GB1584322A

GB1584322A - Fire prevention trough

Info

Publication number: GB1584322A
Application number: GB234678A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-01-21
Filing date: 1978-01-20
Publication date: 1981-02-11
Also published as: CH625960A5; NL7800677A; DE7701672U1; FR2377812A1; FR2377812B1; BE863122A

Abstract

The fireproof tub has shafts (2) which run upwards from the tub base and, on the base side, are hydraulically connected to one another. The shafts (2) only have openings at the top and bottom. The shafts (2) shaped in a honeycomb-type manner are assembled to form a grid and produced from trapezoidally profiled sheet-metal strips (3). The grid is located with its underside at a distance from the tub base in order that the liquid running into the tub can be rapidly distributed over the entire tub base and is at the same level in all shafts (2). As a result, each individual shaft (2) is cut off in a syphon-like manner from the air supply from the bottom. In the event of fire, the flame is extinguished after a short period of time because an insufficient amount of oxygen from the air passes through the narrow shafts (2) to the liquid surface. <IMAGE>

Description

(54) FIRE PREVENTION TROUGH (71) 1, GEORG ScHMIDT-THoMÉE, a citizen of the Federal Republic of Ger many, of Landfriedstrasse 7, 6900 Heidel berg, Federal Republic of Germany, do hereby declare the invention, for which I pray that a Patent may be granted to me, and the method by which it is to be per formed, to be particularly described in and by the following Statement: The invention is based on an incom bustible fire prevention trough for collect ing inflammable liquids, which is fitted with inserts.

To prevent rapidly spreading large-area fires where there are leaking inflammable liquids, it is known for incombustible fire prevention troughs to be provided under the liquid containers involved, to collect the leaking liquid. This safety measure means that any fire which might possibly break out is restricted to the surface of the trough. In this way, inflammable materials which are further away are prevented from being set slight by the fire.

These troughs have the disadvantage that the liquid continues to burn either until it is extinguished or until it has completely burnt out, and has thereby caused greater damage.

In particularly dangerous plant, auto matic extinguishing appliances which ex tinguish the fire. immediately are built into the troughs. However, these extinguishing appliances have the disadvantage that they are complicated and require continuous maintenance. In addition, there is a danger in this instance that the liquid in the trough will catch fire again after com pletion of the extinguishing process and that it will not be possible to extinguish the fire again since all the extinguishing medium has been used.

Furthermore, in the associated com mercial field fire prevention troughs are also available which are filled with rock wool and covered over with a perforated sheet through which the liquids can flow into the rock wool and onto the floor of the trough. Although a fire in this type of trough is smaller than that in an open trough, it must be extingusihed since it will not go out by itself but will continue to burn until the liquid is largely all burnt up, due to the wick effect of the rock wool.

It is the aim of the invention to develop an incombustible fire prevention trough of simple construction in which burning liquids safely go out on their own and reignition is prevented.

This aim is achieved with a fire prevention trough as defined in the following claims.

By dividing up the internal space of the fire prevention trough into relatively small compartments of any desired shape, it is ensured in a simple way that any fire in the liquids which might possibly break out in the trough goes out by itself due to lack of oxygen. The incombustible components which form the compartment arrangement can be produced economically - for example, by stamping out strips of plate and can be inserted in the trough in a simple way.

The invention will now be further described by way of example, with reference to the accompanying drawing, in which: Figure 1 shows part of a compartment arrangement formed from strips of plate for a fire prevention trough in accordance with the invention viewed from above, and Figure 2 is a view of a complete fire prevention trough, with a covering plate.

The incombustible fire prevention trough 1 (Figure 1) for collecting inflammable liquids is divided internally into compartments 2 of any desired shape, which run generally from the floor of the trough upwards, and communicate with each other at the floor of the trough so that the liquid can spread evenly over the floor of the trough. The ratio of compartment height to the maximum transverse dimension of the compartment is at least 2, so that any fire in the liquid which might break out in the trough 1 is extinguished due to lack of oxygen.

However, with most inflammable liquids it is safer to have a compartment height of four or more times the maximum transverse dimension of the compartment.

The self-extinguishing effect of the compartments 2 can be increased if the compartments 2 are arranged at an angle or with a change in direction in their upwards path. To the same end, the compartments 2 can also each have one or more constrictions. For example, small smooth or perforated pieces of plate can be arranged horizontally in the compartments so that at this point the cross-section of the compartment is narrowed to a fraction of the crosssection of the rest of the compartment.

