RU2793276C2 - Explosion-proof housing with split cover - Google Patents

Abstract

FIELD: explosion-proof housing.

SUBSTANCE: explosion-proof housing (10) according to the invention has a cover system (12) consisting of two or more covers (13, 14). The covers (13, 14) are adjacent to the body element (11) with a flame break resistant gap (17). Between the individual covers (13, 14) there is also at least one (20) flame break resistant gap. The remaining end joints (19) or other gaps and passages, have separate seals, primarily in form of a plug (24) of the end joint.

EFFECT: explosion-proof housing.

9 cl, 10 dwg

Description

The invention relates to an explosion-proof housing, in which the openings and joints between the internal cavity of the housing and the environment are so narrow and, moreover, so long that flames or incandescent particles cannot enter the environment. Such enclosures satisfy the type of protection "ex-d", which is also called flameproof enclosure.

Housings of known construction are described, for example, in GB 778040. The housing described there has a housing element with a lid fixed thereon. The lid is held on the housing by means of suitable pressing means, a seal being arranged between the lid and the housing. In order to release excess pressure, the housing is further provided with a pressure relief device formed by means of a porous element held on the opening of the housing.

US 3,617,570 describes a housing whose housing element is closed by a bottom sheet. It is held in place by screws. A joint passing along the contour is made between the bottom sheet and the body element.

The execution of the joint between the housing parts of the flameproof encapsulated housing is also known from DE 19860383 B4. The body parts adjoin each other at a flat joint and are pressed against each other with screws.

The adjoining of the body parts of the flameproof housing to each other through a flat gap, in principle, has shown its suitability. As a result, the flameproof housing can be closed by means of a lid, which is continuously connected to the housing via a flat gap around the perimeter. However, in the case of rather large housings, operational problems arise due to the weight and size of the lid. This is especially true when not only the housing but also the lid is very large, for example, in order to have unhindered access to the elements integrated in the housing if necessary. Large covers in cramped installation environments, such as on ships or offshore platforms, are a major hindrance, as sufficient escape routes must always be available.

It is an object of the invention to provide an explosion-proof enclosure design that at least prevents or reduces one of these problems.

This problem is solved by means of the housing according to claim 1 of the claims.

The housing is provided with a cap system, which includes two or more caps, and a pressure relief device. The lids form a correspondingly flame-burst-resistant gap with the body, which, however, does not occupy the entire perimeter of the lid, but instead extends along the perimeter of the lid system. Between the two lids of the lid system there is another flame-break-resistant gap, which, however, in contrast to the gap passing around the lid system, is not made annularly closed and therefore endless, but runs linearly and therefore has two ends. The ends of the flame-burst-resistant gap made between the covers touch the annular flame-burst-resistant gap passing along the perimeter or end at a small distance from it. At the same time, for the formation of a gap resistant to the breakthrough of a flame, the covers are located with an overlap between them.

Delimited by at least two covers with a housing element, the gap resistant to flame breakthrough is preferably made as a flat gap, which, more preferably, is located in the same plane.

Likewise, the gap which is resistant to flameout between the two covers is preferably a flat gap. It can be located in the same plane as the aforementioned flame-burst-resistant gap extending along the contour, or in a plane offset from this plane. This opens up a lot of possibilities for forming a transition between the flame-break-resistant gap running along the contour and the gap made between the two covers.

In addition, an end joint (butt joint gap) can be provided between both covers, which, except for its ends, does not have to be made resistant to flame breakthrough. On its side facing the environment, i.e. in its transverse direction, it can be protected against flashback by means of a flamebreak-resistant gap formed between the covers. At both ends, the end joint can be provided with an end joint plug which prevents flame breakthrough. As a result, tolerances are possible for the end joint, facilitating the positioning of both covers when closing the housing. For example, hinges having play can be provided to temporarily hold both covers in the open position. In addition, the lids can be connected to the housing element by means of screws, quick connectors, or other locking mechanisms that position both lids relative to each other and still allow a relatively large tolerance (eg, about 1 mm or more). This represents a lighter design and at the same time easier installation when opening and closing the housing.

Embodiments of the invention that achieve one or more of these advantages are the subject of the description, drawing or additional claims. Shown on:

Fig. 1 - housing according to the invention, schematic drawing, main front side perspective view,

Fig. 2 housing according to FIG. 1, top view,

Fig. 3 housing according to FIG. 1, front view, with a special image of the flame-burst-resistant gap,

Fig. 4 is a fragment of the lid according to FIG. 2 in the area of adjacency of its two covers to each other,

Fig. 5 is a modified constructive version of the cover in the image according to FIG. 4,

Fig. 6 is a further modified structural version of the housing and its cover in a fragmentary image, the image according to FIG. 4,

Fig. 7 further modified form of the housing according to the invention with a special image of its locking end joint, top view with transparent covers shown,

Fig. 8-10 show additional embodiments of the housing according to the invention, respectively, in perspective view, with particular attention to the locking of the end joint.

