Revamping of a continuous annealing line at Svenskt Stål AB (SSAB), Sweden

Heated water from the furnace section is pumped in a system linked to the city of Borlänge heating-up 10% of the community’s houses representing roughly 10.000 inhabitants.

The first revamp increased the cooling capacity with installation of the rapid jet cooling system. The second revamp increased the customer’s ability to cool the strip at very high speed thanks to an additional combination zone for heating/cooling. The annual capacity of the furnace is now 500,000 tons per year at 950 °C maximum.

SSAB’s continuous annealing line (CAL) in Borlänge, Sweden is the only installation in Europe serving since years the market for high strength martensitic steels. The heart of the installation is the furnace section with its water quench unit and pickling unit allowing extremely high cooling rates to obtain the required mechanical properties for the special steel grades of this market. SSAB is not only advanced in this cooling technology, but also sets new standards in the environmental protection and use of energy. ANDRITZ Selas has supported this policy by designing the heat exchanger of the new gas jet cooler for operation with hot water. The heated water is pumped in a system linked to the city of Borlänge heating-up 10% of the community’s houses representing roughly 10.000 inhabitants.

Direct-fired furnace of the continuous galvanizing line at Tezcan, Turkey

Technical data of the line

	Continuous annealing line
Line capacity	500.000 tons per year
Max. furnace temperature	950° C
Protective gas (atmosphere)	5% H₂ and 95% N₂
GJC height	25 m
Maximum speed in the GJC	180 m/min
Strip width	600-1,550 mm
Strip thickness	0.35-2.2 mm