EP2201983B1 - Safety device for gas conducting systems - Google Patents

Abstract

The safety valve has a housing (51) with an inner space (52), where a flame sieve (53) is arranged in the inner space such that a cross-section of the inner space is filled completely by the flame sieve. Crossing points (78,79) perpendicular to a bisector (E) of the flame sieve have an offset (b1) from the bisector around center points (J',J) of connection openings (70.5,71.5). Independent claims are also included for: (1) a cage for holding a flame sieve, particularly for a safety valve; (2) a flame sieve insert for a safety valve, particularly for a blast barrier; and (3) a tube expander for a safety valve, particularly for a blast barrier.

Description

Technical area

The invention relates to a safety fitting, in particular a detonation barrier, for gas-conducting systems, in particular for pipelines, comprising a housing with an interior in which a flame screen is arranged such that a cross section of the interior is completely filled by a flame screen, and the housing at a Connecting longitudinal end has a connection opening for connection to the gas-conducting system, which connection opening has a smaller cross-sectional area with respect to the cross-section of the interior, and a center of the connection opening is offset perpendicularly to a mid-perpendicular of the flame sieve, the flame screen being supported by a support grid, which comprises at least three, In essence, extending from an inner periphery of the interior inwardly, struts, which struts meet at exactly one intersection point. Furthermore, the invention relates to a cage for a flame sieve for a detonation barrier and an insert with cage and flame sieve for a detonation barrier.

State of the art

Safety fittings for gas-carrying systems include e.g. Flame, deflagration or detonation breakdown fuses, hereafter referred to as flame, deflagration or detonation barriers or barriers. Such safety valves prevent the propagation of a burning gas front in gas-carrying systems such as e.g. Pipelines or tank systems. If flammable gas ignites in a pipeline, a burn-off or, as a consequence, a deflagration (deflagration) or detonation (explosion) is triggered. For example, if a flame front passes through a pipe, the flame speed increases with the length of the pipe. Up to a tube length of about 50 inner diameters of the tube, the flame propagates at subsonic speed (deflagration). In this case, a deflagration protection is sufficient to secure the side to be protected. The deflagration protection usually has a lower pressure drop than a detonation fuse and can be dimensioned mechanically weaker. For larger pipe lengths of straight tubes with a constant cross section, the flame front supersonic speed can reach (detonation), which is why in this case to secure the side to be protected a detonation fuse is installed. Flame barriers prevent the passage of the flame front in the case of a continuous fire z. B. as a result of deflagration.

A detonation results in a shock wave with significantly higher pressures than a deflagration. The requirements for the mechanical stability of detonation barriers are therefore significantly greater than for pure deflagration barriers.

Common flame barriers are based on the principle of dividing the flame front into a plurality of smaller flames. The heat energy of the individual smaller flames is dissipated, so that the gas is no longer flammable on the flame side of the barrier. For this purpose, known barriers have a z. B. honeycomb structure or porous, usually metallic or ceramic flame sieve (also "flame arrester", "flame filter" or "rust"), which has a plurality of passageways with relatively small cross-sections (capillaries). The flame sifter fills one Section inside the pipeline is completely exhausted, so that a gas flowing in the pipeline has to pass through the flame sieve.

Upon impact of a flame front is thus due to the Durchtrittskapillaren the mentioned subdivision into smaller flames. The heat energy of the smaller flames is released via the flame sieve to a socket or a housing and discharged from there to the outside. In this case, the flame sieve in terms of its dimension in the direction of flow and the capillary diameter or cross-sections of the respective requirement of the corresponding flammable medium d. H. adapted to the respective gas (explosion group).

The subdivision of the tube cross-section into the plurality of smaller passage channels results in an increased flow resistance at the barrier during normal operation. For compensation, known barriers therefore have a widening with an enlarged cross-section compared to the tube diameter, in which the flame sieve is arranged with a cross section corresponding to the cross-section of the widening.

The WO 2000/56406 A (AG Marvac LTD.) Describes, for example, a detonation barrier for a pipeline with two in the flow direction serially arranged flame sieves. The flame sieves are made from a rolled-up double layer of corrugated and smooth steel strips and arranged within a barrel-shaped housing. The housing and the flame sieves have a larger diameter than the pipe. On both sides of the housing tube expander are arranged, to which the pipeline connects. Within the housing, the flame sieves are supported by a grid on the housing of the detonation barrier, since the flame sieves themselves have a comparatively low structural stability against loads in the axial direction.

Such tube expansions have the disadvantage that they form a pocket in horizontal pipes at the bottom due to the expansion, in which dirt and condensation can collect in an undesirable manner. It has therefore been used in known systems to use asymmetric Rohraufweiter, in which the centers of the larger openings of Rohraufweiter not on the Center axis of the pipes connected to the smaller openings lie. The central axis of the barrel-shaped housing of the flame strainer is spaced from the central axis of the pipeline, that is, eccentrically arranged. In particular, the tube expander are formed such that the undersides of the pipeline and the housing or of the flame strainer are at the same vertical level. The flame screens held within the housing are in this case also arranged eccentrically with respect to the axial direction of the pipeline.

It has been found that an eccentric construction method weakens the deflagration and detonation barriers in terms of mechanical stability against deflagration or detonation, and a design of the barrier must therefore be relatively robust in order to achieve a stability corresponding to the axial constructions.

Presentation of the invention

The object of the invention is therefore to provide a safety device associated with the aforementioned technical field for gas-conducting systems, which has improved mechanical stability with a simple construction.

The solution of the problem is defined by the features of claim 1. According to the invention, a safety fitting, in particular a detonation barrier, for gas-conducting systems, in particular for pipelines, comprises a housing with an interior in which a flame screen is arranged such that a cross-section of the interior is completely filled by a flame screen. Furthermore, the housing comprises, at a connecting longitudinal end, a connection opening for connection to the gas-conducting system, which connection opening has a smaller cross-sectional area with respect to the cross-section of the interior, and a center of the connection opening is arranged offset perpendicular to a mid-perpendicular of the flame screen. In this case, the flame sieve is supported by a support grate, which has at least three struts extending essentially from an inner circumference of the inner space, which struts meet at exactly one point of intersection. The crossing point points across the Mid-perpendicular of the flame sieve on an offset from the mid-perpendicular to the center of the connection opening towards. Preferably, the flame sieve is flat.

For simplicity, distances, unless otherwise noted, are distances in absolute value in a direction perpendicular to the mid-perpendicular of the flame screen. Mid-perpendicular here and below denotes an imaginary perpendicular to a plane of the flame sieve, which passes through a center of the flame sieve. Flame sieves usually have a flat disk-shaped design, whereby the plane of the flame sieve is defined by the surface of the flame sieve. Typically, the direction of the mid-perpendicular also corresponds to the orientation of the capillaries of the flame sieve. In the case of unusual, possibly asymmetrical shapes of the flame screen, the term center point is preferably to be identified with a center of gravity of the flame screen surface.

The safety fitting according to the invention is described below without restricting the generality with reference to the example of a detonation barrier. The features mentioned and their combinations are also applicable to other safety fittings such. Deflagration barriers transferable.

In a variety of possible embodiments, the flame sieve is arranged at detonation barriers in a tubular housing portion, wherein tubular means in most cases a hollow tube or a ring with a substantially circular cylindrical inner and outer cross-section. However, the detonation barrier according to the invention is not limited to such embodiments and can also be designed differently. Also conceivable are oval or polygonal cross-sections, if required by the specific application, or embodiments which do not have a tubular housing section and the interior can be formed, for example, directly in tube expansions (described below). Typically, the flame sieve is arranged in the housing of the detonation barrier such that the perpendicular bisector of the flame sieve with a longitudinal central axis z. B. the above-mentioned tubular housing portion coincides, that is arranged coaxially. Further, without limiting the applicability of the following For simplicity, the invention is directed to detonation barriers only, embodiments being also included as deflagration barriers and flame barriers.

