HK1152004A - Flame arrester arrangement - Google Patents

Description

Fire retardant assembly

Technical Field

The invention relates to a firestop assembly having a housing for holding at least two firestop inserts and having an intermediate lining arranged between the two firestop inserts, which firestop inserts have axial through-openings dimensioned for combustible gas, which intermediate lining allows a radial distribution of the gas flow flowing out of one firestop insert and into a downstream adjacent firestop insert.

Background

The firestop insert of the firestop assembly is primarily made from thin stainless steel strip in a coiled process. In this case, the smooth metal strip is wound together with the uniformly corrugated metal strip and the two metal strips form a preferably disk-shaped ring. The through-gap is produced by the corrugated metal strip abutting two adjacent flat metal strips, so that a defined through-gap is produced. In accordance with the combustibility of the gas, the passage gap is not allowed to exceed a predetermined gap cross-sectional area for a predetermined axial length. Thus, to ensure sufficient flow velocity for the combustible gas, the firestop insert may need to be coiled with a large cross-sectional area (i.e., made with a large coil radius). The rings are preferably stacked on top of one another in a spiral manner, but may also each be composed of a smooth metal strip and a corrugated metal strip as a circularly closed ring.

It has proven to be significant that the gap length required for gas cooling given the maximum cross section of the passage gap is not achieved with a single firestop insert, but rather a plurality of, i.e. at least two firestop inserts are provided, it being advantageous to arrange intermediate linings between the firestop inserts, which intermediate linings allow the gas flow flowing out of one firestop insert and into a downstream adjacent firestop insert to be distributed radially.

If, on the other hand, the firestop inserts are stacked directly on top of one another without an intermediate lining, the passage gaps are not precisely aligned with one another in shape, the stacked firestop inserts form composite channels whose effective passage gaps become smaller in an undefined manner with respect to the passage gap of a firestop insert, since the free cross-sectional area of the stack of stacked firestop inserts is reduced. This results in a considerable increase in the pressure loss during throughflow. The intermediate linings provided in this type of fire stopping assembly thus act as spacer elements which prevent the free cross-sectional area of successively arranged firestop inserts from decreasing. In a common arrangement, the housing of the firestop assembly forms a containment shroud with a closed wall. Since the gas can expand in the radial direction between the firestop inserts, it must be taken into account that the gap created between the edge of the firestop insert and the inner wall of the containment shield is smaller than the gap in the firestop insert itself. Otherwise, a bypass would exist around the firestop insert, on which the gas is not cooled in the manner prescribed by the respective firestop insert, so that a spark could occur penetrating the firestop assembly, whereby a disaster could be caused if, for example, an explosion were to be initiated in a gas storage tank that should be protected by the firestop assembly.

In particular in the production of large firestop inserts, which may have a diameter of up to 2m, production technology is problematic if large gaps between the firestop insert and the surrounding housing are to be avoided. Such large firestop inserts are often not precisely circular in shape. It is therefore known to coil such a firestop insert directly in the containment shield and to plug a smooth filter belt into a position that constitutes a large gap, in order thus to create a reliable edge contact between the firestop insert and the containment shield. However, this has the disadvantage that the firestop insert fits securely into the accommodating shield, so that the firestop insert cannot actually be removed for cleaning and replacement purposes, in particular if more dirt or even corrosion occurs between the filter and the accommodating shield.

In order to be able to remove the firestop insert simply for maintenance purposes, it is expedient for the largest possible gap between the firestop insert and the accommodating shield to be present. However, it is necessary here to prevent the flame of the gas stream from flowing around the flame arrester insert or inserts through this radially outer gap and thus to render the flame arrester ineffective.

If a maximum of two flame retardant inserts are used, the radially outer support ring is in direct radially outer contact with the flame retardant inserts, so that a radially outer bypass flow cannot be achieved by the gas flowing through the flame retardant assembly. In the case of more than two firestop inserts it is known to use a containment shield with a stepped wall in which each firestop insert is in sealing contact on the metal of the containment shield. The manufacture of such containment shields is very expensive and cannot be carried out in bulk, since different patterns and diameters are required depending on the number of fire retardant elements. In addition, firestop inserts of different sizes have to be produced in order to be adapted to different gases.

Disclosure of Invention

The object of the invention is therefore to design a firestop assembly of the type mentioned at the outset in such a way that, in particular when three or more firestop inserts are used, the assembly and disassembly of the firestop insert is simplified and accidental bypass of the firestop insert is reliably avoided.

