WO1982002679A1

WO1982002679A1 - A fine spray nozzle

Info

Publication number: WO1982002679A1
Application number: PCT/SE1982/000028
Authority: WO
Inventors: Alf Nilsson
Original assignee: Alf Nilsson
Priority date: 1981-02-04
Filing date: 1982-02-04
Publication date: 1982-08-19
Also published as: SE8100800L; EP0071620A1

Abstract

Fine spray nozzle, particularly for extinguishing fires. The nozzle comprises an approximately rotationally symmetrical nozzle body (1) with a central bore (7). One end of the body (1) is equipped with a device (4) for connecting the nozzle to a hose or the like which is equipped with a corresponding connecting element. The invention is characterised by the fact that the other end of the body (1) is provided with a central cylindrical projection (5) through which the bore (7) extends almost up to the free end of the projection. The projection (5) has openings (11) which extend from the bore (7) and terminate at the outer face of the projection (5). A number of flat conical disc washers (12) are mounted rotatably on the projection (5) and have serrations extending at an angle to the radius on both their faces. The disc washers (12) are arranged in pairs with an intermediate ring (13) mounted rotatably on the projection between each pair of disc washers. On the free end of the projection (5) there is an adjustment element (14) for regulating the slits (15) between the disc washers (12) and thus the amount of pressurised water which flows out between these disc washers (12), having been supplied via the bore (7).

Description

A Fine Spray Nozzle

The present invention relates to a fine spray nozzle, particularly for extinguishing fires, comprising an approximately rotationally symmetrical nozzle body provided with a central bore and one end of which is fitted with a device for connecting the nozzle to a hose or the like which is equipped with a. corresponding connecting element.

When extinguishing fires it is desirable to reduce the damage caused by the water used for extinguishing the fire, and preferably to avoid such damage altogether, and this type of nozzle, which, in various ways produces a forwardsdirected conical cloud of water droplets, has been used for this purpose. However, the nozzles which have been used until now have been found to release large drops, and although water damage has certainly been reduced, it is still considerable.

A requirement has arisen, partly based on theoretical deliberations, for the production of a cloud of extremely finely dispersed water, almost in the form of mist, directed obliquely upwards towards the ceiling of the room, to extinguish fire in a room which is alight all over.

It is the aim of the present invention to produce a nozzle which will produce just such a cloud of very finely dispersed water.

According to the invention the fine spray nozzle has the design and comprises the characteristics which are listed in the accompanying Patent Claims.

The invention is explained by the accompanying drawings, on which:

Figure 1 shows schematically and partly in section a side view of an embodiment of a nozzle according to the invention, and

Figure 2a shows schematically and partly in section a side view of an alternative embodiment of a nozzle according to the invention wherein the opening of the nozzle is controlled automatically by the water pressure.

Figure 2b shows the nozzle further open than in Figure 2a. Figure 3 shows a cross-section along line II - II through the nozzles shown in Figures 1 and 2b.

Figure 4 shows a cross-section along line I - I through the nozzle shown in Figure 2b.

Throughout the following the same reference numerals are used for parts with the same or similar effect.

A body 1 is constructed as a body of rotation with end faces perpendicular to its axis of rotation, like a truncated cone, for example. The base surface 2 of this cone is equipped with a central, pipe connection 4 with an external thread. The top surface 3 of the cone is equipped with a cylindrical projection 5 which has a threaded part 6 at its free end. The projection 5 is provided with a central bore 7 with the same diameter, as the internal diameter of the pipe connection 4 and extending from this connecting part 4 almost up to the threaded part 6, where it terminates in a base 9. The projection 5 bas a number, preferably four, of longitudinally extending, planar chamfers 8 arranged at regular intervals and of such a width, that between them there remain strips 10 of the cylinder surface. The projection 5 is also provided with longitudinal slots 11 extending from the centre of the chamfers

8 into the bore 7 and running from the hilt 1 to the bottom

9 of the bore 7.

Rotatably fitted on the projection 5 there are a number of flat conical disc washers 12, the upper and lower faces of which are each provided with serrations which diverge slightly from the radii of the disc washers 12, being: the same on both the upper and lower faces. The disc washers 12 are arranged in pairs with shim rings 13 provided between the pairs, having the same external and internal diameters as the disc washers 12. Rings 13 are also provided outside the outermost pairs of disc washers 12. The thickness of the rings 13 is adapted so that the section with the disc washers 12 and the rings 13 is the same length as the chamfers 8. On the threaded part 6 beyond this section an adjustment nut 14 is provided and outside this there is a holding nut 16 with a recess 18 which is not threaded right through. By means of the adjustment nut 14 the amount of water per unit of time flowing out through the slits 15 between the disc washers 12 can be varied. The size of the individual drops is thereby influenced so that the finest dispersion is obtained with the smallest width of the slits 15.

The nozzle shown in Figures 2a and 2b comprises a piston 20 which is axially movable, in the bore 7 and the piston rod 21 of which is slidably mounted on the free end wall 22 of the projection 5. A helical spring 23 acts between the wall and the piston 20 so that the pressing down of the piston 20 towards the end wall 22 is counteracted by the spring force. The free end of the piston rod 21 has a thread 24 which fits in the thread of the adjustment nut 14.

