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(11) | EP 0 772 007 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Jet fan |
(57) A jet fan includes a generally cylindrical casing (1), an electric motor (2) accommodated
therein, an impeller (3) connected to the electric motor (2), and at least one booster
ring (8) disposed concentrically with the casing (1) and located downstream thereof
with respect to a direction of an air flow. The booster ring (8) has an aerofoil or
arcuated plate sectional profile as viewed in a direction transverse to a longitudinal
axis of the casing (1). The booster ring (8) has an upper surface of aerofoil or arcuated
plate sectional profile as its inner surface, and also has a leading edge facing an
air outlet of the jet fan and a trailing edge of a diameter smaller than that of the
leading edge but greater than that of the air outlet. |