Impulse turbine for use in bi-directional flows

A bi-directional flow impulse type turbine arrangement for use with a bi-directional reversing flow through the turbine arrangement, the turbine arrangement having an axis and comprising:

• a rotor rotatably mounted to rotate about the axis and having a plurality of rotor blades disposed circumferentially around the rotor,
• a first set of guide vanes circumferentially disposed about the axis for directing the bi-directional reversing flow to and from the rotor blades via a first flow passage defined by a first duct;
• and
• a second set of guide vanes axially spaced from the first set of guide vanes and circumferentially disposed about the axis for directing the bi-directional reversing flow to and from the rotor blades via a second flow passage defined by a second duct,
• wherein the first and second sets of guide vanes are disposed at a greater radius than the rotor blades, such that an entirety of each of the first and second sets of guide vanes is disposed radially outward from each blade tip of the rotor blades.