Purification of Electrical Insulating Liquids
Today's state-of-the-art electrical equipment requires the need for a high degree of insulating fluid purification. Such requirements call for the removal of moisture, gases, solid particulate matter and traces of chemical contamination from the insulating fluid.
Moisture content is recognized as one of the main causes of variation in the electrical properties of insulating materials, both from a chemical and physical point of view. Even in small amounts, moisture can accelerate the aging process.
Under these circumstances, it is important to start initially at the factory with a dry insulation system and pure, dry and degasified dielectric liquid during transformer impregnation and the qualification tests. Later, the same care must be taken during installation in the field and after every maintenance check, requiring exposure of the insulating system to the environment.
The ZYD process, developed by zhongneng, upgrades new insulating liquids and reclaims used dielectric oils through filtration, vacuum dehydration, degasification and clay treatment (when necessary).
ZYD Systems include filters with a 0.5-1.0 micron nominal filtration rating for the removal of particulate. If excessive free water is present in oil, a free water trap is used prior to vacuum dehydration. The ZYD High Vacuum Process then removes dissolved water, free and absorbed air and other gases.
The ZYD Fuller's Earth Filters provide corrective treatment for removal of the products of oxidation, dissolved varnish and gums and other traces of chemical contaminants.
ZYD Systems with High Vacuum Pumps provide fast and complete transformer dry-out and fill with clean, dry and hot oil under vacuum conditions. ZYD Interstage Oil Condensers provide a continuous system for removal of light-end oils for vacuum system protection during transformer dry-out processes.