Different screw air compressors have different requirements for the quality of lubricating oil. It is not that the more expensive the lubricating oil, the better. Because the production materials and production processes of different screw air compressors are different, the viscosity of the lubricating oil is The requirements for kinematic viscosity, density, specific gravity, pour point, flash point, etc. are all different, so there is really more attention to the selection of lubricants. It is difficult for non-professionals to figure out the differences. Today I will Let me show you how to choose the suitable lubricant for your equipment.
The choice of base oil
In compressor oil, base oil accounts for 90% or more. Therefore, the choice of base oil has become the fundamental factor related to the quality of compressor oil. The choice of base oil has two meanings, one is which type to choose, and the other is which performance is required.
The first is the choice of type. Synthetic base oil has good oxidation stability and low carbon deposition tendency. It far exceeds the performance of mineral base oil and has a long service life, which is 5-10 times that of mineral oil. Of course, synthetic base oils are expensive, some are even several times that of mineral oils.
Then there is the choice of performance. The base oil used in compressor oil requires the following performance requirements: the base oil fraction should be narrow, the flash point should be appropriate, to ensure safe use, and reduce the generation of carbon deposits and the loss of oil; heat The oxygen stability should be good to ensure good deposit control; sufficient viscosity-temperature performance to ensure the stability of the oil film; sufficient flow performance to reduce the start-stop and extreme temperature wear, and at the same time, it can also have a cooling effect to a certain extent.
Suitable viscosity
There are three commonly used viscosity grades of screw air compressor oil: 32, 46, and 68. As we all know, under the condition of dynamic viscosity, the oil film thickness increases with the increase of oil viscosity, but the friction will also increase. The lubrication protection caused by the oil film thickness and the increase in friction caused by the compressor power consumption and oil consumption The increase has become the contradiction in the lubrication of screw air compressors.
How to achieve the dual effects of lubrication protection and equipment energy consumption is the never-ending pursuit of air compressor oil technology experts.
In this proposition, recommending the appropriate viscosity for the user is one of them. Under the premise of ensuring lubrication, choosing the right viscosity has an important impact on reducing energy consumption and ensuring the reliable operation of the compressor.
Thermal oxidation stability and deposit control ability
The thermal oxidation stability and deposit control ability of compressor oil are important indicators that determine the service life of compressor oil, are also an important guarantee for reliable compressor operation, and are the key to reducing user operating costs.
The generation of deposits in the oil will not only accelerate the deterioration of the oil, but also increase the viscosity, block the oil, reduce the amount of compressor oil injected, affect the normal circulation of the compressor oil, and cause the compressor to malfunction. Wear and even downtime. The thermal oxidation stability of oil is the key to controlling deposits.
In an air compressor, the compressor oil is in constant contact with the air, and the catalysis of metals will cause the oxidative decomposition of the oil, thereby producing colloidal and acidic substances. These substances are the precursors of sludge and carbon deposits. Therefore, the stability of thermal oxidation and the ability to control deposits are an important part of the technical requirements of the compressor.
Anti-corrosion and anti-rust performance
The oil cooling components in the compressor are mostly copper parts or copper alloys, which are easily corroded and rusted, especially when the moisture content in the air is high, it will catalyze the corrosion and rust reaction to accelerate. Therefore, the compressor oil must be required to have good corrosion resistance.
Demulsification and defoaming performance
Since it is a device that compresses air, it is inevitable that there will be two problems in contact with air. One is that the condensed water in the air caused by compression makes the compressor oil emulsified and loses its lubricating performance; the other is air The mixing of the oil will increase the bubbles in the oil, causing the decrease of lubricity and the generation of compressor cavitation. Therefore, high-quality compressor oil should have good demulsification performance and excellent defoaming ability.