The liquid can still flow easily through the greatly reduced opening created in this way, but atmospheric oxygen can no longer travel down to the surface of the liquid in sufficient quantities to support combustion, so that the partial blaze burning in the compartment is stifled. When fitting several small pieces of plate in the individual compartments, the self-extinguishing effect can be increased still further if the gaps which remain open are offset from each other.

In certain cases the insertion of transverse plates can mean a reduction in production costs, since the cross-section of the compartment can be greater, and correspondingly fewer compartments are required.

In one embodiment of the fire prevention trough 1 according to the invention, the arrangement of compartments 2 is formed from profiled sheets 3 which stand parallel to each other in the trough 1. For the intercommunication between the separate compartments 2 the profiled sheets 3 are either provided with a cut-out on the side nearest the floor or are stood on spacer elements or flat transverse ribs on the floor of the trough.

In one highly satisfactory embodiment, the compartment arrangement is produced as a grid which can be removed from the trough and is made in the form of a gratine, tubes or plates, the type of connection between the profiled sheets 3 used for this purpose being determined according to the known possibilities of fabrication technology, e.g. by folding, welding or spot welding. The grid which can be removed from the trough 1 can be attached to a frame for improved stability, and can be fitted with handles. With the construction described above using individual profile sheets 3, for improved stability these can also be fitted in a frame which can be removed from the trough 1. The removable grid has the advantage that the trough and the grid are easier to clean.

As already mentioned, the liquid running into the compartments 2 should spread out over the whole floor of the trough as rapidly as possible. For this purpose it is necessary for slits or other openings to remain open between the lower face of the grid and the floor of the trough, but on the other hand these must not be large enough for any considerable amount of air to pass on the underside of the grid from one compartment 2 into another. These openings are closed to the passage of air as soon as the leaking liquid has covered the floor of the trough. These openings can be produced in various ways, for example, by providing grooves or other contouring in the floor of the trough, or by inserting wire mesh or the like between the floor of the trough and the grid.Another possibility is for the grid or the individual profiled sheets 3 to have cut-outs on the side nearest the floor, or for spacer elements to be arranged between the grid or profile sheets 3 and the floor of the trough.

To reduce air convection at the trough floor level, a layer of porous or fibrous material, as incombustible as possible, can be inserted between the floor of the trough and the grid, for example, made of pumice, expanded clay, or fine wire wool, glass woo! or mineral wool, and this material can also be used to fill the lower part of the compartments 2. Usually, even if the intermediate layer is omitted, it is still adequate if only the lower part of the compartments 2 is filled with this type of material.

If large amounts of inflammable liquids are to be collected in the fire prevention trough it is advisable to conduct this away.

This is done via drainage holes in the floor of the trough which must be secured against penetration by flashback flames by using known anti-explosion devices or siphons.

In another embodiment of the fire prevention trough (Figure 2) the inner space of the trough 1 is covered somewhat below the upper edge of the trough by a covering plate 12 which is divided, for example, into rectangular areas of equal size with 10 cm long sides. The surface of each individual area is depressed in the form of a funnel, and openings 13 are provided in these individual depressions 11.

The depressions 11 and the openings 13 can be produced in one working process, for example, by stamping. Underneath the openings 13 twelve tubes (not visible in the Drawing) are attached, for example, by welding, and these rest on the floor of the trough to form separate individual compartments, at the same time supporting the covering plate 12. The tubes are tapered towards the floor or are profiled in some other way to encourage the unobstructed flow of the liquid out into the trough.

Instead of arranging them standing on the floor of the trough, it is also possible to provide projections internally on the walls of the trough on which the covering plate 12 rests, so that the required gap is formed between the ends of the tubes and the floor of the trough.

With this arrangement it must be ensured that the air which is compressed as the liquid flows into the trough can escape from inside the trough. The gap (14) between the edge of the trough and the covering plate (12) is normally sufficient for this.

However, small cut-outs (15) in the edge of the covering plate (12) or small holes (16) in those parts of the covering plate which lie highest can be provided for this purpose.

To provide protection against explosion, the space between the separate tubular compartments is filled with the above-mentioned porous or fibrous material, which can easily be inserted between the tubes before the covering plate 12 is inserted in the trough 1, if the covering plate is turned upside down.

To assist understanding of the fire prevention trough according to the invention which is described above, one embodiment is described in the following.

