1. Pressure filtration method: The insulating oil used in power transformers must have insulating properties and thermal conductivity (national standard). At the installation site, the pressure filtration method is commonly used to complete the general drying (removing moisture) and purification (removing dirt) of the insulating oil. Methods.
2. Open valves 8 and 11, then start the oil pump, and then open valves 6 and 7. When stopping the oil, first close 6 and 7, then stop the oil pump, and then close the 8 and 11 valves. ⑵ During normal operation, the pressure gauge works normally under the pressure of 3*10 ~ 4*10 Pa. If impurities and oil paper are blocked, the pressure will increase. When the pressure reaches 6*10 Pa, it must be stopped and the filter paper must be replaced. ⑶ The filter paper is dried in an oven at 80-90℃ for 24 hours before use, and placed in a clean container. ⑷ The filter screen is cleaned every 10~15 hours. At the beginning of filtering the oil, within 3-5 minutes, the oil outlet will be sent back to the dirty oil tank through valve 10 for re-filtering, and the oil in the oil filter will be stored and sent through valve 9. Return the dirty oil system and filter again. The above oil filter should be refined and dried for many times until it is qualified.
3. Transformer charged oil filter: ⑴ When the voltage is higher than 10V, it is not suitable to use the charged oil filter. Because more bubbles are generated during filtration, the bubbles will be freed under the action of higher voltage, which will deteriorate the insulation performance of the oil and cause internal discharge. When performing electrified oil filtering, periodically release the gas released from the oil in the Buchholz relay. ⑵ When filtering the oil with electricity, the oil pipe and the oil filter should be reliably grounded to protect the personal safety of the staff. The staff should be professional, supervised by someone, and wear insulating supplies. ⑶ Operation: connect the pressure-type oil filter button at the 4 and 5 diagonal valve interfaces, the valve 4 draws out the oil, returns to the oil tank from the valve 5, and filters through multiple cycles until it meets the standard.
