Spray nozzle primarily for fire protection

This invention relates to a spray nozzle primarily intended for protection against, and the control of, fire through discharge of a fluid, typically water or other liquid. Nozzles used for such protection incorporate a valve means and a spray head and are generally installed in vehicles, vessels or buildings and include a sensing device operative on detection of a probable fire related occurrence to open the nozzle valve thereby to release a pressurised liquid.

Spray nozzles of the aforementioned kind, once installed, remain in position for considerable periods of time exposed to the local environment and susceptible to contamination. They must function reliably when activated and this is usually achieved through rupture of a pressure capsule releasing the fluid which passes through the nozzle to issue as a fine mist or spray.

It is an object of this invention to provide a spray nozzle which will be less vulnerable to contamination and obstruction of the nozzle opening or internal passageways over extended periods of time.

We disclose a spray nozzle comprising a body having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway and located within an externally opening recess in the body, the recess being closed-off externally by a cap having an external surface flush with the external surface of the body.

Preferably, in this embodiment, the recess is closed-off by the cap which is snap-connected with the body.

We also disclose a spray nozzle comprising a body having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway and located within an externally opening recess in the body, the recess being closed-off by a cap arranged to be ejected from the recess by passage of fluid flow to the nozzle. The cap is preferably snap-connected with the body.

Preferably, in this embodiment, the external surface of the cap lies flush with the external surface of the body.

The snap-connection may be formed by complementary engaging parts, the one part on the body and the other part on the cap. The cap may comprise a disc closing-off a complementary shaped recess in the body. The disc may have an internally projecting annular rib snap-fitting over a cylindrical nose part of the nozzle and sealing the recess and nozzle. The snap-fitting may be achieved by a thickened rim of the annular rib of the cap engaging an annular recess around the cylindrical nose part of the nozzle. The rim and recess configuration may be reversed.

The body may include a plurality of flat zones forming facets each of which includes a nozzle assembly closed by the aforementioned cap arrangement.

The body may comprise a cap with an outward facing faceted surface, and a rearward planar surface having a mounting spigot forming the fluid inlet.

With a construction as disclosed the nozzle, or nozzles, are closed-off against the ingress of contaminants and preferably the cap forms a fluid tight seal. The degree of retention of the cap is arranged such that on the supply of fluid pressure to the nozzle the cap is blown- away.

A further and alternative aspect of this disclosure provides for the location of a filter element, preferably a mesh filter and more preferably a cup mesh filter, to be located

within the inlet passageway. Particularly with misting nozzles, the filter provides protection against blockage of the nozzle through fluid borne contaminants.

The cap will preferably be of a temperature resistant plastics material such as polyphenylene sulphide, the latter having excellent resistance to distortion and temperature typically up to 200° C.

Features of this description are the location of the nozzle or nozzles within, and protected by, the body providing a housing with a clean profiled outer surface and preferably of a domed and faceted shape. The caps closing-off and hermetically sealing the nozzle outlets and further providing a flush outer profile. The clipped in or snap connected caps are arranged to be firmly retained but nevertheless capable of being blown-off when fluid flow is activated, this being achieved by the fracture of a pressure capsule on excessive temperature rise for example.

We also disclose a system primarily intended for protection against, and the control of, fire or overheating through discharge of a fluid, the system comprising a plurality of spray nozzles each having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway, wherein a fluid pressure release means is included in each nozzle activated on temperature rise, the arrangement being such that activation of a fluid release means in one nozzle of the system effects activation of the fluid release means in the other nozzles of the system. Each spray nozzle will preferably have a construction and features as previously described.

Specifically in accordance with the invention we provide: -

1. A spray nozzle comprising a body having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway and located within an externally opening recess in the body, the recess being closed-off externally by a cap having an external surface flush with the surrounding external surface of the body.

2. A spray nozzle according to Claim 1 and comprising a body having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway and located within an

externally opening recess in the body, the recess being closed-off by a cap arranged to be ejected from the recess by passage of fluid flow to the nozzle. 3. A spray nozzle in accordance with claim 2, wherein the external surface of the cap lies flush with the surrounding external surface of the body. 4. A spray nozzle in accordance with claim 1 or 2 or 3, wherein the cap is retained in the recess by an interlocking or snap-connection with the nozzle or with the body. 5. A spray nozzle in accordance with any claim 2 or 3 or 4, wherein the snap-connection is formed by complementary engaging parts, the one part on the body or the nozzle and the other part on the cap. 6. A spray nozzle in accordance with any preceding claim, wherein the cap comprises a disc closing-off a complementary shaped recess in the body. 7. A spray nozzle in accordance with claim 6, wherein the disc has an internally projecting annular rib snap-fitting over a cylindrical nose part of the nozzle and sealing the recess and nozzle. 8. A spray nozzle in accordance with claim 7, wherein the snap-fitting is achieved by an internally thickened rim of the annular rib of the cap engaging an annular recess around the cylindrical nose part of the nozzle.

9. A spray nozzle in accordance with claim 7, wherein the snap-fitting is achieved by an externally thickened rim of the annular rib of the cap engaging an annular projection around the cylindrical nose part of the nozzle.

