Seawater desalination system and energy recovery apparatus

Patent metadata

Field	Value
Publication number	US-10005034-B2
Application number	US-201515504230-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Sep 1, 2014
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

The present invention relates to a seawater desalination system for desalinating seawater by removing salinity from the seawater and an energy recovery apparatus which is preferably used in the seawater desalination system. The energy recovery apparatus includes a cylindrical chamber (CH) being installed such that a longitudinal direction of the chamber is placed in a vertical direction, a concentrated seawater port (P 1 ) for supplying and discharging the concentrated seawater, a seawater port (P 2 ) for supplying and discharging the seawater, a flow resistor ( 23 ) provided at a concentrated seawater port (P 1 ) side in the chamber (CH), and a flow resistor ( 23 ) provided at a seawater port (P 2 ) side in the chamber (CH). Each of the flow resistor ( 23 ) provided at the concentrated seawater port (P 1 ) side and the seawater port (P 2 ) side comprises at least one perforated circular plate, and each perforated circular plate has a plurality of holes formed in an outer circumferential area outside a circle having a predetermined diameter on the perforated circular plate.

First claim

What is claimed is:

1. An energy recovery apparatus for converting pressure energy of concentrated seawater discharged from a reverse-osmosis membrane-separation apparatus to pressure energy of seawater in a seawater desalination system for producing fresh water from the seawater by supplying the seawater pressurized by a pump to the reverse-osmosis membrane-separation apparatus to separate the seawater into fresh water and concentrated seawater, the energy recovery apparatus comprising:
a cylindrical chamber having a space for containing concentrated seawater and seawater therein, the chamber being installed such that a longitudinal direction of the chamber is placed in a vertical direction;
a concentrated seawater port provided at a lower part of the chamber for supplying and discharging the concentrated seawater;
a seawater port provided at an upper part of the chamber for supplying and discharging the seawater;
a flow resistor provided at a concentrated seawater port side in the chamber; and
a flow resistor provided at a seawater port side in the chamber;
wherein each of the flow resistor provided at the concentrated seawater port side and the seawater port side comprises at least one perforated circular plate; and
wherein each perforated circular plate has a plurality of holes formed in an outer circumferential area outside a hypothetical circle which is concentric with the perforated circular plate and has a predetermined diameter, the holes being formed so that an aperture ratio is gradually increased from an outer diameter of the hypothetical circle having the predetermined diameter toward an outer diameter of the perforated circular plate.

2. The energy recovery apparatus according to claim 1 , wherein an area of the perforated circular plate that is free of the holes is an area of a star polygon which has a circle having a predetermined diameter as an incircle and a circle having a diameter equal to or smaller than the outer diameter of the perforated circular plate and greater than the diameter of the hypothetical circle as a circumcircle.

3. The energy recovery apparatus according to claim 1 , wherein the perforated circular plate serves as a first perforated plate, and a second perforated plate is provided to be spaced by a predetermined distance from the first perforated plate.

4. The energy recovery apparatus according to claim 1 , further comprising a doughnut-shaped circular plate having an opening at a center thereof provided between one of the concentrated seawater port and the seawater port or both of the concentrated seawater port and the seawater port, and the flow resistor.

5. An energy recovery apparatus for converting pressure energy of concentrated seawater discharged from a reverse-osmosis membrane-separation apparatus to pressure energy of seawater in a seawater desalination system for producing fresh water from the seawater by supplying the seawater pressurized by a pump to the reverse-osmosis membrane-separation apparatus to separate the seawater into fresh water and concentrated seawater, the energy recovery apparatus comprising:
a cylindrical chamber having a space for containing concentrated seawater and seawater therein, the chamber being installed such that a longitudinal direction of the chamber is placed in a vertical direction;
a concentrated seawater port provided at a lower part of the chamber for supplying and discharging the concentrated seawater;
a seawater port provided at an upper part of the chamber for supplying and discharging the seawater;
a flow resistor provided at a concentrated seawater port side in the chamber; and
a flow resistor provided at a seawater port side in the chamber;
wherein each of the flow resistor provided at the concentrated seawater port side and the seawater port side comprises at least one perforated circular plate;
wherein each perforated circular plate has a plurality of holes formed in an outer area outside a hypothetical circle having a predetermined diameter on the perforated circular plate, the outer area including a forming area where the holes are densely formed and a non-forming area where no hole is formed; and
wherein a bundle-like collected jet flow comprising a group of jet flows which pass through the holes in the forming area is defined and a stationary fluid formed by blocking the flow passing through the perforated circular plate by the non-forming area is defined, the forming area and the non-forming area being alternately distributed in a circumferential direction of the outer area.

6. The energy recovery apparatus according to claim 5 , wherein shear takes place between the collected jet flow and the stationary fluid.

7. An energy recovery apparatus for converting pressure energy of concentrated seawater discharged from a reverse-osmosis membrane-separation apparatus to pressure energy of seawater in a seawater desalination system for producing fresh water from the seawater by supplying the seawater pressurized by a pump to the reverse-osmosis membrane-separation apparatus to separate the seawater into fresh water and concentrated seawater, the energy recovery apparatus comprising:
a cylindrical chamber having a space for containing concentrated seawater and seawater therein, the chamber being installed such that a longitudinal direction of the chamber is placed in a vertical direction;
a concentrated seawater port provided at a lower part of the chamber for supplying and discharging the concentrated seawater;
a seawater port provided at an upper part of the chamber for supplying and discharging the seawater;
a flow resistor provided at a concentrated seawater port side in the chamber; and
a flow resistor provided at a seawater port side in the chamber;
wherein each of the flow resistor provided at the concentrated seawater port side and the seawater port side comprises at least one perforated circular plate;
wherein each perforated circular plate has a plurality of holes formed in an outer area outside a hypothetical circle having a predetermined diameter on the perforated circular plate, the outer area including a forming area where the holes are formed and a non-forming area where no hole is formed; and
wherein the non-forming area is joined to the hypothetical circle and forms a petal-shape non-forming area radially extending toward the outer circumference of the perforated circular plate.

8. An energy recovery apparatus for converting pressure energy of concentrated seawater discharged from a reverse-osmosis membrane-separation apparatus to pressure energy of seawater in a seawater desalination system for producing fresh water from the seawater by supplying the seawater pressurized by a pump to the reverse-osmosis membrane-separation apparatus to separate the seawater into fresh water and concentrated seawater, the energy recovery apparatus comprising:
a cylindrical chamber having a space for containing concentrated seawater and seawater therein, the chamber being installed such that a longitudinal direction of the chamber is placed in a vertical direction;
a concentrated seawater port provided at a lower part of the chamber for supplying and discharging the concentrated seawater;
a seawater port provided at an upper part of the chamber for supplying and discharging the seawater;
a flow resistor provided at a concentrated seawater port side in the chamber; and
a flow resistor provided at a seawater port side in the chamber;
wherein each of the flow resistor provided at the concentrated seawater port side and the seawater port side comprises at least one perforated circular plate; and
wherein each perforated circular plate has a plurality of holes formed in an outer area outside a hypothetical circle having a predetermined radius from th

Assignees

• Ebara Corp

Inventors

• Goto Akira
• Takahashi Tamami
• Nohmi Motohiko
• Goto Masanori

Classifications

• C02F1/441

  by reverse osmosis · CPC title

• C02F2103/08

  Seawater, e.g. for desalination · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• B01D61/06 Primary

  Energy recovery · CPC title

• B01D63/12

  comprising multiple spiral-wound assemblies · CPC title