Present State of Top Gas Pressure Recovery Turbine Plants

Abstract

Recently, top gas pressure recovery turbine plants have been installed in some steel making plants for energy saving. Eleven turbine plants have been operated including two test plants in Japan.
Total operation time of the first plant (Kawasaki Steel Corp. Mizushima Works No. 2 B.F) was approximately 26 400 hours.
There are two basic types of turbines for energy recovery; wet and dry. A radial flow turbine is of the wet type, and an axial flow turbine is of the dry type. Each turbine has special devices designed for prevention of corrosion, erosion and clogging of the turbine by dust and moisture-laden gas. These turbine systems have had no effect in any way on the blast furnace operation. Recovery turbine output of the first plant reaches 20 to 30% of blast blower input energy and its availability, approximately 85%, is over the average of self-thermal power plants in steel making plants.
In the future, economical plants will be developed for further improvement of turbine output and higher reliability of turbine systems including gas cleaning equipment.