The aim is to develop an innovative fire-fighting sprinkler nozzle based on water mist. This innovation aims to reduce the financial costs of sprinkler installations but also to reduce water consumption.
Fire protection installations consist of a network of pipes (Ø 100 to 300 mm) and nozzles supplied by pressurized water from the network (4 to 16 bar «sprinkler»). In the event of a fire, 160 to 320 l/min per nozzle are used.
One way to reduce water consumption is to use a mist where it is the total surface area of the micro droplets, instead of the water bulk, that contributes to the extinguishing of the fire, by choking and cooling. Water mist nozzles already exist on the market; however, they operate with very high pressures (40 to 120 bar) and often have make-up gases (N2) injected into the water to promote misting, which is also very expensive in terms of complete installation.
We offer a water mist nozzle at 6 bar and 20 l/min with air. The reduction in water consumption (-80%) as well as the reduction in installation costs (-40%) in fire prevention are thus drastically reduced. We envision the generation of fog by an innovative technique of «prompt atomization» between a jet of water and a jet of supersonic air. The potential of a fog to extinguish a fire depends on the distribution, density, and speed of the micro-droplets, as well as its coverage on a given surface.
A fundamental understanding and parametric study of the physical phenomena at the origin of the formation of fog within our system are therefore necessary.
Project partner(s)
Project leader - team
Flavio Noca
(HEPIA)