RECENT DEVELOPMENTS AND EXPERIENCES IN MODULAR DRY MECHANICAL VACUUM PUMPING SYSTEMS FOR SECONDARY STEEL PROCESSING

摘要

As the world wide demand for speciality steels continues to increase, significant attention is focused on the VD and VOD processes, with an increasing emphasis on lowering energy consumption, improving production rates, ensuring environmental compliance, and reducing greenhouse gas emissions. The combination of ladle tank installations having low leak rates with specialised, high capacity, dry mechanical vacuum pump systems now enable an integrated and optimised vacuum degassing station design, precisely specified for the needs of the process. High efficiency, 3-stage vacuum pump modules provide the required pumping capacity to suit the process together with a very economical power demand and a low consumption of utilities. Key features are the good operational flexibility of such installations and the integration of pump control, using variable frequency drives for each pump, directly into the control system. Overall efficiency is maximised and operating energy savings of up to 90% or more can be achieved, compared to conventional steam ejector-based systems. Additional major benefits are significant reduction in green house gas emissions and reduced effluent disposal costs.