GB2538995A

GB2538995A - Nozzle

Info

Publication number: GB2538995A
Application number: GB1509533.4A
Authority: GB
Inventors: Barnes Richard; Taylor Tony; Taylor Jordan
Original assignee: SPA Automotive Ltd
Current assignee: SPA Automotive Ltd
Priority date: 2015-06-02
Filing date: 2015-06-02
Publication date: 2016-12-07
Also published as: GB201509533D0

Abstract

A nozzle 1 for discharging a pressurised medium, e.g. a fire extinguisher, comprises a body 2 with an inlet 20 and outlet 21 and an axis (A) passing through the centre of both, a first baffle 3 having a bore 31 substantially aligned with the axis (A), a connecting arm 4 connecting the first baffle and the body, with a plane (P) defined between the body and first baffle and orthogonal to the axis (A), the outlet having a first diameter (d1) and the bore having a second diameter 31 smaller than the first diameter (d1) such that, in use, a pressurised medium introduced into the inlet 20 flows out of the outlet 21 in a flow path in the direction of the axis (A), with a first portion of the flow passing through the bore 31 and continuing in an axial direction to form an axial flow pattern, and with a second portion of the flow being deflected by the first baffle 3 forming a radially dispersed flow pattern which diverges fore and aft of the plane (P) which extends uninterruptedly around the axis (A) for over 180 degrees.

Description

NOZZLE

This invention relates to a nozzle and more particularly to a nozzle for discharging and/or dispensing a fluid or other medium from a source. More specifically, although not exclusively, this invention relates to a discharge and/or dispensing nozzle for use in delivering a fire extinguishing medium from a pressurised vessel.

This invention is particularly, although not exclusively, concerned with such nozzles for use with emergency equipment, for example fire extinguishing equipment or devices, o which may be used or fitted in vehicles such as racing or competition cars, speedboats and aircraft or in offices, factories and houses.

It is known to fit a fire extinguishing device in a vehicle that includes a pressurised vessel or tank containing an extinguishing medium and a distribution head connected to pipes that distribute and deliver the extinguishing medium to likely fire sites, for example the engine or cockpit. The distribution head generally includes a valve for selectively releasing the extinguishing medium from the vessel to the pipes.

GB2305120 discloses one such device in which the orientation of the pipe union is angularly movable relative to the tank. This arrangement simplifies, by virtue of its adjustability, the fitting of the device in a vehicle or the modification of the device after fitting in the vehicle. Delivery of the extinguishing medium to the likely fire sites is achieved by virtue of a series of nozzles connected to the end of the pipes. Whilst this arrangement facilitates fitting and adaptation of the fire extinguishing system, it is always beneficial to simplify the installation further, to reduce the time and effort required for fitting.

It is therefore a first non-exclusive object of the invention to provide a simpler and/or more effective means of delivering a fluid or other medium from a pressure vessel to a particular area. It is a further, more general non-exclusive object of the invention to provide an improved nozzle assembly for controllably releasing or delivering a fluid or other medium from a pressurised vessel.

Accordingly, a first aspect of the invention provides a nozzle, e.g. for discharging and/or dispensing a pressurised medium from a source, the nozzle comprising a body with an inlet and an outlet and an axis passing through the centre of both, a first baffle or deflector having a bore through its thickness that is substantially aligned with the axis and a connecting arm connecting the first baffle or deflector and the body, with a plane defined between the body and the first baffle or deflector and orthogonal to the axis, the outlet having a first diameter and the bore having a second diameter smaller than the first diameter such that, in use, a pressurised medium introduced into the inlet flows out of the outlet in a flow path in the direction of the axis, with a first portion of the flow passing through the bore and continuing in a substantially axial direction to form a substantially axial flow pattern, and with a second portion of the flow being deflected by the first baffle or deflector so as to form a radially dispersed flow pattern which diverges fore and aft of o the plane and extends uninterruptedly around the axis for over 180 degrees.

The connecting arm provides a restriction, e.g. a single restriction, to flow in the radial direction, such that the radially dispersed flow pattern subtends a continuous angle when viewed from the axis.

