1) Project overview:
Industry: Cement industry
System: Package for NOx elimination
Scope: Instrumentation + Control System Design + Wiring schematic
This project covered the full engineering of control and instrumentation for a DeNOx package in a cement plant. It is a skid for eliminating NOx gasses from the process. The solution provides safe start-up and shutdown sequences, stable control, monitoring of NOx level, tracking of the ammonium levels. Everything was in accordance with applicable industrial safety standards.
2) Process & control objective
The system had an objective of removing NOx. The main tasks were:
- Maintain stable operation
- Keep safety into consideration because ammonium is highly explosive
- Monitor NOx and ammonium levels
- Using cascade PID regulators in order to optimize the process
- Communication with an existing system
3) Control system
- Siemens PLC was used and programmed using TIA Portal
- The wiring schematic was done using EPLAN
- Data sheets and other instrumentation
engineering documents were done as usual
PLC topology
4) Instrumentation scope
Key instruments designed and specified:
- Temperature, pressure, flow, level transmitters
- NH3 analyzer
- Valves (Control, shut-off valves and pressure safety valves)
Wiring schematic
5) PLC programming
The PLC programming was done in TIA Portal. Part of the project were also 2 HMIs.
One in the ammonium storage room and one in the container
where the dosing happens.