Improvements to a helical fan/pump/propeeler/trubine

A device comprising a rotor, the rotor comprising:

• an elongate first portion (61) having a longitudinal axis (15) and at least one pair of blades (16), wherein at least one blade (16) extends from the first end portion (13),
• the blade (16) having a root which is substantially helically shaped to the longitudinal axis (15) with a flat and/or concave pressure face,
• a first opening (3) defining the fluid intake provided substantially axially aligned with the substantially helically shaped first portion (61);
• a second opening (4) defining a fluid outlet longitudinally offset from the first opening,
• wherein the first opening (3) is defined by one or more first and second lateral limits (9a and 9b) around the circumference of housing (2) and their corresponding longitudinal limits (48) between a first end (18) of housing (2)
• and wherein the surface area of housing (2) between lateral and longitudinal coordinates (9a, 9b, 48) amounts to at least a fifth of the total surface area of housing (2) and first opening (3) between the first end (18) of housing (2) and the second longitudinal limit (6)