Industry pros from Upper Austria manage to impress with innovative screen cleaning technology

For decades the trash rack cleaners by Upper Austrian steel and mechanical engineering specialist Braun Maschinenfabrik have been inspired by a guiding principle: The ideal screen cleaning machine is the one that is perfectly suited to local on-site ­conditions while meeting all the customer’s needs and wants. Innovation-focussed ingenuity, flexibility, and a high level of knowledge and quality have earned the long-established firm from the Upper Austrian town of Vöcklabruck a reputation as one of the industry’s foremost providers of optimised solutions for reliable, efficient inlet grate cleaning.

Floating debris, such as leaves, waste material, deadwood or various sediments, can cause serious obstructions and reduce the rate of water flow at the screen, as well as the plant’s economic viability, as a result. To ­tackle problems like this head-on, experts in the hydropower industry have come up with various types of screen cleaning machines ­(sometimes also referred to as trash rack ­cleaners). Today these machines operate more or less fully automatically, ensuring ultimate reliability and convenience for the operator. Depending on the requirements imposed on screening systems used in the intake area, a variety of different screen cleaning solutions have come on the market over the last ­decades. The designs basically range from various ­versions of hydraulic screen cleaners and rope-­operated models to horizontally moving machines. It takes extensive special know­ledge for a provider to cover the entire spectrum of types and versions with their port­folio. After all, what is needed is not just the solid competence in experienced mechanical and hydraulic steelwork engineering but also extensive expert knowledge of hydropower operations. Braun Maschinenfabrik, which is headquartered in the Upper Austrian town of Vöcklabruck, has incorporated all this knowledge and has been ranking as one of the industry’s top providers for high-quality screen and screen cleaning solutions for many decades.

No ‘off-the-shelf’ system
Finding the optimum screen cleaning solu­tion for a specific site requires the experience of a seasoned mechanical engineer who knows how to take the specific ambient conditions into account. This is because the screen ­cleaning quality depends crucially on three key factors: the clear bar spacing of the fine mesh grating; the hydrological dynamics in front of the screen (i.e., the possible build-up of turbulences); and the obstructional density of accumulated floating debris. A thorough evaluation of all of these factors tells the ex­perienced mechanical engineer which type of machine is the proper choice for the site in question. Building on the extensive experience of more than 60 years, Braun Maschinen­-fabrik’s portfolio today covers the entire range of common screen cleaner types and versions, in addition to individually custom-engineered solutions. Ready-made off-the-shelf solutions are clearly out of the question for the long-standing provider from Vöcklabruck. Instead, they stand by their maxim that individual requirements call for individual technical solutions. Braun’s engineers are committed to the continuous further development of the machines – a testimony to their creatively innovational skills.

Durability makes for operational safety
Like many others in the industry, Braun ­Maschinenfabrik had modest beginnings as a provider of cleaning machines. In the late 1950s, they had already begun to professionalise and leverage their knowledge of mechanical and hydraulic steelwork engineering to repair and re-engineer screen cleaning machines for the firm’s own hydropower plants. This provided the initial spark that eventually set off the systematic build-up and success story of a whole new business unit as the foundation for the excellent reputation still enjoyed by Braun’s screen cleaning machines today. A key success factor of Braun screen cleaning systems is their highly durable design. Solid, high-quality sheet metal and components, the firm’s own certified welding technology, and proven hydraulic solutions combine to ensure superior stability, ultimate operational safety and long product lifecycles. Braun also acts as a single­-source service provider for everything from project planning and construction to static analysis and electrical planning. The systems are manufactured and pre-assembled at Braun’s facilities in Vöcklabruck. It’s thanks to qualities like these that ensure that the technical solutions provided by the Upper-Austrian specialists are fully and seamlessly integrated.
No wonder, then, that systems by Braun Maschinenfabrik tend to weigh a little more than others. However, the additional weight comes with a great advantage. Compared to the more flimsily constructed machines that are also found on the domestic market, Braun’s solutions are not only proven to last much longer, they ensure reliable operation even under ­challenging conditions. When talking with experienced hydropower operators, there is one sentence that comes up frequently: “This machine is unbreakable.”

Optimum results also in horizontal alignment
As a result of new discoveries in fish ecology, among other things, the last few years have seen an increased use of horizontally moving screen cleaners, especially in the context of low-head facilities. The narrow bar spacing of 15 to 30 mm, combined with a low flow ­velocity, makes it easy for fish to escape the pull of the inlet grate and swim to safety. To ensure an economically viable hydropower operation, hydraulic steelwork engineering specialists like Braun Maschinenfabrik have begun to optimise the streamlined design of the bars. The bar gratings of the horizontally aligned screen cleaners are fitted perfectly to this type of bar design. Best of all, Braun’s ­horizontally aligned screen cleaning machines are designed specifically for a fully automated cleaning process. Custom solutions are always available on request.

Special solutions: Braun’s strong point
Technical special solutions are a definite strong point of the Upper Austrian hydro-steelwork specialists. The firm’s long history includes a sizeable list of worldwide reference projects involving custom designs to meet special requests and individual requirements. One example is the design of special grasping arms fitted with tailor-made hydraulic jibs, optionally equipped with integrated grappling hooks, which enables the removal of particularly unwieldy floating debris in front of the intake area. It is primarily their high level of flexibility and engineering skills that have earned Braun Maschinenfabrik the reputation as one of the industry’s top providers when it comes to special designs or replacement designs for old systems. Many customers also prefer to draw on the expert knowledge of the specialists from Vöcklabruck in dealing with issues of automation or renovation. The same applies to the disposal of floating debris, for which Braun have developed a range of different solutions. From channel system with matching scavenging pumps to conveyor belts, scrapers and containers, there is hardly any solution that Braun have not implemented successfully so far. To ensure proper further ­development along the way, Braun collaborate closely with renowned energy providers that contribute their extensive know-how and latest concepts to the construction process.

Proven all over the world
Besides a great deal of innovational spirit, screen cleaning machines by Braun Maschinenfabrik also incorporate more than 60 years of expert experience. Their screen cleaning systems bring together tradition and innovation in a way that is unmatched by other machines on the hydropower market. Supported by their experienced team of engineers, Braun is able today to offer all common types of screen ­cleaning machines in any size. It has also happened time and again that they developed ­special solutions to meet particularly challenging requirements when other providers had already given up. It is qualities like these that have earned the team from Vöcklabruck an excellent reputation in the industry, with a long list of reference projects to prove it: today, Braun screen cleaning machines are found not only in the German-speaking regions but ­throughout Europe, Asia and the Americas.