A METHOD OF DELIVERING AN AQUEOUS MEDIUM IN CASE OF FIRE HAZARD, AN AQUEOUS MEDIUM NOZZLE FOR REDUCING FIRE HAZARD AND A VEHICLE FOR REDUCING FIRE HAZARD

Abstract

 A method, a nozzle and a firetruck for delivering an aqueous medium such as water in case of fire hazard, wherein
- a jet of gas is provided from a gas nozzle aimed towards a target location,
- the aqueous medium is provided above the jet of gas.
To deliver aqueous medium more effectively to a target location, the aqueous medium is distributed over the jet of gas emanating from the gas nozzle having an elongated aqueous medium outlet opening for aqueous medium as the outlet opening, said elongated aqueous medium outlet opening having a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5, the stream of aqueous medium having a largest thickness divided by an effective width equal to R at said outlet opening.

Description

[0001] The present invention relates to a method of delivering an aqueous medium in case of fire hazard, wherein

• a jet of gas is provided from a gas nozzle aimed towards a target location,
• the aqueous medium is provided as a stream of aqueous medium from an outlet opening of an aqueous medium nozzle above the jet of gas emanating from the gas nozzle.

[0002] Such a method is known in the art. It may involve extinguishing a fire at the target location, such as a forest fire or a hazardous fire at an industrial plant. In addition or alternatively it may involve cooling down an object or area in the vicinity of the fire to protect that and/or to help to prevent the fire from spreading.

[0003] The aqueous medium is typically water, which may contain additives to help for the particular purpose for which the method is used, and may also be foam.

[0004] Typically, the gas nozzle and a water nozzle are mounted on a truck (firetruck). The gas nozzle is, for example, a gas turbine expelling exhaust gas towards the target location. The aqueous medium - for the sake of convenience only reference will be made to water from now on - emanating from the water nozzle is broken up by the jet of gas, resulting in a mist that is deposited at the target location. This has two effects. Firstly, it results in i) extinguishing of the fire, and/or ii) cooling and/or protecting of an object / an area. Secondly, the water droplets of the mist catch noxious compounds or components (such as soot), the spreading of which could constitute a health or environmental hazard.

[0005] The jet of gas does not only break up the water but also helps to transport the water over a longer distance than the water nozzle would do by itself, allowing firefighters to remain at a larger and hence safer distance from the fire.

[0006] The objective of the present invention is to provide a method according to the preamble that allows for a more effective delivery of aqueous medium at the target location.

[0007] To this end, a method according to the preamble is characterized in that the aqueous medium nozzle used has an elongated aqueous medium outlet opening for aqueous medium as the outlet opening, said elongated aqueous medium outlet opening having a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

[0008] Thus the aqueous medium is spread more evenly over the jet of gas from the very beginning, i.e. the stream of aqueous medium will have a largest thickness divided by an effective width equal to R at said outlet opening. This results in a more defined mist helping to achieve the particular goal, such as extinguishing the fire and/or catch noxious compounds and/or components such as soot more efficiently.

[0009] Because the aqueous medium will break up more evenly, the formation of relatively big droplets and of relatively small droplets is reduced. Relatively large droplets drop relatively quickly and have a relatively limited surface area per liter, so they are not as effective at cooling and evaporating (which help to extinguish the fire) and at catching noxious substances. Relatively small droplets may be blown away, in which case they wouldn't reach the target location (such as the fire).

[0010] The aqueous medium outlet opening is in the form of a slit, the slit being transversely oriented with respect to and intersected by the vertical central plane through the gas nozzle and thus with respect to the jet of gas. In contrast, in the method according to the prior art, the water nozzle is a nozzle having a circular slit as the opening. It is known in the prior art to use two of such nozzle openings adjacent to each other above the jet of gas, but to reduce water consumption, the slit width has to be reduced, making the nozzles clog up more easily. This is because the water used to extinguish the fire or to cool may be pumped locally, and may contain debris, plastic, shell fish or shells, pebbles, bottle caps etc.

[0011] The present invention is effective because it can deliver water more accurately (saving water) and reliably (reducing the risk of having to halt the operation to clear a clogged opening for aqueous medium).

