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

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.