Egger axial turbine pump for a mini hydroelectric plant on the Birs river

Electricity production with a part of the water flow from the newly built fish ladder at the Juramill power plant

Egger was consulted by several engineering companies for pumps as turbine (PaT) designed for high flows and low heads, which corresponds to the field of Kaplan turbines. Following a CFD simulation study using scFlow software developed by Cradle/Hexagon, we were able to respond effectively with our RPG / RPP program for elbow propeller pumps.

Egger RPG 351 pipe bend propeller pump in use as a turbine – flow analysis with scFlow

Flow simulation of an Elbow propeller pump as turbine

Since March 2024, a DN 350 axial pump (RPG 351) with suction by the elbow has been operating as a turbine on the Birs river in the canton of Basel-Landschaft in Switzerland. It uses a part of the energy lost in the fish pass of an existing hydroelectric power station equipped with a Kaplan turbine. Our pump-turbine enables the plant to produce between 75 and 125 kWh of electrical energy per day.

Compared with a conventional Kaplan turbine with guide vane, this is a simplified machine in which the elbow replaces the distributor. This success was achieved without modifying any parts of the axial pumps already in our portfolio. The addition of a frequency converter enables the operating point to be set as close as possible to the PaT’s best efficiency point. Installation is based on a vertical motor axis, with horizontal suction and vertical discharge. This means that only one elbow) needs to be installed in the entire system – apart from the pump.

With this new application, Egger is able to offer axial turbine pumps to users with flow rates from 100 to 500 l/s (1600 to 8000 GPM) and heads from 2 to 10 m (6 to 32 ft). They can take advantage of a simple, compact, robust and economical machine for permanent run-of-river power generation, by choosing one of our various DN 250, 300 or 350 counter-clockwise-turning elbow propeller pump versions.