Vacuum Refining Furnace 15T-120T VD / VOD Furnace For Steel Plant

VD/VOD furnaces (Vacuum Degassing Furnace/ Vacuum Oxygen Decarburization Furnace) are core equipment for vacuum refining, mainly used for degassing, decarburization, and alloy fine-tuning. VD focuses on vacuum degassing, while VOD adds vacuum oxygen blowing decarburization, suitable for stainless steel production.

A Vacuum Degasser (VD) serves several purposes: lowering dissolved gas levels (H₂, N₂, O₂) in molten steel, achieving uniform steel composition and bath temperature, removing oxide inclusions, and creating favorable technical conditions for final desulfurization.

During VD operation, argon gas is introduced through a single refractory plug in the ladle bottom to stir the melt and ensure homogeneity. The argon connection is automatically made when the ladle is positioned inside the vacuum tank.

The vacuum tank is evacuated to the required pressure using one of three methods: a steam jet ejector; a combination of steam jet ejectors with a water ring pump; or mechanical pumps. Exhaust gases are removed via the vacuum pumping system and are collected upstream of the pumps, or alternatively, discharged under water in a concrete hotwell equipped with a weir wall. Process gases—including those entrained in the inter‑condenser discharge water—are drawn from the hotwell by a motor‑driven fan and sent to a vent stack fitted with a flare burner. Water from the hotwell is pumped to a cooling tower that is part of the contact water system.

The VOD furnace is primarily used for producing stainless steel. It is essentially a tank degassing unit equipped with an additional oxygen blowing lance and associated components. The reduced CO partial pressure under vacuum allows high‑alloy steel grades to be decarburized down to very low carbon levels.

Steam jet pumps are configured with four or five ejector stages, and the motive steam is condensed using contact water condensers. These pumps can be either full steam pumps or hybrid pumps combined with liquid ring pumps.

Equipment Composition

Vacuum tank and cover

Cover lifting mechanism

Steel ladle and ladle car

Oxygen lance mechanism (for VOD)

Vacuum charging device

Temperature measurement, sampling, and observation system

Vacuum pump system

Oxygen/argon/cooling water system

Single or dual station design

Overhead, pit, or vehicle-mounted arrangement for vacuum tank

Effective dehydrogenation, denitrogenation, and deoxygenation enable ultra-pure steel smelting

The VOD furnace achieves decarburization through vacuum oxygen blowing, enabling the production of ultra-low-carbon stainless steel

Features of VOD furnace steam jet pumps:

Reliably high suction capacity under deep vacuum conditions and also in the medium range for heavy process gas loads

Robust, long‑life design suited to steel plant demands

Simple maintenance requirements

Low wear and tear

Vacuum control via needle valves