On 2018-08-08 14:48:54
oil filter to deal with moisture impurity in insulating oil of importance
The breakdown voltage and dielectric loss factor are commonly used to represent the electrical performance or insulation energy of the oil after purification by the transformer insulating oil filter. Even if there is only a trace of water and impurities, the breakdown voltage of oil will be reduced, in addition to the metal mesh debris, fiber, dust and carbon black suspended matter will also have a negative impact on the breakdown voltage. When the insulating oil is aged to produce acid substances or sludge, or oil mixed with water or impurities will increase the dielectric loss factor, in addition, when loading and unloading oil, the use of improper oil hose or plastic pipe. Causes the oil to dissolve with these materials and deteriorates the oil. At this time oil medium loss factor suddenly increased, sometimes up to 0.1%
When it is found that the insulation oil and oil deteriorates and the electrical properties decline and cannot meet the performance index requirements of the operating oil, the oil filter can be used to purify the oil that has passed through. The common method is to use white earth treatment and then add antioxidant to make all aspects of its performance meet the requirements of the new oil. After the treatment of transformer oil by vacuum oil filter, the pressure resistance of insulating oil increases to meet the following standard requirements;
Oil initial value: Water content: ≤50mg/L, gas content: ≤ 10% (volume fraction), breakdown voltage: ≥25KV
Secondary purification: Water content :≤ 15mg/L, gas content :≤ 0.1% (volume), pressure resistance value :≥ 50KV (bulb) Three purification: residual water content :≤5-10ppm, residual gas :≤0.05%, acetylene content: 0, pressure resistance :≥60KV (bulb) Note: Measurement methods for water and gas content are in accordance with relevant GB, DL or IEC standards.