Nitrogen steels suppression system
When Kentucky-based North American Stainless (NAS) was building a new production line for annealing and pickling of stainless steel, the company needed a fire suppression system that would meet certain requirements at the new facility. The new NAS pickling line, AP4, is one of the largest units of its type in the world, with an annual rolling capacity of more than 1.2 million tons. The new fire suppression system would have to protect more than 200 ft of pickling line, and both flooding and local application solutions would be required.
NAS and its special hazards fire system provider, 3S Inc., decided on the electronic detection equipment, manual pull stations, and Vortex fire suppression system from Victaulic . The Vortex is a twin-fluid, hybrid system that combines two fire suppression technologies—inert gas and water mist—to both absorb heat and extinguish fire. The Vortex discharges water droplets less than 10
“Vortex delivered the performance without the water damage,” said Tom Euson, president of 3S Inc. “In fact, most of the system testing after installation was conducted with the lines running. There was no damage to motors and controls, and there was no water accumulation on the floor.”
Due to the open-space environment of NAS' pickling line, the company needed a fire suppression system capable of protecting the equipment without requiring room integrity and from a great distance away. The Vortex system distributes a high-velocity stream over great distances, which envelopes the hazard in open space. Additionally, the company needed a system that featured a quick system recharge to eliminate equipment downtime. The Vortex system provides each pickling line with three to six discreet zones of coverage with the capability of discharging exterior and corresponding interior zones simultaneously.
The suppression system stores enough nitrogen in bulk tanks central to the lines, for 100% redundancy in the largest zones. The system resets in minutes, and during a hazard, only the lines where the hazard occurred need to shut down for system reset, which translates into a minimum downtime for the facility.
The fire suppression system's effectiveness is a result of the combination of low-pressure discharge and high-velocity delivery. In the Vortex system, water is introduced into a supersonic jet stream of nitrogen and then delivered to the protected area at 40 mph. The blending of nitrogen and water at the emitter helps distribute the mixture at the hazard simultaneously, resulting in heat absorption and extinguishing. The system's low operating discharge pressure of 25lb/ sq in. at the system emitter allowed for the use of plastic pipe for both the nitrogen and the water lines.
Information provided by Victaulic.
At A Glance
North American Stainless (NAS) needed a fire suppression system that met specialized protection requirements for its stainless steel annealing and pickling line. NAS selected the Vortex fire suppression system from Victaulic as the solution to its fire suppression problem.
The twin-fluid—inert gas and water—Vortex fire suppression system met NAS's specialized fire protection requirements by being able to:
• Protect sensitive motors and controls without using large quantities of water
• Be effective in corrosive environments
• Provide open-space effectiveness without requiring room integrity
• Feature minimum facility downtime following system discharges
• Have design flexibility for future facility expansion and ease of maintenance.