La flotta Sea Marconi cresce ancora, e lo fa con un impianto che rappresenta il punto più alto nell’ambito del trattamento dei liquidi isolanti. La Smart DMU (Decontamination Modular Unit) SIGMA è un vero e proprio gioiello tecnologico perché include tutti i punti di forza delle DMU by Sea Marconi raggiunti e consolidati nel corso degli anni, inoltre è più leggero (cellula in lega di alluminio), movimentabile e installabile più facilmente, monitorabile da remoto, oltre ad essere estremamente flessibile. Il SIGMA realizza trattamenti integrati di oli minerali (inibiti e non inibiti) sia nuovi sia in esercizio, esteri naturali ed esteri sintetici. L’impianto può lavorare sia su trasformatori in servizio (on-load) sia fuori servizio (off-load) anche senza presidio fisso di un operatore inviando comunicazioni e allarmi.

A breve il SIGMA sarà impiegato in attività di commissioning per il progetto ITER e per il parco eolico off-shore al largo della Scozia da 450 MW di elettricità, tra i più grandi al mondo. In quest’ultimo caso si tratta di 2 trasformatori da 230 MVA, 64.000 kg di liquido isolante, nella fattispecie un estere sintetico (MIDEL 7131).

Il SIGMA rientra a pieno titolo fra gli Smart DMU proprio per la sue caratteristiche “Smart”: tracciabilità delle condizioni di processo, installazione di pannelli fotovoltaici sulla parte superiore, introduzione di device IOT per il monitoraggio (urti/vibrazioni) del trasporto e dei periodi di stazionamento nelle fasi di logistica, trasmissione remota dei dati (per la big data analysis) oltre al controllo e supervisione remota grazie al sistema SCADA (Supervisory Control And Data Acquisition); con questo strumento gli ingegneri Sea Marconi presenti nella control room di Torino, possono monitorare le performance dei trattamenti svolti dal SIGMA (e da qualunque altra Smart DMU) ed interfacciarsi in tempo reale con i propri operatori sul posto ovunque essi siano per consulenza, formazione o troubleshooting.

L’unità SIGMA esegue il trattamento fisico, il riempimento di trasformatori di potenza sotto vuoto, e grazie ad una potenza riscaldante di ben 200 KW ed un circuito secondario dedicato, è in grado di eseguire anche la disidratazione degli isolanti solidi mediante circolazione di olio caldo con trasformatore sotto carico; inoltre questa unità può collegarsi, da qui la modularità, a delle unità ausiliarie Sea Marconi che ne estendono le capacità per eseguire ad esempio trattamenti fisico-chimici (Dealogenazione chimica CDP PROCESS® e Depolarizzazione selettiva CHEDCOS®).

Il SIGMA sarà impiegato da Sea Marconi per eseguire trattamenti presso i propri clienti, ma allo stesso tempo arricchisce il catalogo impianti destinato alla vendita worldwide. Sea Marconi progetta, sviluppa e produce le sue DMU in Italia, utilizzando componenti, strumenti e materiali di fornitori accuratamente selezionati, preferibilmente italiani e comunque dell’Unione Europea.

After some difficulties imposed by COVID-19, last February 2021 the treatment campaign in Saudi Arabia kicked off. This is an activity out of the ordinary for the amount of electrical equipment to be treated, 23, their size, up to 130 tons of oil, and consequently the total amount of insulating liquid to be treated: 1,750,000 kg. The transformers are mainly located in the central area of the Saudi Kingdom and Riyadh.

Sea Marconi, which received the order thanks to the collaboration with the local technological partner GCC Lab, will carry out selective depolarization treatments from DBDS, aimed precisely at reducing the concentration of DBDS (in the oil), the main cause of the corrosive sulfur phenomenon.
The 23 transformers have a contamination between 60 and 170 mg/kg of DBDS; Sea Marconi guarantees the customer that one year after treatment, the contamination will be <10 mg/Kg. The samples before and after the intervention will be certified and validated by a third party laboratory.

All transformers will be depolarized on-load, which means that the transformer remains in service and loaded for the entire duration of the treatment, using the typical Sea Marconi method: closed circuit, without even partial emptying of the transformer. In doing so, the hot oil constantly flows from the transformer to our integrated treatment unit which progressively brings it back to optimal conditions (in accordance with IEC 60422 Ed. 4-2013, CIGRE 378 – 2009 art. 4.2). Thanks to the use of multi-connection units (designed and built internally) it is possible to treat at the same time the oil contained in the accessory units of the transformer (eg. cable boxes) and also “clean” the dead zones inside the transformer.