The nozzle may further comprise a cowl or canopy connected to the connecting arm, for example wherein the cowl or canopy is configured to restrict or further restrict the flow in a radial direction relative to the axis. The cowl or canopy is preferably integral with the connecting arm.

Thus, the invention provides a simple and effective means of dispersing the pressurised medium, particularly where the nozzle is to be installed adjacent a surface, e.g. wherein the nozzle may be mounted with cowl or canopy adjacent the surface so as to disperse the medium away from the surface.

The cowl or canopy preferably subtends an angle of 120 degrees or less, e.g. 110, 100, 90 degrees or less, when viewed from the axis, for example such that the radially dispersed flow pattern subtends a continuous angle of about 240 degrees or more, e.g. 250, 260, 270 degrees or more, when viewed from the axis. More preferably, the cowl or connecting arm subtends an angle of less than 60 degrees when viewed from the axis, for example such that the radially dispersed flow pattern subtends a continuous angle of about at least 300 degrees when viewed from the axis. In some embodiments, the cowl or connecting arm subtends an angle of about 45 degrees or less, e.g. 30 degrees or less, when viewed from the axis, for example such that the radially dispersed flow pattern subtends a continuous angle of about 315 degrees or more, e.g. 330 degrees or more, when viewed from the axis.

The ratio of the first diameter to the second diameter may be between 10:1 and 1.5:1, for example between 4:1 and 2:1, e.g. between 3.5:1 and 2.5:1, say about 3:1, but is most preferably 11:4.

The body may comprise a bore or passage or passageway that may extend between the inlet and the outlet. The inlet and/or the outlet and/or the bore or passage or passageway io may each or all have a diameter corresponding to the first diameter. Preferably, the second diameter is between 25% and 50% of the first diameter or the first diameter is between 2 and 4 times the second diameter. More preferably, the second diameter is between 30% and 40% of the first diameter or the first diameter is between 2.5 and 3.5 times the second diameter. Most preferably, the second diameter is between 33% and 40% of the first diameter or the first diameter is between 2.5 and 3 times the second diameter. By way of example, the inlet and/or the outlet and/or the bore or passage or passageway of the body may be approximately 11mm with the bore in the baffle or deflector being approximately 4mm.

The first baffle or deflector may comprise a deflection portion which may comprise the bore. The deflection portion may comprise a major, e.g. deflection, surface, which may be facing, e.g. oriented towards, the plane. The major surface may be substantially, e.g. entirely, flat and parallel to the plane. Additionally or alternatively, the deflection plane may comprise two parallel, e.g. substantially parallel, edges or sides or surfaces separated by a width, e.g. a constant width along the height of the edges or sides or surfaces. The width of the deflection portion may be configured to be substantially, e.g. entirely, similar to the diameter of the outlet. Alternatively, the width of the deflection portion may be configured to be less than, for example significantly or slightly less than, the diameter of the outlet. Alternatively, the width of the deflection portion may be configured to be greater than, for example significantly or slightly greater than, the diameter of the outlet.

Additionally or alternatively, the body may further comprise a second baffle or deflector, which may be located, e.g. connected or attached or integrally formed thereon, at the outlet end of the body. The second baffle or deflector may include an aperture, e.g. through its thickness. The aperture may be configured to have a similar, e.g. the same or lesser or greater, diameter to the outlet of the body. The aperture may be substantially, e.g. entirely, aligned with the outlet of the body, for example such that the axis passes through the centre of the aperture.

The cowl or canopy may comprise a major surface, for example where the major surface may be disposed adjacent, e.g. abutting or marginally impinging over, the outlet. The major surface may be substantially flat, e.g. planar or entirely flat. The major surface may be parallel, for example substantially parallel, to the axis. Additionally or alternatively, the to major surface may be orthogonal to, for example substantially orthogonal to, one or both sides or surfaces or edges of the deflection portion.

Additionally or alternatively, the connecting arm may define a distance, for example a distance along the axis, between the body and the first baffle or deflector. The distance between the body and the first baffle or deflector may be between about 4mm and 200mm, say between about 6mm and 150mm, for example between about 8mm and 100mm. Preferably the distance between the body and the first baffle or deflector is between about 10mm and 50mm, and most preferably the distance is about 20mm.

