Patent ID: 12239862

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

As can be seen from the figures, in an embodiment example, the present invention comprises a ventilating firestop which preferably comprises a malleable and spring-loaded mesh12with a fine mesh stripe pattern14of an intumescent which forms an insulating shell in the earliest phase of fire. The mesh12also includes stripes or bands of an intumescent for subsequent volume filling and fire insolation. The mesh12can be bent or rolled into a completely or approximate tubular shape so that an inner volume22is formed. The tube form can be circular, square or other shapes.

The firestop according to the invention can be made with a mesh12without a quenching gap. However, the term “quenching gap mesh” is generally used in the description in connection with the figures, while the more generic term “mesh” is generally used in the patent claims. An intumescent14can be applied to the mesh12in the same way whether the mesh has a quenching gap or not.

The quenching gap mesh12, when this is used, has a mesh size which gives quenching gap, for example, a mesh size of between 0.8 and 8 mm. The mesh size, i.e., the size of the openings30between the wires in the quenching gap net, must be less than or equal to the maximum size of the quenching gap in the particular application as determined by the gas mixture which is developed by the fire, in order to quench.

A pattern of thin stripes, dots, pins or wires14of an intumescent can be applied to the mesh12and which can have a large surface area and a short mutual distance between them with open meshes or openings30between them in the plane in which the fire first strikes. Said intumescent can in a first embodiment be applied to the mesh in a stripe pattern of parallel intumescent stripes. Alternatively, the intumescent can in a second embodiment be applied to the mesh in a check pattern of intumescent stripes. InFIGS.2,4,5,6,7and9the intended fire direction is upwards, and the fire is thus first noted in the lower part of the firestop10. The effect which the fire applies is described in more detail in connection withFIG.15.

To produce a spring-loaded effect in the quenching gap, mesh12, the quenching gap mesh12can be made of braided or knitted spring threads28, or the quenching gap mesh12can be made of braided or knitted steel threads34equipped with preferably spring threads28running in the transverse direction. The spring threads28can have a size of, for example, 1 mm. The steel wires34can also be yielding.

The transverse spring wires28are usually arranged at a distance apart in the longitudinal direction of the quenching gap mesh12and with a mesh size which is larger than the quenching gap and smaller than maximum meshes in order to prevent a loss of expanded intumescent. With maximum meshes is meant here the size of openings/meshes in which an expanded intumescent will be pushed through and fall down. The mesh size can vary with the type of intumescent.

FIGS.10and11show a specific embodiment of the quenching gap mesh12as discussed above, while the remaining figures show the quenching gap mesh illustratively.

InFIG.11, one or more of the wires28or34are covered by the intumescent14and are connected via a wire36to a power source38. On the activation of the power source38, the wire(s) are heated up and said intumescent14will expand.

The quenching gap meshl2is initially intended to be produced in a flat form, but which can be bent into an approximately semicircular shape or into a tubular shape with a spring effect to withstand compression and at the same time react with protrusions or depressions on the surface where it is mounted.FIGS.10and11show, by way of example, that the transverse spring wires28substantially produce the spring effect while the longitudinal wires34are thinner and/or less rigid to provide a mesh which fills uneven surfaces.

The quenching gap mesh12can be produced in a sheet form with longitudinal side edges32, where one or both longitudinal side edges32comprises a mounting flange16. This can be done, either the quenching gap mesh12is produced in a sheet form or is cut into a sheet form, in that one or more of the side edges32are folded to, or mounted on, a mounting flange16.

The mounting flange16can be used to fasten the firestop10in a cavity22between two building parts20by means of a screw, pin18or similar fastening means. The mounting flanges16can also be glued to the surface.FIG.5shows such a fitting, where firstly the one mounting flange16on a first side edge32is attached to the base20by means of a screw or pin18, and inFIG.6wherein also the second mounting flange16on the second side edge32is attached to the base20by means of the screw or pin18.

FIG.7shows an example of a variant which is not formed into a closed tubular shape, and which is only attached to one side edge so that the other part is “free” to move.

Mounting flanges16on the side edges32of the quenching gap mesh12can also be arranged to have a locking integration with each other.

