Flood protection device

Abstract

A flood prevention device, for example an automatically closing air brick, is provided. The flood prevention device can comprise a body having an outer side and an inner side with an opening and a channel formed through the body, and a valve comprising a flap and a buoyancy structure, wherein the flap is pivotally mounted to the body and allows gas to flow through the channel in an open position and seals the channel in a closed position.

Claims

1. A flood protection device for a vent or an air-brick comprising: a body having an outer side having at least one opening and an inner side having at least one opening; at least one channel formed through the body between the outer side and the at least one opening of the inner side; a valve comprising a flap and a buoyancy structure, the flap being pivotally mounted to the body and having an outer side and an inner side, the flap having an open position in which gas is permitted to flow through the at least one channel and a closed position in which the flap is pivoted from the open position to seal the at least one channel; the buoyancy structure being formed on the outer side of the flap such that the valve is buoyant on water, wherein a centre of buoyancy of the valve is always located outwards of the flap and the buoyancy structure will act to move the flap from the open position to the closed position as a rising liquid level rises on the outer side of the flap to a horizontal centre line of the flap; and, wherein the buoyancy structure comprises an air chamber formed on the outer side of the flap and having an open side, the open side of the air chamber being a lowermost side of the air chamber when the flap is in the open position.

2. A device according to claim 1, wherein the air chamber is substantially cuboid.

3. A device according to claim 1 wherein the air chamber is a triangular prism with a base face formed perpendicular to the outer side of the flap and the outer side of the flap forming a longitudinal face of the triangular prism.

4. A device according to claim 3, wherein the air chamber is open at a lowermost of longitudinal faces of the triangular prism.

5. A flood protection device for a vent or an air-brick comprising: a body having an outer side having at least one opening and an inner side having at least one opening of the inner side; at least one channel formed through the body between the outer side and the at least one opening of the inner side; a valve comprising a flap and a buoyancy structure, the flap being pivotally mounted to the body and having an outer side and an inner side, the flap having an open position in which gas is permitted to flow through the at least one channel and a closed position in which the flap is pivoted from the open position to seal the at least one channel; the buoyancy structure being formed on the outer side of the flap such that the valve is buoyant on water, wherein a centre of buoyancy of the valve is always located outwards of the flap and below an uppermost part of the flap and the buoyancy structure will act to move the flap from the open position to the closed position as a rising liquid level rises on the outer side of the flap; and, wherein a lowermost part of the at least one opening of the inner side is formed at a height greater than a minimum height of liquid level at which the flap will be moved to the closed position.

6. A device according to claim 5, wherein the buoyancy structure comprises a sealed air chamber formed on the outer side of the flap.

7. A device according to claim 6, wherein the sealed air chamber is substantially cuboid.

8. A device according to claim 6 wherein the sealed air chamber is a triangular prism with base faces formed perpendicular to the outer side of the flap and the outer side of the flap forming a longitudinal face of the prism.

9. A device according to claim 6, wherein the flap is pivotally mounted to the body at a position below a lower end of the sealed air chamber.

10. A device according to claim 5, wherein the buoyancy structure comprises a float formed of buoyant material mounted to the outer side of the flap.

11. A device according to claim 5, wherein the flap is substantially planar.

12. A device according to claim 5, further comprising a gasket formed on the inner side of the flap.

13. A device according to claim 5, wherein the flap is pivotally mounted to the body at a lower edge of the flap.

14. A device according to claim 5, wherein the flap is substantially vertical in the closed position.

15. A device according to claim 5, wherein the buoyancy structure is formed to support the flap in the open position.

16. A device according to claim 5, wherein the flap is in the open position the buoyancy structure rests upon a supporting structure.

17. A device according to claim 5, wherein the open position is less than 20 from the closed position.

18. An air brick comprising the flood protection device according to claim 5.

Description

DRAWINGS

(1) FIG. 1 is a schematic side view of a first embodiment of the present invention with the valve in the open position;

(2) FIG. 2 is a schematic side view of the first embodiment of the present invention with the valve in the closed position;

(3) FIG. 3 is a schematic isometric view of the first embodiment of the present invention with the valve in the open position;

(4) FIG. 4 is a schematic isometric view of the first embodiment of the present invention with the valve in the closed position;

(5) FIG. 5 is a schematic side view of a second embodiment of the present invention with the valve in the open position; and

(6) FIG. 6 is a schematic side view of a second embodiment of the present invention with the valve in the closed position.

(7) A first embodiment of an air brick 1 according to the first and second aspects of the present invention is illustrated schematically in FIGS. 1 to 4. The air brick 1 comprises a body 2 having an outer side 3 and an inner side 4. For clarity, the body 2 is shown as being transparent in FIGS. 3 and 4, although generally it will not be formed of a transparent material. The body 2 is formed of a plastic material. The outer side 3 is open and the inner side 4 has an opening 5 formed therethrough. A valve 6 is pivotally mounted within the body 2. The valve 6 comprises a planar rectangular flap 7 having an upper edge 8 and a lower edge 9 and a buoyancy structure 10 attached to an outer side of the flap 7. The flap 7 is pivotally mounted to the body 2 at its lower edge 9 such that the lower edge is positioned adjacent the inner side 4 of the body 2. The flap 7 is formed of a resilient and water-resistant polymeric material. The buoyancy structure 10 is mounted on an outer side of the flap 7. The buoyancy structure 10 is an air chamber that is a triangular prism and is open at a lower side. Other than the opening at the lower side the buoyancy structure 10 is airtight. The buoyancy structure 10 and the flap 7 are both formed of a plastic material. The flap 7 has a rubber gasket 11 mounted on an inner side.

