Bavarian industry specialist demonstrates innovative spirit in Tyrol again

For decades, Muhr – the Bavarian hydraulic steel construction and mechanical engineering specialist, has been manufac­turing reliable and highly innovative screen cleaning machines that prove their worth at a wide variety of hydropower plants – all over the world. The sophisticated HYDRONIC and CATRONIC system series enable Muhr to cover the entire current spectrum of screen cleaning machine types, meeting every possible requirement for intake screens. The incessant buzz of innovation at Muhr can also be heard in the Bavarians’ latest reference project in Tyrol. EWR – Elektrizitätswerke Reutte AG’s Weißhaus power station was fitted with a high-performance Hydronic-M-4000-K screen cleaning machine. This was ­equipped with a new type of quick-change coupler for attachments such as rakes and orange peel grabs to guarantee increased productivity and high operational availability.

Economic efficiency remains one of the central day-to-day operating tenets for the vast majority of hydropower plant operators. However, this can only be guaranteed if the full intake screen cross-section is available, allowing flow rates to correspond with the maximum usable volume of head­race water. What was previously laborious manual labour is now generally carried out by modern screen cleaning machinery. Over ­years and decades, each type has been successively adapted to suit the many varieties of tasks and intake screens. Muhr is a family-run company from Brannenburg in Bavaria and has been one of the international hydropower market’s leading suppliers for over six decades. Decades of ­experience and knowledge of the interplay between hydropower and mechanical process engineering are ingrained in the company’s DNA, a company whose original roots lie in mill construction. This background has enabled the business to succeed in constantly developing new hydraulic steel construction solutions and, of course, to drive forward ­design for trash rack cleaning systems and concepts for debris management.

Performance on show in Tyrol
The good reputation earned by Muhr ­solutions preceded the company as it was awarded the contract by Elektrizitätswerke Reutte AG (EWR) for the complete modernisation of the hydraulic steel structures and mechanical engineering at the Weißhaus ­power plant intake. Seemingly inconspicuous from the outside, the Weißhaus power plant is the Tyrolean operator’s largest power plant, achieving an annual generation capacity of 72GWh. The plant is currently being mo­dernised and completely refurbished. This work includes the tunnel, the electrical ­engineering and the turbine. Muhr delivered and installed a state of the art screen cleaner that was already demonstrating its practical suitability over a year ago. Tree trunks, rootstocks and other bulky floating debris are not serious challenges for the new Hydronic-M-4000-K. The ‘M’ in the model name stands for ‘Multifunctional’ and ­epitomises the qualities of the machine: It is a travelling and rotating trash rack cleaning excavator with a claw grabber. It can be ­operated manually, semi-automatically, or ­fully automatically.

High efficiency with a new rapid-coupling system
The Hydronic-M-4000-K has a driver’s cab, enabling screen debris to be approached and picked up with pinpoint accuracy. The ­machine is able to clean the screen to a depth of 17.7 metres, with a stated performance ­capacity of 40kN. This screen cleaner has already demonstrated that it can clean the two 6.5m-wide sections of screen easily, and almost seamlessly. What makes the machine truly special is the innovative quick-change system for the rake and orange peel grab. The quick coupler system was designed by Muhr to enable one person to change the tool in just a few steps; an advantage of this being that a convenient and quick locking mechanism increases productivity – another being the high level of operational availability due to perfect coordination with the screen ­cleaning machine. The new Hydronic­-M-4000-K guarantees permanently unimpeded flow through the Weißhaus power station inlet screen.

The HYDRONIC system series
Muhr’s HYDRONIC series dates back to an innovative leap made in 1981. As one of the very first companies to use hydraulically operated rake systems, Muhr’s continuous development of this solution led to a breakthrough that produced impressive benefits: The hydraulic drive and almost unlimited kinematics and control possibilities give these machines ex­treme functional versatility to travel, turn, ­swivel, pick up and unload all types of alluvial material – manually or fully automatically. The Muhr HYDRONIC series can be built with a wide range of machine types. As well as the ­various systems of the multifunctional ­HYDRONIC M series, such as the one installed at the Weißhaus hydropower station, there is also Muhr’s T series – with telescopic booms, the K series – using articulated arm debris rack cleaners, the H series – fitted with horizontal screen cleaners, and the U series – featuring ­underwater cleaners. Each option is designed to address different requirements and equipped to meet special technical specifications. How­ever, they all share sophisticated design work and control concepts, and boast powerful drive technology with controlled force application. HYDRONIC M series rack cleaners are particularly adaptable and flexible, and based on the experience gained from the successful installation of over 900 systems they can be customised to site conditions and delivered with an extensive programme of equipment modules.

The CATRONIC system series
The second major machine-type in Muhr’s screen cleaner portfolio is the CATRONIC series. There’s the stationary version of the S series, the mobile SV series, and the SH series – the overhead conveyor rack cleaner. CATRONIC is a comprehensive range of cable-­winch-driven screen cleaning machines, all equipped with state-of-the-art drive and ­control technology. Cable debris cleaners have proven to be an effective technical solution in the past, being robust in design and capable of cleaning down to depths of 100m and beyond. Their dimensions are generally very compact. Muhr knows how to combine them easily with existing floating debris disposal systems, and how to integrate the necessary solutions. All three CATRONIC series systems are ­characterised by sophisticated, robust design and a multiple redundant safety concept for seamless operational reliability. CATRONIC screen cleaners are equipped with an innova­tive lifting and tilting mechanism, and an intelligent control system.

Debris handling enhancement
The portfolio of the Bavarian industry experts is rounded off by a sophisticated debris management system that provides operators with a customised solution. Clear answers are required, particularly for stationary screen cleaning systems – on how to deal with debris, and how to transport it onwards and away. The engineers at Muhr provide the right answers, optimising the removal of floating debris as part of an overall concept de­signed to meet local requirements and conditions. Over the past few decades Muhr’s specialists have developed chain conveyors, conveyor belts, scrapers, flume channels and lorry systems. The Bavarians also produce containers with the associated lifting, turning and shifting systems. The family-owned company has earned an excellent reputation within the industry, not least due to its customised solutions – always specifically planned and tailored to each customer’s system requirements.