Oil Processing methods and equipment
Oil processing is the best way to save money on purchasing new oil. Experience indicates that regular oil processing prolongs the life of oil and oil-filled equipment. Below we examine the basic ways of oil processing and oil treating equipment.
Oil processing by sedimentation
This method is suitable for oil that has a low degree of contamination (with mechanical particles and water). If this is so, the oil is placed in a special sedimentation tank for a few hours. Sludge, dust, metal particles and water will eventually sink to the bottom of the tank, whence they are removed through a drain cock. The main disadvantage of oil processing through sedimentation is in its limited application and long duration (in some cases, settling can last more than 10-20 hours).
Oil processing by centrifugation
Historically, the first methods of oil processing were based on physical phenomena. One of the methods of processing liquids from suspended particles and water uses an effect of centrifugal forces. The main disadvantage of centrifugation is its limitations. It is only used when the water in oil is in an emulsion state, and the specific mass of solid impurities exceeds the specific weight of processed oil. It cannot remove dissolved moisture, gases and various fibers, and would require additional methods for complete cleaning.
The equipment for centrifugal oil filtration is centrifuges or separators.
The use of special elements for retaining impurities in oil is called filtration. Stationary filters process the oil directly in the system. Filter presses process the oil that was drained from the equipment. They consist of frames and plates, with filter media in between.
The main disadvantages of filter presses are leaks in their structure, which cause oil oxidation, they also need frequent replacement of filter elements and have a relatively low oil reclamation capacity.
Coagulation is used when the processed oil contains a large number of small mechanical impurities. It is carried out by introducing special substances – coagulants. They enlarge the existing impurities in oil. Then large impurities are removed through sedimentation or filtration.
Evaporation is used to remove moisture from oils. The principle of this process is based on the difference between boiling temperatures of oil fractions and water. The oil is heated to a temperature at which moisture evaporates. Then the evaporated moisture is removed through condensation. The efficiency of oil processing through evaporation depends on the created conditions: temperature and pressure. Their ratio should be optimal.
Also, the water is removed by air stripping dehydrators, which force warm dry air into oil to draw moisture out (usually a special vessel is used to catch the moisture in).
Electrostatic oil processing
The electrostatic method of oil processing uses special electrodes to create an electric field. When processed oil passes through this field the polar particles attract to the electrodes and the neutral particles settle on the corrugated paper located between the electrodes. Paper distorts the electric field, so neutral particles contact it at the points of greatest tension.
The particles of impurities (coal, non-ferrous metals, iron, etc.) in oil receive a positive or negative charge, and respectively they are attracted to the electrode with the opposite charge. The main disadvantage of this approach is the need for frequent cleaning of the electrodes. Also, it is advisable to pre-dry the oil to moisture content below 500 ppm (500 g / t) – to increase the efficiency of the electrostatic process.
Oil processing by adsorption
Adsorption treatment is an integral part of any system for industrial oil regeneration. It is due to the good absorbing properties of adsorbents that remove not only to water and mechanical impurities, but also acidic components and aging products. In general, not all adsorbents demonstrate the same efficiency, and are selected individually according to oil contamination.
Adsorption happens when oil passes through columns filled with absorbing material. A certain limitation of this method is connected with changing the adsorbent, which was saturated with impurities, or reactivating its properties. This inconvenience can be solved with GlobeCore equipment, where the reactivation of adsorbent goes in parallel with oil processing.
Oil processing in vacuum
GlobeCore produces CMM units for vacuum processing of oil. This equipment removes dissolved gases and moisture from oil, and receives the following parameters:
- moisture content by weight below 0,001% (10 g / t);
- volumetric gas content below 0.1%;
- content of mechanical impurities below 8 g / t;
- filtration fineness 5 μm.
In addition to industrial oil processing units, GlobeCore also produces other equipment for transformer maintenance: drying of solid insulation, refilling, vacuum treatment, etc.
Complex oil processing
There is no single way to accomplish oil purification. In practice, the oil always contains impurities of different nature and origin. Therefore, oil processing is complex and is accomplished through several approaches following each other. For example, the mechanical particles are removed through sedimentation or filtration, water and gases through high temperature and deep vacuum, and products of aging – through natural or artificial adsorbents.
GlobeCore Company produces compact and mobile oil processing plants that allow complex oil purification and recovery and are designed according to required capacity.