Introduction to Fire Safety Management

Introduction to Fire Safety Management
this type of drencher is on the stage side of a theatre
proscenium arch to protect the safety curtain.
Window drenchers – as their name implies, window
drenchers are used to protect window openings. They
are placed horizontally level with the top of the window
providing a curtain of water to protect the glass. From
the tail of the defl ector, a jet is thrown inwards onto the
glass near the top of the window, while two streams are
directed at an angle of 45º to the lower corners.
Flooding and inerting systems
Flooding and inerting systems operate by literally fl ooding
an area with a particular extinguishing media. These
systems use a variety of media including dry powder
and various gases. Extinguishing powder systems have
a number of advantages to offer in the form of cost, ease
of maintenance, effi ciency and reliability. Gas fl ooding
systems commonly use carbon dioxide, nitrogen, argon
or a combination of these gases.
Typical fl ooding systems will consist of a central
storage tank or banks of cylinders where gas is stored
under pressure, and a piping system conveys the gas
to the point(s) of discharge. Special nozzles are used
to facilitate the even distribution of the gas. Flooding
systems can either fl ood a total compartment or building
or be used to fl ood the immediate area of a fi re risk.
Release of the fi re-fi ghting medium is either achieved
manually or automatically. Automatic systems use
various methods of detection including:
➤ Temperature sensitive wire – where the insulation of
a wire melts completing a circuit
➤ Heat detectors – which operate at a predetermined
temperature
CO 2 Cylinders
Room Area
220
Pull Station
Underfloor area
Total Flooding System
Gas Operated Siren
Detector
Figure 9.64 A typical layout of a fl ooding system
Discharge nozzle
➤ Gas-fi lled stainless steel tubing – where a fi re is
detected through increased pressure in the tube by
the expansion of the gas
➤ Pressurised plastic tube – which melts releasing its
pressure and triggering the system.
Small fi xed fl ooding systems are increasingly used in
kitchen extraction hoods and ducts where they are
effective in dealing with fi re involving fatty deposits.
Larger systems protect such risks as industrial
quench tanks as well as a range of risks where fl ammable
liquids are sprayed, stored or mixed. Flooding and
inerting systems are fi tted in such locations as:
➤ Computer suites
➤ Archive storage areas
➤ Historic buildings
➤ Electrical switch rooms
➤ Kitchens
➤ Gas turbines.
Figure 9.65 Detail of a fi xed fl ooding system fi tted to a
kitchen range