Situation
Hydroelectricity company. The transformer is located in the Adamello peaks (Lombardy).
Problem
There were extreme logistical difficulties associated with reaching the operating site: the access route was a steep slope at high altitude and there was more than a metre of snow. Helicopter was the only possible means of transporting the oil treatment machinery, so there were stringent weight constraints.
Solution
Sea Marconi overcame the stringent logistical constraints to access the operating site by using a new design of mobile processing unit (DMU).These new units are designed and manufactured to be lightweight (estimated empty weight is 590kg), and smaller in size (L 1,560 x W 1,000 x H 1,440 (mm), so they’re easy to handle. It also means they can be transported by road with no need to unload them from the trailer, so they can be taken to areas with very tight access points (off-shore platforms, quarries, bunkers, underground power stations, etc.)
Because the Sea Marconi decontamination unit is lighter in weight and smaller in size, it was suspended from the helicopter with a chain hooked through its anchoring rings for transportation to the power station.
Specifically, there are two devices that perform the following functions: oil is sucked out and pumped back in (draining and refilling), oil is heated to a preset temperature, solid suspended particles are filtered out, and the transformer is degassed and dried under vacuum.These functions can also be carried out whilst the oil is circulating in a continuous, closed circuit between the unit and the transformer.
The control and safety systems installed mean the system can even be used without intervention by the operator.The unit is designed to operate at the following settings:
- Nominal flow: 160 ÷ 600 l/h
- Maximum heating temperature: 80°C
- Oil temperature in the degassing chamber: 60 ÷ 70°C
- Heating capacity ?t = 40°C at 600l/h
- Max pressure: 6 bar
- Absolute pressure in the degassing chamber: < 1 mBAR at full performance
- Filtration: 2 microns
Structural features
The unit is mounted on a stainless steel AISI 304 frame and is fitted with wheels, fork guides for lifting with a forklift truck, anchoring rings for lifting by crane, and corner blocks for anchoring to road trailers.
All elements of the hydraulic circuit, including connection points for the flexible suction and delivery pipes, are contained in a sealed tank to contain any of accidental loss of oil.
The hydraulic system, degassing chamber, filtration bodies and heater are made of AISI 304 stainless steel.