In FIG. 1 illustrates a housing 10 which is designed as an explosion-proof housing with the type of protection "explosion-proof". The housing 10 has a housing element 11 that encloses an internal cavity for accommodating components that can serve as sources of initiation of an explosion. The body element 11 can be made like a box with walls standing at right angles to each other or otherwise. The body element 11 has an inlet closed by a system 12 of caps. The lid system 12 includes at least a first lid 13 and a second lid 14, which together close the inlet of the housing element 11. Both lids 13, 14 are held on the housing element 11 by clamping means, not shown, and are pressed against each other. For this, screws, tie-down straps or other pressing means are used which press the two covers 13, 14 against the housing element 11 and against each other. In addition, the covers 13, 14, as shown in FIG. 1 in the case of a lid 14, can be held by hinges 15, 16 (and also 15', see FIG. 2 for the example of a lid 13) or similar support means on the body element 11 which, when the lid system 12 is open, bear the weight of the respective lid. 13, 14.

Preferably, the hinges 15, 16 (as well as 15', 16') define a common hinge axis running parallel to one of the sides of the body element 11 with some play, so that when the cover 14 is closed, the orientation of the cover 14 on the body element 11 is possible, for example, by means of dowel pins or the like.

Both covers 13, 14, as seen in FIG. 2 abut a flame-burst-resistant gap 17 on the body member 11. This flame-burst-resistant gap 17 in FIG. 3 is shown again. There it is bounded on the outside by the contour of the housing element 11 and on the inside by a dotted line which marks the border of the inlet of the housing of the element 11. The flame-burst-resistant gap 17 usually has a width of 18, which is sufficient to cool the passing gas and prevent flashback of the flame. The gap 17 provided between the lid system 12 and the body element 11 extends along the entire perimeter of the lid system 11 or body element 17 so that it completely encloses the inlet. The gap 17 follows the shape of the inlet opening and can respectively have an annular polygonal, an annular circular or other shape, but still be closed and therefore continuous. At the end joint between the two covers 13, 14, the body element 11 has at least preferably no contact surface. In other words, the gap 17 then has no ramifications, ie it is straight. On the side of the body element 11 there is no contact surface for the covers 13, 14. Each cover 13, 14 thus bears on the body element 11 only on three sides.

Preferably, gap 17, as seen in FIG. 2 is designed as a flat gap. It is formed between the contact surface formed on the housing element 11 and the corresponding mating contact surfaces on the reverse side of the covers 13, 14. The clamping and holding means of the covers 13, 14 acting on the body 10 hold the covers 13, 14 with a tight fit to the body element. 11. Additional pressing means hold the covers 13, 14 in close contact with each other. The pressing direction of the clamping and holding means which press the covers 13, 14 against the housing element preferably coincides with the pressing direction in which the covers 13, 14 are pressed against each other. Due to this, it is achieved that in any case, even with a pulse-like increase in pressure in the housing 10, the width of the gap between the covers 13, 14 and the housing, as well as the width of the gap between the covers 13, 14, for the most part, is a few hundredths of a millimeter, however, in any case does not exceed the value that prevents the breakthrough of the flame.

Both covers 13, 14 can close the inlet of the housing element 11, preferably each approximately half way. At the same time, in the closed state, they are located opposite each other at the end joint 19, as can be seen in Fig. 4. This end joint has a certain tolerance regarding its width, which is obtained from manufacturing tolerances, temperature changes and tolerances regarding the positioning of both covers 13, 14 on the body element 11. Preferably, the end joint 19 is designed so that the covers 13, 14 are in contact with each other. the other end faces, so that unwanted jamming does not occur or to prevent the covers 13, 14 from closing.