With the offset of the crossing point of the struts of the support grid against a perpendicular bisector of the flame sieve is achieved that a support center of the support grid, d. H. a region in which a supporting action of the supporting grid is largest is arranged in a region which is eccentric with respect to the flame sieve. In conventional constructions, the crossing point of the struts of the support grid in the center of the flame sieve, which corresponds to eccentric arrangement of the flame sieves with respect to the pipe or the connection opening does not correspond to the area of the greatest pressure effect of a shock wave at a detonation.

A shock wave enters the housing of the detonation barrier at the connection opening. Due to the smaller cross-sectional area of the connection opening and the eccentric arrangement of the same, the shock wave propagates asymmetrically within the housing. Consequently, a first contact area of the pressure wave with the flame sieve does not take place in its center, but in a region which is offset in the direction towards the center of the connection opening. Here, the invention, by the support grid of the flame strainer adapted to these circumstances has a support center of gravity with increased mechanical stability in a region which is particularly stressed in a detonation. The increased mechanical stability of the center of gravity support is achieved according to the invention, in which the struts of the support grid in an eccentrically located first contact region of a pressure wave have a crossing point in which converge the struts and preferably connected to each other, for. B. welded or screwed.

The struts of the support grid need not be connected to each other as individual elements, but can also be cut in one piece from a steel sheet layer of sufficient thickness. The term "struts" thus does not refer to individual components of the support grid, from which it must be composed, but to constructive elements, which give the shape of the support grid.

The flame sieve and a dimensioning of the housing of the detonation barrier are to be designed such that the requirements of the respective application are met. For example, in biogas plants for methane or methane-air mixtures, a flow resistance of about 2-3 mbar should not be exceeded. For this purpose, capillaries and the surface of the flame sieve, and thus also a dimensioning of the housing of the detonation barrier, should be selected accordingly. Ideally, detonation barriers in this case are also allowed for significantly higher pressures of, for example, up to 120 mbar or higher.

However, the detonation barrier according to the invention is not limited to such low-pressure applications, but can generally be used both in high-pressure applications (gas pressure above about 2 bar, test pressure about 30 bar) and in other low-pressure applications.

In a preferred embodiment, the support grid has an odd number of struts, in particular the support grid preferably comprises 3 or 5 struts. In this case, preferably one of the struts intersects the perpendicular bisector of the flame sieve. As a rule, support grids with 3 struts are preferably used for smaller cross sections of flame sieves, whereas struts are generally preferred for larger cross sections.

Preferably, angles included between two struts are the same with respect to the point of intersection for all pairs of adjacent struts. In other words, the struts are regularly star-shaped with respect to the point of intersection, i. distributed equally angularly. In this case, due to the offset of the crossing point, the circumferential ends of the struts are distributed unevenly around the circumference of the flame screen, i. H. the pitch angles of imaginary radians to the strut ends of any two pairs of adjacent struts with respect to the mid-perpendiculars of the flame screen do not correspond to each other in this case.

With an odd number of struts, one of the struts can be arranged above the center of the flame sieve, that is to say vertical, with an angular uniform distribution with respect to the point of intersection, while there is no vertical strut directly behind the connection opening. Thus, a gas flow in normal operation is hindered as little as possible. Above the crossing point, however, a vertical strut is advantageous: commercial flame sieves have a central one Central body on. This is used in the production as a wound body for the metal band layers. To further improve the mechanical stability, it is therefore particularly advantageous to support the central body at eccentric crossing point of the support grid by one of the struts. Optionally, the central body z. B. be connected by a screw with the corresponding strut.

In other variants, the support grid includes an even number of struts such. B. four cross-shaped or six star-shaped struts. In the case of 4 struts can then be arranged, for example, in pairs perpendicular to each other. The four struts thus form the arms of a right-angled cross, which is arranged eccentrically with respect to a center of the flame sieve. While arrangements are also possible in this case in which one of the struts supports the center of the flame sieve, embodiments with an odd number of struts are preferable because of the preferred distribution of the struts on the flame sieve surface.

Depending on the requirement, however, the supporting grid can also comprise a different number of struts, not explicitly mentioned here. It is also not necessary that the struts are distributed with respect to the point of intersection angularly equal. It is conceivable, for example, for more struts to be formed in the first contact region of the pressure wave to increase the mechanical stability than in the remaining region of the flame sieve surface. The particularly preferable embodiment of the support grid results from the specific requirements of the particular application of the invention (eg type of gas, expected speed of the pressure wave front etc.) as well as considerations for the simple and economic production of the support grid or detonation barrier (cost of materials, production costs Etc.).

The offset of the crossing point from the mid-perpendicular of the flame sieve may vary depending on the application. It has been found to be particularly suitable that the offset of the crossing point is in the range of 10% -100% of the perpendicular distance of the connection opening center to the perpendicular bisector of the flame sieve, preferably in the range of 25% -100%, advantageously in the range 25% -50%. lies. As a versatile applicable embodiment has for the ratio of the vertical distance of the Anschlussöffnungsmittelpunkts to the crossing point and the offset of the golden section φ = 1.61803 ... proven. The vertical distance of the connection opening center to the point of intersection thus preferably corresponds to φ times the offset of the crossing point from the mid-perpendicular of the flame sieve.

Since the propagation of the pressure wave front depends, inter alia, on the housing design as well as on the type of gas present in the pipeline, circumstances other than the golden section may be preferable as required.

In order to enable a largely undisturbed gas flow, it is advantageous to make the widening of the cross section of the connection opening to the inner cross section of the tubular housing section continuously. For this purpose, the housing at the connection longitudinal end advantageously comprises a largely conical tube expander, which has the connection opening at one of its longitudinal ends and an opening at an opposite longitudinal end, whose cross section corresponds to the internal cross section of the interior of the housing. In order to ensure a continuous transition to the cross section of the eccentrically arranged connection opening, the tube expander is preferably asymmetrical with respect to the mid-perpendicular of the flame screen. H. formed obliquely-conically. Preferably, the tube expander is designed such that the housing of the detonation barrier has at least one continuous straight generatrix over its entire length.

With generatrix here an imaginary longitudinal line of the wall of the housing is called. By having at least one continuous straight line on the housing and in particular in the interior of the housing, it is ensured that, with appropriate alignment of the installed in a horizontal pipe detonation barrier, no depression in the housing or in the interior of the housing is present on a bottom. Thus, no pocket is present in the housing, which would favor an accumulation of dirt and / or condensation.

The pipe expander preferably has a flange on the longitudinal end opposite the connection opening. Thus, the tube expander can be easily attached to a further housing part of the detonation barrier. In particular, for example, a tubular housing part can be fastened via the flange on the tube expander or a further tube expander can be flanged on. With appropriate Execution of a cage for the flame sieve (see below), the cage between the Rohraufweiter and another housing part can be clamped.

In a variant, the pipe expander can also be fastened in a different manner to other housing parts, for. B. welded directly. However, this results in the disadvantage of a comparatively difficult access to the interior of the housing, in the case of z. B. the flame sieve must be replaced. In addition to a flange, any other holding system is conceivable, which allows the desired connection of the tube expander with other housing parts.

