Temperieren mit Kreisstromwasser in chemischen Verfahrensanlagen

Temperature control by recirculating water in chemical process plants. Temperature regulating systems that use water as circulating medium with direct feed of water vapour and cooling water are dynamically fast and favourable in price; therefore they are frequently installed. The designs produced show an according variety. First, the technical construction of such heating and cooling systems is described, concentrating on three different types – one circulation system for temperatures below 100 °C and two systems for higher temperatures with pressure regulation in circulating water by feed of additional water or by an appropriate steam bolster, respectively. Corresponding design factors such as heating and cooling capacity or pressure-maintaining level and NPSH value are treated. It follows a description of the corresponding technical equipment for measurement and control. Depending on requirements, the different possibilities of instrumentation range from simple control to cascade control with limited regulation values and with P/PI-structure changing during the start of process up to computer application. Even the selection of the regulation valves and the choice of valve characteristics are taken into consideration.