Electrostatic purification device of fluid, fluid purification facility, and method of purifying fluid

1 . An electrostatic purification device, the electrostatic purification device comprising:

a purification tank housing configured to accommodate a fluid;

a first electrode and a second electrode provided in the purification tank housing;

a direct current (DC) power supply configured to apply a DC to the first electrode and the second electrode;

a controller configured to:

monitor a current density between the first electrode and the second electrode, and

determine whether purification is completed based on the current density;

a first valve configured to control an introduction flow of the fluid into the purification tank housing;

a second valve configured to control a discharge flow of the fluid from the purification tank housing; and

a heat exchanger configured to cool the fluid accommodated in the purification tank housing,

wherein the controller is further configured to determine that purification is completed based on a degree of decrease in the current density over a predetermined time period being less than a predetermined threshold, and

wherein the controller is further configured to, based on determining that purification is completed, open the second valve while maintaining application of the DC to the first electrode and the second electrode.

2 . The electrostatic purification device of claim 1 , wherein the controller is further configured to close the first valve and the second valve while the DC power supply applies the DC to the fluid.

3 . The electrostatic purification device of claim 1 , wherein the controller is further configured to determine that purification is completed based on the current density decreasing by a first percentage, and

wherein the first percentage is in a range of about 0.5% to about 15%.

4 . The electrostatic purification device of claim 1 , wherein the controller is further configured to determine that purification is completed based on the degree of decrease of the current density being equal to or less than 0.2% within the predetermined time period.

5 . The electrostatic purification device of claim 1 , further comprising:

a gas removal tank connected to and in fluid communication with the purification tank housing through first circulation conduits,

wherein the gas removal tank comprises a gas purge port.

6 . The electrostatic purification device of claim 1 , wherein a gas purge port is provided in an upper portion of the purification tank housing.

7 . The electrostatic purification device of claim 1 , wherein the heat exchanger is connected to and in fluid communication with the purification tank housing through second circulation conduits, and

wherein the heat exchanger is further configured such that the fluid circulates the purification tank housing and the heat exchanger through the second circulation conduits while the DC power supply applies the DC to the first electrode and the second electrode.

8 . A fluid purification system, comprising:

a supply tank of a fluid;

an electrostatic purification device configured to:

receive the fluid from the supply tank, and

purify the fluid;

a filter configured to filter the fluid; and

a storage tank configured to store the fluid that is filtered,

wherein the electrostatic purification device comprises:

a purification tank housing configured to accommodate the fluid;

a first electrode and a second electrode provided in the purification tank housing;

a direct current (DC) power supply configured to apply a DC to the first electrode and the second electrode;

a controller configured to:

monitor a current density between the first electrode and the second electrode, and

determine whether purification is completed based on the current density;

a first valve configured to control an introduction flow of the fluid into the purification tank housing;

a second valve configured to control a discharge flow of the fluid from the purification tank housing; and

a heat exchanger configured to cool the fluid accommodated in the purification tank housing, and

wherein the controller is further configured to determine that purification is completed based on a degree of decrease in the current density over a predetermined time period being less than a predetermined threshold, and

wherein the controller is further configured to, based on determining that purification is completed, open the second valve while maintaining application of the DC to the first electrode and the second electrode.

9 . The fluid purification system of claim 8 , wherein the first valve is positioned to control the fluid to flow from the supply tank to the purification tank housing, and

wherein the second valve is positioned to control the fluid to flow from the purification tank housing to the storage tank.

10 . The fluid purification system of claim 8 , wherein each of the first electrode and the second electrode comprises a plurality of flat plates, and

wherein the first electrode and the second electrode are alternately arranged in parallel to each other.

11 . The fluid purification system of claim 8 , wherein the first electrode and the second electrode are configured to extend to be curved while maintaining a substantially constant distance from each other.

12 . The fluid purification system of claim 8 , wherein the electrostatic purification device further comprises a gas removal tank connected to and in fluid communication with the purification tank housing through first circulation conduits, and

wherein the gas removal tank comprises a gas purge port.

13 . The fluid purification system of claim 8 , wherein the controller is further configured to close the first valve and the second valve while the DC power supply applies the DC to the first electrode and the second electrode.