GB2272836A

GB2272836A - A smoke barrier

Info

Publication number: GB2272836A
Application number: GB9215687A
Authority: GB
Inventors: Derek Alfred Ward
Original assignee: Environmental Seals Ltd
Current assignee: Environmental Seals Ltd
Priority date: 1992-07-23
Filing date: 1992-07-23
Publication date: 1994-06-01
Anticipated expiration: 2012-07-23
Also published as: GB9215687D0; GB2272836B

Abstract

A smoke barrier device for installation in or over an opening to prevent the passage therethrough of smoke, comprises a grill member 1 having apertures 2 therein through which air can flow, and sealing means (7, fig 2) and 11 operable in response to the presence of smoke and/or heat or in response to the detection of smoke and/or heat by associated detection means, to seal the said apertures 2 against the passage of smoke therethrough. <IMAGE>

Description

ImDrovements in or Relating to Smoke Barriers This invention relates to a smoke barrier device for preventing the passage of smoke through an opening such as an opening in a wall or panel, or through ducting, e.g.

ducting of the type used in ventilation or airconditioning systems.

In a first aspect the invention provides a smoke barrier device for installation in or over an opening, to prevent the passage therethrough of smoke, the smoke barrier device comprising a grill member having apertures therein through which air can flow, and sealing means operable in response to the presence of smoke and/or heat or in response to the detection of smoke and/or heat by associated detection means, to seal the said apertures against the passage of smoke therethrough.

The sealing means can take the form of a sliding plate positioned adjacent the grill member and having one or more sealing members, the sliding plate being slidable into a position whereat the sealing member or members seal the apertures in the grill in response to the presence of smoke and/or heat or in response to the detection of smoke and/or heat by associated detection means.

The sliding plate is preferably disposed behind the grill member and can be slidably secured thereto. The sliding plate may be provided with apertures through which air can flow and preferably such apertures are arranged such that they are substantially in register with the apertures of the grill member when the smoke barrier is in an open configuration.

The sliding plate may be actuable in direct response to heat. For example, a fusible link may b provided which melts in the presence of elevated temperatures to allow the plate to drop under the influence of gravity.

Alternatively, a bimetallic strip arrangement may be provided whereby, under normal conditions, the bimetallic strip, or a latch means associated therewith, holds the sliding plate in the "open" position but, in the presence of th elevated temperatures associated with fire, bends to move or cause the movement of the sliding plate to the "closed" position.

In a preferred embodiment, the sealing means is operable in response to the detection of smoke and/or heat by an associated detection means such as a smoke detector.

For example, an electronic or magnetic latch can be provided which is responsive to a signal from the said detection means. The electronic latch can be, for example, a solenoid having a plunger which, in the absence of smoke or fire, engages a suitable detent such as a recess or aperture in the sliding plate to hold the plate in a raised "open" position, but which upon receipt of a signal from the detection means disengages from the detent to allow the plate to fall into a sealing or "closed" position.

Alternatively, the latch can be an electromagnetic latch which is normally energised to hold the sliding plate in the raised position but which is de-energised in response to a signal from the detection means to allow the plate to fall into a sealing position.

It is to be understood that the term "signal" as used herein includes the simple case wherein an applied voltage between the detection means and the latch is cut off.

The sealing members can take the form of brush seals, but may alternatively be in the form of blade seals, for example neoprene blade seals.

In another aspect, the invention provides a system comprising smoke and/or fire detection means and, electronically connected thereto, a smoke barrier device as hereinbefore defined.

The invention will now be illustrated in greater detail, but not limited, by reference to the particular embodiments shown in the accompanying drawings in which: Figure 1 is a front elevation of one embodiment according to the invention; Figure 2 is a sectional side elevation along line I-I in Figure 1; Figure 3 is a view from the rear of the front plate of the embodiment shown in Figure 1; Figure 4 is a view from the front of the sliding plate from the embodiment shown in Figures 1 to 5; Figure 5 is a view from the rear of the intumescent block grill shown in Figure 2.

Turning now to the Figures, it can be seen that the smoke barrier device comprises an outer grill member 1 having a plurality of rows of elongate slots 2 through which air may normally pass. In Figure 1, the elongate slots 2 are shown as being sealed by brush seals 11, the tips of which protrude slightly through slots 2. The outer grill member 1, which has upper 3, lower 4 and side walls 5, in use is placed in or over an opening in a door br wall (W) and is fixed by means of suitable securing elements such as screws (not shown).

Connected to the rear of grill member 1 is a sliding plate 7 which is held in contact with grill member 1 by means of screws 6 located in slots 8 of the sliding plate 7. The plate 7 is slidable with respect to grill member 1 by virtue of the slots 8. Sliding plate 7 is provided with elongate apertures 9 which allow the passage of air therethrough. Along one edge of each aperture 9, the sliding plate has outstanding flanges 10. Affixed to the sliding plate 7 between each pair of adjacent elongate apertures 9, are brush seals 11 (depicted as cross-hatched areas in Figure 4), the filaments or bristles of which are generally directed outwardly of the plate. The brush seals 11 conveniently are affixed to the sliding plate 7 by means of a suitable adhesive. As an alternative to the brush seals 11, blade seals, eg formed of a resilient elastomeric material such as neoprene can be used.

Affixed to the inner surface of upper wall 3 of the grill member 1 is an electromagnet 12 which operates from a 12v or 24v power supply (not shown). When energised, the electromagnet 12 attracts and engages a metal disc 13 secured to the sliding plate 7 by means of bracket 14.

