangular, prefabricated sealing ring 32 closed in the peripheral direction as a sealing body in the relaxed state. As a ring, the seal 32 is closed on the periphery. That is to say that it does not have slits or cutouts which separate the sealing ring 32 transversely to the circumferential direction. The relaxed seal 32 is shown to be rectangular in cross-section. However, seal 32 may likewise be polygonal in other forms in cross-section (e.g., square or, for example, circular, oval or elliptical. seal 32 may, for example, be composed of a polymer. seal 32 composed of metal (e.g., sheet metal) is likewise possible. seal 32 may be adhered to cover 12, in particular to second sealing surface 14 of cover 12, which is not shown in FIG. 3. seal 32 may, for example, be adhered to channel 30, in particular to channel floor 31. seal 32 may be foamed, configured as a stamped seal or injection molded as a continuous round string ring (Endlosrundschnurring.) alternatively to prefabricated seal 32, which may be injection molded (both components together comprising an elastomer), foamed, extruded onto the surface to be sealed off) by suitable additive manufacturing methods . The sealing ring 32 can be precompressed and/or waterproofed in order to provide the sealing ring 32 with predetermined, pronounced properties such as modulus of elasticity or restoring force, water repellency, combustion properties and uv or weathering protection in a targeted manner.

The surface 29 of the cover part 12 adjacent to the groove 30 or the groove wall forms a spacer 33, the spacer 33 taking care of the minimum distance between the first sealing surface 13 and the second sealing surface 14 when the cover part 12 is fixed on the first housing part 11 with the elastically pressed sealing element 32 arranged therebetween. When, in the case of a closed housing 10, the surface 29 of the cover 12 surrounding the groove 30 and the second sealing surface 14 or the surface section surrounding the second sealing surface 14 are in contact, it is ensured that the minimum distance is defined as the distance between the first sealing surface 13 and the second sealing surface 14. The sealing ring 32 is thus pressed in or onto a predetermined amount. This prevents damage or excessive deformation of the sealing element 32 beyond elasticity and on the other hand ensures that the elastic sealing element 32 is sufficiently deformed, i.e. a sufficiently strong spring force is exerted on the cover 12 and the first housing part 11 or the second sealing surface 14 and the first sealing surface 13, in order to keep the separation point between the cover 12 and the first housing part 11 closed in the event of an explosion, in a manner that is also resistant to ignition flashovers. The spacer elements 33 can also be formed, in contrast to the grooves 30, by a structure of projections arranged in rows or projections closed in the circumferential direction (not shown), which project next to the first sealing surface 13 and/or the second sealing surface 14. Alternatively, one or more spacers may be machined into the seal ring (not shown), which prevents compression of the seal ring 32 below a determined amount.

Fig. 5 shows a cross-sectional view through an exemplary embodiment of a relaxed elastically deformable sealing ring according to the dashed section line S1 as indicated in fig. 4. The seal 32 may in particular have a closed-cell material. As is also shown in fig. 5 by way of a partially enlarged illustration, the sealing ring 32 can be or have an unoriented fiber body. The unoriented fibrous body itself has open pores 34. This means that, without the additional measures described below, the gas can pass from the side of the unoriented fibrous body 32 through the unoriented fibrous body through the open pores 34 formed between the irregularly arranged fibers 35 and leave the unoriented fibrous body again. Thus, the unoriented fiber body 32 is not free of through-gaps. This is prevented, however, by the fact that the aperture 34 is at least partially filled with an elastomer 36 in order to close the path (gap) through the aperture 34 and to obtain an aperture 34 that is closed in this sense. The aperture 34 is already closed in the relaxed state of the sealing ring 32 or at least in the elastically deformed state between the first sealing surface 13 and the second sealing surface 14. The seal 32 thus constructed has high mechanical strength. This is particularly advantageous when the housing 10 is reclosable in the event of reuse of the seal 32.

