JIM NADAR, Technical Service with over 25 years of expertise in industry and defence sector, as well as over 12 years of competence in delivering solutions for Condensed Aerosol Generation Fire Suppression System In Bharat (India).

INTRODUCTION

After Halon extinguishers were phased out in the 1980s, Condensed Aerosol Generating Suppression (CAGS) Fire Extinguishing technology, which had originally been developed as a Halon substitute, has received a lot of attention. CAGS Fire extinguishing agents is most efficient, unlike traditional inert gas, foam, water mist, and Halon fire suppression agents, do not need to be driven out by pressurised gases and can extinguish class A, B, C, D, E, and F fires at 30 to 120 g/m3, which is significantly less than that of conventional extinguishing agents like CO2, HFC227ea, IG55, IG100, FK-5-1-12, etc...

HISTORY

Engineered almost 30 years ago in the Soviet Union as a byproduct of research on Russia's solid fuel rocket engines. Unlike most extinguishers, which focus on one of the three elements required for fire, namely heat, fuel, and oxygen, the Russian-developed technology focuses on interrupting the chemical process of fire. CAGS has been created to replace Halon. Condensed aerosols are uniquely safe and effective as fire extinguishing agents when the entire system is designed in accordance with regulations. 

After the dissolution of the Soviet Union, the technology's owners issued licences to interested parties to develop and distribute the items. They also provided licensees with the option of continuing to obtain the potassium-based substance from other sources within Russia. Several firms from throughout the world secured licences and began marketing Russian-sourced CAGS compounds with little refining or with local body structure and activation mechanisms. Because of the presences of Nitrocellulose and Chlorine traces, which are usually referred to as Generation 1, the CAGS compound was confined to specialised applications

RE-ENGINEERED

CAGS Fire Extinguishing technology has progressed from a Generation-I oil tank suppression system to a Generation-II (Aerosol "G") Non toxic & Non Corrosive based system for a wide range of applications such as Communication Base Station, Electric Power Industry, Petroleum Industry, Spacecraft Cargo Room, Weapons Warehouse, Mobiles Engine Room or oil tank, Metallurgy Industry, and many more...

For Industrial & Defence applications, the design of the CAGS Fire Extinguishing Canister has been further refined to achieve >85% discharge efficiency and less weight, i.e. "Low Gross Weight to Active Compound Weight Ratio Not Exceeding 4:1" This makes the CAGS Fire Extinguishing Canister lightweight and can be wall or ceiling mounted without danger of falling under strong vibration or navigation.

In the early 1990s, the Soviet Union (Russia) received the first patent.

CAGS Fire Extinguishing Technology of Generation II is more cleaner, noncorrosive, and has a high discharge efficiency of >95%. When compared to Generation I potassium salt-based CAGS fire extinguishing technology, the CAGS Fire Suppression system greatly solves the corrosion of electrical equipment and electronics.

As substitutes for Halon agents, the ODP and GWP values of CAGS Canister are nearly zero. Despite the fact that Generation II has been evaluated and is being promoted as non-toxic, it does not reduce oxygen in an inhabited environment, it is highly recommended to have an evacuation alarm with prerelease time prior to discharge of CAGS. Avoid prolonged contact with any fine aerosol.

Many nations across the world including Bharat (India) are attempting to develop indigenous compounds in order to capitalise on the commercial opportunities. In the near future, a comparable compound will be developed under the banner Make in Bharat.              

CONSTRUCTION & DISCHARGE MECHANISIM

The CAGS Canister is made up of an Generation-II solid compound made of potassium nitrate, an organic resin, and dicyandiamide in a rigid steel casing that aerosolizes finely divided solid particles typically based on alkali metal salts and gases typically composed of nitrogen, carbon dioxide, and a minor amount of water vapor.

It is self-generated by a thermal process of a solid aerosol-forming chemical housed in a non-pressurized canister with a robust steel casing in an IS 5 Red Colour canister. RAL 3000 is the industry standard. Fire Suppression Using Condensed Aerosol The aerosol-forming component is activated by an actuation mechanism in the canister. The insulating substance, which is mostly made of gypsum, cools the aerosol sufficiently before it is discharged into the enclosure.

The Condensed Aerosol thermal method offers enough energy for a quick discharge and efficient aerosol dispersal. Aerosol distribution does not require any propellant gas. Condensed Aerosol Generating Fire Suppression Canisters include discharge ports in radial or axial orientations for flexible mounting and installation, and are typically installed within the protected danger area. There is no need for pipes.

In terms of Condensed Aerosol Fire extinguishing device configurations, fixed or portable canisters are the most common among Generation II Condensed Aerosol Generating Fire Suppression Systems worldwide, whereas Generation I Condensed Aerosol Generating Fire Suppression Systems are integrated with the entire oil tank. Some countries in Europe, Russia, the United States, Australia, and China, among others, have already developed standards for the manufacturing and quality control of Condensed Aerosol Generating Fire Suppression agents, as well as norms for the design of Condensed Aerosol Generating Fire Suppression Systems under various fire protection scenarios.

PRINCIPAL OF EXTINGUISHING

"Fire propagation" radicals (OH, H, and O) are essential elements in fire propagation. Condensed Aerosol Generating Fire Suppression Agents suppress the fire (mainly) by interfering chemically with these free radicals within the fire zone, so disrupting the ongoing fire reaction. 

