Chemical plants

In chemical plants, individual machines are combined in complex arrangements into plants that enable elaborate chemical reactions – one example being plants for producing nitric acid for fertiliser production. The control technology must meet complex requirements: the turbine needs speed control to drive the compressors. During operation, the expander also contributes to the drive power and must be coordinated with the turbine power. The compressors must maintain certain pressures and flow rates and require reliable protection against surges. In addition, independent safety functions are required to protect the plant against incidents.

Requirements

• Automatic start-up and shutdown of the plant
• Controlled emergency-stop shutdowns
• Speed control
• Surge-limit control and surge prevention
• Overspeed protection