Advantageously, the support grid, in particular the struts of the support grid, with their respective longitudinal ends facing away from the crossing point, are fastened to an inner wall of the housing of the detonation barrier. Preferably, the support grid is mounted in the interior in the region of the flange on the pipe expander.

By the support grid is attached to the housing, a high degree of stability of the support grid can be achieved in a simple way. The struts of the support grid can z. B. directly to the corresponding housing part, preferably the tube expander, welded. Such an embodiment is simple and inexpensive to manufacture. By the support grid is mounted, for example, at the opposite longitudinal end of the connection opening in the interior of the tube expander, the support grid can, for example, with a suitable arrangement of the flame strainer. B. abut in a clamped between two tube expander flame sifter cage directly on the flame sieve and thus optimally fulfill its support function.

In one variant, the support grid may also be fastened to a cage supporting the flame sieve (see, for example, below), which, however, requires an increased outlay in terms of material expenditure and processing during manufacture in order to achieve the desired mechanical stability. Other embodiments also include support grates, which are fastened or anchored both on the housing and on the cage of the flame sieve.

In order to be able to install the detonation barrier as an intermediate fitting in a pipeline, the housing preferably has a second connecting longitudinal end which lies opposite the first (above-mentioned) connecting longitudinal end in the longitudinal direction of the housing. At the second connecting longitudinal end a second connection opening is provided, the center of which is analogous to the connection opening at the first longitudinal connection end in vertical Direction is arranged offset to the mid-perpendicular of the flame sieve. Preferably, the second connection opening has the same cross-sectional area as the first connection opening, so that the two connection openings are formed symmetrically relative to the flame sieve. In this case, the two connection openings are aligned with each other, so that a simple installation in an existing pipeline, for example, is ensured. In particular, the housing has a tube expander on the second connecting longitudinal end, which preferably corresponds to the tube expander on the first connecting longitudinal end. The tube expander correspond to each other with respect to a plane of the flame strainer preferably mirror image.

The housing is formed in the aforementioned embodiment substantially symmetrical with respect to a cross-sectional plane in the longitudinal center of the tubular housing portion and can thus be easily installed in an existing pipeline. If the housing has only one connection opening, then the detonation barrier is suitable for example. B. as the end protection of a gas-carrying pipeline or a general gas-conducting system such as a gas tank system.

In a preferred embodiment, the flame sieve is mounted in a cage with a ring, wherein a passage encompassed by the ring forms a receiving space for the flame sieve and the ring comprises the flame sieve at its periphery. In this case, holding means are preferably provided at openings of the passage of the ring, which prevent axial discharge of the flame strainer from the receiving space. In particular, the holding means comprise at least one of the passage openings of the ring a holding rack, wherein the holding rack is arranged and designed such that the supporting grid completely covers the holding rack.

Due to the construction of known flame sieves of double layers of alternating smooth and corrugated steel strips, which are rolled up into a disk, the flame sieves have a comparatively low mechanical intrinsic stability in the direction of the perpendicular bisector. For stabilization, but also for modular handling or interchangeability of the flame sieve, it is therefore particularly advantageous to support the flame sieve in a cage. Preferably, the cage comprises a ring or a ring socket, in which the flame sieve, ie, for example, the rolled-up to the disc steel bands are used. The ring can z. B. at one of his z. B. circular edges in the passage Having the ring projecting circumferential projection, which prevents the flame screen can be applied to the periphery in this direction from the ring. On the projection, for example, a holder can be fixed, which also holds the flame sieve in a circumferentially spaced-in area.

The chosen example of a circular design is for ease of illustration of the inventive idea and does not limit the invention to circular embodiments. In addition, the flame sieve including cage can also be fixedly mounted in the housing, in which case, however, the entire detonation barrier or the corresponding housing part has to be replaced in order to renew the flame sieve. As a further variant, no cage needs to be present and the flame sieve can be fixed directly in the interior of the housing, which is also disadvantageous in terms of a good interchangeability of the flame sieve.

After inserting the flame sieve into the ring, further retaining means can be attached to the edge of the ring, which hold the flame sieve in the ring. Particularly advantageous embodiments in which the ring of the cage struts of another Halterosts are attached, z. B. are welded to the ring. In this case, the projection and the retaining studs take over the function of the retaining means of the cage and the flame sieve is clamped between the two retaining studs. But it is also conceivable that only one holder is present and the flame strainer on a side facing away from the holder side of the cage by other means such. B. a further cage with flame sieve is supported.

In this case, the holder may be mechanically relatively weak and therefore inexpensive, since it does not need to take over a support function in the event of detonation. The retainer serves only as a holding device which holds the flame sieve in the cage or in the ring of the cage. The struts of Halterosts are preferably fastened with their respective end point facing away from the intersection of the longitudinal end of the ring of the cage. But the holder may also, for example, have an outer retaining ring, to which the holder can be attached to the ring of the cage. Preferably, the holding means or the holder are arranged in the passage of the cage, so that no protrusions are present in the axial direction.

In order not to obstruct the gas flow unnecessarily in normal operation, the holder back is preferably designed and arranged such that a projection of the holder to the flame sieve plane is covered by a corresponding projection of the support grid. In the direction of flow is then obtained by the Halterost no additional obstruction of the gas flow, since he z. B. completely in the "river shadow" of the support grid can be arranged.

The cage with retainer and the flame sieve held therein thus provide a stable unit, which can be used in a simple way, for example, in the housing of the detonation barrier. The cage of the flame strainer is preferably mounted interchangeable in the housing in this case, so that a simple replacement of the flame strainer or the entire unit is possible. The ring can be designed as a mounting device itself, which can be attached directly in the housing, z. B. can be trapped between the flanges of Rohraufweiter.

Preferably, the flame sieve has an axial length in the range of 1 to 3 cm, preferably 19 mm. In the case of a holder in a cage, the ring of the cage also has a substantially the flame sieve length corresponding axial length, the ring for accommodating the struts of the support grid, however, may be formed correspondingly longer by a few millimeters.

With this dimensioning of a flame sieve or a cage with flame sieve, the requirements of a variety of standard applications can be met with a single cage with flame sieve or a single flame sieve and it requires for such applications no serial connection of several flame sieves or cages with flame sieves. However, if required by the specific application, any number of flame sieves or cages with flame sieves can be arranged one behind the other in the flow direction. It has been found that a spacing favors the flame sieves in the direction of flow in the range of a few millimeters, the barrier behavior of the barrier. In a series connection of flame sieves, for example, each of the flame sieves may have a holder for mounting. In this case, however, only a first and possibly a last flame sieve are supported by a support grid according to the invention, while the flame sieves arranged therebetween do not have to have an additional support structure. Preferably, the Halteroste are arranged between adjacent flame sieves and meet next to the Holding function also a function of a spacer, which ensures a minimum distance of adjacent flame sieves in the flow direction.

For this case, the rings of the associated cages may each have front side corresponding circumferential grooves and springs, which allows a stable, for example, coaxial assembly of the rings one behind the other. In this case, the ring may be dimensioned in the axial direction such that the flame sieves have a spacing in composite cages and / or space for z. B. arranged between the flame sieves Halteroste is created. Preferably, in a series arrangement between the flame sifters each only one holding rack is arranged, so that adjacent flame sieves are indeed spaced, but the distance can be chosen small enough so that there is no adverse effect in the detonation due to excessive freedom of movement for the flame sieve.