Alternatively or additionally to the pressure relief device 19, which allows gas exchange between the interior volume of the housing 10 and the outside atmosphere, the housing 10 can be associated with at least one pressure relief device 37 for internal pressure reduction, which limits the explosion pressure to a defined maximum value, which lies below the pressure which would occur in the case of an explosion if the pressure relief device 37 for internal pressure reduction were not present in the otherwise unchanged housing. The pressure relief device 37 for the internal pressure reduction can, for example, have at least one flat part 37 of an open-pored material, which is fastened, for example, to the cover, for example glued thereto. In the exemplary embodiment of the covering element shown in fig. 3, two flat parts 37 are glued to the inside, for example, as internal pressure relief devices 37 made of perforated material.

The device 37 for internal pressure relief is not ignition-resistant, as is the case with the pressure relief device 19, for closing an opening in the side wall 18 of the first housing part 11 for connection between the interior of the housing 10 and the exterior of the housing 10, but is nevertheless provided for allowing the escape of non-combustible gases. More precisely, the device 37 for internal pressure relief is designed and determined to absorb thermal energy in the event of an explosion in order to cool the explosion gases and thus reduce pressure peaks. The action of the pressure relief device 37 for the internal pressure reduction can additionally or alternatively be based on other physical principles in such a way that these flat parts 38, which are composed of an open-pored material for example, are deformed by the explosion pressure impact and thereby absorb kinetic energy and thus bring about a reduction in the pressure peak. However, the pressure relief means 37 for internal pressure reduction preferably does not establish a connection between the interior of the housing 10 and the surroundings of the housing 10 for releasing gas from the housing 10, but the means 37 for internal pressure reduction absorbs a part of the explosion energy in order to moderate the explosion effect, without, however, having to release gas from the interior of the housing 10 towards the exterior. The gaps leading through the porous material of the means 37 for internal pressure reduction are preferably not ignition-resistant. In other words, the open-porous material of the means 37 for internal pressure reduction is not ignition-resistant.

Fig. 6 shows a side view into the interior of the protective housing 10 according to an exemplary embodiment. A spark-generating operating device 25 is clearly shown schematically. In addition or alternatively to the device 37 for internal pressure reduction as shown in fig. 3 and/or the pressure relief device 19 providing a connection between the interior of the housing 10 and the surroundings of the housing 10 without ignition gaps, additional or other devices for internal pressure reduction can be arranged in the interior 23 of the housing 10. For example, a body 39 having an open-cell material may be disposed in the chamber 23, accessible from at least four or at least five sides of the body 39. Alternatively or additionally, one or more of the walls may be provided with an apertured flat material 40. The means 37,39,40 for reducing the internal pressure are used by means of cooling and/or absorption of kinetic energy of the explosion gas and the pressure relief device 19 for exchanging gas between the surroundings of the housing 10 and the interior space 23 is ultimately used to prevent pressure peaks, so that the elastically deformable sealing element 32 can withstand the explosion overpressure that actually occurs and thus ensures a seal against ignition breakdown between the first sealing surface 13 and the second sealing surface 14 in the event of an explosion in the interior of the housing 10. The open-cell material of the body 39 and the flat material 40 need not be ignition resistant.

By means of one or more devices 19,37,39,40 for pressure reduction, in particular a long (closed measured along the circumference) sealing element 32 can be provided or a long (closed measured along the circumference) separation point between the housing parts 11,12 can be sealed against penetration by ignition. In fig. 7, a partial sectional illustration is shown according to the section line S2 as shown in fig. 1. The separation point 26 between the first sealing surface 13 and the second sealing surface 14 has a width W which corresponds to the height H of the sealing body 32 which is elastically deformed therebetween. The width W is measured perpendicular to the direction (depicted by arrow P) or the path that the gas would take in the absence of the seal 32 through the separation site 26 between the first sealing surface 13 and the second sealing surface 14 upon detonation. The width is preferably measured transversely or perpendicularly to the first sealing surface 13 and/or the second sealing surface 14 and corresponds to the distance between the first sealing surface 13 and the second sealing surface 14. The width W is measured perpendicular to the circumferential direction or the length of the separation site 26 or the seal 32. The length of the separation or of the sealing body corresponds to the circumference of the sealing ring 32 or the measured length of the circumferential seal or the length of the line connecting the imaginary center points of the cross-sections of the sealing body 32 to one another. In the embodiment shown in fig. 1,2 and 3, the length of the separation point is the sum of the lengths of the four straight sections of the groove 30. The ratio of the length of the separation site to the width W or the length of the seal to the height may be, for example, 100 or more. In this sense, the seal 32 according to the invention or the separation point 26 between the first sealing surface and the second sealing surface is preferably a longer seal 32 or a longer separation point 26.