However, between the two lids 13, 14, a gap 20 which is resistant to flameout is formed by the fact that one of the lids, here, for example, the lid 14, has a ledge 21 extending over the other lid 13 in the form of a plank. The protrusion 21 on the side facing the lid 13 has a flat surface which rests against the outer side of the lid 13 and forms a strip-like gap 20 with it. It is shown in FIG. 3 again. It runs, as can be seen, across the inlet 17 limited by the gap and covers the gap 17 in two opposite places, which simultaneously represent the ends 22, 23 of the gap 20. The protrusion 21 can be formed laid on the cover 14, screwed, welded, glued to it or a lath milled from it, or otherwise made. On the side facing the lid 13, the protrusion 21 has a regularly shaped, for example flat, for example machined, surface. Also, the lid 13 has a regularly shaped, eg flat, eg machined, surface on the side facing the projection 21, so that both surfaces can be mounted tightly on top of each other. Not shown in FIG. 1, the pressing means press the protrusion 21 against the cover 13 so that the machined surfaces lie firmly on one another. Alternatively, both covers 13, 14 can be made of solid material and provided with a corresponding milled groove at the overlap, so that they are, for example, according to FIG. 5 are linked to each other. As a result of this, the length and narrowness of the gap 20 between the covers 13, 14 can also be ensured to prevent a flame break.

The end joint 19 in the area of the ends 22, 23 may form holes which are not yet flame-break-proof in themselves. Therefore, at both ends 22, 23, respectively, an end joint plug is provided, as shown, for example, in FIG. 8 on the example of the end 23. The plug of the end joint can be formed by a seal, as shown in Fig.8 elastic seal 25, which is inserted into the corresponding hole 26, which is made, for example, as a cylindrical hole at the end of the end joint 19 and is limited by semi-cylindrically rounded end sides both caps 13, 14. The elastic seal 25 may be an elastic cylinder (rubber cylinder or the like) or also a hollow cylinder, which can be formed into different shapes by deformation. For example, an eccentric, a pressure screw or other pressing means located in the center of the elastic seal 25 can be provided for this. Instead of rubber, another deformable material may be used, such as metal, metallized plastic or the like. Instead of selecting a cylindrical hole 26 with a cylindrical seal, other cross-sectional shapes can also be used, such as, for example, a square shape, a polygonal shape, or the like, both for the hole 26 and for the seal 25. The seal 25 bears evenly on both end faces. the sides of the caps 13, 14 and, in addition, tightly closes both the gap 17 and the gap 20, as follows, first of all, from Fig.8. Reshaping the resilient seal 25 may be achieved by means of a stem or other means such as a screw, wedge, cone, compression between caps 13, 14, or other means to exert pressure on the seal 25.

In the previously described form of execution of the housing 10, numerous options are possible regarding both the location of the gap 20 and the end joint 19, and the execution of the plug 24 of the end joint. For example, the cross-section of the butt joint can be reduced by reducing the distance between the flameout-resistant gap 17 and the flameout-resistant gap 20, as shown in FIG. 5. The lid 13 has a suitable recess there for the protrusion 21 of the lid 14, so that the width of the end joint 19 is reduced. At its ends, it, in turn, can be provided with a plug 24 end joint.

According to FIG. 6, it is also possible to place a protrusion 21 of the cover 14 in the inner cavity of the body element 11, so that the protrusion 21 does not extend over the cover 13, as shown in FIG. 4 and 5, and passes under it. As a consequence, the flame-burst-resistant gap 17 and the flame-burst-resistant gap 20 lie in a common plane. The end joint 19 now lies on the side of the cover system 12 that is open to the environment. At the critical transitions between gap 20 and gap 17, in turn, an end cap 24 can be located, which closes the place where gap 20 abuts gap 17.

It is also possible to make the end joint itself flame-break resistant. In FIG. 7 shows for this purpose applicable in the case of the embodiments according to FIG. 1-5 end joint configuration, top view. In this case, both covers 13, 14 in FIG. 7 are shown transparent. In the area of the end 22 of the butt joint 19, the body element 11 has an inwardly directed protrusion extending parallel to the reverse sides of the covers 13, 14, which exceeds the width 18 and is therefore wider than, for example, 25 mm. In the selected embodiment, it has, for example, a width of 60 mm. On top of this protrusion, to which both covers 13, 14 fit tightly, an end joint 19 is formed like a labyrinth, for example in the form of a meander, waves, interlocking teeth, or the like. First of all, a plurality of butt joint portions 27, 28 are provided, respectively, having a length giving resistance to flameout, for example a length of 25 mm or more. In the form of execution according to Fig. 7, there are at least two corners along the end joint 19, but preferably several angles, to provide a flame-outage-resistant end joint geometry. The angles present along the end joint can be 90° or another value.

In all forms of execution of the end joint 19, in which the end joint 19 lies between the gaps 17 and 20, the end sealing of the end joint 19 can occur according to any of those shown in Figs. 8-10 principles. For example, end joint 19, as shown in FIG. 9 can be closed by a lid 29 which covers both the protrusion 21 and the part of the lid 13 lying underneath and the part of the lid 14 adjacent to the end joint 19 and the portion of the body 11. The lid 29 can be fastened by means of suitable fastening means - screws, clips or other .P. on the body element 11 and/or covers 13, 14.

