Ladle Refining Furnace- Typical Water Cooled Roof
Ladle Refining Furnaces (LRFs) are used to remove impurities, improve
homogeneity and hold molten steel and superheat to required tapping
temp. for subsequent casting operations. It is used as a buffer between
the basic melting Furnace such as, Basic Oxygen Furnace (BOF), Arc
Furnace or Induction melting Furnace and the Continuous Casting
Machines.
By allowing the Steel Melting Furnace to be used exclusively as basic
melting units, productivity and lining life increase significantly due
to absence of refining process and lower tapping temperature. Further,
LRF's allow flexible schedulign between availability of caster and
readiness of molten steel from the Furnace. The estimated cycle time
and heating rate for secondary treatment are give below.
Ladle Positioning on Ladle Car
|
1.0 min
|
ladle Car Positioning under Roof
|
1.0 min |
Roof Lowering on ladle
|
1.5 min |
Temperature & Sampling (manual)
|
2.0 min |
Alloy and flux addition (depending on steel grade)
|
5.0 min |
Temperature rise time
|
20.0 min |
Wire feeding, if any
|
3.0 min |
Final temperature and sampling (manual)
|
2.0 min |
Final adjustment, etc. (if required)
|
2.0 min |
Roof raising
|
0.5 min |
Ladle Car Positining out of LRF area
|
1.0 min |
Ladle Lifting from Ladle Car
|
1.0 min |
Total Cycle Time
|
40.0 min |
Heating Rate (Typical)
|
4 to 50C/min.
|
Typical LRF Rating:
Capacity
|
12 Ton
|
15 Ton
|
20 Ton
|
25 Ton
|
30 Ton
|
Transformer
|
2.5 MVA
|
3.0 MVA |
4.0 MVA |
5.0 MVA |
6 MVA |
Electrode Diameter (mm)
|
200
|
200
|
200
|
250
|
300
|
PCD (mm)
|
410
|
410
|
410
|
550
|
600
|
|
