Hitachi, Ltd.

Haruki Sakai

Koji Nakagawa

Yoshiaki Abe

Takeo Takagi

Junichi Kaneko

Hisashi Nishkawa

A centrifugal compressor has diffusers which convert a high velocity, low pressure stream of fluid which flows out of an impeller to a high-velocity high-pressure flow due to the action of a purality of stator blades disposed near the outer periphery of the impeller. In this compressor, the portion of the stator blade or of an auxiliary blade which is provided in the diffuser located on the side of a front shroud is disposed closer to the impeller than the portion thereof located on the side of a main shroud, and the leading edge of the stator blade is thus inclined from the portion thereof located on the side of the main shroud to the portion thereof located on the side of the front shroud. The configuration of the front edge of a stator blade or of an auxiliary blade which is provided in the diffuser is so improved as to restrict back flow which occurs on the side of the front shroud when the flow rate is small and to lower the minimum flow rate. Furthermore, an auxiliary blade and an intermediate blade are disposed between the adjacent stator blades, and the leading edge of the auxiliary blade is so improved as to enlarge the operation range of the diffuser and to improve volume control greatly.

Centrifugal compressor

A vane controller for a plurality of vanes disposed in a fluid conduit has vane shafts connected to the vanes and extending radially and spaced circumferentially around the conduit, and a control ring outside the conduit and movable circumferentially and connected to said vane shafts by levers to cause the vane shafts to rotate in unison to adjust the vane position. To reduce friction, the control ring is movable both circumferentially and axially and is preferably spaced from the conduit wall. A spherical bearing on the ring slidably receives a pin carried by each lever.

Vane controller

In a diffuser for a centrifugal compressor of the type which includes an impeller rotatably provide on a downstream side of the suction casing and a plurality of radial stator blades arranged tangentially with respect to the impeller, auxiliary blades are provided between the impeller and the stator blades, with the auxiliary blades having a chord length shorter than that of the stator blades and being slidable in the axial direction of the impeller. Further, the auxiliary blades are connected to devices designed to move them in the axial direction.

Diffuser for a centrifugal compressor

A diffuser centrifugal compressor of a comprising a plurality of stator blades provided outside an impeller thereof, and which converts kinetic energy of fluid from the impeller into pressure energy by operation of the stator blade. The diffuser is provided with sub-blades near the inner ends of the stator blades, and intermediate blades near outer ends of and between the stator blades.

Growing community of inventors

Ibaraki, Japan

Haruki Sakai