‫گاز كربنيك اطفاء حريق سيستم‬
‫تهيه و تنظيم ‪:‬‬
‫زهركش مجيد‬
CO2 Suppression Systems
CO2‫خصوصيات گاز اطفاء‬
What is CO2 ?





A colourless, dry, odourless, non-corrosive
gas
Density 1.5 times that of air
Occurs naturally in atmosphere (0.03%)
A by-product of combustion process eg. fossil
fuels
Produced as a by-product of industry
CO2‫خصوصيات گاز اطفاء‬
How does it work?




Reduces oxygen to less than 15%
Discharges as liquid, expands at nozzle
into dense cloud of vapour/ dry ice
Expansion creates cooling effect,
expansion ratio 1kg= 0.56m3
Effective on fire classes:
A - Ordinary combustible material
B - Liquid fuel fires
C - Electrical fires
Heat
Oxygen Depletion Curve
Concentration - Vol. %
60
Impaired
Performance Zone
50
Unimpaired
Performance Zone
Inert Agents
40
30
20
FE 13TM
12.3%
NASA Minimum
10
FM-200 ®
Pass Out
0
9
10
12.3
16
Oxygen Conc %
21
CO2‫خصوصيات گاز اطفاء‬

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Inexpensive
Readily available
Effective on wide range of fires
Versatile: high pressure/low pressure
Total flood/local application
Non corrosive: will not contaminate liquids
or food
Clean - no mess, CO2 dissipates to
atmosphere
CO2 & The Environment

Normally present at 0.03% (increasing due to
pollution/combustion)

We breathe in CO2 at 0.03% & breathe it out at 3 4%

Harmless at low concentration

Zero ODP
CO2 & The Environment

Significant GWP but non-emissive

No environmental restrictions on CO2

No restriction on testing (eg FMRC procedures)

CO2 is environmentally friendly
CO2 Safety
Clear exit routes
 Emergency lighting
 Alarms to operate on detection of fire
- discharge delay to allow egress
- delay on door closer to allow egress
 Exit doors to open outwards - panic bolts
 Continuous alarm until atmosphere safe
again

CO2 Safety


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Odoriser - adds distinctive smell to CO2 discharge
Adequate warning signs and instruction inside and
at entrance to risk
Search & rescue drill by trained personnel (Fire
Brigade) with BA sets. A person rendered
unconscious by CO2 protected area can be revived
with prompt first aid
Safe ventilation of CO2 flooded areas
CO2 Safety

Cylinder safety:
- Stored as a liquid at 58bar
- Burst disc
- Transport cover

Container Storage Temperature range:
- Local application: 0ºC to + 46ºC
- Total Flood: -18ºC to + 54ºC
Hazards to Personnel

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Suffocation
Drifting of gas to other areas which may be occupiedwarning signs
Noise from discharge - quite loud
Pre-discharge alarm & time delay: Sufficient to allow
evacuation
Visual alarms where ambient noise level is high
Hazards to Personnel

Direct discharge of CO2 onto person
- skin burns
- eye injury
- ear damage

Precautions to prevent accidental discharge
- isolation valve (BS requirement)
- control head
- lockout at control panel (NFPA/FM requirement)
- lock off/door interlock (BS requirement)

Clearance from live electrical apparatus
- guidance provided in standards
Design Standards &
Approvals
Design Standards

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NFPA 12
BS 5306 Pt 4
Approvals

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FMRC
ABS
LRS
MSA
DNV
CCS (China)
NKK (Japan)
BASEEFA
System Hardware Review

Direct-acting solenoid assembly

Metron actuator

Weight-monitoring device
Direct-Acting Solenoid
Direct-Acting Solenoid

Designed for use with standard 45 kg
CO2 cylinders

Modified version of existing cylinder valve

Control head and nitrogen pilot cylinder
replaced by solenoid assembly coupled to
cylinder valve
Direct-Acting Solenoid
Mode of Operation

Inactivated State - pneumatic actuator subject to
atmospheric pressure only

Receipt of electrical signal from control panel
Solenoid coil activated
CO2 passes from cylinder to pneumatic actuator
Movement of actuator piston opens klem valve

Agent exits via discharge port
Direct-Acting Solenoid
Schematic
Direct-Acting Solenoid
Specification

Voltage range
18V DC to 28V DC
Current at 18V DC
338mA

Current at 28V DC
526mA
Nominal coil resistance
53.2ohm

Minimum firing pulse
60mS
Maximum firing pulse
Unlimited

Electrical connection
Din plug type
DIN 43650
Operating temperature
range
-20º C
to +55º C

Maximum working
pressure
152.5 bar (g)
Environmental
protection
BS EN
60529
1991 IP65
Direct-Acting Solenoid
Benefits

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Less hardware associated with system
Compact actuation assembly
Greater ease of installation
More cost-effective
Simple in-situ testing procedure
Metron Actuator
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D8521-002 at £116.00 net
Direct fitting onto Klem Valve
Manual Override
Single or Multi Cylinder systems
Four-year installed life
Weight Monitoring Device
Development Rationale:


