buradan - Yangın

TÜYAK BİLDİRİLER KİTABI
2009 PROCEEDINGS BOOK
So traditionally we have protected cold areas (both inside and
outside buildings) with air filled systems. When the sprinkler
operates, the air is released which in turn automatically opens
the main water alarm valve and the water follows the air into the
system and to the sprinkler.
This kind of system called a dry-system is used all over the world
but just like standard warehouse protection, when the storage
height reaches certain level you are required to install in-rack
sprinklers.
Dry ESFR System
Figure 24. A photo of a typical dry-ESFR installation.
So can we take advantage of the ESFR in a cold storage environment?
Until recently the answer was no. ESFR’s rely on fast activation and
fast application of the water in order to work and due to the delay in
waiting for the air to leave the system these dry-systems systems
are too slow to allow the use of ESFR sprinklers.
Figure 25. Dry ESFR system
8
TÜYAK 2009
Standard
temperature
void above
Freezer
However, by attaching the ESFR sprinkler to a short length of steel
pipe and adapting the operating mechanism we can now create a
‘dry ESFR’ sprinkler to be attached to the water filled pipes above
the cold storage ceiling.
Because the barrel of the sprinkler is open to the atmosphere there
is no water within it to freeze solid. But when the sprinkler head in
the freezer operates it opens the other end of the barrel which is
connected to the standard water filled sprinkler piping above the
ceiling thereby allowing water into the barrel. This water only takes
a split second to reach the sprinkler and it can begin to attack the
fire immediately.
Figure 26. Some photos of a typical dry-ESFR installation.
On the left you can see the dry sprinklers attaching into the normal
water filled sprinkler pipes above the ceiling On the right we see
the sprinklers inside the freezer. Having no in-rack sprinklers gives
the warehouse operator greater freedom and removes the risk of a
forklift accidentally damaging pipework in the rack.
Flay Spray Technology
Standard prinklers Flat-spray technology
Figure 27. Flay spray technology
We have already heard that one the greatest concerns of the
warehouse operator is yield, or ‘how many goods can I store per
m² of floor space’. One of the ways of increasing this is to decrease
the space between pallets on a rack, in other words squeeze more
goods into the rack vertically.
However, standard sprinklers need a certain amount of space in
order to develop the water spray pattern which limits the vertical
distance between pallets. Without this space the sprinkler cannot
spray adequately.
A new development in sprinkler technology has been the the special
flat-spray sprinkler. This sprinkler has a special deflector design
which sprays the water more horizontally which in turn allows the
good to be stored closer, in fact the minimum distance between the
goods and the deflector of the sprinkler is reduced by 33%.
To put this in perspective, even if you have 8 levels in your rack you
could save an extra half pallet in height. Any warehouse operator will
tell you that an extra half pallet space on top is very useful indeed.
A New Project: ‘ I Want Everything’
Figure 28. A Warehouse