GB2312619A

GB2312619A - Particle and gaseous fire control device

Info

Publication number: GB2312619A
Application number: GB9609198A
Authority: GB
Inventors: Harold Robert Holt
Original assignee: MERWOOD Ltd
Current assignee: MERWOOD Ltd
Priority date: 1996-05-02
Filing date: 1996-05-02
Publication date: 1997-11-05
Also published as: GB9609198D0

Abstract

A particle and gaseous fire control device consisting of a cover 2, a storage container to retain a fire fighting repressive medium, (this may be water, however differing types of fires may require a different type of repressive medium, for example, foam, powder, etc.). The container has a screwed adapter to accept a compressed gas cylinder so that the storage container may be pressurised to urge the fire fighting medium through nozzle(s) 10 to atomise the fire fighting mediumr into a fine mist. A sensor to sense the rise in temperature activates the device on the build up of combustion gases.

Description

PARTICLE AND GASEOUS FIRE CONTROL DEVICE This invention relates to a fire control device and in particular the control of fire combustion gases.

It is known that more people are asphyxiated by combustion gases in fires than are burned, it is also recognised that where sprinkler systems are used a significant saving in both property and life is generally accepted. Unfortunately sprinkler systems are expensive to fit and are unsuitable for smaller industrial and domestic applications. Moreover it is appreciated that when combustion gases collect at the ceiling they subsequently reach a temperature when they ignite, this is known as a flash over and thereafter rapid acceleration of the fire is usually the outcome.

Therefore the control of the combustion gases is desirable to allow a greater time for evacuation and the increased time for conventional fire fighting to take place or the elimination ofthe fire itself.

According to the present invention there is provided a fire control device that when operated expresses a mist that amalgamates with combustion gases thus reducing the risk of these gases igniting.

The present invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 illustrates the device in situ on a ceiling.

Figure 2 shows a plan view lever arrangement for activating the device. Referring to the drawings, the fire control device consists of a cover preferably made from a plastic material, and a sub plate for fixing the device in situ which also acts as a location for a storage container which retains the fire fighting repressive medium, in this example this is water. However differing types of fires may require a different type of repressive medium, for example, foam, powder, etc. The container has a screwed adaptor to accept a compressed gas cylinder so that the storage container may be pressurised to urge the fire fighting medium through nozzle(s) to atomise the fire fighting medium, in this example water, into a fine mist. A sensor activates the device on the build up of combustion gasses.

The present invention will be further described by way of example. The repressive medium storage container 1 is preferably made from aluminum, which releasably locates into the sub plate 8 which is housed within an outer cover 2 preferably made from a fire retarding plastic material. The storage container may have a holding capacity to suit individual sites, however in this example the container is of 2 litres capacity. The container is filled via a screwed cap 12 this may also incorporate the adaptor 13 for accepting a compressed gas canister 6 which is used to pressurise the repressive medium held in the storage container 1. The storage container is filled to a pre determined level, this may be by a visual indicator for e.g. a viewing port or by a measured amount so that the container 1 is filled to the correct fill level. An indication may be given via a pressure sensor or an LED (not shown). In this example water is used as the repressive medium. The device is provided with fixings to enable it to be easily mounted, preferably on the ceiling, in as near central position as possible. For large areas that need protection several devices may be installed, these devices may be interconnected so that a triggered single device will initiate the other interconnected devices. Furthermore the devices may incorporate an adaptor (not shown) for other sensors to be connected to the present invention therefore being easily incorporated into a fire detection system.