Alternatively, a wedge-shaped sealing element 30 of flexible or inflexible, hollow or solid material at the end of the butt joint 19 can be used as end cap 24. The wedge-shaped sealing element 30 can (like the sealing element 25) consist of a porous material. The porosity of the material is chosen in this case such that the material has a blocking effect against flashover.

In all embodiments of the housing 10, it is common that it is provided with at least, preferably, one pressure relief device 31, as shown by way of example in FIG. The pressure relief device 31 includes at least a porous element 32, which is located either in the closed internal cavity of the housing 11 or on the pressure relief hole 33 . The pressure relief hole 33 connects the internal cavity of the housing 10 with the environment and can be located in at least one of the covers 13, 14 and/or in the housing element 11. The pressure relief hole 33 and the pressure relief element 32 located therein prevent the growth of a harmful peak overpressure in the housing 10 when the explosive gas mixture present there ignites, for example during the operation of electrical components. Due to the effective reduction of pressure peaks by means of porous elements 32 with sufficient volume, hot gas streams entering these elements 32 are cooled to such an extent that the reduction in their volume prevents pressure build-up in the housing 10. Additionally, when the porous element 32 is located in the pressure relief hole 33 due to gas bypass into atmosphere, an additional pressure relief effect can be achieved.

Efficient depressurization of the body 10, as well as tight tightening of the system 12 of covers in relation to the body element 11, as well as tight tightening of both covers 13, 14 to each other in the region of the protrusion 21 by means of clamping means located along it, as well as by means of the system located along the perimeter The 12 lids of the pressing means allow for a double or multi-leaf design of the 12 lid system. As a result, the size and weight of the covers 13, 14 are reduced to a size that is easy to handle, while the housing can be made particularly large. In addition, the decrease in the pressure peak achieved by means of the pressure relief device 31 leads to the fact that even in the event of an explosion, the gap geometry inside the housing 10 is maintained and flame breakout does not occur. Flame-break-resistant closed gap geometry can be achieved by one or more hinges, positioning aids, centering pins, gap geometry shaping, butt joint shaping, threading aids, seat molds, or mechanical docking.

The explosion-proof housing 10 according to the invention has a lid system 12 consisting of two or more lids 13, 14. The lids 13, 14 adjoin the housing element 11 at a gap 17 resistant to flameout. gap 20. On the remaining end joints or other gaps and passages, separate seals are located, primarily in the form of a plug 24 of the end joint.

10 - body

11 - body element

12 - cover system

13 - first cover

14 - second cover

15, 15', 16 - hinges

17 - clearance

18 - gap width 17

19 - end joint

20 - clearance

21 - ledge

22, 23 - gap ends 20

24 - end joint plug

25 - elastic seal

26 - hole

27, 28 - sections of the end joint

29 - cover

30 - sealing element

31 - pressure relief device

32 - porous element

33 - pressure relief hole

Claims (13)

1. An explosion-proof enclosure (10), primarily an explosion-proof enclosure having: - a housing element (11), which covers the internal cavity and has an inlet, - pressure relief device (31), - a system (12) of covers, which contains at least the first and second covers (13, 14), moreover, between the covers (13, 14) and the body element (11), as well as between the covers (13, 14), gaps (17, 20) resistant to flame breakthrough are respectively made, and for the formation of a gap (20) resistant to flame covers (13, 14) are located with an overlap. 2. Housing according to claim 1, characterized in that the gaps (17, 20) respectively limited by at least two covers (13, 14) with a body element (11) are flat gaps. 3. A housing according to one of the preceding claims, characterized in that the gap (17) delimited by at least two covers (13, 14) and the housing element (11) lies in the same plane. 4. Housing according to one of the preceding claims, characterized in that the gap (20) provided between at least two covers (13, 14) is a flat gap. 5. Housing according to one of the preceding paragraphs, characterized in that the gap (20) made between at least two covers (13, 14) is oriented parallel to the gap made between at least two covers (13, 14) and the body element (11). (17). 6. Housing according to one of the preceding claims, characterized in that between at least two covers (13, 14) an end joint (19) is made. 7. Housing according to claim 6, characterized in that the end joint (19) is located connecting the gap (20) made between the covers (13, 14) and the gap (17) made between the covers (13, 14) and the body element (11) . 8. Housing according to claim 6, characterized in that the end joint (19) is provided with a plug (24) of the end joint. 9. Housing according to claim 8, characterized in that the plug (24) of the end joint is located at the end relative to the end joint (19).

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