Fig. 8 shows a sectional view through an example of the surfaces of the first housing part 11 and the second housing part 12 facing each other in the case of a closed housing 10 according to a further exemplary embodiment. Depending on the design of the groove and spring connection, the sealing rings 32 are accommodated in grooves 30a,30b arranged opposite each other, which are arranged in the surface of the first housing part 11 and the facing surface of the second housing part 12.

For example, the (primary) closing of the housing 10 can be effected as follows, starting for example from the first housing part 11 (as shown in fig. 2):

a sealing ring 32 (e.g. according to fig. 4) can be placed on the second sealing surface 14, in particular into the groove 30, for example, in order to close the housing 10. Alternatively, the sealing ring 32 may be placed onto the first sealing surface 13, especially in the absence of the groove 30 in the cover 12. The sealing ring 32 can be affixed with the first sealing surface 13 or the second sealing surface 14. Alternatively, the sealing element 32 can be applied, for example in paste-like and/or liquid form, onto the first sealing surface 13 or the second sealing surface 14, where the sealing material is transformed into a (rubbery) elastic state by a chemical and/or physical process.

The covering part 12 (for example according to fig. 3) is arranged on the first housing part 11 such that the sealing element 32 is arranged between the first sealing surface 13 and the second sealing surface 14. The cover 12 is fixed to the first housing part 11 by means of a form-fitting and/or force-fitting connection. By means of a screw connection (as provided according to the exemplary embodiment shown in fig. 1 and 2), this connection is form-fitting in the direction of the elastic deformation of the seal 32 that occurs when the connection is established. Alternatively or additionally, the connection may be force-fitted in the direction of the elastic deformation. In each case, a restoring force of the seal based on the elastic deformation (which restoring force acts to squeeze the covering part 12 and the first housing part 11 apart from one another) is compensated by means of this connection in order to maintain the elastic deformation. After the connection to the elastic deformation at or below the predetermined amount is established, the housing shown in fig. 2 is closed explosion-proof.

However, the explosive mixture can collect in the housing 10. In particular, when the housing 10 is not gas-tight, for example when it has a pressure relief device 19 which creates a connection between the interior space 23 of the housing 10 and the surroundings 21, as in the exemplary embodiment according to fig. 1 and 2, gas can penetrate from the outside into the chamber 23 delimited by the housing and form an explosive mixture there. An electrically operated device 25 arranged in the inner space 23 of the housing 10 can generate a spark. This is also allowed in the case of a protective type explosion-proof enclosure. The explosion ignited in this way causes an overpressure in the interior of the housing 10. The pressure relief device or devices 19,37,39,40 are designed such that the overpressure is nevertheless limited to a defined maximum value (equal to or less than the defined maximum value), which is clearly below a maximum value which would occur in the absence of one or more of the pressure relief devices 18,37,39, 40. The predetermined maximum overpressure is, however, selected to be so small that the sealing element 32 also keeps the separation point 26 between the first sealing surface 13 and the second sealing surface 14 closed against ignition flashover during the occurrence of an explosion. The overpressure (difference between this pressure and atmospheric pressure) due to the explosion can be, for example, 10Bar or more without one or more pressure relief devices 19,37,39, 40. With one or more pressure relief devices 19,37,39,40, the maximum overpressure can be, for example, less than or equal to 1 Bar.

