What is the granularity of lubricating oil? What are the eligibility criteria?
First, the concept of granularity
Particle size refers to the number of solid particles of different particle sizes present in the unit volume of the oil, the unit is per 100 ml, is determined by a special particle size meter. Granularity is an important criterion to judge whether the turbine lubricating oil is qualified. It is generally believed that when the human eye cannot see the oil in no particulate matter, that is, the oil is not contaminated, in fact, particles less than 40μm are not visible to the naked eye, and particles smaller than 40μm have disastrous effects on hydraulic components or bearings, often these tiny particles play a key role in the wear process
Second, the cause of unqualified particle size in turbine lubricating oil
(1) Pollutants left in the process of manufacturing, assembly and overhaul of lubricating oil system components. Such as: hair, iron filings, welding slag, dust, etc. These pollutants were not cleaned up in time and thoroughly during the installation and flushing of the unit.
(2) The sealing performance of the main oil tank is poor, and the pollutants in the air around the oil tank enter the oil tank through the gap and bring into the oil system, polluting the oil quality.
(3) The manual door of the exhaust fan outlet of the main fuel tank of the steam turbine is too large, and small particles enter each bearing box through the oil gear, and then pollute the lubricating oil.
(4) The normal wear of each component of the lubricating oil system and each hydraulic pump, each bearing and the oil supply system will pollute the oil quality.
(5) The main tank is refueled without mixing oil test before normal refueling, and the new oil does not match the old oil, resulting in sludge and polluting the oil.
(6) When the new turbine oil enters the factory, it is unqualified and added to the main tank to pollute the lubricating oil in the main tank.
3. What is the qualification standard for the particle size of turbine lubricating oil?
The standard of oil quality of steam turbine in our country is NAS1638 standard of American Aerospace Industry Federation, which requires that the oil quality must reach grade 8. Therefore, when the oil particle size is greater than 8, it is considered unqualified.
4. How to deal with unqualified turbine lubricating oil particle size?
1. When the particle size of the turbine lubricating oil increases, the oil purification device should be immediately started to filter the lubricating oil without time, and regularly sample the oil quality for testing, and continuously monitor the particle change.
2, immediately check the cause of unqualified particle size, the operation of unqualified particle size is generally due to the quality of oil pollution, according to the cause of investigation targeted treatment, from the source to eliminate the cause of oil pollution.
3, if it is suspected that the oil cooler is leaking, switch the oil cooler, put the standby oil cooler, and run the oil cooler switch;
4, during this period, the oil filter should run 24 hours a day, in addition to the online oil purification device to run the oil filter, should also be put into the plate oil filter for oil, into a point to control the change of particle size.
