Pre-paint blast cleaning of complete welding fabrications
To improve in-house blast cleaning of welding fabrications, one of the largest steel fabricators in Poland invested in a shot blast system RRBK 25/21 from Rösler.
This steel fabricator specializes in manufacturing steel fabrications for warehouses and industrial buildings, for all kinds of sports facilities and shopping centers as well as for power plants and the petro-chemical industry. Besides traditional steel fabrications this company also produces specially developed light-weight steel systems (for example, web beams). The customer processes around 16,000 tons of steel each year.
Custom engineered for the customer’s parts range
Steel fabrications generally require an optimum surface finish prior to painting or powder coating. Such a ”pre-paint“ finish is best achieved by intensive blast cleaning. For this purpose the customer integrated the RRBK 25/21 shot blast unit from Rösler into the overall manufacturing process. This custom engineered system allows the blast cleaning of large, three-dimensional welding fabrications with dimensions of up to 16,000 x 2,500 x 2,100 mm (LxWxH) and weights of up to 24 metric tons.
This Rösler shot blast unit is equipped with twelve Hurricane® turbines, type H 42, with a power of 15 kW each. The turbines are placed around the blast chamber in the shape of two “rings”. This arrangement ensures that rust, scale and welding residues are reliably and completely removed from the surface of the welding fabrications. The main parameters of the blast process - like travel speed through the machine, intensity of the blast process, number of turbines actually blasting, etc. - can be adapted to the different parts types by parts specific programs stored in the PLC. The exit chamber with integrated media collection funnel is equipped with a blow-off station that automatically adjusts to the height of the parts. This blow-off feature reliably removes blast media from the steel fabrications prior to the downstream manufacturing stages.
The large dimensions of the parts, especially their height, require substantial openings in the inlet, blast, and outlet chambers. Strategically placed curtains made from special wear- and heat-resistant rubber, combined with a system of sliding steel plates, prevent the spillage of blast media out of the machine.
The customer also uses the RRBK for the blast cleaning of single steel sheets which may have a thickness of only 3 mm. To prevent warping and to ensure a safe transport of these steel sheets through the machine, the distance between the rollers has been significantly shortened.
Easy and problem-free parts loading/unloading and maintenance
Parts are loaded onto the roller conveyor of the RRBK 25/21 with the building bridge crane. The blast machine was placed into a foundation pit, allowing the operators quick and safe release of the crane hooks from the parts. This also allows easy walking access to the inlet and outlet roller conveyors and the blast chamber. This, in combination with the large maintenance doors typical for Rösler blast machines, allows quick access to all critical machine sections for maintenance and repair work. The cooperation of Rösler with the Polish service provider Awexim Co. Ltd. allows quick and reliable after-sales-service.