Apparatus for purifying waste lubricant and method of purifying waste lubricant using the same

A method for purifying a waste lubricant, by which water and particulate pollutant are eliminated from the waste lubricant, the method comprising the steps of:

• operating a vacuum pump such that a vacuum pressure is transferred to the condensate water container, a condenser, and a vaporizing chamber so as to decompress the interior of the vaporizing chamber in a vacuum state;
• p1 injecting a heated waste lubricant into the interior of the vaporizing chamber by an injection nozzle installed to the vaporizing chamber by vacuum pressure, vaporizing the injected waste lubricant by a vacuum vaporizing temperature, condensing the vaporized water by passing the water through the condenser, and collecting the condensed water in a condensate water container;
• discharging the waste lubricant into a discharging chamber when a predetermined amount of the waste lubricant is stored in the vaporizing chamber or discharging the waste lubricant using discharging means when a predetermined amount of the waste lubricant is stored in the discharging chamber, with the waste lubricant being injected from the injection nozzle;
• applying high voltage to an electrostatic separator consisting of a pair of discharge electrodes and a trapping filter to eliminate the particulate pollutant contained in the waste pollutant carried by an oil pump, and electrically charging the particulate pollutant by corona discharge generated between the pair of electrodes, the electrodes applied with the high voltage of polarity opposite to that of the charged particulate pollutant, so as to eliminate the particulate pollutant by an electrostatic force of the electric field;
• and
• collecting the waste lubricant, from which the particulate pollutant is eliminated, into an oil storing container.