Roller Conveyor Shot Blasting System Automation Replaces Manual Blasting Processes

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Rösler Oberflächentechnik GmbH

FAULHABER Drive Systems

SIMTOS (Seoul International Machine Tool Show)

A flexible roller conveyor shot blasting system processes various steel plates and meets maritime quality requirements, thereby increasing production efficiency.

Maximum efficiency in all areas was the goal. To achieve this, a German manufacturer of drive and maneuvering systems as well as complete control systems for ships and offshore applications invested in the RRB 22/5 roller conveyor blast machine from Rösler. The system, which is optimally integrated into the production process, enables the semi-automated processing of various flame-cut parts and steel sheets. It therefore largely replaces the manual blasting that was previously carried out;

It was the ground-breaking invention of the all-round steerable rudder propeller in 1950 on which the impressive success story of Schottel GmbH is based. The innovation quickly turned the company, founded in 1921, into a globally sought-after developer and manufacturer of marine propulsion systems. With nine series covering a power range from 50 to 30,000 kW, it now offers the largest portfolio of propulsion and control systems for ships and offshore applications of all types and sizes. 

In addition, the company provides comprehensive marine services: intelligent solutions for remote access, data collection, data evaluation, condition monitoring and predictive maintenance. Production takes place at the German sites in Dörth and Wismar. The combination of many years of propulsion experience with high-performance hardware and software as well as the latest scientific findings ensures that all products are state of the art and meet a high level of quality.

Increased Efficiency Through Automation, Flexibilization and Ensuring Greater Availability

Continuous investment is also being made in production. For example, the production processes in the welding shop at the Dörth plant were made more efficient and powerful by integrating a sheet metal line. This included the integration of an automatic sheet metal storage system and a plasma/autogenous flame cutting system as well as the conversion of the blasting process from cabin blasting to continuous blasting. In order to minimize both personnel costs and intralogistics, the new roller conveyor blasting system was placed directly behind the flame cutting system - in line. 

One of the key processing specifications was that the blasted surfaces must have a roughness depth of at least Rz 70 µm. This must be achieved in order to ensure the required adhesion of the paint for maritime applications during subsequent painting. Schottel therefore used an angular, abrasive blasting medium for cabin blasting to ensure the required quality. In addition, the new blasting system had to be able to process parts with very different dimensions and guarantee high availability.

Sophisticated System Concept with High Performance and Flexibility

In his search for a suitable blasting system manufacturer, Frank Steinert, production manager at SCHOTTEL, contacted Rösler Oberflächentechnik GmbH, among others. Based on the standard roller conveyor system RRB 22/5, the German-based system manufacturer designed a solution adapted to the customer's requirements, including special painting. It can process steel plates up to five meters long (approx. 16.4 ft), up to two meters wide (approx. 6.6 ft) and a maximum height of 500 mm (approx. 19.7 in). At the same time, the roller conveyor with a roller pitch of 400 mm (approx. 15.7 in) makes it possible to blast individual parts with a minimum length of 1,500 mm (approx. 59.1 in). With the use of an additional transport frame, solid parts smaller than 1,500 mm can also be processed.

This means that a large proportion of the flame-cut parts used in the end product at Schottel can be manufactured much more efficiently. The blasting program stored in the system control is conveniently selected by the system operator on the touch panel.

The system is made of eight millimetre thick manganese steel as standard, and the blasting chamber also features replaceable, overlapping plates made of the wear-resistant material. Six high-performance Gamma 400G turbines, each with a drive power of 15 kW, ensure consistently good blasting results - three each blast the parts from above and below. They have Y-shaped throwing blades and achieve up to 20 percent higher blasting performance compared to conventional turbines, while at the same time reducing energy consumption. In addition, the Y-shaped throwing blades can be used from both sides, which at least doubles the service life. They can be changed easily using the quick-change system and with the turbine installed. Another plus is the filter unit, which is located on the roof of the system and therefore requires no additional floor space. "The system and equipment concept appealed to us. However, before making the final decision, we wanted to know whether our requirements would also be met," reports Frank Steinert.

Blasting Tests Under Real Production Conditions

Accordingly, blasting tests were carried out with various parts from Scjpttel. In this case, they were not carried out at the Rösler Customer Experience Center, but at a Rösler customer who has been using an almost identical system with identical turbine equipment for around three years. The tests not only proved that the required blasting result is reliably achieved - but also that the blasting grain is round and gentle on the machine. The parts blasted by the reference customer were evaluated using measurement technology. "To be on the safe side, we also subjected the test parts to internal paint adhesion and salt spray tests," adds the production manager. The open discussions that Frank Steinert was able to have with the reference customer regarding operating costs, wear behavior and maintenance frequency were also decisive in the decision for the RRB 22/5. "The results of the blasting tests and the reference customer's experience completely convinced us that the RRB 22/5 is the right solution for us and meets our quality requirements," explains Frank Steinert.

Optimum Integration for Easier and More Convenient Maintenance

The early involvement of the plant manufacturer in the planning at Schottel also proved to be an advantage. This meant that information and layouts were available at an early stage regarding the dimensions to be taken into account for the system and how it could be optimally planned into the hall. As a result, the foundation for the blasting system was not only easier to construct, but also offered the maintenance personnel more space and therefore more comfort.

* Freelance author