Hitachi, Ltd.

Hiroki Miyakawa

Kotaro Kitamura

Yusuke Okawa

Shinichi Yoshikawa

Masayuki Matsuura

Takanori Oshikiri

Koji Fukuzaki

Provided is a reverse osmosis treatment system capable of simultaneously and efficiently recovering energy generated both at brine and permeate sides. The system comprises a branched portion configured to divide second to-be-treated water into third and fourth to-be-treated water; a high-pressure pump configured to pressurize the third to-be-treated water thereby to feed fifth to-be-treated water having a higher pressure than the to-be-treated water before divided; a displacement type of first energy recovery device configured to exchange pressures between the fourth to-be-treated water and brine thus separated by a reverse osmosis treatment device, thereby to produce sixth to-be-treated water having a higher pressure than the fourth one; and a second energy recovery device configured to raise a pressure of the third to-be-treated water located at a downstream side of the branched portion with a pressure of first permeate thus separated by the reverse osmosis treatment device.

Reverse osmosis treatment system for recovering energy generated both at brine and permeate sides during sea water desalination

An object of the present invention is to provide a desalination apparatus in which a high pressure pump can be operated at a high efficient operation point even when temperature, salt concentration or the like of water to be treated vary. The desalination apparatus includes a high pressure pump which is provided in a first flow path and supplies raw water to a first module at high pressure to apply reverse osmotic pressure to a first module and a second module, a third flow path for supplying second concentrated water after separation in the second module to upstream of the high pressure pump in the first flow path, and a fourth flow path for supplying a portion of the first concentrated water after separation in the first module to upstream of the high pressure pump in the first flow path.

Desalination apparatus

Reverse osmosis treatment system for recovering energy generated both at brine and permeate sides during seawater desalination

A reverse osmosis treatment device includes: a first pressure vessel for treating an untreated water to produce a primarily treated water and a first permeated water; a second pressure vessel for treating the primarily treated water to produce a secondarily treated water and a second permeated water; a first cleaning solution tank for storing a first cleaning solution for cleaning the first pressure vessel; and a second cleaning solution tank for storing a second cleaning solution for cleaning the second pressure vessel. Each of the first pressure vessel and the second pressure vessel has therein a reverse osmosis membrane element having a reverse osmosis membrane. The first cleaning solution tank is connected to the first concentrate outlet pipe of the first pressure vessel, and the second cleaning solution tank is connected to the inlet pipe for the primarily treated water of the second pressure vessel.

Reverse osmosis treatment device and method for cleaning reverse osmosis treatment device

Provided is a reverse osmosis treatment apparatus which decreases operation power by utilizing a back pressure caused by regulating an amount of permeated water. The reverse osmosis treatment apparatus includes a first pressure vessel for a primary treatment of untreated water, and a second pressure vessel for a secondary treatment of the water treated by the primary treatment, wherein a reverse osmosis membrane element having a reverse osmosis membrane or the plurality of reverse osmosis membrane elements are arranged in series along a water collection pipe in the first pressure vessel and the second pressure vessel. The first pressure vessel includes a first outlet pipe which discharges permeated water, and a permeated water flow control valve connected to the first outlet pipe and regulating a pressure in the first pressure vessel. An energy recovery apparatus is provided between the first outlet pipe and the permeated water flow control valve.

Growing community of inventors

Tokyo, Japan

Hiroki Miyakawa