In use, when the electomagnet is energised, the sliding plate 7 is held in the raised position in which the slots 3 in the grill member 1 are aligned with the apertures 9 in the sliding plate 7 to allow air flow through the device. If the electromagnet is de-energised, for example in response to the detection of smoke by an associated smoke detection device, the magnetic attraction between electromagnet 12 and metal disc 13 disappears.

Consequently, the sliding plate 7 falls under the influence of gravity such that the brush seals 11 come into register with and seal the elongate slots 2 against smoke penetration. In order to reset the device, the electromagnet is re-energised and the sliding plate 7 is pushed back up into the raised position by inserting a suitable implement through the slot 15 at the mid point along the lower edge of the grill member 1.

The smoke barrier of the invention may optionally incorporate a fire barrier, and such a barrier is illustrated in Figures 2 and 5. Figure 2 shows in cross section an intumescent block grill 16; the construction of the grill being shown in more detail in Figure 5.

Block grill 16 is formed from intumescent mixtures of the type described in our British Patent Application No.

9207659.5 which claims priority from British Patent Application No. 9107466.6. The intumescent mixture is encased in aluminium foil in order to prevent moisture penetration which could adversely affect the intumescent properties of the grill.

In the case of the smoke barrier device being subject to the elevated temperatures associated with fire, the grill 16 intumesces and rapidly swells to fill completely the width of the opening in or over which the smoke barrier device is located.

As an alternative to an electromagnetic latch, a solenoid latch may be used. Such a solenoid, which typically would run from a 12 or 24 volt power supply, would normally be maintained in the non-energised state and would hold the sliding plate 7 in the raised position whilst in this state. In the non-energised state, the solenoid plunger would protrude from the solenoid and would engage a suitable recess or hole in the sliding plate 7. Energising the solenoid would cause withdrawal of the plunger into the solenoid coil, allowing the sliding plate 7 to drop.

A further alternative to the electromagnetic latch can take the form of a fusible link between sliding plate 7 and grill member I which melts at a temperature of between 400C and 70dC to allow the sliding plate to drop.

Moreover, a bimetallic strip arrangement may be used which, in a curved configuration at room temperature, would hold the sliding plate in the raised position, but which would straighten at temperatures in the range 400C to 700C to allow the sliding plate 7 to drop.

The smoke barriers of the type illustrated can be used to cover ducting in inter alia fire walls, doors, glazed partitions or windows, and can be provided with deep side, upper and lower walls to enable them to act as covers for ventilation fans. Where the smoke barrier is located in a fire wall, window, partition or the like, the "rear side" of the device (designated R in Figure 2) may also be fitted with a grill.

It will readily be apparent that numerous modifications and alterations may be made to the smoke barrier illustrated in the accompanying drawings, and all such modifications and alterations are intended to be covered by this application.

Claims

1. A smoke barrier device for installation in or over an opening, to prevent the passage therethrough of smoke, the smoke barrier device comprising a grill member having apertures therein through which air can flow, and sealing means operable in response to the presence of smoke and/or heat or in response to the detection of smoke and/or heat by associated detection means to seal the said apertures against the passage of smoke therethrough.

2. A smoke barrier device according to claim 1 wherein the sealing means is in the form of a sliding plate positioned adjacent the grill member and having one or more sealing members, the sliding plate being slideable into a position whereat the sealing member or members seal the apertures in the grill in response to the presence of smoke and/or heat or in response to the detection of smoke and/or heat by associated detection means.

3. A smoke barrier device according to claim 2 wherein the sliding plate is disposed behind the grill member and is slideably secured thereto.

4. A smoke barrier device according to claim 2 or claim 3 wherein the sliding plate is provided with apertures through which air can flow.

5. A smoke barrier device according to claim 4 wherein the apertures of the sliding plate are arranged such that they are substantially in register with the apertures of the grill member when the smoke barrier is in a open configuration.

6. A smoke barrier device according to any one of claims 2 to 5 wherein the sliding plate is actuable in direct response to heat

7. A smoke barrier device according to claim 6 wherein the sliding plate is actuable in direct response to heat by virtue of having a fusible link which melts in the presence of elevated temperatures to allow the plate to drop under the influence of gravity.

8. A smoke barrier device according to claim 7, which is provided with a bimetallic strip arrangement whereby under normal conditions the bimetallic strip or a latch means associated therewith holds the sliding plate in the open position but, in the presence in the elevated temperatures associated with fire bends to move or cause movement of the sliding plate to the closed position.

9. A smoke barrier device according to any one of the preceding claims wherein the sealing means is operable in response to the detection of smoke and/or heat by an associated detection means.

10. A smoke barrier device according to claim 9 wherein an electronic or magnetic latch is provided which is responsive to a signal from the said detection means.

11. A smoke barrier device according to claim 10 wherein the electronic latch is a solenoid having a plunger which in the absence of smoke or fire, engages a suitable detent in the sliding plate to hold the plate in a raised open position, but which upon receipt of a signal from the detection means disengages from the detent to allow the plate to fall into a sealing or closed position.

12. A smoke barrier device according to claim 10 wherein the latch is an electromagnetic latch which is normally engergised to hold the sliding plate in the raised position but which is de-energised in response to a signal from the detection means to allow the plate to fall into a sealing position.

13. A smoke barrier device according to any one of the preceding claims wherein the sealing means take the form of brush seals or blade seals.

14. A smoke barrier device substantially as described herein with reference to the accompanying drawings.

15. Apparatus comprising smoke and/or fire detection means and, electronically connected thereto, a smoke barrier device as defined in any one of the preceding claims.