An ACH plant was being built and this required pumps to be controlled, as well as Oxygen content. If the oxygen content in the gas exceeded certain parameters then Nitrogen would be added to the reaction immediately. As Hydrogen is a byproduct of the reaction extreme care has to be taken considering the possibility of an explosion due to static electricity. Many earthing probes are installed in the gas lines with a continuous earth strap Connected to stainless steel electrodes which penetrate the gas lines. Temperature profiles and control are also critical while the reaction is in progress. All equipment is rated for use in the hazardous area. An earth matt is installed as Well as a extended rod for conducting lightning to earth.
New Polyamine plant
A mezzanine level was being built at the plant which contained the batching tanks. This allowed for all products to be gravity fed into the reactor. The control room was situated quite a distance away and there were many valves on the tanks to control. A decision was made to fit Profibus PA instruments onto all of the tanks to control levels. The inputs and outputs were connected to ISRPI which is Pepperl and Fuchs intrinsically safe I/O. The inputs and outputs were connected directly into the ISRPI which is mounted in the hazardous area. The panel is rated IP65 and modules can be exchanged or tested while the system is in operation. The ISRPI connects to the control system via Profibus PA and offers analogue modules with 15bit resolution. We have to carefully control the reaction as it is extremely exothermic. Viscosity is also a very important criteria for quality of the end product. Many safety interlocks are programmed into the system to avoid product damage as Well as for safety reasons. All data is logged and can be viewed via trend pages.