The Revamp Project on Laminar Flow System

摘要

No. 1 HSM of China steel revamped 3 down coilers, run out table and laminar flow system successfully within 30 days' shutdown at the end of 2004. The main change items are (1) Add 3 hydraulic down coilers and removed the old down coilers (2) Replace whole laminar flow system and extend the cooling distance with intensive banks (3) Replace the run out table and reduce the distance between run out table rollers (4) Add automatic surface inspection system (ASIS). (5) Add slab sizing press system (SSP). New CTC (coiling temperature control) system, which uses Finite Difference Model (FDM) with phase transformation consideration, was parallel running with old table style model, which stored in Alpha system, around 3 months successfully to reduce the tuning effect with the rolling mill. All run out table were replaced with all foundation modification. Flow meter, intermediate pyrometer, flow pressure and temperature effect are considered in the design stage. The speed effects, different spray patterns, different feedback logics were tested during the tuning stage. The CTC performance was increased to +- 15 deg C 97.2 percent. The benefits of this revamping project about the laminar flow system are (1) Produce dual phase, TRIP steel and carbon steel up to 25.4mm and API X80 up to 20mm (2) Increase the moving power to improve the flying problem of light gauge products (3) Improve the CTC performance (4) Increase the flow rate of bottom side to improve the C-Bow problem of heavy gauge (5) Special control logic to protect the cooling pipe and rollers of run out table.