Charles Pankow Award for Innovation
Lightweight Modular Composite Firewall System, Composite Support & Solutions, Inc.
In December 2006, a transformer explosion in Beaverton, Ore. plunged 50,000 people into darkness and in 2004, a transformer fire cost the Arizona Public Service West Wing substation $29 million. Given the costs associated with such events, how can their impact be mitigated in the future? Composite Support & Solutions Inc., Southern California Edison, San Diego State University Research Foundation and the University of Southern California aimed to do just that when they developed Intelli-Firewall—a lightweight modular firewall system that protects each transformer and isolates the potential damage associated with catastrophic failures.
Major transformers are grouped in banks of four or more, each containing up to 14,000 gallons of highly refined mineral oil. The fires that are commonly associated with catastrophic transformer failures can increase the impact of failure beyond the loss of a singular asset—significantly increasing the severity and duration of power interruptions. While one solution would be to replace all transformers, a single replacement can take up to two years and cost anywhere from $4 million to $6 million.
The spaces between installed transformers are typically narrow making it difficult to install traditional firewalls. However, Intelli-Firewall consists of a 35 feet by 35 feet wall constructed with 28 panels assembled in four vertical sections. The vertical columns holding these sections are prefabricated, fire-protected steel beams with durable bolt-on covers, making the firewall both easy to assemble and remove, should access be necessary to address a transformer maintenance issue. The lightweight nature of the panels allows lifting with a small crane or manlift, and the cellular panels provide the necessary structural characteristics and fire resistance, while at the same time reducing the overall weight of the system.
The team used chemically bonded ceramics (CBCs) as a resin and created an advanced composite material by combining that resin with glass and carbon fibers. Pultrusion technology was adapted to combine CBC material and fibers in unique ways, and the resulting composite material has demonstrated fire resistant characteristics and a mechanical toughness, which were impossible to achieve with the CBC resin alone.
Traditional firewall construction methods use block-by-block masonry construction, extending the installation time, but the new system has cut down the time a transformer must be out of operation for firewall installation from one week to one day, and it can be installed simultaneously with other construction activities.