Automobile applications down under


Pyrogen Fire Suppression System   Vehicle Applications
 Dr Julia Berezovsky. Technical Manager - Pyrogen Corporation Australia.

PyroGen is a Pyrogenic Aerosol Extinguishing System, and is one of the most efficient Halon Alternative agents available.

The principle of extinguishing action employed by PyroGen is unique - a special solid chemical, when electrically or thermally ignited, produces combustion products - micron size dry chemical particles and gases that mix together into an uniform aerosol.

This aerosol is extremely effective in extinguishing fires, especially those involving materials of hydrocarbon origin, such as petroleum, diesel, hydraulic liquid, lubricants, natural gas, wood etc. The micron size aerosol particles exhibit gas like three dimensional qualities that allow the agent to rapidly distribute throughout an enclosure and reach into the most concealed and shielded locations.

PyroGen has a knock-down effect. Its extinguishing action is achieved primarily by interfering chemically with the fire reaction and secondarily by thermal cooling. Normal design concentration is only 100 g/m3, which is more than 3 times lower than that for Halon 1301 (330 g/m3). Such low design concentration coupled with almost instantaneous extinguishing action makes PyroGen one of the most efficient agents currently available.

Apart from being effective, PyroGen is very simple in installation and operation. Pressurized cylinders and propellant gases are not necessary since the pyrogenic mechanism of aerosol generation provides sufficient energy for a rapid discharge and efficient distribution. Aerosol is self generated upon activation of the system. The PyroGen system simply consists of a series of canisters called MAG generators, strategically placed within the risk area and electrically connected to most types of manual or automatic fire control panels.

Operation of PyroGen system could be either electrical or thermal. When an electrical current is supplied to the electrical ignition device of Pyrogen generator, the solid aerosol – forming composition undergoes a combustion reaction to produce its fire extinguishing aerosol.

Electrical operation can be either automatic (heat or flame detectors provide electric power from the fire panel to the Pyrogen generators ignition circuit) or manual (manual push button/switch provides electric power from the fire panel to the Pyrogen generator's ignition circuit).

There is an additional mechanism of activating Pyrogen generator via a built-in pyrotechnic fuse which ignites when in contact with flame or subjected to high temperatures. Ignition of fuse leads to an ignition of the solid aerosol – forming composition. This is thermal automatic operation of Pyrogen generators.

In Marine applications the PyroGen system is operated manually by electrical means. Two independent power supplies are required together with 20 second time delay. For use on commercial vessels these conditions form part of Uniform Shipping Code and are stipulated in approval listed by the Waterways Authority.

In Vehicle applications PyroGen system is operated either manually, automatically or both. Manual operation is electrical by means of a guarded push button switch that can be installed in any suitable location within the vehicle. The switch supplies electric power from the car battery to the MAG generator ignition circuit. Automatic operation is by means of a pyrotechnic fuse that connects MAG generators and is run around the engine compartment. It auto ignites when exposed to temperatures in excess of 170°C, and within less than a second propagates ignition to MAG generators, thus activating the system.

As PyroGen aerosol stays in suspension it is easily removed by any airflow. As such application in vehicle suppression systems would leave no residue and, therefore, no clean-up would be required after use. This does not apply to marine applications as the engine compartment in a vessel is enclosed, forced ventilation will be required after Pyrogen discharge. As forced ventilation may not be immediate, post–discharge clean-up may be required.

PyroGen aerosol is non-conductive and non corrosive. A further advantage is that even if PyroGen aerosol enters the engine or vehicle’s electrical components, they would not be damaged. This has been proved by successful testing of PyroGen as a Strangler System for an emergency shut-down of diesel and gasoline engines. Action of PyroGen aerosol as a strangler was immediate and positive. Subsequent testing of the engine's power output and the chemical analysis of exhaust emission and engine oil demonstrated that the engines suffered no detectable ill effects.

Benefits offered by PyroGen Marine Fire Suppression System have already been recognized by Waterways Authority Australia - for use on commercial vessels. PyroGen has been listed as a total flooding agent by US EPA under its SNAP program and adopted by Standards Australia and New Zealand. PyroGen is listed as a Halon alternative for total flooding applications in normally unoccupied areas. Listing under Powered Aerosols C.

The  PyroGen Vehicle Fire Suppression System has been developed for the protection of engine compartments of small commercial and four wheel drive passenger vehicles.




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