The Development and Field Testing of a High Temperature Ceramic Recuperator

Abstract

Under cost-shared funding with the U.S. Department of Energy and the Gas Research Institute, AiResearch Manufacturing Company, Torrance, California has developed a ceramic/metallic hybrid recuperator to operate in dirty industrial flue gases up to 2500°F. The recuperator assembly is designed to provide up to 2000°F preheated combustion air from 2500°F flue gas. The 2000°F air preheat temperature provides over 50 percent savings in fuel consumption compared to an unrecuperated furnace. The assembly consists of a ceramic recuperator in series with a conventional plate-fin metallic recuperator. The ceramic recuperator consists of 1.5 inch outside diameter silicon carbide tubes with internal cruciform baffles to enhance heat transfer. A recuperator system for a 20 MM Btu/hr furnace was designed, fabricated, and installed in the flue gas of a rotary forging furnace at Cameron Iron Works, Inc., Houston, Texas. The system has operated successfully for about 2500 hours in the six months starting in November 1985. A maximum air preheat temperature of about 1900°F was achieved with a flue gas temperature of about 2100°F.