DryFoam™ is comprised of engineered spheres about 12 mm (1/2
inches) diameter that can be applied directly on flammable
liquids for extended periods of time i.e., years, where they
float and continuously suppress flammable vapors and thereby
prevent combustion. When exposed to intense heat, as from a fire
from above the spheres already floating on a flammable liquid,
the DryFoam™ spheres will rapidly expand, creating a thermal
barrier and preventing ignition of the flammable liquid beneath
the spheres.
The technology is valuable where passive fire protection is
needed from the potential of a leaking source of flammable
liquid e.g., an oil filled transformer and where water-based
fire foams pose a special hazard in electrical areas.
DryFoam™ is also valuable where water is scarce or insufficient
and the spheres can be applied in advance of a fire to prevent a
fire event e.g., on top of a flammable liquid storage tanks'
floating roof.
DryFoam™ can be supplied in perforated bags or rolls that are
easily placed within a liquid mounted seal associated with
floating roof tanks where it protects against a fire in the rim
seal area from lightning strikes or other sources of ignition.
In that application they would serve as a passive and
supplemental fire protection to the existing water-based foam
systems.
The UL listed DryFoam™ spheres take on the contours of any tank
shape, reducing the risk of fire and providing a cost-effective,
long-term solution that is virtually maintenance free.
LNG and LPG applications include pre-positioning DryFoam™
beneath leak points or in boil off pits with some perforated
bags. Should the LNG or LPG product leak, the liquid will
quickly pass to the bottom and the spheres will float on top
providing passive vapor suppression that is dependant on the
vapor pressure of the liquid. Testing has demonstrated about 70%
vapor suppression on LNG and about 85% with LPG.
DryFoam™ is completely passive and therefore doesn't require
water, power, piping or pumps. If applied to an existing rim
seal on an oil storage tank, DryFoam™ acts as primary source of
rim seal protection with the water-based foam acting as
supplemental.
The spheres are very light weight (specific gravity is about
0.18) and will easily float on virtually all liquids. That makes
them easy to install in difficult to reach areas such as under
oil filled transformers. In that application the secondary
catchment that often surround the transformers can be
temporarily filled with water and the spheres simply dumped into
the space where they float into position. Then the water can be
drained leaving the spheres in place and providing the passive
fire protection of any leaked transformer oil.