Likewise, explosions may recur. However, at least during the explosion, the seal 32 remains closed against ignition flashover at the separation point 26 between the first sealing surface 13 and the second sealing surface 14, preferably likewise between explosions. It is therefore preferred that the explosion pressure of the sealing element 32 is not ultimately pressed against the first and second sealing surfaces 13, 14 in this way, but rather that the separation point 26 is already closed against ignition flashover due to the elastic deformation caused by the connection established between the first housing part 11 and the second housing part 12.

The housing 10 is preferably openable without damage. In particular, the housing parts 11,12 need not be damaged or broken. Likewise, the sealing ring 32 preferably remains intact. Preferably, the sealing ring 32 can be used again for the ignition-resistant closure of the housing 10 after opening. However, the housing 18 is preferably re-closable, independent of whether a new seal ring 32 must be used or an old seal ring 32 can be re-used.

In the case of known housings of the protective type "explosion-proof enclosure", in the case of a closed housing, a flat gap is provided in the separation point between the cover and the housing part comprising the interior space, which gap prevents ignition breakdown. In the event of an explosion, gas can therefore pass through the separation point between the cover and the housing part. In the prior art, sealing rings arranged in the separation region cannot prevent this. These sealing rings are only used for the evacuation of moisture from the housing. In the case of the housings known from the prior art with sealing rings and flat slots, the sealing rings, in particular in the event of an explosion, seal the separation between the cover part and the housing part in a manner that cannot be protected against ignition breakdown. The surfaces at the cover and housing part must be obtained in such a way that they define gaps that prevent ignition flashovers. This requires compliance with narrow tolerances in the case of manufacturing the covering member and the housing.

In the case of the housing 10 according to the invention, the housing parts 11,12, in particular the first sealing surface 13 and the second sealing surface 14, can be produced to a greater tolerance than it would have to be for the arrangement of the flat gap at the point 26, which is resistant to ignition flashover. This makes the manufacture of the housing 10 according to the invention simpler.

Based on the simpler requirements for the first and second sealing surfaces 13, 14 or for the first and second housing parts 11,12, the housing 10 can be created such that it can have not only one access opening 22 (as in the case of the housing 10 according to fig. 1), but also a plurality of access openings (at least two) by means of which access to the operating means 25 can be achieved, which, however, in the case of a closed housing 10, is closed in a manner that prevents ignition flashovers with the seal 32 according to the invention. In a variant of the housing 10 as shown in fig. 1, for example, the base cannot be connected in one piece to the remaining tub-shaped or box-shaped first housing part, but rather a separate second housing part can form the base, which is connected to the frame part via a flange connection as a function of the flange connection between the cover 12 and the first housing part 11. The frame part surrounds the interior of the housing and has two opposing access openings, one of which is closed off from the cover and the other from the base in a flashover-proof manner between the first and second sealing surfaces by means of the elastically deformable seal according to the invention. In the embodiment of the housing with one or more access openings, each access opening is preferably also sealed against ignition flashover by means of a respective seal in the event of an explosion.

For the description of the embodiment according to fig. 9a and 9b, the description given with respect to the remaining embodiments can be used, as long as it is not described below, for example, in addition.

Fig. 9a shows an example of a sealing body 32 of this embodiment in the form of a ring or frame in the elastically undeformed state. The seal 32 may have an inner section 32a, which actually causes a seal against ignition flashover, and an outer section 32b surrounding the inner section, which may be connected to the inner section 32a, for example glued or welded. In an embodiment, the inner section 32a and the outer section 32b may be seamlessly and monolithically connected to each other. In other embodiments, sections 32a and 32b may be separate components.

The seal 32 defines an open face F. The normal vector of the opening surface F is displayed in the normal direction R. The inner section 32a may be more flexible in a normal direction R (which is perpendicular to the opening plane) parallel to the opening plane F than the outer section 32 b. The dimension (thickness) of the inner section 32a measured in the normal direction R may be larger than that of the outer section 32b at least in a state of being inelastically deformed in the normal direction R parallel to the opening face F.

The inner section 32a and/or the outer section 32b are preferably constructed of metal. The inner section 32a and/or the outer section 32b may for example constitute a sheet metal strip. The inner section 32a may, for example, be generally made of a plate into which an opening is cut. Alternatively or additionally, the outer section 32b may be made of a plate into which an opening is cut, in which the inner section 32a is arranged. In the outer section 32b, holes are provided through which screws can be guided in order to connect the second housing part 12 and the first housing part 11 to one another.

