Hitachi, Ltd.

Other

Sumio Sudo

Masayuki Yamada

Saburo Maru

Sadashi Tanaka

Kunio Takada

Kenji Otani

Junichi Kurokawa

Akira Manabe

Tomoyoshi Okamura

Takahide Nagahara

Hitoharu Kimura

Norimitsu Kuwabara

Hiromichi Anan

Kouichi Irie

Shizuichi Sakamoto

Tomoyshi Okamura

Yoshihiko Yoshikawa

A turbo-type machine, comprising a casing storing an impeller within an inside thereof, and a plural number of grooves formed on an inner surface of the casing in a direction of pressure gradient of fluid, wherein the grooves are provided from 80 to 150 pieces around a periphery on the inner surface of the casing, and a total width of the grooves all around the inner surface of the casing is from 30% to 50% of a peripheral length on the inner surface of the casing. Also, the area on cross-section of the groove within an area where the blades exist is made larger than that of the groove outside where the blades exist, or openings are drilled on a bottom surface of the grooves, each penetrating through thickness of the casing, or the groove is made in a two-layer structure in the direction of pressure gradient of fluid. Or, a round portion is formed at a tip of the blade , or a fin , thereby suppressing the cavitations to generate, as well as obtaining stabilization of the characteristic curve thereof.

Turbo-type machines

A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside. Each groove has a length of at least part of which is oriented in an axial direction of the casing, a width measured in a circumferential direction, and a depth. The width of each groove is equal to or greater than the depth thereof.

Turbo machines

An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition. In the closed channel flow operation, the underground channel is fully filled with water, and further water level rises into the vertical shafts, so that the underground channel is in a closed channel condition. By changing an outflow factor in accordance with rainfall patterns, the rate of flow into the vertical shafts can be accurately estimated, so that the large-depth underground drainage facility can be run in a stable manner.

Large-depth underground drainage facility and method of running same

A vertical-shaft multi-stage pump has adjustable vanes on its lower stage. A vane angle operating mechanism has an operating shaft extending through a hollow portion of the drive shaft of the upper stage and a link mechanism connected to the operating shaft and the adjustable vane impeller for converting axial motion of the operating shaft into vane angle rotational motion. The pump is particularly suited for use in an underground drainage system.

Underground drainage facility, vertical-shaft multi-stage adjustable

An underground drainage facility including a drainage pump adapted to be operated if an inflow water channel is constructed as a closed channel. Overflow weirs in water channels such as rivers or the like on an inflow side are less than a maximum water level. A vertical-shaft multi-stage adjustable-vane impeller is used as a drainage pump. Consequently, even a drainage pump of a high pressure head and large capacity can perform a waiting running and accommodate a variation in a quantity of inflowing water to the drainage facility.

A vertical shaft pump to be disposed in a pump pit comprises a pump casing having a suction opening, and an impeller disposed in the pump casing below a position corresponding to the lowest water level in the pump pit below which the pump starts to suck air through the suction opening during operation. A series of intake ports are provided in the pump casing below the impeller with equal intervals in the circumferential direction of the pump casing. These intake ports act to introduce atmospheric air into the pump casing through intake pipes when the pressure at the intake ports is lowered below the atmospheric pressure.

Vertical shaft pump

A movable blade pump including an actuating mechanism for imparting rotational movement to blades which mechanism is contained in an impeller boss sealed against the outside and filled with hydraulic fluid and is driven by a hydraulic cylinder device secured to a suction casing below the impeller boss. Feed and discharge of hydraulic fluid into and from the hydraulic piston device are effected through fluid passages formed in the suction casing and a fixed mounting for the hydraulic fluid device, and the blades are set at any angular positions within the range of the stroke of the piston.

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Ibaraki-ken, Japan

Sumio Sudo