The Sea Marconi treatment plant dedicated to this campaign (Smart DMU GAMMA) is one of the most advanced in the sector, it works 24 hours a day, 7 days a week, with only daytime technical staff; in fact, the system is able to work independently and possibly send alarms to available operators. Not only that, thanks to the SCADA system (Supervisory Control And Data Acquisition), the Sea Marconi engineers present in the control room in Turin can monitor the performance of the system and interface in real time with their operators on site for consultancy, training or troubleshooting.

As of today, April 14, 2021, the depolarization of the first transformer is about to end with an excellent result, it has gone from 148 to <5 mg/kg of DBDS. These performance are the result of a series of winning factors, on the one hand there is an extraordinary knowledge of the sector, on the other the use of patented materials and technological solutions of absolute excellence.

In the next few days (August 2015) at the Sea Marconi general offices in Collegno (TO), the Ivorian Electricity Company (CEI) will accept and validate their new purchase: the oil and transformer treatment plant DMU 150.B10.

This is the third plant for the Ivory Coast, confirming maximum client satisfaction for the first two plants, which are currently operating throughout the entire Ivorian territory. CEI is in fact a private company, to whom the State has designated the management of generation and transmission plants and the distribution and commercialisation of electrical energy throughout the entire country.

Speaking of the plant’s technical aspects, its objectives are: oil circulation, heating at a pre-set temperature, mechanical filtration of suspended particles in the oil, degassing and vacuum dehydration of oil. The system is able to perform on-load treatments with the transformer energized and loaded, and also includes a richly equipped monitoring system allowing the plant to operate in complete safety, without the permanent presence of an operator.

Unlike previous plants, this latest one has been requested in a containerized configuration, allowing the plant to operate even in the harshest environmental conditions (rain, sand storms, etc.).

The plant is constructed in AISI 304 stainless steel and is fitted with guide slots for forklifts and eye-bolts for crane lifting. All elements of the hydraulic circuit, including the connection points for intake and output, are assembled above an oil collection tank, an additional measure in the case of accidental losses.

The range of Sea Marconi systems has been enriched by an additional two elements, two mobile units for the physical treatment of oil.
The new plants have been designed and developed to be lightweight (the estimated empty weight is 590 kg), with reduced bulk (L 1,560 x l 1,000 x h  1,440 (mm), and easy to move. This means they can also be transported on road trailers without the need to unload, and allows them to be transported to areas with very tight access points (on off-shore platforms, caves, bunkers, underground power stations, etc.).

Thanks to their structural features, one of these DMUs was recently selected and transported by helicopter to the peaks of the Adamello (Lombardy) to perform a physical treatment on a transformer (following maintenance with emptying and subsequent refilling).
Given that there is more than one metre of snow and in light of the difficult logistics associated with the slope and altitude of the road to the operating site, a helicopter was the only way to reach the transformer. Thanks to its reduced weight and smaller dimensions, using anchoring rings the Sea Marconi decontamination unit was hooked to the helicopter with a chain, which then transported it to the electrical power station.

The machine is mounted onto a AISI 304 stainless steel frame, equipped with fork guides for movement with a forklift, anchoring rings for crane lifting, wheels and corner blocks for anchorage on road trailers.
All elements of the hydraulic circuit, including the connection points of the flexible input and output hoses, are contained in a watertight tank to collect eventual accidental oil spills.
The hydraulic circuit, the degassing chamber, the filter bodies and the heater are in AISI 304 stainless steel.

The partnership between Sea Marconi and local partner “Energy Solution SA DE CV“, a subsidiary of the NIETO group and an important player in the Mexican Oil & Gas sector, is enjoying great success.
In 2014, the Sea Marconi process for the treatment of oils and transformers contaminated by PCBs, was successfully validated. The activity was performed in Torreón on a 33,000 kg oil transformer in on-load mode for the entire duration of the treatment.

The transformer belongs to the Comision Federal de Electricidad (CFE), which provided a positive verdict not only for the performance of the process, but also having understood and appreciated the potential of Sea Marconi systems for integrated treatments. This terminology implies the possibility to “restore” numerous critical properties in the oil and transformer, in the same unit of treatment. The latest generation DMUs (Decontamination Mobile Unit) by Sea Marconi, including the one used in Mexico, are able to resolve both critical issues tied to PCB contamination and those tied to corrosive sulphur or the acidity (a symptom of ageing) of the oil.

Recalling Sea Marconi’s most important activities in 2014, we don’t want to exclude the delivery of an oil treatment system, model DMU 100 5000 24C, to TAESA, an important Brazilian utility.

We are extremely proud of this order, because TAESA already purchased one of our systems in 2009 (read article). Given their high level of satisfaction, in terms of both the system’s performance and the results of the treated oil, they decided to repeat the purchase.
The new system will be used for onsite treatment, in on-load mode (transformer in operation and powered during the entire treatment) on transformers and shunt reactors up to 550 KV containing DBDS and affected by corrosive sulphur.