[0012] The effective width W is measured in a direction perpendicular to the vertical central plane through the gas nozzle. The thickness T (or height if the direction of flow through the elongated aqueous medium outlet opening is horizontal) is measured in a direction parallel to the vertical central plane through the gas nozzle.

[0013] The term "in case of fire hazard" includes prevention of a fire, for example cooling an overheated chemical reactor.

[0014] R is preferably at least 2.5.

[0015] According to a favourable embodiment, R is at least 4, preferably at least 6, more preferably at least 10.

[0016] Thus the aqueous medium is distributed more evenly over the jet of gas, improving the reliable delivery of the aqueous medium in case of a fire hazard.

[0017] According to a favourable embodiment, the thickness of the stream of aqueous medium leaving the at least one aqueous medium outlet opening tapers towards the outer edges of said stream.

[0018] This helps to break up the aqueous medium more evenly. Without wishing to be bound by any particular theory, it is believed that the jet of gas is less powerful at said edges, thus has less energy to break up aqueous medium that falls through said jet of gas.

[0019] According to a favourable embodiment, the stream of aqueous medium emanates from a single elongated aqueous medium outlet opening, said single elongated aqueous medium outlet opening tapering towards both ends of said elongated aqueous medium outlet opening.

[0020] This helps to avoid that debris in various forms is lodged inside the aqueous medium outlet opening, or makes it easy to clear the aqueous medium outlet opening by moving the stuck object towards the center of the elongated opening with a tool such as a screw driver or knife. Thus the operation to deliver aqueous medium at the target location does not have to be interrupted or has to be interrupted only for a very short time, improving the reliability of delivery of aqueous medium at the target location.

[0021] The elongated opening may be straight or curved.

[0022] According to a favourable embodiment, the stream of aqueous medium emanating from the at least one aqueous medium outlet opening is concave at the side of the gas nozzle.

[0023] Phrased differently, the stream of aqueous medium is curved along the jet of gas, improving the reliability with which the aqueous medium is delivered.

[0024] According to a favourable embodiment, a aqueous medium nozzle is used comprising a chamber, said chamber connecting an inlet opening for aqueous medium and an outlet opening for the stream of aqueous medium, wherein the chamber extends below the lowest point of the outlet opening.

[0025] Aqueous medium will flow with a relatively low speed through the chamber compared to the speed through the aqueous medium inlet opening and the aqueous medium outlet opening, as the chamber has a large cross-sectional area. This allows debris supplied with the aqueous medium via the aqueous medium inlet opening to sink to a relatively low section of the chamber in comparison with the height of the aqueous medium outlet opening, reducing the risk of clogging said aqueous medium outlet opening.

[0026] The present invention also relates to an aqueous medium nozzle for reducing a fire hazard with a stream of aqueous medium, said aqueous medium nozzle having an aqueous medium outlet opening; wherein the elongated aqueous medium outlet opening has a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

[0027] Such a nozzle is suitable for use in the method according to the invention. The effective width W is determined by the distance between the most distant parts of the at least one or more outlet openings. The largest thickness is determined by the largest distance perpendicular to a plane defined by the direction of flow of the stream and the direction defined by said two most distant parts.

[0028] R is preferably at least 2.5.

[0029] According to a favourable embodiment, R is at least 4, preferably at least 6, more preferably at least 10.

[0030] Thus a stream of aqueous medium emanating from the water nozzle can be distributed more evenly over a jet of gas, improving the effective delivery of the aqueous medium to a target location in case of a fire hazard.

[0031] According to a favourable embodiment, the water nozzle comprises a single elongated aqueous medium outlet opening, said single elongated aqueous medium outlet opening tapering towards both ends of said elongated aqueous medium outlet opening.

[0032] This helps to avoid that debris in various forms is lodged inside the aqueous medium outlet opening, or makes it easy to clear the aqueous medium outlet opening by moving the stuck object towards the center of the elongated opening with a tool such as a screw driver or knife. Thus the operation to deliver aqueous medium at the target location does not have to be interrupted or has to be interrupted only for a very short time, improving the reliability of delivery of aqueous medium at the target location.

