In 1994, CLG developed and launched an innovative reactor internals technology for fixed-bed hydroprocessing reactor internals called Nautilus. It was applicable for both new reactor designs as well as for retrofits. The patented Nautilus internals design allowed new and retrofitted reactors to successfully employ new high-activity catalysts with low risk of reactor temperature maldistribution and hot spots often associated with high-activity catalysts. The Nautilus design provided complete mixing and equilibration of reactants between catalyst beds, correcting any catalyst bed temperature and concentration maldistribution, with low pressure drop.

Baffled Collector Tray

The key component of the Nautilus internals, as illustrated, is a baffled collector tray which swirls and mixes vapor and liquid entering any inter-bed zone in a reactor, directing the entire stream to a centrally located mixing box. Cold quench gas is introduced above the Nautilus collection tray and is thoroughly mixed with hot effluent vapors. The mixed effluents are then efficiently redistributed across the reactor diameter using a perforated tray and a bubble-cap distributor tray.

The Nautilus internals design has been installed in over 70 reactors worldwide from 1994 to 2003. Figure 2 shows sample temperature profiles from a large (15 ft diameter) reactor with seven catalyst beds. Temperature spreads at intermediate bed inlets were within 2-3°C with 12 thermocouples measuring temperatures across reactor cross-section.

Figure 2

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