How to judge whether the lubricating oil of the ball mill is emulsified?

1. Appearance and state observation
1. Color change
Normal lubricating oil (such as gear oil, hydraulic oil) is usually light yellow, brown or black (new oil is mostly light-colored, and gradually darkens due to impurities after use), and the color is uniform.
If emulsified, the oil will appear milky white, grayish white or creamy yellow, similar to milk or cream, turbid and dull, which is significantly different from the transparent or translucent state of normal oil.
2. Texture and stratification
Normal oil has uniform texture and stable fluidity (showing corresponding viscosity according to different viscosities).
Emulsified oil will have stratification or turbid precipitation: after standing for a period of time, there may be foam floating on the upper layer, milky in the middle layer, and water or impurities precipitated in the bottom layer; or the whole is viscous paste, and the fluidity becomes worse (even loses fluidity).
3. Foam and bubbles
Normal oil will produce a small amount of bubbles during stirring or operation, but they will dissipate quickly after standing.
Emulsified oil will produce a large amount of fine and long-lasting foam due to the mixing of water and air, and the foam is not easy to break (there is still obvious foam residue after standing for more than 30 minutes).
2. Simple physical test
1. Heating test
Pour a small amount of oil sample into a test tube and heat it to 70-80℃ (you can use a hot water bath or alcohol lamp to heat slowly):
If the oil is stratified, the upper layer is transparent oil and the lower layer is water or sediment, which means that it contains water and is not completely emulsified;
If it remains milky and turbid after heating, and there is a "sizzling" sound or water vapor evaporation, it means that the emulsification is serious (water and oil have formed a stable emulsion).
2. Sedimentation test
Pour an appropriate amount of oil sample into a transparent container (such as a beaker) and let it stand for 24 hours:
Normal oil has no obvious change after standing, or only a small amount of impurities are precipitated at the bottom;
Emulsified oil may be stratified after standing (upper layer oil, middle layer emulsion, lower layer water), or the whole is still turbid, indicating that water and oil are mixed and not separated.
3. Viscosity change
Dip the oil with a glass rod and observe its fluidity:
Normal oil has uniform viscosity and is in a continuous line when dripping;
The viscosity of emulsified oil will be significantly reduced due to water dilution (the dripping speed becomes faster and watery), or it will become viscous and abnormal wire drawing due to the influence of emulsified particles.
III. Assist judgment in combination with the operating status of the equipment
1. Observation of the oil tank or oil level gauge
Open the oil tank cap or observe the oil level gauge. If a white foam layer is found on the surface of the oil, or milky white sediment is attached to the inner wall of the oil level gauge, it means that it may have been emulsified.
If there is water accumulation at the bottom of the oil tank (a small amount of liquid can be released through the oil tank drain valve. If it is transparent water and separated from the oil, it means that the water content exceeds the standard and is easy to cause emulsification).
2. Abnormal performance of equipment operation
The lubrication performance of the emulsified oil is greatly reduced, which may cause abnormal temperature increase during equipment operation (such as the temperature of the reducer housing exceeds 70℃), increased vibration or abnormal noise (intensified wear of gears/bearings).
If the lubrication system filter is frequently clogged and there is white sticky material on the filter element, it may be caused by colloid and sediment in the emulsified oil.