Designing and manufacturing a completely new GTP-type generator rotor – Case Suzano S/A, Brazil

One of Suzano’s spare generator rotors was badly damaged during balancing. Thanks to the engineering expertise accumulated working with similar equipment, Fortum eNext was able to manufacture a completely new rotor based on the old design, but enhanced with upgrades and modern material.

Generator rotor and project team

Case description

Brazilian pulp and paper company Suzano contacted Fortum eNext in early 2017 for support because one of their spare rotors had been damaged in the balancing pit after a rewind performed by another company. As the rotor could not be repaired, the customer wanted to know whether it would be possible for Fortum to manufacture a similar type of ASEA-GTP rotor from scratch. The challenge was that ASEA had delivered the last rotor in the 1970s and nobody had manufactured a rotor like this in almost 40 years. Also, the OEM had told the customer that it could not be done.

Having maintained the engineering know-how of the technology and how these rotors are designed and how they should be rewound and high-speed balanced, Fortum eNext was able to offer the delivery of a completely new rotor based on the old design of the one that failed, but enhanced with upgrades and modern material.

Capturing the know-how and the know-why from experienced personnel and transforming that into how a rotor like this should be built today, with modern production equipment, Fortum’s engineering department made the design of the new rotor. 

“I was impressed with how the know-how of designing and high-speed balancing of these rotors has been maintained within Fortum. It’s not easy to find a service provider in Brazil with the equipment, the facilities, and especially a big enough balancing pit like the one in Västerås to overhaul a generator like this,” says Alessandro Moscardini de Morais from Suzano’s Corporate Engineering Department.

"One thing that stands out in this project is the excellent co-operation between our Engineering office, our generator workshop in Sweden, and the very skilled sub-supplier in Finland who did the difficult machining of the rotor parts."
 

Gabor Csaba, Senior Product Manager, Fortum eNext

Suzano site in Brazil

Fact box

Customer: Suzano S/A, Brazil

Plant type: Paper mill

Commissioned: 1972

Generator and turbine: Radial steam turbine

Type: ASEA GTP 1050CZ

Power: 2 x 15 MVA, cosphi 0.85, 3600 rpm

Running season: Continuous

References

Want to learn more? Read also the longer case description.

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Contact our specialist for more information

Gabor Csaba

Gabor Csaba

Ph.D., Principal Generator Specialist
Tel: +46 76 783 4933
gabor [dot] csaba [at] fortum [dot] com