In order to solve this problem, a firestop assembly of the type mentioned at the outset is distinguished in that at least one separate, closed seal is arranged between the firestop insert and the housing or between two firestop inserts in such a way that a bypass of the firestop insert in a space situated radially outside the passage gap is prevented.

The firestop assembly according to the invention can therefore have an arbitrarily large space radially outside the through-passage gap of the firestop insert, so that it is possible to simply assemble and disassemble these firestop inserts.

In an alternative embodiment, in which a closed seal is located between the housing and the firestop insert, the intermediate space between the housing and the firestop insert can be closed for axial throughflow by means of the seal. In a further preferred embodiment of the invention, the sealing elements arranged radially outside the firestop insert can also be designed to engage one another axially without play, so that these are clamped between the axially clamped housing parts and thus act as a radial seal against the outflow of gas from the intermediate lining. In this case, it is advantageous if the seal is formed by a helically intertwined coil of smooth metal strip, so that the application of the seal can take place after the production of the firestop insert, preferably in a coiling technique. The smooth metal strip used to make the seal may have the width of the metal strip of the firestop insert or may have a greater width (relative to the axial length of the firestop assembly) that corresponds to the total axial length of the firestop insert and intermediate liner. If the width of the metal strip of the seal for the coil is the same as the width of the metal strip used for the production of the firestop inserts, a gasket is expediently inserted between the seals of the coil in the intermediate lining, so that the seals of the coil and the gasket form a length in the axial direction which corresponds to the length of the firestop inserts together with their intermediate lining.

In an alternative embodiment, a closed seal may be positioned between the radial edges of the firestop inserts such that a seal is achieved radially outward between the firestop inserts. The intermediate gasket is preferably designed in a reduced manner, by the radial width of the sealing seal, so that it can be inserted between the firestop insert and the sealing ring located between the firestop inserts.

An advantageous configuration of the fire barrier assembly according to the invention is achieved by fire barrier inserts which are provided with a circumferential solid edge radially outside the passage gap, wherein the edges are clamped in a stack between axially clamped housing parts. The solid edges of the firestop insert which bear against one another and are clamped together are thus sealed radially outward. Annular seals may also be interposed between these edges, and these annular seals may render axial clamping of the edges of the firestop inserts unnecessary.

If the firestop insert is provided with a corresponding solid edge, the provision of a hood-like housing can be superfluous, so that the firestop insert does not have to be enclosed again by an additional hood housing in this case. For maintenance purposes, the firestop insert can thus be easily removed after the clamping screw for axially clamping the housing part has been loosened or removed only when necessary.

In other embodiments, the intermediate pad can be constructed, for example, from a wire grid (Drahtgiltter) that serves only as a spacer between firestop inserts. To simplify assembly, the intermediate pad can be connected to the corresponding firestop insert by spot welding, brazing, or the like. Likewise, when gaskets are used between the radially outer, preferably coiled, seals of the firestop insert, corresponding connections can be provided between the intermediate gasket and the corresponding gasket in order to simplify assembly, so that the intermediate gasket and the gasket can be handled uniformly. Here, it is of course also possible to connect the gasket to the adjacent seal of the firestop insert by welding, soldering or the like.

The invention is preferably practiced with coiled firestop inserts. However, the invention can of course also be carried out with all other customary fire-retardant inserts, for example with fire-retardant inserts made of sintered metal, foamed metal, wire-woven grids, expanded metal grids, porous ceramics, perforated plates made of metal or plastic (in particular PTFE), or the like.

Drawings

The invention is explained in detail below on the basis of embodiments shown in the drawings. The figures show:

FIG. 1 is a partial cross-sectional view of a firestop assembly, with four firestop inserts and four corresponding radially directed closure seals,

fig. 2 is a view similar to that of fig. 1, in which a radially closing seal cooperates with a sealing gasket,

details of the fixation of the intermediate gasket on the sealing gasket in figures 2a and 2b,

FIG. 3 is a schematic view of firestop inserts, with an axial seal encircling the edge of the firestop inserts,

figure 4 is a top view of an intermediate pad in the form of a wire mesh,

FIG. 5 is a schematic view of a firestop assembly having three radially outer, circumferential seals closing an axial flow path through a radially outer gap,

fig. 6 is an assembly according to fig. 5, with only one radial seal on the intermediate firestop insert,

fig. 7 is an assembly according to fig. 5, with another embodiment of a radial seal,

fig. 8 is an assembly according to fig. 6, with another embodiment of a radial seal,

fig. 9 is a view similar to the assembly of fig. 1, with a dismounting device for the housing part in the form of a radial rib ring,

fig. 10 is a schematic diagram of an assembly having seven firestop inserts, with surrounding solid edges,

figure 11 shows a variant of the assembly according to figure 10,

FIG. 12 is a variation of the welded shell shroud and layout with one radial seal for each two firestop inserts, with one radial seal for each firestop insert.

