The present invention relates to an installation for fighting fire, in particular for fighting fire in engine rooms in ships, and in similar spaces; fires in such spaces are generally considered as extremely difficult to extinguish.

The object of the invention is to provide a new installation for fighting fire which is more effective than earlier installations.

The installation according to the invention is mainly characterized in that it comprises a plurality of spray heads or sprinklers arranged to produce concentrated fog-like liquid sprays at a high operating pressure and that at least one spray head is directed in such a manner that the fog-like liquid spray thereof collides with the fog-like liquid spray of at least one other spray head or sprinkler.

By a fog-like spray is meant a spray of small droplets having a diameter typically 30 to 150 microns and preferably set in a strong whirling motion.

The spray heads or sprinklers are preferably of a kind as presented e.g. in the international patent applications PCT/FI92/00060 and PCT/FI92/00155. Such spray heads or sprinklers are capable of producing concentrated fog-like liquid sprays having a good penetration power and a small consumption of liquid. The operating pressure is preferably high, at least initially, by which here in general is meant from about 30 bar up to about 300 bar, as compared to an operating pressure of generally 2 to 10 bar in conventional sprinkler installations which produce a rain-like spray. It shall be noted, however, that the values given above are not absolute; definite limiting values are difficult to present.

A sprinkler is in general provided with a

release element, such as a glass ampoule which melts or breaks at a certain temperature and thereby activates the sprinkler. A spray head need not have a release element of its own, it can be governed and activated by e.g. a sprinkler in the neighbourhood, e.g. in a manner as presented in the international patent application PCT/FI92/00316.

A high operating pressure is made possible for sprinklers by employing pressure balance means as presented in the above mentioned application PCT/FI92/00060.

A concentrated fog-like liquid spray is obtained by means of a certain combination of the mutual distance between the nozzles of the spray head or sprinkler, of the direction of the nozzles, of the outlets of the nozzles which determine the droplet size, and of the drive pressure of the liquid. At the right combination of these factors, which combination due to the absence of a reliable theory and formula must be determined by experiments, there is produced a suction which keeps the fog-like liquid spray together. It is hereby essential that air can be sucked in to the spray head behind the nozzles of the spray head, which means that the nozzles must not be too close to e.g. a ceiling; a distance of about five centimetres is usually sufficient.

When the fog-like liquid sprays collide with each other, the droplets of the sprays are scattered and thereby their capability of absorbing heat is increased. This is of significance for smothering the fire and, in addition, for cooling in general and thus for preventing reignition after the fire preliminarily has been suppressed and/or extinguished.

Preferable embodiments of the invention are defined in more detail in claims 2 to 6.

The invention shall in the following be

described in more detail with reference to exemplifying embodiments schematically shown in the attached drawing.

Figure 1 shows the general principle of the invention.

Figure 2 shows a preferred emodiment which in particular is suitable for extinguishing a fire in an engine room in a ship, or in a similar space.

Figure 1 shows two spray heads or sprinklers indicated by 1 and 2 and arranged opposite each other. The spray heads or sprinklers produce fog-like liquid sprays 3 and 4, respectively, which collide with each other and are scattered, at the reference numeral 5, and form a finely distributed fog indicated by the reference numeral 6. The fog 6 has a high capacity to absorb heat.

In figure 2, the reference numeral 7 indicates a number of spray heads or sprinklers arranged above an object 8 which is liable to catch fire, such as a diesel motor in an engine room in a ship. The fog-like liquid sprays are indicated by 9. The reference numerals 10 and 11 indicate two sprinklers or spray heads at the side of the risk object 8, approximately at mid-height thereof, and are directed towards the object 8. A plurality of similar sprinklers or spray heads can of course be arranged, in the viewing direction, according to presumable need, respectively.

Down at the level of the floor 12 of the engine room or the like are arranged a number of sprinklers or spray heads 13 and 14, respectively, in the same manner and with the same options as for the earlier mentioned sprinklers or spray heads 10 and 11.

The fog-like liquid sprays 15 and 16 of the sprinklers or spray heads 10 and 11, respectively, and the fog-like liquid sprays 17 and 18 of the sprinklers or spray heads 13 and 14, respectively, interfere with

each other and with the fog-like liquid sprays 9, and togehter produce a liquid fog having a high capacity to absorb heat.

The sprinklers or spray heads 10, 11 and 13, 14, respectively can, if it is considered favourable, be activated a little later than the upper sprinklers or spray heads 7; in many cases all sprinklers or spray heads can be activated simultaneously when it is established that a fire has started.