In order to eliminate the foam in the lubricating oil, […]
In order to eliminate the foam in the lubricating oil, an anti-foaming agent or the like having a small surface tension is generally added to the lubricating oil. The addition of an anti-foam agent can destroy the foam formed by the lubricating oil and the air, reduce the stability of the foam adsorption film, shorten the existence time of the foam, and thus ensure the normal operation of the equipment. Anti-foaming agents for lubricating oils include silicone oil anti-foaming agents and non-silicone oil anti-foaming agents.
The cause of the bubble
When used, engine oils and industrial oils are often sprayed into mist. This causes some oil to mix in with the lubricating oil, resulting in relatively stable bubbles flowing into the crankcase and into the oil tank. As a result, the engine cannot be replaced. Normal operation. Lubricants in storage and normal use, due to environmental pollution, atomization deterioration, deterioration and other reasons, will cause the surface tension of oil products to drop. If the lubricating oil contains polar additives and anionic surface active groups, it will also cause a drop in surface tension. For such oils, under the influence of external conditions, such as circulation or high-speed stirring, the air is inhaled and bubbles are generated and it is difficult to eliminate them in a short time.
Lubricating oil foam poses a great danger to the use of lubricating oil. A large number of stable foams will increase the volume and easily allow the oil to overflow from the tank. At the same time, it will increase the compressibility of the oil and reduce the oil pressure. If hydraulic oil transfers work by static pressure, once there is foam, it will reduce the oil pressure in the system. This will destroy the function of transferring work in the system. In addition, increasing the contact area of ??lubricating oil and air and accelerating the aging of oil products is particularly serious for air compressor oils. Lubricating oil with bubbles is compressed so that once the bubbles burst under high pressure, the energy generated by the metal is generated by the fire metal and craters are formed on the metal surface.
Lubricants are susceptible to active ingredients in formulations such as detergents, extrusion additives, and corrosion inhibitors, which greatly increase the tendency of the oil to bubble. The foam stability of lubricating oils varies with viscosity and surface tension. The stability of the foam is inversely proportional to the viscosity of the oil. At the same time as the temperature rises, the foam temperature tends to decrease. The less viscous oil forms a large, easily disappearing foam, and dispersed and stable small bubbles are produced in the high-viscosity oil.
The antifoaming agent acts primarily to suppress the formation of oil foam and rupture the foam. The air bubbles will damage the oil evenly along the oil pipeline to the entire lubricating surface and damage the normal operation of the oil. Especially in the hydraulic system, the oil supply is hindered and will have serious consequences. Therefore, the lubricant used under these conditions needs to be used. Adding an additive, the oil is not easy to air bubbles, and even if it has been foamed, it can disappear in a short time.
Anti-foam agents are generally insoluble in oil and are highly dispersed in the presence of colloidal ions in the oil. The dispersed antifoam particles adsorb onto the foam and then become a part of the foam as a foam and then expand on the film. With the smaller expansion of the anti-foaming agent, the film becomes thinner and thinner, and finally breaks to achieve the purpose of breaking the film.