Additionally or alternatively, the first baffle or deflector and/or the cowl or canopy may be configured such that divergence of radial flow fore and aft of the plane may subtend an angle of less than 140 degrees, for example less than 120 degrees, e.g. less than 100 degrees, say less than 80 degrees, relative to the plane. For the avoidance of doubt, fore of the plane is defined herein as being between the plane and the first baffle or deflector, whilst aft of the plane is defined herein as being between the plane and the body.

Another aspect of the invention provides a nozzle, e.g. for discharging and/or dispensing a pressurised medium from a source, the nozzle comprising a body with an inlet and an outlet, a baffle having a bore through its thickness that is substantially aligned with the outlet and a connecting arm connecting the baffle and the body, the outlet having a first diameter and the bore having a second diameter, wherein the first diameter is between 1.5 and 10 times the second diameter, such that, in use, a pressurised medium introduced into the inlet flows out of the outlet with a portion thereof being deflected by the baffle so as to disperse radially with respect to the flow direction.

A further aspect of the invention provides a fire extinguishing apparatus comprising a source of pressurized medium, a connection means and a nozzle according to any preceding description. The source of medium may be fluidly connected by the connection means to the nozzle.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention.

Another aspect of the invention provides a computer program element comprising and/or to describing and/or defining a three-dimensional design for use with a three-dimensional printing means or printer or additive manufacturing means or device, the three-dimensional design comprising an embodiment of the nozzle described above.

A further aspect of the invention provides the computer program element embodied on a computer readable medium. A yet further aspect of the invention provides a computer readable medium having the aforementioned program stored thereon. A yet further aspect of the invention provides a control means or control system or controller comprising the aforementioned computer program element or computer readable medium.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may", "and/or", "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side view of a deflector nozzle according to an embodiment of the invention; Figure 2 is an end view of the deflector nozzle of Figure 1; Figure 3 is a section view of the deflector nozzle of Figures 1 and 2 through line B-B in Figure 2; Figure 4 is a perspective view of the deflector nozzle of Figure 1; lo Figure 5 is an alternative perspective view of the deflector nozzle of Figure 1; Figure 6 is a perspective view of the deflector nozzle of Figure 1 in use; Figure 7 is an end view of the deflector nozzle of Figure 1 in use; and Figure 8 is a plan view of the deflector nozzle of Figure 1 in use.

Referring now to Figure 1 to 5, there is shown a deflector nozzle 1 according to a first embodiment of the invention. The deflector nozzle 1 includes a connector 2 and a primary deflector plate 3 connected by an canopy 4 having an integral arm 4a, all of which are formed from stainless steel. In alternative embodiments the components of the deflector nozzle 1 may be formed from any suitable material, for example a metal or plastic material. Additionally or alternatively, the components may not all be formed from the same materials. In alternative embodiments the canopy 4 may be separate from, but attached to, the arm 4a.

The connector 2 is a tube with an inlet and an outlet end 20, 21. An outer surface 23 of the connector 2 is provided with a thread 24 for threadable engagement with a sealing nut (not shown). A radial recess 25 may be provided in the outer surface 23 of the connector 2, adjacent to the outlet end 21 thereof, where said radial recess 25 is suitable for receiving an 0-ring seal (not shown). An inner surface 22 of the connector 2 is also threaded (not shown), which is suitable for attachment to a fitting (not shown) to which a fluid delivery tube (not shown) may be fluidly connected. A longitudinal axis A is defined as passing through the centre of the inlet and outlet ends 20, 21.

The inner surface 22 of the connector 2 defines a passageway 26 connecting the inlet and outlet ends 20, 21. The passageway 26 is of substantially constant internal diameter d1 of 11mm. Alternatively, the passageway 26 may have any internal diameter d1 suitable for supplying fluid at a pre-determined volumetric flow rate, and/or suitable for attachment to a standard fitting, where the internal diameter d1 may be between about 2mm to about 60mm, say about 3mm to about 50mm, for example about 4mm to about 40mm, e.g. about 5mm to about 30mm, preferably about 6mm to about 20mm, but most preferably about 11mm.

