Transformer Oil Treatment Machine Dry Core
The quality of transformer oil determines the reliability of any power or distribution transformer, which is why a transformer oil treatment machine is an essential part of high-voltage equipment maintenance. Transformer oil performs several important functions at once: it provides insulation between current-carrying elements, removes heat from the windings, suppresses arc discharges, and absorbs moisture and gases formed as a result of oxidation and thermal aging.
The ideal condition of transformer oil is evaluated using several parameters. The dielectric dissipation factor of clean oil at 194 °F and 50 Hz should not exceed 2×10⁻². However, in contaminated oil this value may rise to 0.2, which indicates a significant reduction in dielectric strength. Breakdown voltage is measured using a standard gap with 1-inch electrodes spaced 0.1 in apart; high-quality insulating oil must demonstrate no less than 70 kV. Impurities, fibers, and especially water sharply degrade this parameter, so they must be removed to the lowest possible level.
Before being filled into transformers, the oil must undergo deep thermal-vacuum treatment. Gas content must not exceed 0.5% by weight for hermetically sealed units, and water content must be at or below 0.001%. For non-sealed systems, up to 0.0025% is acceptable. Cleanliness class requirements specify no worse than Class 11 for equipment up to 220 kV and no lower than Class 9 for higher voltages. The DryCore technology is specifically designed to achieve these values.
Contamination Issues of Transformer Oil
The service life of a transformer is significantly longer than that of its oil, which after the first year of operation already requires purification. The oil’s tendency to absorb moisture leads to reduced dielectric strength, increased operating temperature, and accelerated insulation aging. To extend its service life, a set of measures is used: limiting contact with atmospheric air, using filters to absorb water and oxygen, controlling temperature, regularly removing sludge, and performing filtration. All these measures become far more effective when a transformer oil treatment machine is used, as it can deeply dry and degas the oil, fully restoring its dielectric properties.
Design and Operating Principle of DryCore Equipment
DryCore has developed an efficient modular system in which all key components are integrated into an enclosed container: a vacuum chamber, vacuum and oil pumps, heating elements, a two-stage filtration system, and a control cabinet. This layout makes the equipment suitable for on-site operation and minimizes the effect of external factors on process quality.
Drying is based on the thermal-vacuum principle: the oil is heated to a temperature at which water evaporates intensively under reduced pressure, after which moisture and gas vapors are removed by the vacuum system. This eliminates the need for absorbents and avoids the creation of secondary waste. At the same time, the oil passes through filtration stages where mechanical impurities and solid particles are removed. This approach ensures full comprehensive preparation of the insulating fluid for further operation.
An important feature is the ability to vacuum-dry internal transformer cavities and tanks—an essential operation before filling with new or regenerated oil. Thus, the DryCore transformer oil treatment machine provides not only purification but also the complete preparation cycle required before energizing equipment.
Transformer Oil Treatment Machine Dry Core
The DryCore product line includes several models designed for oil treatment under different conditions and with varying throughput, but all share the same technological concept. Regardless of whether it is the DC-44D, DC-26.4D, or DC-18D model, each DryCore transformer oil treatment machine uses the same deep thermal-vacuum processing principle, ensuring a low level of residual gases and moisture as well as a consistently high cleanliness class.
The capacity of each DryCore transformer oil treatment machine depends on the operating mode and model:
DC-44D
• Degassing, drying, and filtration: 44 gpm
• Heating and filtration: 66 gpm
DC-26.4D
• Degassing, drying, and filtration: 26.4 gpm
• Heating and filtration: 30.8 gpm
DC-18D
• Degassing, drying, and filtration: 18 gpm
• Heating and filtration: 31 gpm
All units feature a containerized design, enabling easy transportation and use at substations, service centers, and in field conditions. They can operate in pumping, heating, filtration, degassing, and external system vacuuming modes. Across the entire DryCore line, key advantages include low noise levels, energy efficiency, user-friendly operation, and minimal maintenance requirements. In any configuration, the transformer oil treatment machine provides uncompromising processing quality and guarantees oil with excellent dielectric properties even after a single treatment cycle.
The key advantage is that the DryCore transformer oil treatment machine operates without absorbents, eliminating waste-generation issues. The thermal-vacuum method ensures consistently low gas and moisture levels. DryCore units can easily switch between pumping, heating, degassing, and vacuuming modes, allowing a complete equipment preparation cycle before operation.