WO1991010803A1

WO1991010803A1 - Liquid containment barrier

Info

Publication number: WO1991010803A1
Application number: PCT/GB1991/000037
Authority: WO
Inventors: Harry Roger Hill
Original assignee: Harry Roger Hill
Priority date: 1990-01-13
Filing date: 1991-01-11
Publication date: 1991-07-25
Also published as: GB9000775D0; AU7055491A

Abstract

A liquid containment barrier comprising an inflatable bag (3) beneath a hinged plate structure (1b, 1c) can be raised by inflating the bag (3) to form a barrier, whereby the barrier, in use in an aperture, may be raised to provide a substantially waterproof seal along the length of the aperture.

Description

LIQUID CONTAINMENT BARRIER

Background to the Invention

The present invention relates to liquid containment barriers; especially, but not particularly, for use in buildings or parts thereof at entrance and exit points.

Since the fire at a chemical plant in Europe in 1986 when the residual water from the fire fighting appliances, being contaminated by chemicals from within the buildings, flowed into the river Rhine causing serious pollution, increased efforts have been made to contain water within buildings, particularly those containing hazardous substances. Historically, some methods have used timber balks and sand bagging in the envelope of the structures. Recently more effective means of containment in the form of raised thresholds to doorways have been put into effect.

The United Kingdom Health and Safety Executive published in July

1988 a Guidance Note CS19 entitled '-'Storage of approved pesticides : guidance for farmers and other professional users". In this note the problem of liquid containment was addressed and several solutions proposed: that of setting the floor below ground level, the use of a permanent impervious door sill, the use of an impervious below ground storage tank. Raised thresholds present certain drawbacks with inevitable cost implications in that for vehicles to access the buildings ramps are required at a gradient of, typically, 1:20 taking up valuable space within the buildings and causing drive-by problems externally. Furthermore increasing the height of the threshold in an existing building may necessitate raising the lintel of the doorway in order to retain an acceptable headroom. This has a substantial cost impact.

Below ground storage tanks are expensive to install and do not provide the versatility often required of storage facilities.

Other, more recent mechanical methods of overcoming the containment problem have met with a mixed reception as they have been dependant to a large extent on the human element and the errors contained therein. As a result, local water authorities still support the 'permanent' barrier methods of raised thresholds previously described.

The invention described hereinafter aims to provide for the containment of liquids and/or other substances at any doorway or other aperture in the envelope of a building by means designed to overcome previous reservations by water authorities.

Summarv of the Invention

Accordingly the present invention provides a liquid containment barrier comprising an inflatable bag beneath a hinged plate structure that can be raised by inflating the bag to form a barrier, whereby the barrier, in use in an aperture, may be raised to provide a substantially waterproof seal along the length of the aperture.

The liquid containment barrier is preferably activated by a fire alarm or sensor. The interior facing plate of the liquid containment barrier preferably comprises a multiple skinned plate.

The liquid containment barrier preferably additionally comprises a pneumatic or hydraulic ram which assists in raising the plates.

The liquid containment barrier is preferably mounted in a casing for retro-fit applications.

A specific embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Brief Description of the Drawings

Figure 1 shows, in perspective, a liquid containment barrier assembly in its normal lowered (dormant) position across a doorway with part of the floor cut away.

Figure 2 shov/s, in section, the barrier assembly in its lowered (dormant) position.

Figure 3 shows, in section, the barrier assembly in its raised (active) position.

Figure 4 shows, in section, an enlarged view of interior facing plate lc.

Description of the Preferred Embodiment

Referring to the drawings, the barrier comprises a hinged plate or plates 1 mounted at floor level above a cavity 2 formed in the floor within which a flexible air tight bag, or bags, 3 is, or are, housed. The cavity 2 is located adjacent an aperture, in this case a doorway 4. In the present embodiment there are three hinged metallic plates la-lc, with plate lc facing the interior of the building, and a single bag 3. Plates la and lc are hinged, at 5a and 5c respectively, on either side of the cavity 2. Plate lb is connected to plate lc by hinge 5b. It is to be noted that whilst a substantially air tight bag (or bags) is (or are) preferred, any inflatable bag (or bags) will suffice.

In this lowered (dormant) position the plates la-lc form a substantially planar platform across the cavity 2 over which a vehicle may pass thus avoiding the problems associated with raised sills,

Plate lc, the interior facing plate, is a multiple (in this case double) skinned so-called "snuffer" plate which acts as an insulating barrier in the event of fire (Figure 4). The preferred construction of the double skinned plate lc is that shown with the two skins converging, but they may also be at any angle until the two skins are parallel provided that the top end (opposite the hinge 5c) is closed off.