10. A spray nozzle in accordance with claim 7 or 8 or 9, wherein the outer surface area of the cap is significantly larger than the area embraced within the annular rib and wherein and preferably the area defined by the rib is one third the outer area between the rib and the periphery of the cap disc. 11. A spray nozzle in accordance with any preceding claim, wherein the body includes a plurality of flat zones forming facets each of which includes a recessed nozzle assembly closed by a respective cap.

12. A spray nozzle in accordance with any preceding claim, wherein the body comprises a head with an outward facing faceted surface, and a rearward planar surface having a mounting spigot forming the fluid inlet.

13. A spray nozzle in accordance with any preceding claim, wherein the connection between the cap and body or nozzle is arranged such that on the supply of fluid pressure to the nozzle the cap is jettisoned.

14. A spray nozzle in accordance with any preceding claim, wherein the cap is moulded from a temperature resistant plastics material, preferably polyphenylene sulphide.

15. A spray nozzle in accordance with any preceding claim, wherein the cap closes and hermetically seals the nozzle outlets and provides a flush outer surface profile. 16. A spray nozzle in accordance with any preceding claim, wherein the cap connection is arranged to have firm retention properties but nevertheless capable of being blown-off when fluid flow is activated.

17. A spray nozzle according to any preceding claim and comprising a body having a fluid inlet, a fluid transfer passageway in communication with the inlet and a fluid spray or misting nozzle assembly in communication with the passageway and located within an externally opening recess in the body, wherein a filter element is located within the inlet passageway.

18. A spray nozzle in accordance with claim 17, wherein the filter comprises a mesh filter and more preferably a cup mesh filter. 19. A spray nozzle in accordance with claim 17 or 18 when dependent on any preceding claim 1 to 16.

20. A spray nozzle assembly as described herein and exemplified with reference to the drawings.

An embodiment according to the several aspects of this invention is described as an example and in conjunction with the accompanying drawings, wherein:-

Figure 1 shows a perspective view of a multiple nozzle assembly in accordance with this invention; Figure 2 shows a cross-sectional view of the nozzle assembly of Figure 1;

Figure 3 shows a perspective view of the nozzle assembly of Figure 1, and

Figure 4 is a detail section of the cap and nozzle.

Referring to the drawings a multiple nozzle assembly is shown having a faceted body 1 with six side faces 2 and a central face 3. Each of these faces has an underlying misting nozzle assembly 4 in communication with a fluid transfer passageway 5 connecting with an inlet 6. The body has a threaded spigot 7 to connect with a fluid supply line (not shown) with an O-ring 8 to form a fluid tight seal.

Each nozzle assembly 4 is screw fitted into a respective recess in the body 1 and countersunk within the body. Each nozzle assembly is further closed-off by a cap 9 of moulded polyphenylene sulphide and having a planar outer facing surface 9a flush with the associated surrounding surface of the respective facet 2 of the body 1 and an inner surface 9b with an annular rib 9c including an inward facing lip 9d. Each nozzle assembly 4 has a profiled boss 4a with an outward projecting lip 4b which snap connects with the rib 9c of the cap.

In the example shown the purpose of the nozzle is to provide a fine mist of water, or a water/nitrogen mixture, with a droplet size of 60 to 100 microns using a pressure of 100 to 200 bar. The caps 9 prevent contamination and clogging of the nozzles and are configured, through the engaging lips 9d and 4c, to permit the caps to be blown away from the nozzle opening and the body at a predetermined fluid pressure supplied to the nozzles. This is conventionally achieved by incorporation of a frangible bulb which normally prevents fluid being fed to the nozzles but which fractures at a predetermined temperature to release the fluid pressure allowing fluid flow through the nozzles thus ejecting the caps. Alternatively activation may be achieved through fluid pressure being released to the feed line remotely from the nozzles.

The outer surface area of the caps is significantly larger than the area defined within and by the annular rib 9c In a typical embodiment the inner area, defined by the rib, is one third the outer area between the rib and the periphery.

In a further aspect the inlet includes a cup-shaped mesh filter or strainer 6a of typically 250 mesh included in the inlet 6.

The advantages afforded by the features of this invention are the ease of maintaining the nozzle assembly clean and free from contaminants without introducing foreign matter into the nozzles themselves during cleaning. The strainer 6a, by virtue of the shape, present a large surface area, and the nozzle configuration offers good area coverage.

A preferred construction includes both aspects of this invention according to which a multiple fluid discharge nozzle assembly is provided for fire control has a faceted body 1 with six side faces 2 and a central face 3. Each of these faces has an underlying misting

nozzle assembly 4 in communication with a fluid transfer passageway 5 connecting with an inlet 6. The body has a threaded spigot 7 to connect with a fluid supply line. Each nozzle assembly 4 is screw fitted into a respective recess in the body 1 and countersunk within the body. Each nozzle is closed-off by a cap 9 of a moulded plastic having a planar outer facing surface 9a flush with the associated surrounding surface of the respective facet 2 of the body 1 and an inner surface 9b with an annular rib 9c including an inward facing lip 9d. Each nozzle assembly 4 has a profiled boss 4a with an outward projecting lip 4b which snap connects with the rib 9c of the cap. Application of fluid pressure to the nozzles 4 causes the caps 9 to be blown-off. The caps prevent ingress of foreign matter and offer a smooth outer profile.