in Vol. 4 - November Issue - Year 2003
Shot Blast Systems for Mechanical De-scaling of Wide Strip
View at complete blasting plant
View into blasting cabin
Concept of blasting
Founded in 1900, DISA is the world‘s leading supplier of foundry equipment, metal surface finishing systems, and air pollution control solutions. DISA is constantly setting new standards in the industry through an outstanding commitment to research and development. With 2500 employees, DISA is represented worldwide with production facilities and sales and service subsidiaries on three continents, and an extensive agent network. DISA is part of the A. P. MOLLER-MAERSK GROUP
DISA successfully completed two projects 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 shot blast de-scaling equipment, to be combined with annealing and pickling equipment, for wide strip stainless steel.
DISA is the leading supplier of equipment for the mechanical de-scaling of narrow, medium and wide strip by shot blasting, and has also successfully carried out 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 de-scaling 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 decisively improved, and the wearing life of parts is 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, de-scaled 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 de-scaling, 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 de-scaled 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 worldwide. R&D and production sites for their high-tech production systems are in Austria, Germany, Finland, Denmark, France, Netherlands, USA, Canada. and China.