Rösler vertical shot blast machine for processing sheet steel

The blasting of large, pressure-sensitive sheet metal made of materials such as stainless steel is a special challenge in steel construction that sometimes requires a complete rethink. The solution can then be that sheets do not pass through the shot blasting system in a horizontal position but are blasted “standing up”. Vertical shot blast machines are then used. These pose very special challenges in terms of development and design, but also offer other advantages such as a more compact and shorter system design and the avoidance of abrasive accumulation and abrasive pressure on the sheet metal. Technically speaking, a vertical shot blast machine is simply a modified roller conveyor blast machine.

An example of such a system - and the largest one built by Rösler to date - is the vertical shot blast machine for the Chinese steel producer TISCO.

Rösler shot blast machine at TISCO

In 2020, the Chinese steel giant TISCO (Taiyuan Iron and Steel Group Co., Ltd.) began implementing a highly ambitious project: the intelligent modernization of the production line in the hot rolling mill for stainless steel sheets in Taiyuan, China. Part of this new production line was to include a highly efficient shot blasting system that blasts sheets over four meters wide fully automatically without the need for personnel and prepares them for subsequent pickling. To avoid even minimal damage to the surfaces caused by transport rollers, the parts had to be transported through the shot blasting system in a vertical position. The parts are only lifted into this position shortly before blasting.

How does the system work?

Gigantische Ausmaße: Die Vertikalstrahlanlage ist 14 Meter hoch und steht in einer zweieinhalb Meter tiefen Grube.

In order to meet the demands on surface quality in the required time, our engineers linked two identical individual shot blasting systems to form one unit. The stainless steel sheets are processed one after the other using two different blasting media. For blasting processes where a higher surface roughness is required, each blasting unit can also be operated separately. Each blasting unit has twelve Gamma 400G turbines with a drive power of 37 kW each. Six turbines are positioned at an angle on each side of the blast cabin walls. This arrangement ensures that the sheets are processed homogeneously across their entire width. Both blast chambers are made of manganese steel and are also equipped with ten millimeter thick, replaceable plates made of this resistant material. The blast media preparation, including the blasting media storage tank, is located on the roof of the shot blast machine. For quick and convenient maintenance, an inspection platform is integrated on four different levels, which can be reached via stairs.

Level 2 control for unmanned operation

Unmanned operation of the shot blasting system, as well as the directly connected pickling system, is guaranteed by a level 2 control system. It provides all the information required for the finishing process, such as the sheet type and the required surface roughness. This data is also used to determine whether the sheet should be blasted in both systems or just one.

Facts, figures and data: The system at a glance

Plant complex dimensions: 17 meters long/ 14 meters high
Turbines: 12 Gamma 400G
Maximum abrasive throughput: 12,000 kg/min
Load capacity per meter: Four tons
Processing capacity per year: 315,000 tons
Transport speed: 7 m/min when operating both systems; 4 m/min when operating only one system
Maximum sheet size to be processed: 4,100 mm wide and up to 160 mm thick sheets
Processing result: achieves a surface roughness of up to Ra 4.0 µm and a surface quality of A/B Sa 2.5