A means to address the device may be advantageous so that the remote activation of a device is possible. A means to detect the presence of combustion gasses to activate the device may take a number of forms, for example heat detection by way of a thermistor, bymetal strip, other detection means may be used for e.g. optical detection of smoke particles via infra red or a chemical detection of the combustion gasses. The device may incorporate any one or a combination of detection methods. A means to expel the repressive medium is provided. This may be by pressurising the storage container 1 by inserting a pressurised gas canister in a holder, (not shown) the holder having a screwed end which screws into an adaptor 13 located on container 1, turning the holder causes the gas canister to abut a one way valve (not shown), this valve punctures the end of the gas canister 6 thus pressurising the container 1 holding the repressive medium A further valve (not shown) may be provided to release a controlled amount of repressive medium when the device is triggered, the preferred positioning of the nozzles around the periphery of the device is to give a uniform spread of mist over the devices control area. Other means of dispensing the repressive medium may be used for example a pumped action, by a timed release of compressed gas or centrifugal force, a further example of triggering the device is via mechanical means whereby pressurisation of the storage container holding the repressive medium is activated only when the device is triggered. An intumescent compound 3 is contained in a tube shaped holder 11 so that it may be easily replaced when used, one end of the lever is located in the open end ofthe intumescent holder 11 which locates in a slot provided in the end of the tube holder 11 the other end is positioned over the base of a pressurised gas canister 6 so that when a pre-determined temperature is reached the intumescent compound expands, this has the effect of urging the lever 4 which is movably attached to a pivot 5, this movement is shown by the direction of the arrow, fig 2. The expansion of the intumescent compound causes the pressurised canister to be urged against a seal (not shown) and contacts a valve (not shown) which has a sharp point, the expansion of the intumescent compound applies force to the lever which ultimately causes the puncturing of the pressurised canister 6 thus allowing a pressurisation of the repressive medium storage container 1 which in turn forces water through to an array of atomising nozzles 10 arranged around the periphery of the device. As an alternative to fixed position nozzles a rotating nozzle or nozzles (not shown) may be advantageous to give greater disbursement of the repressive medium. Furthermore a valving arrangement (not shown) may be advantageous to stop and start the flow of repressive medium this has an advantage in that the combustion gasses are subdued without unnecessary wastage of the repressive medium A sensor is provided to detect the reduction of temperature/gaseous products and therefore will restart the dispensing process. This operation will be cyclic until the repressive medium is exhausted. A visual / audible indication of repressive medium depletion is desirable via an LED and / or a sounder.

Claims

-CLAIMS

1 A fire and gaseous control device that consists of a storage container with a reservoir of repressive medium, that may be pressurised, which is affective in subduing gases that are a result of combustion. A means to trigger the dispensing of the repressive medium through a nozzle or nozzles which atomise the repressive medium as it is being dispensed. The device being adapted for fixing to the upper area of rooms ideally ceilings

2 A fire and gaseous control device as claimed in claim 1 wherein the means of storage ofthe repressive medium is a a container that is capable of being refilled and represssiised.

3 A fire and gaseous control device as claimed in claim 1 and 2 wherein the means to trigger the device is by sensing the rise in temperature.

4 A fire and gaseous control device as claimed in any preceding claim wherein the means of triggering the device includes other types of sensors, ionisation, optical, and chemical either singly or in a combination

5 A fire and gaseous control device as claimed in any preceding claim wherein the repressive medium is water.

6 A fire and gaseous control device as claimed in any preceding claim wherein the repressive medium is atomised when being dispensed 7 A fire and gaseous control device as claimed in any preceding claim wherein the repressive medium is forced through an array of nozzles to give a 360 degrees misting ofthe surrounding area 8 A fire and gaseous control device as claimed in any preceding claim wherein the repressive medium is dispensed via a pumping action.

6 A fire and gaseous control device as claimed in any preceding claim wherein the repressive storage container is easily removed from its holder to aid replenishment ofthe repressive medium.

7 A fire and gaseous control device as claimed in any preceding claim wherein the repressive medium is dispensed through a rotating nozzle arrangement.

8 A fire and gaseous control device as claimed in any preceding claim wherein the device has an LED indicator to show the device is operational.

9 A fire and gaseous control device as claimed in any preceding claim wherein the device has an indicator that shows the device has be activated.

10 A fire and gaseous control device as claimed in any preceding claim wherein when the device is triggered it has a cyclic on and off operation.