Visakhapatnam Steel Plant (VIZAG STEEL)
Navaratna PSE under the Ministry of Steel. Visakhapatnam Steel Plant - popularly known as Vizag Steel is the first shore-based integrated steel plant in the country and is known for its quality products and customer delight. A market leader in long steel products, it caters for the requirements of the construction, manufacturing automobile, general engineering and fabrication sectors. RINL-VSP is the first integrated steel plant to be certified for ISO 9001:2008, ISO 14001:2004 and OHSAS 18001:2007 standards. It is also the first PSE to be certified for ISO 50001 - Energy Management Systems and CMMI Level 3 Certification for Software Development.
Challenges
- Control and tuning of the two strand rolling placed at upstream line
- Achieving full capacity at highest speed and sustaining the production levels
Our solution
This mill is designed with twin strand configuration at the intermediate mills. Whereas the fast roughing mill, wire rod mill, coil handling areas are separated for individual lines. There are three billet skids for cold charging and three chain transfers for hot charging located in 0m level, which is transported to furnace at 5m level via billet elevator. The walking beam-type furnace has a storage capacity of 96 billets to heat it to a temperature of 1050°C. Once discharged it passes through the Descaler and enters into a single strand, fast roughing area, consisting of one pendulum shear, six stands, one crop shear and diverter to divert to any one strand of the intermediate mill area. Intermediate area is split into two sections, first section consists of six stands, one shear and second section consists of four stands. After Intermediate area, each of the two strands has its own dedicated lines. Each wire-rod line has one of two-stand Vee-type pre-finishing mill, eight-stand Vee-type finishing mill, four-stand Vee-type reduction and sizing mill, pinch roll, laying head, conveyor and coil handling area.
Any one line can be selected as master line. In master line, the finishing speed is held constant and speed is cascaded upstream till stand seven. For slave line, speed is cascaded upstream till PFM and the finishing speed is kept constant as long the repeater position, after Stand 16, is within the dead band. Once the repeater loop is out of dead band, the speed is corrected till the deviation is within 120mm. The repeater has a loop height capacity of 2250mm and its present dead band setting is 650 to 1400.
WRM-2 Facilities are:
- 6- Stand Single strand Fast Roughing Mill.
- 2- Strand insulated Roller Table.
- 6 Stand Intermediate Mill - I
- 4 Stand Intermediate Mill - II
- 2 x 2 pre-finishing train.
- 2 x 8 -stand No-Twist blocks.
- 2 x 4 stand Reducing and Sizing Mill (RSM)
For two strand rolling, both lines are running as upstream, which is a rare requirement and very challenging to control and tune.
5.5 mm Rolling at 115 mps has been achieved, normally there are not very many examples of such high-speed mills.
Laying Head FEO at 110 mps achieved successfully, which needs absolutely perfect tuning of the Line.
System Details
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- ABB 800xA 5.0 SP2 Rev D
- Control Builder 5.0.2.4
- PEC Firmware 5.0.3.2
- Controller: PPD 113 10k FPGA @ 600 Mhz