APPLICATION: Powerhouse Controls Upgrade

RESTART DATES: Unit 9 & Common – April 1995

COMMERCIAL OPERATION: Topping Turbine – June 1995

Comprehensive control system(s) and plant data acquisition system replacement including:

Combustion, Feedwater and Misc. control systems for (2) existing CE Boilers.

Flame Safety and Burner Management system(s) for (2) existing CE Boilers.

Powerhouse Data Acquisition System.

Supervisory Control and Monitoring of (3) Existing Steam Turbine-Generators.

Supervisory Control and Monitoring of (1) Existing Turbo Blower.

Supervisory Control and Monitoring of (1) New Topping Turbine. (McBurney)

Plant control strategy designed to:

Satisfy Mill and Powerhouse requirements for 900 psi and 325 psi steam.

Maximize Blast Furnace Gas (BFG) utilization.

Minimize Natural Gas useage.

Regulate generation of electricity based upon BFG availability.

Leeds+Northrup MAX 1000 DCS with the following components:

Boiler Control Room: (3) WorkStations including:

(7) Graphics Processors with Touch Screen (OPS).

(1) Applications Processor (EWS)

Dispatch Control Room: (1) Work Station including:

(1) Real-Time Processor

(1) Graphics Processor with Touchscreen (OPS)

Control and I/O Cabinets:

1731 Total I/O Supplied: 420 AI 24 AO 704 DI 272 DO 255 TC 56 PAT

Existing Field Termination Cabinets retained

Conventional Panelboards replaced with CRT based control and information displays

ACS designed control strategy with fully documented SAMA, Loop, and logic drawings