Hitachi, Ltd.

Kenji Otani

Kunio Takada

Sadashi Tanaka

Masayuki Yamada

Sumio Sudo

Saburo Maru

Toshihiro Yamada

Ryoji Okada

Mitsuaki Haneda

Kooji Aizawa

Akira Manabe

Norimitu Kuwabara

Kooju Aizawa

A drainage water pumping system. A number of drainage pumps are positioned at two different levels. Drainage water flowing into a drainage water pumping system from an underground inflow main pipeline is pumped to a discharge destination. Preferably the drainage pumps installed at the lower installation level have a high pump head and a small capacity, while the drainage pumps installed at the higher installation level have a low pump head and a large capacity. The drainage pumps can be in a circular arrangement with a congregated delivery pipeline installed lengthwise at the center of the circular arrangement and having each of the drainage pumps connected to it.

Drainage water pumping station and method for operating the same

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

Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit. The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.

Bearing unit, drainage pump and hydraulic turbine each incorporating the

A plural drainage pumps PH are disposed on the high floor gradation state at the circular shape. A plural drainage pumps PL are disposed on the low floor gradation state at the circular shape. The drainage pump PH disposed on the high floor gradation is installed at the high level. The drainage pump PH is set one having the low pump head and the large capacity in comparison with those of the drainage pump PL disposed on the low floor gradation. An outer shape of an underground pump construction building is formed a circular cone shape spreading toward an upper portion. The discharge water power can be reduced and the construction area for the underground pump construction building can be reduced and further the engineering working amount such as a digging working at the underground can be lessen.

A plurality of drainage pumps are disposed on a high floor gradation state in a circular arrangement. A plurality of drainage pumps are disposed on a low floor gradation state in a circular arrangement. The drainage pumps disposed on the high floor gradation are installed at a high level, with the drainage pumps having a low pump head and a large capacity in comparison with the drainage pumps disposed at the low floor gradation. An outer shape of an underground pump construction building is in the form of a circular cone shape spreading toward an upper portion of the underground pump construction building. The amount of power for discharging the drainage can be reduced and the construction area for the underground pump construction building can be reduced thereby minimizing the necessary requirement for installation of the underground pump construction.

Drainage pump and a hydraulic turbine incorporating a bearing member,

Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit. The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC - 12% sintered article is attained.

When any component equipment of a draining pump plant is failed, the present necessity of drainage and a failure level of a drain pump involved with the failure are evaluated to determine conditions of continuing or stopping operation of the drain pump involved with the failure on the basis of the evaluated values. When the necessity of continuing the drainage operation is high, the operation is continued as far as possible, taking into account the pump failure level. The possibility of the drainage preference operation is thus maximized in the case of not only a minor failure but also a major failure of the pump, for preventing damage from a flood.

Draining pump system and drainage preference operating method therefor

A drainage system comprises a drainage passage for a drain water, a pump for pumping up the drain water from the drainage passage to a drain portion which is arranged above the drainage passage, and a storage tank which has an inlet connected to the drainage passage to receive the drain water therethough from the drainage passage into the storage tank, and a height of the inlet is higher than that of the drainage passage and lower than that of the drain portion so that an ascent of upper surface of the drain water from the drainage passage is restrained after the drain water ascends to the inlet from the drainage passage.

Underground drainage facility and operation method therefor

In a drainage system wherein drain water is collected from a drainage path including a small river, guided to a plurality of drainage pump facilities, and drained into a destination river, a drainage distribution amount is determined for each of the plurality of drainage pump facilities in accordance with an actual precipitation or estimated precipitation, a river water level at a drainage point of each of the plurality of drainage pump facilities is estimated in accordance with the drainage distribution amount and a change in a detected water level at an upstream of the destination river, and the drainage distribution amount for each of the plurality of drainage pump facilities is corrected so as to make the estimated river water level have a value equal to or smaller than an upper limit of the river water level at the drainage point.

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Tsuchiura, Japan

Kenji Otani