In order not to hinder a gas flow unnecessarily in a series connection of flame sieve cages, the holding brackets of the individual cages are aligned with one another in such a way that the individual holding braces preferably completely overlap in a projection onto the flame sieve plane. To ensure the desired arrangement or orientation of the individual cages can, for. B. coat side on the ring of the cages each, for example, a notch or a bore be formed such that the notches or holes have to be aligned with each other in the correct arrangement. For installation, this z. B. a bolt in the bore or notches are introduced to fix the orientation for mounting.

The ring of the cage may also itself form a portion of the housing, i. H. the ring of the cage itself forms part of the housing wall in this case.

In particular, an embodiment of the detonation barrier is advantageous in which two tube expander each have a flange at least on a side facing the flame strainer, and the ring of the cage forms a tubular housing section. The cage with flame sieve is then, preferably as a flame sieve insert, removably mounted in the housing. In particular, the cage is advantageously clamped between the flanges of two tube expanders (as described above).

The flanges, for example, outside of an outer surface of the ring can be connected to each other via long screws, wherein the ring of the cage as

Spacer acts and is clamped by the screwing of the flanges between them. Thus, the ring of the cage is easily accessible from the outside and can be easily replaced without the pipe expander of the housing must be removed from the pipeline. For this purpose, z. As a handle attached to the ring of the cage to further simplify the handling. It is sufficient to loosen the screw connection of the flanges, replace the cage with flame sieve and restore the screw connection.

The invention also includes a cage for holding a flame sieve, in particular for a previously described detonation barrier with a cage for the flame sieve. The cage comprises a ring with a passage, in which passage the flame sieve can be used. Further, the cage comprises at least one retaining ring attached to the ring with at least three struts. The struts extend inwardly from an inner wall of the ring and converge at exactly one point of intersection, with the crossing point of the struts being offset from a center of the ring. In the case of a cage-mounted flame sieve, the center of the ring is preferably located on the mid-perpendicular of the flame sieve, whereby the point of intersection has the offset also with respect to the mid-perpendicular of the flame sieve. In this case, the holder is preferably flat, wherein the struts extend inwardly parallel to a ring plane. A ring plane here refers to a plane which is defined by the ring of the cage.

It is understood that advantageously the previously described embodiments of the detonation barrier, which have a cage for the flame sieve, are provided with a corresponding cage.

The invention further comprises a flame sieve insert for a detonation barrier, in particular for a detonation barrier as described above, comprising a cage with a ring, in particular a cage as described above, and a flame sieve of widely known construction, which is provided by a retaining brace having at least three braces is held, which struts converge from an inner wall of the ring inwardly at exactly one crossing point, wherein the crossing point of the struts with respect to a center of the ring has an offset. It is the Halterost preferably formed flat, wherein the struts extend inwardly parallel to a ring plane.

It is understood that the previously described embodiments of the detonation barrier, which have a cage for the flame sieve, are advantageously provided with a corresponding flame sieve insert.

The invention also includes a tube expander for a detonation barrier having an interior space which is open in the longitudinal direction and having a larger and a smaller longitudinal opening. In particular, the tube expander largely corresponds to the above-described embodiments of an asymmetrical tube expander. In this case, a support grid is arranged in the larger longitudinal opening, which support grid has at least three struts and the struts converge from an inner wall of the interior to the inside in exactly one crossing point. The crossing point of the struts has an offset relative to a center of the opening. In particular, in the case of a safety faucet comprising the tube widener, in which a flame sieve is present, the point of intersection also has the offset relative to the mid-perpendicular of the flame sieve.

Preferably, the support grid is flat, so that the struts converge parallel to an opening plane inwardly at the intersection. An opening plane here refers to a plane in which an edge of the larger longitudinal opening is arranged.

It is understood that advantageously the previously described embodiments of the detonation barrier, which have a tube expander, are provided with a corresponding tube expander.

From the following detailed description and the totality of the claims, further advantageous embodiments and feature combinations of the invention result.

Brief description of the drawings

Fig. 1

Ansicht eines Rohraufweiters einer erfindungsgemässen Detonationsbarriere mit Stützrost;

Fig. 2

Ansicht eines Käfigs mit Halterost und Flammsieb einer erfindungsgemässen Detonationsbarriere;

Fig. 3a-3f

verschiedene beispielhafte Anordnungen von Streben des Stützrosts bzw. des Halterosts;

Fig. 4

Querschnitt durch eine erfindungsgemässe Detonationsbarriere, bei welcher der rohrförmige Gehäuseabschnitt den Ring eines Käfigs mit Flammsieb umfasst;

Fig. 5

Querschnitt durch eine Serienanordnung von drei Flammsieben in Käfigen.

The drawings used to explain the embodiment show schematically:

Fig. 1

View of a tube expander of a detonation barrier according to the invention with supporting grid;

Fig. 2

View of a cage with Halterost and flame sieve of a detonation barrier according to the invention;

Fig. 3a-3f

various exemplary arrangements of struts of the supporting grid or the holding rack;

Fig. 4

Cross-section through a detonation barrier according to the invention, in which the tubular housing section comprises the ring of a cage with a flame sieve;

Fig. 5

Cross section through a series arrangement of three flame sieves in cages.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

FIG. 1 shows a tube expander 30 of a detonation barrier according to the invention (see Fig. 3 ) in an exterior view. The tube expander 30 has a circular connection opening 32 at one of its longitudinal ends and a likewise circular housing-side opening 31 at an opposite longitudinal end, wherein a cross-sectional area of the connection opening 32 is smaller than that of the housing-side opening 31.

A center point I of the housing-side opening 31 lies on a straight line A of a horizontal plane B and a vertical plane C. "Horizontal" and "vertical" here refer to orientations in the intended and functionally installed state of the detonation barrier. In particular, terms such as "below" or "top" on an intended for the application alignment of the detonation barrier and its parts. A plane D, in which the housing-side opening 31 is located, stands perpendicular to the planes B and C and passes through the center I (see Fig. 5 ). The center J of the connection opening 32 is also in the plane C. The viewing direction of the view of Fig. 1 is along the axis A, hereinafter referred to as the longitudinal axis A of the tube expander 30.

The connection opening 32 has a diameter 32.1, which largely corresponds to half the diameter 31.1 of the housing-side opening 31. With reference to the horizontal plane B, the connection opening 32 is arranged below the horizontal plane B such that in a projection along A an outline 32.2 of the connection opening 32 touches an outline 31.2 of the housing-side opening 31 in a point 33 from the inside in the sense of a bevel circle. The point 33 corresponds to a lower intersection 33 of the outline 31.2 of the opening 31 with the plane C.

The tube expander 30 comprises a conically converging wall 34 which completely encloses a shell-side elongated interior 35 of the tube expander 30 which is open at the openings 31 and 32. At the longitudinal end of the housing-side opening 31, the inner space 35 has a cross section corresponding to the opening 31. Starting from the housing-side opening 31, a cross-section of the interior 35 tapers as a function of a distance along A until it has the same cross-section as the connection opening 32 at the longitudinal end of the connection opening 32. The wall 34 thus corresponds to a lateral surface of an oblique truncated cone. In this case, the wall 34 has a surface line through the point 33 in the plane C, which extends parallel to the horizontal plane B or to the longitudinal axis A.

On the housing-side opening 31, an outwardly projecting flange 36 is formed, which with respect to the axis A azimuthally uniformly distributed axial bores 36.1 for connection to a further housing part of a detonation barrier. At the connection opening 32 is another outwardly projecting flange 37 (in Fig. 1 indicated by dashed lines), which allows the connection of the tube expander 30 to, for example, a pipeline.

