METHOD FOR PRODUCTION OF A FIRE FIGHTING FOAM, NOZZLE HEAD AND AN ARRANGEMENT IN A FIRE EXTINGUISHING INSTALLATION

The invention concerns a method for producing a fire fighting foam, whereby water, gas (e.g. air) and foam fluid are mixed and foamed, wherein the gas is added to the water under pressure before the gas/water mixture is leaving a nozzle for spreading the foam. The invention also concerns a nozzle head, comprising a nozzle head insert (1), which is arranged rotatable, under influence of a water pressure, relative to an inlet stub (4), and at least one outlet pipe, which is a foam pipe (15) and which is in fluid communication with the inlet stub (4) via the nozzle head insert. The foam pipe (15) is at its end facing the nozzle head insert (1) equipped with at least one suction port (16), for taking in air into the foam pipe (15), to produce a fire fighting foam. The suction port (16) is at least partly surrounded by a hood (11), which forms a room or pressure chamber (14) in front of the suction port (16), wherein the room or the pressure chamber has an open side facing in the direction of rotation of the nozzle head insert (1), whereby air is forced into the room or pressure chamber (14) during the rotation of the nozzle head insert (1), and an arrangement in a fire extinguishing installation, comprising a nozzle head insert (1), which is arranged rotatable, under influence of a water pressure, relative to an inlet stub (4), on the nozzle head insert at least one nozzle in fluid communication with the inlet stub (4) via the nozzle head insert is arranged. The arrangement also comprises a gas source, which is coupled to a water source for introduction of the gas into the water under pressure. Cette invention se rapporte à un procédé permettant de produire une mousse d'extinction, et consistant à mélanger et à soumettre à une opération moussante de l'eau, un gaz (par exemple de l'air) et une mousse fluide, le gaz étant ajouté à l'eau sous pression avant que le mélange gaz et eau quitte l'ajutage pour disperser la mousse. Cette invention se rapporte également à une tête d'ajutage, comprenant un insert de tête d'ajutage (1), qui est disposé rotatif, sous l'effet de la pression d'eau, par rapport à un manchon d'admission (4), et au moins un conduit d'émission, constitué par un conduit à mousse (15) et qui est placé en communication fluidique avec le manchon d'admission (4) via l'insert de tête d'ajutage. Le conduit à mousse (15) est tourné au niveau de son extrémité face à l'insert de tête d'ajutage (1) pourvue d'au moins un orifice d'aspiration (16), pour aspir