The combination of the piston 20 with its piston rod 21, the helical spring 23 and the adjustment nut 14 provides automatic control of the size of the slits 15 between the disc washers 12. This is achieved in the following way; Under the effect of increasing water pressure the piston 20 is pressed downwards in the Figure, counteracted by the spring force, so that the adjustment nut 14 is also moved downwards. The space available for the disc washers 12 and the rings 13 thereby becomes larger and the slits 15 between the disc washers 12 are widened. If, on the other hand, the water pressure is reduced, for example as a result of several fine spray nozzles connected into the same pressurised water supply pipe being brought into use, then under the effect of the force from the spring 23 and counteracted by the water pressure, the piston is made to move upwards in the Figure, whereupon the slits between the disc washers 12 are narrowed. Thus, a specific equilibrium exists between the water pressure and the spring force and this equilibrium value corresponds to a specific slit width. This can be varied by moving the adjustment nut 14 with the aid of the thread 24 on the piston rod 21. In Figure 2a a narrow slit width has been set and this requires a relatively high water pressure to widen the slits, while a wider slit width is set in Figure 2b.

The nozzle according to the invention is used, for example, by fitting it as the nozzle on the jet-pipe connected to a hosepipe, or as a sprinkler head beneath, a ceiling. When it is to operate as a sprinkler head the disc washers 12 are reversed so that the slits 15 between them slope backwards towards the fixing 1, while the outer face of the holding nut 16 is expediently planar or rounded 17. When it is to be used on a jet-pipe the outside face of the holding nut 16 is expediently shaped as a solid pointed cone 19 with an acute point. The holding nut 16, 19 can be used in this case to knock a hole in the ceiling of the room from above and to introduce the nozzle through this hole, into a position immediately under the ceiling. Here again, the disc washers 12 are turned round so that they slope towards the body 1. In practical tests carried out when burning down abandoned free-standing wooden houses it has been found that .the cloud of fine spray directed obliquely upwards towards the ceiling which is produced from a nozzle thus introduced through the ceiling into a room which is burning all over is quickly vaporised without any drops falling down and, due to the fact that its weight is lower than that of the smoke gas (the weight of water vapour relative to that of carbon dioxide is in the ratio of 18 to 40 at the same temperature), the steam produced remains as an ever-thickening layer under the ceiling until it fills the whole room. The. steam does not support the fire, which is thus extinguished from above, downwards. If it should appear necessary to fight the fire through a door or a wall it is possible to use a nozzle with the disc washers 12 turned so that they slope forwards towards the holding nut 16. In this case the steam formed again rises up, due to its lower volumetric weight and comes to rest as an increasingly thick, layer under the ceiling of the room. Naturally, the nozzle may be used in industry wherever there is a need for a spray of extremely finely dispersed water.

Claims

P a t e n t C l a i m s

1. A fine spray nozzle, particularly for extinguishing fires, comprising an approximately rotationally symmetrical nozzle body (1) provided with a central bore (7) and one end of which is fitted with a device (4) for connecting the nozzle to a hose or the like which is equipped with a corresponding connecting element, characterised in that the other end of the body (1) is provided with a central cylindrical projection (5) through which the bore (7) extends almost to the free end of the projection, and which has openings (11) extending from the bore (7) and terminating at the outer surface of the projection (5), a number of flat conical disc washers (12) being rotatably mounted on this projection (5), both sides of these disc washers having serrations extending at an angle to the radius, the said disc washers (12) being arranged in pairs with an intermediate ring (13) mounted rotatably on the projection between each pair of washers, and an adjustment device (14) being arranged on the free end of the projection (5) for regulating the slits (15) between the disc washers (12) and thus the amount of pressurised water flowing out between these disc washers (12), having been supplied via the bore (7).

2. A fine spray nozzle according to Patent Claim 1, characterised in that the nozzle comprises a piston (20) which can move axially in the bore (7) and is mounted on the free end wall (22) of the projection (5), and a spring (23) acting between the piston and the end wall (22), this piston (20) being effectively connected to the adjustment device (14) in such a way that, under the effect of increasing water pressure and against the effect of the spring (23), the piston (20) causes the adjustment device (14) to increase the slits (15) between the disc washers (10).

3. A fine spray nozzle according to either of Patent. Claims 1 or 2, characterised in that the projection (5) is provided on its outer face with a number, preferably four, of flat, axis-parallel chamfers (8) disposed at regular intervals and extending from that end of the projection (5) which is attached to the body (1) to the bottom (9) of the bore (7), and separated by strips (10) of the cylinder surface, and in that the said openings (11) are formed by slots extending radially right through from the chamfers (8), these slots being substantially the same length as the chamfers (8).

4. A fine spray nozzle according to Patent Claim 1, characterised in that beyond the adjustment device (14) there is a holding nut (16) with a recess which has a thread extending part of the way through it.

5. A fine spray nozzle according to Patent Claim 4, characterised in that the outer face (17) of the holding nut is rounded.

6. A fine spray nozzle according to Patent Claim 4, characterised in that the outer face (19) of the holding nut is shaped as a cone.