Multibed with quench cooling

Figure 86. Multibed converter with quench cooling [864]... 

Figure6.1.12 Multibed NH3 reactor with quench cooling (a) reactor, (1) catalyst, (2) heat exchanger, (3) quench gas inlets, (4) gas inlet, and (5) gas exit (b) temperature profile through reactor (c) NH3 content versus temperature (adapted from Appl, 1999).

Multibed Converters with Direct Cooling (Quench Converters). In... 

The thermodynamic limitation of SO2 oxidation requires an adiabatic multibed reactor with intermittent cooling in external heat exchangers to achieve nearly full conversion. Alternatively, cooling is possible by stepwise quenching with cool air. For today s SO2 oxidation catalysts, typically four stages with intermittent cooling are needed to reach more than 98% conversion. 

The catalyst volume is divided into several beds in which the reaction proceeds adiabatically. Between the individual catalyst beds heat is removed by injection of colder synthesis gas (quench converters) or by indirect cooling with synthesis gas or via boiler feed water heating or raising steam (indirectly cooled multibed converters). 

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