Cleaning of oil-filled electrical cables in four steps
Analysis of the amount and type of oil in the cable. Following this we cultivate the required bacterial culture.
The viscous oil inside the cable can be pumped out under pressure. The cultivated bacterial suspension is injected into the cable to remove the oil bound to the paper insulation.
The bacteria grow outwards from the core, thus removing the oil from the paper insulation and out of the cable. The oil is separated from the bacteria using an oil separator and then disposed of by professionals.
Regeneration of the bacterial culture and re-injection into the cable. The flushing procedure is repeated multiple times. After approximately 14 to 16 weeks the objective has been achieved, with at least 95 percent of the oil removed. The 5 percent residual oil amount is bound to the paper insulation in the cable. The majority of it is therefore immobile and no longer presents an environmental risk.
The cables are now permanently decommissioned and can remain in the ground without causing any problems.