In the interior 35, a support grid 40 is formed in a region of the housing-side opening 31, which comprises five struts 41.1-41.5. The struts 41.1-41.5 are fastened with peripheral ends 44.1-44.5 on an inner wall 35.1 of the interior 35 of the tube expander 30 in attachment points 43.1-43.5. Preferably, the struts 41.1-41.5 in the attachment points 43.1-43.5 welded to the flange 36 at an inner edge 36.2, but can also be attached to the flange 36 in other ways and / or not. The struts 41.1-41.5 extend from the inner wall 35.1 along the plane D into the inner space 35 and converge at a crossing point 42. At the crossing point 42, the struts 41.1-41.5 are connected to each other at longitudinally directed longitudinal ends 45.1-45.5. The support grid 40 may be formed in one piece or may be e.g. composed of individual struts, which are welded together, for example, at the inwardly directed longitudinal ends 45.1- 45.5.

= 1.61803398...verhält, d. h. $\frac{d_2}{d_1}=\phi$

.The crossing point 42 is offset on a cutting line of the planes C and D with respect to the center I down. The crossing point 42 is thus arranged below the horizontal plane B. An offset d ₁ of the cross point 42 in the plane D from the center I is preferably selected such that, in a projection onto the plane D along A, a distance d ₂ of the crossing point 42 from the center J of the connection opening 32 to the offset d ₁ according to the golden section $\phi =\frac{1+\sqrt{5}}{2}$

= 1.61803398 ... behaves, ie $\frac{d_2}{{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0002.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}=\phi$

,

The five struts 41.1-41.5 are angularly distributed equally with respect to the intersection point 42, with which adjacent struts each include a pitch angle α of 72 degrees with respect to the intersection point 42. In general, with uniform distribution of a number of n struts, two adjacent struts each enclose an angle of 360 / n degrees with respect to the point of intersection. The struts 41.1-41.5 are aligned such that one of the struts 41.3 is arranged in the vertical plane C and passes through the center point I. The struts 41.1-41.5 are arranged symmetrically with respect to the plane C in this case. At the inner edge 36.2 of the flange 36 and the housing-side opening 31 results due to the offset d _{1 of} the crossing point 42 an angularly non-uniform distribution of the attachment points 43.1-43.5 with respect to the center I of the opening 31st

FIG. 2 shows a circular cage 1 with an existing flame sieve 2 and attached thereto Halterost 3 for a detonation barrier according to the invention with, for example, a tube expander 30 according to Fig. 1 (see also Fig. 4 ). The cage 1 comprises an outer ring 4, which has a length, not shown, in the direction of a perpendicular bisector E of the flame sieve 2, which is in the range of about 1-3 cm. If the flame sieve 2 with cage 1 is installed in a detonation barrier according to the invention, which has a tube expander 30 according to FIG Fig. 1 has, then the mid-perpendicular E of the flame screen 2 coincides with the above introduced longitudinal axis A of the tube expander 30. The perpendicular bisector E also coincides with the intersecting line of the planes B and C and passes through a center F of the ring 4.

A passage encompassed by the ring 4 forms a receiving space 5, in which the disk-shaped flame sieve 2 is arranged. The flame sieve 2 has an outer diameter, which corresponds to an inner diameter 4.1 of the ring 4 within the scope of an installation tolerance. If the cage 1 for installation in a detonation barrier with pipe expander 30 according Fig. 1 determined, the inner diameter 4.1 of the ring 4 substantially corresponds to the diameter 31.1 of the housing-side opening 31. The diameter 31.1 of the opening 31 may be slightly smaller than the inner diameter 4.1 of the ring 4 to 31 in an area at the edge of the opening Ring 4 and thus also the flame sieve 2 on the periphery in addition to support.

The flame screen 2 has a plurality of capillaries 6 in the axial direction, which in the Fig. 2 are indicated by a net-shaped hatching and cause the flame retardation described above. The flame sieve 2 has a central winding body 2.1, on which the above-mentioned steel sheet strips are wound during the production of the flame sieve 2.

In Fig. 2 is the circular connection opening 32 of the Rohraufweiters 30 of the housing of the detonation barrier indicated as in the installed state of the cage. 1 is arranged. On the ring 4 of the holder 3 is mounted, which has five struts 7.1-7.5. At circumferentially arranged longitudinal ends 8.1-8.5 the struts 7.1-7.5 are each attached to an inner wall 9 of the ring 4 in attachment points 10.1-10.5.

The struts 7.1-7.5 extend perpendicular to the mid-perpendicular E from an inner wall 9 of the ring 4 inwards. Inwardly directed longitudinal ends 11.1-11.5 of the struts 7.1-7.5 converge at a common point of intersection 12 and are interconnected at the point of intersection 12. The point of intersection 12 is arranged offset vertically in the vertical plane C to the mid-perpendicular E of the ring 4 down. An offset d _{3 of} the crossing point 12 perpendicular to the perpendicular bisector E is selected such that it corresponds to an offset of a crossing point of a support grid of a detonation barrier according to the invention from its longitudinal central axis. In the presentation of the Fig. 2 corresponds to the vertical offset d ₃ of the perpendicular bisector E of the ring 4 to the vertical offset d _{1 of} the crossing point 42 from the longitudinal axis A of the tube expander 30 (see Fig. 1 ). Analogously, the struts 7.1-7.5 of the holding grid 3 are aligned in accordance with the struts of a supporting grid of a detonation barrier according to the invention, which can be provided with the flame screening cage 1. In the presentation of the Fig. 2 are the struts 7.1-7.5 of the holding stanchion 3 with respect to the vertical plane C analogous to the struts 41.1-41.5 of the support grid 40 aligned. This ensures that in the assembled state of the detonation barrier, the holder 3 is covered by the support grid 40.

In the Fig. 2 the Halterost 3 is integrally formed and the struts 7.1-7.5 are angularly distributed with respect to the point of intersection 12 angularly star-shaped. However, the invention also detects, for example, grates from separate struts, which are connected to each other at the intersection 12 or grids with arms as the continuous secants of the cage ring, which intersect at the intersection point and are connected to each other (eg, two arms arranged in a cruciform manner). In addition, the ratio of d ₂ to d ₁ or d ₂ to d ₃ need not necessarily be the golden ratio, but may also be chosen differently depending on the application or requirement (see above).

FIGS. 3a-3f show various exemplary arrangements of struts 21.1-21-6 each of a support grid 20.1-20.6 to support a (not shown) flame sieve for a detonation barrier according to the invention. Any Halteroste of cages for holding the flame sieves correspond in shape and arrangement of the respective support grates of the detonation barriers.

The edge 22.1 of a circular interior 22 of a detonation barrier is schematically indicated in all six figures as a circle. The horizontal plane B and the vertical plane C intersect according to the representation of Fig. 1 in a longitudinal axis A, which coincides with a mid-perpendicular of the circular cross-section of the inner space 22. Here, as well as in the above, "horizontal" and "vertical" refers to an intended for installation alignment of the support grates or Halteroste. The support grates 20.1-20.6 are each arranged in a cross-sectional plane which is perpendicular to the longitudinal axis A.

Further, a circular connection opening 25 of a housing of the detonation barrier is indicated, which has a diameter which corresponds to a radius of the inner space 22. A center J of the connection opening is analogous to Fig. 1 lying in the vertical plane C arranged below the horizontal plane B such that a projection of the connection opening 25 along A tangentially touches an edge of the interior 22 at a lowest point from the inside. The representations of the Fig. 3a-3f differ only in the number and arrangement of the struts 21.1-21.6 of the grates 20.1-20.6.