The canopy 4 is a bridging section of constant cross-section, defined in end by a segment of a circle, with a substantially flat first major surface 40 disposed adjacent to, and aligned with, the longitudinal axis A. A curved second major surface 41 abuts the first major surface 40 on both of its major edges. A first end 42 of the canopy 4 extends from the outlet end 21 of the connector 2, whereby the first major surface 40 of the canopy 4 impinges by a minor amount over the passageway 26, thereby defining a small step 43. The primary deflector plate 3 depends from the first major surface 40 of the canopy 4, adjacent a second end 44 thereof. In alternative embodiments the canopy 4 may be a separate component and may affixed by any suitable means to the connector 2 and the primary deflector plate 3.

The primary deflector plate 3 is a thin strip including a blocking region 30 with an aperture 31 through its thickness. The aperture 31 is aligned with the longitudinal axis A and has an internal diameter d2 of 4mm. The internal diameter d2 of the aperture 31 of the primary deflector plate 3 is configured to be less than the diameter d1 of the passageway 26 of the connector 2. In alternative embodiments the ratio of the diameter d1 of the passageway 26 to the diameter d2 of the central aperture 31 may be between 10:1 and 1.5:1, for example between 4:1 and 2:1, e.g. between 3.5:1 and 2.5:1, but is most preferably 11:4. The primary deflector plate 3 has a thickness of 2.3mm. In alternative embodiments the thickness may be of any suitable thickness, say from about 0.4 to about 5mm, for example between about 1 and about 3mm.

The blocking region 30 has a substantially flat major surface 32 which is configured to be facing, and parallel to, the plane P. The blocking region 30 has a shape which is substantially rectangular in end with a two parallel edges 33 defining a height h and separated by a constant width w.

The width w of the blocking region 30 is configured to be the same or greater width than the internal diameter d1 of the passageway 26. In this embodiment, the width w is 11mm which is substantially similar to the internal diameter cl, of the passageway 26. Alternatively, the width w of the blocking region 30 may be configured to be any suitable width w, so that the blocking region 30 has a width w greater than, or less than, the internal diameter d1 of the passageway 26. Additionally or alternatively, the width w of the blocking region 30 need not be constant along its height h and may increase or reduce at one or more locations thereon.

to The major surface of the canopy 4 defines a length I between the outlet end 21 of the connector 2 and the first major surface 32 of the blocking region 30. The length I is 20mm. In alternative embodiments the length I may be between about 4mm and about 200mm, e.g. between about 6mm and about 150mm, say between about 8mm and 100mm, for example between about 10mm and 50mm.

The connector 2 includes a secondary deflector plate 5, located at the outlet end 21 of the connector 2. The secondary deflector plate 5 comprises a continuous radial projection 51 from the outer surface 23 of the connector 2. The radial projection 51 has a thickness in the direction of the axis A which is similar to the thickness of the primary deflector plate 3.

An outer surface of the radial projection 51 defines an external diameter of the secondary deflector plate 5. In alternative embodiments the secondary deflector plate 5 may have a thickness which is different to the thickness of the primary deflector plate 3 and may be, for example, between about 0.4 to about 5mm, e.g. between about 1 and about 3mm.

In alternative embodiments the secondary deflector plate 5 may be a separate component and may be a thin disc with an external diameter and with an aperture through its thickness at its centre, where the aperture may have an internal diameter configured to be substantially similar to the internal diameter d1 of the passageway 26 with which it is substantially aligned.

The second end 44 of the canopy 4 includes two steps 45, 46 located adjacent the first major surface 41, where the steps 45, 46 are of equal size and define angular segments a. In use, a portion of the radial flow of a fluid flowing through the nozzle will be directed according to the angle of the angular segments a.