The bag 3 is connected via a hollow line (or lines) 6 to a control valve 7 which in turn is connected to a reservoir, typically a cylinder (or cylinders) 8, of compressed air or other suitable gas (or liquid) which may be situated remotely from the building. The control valve 7 is further connected to a trigger/sensor device 9. Additionally, to complete the barrier two end containment piers or end plates 10 are provided, attached and sealed to the building at the interior facing edges adjacent the aperture. Within one (or both) of the piers or end plates 10 is a pneumatic (or hydraulic) ram 11, one end of which is attached to the interior side wall of the pier or end plate 10, the other end of which is linked to the hinge 5b. The ram 1 1 may be connected to a separate pressurised fluid source (not shown), but is. also triggered by the device 9. A separate second control valve (not shown) actuates the ram 11, although in some circumstances the same control valve 7 may be used. In order to operate the barrier from the lowered (dormant) position shown in Figure 2 in which the bag 3 is collapsed beneath the plates

1, to the fully sealed (active) position shown in Figure 3, the trigger/sensor device 9 on being activated by a building fire alarm or detector, or by its own sensing device (none of which are shown in the drawings), opens the control valve 7 which evacuates air under pressure from the cylinder 8 into the deflated air tight bag 3 located in the floor cavity 2 and which also opens the second control valve which evacuates fluid under pressure from the second pressurised source (not shown) to actuate the ram 11. The pressurised air tight bag 3 now expands, displacing the hinged plates la-lc into position with the assistance of the ram 11, an operation that will now be described in more detail.

Once the control valve 7 and the second control valve actuate the system the ram 1 1 lifts hinge 5b, beginning to lift the plates lb and lc into a position intermediate the lowered (dormant) and raised (active) positions. The bag 3 as it inflates displaces the hinged plates la-lc in to their raised (active) positions in which they form a substantially n-sectioned barrier. The ram 11 speeds up the response time of the liquid containment barrier by reducing the amount of work required of the inflating bag 3.

In the lowered (dormant) position the platform formed by plates lb and lc lies over plate la. As the plates la-lc are raised by the ram 11 and the bag 3, plates la and lc are displaced to upright positions substantially perpendicular to the floor. As plate la is displaced its free (non-hinged) end lifts the free (non-hinged) end of plate lb until the two plates reach their raised (active) positions, at which point any known mechanism may be used to interlock the plates together - such as the so-called 'dog-tooth' which may be a self-locking and subsequently self-releasing mechanism. When fully pressurised the bag 3 forms a contiguous seal within the cavity 2 against the plates la-lc and the piers or end plates 10 for an acceptable height above the floor level of the building thus retaining any liquids contained therein. Furthermore, whilst at working pressure the bag 3 ensures that the integrity of the box configuration formed by the plates la-lc by means of the plate interlock as well as sealing with the plates la-lc, piers or end plates 10 and the below floor cavity 2 thus retaining any liquid in the building. The hinged plates la-lc in turn form a protective box over the bag 3. Additionally, the weight of any liquids contained by the barrier would provide increased sealing pressure. Thus the barrier provides a substantially waterproof seal along the length of the aperture.

The bag 3 may also include a manually operable release valve allowing the bag to be deflated after testing or in order to return the barrier to its lowered (dormant) position after use.

Figures 2 and 3 clearly show the system mounted within a rigid metal casing 12 (located at the periphery of the cavity 2) which extends along the length of the cavity 2 and incorporates the two piers or end plates 10. This casing allows the barrier to be used for retro-fit applications.

The barrier described herein provides a relatively economical method of liquid containment that need not result in the practical disadvantages exhibited by the known systems.

Claims

1. A liquid containment barrier comprising an inflatable bag beneath a hinged plate structure that can be raised by inflating the bag to form a barrier, whereby the barrier, in use in an aperture, may be raised to provide a substantially waterproof seal along the length of the aperture.

2. A liquid containment barrier according to Claim 1 characterised in that the liquid containment barrier is activated by a fire alarm or sensor.

3. A liquid containment barrier according to Claim 1 or Claim 2 characterised in that the interior facing plate of the liquid containment barrier comprises a multiple skinned plate.

4. A liquid containment barrier according to any preceding claim characterised in that the barrier additionally comprises a pneumatic or hydraulic ram which assists in raising the plates.

5. A liquid containment barrier according to any preceding claim characterised in that the barrier is mounted within a casing for retro¬ fit applications.

6. A liquid containment barrier according to any preceding claim characterised in that, in use, in its lowered state the plates form a substantially planar platform over which a vehicle may pass.

7. A liquid containment barrier according to any preceding claim characterised in that the barrier additionally comprises piers or end - plates at each respective end of the barrier; the piers or plates, in use, being attached to the interior facing edges adjacent the aperture.

8. A liquid containment barrier according to any preceding claim characterised in that the bag is substantially air tight.

9. A liquid containment barrier according to any preceding claim characterised in that the bag is inflated by a gas.

10. A liquid containment barrier according to any preceding claim characterised in that the plate structure comprises three hinged plates which, in their raised positions, form a substantially n-sectioned barrier.

11. A liquid containment barrier according to Claim 10 characterised in that the interior facing plate is hinged at one vertex and one end of the n-section, the exterior facing plate is hinged at one end of the n-section, the intermediate plate is hinged at the same vertex as the interior facing plate, and the ends of the exterior facing and intermediate plates opposite their hinged ends being free.

12. A liquid containment barrier as described herein with reference to, and as shown in, the accompanying drawings.