Fig. 3a shows the grate 20.1, which comprises four struts 21.1, which converge starting from the edge 22.1 in a relation to the center I along the vertical C downwardly offset intersection point 24.1. The struts 21.1 are arranged symmetrically with respect to the plane C. The struts 21.1 are aligned perpendicular to A such that two with respect to the horizontal plane B upwardly extending struts are at an angle γ <90 degrees to the plane C and two downwardly extending struts have an angle δ to the plane C, where γ <δ <90 degrees.

Fig. 3b shows the grate 20.2 with four struts 21.2, wherein two of the struts 21.2 are arranged in parallel and with respect to a crossing point 24.2, in which the struts 21.2 converge. The two parallel struts thus together give each a secant of the circular interior 22, which go through the intersection point 24.2. Adjacent struts each enclose a right angle with each other, resulting in a cross-shaped grate 20.2 with four arms. The intersection point 24.2 is arranged analogously to the intersection point 24.1. The struts 21.2 are arranged symmetrically with respect to the plane C.

Fig. 3c shows the grate 20.3 with five struts 21.3, with four struts extending from an analogous to the intersection point 24.1 arranged crossing point 24.3 downward and a strut extends in the vertical plane C up to the edge 22.1 and the longitudinal axis A intersects. The struts 21.3 are arranged symmetrically with respect to the plane C.

Fig. 3d shows the grate 20.4, which comprises four struts 21.4, wherein each pair of struts results in a straight secant of the interior 22. The struts 21.4 are arranged such that one of the resulting secants is parallel to the horizontal plane B and the other secant is arranged in the vertical plane C. The struts 21.4 run together in an analogous to the intersection point 24.1 arranged crossing point 24.4 together. The struts 21.4 thus result in a rectangular cross shape of the grate 20.4, which is aligned horizontally or vertically (in contrast to the diagonally oriented cross shape of the grate 20.2 of Fig. 3b ).

Fig. 3e shows the grate 20.5, which has three struts 21.5, wherein two struts are arranged parallel to the horizontal plane B and starting from a similar to the intersection point 24.1 arranged crossing point 24.5, a third strut in the vertical plane C extends up to the edge 22.1 and thereby the longitudinal axis A. cuts.

Fig. 3f shows the grate 20.6 with three struts 21.6, which with respect to a crossing point 24.6 evenly distributed star-shaped, that are arranged at the same pitch angle with respect to the intersection point 24.6. The struts 21.6 thus have a pitch angle of 120 degrees with respect to the crossing point 24.6. The crossing point 24.6 is arranged analogously to the intersection point 24.1. The aspiration 21.6 are aligned such that one of the struts extends in the vertical plane C up to the edge 22.1 down and thereby cuts the longitudinal axis A.

It is understood that the illustrated arrangements of the struts are purely exemplary and in no way limit possible designs of grates for a detonation barrier according to the invention. Basically, however, embodiments of the support or Halteroste be preferred, which have a strut which passes through the center I, so that in a concentrically existing flame sieve, a center of the flame sieve is supported by this strut.

FIG. 4 shows a longitudinal cross section through a detonation barrier 50 according to the invention with a housing 51. The sectional plane corresponds to the previously described vertical plane C, which comprises a perpendicular bisector E of a arranged in an inner space 52 of the housing 51 Flammsiebs 53. The detonation barrier 50 is designed to be substantially symmetrical with respect to a plane M which is perpendicular to the plane C and in which the flame sieve 53 is arranged.

The flame strainer 53 is supported in an annular cage 54 (eg, according to FIGS Fig. 2 ). The cage 54 has an outer Umfassungsring 55 with a passage 55.2, which forms a tubular portion 51.1 of the housing 51 in the illustrated embodiment. The flame sieve 53 is arranged in the passage 55.2 within the ring 55 and clamped between two 5-fold holder neck 56 and 57 (analogous to the representation of Fig. 2 ). The grates 56 and 57 each have 5 struts 56.1 and 57.1, which extend from the ring 55 parallel to the plane M inwards and converge to exactly one intersection point 58 and 59 per grate 56 and 57, respectively. The struts 56.1 and 57.1 are attached to attachment points 56.2 and 57.2 on the ring 55 and connected to each other at the intersections 58 and 59. The holder yoke 56 is attached to one of an inner wall 55.3 of the ring 55 inwardly projecting into the passage 55.2 circumferential projection 55.1, which together with the Halterost 56 a retaining means of the ring 55 results. Halterost 56 and projection 55.1 thus prevent the flame strainer 53 can be discharged from the ring 55 in the axial direction. The grate 57 is attached directly to the inner wall 55.3 of the ring 55. In each case one of the struts of Halteroste 56 and 57 extends from the intersection point 58 and 59 in the Level C vertically upwards and thus passes through the perpendicular bisector E of the flame sieve 53. A central bobbin 53.1 of the flame strainer 53 is thus supported by the holder neck 56 and 57.

The cage 54 is clamped at its ring 55 between flanges 70.1 and 71.1 of two pipe expanders 70 and 71. The Rohraufweiter 70 and 71 correspond largely to in the Fig. 1 illustrated embodiment of the tube expander 30 and are arranged mirror-symmetrically with respect to the plane M. The in Fig. 1 inserted longitudinal axis of the tube expander 70 and 71 are arranged coaxially and form a hereinafter referred to as housing longitudinal axis L axis in the plane C. The perpendicular bisector E of the flame strainer 53 coincides with the housing longitudinal axis L. The housing 51 of the detonation barrier 50 thus comprises the tubular section 51.1 formed by the ring 55 and the two tube expander 70 and 71.

The tube expander 70 and 71 each have at an opening 70.2 and 71.2, in the area of the flanges 70.1 and 71.1 are formed, an inner diameter and cross-section, which largely corresponds to the inner diameter or the cross section of the passage 55.2 of the ring 55. The flanges 70.1 and 71.1 project outwardly from an outer wall of the pipe expander 70 and 71 such that a screw connection 72 of the flanges 70.1 and 71.1 outside the ring 55 is possible. By the screw 72, the ring 55 of the cage 54 is clamped between the flanges 70.1 and 71.1, so that the openings 70.2 and 71.2 connect to the passage 55.2 of the ring 55.

In the openings 70.2 and 71.2 each support grates 76 and 77 are formed. These have in each case 5 struts 76.1 and 77.1, which are arranged according to the struts 56.1 and 57.1 of the support brackets 56 and 57. The struts 76.1 and 77.1 extend from an inner wall 70.3 and 71.3 of the tube expander 70 and 71 parallel to the plane M inwards and converge at exactly one intersection point 78 and 79, respectively. The struts 76.1 and 77.1 are fastened at attachment points 76.2 and 77.2 on the inner wall 70.3 and 71.3 in the opening 70.2 and 71.2, for example, welded, and are connected to each other at the crossing points 78 and 79.

The struts 76.1 and 77.1 are designed to be more massive than the struts 56.1 and 57.1, since they have to support the flame sieve 53 in the event of detonation against the action of a pressure wave front. In particular, the struts 76.1 and 77.1 are designed such that the struts 56.1 and 57.1 are covered in a projection onto the plane M by the struts 76.1 and 77.1. The intersection points 58 and 59 of the Halteroste 56 and 57 and the crossing points 78 and 79 of the support grates 76 and 77 are arranged in the direction of A and L one behind the other.

With increasing distance from the openings 70.2 and 71.2, the tube expander 70 and 71 taper and have at a connection-side longitudinal end 70.4 and 71.4 each have a circular connection opening 70.5 and 71.5. The connection openings 70.5 and 71.5 have an opening diameter which is smaller than the diameter of the openings 70.2 and 71.2 and correspond in their opening cross-section of a pipeline 73, in which the detonation barrier 50 is installed.