FIGS.8and9show an alternative embodiment of a ventilating firestop in which the quenching gap mesh12correspondingly has longitudinally running side edges32, but where a first side edge is formed with an S-shape24and a second side edge is formed with a half ball shape26. The half ball shape26can enter into a locking engagement by the insertion under the S-shape24when it is attached to the surface20, as shown inFIG.9.

TheFIGS.12and13further show variants of the mounting flange16, where one or two vertical edges/folds can be folded by a folding and flange machine standing, for example, at right angles to the mesh. This makes the mounting flange16rigid enough to secure the quenching gap mesh12to hard or soft surfaces, such as wood or rock wool.

Locking of the side edges32of the firestop10results in a fixed expansion volume22(as shown inFIGS.14and15). The fixed expansion volume being similar to said cavity22between two building parts20.

FIGS.14and15show the difference between prior art and the invention, performed in a three-step function.

FIG.14shows an example of prior art where an intumescent114is placed in a mesh structure112between two building parts20to maximize air passage and such that the intumescent114can fill the entire void between the intumescent and opposite sides when all the intumescent is expanded in heat and in that it blocks against the fire (the figure to the right).

According to the invention as shown inFIG.15, an intumescent14is placed in several thin stripes which forms a fine mesh stripe pattern, in at least one plane transverse to the air direction facing the actual fire load and so closed that ventilation is good enough. In that the stripes expand towards each other in heat, a shield or shell barrier40is formed which quickly closes the vent completely in the first minutes of the attack phase (as shown in the figure in the middle). After that, sustained heat from the fire will activate the rest of the intumescent in the vent to give a lasting volume sealing during the full filling phase (as shown in the figure to the right). This other intumescent can also be fine meshed, but preferably coarse meshed and with wider stripes or bands. The intumescent for the formation of the shield and volume filling are separated from each other.

The invention also works if the direction of the fire is opposite to that shown inFIG.15.

Thus, a firestop10according to the invention can be comprising many fine stripes14of an intumescent rather than conventional thick stripes and gratings and in that the stripes are coated directly on the quenching gap mesh12with optimized ventilation distances in between. The heat of the flame and the large contact surface with an intumescent make the stripes expand very quickly to a closed shield40which blocks flames for many minutes. In the exposure phase, the heat activates an endothermic chemical process (heat consuming) in the intumescent material that takes heat from the fire gas/flames, and in that there is such a large area of intumescent surface concentrated at the outermost mesh layer that meets the flames, the process will further effectively extend the quenching gap effect such that several layers of quenching gap mesh can be avoided (several layers required in prior art).

In the next phase of the fire resistance time, more intumescent14expands downstream from said shield40, but slowly due to the heat shield to the shield40, and it is beneficial for building up an even and compact volume of an expanded intumescent.

At the same time, it is a preferred application of the invention that it is rolled 360 degrees and into a tubular shape where the long sides are attached to each other. The effect of this is that expansion will always take place in a given volume22, either the environment forms the filter into an oval, into a flattened shape or into a square shape inside a suitable frame or otherwise. Because there are sealed stripes14with fine intumescent threads, also in the next layer the fire must pass, robust reliability is achieved. A fixed expansion volume further enables the use of an optimal amount of intumescent to ensure the longest possible fire resistance time, at the same time as any falling out of intumescent is virtually impossible. Intumescent that falls out/down leaves openings for fire and is known as one of the two biggest weaknesses with conventional solutions, where the passage of flames in the early phase is the other.

As an additional guarantee for rapid reaction also against smoke passage, the wires can be extruded with heating element wire before coating on the quenching gap mesh12, as shown inFIG.11. A short and adapted electrical current passage will cause the intumescent to expand and seal in a few seconds, while there is still only a little smoke in the room with the fire. Activation can happen from a smoke detector or manually, and a relatively small battery can be used.

As a further improvement of rapid expansion and less dust collection, metal powder/electrode-lacquered intumescent stripes (current) or “nano hair” coatings with high heat transfer performance can be used.

The firestop10can further be comprising an expansion pocket, for example, where the expansion pocket comprises an expandable intumescent interposed between several quenching gap meshes12.