[0033] The elongated opening may be straight or curved.

[0034] According to a favourable embodiment, the single aqueous medium outlet opening is arcuate.

[0035] This allows for the production of a stream of aqueous medium that is curved along the jet of gas, improving the reliability with which the aqueous medium is delivered.

[0036] According to a favourable embodiment, the aqueous medium nozzle comprises a chamber, said chamber connecting an inlet opening for aqueous medium and an outlet opening for the stream of aqueous medium, wherein the chamber extends below the lowest point of the outlet opening.

[0037] In use, aqueous medium will flow with a relatively low speed through the chamber as it has a large cross-sectional area, allowing debris to sink to a relatively low section of the chamber in comparison with the height of the outlet opening.

[0038] According to a favourable embodiment, a section of the chamber that is relatively low with respect to the aqueous medium outlet opening comprises a valve.

[0039] Such a nozzle is easy to clean, much quicker than existing nozzles that require disassembly to some extent. The valve is for example a ball valve.

[0040] Finally, the present invention relates to an apparatus for reducing a fire hazard, said apparatus comprising

• a gas nozzle mounted on a frame, said gas nozzle being a gas nozzle for providing a jet of gas towards a target location, and
• a aqueous medium nozzle arranged above the gas nozzle, said aqueous medium nozzle having an aqueous medium outlet opening;, wherein the elongated aqueous medium outlet opening has a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

[0041] Such an apparatus, which may for example be positioned near a chemical reactor, allows the aqueous medium to be spread more evenly over the jet of gas from the very beginning, resulting in a more defined mist helping to extinguish the fire and/or catch noxious compounds and/or components such as soot more efficiently.

[0042] R is preferably at least 2.5.

[0043] According to a favourable embodiment, the apparatus is a vehicle.

[0044] Such an apparatus is for example a trailer but preferably a powered verhicle such as a fire truck.

[0045] According to a favourable embodiment, the aqueous medium nozzle is an aqueous medium nozzle according to any of the claims 7 to 12.

[0046] The present invention will now be illustrated with reference to the drawing where

Fig. 1A and Fig. 1B show perspective top view and a rear view of a firetruck respectively; and

Fig. 2A to Fig. 2F show a nozzle of the firetruck of Fig. 1A and Fig. 1B in respectively a perspective top view, a perspective bottom view, a top view, a front view, a side view and a cross-sectional view along a line indicated in Fig. 2E.

Fig. 1A and Fig. 1B show perspective top view and a rear view of a firetruck 100 respectively.

[0047] The firetruck 100 comprises a gasturbine 110 for producing a jet of exhaust gas discharged via gas nozzle 111. The gasturbine 110 comprises an air inlet 112 and is connected to fuel tanks 113 (gas tanks 113).

[0048] To provide a stream of aqueous medium, typically water, to a target location where it is needed, such as a fire, a aqueous medium nozzle 150 comprising an outlet opening 151 is provided. The aqueous medium nozzle 150 is fed via a hose 152 by a pump 153 receiving water from a pond or other source of water via hose 154.

[0049] A firetruck 100 as described above is known in the art.

[0050] In accordance with the present invention, the water is distributed over the jet of gas such that the stream of water has at the aqueous medium outlet opening 151 a largest thickness of the stream T and an effective width W wherein ratio R equals W/T, which ratio R in the present embodiment is equal to 19 (see Fig. 2D).

[0051] Fig. 2A to Fig. 2F show a nozzle of the firetruck of Fig. 1A and Fig. 1B in respectively a perspective top view, a perspective bottom view, a top view, a front view, a side view and a cross-sectional view along the line indicated in Fig. 2E.

[0052] The water nozzle 150 comprises two water inlet openings 251 that are in fluid connection with the outlet opening 151 via a chamber 255. Two hoses 152 will be connected to said water inlet openings 251. Water from the pump 153 is pumped with a pressure of 10 Bar through the water outlet opening 151, above the jet of gas, which will break up the stream of water leaving the nozzle 150.