Fig. 9b shows, in a cross-sectional view, the inner section 32a of the sealing body 32, elastically deformed parallel to the normal direction of the opening plane F between the first housing part 11, the housing body with the flange 24 with the first sealing surface 13, and the second housing part 12, the cover with the second sealing surface 14. The outer section 32b forms a spacer or limits the dimension to which the inner section 32a can be compressed parallel to the normal direction R of the opening face F of the inner section 32 a. Thus, damage at the inner section 32a is avoided, while at the same time giving the assembler the basis for when the inner section 32a is sufficiently compressed in order to establish ignition flashover resistance.

In the assembly according to fig. 9b, the space in the separation point between the first sealing surface 13 of the flange 24 of the housing body 11 and the sealing body 32 is so narrow and so long on the basis of the dimensions of the inner section 32a that the explosive gas can escape from the inner space 23 of the housing 10 at the highest cooling so that ignition of the atmosphere outside the housing 10 cannot be achieved. The same applies to the space in the separation region between the second sealing surface 14 of the cover 12 and the sealing body 32. The seal 32 itself is seamless. In the event of an explosion, gases cannot pass from the interior 23 of the housing through the sealing body 32 through the intermediate space between the first sealing surface 13 and the second sealing surface 14, since a cross section through the sealing body 32 does not establish a gas connection between the interior 23 of the housing 10 and the external environment 21 of the housing 10.

The solution according to the invention can equally be used for housings 10 with larger access openings. The ratio of the length of the space 26 between the first sealing surface 13 and the second sealing surface 14, which is filled by means of the sealing body 32, to the width W of the space 26 between the first sealing surface and the second sealing surface is, for example, at least 100. The width W is measured in the direction of elastic compression of the sealing body 32 or parallel to the normal direction R.

Fig. 10a to 10d show an example of a further embodiment of the housing 10 according to the invention, for which the description of the further embodiment can be used, unless otherwise described below.

The housing 10 has a housing body 11 (first housing part) in the form of a frame and two cover elements 41a,41b (further second housing parts) which can close one side of the housing body 11. Between the cover elements 41a,41b and the housing body 11, flat parts are arranged, which form an intermediate frame 42. The intermediate frame constitutes the second housing part 12. The cover elements 41a,41b may be hinged at the intermediate frame. The intermediate frame 42 has, for example, in the middle, a bridge 43 which divides the access opening 22 into two partial openings into the housing body.

As can be seen in particular from fig. 10d, a frame-like sealing body 32 is arranged between the first sealing surface 13 of the flange section 24 of the housing body 11 and the second sealing surface 14 of the intermediate frame 42. A frame-like flat component is arranged as a further sealing body 47 between the further second sealing surface 45 of the intermediate frame 42 and the sealing surface 46 (third sealing surface) of the cover element 41 a. Between the further cover element 41b and the flange section 24 is the component, respectively. The further sealing body 47 can extend in the closed state between the two cover elements 41a,41b on the one hand and the intermediate frame 42 on the other hand (see fig. 10b, which shows the further frame-like sealing body 47 with the bridge sections 47 a) or there is a separate sealing body for each partial opening. The sealing body 32 and the further sealing body 47 are preferably more flexible than the intermediate frame 42 in a direction parallel to the normal direction R of the opening surface. The additional sealing body 47 may have one or more of the features described herein in association with the sealing body 32.

