Vaccum Degassing

Home / Vaccum Degassing
business-area

The purpose, of using Vacuum Degassing Process on Liquid Steel , is as following

  1. To reduce hydrogen level of the liquid metal to safer levels for FORGING.
  2. Effective elimination of inclusions & to improve cleanliness of steel
  3. Homogenisation of molten metal
  4. Reduction of Sulpher, Nitrogen & Oxygen level

VACUUM OXYGEN DECARBURIZATION (VOD):

The purpose of the VOD is to bring changes in the chemical composition of Liquid Steel . As evident , from the process name , Oxygen is used , under Vacuum , in the Vacuum Oxygen Decarburisation Process.

Following types of steel are produced from VOD

* Very low carbon Stainless Steel , using high carbon ferro chrome.
* Economic production of all ELCN ( Extra Low Carbon ,Nitrogen) grades.

VCD ( Vacuum Carbon Decarburization) & VD are the further steps performed on the Liquid Steel.
Business_image

TYPES OF VD/VOD EQUIPMENTS , WE SUPPLY :

These equipment are quite useful for Small Batch Of Liquid Steel. The Suction Volume is quite low & due to this Vacuum Pump suction capacity is reduced signifacntly. Ladle Degassing is usuful for Steel Plants based on small EAF / Induction Furnaces & can be supplied upto 20T Capacity.

In Tank/Vessel Degassing the Ladle is placed into a fixed Tank/Vessel . Due to this quite intensive argon stirring is possible. Also leakage issue (observed in Ladle Degassing , if Ladle Flange is not clean) are not encountered. All large capacity steel plants are equipped with Tank Degassing facilities.

This is a modern method for Casting Ingots Under Vacuum. The salient features of this process are :
  • A.Temperature losses associated with other VD processes are avoided.
  • B. In the process streams degassing is applicable , which results in lower level of Hydrogen in the ingot.
  • C. The biggest advantage from this process is that we can cast bigger size of the Ingots form the furnace capacity , by providing additional liquid metal for the process.
As an example , if there are one EAF of 150T Capacity & two LFs of 150T Capacity , then it is possible to cast 450T Capacity Ingots , normally required for power plants.

VACUUM GENERATION UNITS For creating vacuum , we design our system on following variants of equipments

Business_image
1. STEAM EJECTOR SYSTEM :

This system is based on Ejectors & Condensers for creating vacuum. As there are very few moving parts in the ejectors , this is quite robust & reliable. This system is prefered where availability of water is abundant.

Business_image
2. MECHANICAL PUMPS :

This system comprises of different types of Mechanical Pumps arranged in different sequences. This system is catching up very fast with Ejector based System as their have been several developments in recent past.

Business_image
3. COMBINATION OF EJECTOR & MECHANICAL PUMPS :

This is a system in which both Ejectors & Mechanical Pumps are used . Mechanical pumps are used in the last stage , reducing the steam consumption & wastage .