Montana-Dakota Utilities Co installed a field-based process control system.

As a part of a retrofit and upgrade project, Montana-Dakota Utilities Co. (MDU), Sidney, MT, has installed a field-based process control system from Fisher-Rosemount, St. Louis, in its Lewis & Clark Station, Sidney, MT. The plant automation system replaces 42-year-old pneumatic controls.

As a part of the retrofit, all station equipment except the turbine and coal handling was automated. The new equipment includes the boiler, burner management, natural gas delivery, condensate and feedwater systems, scrubber, fuel/air ratio, fans and dampers, and fire system start. MDU undertook the retrofit in part be-cause it could not qualify for spinning re-serve duty with its previous process equipment. With the new control system, load can be raised 5 MW in less than 10 min.

Fisher Rosemount's PlantWeb field-based process control architecture relies on its DeltaV controllers, which were mounted near the equipment controlled. Foundation Fieldbus fieldbus control communications, PC workstations, Ethernet supervisory network and Windows-based configuration software programmable by MDU engineers are a part of the plant-wide system.