As shown inFIG.16, a quenching gap mesh12with an intumescent stripe pattern14can be placed in the opening in a building structure as a strip or the like and attached as explained above. In addition, an externally perforated cover42can be used.

The expansion pocket44contributes to that the firestop10, under the influence of fire heat, can fill not only the ventilating empty space22in which it stands, but also fill in the expansion which can result from the building parts20bending in the fire and increasing the void space. The expansion pocket “inflates” with “limited space” for expansion. Whether the building parts are slightly compressed or give outwards, the expansion pocket will contribute to the firestop closing tightly against them when it is “inflated”. The expansion pocket can be in a mesh and will normally be ventilating, but not letting through an intumescent which is activated to expand in fire. Parts of the expansion pocket can be held together by threads or the like fastened between parts of the expansion pocket's mesh, where the threads can be sacrificed.

FIG.16shows that a ventilating expansion pocket can attach itself to a single fire sheet when it expands. Even if it is attached only from the outside, it can neither push itself out of the opening outwards nor inwards when it expands. It does not have a gasket as in ordinary vents between the frame and sheet and is mounted quickly.

A firestop according to the invention can be produced in that an intumescent is applied in stripes14by extrusion.

The stripe pattern14of an intumescent can alternatively be glued or sprayed on the quenching gap mesh12in parallel or transversely with the ventilating mesh openings30in between, in one or more layers. This also applies to extrusion.

Furthermore, said stripes14of an intumescent can be fastened with seams to the quenching gap mesh12, such as seams of sacrificial-based polyester or cotton.

A firestop according to the invention can also be produced with several quenching gap meshes12with inlaid, intermediate intumescent stripes14between respective quenching gap meshes12.

In use, the flat-produced firestops can be folded or rolled into one or more short rollers which are fitted together with, for example, two or more continuous steel wires which are cut and bent at the ends. This then constitutes an element for use in an air transfer grille, eaves vent, outer wall vent etc., where an intumescent will not glide over time. Transverse locks are secured without a throughgoing connection in the direction of fire spread and vents will be packed tightly and accurately and not bulge out in the middle.

An example of optimal application in an air gap can be a 2 mm quenching gap mesh, but this is primarily needed only at the bottom where the fire hits. Other mesh can be in a spring thread of a coarser mesh, e.g., 12 mm. 12 mm is enough to hold most of the intumescent in place, but can push a suitably small amount through which seals against the connections.

FIG.17shows in more detail a cross-section of intumescent threads14at a distance a apart and with a diameter b in a fine meshed intumescent pattern on the load-bearing mesh12. In the event of a fire, as shown, an expanding intumescent mass14′ meets between two wires14when the expanded thickness, for example, is ½ a for the formation of the shield40. In a preferred embodiment, but not limited to, a can be larger than2band less than5b, when the wire diameter b is 1-5 mm.

The load-bearing mesh can be in metal, glass fiber or other poorly combustible material with a preferred wire diameter of 0.1-1 mm but not limited to this.

Nearly finished expanding intumescent mass14′ is shown in dashed lines. An early-activated fire shield40, including a load-bearing mesh12, achieves at least thickness c. Shell thickness c can vary according to how long it shall insulate. A preferred thickness is 10-30 mm without listed articles. With listed articles in the form of a fixed quenching gap mesh, the thickness c can be less than 10 mm. In tests of fire shells according to the invention, a fire insulation time of 3-10 minutes has been achieved, but the shell according to the invention can be dimensioned to function for a longer time period. Additional fire insulation time can be achieved with the last step where more expanded intumescent fills the entire firestop.

In a practical embodiment, the fine mesh stripe pattern which forms the shield40and which expands rapidly can be very thin stripes, for example 2×2 mm, and be a short distance from each other and in all have a very large surface area per unit mass.

The remaining stripes of intumescent mesh that fill the volume22can be more arbitrary and coarsely meshed, and in typical applications, bands of, for example, 35×3 mm in cross-section and with distances of 20-50 mm from each other can be used. Alternatively, the stripes for volume filling can also be fine meshed.