Enables penetration of
European specs
Improved system
reliability
Weight Monitoring Device
Features:
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Robust construction - all metal
One man installation
Reliable - components selected for long life
Low maintenance - 6 monthly visual
inspection
Simple test procedure
Remote monitoring via optional switch
Weight Monitoring Device
Assembly Diagram
•
Downward force of cylinder exceeds leverage on weight rod
• Loss of mass 10% Reduces downward force and weight rod falls
operating switch
Weight Monitoring Device
Microswitch Details
Weight Monitoring device
System Arrangement
Installation

Requires supporting frame

Frame supports manifold

No racking required
Weight Monitoring Device
System Actuation Options:

Standard Solenoid Control Head & Pilot Nitrogen
Cylinder

Direct-Acting Solenoid Assembly

Metron Operated Actuator Assembly
Weight Monitoring Device
Benefits:

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Increased market acceptance
Capital cost offset by reduced servicing and
installation time
More accurate determination of CO2 mass
Increased system reliability
Gas loss detected automatically
Greater safety in cylinder storage area - detection of
leaking CO2
Lower cost of ownership - reduced maintenance
Typical Applications
Total Flood
Local Application
Switch Gear Rooms
Aluminium/ Steel Rolling Mills
Cable Basements
Flow Coating Machines
Fuel Stores
Paint Booths
Generators
Spark Erosion Machines
Gas Turbines
Kitchen Range Hood, Ducts
Archive/Stores
Quench Tanks
High Tech Filters
High Value Machine Tools
Unsuitable Applications

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Reactive metals, e.g. Magnesium
Chemicals which generate their own oxygen
e.g. Cellulose Nitrate
Metal hydrides
Inerting - static discharge creates a hazard and a
potential explosion
Note: Where product is stored under another medium, e.g. Sodium
under Kerosene (Paraffin), Magnesium chips under oil; CO2 will
prevent spread of fire to these materials.
System Choices

Total Flooding:
- enclosed space
- surface fires (limited leakage)
- deep seated (no leakage)

Local Application:
- flat coated or liquid surface
- 3 dimensional irregular shaped risks with or
without partial enclosure.
System Choices

Hose Reel:
- Manual system
- Uses high pressure hose & applicator
- Useful for rapid knock down of spill fire in
production areas.
System Design


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Surface Fire
- discharge time 60 seconds
Deep Seated Fire
- discharge time up to 7 minutes
Other Variables
- Material Conversion Factor (MCF)
- temperature compensation
- leakage compensation
- forced ventilation
System Design
Use the design tools
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Preliminary Design Schedule
Equipment Matrix
CO2 Flow Calculation Program
The Manual
START
YES
NO
NO
Is the risk enclosed
by a 1/2 hour fire rated
construction?
YES
Are there any openings
which cannot be closed
at discharge?
A: Calculate in M2 the area of
uncloseable openings
Install dampers etc
as required
B: Calculate 10% of the total area in m2
of all sides top and bottom of the enclosure
C: Calculate 10% of the volume in m3
NO
Add extra CO2 at the rate of 5kg/m2
opening (multiply as necessary by material
conversion
Total Flooding System Calculation
Is ‘A’ greater
than ‘B’ or ‘C’ ?
NO
Will the fire be
deep seated?
YES
YES
NO
Local application system calculation
Surface Fire: Basic Quantity
6m
9m
3m
•
•
•
•
V = 9 x 6 x 3 = 162m3
Volume factor: 0.8kg/m3…..(from manual 2.1)
Basic quantity of CO2 = 162 x 0.8 = 129.6kg
Total gas supplied: 45 X 3 = 135kg
Material Conversion Factor


Check Fuel Hazard Against Table 2
Multiply the Basic Quantity by MCF, e.g.
Vol 162m3
Basic Quantity = 129.6kg

Butadine: MCF = 1.3
CO2 Quantity =129.6 x 1.3 = 168kg
= 4x45Kg CO2 Cylinders

If possible check competitors calculation.
Uncloseable Openings
162m3
Vol =
Surface
Area = 198m2
9m
6m
3m
• Method A
Permissible Max Leakage Area = 10% of vol 162m3 = 16.2m2
• Method B
Permissible Max Leakage Area = 10% of SA 198m2 = 19.8m2
• Always use the lowest figure compensate at 5Kgm2
Total Flood
Temperature Correction

Usable range: -20ºC to +100ºC

Above 100ºC add 2% CO2 every 5ºC

Below -20ºC add 2% CO2 every 1ºC
Deep Seated Fire
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Refer to table 3 for hazard selection
20 minutes minimum hold time
Leakage is not desirable
(except high level venting)

