Ebara Corporation

Tsuneo Asanagi

Kazuo Yamaguchi

Akihiro Ushitora

Toshiyuki Hasegawa

A vacuum pump control apparatus for an evacuating-type waste water collecting system is disclosed. In the system, waste water discharged from houses and facilities is collected into a water collecting tank by vacuum sewer pipes provided with a negative pressure therein, and the waste water collected in the water collecting tank is discharged by a booster pump while the air in the water collecting tank is discharged by a vacuum pump. The vacuum pump control apparatus comprises a gas-liquid ratio detection arrangement for detecting the ratio of the amount of air to the amount of waste water to be collected into the water collecting tank, and a control system for regulating the operating time of the vacuum pump based upon the gas-liquid ratio detected by the gas-liquid ratio detecting arrangement, so that a target value of the gas-liquid ratio is recovered when it falls below the target value. By this apparatus, the gas-liquid ratio within the vacuum sewer pipes is kept to an ideal value to thereby prevent an air lock from forming in the vacuum sewer pipes.

Vacuum pump control apparatus for an evacuating type waste water

A vacuum type sewage collecting system, for collecting sewage from a plurality of houses or the like, stores sewage in a sewage reservoir and then delivers the sewage to a sewage treatment station through a vacuum valve and a vacuum sewage pipe. A controller is provided for properly controlling opening/closing operations of the vacuum valve. The controller includes a first vacuum chamber connected to the vacuum sewage pipe via a fluid flow resisting device, a second vacuum chamber likewise connected to the vacuum sewage pipe, an atmospheric pressure introducing unit for introducing an atmospheric pressure into the first vacuum chamber when a detected quantity of sewage stored in the sewage reservoir exceeds a predetermined value, and a shifting unit for selectively introducing negative pressure to the vacuum valve to open or close the latter depending on the present differential pressure between the first vacuum chamber and the second vacuum chamber. A first opening/closing valve is disposed in a parallel relationship relative to the fluid flow resisting device such that the first opening/closing valve is closed when the negative pressure in the vacuum sewage pipe is lower than a preset value. Alternatively, a closed type air tank is connected to the first vacuum chamber via a second opening/closing valve such that the second opening/closing valve is opened when the negative pressure in the vacuum sewage pipe is lower than the preset value.

Vacuum type sewage collecting system and vacuum valve controller for the

A vacuum-type sewage collecting apparatus collect sewage discharged from a plurality of houses or facilities in an accumulating tank through a vacuum sewage pipe network, the inner pressure of which is negative. The vacuum sewage pipe network includes a plurality of upper stream pipes and lower stream pipes fastened to each other in a branch-like fashion. Each lower stream pipe has a sawtooth-like shape formed by alternately disposed downwardly-sloping portions extending gently downwards toward said accumulating tank, and lift portions fastened to the lowermost portion of a respective downwardly-sloping portion and extending upwardly with a steep slope. The upper stream pipe is connected to the lower stream pipe in a range in which a horizontal plane, which extends through an upper end portion of the lower stream pipe at the position in which the downwardly-sloping portion adjoins the lift portion, is higher than the center of the lower stream pipe. The upper stream pipe opens to the lower stream pipe at a position diagonally above the center of the lower stream pipe as viewed in a plane perpendicular to the pipe central axis. At least a portion of the opening is higher than the horizontal plane, and the upper stream pipe extends from the lower stream pipe diagonally upwards.

Pipe connection structure and vacuum-type sewage collecting apparatus

A laying structure for a vacuum sewer pipe of a vacuum sewage collecting system for collecting sewage discharged from homes and facilities into a collecting tank through a vacuum sewer pipe kept negative in pressure internally is disclosed. The vacuum sewer pipe includes a portion laid in a plain topography which comprises a downward pitch portion sloped toward downstream, and a short upward pitch portion connected to the downstream end of the downward pitch portion to return a depth of the vacuum sewer pipe to an original level, the downward pitch portion and the upward pitch portion are alternated at least once. The upward pitch portion starts from a spot deepened from the original laying level by a depth corresponding to 0.8 to 1.0 times of a bore of the vacuum sewer pipe. By this arrangement, an air lock is not produced at the upward pitch portion even if the quantity of air flowing in the vacuum sewer pipe is low.

Laying structure for vacuum sewer pipe of vacuum sewage collecting system

A vacuum-type sewage collecting apparatus is arranged in such a manner that sewage discharged from the houses or facilities is once accumulated in a cesspool, and the sewage accumulated in the cesspool is then collected through a vacuum valve and a vacuum sewage pipe, the interior of which is under a negative pressure. The vacuum valve is operated by negative pressure taken from a vacuum source and supplied to the vacuum valve via a connecting pipe. The negative pressure for operating the vacuum valve is taken from a portion of a vacuum sewage pipe which is elevated at a level higher than that of the vacuum valve and is disposed downstream of the vacuum valve. Alternatively, the negative pressure may be directly taken from an accumulating tank, the inner pressure of which has been evacuated by a vacuum pump, from a pipe which establishes a connection between the accumulating tank and the vacuum pump, or from a tank connected to the pipe connecting the accumulating tank and the vacuum pump. In this way, a high negative pressure can be supplied to the vacuum valve to effectively and completely open the vacuum valve to thereby perform an efficient discharge of the sewage through the same valve.

Growing community of inventors

Kanagawa, Japan

Tsuneo Asanagi