A plane P is defined intermediate the connector 2 and the primary deflector plate 3, orthogonal to the longitudinal axis A. The plane P is orthogonal to the longitudinal axis A. In use, a fitting (not shown) is threadably attached to the inner surface 22 of the connector 2, with a sealing nut including an 0-ring seal (not shown) fitted to the thread 24 on the outer surface 23 of the connector 2, thereby providing a sealed fluid connection to the deflector nozzle 1. A fluid delivery tube (not shown) is connected at one end to the fitting and at its other end to a pressurised source of fluid (not shown). Suitable fluids may include water, potassium acetate, aqueous film-forming foam, hydrofluorocarbons (HFCs), etc. Referring now to Figure 6, the deflector nozzle 1 is shown in use where pressurised fluid from a source (not shown) is delivered to the deflector nozzle 1 via the fluid supply apparatus FS, which is fluidly connected thereto. The fluid flows in a direction substantially along the longitudinal axis A, through the inlet end 20 of the connector 2, along the passageway 26 and out through the outlet end 21 of the connector 2 (see Figure 3). The majority of the fluid flows substantially longitudinally, adjacent to the canopy 4, towards the primary deflector plate 3. The flow of fluid is separated at the primary deflector plate 3 into a deflected flow DF which deflects from the primary deflector plate and into a longitudinal flow LF which passes through the aperture 31 (see Figure 3) of the primary deflector plate 3.

The skilled person will appreciate that fluid flowing from the outlet end 21 of the connector 2 towards the primary deflector plate 3 will not retain a constant cross-section but will gradually diverge. The length I of the canopy 4, in combination with the pressure/flow rate at which the fluid is supplied, effects the divergence of the fluid flow after leaving the outlet end 21 of the connector 2 and prior to reaching the primary deflector plate 3. This divergence, in combination with the ratio of the diameter d2 of the central aperture 31 compared to the diameter d1 of the passageway 26 of connector 2, determines the proportion of fluid which impacts the primary deflector plate 3, hence becoming deflected flow DF, to the proportion of fluid which passes through the central aperture 31 and hence remains longitudinal flow LF.

Referring now to Figure 7, there is shown an end view of the deflector nozzle 1 during use, where the dotted lines 6a, 6b denote the nominal outer limits of radial fluid flow from the deflector nozzle 1 along the majority of the length I of the canopy 4. As has been described above, a portion of the fluid impacting the primary deflector plate 3 will be deflected radially with respect to the longitudinal axis A. All things being equal, the fluid will flow evenly in all radial directions. However, the canopy 4 restricts the radial flow of the fluid around the longitudinal axis A to an angle p of less than about 300 degrees. In alternative embodiments, the canopy 4 may be configured and/or positioned to restrict the radial flow of the fluid relative to the longitudinal axis A to any suitable angle p, for example an angle p of less than about 330 degrees, say less than about 300 degrees, e.g. less than about 270 degrees.

Adjacent to the deflector plate 3, the nominal outer limits of a portion of the radial fluid flow are denoted by dotted lines 6c, 6d, as defined by the steps 45, 46. This portion of the radial fluid flow therefore is restricted to a radial flow of fluid around the longitudinal axis A of an angle greater than p but less than 360 degrees.

Referring now to Figure 8, there is shown a plan view of a deflector nozzle 1 during use, showing the range of coverage of deflected flow DF, upstream and downstream of the plane P, where downstream is defined as flow occurring between the plane P and the connector 2, and upstream is defined as flow occurring between the plane P and the primary deflector plate 3. The range of coverage defines a pitch angle y. The deflector nozzle 1 is symmetrical in plan and therefore flow from only one side thereof need be described.

The magnitude of the pitch angle y is dependent on a combination of the diameter of the secondary deflector plate 5, the width w of the blocking region 30 of the primary deflector plate 3 and the length I of the major surface 40 of the canopy 4. A portion of the fluid deflected from the primary deflector plate 3 will also be deflected by the secondary deflector plate 5, which thereby restricts said deflected flow DF away from the direction of initial flow. The divergence of flow upstream and downstream of the plane, the pitch angle y, may be any suitable angle and may be, from one side of the nozzle, less than 140 degrees, for example less than 120 degrees, e.g. less than 100 degrees, say less than 80 degrees.

