Oil and water in a vacuum pump are two immiscible liquids, but under certain conditions, a stable or unstable emulsion will be formed. In contact with water, whether the oil is emulsified or not and the degree of emulsification are mainly determined by the composition of the vacuum oil, the purity of the water, and the nature of the components contained, and are also related to the temperature and vibration of the vacuum oil-water system.

Take the emulsification that usually occurs in oil as an example. When there are some surface active substances (such as carboxylic acid derivatives) that have both lipophilic and hydrophilic groups in vacuum oil or water, they will When appropriate, they associate together to form a dense monolayer in which water is enclosed. A large number of associations are evenly dispersed in the oil to form a water-in-oil emulsion. It can be seen that controlling the existence of surfactants in oil-water and destroying the dense monolayer of surfactants enclosing water is the fundamental way to prevent and resist the emulsification of the two-phase coexistence system.

Modulating vacuum oil with highly refined base oil is of great significance to improve the anti-emulsification performance of refined oil, but vacuum oil contains various functional additives (mostly surfactants), which will inevitably affect the separation ability of vacuum oil to water. Therefore, oil product development and production personnel add a certain proportion of demulsifiers with special properties to the vacuum oil to suppress this effect, so as to ensure that the vacuum oil has good demulsibility.