Development of Efficient Combustion Technology Applying High Cycle Regenerative Heat Exchange System

We have developed a cost effective and environmentally safe high cycle regenerative heat exchange system. This system is equivalent to a regenerative burner when the combustion air is used for the preheated gas. W e have implemented biggest regenerative burners in both radiant tube (R/T) type and direct firing type by developing the following technologies: (1) a low NOx emission combustion technology at high preheat temperature, (2) an optimal control technology on the gas flow rate through the regenerator. The R/T burner is now used in No.2 Continuous Annealing Line and the direct firing burner is used in the reheating furnace of the wide flange beam mill at Mizushima Works. Using these burners, the fuel of 15% or more has been saved. We have also implemented a non-oxidizing heating system (N2 jet heater) using high-temperature inert gas injection by developing the following technologies: (1) a regenerative heat exchange system with an internal combustion chamber, (2) a valveless high temperature gas injection system, (3) an atmosphere control technology in a furnace in order to accomplish the non-oxidizing heating over 1,773K, which was considered very difficult with the existing technologies. The system was introduced in the No.4 Slab Caster first time in the world and improved the quality of cast slabs.