Detailed Description

Fig. 1 shows a housing 1 having two flange-like housing parts 2, 3, which can be clamped to one another in the axial direction by means of clamping screws (not shown). The flange-type housing parts 2, 3 act on the housing rings 4, 5 connected to them, between which four firestop inserts 6 are inserted axially, each having an intermediate lining 7. On its radially outward outer lateral surface, the housing rings 4, 5 have circumferential grooves 8, into which sealing rings 9 in the form of O-rings engage. A cylindrical housing wall 10, which seals off the space for the firestop insert 6 with the sealing rings 9, is slipped onto the housing rings 4, 5. These flame arrester inserts end radially at a distance from the cylindrical housing wall 10 and are provided on their outer side with closed seals 11, the axial length of which corresponds to the sum of the axial lengths of the flame arrester inserts and the associated intermediate lining 7. The housing parts 2, 3 and the housing rings 4, 5 exert a clamping pressure on the sealing elements 11 which bear against one another for axial clamping, so that these seal elements are pressed against one another over their axial length and thus form a radial seal with respect to the intermediate packing 7. These seals 11 are preferably formed by a spiral-shaped loop of metal strip, the width of which is the axial length of one seal 11. The rolled-up coil set for the sealing element 11 is selected to be so large that the cover surface F, i.e. the radial thickness of the sealing element 11, is so large that the sealing element 11 can withstand the clamping pressure.

As can be seen in fig. 1, a radially outer gap 12 to the cylindrical housing wall can be present radially outside the seal 11, since a seal in the radial direction is reliably achieved over the axial length of the stack of firestop insert 6 and intermediate lining 7.

In the embodiment shown in fig. 2, the seal 11 has an axial length that corresponds to the axial length of the firestop insert 6. For the axial length of the intermediate linings 7, sealing washers 13 are inserted between the seals 11, these sealing washers 13 taking care that the stack consisting of the seals 11 and the sealing washers 13 has the axial length, which the firestop insert 6 together with the intermediate linings 7 has.

Fig. 2a shows that a welded connection 14 is provided between the sealing washer 13 and the intermediate washer 7, which is designed as a wire grid, so that the intermediate washer 7 and the sealing washer 13 can be handled in a unified manner.

In the variant according to fig. 2b, there are welded connections 14 both between the intermediate gasket 7 and the sealing washer 13 and between the seal 11 and the sealing washer 13, so that the firestop insert 6 forms a uniformly actuatable component with the intermediate gasket 7, the seal 11 and the sealing washer 13, which are connected thereto by means of a weld or solder joint.

In the variant according to fig. 3, two firestop inserts 6 with a schematically illustrated intermediate lining 7 are clamped between the housing rings 4, 5, wherein the intermediate lining 7 has a radial extension which is slightly smaller than the radial extension of the firestop inserts 6. A sealing ring 15 as a metal flat seal is located in the remaining radial edge region of the firestop insert. By the pressure exerted by the housing rings 4, 5, the firestop inserts 6 and the sealing ring 15 are pressed sealingly against one another, so that no gas can flow radially outward from the intermediate lining 7 into the radial gap 12 also provided here.

Fig. 4 shows the configuration of the intermediate lining 7 in a view, which is integrally connected to the sealing ring 15, here in the form of a wire grid, for example by welding.

In the embodiment shown in fig. 5, three firestop inserts 6 and two intermediate gaskets 7 between the firestop inserts are disposed and axially clamped between the shell rings 4, 5. The cylindrical housing wall 10 has three circumferential grooves 16 on its inside, into which sealing rings 17 engage, which seal the radially outer gap 12 in the axial direction against throughflow. Thus, although gas can flow from the intermediate gasket into this radially outer gap, any of the bypass firestop inserts 6 will not be bypassed externally by gas flow, since the axial passage is closed by the sealing ring 17.