The connection openings 70.5 and 71.5 are arranged eccentrically offset with respect to the longitudinal axis L and the horizontal plane B and aligned with each other. In particular, the tube expander 70 and 71 with respect to the longitudinal axis L are formed asymmetrically such that a bottom 52.2 of the interior 52 of the housing 51 of the detonation barrier 50 is continuously formed horizontally from the longitudinal end 70.4 to the longitudinal end 71.4. The housing 51 thus has, at least in the interior 52, a continuous straight surface line from the longitudinal end 70.4 to the opposite longitudinal end 71.4. A projection of the connection openings 70.5 and 71.5 onto the plane M of the flame sieve 53 along the longitudinal axis L is thus arranged in the lower half of the flame sieve 53. An outline of the inner cross section of the connection openings 70.5 and 71.5 nestles in a deepest point tangentially from the inside to an inner contour of the ring 55 (see. Fig. 2 ).

An axis N through the centers J 'and J of the connection openings 70.5 and 71.5 is thus arranged parallel to the longitudinal axis L. According to the invention, the points of intersection 58 and 59 of the holding bars 56 and 57 and the points of intersection 78 and 79 of the supporting grates 76 and 77 are offset from the axis L towards the axis N. In particular, corresponds the ratio b ₂ / b _{1 of} the distance b ₂ from the axis N to the crossing points 58, 59, 78 and 79 and the offset b _{1 of} the crossing points 58, 59, 78 and 79, respectively, from the longitudinal axis L and the perpendicular bisector E, respectively of the flame strainer 53 the golden section.

A pressure wave front 75 entering into the housing 51 of the detonation barrier 50 during a detonation out of the pipeline 73 through the connection opening 71.5 also expands asymmetrically within the asymmetrical tube expander 70 or 71. For this reason, the pressure wave front 75 strikes the flame strainer 53 in a region below the longitudinal axis L or the mid perpendicular E, ie below the horizontal B. The crossing points 78 and 79 are due to the offset b ₁ in the region of the "first contact" of the pressure wave front 75 arranged with the flame strainer 53, which results in this same area a center of gravity of the grates 76 and 77. In order for the optimal support function of the grates 76 and 77 is ensured in a case of detonation most heavily loaded area, whereby the mechanical stability of the detonation barrier 50 is significantly improved overall.

Modifications of the invention are also conceivable which, for example, comprise only a support grid in one of the tube expander, e.g. depending on which side of the pipeline a detonation is expected. Likewise, a retaining grid of the cage is conceivable, which is also designed as a support grid, so that no further support grid on the housing of the detonation barrier needs to be more appropriate. Further advantageous modifications within the scope of the invention according to the claims are directly accessible to the person skilled in the art.

FIG. 5 shows a detail of a series connection of three cages 100, 101 and 102 with annular sockets 100.1, 101.1 and 102.1, each with circular passages 100.2, 101.2 and 102.2. Within the passages 100.2, 101.2 and 102.2, a respective disk-shaped flame sieve 104, 105 or 106 is arranged such that a plane of the annular sockets 100.1, 101.1 and 102.1 coincides with a plane of the flame sieves 104, 105 and 106 and the flame sieves 104, 105 and 106 are arranged coaxially with their mid-perpendicular (not shown). The mid-perpendiculars of the flame sieves 104, 105 and 106 are also arranged coaxially with the mid-perpendiculars of the annular sockets 100.1, 101.1 and 102.1.

The presentation of the Fig. 5 shows a cross section in a cross-sectional plane, which includes the mid-perpendicular of the three flame sieves 104, 105 and 106 and the previously introduced level C corresponds.

The socket 100.1 of the first cage 100 has, at a first opening 100.3 of the passage 100.2 on a first end face 100.4 of the socket 100.1, a projection 100.5 projecting inwards into the passage 100.2. The associated flame sieve 104 rests in an outer edge region on the projection 100.5. On the projection 100.5 struts 100.7 of a holder grid 100.6 are mounted, wherein in the illustration of Fig. 5 only one uppermost of the struts 100.7 is visible. The uppermost strut extends along the cross-sectional plane C from a crossing point (not shown) of the holder 1006 upwards to the holder 100.1. The Halterost 100.6 corresponds to eg the Halterost 3 of Fig. 2 , At an opening 100.8 of the passage 100.2 opposite the direction of the center perpendicular of the flame sieve 104, the flame sieve 104 terminates substantially with an end face 100.9 of the holder 100.1. On the front side 100.9 an annular projection 100.10 is formed, which projects at an outer edge 100.11 of the socket 100.1 in the axial direction.

The socket 101.1 of the second cage 101 terminates with an end face 101.4 on the end face 100.9 of the first cage 100, wherein an annular groove 101.12 corresponding to the projection 100.10 is formed on the end face 101.4. The projection 100.10 is arranged in the groove 101.12, so that the adjacent end faces 100.4 and 101.9 abut each other.

The version 101.1, analogous to the version 100.1, has a protrusion 101.5, which protrudes inwardly at a first opening 101.3 on the end face 101.4, with a retaining 101.6. The retainer 101.6 rests on the flame sieve 104 and on the flame sieve 105 and thus fulfills a double holding function. The flame sieve 105 terminates at an opposite opening 101.8 of the passage 101.2 with an end face 101.9 of the mount 101.1. On the end face 101.9 a projection 101.10 corresponding to the annular projection 100.10 is formed on the socket 101.1.

The socket 102.1 of the third cage 102, which adjoins the second cage 101, has, on the end face 102.4 facing the cage 101, analogous to the first one Cage 100 an annular groove 102.12, in which the projection 101.10 of the second cage 101 is arranged. In this case, the end face 101.9 and the end face 102.4 of the sockets 101.1 and 102.1 abut one another. Analogous to Halterost 101.6 a Halterost 102. 6 is provided on an inwardly projecting projection 102.5 of the socket 102. The holder 102.6 is resting against the flame sieves 105 and 106.

At an opposite end face 102.9 of the socket 102.1 no projection and no groove are formed. In contrast to the two cages 100 and 101, however, the flame sieve 106 at an opening 102.8 on the end face 102.9 does not terminate with the end face 102.9, but the socket 102.1 projects beyond the flame sieve 106 in the axial direction. In the space created by the projection of the version 102.1 free space in the passage 102.2 a final Halterost 102.13 is provided, which is connected to an inner wall 102.14 of the socket 102.1 with this. The holder 102.13 closes off with the end face 102.9.

The three cages 100, 101 and 102 may, for. B. connected to each other, for example, welded, be. It is also conceivable that the sockets 100.1, 101.1 and 101.2 are screwed together in a flange manner by a ring of screw connections on the circumference of the sockets 100.1, 101.1 and 102.1. In this case, the cages 100, 101 and 102 are aligned such that the holding bars 100.6, 101.6 and 102.6 lie in a projection along the mid-perpendicular of the flame sieves 104, 105 and 106 coincident. In the presentation of the Fig. 5 In addition, flanges and housing walls of adjacent tube expanders of a detonation barrier provided with the series arrangement of the cages 100, 101 and 102 are indicated by dashed lines. The series arrangement of cages 100, 101 and 102 is analogous to the individual cage of Fig. 4 sandwiched between the flanges of the tube expander.

