Well pumps with maximum yield: an enormous saving in energy costs

The Prime Tower is a visually unique landmark under construction in the heart of Zurich. The angular high-rise building stretches 126 metres across 36 floors, and is claimed to set a new benchmark for commercial properties in terms of architecture, transparency, appeal and technical perfection.

In February 2008 work began on the preparation of the Prime Tower and the adjacent Cubus and Diagonal buildings. German groundwater drawdown specialists Brunnenbau Conrad GmbH were awarded the contract for lowering the groundwater for the build.

The application of wastewater pumps

In order to reduce the groundwater level by more than 1000 mc/h, a solution was developed on-site using voluminous sump pits with submersible wastewater pumps. A secondary problem for the constructors was location. The water required a deviation of more than 1,000 metres through the urban area of Zurich to the river Limmat, as well as the consideration of seepage. Two booster sets were specified to overcome the falls in pressure and absolute heights.

In collaboration with building company Bauer Spezialtiefbau, Brunnenbau Conrad GmbH drew up the pit proposal with the use of ITT Lowara Z series 6” submersible pumps. The pumps are designed to guarantee the continuous distribution from the pit to seepage or deviation into the drainage ditch, which is enabled through the automatic control of sliding valves.

The configuration included twenty-two Z 660-04 pumps installed in double configuration across the majority of the 16 pits, which were delivered by ITT Lowara Deutschland GmbH, Grossostheim.

Z series submersible pumps

The stainless steel Z series submersible pumps are ideal for lowering groundwater, for drainage in the building and mining sector, as well as for water supply, pressure boosting and irrigation. With flow rates of up to 78 mc/h and heads of up to 700m, the pumps offer yields of up to 77%.

The construction of the Prime Tower business complex is expected to be complete in Spring 2011, featuring cultural and gastronomic elements and a rentable area of 39,500 square metres. The exceptional ITT Lowara pump yield has given the client the best possible financial start, with a saving on energy costs of more than EURO130.000.00 across the one-year build.