Fig. 6 shows a similar assembly, wherein only the middle firestop insert 6 is closed radially outwards by a sealing ring 17. This is sufficient if the housing rings 4, 5 bear sealingly against the radial edge of the outer firestop insert 6, so that by clamping the outer firestop insert 6 no bypass of the outer firestop insert 6 can occur. The sealing ring 17 thus serves to prevent the intermediate firestop insert 6 from being bypassed.

Fig. 7 shows an assembly similar to fig. 5, in which the sealing ring 17' is not configured as a flat sealing ring, but as a sealing ring with a circular cross section in the manner of an O-ring. A corresponding variant of the embodiment according to fig. 6 is located in fig. 8. In some cases, the sealing rings 17, 17' may be constructed of a thermally stable plastic or elastomer. The sealing rings 17, 17' are preferably made of a soft metal, for example soft copper.

The embodiment of the firestop assembly shown in fig. 9 provides that a screw 18 is screwed into the housing ring 5, which screw is supported with its blunt end on the end face of the cylindrical housing wall 10. The housing ring 5 preferably has a plurality of such bolts 18, which make the disassembly of the firestop assembly simple. That is, by screwing in the bolts 18, the housing ring 5 can be pulled off the cylindrical housing wall 10 by screwing, whereby the assembly consisting of firestop insert 6, intermediate gasket 7 and seal 11 is freely accessible. Since an outer radial gap 12 is provided with respect to the cylindrical housing wall, the firestop insert 6 together with the intermediate lining 7 and the seal 11 can be removed in a simple manner individually or jointly and cleaned or replaced for maintenance purposes.

The firestop insert 6 described in the preceding examples is composed of spiral or concentric, abutting rings, each of which is composed of a smooth metal strip and a corrugated metal strip. The corrugated metal strip is preferably formed with corrugations that are inclined with respect to the longitudinal direction of the strip. Here, the hatching in the figures is reversed: in order to achieve a uniform throughflow of the flame retardant inserts 6, flame retardant inserts 6 wound in different directions are connected to one another in such a way that the gas flows through the stack of flame retardant inserts in a zigzag-shaped manner, since the passage gaps formed by the corrugated strips run in different oblique directions.

In the embodiment shown in FIG. 10, the firestop insert 6' is provided with a surrounding solid edge 19 having a surrounding, open groove on one side for receiving a seal 20. In this embodiment, the housing rings 4, 5 are provided with projections 21 having openings for the passage of clamping bolts 22. The clamping screw 22 rests with a screw head 23 on one of the projections 21 and with a nut 24 surrounding the screw on the other of the projections 21, so that with a plurality of such clamping screws 22 distributed over the circumference, the housing rings 4, 5 are tensioned axially against one another and the stack of firestop inserts 6' is clamped between them.

In the embodiment according to fig. 10, each of the firestop inserts 6' is reinforced by a pin (Bolzen) drilled radially through it. Such reinforcement of firestop insert 6 'is known in principle for large, coiled firestop inserts 6'.

Fig. 11 shows two variants of an embodiment in which the clamping screw 22 is connected to the housing rings 4, 5 for carrying out the axial clamping.

In the variant according to fig. 11b, the clamping screw here extends through a through-hole in the solid edge 19 of the firestop insert 6 ', thereby ensuring an additional orientation of the firestop insert 6'.

In the embodiment of fig. 12, eight firestop inserts 6 are provided, which are arranged between the housing rings 4, 5. In this embodiment, the cylindrical housing wall 10 is connected to the housing 1 by a weld seam 26.

The seal 11' is embodied according to fig. 12a over an axial length which corresponds to the total axial length of the two firestop inserts 6 and the two intermediate linings 7. Four closed seals 11' are therefore used for the eight firestop inserts 6 and the eight intermediate gaskets 7, which are clamped between the housing rings 4, 5. To connect these seals 11 'and the firestop insert 6, radial pin sections 25' are introduced, which are preferably introduced by galvanic corrosion with a defined through-passage of the firestop insert 6. In contrast to the pin 25 according to fig. 10, the pin section 25 'extends over only a radial partial region, whereas the pin 25 extends over the entire diameter of the firestop insert 6'.

Fig. 12b shows that if the seal 11 has the axial length of only one firestop insert 6 and corresponding intermediate spacer 7 as shown in fig. 1, it can of course also be reinforced by means of the pin segments 25'.

