ABOUT TRANSFORMER OIL FROM HYDROFINED BASE STOCKS
Transformer Oil or Dielectric Insulation Oil and other oils required for electrical machinery and installations can be manufactured using hydro finished base oils of group II +. The base stocks are selected based on viscosity requirements of the user. In colder countries pour point is also a critical property for base oil selection.
Transformer Oil (TO) be used for filling the transformer with a primary objective of providing electrical insulation between the primary and secondary coils. Dissipation of heat generated during the process is also an important function. Electrical insulation is favored by high viscosity and heat dissipation is favored by low viscosity and circulation of fluid. Base oil viscosity at a compromise level is selected. Viscosity ranges for base oil slightly defer country to country, generally in the range of 10 to 40 cst. at 400 Degree C. During the service temperature of oil rises to about 60-800 Degree C. Viscosity of oil decreases due to temperature rise. Transformer has large extended surfaces exposed to atmosphere. The oil circulates through these tubes and dissipates heat into the atmosphere.
Transformer Oils are very sensitive to contamination by water or dirt and fibers as there are serious loss electrical properties. Dust particles and textile fibers absorb moisture and orient in an alignment or bridge to connected high voltage and low voltage side resulting into ‘Arcing’ and dielectric breakdown. While major breakdown are rare and lead to ultimate failure of machine, formation of small local arcs are common. It does not cause immediate damage to machine but damages the oil. These small arcs expose the oil to a very high corona temperature for split second, resulting into thermal breakdown of oil constituents. Some of these are gaseous and accumulate in the vapor space within the machine; others polymerize and settle down forming sludge. Over a period of time excess accumulation of gases and sludge may lead to serious dislocation of operation or even explosion. Thermal breakdown and oxidative degradation of oil could be reduced by incorporation of appropriate low temperature oxidation inhibitors and additives. Some users insist upon ‘uninhibited’ products in some cases oxidation inhibitors are to be blended. Manufacture of TOs therefore has following process steps.
The basic process for the manufacture of transformer oil consists of processing of Group II + base oils or equivalent mixed with special type of additives. Mineral Base oil at 650C is first dehydrated filtered through specially designed filters. The filtered oil is then processed under vacuum in a de-hydration and filtration system. Transformer oil so produced meets BIS 335, 1993.
All operations of the plant are fully integrated through a common control panel.
The plant consists of Feed and discharge pumps, Four stage Filtration plant ,Vacuum pumps(1&2stage),4 no’s absorbent column(2 no’s as stand by), Homogenizing tank with recirculation system, all piping, valves and instrumentation, Feed and Storage tanks, Filling manifold, Thermic fluid heater, Cooling tower(if required),Air compressor, Complete skid .Plant designed as per IS 6034 1989
The plant is rated for continuous operation having built-in dust-proof, control panel, annunciation system, fault indication with various inter-locking systems, temperature indicator, ammeter, volt meter, flow meter. A Control panel with safety features for the following is provided:
1.High and low level indicators level in degassing chamber..
ii. Emergency stop for plant.
iii. Overload cut out.
i. Oil draining and filling operation.
ii. Pressure relief valves.
iii. Bypass system for absorbent column.
1.BDV OIL TESTING KIT (FULLY AUTOMATIC WITH MICRO PROCESSER PRINTER RANGE 0 TO 100KV)
2.ON LINE PPM MEASURING INSTRUMENT
3.TAN DELTA INSTRUMENT
4.RESISTIVITY MEASURING INSTRUMENTS
Entire process controlled up to homogenization and filling by a microprocessor/microcontroller PLC based system. Provision to control full system from the display unit. High contrast color HMI touch screen system. Inbuilt memory for storage of data. On line PPM meter. Digital flow meter. External pen drive, Printer.Windows 10 compatible.
TRANSFORMER OIL FILTERATION PLANTS
Due to the ever increasing cost of base oils FE have designed mobile transformer oil filtration plants for filtering of transformer oil to achieve following improvements after filtration as per IS 335-1993 for new transformer oil and IS 1866 for used transformer oil. The plants are tailor made to mount local vehicles. Capacity ranges from 500 Ltrs/hr. to 5000 Ltrs/hr
IMPORTANT COMPONENTS FOR SINGLE STAGE HIGH VACUUM SINGLE STAGE MOBILE TRANSFORMER OIL FILTRATION PLANT S. The plant shall generally confirm to is-6034-1989 and its latest revision.