SUCCESSFUL COMPLETION OF TWO PROJECTS FOR MECHANICAL DESCALING OF WIDE STRIP IN ASIA

In recent months, DISA Industrie AG, Schaffhausen, Switzerland, has successfully completed two contracts for companies in the Asiatic region. The order originated from the general contractor for the projects, Andritz-Group and was for the planning and supply of HB shotblast descaling equipment, to be combined with annealing and pickling equipment, for wide strip stainless steel.

DISA is the leading supplier of equipment for the mechanical descaling of narrow, medium and wide strip by shot blasting, and has also successfully realized a number of large projects in the past. For this field of application, DISA has at its disposal extensive experience and high quality, reliable equipment. At high blast wheel capacity and maximum energy input, DISA equipment guarantees a qualitatively high and uniform descaling operation. The effective dust removal concept prevents dust deposits on the steel strip, and provides for a flawless separation function: undersized abrasive grain and scale are discarded reliably from the shot circuit. The degree of cleanliness of the strip and the surface quality (uniform roughness) can thereby be improved decisively, and the life of wearing parts are prolonged.

Baosteel Group Ningbo Baoxin Stainless Steel Company Ltd., in Ningbo, China, one of the largest producers of stainless steel, placed an order with Sundwig GmbH of the Andritz-Group for a new complete annealing and pickling line for hot rolled steel strip. Important parts of the new production line are two DISA shot blast systems of HB 2x4 design operating in series. With the blast cleaning machines, the scale developing from annealing is removed reliably and in an environmentally friendly way. The plant is designed for a production capacity of 700,000 tons of stainless steel strip per year. With strip widths of 650 - 1350 mm and output speeds of up to 91 m/min. The 3 - 6 mm thick hot-rolled strip is heat treated, descaled by shot blasting, and pickled. More than 5 km of steel strip can be produced per hour. The plants operate round the clock for about 7000 hours per year.

For mechanical descaling, 16 blast wheels of a power rating of 110 kW each are used. Shot throughput is more than 1100 t/h.

The manufacture and pre-assembly of the key components is being performed in the DISA subsidiary Pribram / CZ, and shall be completed by the end of March 2004. Other components are being produced locally - in the new manufacturing shops in DISA Changzhou, China. By way of the strong local subsidiary, DISA can also give the customer quick and competent maintenance support after the commissioning of the plants.

The Taiwan based Yieh United Steel Corp. is making investments in a new hot rolling, stainless steel line via it’s daughter Company Lianzhong Stainless Steel Corp. in Guangzhou, China. The order is likewise being handled by the Andritz-Group as the general contractor.
Here also, two HB 2x4 blast cleaning machines operating in series are to be employed. With strip widths of maximum 1600 mm and thicknesses of up to 10 mm, the strip is descaled at throughput speeds of up to 127 m/min.

About the Andritz-Group
The Andritz-Group, listed on the stock exchange and with headquarters in Graz, Austria, is one of the world leaders in the field of high-tech production systems for the pulp and paper industry and other specialised industrial branches. As per June 30, 2003, Andritz employs 4518 people world-wide. R&D and production sites for their high-tech production systems are in Austria, Germany, Finland, Denmark, France, Netherlands, USA, Canada. and China.