At the site of Bochumer Verein Verkehrstechnik (BVV), founded in 1842, wheels for rail vehicles are forged and combined to form complete wheelset systems. In order to adapt to the increasing demand in rail transport, the production plant was gradually modernized in 2022. This included a modern, highly efficient coating line. More specifically, a solution for single-wheel coating for primer and top coat application that can be easily integrated into the complex production process. BVV attached great importance to sustainable and resource-saving production.

More efficient production processes thanks to new coating system

Walther Spritz- und Lackiersysteme GmbH, together with J. Wagner GmbH - both companies of the WAGNER Group - made it possible to install such a custom-fit solution. To meet the different requirements, the new coating line is divided into two segments. In the first segment, the rail wheels are masked manually and primed with the WAGNER AirCoat GM 4700AC manual gun. In the second step, a robot applies the top coat fully automatically with the WAGNER AirCoat gun GA 4000AC. Both guns enable excellent atomization, efficient paint application with very low overspray and uniform coating thicknesses. Ideal, therefore, for BVV's requirements: the company can expand its production capacities while saving considerable application material. In addition, the guns are very compact and easy to operate.

Inlet and exhaust air supply with heat recovery saves energy

The modernization of the plant was carried out during ongoing production. The inlet and exhaust air supply had to be adapted to the conditions of the factory hall: The exhaust air pipes were laid over a long distance under the hall ceiling and led out above the roof. This was particularly necessary to meet emission control requirements. The new coating plant has regenerative cross-flow heat exchangers, whereby up to 50% of the energy is recovered from the exhaust air.

Material supply as center

Individual components such as pressure tanks, agitators, automatic lid-lifting devices, collecting trays and pneumatic control components have been combined into high-performance systems by Walther Spritz- und Lackiersysteme GmbH. The material to be processed is conveyed from different delivery containers. Overfill safety, best possible residual emptying, ease of operation, requirements of the Water Resources Act (WHG) and operational constraints were essential parameters in the project planning. Thanks to its economical use of resources, the new system enables BVV to reduce material consumption and cut costs, especially for paint disposal.

Primer

• Paint booth
• Inlet and exhaust air system with gas surface burner and energy recovery
• Paint supply room
• Material supply for two solvent-based primers from 30-liter containers
• Compressed air agitators on pneumatic reciprocators
• Pneumatic piston pumps Leopard 35-70
• Piping to the paint booth with automatic shutoff
• AirCoat manual gun GM 4700AC
• GM 1030G for small touch-ups
• Exhaust air output is throttled when the spray guns are not in use and is automatically shut off after a certain time has elapsed

Top coat

• Paint booth
• Inlet and exhaust air system with gas surface burner and energy recovery
• Paint supply room
• Material supply for two solvent-based and two water-based top coats from 30-liter containers plus corresponding cleaners
• Electric agitators and level limit switches on pneumatic reciprocator
• Leopard 35-70 pneumatic piston pumps for the coatings, Puma 28-40 for the cleaners
• Fully automatic application by robot with AirCoat automatic gun GA 4000AC
• GM 1030G for small touch-ups
• Fire detection system