In the assembly according to fig. 10d, the space in the separation point between the first sealing surface 13 of the flange 24 of the housing body 11 and the sealing body 32 is so narrow and so long that the explosive gas can leave the housing 10 from the interior space 23 maximally cool such that ignition of the atmosphere outside the housing 10 cannot be achieved. The same applies to the space in the separation point between the second sealing surface 14 of the intermediate frame 42 and the sealing body 32 and to the space in the separation point between the further second sealing surface of the intermediate frame 42 and the further sealing body 47 and also to the space in the separation point between the third sealing surface of the cover element 41a,41b and the further sealing body 47. However, in the event of an explosion, gas cannot pass through the sealing body 32 through the intermediate space between the first sealing surface 13 and the second sealing surface 14 and also cannot pass through the sealing body 47 through the intermediate space between the further second sealing surface 45 and the third sealing surface 46, since a gas connection between the interior space 23 of the housing 10 and the external environment 21 of the housing 10 is not established through a cross section of the sealing body 32 or through a cross section of the sealing body 47.

For elastic deformation of the sealing body 32 between the intermediate frame 42 and the first housing part 11 and of the further sealing body 47 between the intermediate frame 42 and the cover elements 41a, b, the cover elements 41a,41b can be screwed together with the collar 24 of the first housing part 11, for example.

In a preferred embodiment of the housing 10 according to the invention, the ignition-through-proof sealing of the separation point 26 between the first housing part 11 and the second housing part 12 is established solely on the basis of the elastic deformation of the sealing element 32. In particular, the casting of the separation point between the first housing part and the second housing part after the connection between the first housing part and the second housing part has been established is not necessarily required for achieving a closure of the separation point against ignition flashovers and is preferably likewise not achieved. The elastic deformation of the sealing element 32 is preferably obtained between the first housing part 11 and the second housing part 12 in the case of a positive and/or non-positive connection, preferably, however, a non-material-fit connection. The first sealing surface 13 and the second sealing surface 14 are preferably oriented transversely, in particular perpendicularly, to the force with which the first housing part 11 and the second housing part 12 are pressed against one another when the connection between the first housing part 11 and the second housing part 12 is established. A force-and/or form-fitting connection is produced between the first housing part 11 and the second housing part 12, which compensates for the force with which the elastically deformable sealing element 32 is applied to the first sealing surface 13 and the second sealing surface 14 in order to press them away from one another and furthermore withstands a force impulse in the event of an explosion in order to keep the housing 10 closed in a manner that is resistant to ignition flashovers.

A protective casing 10 in an explosion-proof enclosure of the explosion-proof type is created according to the invention. The housing 10 is preferably associated with at least one device 19,36,38,39 for reducing the explosion pressure. The housing 10 has a first housing part 11 with a first sealing surface 13 and a second housing part 12 with a second sealing surface 14, wherein in the explosion-proof closed state of the housing 10 the elastic seal 32 is held between the first sealing surface 13 and the second sealing surface 14 in an elastically deformed manner and thus in the event of an explosion in the interior of the housing 10 the space 26 between the first sealing surface 13 and the second sealing surface 14 is closed in an ignition-proof manner. The ignition flashover protection assembly according to the invention can replace a flat gap between, for example, the surface of the cover and the surface of the housing part, which requires compliance with relatively narrow manufacturing tolerances.

List of reference numerals

10	Protective shell
		11	First housing part
12	Covering/second housing part
		13	First sealing surface
14	Second sealing surface
		15	Electrical bushing
16	Operating device
		17	Display unit
18	Side wall
		19	Pressure relief device
20	Pressure relief body
		21	External surroundings
22	Access opening
		23	Chamber/interior space
24	Flange
		25	Electrically operated apparatus or devices
26	Spatial/separation site
		27	Hole(s)
28	Hole(s)
		29	Noodle
30,30a,30b	Trough
		31	Trough base
32	Seal/seal ring/seal body
		32a	Inner section
32b	Outer segment
		33	Spacer
34	Pores of
		35	Fiber
36	Elastic body
		37	Pressure relief devices (devices for internal pressure reduction 37)
38	Flat component
		39	Main body
40	Flat material
		41a	Covering element
41b	Covering element
		42	Intermediate frame
43	Bridging piece
		44	Opening of the container
45	Additional second sealing surface
		46	Third sealing surface
47	Additional sealing body
		47a	Bridge section
S	Section line
		S2	Section line
W	Width of
		H	Height
P	Arrow head
		F	Open face
R	Normal direction of rotation