During operation of a fire extinguishing device it is essential that fluid flow be directed towards areas of the surrounding environment most likely to require fire extinguishing and/or suppression. Certain locations or areas of the surrounding environment may be determined to be less essential and therefore it is desirable to restrict flow into these locations or areas. For example, in a vehicle it may be desirable to concentrate fluid flow onto an engine and not onto a bonnet adjacent the engine. Additionally or alternatively, it may be desirable to restrict fluid flow from impinging on the source of that fluid flow.

Advantageously, a deflector nozzle 1 according to the invention may be fluidly connected to a fire extinguishing device with the deflector nozzle 1 arranged in such a way that the primary deflector plate 3, canopy 4 and secondary deflector plate 5 restrict fluid from io flowing towards specific areas of the surrounding environment, thereby concentrating fluid flow on essential areas thereof.

Testing The applicant tested a deflector nozzle 1 according to the invention.

A rig was set up as shown in Figure 6, comprising a single deflector nozzle 1 intruding into a testing container 11 having fire locations which were occluded from the deflector nozzle 1 by the use of covers and other barriers. Fires were begun at the fire locations, utilizing petrol, plastics and cotton materials, and were allowed to burn for a period of five minutes. A pressurized fluid extinguishant was supplied through the deflector nozzle 1, into the testing container 11.

Result All of the fires were extinguished by the single deflector nozzle 1 in every test conducted. Earlier tests using a conventional nozzle designs required multiple nozzles in order to achieve the same effect.

The applicant has surprisingly found that only one deflector nozzle 1 according to the invention is necessary to fully extinguish a fire, even with occluded fire locations. Advantageously, using a deflector nozzle 1 according to the invention, the number of nozzles may therefore be reduced whilst maintaining the same ability to extinguish fires.

Without wishing to be bound by any theory it is believed that fluid flowing through the deflector nozzle further deflects from surfaces within the fire region and hence becomes incident on the fire from yet further directions, providing an enhanced extinguishing effect.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, although the embodiment of the deflector nozzle described above includes a secondary deflector plate it is envisaged that in alternative embodiments the deflector nozzle may not include said feature. Further, the component parts of the deflector nozzle may be formed integrally, for example the connector, primary and/or secondary deflector plate and the connector may be formed integrally from a single block of material. Alternatively, one or more of the component parts, for example the primary deflector plate, may be formed separately.

Additionally or alternatively, the deflector nozzle may include one or more additional deflector plates, which may be disposed along the longitudinal axis of the deflector nozzle, and may be located between the connector and the primary deflector plate. The additional one or more deflector plates may be configured to have a similar or different size and dimensions to the primary deflector plate. The additional one or more deflector plates may each include an aperture through their thicknesses which may or may not be aligned with the longitudinal axis of the deflector nozzle. The apertures of the one or more additional deflector plates may be configured to have a diameter greater than, less than or substantially similar to the aperture of the primary deflector plate.

The additional one or more deflector plates may be formed separately from one or more other component parts of the deflector nozzle. In embodiments including additional one or more deflector plates the canopy may have a greater length.

Additionally or alternatively, a separately formed primary deflector plate and/or separately formed additional one or more deflector plates may be permanently or removably affixed to the other component parts of the deflector nozzle, for example affixed to the canopy. In embodiments where the primary deflector plate and/or one or more additional deflector plates are removably affixed to the canopy, the major surface of the canopy may include one or more recesses configured to receive the aforementioned deflector plates.

Additionally or alternatively the primary deflector plate and/or the one or more additional deflector plates may have a surface configured to engage with the one or more recesses. A fixing mechanism may be disposed in or associated with the one or more recesses, where the fixing mechanism may include, for example, a catch or screw member.

Additionally or alternatively, the canopy may include a wall portion depending orthogonally from one or both side(s) thereof and configured to restrict, or partially restrict, fluid flow from that side. The wall may extend along the entire length of the canopy or may extend along only part of its length. The wall may further include one or more apertures through its thickness which may be configured to allow passage of a partial fluid flow through the wall.

It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear lo advantages over the prior art and are therefore within the scope of the invention described herein.

