Cutting-edge technology from ANDRITZ for maximum performance: One turns an ancient Archimedean principle around, while the other runs in reverse.

Both generate energy in an innovative way from sources that have barely been tapped so far: The hydrodynamic screw turbine and the centrifugal pump – two technologies from ANDRITZ HYDRO with a lot of green potential.

Low investment costs and the opportunity to use even small hydroelectric potential and waste energy are benefits offered by the ANDRITZ hydrodynamic screw turbine and centrifugal pump. Which of these two technologies from the HYDRO business unit is used depends on the head and other project specifics. Both mini-hydro solutions have already proved successful in numerous applications and convince customers with their high energy yield. Combining ecological and economic benefits, hydroelectric power generation has also been assuming an increasingly significant role in energy supply.

MODERNIZING AN OLD PRINCIPLE
The inspiration for hydrodynamic screw turbine technology was an ingenious idea from ancient Greece. More than 2,000 years ago, mathematician and physicist Archimedes designed the Archimedean screw, which enables water to flow uphill. Turning this principle around, ANDRITZ uses the position and energy difference in downflowing water in the hydrodynamic screw turbine to generate electricity. What’s special about this? Efficient use of hydropower is possible even at a very low head and water flow (max. 10 m head, water flow up to 10 m³/sec), cost-saving and environment-friendly at power ratings up to 500 kW. „The hydrodynamic screw turbine can also deal very well with fluctuating water levels, achieving efficiencies of up to 92 percent,” explains Head of Development Ludger Glosemeyer. Thanks to the low investment and operating costs, this is a lucrative way for local authorities, companies or private individuals who own water rights to generate energy. Moreover, each kilowatt hour of electricity generated using a hydrodynamic screw turbine relieves the environment of up to 1 kg of carbon dioxide. The hydrodynamic screw turbine adapts easily to the existing conditions, ensuring no major interference with the surrounding landscape. Fish and other aquatic animals can pass through unharmed. „In addition, the screw enriches the oxygen content in deeper bodies of water, resulting in improved water quality,” Glosemeyer adds. There are around 200 ANDRITZ hydrodynamic screw turbines installed worldwide. ANDRITZ has gained an excellent reputation here due to the high manufacturing quality, almost maintenance-free operation and low noise levels.

ENERGY-EFFICIENT IN FORWARD AND REVERSE MODE
The innovative pump technology from ANDRITZ lays the foundations for continuous improvement and the optimal installation of pumps. The concept of operating pumps in reverse mode has been applied successfully for some time, resulting in a centrifugal pump doubling as a turbine. ANDRITZ centrifugal pumps operate worldwide, conveying many different kinds of liquids. The pumps feature high efficiency and low energy consumption. Used as miniturbines, they recover energy in industrial processes or generate electricity from low hydroelectric potential. „Energy is lost in many industrial processes, for example when pressure has to be generated ahead of a filter, before being released without use as it is no longer needed later in the process,” Sales and Project Manager Bruno Mellacher explains. „This energy can be recovered efficiently with ANDRITZ centrifugal pumps, even at comparatively low pressures.” Two pumps are coupled to one another for this purpose. The pump running in reverse (mini-turbine) absorbs the excess pressure and assists the pump running in normal operation. In this way, more than 50 percent of the energy that would otherwise be lost is recycled, thus reducing energy costs. Hitherto untapped hydropower potential is used profitably with the aid of mini-turbines in numerous other areas, such as pressure-reducing stations in water pipelines or residual water outputs from hydropower stations. Here, mini-turbines are combined with generators to produce up to 1 MW of output per unit. ANDRITZ HYDRO is currently building a mini-hydropower plant as part of a huge agricultural irrigation project in southern Lebanon. The supply includes four double- flow pumps in order to use the pressure in the water pipeline upstream of the equalizing basin to generate electricity. At peak times, the plant on the Litani River, which is scheduled to be commissioned in the spring of 2016, will provide an output of more than 4.7 MW. Two ANDRITZ centrifugal pumps are being used successfully to recover energy in a pulp and paper mill in Germany. A total of nine ANDRITZ centrifugal pumps are being used to generate electricity in water pipelines in Austria, South Korea, and South Africa. In South Africa, for instance, the recovered energy is used to power a communication system and an active anticorrosion system protecting the pipes. In addition, ANDRITZ centrifugal pumps are used in microhydropower plants, helping foresters’ lodges or mountain refuges, private households, and commercial or industrial plants to generate their own electricity or supply it to an existing power grid.

FULLY AUTOMATIC AND REMOTELY ACCESSIBLE
The modern ANDRITZ automation system ensures reliable and undisturbed operation of the power plant and the intake waterway at all times. Operations are monitored and controlled either at the console on site or from a distance. The integrated control of all parts of the installation takes into account primary technology such as the genset, the weir and switching installations as well as operation standards, improving availability of the overall system. In regular operations, it reliably monitors and controls each part of the installation, turning it into a safe operational state. This is as true for mains parallel operations as it is for isolated operations with the option of a black start. Both standardised (compact or premium lines) and customised solutions are available. Parts of existing weir installations can be integrated. A competent automation system is indispensable for optimised operations and maintenance of hydropower installations. „Small hydropower plants must operate reliably in fully automatic mode and unmanned; in addition, operators want to be able to retrieve energy generation data online around the clock, on a cell phone for example,” says Armin Martinz, Automation Manager for the Pumps division. To meet these requirements, ANDRITZ provides the ANDRITZ Hydrodynamic Screw Controller for hydrodynamic screws and the ANDRITZ Pump Controller for pumps used as turbines. „Both systems control and protect the entire plant with the latest, scalable technology in an industrial design and offer safe remote access via PC or Smartphone in addition to numerous other features,” Martinz emphasizes. Both of these technologies incorporate comprehensive process knowhow, a long ANDRITZ tradition and decades of experience in the construction of hydroelectric machines. All of this is continuously extended by intelligence gained in in-house test facilities as well as external plants. Even elevated customer requirements are fulfilled 100 percent in the framework of a comprehensive service package. Customers benefit from cutting-edge control and monitoring concepts, more flexible and successive extendibility and self-monitoring system software as well as specific modules such as web cam integration, text message alarms sent to mobile phones, a secure remote access for computers and mobile devices and optional remote maintenance by ANDRITZ. Maintenance and troubleshooting costs are reduced to a minimum.