In modern industrial production and scientific research, obtaining a high vacuum environment is of utmost importance, and vacuum diffusion pump oil plays an indispensable role in this process. It is like a behind-the-scenes hero, silently assisting various high-vacuum equipment to operate stably and providing key support for the development of numerous fields. Now, let's delve deeper into the working principle of vacuum diffusion pump oil. 
The oil diffusion pump is the main equipment for obtaining high vacuum, and its operation relies on low-pressure, high-speed, and directional flow of oil vapor jets for vacuum extraction. When the oil diffusion pump is pre-pumped to a vacuum lower than 1 pascal by the pre-stage pump, the oil pan begins to heat up, the pump oil boils, and the nozzle sprays a high-speed vapor flow. At this time, the gas molecules in the thermal motion diffuse into the vapor flow and collide with the directionally moving oil vapor molecules, thereby acquiring momentum and generating a directional flow in the same direction as the movement of the oil vapor molecules. At the pre-stage, the oil vapor is condensed, the gas molecules are released, and then it is drawn away by the pre-stage pump to achieve the purpose of vacuum extraction. 
However, the vapor pressure of the pump oil directly affects the vacuum performance of the pump, and the pump oil used in the diffusion pump is a mixture of different components with varying vapor pressures. Therefore, to improve the vacuum extraction and vacuum performance of the oil diffusion pump, the pump itself needs to perform fractionation and purification of the pump oil during operation. During fractionation, the different evaporation temperatures of the pump oil components are utilized to make the light distillate oil evaporate from the outer layer and enter the low-vacuum working nozzle, and the heavy distillate oil flows from the outer layer to the oil pan center and evaporates into the high-vacuum working nozzle. Purification is achieved by continuously removing the light distillate that has not fully condensed by the pre-stage pump, making the pump oil increasingly pure. 
The working principle of vacuum diffusion pump oil is intricate and complex, from oil vapor jet vacuum extraction to its own fractionation and purification. Each step is closely linked, working together to achieve a high vacuum environment. Based on this working principle, it plays an irreplaceable role in fields with strict requirements for high vacuum, such as vacuum smelting, vacuum coating, and space simulation experiments, driving the continuous development of related industries.