Künz GmbH of Vorarlberg, Austria’s westernmost province, has been providing screen cleaning machinery for the hydropower market since the mid-1960s. The company has remained true to one principle to this day: An ideal trash rack cleaning machine is one that has been closely adapted to a customer’s wishes and requirements. Künz supplies carefully customised screen cleaning machinery – especially to medium-sized and large-scale plants. A vast wealth of experience gained over more than half a century has made the Vorarlberg-based company one of the leading suppliers in this field – and justifiably so. Künz technology now enjoys an excellent inter­national reputation, too.

The Ryburg-Schwörstadt run-of-river power station is located fairly near the headquarters of Künz GmbH in Vorarlberg. Today, the German-Swiss border hydropower plant, built between 1927 and 1931, is still regarded as a technical masterpiece. At a total output of 120 MW it is still the largest such plant on the High Rhine. Recent modernisation of the headrace area also incorporated a much-needed renewal of the plant’s screen cleaning and crane technology. This was an ideal case for an experienced industry expert like Künz due to the need for outstanding expertise in screen-cleaning technology, and a concept that seamlessly integrated proven screen cleaning infrastructure with the existing power plant cranes – such as the dam gantry crane. In more detail, the two existing screen cleaning machines were replaced with a powerful R100 cable screen cleaning ­machine unit to meet high performance and availability requirements. Debris is dis­charged into a standard roll-off container borne by the screen cleaning machine. The containers are provided at the storage area, from where they are transported to the screen cleaning machine with the dam gantry crane. This ensures efficient screen cleaning without any loss of time. In the event of flooding, the additional loading crane mounted on the dam gantry crane enables surface debris to be removed independently of the existing screen cleaning infrastructure.
The additional refurbishment by the Künz retrofit department of the heavy-duty power­house cranes, originally installed in 1929, was a particularly noteworthy achievement. This returned the crane to state-of-the-art status, consequently enhancing the performance of the entire system. The decision to refurbish the heavy-duty crane further underlines the significance of retrofit solutions to the industry, and highlights the immense demand for modernised cranes. The ability to offer customised solutions has made Künz a popular choice in this field. A retrofit is both cost-efficient, and sets an example in sustainability and responsibility. At the Ryburg-Schwörstadt power station, Künz provided operators with a comprehensive ­solution, modernising its entire load-lifting capabilities.

Upper Salmon hydropower station
The Austrian company has also established its expert credentials overseas multiple times; most recently at the Upper Salmon power plant in the US state of Idaho. Built in 1937 and 1947 respectively, the overall 4-turbine infrastructure generates an output capacity of 35 MW. The specific project remit was to replace the existing telescopic screen cleaning machine with an ultra-modern Künz RRM-H500 – another milestone achievement for Künz. Due to the structural conditions ­created by the existing infrastructure, it was necessary to implement a special half-portal to enable the RRM-H500 to clean the inlet at ­maximum efficiency. Debris is discharged straight into a dump truck, ensuring optimised operation. A particularly significant aspect of the project is the fact that an almost identical trash rack cleaning machine was implemented at the plant further upstream, emphasising the versatility and effectiveness of the technology deployed. Delivery of the sixth trash rack cleaning machine for the hydropower operators at Idaho Power has enabled Künz to consolidate its position as a leading provider of innovative hydropower plant cleaning solutions on the American and Canadian markets.

Wipfeld hydropower station
Künz recently provided further proof of its expertise in screen-­cleaning technology at the Wipfeld power plant on the River Main in Germany, a hydroelectric plant that went into operation in 1951. Today, the power plant operated by Uniper supplies enough electricity for around 5,700 average households. Künz replaced the previously fitted cable­-screen cleaning machine with a design-adapted RRM-H200. A special half-portal was installed in response to the structural conditions of the building, and now the RRM-H200 can guarantee the inlet is cleaned efficiently. Collected trash is discharged straight into a new debris pit. Installation of the first H200 unit along the Main River is evidence of Künz’s presence in this key region. Another two H200s have also been produced for Uniper power plants on the Main River, and installation is scheduled for this year. Successful completion of these projects reaffirms the confidence shown by customers in the quality and performance of Künz products. Künz provides answers to the challenges faced by the hydropower industry with an innovative spirit, state-of-the-art technologies and ideally-­customised solutions.