aft technology
TRANSCRIPT
AFT TECHNOLOGY
AFT has applied advanced aerodynamics technology from flow engineering applications involving liquid/gas mixtures to create A FT
water mist f irefighting systems. The AFT technology creates a narrow distribution of ultra f ine water mist, foam or CAFS using
speciality nozzles.
The droplets create an enlarged surface area (almost 50 times) as compared to a conventional water tender. This results in rapid
cooling due to extensive heat absoption and the resultant steam generated expands 1640 times in volume thus inserting the
atmosphere around the f ire. The combined effect of cooling and blanketing results in effective rapid extinguishing.
Water Mist
NFPA 750 defines water mist as “a water spray with for which the Dv0.99, for the f low -weighted cumulative volumetric distribution of
water droplets is less than 1000 microns at the minimum design operating pressure of the water mist nozzle”.
Current water mist systems today deliver anywhere between 50-999µm. Based on pressure used to create droplets, the
classif ication of water mist is as below.
o Low pressure: Systems which operate with pressures less than or equal to 12 bar
o Medium pressure: Systems operating between 12-34.5 bars
o High pressure: Systems which use pressure greater than 34.5 bar
AFT’s Difference
o AFT’s firefighting nozzles deliver the optimum droplet size of 150 microns and therefore outperform any other comparable product.
o Many companies assert having low-pressure fire extinguishers. AFT’s portable devices demonstrate it with a working pressure of less than
10 bars!
The chart compares the speed of cooling between a 5 mm droplet to various droplets of water mist. As we can see, the AFT droplet
size of 150µm cools 40 times faster than a 5mm droplet.
Atomisation
Using the atomization technology, the water mist is developed by using the kinetic energy of compressed air and mixed w ith the
liquid in specially designed multiple nozzle systems. Atomisation works w ith compressed air to pressurise the system, propell the
liquid and mix it w ith the liquid for creating mist.