Tower optimization heat exchangers

Fractionating towers optimal reflux ratio, heat exchange, and so forth... 

The results presented In Table III show that as the capital Investment in the tower (Ztower) increases at larger tower heights, the available-energy destruction decreases. Thus the optimal design reflects the classical trade-off between capital investment and fuel cost. It is important to note that heat exchanger design plays a major role in separation systems (16). 

Pump-Around Many fractionation towers have pump-arounds to remove excess heat in the key sections of the tower. The effect of increasing pump-around rate is reduced internal reflux rate in the trays above the pump-around, but increased internal reflux rate below the pump-around. Thus, change in pumparound duty affects fractionation. On the other hand, pump-around rates and return temperature have effects on heat recovery via the heat exchanger network. It is not straightforward in optimizing pump-around duties and temperamres since the effects on both fractionation and heat recovery can only be assessed in a simulation model. An APC application incorporated with process simulation should be able to handle this optimization. 

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