When the hydraulic system is working, the foam produced by hydraulic oil products seriously affects the dynamics of the hydraulic system, and may cause changes in bulk modulus, resulting in a series of problems such as cavitation, noise, oil degradation, oil temperature rise, oil quality degradation, etc.
Production of oil foam in hydraulic system 1. Hydraulic oil produces foam Some additives in hydraulic oil products are easy to produce foam. When the hydraulic oil works, due to agitation and transmission, the oil itself will produce more foam. When the hydraulic oil is working, due to the increase of working temperature, load pressure and operating time, the oil itself may be oxidized and decomposed, producing more foam components or destroying the original defoamer components, which will also increase the hydraulic oil foam. 2. Hydraulic equipment will increase oil foam Air mixed with oil products is the main reason for oil products to produce foam. In actual work, air may mix into the oil in various ways. For example, the connection part of the pipeline is not tight enough, the suction pipeline of the pump or the pipe seal has leakage, the oil inlet of the oil tank is high, and the oil in the oil tank is reduced, which will cause more foam when air enters the oil.
Elimination of oil foam in hydraulic system The way to reduce or eliminate oil foam in the hydraulic system is fundamentally to use a well sealed hydraulic system and low foam hydraulic oil. According to the development trend of modern hydraulic equipment with high pressure, high temperature, high speed, high precision and small volume, the research and development and production of hydraulic oil compound meet the requirements of high foam performance in hydraulic systems. For example, ashless anti-wear hydraulic oil compound agent, anti-wear hydraulic oil compound agent and low zinc anti-wear hydraulic oil compound agent all have good Anti Foam characteristics, which can effectively ensure the smooth pressure of the hydraulic system. The hydraulic oil modulated with high-quality hydraulic oil compound can effectively reduce or eliminate the problems caused by foam when the hydraulic system is working. In addition, the following technologies can eliminate or reduce the oil foam in the hydraulic system. ① The foam in the working oil can be removed by connecting the defoamer device in the hydraulic system. ② The most common way to solve the problem of excessively high oil foam is to select appropriate defoamer and add it to the relevant oil products to control or eliminate foam. Defoamers should generally have the following properties: ✅ Low surface tension; ✅ Has good diffusion and permeability; ✅ Has strong defoaming ability, and the dosage should be as small as possible; ✅ Good compatibility with other additives in the oil; ✅ Has good heat resistance and chemical stability; ✅ There is small solubility in the foaming system; ✅ No physiological activity, safe and reliable.
