摘要:
To provide a can manufacturing pump impeller in which a stress of a base portion of a blade is prevented from increasing while improving the strength of a joint portion of a hub and a boss. In order to reinforce a joint portion of a hub and a boss, a plate is jointed to the inside of an impeller. In order not to overlap a base portion of a blade and the plate with each other on the hub, an opening portion is provided in the plate around the base portion of the blade on the hub. As a shape of the opening portion, a semicircular shape, a semielliptical shape, a rectangular shape, or a trapezoidal shape can be selected. Further, as a plate shape, a flat plate structure, a shell structure, or a curved structure can be selected.
摘要:
At a vaned diffuser or a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller 3 rotating about a rotating. shaft 2 within a casing 1 and having a vaned diffuser 4 or volute 12 fixed to the casing 1 is constructed such that radius of the vane trailing edge of the impeller 3 and radius of the vane leading edge of the diffuser 4 or radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller 3 and the vane leading edge of the diffuser 4 or the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.
摘要:
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.
摘要:
A centrifugal compressor comprises a centrifugal impeller and a vaned diffuser. The diffuser includes a pair of diffuser plates and a plurality of guide vanes arranged between the pair of diffuser plates in a circular cascade manner. The guide vanes are equal in leading-edge radius to each other, but are different in length from each other. At least one short guide vane is arranged between the adjacent long guide vanes. The total number of the guide vanes is more than the number of blades of the impeller. A throat is formed in only a part of flow passages between the guide vanes.
摘要:
To provide a can manufacturing pump impeller in which a stress of a base portion of a blade is prevented from increasing while improving the strength of a joint portion of a hub and a boss. In order to reinforce a joint portion of a hub and a boss, a plate is jointed to the inside of an impeller. In order not to overlap a base portion of a blade and the plate with each other on the hub, an opening portion is provided in the plate around the base portion of the blade on the hub. As a shape of the opening portion, a semicircular shape, a semielliptical shape, a rectangular shape, or a trapezoidal shape can be selected. Further, as a plate shape, a flat plate structure, a shell structure, or a curved structure can be selected.
摘要:
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.
摘要:
A turbo-type fluid machine comprises a mouth ring part provided between a shroud of an impeller and a pump casing and having a seal function. The mouth ring part comprises an impeller ring on a side of the shroud of the impeller and a casing ring provided on a side of a non-rotating body wall surface of the casing. The impeller ring is structured to have a stepped portion that is in the form of a staircase with at least two steps to be small in diameter toward a suction side of the impeller and large in diameter toward an outlet of the impeller. The casing ring is labyrinth-shaped to comprise a projection and a recess. A narrow clearance part having a narrow radial clearance is formed between the projection and the impeller ring. A flow passage spatial portion defining an enlarged portion of the narrow radial clearance is formed by the recess and the stepped portion of the impeller ring.
摘要:
At a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller 3 rotating about a rotating shaft 2 within a casing 1 and having a volute 12 fixed to the casing 1 is constructed such that radius of the vane trailing edge of the impeller 3 and radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller 3 and the vane leading edge of the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.
摘要:
A highly efficient centrifugal type fluid machine is configured so that the vane outlet angle or the vane outlet diameter at a side plate end (4a) of a single stage or a plurality of stages of a diffuser (D) is made larger than the vane outlet angle or the vane outlet diameter at a core plate end (4b), and the vane curve at a pressure surface end of a single stage or a plurality of stages of the diffuser (D) is formed to have the same radius of curvature at the side plate end (4a) and at the core plate end (4b), while the vane curve at a negative pressure surface end is formed to have a radius of curvature so that the vane thickness at the core plate end (4b) is larger than that at the side plate end (4a).
摘要:
In a drainage pump station, a driving machine has a capacity greater than a shaft power necessary for no-discharge operation of a pump, and during severe flooding the pump is operated at an overload exceeding its design capacity. During maintenance operation water is fed from a river on the delivery side of the pump station into the station. When an inflow of rainwater into the pump station is great the pump is operated at the necessary capacity, when it becomes small the water level is kept above a rated value, and when the inflow rate is zero the pump discharge is increased to a capacity at which sediment can be discharged. A suction blower is disposed at the top of a suction sump and interstage valves are disposed in entrances of vertical shafts to effect efficient ventilation of the underground waterway. A feed channel is operated as a pressure channel and the pump is of variable capacity and the water level in the underground waterway is controlled to be constant.