What is the black substance attached to the surface of the running bearing shells?
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In our facility, black substances are often found adhering to the surface of the compressor bearing shells. The experienced workers say that these are deposits caused by cooking fumes. Could some expert please explain what those substances are and why they form?
Is there carbon buildup on the bearing shells?~~~
It is caused by too many impurities in the lubricating oil; as these impurities pass over the bearing surface and the high temperature there causes them to oxidize, they end up floating on the surface of the bearing.
Carbon deposition on the surface area of bearing shells is usually caused by: 1. High temperatures; 2. Impurities in the lubricating oil; 3. Quality issues with the bearing shells themselves
The main causes of carbon buildup are excessive oil temperature and deteriorating oil quality. The main components of carbon deposits are carbonaceous deposits formed by the high-temperature oxidation of lubricating oil, as well as metal compounds resulting from the additives present in the lubricating oil~~
Multiple filtration options available, including external circulation filtration! Removing oxidative precipitates leads to a significant improvement in the lubricating effect
In most cases, it is due to excessive clearance, with carbon deposits formed at high temperatures adhering to the surface of the bearing shells.
You are that crew from that company. This is due to the formation of carbon deposits and a paint film
Carbon deposits and paint films of the lubricating oil type: 1. Oil oxidation – The oxidation of hydrocarbon-based oils follows a free-radical chain reaction mechanism, and upon oxidation, peroxides such as carboxylic acids, esters, and alcohols are formed. These peroxides undergo further polycondensation reactions to produce high-molecular-weight polymers. 2. The “micro-combustion” of oil products leads to the formation of a paint film. Under normal conditions, hydraulic oil will dissolve a certain amount of air; once this limit is exceeded, the air that enters the oil exists in the oil in a suspended form. Once the hydraulic oil is pumped from the low-pressure area to the high-pressure area, these small bubbles suspended in the oil are rapidly compressed, causing the temperature of the oil in those micro-regions to rise sharply, sometimes even to 1100 degrees Celsius. This leads to an adiabatic \"micro-combustion\" in those oil micro-regions, resulting in the formation of extremely small insoluble particles. These insoluble substances are polar and highly unstable; they tend to adhere to metal surfaces at low temperatures, thereby forming a coating film. Relatively speaking, the oxidation of oils is a slow process, whereas the formation of a varnish layer through the adiabatic ‘micro-combustion’ of oils occurs more rapidly.