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PCB Training workshop in Istanbul 15 -19 July 2013

Retrofilling transformer with decontamination

Retrofilling transformer : Emptying the equipment of its dielectric fluid and replacing this with new PCB free oil or refurbished

Retrofilling transformer with decontamination Parameters affecting the decision for Retrofilling or not: -Importance of this transformer; -Location; -External condition of transformer, data of manufacture; (leaks, corrosion ) -Functionality of transformer; -Cost for disposal replacing of replaced oil; -Cost to purchase new transformer; -Cost of replacing the oil; -PCBs concentration of the oil.

Retrofilling transformer with decontamination Important information’s for supporting the decision between retrofilling the transformer or replace with a new transformer: -Simple replacement will reduce the contamination to 10%; -Cost effectiveness decontamination, for power transformers, if the max concentration of 500ppm, for in situ PCB decontamination method; -Higher contaminated transformers are technically possible to treat but the cost is rising a lot; -A new transformer costs three time more than the disposal costs of a transformer;

Retrofilling decision taking

The improvement of the dielectric properties of used oil can be performed using mobile or stationary systems. Those systems consist of: -Vacuum system; -Two or three phase decanter; -Filter for particles and trap for dehydration of the oil.

Retrofilling and decontamination Case study The dielectric oil from a power transformer is contaminated with PCBs; (identified)

Act as follows: -Plan within the next retrofilling and the in situ PCBs decontamination -Ask specialized subcontractors to do the Retrofilling transformer and simultaneously to destroy the PCB from the oil. Usually they use to destroy PCBs sodium.

Power transformer

Retrofilling – decontamination-Sampling

Verifying decontaminations success!!

 After 90 days of finishing the decontamination process the PCBs level in the oil must remain under 50ppm. (porous parts dilutes PCB in the treated oil)

 Consider that after finishing the decontamination

because the porous materials absorbs PCBs the oil measured PCBs concentrations should be between 1020 ppm.

Retrofilling – waste disposal

ď‚— The waste arising from retrofilling are classified as possible hazardous waste and must be disposed according the local regulations.

Retrofilling – waste disposal  Than you very much for your attention

 Panos Ioakimidis  

7 retroffilin panos