Rösler Oberflächentechnik GmbH, Werk Memmelsdorf

Efficient blast cleaning of different size steel pipes

The experience and know how of the Rösler team convinced Terex cranes, a world wide leading crane manufacturer, to purchase the new pipe blaster RDR 500 for their plant in Zweibruecken where lattice boom cranes are manufactured.

At this location Terex® produces lattice boom cranes with a payload of more than 300 tons which can move under full load (“pick & carry”). At the Zweibruecken site the CC 8800-1 TWIN is built. The biggest and strongest crane in the world it can lift 3200 tons and still move under full load. An essential section of this type of crane is the lattice boom that is fabricated from steel tubes of different diameters and lengths. The new tube/pipe blaster RDR 500 allows Terex® to de-scale and de-rust tubes with a length of up to 18,000 mm and a diameter of up to 500 mm prior to flame cutting.

Processing trials ensure a stable and consistent blast process
A major factor in the decision for the RDR was that Rösler has already supplied a number of nearly identical tube blast systems to OEM’s as well as steel trading companies. Another important point was that Rösler was able to adapt the machine design to the Terex® requirements by conducting processing trials in the Rösler test lab. The trials showed that the required degree of cleanliness, according to the Swedish Standard of SA 2.5 (“near white”) surface conditions are achieved in the machine with travel speeds from 2.0 to 6.5 m/min due to the two high performance Hurricane® H42 blast wheels which are driven by 22 kW motors. These easy to maintain single disk blast wheels are mounted sequentially on the blast chamber. The blast chamber itself is fabricated from wear resistant manganese steel. The precisely defined blast angle ensures that the required blast results
are consistently achieved in the specified time, even with tubes with a relatively large diameter.

Optimum interface between blast and flame cutting operation
Since the Terex® specifications only call for the blast cleaning of the outer tube surface the open tube ends are masked, however, Rösler also offers solutions for applications where
blast cleaning of the inside and outside of the tubes is required. Transport of the tubes through the blast machine which is equipped with an entrance and exit vestibule takes place with two 18 meter long roller conveyors with a rated load of 500 kg per running meter. The blast cleaned tubes are directly transported from the exit vestibule into the flame cutting system. Since the supplier of the flame cutting system, HGG Profiling Equipment BV from the Netherlands, and Rösler have had a long term and friendly cooperation, the interface issues between the controls of the two systems could be easily resolved.

Maintenance made easy
Besides blast performance and a very robust machine construction the maintenance friendly design of the tube blaster was another factor that convinced Terex® to buy the Rösler equipment: Very large inspection/maintenance doors in the entrance and exit vestibules as well as in the blast chamber allow easy and ergonomic access to all areas requiring maintenance. The maintenance door in the blast chamber is protected against wear from the blast by slide-in manganese plates which cover the inspection door without showing any gap.