(8) The flap 7 can be pivoted about its lower edge 9 between an open position and a closed position. The open position is shown in FIGS. 1 and 3 and is approximately 20 from the closed position, which is shown in FIGS. 2 and 4. In the open position the flap 7 is supported by the buoyancy structure 10 resting on a lower portion of the body 2. In the closed position the flap 7 is substantially vertical and seals the opening 5 of the body 2 by means of the gasket 11 pressing against the body 2 around the opening 5. The opening 5 is formed such that a lowermost part of the opening 5 is at a height greater than a minimum height of liquid level at which the flap 7 will be moved to the closed position.

(9) In FIGS. 1 and 3 the flap 7 is shown in the open position. In this position air is free to flow through the air brick 1. In particular, air can pass over the upper edge 8 of the flap 7, through the opening 5, and through the air brick 1. In FIGS. 2 and 4 the flap 7 is shown in the closed position. In this position the air brick 1 is sealed as the flap 7 is positioned directly in front of the opening 5 of the inner side 4 and the gasket 11 is acting to seal the flap 7 against the inner side 4 of the body 2 around the opening 5.

(10) The air brick 1 operates in the following manner. In normal conditions the flap 7 is in the open position as shown in FIGS. 1 and 3. Air is free to pass through the air brick 1 and the building in which the air brick is located is ventilated. In all non-flood conditions the air brick 1 will remain in this position.

(11) In a flood situation external water levels will rise. When the external water level reaches the bottom of the air brick 1 it will enter the body 2 from the outer side 3. The water will not be able to pass through the air brick 1 as the water level will be below the height of the opening 5.

(12) As the water level rises it will enter under the buoyancy structure 10. A volume of air 12 is contained within the buoyancy structure 10. As the buoyancy structure 10 is only open at a lower side and is otherwise airtight the volume of air 12 within the buoyancy structure will be trapped by a rising water level providing buoyancy to the flap. The buoyancy structure 10 is formed such that the volume of air 12 trapped therein by a rising water level makes the flap 7 buoyant on water and the centre of buoyancy of the valve 6 is always located outwards of the flap 7 and below a the lowermost part of the opening 5. Therefore, as the water level rises the buoyancy of the volume of air 12 acts to rotate the flap 7 from the open position to the closed position, thereby sealing the air brick 1. Importantly, the air brick will be completely sealed against fluid (liquid and gas) ingress long before the water level rises to the top edge of the flap 7 and before the water level reaches the height of the opening 5. Therefore, at no point can water pass through the opening 5. When the water level recedes the flap 7 will move back from the closed position to the open position under its own weight and the air brick 1 will allow air flow again.

(13) Having the flap 7 of the valve 6 in the closed position and sealing the air brick 1 long before a rising water level reaches the top edge of the flap 7 and before the water level reaches the height of the opening 5 is advantageous as it ensures that no water will pass through the air brick 1. This is particularly advantageous if the rising water is turbulent and not calm as in turbulent conditions if the flap 7 is not in the closed position when the water level is at or near the top edge of the flap 7 water may splash over the top of the flap and through the air brick 1.

(14) If, after the flap 7 is in the closed position, the water level continues to rise the volume of air 12 within the buoyancy structure will be compressed by the increased pressure of the water. As the volume of air 12 is compressed this will decrease the buoyancy of the valve 6. However, the increased pressure of the volume of air 12 will exert a positive pressure on the flap 7 thereby acting to retain it in the closed position in accordance with Boyle's Law.

(15) A schematic of an alternative embodiment of an air brick 1 according to the first (but not the second) aspect of the present invention is shown in FIGS. 5 and 6. The structure of the alternative embodiment of the invention is substantially the same as the embodiment of FIGS. 1 to 4 with the exception of the structure of the buoyancy structure 10 and operates in substantially the same manner. Therefore, the same reference numerals have been used to indicate the equivalent structures of the alternative embodiment.

(16) The alternative embodiment differs in the structure of the buoyancy structure 10. The buoyancy structure 10 comprises a support arm 20 with a float member 21 mounted on an outer end of the support arm. The support arm 20 extends outwards from an outer side of the flap 7 in a direction normal to the flap 7. The support arm 20 supports the flap 7 in the open position, as shown in FIG. 5. In particular, the valve 6 rests against a lower portion of the body 2 by means of the support arm 20. The support arm 20 extends from a part of the flap 7 below a horizontal centre line of the flap 7.

(17) The float member 21 mounted on an outer end of the support arm 20 is formed of a material that is buoyant on water and is formed and positioned such that a rising water level makes the flap 7 buoyant on water, the centre of buoyancy of the valve 6 always being located outwards of the flap 7 and below a horizontal centre line of the flap 7. Therefore, as the water level rises the buoyancy of the float member 21 acts to rotate the flap 7 from the open position to the closed position, thereby sealing the air brick 1. Importantly, the air brick 1 will be completely sealed against fluid ingress long before the water level rises to the top edge of the flap 7 and before the water level reaches the height of the opening 5. When the water level recedes the flap 7 will move back from the closed position to the open position under its own weight and the air brick 1 will allow air flow again.