[0053] Because the chamber 255 has a relatively large cross-section, the flow rate of water is relatively low, allowing debris such as pebbles, muscles etc. to sink. This debris is collected in the lower portions of the chamber 255 where removable caps 256 are provided allowing cleaning at a later stage.

[0054] The sickle-shaped outlet opening 151 allows for easy cleaning if debris get stuck, because it can be moved towards a wider section of the outlet opening 151, e.g. with a screw driver.

[0055] In the embodiment discussed here, the outlet opening 151 is provided on a removable plate, so as to change the outlet opening 151 if so desired.

Claims

1. A method of delivering an aqueous medium in case of fire hazard, wherein

- a jet of gas is provided from a gas nozzle (111) aimed towards a target location,

- the aqueous medium is provided as a stream of aqueous medium from an outlet opening (151) of an aqueous medium nozzle (150) above the jet of gas emanating from the gas nozzle (111);

characterized in that the aqueous medium nozzle (150) used has an elongated aqueous medium outlet opening (151) for aqueous medium as the outlet opening (151), said elongated aqueous medium outlet opening (151) having a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

2. The method according to claim 1, wherein R is at least 4, preferably at least 6, more preferably at least 10.

3. The method according to claim 1 or 2, wherein the thickness of the stream of aqueous medium leaving the at least one aqueous medium outlet opening (151) tapers towards the outer edges of said stream.

4. The method according to claim 3, wherein the stream of aqueous medium emanates from a single elongated aqueous medium outlet opening (151), said single elongated aqueous medium outlet opening (151) tapering towards both ends of said elongated aqueous medium outlet opening (151).

5. The method according to any of the preceding claims, wherein the stream of aqueous medium emanating from the at least one aqueous medium outlet opening (151) is concave at the side of the gas nozzle (111).

6. The method according to any of the preceding claims, wherein a aqueous medium nozzle (150) is used comprising a chamber (255), said chamber (255) connecting an inlet opening (151) for aqueous medium and an outlet opening (151) for the stream of aqueous medium, wherein the chamber (255) extends below the lowest point of the outlet opening (151).

7. An aqueous medium nozzle (150) for reducing a fire hazard with a stream of aqueous medium, said aqueous medium nozzle (150) having an aqueous medium outlet opening (150);
wherein the elongated aqueous medium outlet opening (151) has a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

8. The aqueous medium nozzle (150) according to claim 7, wherein R is at least 4, preferably at least 6, more preferably at least 10.

9. The aqueous medium nozzle (150) according to any of the claims 7 or 8, wherein the water nozzle (150) comprises a single elongated aqueous medium outlet opening (151), said single elongated aqueous medium outlet opening (151) tapering towards both ends of said elongated aqueous medium outlet opening (151).

10. The aqueous medium nozzle (150) according to any of the claims 7 to 9, wherein the single aqueous medium outlet opening (151) is arcuate.

11. The aqueous medium nozzle (150) according to any of the claims 7 to 10, wherein the aqueous medium nozzle (150) comprises a chamber (255), said chamber (255) connecting an inlet opening (151) for aqueous medium and an outlet opening (151) for the stream of aqueous medium, wherein the chamber (255) extends below the lowest point of the outlet opening (151).

12. The aqueous medium nozzle (150) according to any of the claims 7 to 11, wherein a section of the chamber (255) that is relatively low with respect to the aqueous medium outlet opening (151) comprises a valve.

13. An apparatus for reducing a fire hazard, said apparatus comprising

- a gas nozzle (111) mounted on a frame, said gas nozzle (111) being a gas nozzle (111) for providing a jet of gas towards a target location, and

- a aqueous medium nozzle (150) arranged above the gas nozzle (111), said aqueous medium nozzle (150) having an aqueous medium outlet opening (150); characterized in that the elongated aqueous medium outlet opening (151) has a largest thickness T and an effective width W wherein ratio R equals W/T and is at least 1.5.

14. The apparatus according to claim 13, wherein the apparatus is a vehicle.

15. The apparatus according to any of the claims 13 or 14, wherein the aqueous medium nozzle (150) is an aqueous medium nozzle according to any of the claims 7 to 12.

Drawing