Economical vacuum degassing of steel with the use of mechanical pumps

Abstract

If greater use is to be made of vacuum technologies in out-of-furnace treatments of steel within Russia, more stringent requirements will have to be met in regard to the reliability, productivity, and efficiency of the pieces of equipment used to create the vacuum-the vacuum pumps. Unfortunately, Russian-made vacuum pumps do not presently meet these requirements.

The equipment traditionally used to create a vacuum in units designed to treat steel outside the steelmaking furnace is based on steam-jet ejectors. This article compares the operating costs of a vacuum-degassing unit for 90-ton heats when the unit is equipped with mechanical pumps and when it has a steam-jet-ejector station. In the latter case, liquid-ejector pumps are used as the starting stage. It was found that the costs of the material resources and maintenance of the auxiliary equipment of a vacuum-degassing unit with mechanical pumps are roughly 10 times less than the analogous costs of a vacuum system with steam-jet ejectors. Another important advantage of vacuum-degassing units with mechanical pumps is that they are environmentally safe.