Transformer Oil Filtration
The use of industrial type oils for power and hydraulic equipment has a number of conditions that must be observed. The purity of the oil consumed is one of the most important factors determining the correctness and durability of the equipment. Therefore, the purification of waste oil today is an integral attribute of the maintenance of various equipment.
When refining petroleum products, manufacturers are trying to make oil of the highest class, but even in conditions of careful transportation, storage, storage and, directly, operation, changes in the composition are inevitable. It becomes obvious that the replacement of old oil with a new, but not refined one, cannot guarantee the operation of the equipment without failures in the future. Moreover, with too much workload and the need to operate the plant without interruptions for a long time, the power engineers cannot afford to change it too often. Oil filtration of used oil with the use of special installations significantly reduces costs, time spent and effort.
Machine oils that have been in use (or storage) for a long time tend to change their physico-chemical characteristics under the influence of certain internal and external factors.
Let us consider in more detail what is included in their number:
- Interacting with air, it contributes to the oxidation, decomposition, polymerization and condensation of organic compounds of carbon and hydrogen;
- oxygen, as the unchanged product of the oxidation of engine oil as a result of storage in the warehouse and transportation;
- mechanical impurities (products of combustion, friction, fibrous substances, metal chips, solid deposits), which enter the oil from the mechanisms of the equipment;
- dissolved / undissolved moisture in oil. Formed in the form of condensate on the surface of the initially heated oil in the cooling system of the installation.
The most well-known physical methods: settling, filtration, centrifugation and vacuum drying. Consider how they act in more detail.
Settling is the first and most important stage of regeneration. The oil in suspension is saturated with impurities of fine particles from the wear of parts and moisture. The method of settling is based on heating the oil to a certain temperature (optimally 80-90 C). Marks of 100 C should be avoided, as this contributes to the foaming and boiling of water in the oil. Heating helps to reduce the binding characteristics of the oil, as a result of which its density decreases and heavy elements settle under the influence of gravity. With long-term storage of oils, some insoluble particles themselves can settle to the bottom of the boxes, producing, in some way, natural cleaning.
Centrifugation is carried out using centrifugal forces. The centrifuge works in such a way that the heaviest particles that have accumulated in the waste oil are forced out to the walls of the vessel, forming an annular layer. The next layer is formed by the molecules of the displaced water, and the final layer – the purified oil. Installations are designed with the expectation of recovering the regeneration product directly from the installation during the process, and the settled contamination products are removed from the equipment walls after completion of the work.