Types Of Mineral Oils
Mineral oil compounds distilled from oil fractions. Those used as a refrigeration lubricants grouped into four categories: paraffins, naphthenes, Aro-matics, and nonhydrocarbons, based on their molecular structure. Paraffin, mineral oils have molecular structures straight and branched chain saturated hydrocarbons molecules. The molecular structure of saturated hydrocarbons containing the maximum number of hydrogen atoms, which can be combined with carbon atoms in dieir molecules. Chain bonding indicates that the atoms in the form of bonds, which are not connected in a way that will form a loop or ring.
Naphthenes characterized by the ring structure is formed with saturated hydrocarbons. The ring structure indicates that the atomic bonds form loops than chain. Aromatic compounds are unsaturated ring hydrocarbons that have fewer hydrogen atoms than it takes to fully bond with the carbon atoms in the molecule. Nonhydrocarbon oils contain atoms of other elements except for hydrogen and carbon in the molecule. These molecular differences create differences in the properties.
Oil formed saturated hydrocarbons (paraffins and naphthenes)have very good chemical stability, but is not mixed with refrigerants such as R-22. They also lack the body necessary for the development of hydrodynamic seal to keep the moving parts, separated and wear limit.
Oil is formed widi unsaturated hydrocarbons bonds (aromatic) more mixed with refrigerants and better hydrodynamic sealing ability, keeping moving parts, separated by a layer of grease. Unfortunately, they have a lower level of chemical resistance, which makes them more reactive system. Nonhydrocarbons have the best hydrodynamic characteristics of the seals, requiring less oil to save the components are divided than aromatic oils. They are also the most reactive oil. Oil may be developed from a combination of these groups, giving characteristics needed to meet the application requirements...