Mitsubishi Heavy Industries Engineering, Ltd.

Mitsubishi Heavy Industries Limited

The University of Tokyo

Aqua Systems Limited

Mitsubishi Heavy Industries, Co., Ltd.

Naikai Salt Industries Co., Ltd.

Takeshi Yasunaga

Kiichi Tokunaga

Yoshiaki Ito

Makoto Ohta

Yuta Hashimoto

Shunichi Ikesue

Akira Hashimoto

Yoshinori Kobayashi

Shozo Kaneko

Masami Miura

Kentaro Hayashi

Kazuhisa Takeuchi

Katsunori Matsui

Hideaki Hashimoto

Hideo Iwahashi

Masayuki Tabata

Masahiro Kishi

Yasuhide Gouda

Yasuyoshi Takamoto

This water treatment system is provided with: a reverse osmosis membrane device; a biofilm treatment device that has a carrier, on a surface of which is formed a biofilm, and that treats water to be treated before the water to be treated is transmitted through the reverse osmosis membrane device; and at least one of a water to be treated stoppage period circulation means and a water to be treated stoppage period supply means that are driven when the intake of new water to be treated is stopped. The water to be treated stoppage circulation means supplies and circulates water to be treated from a water to be treated discharge outlet side of the biofilm treatment device to a water to be treated supply port side. The water to be treated stoppage period supply means supplies new water to be treated to the biofilm treatment device.

Water treatment system

To enable energy-saving operation and stable supply of permeate water while water quality level of the permeate water is satisfied during operation, clarified seawater sw subjected to pretreatment and stored in to-be-treated water tankis supplied to reverse osmosis membrane modulevia clarified seawater supply passage. Permeate water pw obtained by an earlier stage element of the reverse osmosis membrane elementsof the reverse osmosis membrane moduleis sent to a subsequent process from permeate water sending passage, and permeate water pw obtained by the reverse osmosis membrane elementis circulated into the to-be-treated water tankvia permeate water circulation passage. The flow rate of the clarified seawater sw supplied to the reverse osmosis membrane moduleis controlled by variable flow rate high-pressure pumpprovided in the clarified seawater supply passage, and opening degree of flow regulating valveprovided in the permeate water circulation passageis controlled, whereby the circulation flow rate of the permeate water is controlled.

Method of operating reverse osmosis membrane apparatus

A reverse osmosis membrane apparatus has a plurality of high pressure vesselsandin parallel with each other with respect to introducing passageof clarified seawater obtained by subjecting raw seawater to sterilization and removal of relatively large foreign substances. The high pressure vesselsandhave first-stage reverse osmosis membrane elementsand, respectively. Concentrated seawater subjected to membrane separation in the high pressure vesselsandflows into a high pressure vessel. In the high pressure vessel, a plurality of reverse osmosis membrane elementsare arranged in series. When a detected value obtained by a differential pressure meterorprovided for the high pressure vesselorexceeds a threshold value, introduction of the clarified seawater is stopped, and the reverse osmosis membrane element is washed or replaced.

Reverse osmosis membrane apparatus and method of operating same

Provided is a wave-power generator capable of adjusting a natural period (natural frequency) in response to a changing wave period. The wave-power generator includes a weight that is installed in a floating body via a spring and that linearly reciprocates in response to a fluctuation of a water surface and a generator that generates power by being driven based on the linear reciprocating motion of the weight. An additional-mass body for adding a mass to the mass of the weight is further included.

Natural-frequency adjusting mechanism for wave-power generator

A wave power generator that can efficiently perform power generation in response to ocean-wave periods, which are waves of varying period, is provided. A vibration receiving portion that is provided in a float floating at a wave surface and that performs power generation by means of vibrations exerted thereon; a mass body that applies a mass loading on the vibration receiving portion from above; a plurality of elastic members that support the mass body in series; and a plurality of locking mechanisms that restrict/release the motion of the plurality of elastic members are provided.

Wave power generator

Growing community of inventors

Tokyo, Japan

Takeshi Yasunaga