Claims

CLAIMS1. A nozzle for discharging a pressurised medium from a source, the nozzle comprising a body with an inlet and an outlet and an axis passing through the centre of both, a first baffle having a bore through its thickness that is substantially aligned with the axis and a connecting arm connecting the first baffle and the body, with a plane defined between the body and the first baffle and orthogonal to the axis, the outlet having a first diameter and the bore having a second diameter smaller than the first diameter such that, in use, a pressurised medium introduced into the inlet o flows out of the outlet in a flow path in the direction of the axis, with a first portion of the flow passing through the bore and continuing in a substantially axial direction to form a substantially axial flow pattern, and with a second portion of the flow being deflected by the first baffle so as to form a radially dispersed flow pattern which diverges fore and aft of the plane which extends uninterruptedly around the axis for over 180 degrees.
Nozzle according to Claim 1, further comprising a cowl connected to the connecting arm, the cowl configured to restrict the flow radially around the axis.
3. Nozzle according to Claim 2, wherein the cowl subtends an angle of 90 degrees or less when viewed from the axis, such that the radially dispersed flow pattern subtends a continuous angle of 270 degrees or more when viewed from the axis.
4. Nozzle according to Claim 2, wherein the cowl subtends an angle of 60 degrees or less when viewed from the axis, such that the radially dispersed flow pattern subtends a continuous angle of 300 degrees or more when viewed from the axis.
5. Nozzle according to any of Claims 2 to 4, wherein the first baffle and/or the cowl is configured such that divergence of radial flow fore and aft of the plane subtends an angle of less than 140 degrees, for example less than 120 degrees, e.g. less than degrees, say less than 80 degrees, relative to the plane.
Nozzle according to any preceding Claim, wherein the ratio of the first diameter to the second diameter is between 4:1 and 2:1.
Nozzle according to any of Claims 1 to 5, wherein the ratio of the first diameter to the second diameter is 3:1.
8. Nozzle according to any of Claims 1 to 5, wherein the ratio of the first diameter to the second diameter is 11:4.
Nozzle according to any preceding Claim, wherein the body further comprises a second baffle, located at the outlet end of the body.
10. Nozzle according to any preceding Claim, wherein the connecting arm defines a distance between the body and the first baffle.
11. Nozzle according to Claim 10, wherein the distance between the body and the first baffle is between about 4mm and 200mm, say between about 6mm and 150mm, for example between about 8mm and 100mm, preferably between about 10mm and 50mm, and most preferably the distance is about 20mm.
12. Nozzle according to any preceding Claim, wherein the first baffle comprises a deflection portion comprising the bore.
13. Nozzle according to Claim 12, wherein the deflection portion further comprises a major surface facing the plane, which is substantially flat and parallel to said plane.
14. Nozzle according to Claim 12 or 13, wherein the deflection portion further comprises two substantially parallel edges separated by a width.
15. Nozzle according to Claim 14, wherein the width of the deflection portion is configured to be substantially similar to the diameter of the outlet.
16. Nozzle according to Claim 14, wherein the width of the deflection portion is configured to be less than the diameter of the outlet.
17. Nozzle according to Claim 14, wherein the width of the deflection portion is configured to be greater than the diameter of the outlet.
18. Nozzle according to any of Claims 13 to 17, wherein the cowl comprises a major surface disposed adjacent the outlet, the major surface being substantially flat and parallel to the axis.
19. Nozzle according to Claim 18, wherein the major surface of the cowl is orthogonal to one or both sides of the deflection portion.
20. Nozzle according to any preceding Claim, wherein the body further comprises a second baffle located at the outlet end of the body.
21. A nozzle for discharging a pressurised medium from a source, the nozzle comprising a body with an inlet and an outlet, a baffle having a bore through its thickness that is substantially aligned with the outlet and a connecting arm connecting the baffle and the body, the outlet having a first diameter and the bore having a second diameter, wherein the first diameter is between 1.5 and 10 times the second diameter such that a pressurised medium introduced, in use, into the inlet flows out of the outlet with a portion thereof being deflected by the baffle so as to disperse radially with respect to the flow direction.
22. A fire extinguishing apparatus including a source of pressurized medium, a connection means and a nozzle according to any preceding Claim, wherein the source and nozzle are fluidly connected by the connection means.