It will be readily apparent from the description of these embodiments that other different structural configurations may be realized within the scope of the claimed invention. It is also possible to use cylindrical housing walls 10 or housing rings 4, 5 with stepped wall areas which make it possible to arrange flame arrestor inserts 6 of different sizes in stages. However, it is preferred to use the same size firestop insert 6 to avoid the disadvantage of increasing the cost for manufacturing the housing and clamping the stack of firestop inserts 6.

Claims (18)

1. Firestop assembly having a housing (1) for holding at least two firestop inserts (6, 6 ') and having an intermediate lining (7) arranged between the two firestop inserts (6, 6') which has a plurality of axial passage gaps dimensioned for combustible gas and which allows a gas flow flowing out of one firestop insert (6, 6 ') and into a downstream adjacent firestop insert (6, 6') to be distributed in the radial direction, characterized in that at least one separate, closed seal (11, 11 ', 15, 17, 17', 20) is arranged between the firestop insert (6, 6 ') and the housing (1) or between two firestop inserts (6, 6') in such a way that the firestop insert (6) is prevented from being inserted in a space (12) located radially outside the passage gaps, 6') is bypassed.

2. A firestop assembly as claimed in claim 1, wherein the firestop insert (6, 6') is of disc-like configuration with the same cross-section.

3. A firestop assembly as claimed in claim 1 or 2, wherein the housing (1) has at least two axially mutually compressed housing parts (4, 5), the firestop insert (6, 6') being located between these housing parts.

4. Firestop assembly according to one of claims 1 to 3, characterised in that at least three firestop inserts (6, 6') are provided.

5. A firestop assembly as claimed in any one of claims 1 to 4, wherein said at least one closed seal (11, 11 ', 17, 17') is formed radially outwardly of the at least one firestop insert (6).

6. A firestop assembly as claimed in claim 5, wherein said separate, closed seal (11, 11') is formed by helically intertwined turns of smooth metal tape.

7. A firestop assembly as claimed in claim 5 or claim 6, wherein each firestop insert (6) has a radially outwardly positioned, closed seal (11, 11').

8. A firestop assembly as claimed in any one of claims 5 to 7, wherein said seal (11, 11 ') has an axial length corresponding to the axial length of the firestop insert (6, 6') plus the axial length of the intermediate pad (7).

9. A firestop assembly as claimed in any one of claims 5 to 7, wherein the seals (11, 11') have an axial length which corresponds to the axial length of the firestop insert (6), and wherein, for the intermediate pad (7), a closed sealing gasket (13) is arranged between the seals (11) of the firestop insert (6), the length of which is the axial length of the intermediate pad (7).

10. Firestop assembly according to one of claims 3 to 6 and one of claims 7 to 9, characterised in that the closing seal (11, 11') is arranged between the housing parts (4, 5) which are pressed axially against one another and receives the clamping pressure of these housing parts (4, 5).

11. A firestop assembly as claimed in any of claims 1 to 10, wherein a circumferential gap (12) to a wall (10) of the housing (1) is provided radially outside the firestop insert (6, 6 ') to simplify the installation and removal of the firestop insert (6, 6').

12. A firestop assembly as claimed in claim 11, wherein the at least one closing seal (17, 17 ') is directed axially through a radially outer gap (12) between the closing firestop insert (6, 6') and the housing (1).

13. A firestop assembly as claimed in any of claims 1 to 4, wherein said at least one closed seal (15, 20) is located on a radial edge between two firestop inserts (6, 6').

14. Firestop assembly according to claim 13, characterised in that said intermediate gasket (7) is of reduced construction by the radial thickness of the closing seal (15).

15. A firestop assembly as claimed in any one of claims 1 to 14, wherein the firestop insert (6') is provided with a circumferential solid edge (19) radially outside the passage gap, which edges (19) are clamped in a stack between the axially mutually pressed housing parts (4, 5).

16. A firestop assembly as claimed in claim 15, wherein an annular seal (20) is interposed between said edges (19).

17. A firestop assembly as claimed in any one of claims 1 to 16, wherein the firestop insert (6, 6') has a circular cross-section.

18. Firestop assembly according to one of claims 1 to 17, characterised in that the passage gap of the firestop insert (6, 6') consists of mutually abutting rings which jointly consist of a smooth metal strip and a corrugated metal strip.