Water treatment apparatus including underwater plasma discharge module

Patent metadata

Field	Value
Publication number	US-11485658-B2
Application number	US-202016798289-A
Country	US
Kind code	B2
Filing date	Feb 21, 2020
Priority date	Apr 26, 2019
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A water treatment apparatus including an underwater plasma discharge module is provided. The water treatment apparatus includes a dissolved air flotation device configured to remove foreign matter contained in water and an underwater plasma discharge module disposed at a preceding stage of the dissolved air flotation device and configured to cause a portion of the water to be introduced into the dissolved air flotation device to perform underwater plasma discharging, wherein the dissolved air flotation device comprises a mixing and coagulation basin configured to coagulate or flocculate the foreign matter contained in the water to form and grow flocs of the foreign matter, and a flotation basin configured to raise and remove the flocs by supplying microbubbles to the water passing through the mixing and coagulation basin.

First claim

What is claimed is:

1. A water treatment apparatus comprising:
a dissolved air flotation device configured to remove foreign matter contained in water, the dissolved air flotation device including:
a mixing and coagulation basin configured to coagulate or flocculate the foreign matter contained in the water, to form and grow flocs of the foreign matter, and
a flotation basin configured to raise and remove the flocs by supplying microbubbles to the water passing through the mixing and coagulation basin; and

an underwater plasma discharge module disposed at a preceding stage of the dissolved air flotation device and configured to perform underwater plasma discharging with respect to a portion of the water to be introduced into the dissolved air flotation device, the underwater plasma discharge module including a reactor formed by
a plasma electrode module that is configured to generate plasma and includes a continuous surface facing in a first direction of the underwater plasma discharging,
a ground electrode having a continuous surface facing the continuous surface of the plasma electrode module,
an input port formed in the continuous surface of the ground electrode, through which the water flows into the reactor in a second direction opposite to the first direction, and
an output port formed in the continuous surface of the ground electrode, through which purified water flows out of the reactor in the first direction,
wherein the reactor is configured to pass the water from the input port to the output port along a generally straight path between the continuous surfaces of the plasma electrode module and the ground electrode.

2. The water treatment apparatus according to claim 1 , wherein the mixing and coagulation basin comprises a measuring unit configured to measure a concentration of the foreign matter contained in the water and a controller configured to control an operation of the underwater plasma discharge module according to a measurement value output from the measuring unit.

3. The water treatment apparatus according to claim 1 , wherein the flotation basin comprises an air injector configured to raise the flocs contained in the water passing through the mixing and coagulation basin and a floc remover configured to remove the flocs floating on the water.

4. The water treatment apparatus according to claim 3 , further comprising a filter configured to filter out the foreign matter remaining in the water passing through the floc remover.

5. The water treatment apparatus according to claim 1 , wherein the reactor further comprises a gap adjuster configured to adjust a gap between the ground electrode and the plasma electrode module.

6. The water treatment apparatus according to claim 1 ,
wherein the plasma electrode module comprises:
a conductive substrate including a plurality of holes;
a ceramic layer surrounding a surface of the conductive substrate except for a surface in each of the holes; and
a plurality of plasma electrodes that are disposed in the plurality of holes of the conductive substrate, respectively, and has a multilayer structure including a ground portion, a fixed portion, and a discharge portion which are sequentially stacked, and

wherein the ground portion is in contact with the conductive substrate and the plasma is generated on the discharge portion.

7. The water treatment apparatus according to claim 6 , wherein the ground portion, the fixed portion, and the discharge portion are integrally formed as a one-piece body and are made of a same material having corrosion resistance.

8. The water treatment apparatus according to claim 6 , wherein the conductive substrate has a plate shape or a columnar shape.

9. A water treatment apparatus comprising:
a dissolved air flotation device configured to remove foreign matter contained in water, the dissolved air flotation device including:
a mixing and coagulation basin configured to coagulate or flocculate the foreign matter contained in the water, to form and grow flocs of the foreign matter, and
a flotation basin configured to raise and remove the flocs by supplying microbubbles to the water passing through the mixing and coagulation basin; and

an underwater plasma discharge module disposed at a subsequent stage of the dissolved air flotation device and configured to perform underwater plasma discharging with respect to at least a portion of the water to be discharged from the dissolved air flotation device, the underwater plasma discharge module including a reactor formed by
a plasma electrode module that is configured to generate plasma and includes a continuous surface facing in a first direction of the underwater plasma discharging,
a ground electrode having a continuous surface facing the continuous surface of the plasma electrode module,
an input port formed in the continuous surface of the ground electrode, through which the water flows into the reactor in a second direction opposite to the first direction, and
an output port formed in the continuous surface of the ground electrode, through which purified water flows out of the reactor in the first direction,
wherein the reactor is configured to pass the water from the input port to the output port along a generally straight path between the continuous surfaces of the plasma electrode module and the ground electrode.

10. The water treatment apparatus according to claim 9 , wherein the microbubbles are supplied into a portion of purified water resulting from the underwater plasma discharging performed by the underwater plasma discharge module, and the purified water in which the microbubbles are contained is used as a microbubble source for the flotation basin.

11. The water treatment apparatus according to claim 10 , wherein the mixing and coagulation basin comprises a measuring unit configured to measure a concentration of the foreign matter contained in the water and a controller configured to control an operation of the underwater plasma discharge module according to a measurement value output from the measuring unit.

12. The water treatment apparatus according to claim 9 , wherein the flotation basin comprises an air injector configured to raise the flocs to a surface of the water passing through the mixing and coagulation basin and a floc remover configured to remove the flocs floating on the surface of the water.

13. The water treatment apparatus according to claim 12 , further comprising a filter configured to filter the foreign matter remaining in the water passing through the remover.

14. The water treatment apparatus according to claim 9 , wherein the reactor further comprises a gap adjuster configured to adjust a gap between the ground electrode and the plasma electrode module.

15. The water treatment apparatus according to claim 9 ,
wherein the plasma electrode module comprises:
a conductive substrate including a plurality of holes;
a ceramic layer surrounding a surface of the conductive substrate except for a surface in each of the holes; and
a plurality of plasma electrodes that are disposed in the plurality of holes of the conductive substrate, respectively, each having a multilayer structure including a ground portion, a fixed portion, and a discharge portion which are sequentially stacked, and

wherein the ground portion is in contact with the conductive substrate and the plasma is generated on the discharge portion.

16. The water treatment apparatus according to claim 15 , wherein the ground portion, the fixed portion, and the discharge portion are integrally formed as a one-piece body and are made of a same material h

Assignees

• Doosan Enerbility Co Ltd

Inventors

• Park Yong Hae

Classifications

• C02F1/4608 Primary

  using electrical discharges · CPC title

• C02F1/24

  by flotation (C02F1/465 takes precedence) · CPC title

• C02F2305/023

  Reactive oxygen species, singlet oxygen, OH radical · CPC title

• C02F1/78

  with ozone {(C02F1/4672 takes precedence)} · CPC title

• C02F1/5227

  Processes for facilitating the dissolution of solid flocculants in water · CPC title