For some enterprises with very large annual consumption of refrigeration oil, the reuse of refrigeration oil can not only save money, but also receive good environmental and social benefits. The following briefly introduces the recovery and reuse of refrigerator oil:
First, the treatment process
In order to remove the foreign matter in the lubricating oil and make it conform to the national standard, we have performed the following treatment on the refrigerating machine oil, and the process is as follows:
The oil to be treated is left to settle, the oil feet and moisture are removed, and then it enters the glass tank of the pond. The mixture is heated and stirred. An appropriate amount of filter agent (about 10%) is added. A stationary sedimentation, a filtration, a processed oil to be inspected, a quality index test, an oil additive is added, and individual parameters are adjusted to a qualified regenerated oil.
According to the above process, the treated lubricating oil is very close to the new oil when viewed from the outside, and the color is slightly yellow, clear, and free of impurities. The appearance is clear and qualified, no moisture, no mechanical impurities, no water-soluble acids and bases, and the acid value (mgKOH) is only 0.02, which is lower than the requirements of the new oil standard. Only the viscosity, flash point and freezing point are higher than the new oil. Let's analyze the reasons.
1. Viscosity indicates the ability of a liquid to prevent movement. The viscosity of a liquid is almost entirely determined by the force of a molecule. The influencing factors are: increasing temperature and decreasing viscosity; increasing pressure and increasing viscosity. These two reasons are the effects of external factors on viscosity. For a certain type of lubricant, its viscosity mainly depends on the weight of the fraction, that is, the inherent composition of the lubricant plays a decisive role. For the recovered lubricating oil, the viscosity is higher than that of the new oil, which means that during the adsorption process of the filter, not only the moisture and impurities in it are adsorbed, but a small amount of deteriorated hydrocarbons and a few light fractions are adsorbed and filtered out. The viscosity of the recovered oil is higher than that of the new oil.
2. The flash point and ignition point of an oil product are indicators for judging the severity and fire danger of the oil product fraction. The flash point is closely related to the evaporation of the oil. The lighter the oil fraction, the better the evaporation and the lower the flash point. Especially for piston compressors, the exhaust temperature is high, generally not higher than 145 ℃, so the flash point of the lubricant must be higher than 170 ℃. The oil requires a high temperature of 170 ° C, which also indicates that the distillate fraction of the oil is heavier than that of the new oil, which is consistent with the increase in viscosity. Internal combustion engine oil
3. For freezing lubricating oil, the freezing point is a very important parameter. For N46 refrigerating machine oil, its freezing point must be lower than -40 ° C, so as to avoid condensation of the lubricant during use. Light fraction, low freezing point, heavy fraction, high freezing point. The frozen lubricating oil we use has been dewaxed and a certain amount of pour point depressant has been added. After the recovery of the lubricating oil, the freezing point is increased, and the reason is that a small part of the light fraction is adsorbed and filtered, and the fraction is heavier than the original new oil. However, another important reason for the increase of the freezing point is that the pour point depressant in the lubricating oil is damaged to some extent during the use and recovery process. This has been confirmed through experiments.
From the above analysis, it is known that the increase in flash point is beneficial to frozen lubricating oil, and the increase in freezing point is very harmful. It is because the pour point depressant is damaged during the use and recovery of oil products. We can pass Add T801 pour point depressant to achieve the purpose of lowering the freezing point. Viscosity is a property of the recovered oil, so we can mix the recycled oil with new oil in a certain proportion during use to achieve good results. All parameters of the oil product meet the requirements, and the recovered oil can be put into use.
Third, the cost of recycled oil
The recycling cost of recycled oil is much lower than the purchase of new oil. Not only is the cost low, but also the economic loss and environmental pollution caused by casual disposal can be avoided. The cost calculation of recycled oil will not be discussed here.