Hickham Industries, Inc. recently secured a $3.5 million contract with a copper company to completely rebuild and recommission a 50 MW steam turbine generator for the company's power plant in Utah. A new Bently Nevada monitoring system and a new OEM turbine controls package will also be installed during the

turbine rebuild.

   Turbine Generator unit NO.1 at the Utah Company's power plant suffered severe damage when the turbine rotor lost thrust and migrated nearly half an inch toward the generator end of the turbine. This situation damaged the rotor, diaphragms, bearings and seals. Though the turbine had been plagued with a number of problems since 1982, this was by Coupled HP/LP rotors during operating speed balancing (3 bearing balance)  far the worst case in the history of this turbine.

   Upon receipt of the contract to repair the turbine, HII dispatched a diagnostic team to the job site for an investigation into the root cause of the failure. Superyised by John East, Hil's TechnicalServices Department determined, the, root cause of the failure anddrafted the specifications for '8 new turbine

monitoring system, which when properly implemented.will shut the unit down prior to any damage

occurring.

   The H.P. rotor is being weld repaired via Hil's submerged-arc process with a recently developed

"narrow groove" welding process. After all weld repairs are completed, seventeen rows of new blades will be installed in the rotors. Upon completion of the H.P. and L.P. rotor repairs, the rotors will be coupled together and balanced in Hll's vacuum balance bunker in a three " bearing configuration.

   All diaphragms manufactured with cast steel inner and outer webs are being weld repaired and machined. The larger cast iron diaphragms are being fitted with steel inserts designed to add strength. All diaphragms will be equipped with new labyrinth seals. The thrust bearing will be upgraded to a low profile "self leveling" type. This will more than double the bearing's load carrying capacity.

   With the assistance of the Technical Services Department, Hil's Field Service Division will complete the turbine rebuild onsite.Owing start-up, HII will spend approximately seven days monitoring case thermal  growth and the overall performance of the unit.

The entire project is being completed on an emergency basis. The target commercial operation date is set or the middle of April, 2001.

Warren Holmes

Hickham Industries