Hitachi Plant Technologies, Ltd.

Hitachi Industries Co., Ltd.

Yasuhiro Inoue

Akira Manabe

Takanori Ishii

Ryuichiro Iwano

Sadashi Tanaka

Takashi Aki

Seiji Kawabata

Radial cross sections of front sides in rotational direction of impellers attached to a pump shaft obliquely to a circumferential direction from an upstream side toward a downstream side have concave shapes protruding toward the upstream side, and radial cross sections of rear sides in rotational direction of the impellers have concave shapes protruding toward the downstream side.

Axial flow pump

The guide vanes comprise two kinds of guide vanes which are alternately placed in the circumferential direction of a shroud. One kind of the guide vanes have a longer length than the other kind of the guide vanes, in the region which is close to the surface of the hub, but have substantially the same length as the other kind of the guide vanes, in the region which is close to the shroud. The leading edges of the second kind of guide vane are located further downstream in the pump axial direction than the leading edges of the first kind of guide vanes.

Axial flow pump and diagonal flow pump

A prewhirl type inlet casing for inducing a spiral stream in fluid has a suction passage arranged on an upstream side, being orthogonal to a rotary shaft of fluid machinery, and an internal passage connected to the suction passage, the internal passage being formed in a spiral shape so as to induce a swirl stream orthogonal to the rotary shaft in the fluid. A guide vane provided in the fluid passage in the inlet casing has a rectifying function capable of distributing flow rates in the swirl stream of the fluid in the internal passage between the swirl center side and the swirl outer peripheral side, and causing the fluid to deflect into the swirling direction of the swirl stream induced by the internal passage.

Inlet casing and suction passage structure

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Kasumigaura, Japan

Yasuhiro Inoue