New Pumping Stations for India

The Indian state of Andhra Pradesh has been hit time and again by widespread drought, particularly in the years 2002 to 2004. As some 70% of the population makes a living directly or indirectly from agriculture, the Indian government launched the Jalayagnam project for irrigation of agricultural land. The Pumps Division, a part of the ANDRITZ HYDRO business area of the international technology Group ANDRITZ, is contributing to a total of eleven sub-projects in this large venture, which is also to build numerous pumping stations on greenfield sites in the next five years.

In order to transport water over long distances, very large volumes of water are conveyed typically with a small number of large vertical volute pumps. For the Bheema sub-project, ANDRITZ (Germany) supplied three vertical volute pumps each for two pumping stations in the second half of 2008. Construction of these pumping stations is now in the closing stages and start-up will follow shortly. The first of these, with three units, conveys a total of 63 m³/s water to a level 38 m higher up. There, some of this water is distributed through canals. Then a second pumping station pumps approximately 32.3 m³/s into a canal system that is 22 m higher up. The pumps are driven by synchronous motors with nominal ratings of 12 MW and 4 MW, respectively. These pump units are designed with a three-bearing concept, where each pump has one guide bearing in the motor, one at the pump impeller, and a combined thrust and guide bearing between pump and motor. Volute and draft tube of the pump are steel structures embedded in concrete.

The special aspect of the pumps supplied is that they are very similar to turbines due to their size and the integrated guide vane mechanism. The guide vane mechanism is adjusted by means of a hydraulic servomotor to suit the changing tailwater level. This achieves a broader efficiency progression compared to conventional pumps, as well as much lower power input on start-up of the pump if the guide vane mechanism is closed.