Thus, a precise alignment of the flame sieves and a modular construction of the detonation barrier is made possible in a simple manner. Due to the projection / groove construction of adjacent sockets, the cages can be easily combined and aligned with each other. In addition, by arranging only one holding gap between adjacent flame sieves, it is possible to prevent a spacing of the flame sieves in the axial direction from exceeding a preferred value. Due to the dual function of Halteroste also results in a material savings and a simplified design. In summary, it can be stated that the invention provides a detonation barrier or deflagration barrier and flame barrier for gas-conducting systems such as pipelines, which has improved mechanical stability with a simple design. In particular, when hitting a pressure or shock wave, a flame screen of the detonation barrier is optimally stabilized and supported by the construction according to the invention, so that a high dielectric strength is achieved with a simple design.

Claims (13)

1. Safety fitting, in particular a detonation barrier (50), for gas-carrying systems, in particular for pipelines (73), comprising a housing (51) having an internal area (52) in which a flame trap (53) is arranged such that a cross section of the internal area (52) is completely filled by the flame trap (53), and, at a connecting longitudinal end (71.4), the housing (51) comprises a connecting opening (71.5) for connection to the gas-carrying system, which connecting opening (71.5) has a cross-sectional area which is less than the cross section of the internal area (52), and a centre point (J) of the connecting opening (71.5) is arranged offset at right angles to a central perpendicular to the flame trap (53), with the flame trap (53) being supported by a supporting grill (40, 76, 77) which has at least three struts (76.1, 77.1), which extend inwards essentially from an internal circumference of the internal area (52) and meet at one, and only one, crossing point (78, 79),
   characterized in that
   the crossing point (78, 79) has an offset (b₁), transversely with respect to the central perpendicular (E) to the flame trap (53), from the central perpendicular (E) towards the centre point (J) of the connecting opening (71.5).
2. Safety fitting according to Claim 1, characterized in that the supporting grill (76, 77) has an odd number of struts (76.1, 77.1), in particular 3 or 5 struts (76.1, 77.1), and one of the struts in this case preferably intersects the central perpendicular (E) to the flame trap (53).
3. Safety fitting according to Claim 1 or 2, characterized in that, with respect to the crossing point (78, 79), an angle which is included between two struts is the same for all pairs of adjacent struts.
4. Safety fitting according to one of Claims 1 to 3, characterized in that the offset (b₁) of the crossing point (78, 79) is in the range from 10% to 100% of the perpendicular distance between the connecting opening centre point (J) and the central perpendicular (E) to the flame trap (53), preferably in the range from 25% to 100%, and the ratio of the perpendicular distance (b₂) of the connecting opening centre point (J) and the crossing point (78, 79), to the offset (b₁) preferably corresponds to the golden section.
5. Safety fitting according to one of Claims 1 to 4, characterized in that the housing (51) comprises a pipe expander (71) at the connecting longitudinal end (71.4), which pipe expander (71) has the connecting opening (71.5) at one of its longitudinal ends and an opening (71.2) at an opposite longitudinal end, the cross section of which opening (71.2) corresponds to an internal cross section of the internal area (52), and in particular the pipe expander (71) is designed to be asymmetric with respect to the central perpendicular (E) to the flame trap (53), preferably such that the housing (51) has at least one continuous straight envelope line over its entire length.
6. Safety fitting according to Claim 5, characterized in that the pipe expander (71) has a flange (71.1) at the opposite longitudinal end to the connecting opening (71.5).
7. Safety fitting according to one of Claims 5 and 6, characterized in that the supporting grill (77), in particular the struts (77.1) of the supporting grill (77) together with their respective longitudinal end which is remote from the crossing point (79), is attached to an inner wall (71.3) of the housing (51), and the supporting grill (71) is preferably fitted to the pipe expander (71), in the area of the flange (71.1), in the internal area (52).
8. Safety fitting according to one of Claims 1 to 7, characterized in that the housing (51) has a second connecting longitudinal end (70.4), which is opposite the first connecting longitudinal end (71.4) in the longitudinal direction (L) of the housing (51), and at which second connecting longitudinal end (70.4) a second connecting opening (70.5) is provided, whose centre point (J') is arranged offset in the vertical direction with respect to the central perpendicular (E) to the flame trap (53), analogously to the connecting opening (71.5) at the first connecting longitudinal end (71.4), and which second connecting opening (70.5) preferably has the same cross-sectional area as the first connecting opening (71.5), such that the first and the second connecting openings (70.5, 71.5) are aligned with one another, and in particular the housing (51) has a pipe expander (70) at the second connecting longitudinal end (70.4), which pipe expander (70) preferably corresponds to the pipe expander (71) at the first connecting longitudinal end (71.4).
9. Safety fitting according to one of Claims 1 to 8, characterized in that the flame trap (53) is held in a cage (54) with a ring (55), with an aperture (55.2), which is surrounded by the ring (55), forming a holding area for the flame trap (53), and with the ring (55) surrounding the circumference of the flame trap (53), preferably with holding means (55.1, 56) being provided on aperture openings in the ring (55), which holding means (55.1, 56) prevent the flame trap (53) from being moved axially out of the holding area and, in particular, the holding means (55.1, 56) comprise a holding grill (57) on at least one of the aperture openings of the ring (55), with the holding grill (57) being arranged and designed such that the supporting grill (77) completely covers the holding grill (57) in a flow direction.
10. Safety fitting according to Claim 9, characterized in that the cage (54) is fitted together with the flame trap (53) replaceably in the housing (51), in particular is clamped in between the flanges (71.1) of the pipe expander (71) and a corresponding flange (70.1) on the pipe expander (70).
11. Cage (1) for holding a flame trap (2), in particular for a safety fitting according to one of Claims 9 or 10, with the cage (1) comprising a ring (4) with an aperture, in which aperture the flame trap (2) can be arranged and, furthermore, a holding grill (3), which is fitted to the ring (4) and has at least three struts (7.1-7.5) is provided, which struts (7.1-7.5) run together inwards at one and only one crossing point (12), from an inner wall (9) of the ring (4), characterized in that the crossing point (12) of the struts (7.1-7.5) has an offset (d₃) with respect to the centre point (F) of the ring (4), and, particularly when a flame trap (2) has been inserted into the cage (1), has the offset (d₃) with respect to the central perpendicular (E) to the flame trap (2).
12. Flame trap insert for a safety fitting, in particular for a detonation barrier, preferably for a safety fitting according to one of Claims 9 and 10, comprising a cage (1) having a ring (4) with an aperture, in particular a cage (1) according to Claim 11, and having a flame trap (2) which is arranged in the aperture and is held by a holding grill (3) having at least three struts (7.1-7.5), which struts (7.1-7.5) of the holding grill (3) run together inwards at one and only one crossing point (12), from an inner wall (9) of the ring (4), characterized in that the crossing point (12) of the struts (7.1-7.5) has an offset (d₃) with respect to a central perpendicular (E) to the flame trap (53).
13. Pipe expander (30) for a safety fitting, in particular for a detonation barrier, preferably for a safety fitting according to one of Claims 5 to 10, with the pipe expander (30) having an internal area (35), which is open in the longitudinal direction (A) and has a larger longitudinal opening (31) and a smaller longitudinal opening (32), with a supporting grill (40) being arranged in the larger longitudinal opening (31), which supporting grill (40) has at least three struts (40.1-40.5), and the struts (40.1-40.5) run together inwards at one and only one crossing point (42) from an inner wall (35.1) of the internal area (35), characterized in that the crossing point (42) of the struts (40.1-40.5) has an offset (d₁) with respect to a centre point (I) of the larger longitudinal opening (31), particularly in the case of a safety fitting which comprises the pipe expander, in which safety fitting a flame trap (2) is provided, and the crossing point (42) has the offset (d₁) with respect to the central perpendicular (E) to the flame trap (2).

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