The Condensed Aerosol Generating Suppression agent is released as micro solid particles, mostly composed of potassium radicals. The Condensed Aerosol Generating Fire Suppression interacts with the fire radicals formed during combustion (hydrogen, oxygen, and hydroxyls) and extinguishes the fire when injected into the blazing zone of a fire. Because tiny aerosol particles have a wide surface area for trapping radicals, they are excellent extinguishing agents. Coolants in Condensed Aerosol Fire Suppression systems are studied for the first time, as they are responsible for lowering Condensed Aerosol temperature to reduce secondary fire danger. Cooling effects are typically obtained by coolant vaporisation and endothermic chemical breakdown. 

EXTINGUISHING CONCENTRATION     

To design the system, the applicable standards of ISO 15779, EN 15276-1, BRL-K23001, NFPA2010, UL topic 2775, as well as the manufacturer's design and test data and the authority having jurisdiction, should be applied.

The following extinguishing concentration was calculated using test data

 From multiple Condensed Aerosol companies in compliance with International Standards.

* Determined by class B or C/E involvement,

** Determined by class A or C/E involvement, 

*** Determined by class A or B involvement

The above concentrations excludes discharge efficiency for specific canister, refer Table “Efficiency of generators type” from the notified bodies detailed test report (Request Manufacturer for the test report) confirming to ISO 15779 / EN 15276-1 / BRL-K23001 / NFPA2010 to find the discharge efficiency, also excludes all safety factor.

In addition to Minimum Safety Factor 1.3 additional K1, K2, K3 & K4 needs to be considered for more details & Free Engineering mail to info@jimreeves.in.

Design Concentration (Kg) = DC

DC = (V x C x SF x K1 x K2 x K3 x K4) 1000

V = Volume (M3), 

C = Min. Concentration (gm/M3), 

SF= Minimum Safety Factor (1.3),  

K1= Coefficient Non-Uniformity Aerosol Distribution,  

K2 = Coefficient Leakage Factor, K3 = Coefficient  for Cable Tunnels,

K4 = Coefficient for Altitude or Temp.

ADVANTAGE OF CAGS FIRE SYSTEM

➭ Non Toxic

➭ Fit & Forget 

➭ No Re-ignition

➭ Non Corrosive 

➭ Non Conductive

➭ No Water damage

➭ No Pressure built-up

➭ No Oxygen depletion

➭ Zero Pressure storage

➭ Fail Safe & Highly reliable

➭ No high pressure Cylinder

➭ No Pipe work & Manifolds

➭ Wall/Ceiling Mounted

➭ Large sizes & capacity 

➭ Suitable fire class  A, B, C, E, F

➭ Zero Ozone depletion

➭ Zero Global Warming

➭ Environment-friendly 

➭ Prevent Flash-over

➭ Prevent Back-draft

➭ Easy to find fire source

➭ Shelf life not less than 15 Yrs

➭ Fixed / Portable Options

➭ Self activation >3000 C

➭ Can replace existing System 

VARIANTS

FIXED AUTOMATIC SYSTEM, MANUAL FLOODING TOOL, STANDALONE

The canister sizes range from a rupee coin to nearly a foot. 

APPLICATIONS

✓ Battery Energy Storage

✓ Transformer Rooms

✓ Duct Protection

✓ Flammable Liquid Storage

✓ High Rise Building

✓ Server Room / Data Centre

✓ Gas Turbine Enclosures

✓ Switchgear Rooms

✓ Generator Rooms

✓ Engine Compartments

✓ Wind Turbines

✓ Machinery and Engine Room

✓ Firefighter First Responder

✓ Dust Collections Etc…

SELECT THE RIGHT CAGS FIRE SYSTEM

There are several Condensed Aerosol Generating Fire Suppression products on the market; customers should consider the following critical factors before purchasing the product.

➭ Check the kind of aerosol compound type (1st / 2nd Generation). Condensed Aerosol extinguishing compound should be free of chlorine, nitrocellulose, and pyrotechnics.

➭ Check the Active Compound Extinguishing Concentration (Check the pre-burn time, soak time, and aerosol density depending on the fire class specified in the Notified Body Test Report).

➭ Check the product's discharge efficiency that should not be less than 85%, which may be confirmed using the table "Efficiency of the generator types" from the notified body test report.

➭ For Aerosol Compound Acute Oral, Acute Inhalation, Acute Dermal Toxicity, and Acute Ocular (Eye) Toxicity, look for a Non Toxic Certificate from an International Testing Lab or a NABL Accredited Lab.

➭ According to ISO 15779, the canister shall have a hold time (Re-Ignition Prevention) of more than 25mts to stop re-ignition, and the relevant notified body report should be confirmed.

➭ Check the gross weight of the canister, which should be lighter in weight, with maximum active compound weight to gross weight ratio of 1:4 being optimum.

➭ Check the service life, which should not be less than 15 years, and verify the appropriate notified body test result.

➭ Best condensed Aerosol has a wide working temperature range of -50 degrees Celsius to +75 degrees Celsius

➭ The system must be effective against all fundamental fire classes (A, B, C, and E). 

(This "Expert Talk" Published in March 2024 Edition)