Extended discharge where leakage
unavoidable

Refer to KFP for guidance
Deep Seated Fires
10m
5m
3m
Switch Room
3
Vol= 150 m
3
Flooding Factor 1.35 kg/m
Basic quantity is found from Table 3. Do not use Table 1.
Therefore basic quantity is:
150 x 1.35 = 202.5kg
i.e. 5 Kidde 45kg Cylinders
Extended Discharge
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Typical Applications
- rotating electrical machinery
Extinguishing concentration
- achieve in 1 min
- maintain 30% for run-down-time
Initial/extended discharge
Refer to Table 4 for additional gas quantity
CO2 Design - Local Application - 1


Protection against surface fires in:
- Flammable liquids, vapours, shallow solids
- Open areas
CO2 discharged directly at the fire: nozzle position critical
Hazards
Risk
Dip Tank
Solvent
Quench Tank
Hot Oil
Printing Press
Solvent
Textile Machines
Dust/ Fluff
Coating Machines
Solvent
Kitchen Range
Grease, Hot Oil
CO2 Design - Local Application - 2


In all the above cases protection should
include extract ducts, fume hood filters.
Services must be shut down e.g:
- Ventilation fans
- Solvent pumps
- Heaters etc.
CO2 Quantity
Two methods of calculation depending on the hazard:

Rate by Area- Using known nozzle characteristics the discharge
rate can be calculated from the number of nozzles required to
protect a given surface area. (See table 5)

Rate by volume- Use to protect irregular 3D objects where it
cannot be reduced to equivalent surface area or if an enclosure
exists it does not meet the requirement for total flood


Discharge duration: 30 seconds
For high pressure systems increase gas quantity by 40% as only
70% of cylinder is effective
Local Application Rate
by Area Method

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Used for flat surfaces
Flammable liquid fires - 150mm freeboard is required
150mm freeboard

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Area of protection and rate of discharge varies with distance between
nozzle and hazard surface.
Within limitations in Manual 7.3.2.
Local Application Rate
by Area Method
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The area of hazard surface protected by each
nozzle is determined by its side of square
Select nozzle carefully to minimise quantity of CO2
required
See KFP CO2 design manual Table 5
Position nozzle centred over and at 90º to hazard.
(May also be installed at between 45º - 90º)
- Refer to 7.2 Fig 1 & Table 6
Rate by Area Method
1.07
0.92
1.07
Surface Area: 0.92 x 1.07m = 0.99m2 (Side of square = 1.08m)
2 Nozzles at height 1.14m
Side of Square = 1.08m
Flow Rate = 25.2 kg/m, Total flow = 2 x 25.2 = 50.4kg
CO2 required = 50.4 x 1.4 x 0.5 = 35.3kg
Local Application
Rate by Volume Method
Also known as “Assumed Volume” method
- 3 dimensional irregular objects which cannot be
reduced to equivalent surface areas.
- where the degree of enclosure does not conform to total
flooding requirements.
 Total discharge rate based on volume of an imaginary
enclosure.
 This hypothetical volume must have a floor.
 Assumed walls & ceiling to be 0.6m from hazard (except
actual walls) and must enclose all areas of leakage,
splashing or spillage.

Local Application Rate
by Volume Method
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A minimum dimension of 1.2m shall be used.
No allowance to be made for solid objects within the
assumed volume.
Discharge rate for basic system: 16kg min m3
A reduction in the rate may be made when:
- There are permanent fixed walls 0.6m
above the risk
- The rate must not be less than 4kg min m3
- See KFP CO2 design manual Fig. 2
Rate by Volume Method
Vol A= 1x2x3=6m3
0.6
3.0
2.0
1.0
0.6
Assumed Vol
0.6
Vol B = 1.6 x 3.2 x 4.2=21.5m3
Therefore @ 16kg min m3 = 344kg
CO2 quantity actual = 344 x 1.4 x 0.5 = 240kg
0.6
0.6
Nozzle Location
Rate by Volume Method




Use enough to cover the entire hazard
volume.
Position of nozzle & objects must be
considered so as to retain CO2 within the
hazard volume.
Use table 5 as a guide for distance and area
covered.
Note: This method of system design always
uses more gas than the rate by area method.
Sales Features of CO2
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CO2 is cost-effective
KFP is internationally competitive
Convenient to engineer systems
Robust, reliable product
Widespread refilling facilities
A Comparison of CO2
and Inert Blend Gases
Composition A single gas (100% CO2 )
Blend of gases (52% N2,
40 % Air, 8% CO2)
Storage
Pressure
850psi (58 bar)
2175psi (150 bar)
Application
Flexibility
Three application methods;
total flooding, local application,
hand hose lines
Only one application
method; total flooding
A Comparison of CO2
and Inert Blend Gases
Agent
Efficiency
Just one cylinder provides 200
cubic feet (56 cubic metres) of
protection
Takes three cylinders to provide
200 cubic feet (56 cubic metres)
of protection-three times the floor
space required
Recharge
Simple operation- worldwide
availability
Complicated blending operation
limited availability
Extinguishing Oxygen reduction- oxygen
Method
content drops from 21% to
Oxygen reduction-Oxygen
15% unsuitable for 12%- potential
asphixiant with occupied spaces
strict EPA SNAP design
requirement when used in
occupied spaces