Example On the floor of a 45 x 45 cm square trough 1, 13 cm high, made of 2 mm thick aluminium plate, there is a 45 x 45 cm screen made of V2A steel wire with 64 meshes per cubic centimetre.

Then 10 cm wide, 45 cm long profiled strips 3 made of 0.5 mm thick aluminium plate are arranged in the trough in such a way that, when assembled, the individual strips 3 form a 10 cm high grid with honeycomb-shaped compartments 2 each with a diameter of 1 em.

The grid is now flooded with 5 1 of petrol and set alight. An initial high flame occurs, which then becomes smaller, and is extinguished after approximately half a minute, as soon as the petrol adhering to the surface of the aluminium has been burnt up. In the floor of the trough about 4.8 1 of petrol has collected, without burning.

The fire prevention trough according to the invention is suitable not only for placing under laboratory and technical apparatus, but also for use under fixed storage containers, and movable containers such as railway tankers and tanker vehicles (attached to a chassis).

WHAT I CLAIM IS:- 1. An incombustible fire prevention trough for collecting inflammable liquids in which the interior of the trough is divided into vertically extending compartments communicating with each other adjacent to the floor of the trough, the ratio of the height of each compartment to the maximum transverse dimension of that compartment being at least 2.

2. A fire prevention trough according to claim 1, in which the compartments form a grid extending across the entire horizontal cross-section of the trough.

3. A fire prevention trough according to claim 1 or claim 2, in which the compartments are formed by a plurality of profiled metal strips resting on the floor of the trough.

4. A fire prevention trough according to claim 1 or claim 2, in which the compartments are formed by partitions extending down almost to the floor of the trough.

5. A fire prevention trough according to any of claims 1 to 4, in which the compartments have constrictions intermediate the upper and lower extremities.

6. A fire prevention trough according to any of claims 1 to 5, in which a layer of non-inflammable porous or fibrous material rests on the floor of the trough.

7. A fire prevention trough according to any of claims 1 to 6, in which the otherwise open top of the trough is obstructed by a covering plate provided with a plurality of funnel-shaped depressions, and in the depressions the covering plate is provided with openings which are connected to compartments arranged beneath them.

8. A fire prevention trough according to claim 7, in which openings are provided around the edges of the covering plate for air to escape outwardly from the interior of the trough.

9. A fire prevention trough according to any preceding claim, in which the ratio of the height of each compartment to the maximum transverse dimension of that compartment is at least 4.

10. The fire prevention trough defined in the foregoing Example.

11. A fire prevention trough substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 of the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of the trough. With this arrangement it must be ensured that the air which is compressed as the liquid flows into the trough can escape from inside the trough. The gap (14) between the edge of the trough and the covering plate (12) is normally sufficient for this. However, small cut-outs (15) in the edge of the covering plate (12) or small holes (16) in those parts of the covering plate which lie highest can be provided for this purpose. To provide protection against explosion, the space between the separate tubular compartments is filled with the above-mentioned porous or fibrous material, which can easily be inserted between the tubes before the covering plate 12 is inserted in the trough 1, if the covering plate is turned upside down. To assist understanding of the fire prevention trough according to the invention which is described above, one embodiment is described in the following. Example On the floor of a 45 x 45 cm square trough 1, 13 cm high, made of 2 mm thick aluminium plate, there is a 45 x 45 cm screen made of V2A steel wire with 64 meshes per cubic centimetre. Then 10 cm wide, 45 cm long profiled strips 3 made of 0.5 mm thick aluminium plate are arranged in the trough in such a way that, when assembled, the individual strips 3 form a 10 cm high grid with honeycomb-shaped compartments 2 each with a diameter of 1 em. The grid is now flooded with 5 1 of petrol and set alight. An initial high flame occurs, which then becomes smaller, and is extinguished after approximately half a minute, as soon as the petrol adhering to the surface of the aluminium has been burnt up. In the floor of the trough about 4.8 1 of petrol has collected, without burning. The fire prevention trough according to the invention is suitable not only for placing under laboratory and technical apparatus, but also for use under fixed storage containers, and movable containers such as railway tankers and tanker vehicles (attached to a chassis). WHAT I CLAIM IS:-

1. An incombustible fire prevention trough for collecting inflammable liquids in which the interior of the trough is divided into vertically extending compartments communicating with each other adjacent to the floor of the trough, the ratio of the height of each compartment to the maximum transverse dimension of that compartment being at least 2.

10. The fire prevention trough defined in the foregoing Example.